Inspection system, inspection program, and inspection method

Abstract

To obtain an inspection system capable of confirming a coating state of a coating material on the surface of a recording medium more accurately than in the case of performing inspection on the basis of only a measurement result of the recording medium with the coating material coated thereon.SOLUTION: An inspection system includes: an electric measuring instrument for applying voltage between a pair of electrodes 32, 33 to measuring the electric resistance of paper P between the pair of electrodes 32, 33 brought into contact with the surface of the paper P whose surface is coated with a precoat layer 106 containing an organic compound with a distance between the pair of electrodes 32, 33 being set to 0.5 mm or more and 1.5 mm or less; and at least one processor. The processor inspects a coating state of a coating material of the precoat layer on the surface of the paper P on the basis of a difference between electric resistance of the paper P coated with the precoat layer 106 and electric resistance of paper without being coated with the precoat layer.SELECTED DRAWING: Figure 15

Description

[Technical Field]

[0001] The present invention relates to an inspection system, an inspection program, and an inspection method. [Background technology]

[0002] Patent Document 1 listed below discloses a surface condition measurement method for determining the vertical spectral surface reflectance on the surface of a light-transmitting coating film to measure the presence or absence of a light-transmitting substance on the light-transmitting coating film, the surface condition measurement method including the steps of: concentrating spectral light from a light source emitting spectral light in a desired wavelength range via a focusing optical system in a confocal optical system; making the focused beam incident on the light-transmitting coating film so that the focal point of the focused beam is on the surface of the light-transmitting coating film; returning reflected light from the surface of the light-transmitting coating film to the confocal optical system via the focusing optical system and guiding it to a spectroscopic means via a detection light transmission fiber for dispersion; supplying metal soap, as the light-transmitting substance, onto the photosensitive layer of an electrophotographic photosensitive member, as the light-transmitting coating film; and calculating the vertical spectral surface reflectance based on the obtained spectral intensity, and measuring the presence or absence of the metal soap from the vertical spectral surface reflectance specific to the metal soap substance.

[0003] Patent Document 2 listed below discloses a cigarette paper inspection device for inspecting cigarette paper for cutting tobacco coated with a striped low-flame-spreading substance, the device comprising: a pair of electrodes provided on a cigarette paper transport path along which the cigarette paper is unwound and continuously transported, and which sandwich the cigarette paper from both sides; an electrical resistance measuring unit which measures the electrical resistance of the cigarette paper sandwiched between the pair of electrodes; and a cigarette paper inspection unit which determines whether or not there is a defect in the coating state of the low-flame-spreading substance on the cigarette paper from the electrical resistance of the cigarette paper measured by the electrical resistance measuring unit, and outputs the determination result. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4481850 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-310232 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, in order to improve the image quality of printed matter, a coating material containing an organic compound may be applied to the surface of a recording medium such as paper, but the state of application of the coating material on the surface of the recording medium is often not apparent at a glance.

[0006] The present invention aims to provide an inspection system, inspection program, and inspection method that can accurately confirm the coating condition of a coating material on the surface of a recording medium, compared to inspection based solely on the measurement results of the recording medium to which the coating material has been applied. [Means for solving the problem]

[0007] The inspection system of the first aspect comprises an electrical measuring instrument that measures the electrical resistance of a recording medium between a pair of electrodes, the distance between which is between 0.5 mm and 1.5 mm and that contacts the surface of the recording medium coated with a coating material containing an organic compound, by applying a voltage between the pair of electrodes, and at least one processor, and the processor inspects the coating state of the coating material on the surface of the recording medium based on the difference between the electrical resistance of the recording medium coated with the coating material and the electrical resistance of a recording medium not coated with the coating material.

[0008] The inspection system according to the second aspect is the inspection system according to the first aspect, wherein the electrical measuring instrument comprises a power supply that applies a voltage between the pair of electrodes and a measuring unit that measures the electrical resistance of the recording medium between the pair of electrodes.

[0009] A test system according to a third aspect is the test system according to the second aspect, wherein the voltage applied from the power supply is 100V or more and 300V or less.

[0010] The inspection system according to the fourth aspect is an inspection system according to any one of the first to third aspects, and includes a near-infrared sensor that is provided at a position opposite the recording medium, irradiates near-infrared rays onto the surface of the recording medium, and detects whether or not the coating material is applied to the surface of the recording medium.

[0011] An inspection system according to a fifth aspect is the inspection system according to the fourth aspect, wherein the near-infrared sensor is configured to irradiate the surface of the recording medium with near-infrared light of a first wavelength, which is a wavelength absorbed by components of the coating material, and near-infrared light of a second wavelength, which is a wavelength different from the first wavelength and does not contain components that absorb the second wavelength, and the processor detects whether or not the coating material is applied to the surface of the recording medium based on the ratio between the peak intensity when the near-infrared light of the first wavelength is irradiated onto the surface of the recording medium and the peak intensity when the near-infrared light of the second wavelength is irradiated onto the surface of the recording medium.

[0012] The inspection system according to the sixth aspect is an inspection system according to any one of the first to fifth aspects, and has an image sensor that is positioned opposite the recording medium and acquires adhesion information and color information of the recording medium from imaging data that captures the surface of the recording medium.

[0013] A seventh aspect of the present invention relates to an inspection system according to the sixth aspect, wherein the image sensor is a C-MOS sensor.

[0014] The inspection program according to the eighth aspect causes a computer to execute the steps of acquiring the electrical resistance of a recording medium that is not coated with a coating material containing an organic compound on its surface, contacting a pair of electrodes with the surface of the recording medium that has the coating material coated on its surface to measure the electrical resistance of the recording medium that has the coating material coated on its surface, and inspecting the coating state of the coating material on the surface of the recording medium based on the difference between the electrical resistance of the recording medium that has the coating material coated on it and the electrical resistance of the recording medium that has not been coated with the coating material.

[0015] The inspection method according to the ninth aspect includes an acquisition step of acquiring the electrical resistance of a recording medium that does not have a coating material containing an organic compound applied to its surface; a measurement step of contacting a pair of electrodes with the surface of the recording medium that has the coating material applied to its surface and measuring the electrical resistance of the recording medium that has the coating material applied to its surface; and an inspection step of inspecting the application state of the coating material on the surface of the recording medium based on the difference between the electrical resistance of the recording medium that has the coating material applied to its surface and the electrical resistance of the recording medium that has not been applied to its surface.

[0016] An inspection method according to a tenth aspect is the inspection method according to the ninth aspect, and includes, at least before the measurement step, a detection step of irradiating near-infrared rays onto the surface of the recording medium and detecting whether or not the coating material is applied to the surface of the recording medium.

[0017] The inspection method according to the eleventh aspect is the inspection method according to the ninth aspect, and further includes, at least prior to the measurement step, a determination step of determining whether or not there is dirt on the surface of the recording medium based on surface information of the recording medium obtained from imaging data of the surface of the recording medium. [Effects of the Invention]

[0018] The inspection system according to the first aspect can accurately check the state of application of the coating material on the surface of the recording medium, compared to when inspection is based solely on the measurement results of the recording medium to which the coating material is applied. Furthermore, compared to when the distance between the pair of electrodes is greater than 1.5 mm, current is prevented from flowing into the layer of the recording medium inside the coating material, and compared to when the distance between the pair of electrodes is less than 0.5 mm, short circuits are less likely to occur.

[0019] According to the inspection system of the second aspect, the measurement unit measures the electrical resistance of the recording medium between the pair of electrodes.

[0020] According to the inspection system of the third aspect, discharge is less likely to occur compared to when the voltage is higher than 300V, and the measurement accuracy of the electrical resistance is improved compared to when the generated voltage is lower than 100V.

[0021] According to the inspection system of the fourth aspect, erroneous detection of stains on the surface of the recording medium or non-coating is suppressed compared to when only the electrical resistance of the recording medium is measured.

