JPH0815029A - Long object color difference inspection method - Google Patents

Abstract

PURPOSE:To simplify the work and prolong the life of a flash lamp by changing the interval of color measuring with a color sensor after an inspection length exceeds a certain distance from the head of an inspection object. CONSTITUTION:Just after the start of measurement, the power of transportation system is turned on and a fabric 11 runs. Then, whether the inspection length is over the length set in advance or not is confirmed. If it is below, the color measurement with a color sensor 9 is done at intervals P1 and if it is over, it is done at larger intervals P2. Since the dyed state at the head of a fabric 11 is instable, color measurement is done in detail, and since the other part is relatively not irregularly colored, the color measurement is done roughly. In this manner, color measuring points are recognized with the pulse from an encoder 3, color measurement is executed, and the color measurement data is collected, processed and indicated on a display part 4. By this, sufficient data collection of color measurement can be done without loss, the flash times of the flash lamp for the color sensor 9 is reduced and the life of the lamp can be prolonged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting a color difference of an object, and more particularly to a method for inspecting a color difference of a fabric or the like mainly using a color sensor.

[0002]

2. Description of the Related Art Generally, in the process of dyeing industrial products such as cloth, film and board, for example, wool fabric or cotton fabric, color unevenness occurs due to non-uniform dispersion of dye, or partial coloring due to overheating or foreign matter mixing. Or stains that are colored brown by oil or the like. Such color unevenness, stains, etc. occur locally and suddenly, and are considered to be fatal defects in the appearance of industrial products. It is the current situation. For this reason, the labor required for the inspection is large, and the following inspection methods are conventionally known in order to rationalize the labor. (1) Scans the luminous flux of the laser beam at a high speed in a direction perpendicular to the transport direction of the product (measured object), and focuses on the point where the reflectance of the abnormal part changes from that of the normal part to detect scratches, etc. I do. (2) A television camera using an image sensor scans the surface of a product, extracts and processes an image signal, and obtains a color unevenness signal. (3) A photoelectric colorimeter (color sensor) or a spectrophotometer is arranged above or below the product conveyed at a required speed, and the color of the surface of the object is continuously measured.

[0003]

However, in the above-mentioned conventional inspection method, although it is possible to achieve a purpose for the condition corresponding to the principle, it is possible to inspect the color difference of the fabric online. Not efficient enough. 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 a flaw that scatters light and to attach a foreign substance, but cannot detect a color difference. In addition, the method using an image sensor uses an image analysis device and requires data processing by software, which increases the time required for detection, increases equipment costs, and causes television cameras to have insufficient color discrimination performance. Therefore, it is not possible to perform an inspection comparable to the human eye, and it is not possible to meet the required speed of the process. Furthermore, many methods and devices have been proposed for the method using a color sensor or a spectrophotometer, but how to obtain a plurality of colorimetric data for a long object such as a woven fabric, etc. Saying has a very important meaning. Conventionally, a method has been adopted in which a plurality of color sensors are arranged at a certain fixed interval and data is collected at a fixed time or at a fixed distance. In other words, the color difference in the width direction of the inspection object is compared with each other to detect the color difference, and the medium rare inspection is performed. Further, in the length direction, the color difference (tailing) in the length direction is detected from the mutual comparison between the color value at the beginning of the inspection object and each colorimetric value. However, especially in the case of cotton fabrics, the inspection length of the fabric having the same hue may be considerably long, and it is not easy to see all the colorimetric data displayed on the same screen and printed out. Further, since the light emitting lamp of the color sensor emits light for each color measurement, there is a problem that the life of the lamp is shortened.

[0004]

In order to solve the above-mentioned problems, the present invention is a method for on-line inspection of color unevenness of a long object such as a woven fabric which is conveyed at a required speed. Conveying section for running a strip in a strip shape Keyboard for inputting inspection conditions, input section for inputting start / stop, display section for displaying inspection condition or result graph, output section for outputting results, and conveyance of these Section, an input section, a display section, an output section, and a plurality of color sensors located above or below the elongated object, and a long object surface between the color sensor and the elongated object. It is equipped with a calibration mechanism that automatically calibrates the color sensor with one or more calibration objects that move in parallel with the inspection object, and the inspection length exceeds L (m) from the beginning of the inspection object. , Change the color measurement interval of the color sensor It was done like this.

Colorimetric data is collected at a constant interval for a long object such as a woven fabric having a relatively long inspection length, but it is finely measured up to a certain distance from the beginning, and thereafter. By increasing the colorimetric interval, necessary and sufficient data can be collected, color difference data display and output graphs can be simplified, and the number of times the color sensor light-emitting lamp emits light is reduced to substantially extend the lamp life. can do. An embodiment of the present invention will be described below with reference to FIGS.

