KR100424699B1 - Automatic calibration system for line scan camera - Google Patents

Abstract

The calibration system of a line scan camera according to the present invention is a calibration system of a line scan camera, which is coupled to an illumination system that emits light to an object, and captures an object performing linear motion at a high speed. And a capture and central processor. The standard object is formed with a predetermined standard pattern. The illumination system driver adjusts the driving current of the illumination system according to the input control signal. The image capturing unit processes a series of image data from a line scan camera for a standard object and outputs image data in units of frames. The central processing unit adjusts operating conditions of the line scan camera by processing image data from the image capturing unit while controlling a driving current of the illumination system driver by executing a calibration program by a user.

Description

Automatic calibration system for line scan camera

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a calibration system of a line scan camera, and more particularly, to a line scan camera that is coupled to an illumination system that emits light to an object to image the object performing linear motion at high speed. Of the calibration system.

Since the line scan camera performs a function of capturing an object that performs a linear motion at a high speed, it is frequently used to photograph a part to be mounted in a part mounter.

1 shows the function of a typical line scan camera C included in a component mounter. Referring to FIG. 1, the nozzle N is attached to the head H of the component mounter, and the component P, for example, the integrated circuit element is sucked and mounted by the pressure change in the nozzle N. As shown in FIG. Here, the line scan camera C is located on the common path of the head H, and picks up the component P adsorbed by the nozzle N, and outputs data. That is, as the component P passes through the line scan camera C, the line scan camera C outputs image data of continuous lines. Image data from the line scan camera C is provided to a vision system included in the component mounter, in which image frames are captured. Here, in order to make the illuminance of the illumination system I coupled with the line scan camera C uniform for all imaging areas of the line scan camera C, the illumination system I includes a plurality of light sources, for example, three Light emitting diodes are arranged.

In order not to deteriorate the performance of the line scan camera C, it is necessary to periodically adjust the calibration conditions, that is, the operating conditions of the line scan camera C. More specifically, it is necessary to periodically compensate for illuminance of the illumination system I and periodically update the gain and offset of the line scan camera C with respect to the input signal.

However, in the related art, since there is no integrated calibration system, the user has to perform individual and manual calibration, and thus there is a problem that the accuracy of calibration is lowered. For example, in order that the illuminance of the illumination system I combined with the line scan camera C is uniform for all imaging areas of the line scan camera C, the luminance of each light source of the illumination system I is made uniform. Each light source was newly selected. In addition, separate hardware and software were used to select the gain and offset of the line scan camera C.

It is an object of the present invention to provide an integrated and automated calibration system capable of easily and accurately calibrating a line scan camera.

1 is a side view showing the function of a typical line scan camera included in a component mounter.

2 is a block diagram illustrating a calibration system of a line scan camera according to a first embodiment of the present invention.

3 is a block diagram illustrating a calibration system of a line scan camera according to a second embodiment of the present invention.

FIG. 4 is a side view illustrating an appearance of the calibration system of FIG. 3.

FIG. 5 is a diagram illustrating contents displayed on the monitor of FIG. 2 or 3.

<Explanation of symbols for the main parts of the drawings>

H ... mounting head, N ... nozzle,

P ... parts, I ... lighting system,

C ... line scan camera, 1,5 ... personal computer,

1a, 5a image capture section, 1b, 5b central processing element,

1c, 5c ... communication interface, 1d, 5d ... video interface,

2 monitors, 3 standard diffusers,

4 ... light meter drive, S ... rotation detector,

6, cylinder, M ... motor,

7 encoder, 8 motor drive,

P ... power supply, 2s ... monitor screen,

PR ... image profile, RE ... test result data,

IM ... Video, PB ... Auto calibration button.

A calibration system of a line scan camera of the present invention for achieving the above object is a calibration system of a line scan camera, which is coupled to an illumination system that emits light to an object, to image the object performing a linear motion at a high speed. A lighting system driver, an image capturing unit, and a central processing unit. The standard object is formed with a predetermined standard pattern. The illumination system driver adjusts a driving current of the illumination system according to an input control signal. The image capturing unit processes a series of image data from the line scan camera for the standard object, and outputs image data in units of frames. The central processing unit adjusts operating conditions of the line scan camera by processing image data from the image capturing unit while controlling a driving current of the illumination system driver by executing a calibration program by a user.

