Recording device, control method of recording device, and program

Abstract

To achieve highly accurate calibration without using a calibration plate.SOLUTION: An embodiment of the present invention is a recording device having: a recording head that discharges first ink from a nozzle, records a first adjustment pattern by the number of first ink emissions, and records a second adjustment pattern by the number of second ink emissions; storage means that stores reflection ratio data being a reflection ratio for each discharge amount of the first ink discharged from the nozzle; a sensor that reads an image recorded in a recording medium; first calculation means that calculates a reflection ratio on the basis of a first reflection coefficient acquired by the sensor reading the first adjustment pattern and a second reflection coefficient acquired by the sensor reading the second adjustment pattern; and second calculation means that calculates a discharge amount of the first ink in the nozzle on the basis of the reflection ratio calculated by the first calculation means and the reflection ratio data.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present disclosure relates to a recording apparatus that records an image by ejecting ink from nozzles of a recording head.

Background Art

[0002] An inkjet recording apparatus is known that ejects ink onto a non-absorbent or low-absorbent recording medium and dries the ejected ink using a fixing device having a heating and blowing function to perform recording. In such an apparatus, image recording may be performed using a transparent recording medium or a colored recording medium having a low reflectance compared to a white recording medium. Further, in order to record a higher-quality image, it is necessary to adjust the recording head and the recording apparatus using the recording medium on which the image is actually recorded.

[0003] In Patent Document 1, a black image is formed on a white recording medium, and a white image is formed thereon to enable colorimetry of the white image. By the way, in order to perform density detection in a colorimeter, it is necessary to make the amount of light emitted from the light-emitting part in the optical sensor constant. Generally, a method of making the amount of light emitted constant using a white calibration plate before colorimetry is adopted.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in order to perform colorimetry of a white image using a white calibration plate, it is necessary to provide components such as a white calibration plate and a shutter for protecting it, which increases the cost. On the other hand, in order to prevent cost increase, if colorimetry of a white image is attempted without using a white calibration plate, the colorimetry accuracy of the white image decreases due to variations in the amount of light emitted from the light-emitting part.

[0006] Therefore, in view of the above problems, the present disclosure aims to achieve high-precision calibration without using a calibration plate.

Means for Solving the Problems

[0007] One embodiment of the present invention is a recording head that discharges a plurality of inks including a first ink from nozzles, the recording head discharging the first ink to record a first adjustment pattern at a first ink emission count and a second adjustment pattern at a second ink emission count, storage means for storing reflectance data that is the reflectance for each discharge amount of the first ink discharged from the nozzles, a sensor for reading an image recorded on a recording medium, a first calculation means for calculating a reflectance based on a first reflection coefficient obtained by reading the first adjustment pattern by the sensor and a second reflection coefficient obtained by reading the second adjustment pattern by the sensor, and a second calculation means for calculating the discharge amount of the first ink in the nozzles based on the reflectance calculated by the first calculation means and the reflectance data. The recording apparatus is characterized by having the above.

Effects of the Invention

[0008] According to the present disclosure, it becomes possible to achieve high-precision calibration without using a calibration plate.

Brief Description of the Drawings

[0009]

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Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments in the present disclosure will be described in detail with reference to the drawings. First, the content common to the first to fourth embodiments described later will be described.

[0011] [Common Embodiments] (Configuration of Inkjet Recording Apparatus) FIG. 1 is a perspective view showing the appearance of an inkjet recording apparatus 10 (hereinafter referred to as the recording apparatus 10) according to the present embodiment. The recording apparatus 10 is a so-called serial scanning type recording apparatus, and scans a recording head in the X direction (also referred to as the scanning direction and the main scanning direction) orthogonal to the Y direction (the conveyance direction, also referred to as the sub-scanning direction) in which the recording medium 40 is conveyed at the recording position on the platen 4 to record an image. Here, the Z direction orthogonal to the X direction and the Y direction is defined as the height direction, and this XYZ coordinate system is commonly used in the present disclosure.

[0012] The configuration of the recording apparatus 10 and the outline of the operation during recording will be described with reference to FIG. 1. First, the recording medium 40 held by the spool 6A (see FIG. 2) and the spool 6B is conveyed in the Y direction by a conveyance roller driven via a gear by a conveyance motor (not shown). On the other hand, at a predetermined conveyance position, the carriage unit 2 is reciprocally scanned (reciprocally moved) along a guide shaft 8 extending in the X direction by a carriage motor (not shown). Then, in the process of this scanning, an ejection operation of ejecting ink from the nozzles of the recording head that can be attached to the carriage unit 2 is performed at a timing based on the position signal obtained by the encoder 7, and a certain band width corresponding to the array range of the nozzles is recorded. In the present embodiment, the configuration is such that scanning is performed at a scanning speed of 40 inches per second and the ejection operation is performed at a recording resolution of 1200 dpi (interval of 1 / 1200 inch). Thereafter, the recording medium 40 is conveyed, and recording is further performed for the next band width. Note that the recording head can also be scanned at a speed of 40 inches per second or more.

[0013] Ink is supplied from an ink tank (not shown) to the recording head by a tube 45. Since the tube 45 comes into contact with a frame (not shown) during the scanning of the carriage unit 2, the tube 45 is protected by a tube guide 19.

[0014] Furthermore, a carriage belt can be used to transmit the driving force from the carriage motor to the carriage unit 2. However, instead of the carriage belt, other driving methods can also be used, such as a lead screw that is rotationally driven by the carriage motor and extends in the X direction, and an engaging portion provided on the carriage unit 2 that engages with the groove of the lead screw.

[0015] The fed recording medium 40 is sandwiched and conveyed between the paper feed roller and the pinch roller, and is guided to the recording position on the platen 4. Here, the "recording position" refers to a position within the range of the area where the recording head can scan, and is the position where recording is performed by the recording head. Also, a configuration for performing image recording around this recording position is referred to as an "image recording unit (image recording means)". In the normal standby state of the recording apparatus 10, since capping is applied to the face surface of the recording head, the cap is opened prior to recording to make the recording head and the carriage unit 2 in a scanable state. Then, after the data for one scan is accumulated in the buffer, the carriage unit 2 is scanned by the carriage motor, and recording is performed as described above.

[0016] FIG. 2 is a schematic side view of the recording apparatus main body. A heater 50 supported by a frame (not shown) is disposed in a curing region located on the downstream side in the Y direction from the position where the recording head 9 mounted on the carriage unit 2 reciprocally scans in the X direction, and dries the liquid ink on the recording medium 40 by heat. Hereinafter, a configuration for performing image fixing around the curing region is referred to as an "image fixing unit (image fixing means)".

[0017] The heater 50 is covered by a heater cover 51, and the heater cover 51 has the function of efficiently irradiating the heat of the heater 50 onto the recording medium 40 and the function of protecting the heater 50. After the recording medium 40 is recorded by the recording head 9, it is wound up by the spools 6A and 6B to form a roll-shaped winding medium. Specifically, the heater 50 may include a sheathed heater, a halogen heater, etc. The heating temperature of the heating unit in the above-described image fixing unit is set in consideration of the film-forming property and productivity of the water-soluble resin fine particles and the heat resistance of the recording medium 40. Incidentally, as the heating unit (heating means) in the image fixing unit, heating by hot air blowing from above, heating by a contact-type heat conduction heater from below the recording medium 40, etc. may be used. Regarding the installation location of the heating unit (heating means) in the image fixing unit, although there is one location in this embodiment, as long as the measured temperature by a radiation thermometer (not shown) on the recording medium 40 does not exceed the set value of the heating temperature, two or more locations may be provided and used in combination.

