JP2017170628A - Heating control device, device for discharging liquid, heating control system, heating control method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating control device that maintains productivity and suppresses right/left deviation of a property related to hue of a liquid adhering matter on an object in bi-directionally discharging liquid, and to provide a device for discharging liquid.SOLUTION: A heating control device includes: a recording head for discharging ink while reciprocating in a scan direction relative to a roll sheet; a heating unit for heating the roll sheet when the recording head discharges ink; and a heating temperature control part 212 for controlling heating temperature of the heating unit at the time of ink discharge based on image characteristic of a test chart recorded by the ink discharged on the roll sheet.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a heating control device, a device for discharging liquid, a heating control system, a heating control method, and a program.

  Conventionally, as a method of recording on a recording medium (object) such as plain paper, the recording head moves both in the forward and backward directions in the scanning direction of the recording head (liquid ejection head) in order to improve the recording speed. A bidirectional recording method is known in which an image is recorded by ejecting ink during the operation.

  In this bidirectional recording method, when an image is recorded by ejecting ink in the forward path and the backward path, the landing time difference of the ink ejected in the scanning area (band) is different, and the image characteristics (density, tint) of the recorded image are different. , Brightness) sometimes caused a left-right deviation.

  Therefore, a technique for suppressing the left-right deviation of the image characteristics due to the difference in the landing time of the ink in the band is disclosed. For example, a printing apparatus is disclosed that performs recording by providing a waiting time of a certain time by turning the forward path and the backward path in order to suppress left-right deviation of image characteristics (see Patent Document 1).

  However, in the printing apparatus of Patent Document 1, since a fixed waiting time is provided for the return path and the return path, the recording speed, which is one of the characteristics of the bidirectional recording system, cannot be improved, and the productivity is reduced. There was a problem that.

  The present invention has been made in view of the above, and while maintaining productivity, heating that suppresses the left-right deviation of the characteristics related to the color of the liquid deposit on the object when the liquid is discharged bidirectionally. It is an object of the present invention to provide a control device, a device for discharging liquid, a heating control system, a heating control method, and a program.

  In order to solve the above-described problems and achieve the object, the present invention includes a liquid discharge head that discharges liquid while reciprocating in a scanning direction with respect to an object, and the liquid discharge head at the time of discharging the liquid. A heating unit that heats the object, and a control unit that controls the heating temperature of the heating unit when discharging the liquid, based on characteristics relating to the color of the liquid deposit formed by discharging the liquid onto the object And comprising.

  According to the present invention, it is possible to maintain the productivity and to suppress the left-right deviation of the characteristics relating to the color of the liquid deposit on the object when the liquid is discharged in both directions.

FIG. 1 is a schematic perspective view of an ink jet recording apparatus according to an embodiment. Drawing 2 is an explanatory view of the heating unit of an embodiment. FIG. 3 is a diagram illustrating the recording head and the colorimeter supported by the carriage according to the embodiment. FIG. 4 is a diagram showing a mechanical configuration of a reflective colorimetric sensor. FIG. 5 is a diagram illustrating a hardware configuration of the ink jet recording apparatus according to the embodiment. FIG. 6 is a diagram illustrating a functional configuration of the ink jet recording apparatus according to the embodiment. FIG. 7 is a diagram showing a state of penetration of ink droplets having different landing time differences into the paper. FIG. 8 is a diagram showing the relationship between the landing time difference and the density of the dots of the ink that has landed twice. FIG. 9 is an image diagram of left-right density deviation in bidirectional recording. FIG. 10 is an explanatory diagram related to the test chart. FIG. 11 is a flowchart illustrating the flow of the heating temperature determination process of the heating unit in the inkjet recording apparatus of the embodiment.

  Exemplary embodiments of a heating control device, a device for discharging a liquid, a heating control system, a heating control method, and a program will be described below in detail with reference to the accompanying drawings. In the following embodiments, an example in which an apparatus for discharging a liquid provided with a heating control apparatus is applied to an inkjet recording apparatus will be described. Hereinafter, a case where an image or the like is recorded (printed) using ink (or ink droplets) as an example of the liquid will be described. The image is an example of a liquid deposit, and recording corresponds to formation.

  As described above, in the bidirectional recording method, an image is recorded by ejecting ink while the recording head is moving in both the forward path and the backward path in the scanning direction of the recording head, which is an example of a liquid ejection head. In this bidirectional recording method, the landing time difference of the ink ejected in the forward path and the backward path in the scanning area (band) is different, and there is a case where the left and right deviations occur in the image characteristics (density, color, lightness). . The left and right are the left and right with respect to the transport direction, and indicate the width direction (main scanning direction) of the recording medium. Note that a recording medium such as paper is an example of an object, and the image characteristics correspond to characteristics relating to color.

