JP2011126123A - Inkjet recorder and recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recorder capable of correctly grasping an impact amount of ink acceptable for a recording medium, and a recording method. <P>SOLUTION: The inkjet recorder records a plurality of test patterns with different impact amounts of ink. A variable for detecting the limitation of ink-receiving performance of the recording medium in each test pattern and a threshold of the variable corresponding to the type of the detected recording medium are compared by the inkjet recorder. Based on the compared result, the inkjet recorder selects the test pattern with the most impact amount of ink among a plurality of test patterns in a range not exceeding the receiving performance of the recording medium. Then, the ink-discharging operation with a recording head is controlled by the inkjet recorder based on the selected test pattern. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus that records a test pattern in order to select and create parameters used for recording a recorded image, and a recording method using the ink jet recording apparatus.

  In recent years, ink jet recording apparatuses that perform recording by ejecting ink droplets from a recording head have been rapidly spreading. The ink jet recording apparatus is advantageous in that it can be easily downsized and color recording can be performed relatively easily.

  When recording is performed by the ink jet recording apparatus, image processing such as color correction and ink color separation is appropriately performed on the input image in accordance with the characteristics of the recording medium to improve the image quality of the recorded image. For example, a plurality of test patterns are recorded on a recording medium by a recording device, and an appropriate parameter is selected from an application or driver for driving the recording device based on an image on which the test pattern is recorded. Sometimes done. As a result, by selecting parameters suitable for the recording medium and the recording environment and performing recording, it is possible to obtain a good recorded image.

  As described above, when the test pattern is recorded in advance on the recording medium, the parameters suitable for recording are selected, and the parameters used for recording are determined based on the selected test pattern, the ink ejection rate to the recording medium May be determined from the test pattern. Patent Document 1 discloses a recording apparatus in which an ink ejection rate is determined from a test pattern, a parameter used for recording is selected and created according to the determined ink ejection rate, and recording is performed according to the parameter. It is disclosed.

JP-A-8-72236

  However, the amount of ink that can be absorbed by the recording medium varies depending on the conditions under which recording is performed. For example, the amount of ink that can be received by the recording medium varies depending on the thickness of the recording medium. Also, the amount of ink that can be received by the recording medium varies depending on the external environment such as ambient temperature and humidity. On the other hand, in the method according to Patent Document 1, it is stated that the printing apparatus corrects the ink shot amount according to the external environment. However, in Japanese Patent Laid-Open No. 2004-260688, the ink ejection rate is corrected by estimating the variation in the amount of ink that can be received by the recording medium in accordance with changes in the external environment. The amount of correct ink may not be accurate. Therefore, parameters and recording modes used for recording may be selected and created based on an inaccurate ink amount of the recording medium, and recording may be performed, which may reduce the quality of the recorded image. .

  Accordingly, in view of the above circumstances, an object of the present invention is to provide an ink jet recording apparatus and a recording method capable of accurately grasping the amount of ink that can be received by a recording medium.

  The ink jet recording apparatus of the present invention is a recording in which recording is performed in an ink jet recording apparatus having a recording head for recording by ejecting ink onto a recording medium and a recording control means for controlling the ink ejection operation by the recording head. Recording medium type detecting means for detecting the type of medium, test pattern recording means for recording a plurality of test patterns having different ink ejection amounts, and the capacity of the recording medium to receive ink set for each type of recording medium Threshold storage means for storing a threshold value of a variable for detecting a limit; the variable in each of the test patterns; and the threshold value of the variable corresponding to the type of the recording medium detected by the recording medium type detection means. Based on the results of the comparison, the plurality of test patterns should not exceed the capacity of the recording medium. A test pattern selection unit that selects a test pattern having the largest amount of ink applied in the range, and the recording control unit discharges ink by the recording head based on the test pattern selected by the test pattern selection unit. The operation is controlled.