[0018] Here, the recording apparatus 10 of this embodiment can perform so-called multi-pass recording in which an image is recorded on a predetermined area (1 / n band) on the recording medium 40 by scanning the recording head 9 a plurality of times (n times). Multi-pass recording will be described in detail later.

[0019] <Configuration of the recording head> FIG. 3 shows the nozzle surface 34 of the recording head 9 in this embodiment. The recording head 9 has nozzle arrays that eject inks containing coloring materials. Specifically, they are a nozzle array 33K that ejects black ink, a nozzle array 33C that ejects cyan ink, a nozzle array 33M that ejects magenta ink, a nozzle array 33Y that ejects yellow ink, and a nozzle array 33W that ejects white ink. Incidentally, in this specification, when there is no need to particularly distinguish by color, they are collectively referred to as the nozzle array 33. Also, this collective naming rule is similarly applied to components other than the nozzle arrays.

[0020] In the recording head 9, these nozzle arrays are arranged in the order of nozzle arrays 33K, 33C, 33M, 33Y, 33W from the left side to the right side in the +X direction (in the figure). These nozzle arrays 33K, 33C, 33M, 33Y, 33W are each composed of 1280 nozzles 30 that discharge respective inks arranged in the Y direction (array direction) at a density of 1200 dpi. The recording head 9 discharges ink from the nozzles using a discharge energy generating element such as an electrothermal conversion element (heater) or a piezo element. When using an electrothermal conversion element, the ink can be foamed by its heat generation, and the foaming energy can be utilized to discharge the ink from the nozzles. Note that the discharge amount of ink discharged from one nozzle 30 at a time (referred to as the ink discharge amount) in the present embodiment is about 4.5 pl at the time of factory shipment, but it may change over time.

[0021] These nozzle arrays 33K, 33C, 33M, 33Y, 33W are connected to ink tanks (not shown) that store the corresponding inks, and the ink is supplied. Note that the recording head 9 and the ink tank used in the present embodiment may be integrally configured, or they may be configured to be separable from each other.

[0022] <Optical sensor> FIG. 4(a) is a schematic diagram showing the schematic configuration of the optical sensor, and FIG. 4(b) is a diagram showing the detection spot. The optical sensor 200 is fixedly provided on the carriage unit 2 such that the measurement region is located on the +Y direction downstream side of the nozzle array 33 of the recording head 9. The lower surface 200a of the optical sensor 200 coincides with the nozzle surface 34 in the Z direction, or is located on the +Z direction downstream side of the nozzle surface 34.

[0023] The optical sensor 200 includes a light emitting unit 202 realized by visible LEDs such as red, green, and blue, and a light receiving unit 204 realized by a photodiode. The light emitting unit 202 and the light receiving unit 204 are provided on the lower surface 200a of the optical sensor 200. The light emitting unit 202 irradiates light onto the recording medium 40, and the light receiving unit 204 receives the reflected light reflected by the recording medium 40. Therefore, in the optical sensor 200, the light 206 irradiated from the light emitting unit 202 is diffusely reflected by the recording medium 40, and this reflected light 208 is received by the light receiving unit 204. The diameter of the detection spot 210 where the light 206 irradiated from the light emitting unit 202 is diffusely reflected by the recording medium 40 is, for example, approximately 3 mm in diameter.

[0024] In the light receiving unit 204, the detection signal (analog signal) of the received reflected light 208 is transmitted via a flexible cable (not shown) or the like to a control circuit on the electric substrate of the recording apparatus 10 and is converted into a digital signal by an A / D converter in the control circuit. When detecting the optical characteristics of the adjustment pattern described later, the conveyance along the Y direction of the recording medium 40 and the movement along the X direction of the carriage unit 2 to which the optical sensor 200 is attached are alternately performed. Thereby, synchronizing with the timing based on the position signal obtained by the encoder 7, the optical sensor 200 detects the density of the image recorded on the recording medium 40 as the optical reflectance.

[0025] <Configuration of the recording system> Hereinafter, the configuration related to the control of the recording apparatus 10 will be described with reference to FIG. 5. FIG. 5 is a block diagram showing the configuration of the control system of the recording apparatus 10.

[0026] The control unit 100 that controls the entire recording device 10 includes a central processing unit (CPU) 102, a ROM 104, a RAM 106, and a memory 108. The CPU 102 performs operation control of each component in the recording device 10 and processing of the input image data based on various programs. The ROM 104 functions as a memory that stores various controls executed by the CPU 102 and processing programs for image data. Various data used for controlling the recording device 10 are stored in the RAM 106. Various data such as mask patterns and adjustment patterns, which will be described later, are stored in the memory 108. Further, the control unit 100 includes an input / output port 110, and is connected to various drivers and drive circuits via this input / output port 110.

[0027] The control unit 100 is connected to the interface circuit 112 via the input / output port 110, and is connected to the host device 114 via this interface circuit 112. Also, the control unit 100 is connected to an operation panel 124 operable by the user via the input / output port 110. The user inputs image data to the recording device 10 via the host device 114, and inputs various information to the recording device 10 via the host device 114 and the operation panel 124. Further, the control unit 100 is connected to a motor driver 116 via the input / output port 110, and controls the driving of the motor 118 via this motor driver 116. Note that in FIG. 5, various motors in the recording device 10, such as the motor that moves the carriage unit 2 and the motor that drives the conveyance unit that conveys the recording medium 40, are collectively shown as the motor 118.

[0028] Further, the control unit 100 is connected to the head driver 120 via the input / output port 110, and controls the recording head 9 via the head driver 120 to eject ink. The control unit 100 is connected to the drive circuit 122 via the input / output port 110, and controls the drive of the heating unit 16 via the drive circuit 122. Further, the control unit 100 is connected to the optical sensor 200 via the input / output port 110, controls the drive of the optical sensor 200, and detects the optical characteristics of the adjustment pattern based on the output from the optical sensor 200. Thus, in the present embodiment, the control unit 100 and the optical sensor 200 function as a detection unit capable of detecting the optical characteristics of the image recorded on the recording medium 40.

[0029] In the control unit 100, the CPU 102 converts the image data input from the host device 114 into recording data and stores it in the RAM 106. Specifically, when the CPU 102 acquires image data represented by information of 8 bits and 256 values (0 - 255) for each of RGB, the CPU 102 converts this image data into multi-value data represented by a plurality of types of inks used for recording (K, C, M, Y, W in the present embodiment). By this color conversion process, multi-value data represented by information of 8 bits and 256 values (0 - 255) that determines the gradation of each of the K, C, M, Y, and W inks in each pixel group composed of a plurality of pixels is generated.

[0030] Next, quantization of the multi-valued data represented by K, C, M, Y, and W is performed to generate quantization data (binary data) represented by 1-bit binary information (0, 1) that determines ejection or non-ejection of each of the K, C, M, Y, and W inks for each pixel. As this quantization process, various known quantization methods such as error diffusion method, dither method, and index method can be used. Thereafter, a distribution process is performed to distribute the quantization data over a plurality of scans for the unit area of the recording head 9. By this distribution process, recording data represented by 1-bit binary information (0, 1) that determines ejection or non-ejection of each of the K, C, M, Y, and W inks for each pixel in each of the plurality of scans for the unit area of the recording medium 40 is generated. This distribution process is executed using a mask pattern that corresponds to the plurality of scans and determines allowance or non-allowance of ink ejection for each pixel. Note that the generation of such recording data is not limited to being executed by the control unit 100, and it may be executed by the host device 114, or some processes may be performed by the host device 114 and the remaining processes may be performed by the control unit 100.

