JP2020169875A - Printed matter inspection device and printed matter inspection method - Google Patents

Abstract

To inspect the print quality of printed matters for which inspection standard data is not prepared in advance.SOLUTION: A printed matter inspection device for inspecting the print quality of an inspection target included in a printed matter includes: a storage unit for storing standard data used as a standard for passing or failing an inspection; a light source unit for irradiating the inspection target with light; a light-receiving unit for receiving light indicating optical features of the inspection target; and a determination unit for comparing inspection data obtained based on the light received by the light-receiving unit with the standard data to determine whether the inspection target passes or fails the inspection. The standard data is created by the printed matter inspection device based on light received by the light-receiving unit when the light source irradiates a sample prepared as an inspection standard of inspection with light during the inspection of the inspection target.SELECTED DRAWING: Figure 1

Description

The present invention relates to a printed matter inspection device and a printed matter inspection method for inspecting the print quality of a printed matter.

Conventionally, various printing techniques for preventing counterfeiting have been used for printed matter used as a valuable medium. For example, a security mark used for authenticity determination is printed on a banknote. Some security marks are printed using special ink that emits light when irradiated with light of a predetermined wavelength. By irradiating the security mark with light of a predetermined wavelength and confirming the light emission, the authenticity of the bill can be confirmed.

Patent Document 1 discloses a device that detects a security mark and determines authenticity. The user of the device presses a button provided on the device to start the authenticity determination of the security mark. The device irradiates the security mark with light from the light source and determines the authenticity based on the light emission state of the security mark. The device notifies the user of the determination result by turning on different lamps depending on whether the determination is true or false.

The technique of authenticity determination by the apparatus can be used to inspect the print quality of the printed matter at the time of producing the printed matter. For example, when printing a security mark with a printing device, a authenticity determination technique is used. If there is no problem with the print quality of the security mark and the light is emitted normally, the security mark is judged to be true. If there is a problem with the print quality and the security mark does not emit light normally, the security mark is determined to be false. The print quality of the security mark can be confirmed based on the result of the authenticity determination by the device.

U.S. Pat. No. 8,937,712

However, if the conventional device is used as it is, the printed matter may not be easily inspected. The authenticity determination is performed by preparing reference data as a determination criterion in advance and comparing the data obtained from the determination target with the reference data. For example, when a printed matter is created using a new ink, the inspection cannot be performed unless the reference data for this ink is prepared in advance. For this reason, for example, when checking whether stable printing can be performed with a printing device while adjusting the characteristics of the ink used for printing or adjusting the printing method, the print quality is inspected. I couldn't.

The present invention has been made in view of the above problems of the prior art, and provides a printed matter inspection apparatus and a printed matter inspection method capable of inspecting the print quality of a printed matter for which data as an inspection standard is not prepared in advance. The purpose.

In order to solve the above-mentioned problems and achieve the object, the present invention is a printed matter inspection apparatus for inspecting the print quality of an inspection target contained in a printed matter, and is a storage for storing reference data used as a criterion for passing or failing the inspection. The reference data includes a unit, a light source unit that irradiates the inspection target with light, a light receiving unit that receives light indicating the optical characteristics of the inspection target, and inspection data obtained based on the light received by the light receiving unit. The reference data is provided from the light source unit to a sample prepared as an inspection standard for the inspection when the inspection target is inspected. It is characterized in that it is created based on the light that is irradiated with light and received by the light receiving unit.

Further, in the above invention, when inspecting a first type of inspection target, the present invention prepares first reference data from a sample prepared for the inspection and inspects the first type. When inspecting a second type of inspection object different from the above, it is characterized in that a second reference data is created from a sample prepared for the inspection and the inspection is performed.

Further, the present invention is characterized in that, in the above invention, the information for identifying the sample used for creating the reference data is stored in the storage unit in association with the inspection pass / fail determination result.

Further, the present invention is characterized in that, in the above invention, an operation unit for performing an instruction operation related to inspection is further provided, and the reference data is created in response to the instruction operation by the operation unit.

Further, the present invention is characterized in that the above invention further includes a display unit for displaying the inspection pass / fail determination result.

Further, the present invention is characterized in that, in the above invention, the display unit switches between a screen for confirming the determination result at the time of inspection and a screen for confirming the inspection result after the inspection.

Further, the present invention is characterized in that, in the above invention, the type of light emitted from the light source unit is at least one of visible light, ultraviolet light, and infrared light.

Further, the present invention is characterized in that, in the above invention, the type of light received by the light receiving unit from the inspection target is at least one of visible light, ultraviolet light, and infrared light.

Further, in the present invention, in the above invention, the light receiving portion includes reflected light reflected by the inspection target, transmitted light transmitted through the inspection target, fluorescence emission generated in the inspection target, and phosphorescence generated in the inspection target. It is characterized by receiving at least one of light emission.

Further, the present invention is characterized in that, in the above invention, the reference data is at least one of the intensity of the light received by the light receiving unit and the feature appearing in the time series waveform of the intensity.

Further, the present invention is a printed matter inspection method for inspecting the print quality of an inspection target contained in a printed matter, in which a step of irradiating the inspection target with light from a light source unit and receiving light indicating the optical characteristics of the inspection target are received. The process of receiving the inspection data, the process of acquiring the inspection data based on the light received by the light receiving unit, and the inspection data are compared with the reference data prepared as the inspection pass / fail criteria, and the inspection pass / fail of the inspection target is compared. The reference data includes a step of irradiating a sample prepared as an inspection standard for the inspection with light from the light source unit and receiving light received by the light receiving unit when the inspection of the inspection target is performed. It is characterized in that it is created based on.

