Information processing device and recording medium

Abstract

The present invention provides an information processing device and a recording medium. The information processing device includes a processor, the processor obtaining a first characteristic value representing a shape characteristic of a medium surface, and calculating a contact angle of a liquid droplet with respect to the medium based on the first characteristic value.

Description

Technical Field

[0001] The present invention relates to an information processing device and a recording medium storing an information processing program. Background Art

[0002] Patent document 1 discloses a contact angle measurement method. In the contact angle measurement method of patent document 1, the following means are provided: when measuring the contact angle value when a liquid drop is dropped on a sample by image processing, the contact angle θ over time is measured, and an approximate straight line is prepared in the coordinates with the time t after drop dropping as the horizontal axis and the contact angle θ as the vertical axis based on the obtained value, and the intercept of the approximate straight line is calculated as the contact angle value θs that can evaluate the surface energy of the sample.

[0003] Patent document 2 discloses a contact angle / surface shape composite measuring device. The contact angle / surface shape composite measuring device of Patent document 2 comprises: a droplet dropping unit, a shape measuring unit, a position control unit and a computer. The droplet dropping unit drops a droplet to a desired position on the surface of a sample. The shape measuring unit measures the three-dimensional shape of the sample surface and the shape of the droplet by a non-contact optical method. The position control unit causes the positions of the droplet dropping unit and the shape measuring unit to be relatively displaced relative to the sample. The computer performs: operation control of the droplet dropping unit, the shape measuring unit and the position control unit; acquisition of position information and image information; and calculation of the contact angle based on the shape of the droplet.

[0004] Patent document 3 discloses a method for measuring the contact angle of a droplet on a sample. In the contact angle measurement method of patent document 3, first, an area where the contact angle of the droplet on the sample can be optically measured is used as a reference area, and the cantilever of a scanning probe microscope is used to measure the adhesion force in the reference area on the sample based on the force curve between the probe tip acting on the cantilever and the sample. Next, an optical microscope is used to observe the droplet dripped onto the reference area from the side, and the contact angle of the reference area is measured. Based on the adhesion force of the reference area, the contact angle of the reference area, and the Young's modulus, a relationship between the adhesion force and the contact angle is obtained in advance. Next, in the area where the contact angle on the sample is to be measured, the adhesion force is measured based on the force curve between the probe tip acting on the cantilever and the sample. Finally, the adhesion value of the area to be measured is inserted into the relationship to obtain the contact angle of the area to be measured.

[0005] [Prior art literature]

[0006] [Patent Document]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2007-108007

[0008] [Patent Document 2] Japanese Patent Application Publication No. 2003-232712

[0009] [Patent Document 3] Japanese Patent Application Publication No. 2010-54312 Summary of the invention

[0010] Problem that the invention aims to solve

[0011] The following method is known: when measuring the contact angle of liquid on a medium for printing, etc., droplets are dropped onto the medium for printing, etc., and the results are analyzed using a laser irradiation device, a laser light source and a detector (conductivity sensor, friction sensor, gas sensor, etc.).

[0012] However, since the above-mentioned laser irradiation device or the like is large and expensive, it is difficult to easily measure the above-mentioned contact angle.

[0013] One aspect of the present invention relates to an information processing device and a recording medium recording an information processing program, which can easily calculate the contact angle of droplets on a medium used for printing, etc., compared with the case where droplets are actually dropped and a laser irradiation device, etc. is used.

[0014] Means of solving the problem

[0015] The information processing apparatus according to the first aspect includes a processor, wherein the processor obtains a first characteristic value indicating a shape characteristic of a surface of a medium, and calculates a contact angle of a liquid droplet with respect to the medium based on the first characteristic value.

[0016] According to the information processing device of the second aspect, according to the information processing device of the first aspect, the processor uses the brightness statistics obtained from the diffuse light quantity image as the first characteristic value to calculate the contact angle of the droplet on the medium, wherein the diffuse light quantity image represents the amount of light reflected and diffused on the surface of the medium among the light incident on the surface of the medium.

[0017] According to the information processing device of the third aspect, according to the information processing device of the second aspect, the processor calculates the brightness of the most frequent value as the brightness statistical value based on the brightness of multiple pixels within a unit area constituting the diffuse light image, wherein the brightness of the most frequent value represents the smoothness of the surface of the medium.

[0018] An information processing device according to a fourth aspect is the information processing device according to the first aspect, wherein the processor obtains a second characteristic value representing a physical property of the surface of the medium, and calculates the contact angle based on at least one of the first characteristic value and the second characteristic value.

[0019] An information processing apparatus according to a fifth aspect According to the information processing apparatus according to the fourth aspect, the processor uses a resistance value on the surface of the medium as the second characteristic value.

