Detection device and detection method

Abstract

To provide a detection device that is able to detect a sign of a surface state failure of a printed material caused by a change in physical properties with time.SOLUTION: A detection device 1 includes: an imaging unit 10 that captures an image of a screen printing device 90; a measurement unit 27 that measures an ink stringing length, based on the image captured by the imaging unit; and a determination unit 28 that compares the ink stringing length, measured by the measurement unit, with a predetermined threshold value to determine a quality of a surface state of a printed material.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a detection device and a detection method. [Background technology]

[0002] Screen printing is a printing method in which ink is placed on a screen and then rubbed with a squeegee to transfer the ink to the print medium. The screen has a structure in which the areas not required for printing are filled in.

[0003] Conventionally, various high-resolution screen printing methods have been developed (for example, Patent Document 1 listed below). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-244203 Summary of the Invention [Problem to be solved by the invention]

[0005] In screen printing, the physical properties of the ink placed on the screen change over time as it dries, and specifically, the viscosity can increase. This change in physical properties over time can lead to poor surface condition in the printed material, and there is a need to detect signs of poor surface condition.

[0006] The present invention was invented to solve the above-mentioned problems, and aims to provide a detection device and detection method that can detect signs of poor surface condition of printed matter caused by changes in physical properties over time. [Means for solving the problem]

[0007] The above object of the present invention can be achieved by the following means.

[0008] (1) A detection device for detecting signs of poor surface condition of a screen-printed object, an imaging unit that images a printing location of the screen printing device; a measuring unit that measures the length of the ink stringing based on the image captured by the photographing unit; a judgment unit that compares the stringiness of the ink measured by the measurement unit with a predetermined threshold value and judges whether the surface condition of the printed matter is good or bad.

[0009] (2) The detection device according to (1), further comprising a notification unit that notifies that the determination unit has determined that the surface condition of the printed matter is a sign of becoming poor.

[0010] (3) The detection device according to (2), wherein the notification unit notifies by displaying the notification on a display.

[0011] (4) The detection device according to (2) or (3), wherein the notification unit notifies by sound.

[0012] (5) The detection device according to any one of (1) to (4), further comprising a stopping unit that stops the operation of the screen printing device when the judgment unit determines that the condition of the printed matter is a sign of becoming poor.

[0013] (6) The detection device described in any one of (1) to (5) further includes a command unit that issues a command to a supply device that supplies the ink to supply the ink when the judgment unit determines that the surface condition of the printed material is a sign of becoming poor.

[0014] (7) A method for detecting a sign of poor surface condition of a screen-printed object, comprising: a photographing step of photographing a printing portion of the screen printing device; a measuring step of measuring the length of the ink stringing based on the image captured in the photographing step; a determining step of comparing the length of the ink stringiness measured in the measuring step with a predetermined threshold value to determine whether the printed matter is good or bad. [Effects of the Invention]

[0015] According to the above-described detection device and detection method, the length of ink stringing is measured while photographing the printing area of ​​the screen printing device, and the quality of the printed material is determined by comparing it with a threshold value, making it possible to detect signs of poor surface condition of the printed material caused by changes in physical properties over time. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 illustrates a screen printing apparatus and a detection apparatus. [Figure 2] FIG. 10 is a diagram showing a state when printing is performed by a screen printing device. [Figure 3] FIG. 3 is an enlarged view showing part A in FIG. 2. [Figure 4] FIG. 10 is a diagram showing how stringiness occurs during screen printing. [Figure 5] FIG. 10 is a diagram for explaining the stringing length, showing the case where the stringing length is relatively short. [Figure 6] FIG. 10 is a diagram for explaining the stringing length, showing the case where the stringing length is relatively long. [Figure 7] FIG. 2 is a block diagram showing a control unit of the detection device according to the present embodiment. [Figure 8] FIG. 2 is a block diagram showing a CPU of a control unit of the detection device according to the present embodiment. [Figure 9] 3 is a flowchart showing the procedure of a detection method according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are given the same reference numerals, and duplicate explanations will be omitted. Furthermore, the dimensional proportions in the drawings are exaggerated for the convenience of explanation, and may differ from the actual proportions.

[0018] First, the configuration of a screen printing apparatus 90 will be described with reference to Fig. 1 to Fig. 3. Fig. 1 is a diagram showing the screen printing apparatus 90 and a detection device 1. Fig. 2 is a diagram showing the state when printing is performed by the screen printing apparatus 90. Fig. 3 is an enlarged view showing part A in Fig. 2.