  Specifically, in the case where the ink landing time difference is large (outward writing position), the ink ejected in the forward path is dried and then the ink in the backward path is ejected. On the other hand, when the ink landing time difference is small (outward writing end position, recording head folding position), the ink ejected in the backward path is ejected before the ink ejected in the outbound path is dried.

  For this reason, when ink is ejected in the backward path, a difference occurs in the drying mode of the ink ejected in the forward path, so that a left-right deviation occurs in the image characteristics (density, color, lightness). For the above reasons, the landing time difference of the ink in the bidirectional recording system becomes large between both end portions of the image, and the lateral deviation becomes more remarkable as the width of the paper (object) increases. Accordingly, an ink jet recording apparatus that suppresses left / right deviation of image characteristics (characteristics related to colors) while maintaining productivity will be described below.

  FIG. 1 is a schematic perspective view of an ink jet recording apparatus according to an embodiment. An ink jet recording apparatus 100 shown in FIG. 1 is an example of a serial type ink jet recording apparatus that moves a recording head in a uniaxial direction and transports a recording medium in a direction orthogonal to the moving direction of the recording head. The ink jet recording apparatus 100 performs recording while scanning the recording head in the width direction of the recording medium, conveys the recording medium after one or more scans are completed, and records the next recording line.

  The configuration of the scanning mechanism and the like hidden behind the ink jet recording apparatus 100 is indicated by a broken line. In the following embodiments, an example is shown in which an image (liquid deposit) is recorded (formed) by ejecting ink onto a sheet that is an example of an object.

  As shown in FIG. 1, the ink jet recording apparatus 100 includes a main scanning mechanism 2, a transport mechanism 3, and a roll paper storage unit 4. These units are arranged inside the apparatus main body 100a.

  In the main scanning mechanism 2, a guide rod 13 and a guide rail 14 are stretched between both side plates. The guide rod 13 and the guide rail 14 hold the carriage 15 so as to be slidable in the arrow A direction (main scanning direction). The carriage 15 is mounted with a recording head 15a (see FIG. 3) that ejects ink droplets of black (K), yellow (Y), magenta (M), and cyan (C). The recording head 15a records an image on the paper by ejecting ink while reciprocating in the main scanning direction (moving in the direction of arrow A) with respect to the paper.

  The main scanning mechanism 2 is disposed on one side in the paper width direction, a drive pulley 22 that is driven to rotate by the main scanning motor 21, and the other side in the paper width direction. A driven pulley 23 and a belt member 24 wound around the drive pulley 22 and the driven pulley 23 are provided.

  The driven pulley 23 is tensioned outward by a tension spring or the like, that is, in a direction away from the drive pulley 22. The belt member 24 pulls the carriage 15 in the width direction of the sheet by being partly fixed and held by a belt fixing portion provided on the back side of the carriage 15.

  Further, in order to detect the main scanning position of the carriage 15, an encoder sheet 40 (see FIG. 3) is arranged along the paper width direction (main scanning direction) of the carriage 15. The main scanning position of the carriage 15 is detected by reading the encoder sheet 40 by an encoder sensor provided on the carriage 15.

  In the recording area of the main scanning area of the carriage 15, the roll paper 30 is intermittently conveyed by the conveyance mechanism 3 in a conveyance direction (in the direction of arrow B in FIG. 1) that is a direction orthogonal to the width direction of the sheet. The The roll paper 30 is obtained by winding a paper (object) in a roll shape. The transport direction indicated by the arrow B direction is the sub-scanning direction.

  A main area containing ink of each color to be supplied to the sub-tank of the recording head 15a is located outside the carriage movement area in the width direction of the paper and on one end side of the main scanning area (left side in FIG. 1). The cartridge 18 is detachably attached to the apparatus main body 100a.

  In addition, an empty discharge receiver that receives ink droplets when performing an empty discharge operation for discharging ink droplets that do not contribute to recording in order to discharge thickened ink is provided in a region on one end side thereof. . When a predetermined condition is satisfied, each recording head 15a performs idle ejection for maintaining and recovering ink ejection performance at the idle ejection position of the idle ejection receiver.

  On the other hand, a maintenance / recovery mechanism 19 that performs maintenance / recovery of the recording head 15a is located outside the movement area of the carriage 15 and on the other end side of the main scanning area, that is, on the carriage home position side (right side in FIG. 1). Has been placed. The maintenance / recovery mechanism 19 includes caps for capping each nozzle surface of the recording head 15a, a wiper blade as a blade member for wiping the nozzle surface, and the like.