  Also, the recording method of the present invention performs recording using an ink jet recording apparatus having a recording head for recording by discharging ink onto a recording medium and a recording control means for controlling the ink discharging operation by the recording head. In the recording method, a recording medium type detecting step for detecting a type of a recording medium on which recording is performed, a test pattern recording step for recording a plurality of test patterns having different ink placement amounts, and a recording medium in each of the test patterns is an ink And comparing the variable for detecting the limit of the acceptability to receive the threshold value of the variable corresponding to the type of the recording medium detected in the recording medium type detection step, and based on the comparison result, The test pattern with the largest amount of ink applied is within the range that does not exceed the capacity of the recording medium. A test pattern selecting step of-option, on the basis of the test patterns selected by the test pattern selection process, and having a discharge operation control step of controlling the discharging operation of the ink by the recording head.

  According to the present invention, since it is possible to accurately grasp the amount of ink that can be received by the recording medium, parameters and recording modes used for recording can be selected based on the amount of ink that can be accurately received by the recording medium. Can be created and recorded. Therefore, the quality of the recorded image can be kept high.

It is the typical perspective view shown about the principal part of the inkjet recording device which concerns on embodiment of this invention. FIG. 2 is a schematic side view showing an enlarged view of a carriage periphery in the ink jet recording apparatus of FIG. 1. FIG. 2 is a schematic cross-sectional view showing an enlarged area around a multi-sensor in the ink jet recording apparatus of FIG. 1. FIG. 2 is a block diagram of a control system in the ink jet recording apparatus of FIG. 1. 2 is a flowchart showing a control flow when recording is performed by the ink jet recording apparatus of FIG. 1. It is explanatory drawing for demonstrating the test pattern recorded by the inkjet recording device of FIG. 6 is a graph showing the relationship between the optical density and the ink ejection amount, with the horizontal axis representing the ink ejection amount and the vertical axis representing the optical density from the plurality of test patterns in FIG. 5. FIG. 2 is an explanatory diagram for explaining a shift between an ideal scheduled recording line and a recorded line as a result of blurring of a line actually recorded by the ink jet recording apparatus of FIG. 1.

  Hereinafter, an inkjet recording apparatus according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic perspective view of a main part for explaining a schematic configuration of an ink jet recording apparatus 100 to which the present invention can be applied. The ink jet recording apparatus 100 is a serial scanning type recording apparatus, and is guided by a guide shaft 120 so that the carriage 101 can move in the main scanning direction. The carriage 101 is formed to be reciprocally movable in the main scanning direction by a driving force transmission mechanism such as a carriage motor and a belt for transmitting the driving force. An ink jet recording head 102 and an ink tank 121 that supplies ink to the ink jet recording head 102 are mounted on the carriage 101. The recording head 102 and the ink tank 121 may constitute an ink jet cartridge. The ink jet recording apparatus 100 sequentially records images on the recording medium 103 by repeating a recording operation and a conveying operation for conveying the recording medium 103 in the sub-scanning direction by a distance corresponding to the recording width. In the recording operation, the ink jet recording apparatus 100 performs recording by ejecting ink toward the recording area of the recording medium 103 while moving the recording head 102 in the main scanning direction.

  FIG. 2 is a cross-sectional view schematically showing an enlarged view around the inkjet recording head 102 in the inkjet recording apparatus 100. The ink jet recording head 102 has a plurality of ejection openings capable of ejecting a plurality of color inks and black ink.

  A plate-like platen 104 for receiving the recording medium 103 is provided at a position corresponding to the ink jet recording head 102 in the ink jet recording apparatus. The platen 104 is provided with a plurality of fine suction ports, and the air is sucked from the suction ports, whereby the recording medium 103 is sucked and adhered to the platen 104.

  The ink jet recording apparatus 100 is provided with a paper discharge roller 105 for conveying a recording medium. An auxiliary roller 106 is provided at a position corresponding to the transport roller 105 so as to rotate following the transport roller 105. The recording medium 103 is conveyed in the sub-scanning direction on the platen 104 by driving the conveying roller 105 with the recording medium 103 sandwiched between the conveying roller 105 and the auxiliary roller 106.

  Further, the carriage 101 is provided with an optical sensor 107 for reading a maximum ink ejection amount determination pattern on a recording medium to be described later. The optical sensor 107 has a light emitting means that can irradiate the ink droplets that have been ejected onto the recording medium with irradiation light. Further, the optical sensor 107 has a light receiving means capable of receiving the reflected light reflected by the ink droplets on the recording medium when the light emitted from the light emitting means is reflected. As the light receiving means in the optical sensor 107, a known CCD camera can be used. The carriage 101 is provided with a multi-sensor 108 for determining the thickness of the recording medium and the type of the recording medium.