According to the present invention, when performing an inspection, it is possible to create reference data as an inspection standard from a sample. For example, even when the ink used for printing the security mark is changed in the printing device, reference data can be created using the changed ink as a sample, and the print quality of the security mark printed by the printing device can be inspected.

FIG. 1 is a block diagram showing a configuration of a printed matter inspection device according to the present embodiment. FIG. 2 is a diagram showing the appearance of the sensor unit and the operation terminal. FIG. 3 is a diagram for explaining the sensor unit. FIG. 4 is a diagram for explaining a measurement unit included in the sensor unit. FIG. 5 is a flowchart showing a printing inspection method. FIG. 6 is a diagram showing an example of an inspection screen displayed on the display unit of the operation terminal at the start of the print inspection. FIG. 7 is a diagram showing an example of an inspection result confirmation screen displayed on the display unit of the operation terminal. FIG. 8 is a diagram for explaining a method for inspecting a printed matter in which fluorescence emission and phosphorescence emission are observed.

Hereinafter, embodiments of the printed matter inspection apparatus and the printed matter inspection method according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram showing a configuration of a printed matter inspection device 1 according to the present embodiment. Hereinafter, the printed matter inspection device 1 is simply referred to as the inspection device 1. As shown in FIG. 1, the inspection device 1 includes a sensor unit 10 and an operation terminal 40. The sensor unit 10 and the operation terminal 40 are communicably connected to each other.

The sensor unit 10 includes a light source unit 20 and a light receiving unit 30. The light source unit 20 irradiates the inspection target with light. The inspection target may be characters printed on the printed matter, marks, or patterns. In the present embodiment, a case where the light source unit 20 irradiates ultraviolet light by using an LED (Light Emitting Diode) will be described as an example. The light source unit 20 includes a sensor used for adjusting the intensity of the light emitted from the LED, which will be described in detail later.

The light receiving unit 30 irradiates the inspection target from the light source unit 20 and receives the light reflected by the inspection target. Further, the light receiving unit 30 receives light emitted from the inspection target by the light emitted from the light source unit 20. That is, the light receiving unit 30 can detect the reflected light by the inspection target and the light emission generated in the inspection target. In the present embodiment, a case where the light receiving unit 30 detects three types of light, that is, visible light in the green wavelength region, visible light in the red wavelength region, and visible light in the blue wavelength region, will be described as an example. ..

The light receiving unit 30 outputs a signal according to the intensity of the received light. Based on the signal output from the light receiving unit 30, the inspection device 1 irradiates the inspection target with light from the light source unit 20 to measure a feature amount indicating the optical characteristics of the light observed by the inspection target.

As shown in FIG. 1, the operation terminal 40 includes a control unit 50, an operation unit 60, a display unit 70, and a storage unit 80. For example, the computer device can be used as the operation terminal 40. The operation unit 60 is used to perform operations related to inspection. For example, an operation for performing an inspection by the sensor unit 10 and an operation for confirming the inspection result are performed using the operation unit 60. The display unit 70 is used to display information related to inspection. For example, when the sensor unit 10 performs an inspection, information on the inspection is displayed on the display unit 70, and when the inspection result is confirmed, the information on the inspection result is displayed on the display unit 70.

The storage unit 80 is a non-volatile storage device. The storage unit 80 is used to store information necessary for the function and operation of the inspection device 1. For example, the information necessary for performing the inspection and the information obtained by the inspection are stored in the storage unit 80. The control unit 50 controls the sensor unit 10, the display unit 70, and the storage unit 80 while using the information stored in the storage unit 80 according to the operation performed by the operator in the operation unit 60. The function and operation of the inspection device 1 are realized by the control unit 50 controlling each unit.

FIG. 1 shows the minimum configuration of the inspection device 1 in which one operation terminal 40 is connected to one sensor unit 10. The person in charge of inspection can operate one operation terminal 40 to perform the inspection and confirm the details of the inspection result.

FIG. 2 is a diagram showing the appearance of the sensor unit 10 and the operation terminals 40 (40a, 40b). As shown in FIG. 2, the inspection device 1 may be configured to include a plurality of operation terminals 40a and 40b. The sensor unit 10 and the operation terminal 40a are communicably connected, and another operation terminal 40b is communicably connected to the operation terminal 40a. The connection method is not limited to the wired connection and may be a wireless connection. The operator in charge of the inspection operates the operation terminal 40a, and the operator who confirms the inspection result operates the operation terminal 40b. The operator of the operation terminal 40a and the operator of the operation terminal 40b may be the same or different.

The operator in charge of the inspection places the sheet 100 including the inspection target on a flat inspection table, and places the sensor unit 10 on the inspection target as shown in FIG. The operator operates the operation terminal 40a for inspection to perform the inspection. The sensor unit 10 is a compact and lightweight portable device. The operator can hold the sensor unit 10 in his hand and perform the inspection at a plurality of positions on the sheet 100 while moving the position of the sensor unit 10 on the sheet 100. The operator who has completed the inspection of the sheet 100 can prepare another sheet on the inspection table and place the sensor unit 10 on the inspection target included in the sheet to perform the next inspection. The obtained inspection result is stored in the storage unit 80 of the operation terminal 40a.