[0031] <Multi-pass recording method> In the present embodiment, an image is recorded by so-called multi-pass recording in which recording is performed by scanning a predetermined area on the recording medium 40 a plurality of times using each of the K, C, M, Y, and W inks.

[0032] First, multi-pass recording using the entire nozzle array area will be described below by taking white ink and black ink as examples. In this specification, white ink is referred to as W ink and black ink is referred to as K ink.

[0033] FIG. 6(a) is a diagram for explaining a multi-pass recording method using the entire nozzle array regions of W ink and K ink. Here, six nozzle groups A1 to A6 formed by dividing the nozzle arrays 33W and 33K in the Y direction are each caused to eject W ink and K ink in each of six scans of a predetermined region. The recording data of the W ink and the K ink are distributed to each scan so that the image recording is completed in six scans each. Incidentally, actually, the recording medium 40 is conveyed downstream in the Y direction after one scan of the recording head 9, but in FIG. 6, for simplicity, it is described that the recording head 9 is moved upstream in the Y direction after one scan.

[0034] First, in the first scan (the first pass), the recording head 9 is scanned in a positional relationship where a predetermined region 80 on the recording medium 40 faces the nozzle group A1 of the nozzle arrays 33W and 33K. At this time, according to the respective recording data of the W ink and the K ink corresponding to the first pass, the W ink and the K ink are ejected from the nozzle group A1 onto the predetermined region 80. After the first pass is completed, the recording medium is conveyed in the Y direction by a distance corresponding to one nozzle group. Thereafter, the second scan (the second pass) is performed, and the W ink and the K ink are ejected from the nozzle group A2 onto the predetermined region 80. Thereafter, the conveyance of the recording medium and the ejection from the recording head 9 are performed alternately, and the ejection from the nozzle groups A3 to A6 in the third to sixth scans of the predetermined region 80 is executed. In this way, the multi-pass recording of the predetermined region 80 is completed.

[0035] Subsequently, a multi-pass recording method in which the regions of the nozzle arrays used are varied according to the ink color will be described. FIG. 6(b) is a diagram showing that among the nozzle groups A1 to A6 shown in FIG. 6(a), the K ink is ejected from the nozzle groups A1 to A3, and the W ink is ejected from the nozzle groups A4 to A6. Here, the recording data of the K ink are distributed so that the image recording is completed in the first to third scans, and the recording data of the W ink are distributed so that the image recording is completed in the fourth to sixth scans.

[0036] First, in the first scan (the first pass), the recording head 9 is scanned at a position where a predetermined area 80 on the recording medium 40 faces the nozzle group A1 of the nozzle row 33K. At this time, in accordance with the recording data of the K ink corresponding to the first pass, the K ink is ejected from the nozzle group A1 onto the predetermined area 80. After the first pass is completed, the recording medium is conveyed in the Y direction by a distance corresponding to one nozzle group. Thereafter, ejection from the recording head 9 and conveyance of the recording medium are performed alternately, and the second to third scans (the second to third passes) are performed, and the K ink is ejected from the nozzle groups A2 to A3 onto the predetermined area 80, and the image of the K ink is completed by the recording in the third pass. Subsequently, in accordance with the recording data of the W ink corresponding to the fourth scan, the W ink is ejected from the nozzle group A4 onto the predetermined area 80. Thereafter, conveyance of the recording medium and ejection from the recording head 9 are performed alternately, and ejection of the W ink from the nozzle groups A4 to A6 in the fourth to sixth scans with respect to the predetermined area 80 is executed. In this way, the multi-pass recording with respect to the predetermined area 80 is completed.

[0037] In this manner, by separating the nozzle row groups to be used into the W ink and the K ink, the image of the K ink can be completed in the first three scans out of the six scans with respect to the predetermined area, and the image of the W ink can be completed in the last three scans. As a result, in a predetermined recording area, during the same recording scan, while recording the K ink as a base, the image of the W ink can be superposed and recorded on the image of the K ink.

[0038] <Ink> Hereinafter, the K, C, M, Y, and W inks used in this embodiment will be described. These inks contain a solid component for recording an image and a liquid component that volatilizes. Examples of the solid component include color materials such as pigments and dyes, and examples of the liquid component include water and water-soluble organic solvents. Each ink contains water-soluble resin fine particles for improving the abrasion resistance (fixing property) of the recording image by bringing the recording medium and the color material into close contact.

[0039] The white (W) ink of the present embodiment contains a white colorant as a coloring material, and titanium oxide particles can be preferably used as such a white colorant. Titanium oxide has rutile type, anatase type, and brookite type according to its crystal structure, and the rutile type with low photocatalytic activity is preferable. Examples of the production method of titanium oxide include the sulfuric acid method and the chlorine method. From the viewpoint of ink stability, the content (mass%) of titanium oxide particles in the ink is preferably 5 mass% or more and 20 mass% or less based on the total mass of the ink.

[0040] The zeta potential of the titanium oxide particles in pure water is preferably 0 mV or more. The zeta potential is an index indicating the charged state of the surface of the titanium oxide particles and can be measured by the electrophoretic light scattering method. When the positive charge amount is larger than the negative charge amount on the surface of the titanium oxide particles, it is easy to adsorb to a resin having an anionic group, and the dispersion stability of titanium oxide is improved. Further, in order for the anionic groups of the resin not to be excessively consumed and for the charge repulsion between the titanium oxide particles not to be insufficient, the zeta potential is preferably 40 mV or less.

[0041] As the white colorant of the white ink, in addition to the titanium oxide particles, it is also possible to use resin particles having a hollow structure in combination. Examples of the resin particles having a hollow structure include the following. For example, resin particles containing units derived from styrene and acrylic such as MH5055 (manufactured by Nippon Zeon), Rohm & Haas OP-62, OP-84J, OP-91, HP-1055, HP-91, ULTRA (above manufactured by Rohm & Haas). Also, resin particles containing units derived from crosslinked styrene and acrylic such as SX-863(A), 864(B), 866(A), 866(B), 868 (above manufactured by JSR), Rohm & Haas ULTRA E, ULTRA DUAL (above manufactured by Rohm & Haas), etc.

[0042] In addition, although the W ink contains the above white colorant as the main component, in order to adjust a slight white color tone visually recognized by reflected light or the like, it is also possible to contain other colorants within a range that does not impair the whiteness.

[0043] <Recording medium> The recording apparatus in this embodiment performs recording on a low-permeability recording medium that is difficult for moisture to penetrate. As described above, the low-permeability recording medium here is a medium that has no water absorbency at all or has an extremely small absorption amount. Therefore, with water-based ink that does not contain an organic solvent, the ink is repelled and an image cannot be formed on the medium. On the other hand, it is excellent in water resistance and weather resistance and is suitable as a medium for forming printed matter for outdoor use. Usually, a recording medium with a water contact angle of 45° or more, preferably 60° or more at 25°C is used.