  FIG. 3 is an enlarged schematic cross-sectional view of the multisensor 108. In order to detect the thickness of the recording medium 103, the multi sensor 108 includes an infrared LED 221 as a light emitting unit and a reading sensor 203 as a light receiving unit. When detecting the thickness of the recording medium 103, light is irradiated from the infrared LED 221 attached to the platen 104 toward the reading sensor 202 through the recording medium 103. Here, the light irradiated by the infrared LED 221 is infrared. At this time, by detecting the amount of light received and read by the reading sensor 202, the amount of light irradiated from the platen 104 side and passing through the recording medium 103 is detected, and the thickness of the recording medium 103 is detected. Is done.

  The multi-sensor 108 has an infrared LED 220 as a light emitting unit and a reading sensor 203 as a light receiving unit in order to detect the reflectance of the recording medium 103. When detecting the reflectance of the recording medium 103, infrared light is emitted from the infrared LED 220 attached to the carriage 101 toward the recording medium 103. At this time, of the light emitted from the infrared LED 220, the light reflected by the recording medium 103, reaches the reading sensor 203, and the amount of light received by the reading sensor 203 is read. Thus, the reflectance of the recording medium 103 is detected by detecting the amount of reflected light.

  FIG. 4 is a block diagram showing the configuration of the control system in the inkjet recording apparatus 100. An interface 201 for inputting image data from an external personal computer or the like is connected to the control unit 300. The control unit 300 includes a CPU 301, a ROM 302, and a RAM 303. The control unit 300 controls the inkjet recording apparatus 100 based on various signals, data, and the like input from the interface 201, sensor 202, sensor 203, optical sensor 107, and operation panel 204. Here, the control unit 300 drives and controls the inkjet recording head 102, the carriage driving device 210 that drives the carriage 101, and the recording medium conveyance unit 211. As described above, the control unit 300 functions as a recording control unit that controls the ink ejection operation by the recording head 102.

  Next, control of the inkjet recording apparatus 100 when recording is performed by the inkjet recording apparatus 100 will be described with reference to FIG. FIG. 5 is a flowchart showing a control flow when recording is performed by the inkjet recording apparatus 100 of the present embodiment. First, in step S <b> 1, the recording medium 103 is set in the paper feeding unit of the inkjet recording apparatus 100. Then, the recording medium 103 is conveyed to a position corresponding to the carriage 101 by driving the recording medium conveying unit 211. Next, in step S2, the type of recording medium (glossy paper, plain paper, matte paper, art paper, synthetic paper, cloth, etc.) is selected (recording medium type detection step). At this time, the thickness and reflectance of the recording medium 103 are detected by the multisensor 108 shown in FIG. 4, and the type of the recording medium is automatically determined from these detected values. As described above, in this embodiment, the multi-sensor 108 functions as a recording medium type detection unit that detects the type of recording medium on which recording is performed. Note that the type of the recording medium may be input by the user.

  In order to set the maximum ink ejection amount in step S3, as shown in FIG. 6, a plurality of maximum ink ejection amount determination patterns as test patterns are recorded on the recording medium while changing the ink ejection amount. (Test pattern recording process). In the present embodiment, the recording head 102 records a plurality of maximum ink ejection amount determination patterns on a recording medium, and the recording head 102 functions as a test pattern recording unit that records a plurality of test patterns having different ink ejection amounts. In the present embodiment, a plurality of maximum ink ejection amount determination patterns are recorded while changing the ink ejection amount per unit area by 40%. Note that the interval between the ink ejection amounts in the plurality of maximum ink ejection amount determination patterns is not limited to 40%. A plurality of maximum ink hit amount determination patterns may be recorded while changing the ink hit amount at intervals smaller than 40%, or a plurality of maximum ink hits while changing the ink hit amount at intervals larger than 40%. A driving amount determination pattern may be recorded. Further, the maximum ink ejection amount determination pattern is recorded when the ink ejection amount per unit area on the recording medium is 120 to 240%. Here, the ink ejection amount refers to the ratio (recording duty) of the area occupied by the ejected ink to the recording medium per unit area. For example, when the ink ejection amount is 100%, it is assumed that an ink droplet corresponding to a dot having an area just equal to the unit area is ejected as a result of the ink being ejected onto the recording medium. In addition, when recording is performed by scanning the same location a plurality of times, or when different types of ink are applied in an overlapping manner, an ink droplet corresponding to a dot with an ink placement amount of 100% has been applied twice in the same location. In the state, the ink shot amount indicates 200%.

