JPS63106265A - Defect display method - Google Patents

Abstract

PURPOSE:To easily remove a defect, by moving a video camera so as to position the defect, detected from a running sheet, in a field of vision and recording position information of the defect in a magnified stationary picture obtained by emitting strobe light. CONSTITUTION:If a defect is detected from a sheet 1 running along a drum 2, a position signal SD1 in the width direction is transmitted being input to a controller 6. Subsequently, a video camera 4 moves in a predetermined speed to a position where the defect can be obtained being positioned within a field of vision. A pulse signal PC, generated from rotation of the drum 2, is also input to the controller 6, and a position of the defect is obtained. If the defect is placed in the field of vision, a strobopower supply unit 7, being synchronized with the controller 6, emits strobe light 3, and a magnified stationary picture of the defect is obtained by the camera 4. The picture of the defect and its position information are stored in a memory 5 being recorded in a video deck (video recording and reproducing device) 9 and displayed in a monitor 8 till the next defect is generated. In this way, the fine defect is visually found out with no neccessity for stopping the sheet, and a defective part is easily removed.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a method for detecting and displaying defects in a running sheet, and in particular, a method for detecting and displaying defects in a running sheet, and in particular, a method for detecting and displaying defects in a running sheet, and in particular for detecting and displaying defects without stopping the running of the sheet (accurately confirming the defect position, It also provides a method for clearly displaying the details of defects.

(Prior art) Traditionally, paper factories, plastic film factories, etc.
Continuous sheets produced using paper machines, stretching machines, etc. are wound up or made into flat sheets using a sliver or cutter as needed.

These sheets are strictly controlled to prevent foreign matter from entering or adhering to them during the manufacturing process, but the number of occurrences cannot be reduced to zero.For example, there may be large dust or oil stains on some parts of the sheet. If there is a defect, ink may run out during printing at a printing factory or the plate cylinder may be stained. Furthermore, when sheets are used for food packaging, defects caused by insects adhering to them are not only unsanitary, but also seriously degrade the product image, so even a single insect cannot be tolerated. Therefore, it is necessary to prevent insects from getting into the sheets, and at the same time, to reliably remove sheets with defects caused by insects.

Conventionally, a method has been adopted in which a transmission type or reflection type defect detection device is provided in the sheet manufacturing process to mark defective portions of the sheet and remove them in a subsequent process. These defect detection devices all utilize the phenomenon of fluctuations in the amount of light based on the defects present in the sheet, and they determine the presence and size of defects, and detect the defects so that the size exceeds a certain standard. In such cases, the sheet is marked as a major defect, while small defects that do not meet the standards are used as products without any marking.

However, although defects caused by insect adhesion are equivalent to major defects in food sheets, the defects are so small that they may be overlooked as minor defects.

Since it is difficult to distinguish between defects caused by insect adhesion and other minor defects without stopping the sheet while it is running, it is necessary to increase the defect detection sensitivity for food-grade sheets so as not to overlook defects caused by insect adhesion. This method is used to mark even small defects and remove them in later processes.

However, in order to eliminate defects associated with the attachment of small insects,
It is economically very disadvantageous to remove many minor defects that do not need to be removed.

As a result of intensive research into the detection of defects caused by insects, the applicant calculated the electrical signal level value obtained as a reflection type light intensity change and the electrical signal level value obtained as a transmission type light intensity change for the same defect. It was discovered that defects caused by insects can be distinguished from other defects by this method, and the patent was previously filed as Japanese Patent Application Laid-Open No. 175552/1983. According to this method, it is possible to distinguish between defects caused by insects and other defects even for small defects, but it is difficult to distinguish between defects such as oil adhesion or stains and defects caused by insects, and it is even more difficult to distinguish between defects caused by insects. It is desired to develop a method for determining defects.

(Problems to be Solved by the Invention) The present invention provides a method for easily confirming and determining detected defects without stopping the running of the sheet, and in particular for efficiently identifying and removing specific defects caused by insects, etc. It provides:

(Means for Solving the Problem) The present invention detects defects in a running sheet, sets the viewing position of a video camera in the width direction according to a position signal of the defect in the width direction, and detects defects in the video camera's field of view. Defect position information, such as the position of the defect in the width direction and the travel distance from the top of the sheet, is also recorded and played back in an enlarged still image taken by firing a strobe in synchronization so that the defect is located within the width direction. This is a characteristic defect display method.

(Function) In the method of the present invention, first, a transmissive or reflective defect detection device in which detection elements are arranged in the width direction detects where a defect has occurred in the running sheet in the width direction.
Next, the field of view position of the video camera in the width direction is set according to the device signal constituted by the detection device. 1 corresponding to the relevant position from among the plurality of fixed video cameras arranged continuously in
This can be done by a method such as selecting an item.

In that case, 1 in the width direction according to the position signal of the defect in the width direction.
The method of moving a plurality of video cameras arranged for photographing allows the use of relatively high-resolution video cameras, and is also economically advantageous.

The field of view position of the video camera in the width direction is set, and it is installed near the shooting point in time for the defect to pass through the shooting point, which is calculated based on the generated position signal, sheet running speed, and distance between the detection point and the shooting point. The strobe flash fires and an enlarged still image of the defect is taken. Further, the position of the defect in the machine direction, that is, the distance from the top of the sheet, the position in the width direction, etc., are recorded as defect position information in accordance with the enlarged still image of the defect. Then, by displaying an enlarged still image of the defect on a display, it is determined whether the defect is a defect that should be removed. If it is determined that the defect is a defect that should be removed, the , the next step will remove exactly that part.