[0019] As shown in FIGS. 1 to 3, the screen printing apparatus 90 has a stage 91 on which the printing substrate 80 is placed, a screen plate 92 placed on the stage 91, and a squeegee 93 that moves over the screen plate 92.

[0020] The screen printing device 90 is a device that prints ink 50 on the surface of a printing substrate 80 that is arranged in a flat state. As shown in FIG. 3, the squeegee 93 moves to the left with ink 50 arranged on the left side of the squeegee 93 and on the screen plate 92. A predetermined hole shape is formed in the screen plate 92, and the ink that has moved into the hole shape is transferred to the printing substrate 80. Note that the printing substrate 80 may be a roll-shaped substrate that is arranged in a flat state in advance.

[0021] The stage 91, screen plate 92, and squeegee 93 may be of known types.

[0022] When printing is performed using the screen printing apparatus 90 in this manner, as shown in Figures 4 to 6, a stringy state occurs behind the squeegee 93 in the direction of travel (leftward) while remaining in contact with the screen plate 92. Figure 4 is a diagram showing how stringyness occurs during screen printing. Figure 5 is a diagram for explaining the stringy length, showing a case where the stringy length is relatively short. Figure 6 is a diagram for explaining the stringy length, showing a case where the stringy length is relatively long.

[0023] In this specification, the height H from the surface of the printing substrate 80 to the point where the ink makes wavy contact with the screen 92 is referred to as the "stringing length," as shown in Figures 5 and 6. When the initial amount of solvent is high, the viscosity is relatively low, so the stringing ends immediately near the rear of the printed area, as shown in Figure 5. In contrast, as the ink solvent evaporates over time and the curing reaction progresses, and the viscosity increases, the stringing continues far behind the printed area, as shown in Figure 6. In other words, as the ink solvent evaporates over time and the curing reaction progresses, and the viscosity increases, the stringing length increases.

[0024] The inventors of the present invention checked the surface condition and stringiness of printed matter as appropriate, and found that, with a stringiness length of 500 μm as the threshold, a stringiness length of less than 500 μm indicates that the surface condition of the printed matter is good, while a stringiness length of 500 μm or more is a sign that the surface condition of the printed matter will become poor. Note that this threshold is merely an example and is not limited to this numerical value.

[0025] Next, the configuration of the detection device 1 according to this embodiment will be described with reference to Fig. 1, Fig. 7, and Fig. 8. Fig. 7 is a block diagram showing the control unit 20 of the detection device 1 according to this embodiment. Fig. 8 is a block diagram showing the CPU 21 of the control unit 20 of the detection device 1 according to this embodiment.

[0026] As shown in FIG. 1, the detection device 1 includes an imaging unit 10 and a control unit 20.

[0027] The photographing unit 10 photographs the printing location of the screen printing apparatus 90. The photographing unit 10 is, for example, a video camera.

[0028] The control unit 20 controls the imaging unit 10 and performs various processes. As shown in Fig. 7, the control unit 20 includes a CPU (Central Processing Unit) 21, a memory 22, a hard disk 23, a display unit 24, an input unit 25, and a communication unit 26.

[0029] The CPU 21 controls each part and executes various arithmetic processing in accordance with programs stored in the memory 22 and the hard disk 23 .

[0030] The memory 22 is composed of a ROM (Read Only Memory) that stores various programs and various data, a RAM (Random Access Memory) that temporarily stores programs and data as a working area, and the like.

[0031] The hard disk 23 stores various programs including the operating system and various data.

[0032] The display unit 24 is, for example, a liquid crystal display, and displays various information, which will be described later.

[0033] The input unit 25 includes a pointing device such as a mouse and a keyboard, and is used to input various types of information.

[0034] The communication unit 26 is an interface for communicating with other devices.

[0035] As shown in FIG. 8, the CPU 21 functions as a measurement unit 27, a determination unit 28, and a notification unit 29 by executing various programs.

[0036] Here, the measuring unit 27 measures the stringiness of the ink based on the image captured by the photographing unit 10. The measuring unit 27 is a so-called image analysis device.

[0037] The judgment unit 28 compares the stringiness of the ink measured by the measurement unit 27 with a predetermined threshold value to judge whether the surface condition of the printed material is good or bad. The predetermined threshold value is not particularly limited, but is, for example, about 500 μm. The hard disk 23 serves as a storage unit and stores the predetermined threshold value.

