JP2006217374A - Imaging timing adjustment method and device in image processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging timing adjustment method and device in an image processing apparatus, wherein an imaging timing is adjusted automatically accurately, according to the change of a product carrying speed, using a simple configuration. <P>SOLUTION: Since a pulse period or a pulse width detected from the output pulse of a synchronous sensor 1 is varied, according to the change of a carrying speed of a carrying mechanism, an image is photographed at an imaging timing, delayed by an imaging delay time, obtained on the basis of the detection result. Thus the imaging timing is delayed so as to prevent the occurrence of the deviation of imaging position, regardless of the change in the carrying speed of a product P, whereby the imaging timing can be adjusted automatically accuratetly accordance with the change in the carrying speed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image processing apparatus that performs image processing on a captured product and determines the quality of the product, and more particularly to a method and apparatus for automatically adjusting imaging timing.

  As shown in FIG. 1, as an image processing apparatus, image data of products P captured by the imaging camera 2 while a large number of products P are sequentially transported at predetermined intervals by a transport mechanism 4 such as a transport conveyor. A device that performs image processing in the processing unit 3 and determines the quality of the product P is known. Usually, since a predetermined time (for example, several tens of milliseconds) is required for image processing of the imaged product P, in order to give the imaging timing to the imaging camera 2, the mark M attached to each predetermined position of each product P (FIG. 3). ) And a synchronous sensor 1 such as a photoelectric sensor that outputs a pulse signal is used.

  By the way, when the type of the product to be determined is changed, the image pickup position of the product is different for each type, and therefore it is necessary to move one of the synchronization sensor 1 and the image pickup camera 2 in accordance with the shift of the image pickup position. However, when there is a restriction in the mounting position of the synchronization sensor 1 or the imaging camera 2 or when it is troublesome to move the position each time, as shown in FIG. 4, imaging is performed from the rising edge of the output pulse of the synchronization sensor 1. It is necessary to provide a delay time for delaying the imaging timing by the position shift. Further, as shown in FIG. 3, it is necessary to provide a delay time for delaying the imaging timing even when the position of the mark M attached to the product P and the imaging position do not originally match. However, when the transport speed changes due to the rattling of the transport conveyor 4 itself or the vibration when the product P is placed on the transport conveyor 4, the delay time changes inversely with the transport speed. If it changes, the imaging position will shift.

  On the other hand, conventionally, a method is known in which the resolution and the imaging range of the image processing apparatus are expanded so that the imaging position can be accommodated due to a change in the conveyance speed. However, there is a problem that the apparatus is increased in size and cost.

On the other hand, it is also known to take an image a plurality of times after the synchronous sensor is activated and to calculate an average value by statistically processing these imaged data with respect to a product shift due to a change in conveyance speed (for example, Patent Document 1). By statistically processing the imaged data and averaging it, the problem of variation in measured values can be solved.
JP 2004-145504 A

  However, since Patent Document 1 performs statistical processing after performing image processing that requires a predetermined time a plurality of times, the processing takes time. Not enough to adjust. Also, the processing circuit has a complicated configuration.

  The present invention solves the above-described problems, and provides an imaging timing adjustment method and apparatus in an image processing apparatus capable of automatically adjusting imaging timing with a simple configuration and accurately responding to changes in conveyance speed. The purpose is that.

  In order to achieve the above object, an imaging timing adjustment method and apparatus in an image processing apparatus according to the present invention are provided at a predetermined position of a transport mechanism that transports a plurality of products at predetermined intervals, and each product to be transported. A synchronous sensor that sequentially detects marks and outputs a continuous pulse signal, an imaging camera that images the product at the imaging timing determined by the output pulse of the synchronous sensor, and image processing of the imaging data of the captured product In an image processing apparatus comprising an image processing unit for determining whether the image is good or bad, an imaging timing obtained by obtaining an imaging delay time based on a pulse period or a pulse width detected from an output pulse of the synchronous sensor and delaying by the imaging delay time The imaging timing is controlled so as to image the product.

  According to this configuration, since the pulse period or pulse width detected from the output pulse of the synchronous sensor changes in accordance with the change in the conveyance speed of the conveyance mechanism, the imaging is delayed by the imaging delay time obtained based on this. Since imaging is performed at the timing, the imaging timing is delayed so as not to cause a shift in the imaging position even if the product conveyance speed changes. Therefore, the imaging timing is automatically adjusted in response to the change in the conveyance speed. Can be adjusted.

