JPH0625969A - Apparatus for inspecting color-difference of sheet-formed material - Google Patents

Abstract

PURPOSE:To provide a color difference inspection apparatus capable of getting a color difference inspection result in real time and extremely high efficiency by providing a plurality of CPUs and carrying out the control of an input system, the simultaneous colorimetry with plural color sensors, the data collection and the control of the graphic display of a color-difference variation curve using each CPU. CONSTITUTION:The color difference inspection apparatus is provided with a 1st CPU for controlling the transfer-control part of a sheet-formed specimen, a device for inputting the inspection conditions, etc., a displaying part and a device for outputting the inspection result and a 2nd CPU for controlling the colorimetry and display with plural color sensors. The apparatus is furnished with an automatic calibration mechanism part to decrease the discrepancy between the plural color sensors.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for inspecting a color difference of an object, and more particularly, an apparatus for inspecting a color difference of a sheet-like material such as a woven fabric, a knit fabric, a non-woven fabric or a film mainly using a color sensor. Regarding

[0002]

2. Description of the Related Art Generally, in the process of dyeing industrial products such as cloths, films and plates, for example, woolen fabrics or cotton fabrics, uneven coloring occurs due to uneven dispersion of dyes, or partial coloring due to the inclusion of foreign substances that overheat. Occur,
Alternatively, oily stains may cause brown stains. Such color unevenness, stains, etc. occur locally and suddenly, and are considered to be fatal defects in the appearance of industrial products.Therefore, inspectors always visually inspect all products and all of them. It is the current situation.

Therefore, the labor required for the inspection is large, and in order to rationalize the labor, the following inspection methods are conventionally known. (1) Scanning the light flux of the laser beam at a high speed in a direction perpendicular to the product (measurement object) conveyance direction, and focusing on the point that the reflectance of the abnormal part changes with respect to the normal part, to detect scratches etc. To do. (2) A television camera using an image sensor scans the surface of the product, extracts an image signal and processes it to obtain a color unevenness signal. (3) A photoelectric colorimeter (color sensor) or a spectrophotometer is arranged above or below a product conveyed at a required speed,
The surface color of an object is continuously measured.

[0004]

However, in the above-mentioned conventional inspection method, although it is possible to attain a purpose for a condition corresponding to the principle, it is possible to check the color difference of the sheet-like object online. Is not sufficient in terms of inspection efficiency.
That is, in the method using the luminous flux of the laser beam, since the laser beam is monochromatic light, it is possible to detect scratches that scatter the light and adhesion of foreign matter, but it is not possible to detect a color difference. In addition, the method using an image sensor requires an image analysis device and requires data processing by software, which increases the time required for detection and increases the equipment cost, and TV cameras have a poor color discrimination performance. It is not enough to perform inspections comparable to the human eye, and it is also not possible to meet the required speed of the process. Further, in regard to the method of using a color sensor or a spectrophotometer, many methods and devices have been proposed, but if there is any disclosure that discloses a method of calibrating a plurality of color sensors and improving the efficiency of the online inspection, there is nothing. Absent. Therefore, in the present invention, a plurality of color sensors are used to detect the color difference of a sheet-like material such as a woven fabric or a film, and a plurality of CPUs are used to control the transport system and the color measurement / display system. In the color difference inspection device with control configuration, equipped with a mechanism for easily and accurately calibrating the color sensor, the color difference can be detected during the transportation of the object to be measured, and the color difference data can be displayed in real time. It is intended to submit a color difference inspection device.

[0005]

In order to solve the above-mentioned problems, the present invention is an apparatus for inspecting online for color unevenness of a sheet-like object such as a woven fabric or a film conveyed at a required speed. A transport unit that allows a sheet-like object to travel in a strip shape, an input unit that inputs inspection conditions, a first display unit that displays inspection conditions, a first output unit that outputs results, and a transport unit, an input unit, a first A first part for controlling the display part and the first output part
A plurality of color sensors provided with a CPU and located above or below the sheet-like material, and one or more calibration objects moving between the color sensor and the sheet-like material in parallel to the surface of the sheet-like material, A calibration mechanism that automatically calibrates the color sensor and a first CP connected to the color sensor.
A second display unit for processing the color measurement and the read data of a color sensor controlled by a second CPU connected to U via a communication line to detect and display the color difference of the sheet-like material, and outputting the result. It is calibrated from the second output section.