[0022] According to the inspection system of the fifth aspect, organic materials contained in the coating material can be detected by irradiating the surface of the recording medium with near-infrared rays of a first wavelength and near-infrared rays of a second wavelength, which have different characteristics depending on the components of the coating material.

[0023] According to the inspection system of the sixth aspect, erroneous detection of dirt on the surface of the recording medium is suppressed compared to when only the electrical resistance of the recording medium is measured.

[0024] According to the inspection system of the seventh aspect, the generation of electrical noise is suppressed compared to when a CCD sensor is used.

[0025] According to the inspection program of the eighth aspect, the state of application of the coating material on the surface of the recording medium can be confirmed with higher accuracy compared to when inspection is performed based only on the measurement results of the recording medium on which the coating material is applied.

[0026] According to the inspection method of the ninth aspect, the state of application of the coating material on the surface of the recording medium can be confirmed with higher accuracy compared to when inspection is performed based only on the measurement results of the recording medium on which the coating material is applied.

[0027] According to the inspection method of the tenth aspect, the number of recording media whose electrical resistance is measured by the measurement process can be reduced compared to when detecting whether or not a coating material is applied to the surface of the recording medium after the measurement process.

[0028] According to the inspection method of the eleventh aspect, the number of recording media whose electrical resistance is measured in the measurement process can be reduced compared to when the presence or absence of contamination on the surface of the recording media is determined using imaging data after the measurement process. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a diagram showing a schematic configuration of an inspection system according to a first embodiment. [Figure 2] FIG. 2 is a configuration diagram showing a media sensor used in the inspection system according to the first embodiment. [Figure 3] FIG. 2 is a block diagram showing the hardware configuration of a user terminal used in the inspection system. [Figure 4] 1A to 1E are diagrams showing the process of ink soaking into a swelling-type receiving layer. [Figure 5] 1A to 1E are diagrams showing the process of ink soaking into a matte-type receiving layer. [Figure 6] 1A and 1B are diagrams showing the process of ink soaking into paper on which no coating material is applied. [Figure 7] FIG. 10 is a diagram showing a line image when ink is ejected onto paper on which no coating material is applied. [Figure 8] 1A and 1B are diagrams showing the process of ink soaking into paper on which a coating material has been applied. [Figure 9] 10A and 10B are diagrams illustrating line images formed when ink is ejected onto paper on which a coating material has been applied. [Figure 10] 10 is a graph showing the relationship between the change in basis weight due to the coating material of the paper and the line width of the image. [Figure 11] 10 is a graph showing the relationship between the change in basis weight and the image density depending on the coating material of the paper. [Figure 12] 10 is a graph showing the relationship between a change in basis weight due to the coating material of the paper and a change in resistance value measured by a media sensor. [Figure 13] 10 is a graph showing the relationship between the amount of change in resistance value by a media sensor and the line width of an image. [Figure 14]FIG. 2 is a configuration diagram showing a resistance value measuring device used in the inspection system of the first embodiment. [Figure 15] FIG. 2 is a diagram showing a state in which the electrical resistance of a recording medium is measured by a resistance value measuring device of the inspection system of the first embodiment. [Figure 16] 10 is a diagram showing a state in which the electrical resistance of a recording medium is measured by a resistance value measuring device when the amount of coating material applied is small. FIG. [Figure 17] 10 is a diagram showing a state in which the electrical resistance of a recording medium is measured by a resistance value measuring device when the amount of coating material applied is appropriate. FIG. [Figure 18] 10 is a diagram showing a state in which the electrical resistance of the surface of a recording medium is measured by a resistance value measuring device when a large amount of coating material is applied. FIG. [Figure 19] FIG. 1A is a diagram showing a first example in which the electrical resistance is measured to a shallow depth by the resistance value measuring instrument, and FIG. 1B is a diagram showing a second example in which the electrical resistance is measured to a deep depth by the resistance value measuring instrument. [Figure 20] FIG. 10 is a diagram showing the relationship between the depth at which electrical resistance is measured by a resistance measuring instrument and the electrical resistance value. [Figure 21] 10 is a graph showing the relationship between the distance between a pair of electrodes and the change in electrical resistance value when the coating material is not applied and when the coating material is optimally applied. [Figure 22] FIG. 10 is a configuration diagram showing a modified example of the resistance value measuring device. [Figure 23] FIG. 1 is a diagram showing the relationship between near-infrared wavelength and chemical structure assignment. [Figure 24] 1 is a graph showing the relationship between the number of the wire bar used to apply the coating material (amount of coating) and the peak intensity ratio between the wavelengths of 1700 nm and 1850 nm of near-infrared light. [Figure 25] 1 is a graph showing the relationship between the amount of coating material applied (cell capacity) and the peak intensity ratio of near-infrared light at wavelengths of 1700 nm and 1850 nm. [Figure 26] 4 is a flowchart showing the flow of an inspection process of a user terminal used in the inspection system of the first embodiment. [Figure 27] FIG. 10 is a configuration diagram showing a media sensor used in an inspection system according to a second embodiment. [Figure 28] 10 is a flowchart showing the flow of an inspection process of a user terminal used in the inspection system of the second embodiment. [Figure 29] FIG. 10 is a configuration diagram showing a media sensor used in an inspection system according to a third embodiment. [Figure 30] 10 is a flowchart showing the flow of an inspection process of a user terminal used in the inspection system of the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, an example of an embodiment of the technology of the present invention will be described with reference to the drawings. Note that the same or equivalent components and parts in each drawing are given the same reference numerals. Also, the dimensional proportions in the drawings are exaggerated for the convenience of explanation and may differ from the actual proportions.

[0031] [First embodiment] FIG. 1 is a diagram showing a schematic configuration of an inspection system according to the first embodiment.

[0032] <Overall configuration of the inspection system> 1, the inspection system 1 includes a user terminal 10 as an example of an information processing device, and a media sensor 20 that measures the electrical resistance of the surface of the paper P. As an example, the inspection system 1 is disposed on a support 30 of the paper P, and the media sensor 20 is in contact with the surface S1 of the paper P.

[0033] As an example, the media sensor 20 is not electrically connected to the user terminal 10, and the measurement value by the media sensor 20 is received by a receiving unit of the user terminal 10 via a wireless communication device. In the first embodiment, the electrical resistance of the paper P is measured by an electrical sensor 22 (see FIG. 2) of the media sensor 20, which will be described later. The configuration of the media sensor 20 will be described later.

[0034] In recent years, in order to improve the image quality of printed matter, a coating material containing an organic compound is sometimes applied to the surface S1 of the paper P. If the coating condition of the coating material on the surface S1 of the paper P is not good, there is a possibility that the image quality will be reduced when an image is formed on the surface S1 of the paper P by a printer (not shown). In the inspection system 1, the electrical sensor 22 of the media sensor 20 measures the electrical resistance of the paper P, thereby inspecting the coating condition of the coating material on the surface S1 of the paper P.

[0035] The user terminal 10 receives a signal detected by the media sensor 20. Based on the signal detected by the electrical sensor 22 of the media sensor 20, the user terminal 10 inspects the state of application of the coating material on the surface S1 of the paper P. As an example, the user terminal 10 is a personal computer (PC). The user terminal 10 has an input unit 15 and a display unit 16. In the user terminal 10, for example, information about the paper P is input using the input unit 15. The information about the paper P includes the paper name (paper brand) or the product number of the paper P. In the user terminal 10, for example, the electrical resistance of the paper P when no coating material is applied is obtained from the information about the paper P.