[0044] Examples of the low-permeability recording medium include a recording medium in which a plastic layer is formed on the outermost surface of the base material, a recording medium in which an ink receiving layer is not formed on the base material, or a sheet, film, banner, etc. made of glass, Yupo, plastic, etc. Examples of the above-mentioned plastic include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, polypropylene, etc. Since these low-permeability recording media are excellent in water resistance, light resistance, and abrasion resistance, they are generally used when recording records for outdoor display.

[0045] As an example of a method for evaluating the permeability of a recording medium, the Bristol method described in the "Liquid Absorbency Test Method for Paper and Paperboard" of JAPAN TAPPI Paper Pulp Test Method No. 51 can be used. In the Bristol method, a predetermined amount of ink is injected into a holding container having an opening slit of a predetermined size, and the ink is brought into contact with a recording medium processed into a strip shape and wound around a disk through the slit. Then, while fixing the position of the holding container, the disk is rotated and the area (length) of the ink band transferred to the recording medium is measured. From the area of this ink band, the transfer amount (ml·m-2) per unit area per second can be calculated. In this embodiment, a recording medium with an ink transfer amount (water absorption amount) at 30 msec1 / 2 by the above-mentioned Bristol method less than 10 ml·m-2 is regarded as a low-permeability recording medium.

[0046] [First Embodiment] In this embodiment, a method for calculating the discharge amount of W ink will be described. Since the ink and the recording medium have the same color, the density difference of the W ink patches recorded on the white recording medium cannot be measured. Also, since the density difference of the W ink patches recorded on the transparent recording medium is also affected by the platen 4, the density difference cannot be measured.

[0047] In this embodiment, first, an image (base image) serving as a base is recorded on the recording medium 40 with K ink. After the K ink image is sufficiently fixed, an adjustment pattern is recorded with W ink on top of the base. As a result, the density difference due to the difference in the exposed amount of the base K ink according to the W ink amount can be measured, and color calibration of the W nozzles of the recording head 9 can be performed. Note that the ink for recording the base is preferably K ink with high light absorption characteristics, but this is not limiting, and other inks containing colored pigments (for example, C ink) can also be adopted as long as the measurement of a desired density difference is possible.

[0048] Here, the density calculation of the W ink will be described. For colored inks, the absorption of light increases as the amount of ink injected onto the recording medium 40 increases. Therefore, when the amount of colored ink injected is X%, the density value can be defined as follows, where P(X) is the reflection coefficient of the patch output by the sensor and P(0) is the reflection coefficient of the white calibration plate output by the sensor.

[0049] D(X)=-log(P(X) / P(0)) ··· Equation (1) On the other hand, unlike colored inks, for W ink, the amount of reflected light increases as the amount of ink injected onto the recording medium 40 increases. Therefore, when the amount of W ink injected is X%, the density value can be defined as follows, where P(X) is the reflection coefficient of the patch, P(0) is the reflection coefficient of the white calibration plate, and P(1) is the reflection coefficient of only the ink for recording the base (for example, K ink) (i.e., the base).

[0050] D(X)=-log(P(0)-P(X) / P(0)-P(1)) ··· Equation (2) When measuring the density using formulas (1) and (2), it is important to correctly obtain the reflectance P(0) of the white calibration plate. However, conventionally, for the purpose of reducing manufacturing costs, there are cases where a white calibration plate is not built into the recording device. In that case, in density measurement for colored inks, the density may be measured based on the relative relationship with the paper white obtained using the reflectance of the patch in the paper white area instead of the white calibration plate. On the other hand, in density measurement of W ink, there is a problem that the measurement accuracy of the white density becomes unstable because there are variations in the reflectance of the recording medium 40.

[0051] In view of the above circumstances, in this embodiment, a method of calculating the W ink ejection amount based on the reflectances of two patches with different driving amounts without performing white density measurement is proposed.

[0052] First, a method for acquiring the information that needs to be pre-stored in the main body of the recording device 10 will be described.

[0053] FIG. 7 is an explanatory diagram of a measurement pattern for measuring the reflectance for each W ink amount on the K ink. As shown in the figure, when recording K ink on the recording medium 40, it is desirable to increase the ink amount of the K ink on the paper surface. Specifically, it is desirable that the driving amount is such that the reflectance is 1% or less. Using the recording head 9 for which the W ink ejection amount is known, patches with different ink amounts of W ink are recorded on the fixed K ink. In this embodiment, a plurality of patches with different W ink amounts per 600 dpi are recorded. Note that since it is desirable to have a larger number of data acquisitions, it is desirable to record more patches with different W ink amounts. After recording the patches, the reflectances of each patch with different W ink amounts recorded on the K ink are measured using the optical sensor 200.

[0054] FIG. 8 shows the correlation between the amount of W ink on the K ink and the reflection coefficient. Specifically, FIG. 8(a) shows the measurement results of the reflection coefficient for each amount of W ink on the K ink. In this embodiment, when obtaining the reflection coefficient for each amount of W ink on the K ink, since patches are printed on the K image, there is a characteristic that the reflection coefficients for each amount of W ink are the same on various recording media.

[0055] FIG. 8(b) is a graph showing the relationship between each amount of W ink on the K ink and the reflection coefficient, with the amount of W ink on the horizontal axis and the reflection coefficient on the vertical axis. When the amount of W ink is up to around 40 ng, since the W ink does not cover the entire surface of the K ink, the amplification amount of the reflection coefficient with the increase in the amount of W ink is large. On the other hand, when the amount of W ink is 40 ng or more, since the W ink covers the entire surface of the K ink, the amplification amount of the reflection coefficient with the increase in the amount of W ink decreases. Thus, the amplification amount of the reflection coefficient changes according to the amount of W ink.

[0056] FIG. 9 shows the reflection ratios of the first W ink emission number and the second W ink emission number on the K ink for each W ink discharge amount. In FIG. 9, it shows the amount of W ink and the reflection coefficient when the first W ink emission number is 20 dots per 600 dpi and the second W ink emission number is 2 dots per 600 dpi.

[0057] Since the first W ink emission number is 20 dots, when the W ink discharge amount is 5 ng, the amount of W ink is 100 ng and the reflection coefficient is 762. Similarly, when the W ink is 6 ng, the reflection coefficient is 792, and when the W ink discharge amount is 7 ng, the reflection coefficient is 803.

[0058] Since the second W ink emission number is 2 dots, when the W ink discharge amount is 5 ng, the amount of W ink is 10 ng and the reflection coefficient is 331. Similarly, when the W ink discharge amount is 6 ng, the reflection coefficient is 374, and when the W ink discharge amount is 7 ng, the reflection coefficient is 411.

[0059] Next, calculate the reflection ratio between the first W-ink emission number and the second W-ink emission number on the K-ink. When the W-ink discharge amount is 5 ng, the reflection ratio between the first W-ink emission number and the second W-ink emission number on the K-ink is 331 / 762 = 0.434. Similarly, when the W-ink discharge amount is 6 ng, the reflection ratio is 0.472, and when the W-ink discharge amount is 7 ng, the reflection ratio is 0.512.

[0060] Thus, it can be seen that the reflection ratio between the first W-ink emission number and the second W-ink emission number on the K-ink changes for each W-ink discharge amount. This is because by changing the W-ink emission number on the K-ink, the amplification amount of the reflection coefficient with respect to the amplification amount of the W-ink discharge amount changes.

[0061] Hereinafter, the method for calculating the W-ink discharge amount according to the present embodiment, that is, the method for calculating the W-ink discharge amount by utilizing the fact that the reflection ratio is different for each W-ink discharge amount, will be described in detail.