  Preferably, a delay time coefficient for calculating an imaging delay time provided for the pulse period or pulse width of the output pulse of the synchronous sensor is stored in advance, and the pulse period or pulse width of the output pulse of the synchronous sensor is stored. The imaging delay time is calculated based on the detected pulse period or pulse width of the output pulse of the synchronous sensor and the delay time coefficient, and the imaging timing delayed by the calculated imaging delay time is calculated. The imaging timing is controlled by outputting to the camera and imaging the product at the imaging timing. Therefore, the imaging timing can be automatically adjusted with a simple configuration in response to a change in the conveyance speed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 2 is a block diagram showing an imaging timing adjustment apparatus in the image processing apparatus according to an embodiment of the present invention. The image processing apparatus sequentially detects a transport mechanism 4 (for example, the transport conveyor in FIG. 1) that transports a plurality of products P at predetermined intervals, and a mark M attached to each predetermined position of the plurality of products P to be transported. A synchronous sensor 1 that outputs a continuous pulse signal, an input circuit 11 that receives an output pulse of the synchronous sensor 1, an imaging camera 2 that images the product P at an imaging timing determined by the output pulse of the synchronous sensor 1, and The image processing section 3 for determining the quality of the product P by performing image processing on the captured image data of the product P and the imaging timing control means 10 are provided. The positions of the synchronization sensor 1 and the imaging camera 2 are fixed. For example, a photoelectric sensor is used as the synchronization sensor 1.

  As shown in FIG. 3, the product P is, for example, a packaging bag for packaging food, and is produced in a state where a large number of individual bags are continuously formed, and is cut off at a perforation when used. On this product P, marks M are printed in advance at predetermined intervals and positions for each bag, and the synchronization sensor 1 sequentially detects the marks M and outputs a continuous pulse signal. A perforation is formed at a position that coincides with the mark M, and a character such as “best before date 2005.6” is printed at a position shifted from the position of the mark M, and the position of this character becomes the imaging position.

  In this apparatus, since the pulse period or pulse width detected from the output pulse of the synchronous sensor 1 changes according to the change in the conveyance speed of the conveyer 4, this pulse period or pulse width is used for the calculation of the imaging delay time. Thus, even if the transport speed of the transport conveyor 4 changes, the image capturing timing is adjusted so that the image capturing position does not deviate, and the printed characters are accurately imaged to determine the quality of the product. .

  The imaging timing control means 10 in FIG. 2 obtains an imaging delay time from the pulse period or pulse width detected from the output pulse of the synchronous sensor 1, and images the product P at the imaging timing delayed by this imaging delay time. Thus, the imaging timing is controlled, and includes a delay time coefficient storage means 5, a signal detection means 6, a delay time calculation means 7, and an imaging timing output means 8.

  The delay time coefficient storage means (set value storage memory) 5 stores in advance a delay time coefficient for calculating an imaging delay time provided for the pulse period or pulse width of the output pulse of the synchronous sensor 1. The set value storage memory 5 also stores input logic coefficients, which will be described later.

  The signal detection means 6 detects the pulse period or pulse width of the output pulse of the synchronous sensor 1. The signal detection means 6 is, for example, a counter. When detecting the pulse period, the signal detection means 6 counts the time from the rising edge of the pulse of the synchronous sensor 1 to the rising edge of the next pulse, and when detecting the pulse width, The pulse width is counted as a time width.

The delay time calculation means 7 calculates the imaging delay time based on the pulse period or pulse width of the output pulse of the synchronous sensor 1 detected by the signal detection means 6 and the delay time coefficient stored in the set value storage memory 5. To do.
As shown in FIG. 3, when detecting the pulse period, the imaging delay time B is set to A as the pulse period and K1 as the delay time coefficient.
B = K1 × A
It is calculated by the operation of That is, the imaging delay time B is set to a value proportional to the pulse period A.
In addition, when detecting the pulse width, the imaging delay time B is set to C and the delay time coefficient is K2.
B = K2 × C
It is obtained by the operation of That is, the imaging delay time B is set to a value proportional to the pulse width C.

  The imaging timing output means 8 in FIG. 2 outputs the imaging timing delayed by the imaging delay time calculated by the delay time calculating means 7 to the imaging camera 2, and the product P at the imaging timing delayed by the imaging delay time. To image. The imaging timing output means 8 is, for example, a counter. When the calculated imaging delay time is counted and reached, the imaging timing obtained by delaying the time from the rising edge of the output pulse of the synchronous sensor 1 is captured by the imaging camera. 2 and image the product P at this timing.

  When the transport speed of the transport conveyor 4 does not change and is constant, the pulse period or pulse width of the output pulse of the synchronous sensor 1 matches the set value based on the transport speed, so the imaging delay time is a constant value. The imaging timing output means 8 outputs a fixed imaging timing.

  The apparatus further includes an input logic switching circuit 12. The input logic switching circuit 12 switches the input logic of the output pulse of the synchronous sensor 1 input via the input circuit 11 based on the input logic coefficient stored in the set value storage memory 5. In the reflective and transmissive photoelectric sensors, the on / off state of the pulse is contradictory, so by switching the logic of the output pulse that is input according to the type of the type, it is possible to switch any type of photoelectric sensor. Can be handled automatically.

