JP3634765B2 - Flat cable inspection method and inspection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flat cable inspection method and an inspection apparatus for inspecting the state of a conductor and insulating coating of a flat cable (flat flexible cable) in a nondestructive manner.
[0002]
[Prior art]
In the flat cable manufacturing process, in order to maintain its quality, the inspection device inspects the shape and positional relationship of a plurality of conductors constituting the flat cable, the state of insulation coating, and the presence or absence of impurities.
Conventionally, this type of inspection is performed using an inspection apparatus configured as shown in FIG. 3, for example.
[0003]
This inspection apparatus illuminates the flat cable 1 using a planar light source 2 made of, for example, a plurality of light-emitting diodes arranged on one side of the flat cable 1, and picks up a transmission image with the CCD camera 3. The image analysis means 4 is configured to analyze.
At this time, by displaying the captured image on the image monitor 5, the inspection can be performed visually.
[0004]
[Problems to be solved by the invention]
However, even when trying to inspect the flat cable continuously conveyed in the longitudinal direction in the flat cable manufacturing line in real time using the above-described inspection apparatus, the CCD camera 3 is, for example, 1 in 1/30 second. Since a single image is picked up, it is possible to obtain only unclear images with poor resolution in the transport direction. Therefore, image analysis is difficult, and visual inspection by the image monitor 5 is also difficult.
[0005]
In order to avoid such a problem, it is conceivable that the flat cable is stopped on the flat light source and the transmitted image is taken with a CCD camera. However, in this case, there is a problem that it takes too much time to perform the inspection over the longitudinal direction of the flat cable.
The present invention has been made to solve such problems, and in a flat cable production line, a flat cable that is continuously manufactured and moved is inspected with high accuracy in the longitudinal direction. It is an object of the present invention to provide a flat cable inspection method and inspection apparatus that can perform the above.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, in claim 1, light is emitted from a light source disposed on one side of a moving flat cable, and transmission of the flat cable obtained by the irradiated light is performed. In an inspection method in which an image is picked up by a CCD camera, and this picked-up image is analyzed to inspect the state of a flat cable conductor or insulation coating, the light source is synchronized with the CCD camera image pickup period and at the same period. A flat cable inspection method using a stroboscopic light source that emits light is provided, and in claim 3 , an inspection device that realizes the inspection method is provided.
[0007]
According to the inspection method and the inspection apparatus configured as described above, the transmission image of the moving flat cable is synchronized with the imaging cycle of the CCD camera and is instantaneously emitted at the same cycle. Since each image can be obtained as a still image regardless of movement, an inspection method and an inspection apparatus that can inspect the longitudinal direction of the flat cable with high accuracy are provided.
[0008]
According to claim 2 , if the distance of the flat cable moving within the period of the imaging cycle is the same as the distance between two predetermined points included in the viewing angle at which the CCD camera images the flat cable, the CCD The camera can inspect the longitudinal direction of the flat cable continuously without interruption.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a flat cable inspection method and inspection apparatus according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an embodiment of a flat cable inspection apparatus according to the present invention.
[0010]
Similar to the conventional apparatus shown in FIG. 3, the flat cable inspection apparatus includes a CCD camera 3, an image analysis means 4, and an image monitor 5, a strobe light source 10 as an illumination light source of the flat cable 1, and a strobe light source 10. And a strobe lighting unit 11 for driving.
The flat cable 1 is continuously manufactured by a manufacturing apparatus (not shown), is transported in the longitudinal direction thereof, and is taken up by a winder (not shown). The inspection apparatus according to this embodiment is provided on the production line of such a flat cable 1 and is provided so as to continuously move in the direction of arrow A.
[0011]
Specifically, a strobe light source 10 that is periodically driven to emit light by the strobe lighting unit 11 to illuminate the flat cable 1 is disposed on one side of the flat cable 1, and the strobe light source is sandwiched between the flat cable 1. The CCD camera 3 disposed opposite to the camera 10 captures a transmission image of the flat cable 1 by illumination light from the strobe light source 10. The periphery of the strobe light source 10 and the CCD camera 3 is shielded so that only light transmitted through the flat cable 1 is incident on the CCD camera 3 or almost no other light is incident.
[0012]
An image captured by the CCD camera 3 is input to the image analysis means 4 as an image signal and analyzed. When the CCD camera 3 is a monochrome camera, the image analysis means 4 pays attention to the luminance signal level of the image signal. When the CCD camera 3 is a color camera, the image analysis means 4 determines the luminance signal level of the image signal. In addition, paying attention to the color signal level, the state of the conductor and insulation coating of the flat cable 1 is confirmed.
[0013]
As will be described later, the strobe light source 10 emits light in synchronization with a signal that defines the imaging cycle of the CCD camera 3, and the light emission time is T seconds (hereinafter referred to as "light emission time T"). To do.