[0036] For example, the user terminal 10 determines whether the state of application of the coating material on the surface S1 of the paper sheet P is good (coating state OK) or whether the state of application of the coating material on the surface S1 of the paper sheet P is not good (coating state NG). The user terminal 10 also displays the determination result of the state of application of the coating material on the surface S1 of the paper sheet P on the display unit 16. If the state of application of the coating material on the surface S1 of the paper sheet P is good, good image quality can be maintained when an image is formed on the paper sheet P by a printer (not shown). If the state of application of the coating material on the surface S1 of the paper sheet P is not good, there is a possibility that the image quality will deteriorate when an image is formed on the paper sheet P by a printer (not shown). The specific configuration and operation of the user terminal 10 for determining the state of application of the coating material on the surface S1 of the paper sheet P will be described later.

[0037] The user terminal 10 determines the state of application of the coating material on the surface S1 of the paper P and outputs the determination result on the display unit 16, thereby providing the user with information to determine whether or not the paper P can be used with the printer. The printing method of the printing unit of the printer is not particularly limited. For example, the printer may be a type that forms an image on the paper P using an electrophotographic method, or a type that forms an image on the paper P using an inkjet method. Alternatively, the printer may be a type that prints on the paper P using a printing plate.

[0038] <Media sensor configuration> FIG. 2 is a configuration diagram showing the media sensor 20. As shown in FIG. 2, the media sensor 20 includes an electric sensor 22 and a near-infrared sensor 24. The electric sensor 22 includes a resistance value measuring device 23 that measures the electrical resistance of the paper P. The electric sensor 22 is an example of an electrical measuring device. The resistance value measuring device 23 includes a pair of electrodes 32, 33 (see FIG. 14), which will be described later. The pair of electrodes 32, 33 are provided in positions on the housing of the media sensor 20 that allow them to come into contact with the surface S1 of the paper P. By bringing the pair of electrodes 32, 33 into contact with the surface S1 of the paper P, the electrical resistance of the paper P between the pair of electrodes 32, 33 is measured. Measurement of the electrical resistance of the paper P by the resistance value measuring device 23 will be described later.

[0039] The near-infrared sensor 24 is provided in a position facing the paper sheet P on the housing of the media sensor 20. The near-infrared sensor 24 does not necessarily need to contact the surface S1 of the paper sheet P. The near-infrared sensor 24 irradiates the surface S1 of the paper sheet P with near-infrared rays and detects whether or not a coating material is applied to the surface S1 of the paper sheet P. As an example, the near-infrared sensor 24 includes a near-infrared spectroscopic sensor 25 and a white light source 26. The white light source 26 emits white light. The near-infrared spectroscopic sensor 25 is a device that irradiates a sample to be measured (in this embodiment, the surface of the paper sheet P) with near-infrared rays and measures the intensity of the reflected or transmitted near-infrared rays. The near-infrared spectroscopic sensor 25 can analyze the sample non-destructively. The wavelength of the near-infrared rays used by the near-infrared spectroscopic sensor 25 and the detection of the coating material by the near-infrared sensor 24 will be described later.

[0040] <User device configuration> Fig. 3 is a block diagram showing the hardware configuration of the user terminal 10. As shown in Fig. 3, the user terminal 10 has a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, a storage 14, an input unit 15, a display unit 16, a communication interface 17, and an input / output interface 18. Each component is connected to each other via a bus 19 so as to be able to communicate with each other.

[0041] The CPU 11 is a central processing unit that executes various programs and controls each part. That is, the CPU 11 reads a program from the ROM 12 or the storage 14 and executes the program using the RAM 13 as a work area. The CPU 11 controls each of the above components and performs various arithmetic processing according to the program recorded in the ROM 12 or the storage 14. In this embodiment, an inspection program is stored in the ROM 12 or the storage 14.

[0042] The ROM 12 stores various programs and various data. The RAM 13 temporarily stores programs or data as a working area. The storage 14 is configured with an HDD (Hard Disk Drive) or SSD (Solid State Drive) and stores various programs including the operating system and various data.

[0043] The communication interface 17 is an interface for communicating with other devices, and uses standards such as Ethernet (registered trademark), FDDI, and Wi-Fi (registered trademark). In this embodiment, communication is performed with the media sensor 20 via the communication interface 17, and a detection signal from the media sensor 20 is input to the CPU 11 via the communication interface 17. The input / output interface 18 is an interface for inputting and outputting signals to and from other devices.

[0044] The input unit 15 includes a pointing device such as a mouse and a keyboard, and is used to perform various inputs. The display unit 16 is, for example, a liquid crystal display, and displays various types of information. The display unit 16 is an example of a display device. The display unit 16 may employ a touch panel system and function as the input unit 15.

[0045] <Effects of coating materials on the paper surface> Here, the effect of applying a coating material containing an organic compound to the surface of the paper P will be described.

[0046] As shown in FIG. 4, a receiving layer (i.e., precoat layer) 102 formed from a swelling-type coating material is provided on the surface of a substrate 100 that constitutes paper P. The receiving layer 102 is made of a resin that easily absorbs the ink solvent. Therefore, as shown in FIGS. 4(A) to (C), when ink I is ejected and lands on the receiving layer 102, the solvent (moisture) of the ink I soaks into (swells) the receiving layer 102. As shown in FIGS. 4(D) to (E), when the ink I is dried, the solvent of the ink I volatilizes, and the ink I is fixed to the receiving layer 102.

[0047] As shown in FIG. 5, a receiving layer (i.e., precoat layer) 104 formed from a matte-type (porous) coating material is provided on the surface of a substrate 100 that constitutes paper P. The receiving layer 104 has multiple cavities and has a sponge-like structure. As shown in FIGS. 5(A) to 5(E), when ink I lands on the receiving layer 104, the ink I soaks into the cavities of the receiving layer 104. When the ink I dries, the solvent in the ink I volatilizes, and the ink I is fixed to the receiving layer 104. The coating of the receiving layer 104 has a matte feel.

[0048] 6(A) and (B) show the state of ink when a precoat layer made of a coating material is not formed on the surface of the paper 110. As shown in FIGS. 6(A) and (B), when a precoat layer is not formed on the surface of the paper 110, the ink I penetrates and bleeds into the paper 110 when it lands on the surface of the paper 110. As a result, as shown in FIG. 7, the line image 112 made of the ink I on the surface of the paper 110 becomes bled.

[0049] 8(A) and (B) show the state of ink when a precoat layer made of a coating material is formed on the surface of paper 110. As shown in FIGS. 8(A) and (B), when a precoat layer 106 made of a coating material is formed on the surface of substrate 100 that constitutes paper P, when ink I lands on precoat layer 106 of paper P, precoat layer 106 suppresses penetration and bleeding of ink I. Therefore, as shown in FIG. 9, a line image 108 made of ink I on the surface of paper P is clear and sharp.

[0050] FIG. 10 is a graph showing the relationship between the change in basis weight due to the coating material of paper P and the line width of an image. As shown in FIG. 10, as the amount of coating material applied to the surface of paper P increases, the line width of the image decreases when the same amount of ink is ejected. Also, FIG. 11 is a graph showing the relationship between the change in basis weight due to the coating material of paper and the image density. As shown in FIG. 11, as the amount of coating material applied to the surface of paper increases, the image density increases when the same amount of ink is ejected.

[0051] 12 is a graph showing the relationship between the change in basis weight due to the coating material of the paper P and the amount of change in resistance value (amount of change in electrical resistance value) measured by the electrical sensor 22 of the media sensor 20. As shown in FIG. 12, as the amount of coating material applied to the surface of the paper P increases, the amount of change in electrical resistance value measured by the electrical sensor 22 of the media sensor 20 increases. When no coating material is applied to the surface of the paper P (when no coating material is applied), the amount of change in electrical resistance value measured by the electrical sensor 22 of the media sensor 20 is zero.

[0052] FIG. 13 is a graph showing the relationship between the amount of change in resistance (amount of change in electrical resistance) by the electrical sensor 22 of the media sensor 20 and the line width of the image. As shown in FIG. 13, as the amount of change in electrical resistance by the electrical sensor 22 of the media sensor 20 increases, the line width of the image decreases when the same amount of ink is ejected. When the line width is greater than approximately 53 μm, there is room for improvement in image quality. Furthermore, when the line width is approximately 53 μm or less, the image quality is generally good, and when the line width is approximately 48 μm or less, the image quality is even better.

