JP2010145103A - Surface inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To constitute inexpensively a surface inspection device 100 by using a USB camera 3, and to solve a deficiency occurring when using the USB camera 3. <P>SOLUTION: This device is equipped with: the USB camera 3 for imaging the surface of an inspection object W; a memory part 43 for performing at any time, overwrite updation of image data outputted from the USB camera 3 by API (Application Program Interface) of a GPU (Graphic Processing Unit) 42; and an image processing part 442 for acquiring image data of the inspection object W from the memory part 43, and processing the data. When acquiring image data before and after change of the inspection object W, the image processing part 442 acquires in a plurality of times, image data from the memory part 43 after the changing time, and uses the image data as image data after the change, when acquiring image data different from image data acquired in the first place after the changing time. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a surface inspection apparatus using a USB camera connected to a USB port.

  Conventionally, as a surface inspection apparatus, for example, as shown in Patent Document 1, a light source that irradiates an inspection object with inspection light and an imaging unit that images scattered light caused by defects such as scratches on the inspection object. And a memory unit that obtains image data from the imaging unit and overwrites and updates, and an image processing unit that obtains image data from the memory unit and performs image processing. Here, the imaging unit has a trigger transmission function and uses a camera that outputs image data including imaging time information, and outputs a trigger signal for erasing image data already stored in the memory unit. After erasing the image data in the memory unit, new image data is transmitted.

  However, a camera having this trigger transmission function is expensive, and as a result, there is a problem that the entire apparatus becomes expensive.

  For this reason, it is conceivable to configure the surface inspection apparatus using a relatively inexpensive USB camera that does not have a trigger transmission function.

  However, a USB camera is connected to a computer via a connector port such as a USB port, and control for storing image data obtained by the USB camera in a memory unit is performed by using a GPU API (for example, Windows) provided separately from the CPU. (Registered Trademark) DirectX). At this time, when other devices are connected to the connector port, each image data transmitted from the USB camera is not always transmitted to the memory unit, and the image data is transmitted from the USB camera. The image data in the memory unit may not be updated every time.

On the other hand, the image processing necessary for the surface inspection acquires image data from the memory unit under the control of the CPU. At this time, whether the image data stored in the memory unit is the latest image data or the like. There is a problem that the imaging time cannot be determined from the CPU. Then, even if the CPU acquires image data at a predetermined time, there is a possibility that the image data may actually be image data before the predetermined time, and the reliability of the inspection result of the surface inspection is lost.
JP 2007-285911 A

  Accordingly, the present invention has been made to solve the above-mentioned problems all at once, and is intended to solve a problem caused when a USB camera is used while configuring a surface inspection apparatus at a low cost using a USB camera. This is the main desired issue.

  That is, the surface inspection apparatus according to the present invention is a surface inspection apparatus that images the surface of an inspection object and inspects the surface of the inspection object by an image obtained thereby, and images the surface of the inspection object. A USB camera, a memory unit in which image data output from the USB camera is overwritten and updated at any time by an application program interface (API) of a graphic processing unit (GPU), and image data of the inspection object is stored in the memory unit An image processing unit that acquires and processes image data from the memory unit a plurality of times after the change time when the image processing unit acquires image data before and after the change of the inspection object. When image data different from the image data acquired first after the change time is acquired, Characterized in that the image data after changing the data.

  In such a case, when the surface inspection apparatus is configured at low cost using a USB camera and the image processing unit acquires image data different from the image data acquired first after the change time, the image data Is used as the image data after the change, so that it is possible to solve the problem that occurs when the USB camera is used without acquiring the image data before the change time and determining that the image data is the image data after the change. it can.

  In addition, in order to change the inspection object automatically and enable continuous inspection of the inspection object, a posture change mechanism that changes the posture of the inspection object and a mechanism control unit that controls the posture change mechanism And the mechanism control unit transmits to the image processing unit a time signal indicating the time when the attitude of the image processing unit is changed, and the image processing unit recognizes the change time based on the time signal. It is desirable to be a thing.

  When the inspection object has a rotating body shape and the posture change mechanism rotates the inspection object around a central axis, it is difficult to distinguish images at first glance. Where the point becomes remarkable, according to the present invention, this problem can be preferably solved.