Since the calibration plate is moved by a linear motor, calibration between a plurality of color sensors can be performed very easily and accurately, and a control system using a plurality of CPUs is used. Enter inspection conditions,
Real-time screen display, output of results, and the like can be easily controlled, information desired to be inspected can be instantly obtained, and inspection efficiency can be significantly improved.
An embodiment of the present invention will be described below with reference to FIGS.

(Example 1) A general inspection procedure in an online color difference inspection when a color sensor is used will be shown.
It is a General Flow Chart. That is, the reference value for performing the color difference inspection, that is, the reference color value is set by inputting conditions such as the product name of the object to be measured, the inspection date, the inspection speed and the like. The power of the transport system is turned on and the measurement is started. In the measurement of the color sensor, data is collected at regular intervals, so that the inspection can be performed while identifying the measurement points. If it is a measuring point, the color is measured to collect data and display it on the screen. When the measurement end point comes, the power of the conveying system is turned off, the results are totaled, and the necessary color difference variation graph is printed out.

FIG. 2 shows a basic system configuration block diagram for applying this procedure to a color difference inspection apparatus for a sheet-like material to improve inspection efficiency. First, this system has a plurality of CPUs. (1st CPU and 2nd CPU) 1st
As a (peripheral) device connected to the CPU, there is a conveyance section (driving section), which includes a conveyance motor for moving a sheet-like object, drive motors for focusing a color sensor on a colorimetric position, and meandering prevention. It includes mechanical devices such as wrinkle straightening and tension control (neither shown). Next, there is an input unit, which is a device for inputting inspection conditions, and includes a keyboard, a bar code reader, a voice input device, and a switch input device for instructing start / stop / forward / backward movement of the transport system. Furthermore, the first to always monitor the inspection conditions before / after / after the inspection.
It is provided with a display unit (CRT) and is composed of a first output unit (printer) that prints out inspection conditions and inspection results. As a device connected to the second CPU, in order to perform color difference inspection of a plurality of color sensors, particularly sheet-like objects, it is desired to intensively check the color difference between the center and both sides to detect the presence or absence of color unevenness. The most efficient arrangement method is to install three color sensors vertically to the. Second
Although it is easy to directly connect an input device (not shown) to the CPU, the second CPU has a communication line connected to the first CPU, and the input condition from the input unit connected to the first CPU is Since it can be transmitted to the second CPU, the second
The input device is unknown to the CPU. Further, it is important for the inspection to know the variation of the color difference in real time during the inspection. For that purpose, the second display section (graphic display) for displaying the data obtained by sequentially measuring the color in a graph
Is equipped with. It can be said that the most efficient inspection device configuration is that the graphs displayed on the screen are printed out at the same time when the measurement is completed.

FIG. 3 shows a conceptual diagram of the system configuration of the present invention, and the block diagram will be described in more detail. 1st CP
The U, the first display unit, the first output unit, and the like are configured by, for example, a personal computer PC-9801 (manufactured by NEC). The first CPU is provided with a built-in storage device of about 100 MB (megabytes), and is configured to record inspection conditions, data and the like. Further, an input / output interface board and an A / D conversion board are connected to the input / output (I / O) terminals of the first CPU to control the carrier system (driving motor) and switch input signals. Further, in order to use a plurality of color sensors, it is necessary to calibrate each color sensor, and there are absolute value calibration (white plate calibration) and reference color calibration according to an object to be measured. In order to perform this efficiently, as shown in FIG. 3, one or more calibration objects that are parallel to the surface of the sheet-like object and are located between the color sensor and the sheet-like object are installed in the linear motor. Therefore, when the calibration is performed, the calibration plate is moved to a predetermined position of each color sensor by the linear motor, so that the calibration can be performed easily and accurately. And control of this linear motor is also 1st CPU (PC-9801)
Is in charge. As the input part, the inspection condition input device such as a keyboard and a bar code reader and the start / start of the transport system
A switch input device for controlling stop / forward / reverse command. Next, the second CPU controls color measurement by a plurality of color sensors, processes the data obtained by the color measurement, and displays the color difference variation graph on the second display unit (graphic display) in real time. There is. Therefore, it is necessary to perform color measurement (three color sensors) and data display (three) simultaneously and sequentially.
In the computer field, a 68208 (Motorola) processor system based on OS 9 (operating system), which is well known in the computer field, is used as the CPU configuration. The first output unit prints out inspection conditions and detailed numerically analyzed data as necessary. The second output section, when the measurement is completed,
The color difference variation graph displayed on the second display unit is printed out. The first CPU and the second CPU are connected by, for example, an RS232C communication line, and are used for transmission of inspection conditions, colorimetric commands, and the like (first CPU → second CP).
U), transmission of data obtained by the color sensor (second CP
U → first CPU) and the like are performed bidirectionally. Second C
The PU and the three color sensors are also connected by the RS232C communication line, and the command data and the like are bidirectionally transmitted. With the above-mentioned configuration, the fee-based calibration operation is mechanically facilitated when using a plurality of color sensors, so that the color difference inspection of the sheet-like material can be performed more quickly online. This is a device that can further improve inspection efficiency such as real-time color measurement and data display.