  In the present embodiment, it is preferable that the maximum ink ejection amount determination pattern performs recording up to the ink ejection amount in an area exceeding the allowable value of the recording medium in order to calculate the limit value of the ink ejection amount permitted by the recording medium. . In the present embodiment, recording is performed up to an ink ejection amount in an area that exceeds the allowable value of the recording medium with respect to the ink ejection amount under any of the following three conditions (amount of ink saturation, amount of deviation regarding bleeding, amount of blurring regarding density). It is preferable to carry out.

  The plurality of maximum ink hit amount determination patterns recorded in this way are read by the optical sensor 107 (step S4). Then, the maximum ink hit amount determination pattern is selected from a plurality of recorded maximum ink hit amount determination patterns within a range not exceeding the ink receiving ability of the recording medium (test pattern selection step). Then, based on the selected maximum ink deposition amount determination pattern, the maximum ink ejection amount under the conditions at this time is calculated (step S5). This calculation method will be described later in detail. Then, a printing mode and image processing parameters are created and selected according to the maximum ink ejection amount on the printing medium calculated in step S5 (step S6). In selecting a recording mode, a suitable recording mode is selected from a plurality of recording modes stored in advance in a memory such as ROM and RAM of the recording apparatus as shown in Table 1, and the selected recording mode is used. Recording may be performed. As described above, the control unit 300 controls the ink ejection operation by the recording head 102 based on the selected test pattern (ejection operation control process).

  Then, recording is started using the recording mode and image processing parameters selected in step S6 (step S7).

(Explanation of calculation of maximum ink ejection amount on recording medium)
Here, a method for calculating the maximum ink ejection amount in the recording medium will be described in detail.

  With respect to the maximum ink ejection amount determination pattern shown in FIG. 6, a test pattern is recorded that can measure at least ink saturation, a boundary between different types of ink, and a deviation relating to density.

  Further, in the ink jet recording apparatus of the present embodiment, a variable is set for each type of recording medium, and a variable for detecting the limit of the ability of the recording medium to receive ink is set. In the present embodiment, for each condition such as the detected ink saturation, the amount of deviation related to bleeding, and the amount of deviation related to density, a variable for detecting the limit of the receiving ability of the recording medium to receive ink under these conditions. Is set. As described above, in this embodiment, a plurality of types of variables are used for detecting the limit of the receiving ability to receive ink on the recording medium. Each of the variables has a threshold value that becomes a limit of the ability to receive ink by the recording medium in order to keep the quality of the recorded image high for each type of recording medium. In the present embodiment, this threshold varies depending on the type of material forming the recording medium, and a threshold corresponding to the material of the recording medium is set. In the present embodiment, these threshold values are stored in storage means such as the ROM 302 and the RAM 303. As described above, in this embodiment, the ROM 302 and the RAM 303 function as a threshold storage unit that stores a threshold value of a variable for detecting the limit of the receiving ability of the recording medium to receive ink. In particular, in the present embodiment, the ROM 302 and the RAM 303 store threshold values for a plurality of variables set for a plurality of types of variables for each type of recording medium. When calculating the maximum ink ejection amount in the recording medium here, the maximum ink ejection amount that does not exceed the threshold is calculated for each condition. Then, among the calculated ink ejection amounts relating to the respective conditions, the minimum ink ejection amount may be set as the maximum ink ejection amount for the recording medium. By calculating the maximum ink ejection amount in this way, the ink ejection amount is set so as not to exceed the threshold value for each condition for all conditions, so that the quality of the recorded image is kept high. Further, since the maximum ink hit amount is calculated in the range of ink hits that do not exceed the thresholds for each condition for all the conditions, the ink density is expressed in a wide range. The image quality is further improved.