The operator who confirms the inspection result operates the operation terminal 40b to confirm the inspection result. For example, the operator in charge of inspection operates the operation terminal 40a to execute the inspection a plurality of times. If an inspection target that fails the inspection appears during the inspection, the operator in charge of confirmation operates the operation terminal 40b to confirm the details of the inspection result. By connecting a plurality of operation terminals 40a and 40b, the inspection can be continued on another operation terminal 40a while the inspection result is confirmed on the operation terminal 40b.

The display contents differ between the inspection screen (see FIG. 6) displayed on the operation terminal 40a and the inspection result confirmation screen (see FIG. 7) displayed on the operation terminal 40b, but the details will be described later. When using one operation terminal 40 as shown in FIG. 1, the operator can operate the operation unit 60 to switch the screen displayed on the display unit 70. The operator displays the inspection screen at the time of inspection and displays the inspection result confirmation screen at the time of confirming the inspection result.

FIG. 3 is a diagram for explaining the sensor unit 10. The sensor unit 10 includes a base unit 12 and a main body unit 11. The main body 11 can be opened and closed with respect to the base 12. For example, the base portion 12 and the main body portion 11 are connected by a hinge structure. FIG. 3A is a perspective view showing a state in which the main body portion 11 is opened with respect to the base portion 12. FIG. 3B is a side view showing a state in which the main body portion 11 is closed with respect to the base portion 12.

As shown in FIG. 3A, the main body 11 is provided with a measuring unit 14 including a light source unit 20 and a light receiving unit 30. A transparent member 13 is fitted in the base portion 12. The transparent member 13 has an inspection window 13b at a substantially central portion. The inspection window 13b is a through hole provided in the transparent member 13. As shown in FIG. 3B, the inspection window 13b is formed at a position corresponding to the measuring unit 14 when the main body portion 11 is closed. At the time of inspection, the light emitted from the light source unit 20 reaches the inspection target through the inspection window 13b. The light reflected by the inspection target and the light emitted from the inspection target reach the light receiving unit 30 through the inspection window 13b.

As shown in FIG. 3A, a line 13a used for adjusting the position of the sensor unit 10 is drawn on the transparent member 13. The line 13a is drawn on the outside of the inspection window 13b so as to be aligned with two straight lines that pass through the center of the rectangular inspection window 13b and are orthogonal to each other. Each line 13a is drawn parallel or perpendicular to each side of the rectangular inspection window 13b.

The operator places the sensor unit 10 on the sheet 100 as shown in FIG. As shown in FIG. 3A, the operator visually confirms the line 13a of the transparent member 13 and the inspection target on the sheet 100 that can be seen under the transparent member 13 with the main body 11 open. , Adjust the position of the sensor unit 10. For example, the operator adjusts the position of the sensor unit 10 on the sheet 100 so that at least a part of the inspection target is located inside the inspection window 13b.

When the position adjustment of the sensor unit 10 is completed, the operator closes the main body unit 11 as shown in FIG. 3 (b). The bottom surface of the base portion 12 is flat so that light does not enter the inspection window 13b through the gap between the base portion 12 and the sheet 100. Further, the outer peripheral portion of the lower surface of the main body portion 11 is in contact with the upper surface of the base portion 12, so that light does not enter the inspection window 13b through the gap between the main body portion 11 and the base portion 12. As a result, the measuring unit 14 can detect the light indicating the optical feature of the inspection target and acquire the feature amount without being affected by the ambient light.

FIG. 4 is a diagram for explaining the measurement unit 14 shown in FIG. 3A. FIG. 4A shows the appearance of the measuring unit 14. FIG. 4B is a schematic view showing an inspection method performed by closing the main body 11 as shown in FIG. 3B.

As shown in FIG. 4A, the light receiving unit 30 includes three channels of light receiving units 30a to 30c. The light receiving unit 30a measures the intensity of light in the green visible light wavelength region. The light receiving unit 30b measures the intensity of light in the red visible light wavelength region. The light receiving unit 30c measures the intensity of light in the blue visible light wavelength region.

The inspection is performed with the main body 11 closed as shown in FIG. 3 (b). After closing the main body 11, the operator in charge of the inspection operates the operation unit 60 of the operation terminal 40 to start the inspection. When the inspection is started, the control unit 50 of the operation terminal 40 controls the light source unit 20, and the light source unit 20 irradiates the inspection target with light. As shown by an arrow in FIG. 4B, ultraviolet light is emitted from the light source unit 20. The ultraviolet light is applied to the inspection target on the sheet 100 through the inspection window 13b. The ultraviolet light reflected by the inspection target and the light emitted from the inspection target due to the excitation by the ultraviolet light reach the light receiving units 30a to 30c of each channel. Since the light receiving unit 30 is configured to detect green visible light, red visible light, and blue visible light, the light receiving unit 30 does not detect the ultraviolet light reflected by the inspection target.

When the inspection target on the sheet 100 is printed using ink that is excited by ultraviolet light and emits light in the blue visible light wavelength region, the light receiving unit 30c detects the blue visible light. Similarly, when the inspection target emits light in the green visible light wavelength range, the light receiving unit 30a detects the light emission, and when the inspection target emits light in the red visible light wavelength range, the light receiving unit 30b detects the light emission.

Each of the light receiving units 30a to 30c outputs a signal corresponding to the detected light intensity. The control unit 50 of the operation terminal 40 stores the strength of the signals output from the light receiving units 30a to 30c in the storage unit 80 at predetermined time intervals (sampling intervals). From the information stored in the storage unit 80, it is possible to confirm the time-series waveform of the light emission intensity detected by each of the light receiving units 30a to 30c.