  As described above, according to the present invention, the surface inspection apparatus can be configured at a low cost using a USB camera, and problems caused when the USB camera is used can be solved.

  Next, the surface inspection apparatus 100 according to the present invention will be described with reference to the drawings. 1 is a schematic diagram illustrating the configuration of the surface inspection apparatus 100 according to the present embodiment, FIG. 2 is a diagram illustrating a specific arrangement of the USB camera 3 and the polarizing plate in the surface inspection apparatus 100, and FIG. 3 is a surface inspection apparatus. FIG. 4 is a diagram showing the image data transmission timing of the USB camera 3, the storage timing of the memory unit 43, and the image acquisition timing of the image processing unit 442.

<Device configuration>
The surface inspection apparatus 100 according to the present embodiment detects the presence or absence of a scratch W1 or the like on the surface of an inspection object W such as a columnar iron material having a rotating body shape. As shown in FIG. The light irradiation unit 2 that irradiates the inspection object L1 to the object W, the USB camera 3 that images the scattered light L2 generated from the inspection object W irradiated with the inspection light L1, and the posture of the inspection object W A posture changing mechanism (not shown) to be changed, and the USB camera 3 are connected via a USB port, and an information processing device (computer) 4 that controls the posture changing mechanism.

  Each part will be described below.

  The light irradiation unit 2 irradiates the inspection object W with parallel light, and is an LED 21 such as a high-intensity LED that is a light source, and a Fresnel lens 22 that converts light emitted from the LED 21 into parallel light. It has. A polarizing plate 5 is provided in front of the light emission side of the Fresnel lens 22. Moreover, the light irradiation part 2 is provided 1 each corresponding to each of several USB camera 3 mentioned later.

  The USB camera 3 is, for example, a WEB camera that images the outer peripheral upper surface of the inspection target W and outputs image data to the information processing apparatus 4 at any time, for example, at a frequency of 60 Hz, and above the inspection target W, the inspection target A plurality are provided so as to surround the object W. Specifically, as shown in FIG. 2, in order to image the outer peripheral upper surface of the inspection object W, eight are provided at equiangular intervals. That is, the USB camera 3 is provided at 45 degree intervals so as to surround the inspection object W. In addition, a polarizing plate 6 is provided in front of the USB camera 3 to capture only the scattered light L2 without imaging the reflected light L3 reflected by the inspection object W irradiated with the inspection light L1. Yes. Each v camera 3 is connected to the information processing apparatus 4 by a USB connector 41.

  The posture change mechanism changes the posture of the inspection object W by rotating the inspection object W having a rotating body shape around the central axis, and supports, for example, both end faces of the inspection object W; And an actuator such as a motor for rotating the inspection object W around the central axis by rotationally driving the support member.

  The information processing apparatus 4 acquires image data transmitted from the USB camera 3 as needed, performs surface inspection of the inspection object W using the obtained image data, and controls the posture change mechanism. As shown in FIG. 3, the specific device configuration includes a USB connector 41, an AD converter (not shown), a graphic processing unit (GPU) 42, a memory unit 43, a central processing unit (CPU) 44, and a display 45. It is a general purpose or dedicated computer equipped with the above. Then, in accordance with a predetermined program stored in a predetermined area of the main memory (not shown), the CPU 44 and peripheral devices cooperate to exert functions as the mechanism control unit 441, the image processing unit 442, and the like.

  The GPU 42 transmits image data transmitted as needed from the USB camera 3 connected to the USB connector 41 to the memory unit 43 through an application program interface (API) such as DirectX provided by Windows (registered trademark).

  The memory unit 43 is a volatile memory such as DRAM or VRAM, for example, and overwrites and stores the image data transmitted from the GPU 42 each time. A plurality of memory units 43 are provided corresponding to the respective USB cameras 3.

  The mechanism control unit 441 controls the actuator of the posture change mechanism, outputs a drive signal to the actuator, and drives the actuator (specifically, the time when the rotation of the inspection object W ends). ) Is transmitted to the image processing unit 442.