[0020] An information processing apparatus according to a sixth aspect According to the information processing apparatus according to the fourth aspect, the processor uses, as the second characteristic value, an amount of infrared rays absorbed out of an amount of infrared rays irradiated to the surface of the medium.

[0021] According to the seventh aspect of the information processing device, according to the fourth aspect of the information processing device, the processor uses both the resistance value on the surface of the medium and the amount of infrared rays absorbed from the amount of infrared rays irradiated on the surface of the medium as the second characteristic value.

[0022] The information processing program stored in the recording medium according to the eighth aspect causes a computer to execute the following processing: obtaining a first characteristic value indicating a shape characteristic of a medium surface, and calculating a contact angle of a liquid droplet with respect to the medium based on the first characteristic value.

[0023] Effects of the Invention

[0024] According to the information processing apparatus of the first aspect and the information processing program stored in the recording medium according to the eighth aspect, the contact angle can be easily calculated compared with the case where a liquid droplet is actually dropped and a laser irradiation device or the like is used.

[0025] According to the information processing device of the second aspect, the contact angle can be easily calculated optically compared to the case of using a laser irradiation device or the like.

[0026] According to the information processing device according to the third aspect, the contact angle can be calculated mathematically more easily than by performing image processing or the like.

[0027] According to the information processing apparatus of the fourth aspect, the calculation of the contact angle can be performed by using any of the shape characteristic, the physical characteristic, and the shape characteristic and the physical characteristic.

[0028] According to the information processing device of the fifth aspect, the contact angle can be calculated electrically and easily compared to the case where a parameter other than the resistance value is used.

[0029] According to the information processing device of the sixth aspect, the contact angle can be calculated optically more easily than when using parameters other than the infrared ray.

[0030] According to the information processing device of the seventh aspect, the contact angle can be optically calculated more easily than when using the resistance value or a parameter other than infrared rays. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The structure of the droplet contact angle calculation device ESS according to the exemplary embodiment is shown.

[0032] Figure 2 1 is a functional block diagram of a droplet contact angle calculation device ESS according to an exemplary embodiment.

[0033] Figure 3 The unit structure of the droplet contact angle calculation device ESS according to the exemplary embodiment is shown.

[0034] Figure 4 It is a schematic diagram showing the surface of the printing medium PM according to the illustrated embodiment.

[0035] Figure 5 (A) is a first detailed view showing the surface of the printing medium PM according to the exemplary embodiment, Figure 5 (B) is a second detailed diagram showing the surface of the printing medium PM according to the illustrated embodiment.

[0036] Figure 6 It is a diagram showing the irradiation of white light HS and the imaging of diffused light KS in the brightness detection unit KKU according to the illustrated embodiment.

[0037] Figure 7 It is a flowchart of the operation of the brightness detection unit KKU according to the exemplary embodiment.

[0038] Figure 8 The diffused light amount image GZ according to the illustrated embodiment is shown.

[0039] Fig. 9 A distribution diagram BPZ of an exemplary embodiment is shown.

[0040] Fig.10 FIG. 1 is a diagram showing measurement of a resistance value using the resistance value measurement unit TSU according to the exemplary embodiment.

[0041] Fig.11 1 is a flowchart showing the operation of the resistance value measuring unit TSU according to the exemplary embodiment.

[0042] Fig.12 1 is a diagram showing the measurement of infrared absorption amount SK using the infrared absorption amount detection unit SKU according to the illustrated embodiment.

[0043] Fig.13 1 is a flowchart showing the operation of the infrared absorption amount detection unit SKU according to the illustrated embodiment.

[0044] Fig.14 1 is a flowchart of calculation of the contact angle SSK in the droplet contact angle calculation apparatus ESS according to the exemplary embodiment.

[0045] Fig.15 denoted a first relationship between a predicted value and a true value of the contact angle SSK according to the illustrated embodiment.

[0046] Fig.16 denoted a second relationship between the predicted value and the true value of the contact angle SSK according to the illustrated embodiment.

[0047] Fig.17 denoted a third relationship between the predicted value and the true value of the contact angle SSK according to the illustrated embodiment. DETAILED DESCRIPTION

[0048] <Exemplary Embodiment>

[0049] Hereinafter, an exemplary embodiment of a droplet contact angle calculation device as an example of the information processing device of the present invention will be described.

[0050] <Structure of the illustrated embodiment>

[0051] <Structure of Droplet Contact Angle Calculation Device ESS>

[0052] Figure 1 The structure of the droplet contact angle calculation device ESS according to the exemplary embodiment is shown below. Figure 1 The structure of the droplet contact angle calculation device ESS according to the illustrated embodiment will be described.