Next, the inspection method will be described. When the operator performs a predetermined operation on the operation unit 60 of the operation terminal 40, the login screen is displayed on the display unit 70. When the operator in charge of inspection inputs the user ID and password assigned to him / her on this login screen and performs the login operation, the inspection screen for performing the print inspection is displayed. On the other hand, on the login screen, when the operator in charge of confirming the inspection result inputs his / her own user ID and password to perform the login operation, the inspection result confirmation screen for confirming the inspection result is displayed.

The user ID is identification information for identifying each operator. The user ID and password are registered in the storage unit 80 in advance. For example, the operator who can display the inspection result confirmation screen is limited to the manager of the print inspection. Hereinafter, the inspection result confirmation screen in which the operator confirms the inspection result of the print inspection will be described after explaining the method of the print inspection performed by the operator in charge of the inspection using the inspection screen.

FIG. 5 is a flowchart showing a printing inspection method. FIG. 6 is a diagram showing an example of an inspection screen 90 displayed on the display unit 70 of the operation terminal 40 at the start of the print inspection. When the operator in charge of inspection performs a login operation, the inspection screen 90 shown in FIG. 6 is displayed on the display unit 70. The operator operates the operation terminal 40 to proceed with the print inspection as shown in FIG.

As shown in FIG. 6, on the inspection screen 90, a plurality of windows 91 (91a, 91b) for displaying information, a plurality of boxes 92 (92a to 92e) for inputting information, and an instruction operation for performing an instruction operation are performed. A plurality of buttons 93 (93a to 93e) are displayed. The user ID entered at the time of login is automatically entered in the input box 92a.

In the message window 91a, information for guiding the operator who has started the inspection to perform the next operation is displayed. The operator performs operations in order according to the guidance display. First, the operator confirms the operation of the sensor unit 10. The operator presses the light source confirmation button 93a on the inspection screen 90 to confirm the operation of the light source unit 20 (step S1 in FIG. 5). The light source unit 20 includes an LED that irradiates the inspection target with light and a sensor that measures the intensity of the light emitted from the LED.

A calibration sheet is prepared in advance for checking the operation of the light source unit 20. The operator places the sensor unit 10 on the calibration sheet, and presses the light source confirmation button 93a with the main body unit 11 closed as shown in FIG. 3 (b). In response to this operation, the control unit 50 passes a predetermined current through the LED of the light source unit 20 to light it, and measures the light emission intensity by the sensor of the light source unit 20. If the measured emission intensity is within a preset range, the control unit 50 determines that the operation of the light source unit 20 is normal. If the emission intensity is not within the set range, the control unit 50 calibrates the light source unit 20. Specifically, the control unit 50 adjusts the current value to be passed through the LED while checking the light emission intensity measured by the sensor so that the light emission intensity falls within the set range. When the control unit 50 adjusts the current value, in the subsequent processing, the light source unit 20 is turned on by using the adjusted current value.

Next, the operator presses the sensor confirmation button 93b on the inspection screen 90 to confirm the operation of the light receiving unit 30 (step S2). A calibration sheet is prepared in advance for checking the operation of the light receiving unit 30. The operator places the sensor unit 10 on the calibration sheet, and presses the sensor confirmation button 93b with the main body unit 11 closed as shown in FIG. 3 (b). In response to this operation, the control unit 50 lights the light source unit 20 whose operation has been confirmed earlier. The light source unit 20 emits light with an emission intensity within a preset range. The control unit 50 measures the intensity of the light received by the light receiving unit 30.

If the light receiving intensity is within a preset range, the control unit 50 determines that the operation of the light receiving unit 30 is normal. When the light receiving intensity is not within the set range, the control unit 50 calibrates the light receiving unit 30. For example, the control unit 50 sets a correction coefficient applied to the signal output from the light receiving unit 30 so that the light receiving intensity falls within the set range.

The operation check is performed for all the light receiving units 30a to 30c of channels 1 to 3. The sensor unit 10 includes a light source unit 20 that irradiates ultraviolet light, and three-channel light receiving units 30a to 30c that measure light intensity in the green visible light wavelength range, the red visible light wavelength range, and the blue visible light wavelength range. And include. When the calibration sheet is irradiated with ultraviolet light from the light source unit 20, light emission in the green visible light wavelength range, light emission in the red visible light wavelength range, and light emission in the blue visible light wavelength range are observed. It is configured as. For example, the region on the calibration sheet corresponding to the inspection window 13b shown in FIG. 3 is divided into three parts, and when irradiated with ultraviolet light, an ink that emits light in the green visible light wavelength range and an ink that emits light in the red visible light wavelength range. , Ink that emits light in the visible light wavelength range of blue is applied to each region to prepare a calibration sheet. Further, for example, a calibration sheet is prepared by applying an ink in which light emission including a green visible light wavelength component, a red visible light wavelength component, and a blue visible light wavelength component is observed when irradiated with ultraviolet light. Information on the emission intensity to be measured by the light receiving units 30a to 30c of each channel at the time of operation confirmation using the calibration sheet is stored in the storage unit 80 in advance. The control unit 50 uses this information to check the operation of the light receiving unit 30 as described above.

If the emission intensity is not within the set range when the operation of the light source unit 20 is confirmed, the control unit 50 displays a message in the message window 91a prompting the operator to confirm that there is no problem with the light source unit 20 and the calibration sheet. Similarly, even if the light receiving intensity is not within the set range when the operation of the light receiving unit 30 is confirmed, the control unit 50 sends a message prompting the operator to confirm that there is no problem with the light receiving unit 30 and the calibration sheet in the message window 91a. Display on. As a result, the operator can check the states of the light source unit 20, the light receiving unit 30, and each calibration sheet, remove dirt as necessary, and reconfirm the operation.