  Table 2 shows thresholds relating to the respective conditions for each type of recording medium. As shown in Table 2, the reason for changing the threshold depending on the type of the recording medium is that the required image characteristics differ depending on the type of the recording medium. For example, when the recording medium is glossy paper, it is often used for photo purposes. Therefore, it is better to set the ink ejection amount with priority on the fine sharpness in the recorded image. For this reason, when the recording medium is glossy paper, it is better to give priority to the amount of deviation relating to bleeding and the amount of deviation relating to density, and to set the maximum ink ejection amount in a state where the recording medium has a margin with respect to these conditions. .

  On the other hand, cloth-type recording media such as cross media have many uses as seen from a distance. For this reason, it is better to set the maximum ink ejection amount by giving priority to the conditions related to the saturation of the ink on the recording medium than giving priority to the sharpness as in the case of glossy paper. For this reason, the maximum ink ejection amount is calculated in a state where the recording medium has a margin with respect to the conditions regarding the saturation of the ink on the recording medium.

  First, a method for calculating the maximum ink ejection amount within a range that does not exceed the limit of the ink absorption capability of the recording medium will be described as to whether the recording medium is saturated with ink. When detecting whether or not the ink is saturated in the recording medium when ink is applied to the recording medium, the relationship between the optical density (OD) and the amount of ink applied can be determined by examining the slope A of the tangent at that amount. good. The optical density for each ink ejection amount on the recording medium can be obtained by detecting the optical density of each of the plurality of maximum ink ejection amount discrimination patterns recorded while changing the ink ejection amount.

  FIG. 7 is a graph showing the relationship between the optical density (OD) and the ink ejection amount, with the horizontal axis representing the ink ejection amount (%) and the vertical axis representing the optical density (OD). The optical density of each maximum ink hit amount determination pattern here is detected by an optical sensor 107 provided on the carriage 101. As shown in FIG. 7, the slope A is larger when the recording medium is glossy paper than when the recording medium is cloth when the ink ejection amount is 160%. If the value of the slope A is large, it indicates that there is still room for the ratio of the area occupied by the ink to increase as ink is applied to the recording medium. That is, it is shown that the density of the image is further increased by further ejecting ink into the recording medium, and the recording medium is not yet saturated with ink. Therefore, if the inclination A does not exceed the threshold value and shows a tendency to increase, it indicates that the recording medium is not yet saturated.

  On the other hand, if the value of the slope A is small, the ratio of the ink area to the recording medium does not change much even if ink is further applied to the recording medium, and the image density does not increase. Therefore, in a region where the value of the slope A is small, it indicates that the recording medium is sufficiently filled with ink, and in that portion, the density is almost saturated with respect to the ink ejection amount. .

  For example, in the case of glossy paper in the present embodiment, as a result of determining from the maximum ink amount determination pattern, the slope A of the graph just satisfies the threshold value of 0.03 or less with a test pattern of 240%. Therefore, it is determined that the maximum ink placement amount of the glossy paper of this embodiment is 240%. Further, in the case of mat-coated paper, the slope A of the graph is 160% or more in the 160% pattern, but the density threshold value 0.02 or less is satisfied in the 200% pattern. Therefore, the maximum ink ejection amount on this recording medium may be determined to be 180%.

  However, as described above, a plurality of test patterns shown in FIG. 6 are formed by changing the ink ejection amount by 40%. As described above, since a plurality of test patterns are discretely formed with respect to the ink ejection amount, it is difficult to calculate the slope A of the graph with the ink ejection amount in which each test pattern is formed. Therefore, the slope of the graph between the ink placement amount x1 and the ink placement amount x2 that is 40% larger than the ink placement amount x1 is calculated, and the value of the ink placement amount x1 when the slope falls below the threshold value is It may be set as the maximum ink ejection amount on this recording medium. Further, the value of the ink ejection amount x2 when the slope of the graph between x1 and x2 falls below the threshold value may be set as the maximum ink ejection amount on this recording medium, or the ink ejection amount x1 when the slope falls below the threshold value. , X2 may be set as the maximum ink ejection amount.