[0053] 12 and 13 show that when the change in electrical resistance measured by the electrical sensor 22 of the media sensor 20 satisfies the control value, i.e., when it exceeds the control value of "-1" (in this example, when the change is greater than "-1"), the image quality is generally good. Note that Figures 6 to 13 show Npi fine paper manufactured by Nippon Paper Industries Co., Ltd. as a representative example.

[0054] <Configuration of Electrical Sensor> Next, a specific configuration of the electric sensor 22 will be described.

[0055] As described above, the electrical sensor 22 includes a resistance value measuring device 23. As shown in FIG. 14, the resistance value measuring device 23 includes a pair of electrodes 32, 33 and a power supply 34 that applies a voltage between the pair of electrodes 32, 33. The pair of electrodes 32, 33 are arranged so as to contact the surface of the paper P (see FIG. 15). The resistance value measuring device 23 also includes a measuring unit 36 ​​that measures the electrical resistance of the paper P between the pair of electrodes 32, 33. A voltage V is applied between the pair of electrodes 32, 33 from the power supply 34. The voltage V is, for example, a DC voltage. The measuring unit 36 ​​is an ammeter that measures the electrical resistance based on the value of the current flowing through the paper P between the pair of electrodes 32, 33. Note that in the resistance value measuring device 23, there is a leakage current that flows from the electrode 32 to the paper P side.

[0056] In this embodiment, the distance A between the pair of electrodes 32, 33 is set to 0.5 mm or more and 1.5 mm or less. Here, the distance A is the distance between the edge of one electrode 32 and the edge of the other electrode 33. As shown in FIG. 15 , a precoat layer 106, which is coated with a coating material containing an organic compound, is formed on the surface of the substrate 100 of the paper P, and the pair of electrodes 32, 33 are in contact with the surface (upper surface) of the precoat layer 106. By setting the distance A between the pair of electrodes 32, 33 within the above range, the measurement unit 36 ​​measures the electrical resistance of the surface portion of the paper P between the pair of electrodes 32, 33. Here, the electrical resistance of the surface portion of the paper P mainly means the electrical resistance of the portion of the precoat layer 106 or the portion including the precoat layer 106 when the precoat layer 106 is formed on the surface of the paper P.

[0057] The electrical resistance measured by the resistance value measuring device 23 of the electrical sensor 22 is input to the CPU 11 of the user terminal 10 (see FIG. 1). The CPU 11 has previously acquired the electrical resistance of a sheet of paper P on which no precoat layer is formed (no coating material is applied). For example, the electrical resistance of a sheet of paper P on which no precoat layer is formed is acquired from information on the paper name of the sheet of paper P input via the input unit 15. Alternatively, the electrical resistance of the sheet of paper P1 may be measured by the electrical sensor 22. The CPU 11 inspects the state of application of the coating material on the surface of the sheet of paper P based on the difference between the electrical resistance of a sheet of paper P on which a precoat layer 106 is formed (coated with a coating material) and the electrical resistance of a sheet of paper P on which no precoat layer is formed (no coating material is applied). In addition to this method of calculating the difference in electrical resistance of the sheet of paper P before and after the coating material is applied, the difference in electrical resistance of two sheets of the same brand of paper, one coated with a coating material and the other not coated with a coating material, may also be calculated.

[0058] 16 to 18 show how the electrical resistance of paper P is measured by a pair of electrodes 32, 33 when the amount of precoat layer 106 applied to the surface of paper P varies. As shown in Fig. 16, when the amount of precoat layer 106 applied to the substrate 100 of paper P is small, that is, when the application state of the coating material is incomplete (in the case of poor application), the electrical resistance value becomes higher due to the influence of the uncoated portions of paper P.

[0059] As shown in Figure 17, when the amount of precoat layer 106 formed on the substrate 100 of the paper P is appropriate, i.e., when the surface of the paper P is completely covered with the precoat layer 106 (good coating), the electrical resistance value decreases because there is no influence from the uncoated parts of the paper.

[0060] As shown in Figure 18, when the amount of precoat layer 106 formed on the substrate 100 of the paper P is large, i.e., when the surface of the paper P is completely covered with the precoat layer 106 and the precoat layer 106 is thick (when too much coating material is applied), the electrical resistance value does not change even if the thickness of the precoat layer 106 changes.

[0061] 19(A) and (B) show how the electrical resistance of paper P is measured by the pair of electrodes 32, 33 when the distance A between the pair of electrodes 32, 33 is changed. As shown in Fig. 19(A), when the distance A between the pair of electrodes 32, 33 is smaller than that in Fig. 19(B), the measurement depth of the electrical resistance value by the pair of electrodes 32, 33 becomes shallower. Therefore, it is possible to measure only the electrical resistance value of the portion of the precoat layer 106 on the surface of the paper P (i.e., the surface portion of the paper P).

[0062] 19(B), when the distance A between the pair of electrodes 32, 33 is larger than that in FIG. 19(A), the measurement depth of the electrical resistance value by the pair of electrodes 32, 33 becomes deeper. As a result, the electrical resistance value measured is the combined value of the precoat layer 106 on the surface of the paper P and the portion of the base material 100 inside the paper P.

[0063] Fig. 20 is a diagram showing the relationship between the measurement depth of the electrical resistance and the electrical resistance value measured by the resistance value measuring instrument 23. As shown in Fig. 20, the electrical resistance value is greater for a sheet P on which no coating material is applied than for a sheet P on which a coating material is applied. Furthermore, for a sheet P on which a coating material is applied, the electrical resistance value is greater when the measurement depth of the electrical resistance is deep than when the measurement depth of the electrical resistance is shallow.

[0064] Therefore, in order to inspect the state of application of the precoat layer 106 on the surface of the paper P, it is preferable that the distance A between the pair of electrodes 32, 33 is small so that the measurement depth of the electrical resistance is shallow.

[0065] Here, preferred ranges of the distance A between the pair of electrodes 32, 33 and the voltage V applied between the pair of electrodes 32, 33 from the power source 34 will be described.

[0066] Table 1 shows the results of evaluating the electrical resistance measurements when the distance A between the pair of electrodes 32, 33 and the DC voltage applied between the pair of electrodes 32, 33 from the power supply 34 are changed. In Table 1, ◎ indicates a case where the electrical resistance measurement was good, △ indicates a case where the electrical resistance measurement was somewhat poor, and × indicates a case where the electrical resistance measurement was impossible.

[0067] [Table 1]

[0068] As shown in Table 1, when the distance A between the pair of electrodes 32, 33 is 10 mm or more, the distance A is too large relative to the thickness of the precoat layer 106 and the substrate 100 in the paper P, and it was confirmed that the current flows into the substrate 100. When the distance A between the pair of electrodes 32, 33 is 0.1 mm or less, it is confirmed that the distance A is too narrow, and residual precoat liquid or paper dust becomes stuck between the electrodes 32, 33, making it easy for a short circuit to occur, or that even a slight distortion of the electrodes 32, 33 makes it easy for a short circuit to occur. It was also confirmed that when the DC voltage is 400 V or more, discharge is theoretically likely to occur (parallel plate discharge principle). Furthermore, it was confirmed that when the DC voltage is 2 V or less, the voltage is too small and no current flows through the paper P.

[0069] 21 is a graph showing the relationship between the distance A between the pair of electrodes 32, 33 and the change in the electrical resistance of the paper P when the precoat layer 106 is not applied and when an appropriate amount of the precoat layer 106 is applied. The change in the electrical resistance when the precoat layer 106 is not applied and when an appropriate amount of the precoat layer 106 is applied is the value obtained by subtracting the "electrical resistance when the precoat layer 106 is not applied" from the "electrical resistance when the appropriate amount of the precoat layer 106 is applied."