The functions of this system will be described with reference to the flowcharts of FIGS. Note that C and D in the flowchart of FIG. 4 are connected to C and D of FIG. In the flowchart of FIG. 4 and FIG. 5, the first CPU side (for example, PC-9801 control side) and the second CPU side (for example, 6-9
The operation of the 8020 control side) is shown separately. First CPU
Since the second CPU and the second CPU are connected by the RS232C communication line, the first CPU side or the second CPU in the flowchart is
It is defined that the condition command and data at that time are transmitted from the CPU side in the direction of the dotted arrow. Explaining the first CPU side, when the power is turned on, an initial state is set, and inspection conditions and the like are input. Bar code input should be used as much as possible to eliminate typos, and inspection date, inspection time, etc. are the first
It is automatically set by the CPU. Further, it is efficient to input a predetermined value as the inspection speed and input the set speed only when necessary. If all of these conditions are set, the condition set by the first CPU is changed to the second CP.
Transmit to U. Next, check whether to perform white calibration. This is to calibrate the absolute value of the colorimetric value of the color sensor, which is a necessary operation for what is called the current color sensor. As a general rule, it should be done before color measurement as much as possible, but in normal use, calibration several times a day is sufficient. This white calibration plate is fixed to the linear motor in this embodiment as shown in FIG. 3, and it is only necessary to move it to the position of the three color sensors. Similarly, the reference color calibration is necessary to reduce the inter-device error of each color sensor so that the plurality of color sensors show the same colorimetric value when the same object is colorimetrically measured. This operation is not mentioned here because there is an optimum calibration method depending on the color sensor used. (For example, JP-A-62-1
Therefore, there is no error between devices of multiple color sensors (strictly, it is minimized).
Is defined as the standard color calibration.

Since the reference color calibration is to measure the color of a reference sample as an object to be measured, the colorimetric value obtained at this time is stored in the storage device as the reference color value. If the reference color calibration has already been performed, the corresponding data is retrieved from the storage device and set. Here, CIE
Using the L * a * b * color system (1976), the reference color value is represented by (L ₀ * a ₀ * b ₀ *). On the first CPU side,
Either the standard color value is set by the standard color calibration or the data is retrieved from the storage device. Finally, when the reference color value setting confirmation signal is output from the second CPU side, the condition setting up to the color measurement on the first CPU side is completed.
When it is confirmed that there is no abnormality in the transport system or peripheral equipment and the inspection start signal is input by the switch, the transport system monitor is turned on and the sheet-like object enters the running state and at the same time the second
A colorimetry start command is transmitted to the CPU side. While the color sensor is actually measuring the color, the operation of the first CPU mainly checks the abnormal signal detection of the transport system or receives the color measurement data sent from the second CPU and stores the data in the storage device. The action of doing. When an abnormal signal is detected, the transportation system is stopped and stands by. If not, check if the measurement is complete. When the end signal is obtained, the conveying system is stopped and the end signal is transmitted to the second CPU to process the necessary data and print it out to the first output unit. As described above, the first CPU mainly controls the transport system during color measurement. During the inspection, the inspection conditions and the like remain displayed on the first display unit so that the inspector can always confirm the contents.

