JP2002304922A - Flat cable inspection method and inspection device - Google Patents

Abstract

(57) [Summary] [Problem] In a flat cable manufacturing line,
The condition of the conductors and insulation of a continuously manufactured and moving flat cable is inspected non-destructively along the length of the flat cable. SOLUTION: The flat cable obtained by irradiating light from a strobe light source which emits light instantaneously in synchronization with a signal defining an imaging cycle of a CCD camera arranged on one side of a moving flat cable manufactured and manufactured on a manufacturing line. By capturing the transmission image of the cable with a CCD camera, the transmission image of the flat cable is captured as a still image almost every frame, and the clarity of the image in the moving direction of the flat cable is improved. The flat cable is inspected with high precision without interruption in the longitudinal direction by setting the distance that moves within the imaging cycle within the viewing angle of the CCD camera.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat cable inspection method and apparatus for non-destructively inspecting the state of a conductor and an insulating coating of a flat cable (flat flexible cable).

[0002]

2. Description of the Related Art In a flat cable manufacturing process, in order to maintain the quality of the flat cable, 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 foreign substances are inspected by an inspection apparatus. You. Conventionally, this type of inspection is performed using an inspection apparatus configured as shown in FIG. 3, for example.

In this inspection apparatus, a flat cable 1 is illuminated by using a flat light source 2 composed of, for example, a plurality of light emitting diodes disposed on one side of the flat cable 1, and a transmission image of the flat cable 1 is transmitted by a CCD camera 3. It is configured to be imaged and analyzed by the image analysis means 4. At this time, by displaying the captured image on the image monitor 5, the inspection can be performed visually.

[0004]

However, using the above-described inspection apparatus, a flat cable that is conveyed continuously in the longitudinal direction in a flat cable manufacturing line is used.
Even if you try to inspect cables in real time, CCD
Since the camera 3 captures one image every 1/30 second, for example, the resolution in the transport direction is poor and only an unclear image can be obtained. For this reason, image analysis is difficult, and visual inspection using the image monitor 5 is also difficult.

In order to avoid such a problem, it is conceivable to stop the flat cable above the flat light source and capture the transmitted image 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 in order to solve such a problem. In a flat cable manufacturing line, a flat cable that is continuously manufactured and moved is inspected with high precision over its longitudinal direction. It is an object of the present invention to provide a flat cable inspection method and an inspection apparatus which can perform the inspection.

[0006]

According to the present invention, there is provided, in accordance with the present invention, a method of irradiating light from a light source disposed on one side of a moving flat cable. In an inspection method in which a transmission image of a flat cable obtained by light is captured by a CCD camera, and the captured image is analyzed to inspect the state of the conductor or insulating coating of the flat cable, the imaging cycle of the CCD camera and the light source are used as light sources. 5. A flat cable inspection method using a strobe light source that emits light at the same period is provided.
Then, an inspection apparatus that realizes this inspection method is provided.

According to the inspection method and the inspection apparatus configured as described above, the transmitted image of the moving flat cable is moved by the strobe light source that emits light instantaneously at the same cycle as the imaging cycle of the CCD camera. Nevertheless, since almost every image is obtained as a still image, the longitudinal direction of the flat cable can be inspected with high accuracy. According to the second aspect, since the strobe light source emits light in synchronization with the imaging cycle of the CCD camera, the strobe light source emits light accurately in synchronization with the imaging cycle, so that a transmission image of a flat cable can be taken in each imaging cycle. A method is provided, and in claim 5, an inspection apparatus for realizing this inspection method is provided.

According to a third aspect of the present invention, 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. Thus, the CCD camera can continuously inspect the flat cable in the longitudinal direction without interruption.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A flat cable inspection method and an inspection apparatus according to an embodiment of the present invention will be described below 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.

The flat cable inspection apparatus comprises a CCD camera 3, an image analysis means 4 and an image monitor 5, as in the conventional apparatus shown in FIG. 3, and a strobe light source 10 as an illumination light source for the flat cable 1. A strobe lighting unit 11 for driving a strobe light source 10; The flat cable 1 is continuously manufactured by a manufacturing device (not shown), conveyed in the longitudinal direction, and taken up by a winder (not shown). The inspection device according to this embodiment is provided on a production line of such a flat cable 1 and is provided so as to move continuously in the direction of arrow A.

Specifically, on one side of the flat cable 1, a strobe light source 10, which is periodically driven to emit light by a strobe lighting unit 11 and illuminates the flat cable 1, is arranged. The CCD camera 3 disposed opposite to the strobe light source 10 captures a transmission image of the flat cable 1 by the illumination light from the strobe light source 10. The strobe light source 10 and the periphery of the CCD camera 3 are shielded so that the light incident on the CCD camera 3 is only transmitted light of the flat cable 1 or almost no other light is incident.

An image picked up by the CCD camera 3 is input as an image signal to the image analysis means 4 and analyzed. CC
When the D camera 3 is a monochrome camera, the image analysis unit 4 pays attention to the luminance signal level of the image signal, and
When the D camera 3 is a color camera, the image analysis means 4 pays attention to the luminance signal level and the chrominance signal level of the image signal, and confirms the state of the conductor and the insulating coating of the flat cable 1.