[0062] FIG. 10 is a flowchart of the W-ink discharge amount calculation process according to the present embodiment. A series of processes shown in the flowchart of FIG. 10 are performed by the CPU 102 expanding and executing program codes stored in the ROM 104 in the RAM 106. Alternatively, part or all of the series of processes shown in FIG. 10 may be executed by other hardware such as an ASIC or an electric circuit. Note that for each process in the flowchart described below, the symbol S means that it is a step in the flowchart.

[0063] When a user who wants to adjust the white density operates the recording device 10 or the host device 114, the W-ink discharge amount calculation process shown in FIG. 10 is started.

[0064] In S1001, the CPU 102 executes a recording process of recording a K-ink image on the recording medium 40.

[0065] In S1002, the CPU 102 executes a drying process for drying the K ink image recorded in S1001. Note that as the drying in this step, natural drying, heat fixing, or UV curing using UV ink may be used.

[0066] In S1003, the CPU 102 executes a recording process of recording a first adjustment pattern with a first W ink emission number using W ink on the K ink image recorded in S1001.

[0067] In S1004, the CPU 102 executes a recording process of recording a second adjustment pattern with a second W ink emission number using W ink on the K ink image recorded in S1001. Note that in this embodiment, the value of the second W ink emission number is set to be less than the value of the first W ink emission number so that the reflection coefficient A is larger than the reflection coefficient B (details will be described later).

[0068] Here, FIG. 11 shows an example of a pattern for calculating the W ink ejection amount recorded in this embodiment. This pattern for reference of ink ejection amount consists of a first adjustment pattern recorded in S1003 and a second adjustment pattern recorded in S1004. As shown in FIG. 11, the two patterns, specifically the first adjustment pattern and the second adjustment pattern, are recorded side by side in the Y direction (conveying direction). Note that in FIG. 11, the first W ink emission number when recording the first adjustment pattern is 20 dots per 600 dpi, and the second W ink emission number when recording the second adjustment pattern is 2 dots per 600 dpi.

[0069] In S1005, the CPU 102 dries and fixes the W ink image recorded on the K ink image in S1003 and S1004. Note that since the surface shape of the image affects the reflection coefficient, heat fixing is adopted as the fixing method in this step, and it is desirable that the density of the W ink image is stable.

[0070] In S1006, the CPU 102 reads the first adjustment pattern using the optical sensor 200 and calculates the reflection coefficient A based on the result of the reading.

[0071] In S1007, the CPU 102 reads the second adjustment pattern using the optical sensor 200, and calculates the reflection coefficient B based on the result of the reading. Incidentally, before S1006, light amount adjustment is performed using the first adjustment pattern so that the reflected light of the first adjustment pattern and the reflected light of the second adjustment pattern are within the light receiving range of the optical sensor 200. By doing so, any adjustment pattern can be read.

[0072] In S1008, the CPU 102 calculates the reflection ratio C (= B / A) based on the reflection coefficient A calculated in S1006 and the reflection coefficient B calculated in S1007 (that is, by dividing the reflection coefficient B by the reflection coefficient A).

[0073] In S1009, the CPU 102 acquires reflection ratio data for each discharge amount of W ink. Specifically, the reflection ratio data acquired in this step is a table in which the reflection ratios for each discharge amount of W ink as shown in FIG. 9 are held, and this table is stored in advance in the ROM 104 or the memory 108.

[0074] In S1010, the CPU 102 calculates the W ink discharge amount by comparing the reflection ratio data for each discharge amount of W ink acquired in S1009 with the reflection ratio C calculated in S1008. Specifically, if there is a value that matches the reflection ratio C among the plurality of reflection ratio values held in the table, the W ink discharge amount corresponding to the matching value is selected. On the other hand, if there is no match, the W ink discharge amount corresponding to the value closest to the reflection ratio C among the reflection ratio values held in the table is selected, or the W ink discharge amount is calculated by interpolation. Here, as an example, the calculation of the W ink discharge amount in the case where the reflection ratio C is 0.453 will be described. This value of 0.453 is the intermediate value between the reflection ratio 0.432 when the W ink discharge amount is 5 ng and the reflection ratio 0.472 when the W ink discharge amount is 6 ng in the relationship with each value of the reflection ratio for each discharge amount of W ink shown in FIG. 9. Therefore, in this case, the W ink discharge amount is calculated as 5.5 ng, which is the intermediate value between 5 ng and 6 ng.

[0075] Finally, in S1011, the CPU 102 stores the W ink ejection amount calculated in S1010 in a storage area (ROM 104 or memory 108), and a series of processes ends. In the above embodiment, the calculation of the W ink ejection amount by interpolation using the W ink ejection amounts in three stages (see FIG. 9) has been described. However, it is desirable to store in advance the reflectance ratios corresponding to each W ink ejection amount not only in three stages but also in more (that is, four or more stages).

[0076] As described above, in the present embodiment, for each W ink ejection amount, the reflectance ratios of the first W ink emission number and the second W ink emission number are stored in advance, and by comparing the stored reflectance ratio with the measured reflectance ratio, a highly accurate W ink ejection amount can be calculated. Thereby, it becomes possible to realize colorimetry of a white image and white calibration with high accuracy without using a white calibration plate.

[0077] [Second Embodiment] In the first embodiment, the calculation of the W ink ejection amount using two patches has been described. However, when there is a reading error in the optical sensor, an error also occurs in the calculation of the ejection amount. To reduce such an error, in the present embodiment, a method of calculating the W ink ejection amount using a plurality of patches will be described. Hereinafter, the description of the same content as above will be omitted as appropriate.

[0078] FIG. 12 shows a pattern for calculating the W ink ejection amount according to the present embodiment. As shown in FIG. 12, the same adjustment pattern is recorded at four positions where the X-direction (main scanning direction) positions are different. Further, five patterns with different ejection amounts of W ink are arranged and recorded in the Y direction (conveying direction, sub-scanning direction). In the present embodiment, the description is made with four patterns in the X direction and five patterns in the Y direction arranged, but the number of patterns in the X direction and the number of patterns in the Y direction are not limited thereto and may increase or decrease.

[0079] FIG. 13 is a flowchart of the W ink discharge amount calculation process according to the present embodiment. A series of processes shown in the flowchart of FIG. 13 are performed by the CPU 102 by expanding and executing program codes stored in the ROM 104 in the RAM 106. Alternatively, part or all of the series of processes shown in FIG. 13 may be executed by hardware such as another ASIC or electric circuit.

[0080] Similar to the first embodiment, when a user who wants to adjust the white density operates the recording apparatus 10 or the host apparatus 114, the W ink discharge amount calculation process shown in FIG. 13 is started.

[0081] S1301 and S1302 are the same as those in the first embodiment (see S1001 and S1002 in FIG. 10).

[0082] In S1303, the CPU 102 executes a recording process of recording each adjustment pattern from the first adjustment pattern to the nth adjustment pattern (recorded with the nth number of emissions) on the K ink image recorded in S1301 (n is an integer greater than 2). In the recording process of this step, a plurality of combinations of the first adjustment pattern to the nth adjustment pattern are recorded. More specifically, in the example of FIG. 12, each of the first adjustment pattern to the fifth adjustment pattern is arranged at a different position in the conveyance direction (Y direction) of the recording medium. Also, four combinations of the first adjustment pattern to the fifth adjustment pattern are recorded. Each of these combinations is arranged at a different position in the main scanning direction (X direction) of the recording head.

