JP6553581B2 - Optical connector end face inspection apparatus and acquisition method of focused image data thereof - Google Patents

Description

  The present invention relates to an end face inspection apparatus, for example, an optical connector end face inspection apparatus that inspects an end face of an optical connector.

  At the end of an optical fiber cable used for various types of communication, an optical connector for relaying or for connection to another device is provided. The optical connector is configured such that an optical fiber is inserted into the inner peripheral portion of a ferrule formed in a cylindrical shape, and a plug housing that holds the ferrule and is connected and fixed to another device or a relay adapter is mounted. .

  In this optical connector, the communication quality of the optical fiber is degraded if the end face of the ferrule (including the optical fiber) which is the connection portion is scratched or soiled. For this reason, when connecting an optical fiber cable, an end face inspection device for inspecting the state of the end face of the formed optical connector is used.

  In this end face inspection apparatus, the end face of the ferrule of the optical connector is imaged with a camera, and the captured image is enlarged and observed to find scratches and dirt.

  Non-Patent Document 1 discloses that an operator manually fine-tunes the focus of an image captured by a camera and acquires an in-focus image.

  However, in such an end face inspection apparatus, the operator has to make fine adjustments manually so that the focus is achieved, and it takes time to make fine adjustments. In addition, the operator has to perform an operation for acquiring an in-focus image while looking at an image displayed on the display unit of the end face inspection device, and it takes time to acquire an in-focus image. .

  In order to cope with such a problem, Patent Document 1 proposes to perform image processing on image data obtained by focusing on the end face of the ferrule of the optical connector by autofocus.

JP 2004-77376 A

Tamura Murakami, Tatsuyuki Maki, Daiki Fukutomi, Tomohide Yamazaki, "Development of MT9083 Access Master Fiber Visualizer and Optical Connector Edge Inspection Function", Anritsu Technical, No. 89, March 2014 http: // downloadfile. anritsu. com / RefFiles / ja-JP / About-Anritsu / R_D / Technical / 89 / 89_011. pdf

  However, such an end face inspection apparatus uses an autofocus mechanism that adjusts the focus position of the lens unit with a motor based on distance measurement information of a distance measurement sensor, for example. There was a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical connector end face inspection apparatus that can acquire focused image data of an end face of an optical connector with a simple and inexpensive configuration.

The optical connector end surface inspection apparatus of the present invention moves the focus position of the optical system by an optical system that forms an image of the end surface of the optical connector fixed at a predetermined position at the position of the image sensor and the operator's manual operation. An optical system driving mechanism, and the image sensor at a preset time interval in parallel with an operator manually operating the optical system driving mechanism to pass through a position where the end face of the optical connector is in focus once Is obtained, and it is determined whether or not the image data is in focus. When image data in focus is detected, the image data in focus is output to the image analysis unit to output the light. And a focus detection unit that determines whether the end face of the connector is good or bad.

With this configuration, image data is acquired at a preset time interval in parallel with the operator manually operating the optical system drive mechanism and passing the position where the end face of the optical connector is in focus once. It is determined whether or not the image is in focus, and when image data in focus is detected, the image data in focus is output to the image analysis unit, and the quality of the end face of the optical connector is determined. For this reason, when the optical system driving mechanism is manually operated and the focus position is moved to the vicinity of the end face of the optical connector , image data near the focus position can be acquired, and the end face of the optical connector can be obtained with a simple and inexpensive configuration. Focused image data can be acquired.

In the optical connector end face inspection apparatus of the present invention, the focus detection unit determines whether or not the image data is in focus based on a part of the image data.

  With this configuration, it is determined whether or not the image is in focus with reference to a part of the image data. For this reason, the processing load can be reduced as compared with the case where focusing is determined by referring to the entire image data.

In the optical connector end face inspection apparatus of the present invention, the focus detection unit detects a shape existing on the end face of the optical connector from the image data, and when the shape is detected, the focus detection unit focuses on the peripheral portion of the shape. It is determined whether or not.

With this configuration, the shape existing on the end face of the optical connector is detected from the image data, and when the shape is detected, it is determined whether or not the focus is achieved by referring to the peripheral portion of the shape. For this reason, it is possible to reduce the influence of noise as compared to determining the focus by referring to the entire image data, and it is possible to determine the focus only when the optical connector to be inspected exists. it can.