According to the calibration system of the present invention, the central processing unit processes the image data from the image capturing unit to adjust operating conditions of the line scan camera. That is, the compensation data of the illuminance of the illumination system, the gain and offset of the input signal may be adjusted by the central processor, and may be stored and applied to the line scan camera C. As described above, the integrated and automated calibration system of the present invention enables easy and accurate calibration of the line scan camera.

Hereinafter, preferred embodiments according to the present invention will be described in detail.

Referring to FIG. 2, the calibration system of the line scan camera C according to the first embodiment of the present invention is combined with an illumination system I that emits light to an object, and performs an object performing linear motion at a high speed. As a calibration system of a line scan camera C for imaging, a standard diffuser plate 3 as a standard object, an illumination system driver 4, an image capturing unit 1a, a central processing element 1b, a communication interface 1c, an image Interface 1d and monitor 2; Here, the central processing element 1b, the communication interface 1c and the image interface 1d are included in the personal computer 1, and the image capturing unit 1a is connected to the main board in the personal computer 1. It is inserted and connected to the input / output port of the central processing element 1b.

The standard diffuser plate 3 as a standard object is formed with a standard pattern consisting of three bands each having a different gradation. The illumination system drive part 4 adjusts the drive current of the illumination system I according to the input control signal from the communication interface 1c, for example, RS232C serial communication interface. The image capturing unit 1a processes a series of image data from the line scan camera C with respect to the standard diffuser plate 3, and outputs image data in units of frames. The central processing element 1b processes the image data from the image capturing unit 1a while controlling the drive current of the illumination system driver 4 by executing an integrated calibration program by the user, thereby providing a line scan camera C. Adjust the operating conditions. Here, the central processing element 1b communicates with the illumination system driver 4 and the line scan camera C via the communication interface 1c according to a predetermined communication protocol, for example, the RS232C serial communication protocol. do.

On the other hand, after setting the operating conditions of the line scan camera C, the central processing element 1b processes the image data from the image capturing unit 1a and inputs it to the image interface 1d. In addition, the central processing element 1b analyzes the image data from the image capturing unit 1a by executing the integrated calibration program by the user, thereby inspecting the inspection result data of the illumination system I and the line scan camera C. Is input to the video interface 1d. The video interface 1d interfaces the video data from the central processing element 1b to the monitor 2. Accordingly, the monitor 2 displays the image and profile of the standard diffuser plate 3 and the inspection result data of the illumination system I and the line scan camera C.

The operation of the central processing element 1b for executing the integrated calibration program by the user will be described as follows.

First, the illumination system driver 4 is controlled so that the drive current is 0 (zero) milli-amperes (mA), and then the image data from the image capture unit 1a is processed to obtain its gray scale value. The offset of the analog / digital converter (not shown) in the line scan camera C is transmitted to the line scan camera C via the communication interface 1c. The line scan camera C resets the offset to be applied to the analog / digital converter according to the data from the communication interface 1c. Accordingly, more accurate analog / digital conversion can be performed in the line scan camera C. FIG.

Next, after controlling the illumination system driver 4 to maximize the drive current, the image data from the image capture unit 1a is processed to obtain its gradation value, and the corresponding illuminance of the line illumination system I is determined. Compensation data, that is, data of a compensation ratio corresponding to each pixel, is transmitted to the line scan camera C through the communication interface 1c. Accordingly, the line scan camera C stores the data of the compensation ratio, and executes an internal compensation program during the subsequent operation, and outputs the input gray level of each pixel by multiplying the compensation ratio to output uniform illumination for all pixel areas. Can reflect.

Next, the illumination system driver 4 is processed to process the image data from the image capturing unit 1a while gradually changing the level of the driving current, thereby gaining gain for each element in the line scan camera C. And an offset value. Accordingly, the performance of the line scan camera C can be maintained continuously.