The operator who has completed the operation check of the inspection device 1 inputs the information regarding the reference sample to the operation terminal 40 (step S3). The reference sample is a sample for acquiring reference data as a criterion for judging pass / fail of inspection at the time of inspection. The reference sample differs depending on the inspection target, and when the inspection target is changed, the reference sample may be changed. Therefore, the inspection device 1 requires the operator to input information for specifying the reference sample used for the inspection.

As shown in FIG. 6, the operator inputs the name of the reference sample in the input box 92b according to the information displayed in the message window 91a. The control unit 50 stores the input information in the storage unit 80.

Subsequently, the operator acquires reference data as a pass / fail determination criterion at the time of inspection (step S4 in FIG. 5). Specifically, the operator sets the sensor unit 10 on the reference sample and presses the measurement button 93c. When the measurement button 93c is pressed, the control unit 50 irradiates ultraviolet light from the light source unit 20, and the light receiving units 30a to 30c measure the light intensity. The control unit 50 stores the measurement result and the reference data created based on the measurement result in the storage unit 80. The name of the reference sample, the measurement result of the reference sample, and the reference data are stored in association with each other.

Reference samples are prepared according to the optical characteristics to be inspected. For example, when printing a security mark on paper sheets using ink that emits light in a predetermined wavelength range when irradiated with ultraviolet light, the inspection device 1 creates reference data using the ink as a reference sample. be able to. It is also possible to create reference data using a security mark printed on a sheet of paper with a printing device as a reference sample. Specific examples of the reference data will be described later.

The operator who has completed the acquisition of the reference data starts the inspection of the inspection target. The operator inputs information about the inspection target into the operation terminal 40 in the input boxes 92c to 92e of the inspection screen 90 according to the information displayed in the message window 91a as shown in FIG. 6 (step S5). The information required to be input by the operator can be changed by setting. In the example shown in FIG. 6, the batch name, the sheet name, and the inspection target name are input as the information regarding the inspection target.

For example, a printing device may print a plurality of paper leaf designs on one sheet, and the sheet may be cut to produce a plurality of paper leaves. When creating paper leaves by cutting out small pieces from large format printing in this way, the operator inputs the information of each sheet (large format printing) as the sheet name and inputs the information of the inspected paper leaves (small pieces). Enter as the inspection target name. The batch name is used as a unit that can include a plurality of sheets (large format printing).

When printing a plurality of types of sheets with a printing device, each type of sheet can be distinguished by a batch name. For example, when printing paper sheets of type A with a printing device and performing inspection with the inspection device 1, the operator inputs "batch001" in the batch name input box 92c. When inspecting the first large-format print, the operator inputs "Sheet001" in the sheet name input box 92d. For example, when the identification information is printed on each paper leaf included in the large-format printing, such as the serial number of a banknote, the inspected paper leaf such as "XY123 ..." is displayed in the input box 92e of the inspection target name. Enter the identification information of. The information input to the input boxes 92c to 92e is stored in the storage unit 80 in association with the data obtained in the inspection and the inspection result. This makes it possible to identify the sheets and paper sheets corresponding to the inspection results when confirming the inspection results later.

The operator who has completed the input of information regarding the inspection target sets the sensor unit 10 on the inspection target as shown in FIG. 2 and presses the measurement button 93c on the inspection screen 90 shown in FIG. 6 to perform the inspection. When the measurement button 93c is pressed, the control unit 50 controls the sensor unit 10 to acquire inspection data (step S6). Specifically, the control unit 50 controls the light source unit 20 to irradiate ultraviolet light, controls the light receiving unit 30, and measures the light intensity with the light receiving units 30a to 30c of each channel. The control unit 50 acquires inspection data for comparison with the reference data created earlier based on the measurement result. The control unit 50 stores the measurement result and the inspection data obtained based on the measurement result in the storage unit 80.

The control unit 50 compares the reference data previously stored in the storage unit 80 in step S4 with the inspection data obtained from the inspection target in step S6, and determines whether the inspection is acceptable or not. The control unit 50 determines that the reference data and the inspection data match within a predetermined error range as a pass, and if they do not match, determines that the data fails. The control unit 50 displays the inspection result on the inspection result window 91b of the inspection screen 90. As shown in FIG. 6, the inspection result displayed in the inspection result window 91b includes a number (No.) indicating the inspection order, a name of the inspection target, a judgment result indicating inspection pass / fail, and an inspection date and time. Is done.

The operator confirms the inspection pass / fail determination result displayed on the inspection screen 90 (step S7). If the paper sheets to be inspected remain (step S8; No), the operator starts the next inspection. The operator repeats the operations of steps S5 to S7 until the inspection is completed. When the inspection is completed (step S8; Yes), the operator finishes the inspection.

The operator can save the inspection result by pressing the save button 93d on the inspection screen 90. When the save button 93d is pressed, the control unit 50 saves the information obtained during the inspection in the storage unit 80. The information about the inspection stored in the storage unit 80 is maintained in the storage unit 80 so as not to be overwritten. When the operator presses the end button 93e of the inspection screen 90, the inspection screen 90 is closed.