  In the ink jet recording apparatus, for example, an empty discharge receiver may be provided on the carriage home position side (right side in FIG. 1) and included in the maintenance and recovery mechanism in the same manner as the cap and the wiper blade. Further, in the ink jet recording apparatus, it is also possible to provide idle discharge receivers on both the carriage home position side (right side in FIG. 1) and the idle discharge position side (left side in FIG. 1).

  The roll paper storage unit 4 stores a roll paper 30 around which paper is wound as a recording medium for image recording. The roll paper storage unit 4 can also store roll papers having different paper width sizes.

  The roll paper 30 is accommodated in the roll paper accommodating portion 4 by mounting flanges 31 on both sides of the paper roll and placing the flanges 31 on the flange receivers 32. A support roller is provided inside the flange receiver 32, and the support roller contacts the outer periphery of the flange 31, so that the flange 31 rotates and the roll paper 30 is sent out to the conveyance path. Note that the paper is not limited to the roll paper 30 and can be applied to a serial inkjet printer that supports only small cut paper. Further, the present invention can also be applied to a flat-bed type inkjet apparatus in which a base material is disposed on a fixed base and an image is formed by moving a recording head in both the main scanning direction and the sub-scanning direction.

  Next, the heating unit provided in the transport mechanism 3 will be described. Drawing 2 is an explanatory view of the heating unit of an embodiment. The heating unit 50 heats the paper when ink is ejected by the recording head 15a, that is, when an image is recorded, and is an example of a heating unit.

  Specifically, as shown in FIG. 2, the transport mechanism 3 is provided with a heating unit 50 for heating the roll paper 30 transported in the transport direction (arrow B direction in FIG. 2). The heating unit 50 heats the roll paper 30 at an arbitrary temperature, thereby raising the temperature of the roll paper 30 and promoting the drying of the ink ejected from the carriage 15, so that an image is printed on the recording medium earlier than natural drying. It is to fix.

  The heating unit 50 is divided into eight equal blocks a to h (an example of a predetermined area) along the arrow A direction in which the carriage 15 reciprocates. The heating unit 50 can be arbitrarily set for each of the blocks a to h. Therefore, when ink is ejected from the carriage 15 (when an image is recorded), the roll paper 30 is adjusted to an arbitrary temperature for each of the blocks a to h along the direction of the arrow A and heated.

  The blocks a to h are areas corresponding to the test patches 71 (see FIG. 3) of the test chart 70 recorded on the paper. The heating unit 50 heats the sheet at a predetermined temperature that is set even when the test chart 70 is recorded on the sheet.

  Next, the colorimeter 16 supported by the carriage 15 of the ink jet recording apparatus 100 and the recording head 15a that ejects ink will be described. FIG. 3 is a diagram illustrating the recording head and the colorimeter supported by the carriage according to the embodiment. FIG. 3A is a diagram illustrating an arrangement state of the recording head. FIG. 3B is a diagram illustrating details of the recording head. The colorimeter 16 is an example of a measurement unit.

  As shown in FIG. 3A, in the ink jet recording apparatus 100 of this embodiment, a recording head 15a and a colorimeter 16 are supported by a carriage 15 held by a guide rod 13 and a guide rail 14. A test chart 70 is recorded on the roll paper 30 shown in FIG. 3A by the recording head 15a. In the test chart 70, eight test patches 71 corresponding to the blocks a to h (see FIG. 2) of the heating unit 50 are arranged and recorded along the main scanning direction.

  The colorimeter 16 performs colorimetry on the test patch 71 of the test chart 70 recorded on the roll paper 30, and here measures density, which is an image characteristic (characteristic related to color). Specifically, the colorimeter 16 moves on the roll paper 30 on which the test patch 71 is recorded by conveying the roll paper 30 in the direction of arrow B and reciprocating the carriage 15 in the direction of arrow A. When the colorimeter 16 moves to a position facing the test patch 71, the colorimeter 16 measures the density of the test patch 71. Thereby, the image characteristic along the main scanning direction can be measured. Thereafter, the heating temperature of the heating unit 50 is determined based on the densities of the eight test patches 71 obtained by the measurement.

  In the present embodiment, the image characteristic of the test chart 70 measured by the colorimeter 16 is the density, but the color and brightness may be used. That is, in the inkjet recording apparatus 100, the heating temperature of the heating unit 50 can be determined based on image characteristics including at least one of density, color, and brightness.