[0038] The notification unit 29 notifies the operator that the determination unit 28 has determined that there is a sign that the surface condition of the printed material will become poor. Specifically, if the length of the ink stringiness is longer than a predetermined threshold, the notification unit 29 determines that there is a sign that the surface condition of the printed material will become poor and notifies the operator. The notification method used by the notification unit 29 is not particularly limited, but examples include displaying the information on the display unit 24 or sounding an alarm.

[0039] Hereinafter, a method for detecting the surface condition of a screen-printed product using the detection device 1 will be described with reference to FIG.

[0040] FIG. 9 is a flowchart showing the steps of the detection method performed by the detection device 1.

[0041] As shown in FIG. 9, the detection method includes an imaging step S01, a measurement step S02, a determination step S03, and a notification step S04.

[0042] In the photographing step S01, the photographing unit 10 photographs the printing location of the screen printing device 90.

[0043] In the measuring step S02, the measuring unit 27 measures the stringiness of the ink based on the image captured in the photographing step S01.

[0044] In the determination step S03, the determination unit 28 compares the length of the ink stringiness measured in the measurement step S02 with a predetermined threshold value to determine whether the surface condition of the printed matter is good or bad.

[0045] In the notification step S04, the notification unit 29 notifies the user that the determination in the determination step S03 indicates that the surface condition of the printed matter is a sign of becoming poor.

[0046] In the notification step S04, if it is determined that there is a sign that the surface condition of the printed matter will become poor, the operator may, for example, stop printing or supply ink.

[0047] The detection device 1 and detection method according to the present invention have been described above through the embodiments, but the present invention is not limited to the above-described embodiments and can be modified in various ways within the scope of the claims.

[0048] For example, in the above-described embodiment, when the determination unit 28 determines that there is a sign that the surface condition of the printed material will become poor, the notification unit 29 notifies the operator of that information. However, the control unit of the detection device may also have a stopping unit that stops the operation of the screen printing device 90 when there is a sign that the surface condition of the printed material will become poor. Specifically, when there is a sign that the surface condition of the printed material will become poor in the determination step S03, the stopping unit stops the screen printing operation. With this configuration, printing can be stopped automatically, improving workability.

[0049] In the above-described embodiment, when the determination unit 28 determines that the surface condition of the printed material is a sign of becoming poor, the notification unit 29 notifies the operator of this information. However, the control unit of the detection device may also include a command unit that issues a command to an ink supply device that supplies ink when the determination unit determines that the surface condition of the printed material is a sign of becoming poor. Specifically, the command unit issues a command to the ink supply device to supply ink. This configuration enables continuous screen printing without stopping printing. [Explanation of symbols]

[0050] 1 detection device, 10 photography department, 20 control section, 27 Measuring part, 28 Judgment Department; 29 Notification Department; 80 Printing substrate, 90 screen printing equipment, S01 Shooting process, S02 measurement process, S03 Judgment process, S04 Notification process.

Claims

1. A detection device for detecting signs of poor surface condition of a screen-printed object, an imaging unit that images a printing location of the screen printing device; a measuring unit that measures the length of the ink stringing based on the image captured by the photographing unit; a judgment unit that compares the stringiness of the ink measured by the measurement unit with a predetermined threshold value and judges whether the surface condition of the printed matter is good or bad.

2. The detection device according to claim 1 , further comprising a notification unit that notifies the user that the determination unit has determined that the surface condition of the printed matter is a sign of becoming poor.

3. The detection device according to claim 2 , wherein the notification unit notifies the user by displaying the notification on a display.

4. The detection device according to claim 2 or 3, wherein the notification unit notifies by sound.

5. The detection device according to claim 1 , further comprising a stopping unit that stops operation of the screen printing device when the determining unit determines that the surface condition of the printed matter is a sign of becoming poor.

6. The detection device according to claim 1 , further comprising a command unit that issues a command to a supply device that supplies the ink to supply the ink when the judgment unit determines that the surface condition of the printed material is a sign of becoming poor.

7. A method for detecting a sign of poor surface condition of a screen-printed object, comprising: a photographing step of photographing a printing portion of the screen printing device; a measuring step of measuring the length of the ink stringing based on the image captured in the photographing step; a determining step of comparing the length of the ink stringiness measured in the measuring step with a predetermined threshold value to determine whether the surface condition of the printed matter is good or bad.

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