  In order to calculate the maximum ink ejection amount of the recording medium under these conditions, the maximum ink ejection amount in the range where the slope A is equal to or larger than the threshold in the relationship between the optical density and the ink ejection amount shown in FIG. Select the pattern to be That is, a pattern having the maximum ink ejection amount in the range where the slope A is equal to or greater than the threshold value is selected. Then, from the selected test pattern, the maximum ink hit amount on the recording medium in the range where the slope A is equal to or larger than the threshold value is calculated. At this time, the slope of the graph as a variable in each test pattern is compared with a threshold relating to the slope of the graph corresponding to the detected type of the recording medium. Then, based on the comparison result, a test pattern having the largest ink ejection amount is selected from a plurality of test patterns within a range not exceeding the ink receiving ability of the recording medium. At this time, in this embodiment, based on the signal value from the optical sensor 107, the control unit 300 selects a test pattern having the largest ink ejection amount from a plurality of test patterns within a range not exceeding the ink receiving ability of the recording medium. select. Thus, the control unit 300 functions as a test pattern selection unit. As a result, the maximum ink ejection amount can be calculated within the range of the ink ejection amount where the ink is not saturated on the recording medium.

  Next, a description will be given of a method for calculating the maximum ink ejection amount within a range that does not exceed the limit regarding the ink receiving ability of the recording medium with respect to the deviation amount related to bleeding.

When considering the effect of blur on the recorded image with respect to the amount of deviation due to bleeding, the standard deviation of the deviation from the ideal recording position of the recorded image (recording position standard deviation) ) Is used. For the displacement (rippling) of the position of the recorded image due to blurring, the radgetness according to ISO 13660 is used. FIG. 8 shows a shift amount when a shift occurs between an ideal scheduled recording line and a recorded line as a result of blurring of the actually recorded line. If the shift amounts of the shift generated between the line recorded by blurring and the ideal scheduled recording line are d1, d2,... Di, the standard deviation regarding the shift is expressed by the following equation.
Standard deviation of deviation (μm) related to bleeding = √Σdi ² / n
The value of this standard deviation increases as the amount of bleeding increases.

  In general, this blur increases as the amount of ink applied to the recording medium increases. If the amount of ink applied is excessively increased and the bleeding is excessively increased accordingly, this may affect the recorded image and reduce the quality of the recorded image. Therefore, as shown in Table 2, a threshold value is set for each recording medium with respect to the standard deviation of the deviation amount related to the blur so that the blur does not affect the recorded image. In the present embodiment, the ROM 302 and the RAM 303 store threshold values for the recording position standard deviation for each type of recording medium.

  In this embodiment, a test pattern having the largest ink ejection amount is selected from the plurality of maximum ink ejection amount determination patterns recorded in step S3 within a range that does not exceed the threshold for the standard deviation of the deviation amount related to bleeding. Is done. Then, based on the test pattern selected at this time, the maximum ink hit amount on the recording medium is calculated in a range where the standard deviation of the amount of deviation regarding bleeding on the recording medium is equal to or less than the threshold value.

  As described above, the variable for detecting the limit of the receptive capacity for receiving ink of the recording medium here is the recording position standard which is the standard deviation of the deviation amount of the recording position from the ideal recording position in the recorded image. Deviation is used. Then, a test pattern having the largest ink ejection amount is selected from a plurality of test patterns in a range where the recording position standard deviation is equal to or less than a threshold value for the recording position standard deviation corresponding to the type of the detected recording medium.

  Next, a description will be given of a method for calculating the maximum ink ejection amount within a range that does not exceed the limit of the recording medium with respect to the deviation amount related to density.

If the amount of ink applied per unit area to the recording medium is excessively large, microbeading may occur in the recorded image due to insufficient ink receptivity by the recording medium. Therefore, regarding the amount of deviation of the density from the ideal density, when considering the effect of the density deviation on the recorded image, the standard deviation of the deviation of the density in the recorded image from the ideal density (density standard). Deviation) is used. Assuming that OD1, OD2,... ODi are the deviation amounts of the deviation generated between the density of the pattern recorded in the test pattern and the ideal density, the standard deviation regarding the density is expressed by the following equation.
Standard deviation of deviation with respect to concentration = √ΣODi ² / n

  The standard deviation value increases as the deviation amount related to the density increases. Further, the deviation amount related to the density generally increases as the ink ejection amount increases. If the ink ejection amount becomes excessively large and the deviation amount related to the density becomes excessively large accordingly, this may affect the recorded image and may deteriorate the quality of the recorded image. Therefore, as shown in Table 2, a threshold value is set for each recording medium with respect to the standard deviation of the deviation amount relating to the density so that the deviation relating to the density does not affect the recorded image. In the present embodiment, the ROM 302 and RAM 303 store threshold values for density standard deviation for each type of recording medium. In the present embodiment, the density shift amount ODi is detected by the optical sensor 107.