In the optical connector end face inspection device according to the present invention, the focus detection unit focuses the image data output from the image sensor at a preset time interval only while the optical system driving mechanism is operated. It is determined whether or not the

  With this configuration, it is determined whether or not the image data is in focus at predetermined time intervals only while the optical system drive mechanism is operated. For this reason, it is possible to limit the time for performing in-focus determination, and to reduce the processing load.

Further, the focused image data acquisition method of the optical connector end surface inspection apparatus of the present invention includes an optical system that forms an image of the end surface of the optical connector fixed at a predetermined position at the position of the image sensor, and a manual operation by the operator. the optical system drive mechanism for moving the focus position of the optical system, a focused image data acquisition method for an optical connector end face inspection apparatus wherein the operator with the manual operation of the optical system drive mechanism beam by A step of acquiring image data by the image sensor at a preset time interval in parallel with passing through the position where the end face of the connector is focused once, and determining whether the image data is in focus the method comprising the on condition that it is determined that the focus of the image data is correct, the scan by using the image data to which the focus is correct performing quality determination of the end face of the optical connector Tsu and up, and has a.

With this configuration, image data is acquired at a preset time interval in parallel with the operator manually operating the optical system drive mechanism and passing the position where the end face of the optical connector is in focus once. It is determined whether or not the image is in focus, and when image data in focus is detected, the image data in focus is output to the image analysis unit, and the quality of the end face of the optical connector is determined. For this reason, when the optical system driving mechanism is manually operated and the focus position is moved to the vicinity of the end face of the optical connector , image data near the focus position can be acquired, and the end face of the optical connector can be obtained with a simple and inexpensive configuration. Focused image data can be acquired.

The present invention can provide an optical connector end face inspection apparatus that can acquire focused image data of an end face of an optical connector with a simple and inexpensive configuration.

FIG. 1 is a schematic configuration view of an end face inspection apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a focus degree determination method of the end face inspection apparatus according to the embodiment of the present invention. FIG. 3 is a view showing a method of determining the degree of focusing of the conventional edge inspection apparatus.

Hereinafter, an optical connector end surface inspection device (hereinafter simply referred to as “end surface inspection device”) according to an embodiment of the present invention will be described in detail with reference to the drawings.

  In FIG. 1, an end surface inspection apparatus 1 according to an embodiment of the present invention includes an optical system 2, an optical system driving mechanism 3, an image sensor 4, an image capturing unit 5, an image memory 6, and a focus detection unit 7. And an image analysis unit 8 and a display unit 9.

  The end face inspection apparatus 1 according to the present embodiment uses the optical system 2 for the end face of the optical fiber 12 included in the ferrule 11 and the ferrule 11 of the optical fiber cable 10 with the optical connector held by the connector holding unit (not shown). The image is enlarged and imaged by the image sensor 4.

  The optical system 2 includes a lens 21, a half mirror 22, and an illumination LED (Light Emitting Diode) 23.

  The lens 21 is installed to face the end faces of the ferrule 11 and the optical fiber 12 of the optical fiber cable 10 held by the connector holding portion, and the optical axis thereof is substantially coaxial with the central axes of the ferrule 11 and the optical fiber 12 It is installed to be located.

  The lens 21 moves in a direction parallel to the optical axis when the optical system driving mechanism 3 is operated by an operator, so that the focus of an image formed on the image sensor 4 can be adjusted.

  The half mirror 22 is disposed behind the lens 21, and illuminates the illumination light from the illumination LED 23 to the end faces of the ferrule 11 and the optical fiber 12 through the lens 21. The illumination light applied to the end faces of the ferrule 11 and the optical fiber 12 is reflected by the end faces of the ferrule 11 and the optical fiber 12, and the reflected light is applied to the image sensor 4 through the lens 21 and the half mirror 22. The image sensor 4 converts the irradiated reflected light into image data and outputs it.

  The image capturing unit 5 acquires image data output from the image sensor 4 and stores it in the image memory 6. The image memory 6 temporarily stores image data.