[0053] like Figure 1 As shown, the droplet contact angle calculation device ESS of the illustrated embodiment includes an input unit 11 , a CPU 12 (Central Processing Unit), an output unit 13 , a storage medium 14 , and a memory 15 .

[0054] The input unit 11 is composed of, for example, a sensor, a photodiode, a keyboard, a mouse, and a touch panel. The CPU 12 is an example of a processor and is a well-known computer core that operates hardware according to software. The output unit 13 is composed of, for example, a light-emitting diode, a printer, a liquid crystal monitor, and a touch panel. The storage medium 14 is composed of, for example, a hard disk drive (HDD), a solid state drive (SSD), and a ROM (Read Only Memory). The memory 15 is composed of, for example, a DRAM (Dynamic Random Access Memory) and an SRAM (Static Random Access Memory).

[0055] The storage medium 14 stores a program PR and a contact angle calculation formula EQ.

[0056] The program PR is a set of instructions that defines the content of processing to be executed by the CPU 12 .

[0057] The contact angle calculation formula EQ is a formula for calculating the contact angle.

[0058] Here, the “contact angle” refers to the contact angle of the printing medium PM such as paper (for example Figure 4 The angle between the surface of the liquid droplet and the surface of the liquid droplet is shown. The printing medium PM such as paper is an example of the "medium".

[0059] The contact angle calculation formula EQ is as follows.

[0060] Contact angle SSK = A × brightness statistics KT + B × resistance value DT + C × infrared absorption SK1 / infrared absorption SK2 + D…(1)

[0061] The “brightness statistic KT” represents the smoothness HD of the surface of the printing medium PM (using Figure 4 , Figure 5 (A) Figure 5 (B) will be described later. ).

[0062] The “brightness statistical value KT” is an example of the “first characteristic value” indicating the “shape characteristic” of the surface of the printing medium PM.

[0063] The “resistance value DT” is represented by the common logarithm value (logΩ) of the resistance value per unit length of the surface of the printing medium PM.

[0064] The “infrared absorption amount SK1” refers to the amount of infrared rays absorbed by the surface of the printing medium PM when the surface of the printing medium PM is irradiated with infrared rays having a wavelength of 1400 nm.

[0065] "Infrared absorption amount SK2" refers to the amount of infrared light absorbed by the surface of the printing medium PM when infrared light with a wavelength of 1250nm is irradiated to the surface of the printing medium PM. The infrared absorption amounts SK1 and SK2 are calculated as the ratio of the actual light receiving amount to the light receiving amount when the irradiated infrared light is 100% reflected. The case where the irradiated infrared light is 100% reflected means that no infrared light is absorbed.

[0066] The “resistance value DT”, “infrared absorption amount SK1 ”, and “infrared absorption amount SK2 ” are examples of “second characteristic values” indicating the “physical properties” of the surface of the printing medium PM.

[0067] The reason for using two infrared wavelengths of 1250nm and 1400nm is as follows. By using the former wavelength of 1250nm, the infrared absorption amount can be measured regardless of the material of the printing medium PM. Therefore, the infrared absorption amount obtained by measuring the former wavelength of 1250nm is used as a reference amount (reference value), and the infrared absorption amount obtained by measuring the latter wavelength of 1400nm can be corrected (calibrated).

[0068] "Constant A", "Constant B" and "Constant C" are respectively constants obtained by experiments and used to obtain the contact angle SSK of the printing medium PM from the brightness statistical value KT, resistance value DT and infrared absorption amounts SK1 and SK2 of the printing medium PM, the object for which the contact angle SSK is to be predicted.

[0069] “Constant A”, “Constant B”, and “Constant C” are, for example, numerical values ​​determined in advance by an experimenter in an environment that is different from the liquid drop contact angle calculation device ESS and that can perform measurements with higher accuracy (for example, an environment using a laser microscope, etc.). More specifically, “Constant A”, “Constant B”, and “Constant C” are determined by experimentally using a plurality of printing media PM that are different from the above-mentioned “printing media PM as an object for which the contact angle SSK is to be predicted”, and specifying the relationship between each contact angle SSK of the plurality of printing media PM and each brightness statistical value KT, resistance value DT, and infrared absorption amount SK1, SK2 of the plurality of printing media PM.

[0070] "Constant D" is a constant used to supplement the calculation when the contact angle SSK is calculated using the brightness statistical value KT, the resistance value DT, the infrared absorption amounts SK1, SK2, and the constants A, B, and C. The combination of "Constant A", "Constant B", "Constant C", and "Constant D" is prepared in advance corresponding to the case where all of the brightness statistical value KT, the resistance value DT, and the infrared absorption amounts SK1, SK2 are used or the case where none of them are used.