The information stored in the storage unit 80 for one inspection target includes the information input in the input boxes 92a to 92e and the information displayed in the inspection result window 91b, and the information received by the light receiving units 30a to 30c of each channel. The measurement result and the inspection data obtained from the measurement result are included. In addition, the value and time of the current passed to light the LED of the light source unit 20 at the time of inspection, and the sampling interval and the number of samplings in which the measured values are recorded by the light receiving units 30a to 30c of each channel are included. These information are stored in the storage unit 80 in a state of being associated as information regarding one inspection target. Information is stored for all inspection targets.

As described above, the inspection device 1 has one feature in that reference data serving as an inspection standard is created at the time of inspection and one or a plurality of inspection targets are inspected using the reference data. For example, when inspecting a first type of inspection target, the inspection device 1 creates reference data from the first reference sample prepared for this inspection, and starts the inspection based on the reference data. .. When inspecting a second type of inspection object different from the first type, the inspection device 1 creates reference data from the second reference sample prepared for this inspection, and based on the reference data. Start the inspection. That is, the inspection device 1 can create reference data from the reference sample and perform the inspection based on the reference data even when the reference data is not prepared in advance.

The information stored in the storage unit 80 of the operation terminal 40 at the time of inspection can be displayed and confirmed on the display unit 70 of the operation terminal 40. FIG. 7 is a diagram showing an example of an inspection result confirmation screen 94 displayed on the display unit 70 of the operation terminal 40. The confirmation screen 94 is a screen for confirming the details of the inspection result. On the confirmation screen 94, in addition to the inspection pass / fail determination result, reference data and inspection data that are not displayed on the inspection screen 90 are displayed. When the administrator performs a login operation on the login screen of the operation terminal 40, the confirmation screen 94 shown in FIG. 7 is displayed on the display unit 70. The information displayed on the confirmation screen 94 includes information stored in the storage unit 80 at the time of inspection and information created from the information stored in the storage unit 80.

On the confirmation screen 94, a plurality of windows 95 (95a to 91d) on which information is displayed and a plurality of buttons 96 (96a to 96c) for performing instruction operations are displayed. The inspection information window 95a includes information on the operator who performed the inspection, information on the inspection target, and information on the inspection content. The inspection result window 95b includes light information measured by the light receiving units 30a to 30c of each channel and the inspection result.

In the waveform window 95c, information on the reference sample and information on the inspection target are displayed in a comparable manner. Specifically, at the time of creating the reference data, the measured values obtained by the light receiving units 30a to 30c of each channel and the waveform obtained by the approximation processing of the measured values are displayed. Further, at the time of inspection, the measured values obtained by the light receiving units 30a to 30c of each channel and the waveforms obtained by the approximation processing of the measured values are displayed. The measured values and waveforms are displayed on a graph with the Y-axis (vertical axis) as the light intensity and the X-axis (horizontal axis) as the time. The display range of the graph can be changed by the maximum and minimum values of the X-axis and the maximum and minimum values of the Y-axis on the right side of the waveform window 95c.

In the value window 95d, the value of the reference data used for the pass / fail judgment of the inspection and the value of the inspection data are displayed. For example, when the inspection pass / fail determination result is rejected, the operator can confirm the reason for the failure from the information displayed in the value window 95d.

FIG. 7 shows an example of an inspection result confirmation screen of an inspection performed using the emission intensity of fluorescence emission, the emission intensity of phosphorescence emission, and the time constant of the attenuation waveform of phosphorescence emission as reference data. Therefore, in the inspection result window 95b, the inspection result of fluorescence emission, the inspection result of phosphorescence emission, and the inspection result of the time constant are displayed. In the waveform window 95c, a value obtained by measuring fluorescence emission and phosphorescence emission and an approximate curve obtained by approximating the value with a curve are displayed. In the value window 95d, the value of the emission intensity of the fluorescence emission and the value of the emission intensity of the phosphorescence emission used for the pass / fail determination are displayed. Further, in the value window 95d, the value of the time constant (τ) used for the pass / fail judgment and the value obtained by the model formula (Y = A0 + A1 × exp (−X / τ)) when obtaining the time constant. A0 and A1 are displayed. The method for inspecting fluorescence emission and phosphorescence emission will be described later.

The name in the value window 95d corresponds to the inspection target name input at the time of inspection on the inspection screen 90 shown in FIG. Based on this name and the batch name and sheet name displayed in the inspection information window 95a, it is possible to specify the inspection target from which the inspection result displayed on the confirmation screen 94 is obtained. When the inspection is performed a plurality of times, the inspection target for which the inspection result is displayed on the screen can be changed by pressing the front button 96a and the rear button 96b of the confirmation screen 94 shown in FIG.

The inspection device 1 is, for example, inspecting a printed matter printed with an ink in which fluorescence emission is observed, an inspection of a printed matter printed in ink in which phosphorescence emission is observed, and printing with an ink in which fluorescence emission and phosphorescence emission are observed. It can be used for inspection of printed matter. The inspection method will be described by taking as an example a security mark printed on paper sheets using ink in which fluorescence emission and phosphorescence emission are observed when irradiated with ultraviolet light.

FIG. 8 is a diagram for explaining a method for inspecting a printed matter in which fluorescence emission and phosphorescence emission are observed. In FIGS. 8A to 8C, the vertical axis represents the light intensity and the horizontal axis represents the time. FIG. 8A shows a time-axis waveform of ultraviolet light emitted from the light source unit 20 to the security mark. FIG. 8B shows a time-axis waveform of the emission intensity of the emission observed at the security mark of the reference sample by irradiation with the ultraviolet light shown in FIG. 8A. FIG. 8 (c) shows a time-axis waveform of the emission intensity of the emission observed at the security mark to be inspected by irradiation with the ultraviolet light shown in FIG. 8 (a).