[0070] As shown in Figure 21, measurements were taken of paper P without coating and with an appropriate amount of coating, and the distance A between the pair of electrodes 32, 33 and the DC voltage were selected to produce a difference in electrical resistance of 1.0 Log Ω or more (single digit or more). Because there is a measurement error of approximately ±0.1 Log Ω, a large signal (S / N ratio) is required to quantify the coating amount. When a DC voltage of 100 V was applied, a difference of about one digit could be detected when the distance A between the pair of electrodes 32, 33 was 1.5 mm or less. However, when the distance A between the pair of electrodes 32, 33 was less than 0.5 mm, short circuits frequently occurred. Furthermore, when a DC voltage of 20 V was applied, a sufficient difference was not obtained even when the distance A between the pair of electrodes 32, 33 was 0.5 mm or less. Therefore, it is preferable that the distance A between the pair of electrodes 32, 33 be 0.5 mm or more and 1.5 mm or less, and that the voltage applied between the pair of electrodes 32, 33 from the power source 34 be 100 V or more and 300 V or less. This enabled the discovery of the relationship between the distance A between the pair of electrodes 32, 33 and the applied voltage V, which allows the current to flow predominantly through the precoat layer 106 (i.e., is optimal for measuring the coating state of the precoat layer 106).

[0071] Fig. 22 shows a resistance value measuring device 130 according to a modified example. As shown in Fig. 22, the resistance value measuring device 130 includes a pair of electrodes 132, 133, a power source 34 that applies a voltage between the pair of electrodes 132, 133, and a measuring unit 36 ​​that measures the electrical resistance of the paper P between the pair of electrodes 132, 133. One electrode 132 is annular. The other electrode 133 is circular and is disposed at the center of the one electrode 132.

[0072] In resistance value measuring device 130 according to the modified example, distance A between a pair of electrodes 132, 133, i.e., the distance from the radial peripheral edge of one electrode 132 to the inner peripheral part of the other electrode 133, is set to 0.5 mm or more and 1.5 mm or less. The other configuration is the same as that of resistance value measuring device 23.

[0073] In such a resistance value measuring device 130, by contacting a pair of electrodes 132, 134 with the surface of the precoat layer 106 of the paper P, the measuring unit 36 ​​measures the electrical resistance of the surface portion of the paper P between the pair of electrodes 32, 34.

[0074] <Configuration of near-infrared sensor> Next, the near-infrared sensor 24 (see FIG. 2) will be described. In the near-infrared sensor 24, a near-infrared spectroscopic sensor 25 and a white light source 26 are disposed in positions facing the paper P. As described above, the precoat layer 106 of the paper P is composed of a coating material containing an organic compound. This increases the amount of CH, CH2, and CH3 groups near the surface of the precoat layer 106. The increase in the amount of CH, CH2, and CH3 groups varies depending on the amount of coating material applied.

[0075] The near-infrared sensor 24 detects whether the surface of the paper P has been treated with the precoat layer 106 (i.e., whether the material for the precoat layer 106 has been applied) by irradiating the surface of the paper P with near-infrared light of a predetermined wavelength using the near-infrared spectroscopic sensor 25. As an example, the near-infrared spectroscopic sensor 25 is configured to irradiate the surface of the paper P with near-infrared light of a first wavelength, which is a wavelength absorbed by components of the applied material, and near-infrared light of a second wavelength different from the first wavelength. The applied material does not contain components that absorb the second wavelength. The user terminal 10 detects whether the surface of the paper P has been treated with the precoat layer 106 based on the ratio between the peak intensity when the surface of the paper P is irradiated with near-infrared light of the first wavelength and the peak intensity when the surface of the paper P is irradiated with near-infrared light of the second wavelength. Here, near-infrared light has a wavelength range between 780 nm and 2500 nm, which is located between the visible and infrared regions.

[0076] FIG. 23 shows the wavelength of near-infrared light and the attribution of chemical structure. As shown in FIG. 23, the organic compounds contained in the precoat layer 106 are derived from near-infrared light with a wavelength of 1700 nm (e.g., absorb near-infrared light with a wavelength of 1700 nm), but are not attributable to the organic compounds contained in the precoat layer 106 (e.g., barely absorb near-infrared light with a wavelength of 1850 nm). In this embodiment, the presence or absence of treatment of the precoat layer 106 is compared based on the ratio of the peak intensity at a wavelength of 1700 nm derived from the organic compounds contained in the precoat layer 106 to the peak intensity at 1850 nm not attributable to the organic compounds. Here, the wavelength of 1700 nm is an example of near-infrared light with a first wavelength, and the wavelength of 1850 nm is an example of near-infrared light with a second wavelength. Note that instead of the above configuration, the near-infrared sensor may use a light-emitting diode and a photodiode that emit near-infrared light with wavelengths of 1700 nm and 1850 nm.

[0077] Figure 24 shows the relationship between the number of the wire bar used to apply the coating material (coating amount) and the peak intensity ratio of near-infrared radiation at wavelengths of 1700 nm and 1850 nm. In Figure 24, the larger the number of the wire bar used to apply the coating material, the larger the amount of coating material applied. As shown in Figure 24, it was confirmed that the greater the amount of coating material applied, i.e., the greater the amount of precoat layer 106 applied to the surface of paper P, the higher the peak intensity ratio (peak intensity ratio of near-infrared radiation at wavelengths of 1700 nm and 1850 nm) resulting from the organic compounds contained in precoat layer 106.

[0078] Figure 25 shows the relationship between the amount of application (cell capacity) of the precoat layer 106 and the peak intensity ratio of near-infrared light at wavelengths of 1700 nm and 1850 nm. In Figure 25, Npi woodfree (plain printing paper) manufactured by Nippon Paper Industries Co., Ltd. is used as the paper P. As shown in Figure 25, it was confirmed that the peak intensity ratio (peak intensity ratio of near-infrared light at wavelengths of 1700 nm and 1850 nm) resulting from the organic compounds contained in the precoat layer 106 increases as the amount of application of the precoat layer 106 increases.

[0079] <Actions and Effects of the First Embodiment> Next, the operation and effects of the first embodiment will be described.

[0080] 26 is a flowchart showing the flow of inspection processing for the application state of the application material by the user terminal 10. In the user terminal 10, the CPU 11 reads out an inspection processing program from the ROM 12 or the storage 14, loads it into the RAM 13, and executes it, thereby performing information processing.

[0081] When the media sensor 20 is placed on the sheet P on the support 30, an inspection process for the state of application of the coating material on the surface of the sheet P is started. As shown in FIG. 26, the CPU 11 acquires physical property values ​​from the paper name of the target sheet P (step S201). For example, the paper name of the sheet P is input via the input unit 15 of the user terminal 10. The CPU 11 acquires, from the paper name of the sheet P, the electrical resistance when the precoat layer 106 is not provided on the surface of the sheet P (when the coating material is not applied), as a physical property value.

[0082] The CPU 11 detects the surface properties of the paper P using the near-infrared sensor 24 of the media sensor 20 (step S202). For example, the CPU 11 detects the ratio between the peak intensity at a wavelength of 1700 nm, which is attributable to the organic compounds contained in the precoat layer 106, and the peak intensity at 1850 nm, which is not attributable to the organic compounds. The CPU 11 compares whether the precoat layer 106 is treated or untreated based on the ratio of the detected peak intensities (i.e., determines whether the precoat layer 106 is coated with a material).

[0083] The CPU 11 determines whether the material of the precoat layer 106 on the surface of the paper P has been confirmed (step S203). For example, the CPU 11 determines that the material of the precoat layer 106 (i.e., the organic compound) has been confirmed when the ratio of the peak intensity at a wavelength of 1700 nm attributable to the organic compound contained in the precoat layer 106 to the peak intensity at 1850 nm not attributable to the organic compound is equal to or greater than a predetermined threshold.