  Further, the colorimeter 16 may be any means that can measure image characteristics (density, color, lightness) from the test chart 70 recorded on the roll paper 30, and may be a colorimetric sensor, a spectrocolorimeter, a colorimetry. A camera or the like can be used. For example, in the case of a colorimetric camera, the image characteristics can be measured by calculating the colorimetric values of the test patch 71 based on the RGB values of the test patch 71 obtained by imaging.

  Hereinafter, in the present embodiment, a case where a reflective colorimetric sensor is used as the colorimeter 16 will be described. FIG. 4 is a diagram showing a mechanical configuration of a reflective colorimetric sensor. 4A is a longitudinal sectional view of the colorimetric sensor, and FIG. 4B is a bottom view of the colorimetric sensor.

  As shown in FIG. 4A, the colorimeter 16 is a colorimetric sensor in which an illumination light source 62, a light receiving unit 63, and a light shielding wall 64 are mounted on a substrate 61 fixed to the carriage 15. . The illumination light source 62 is configured using, for example, an LED.

  The light receiving unit 63 is configured by combining a plurality of light receiving elements 63a, 63b, and 63c having different spectral sensitivities (RGB sensitivities). In the example of FIG. 4B, the light receiving unit 63 is configured by a combination of a light receiving element 63a having a high R sensitivity, a light receiving element 63b having a high G sensitivity, and a light receiving element 63c having a high B sensitivity. . In addition to the light receiving elements 63a, 63b, and 63c, the light receiving unit 63 may be configured by further combining light receiving elements having spectral sensitivities of other colors such as gray, cyan, and orange.

  As shown by the arrow in FIG. 4A, the colorimeter 16 irradiates the test patch 71 printed on the roll paper 30 with illumination light from the illumination light source 62 and is reflected by the test patch 71. By making the reflected light incident on the light receiving unit 63, the color information of the test patch 71 is obtained.

  The light shielding wall 64 is disposed on the substrate 61 so as to surround each of the illumination light source 62 and the light receiving unit 63, blocks the influence of external light, and the illumination light from the illumination light source 62 directly enters the light receiving unit 63. It has a function to prevent (block stray light).

  Returning to the description of FIG. As shown in FIG. 3B, the recording head 15a is composed of nozzle rows K1, K2, C1, C2, M1, M2, Y1, and Y2 that discharge ink of each color of KCMY. The odd-numbered nozzle row and the even-numbered nozzle row are arranged at positions shifted by ½ of the nozzle pitch, thereby doubling the printing resolution per scan.

  Further, the nozzle rows that discharge CMY inks are arranged symmetrically in the main scanning direction in order to avoid bidirectional color differences due to the landing order of the ink colors. Specifically, the nozzle row M1 and then the nozzle row Y1 are provided to the left of the nozzle row C1, and the nozzle row M2 and then the nozzle row Y2 are provided to the right of the nozzle row C2 and It is arranged symmetrically at the boundary of the nozzle row C2. Note that the arrangement of the recording heads 15a is not limited to this, and the order of the CMY inks may be changed as long as the order of the colors of the CMY inks is symmetrical.

  Next, the hardware configuration of the inkjet recording apparatus 100 will be described. FIG. 5 is a diagram illustrating a hardware configuration of the ink jet recording apparatus according to the embodiment. As shown in FIG. 5, the ink jet recording apparatus 100 performs the reciprocating movement of the carriage 15 in the main scanning direction, the movement of the roll paper 30 in the transport direction, the ejection of ink by the recording head 15a, the heating of the heating unit 50, and the like. Done.

  As shown in FIG. 5, the inkjet recording apparatus 100 includes a CPU 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, an NVRAM (Non-Volatile Random Access Memory) 104, and an ASIC (Application Specific). Integrated Circuit) 105, host I / F 106, and I / O 107, carriage 15, main scanning motor 21, sub-scanning motor 112, heating unit 50, environmental sensor 118, and colorimetry. The instrument 16 and the operation panel 117 are connected. Since the carriage 15, the heating unit 50, and the colorimeter 16 have been described above, description thereof will be omitted.

  The CPU 101 is a central processing unit, and controls the entire inkjet recording apparatus 100 by executing various programs stored in the ROM 102 or the like.

  The ROM 102 is a nonvolatile memory, and stores a control program for the inkjet recording apparatus 100 and other fixed data. A RAM 103 is a volatile memory and is used as a work area for the CPU 101. The NVRAM 104 is a non-volatile memory and temporarily stores image data and the like.

  The ASIC 105 performs various signal processing, image processing for rearranging, and input / output signal processing for controlling the entire apparatus.

  The host I / F 106 is a communication interface for transmitting and receiving signals and various data to and from the host 900 that is an external device connected to a cable or a network.

