JP3384631B2 - Inspection device for winding state of sheet - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet winding state inspection device for inspecting the winding state of a separator or the like of a cylindrical battery.

[0002]

2. Description of the Related Art In a cylindrical battery, a sheet-shaped electrode and a sheet-shaped separator are combined and spirally wound in a cylindrical case. Conventionally, the inspection of the winding state of the separator has been performed by visual inspection. Therefore, there is a problem that the inspection standard varies and stable inspection cannot be performed.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sheet body winding state inspection device capable of stably inspecting the sheet body winding state.

[0004]

SUMMARY OF THE INVENTION A sheet body winding state inspection apparatus according to the present invention stores an image pickup means for picking up an end face of a spirally wound sheet body, and an end face image of the sheet body picked up by the image pickup means. Image memory, setting means for setting one or more windows extending in the radial direction of the end face image of the sheet body in the image memory, and thickness of the sheet body based on the image in the window , Calculating means for calculating one or an arbitrary combination arbitrarily selected from the intervals and the number of windings for each window, and judging means for judging whether the winding state of the sheet body is good or bad based on the calculation result of the calculating means. It is characterized by having.

[0005]

Function: An image is taken of the end surface of the spirally wound sheet body. The end surface image of the sheet body taken by the image pickup means is stored in the image memory. For the end surface image of the sheet body in the image memory, one or a plurality of windows extending in the radial direction of the end surface image of the sheet body are set. Based on the image in the window, one or an arbitrary combination arbitrarily selected from the thickness of the sheet body, the interval, and the number of turns is calculated for each window. Then, the quality of the winding state of the sheet body is determined based on the calculation result.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a separator winding state inspection device for a cylindrical battery will be described below with reference to FIGS.

FIG. 1 shows the overall structure of the inspection apparatus.

As the inspection object 10, a sheet-shaped electrode (not shown) and a sheet-shaped separator 12 are combined and spirally wound into a bottomed cylindrical case 11 of a cylindrical battery. ing. The inspection target 10 is set at a predetermined position.

The ring illumination device 20 irradiates the inspection object 10 with light from the opening side of the bottomed cylindrical case 11. The reflected light from the inspection object 10 is incident on the camera 1, and the end surface of the separator 12 is photographed by the camera 1. The camera 1 has, for example, 512 × 512 pixels and 256 pixels.
A gradation CCD camera is used.

The image signal obtained by the camera 1 is A
After being converted into digital data by the / D converter 2, it is stored in the image memory 3. The CPU 4 inspects the winding state of the separator 12 based on the image data stored in the image memory 3.

FIG. 2 shows a processing procedure by the CPU 4.

First, the image pickup device 1 picks up an image of the inspection object 10, and an end face image (inspection image) of the inspection object 10 is stored in the image memory 3 (step 1). FIG. 3 shows a captured image. As shown in FIG. 3, an open end image of the case 11 and an end face image of the spirally wound separator 12 appear in the captured image.

Next, the center position of the inspection object image is calculated based on the end face image of the inspection object 10 stored in the image memory 3 (step 2). Since the inspection target 10 is set at a predetermined position, the center position of the inspection target image is
It is located almost in the center of the image area. Therefore, the center position of the inspection target image is obtained as follows, for example.

That is, first, as shown in FIG. 4, x1 and x2 which are X coordinates at two points where the opening edge image of the case 11 and the width center line of the Y direction length of the image area S intersect, and the case The Y-coordinates y1 and y2 at two points where the opening edge image 11 and the width center line of the X direction length of the image area S intersect are obtained. Then, the center coordinate x of the inspection target image is calculated by the following equation.
Calculate 0 and y0.

[0015]

## EQU1 ## x0 = (x1 + x2) / 2 y0 = (y1 + y2) / 2

Next, a predetermined number N of strip-shaped windows 30 extending in the radial direction from the center of the inspection target image are set for the inspection target image stored in the image memory 3 (step 3). In this example, as shown in FIG. 3, 16 windows 30 are set.