[0083] In S1304, the CPU 102 dries and fixes the W ink image recorded on the K ink image in S1303.

[0084] In S1305, the CPU 102 reads each adjustment pattern from the first to the nth adjustment pattern using the optical sensor 200, and calculates a reflection coefficient corresponding to each adjustment pattern based on the result of the reading. In the example of FIG. 12, each adjustment pattern from the first to the fifth adjustment pattern is read.

[0085] In S1306, the CPU 102 calculates the reflection ratios of the first adjustment pattern and each of the other adjustment patterns. In the example of FIG. 12, four reflection ratios are calculated in this step.

[0086] Here, the calculation of the reflection ratios according to the present embodiment, that is, the reflection ratios of the first adjustment pattern and each of the second to fifth adjustment patterns will be described. First, the reflection coefficients of the first to fifth adjustment patterns with the same X-direction position (the X-direction position at this time is referred to as the first position) are obtained, and based on the obtained reflection coefficients, the reflection ratios of the first adjustment pattern and each of the second to fifth adjustment patterns are calculated. Similarly, at each of the second to fourth positions different from the first position, the reflection ratios of the first adjustment pattern and each of the second to fifth adjustment patterns are calculated. Next, the average value of the reflection ratios of the first adjustment pattern and the second adjustment pattern at each of the first to fourth positions (that is, the average value of the four reflection ratios) is calculated, and the calculated average value is used as the reflection ratio of the first adjustment pattern and the second adjustment pattern.

[0087] Similar to the reflection ratio of the first adjustment pattern and the second adjustment pattern, the reflection ratios of the first adjustment pattern and the third adjustment pattern, the reflection ratio of the first adjustment pattern and the fourth adjustment pattern, and the reflection ratio of the first adjustment pattern and the fifth adjustment pattern are calculated. By calculating the reflection ratio as an average value in this way, even if there is a reading error of the optical sensor between different X-direction positions, the influence of the error can be reduced. In the present embodiment, the average value of the four reflection ratios is calculated, but it is not limited to this, and the average value of the two middle reflection ratios may be calculated by excluding the upper and lower reflection ratios.

[0088] In S1307, the CPU 102 obtains the reflection ratio data of each adjustment pattern for each discharge amount of the W ink.

[0089] In S1308, the CPU 102 calculates the discharge amount of W ink by comparing the reflectance ratio data of each adjustment pattern for each discharge amount of W ink acquired in S1307 with the reflectance ratio for each adjustment pattern calculated in S1306. In the example of FIG. 12, since there are reflectance ratios between the first adjustment pattern and each of the second to fifth adjustment patterns, the discharge amount is calculated between the first adjustment pattern and each of the second to fifth adjustment patterns, and as a result, four discharge amounts are calculated. The average value of these four discharge amounts is calculated as the discharge amount of W ink. Here, the average value of four values is used, but it is not limited to this, and the average value of the middle two values may be used by excluding the upper and lower values.

[0090] Finally, in S1309, the CPU 102 stores the discharge amount of W ink calculated in S1308 in the ROM 104, and a series of processes ends.

[0091] As described above, in the present embodiment, a plurality of patterns are arranged in each of the X direction and the Y direction. Thereby, the influence of the reading error of the optical sensor can be reduced and the discharge amount of W ink can be calculated.

[0092] [Third Embodiment] In the first embodiment and the second embodiment, the discharge amount of W ink is calculated, but in the present embodiment, the discharge amount of colored ink is calculated.

[0093] FIG. 14 is a diagram showing a pattern for calculating the discharge amount of K ink according to the present embodiment. As shown in FIG. 14, two patterns, specifically, the first adjustment pattern and the second adjustment pattern, are recorded side by side in the Y direction (conveying direction). In the present embodiment, recording is performed using K ink, but it is not limited to this, and recording may be performed using other colored inks such as C ink, M ink, and Y ink.

[0094] FIG. 15 shows the reflectance ratios of the first K ink firing number and the second K ink firing number for each discharge amount of K ink. In FIG. 15, the first K ink firing number shows the K ink amount and the reflection coefficient when 1 dot is recorded per 600 dpi, and the second K ink firing number shows the K ink amount and the reflection coefficient when 2 dots are recorded per 600 dpi.

[0095] Since the number of the first K-ink emissions is 1 dot, when the discharge amount of K-ink is 5 ng, the amount of K-ink is 5 ng and the reflection coefficient is 634. Similarly, when the discharge amount of K-ink is 6 ng, the reflection coefficient is 583, and when the discharge amount of K-ink is 7 ng, the reflection coefficient is 534.

[0096] Since the number of the second K-ink emissions is 2 dots, when the discharge amount of K-ink is 5 ng, the amount of K-ink is 10 ng and the reflection coefficient is 402. Similarly, when the discharge amount of K-ink is 6 ng, the reflection coefficient is 328, and when the discharge amount of K-ink is 7 ng, the reflection coefficient is 265.

[0097] Next, the reflection ratio between the number of the first K-ink emissions and the number of the second K-ink emissions is calculated. When the discharge amount of K-ink is 5 ng, the reflection ratio between the number of the first K-ink emissions and the number of the second K-ink emissions is 402 / 634 = 0.634. Similarly, when the discharge amount of K-ink is 6 ng, the reflection ratio is 0.563, and when the discharge amount of K-ink is 7 ng, the reflection ratio is 0.496.

[0098] Thus, similar to the W-ink described in the first embodiment, the reflection ratio also changes for each discharge amount of K-ink, which is a colored ink.

[0099] FIG. 16 is a flowchart of the K-ink discharge amount calculation process according to the present embodiment. When a user who wants to adjust the black density operates the recording apparatus 10 or the host apparatus 114, the K-ink discharge amount calculation process shown in FIG. 16 is started.

[0100] In S1601, the CPU 102 executes a recording process of recording a first adjustment pattern with the number of the first K-ink emissions using K-ink on a recording medium.

[0101] In S1602, the CPU 102 executes a recording process of recording a second adjustment pattern with the number of the second K-ink emissions using K-ink on the recording medium.

[0102] In S1603, the CPU 102 reads the first adjustment pattern using the optical sensor 200 and calculates the reflection coefficient A based on the result of the reading.

[0103] In S1604, the CPU 102 reads the second adjustment pattern using the optical sensor 200 and calculates the reflection coefficient B based on the result of the reading.

[0104] In S1605, the CPU 102 calculates the reflection ratio C (= B / A) based on the reflection coefficient A calculated in S1603 and the reflection coefficient B calculated in S1604.

[0105] In S1606, the CPU 102 acquires the reflection ratio data for each discharge amount of K ink from the storage area (ROM 104 or memory 108).

[0106] In S1607, the CPU 102 calculates the K ink discharge amount by comparing the reflection ratio data for each discharge amount of K ink acquired in S1606 with the reflection ratio C calculated in S1605.

[0107] Finally, in S1608, the CPU 102 stores the K ink discharge amount calculated in S1607 in the storage area (ROM 104 or memory 108), and a series of processes ends.

[0108] As described above, in the present embodiment, for each K ink discharge amount, the reflection ratio between the first K ink emission number and the second K ink emission number is stored in advance, and the stored reflection ratio is compared with the measured reflection ratio. Thus, similar to the W ink described in the first embodiment, the ink discharge amount of the colored ink K ink can be calculated.