[0071] <Function of the droplet contact angle calculation device ESS>

[0072] Figure 2 1 is a functional block diagram of a droplet contact angle calculation device ESS according to an exemplary embodiment.

[0073] like Figure 2 As shown, the droplet contact angle calculation device ESS of the illustrated embodiment includes a measuring unit (acquisition unit) 21 , a calculation unit 22 , a control unit 23 , and a storage unit 24 .

[0074] Regarding the relationship between the hardware structure and the functional structure in the droplet contact angle calculation device ESS, in terms of hardware, the CPU 12 executes the program PR stored in the storage medium 14 (a part of the function of the storage unit 24) using the memory 15 (which realizes another part of the function of the storage unit 24), and, as the control unit 23, realizes the functions of the measurement unit 21 and the calculation unit 22 by controlling the operations of the input unit 11 and the output unit 13 as needed. The functions of each unit will be described later.

[0075] <Unit Structure of Droplet Contact Angle Calculation Device ESS>

[0076] Figure 3 The unit structure of the droplet contact angle calculation device ESS according to the exemplary embodiment is shown.

[0077] like Figure 3 As shown, the droplet contact angle calculation device ESS of the illustrated embodiment includes three units, namely, a brightness detection unit KKU, a resistance value measurement unit TSU, and an infrared absorption amount detection unit SKU.

[0078] like Figure 3 As shown, the brightness detection unit KKU has a white light emitting diode 31 and a CMOS sensor 32. The white light emitting diode 31 corresponds to the output unit 13 ( Figure 1 ), and the CMOS sensor 32 corresponds to the input unit 11 ( Figure 1 as shown. ).

[0079] like Figure 3 As shown in FIG. 1 , the brightness detection unit KKU includes a resistance value measuring device 41 . The resistance value measuring device 41 corresponds to the input unit 11 and the output unit 13 .

[0080] like Figure 3 As shown, the infrared absorption amount detection unit SKU has an infrared light emitting diode 51 and a photodiode 52. The infrared light emitting diode 51 corresponds to the output part 13, and the photodiode 52 corresponds to the input part 11.

[0081] <Factual Relationship Assumed by the Droplet Contact Angle Calculation System ESS of the Exemplary Embodiment>

[0082] Figure 4 It is a schematic diagram showing the surface of the printing medium PM according to the illustrated embodiment.

[0083] Figure 5 (A) is a first detailed view showing the surface of the printing medium PM according to the illustrated embodiment.

[0084] Figure 5 (B) is a second detailed diagram showing the surface of the printing medium PM according to the illustrated embodiment.

[0085] like Figure 4 As shown, the surface of the printing medium PM has a plane HM and holes AN. On the surface of the printing medium PM, if the area of ​​the plane HM is compared with the area of ​​the holes AN, the area of ​​the plane HM is much larger. Therefore, the contact angle SSK, which is the surface property of the printing medium PM, is determined by the property of the plane HM of the printing medium PM.

[0086] Hereinafter, the printing medium PM whose plane HM is “rough” is referred to as “printing medium PM (AR)”, and the printing medium PM whose plane HM is “smooth” is referred to as “printing medium PM (NM)”.

[0087] The plane HM of the surface of the printing medium PM (AR) is as follows: Figure 5 As shown in (A), the incident white light HS is diffusely reflected to reflect diffused light KS11, KS12, and KS13 with a large amount of light.

[0088] like Figure 5 As shown in (B), in contrast to the above, the plane HM on the surface of the printing medium PM (NM) diffusely reflects the irradiated white light HS, but reflects diffused light KS21, KS22, and KS23 with a small light amount.

[0089] Therefore, in more detail, the contact angle SSK of the printing medium PM is determined by the “smoothness HD” indicating how rough or smooth the plane HM on the surface of the printing medium PM is.

[0090] <Operation of the Droplet Contact Angle Calculation Apparatus ESS According to the Exemplary Embodiment>

[0091] For ease of explanation and understanding, it is assumed below that the printing medium PM is pre-set in relation to the droplet contact angle calculation device ESS at a position where the brightness statistical value KT, resistance value DT and infrared absorption amount SK of the printing medium PM can be measured and detected.

[0092] <Operation of Brightness Detection Unit KKU>

[0093] Figure 6 It is a diagram showing the irradiation of white light HS and the imaging of diffused light KS in the brightness detection unit KKU according to the illustrated embodiment.

[0094] Figure 7 1 is a flowchart showing the operation of the brightness detection unit KKU according to the exemplary embodiment. Figure 6 , Figure 7 The operation of the brightness detection unit KKU according to the illustrated embodiment will be described.