[0084] If the material of the precoat layer 106 is not confirmed (step S203: NO), the CPU 11 determines that the state of application of the precoat layer 106 on the surface of the paper P is NG (step S204). The state of application of the precoat layer 106 is NG, for example, when the precoat layer 106 is not formed on the surface of the paper P, or when the application of the precoat layer 106 is insufficient (for example, when the application is small and uneven).

[0085] If the material of the precoat layer 106 is confirmed (step S203: YES), the CPU 11 measures the electrical resistance of the paper P using the electrical sensor 22 of the media sensor 20 (step S205). As a result, the electrical resistance of the surface portion of the paper P is measured by the resistance value measuring device 23 of the electrical sensor 22.

[0086] The CPU 11 determines whether the difference between the measured electrical resistance and the electrical resistance when the paper is not coated satisfies a predetermined control value (step S206). The electrical resistance when the paper is not coated is acquired as a physical property value of the paper P from the paper name, and is the electrical resistance when the precoat layer 106 is not provided on the surface of the paper P. For example, if the difference between the measured electrical resistance and the electrical resistance when the precoat layer 106 is not provided on the surface of the paper P is equal to or greater than the predetermined control value, it is determined that the predetermined control value is satisfied (see FIGS. 12, 13, etc.).

[0087] If the difference between the measured electrical resistance and the electrical resistance when not coated does not satisfy the predetermined control value (step S206: NO), the CPU 11 determines that the state of application of the precoat layer 106 on the surface of the paper P is NG (step S207). The state of application of the precoat layer 106 is NG includes cases where the precoat layer 106 is not formed on the surface of the paper P, or where the application of the precoat layer 106 on the surface of the paper P is insufficient.

[0088] If the difference between the measured electrical resistance and the electrical resistance when not coated satisfies the predetermined control value (step S206: YES), the CPU 11 determines that the state of application of the precoat layer 106 on the surface of the paper P is OK (step S208). The state of application of the precoat layer 106 being OK includes cases where the precoat layer 106 is applied in an appropriate amount and approximately uniformly on the surface of the paper P. For example, the determination result of the state of application of the precoat layer 106 on the paper P is displayed on the display unit 16 of the user terminal 10. This ends the processing based on the inspection processing program.

[0089] In the inspection system 1 described above, the distance between the pair of electrodes 32, 33 is set to be 0.5 mm or more and 1.5 mm or less. The pair of electrodes 32, 33 are brought into contact with the surface of a sheet of paper P coated with a coating material containing an organic compound, and a voltage is applied between the pair of electrodes 32, 33, thereby measuring the electrical resistance of the sheet of paper P between the pair of electrodes 32, 33. Furthermore, the CPU 11 inspects the state of application of the coating material on the surface of the sheet of paper P based on the difference between the electrical resistance of the sheet of paper P coated with the coating material and the electrical resistance of the sheet of paper not coated with the coating material.

[0090] Therefore, the inspection system 1 can more accurately check the state of application of the coating material on the surface of the recording medium compared to inspections based only on the measurement results of the recording medium on which the coating material is applied. Furthermore, the inspection system 1 prevents current from sneaking into the layer of paper P inside the coating material compared to when the distance between the pair of electrodes is greater than 1.5 mm, and is less likely to cause a short circuit compared to when the distance between the pair of electrodes is less than 0.5 mm.

[0091] In the inspection system 1, the resistance value measuring instrument 23 includes a power supply 34 that applies a voltage between the pair of electrodes 32, 33, and a measuring unit 36 ​​that measures the electrical resistance of the paper P between the pair of electrodes 32, 33. Therefore, in the inspection system 1, the measuring unit 36 ​​measures the electrical resistance of the paper P between the pair of electrodes 32, 33.

[0092] In the inspection system 1, the voltage applied from the power supply 34 is between 100 V and 300 V. Therefore, in the inspection system 1, discharge is less likely to occur compared to when the voltage is greater than 300 V, and the measurement accuracy of the electrical resistance is improved compared to when the generated voltage is less than 100 V.

[0093] The inspection system 1 is provided with a near-infrared sensor 24 that irradiates the surface of the paper P with near-infrared rays and detects whether or not a coating material is applied to the surface of the paper P. Therefore, the inspection system 1 reduces the false detection of dirt on the surface of the paper P or of uncoated paper compared to when only measuring the electrical resistance of the recording medium.

[0094] In the inspection system 1, the near-infrared spectroscopic sensor 25 irradiates the surface of the paper P with near-infrared light of a first wavelength, which is a wavelength absorbed by components of the coating material, and near-infrared light of a second wavelength different from the first wavelength. The coating material does not contain components that absorb the second wavelength. Therefore, the inspection system 1 can detect organic materials contained in the coating material by irradiating the surface of the paper P with near-infrared light of the first wavelength and near-infrared light of the second wavelength.

[0095] The inspection program stored in the user terminal 10 includes a step of acquiring the electrical resistance of a sheet of paper that is not coated with a coating material containing an organic compound on its surface, and a step of bringing a pair of electrodes 32, 33 into contact with the surface of the sheet of paper P that has the coating material coated on its surface, thereby detecting the electrical resistance of the sheet of paper P that has the coating material coated on its surface. and inspecting the state of application of the coating material on the surface of the paper P based on the difference between the electrical resistance of the paper P on which the coating material is applied and the electrical resistance of the paper P on which the coating material is not applied. Therefore, the inspection program stored in the user terminal 10 can accurately check the state of application of the coating material on the surface of the paper P compared to an inspection based only on the measurement results of the recording medium on which the coating material is applied.

[0096] The inspection method also includes an acquisition step of acquiring the electrical resistance of paper that is not coated on its surface with a coating material containing an organic compound, a measurement step of bringing a pair of electrodes 32, 33 into contact with the surface of paper P that has been coated with a coating material and measuring the electrical resistance of the coated paper P, and an inspection step of inspecting the state of application of the coating material on the surface of paper P from the difference between the electrical resistance of paper P that has been coated with the coating material and the electrical resistance of paper that has not been coated with the coating material. Therefore, the inspection method can more accurately confirm the state of application of the coating material on the surface of paper P compared to inspection based only on the measurement results of a recording medium that has been coated with the coating material.

[0097] Furthermore, the inspection method includes, at least prior to the electrical resistance measurement step, a detection step of irradiating near-infrared rays onto the surface of the paper P and detecting whether or not a coating material has been applied to the surface of the paper P. Therefore, the inspection method can reduce the number of papers P whose electrical resistance is measured in the inspection step compared to when detecting whether or not a coating material has been applied to the surface of the recording medium after the measurement step.

[0098] Second Embodiment Next, an inspection system according to a second embodiment will be described. Note that the same components as those in the first embodiment described above are given the same reference numerals and the description thereof will be omitted.

[0099] In the inspection system of the second embodiment, a media sensor 150 is provided instead of the media sensor 20 of the first embodiment. The media sensor 150 includes an electric sensor 22 and an imaging sensor 152 that captures an image of the surface of the paper P. The imaging sensor 152 is an example of an image sensor.

[0100] The image sensor 152 is disposed opposite the paper P, and acquires adhesion information and color information of the paper P from image data obtained by capturing an image of the surface of the paper P. The image sensor 152 is equipped with a white light-emitting diode 153 that emits white light, and a C-MOS (Complementary Metal Oxide Semiconductor) sensor 154 that captures the surface of the paper P. The C-MOS sensor 154 is a semiconductor sensor that senses light and converts it into an electrical signal, and has many light-receiving elements and amplifiers that amplify the electrical signal arranged in an array. The C-MOS sensor 154 has a structure in which one amplifier is paired with one photodiode. The C-MOS sensor 154 operates at a lower voltage than a CCD sensor, making it easier to speed up readout. The C-MOS sensor 154 also generates less electrical noise than a CCD sensor.