  The I / O 107 inputs detection signals from the environment sensor 118, the colorimeter 16, and other various sensors and notifies the CPU 101 of them.

  The main scanning motor 21 is a drive motor that moves the carriage 15 in the main scanning direction. The sub-scanning motor 112 is a drive motor that transports the roll paper 30 in the transport direction.

  The environmental sensor 118 is a sensor that detects the environmental temperature and the environmental humidity of the inkjet recording apparatus 100. The operation panel 117 inputs and displays information for the ink jet recording apparatus 100.

  Here, the host 900 which is an external device is, for example, a PC (Personal Computer), other data processing device, an image reading device such as an image scanner, an imaging device such as a digital camera, or the like. The host 900 is connected to the inkjet recording apparatus 100 via a network such as a LAN.

  Specifically, the network transmission control unit of the host 900 is connected to the ink jet recording apparatus 100 via the network, receives the print processing status from the ink jet recording apparatus 100, and if printing is possible, to the ink jet recording apparatus 100. Send print data and so on. In the present embodiment, the host 900 develops image data included in the print data into bitmap data by the printer driver 910 provided in the host 900 and transfers the print data to the inkjet recording apparatus 100. In the inkjet recording apparatus 100, the CPU 101 reads out bitmap data stored in the reception buffer in the host I / F 106 and executes print processing.

  Note that the conversion of image data into bitmap data may be performed in the inkjet recording apparatus 100. In this case, for example, font data or the like is stored in the ROM 102, and the CPU 101 reads out the image data stored in the reception buffer in the host I / F 106 and converts it into bitmap data.

  Next, the functional configuration of the inkjet recording apparatus 100 will be described. FIG. 6 is a diagram illustrating a functional configuration of the ink jet recording apparatus according to the embodiment. As shown in FIG. 6, the inkjet recording apparatus 100 includes a head drive control unit 201, a main scanning motor drive control unit 203, a sub-scanning motor drive control unit 204, a print processing unit 211, and a heating temperature control unit 212. It has.

  The head drive control unit 201 controls the drive of the recording head 15a by generating a drive waveform of the corresponding nozzle based on the ink discharge color and the ink discharge amount for each pixel. The main scanning motor drive control unit 203 controls driving of the main scanning motor 21. The sub scanning motor drive control unit 204 controls driving of the sub scanning motor 112.

  The print processing unit 211 records an image on a recording medium such as the roll paper 30 with ink ejected from the recording head 15a. In the present embodiment, the print processing unit 211 records on the roll paper 30 a test chart 70 in which a plurality of test patches 71 are arranged along the scanning direction with ink ejected from the recording head 15a that reciprocates in the scanning direction. . The print processing unit 211 is an example of a formation processing unit.

  The heating temperature control unit 212 heats when the ink is ejected from the recording head 15a (when the image is recorded) based on the image characteristics measured from the image recorded by ejecting the ink from the recording head 15a onto the recording medium. The heating temperature of the unit 50 is determined and the heating unit 50 is controlled.

  In the present embodiment, the heating temperature control unit 212 measures the test chart 70 recorded by the print processing unit 211 with the colorimeter 16 and based on the measured density (image characteristics), the heating temperature of the heating unit 50. And the heating unit 50 is set to the determined heating temperature. The heating temperature control unit 212 can set the heating temperature of the heating unit 50 for each of the blocks a to h (an example of a predetermined region) of the heating unit 50. The heating temperature control unit 212 is an example of a control unit.

  Next, a method for determining the heating temperature of the heating unit 50 will be described. In the following, first, the left and right density deviations of an image recorded by the bidirectional recording method will be described (FIGS. 7 to 9), and then the heating temperature determination method will be described (FIGS. 10 and 11).

  FIG. 7 is a diagram showing a state of penetration of ink droplets having different landing time differences into the paper. FIG. 7 (a) shows the ink droplet penetration state when the landing time difference is small, and FIG. 7 (b) shows the comparison of the ink droplets when the landing time difference is larger than that in FIG. 7 (a). The penetration state is shown.

  7A and 7B, an ink droplet D1 indicates an ink droplet ejected by the recording head 15a in the forward path, and an ink droplet D2 indicates an ink droplet ejected by the recording head 15a in the same position on the return path. Show. The dots d1 and d2 formed by the ink droplets D1 and D2 on the roll paper 30 having a thickness P are shown by a cross-sectional view inside the roll paper 30.

