JPS60209064A - Measurement of density of knitted fabric - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring the quality of woven and knitted fabrics.

Conventionally, various methods have been used to measure the density, which is one of the morphological characteristics of woven and knitted fabrics, that is, the number of yarns or stitches in the warp and weft directions per unit length of the fabric, such as woven and knitted fabrics. One method is to unravel the fabric and take out the threads one by one and measure the number of threads. Another method is to use a lens system to magnify the unit field of view and measure the density from the enlarged image. Using a transparent plate with vertical stripes carved at varying intervals, the densitometer is superimposed on the fabric surface with different orientations in the vertical and horizontal directions, and the density is calculated from the moiré fringes observed in each case. There are ways to measure it.

Among these methods, the method of loosening the woven or knitted fabric and measuring the number of threads is the most reliable method.

It takes time to produce results and is a completely destructive test that involves cutting out a portion of the fabric for measurement. Further, although the method of enlarging and measuring with a lens system is a non-destructive testing method, it is essentially the same as the method of loosening and measuring the fabric, and the work itself is detailed and complicated. On the other hand, the method using a densitometer is a nondestructive testing method similar to the method using the lens system described above, and moreover, the measurement can be performed in a much shorter time than the above two methods.

However, all of these methods involve human intervention, which not only inevitably causes various measurement errors, but also makes it impossible to measure automatically, and furthermore, the measurement results cannot be transferred in real time to other devices. Nor can it be used as a source of information for input into the .

In view of the above, the present invention provides a method for automatically and highly accurately measuring the density of woven or knitted fabrics without human intervention, and in particular, the present invention provides a method for automatically and highly accurately measuring the density of woven or knitted fabrics, and in particular, by measuring images of woven or knitted fabrics and sequential intervals. The present invention aims to provide a method in which density measurement is performed through information processing equivalent to superimposition of images of finely pitched parallel stripes arranged at different pitches.

In order to achieve such an objective, the density measurement method of the present invention includes the following steps:
By capturing an image of the woven fabric to be measured with an imaging device and converting it into an electrical signal, fabric image information containing information about the density of the woven fabric is obtained, and fine-pitch parallel images arranged at sequentially changing intervals are generated. An information processing device that has previously stored an image of stripes as stripe image information in a memory performs information processing corresponding to the superposition of the fabric image and stripe image, and information on an image corresponding to moire stripes obtained by the processing is performed. It is characterized by increasing the density of the woven or knitted fabric.

The method of the present invention will be explained in more detail below with reference to the drawings.

FIG. 1 shows the configuration of an apparatus used to implement the present invention,
1 is a woven or knitted fabric to be measured; 2 is an imaging device comprising an optical system 3 with a zooming mechanism and an imaging tube 4; 5 is an interface; 6 is an information processing device consisting of an electronic computer;
8 indicates a display device, and 8 indicates a checkered image information memory.

When measuring the density of a woven or knitted fabric, the above-mentioned apparatus uses an optical system 3 to obtain a fabric image (Fig.
A field of view and magnification are determined by a zooming mechanism, and an image is captured by an image pickup tube 4 such as a vidicon camera or a COD camera, where it is converted into fabric image information as an electrical signal. This fabric image information has information regarding the density of the woven fabric obtained from the reflection or transmission characteristics of the surface of the woven fabric, and is sent to the information processing device B via the interface 5, and is stored in the internal memory. is memorized.

In the information processing device 8, moire fringe image information for density measurement (see FIG. 2 C and E) is electronically generated in the same manner as when a moire image is obtained by a densitometer, and the moire fringe image information is Information processing is performed to obtain the density of the woven or knitted fabric from the pattern.

To explain this more specifically, the checkered image information memory 8 contains striped image information that is configured in advance in imitation of the checkered stripes in a general-purpose densitometer, that is, as shown in FIG. 2B and D, the intervals are changed sequentially. An image of parallel stripes arranged at a fine pitch is stored, and in the information processing device B, information processing corresponding to the superposition of the fabric image and the stripe image is performed, and the image obtained by the processing is ' The density can be determined from the information of the image corresponding to moiré fringes. That is, when the brightness of the surface of the woven or knitted fabric and the brightness of the striped image are superimposed, a new state of thick stripes is created depending on whether the period in the striped direction is synchronized or not. The period of the striped image corresponding to the widest part of the coarse or dense state is displayed as the density of the fabric.

The above processing is performed on the woven or knitted fabric in both the warp and width directions, thereby obtaining information on images corresponding to moiré fringes in each direction (see FIGS. 2C and E). Based on the image information, the information processing device 6 determines the density of the woven fabric 1 in both the vertical and horizontal directions,
Their densities are displayed on display M7. Naturally, when measuring the density, correction is made in accordance with the magnification of the zooming mechanism of the optical system 3.

FIG. 2 visually represents the information processing process performed in the information processing device 8. As shown in FIG. That is, A, B, C, and A in the same figure.

D and E show the processing steps for measuring the density in the warp direction and the weft direction of the woven fabric l, respectively, and the woven fabric image (A) and the striped image in the warp direction (B) are superimposed. By doing so, a moiré fringe image (C
) is obtained, and by superimposing the woven fabric image (A) and the horizontal striped image (D), a moire striped image (E) showing the density in the horizontal direction is obtained.

In the above description, a case has been described in which an electronic computer is used as the information processing device. However, instead of this, a two-dimensional image information memory that stores fabric image information, and the fabric image information and plaid image information stored in the memory 8 are used. An arithmetic device that creates a logical sum of corresponding pixels with horizontal or vertical stripe image information can be used, and image information corresponding to moiré stripes can also be obtained using these devices.

As is clear from the detailed description in Section L below, according to the present invention, density measurement of woven or knitted fabrics can be performed automatically, non-contact, at high speed, and with high accuracy without damaging the fabric. .

[Brief explanation of drawings]

FIG. 1 is a block diagram of an apparatus used to carry out the present invention, and FIG. 2 is an explanatory diagram showing an information processing process of an image of a woven or knitted fabric. l... Woven or knitted fabric, 2... Imaging device, 6... Information processing device.

Claims (1)

[Claims] By capturing an image of the woven or knitted fabric, which is the subject of JW determination, with an imaging device and converting it into an electrical signal, it becomes fabric image information with information about the density of the woven fabric. In an information processing device in which an image of stripes with parallel pitches is stored in advance in a memory as stripe image information,
A method for measuring the density of a woven or knitted fabric, characterized in that information processing corresponding to the superimposition of the fabric image and the striped image is performed, and the density of the woven or knitted fabric is calculated from the information obtained from the image corresponding to moiré stripes obtained by the processing. .