[0095] Step S10: A user (not shown) of the liquid droplet contact angle calculation device ESS enters a value from the input unit 11 (e.g. Figure 1 ) Press the button (not shown) for calculating the brightness statistics KT. In response to the pressing, in the droplet contact angle calculation device ESS, the CPU 12 ( Figure 1 As shown. ) as the measuring section 21 ( Figure 2 ) is started as the output unit 13 (shown in Figure 1 ). Thus, Figure 6 As shown, the white light emitting diode 31 irradiates the printing medium PM with white light HS.

[0096] like Figure 6 As shown, the white light emitting diode 31 of the brightness detection unit KKU preferably irradiates the printing medium PM with white light HS at approximately 16 degrees toward the printing medium PM.

[0097] return Figure 7 , the operation of the droplet contact angle calculation device ESS is further described.

[0098] Step S11: In step S10, when the white light HS is irradiated, in the droplet contact angle calculation device ESS, the CPU 12 as the measuring unit 21 starts the input unit 11 ( Figure 1 As shown in FIG. 1 , the CMOS sensor 32 is operated. Thus, the CMOS sensor 32 receives the diffused light KS emitted from the surface of the printing medium PM, namely, the diffused light KS11 to KS23 ( Figure 5 (A), (B) shown. ) and other diffuse light KS.

[0099] Figure 8 The diffused light amount image GZ according to the illustrated embodiment is shown.

[0100] The diffuse light KS is received by the CMOS sensor 32, such as Figure 7 As shown, the CPU 12 as the measuring unit 21 generates a diffused light amount image GZ indicating the amount of light diffused on the surface of the printing medium PM, particularly on the plane HM, that is, the brightness of a plurality of pixels per unit area.

[0101] like Figure 8 As shown in FIG. 1 , a square area of, for example, 5 mm in length and width on the surface of the print medium PM is captured as the diffuse light quantity image GZ. Figure 8As shown, the diffuse light quantity image GZ is composed of, for example, 650×650 pixels GS (about 420,000 pixels GS in total). Each pixel GS represents the brightness KD of the surface of the printing medium PM by 8 bits (256 levels from 0 to 255), in other words, the intensity of the diffuse light KS.

[0102] return Figure 7 , the operation of the droplet contact angle calculation device ESS is further described.

[0103] Step S12 : In step S11 , when the diffused light amount image GZ is generated, the CPU 12 as the measuring unit 21 generates a distribution map BPZ indicating the distribution of the brightness KD on the surface of the printing medium PM.

[0104] Fig. 9 A distribution diagram BPZ of an exemplary embodiment is shown.

[0105] More specifically, if Fig. 9 As shown, the CPU 12 creates a diffuse light quantity image GZ (in Figure 8 ) and the distribution diagram BPZ of the relationship between the plurality of pixels GS (about 420,000 pixels mentioned above) and the brightness KD shown in each pixel GS. Fig. 9 As shown, the distribution graph BPZ indicates that the relationship between the brightness KD and the frequency (the number of pixels GS) is close to a normal distribution.

[0106] Here, the printing medium PM (AR) ( Figure 5 ) and the printing medium PM (NM) (shown in (A) of FIG. Figure 5 (B). ) When making a distribution map BPZ, if Fig. 9 As shown, the mode SH2 of the brightness (the number of pixels GS) of the former printing medium PM (AR) is greater than the mode SH1 of the brightness (the number of pixels GS) of the latter printing medium PM (NM).

[0107] The reason why the above-mentioned mode SH2 is larger than the mode SH1 is as follows: Figure 5 (A) and (B) are because the amount of diffused light KS11, KS12, KS13 on the plane HM of the printing medium PM (AR) is greater than the amount of diffused light KS21, KS22, KS23 on the plane HM of the printing medium PM (NM).

[0108] In short, by obtaining the position of the most frequent value SH of the printing medium PM where the contact angle SSK is unclear, the "smoothness HD" indicating how rough or smooth the surface HM of the above-mentioned printing medium PM is obtained, thereby making the contact angle SSK clear.

[0109] return Figure 7 , the operation of the droplet contact angle calculation device ESS is further described.

[0110] Step S13: In step S12, if the distribution diagram BPZ of the brightness KD is generated, the CPU 12 as the calculation unit 22 (shown in FIG. Figure 2 . ), the brightness KD of the pixel GS with the largest number in the distribution diagram BPZ, that is, the most frequent value SH is obtained. Thus, the CPU 12 calculates the brightness statistical value KT.

[0111] <Operation of Resistance Measurement Unit TSU>

[0112] Fig.10 FIG. 1 is a diagram showing resistance value measurement in the resistance value measurement unit TSU according to the exemplary embodiment.