The second CPU side will be described. When the power is turned on, the initial state is set. When the inspection condition is received from the first CPU, the presence or absence of a white calibration signal is checked next.
If yes, perform white calibration. (The actual operation depends on the color sensor used, and description thereof will be omitted.) At this time, in this embodiment, the white calibration plate is fixed to the linear motor, and the color sensor and the sheet-shaped object surface are Between them, and move parallel to the sheet surface,
Move to the position of each color sensor. Calibration is performed by stopping at a predetermined position of each color sensor. When the calibration is completed, an end signal is sent to the first CPU. Next, the presence or absence of reference color calibration is checked. The reference calibration object (reference sample) is also fixed to the linear motor, and when performing the calibration, the reference sample is moved by the linear motor and calibration is performed in order as in the case of the white plate. And at this point, the second
A reference color value (L ₀ * a ₀ * b ₀ *) for inspecting the color difference of the measured object is set on the CPU side. After this, a setting confirmation signal is sent to the first CPU to complete the setting before measurement. Next, the presence or absence of the measurement start signal is checked. The operation of the second CPU after receiving the measurement start signal is mainly to identify the colorimetric points of the sheet-like object, perform colorimetric measurement on a plurality of color sensors in the same manner, and collect colorimetric data. , In real time as a color difference variation graph on the second display unit. At this time, in the color measurement of the present system, a method is adopted in which a plurality of data obtained at a constant interval are combined into one block of data. For example, data obtained by measuring 5 points at 1 m intervals is averaged, and the averaged colorimetric value is measured.
It is a representative point of ~ 5 m. By doing this, in the case of a long inspection object such as a sheet-like object, data is actually taken in detail and in detail, the necessary and sufficient number of data is displayed, and the data is compressed and recorded. There is also an advantage that it can be done. In addition, a rotary encoder (not shown) is used for the transport system motor to measure the length of the sheet.
It is possible to measure by attaching and counting the well-known number of pulses. Therefore, if the set length is reached,
After confirming the end of color measurement, the second output section (printer)
Immediately output the color difference variation graph displayed on the display. With such a structure, the inspection efficiency is remarkably improved.

(Embodiment 2) FIG. 7 shows an example of a detachable calibration mechanism, which comprises a calibration object and a calibration object holder. With such a structure, the reference color calibration using various reference samples can be performed more easily and the inspection efficiency can be improved. FIG. 6 is an example of a color difference variation graph output by the woolen fabric color difference inspection device having such a configuration. It is an inspection result when a woolen fabric having a length of 55 m and a width of 1.6 m is run at a cloth speed of 35 m / min. The horizontal axis represents the length (unit: m) and the vertical axis represents the color difference value ΔE, and the data measured by the three color sensors are recorded at regular intervals. The graph below is also plotted with the vertical axis representing the color difference on the lightness axis (L * axis). The above numerical values and the like are examples of conditions, color difference determination results, and the like that are output as necessary.

[0014]

As described above, according to the present invention, when a color difference inspection of a sheet-like object is performed, a plurality of CPUs controls the transport system and the input system, simultaneous color measurement of a plurality of color sensors, and data collection. By controlling the CPU and the color difference variation graph display, the color difference (color unevenness, stain, etc.) inspection result can be obtained in real time, and it can be used as an extremely efficient sheet color difference inspection apparatus. It was

[Brief description of drawings]

FIG. 1 is a General Fl showing a general inspection procedure in an online color difference inspection when a color sensor is used.
ow Chart.

FIG. 2 is a basic system configuration block diagram of the sheet-shaped material color difference inspection device according to the present invention.

FIG. 3 is a system configuration conceptual diagram.

FIG. 4 is an operation flowchart of a sheet-shaped material color difference inspection device including two CPUs as an embodiment of the present invention.

FIG. 5 is an operation flowchart of the sheet-shaped material color difference inspection apparatus including two CPUs (sequential to FIG. 4) as one embodiment of the present invention.

FIG. 6 is an output example of a color difference variation graph.

FIG. 7 is an example of a calibration mechanism diagram that is detachable.

[Explanation of symbols]

1: 1st CPU, 2: 1st display part, 3: 1st output part,
4: Transport drive motor, 5: Transport system drive control input section (switch), 6: Inspection condition input section (keyboard),
7: 2nd CPU, 8: 2nd display part, 9: 2nd output part, 1
0: color sensor, 11: white calibration plate, 12: reference sample of measurement object, 13: linear motor, 14: guide rail, 15: sheet-like object, 16: calibrator holder,
17: Calibration object

Claims (1)

[Claims] 1. A first CPU, which controls the transport unit for running a sheet-like object in a strip shape, an input unit for inputting inspection conditions, a first display unit for displaying inspection conditions, and a first output unit for outputting inspection results. A calibration mechanism unit that calibrates the color sensor with one or more calibration objects that move between the color sensor and the sheet-like object in parallel with the surface of the sheet-like object; and a first CPU connected to the color sensor A sheet-shaped material color difference inspection device, comprising a color display unit and a second output unit for outputting and displaying an inspection result, which are calibrated by a second CPU connected by a communication line.