  The focus detection unit 7 reads the image data from the image memory 6 and detects whether or not the image is in focus. The focus detection unit 7 transmits an image capture command to the image capture unit 5 and stores the image data in the image memory 6.

  The focus detection unit 7 causes the image capture unit 5 to store the image data in the image memory 6 at a preset time interval (for example, an interval of 33 ms), and determines whether or not each stored image data is in focus. In-focus level determination processing is performed.

  The focus detection unit 7 performs edge conversion of image data as shown in FIG. 2 by filter processing. The focus detection unit 7 detects a circle, which is an end surface shape of the optical fiber 12 to be inspected, from the image data subjected to edge conversion by processing such as pattern matching.

  When the focus detection unit 7 detects a circle that is the end face shape of the optical fiber 12 to be inspected, the focus detection unit 7 limits the detected circle to the peripheral portion of the detected circle as indicated by a frame A in FIG. As described above, the luminance difference between the original image data and the adjacent pixel is calculated, and the image data having the luminance difference exceeding the threshold value is set as the in-focus image data. In addition, 1 square of the grid in FIG. 2 represents one pixel.

  In the conventional focus degree determination process, as shown in FIG. 3, the luminance difference between adjacent pixels is calculated as indicated by the arrows in FIG. 3 in the horizontal axis direction of the acquired image data. When in focus, the change in luminance value between adjacent pixels increases. When the focus is deviated, the image is blurred, and the luminance difference between adjacent pixels is reduced. Conventionally, a luminance difference with an adjacent pixel is calculated for all the pixels of the acquired image data, and if the luminance difference exceeds a threshold value, it is determined that the in-focus state is obtained.

  In such processing, erroneous detection may occur due to the influence of ambient noise (noise) or block noise generated when a compressed image depending on the file format of image data is developed.

  If the optical fiber cable 10 is not detected in the end face inspection apparatus 1, the in-focus degree determination process is performed regardless of the fact that the optical fiber cable 10 is not inserted. End up.

  In the focusing degree determination process of the present embodiment, the determination can be performed only when the optical fiber cable 10 is reliably inserted without being affected by noise.

  When the focus detection unit 7 detects focused image data in focus, the focus detection unit 7 outputs the image data to the image analysis unit 8.

  Based on the in-focus image data detected by the focus detection unit 7, the image analysis unit 8 determines how much an element such as a scratch, dirt, or dust is included in the ferrule 11 or the optical fiber 12, and determines the quality of the end surface. .

  The display unit 9 displays an image of the end face of the ferrule 11 or the optical fiber 12 output from the image analysis unit 8, a result of the quality determination of the end face, and the like. The display unit 9 is configured by an image display device such as a liquid crystal display.

  Here, the end face inspection device 1 is configured by a computer device (not shown). The computer device includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), a hard disk drive, an input / output port, and an operation input device (hard key, touch panel, etc.). ).

  A program for causing the computer device to function as the end face inspection device 1 is stored in the ROM and the hard disk device of the computer device. That is, when the CPU executes a program stored in the ROM with the RAM as a work area, the computer device functions as the end face inspection device 1.

  As described above, in the present embodiment, the focus detection unit 7 and the image analysis unit 8 are configured by a CPU.

  In the end surface inspection apparatus 1 having such a configuration, when the end surfaces of the ferrule 11 and the optical fiber 12 of the optical fiber cable 10 are inspected, when the power of the end surface inspection apparatus 1 is turned on (inspection object is not attached) The unit 7 causes the image capturing unit 5 to store the image data in the image memory 6 at a preset time interval, and starts focusing degree determination processing for each of the stored image data. In this case, since the focus detection unit 7 cannot detect a circle that is the end face shape of the optical fiber 12 to be inspected in the image data, the focus detection unit 7 does not perform processing such as calculation of a luminance difference, while the image analysis unit 8 Is output. The image data that is sequentially captured is sent to the display unit 9 and displayed as it is, except when a determination result (to be described later) and focused image data are displayed together.