As shown in FIG. 8A, when the LED of the light source unit 20 is turned on and the ultraviolet light having the emission intensity S1 is irradiated, the security mark emits fluorescence. As shown in FIG. 8B, fluorescence emission of emission intensity R2 is observed at the same time as irradiation with ultraviolet light. The security mark emits phosphorescent light in response to ultraviolet light. Since the emission intensity of phosphorescence emission gradually increases and saturates after irradiation with ultraviolet light, the emission intensity R3 at time T1 becomes larger than the emission intensity R2 immediately after the start of irradiation with ultraviolet light.

As shown in FIG. 8A, the LED of the light source unit 20 is turned off at time T2 to stop the irradiation of ultraviolet light. Fluorescence emission disappears as soon as the ultraviolet light irradiation is stopped. On the other hand, as shown in FIG. 8B, the emission intensity of phosphorescence emission gradually attenuates after the ultraviolet light irradiation is stopped. Therefore, the emission intensity R1 at time T3 is the emission at time T2 when the ultraviolet light irradiation is stopped. It is smaller than the intensity R4. Phosphorescent emission gradually attenuates and disappears, and the emission intensity becomes 0 (zero).

In the measurement for acquiring reference data (step S4) and the measurement for acquiring inspection data (step S6) shown in FIG. 5, the control unit 50 controls the light source unit 20 as shown in FIG. 8A. It is done by.

Specifically, when the reference data is acquired in step S4 shown in FIG. 5, the control unit 50 of the inspection device 1 controls the light source unit 20 as shown in FIG. 8A to irradiate the reference sample with light. To do. The control unit 50 controls the light receiving unit 30 to measure the emission intensity of the reference sample at predetermined sampling intervals. The measured value 111 measured as shown by a black circle in FIG. 8B is stored in the storage unit 80. The control unit 50 applies a curve approximation according to the model formula 112 shown in FIG. 8B to a large number of stored measured values 111 to obtain an approximate curve 113. For the approximate curve 113, for example, the values of the constants A0 and A1 and the value of the time constant τ included in the model equation 112 are stored in the storage unit 80.

When the inspection data is acquired in step S6 shown in FIG. 5, the control unit 50 of the inspection device 1 controls the light source unit 20 and the light receiving unit 30 in the same manner as when the reference data is acquired from the reference sample to be inspected. Get the measured value of. Specifically, the control unit 50 controls the light source unit 20 as shown in FIG. 8 (a), and the emission intensity of the inspection target measured by the light receiving unit 30 as shown by a white circle in FIG. 8 (c). The measured value 114 of is stored in the storage unit 80. The control unit 50 applies the curve approximation according to the model formula 112 shown in FIG. 8 (b) to a large number of stored measured values 114 to obtain the approximate curve 115 shown by the broken line in FIG. 8 (c). For the approximate curve 115, the values of the constants A0 and A1 and the values of the time constant τ included in the model equation 112 are stored in the storage unit 80 as in the reference sample.

The judgment of pass / fail of the inspection is performed by comparing the measurement result of the reference sample shown in FIG. 8B with the measurement result of the inspection target shown in FIG. 8C. The inspection pass / fail judgment method can be changed by setting.

For example, all the measured values 111 shown in FIG. 8B can be used as reference data, and the corresponding measured values 114 shown in FIG. 8C can be used as inspection data for determination. If the reference data and the inspection data match within a predetermined error range, the control unit 50 passes the inspection pass / fail judgment result, and if they do not match, rejects the inspection.

Further, for example, the value of one or several points between the time 0 (zero) and T2 shown in FIG. 8 (b) and the value of one or several points before the emission intensity after the time T2 becomes 0 (zero). The value and the values of the constants (A0, A1) and the time constant (τ) of the model formula 112 obtained for the approximate curve 113 can also be used as reference data. The values corresponding to these are obtained from the measured values 114 of the inspection target and the approximate curve 115 shown in FIG. 8C to be used as inspection data, and are compared with the reference data. If the reference data and the inspection data match within a predetermined error range, the control unit 50 passes the inspection pass / fail determination result, and if they do not match, rejects the inspection.

Although the waveform for one channel is shown in FIG. 8, reference data and inspection data are acquired, compared, and determined for the light receiving units 30a to 30c of all channels. If there is even one channel whose inspection data does not match the reference data, the inspection pass / fail judgment result is rejected.

In addition, a measurement method for acquiring reference data and inspection data, a method for acquiring reference data and inspection data from measured values, a type of data stored in the storage unit 80, a method for comparing reference data and inspection data, and comparison results. The inspection pass / fail judgment method based on the above can be changed by setting. The settings are appropriately changed based on the optical characteristics of the inspection target.

In the present embodiment, an example of irradiating ultraviolet light from the light source unit 20 is shown, but the type of light emitted by the light source unit 20 is not particularly limited. For example, the light source unit 20 may irradiate visible light, or may irradiate infrared light. Further, the light source unit 20 may irradiate one type of light, or may irradiate a plurality of types of light having different wavelength ranges. When the light source unit 20 irradiates a plurality of types of light, it may irradiate a plurality of types of light at the same time, or may irradiate one type at a time. The number, type, and irradiation method of the light emitted by the light source unit 20 are appropriately set according to the optical characteristics of the inspection target.