[0006]

1 is a schematic diagram of a basic system configuration of a textile color difference inspection apparatus using a plurality of color sensors proposed in the present invention. The CPU, display unit, output unit, etc. of this system are, for example, a personal computer PC-9801.
(Made by NEC). As a peripheral device connected to the CPU, there is a carrying unit (driving unit), and a linear motor for moving a calibration plate for a driving motor for driving a long object and a driving motor for focusing a color sensor on a color measurement position. It also includes mechanical devices such as motors, anti-meander, wrinkle-rolling, tension control (neither shown). A rotary encoder is installed on the transport roller or the transport motor shaft in order to control the color measurement timing of the plurality of color sensors. These are controlled by connecting an input / output interface board and an A / D conversion board to the input / output (I / O) terminals of the CPU. The input unit is a device for inputting inspection conditions, such as a keyboard, a bar code reader, a voice input device, and a start / start of a transport system.
It comprises a switch input device for instructing stop / forward / reverse. A plurality of (three in FIG. 1) color sensors are installed perpendicular to the running direction of the long object. This is because, in the case of textiles and the like, the color difference between the left and right, that is, the medium rareness is accurately detected. Color sensor for example
It is connected to the CPU and controlled by a communication line such as RS-232C. The CPU is provided with a storage device of about 100 MB so that inspection conditions, data and the like can be recorded.

FIG. 2 shows an operation flowchart of the color difference inspection apparatus according to the present invention, and the details of the function will be described. First, conditions such as the product name of the object to be measured, the inspection date, and the inspection speed are input. Then, a reference value for performing the color difference inspection, that is, a reference color value is set. By setting the reference color value, the detection of the color difference with the inspection object can be calculated. When the measurement is started, the power of the conveying system is turned on and the fabric runs. It is checked whether it is the end point of the measurement inspection length. If not finished
Check whether the inspection length L (m) set in advance is exceeded or not. If it does not exceed, color measurement of the color sensor up to that point is performed at P1 intervals, and if it is confirmed that it has exceeded, color measurement is performed at P2 intervals. More specifically, when the same hue is inspected with, for example, a cotton fabric, the length may be about 2000 m. Due to the characteristics of the dyeing equipment, the dyeing state is expected to be unstable at a certain length, the so-called rising portion, from the top of the lot. Therefore, for that part, the color is measured in detail, and after that, there is almost no color unevenness due to the stability of the equipment, so that it is possible to manage the data with a fairly rough color measurement. Therefore, from the beginning to, for example, L = 500 (m), colorimetric data is collected at fixed distance intervals of P1 = 50 m, and after exceeding 500 (m), P2 = 100 (m) or P2 = 200. It is good to consider the inspection efficiency to collect and manage the colorimetric data at a fixed distance of (m).

In either case, if it is a colorimetric point, the color is measured and data is collected, and CRT display is performed. The colorimetric point is recognized by measuring the pulse input from the rotary encoder to check the cloth running length and executing colorimetry. Further, L (m) set in this inspection is variable, and the same result is obtained even if a plurality of distances are set. FIG. 3 is a graph showing the color difference variation as a result of assuming such a case. The horizontal axis represents the length (m) and the vertical axis represents the color difference value of ΔE, and the output values from the three color sensors are plotted. When the inspection end point comes, turn off the transportation power, aggregate the measurement results,
The color difference variation graph and the result are printed out. Since the inspection length of the inspection object is originally shorter than L (m), the conventional color measurement is performed at a constant distance.

[0009]

As described above, according to the present invention, when a color difference inspection is performed on a long object, especially a fabric, when the inspection length exceeds a certain distance L (m) from the beginning, the color sensor Since the colorimetric data is collected by changing the colorimetric interval of, it is possible to obtain necessary and sufficient colorimetric data according to the length of the object to be inspected without any waste in the inspection data collection. It has become possible to use it as a color difference inspection device.

[Brief description of drawings]

FIG. 1 shows a schematic diagram of a basic system configuration of a color difference inspection apparatus according to the present invention.

FIG. 2 is an operation flowchart of an online color difference inspection device using a color sensor.

[Figure 3] Example of color difference variation graph

[Explanation of symbols]

1: Input unit, 2: Keyboard, 3: CPU, 4: Display unit, 5: Output unit, 6: Linear motor, 7: Reference cloth calibration plate, 8: White calibration plate, 9: Color sensor, 10: Guide rail , 11: textile, 12: X-axis stage, 13: rotary encoder

Claims (1)

[Claims] 1. A transport unit for running a long object in a strip shape, an input unit for inputting inspection conditions, a display unit for displaying inspection conditions and results, and an output unit for outputting the results, and a CPU for overall control of these, A plurality of color sensors connected to the CPU and positioned above or below the long object, and one or more calibration objects moving between the color sensor and the long object in parallel with the surface of the long object, In a color difference inspection method using a color difference inspection device configured to calibrate a color sensor, a color measurement of the color sensor is performed after the inspection length exceeds a certain length L (m) from the beginning of the inspection object. A long object color difference inspection method characterized by changing an interval.