Thus, according to the method of the present invention, it is possible to accurately identify defects that cannot be identified using conventional methods and that require visual inspection without stopping the sheet from running.
Furthermore, the defects can be reliably removed in the next process.

The method of the invention will be explained in more detail with reference to FIGS. 1 and 2, although the invention is of course not limited to these embodiments.

FIG. 1 is a block diagram showing an embodiment of the display method of the present invention.

When a defect occurs in the traveling sheet 1, a defect detection device having detection elements arranged in the width direction detects it and transmits a width direction position signal SD. Corresponding to this position signal SDI, the video camera 4 installed in the next process
A position signal SD in the width direction generated by moving at a speed of about s and stopping at a point where defects can be photographed, and a pulse signal P generated from the rotation of the drum 2 proportional to the traveling speed of the sheet.
G is input to the controller 6, and the strobe power supply unit 7 is controlled in synchronization with the controller 6 so that the strobe 3 emits light when the defect enters the field of view, and the defect is magnified and stopped at the field of view position of the video camera 4. Take an image.

The video camera 4 can use a two-dimensional CCD, a shooting tube, etc. The enlarged still image taken is recorded in the image memory 5 as a video signal, and at the same time the video deck 9 enlarges it for about 2 seconds to allow visual judgment. Record still images on magnetic tape. Furthermore, the contents of the memory 5 can be visually observed on the monitor 8 until the next defect occurs and is input to the memory 5.

At the same time, the enlarged still images of these defects show the distance that the sheet traveled until the defect occurred using the controller 6.
D and the pulse signal PC, and is recorded and displayed as defect position information together with the position signal SD, etc.

In addition, the video cameras used to photograph defects in the method of the present invention are installed in multiple units to shorten the moving time of the cameras.
Although the responsiveness can be improved, the number of installed units is appropriately determined depending on the distance between the defect detection position and the photographing position, the sheet speed, etc.

Further, it is desirable that the defect detection device has a function of determining defects that should be removed as much as possible. For example, when removing defects caused by insects,
It is recommended to install a device that determines the defect by calculating the electric signal level value obtained as a reflection type light amount change and the transmission type light amount change value for the same defect as described in No. 2. Effective. That is, defects are classified in advance into defects caused by general dust, etc. and defects caused by insect groups consisting of insects, oil stains, and stains, and the defects are limited to defects in the insect group, and then the defect display method of the present invention is used. Then, the image recording memory can be used effectively and the discrimination work can be reduced.

By the way, in the display method of the present invention, for example, when the strobe 3 emits light 30 times/second for 10 μs, the amount of sheet movement during the photographing period at a sheet running speed of 100 to 1000 m/min is 0.0167 to 0.00 m/min. 167m, and if the video camera is looking at an area of 30x45m, then 45W
Since M is divided into 256 pixels, the image resolution is approximately 0.
．． 176m, V/ (60X30)m (with running seat)
It is possible to photograph and record defects that occur at intervals greater than V (sheet running speed m/min).

FIG. 2 is a partial block diagram showing a method for further improving the response speed, for example, making it possible to respond even when a large number of defective signals are input. In such a system, a plurality of video cameras and strobes are installed.

That is, the defect position signal 5DI-3 in the width direction detected by the defect detection device segmented in the width direction of the sheet.
When D is input, the video camera 4 that corresponds to the defect position among the plurality of video cameras C2 to C, each of which can move within a specific range moves to a predetermined position, and the width input to the controller 6 is moved. Based on the defect position signal in the direction and the pulse signal PG proportional to the sheet running speed, a predetermined strobe is emitted in synchronization with the defect position passing through the viewing position of each video camera to capture an enlarged still image. . The images taken at this time are captured by a method such as constantly scanning a video camera selection signal, or by selecting a video camera according to the position when a defect position signal is generated, and are sequentially transferred to multiple memories. It is also sent to the video deck.

(Effects) According to the method of the present invention, defects that cannot be detected by optical means and cannot be confirmed or determined without human visual inspection can be confirmed and determined without stopping the running of the sheet. Therefore, defects can be removed easily and efficiently in the next process.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the display method of the present invention. FIG. 2 is a partial block diagram showing a method for further improving the response speed and making it possible to respond even when a large number of defective signals are input. (1)...Seat (2)...Drum (3)...Strobe (4)...Video camera (5)...
・Memory (6)...Controller (
7)...Strobe power supply (8)...Monitor (
9)...Video deck 0Φ...Pulse generator PC...Pulse signal 5DI-5D proportional to running speed
, ...Position signals CI to C7 of defects in the sheet width direction...
·Video camera

Claims (2)

[Claims] (1) Detect defects in the running sheet, set the field of view position of the video camera in the width direction according to the position signal of the defect in the width direction, and synchronize so that the defect is located within the field of view of the video camera. A defect display method characterized by recording and reproducing defect position information such as the position of the defect in the width direction and the traveling distance from the top of the sheet in an enlarged still image taken by emitting a strobe light. (2) Defect display according to claim (1), characterized in that the viewing position of the video camera in the width direction is set by moving the video camera according to the position signal of the defect in the width direction. Method.