[0113] Fig.11 1 is a flowchart showing the operation of the resistance value measuring unit TSU according to the exemplary embodiment.

[0114] The following is a diagram showing the operation of the resistance value measuring unit TSU. Fig.10 as well as Fig.11 , the operation of the resistance value measuring unit TSU according to the illustrated embodiment will be described.

[0115] Step S20: The user of the liquid droplet contact angle calculation device ESS enters the liquid droplet contact angle calculation device ESS from the input unit 11 (eg, Figure 1 ) Press a button (not shown) for calculating the resistance value DT. In response to the pressing, in the droplet contact angle calculation device ESS, the CPU 12 ( Figure 1 As shown. ) as the measuring unit 21 ( Figure 2 ), start the output unit 13 (shown in Figure 1 . ) The resistance value measuring device 41 operates. As a result, the resistance value measuring device 41 applies a voltage between the two electrodes 42A and 42B on the printing medium PM.

[0116] Here, since the resistance value DT of the printing medium PM is extremely large, it is preferable that the distance between the two electrodes 42A and 42B is, for example, approximately 1 mm, and the applied voltage is approximately several hundred V or more (eg, 200 V).

[0117] Step S21: In step S20, when a voltage is applied between the two electrodes 42A and 42B, the CPU 12 functions as the measuring unit 21 (shown in FIG. Figure 2 . ) instructs the resistance value measuring device 41 to measure the resistance value of the printing medium PM, that is, the resistance value DT. Thus, the resistance value measuring device 41 measures the resistance value DT of the printing medium PM.

[0118] <Operation of the infrared absorption detection unit SKU>

[0119] Fig.12 1 is a diagram showing measurement of the infrared absorption amount SK of the infrared absorption amount detection unit SKU according to the illustrated embodiment.

[0120] Fig.13 1 is a flowchart showing the operation of the infrared absorption amount detection unit SKU according to the illustrated embodiment.

[0121] The following uses the operation of the infrared absorption detection unit SKU. Fig.12 and Fig.13 , the operation of the infrared absorption detection unit SKU of the illustrated embodiment is described.

[0122] Step S30: The user of the liquid droplet contact angle calculation device ESS enters the liquid droplet contact angle calculation device ESS from the input unit 11 (eg, Figure 1 ) Press a button (not shown) for calculating the infrared absorption amount SK. In response to the pressing, in the droplet contact angle calculation device ESS, the CPU 12 ( Figure 1 As shown. ) as the measuring unit 21 ( Figure 2 ), start the output unit 13 (shown in Figure 1 ). Thus, the infrared light emitting diode 51 irradiates the surface of the printing medium PM with infrared light SG1.

[0123] Step S31: In step S30, when the infrared ray SG1 is irradiated to the surface of the printing medium PM, the CPU 12 as the measuring unit 21 instructs the input unit 11 (in Figure 1 ) is operated by the photodiode 52, for example, switching the circuit wiring between the CPU 12 and the photodiode 52 so as to feed back the detection result of the photodiode 52 to the CPU 12. Thus, the photodiode 52 measures the amount of infrared rays SG2 reflected on the surface of the printing medium PM, that is, the reflection amount.

[0124] Step S32: In step S31, if the reflected amount of infrared ray SG2 is measured, the CPU 12 as the calculation unit 22 (such as Figure 2 ), the amount of infrared SG2 reflected by the photodiode 52 measured in step S31 is subtracted from the amount of infrared SG1 irradiated from the infrared light emitting diode 51 in step S30. Thus, the CPU 12 calculates the amount of infrared SG3 absorbed by the surface of the printing medium PM (absorption amount), that is, the infrared absorption amounts SK1 and SK2.

[0125] The infrared absorption amount is measured by combining the above steps S30 to S32 as one set, and performing two sets of measurements. In the first set, the above 1400 nm is used as the wavelength of the infrared ray SG1, and in the second set, the above 1250 nm is used as the wavelength of the infrared ray SG2.

[0126] <Calculation of contact angle SSK>

[0127] Fig.14 FIG. 1 is a flowchart showing the calculation of the contact angle SSK in the droplet contact angle calculation apparatus ESS according to the exemplary embodiment. Fig.14 Flowchart to describe the calculation of contact angle SSK.

[0128] In step S40, in the droplet contact angle calculation device ESS, the CPU 12 ( Figure 1 As shown. ) group is the calculation unit 22 ( Figure 2 As shown in FIG. 1 , the brightness statistical value KT calculated in the above step S13, the resistance value DT measured in the above step S21, and the infrared absorption amounts SK1 and SK2 calculated in the above step S32 are substituted into the contact angle calculation formula EQ. Thus, the contact angle SSK is calculated.