  As described above, the variable for detecting the limit of the receptive capacity to receive ink of the recording medium here is a density standard deviation which is a standard deviation of a deviation amount from an ideal density of the recorded image. is there.

  Then, a test pattern having the largest ink ejection amount is selected from a plurality of maximum ink ejection amount determination patterns recorded in step S3 within a range where the standard deviation of the deviation amount relating to the density does not exceed the threshold value. As described above, a test pattern having the largest ink ejection amount is selected from a plurality of test patterns within a range equal to or less than the threshold value for the density standard deviation corresponding to the type of the recording medium in which the density standard deviation is detected. Then, based on the test pattern selected at this time, the maximum ink ejection amount on the recording medium is calculated in a range where the standard deviation of the deviation amount relating to the density on the recording medium is equal to or less than the threshold value.

  As described above, the maximum ink ejection amount is calculated within a range that does not exceed the threshold in each of the conditions of the ink saturation, the deviation amount relating to the bleeding, and the deviation amount relating to the density. Then, the maximum ink ejection amounts under the respective conditions are compared with each other, and the minimum ink ejection amount among these maximum ink ejection amounts is set as the maximum ink ejection amount in the recording medium to be detected. Then, the ink ejection operation is controlled based on the ink ejection amount in the test pattern having the smallest ink ejection amount among the selected test patterns. That is, the control unit 300 controls the ink ejection operation by the recording head 102 based on the test pattern having the smallest ink ejection amount among the plurality of test patterns selected for each of the plurality of variables. The plurality of variables in the present embodiment are a slope A, a recording position standard deviation, and a density standard deviation in the relationship between the optical density and the ink ejection amount. Of the maximum ink ejection amount for each variable, the minimum ink ejection amount is set as the maximum ink ejection amount for the recording medium. Therefore, the maximum ink ejection amount within a range not exceeding the limit of the recording medium for all conditions. Is set. Accordingly, it is possible to suppress the occurrence of ink bleeding, microbeading, and the like that affect the recorded image due to the ink being excessively applied beyond the limit of the recording medium.

  Table 3 shows an example of the calculation result of the actual maximum ink ejection amount for each recording medium. The maximum ink ejection amount is calculated within a range that does not exceed the threshold value for each condition, and the minimum ink ejection amount under each condition is calculated as the maximum ink ejection amount for each recording medium.

  Although the present embodiment has been described using a serial scan type inkjet recording apparatus, the present invention is not limited to this. However, the present invention is also applicable to a full-line type recording apparatus that extends over the entire width direction of the recording medium and performs recording using a recording head that does not perform scanning.

  In the present specification, “recording” is used not only for forming significant information such as characters and graphics but also for any case. It also represents the case where images, patterns, patterns, etc. are widely formed on a recording medium, or the recording medium is processed, regardless of whether it is manifested so that it can be perceived by human eyes. And

  The “recording device” includes a device capable of recording such as a printer, a printer multifunction device, a copier, and a facsimile device, and a manufacturing device that manufactures an article using an inkjet technique.

  “Recording medium” means not only paper used in general recording apparatuses but also a wide range of materials that can accept ink, such as cloth, plastic film, metal plate, glass, ceramics, wood, leather, etc. Shall.

  Furthermore, “ink” (sometimes referred to as “liquid”) should be interpreted widely as in the definition of “recording”. By being applied on the recording medium, it can be used for formation of images, patterns, patterns, etc., processing of the recording medium, or ink processing (for example, solidification or insolubilization of the colorant in the ink applied to the recording medium). It shall represent a liquid.