[0101] Other configurations of the inspection system of the second embodiment are similar to those of the inspection system 1 of the first embodiment.

[0102] Next, the operation and effects of this embodiment will be described.

[0103] 28 is a flowchart showing the flow of inspection processing for the application state of the application material by the user terminal 10. In the user terminal 10, the CPU 11 reads out an inspection processing program from the ROM 12 or the storage 14, expands it into the RAM 13, and executes it, thereby performing information processing.

[0104] When the media sensor 150 is placed on the sheet P on the support 30, an inspection process for the state of application of the coating material on the surface of the sheet P is started. As shown in FIG. 28, the CPU 11 acquires physical property values ​​from the paper name of the target sheet P (step S301). For example, the paper name of the sheet P is input via the input unit 15 of the user terminal 10. The CPU 11 acquires, from the paper name of the sheet P, the electrical resistance when the precoat layer 106 is not provided on the surface of the sheet P (when the coating material is not applied), as a physical property value.

[0105] The CPU 11 captures an image of the surface of the paper P using the imaging sensor 152 of the media sensor 150 (step S302). In this embodiment, the CPU 11 acquires adhesion information and color information of the paper P from the imaging data of the surface of the paper P. The adhesion information of the paper P is, for example, information on whether any foreign matter or other adhesions are attached to the paper P.

[0106] The CPU 11 determines whether or not there is dirt on the surface of the paper P (step S303). In this embodiment, the CPU 11 determines whether or not there is dirt on the surface of the paper P from the adhesion information and color information of the paper P. For example, if the color information of the paper P includes adhesion information of foreign matter or the like that is different from the color of the paper P (if the color of the adhesion matter that is different from the color of the paper P is detected), the CPU 11 determines that there is dirt on the surface of the paper P.

[0107] If there is dirt on the surface of the paper P (step S303: YES), the CPU 11 determines that the state of application of the precoat layer 106 on the surface of the paper P is NG (step S304). This confirms that there is an error in the state of application of the precoat layer 106 due to the dirt on the paper P (i.e., it confirms that the precoat layer 106 is not formed normally).

[0108] If there is no dirt on the surface of the paper P (step S303: NO), the CPU 11 measures the electrical resistance of the paper P using the electrical sensor 22 of the media sensor 20 (step S305). As a result, the electrical resistance of the surface portion of the paper P is measured by the resistance value measuring device 23 of the electrical sensor 22.

[0109] The CPU 11 determines whether the difference between the measured electrical resistance and the electrical resistance when the precoat layer 106 is not applied satisfies a predetermined control value (step S306). The electrical resistance when the precoat layer 106 is not applied is acquired as a physical property value of the paper P, and is the electrical resistance when the precoat layer 106 is not provided on the surface of the paper P.

[0110] If the difference between the measured electrical resistance and the electrical resistance when not coated does not satisfy the predetermined control value (step S306: NO), the CPU 11 determines that the coating state of the precoat layer 106 on the surface of the paper P is NG (step S307).

[0111] If the difference between the measured electrical resistance and the electrical resistance when the paper P is not coated satisfies the predetermined control value (step S306: YES), the CPU 11 determines that the state of the precoat layer 106 on the surface of the paper P is OK (step S308). For example, the determination result of the state of the precoat layer 106 on the paper P is displayed on the display unit 16 of the user terminal 10. This ends the processing based on the inspection processing program.

[0112] In addition to the effects of the same configuration as the inspection system of the first embodiment, the inspection system described above also provides the following effects.

[0113] In the above-described inspection system, an image sensor 152 that captures an image of the surface of the paper P is provided at a position facing the paper P, and adhesion information and color information of the paper P are obtained from the image data captured of the surface of the paper P. Therefore, the inspection system reduces false detection of dirt on the surface of the paper P compared to when only the electrical resistance of the recording medium is measured.

[0114] The imaging sensor 152 also includes a C-MOS sensor 154. Therefore, the inspection system reduces the occurrence of electrical noise compared to when a CCD sensor is used.

[0115] The inspection method also includes, at least prior to the electrical resistance measurement step, a determination step of determining whether or not there is dirt on the surface of the recording medium based on surface information of the recording medium obtained from image data of the surface of the paper P. Therefore, the inspection method can reduce the number of papers P whose electrical resistance is measured in the measurement step compared to when detecting whether or not a coating material is applied to the surface of the recording medium after the measurement step.

[0116] Third Embodiment Next, an inspection system according to a third embodiment will be described. Note that the same components as those in the first and second embodiments will be given the same reference numerals and descriptions thereof will be omitted.

[0117] In the inspection system of the third embodiment, a media sensor 170 is provided instead of the media sensor 20 of the first embodiment. The media sensor 170 includes an electric sensor 22, a near-infrared sensor 24, and an imaging sensor 152 that captures an image of the surface of the paper P.

[0118] The configurations of the electric sensor 22 and the near-infrared sensor 24 are the same as those in the first embodiment, and the configuration of the image sensor 152 is the same as that in the second embodiment.

[0119] 30 is a flowchart showing the flow of inspection processing for the application state of the application material by the user terminal 10. In the user terminal 10, the CPU 11 reads out an inspection processing program from the ROM 12 or the storage 14, expands it into the RAM 13, and executes it, thereby performing information processing.

[0120] When the media sensor 170 is placed on the sheet P of the support 30, an inspection process for the state of application of the coating material on the surface of the sheet P is started. As shown in Fig. 30, the CPU 11 acquires physical property values ​​from the paper name of the target sheet P (step S401). For example, the CPU 11 acquires, as a physical property value from the paper name of the sheet P, the electrical resistance when the precoat layer 106 is not provided on the surface of the sheet P (when the coating material is not applied).

[0121] The CPU 11 captures an image of the surface of the paper P using the image sensor 152 of the media sensor 150 (step S402). In this embodiment, the CPU 11 acquires adhesion information and color information of the paper P from the image data of the surface of the paper P.

[0122] The CPU 11 determines whether or not there is dirt on the surface of the paper P (step S403). In this embodiment, the CPU 11 determines whether or not there is dirt on the surface of the paper P based on adhesion information and color information of the paper P.

[0123] If there is dirt on the surface of the paper P (step S403: YES), the CPU 11 determines that the state of application of the precoat layer 106 on the surface of the paper P is NG (step S404).

[0124] If there is no dirt on the surface of the paper P (step S403: NO), the CPU 11 detects the surface properties of the paper P using the near-infrared sensor 24 of the media sensor 20 (step S405). For example, the CPU 11 detects the ratio between the peak intensity at a wavelength of 1700 nm that is attributable to the organic compounds contained in the precoat layer 106 and the peak intensity at 1850 nm that is not attributable to the organic compounds.

[0125] The CPU 11 determines whether the material of the precoat layer 106 on the surface of the paper P has been confirmed (step S406). For example, the CPU 11 determines that the material of the precoat layer 106 (i.e., the organic compound) has been confirmed when the ratio of the peak intensity at a wavelength of 1700 nm attributable to the organic compound contained in the precoat layer 106 to the peak intensity at 1850 nm not attributable to the organic compound is equal to or greater than a predetermined threshold.

[0126] If the material of the precoat layer 106 is not confirmed (step S406: NO), the CPU 11 determines that the state of application of the precoat layer 106 on the surface of the paper P is NG (step S407).

[0127] If the material of the precoat layer 106 is confirmed (step S406: YES), the CPU 11 measures the electrical resistance of the paper P with the electrical sensor 22 of the media sensor 20 (step S408).

[0128] The CPU 11 determines whether the difference between the measured electrical resistance and the electrical resistance when the precoat layer 106 is not applied satisfies a predetermined control value (step S409). For example, if the difference between the measured electrical resistance and the electrical resistance when the precoat layer 106 is not applied to the surface of the paper P is equal to or greater than the predetermined control value, it is determined that the predetermined control value is satisfied.