As described above, the CCD camera 3 captures one image per 1/30 second, and the captured one image is configured as an image signal of one frame, and the CCD camera 3 captures 30 images per second. Is output to the image analysis means 4 as an image signal. The CCD camera 3 generates a frame synchronization signal for constituting this frame by its internal circuit (not shown).
[0014]
As described above, the CCD camera 3 captures one image per 1/30 second, and thus performs an electronic 1/30 second shutter operation. The frame synchronization signal for constituting one frame of image signal is also a signal that defines the imaging cycle of the CCD camera 3.
The frame synchronization signal is output from the CCD camera 3 and input to the strobe lighting unit 11 via the signal line 6.
[0015]
Since the strobe lighting unit 11 emits the strobe light source 10 in synchronization with the frame synchronization signal, the light emission period of the strobe light source 10 coincides with the imaging period (1/30 second) of the CCD camera 3. The light emission time T is controlled by the strobe lighting unit 11.
The CCD camera 3 determines the imaging viewing angle θ so that the flat cable 1 that is continuously conveyed can be imaged without interruption every imaging cycle (1/30 seconds). Specifically, as shown in FIG. 2, when the moving distance of the flat cable 1 within the period of the imaging cycle is L, the CCD is configured to image the flat cable 1 over a length W (W> L). The viewing angle θ of the camera 3 is determined.
[0016]
Therefore, the CCD camera 3 can capture a transmission image in the longitudinal direction of the flat cable 1 without interruption. The strobe light source 10 emits light for 1/50000 seconds in synchronization with the frame synchronization signal.
Then, the CCD camera 3 captures an image of the flat cable 1 only for the light emission time T (1/50000 seconds) of the strobe light source 10, and this light emission time T is extremely short compared to the imaging cycle. The image captured by 3 can be regarded as an image captured as a still image for each frame. That is, although the flat cable is continuously moving, the image picked up by the CCD camera 3 has an effect that almost a good definition (resolution) as a still image can be obtained.
[0017]
If it does so, it will become possible for the image analysis means 4 to analyze a clear image, and there exists an effect that the flat cable 1 can be test | inspected with high precision.
In addition, since the imaging viewing angle θ is determined so that the flat cable 1 continuously conveyed can be imaged without interruption every imaging cycle (1/30 second), the longitudinal direction of the flat cable 1 is determined. Thus, it is possible to perform a predetermined inspection without interruption.
[0018]
The CCD camera is not limited to one that captures 30 images per second, and may be one that captures 60 images per second, for example. In this case, the shutter speed of the CCD camera is 1/60 second. The imaging device of the camera that captures the transmission image of the flat cable is not limited to a CCD as long as it can convert an image formed on the photoelectric conversion surface of the imaging device into an electrical signal.
[0019]
Note that when the imaging cycle of the CCD camera and the light emission cycle of the strobe light source are the same, a circuit that generates a frame synchronization signal of the CCD camera and a circuit that controls the light emission cycle of the strobe lighting unit that drives the strobe light source Both are driven by high-precision and high-stability separate oscillators, and even when both periods do not match completely, the light emission timing of the strobe light source can be maintained within the CCD camera imaging period. This includes cases where
In such a case, both periods can be considered substantially the same.
[0020]
【The invention's effect】
As described above, according to the flat cable inspection method and inspection apparatus of the present invention, in order to inspect the flat cable that is continuously manufactured and moved in the production line, the flat cable is moved, It is possible to obtain an image with good sharpness (resolution) as almost a still image, and a clear transmission image of a flat cable is analyzed by an image analysis means, and an inspection is performed in the longitudinal direction of the flat cable. An inspection method and an inspection apparatus are provided.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a flat cable inspection apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram showing a moving distance of a flat cable and a viewing angle of a CCD camera in the flat cable inspection apparatus of FIG.
FIG. 3 is a diagram showing an example of a configuration of a conventional flat cable inspection apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Flat cable 3 CCD camera 4 Image analysis means 5 Image monitor 10 Strobe light source 11 Strobe illumination unit

Claims (3)

Light is emitted from a light source disposed on one side of the moving flat cable, a transmission image of the flat cable obtained by the irradiation light is taken by a CCD camera, and the taken image is analyzed to analyze the flat cable. -In the inspection method to inspect the condition of the cable conductor or insulation coating,
As the light source, the synchronized with the imaging frequency of the CCD camera, and the flat cable inspection method characterized by using a strobe light source which emits light in the same period. 2. The flat cable according to claim 1, wherein the flat cable moves a distance between two predetermined points included in a viewing angle of the CCD camera during the imaging period. Inspection method. A strobe light source that emits light from one side of the moving flat cable;
A CCD camera that captures a transmission image of the flat cable obtained by light emitted from the strobe light source;
Image analysis means for analyzing an image obtained from the CCD camera,
The flat cable inspection apparatus, wherein the strobe light source emits light in the same period as that of the CCD camera.

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