DESCRIPTION OF SYMBOLS 100 Inkjet recording apparatus 102 Recording head 103 Recording medium

Claims (6)

In an ink jet recording apparatus comprising: a recording head that performs recording by discharging ink to a recording medium; and a recording control unit that controls an ink discharging operation by the recording head.
Recording medium type detecting means for detecting the type of recording medium on which recording is performed;
Test pattern recording means for recording a plurality of test patterns having different ink ejection amounts;
Threshold storage means for storing a threshold value of a variable that is set for each type of the recording medium and that detects a limit of the receiving ability of the recording medium to receive ink;
The variable in each of the test patterns and the threshold value of the variable corresponding to the type of the recording medium detected by the recording medium type detection means, based on the comparison results, from the plurality of test patterns, A test pattern selection means for selecting a test pattern having the largest amount of ink ejection within a range not exceeding the receiving capacity of the recording medium;
The ink jet recording apparatus, wherein the recording control unit controls an ink ejection operation by the recording head based on a test pattern selected by the test pattern selecting unit. A plurality of variables are used for detecting the limit of the capacity of receiving the ink of the recording medium,
The threshold storage means stores thresholds of a plurality of variables set for a plurality of types of the variables for each type of recording medium,
The test pattern selection unit compares the variable in the test pattern with a threshold value of the variable corresponding to the type of the recording medium detected by the recording medium type detection unit for each of a plurality of types of variables. On the basis of the result, the test pattern having the largest ink ejection amount is selected from the plurality of test patterns within a range not exceeding the receiving capacity of the recording medium,
The recording control unit controls an ink ejection operation by the recording head based on a test pattern having the smallest ink ejection amount among a plurality of test patterns selected for each of a plurality of variables by the test pattern selection unit. The ink jet recording apparatus according to claim 1. The variable for detecting the limit of the receptive capacity for receiving ink of the recording medium is the graph when the horizontal axis represents the ink ejection amount, and the vertical axis represents the optical density of the ink droplets recorded. The slope of
The threshold storage means stores a threshold for the slope of the graph for each type of recording medium,
The test pattern selecting means selects a test pattern having the largest ink ejection amount from the plurality of test patterns in an ink ejection amount range in which the slope of the graph is equal to or greater than a threshold value. 2. An ink jet recording apparatus according to 2. The variable for detecting the limit of the receiving ability to receive ink of the recording medium is a recording position standard deviation which is a standard deviation of a deviation amount from an ideal recording position of a recording position in a recorded image,
The threshold storage means stores a threshold for the recording position standard deviation for each type of recording medium,
The test pattern selection means is a range in which the recording position standard deviation is equal to or less than a threshold for the recording position standard deviation corresponding to the type of recording medium detected by the recording medium type detection means from the plurality of test patterns. 4. The ink jet recording apparatus according to claim 1, wherein a test pattern having the largest ink ejection amount is selected. The variable for detecting the limit of the capacity of receiving the ink of the recording medium is a density standard deviation which is a standard deviation of a deviation amount from an ideal density of the density in the recorded image,
The threshold value storage means stores a threshold value for the density standard deviation for each type of recording medium,
The test pattern selection means is the most in the range where the density standard deviation is equal to or less than a threshold value for the density standard deviation corresponding to the type of the recording medium detected by the recording medium type detection means from the plurality of test patterns. 5. The ink jet recording apparatus according to claim 1, wherein a test pattern having a large ink ejection amount is selected. In a recording method for recording using an ink jet recording apparatus having a recording head for recording by discharging ink to a recording medium and a recording control means for controlling an ink discharging operation by the recording head.
A recording medium type detection step for detecting the type of recording medium on which recording is performed;
A test pattern recording process for recording a plurality of test patterns having different ink ejection amounts;
The variable for detecting the limit of the ability of the recording medium to receive ink in each test pattern is compared with the threshold value of the variable corresponding to the type of the recording medium detected in the recording medium type detection step. A test pattern selecting step for selecting a test pattern having the largest amount of ink ejection within a range not exceeding the receiving capacity of the recording medium from the plurality of test patterns based on the comparison result;
And a discharge operation control step of controlling an ink discharge operation by the recording head based on the test pattern selected in the test pattern selection step.

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