[0129] In addition, the CPU 12 outputs the calculated contact angle SSK to an output unit 13 (such as a printer, a liquid crystal monitor, etc.) according to a request from a user of the liquid droplet contact angle calculation device ESS. Figure 2 as shown. ).

[0130] More specifically, the CPU 12 may perform the following substitution.

[0131] (1) When only the brightness statistical value KT is calculated, only the brightness statistical value KT is substituted into the contact angle calculation formula EQ.

[0132] (2) When the brightness statistical value KT is calculated and the resistance value DT is measured, the brightness statistical value KT and the resistance value DT are substituted into the contact angle calculation formula EQ.

[0133] (3) When the brightness statistical value KT and the infrared absorption amounts SK1 and SK2 are calculated, the brightness statistical value KT and the infrared absorption amounts SK1 and SK2 are substituted into the contact angle calculation formula EQ.

[0134] (4) When measuring the resistance value DT and calculating the infrared absorption amounts SK1 and SK2, the resistance value DT and the infrared absorption amounts SK1 and SK2 are substituted into the contact angle calculation formula EQ.

[0135] <Comparison between the predicted contact angle calculated by the contact angle calculation formula EQ and the true contact angle>

[0136] Fig.15 denoted a first relationship between a predicted value and a true value of the contact angle SSK according to the illustrated embodiment.

[0137] Fig.16 denoted a second relationship between the predicted value and the true value of the contact angle SSK according to the illustrated embodiment.

[0138] Fig.17 denoted a third relationship between the predicted value and the true value of the contact angle SSK according to the illustrated embodiment.

[0139] The “predicted value of the contact angle SSK” refers to the value of the contact angle SSK of the printing medium PM obtained by substituting one or more of the brightness statistical value KT, the resistance value DT, and the infrared absorption amounts SK1 and SK2 into the contact angle calculation formula EQ.

[0140] Fig.15 The “predicted value of the contact angle SSK” in EQ is the value of the contact angle SSK of the printing medium PM obtained by substituting only the brightness statistical value KT into the above-mentioned contact angle calculation formula EQ.

[0141] Fig.16 The “predicted value of the contact angle SSK” in ∝ is the value of the contact angle SSK of the printing medium PM obtained by substituting the resistance value DT and the infrared absorption amounts SK1 and SK2 into the contact angle calculation formula EQ described above.

[0142] Fig.17 The “predicted value of the contact angle SSK” in ∝ is the value of the contact angle SSK of the printing medium PM obtained by substituting all of the brightness statistic KT, the resistance value DT, and the infrared absorption amounts SK1 and SK2 into the above-mentioned contact angle calculation formula EQ.

[0143] The so-called "true value of the contact angle SSK" refers to the angle between the surface of the droplet and the surface of the printing medium PM obtained by imaging with a high-resolution / high-speed camera (e.g. 0.1-0.5 μm / pixel, 10-20 μsec / frame).

[0144] exist Figure 15 to Figure 17 In the example, the points drawn (depicted) are points of each of a plurality of sheets of paper. The plurality of sheets of paper are specified by parameters. The parameters are, for example, the type of paper and the brand of paper (manufacturing company, factory).

[0145] The types of paper are, for example, glossy coated paper and matte coated paper, etc. The brands of paper are paper manufacturing companies (eg, manufacturing company A and manufacturing company B) and paper factories (eg, factories a1 and a2 of paper manufacturing company A).

[0146] For example, in Figure 15 to Figure 17In the diagram, one sheet of paper (plotted dots) is, for example, glossy coated paper, indicating that it is manufactured in factory a1 of manufacturing company A. The other sheet of paper (plotted dots) is, for example, glossy coated paper, indicating that it is manufactured in another factory a2 of manufacturer A. Another sheet of paper (plotted dots) is, for example, glossy coated paper, indicating that it is manufactured in factory b of manufacturer B.

[0147] like Figure 15 to Figure 17 As shown in FIG. 1 , a straight line can be drawn between a plurality of plotted points representing predicted values ​​of the contact angle SSK and true values ​​of the contact angle SSK using the least square method. Therefore, it can be said that there is a linear correlation between the true value of the contact angle SSK of the printing medium PM and the predicted value of the contact angle SSK of the printing medium PM, regardless of the type of paper and the brand of paper mentioned above.