  As shown in FIG. 7A, when the landing time difference is small, the dot d1 of the ink droplet D1 ejected in the forward landing path is not dried, and the dot of the ink droplet D2 ejected in the backward path d2 will land. In this way, when the dot d2 of the ink droplet D2 lands on the dot d1 of the ink droplet D1 that has not been sufficiently dried, the dot d2 of the ink droplet D2 easily penetrates into the roll paper 30, and the density of the dot d2 is low. Tend to be.

  On the other hand, as shown in FIG. 7 (b), when the difference in landing time is large compared to the case of FIG. 7 (a), the dot d1 of the ink droplet D1 ejected in the forward landing path is dried. In this state, the dot d2 of the ink droplet D2 ejected in the return path lands. Thus, when the dot d2 of the ink droplet D2 lands on the dot d1 of the ink droplet D1 that has been sufficiently dried, the dot d2 of the ink droplet D2 is less likely to penetrate into the roll paper 30, and the dot d2 has a high density. Can keep.

  That is, in FIG. 7B, an image having a higher density than that in FIG. 7A is recorded. As described above, the density difference (deviation of image characteristics) caused by the difference in the landing time of the ink droplets contributes to the ink permeability. For this reason, the permeability of ink with respect to the paper differs depending on the penetration characteristics depending on the type of paper and the printing environment (temperature / humidity).

  Next, the relationship between the ink landing time difference and the dot density of the landed ink will be described. FIG. 8 is a diagram showing the relationship between the landing time difference and the density of the dots of the ink that has landed twice. FIG. 8 shows the difference in landing time (second (s)) on the horizontal axis and the density (ratio) of ink dots that have been landed twice on the vertical axis, and the difference in landing time and the density of the ink dots that have landed twice. Represents a graph plotting the relationship between and.

  As shown by the plot trajectory shown in FIG. 8, the dot density increases as the landing time difference increases, and the density tends to saturate when the landing time difference exceeds a certain value. This is because when the difference in landing time exceeds a certain value, the first ink droplet is completely dried and the second ink droplet lands on the return path (or forward path).

  Specifically, the larger the landing time difference is, the first ink droplet landed on the forward path (or the return path) is completely dried, and the second ink droplet landed on the return path (or the forward path) and overlapped thereon. . For this reason, the larger the landing time difference, the more difficult the second ink penetrates into the paper, and the dot density tends to increase.

  On the other hand, as the landing time difference is smaller, the first ink droplet landed on the forward path (or the return path) is not completely dried, and the second ink droplet is landed and overlapped thereon on the return path (or the forward path). For this reason, the smaller the landing time difference, the more easily the second ink penetrates into the paper, and the dot density tends to decrease.

  Next, the right and left density deviations when performing high-speed printing in which one band region is completed by two (reciprocating) scans in bidirectional recording will be described. FIG. 9 is an image diagram of left-right density deviation in bidirectional recording.

  In FIG. 9, ink is ejected from the recording head 15a while scanning the carriage 15 in the forward direction (arrow A1 direction) in the first scan (first time), and the backward direction (arrow A2 direction) in the second scan (second time). Ink is ejected from the recording head 15 a while scanning the carriage 15.

  In this case, the dot density is low at the left end (corresponding to FIG. 7A) where the ink landing time difference between the first and second scans is small. On the other hand, at the right end (corresponding to FIG. 7B) where the landing time difference is large, the dot density is high. Therefore, as shown in FIG. 9, at the left and right end portions in one band, there are a “thin” portion on the left side and a “dark” portion on the right side, which are recognized as left and right density deviations.

  In FIG. 9, the dot density has been described, but in the case of color and lightness, as in the case of density, a left-right deviation occurs due to a difference in ink penetration depth due to a difference in landing time.

  In this embodiment, in order to suppress the density deviation between the left and right due to the difference in ink landing time, the heating unit 50 that heats the roll paper 30 based on the image characteristics measured by the heating temperature control unit 212 from the test chart 70. Control the heating temperature. FIG. 10 is an explanatory diagram related to the test chart. FIG. 10A is a diagram of a test chart composed of test patches. FIG. 10B shows the density distribution of the test chart.

  In the test chart 70 of FIG. 10A, eight test patches 71 corresponding to the blocks a to h of the heating unit 50 are recorded in the main scanning direction, and the eight test patches 71 are recorded in seven rows. . The heating temperature control unit 212 sets the heating temperature of the heating unit 50 for each scanning region (band), and prints the test chart 70 by bidirectional recording. In the present embodiment, the heating temperature of the heating unit 50 is set in increments of 5 ° C. from + 0 ° C. to + 30 ° C. with the ambient temperature at the time of printing the test chart 70 as a reference. FIG. 10 shows a case where the forward path in bidirectional recording is the A2 direction and the return path is the A1 direction.