  The image processing unit 442 is for obtaining image data stored in the memory unit 43 and performing surface inspection. Specifically, the image processing unit 442 acquires image data of the surface of the inspection target W in each posture and performs image processing for performing a surface inspection of the inspection target W in each posture. More specifically, the image processing unit 442 acquires a plurality of pieces of image data in each posture, integrates the plurality of pieces of image data, increases the luminance of the scattered light L2 generated by the scratch W1, and removes noise. The image data is output to the display 45. Thereby, an image of the outer peripheral upper surface of the inspection object is displayed, and when there is a scratch W1, the scratch W1 is displayed with emphasis, and the scratch W1 on the outer peripheral upper surface can be inspected.

  Therefore, when acquiring the image data before and after the change of the inspection object W, the image processing unit 442 of the present embodiment acquires the image data from the memory unit 43 a plurality of times after the change time, and first acquires the image data after the change time. When image data different from the image data is acquired, the image data is set as image data after change.

  Specifically, as illustrated in FIG. 4, the image processing unit 442 acquires a plurality of different image data before rotation, and after receiving a time signal from the mechanism control unit 441, a plurality of different image data after rotation. Get image data. At this time, after receiving the time signal, the image processing unit 442 first acquires the image data (image data acquired at the timing (i) in FIG. 4) among the acquired image data, and thereafter When image data different from the first acquired image data is obtained by comparing with the acquired image data (image data acquired at the timing (ii) in FIG. 4), the image acquired after that is acquired. The data is the rotated image data.

<Effect of this embodiment>
According to the surface inspection apparatus 100 according to the present embodiment configured as described above, the surface inspection apparatus 100 is configured at low cost using the USB camera 3, and the image data first acquired by the image processing unit 442 after the change time is obtained. When the image data different from the image data is acquired, the image data is used as the image data after the change. Therefore, the image data before the change time is acquired, and the image data is not determined as the image data after the change. Problems caused when the camera 3 is used can be solved.

<Other modified embodiments>
The present invention is not limited to the above embodiment.

  For example, the rotation of the inspection object W in the embodiment is to rotate the inspection object W around the central axis by the posture change mechanism, but other rotation modes may be used.

  In addition, the change in the inspection object W in the above embodiment is a change in the posture of the inspection object W by the attitude change mechanism. In addition, by conveying a plurality of inspection objects W by a conveyance mechanism such as a belt conveyor. The inspection object W itself may be changed.

  Further, the number and arrangement of the USB cameras 3 are not limited to the above embodiment as long as the surface of the inspection object W can be imaged.

  Furthermore, in the above-described embodiment, the inspection object W having a rotating body shape is inspected. However, in addition, a curved surface may be inspected, and a planar surface may be inspected. May be.

  In addition, some or all of the above-described embodiments and modified embodiments may be combined as appropriate, and the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. .

The schematic diagram which shows the structure of the surface inspection apparatus which concerns on this embodiment. The figure which shows the specific arrangement | positioning of the USB camera and polarizing plate of the embodiment. The schematic diagram which shows the apparatus structure of the surface inspection apparatus of the embodiment. The figure which shows the image data transmission timing of a USB camera, the storage timing of a memory part, and the image acquisition timing of an image acquisition part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Surface inspection apparatus W ... Inspection object 3 ... USB camera 42 ... Graphic processing unit (GPU)
43: Memory unit 441: Mechanism control unit 442: Image processing unit

Claims (3)

A surface inspection device that images the surface of an inspection object and inspects the surface of the inspection object by an image obtained thereby,
A USB camera that images the surface of the inspection object;
A memory unit in which image data output from the USB camera is overwritten and updated at any time by an application program interface of the graphic processing unit;
An image processing unit that acquires and processes image data of the inspection object from the memory unit, and
When the image processing unit acquires the image data before and after the change of the inspection object, the image processing unit acquires the image data from the memory unit a plurality of times after the change time, and is different from the image data acquired first after the change time. A surface inspection apparatus that, when data is acquired, sets the image data as changed image data. A posture change mechanism for changing the posture of the inspection object;
A mechanism control unit that controls the posture change mechanism;
The mechanism control unit transmits a time signal indicating the time when the attitude of the image processing unit is changed to the image processing unit,
The surface inspection apparatus according to claim 1, wherein the image processing unit recognizes a change time from the time signal. The inspection object has a rotating body shape,
The surface inspection apparatus according to claim 2, wherein the posture changing mechanism rotates the inspection object around a central axis.