[0109] [Fourth Embodiment] In the third embodiment, a method for calculating the ink ejection amount of colored ink by recording an adjustment pattern on a recording medium using colored ink was described. However, since the reflectance ratio varies depending on the type of recording medium, it is cumbersome in that it is necessary to acquire or store in advance the reflectance ratio for each recording medium. In the present embodiment, in order to eliminate such cumbersome work, the ink ejection amount of colored ink is calculated using two adjustment patterns recorded on the image of W ink.

[0110] FIG. 17 is a diagram showing a pattern for calculating the K ink ejection amount according to the fourth embodiment. As shown in FIG. 17, an image serving as a base is recorded on a recording medium 40 using W ink, and two patterns, specifically, a first adjustment pattern and a second adjustment pattern, are recorded side by side in the Y direction (conveying direction) on the base. Before recording the adjustment pattern, since the base is recorded using W ink, there is a feature that the reflection coefficient for each K ink amount is the same for various recording media.

[0111] FIG. 18 is a flowchart of the K ink ejection amount calculation process according to the present embodiment.

[0112] This embodiment is different from the third embodiment in that in S1801 and S1802, a base W ink image is recorded and dried. Incidentally, regarding S1803 and later, although there is a difference in that the adjustment pattern is recorded not on the recording medium but on the W ink image, the other contents are the same as those of the third embodiment (see FIG. 16).

[0113] As described above, according to the present embodiment, by using two patches recorded on the W ink, the ejection amount of colored ink can be calculated regardless of the type of recording medium.

[0114] [Other Embodiments] The present disclosure can also be implemented by supplying a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and causing one or more processors in a computer of the system or apparatus to read and execute the program. It can also be implemented by a circuit (for example, an ASIC) that realizes one or more functions.

[0115] [Technical Features of the Present Disclosure] The present disclosure includes the following configurations.

[0116] (Configuration 1) A recording head that discharges a plurality of inks including a first ink from nozzles, the recording head discharging the first ink to record a first adjustment pattern at a first ink emission number and a second adjustment pattern at a second ink emission number, storage means for storing reflectance data that is the reflectance for each discharge amount of the first ink discharged from the nozzles, a sensor for reading an image recorded on a recording medium, a first calculation means for calculating a reflectance based on a first reflection coefficient obtained by reading the first adjustment pattern by the sensor and a second reflection coefficient obtained by reading the second adjustment pattern by the sensor, and a second calculation means for calculating the discharge amount of the first ink in the nozzles based on the reflectance calculated by the first calculation means and the reflectance data. A recording apparatus characterized by having the above. (Configuration 2) The recording apparatus according to Configuration 1, characterized in that the value of the first ink emission number and the value of the second ink emission number are different. (Configuration 3) The recording apparatus according to Configuration 1 or 2, characterized in that the values of the first ink emission number and the second ink emission number are set such that the value of the first reflection coefficient is larger than the value of the second reflection coefficient. (Configuration 4) The recording apparatus according to any one of Configurations 1 to 3, characterized in that the value of the second ink emission number is less than the value of the emission number of the first ink. (Configuration 5) The recording apparatus according to any one of Configurations 1 to 4, characterized in that light amount adjustment of the sensor is performed using the first adjustment pattern recorded on the recording medium. (Configuration 6) The recording apparatus according to any one of Configurations 1 to 5, wherein the first calculation means calculates a reflection ratio by dividing the second reflection coefficient by the first reflection coefficient. (Configuration 7) The recording apparatus according to any one of Configurations 1 to 6, wherein the second calculation means calculates, as the discharge amount of the first ink in the nozzle, the discharge amount corresponding to the matching reflection ratio when the reflection ratio calculated by the first calculation means matches any of the reflection ratios indicated by the reflection ratio data stored in the storage means. (Configuration 8) The recording apparatus according to any one of Configurations 1 to 7, wherein the second calculation means calculates, as the discharge amount of the first ink in the nozzle, the discharge amount corresponding to the reflection ratio closest to the reflection ratio calculated by the first calculation means among the reflection ratios indicated by the reflection ratio data when the reflection ratio calculated by the first calculation means does not match any of the reflection ratios indicated by the reflection ratio data stored in the storage means. (Configuration 9) The recording apparatus according to any one of Configurations 1 to 8, wherein the second calculation means calculates the discharge amount of the first ink in the nozzle by interpolation calculation using the first discharge amount corresponding to the first reflection ratio and the second discharge amount corresponding to the second reflection ratio when the reflection ratio calculated by the first calculation means does not match any of the reflection ratios indicated by the reflection ratio data, is smaller than the first reflection ratio indicated by the reflection ratio data, and is larger than the second reflection ratio indicated by the reflection ratio data. (Configuration 10) The recording apparatus according to any one of Configurations 1 to 9, wherein the first ink is a white ink containing a white coloring material. (Configuration 11) The recording apparatus according to any one of Configurations 1 to 10, wherein a second ink containing a colored coloring material is discharged from the recording head. (Configuration 12) The recording apparatus according to any one of Configurations 1 to 11, wherein after the second ink is discharged by the recording head to record a base image, the first ink is discharged onto the base image to record the first adjustment pattern and the second adjustment pattern. (Configuration 13) The recording head records the first to nth adjustment patterns (n being an integer greater than 2) including the first adjustment pattern and the second adjustment pattern, and the nth adjustment pattern is recorded with the nth ink emission number. The recording device according to any one of Configurations 1 to 12, characterized in that. (Configuration 14) Each of the first to nth adjustment patterns is arranged at a different position in the conveyance direction of the recording medium, and when a plurality of combinations of the first to nth adjustment patterns are recorded, each of the plurality of recorded combinations is arranged at a different position in the main scanning direction of the recording head. The recording device according to any one of Configurations 1 to 13, characterized in that. (Configuration 15) The first calculation means calculates a reflection ratio corresponding to each adjustment pattern based on a first reflection coefficient obtained by reading the first adjustment pattern and a second reflection coefficient obtained by reading each adjustment pattern other than the first adjustment pattern. The recording device according to any one of Configurations 1 to 14, characterized in that. (Configuration 16) The second calculation means calculates an average value of the discharge amounts corresponding to each adjustment pattern as the discharge amount of the first ink. The recording device according to any one of Configurations 1 to 15, characterized in that. (Configuration 17) The second ink is black ink. The recording device according to any one of Configurations 1 to 16, characterized in that. (Configuration 18) The first ink is a colored ink containing a colored material. The recording device according to any one of Configurations 1 to 17, characterized in that. (Configuration 19) In the recording head, a white ink containing a white material is discharged as the second ink. The recording device according to any one of Configurations 1 to 18, characterized in that. (Configuration 20) After the second ink is discharged by the recording head to record a base image, the first ink is discharged onto the base image to record the first adjustment pattern and the second adjustment pattern. The recording device according to any one of Configurations 1 to 19, characterized in that. (Configuration 21) The recording apparatus further includes a drying unit that dries the image recorded on the recording medium by the recording head. After the base image is recorded by the recording head, before the first adjustment pattern and the second adjustment pattern are recorded, the drying unit dries the base image. The recording apparatus according to any one of Configurations 1 to 20, characterized in that. (Configuration 22) The recording apparatus according to any one of Configurations 1 to 21, characterized in that it does not have a calibration plate. (Control Method) A recording head that discharges a plurality of inks including a first ink from nozzles, the recording head discharging the first ink and recording a first adjustment pattern at a first ink discharge rate and a second adjustment pattern at a second ink discharge rate, A control method for a recording apparatus, comprising: a storage unit that stores reflectance data that is a reflectance for each discharge amount of the first ink discharged from the nozzles; and a sensor that reads an image recorded on a recording medium. A first calculation step of calculating a reflectance based on a first reflectance coefficient obtained by reading the first adjustment pattern by the sensor and a second reflectance coefficient obtained by reading the second adjustment pattern by the sensor; and a second calculation step of calculating a discharge amount of the first ink in the nozzles based on the reflectance calculated in the first calculation step and the reflectance data. (Program) A recording apparatus control method having a computer, a recording head that discharges a plurality of inks including a first ink from nozzles, the recording head discharging the first ink to record a first adjustment pattern at a first ink emission count and a second adjustment pattern at a second ink emission count, storage means that stores reflection ratio data which is the reflection ratio for each discharge amount of the first ink discharged from the nozzles, and a sensor that reads an image recorded on a recording medium, the method comprising: a first calculation step of calculating a reflection ratio based on a first reflection coefficient obtained by reading the first adjustment pattern with the sensor and a second reflection coefficient obtained by reading the second adjustment pattern with the sensor; and a second calculation step of calculating the discharge amount of the first ink at the nozzles based on the reflection ratio calculated in the first calculation step and the reflection ratio data. A program for executing the control method characterized by the above.