  When the test chart 70 is printed, the colorimeter 16 measures the density that is the image characteristic of the test patch 71 on the test chart 70. And the heating temperature control part 212 graphs along a main scanning direction for every scanning area | region (band) based on the measured density | concentration, as shown in FIG.10 (b). The graphed data is stored in a storage unit such as the NVRAM 104, for example. In FIG. 10B, the horizontal axis represents the image position on the paper, the vertical axis represents the density, and the graph is plotted along the main scanning direction for each scanning region (band) (that is, for each heating temperature). The relationship between image position and density is shown.

  As shown in FIG. 10B, when the heating temperature by the heating unit 50 is + 0 ° C., the left-right density difference (the density difference between the position corresponding to the block a and the position corresponding to the block h) is large. It can be seen that the difference between the left and right density decreases as the heating temperature is increased. This is because, by heating the roll paper 30 by the heating unit 50, the ink dots ejected in the forward path are dried, so that the ink ejected in the forward path is dried in a state where the ink ejected in the forward path is dry even when the landing time difference is small. Because it is done.

  The heating temperature control unit 212 determines the heating temperatures of the blocks a to h of the heating unit 50 from the graphed density data as shown in FIG. Specifically, for example, the heating temperature control unit 212 determines the heating temperature of each of the blocks a to h of the heating unit 50 so that the left-right concentration deviation is smaller than a predetermined threshold value. As described above, the image characteristic of the test chart 70 printed on the paper (roll paper 30 or the like) on which the image is actually printed is measured in the same environment (temperature / humidity) as when printing, and the heating temperature of the heating unit 50 is blocked. Thus, when performing bidirectional recording, the image characteristics can be made uniform in the main scanning direction regardless of the paper brand and printing environment. As a result, it is possible to print an image in which the left-right deviation of the image characteristics due to the difference in landing time between the forward path and the return path is suppressed. FIG. 10 shows an example in which the heating temperature is determined based on the concentration, but the same applies to the case of color and lightness. In addition, as a heating control apparatus, the recording head 15a, the heating unit 50, the colorimeter 16, the print processing part 211, and the heating temperature control part 212 should just be provided at least.

  Next, the flow of processing for determining the heating temperature of the heating unit 50 in the inkjet recording apparatus 100 will be described. FIG. 11 is a flowchart illustrating the flow of the heating temperature determination process of the heating unit in the inkjet recording apparatus of the embodiment.

  First, the print processing unit 211 prints the test chart 70 in a state where the heating unit 50 heats the roll paper 30 with the set heating temperature (step S101). The colorimeter 16 measures the image characteristics of the printed test chart 70 (step S102), and the heating temperature control unit 212 graphs the measured image characteristics (step S103).

  The heating temperature control unit 212 determines a heating temperature with less left-right deviation of the image characteristics based on the graphed data of the image characteristics (Step S104), and sets the heating temperature of the heating unit 50 to the determined heating temperature. (Step S105). The inkjet recording apparatus 100 prints a desired image in a state where the heating unit 50 heats the roll paper 30 at the set heating temperature.

  As described above, in the inkjet recording apparatus 100 of the present embodiment, first, the test chart 70 is printed in a state where the sheet is heated by the heating unit 50 at the heating temperature set for each scanning region, and the printed image of the test chart 70 is printed. Measure characteristics. Based on the measured image characteristics (for example, density), the heating temperature of the heating unit 50 that reduces the left-right deviation of the image characteristics is determined, the determined heating temperature is set in the heating unit 50, and a desired image is printed. As a result, productivity is maintained, and characteristics (image characteristics) related to the color of liquid deposits (images) on the object (on the paper) when the liquid is discharged bidirectionally (during bidirectional recording) Deviation can be suppressed.

  Note that the program executed by the inkjet recording apparatus 100 of the present embodiment is provided by being incorporated in advance in a ROM or the like. The program executed by the inkjet recording apparatus 100 of the present embodiment is a file in an installable format or an executable format, and is a computer such as a CD-ROM, flexible disk (FD), CD-R, DVD (Digital Versatile Disk). The information may be provided by being recorded on a recording medium that can be read by the user.

  Furthermore, the program executed by the ink jet recording apparatus 100 according to the present embodiment may be configured to be provided by being stored on a computer connected to a network such as the Internet and downloaded via the network. Further, the program executed by the inkjet recording apparatus 100 of the present embodiment may be configured to be provided or distributed via a network such as the Internet.