Next, for each window 30, step 4
The processes of to 8 are executed. That is, in step 4, the projection operation in the width direction of the window 30 is performed. Figure 5
Shows an image in one window, and FIG. 6 shows a projection result for the image of FIG.

In step 5, edge detection processing is performed. That is, as shown in FIG. 6, the projection result obtained in step 4 is cut at a constant threshold value M to separate the image of the separator 12 from the background. In this example, the image of the separator 12 is determined to be equal to or less than the threshold value of the projection result.

In step 6, the thickness wk1 to wk7 (see FIG. 6) of each separator image detected in step 5 is calculated.

In step 7, the intervals dk1 to dk6 between the separator images detected in step 5 (see FIG. 6).
Is calculated.

In step 8, the number Nk of separator images detected in step 5 is calculated.

When the processes of steps 4 to 8 are carried out for all windows 30 (step 9), statistics are calculated (step 10). The statistics calculated here include the following.

Sum of Number Nk of Separator Images Calculated for Each Window 30 Average of Thickness wki of Separator Images Calculated for All Windows 30 Variance of Thickness wki of Separator Images Calculated for All Windows 30 All Windows Average of Separator Image Interval dki Calculated for 30 Variance of Separator Image Interval dki Calculated for All Windows 30

Next, it is judged whether or not each statistic is within a predetermined range (step 11). That is, it is determined whether or not each statistic is within the range of the following equation.

[0025]

[Formula 2] Nl ≦ total number Nk of separator images ≦ Nu W1l ≦ average separator image thickness wki ≦ W1u W2l ≦ separator image thickness wki variance ≦ W2u D1l ≦ average separator image spacing dki ≦ D1u D2l ≦ separator image interval dki variance ≦ D2u

In the above equation 2, Nl, Nu, W1
l, W1u, W2l, W2u, D1l, D1u, D2l
And D2u are predetermined values.

In step 11, all statistics are
If it is within the predetermined range shown by the above mathematical formula 2, the inspection target 10 is determined as a non-defective product (step 12). In step 11, if some of the statistic values are out of the predetermined range expressed by the above mathematical expression 2, the inspection target 10 is determined to be defective (step 13).

According to the above-mentioned embodiment, it is possible to suppress the variation of the inspection standard, and to inspect the winding state of the separator at high speed and stably.

In the above-described embodiment, the criteria for judging whether the inspection object 10 is good or bad is set with respect to the statistics of the number, thickness and spacing of the separator images calculated for all the windows 30. The determination condition may be set for each of the windows 30, the number of separator images, the thickness, and the interval.

Further, although the above description has been made on the case of inspecting the winding state of the separator of the cylindrical battery, the present invention can be applied to the case of inspecting the winding state of other sheet bodies which are spirally wound. it can. Another example of the winding state of the sheet body is shown in FIG.

[0031]

According to the present invention, it is possible to stably inspect the winding state of the sheet body.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of an inspection device.

FIG. 2 is a flowchart showing a processing procedure by a CPU.

FIG. 3 is a schematic diagram illustrating an inspection target image captured by a camera.

FIG. 4 is an explanatory diagram for explaining a method of calculating a center position of an inspection target image.

FIG. 5 is a schematic diagram showing an image in one window.

FIG. 6 is a schematic diagram showing a projection calculation result for the image of FIG.

FIG. 7 is an end view showing an example of another spirally wound sheet body.

[Explanation of symbols]

1 camera 3 image memory 4 CPU 10 inspection target

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Claims (2)

(57) [Claims] 1. An image pickup means for picking up an end face of a spirally wound sheet body, an image memory for storing an end face image of the sheet body picked up by the image pickup means, and an end face image of the sheet body in the image memory. A setting means for setting one or a plurality of windows extending in the radial direction of the end face image of the sheet body; one or arbitrary selected arbitrarily from the thickness of the sheet body, the interval and the number of windings based on the image in the window A winding state inspection device for a sheet body, comprising: a calculating unit that calculates the combination of the above items for each window; and a determining unit that determines whether the winding state of the sheet body is good or bad based on the calculation result of the calculating unit. 2. The sheet winding state inspection device according to claim 1, wherein the sheet body is a separator of a cylindrical battery.