In the present embodiment, an example in which the light receiving unit 30 detects the green visible light, the red visible light, and the blue visible light wavelength range is shown, but the type of light detected by the light receiving unit 30 is the optical of the inspection target. It is set appropriately according to the characteristics. The light receiving unit 30 is configured so that light in this wavelength range can be detected according to the wavelength range of light to be detected at the time of inspection. For example, when light in the infrared wavelength region is to be inspected, any one channel of the light receiving unit 30 detects the light in the infrared wavelength region. Further, for example, when light in the ultraviolet wavelength region is to be inspected, any one channel of the light receiving unit 30 detects the light in the ultraviolet wavelength region. The light receiving unit 30 may be configured by only the light receiving element, or may be configured by combining the light receiving element with a filter. The light receiving unit 30 may be in a mode of detecting one type of light, or may be in a mode of detecting a plurality of types of light having different wavelength ranges.

In the present embodiment, the inspection device 1 shows a configuration in which the light receiving unit 30 receives the light reflected by the inspection target and the light emitted by the inspection target. However, the type of light used by the inspection device 1 for the inspection is as follows. Not limited to these. A mode in which the light receiving unit 30 receives at least one of reflected light reflected by the inspection target, transmitted light transmitted through the inspection target, fluorescence emission generated by the inspection target, and phosphorescence emission generated by the inspection target. It may be. For example, if the inspection device 1 has a different light receiving unit or light source unit at a position corresponding to the measuring unit 14 with the sheet 100 shown in FIG. 3B sandwiched therein, the inspection target on the sheet 100 is transmitted. Light can be used for inspection.

As described above, the inspection device 1 can create reference data from the reference sample at the time of inspection. This makes it possible to inspect the print quality of printed matter for which reference data has not been prepared in advance. For example, reference data can be created using the ink used for printing printed matter as a reference sample. For example, reference data can be created using a sample of printed matter as a reference sample. As a result, the print quality of the printed matter can be easily inspected.

As described above, the printed matter inspection apparatus and the printed matter inspection method according to the present invention are useful for inspecting the print quality of printed matter for which data as an inspection standard is not prepared in advance.

1 Printed matter inspection device 10 Sensor unit 11 Main unit 12 Base unit 13 Transparent member 13a Line 13b Inspection window 14 Measuring unit 20 Light source unit 30 (30a to 30c) Light receiving unit 40 (40a, 40b) Operation terminal 50 Control unit 60 Operation unit 70 Display unit 80 Storage unit

Claims (11)

A printed matter inspection device that inspects the print quality of the inspection target contained in printed matter.
A storage unit for storing reference data used as an inspection pass / fail criterion, and
A light source that irradiates the inspection target with light,
A light receiving unit that receives light indicating the optical characteristics of the inspection target, and
The inspection data obtained based on the light received by the light receiving unit is compared with the reference data to provide a determination unit for determining the inspection pass / fail of the inspection target.
The reference data is created based on the light received by the light receiving unit by irradiating the sample prepared as the inspection standard for the inspection with light from the light source unit when the inspection of the inspection target is performed. A printed matter inspection device characterized by. When inspecting the first type of inspection target, the first reference data is created from the sample prepared for the inspection and the inspection is performed.
According to claim 1, when inspecting a second type of inspection target different from the first type, a second reference data is created from a sample prepared for the inspection and the inspection is performed. The described printed matter inspection device. The printed matter inspection apparatus according to claim 1 or 2, wherein the information for identifying the sample used for creating the reference data is stored in the storage unit in association with the inspection pass / fail determination result. It also has an operation unit for performing instruction operations related to inspection.
The printed matter inspection apparatus according to any one of claims 1 to 3, wherein the reference data is created in response to an instruction operation by the operation unit. The printed matter inspection apparatus according to any one of claims 1 to 4, further comprising a display unit for displaying an inspection pass / fail determination result. The printed matter inspection device according to claim 5, wherein the display unit switches between a screen for confirming the determination result at the time of inspection and a screen for confirming the inspection result after the inspection. The printed matter inspection apparatus according to any one of claims 1 to 6, wherein the type of light emitted from the light source unit is at least one of visible light, ultraviolet light, and infrared light. The printed matter according to any one of claims 1 to 7, wherein the type of light received by the light receiving unit from the inspection target is at least one of visible light, ultraviolet light, and infrared light. Inspection equipment. The light receiving unit receives at least one of reflected light reflected by the inspection target, transmitted light transmitted through the inspection target, fluorescence emission generated in the inspection target, and phosphorescence emission generated in the inspection target. The printed matter inspection apparatus according to any one of claims 1 to 8, wherein the printed matter inspection apparatus is characterized in that. The printed matter inspection apparatus according to claim 9, wherein the reference data is at least one of the intensity of the light received by the light receiving unit and the feature appearing in the time-series waveform of the intensity. It is a printed matter inspection method that inspects the print quality of the inspection target contained in the printed matter.
The process of irradiating the inspection target with light from the light source
The step of receiving light indicating the optical characteristics of the inspection target on the light receiving portion, and
The process of acquiring inspection data based on the light received by the light receiving unit, and
It includes a step of comparing the inspection data with the reference data prepared as the inspection pass / fail criteria to determine the inspection pass / fail of the inspection target.
The reference data is created based on the light received by the light receiving unit by irradiating the sample prepared as the inspection standard for the inspection with light from the light source unit when the inspection of the inspection target is performed. A printed matter inspection method characterized by.

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