  A program executed by the inkjet recording apparatus 100 of the present embodiment includes a module configuration including the above-described units (a head drive control unit, a main scanning motor drive control unit, a sub-scanning motor control unit, a print processing unit, and a heating temperature control unit). As actual hardware, the CPU (processor) reads the program from the ROM and executes it, so that the respective units are loaded onto the main storage device, and the respective units are generated on the main storage device. It has become. In addition, for example, some or all of the functions of the above-described units may be realized by a dedicated hardware circuit.

  In the above embodiment, an example in which an image, which is an example of a liquid deposit, is recorded (formed) on a sheet, which is an example of an object, is not limited to this. That is, the present invention can be applied as long as a liquid deposit having a color is formed on an object by discharging the liquid with a liquid discharge head and drying is performed. In the present embodiment, an example in which an image that is a liquid deposit is recorded on a sheet has been shown. However, the liquid deposit may be formed on an object having irregularities such as wallpaper.

  Further, in the above-described embodiment, the apparatus for ejecting the liquid provided with the heating control apparatus of the present invention has been described with reference to an example in which the apparatus is applied to an ink jet recording apparatus having a recording head that ejects ink and records on a recording medium. However, any apparatus that discharges liquid and records on a recording medium, such as a multifunction machine, a copier, a printer, or a facsimile machine, having at least two functions of a copy function, a printer function, a scanner function, and a facsimile function. Can be applied.

DESCRIPTION OF SYMBOLS 2 Main scanning mechanism 3 Conveyance mechanism 4 Roll paper accommodating part 13 Guide rod 14 Guide rail 15 Carriage 15a Recording head 16 Colorimeter 18 Main cartridge 19 Maintenance recovery mechanism 21 Main scanning motor 22 Drive pulley 23 Driven pulley 24 Belt member 30 Roll paper DESCRIPTION OF SYMBOLS 31 Flange 32 Flange receptacle 40 Encoder sheet 50 Heating unit 61 Board | substrate 62 Illumination light source 63 Light-receiving part 63a, 63b, 63c Light-receiving element 64 Light-shielding wall 70 Test chart 71 Test patch 100 Inkjet recording device 100a Device main body 112 Sub-scanning motor 117 Operation panel 118 Environmental sensor 201 Head drive control unit 203 Main scanning motor drive control unit 204 Sub-scanning motor drive control unit 211 Print processing unit 212 Heating temperature control unit 900 Host 910 Pre Motor driver

JP 2004-181698 A

Claims (10)

A liquid ejection head that ejects liquid while reciprocating in the scanning direction with respect to the object;
A heating unit that heats the object when the liquid is ejected by the liquid ejection head;
A control unit that controls the heating temperature of the heating unit when discharging the liquid, based on characteristics related to the color of the liquid deposit formed by discharging the liquid onto the object;
A heating control device. A formation processing unit that forms a test chart on the object by the liquid discharged from the liquid discharge head;
A measurement unit that measures characteristics relating to the color of the test chart formed on the object,
The heating control device according to claim 1, wherein the control unit controls a heating temperature of the heating unit based on characteristics relating to the color of the test chart.   The heating control apparatus according to claim 2, wherein the heating unit heats the object when the test chart is formed on the object.   The heating control apparatus according to claim 2, wherein the formation processing unit forms the test chart in which a plurality of test patches are arranged along the scanning direction. The heating unit heats the object for each predetermined region corresponding to each of the test patches along the scanning direction,
The heating control device according to claim 4, wherein the control unit controls a heating temperature of the heating unit for each of the predetermined regions based on characteristics regarding the color of the test chart.   The heating control device according to any one of claims 1 to 5, wherein the color-related characteristics include at least one of density, color, and brightness.   The apparatus which discharges the liquid provided with the heating control apparatus as described in any one of the said Claims 1-6.   A heating control system comprising the heating control device according to any one of claims 1 to 6. In the heating control method executed in the heating control device,
The heating control device
A liquid ejection head that ejects liquid while reciprocating in the scanning direction with respect to the object;
A heating unit that heats the object when the liquid is ejected by the liquid ejection head,
A heating control method including a control step of controlling a heating temperature of the heating unit at the time of discharging the liquid based on a characteristic relating to a color of a liquid deposit formed by discharging the liquid onto the object. Provided in an apparatus for ejecting liquid, comprising: a liquid ejection head that ejects liquid while reciprocating in a scanning direction with respect to an object; and a heating unit that heats the object when the liquid is ejected by the liquid ejection head. On the computer,
The program for performing the control step which controls the heating temperature of the said heating part at the time of discharge of the said liquid based on the characteristic regarding the color of the liquid deposit formed by discharging the said liquid to the said target object.