  From such a state, the optical fiber cable 10 with an optical connector is held by the connector holding portion, and the optical system drive mechanism 3 is operated by the operator. For example, the optical system drive mechanism 3 moves the end of the movable range of the lens 21 from end to end. During this time, the focus detection unit 7 detects a circle which is the end face shape of the optical fiber 12 to be inspected in the image data, and the lens 11 of the optical fiber cable 10 and the end face of the optical fiber 12 are in focus. In the vicinity of the position, a circle is detected in the image data.

  When the focus detection unit 7 detects a circle that is the end surface shape of the optical fiber 12 to be inspected in the image data and determines that the focus is in focus in the focusing degree determination process, the image analysis unit 8 receives the image data. While outputting, it transmits an image analysis instruction to the image analysis unit 8. When the image analysis command is received from the focus detection unit 7, the image analysis unit 8 determines whether the end face is acceptable or not based on the image data input by the focus detection unit 7, and causes the display unit 9 to display the focused image data together with the result. .

  As described above, since the in-focus degree determination process is performed to determine whether each image data captured at preset time intervals is in focus, the optical system drive mechanism 3 focuses on the end surface of the inspection target. It is possible to obtain image data in focus on the end face of the inspection object and obtain a pass / fail judgment result only by moving the lens 21 in the vicinity of the point at which

  In the above example, the end of the movable range of the lens 21 is moved from the end to the end, but the image data taken in by the image sensor 4 is moved with reference to the display unit 9. May be.

  In the above-described example, the focus detection unit 7 acquires the image data and performs the in-focus determination process when the power of the end face inspection apparatus 1 is turned on. However, a switch or the like for performing the in-focus determination process is provided. Only when the switch is turned on, image data acquisition, focus determination processing, and the like may be performed. Further, a sensor that detects whether or not the optical system driving mechanism 3 is operated may be provided, and image data acquisition, focus determination processing, and the like may be performed only while the optical system driving mechanism 3 is operated. .

  Moreover, in this embodiment, although the case where the ferrule 11 and the end face of the optical fiber 12 are inspected is shown, it is not limited to this, for example, it can be used when inspecting the end face of a solid member.

  While embodiments of the present invention have been disclosed, it will be apparent to one skilled in the art that modifications can be made without departing from the scope of the present invention. All such modifications and equivalents are intended to be included in the following claims.

1 End face inspection device (Optical connector end face inspection device)
Reference Signs List 2 optical system 3 optical system drive mechanism 4 image sensor 7 focus detection unit 21 lens 22 half mirror 23 LED for illumination

Claims (5)

An optical system (2) that forms an image of the end face of the optical connector fixed at a predetermined position at the position of the image sensor (4);
An optical system drive mechanism (3) for moving the focus position of the optical system by the manual operation of the operator;
The image data output from the image sensor at a preset time interval in parallel with the operator manually operating the optical system driving mechanism to pass the position where the end face of the optical connector is in focus once. Obtaining, determining whether or not the image data is in focus, and detecting the in-focus image data, outputs the in-focus image data to the image analysis unit (8) to output the end face of the optical connector An optical connector end surface inspection apparatus comprising: a focus detection unit (7) that makes a judgment on the quality of the optical system. The optical connector end surface inspection device according to claim 1, wherein the focus detection unit determines whether or not a focus is achieved based on a part of the image data. The focus detection unit detects a shape existing on an end face of the optical connector from the image data, and determines whether or not the peripheral portion of the shape is in focus when the shape is detected. The optical connector end face inspection apparatus according to claim 1. The focus detection unit determines whether or not the image data output from the image sensor is in focus at a preset time interval only while the optical system driving mechanism is operated. Item 4. The optical connector end surface inspection device according to any one of Items 3 to 4. An optical system (2) that forms an image of the end face of the optical connector fixed at a predetermined position at the position of the image sensor (4);
An optical system drive mechanism (3) for moving the focus position of the optical system by the manual operation of the operator;
A method of acquiring focused image data of an optical connector end face inspection apparatus comprising:
Image data is acquired by the image sensor at a preset time interval in parallel with the operator manually operating the optical system drive mechanism to pass the position where the end face of the optical connector is in focus once. Step and
Determining whether the image data is in focus;
Wherein on condition that it is determined that the focus of the image data is correct, if the optical connector end face inspection device and a step of performing a quality determination of the end face of the optical connector by using the image data to which the focus is correct Focused image data acquisition method.

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