Next, the image data from the image capturing unit 1a is analyzed to input inspection result data of the illumination system I and the line scan camera C into the image interface 1d. The video interface 1d interfaces the video data from the central processing element 1b to the monitor 2. Accordingly, the monitor 2 displays the image and profile of the standard diffuser plate 3 and the inspection result data of the illumination system I and the line scan camera C.

3 shows a calibration system of a line scan camera C according to a second embodiment of the present invention. 4 shows the appearance of the calibration system of FIG. In Figs. 3 and 4, the same reference numerals as those in Fig. 2 indicate the objects of the same function. 3 and 4, the encoder 7, the motor driver 8, the motor M, the cylinder 6, and the rotation detector S are additionally installed in the embodiment of FIG. Since the elements not added are as described with reference to FIG. 2, only the elements added above will be described with reference to FIGS. 3 and 4.

To the cylinder 6, predetermined test pattern paper is attached so that the whole may be wrapped. The motor driver 8 transmits the sensing signal from the rotation sensor S to the central processing element 5b via the encoder 7 and the communication interface 5c. Accordingly, the central processing element 5b controls the operation of the motor driver 8 by communicating with the encoder 7 via the communication interface 5c. The motor driver 8 drives the motor M in accordance with the target data from the encoder 7 and the detection signal from the rotation detector S. FIG. Further, the central processing element 5b analyzes the image data from the image capturing unit 5a and checks the inspection result data of the line scan camera C, for example, the resolution of the line scan camera C. To enter.

FIG. 5 shows the contents displayed on the monitor M of FIG. 2 or 3. Referring to FIG. 5, the screen 2s of the monitor M displays a profile PR, an inspection result data RE, an image IM, and an automatic calibration button PB of an input image. By clicking the automatic calibration button PB, the user automatically adjusts the compensation data of illuminance of the illumination system (I of FIGS. 2 to 4), the gain and offset of the input signal, and automatically adjusts the line scan camera. (C) can be stored, and the profile (PR), the test result data (RE) and the image (IM) of the input image can be monitored.

As described above, according to the calibration system of the line scan camera according to the present invention, the central processing unit processes the image data from the image capturing unit to adjust operating conditions of the line scan camera. That is, the compensation data of the illuminance of the illumination system, the gain and the offset of the input signal may be adjusted by the central processing unit, and may be stored and applied to the line scan camera C. As described above, the integrated and automated calibration system of the present invention enables easy and accurate calibration of the line scan camera.

The present invention is not limited to the above embodiments, but may be modified and improved by those skilled in the art within the spirit and scope of the invention as defined in the claims.

Claims (5)

A calibration system of a line scan camera coupled with an illumination system that emits light onto an object, for imaging the object performing linear motion at high speed, A standard object formed with a predetermined standard pattern, An illumination system driver for adjusting a driving current of the illumination system according to an input control signal; An image capturing unit processing a series of image data from the line scan camera for the standard object and outputting image data in units of frames; and And a central processor configured to adjust operating conditions of the line scan camera by processing image data from the image capturing unit by controlling a driving current of the illumination system driver by executing a calibration program by a user. The method of claim 1, A calibration system for adjusting operating conditions of the line scan camera by the central processing unit communicating with the line scan camera according to a predetermined communication protocol. The method of claim 1, And a control system controlling the driving current of the illumination system driver by communicating with the illumination system driver by the central processor in accordance with a predetermined communication protocol. The method of claim 1, An image interface for interfacing the image data from the central processing unit, and A monitor for displaying image data from the image interface, And after the central processing unit adjusts operating conditions of the line scan camera, analyzes the image data from the image capturing unit, and inputs test result data of the illumination system and the line scan camera to the image interface. The method of claim 4, wherein A cylindrical object attached so that a predetermined pattern sheet surrounds the whole, and Further comprising a drive for rotating the cylindrical object, And a central processing unit rotating the cylindrical object by controlling the driving unit, analyzing image data from the image capturing unit, and inputting test result data of the line scan camera to the image interface.