  An example of the imaging timing adjustment operation in the apparatus having the above configuration will be described with reference to FIGS. In this example, the pulse period of the output pulse of the synchronous sensor 1 is used for calculating the imaging delay time.

  In the set value storage memory 5 of FIG. 2, a delay time coefficient K1 for calculating the imaging delay time B provided for the pulse period A of the output pulse of the synchronous sensor 1 is stored in advance.

  First, the signal detection means 6 detects the pulse period A (FIG. 3) in the output pulse of the synchronous sensor 1 that changes in accordance with the change in the conveyance speed of the conveyor 4 detected by the synchronization sensor 1. Next, the delay time calculation means 7 calculates the imaging delay time B (FIG. 3) by B = K1 × A based on the pulse period A of the detected pulse signal and the delay time coefficient K1.

  Then, the imaging timing output means 8 outputs the imaging timing delayed by the calculated imaging delay time B to the imaging camera 2. When imaging of the product P is started by the imaging camera 2 at the imaging timing delayed by the imaging delay time B, the image processing unit 3 performs image processing on the imaging data of the captured product P, and the quality of the product P is determined. Determined.

  As described above, according to the present invention, the pulse period or pulse width detected from the output pulse of the synchronous sensor 1 changes in accordance with the change in the transport speed of the transport conveyor 4, so that the imaging obtained based on this changes. Since imaging is performed at the imaging timing delayed by the delay time, the imaging timing is delayed so that the imaging position does not deviate even if the conveyance speed of the conveyor 4 changes. Thus, the imaging timing can be automatically adjusted.

  In the above embodiment, the input logic switching circuit 12 for switching the input logic is provided, but this may be omitted.

It is a block diagram of the image processing apparatus provided with the conveyance conveyor, the synchronous sensor, the imaging camera, and the image process part. It is a block diagram which shows the imaging timing adjustment apparatus in the image processing apparatus which concerns on one Embodiment of this invention. It is a chart figure which shows the operation | movement which calculates delay time. It is a chart figure which shows the relationship between the output pulse of a synchronous sensor, and delay time.

Explanation of symbols

1: Synchronous sensor 2: Imaging camera 3: Image processing unit 4: Conveying mechanism (conveying conveyor)
5: Delay time coefficient storage means (setting value storage memory)
6: Signal detection means 7: Delay time calculation means 8: Imaging timing output means 10: Imaging timing control means M: Mark P: Product

Claims (4)

Determined by a transport mechanism that transports a plurality of products at predetermined intervals, a synchronization sensor that sequentially detects marks attached to each of the transported products and outputs a continuous pulse signal, and an output pulse of the synchronization sensor An image processing apparatus including an imaging camera that captures a product at a captured imaging timing, and an image processing unit that performs image processing on imaging data of the captured product and determines whether the product is good or bad,
An imaging delay time is obtained from a pulse period or a pulse width detected from an output pulse of the synchronous sensor, and the imaging timing is controlled so that the product is imaged at an imaging timing delayed by the imaging delay time. The imaging timing adjustment method in an image processing apparatus. In claim 1,
A delay time coefficient for calculating an imaging delay time provided in advance for the pulse period or pulse width of the output pulse of the synchronous sensor;
Detecting the pulse period or pulse width of the output pulse of the synchronous sensor;
Calculate the imaging delay time based on the detected pulse period or pulse width of the output pulse of the synchronous sensor and the delay time coefficient,
An imaging timing adjustment method in an image processing apparatus, which controls imaging timing by outputting imaging timing delayed by the calculated imaging delay time to the imaging camera and imaging a product at the imaging timing. Determined by a transport mechanism that transports a plurality of products at predetermined intervals, a synchronization sensor that sequentially detects marks attached to each of the transported products and outputs a continuous pulse signal, and an output pulse of the synchronization sensor An image processing apparatus including an imaging camera that captures a product at a captured imaging timing, and an image processing unit that performs image processing on imaging data of the captured product and determines whether the product is good or bad,
An imaging timing control means for obtaining an imaging delay time based on a pulse period or a pulse width detected from the output pulse of the synchronous sensor and controlling the imaging timing so that the product is imaged at an imaging timing delayed by the imaging delay time. An imaging timing adjustment apparatus in an image processing apparatus, comprising: In claim 3,
The imaging timing control means includes
A delay time coefficient storage means for storing in advance a delay time coefficient for calculating an imaging delay time provided for a pulse period or a pulse width of an output pulse of the synchronous sensor;
Signal detection means for detecting a pulse period or a pulse width of the output pulse of the synchronous sensor;
A delay time calculating means for calculating an imaging delay time based on the detected pulse period or pulse width of the output pulse of the synchronous sensor and the delay time coefficient;
Imaging timing output means for outputting an imaging timing obtained by delaying the calculated imaging delay time to the imaging camera and imaging a product at the imaging timing;
An imaging timing adjustment apparatus in an image processing apparatus comprising:

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