Explanation of Signs

[0117] 9 Recording head 10 Recording apparatus 40 Recording medium 100 Control unit 102 CPU 104 ROM 108 Memory 200 Optical sensor

Claims

1. A recording head that ejects a plurality of inks including a first ink from nozzles, wherein the first ink is ejected to record a first adjustment pattern at a first ink ejection count and a second adjustment pattern at a second ink ejection count, the recording head; Storage means for storing reflectance data that is the reflectance for each ejection amount of the first ink ejected from the nozzles; A sensor for reading an image recorded on a recording medium; First calculation means for calculating a reflectance based on a first reflectance coefficient obtained by reading the first adjustment pattern by the sensor and a second reflectance coefficient obtained by reading the second adjustment pattern by the sensor; Second calculation means for calculating the ejection amount of the first ink in the nozzles based on the reflectance calculated by the first calculation means and the reflectance data; having; A recording apparatus characterized by the above.

2. The value of the first ink ejection count and the value of the second ink ejection count are different. The recording apparatus according to claim 1, characterized by the above.

3. The value of the first ink ejection count and the value of the second ink ejection count are set such that the value of the first reflectance coefficient is greater than the value of the second reflectance coefficient. The recording apparatus according to claim 1 or 2, characterized by the above.

4. The value of the second ink ejection count is less than the value of the ejection count of the first ink. The recording apparatus according to claim 3, characterized by the above.

5. Using the first adjustment pattern recorded on the recording medium, the light amount of the sensor is adjusted. The recording apparatus according to claim 1 or 2, characterized by the above.

6. The first calculation means calculates the reflectance by dividing the second reflectance coefficient by the first reflectance coefficient. The recording apparatus according to claim 1 or 2, characterized by the above.

7. When the reflectance calculated by the first calculation means matches any of the reflectances indicated by the reflectance data stored in the storage means, the second calculation means calculates the ejection amount corresponding to the matching reflectance as the ejection amount of the first ink in the nozzles. The recording apparatus according to claim 6, characterized by the above.

8. When the reflectance calculated by the first calculation means does not match any of the reflectances indicated by the reflectance data stored in the storage means, the second calculation means calculates, as the discharge amount of the first ink in the nozzle, the discharge amount corresponding to the reflectance closest to the reflectance calculated by the first calculation means among the reflectances indicated by the reflectance data. The recording apparatus according to claim 6, wherein.

9. When the reflectance calculated by the first calculation means does not match any of the reflectances indicated by the reflectance data stored in the storage means, and is smaller than the first reflectance indicated by the reflectance data and larger than the second reflectance indicated by the reflectance data, the second calculation means calculates the discharge amount of the first ink in the nozzle by interpolation calculation using the first discharge amount corresponding to the first reflectance and the second discharge amount corresponding to the second reflectance. The recording apparatus according to claim 6, wherein.

10. The first ink is a white ink containing a white coloring material. The recording apparatus according to claim 1 or 2, wherein.

11. In the recording head, a second ink containing a colored coloring material is discharged. The recording apparatus according to claim 10, wherein.

12. After the second ink is discharged by the recording head to record a base image, the first ink is discharged onto the base image to record the first adjustment pattern and the second adjustment pattern. The recording apparatus according to claim 11, wherein.

13. The recording head records the first adjustment pattern to the nth adjustment pattern (n is an integer greater than 2) including the first adjustment pattern and the second adjustment pattern, and the nth adjustment pattern is recorded with the nth ink firing number. The recording apparatus according to claim 10, wherein.

14. Each of the first adjustment pattern to the nth adjustment pattern is arranged at a different position in the conveyance direction of the recording medium. When a plurality of combinations of the first adjustment pattern to the nth adjustment pattern are recorded, each of the plurality of recorded combinations is arranged at a different position in the main scanning direction of the recording head. The recording apparatus according to claim 13, wherein.

15. ​ The first calculation means calculates a reflection ratio corresponding to each adjustment pattern based on a first reflection coefficient obtained by reading the first adjustment pattern and a second reflection coefficient obtained by reading each adjustment pattern other than the first adjustment pattern. The recording apparatus according to claim 14, characterized in that.

16. The second calculation means calculates an average value of discharge amounts corresponding to the respective adjustment patterns as the discharge amount of the first ink. The recording apparatus according to claim 15, characterized in that.

17. The second ink is black ink. The recording apparatus according to claim 12, characterized in that.

18. The first ink is a colored ink containing a colored material. The recording apparatus according to claim 1 or 2, characterized in that.

19. In the recording head, white ink containing a white material is discharged as the second ink. The recording apparatus according to claim 18, characterized in that.

20. After the second ink is discharged by the recording head to record a base image, the first ink is discharged onto the base image to record the first adjustment pattern and the second adjustment pattern. The recording apparatus according to claim 19, characterized in that.

21. The recording apparatus further includes a drying means for drying an image recorded on the recording medium by the recording head, and after the base image is recorded by the recording head, before the first adjustment pattern and the second adjustment pattern are recorded, the drying means dries the base image. The recording apparatus according to claim 20, characterized in that.

22. Not having a calibration plate. The recording apparatus according to claim 1 or 2, characterized in that.

23. A recording head that discharges a plurality of inks including a first ink from nozzles, the recording head that discharges the first ink to record a first adjustment pattern at a first ink firing number and records a second adjustment pattern at a second ink firing number, A storage means for storing reflection ratio data that is a reflection ratio for each discharge amount of the first ink discharged from the nozzle, A sensor for reading an image recorded on a recording medium, A control method for a recording apparatus having, A first calculation step of calculating a reflection ratio based on a first reflection coefficient obtained by reading the first adjustment pattern by the sensor and a second reflection coefficient obtained by reading the second adjustment pattern by the sensor, ​ A second calculation step of calculating the discharge amount of the first ink in the nozzle based on the reflection ratio calculated in the first calculation step and the reflection ratio data; having; A control method characterized by this.

24. A program for causing a computer to execute the method according to claim 23.

Images