[0148] In other words, it can be said that the predicted value of the contact angle SSK of the printing medium PM obtained by the above contact angle calculation formula EQ can represent and symbolize the true value of the contact angle SSK of the printing medium PM. That is, instead of obtaining the true value of the contact angle SSK of the printing medium PM in a large-scale and expensive environment using a laser microscope, etc., the contact angle SSK of the printing medium PM can be estimated by substituting the brightness statistical value KT, the resistance value DT, and the infrared absorption amounts SK1 and SK2 obtained in a small-scale and inexpensive environment such as a white light emitting diode 31 and a CMOS sensor 32 into the above contact angle calculation formula EQ.

[0149] <Modification>

[0150] Regarding the substitution into the contact angle calculation formula EQ, for example, (1) the brightness statistic KT and the resistance value DT can be substituted; (2) the brightness statistic KT and the infrared absorption amounts SK1 and SK2 can be substituted; (3) only the resistance value DT can be substituted; (4) only the infrared absorption amounts SK1 and SK2 can be substituted.

[0151] <Supplementary information about processor and program>

[0152] In addition, in the above-mentioned embodiments, the processor refers to a processor in a broad sense, including general-purpose processors (such as CPU: Central Processing Unit, etc.) and special-purpose processors (such as GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic devices, etc.).

[0153] In the above-mentioned embodiments, the actions of the processors may be implemented by a single processor or by cooperation of a plurality of processors. In addition, the order of the actions of the processors is not limited to the order in the above-mentioned embodiments and may be changed as appropriate.

[0154] In the above-mentioned embodiment, the program PR can also be provided by being recorded in a recording medium such as a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory), and a USB (Universal Serial Bus) memory instead of being pre-stored (installed) in the storage medium 14, or it can be downloaded from an external device via a network.

[0155] The above description of the embodiments of the present invention is provided for the purpose of illustration and description. The present invention is not intended to be exhaustive or to limit the present invention to the precise form disclosed. Obviously, many modifications and variations will be apparent to those skilled in the art. The embodiments are selected and described in order to best explain the principles of the present invention and its practical application, so that other technical personnel in the art can understand the various embodiments of the present invention and have various modifications suitable for the specific use expected. The scope of the present invention is intended to be limited by the appended claims and their equivalents.

Claims

1. An information processing device comprising a processor, The processor obtains a first characteristic value representing a shape characteristic of a surface of a medium, The processor uses the brightness statistics obtained from the diffuse light image as the first characteristic value to calculate the contact angle of the droplet to the medium by the following formula: Contact angle = A × brightness statistics in, The brightness statistic is the smoothness of the surface of the medium. A is a constant determined in advance by experiments, The diffused light amount image indicates the amount of light reflected and diffused on the surface, among the light incident on the surface of the medium.

2. The information processing device according to claim 1, wherein: The processor calculates the brightness of a mode value as the brightness statistical value based on the brightness of a plurality of pixels within a unit area constituting the diffuse light amount image, wherein the brightness of the mode value indicates the smoothness of the surface of the medium.

3. The information processing device according to claim 1 or 2, wherein: The processor obtains a second characteristic value representing a physical characteristic of a surface of the medium, The processor calculates the contact angle according to the first characteristic value and the second characteristic value, The physical property is at least one of a resistance value on the surface of the medium and an amount of infrared rays absorbed out of an amount of infrared rays irradiated to the surface of the medium.

4. The information processing device according to claim 3, wherein: The processor uses a resistance value on the surface of the medium as the second characteristic value.

5. The information processing device according to claim 3, wherein: The processor uses, as the second characteristic value, an amount of infrared light absorbed among an amount of infrared light irradiated to the surface of the medium.

6. The information processing device according to claim 3, wherein: The processor uses, as the second characteristic value, both a resistance value on the surface of the medium and an amount of infrared rays absorbed from among an amount of infrared rays irradiated to the surface of the medium.

7. A storage medium storing an information processing program for causing a computer to execute the following processing: obtaining a first characteristic value representing a shape characteristic of a surface of a medium; and Using the brightness statistics obtained from the diffuse light image as the first characteristic value, the contact angle of the droplet to the medium is calculated by the following formula: Contact angle = A × brightness statistics in, The brightness statistic is the smoothness of the surface of the medium. A is a constant determined in advance by experiments, The diffused light amount image indicates the amount of light reflected and diffused on the surface, among the light incident on the surface of the medium.

8. A computer program product, comprising an information processing program, the information processing program being configured to cause a computer to execute the following processing: obtaining a first characteristic value representing a shape characteristic of a surface of a medium; and Using the brightness statistics obtained from the diffuse light image as the first characteristic value, the contact angle of the droplet to the medium is calculated by the following formula: Contact angle = A × brightness statistics in, The brightness statistic is the smoothness of the surface of the medium. A is a constant determined in advance by experiments, The diffused light amount image indicates the amount of light reflected and diffused on the surface, among the light incident on the surface of the medium.

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