[0129] If the difference between the measured electrical resistance and the electrical resistance when not coated does not satisfy the predetermined control value (step S409: NO), the CPU 11 determines that the coating state of the precoat layer 106 on the surface of the paper P is NG (step S410).

[0130] If the difference between the measured electrical resistance and the electrical resistance when the paper P is not coated satisfies the predetermined control value (step S409: YES), the CPU 11 determines that the state of the precoat layer 106 on the surface of the paper P is OK (step S411). For example, the determination result of the state of the precoat layer 106 on the paper P is displayed on the display unit 16 of the user terminal 10. This ends the processing based on the inspection processing program.

[0131] The above inspection system has the same configuration as the inspection system of the first embodiment or the inspection system of the second embodiment, and can provide the same effects.

[0132] 〔others〕 In the first or third embodiment, the electrical resistance of the paper P when no coating material is applied is obtained as the physical property value of the paper P, and then the surface physical properties of the paper P are detected by the near-infrared sensor 24, but these orders may be reversed.

[0133] In the second or third embodiment, the electrical resistance of the paper P when no coating material is applied is obtained as a physical property value of the paper P, and then the surface of the paper P is photographed by the image sensor 152, but this order may be reversed.

[0134] In the third embodiment, the surface of the paper P is photographed by the imaging sensor 152 and then the surface properties of the paper P are detected by the near-infrared sensor 24, but this order may be reversed.

[0135] In the first to third embodiments, the electrical resistance when no coating material is applied is obtained as a physical property value of the paper P from the paper name of the paper P, but the present invention is not limited to this configuration. For example, paper that is not coated with a coating material may be obtained, and the electrical resistance of the surface portion of this paper may be directly measured by the electrical sensor 22.

[0136] In the first to third embodiments, data is transmitted and received between the user terminal 10 and the media sensor via wireless communication, but the user terminal 10 and the media sensor may be connected by wire.

[0137] In each of the above embodiments, the hardware structure of a processing unit that executes various processes can be any of the following processors: As described above, the various processors include a CPU, which is a general-purpose processor that executes software and functions as various processing units, as well as dedicated electrical circuits that are processors having a circuit configuration specifically designed to execute specific processes, such as a programmable logic device (PLD), which is a processor whose circuit configuration can be changed after manufacture, such as an FPGA (Field Programmable Gate Array), and an ASIC (Application Specific Integrated Circuit).

[0138] A single processing unit may be configured with one of these various processors, or may be configured with a combination of two or more processors of the same or different types (e.g., a combination of multiple FPGAs and / or a combination of a CPU and an FPGA). Also, multiple processing units may be configured with a single processor.

[0139] An example of configuring multiple processing units with one processor is a form in which one processor is configured by combining one or more CPUs and software, and this processor functions as multiple processing units. Secondly, there is a form in which a processor is used that realizes the functions of the entire system including multiple processing units with a single IC (Integrated Circuit) chip, as typified by a System on Chip (SoC). In this way, various processing units are configured using one or more of the above various processors as a hardware structure.

[0140] Furthermore, more specifically, the hardware structure of these various processors can be an electric circuit that combines circuit elements such as semiconductor elements.

[0141] Although the embodiments of the present disclosure have been described above, it goes without saying that the present disclosure is not limited to the above embodiments and can be embodied in various forms without departing from the spirit of the present disclosure. [Explanation of symbols]

[0142] 1. Inspection system 10 User Devices 11 CPU 12 ROM 13 RAM 14. Storage 15 Input section 16 Display section 17 Communication Interface 18 Input / Output Interface 19 Bus 20 Media Sensor 22 Electrical sensor (an example of an electrical measuring instrument) 23 Resistance measuring instrument 24 Near-infrared sensor 25 Near-infrared spectroscopic sensor 26 White light source 30 Support 32, 33 Electrodes (an example of a pair of electrodes) 34 Power supply 36 Measuring part 100 Base material 106 Precoat layer (an example of coating material) 130 Resistance Measuring Instrument 132, 133 electrodes (an example of a pair of electrodes) 150 Media Sensor 152 Image Sensor 154 C-MOS sensor 170 Media Sensor P Paper (an example of a recording medium)

Claims

1. an electric measuring instrument that measures the electrical resistance of a recording medium between a pair of electrodes, the distance between the pair of electrodes being 0.5 mm or more and 1.5 mm or less, and that applies a voltage of 100 V or more between the pair of electrodes that are in contact with the surface of the recording medium coated with a coating material containing an organic compound on the surface; at least one processor; Equipped with the recording medium has a surface receiving layer coated with ink as a coating material containing the organic compound, The processor inspects the coating condition of the coating material on the surface of the recording medium based on the difference in electrical resistance between the recording medium coated with the coating material and the recording medium not coated with the coating material.

2. The electrical measuring instrument is a power source that applies a voltage between the pair of electrodes; The inspection system according to claim 1 , further comprising: a measuring unit that measures the electrical resistance of the recording medium between the pair of electrodes.

3. 3. The inspection system according to claim 2, wherein the voltage applied from the power supply is between 100V and 300V.

4. 4. The inspection system according to claim 1, further comprising a near-infrared sensor provided at a position facing the recording medium, irradiating the surface of the recording medium with near-infrared rays and detecting whether or not the coating material is applied to the surface of the recording medium.

5. the near-infrared sensor is configured to irradiate the surface of the recording medium with near-infrared light of a first wavelength, which is a wavelength absorbed by a component of the coating material, and near-infrared light of a second wavelength, which is a wavelength different from the first wavelength and is not contained in the coating material, and 5. The inspection system according to claim 4, wherein the processor detects whether or not the coating material is applied to the surface of the recording medium based on a ratio between a peak intensity when the surface of the recording medium is irradiated with near-infrared light of the first wavelength and a peak intensity when the surface of the recording medium is irradiated with near-infrared light of the second wavelength.

6. 6. The inspection system according to claim 1, further comprising an image sensor provided at a position facing the recording medium, the image sensor acquiring adhesion information and color information of the recording medium from imaging data obtained by photographing the surface of the recording medium.

7. 7. The inspection system of claim 6, wherein the image sensor is a CMOS sensor.

8. A step of obtaining an electrical resistance of a recording medium on whose surface a coating material containing an organic compound is not applied; a step of bringing a pair of electrodes into contact with the surface of a recording medium on which ink has been applied as the coating material to a surface receiving layer, and applying a voltage of 100 V or more between the pair of electrodes to measure the electrical resistance of the recording medium on which the coating material has been applied; inspecting the state of application of the coating material on the surface of the recording medium based on the difference between the electrical resistance of the recording medium on which the coating material is applied and the electrical resistance of the recording medium on which the coating material is not applied; An inspection program that causes a computer to execute the above.

9. an acquiring step of acquiring the electrical resistance of a recording medium on whose surface a coating material containing an organic compound is not applied; a measuring step of bringing a pair of electrodes into contact with the surface of a recording medium on which ink has been applied as the coating material to a surface receiving layer, and applying a voltage of 100 V or more between the pair of electrodes to measure the electrical resistance of the recording medium on which the coating material has been applied; an inspection step of inspecting the state of application of the coating material on the surface of the recording medium based on the difference in electrical resistance between the recording medium on which the coating material is applied and the recording medium on which the coating material is not applied; An inspection method having the following.

10. At least prior to the measuring step, 10. The inspection method according to claim 9, further comprising a detecting step of irradiating a surface of the recording medium with near-infrared rays and detecting whether or not the coating material is applied to the surface of the recording medium.

11. At least prior to the measuring step, The inspection method according to claim 9 , further comprising a determination step of determining whether or not the surface of the recording medium is dirty based on surface information of the recording medium obtained from image data obtained by photographing the surface of the recording medium.

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