As will be described later, the strobe light source 10 has a C
It is assumed that light is emitted in synchronization with a signal that defines the imaging cycle of the CD camera 3, and the emission time is T seconds (hereinafter, referred to as “emission time T”). CCD as described above
The camera 3 captures one image per 1/30 second, and the captured one image is configured as an image signal of one frame. The CCD camera 3 captures 30 images per second as an image signal. It is output to the analysis means 4. The CCD camera 3 generates a frame synchronizing signal for constituting this frame by an internal circuit (not shown).

As described above, since the CCD camera 3 captures one image every 1/30 second, it means that the electronic shutter operation is performed for 1/30 second. Further, the frame synchronization signal for forming an image signal of one frame is also a signal that defines an imaging cycle of the CCD camera 3. This frame synchronizing signal is output from the CCD camera 3 and the signal line 6
Is input to the strobe lighting unit 11 via the.

The strobe lighting unit 11 causes the strobe light source 10 to emit light in synchronization with the frame synchronization signal.
The light emission cycle of the strobe light source 10 matches the imaging cycle of the CCD camera 3 (1/30 second). The light emission time T is controlled by the strobe lighting unit 11. In addition, CCD
The camera 3 is a flat cable 1 that is transported continuously.
The imaging viewing angle θ is determined so that the image can be captured without interruption every imaging cycle (1/30 second). Specifically, as shown in FIG. 2, when the moving distance of the flat cable 1 during 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.

Therefore, the CCD camera 3 can take a transmission image in the longitudinal direction of the flat cable 1 without interruption. Then, the strobe light source 10 emits light, for example, for 1 / 50,000 second in synchronization with the frame synchronization signal. Then, the CCD camera 3 sets the light emission time T of the strobe light source 10.
(1 / 50,000 seconds), the image of the flat cable 1 is captured. Since the light emission time T is extremely short compared to the image capturing cycle, the image captured by the CCD camera 3 is a still image for each frame. Can be regarded as an image taken as. That is, although the flat cable is continuously moving, the image picked up by the CCD camera 3 has an effect that good sharpness (resolution) as a still image can be almost obtained.

Then, the image analysis means 4 can analyze a clear image, and the flat cable 1
Has an effect that the inspection can be performed with high accuracy. Further, the flat cable 1 that is continuously conveyed is connected to the imaging cycle (1
(/ 30 seconds), the imaging viewing angle θ is determined so that the imaging can be performed without interruption, so that the predetermined inspection can be performed without interruption over the longitudinal direction of the flat cable 1. Play.

Note that the CCD camera is not limited to the one that captures 30 images per second.
It may be one that captures zero images. In this case, the shutter speed of the CCD camera is 1/60 seconds. 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 converts an image formed on the photoelectric conversion surface of the imaging device into an electric signal.

The case where the imaging cycle of the CCD camera and the light emission cycle of the strobe light source are the same means that the circuit for generating the frame synchronization signal of the CCD camera and the light emission cycle of the strobe lighting unit for driving the strobe light source are controlled. The circuit is driven by separate oscillators, both of high accuracy and stability, and even if both periods are not perfectly matched,
This includes the case where the flash timing of the strobe light source can be maintained within the imaging cycle of the D camera. In such a case, both periods can be considered substantially the same.

[0020]

As described above, according to the method and apparatus for inspecting a flat cable according to the present invention, a flat cable is inspected on a production line to inspect a flat cable that is continuously manufactured and moving. It is possible to obtain an image of good sharpness (resolution) almost as a still image while moving the image, and to analyze a clear transmission image of the flat cable by the image analysis means, and to obtain the image in the longitudinal direction of the flat cable. An inspection method and an inspection apparatus capable of performing an inspection over the entirety are provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a flat cable inspection device 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 device of FIG.

FIG. 3 is a diagram showing an example of a configuration of a conventional flat cable inspection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flat cable 3 CCD camera 4 Image processing means 5 Image monitor 10 Strobe light source 11 Strobe lighting unit

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tomohiro Fuka 1000 Amako, Kora-cho, Inukami-gun, Shiga Prefecture F-term in Furukawa Automotive Parts Co., Ltd. (Reference) 2G051 AA31 AB02 BC02 CA03 CB02 CD06 DA06

Claims (5)

[Claims] 1. A light source arranged on one side of a moving flat cable irradiates light, and a transmission image of the flat cable obtained by the irradiating light is CCD.
In an inspection method of capturing an image with a camera and analyzing the captured image to inspect a state of a conductor or an insulation coating of the flat cable, a strobe light source that emits light at the same cycle as an imaging cycle of the CCD camera is used as the light source. A flat cable inspection method characterized by being used. 2. The flat cable inspection method according to claim 1, wherein the strobe light source that emits light in the same cycle as the imaging cycle emits light in synchronization with the imaging cycle. 3. 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 cycle. Inspection methods. 4. A strobe light source for emitting light from one side of a moving flat cable, a CCD camera for capturing a transmission image of the flat cable obtained by light emitted from the strobe light source, An image analyzing means for analyzing an image obtained from a CCD camera, wherein the strobe light source emits light at the same period as the imaging period of the CCD camera. 5. The flat cable inspection apparatus according to claim 4, wherein the strobe light source that emits light in the same cycle as the imaging cycle emits light in synchronization with a signal that specifies the shutter operation.