KR20180038857A - Visual inspection apparatus and method of optical calibration of the same - Google Patents

Abstract

According to one embodiment of the present invention, provided is an appearance inspection apparatus, which comprises: a lighting apparatus which illuminates a product to be inspected; a camera apparatus which captures the product to be inspected in order to provide an image signal; and an optical system control apparatus which obtains images from the image signal of the camera apparatus, and sets a white balance ratio value of each of colors to enable a measurement brightness value of each of the colors measured from the images to be converged on a target brightness value while controlling the white balance ratio value of each of the colors. When the measurement brightness value of a color is not converged on the target brightness value, the optical system control apparatus controls a white balance ratio value of the color to enable the measurement brightness value of the color to re-converge on the target brightness value after rebalancing a camera gain.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a visual inspection apparatus and an automatic calibration method for the optical system,

The present invention relates to an appearance inspection apparatus that can be applied to a vision measurement and inspection system and a method of automatically calibrating the optical system.

Typically, the vision measurement and inspection system is a facility for measuring or inspecting a target product using a vision optical system. For example, the product to be examined may be a variety of electronic components such as a passive device, an image sensor module (ISM), and a substrate.

Such a vision measurement and inspection system may include a plurality of visual inspection devices for inspecting a plurality of products and inspection surfaces of each product. The plurality of visual inspection apparatuses can acquire images using the illumination and the camera set as passive elements, and can judge appearance defects on the products based on the obtained images. Here, if the product to be inspected is used in a state in which a defect occurs, it may cause a fatal loss. Therefore, a visual inspection process is required as one of production processes of the product to be inspected.

Here, as a product to be inspected, a passive element may be a device that consumes, accumulates, and emits power supplied from the outside. For example, passive devices include MLCC (Multi Layer Ceramic Capacitor), BLCC (Boundary Layer Ceramic Capacitor), VLC (Vertically Laminated Capacitor) and EMC (Electro Magnetic Compatibility).

However, in a plurality of visual inspection apparatuses, the reflectance may be greatly different for each product, and the image quality may vary greatly depending on the setting of the vision optical system, and the measurement and inspection performance depend on the image quality.

In order to perform efficient inspection using a plurality of visual inspection devices, it is necessary to acquire a uniform quality image for each product. For this purpose, it is necessary to appropriately adjust and set the optical system to suit the product before measurement and inspection .

Conventionally, the method of adjusting the optical system is a method in which the operator manually adjusts manually depending on the worker experience value in the field.

Such a manual adjustment may cause a deviation for each operator, which reduces the accuracy of the inspection, thereby deteriorating the inspection reliability.

Further, it takes a lot of time to manually adjust the optical system for each of the plurality of visual inspection devices individually.

In particular, when there are many kinds of products to be inspected, since the reflectance differs according to product types, models, and capacities in the conventional adjustment method, even though the light amount of illumination is maximized, Or the measurement value may not converge to the target value even if the light amount of the illumination is minimized. In this case, in the conventional method, the adjustment of the camera is regarded as a failure and the manual adjustment is again required. Therefore, there is a problem that the product is often manually adjusted again.

On the other hand, in the conventional vision measurement and inspection system, a correction method of an optical system has been proposed. However, if a white balance ratio value does not converge to a target value primarily by color, an appropriate alternative is not proposed.

Japanese Patent Application Laid-Open No. 2001-249084

An embodiment of the present invention can automatically perform calibration for an optical system in an apparatus for visual inspection of a vision measurement and inspection system, and when the measured brightness value for each color does not converge to a target brightness value, A visual inspection apparatus and an optical system automatic calibration method for re-balancing the measured luminance value by color to converge to a target luminance value are provided.

According to an embodiment of the present invention, there is provided an illumination device for illuminating a product to be inspected; A camera device for photographing the inspection target product and providing a video signal; And adjusting a white balance ratio value of each color in which a measured luminance value of each color obtained from the image converges on a target luminance value while adjusting an image white balance ratio value of each color, An optical system control device for setting; Wherein the optical system controller balances the camera gain when the measured luminance value of the corresponding color does not converge to the target luminance value and then rebalances the measured value of the corresponding color to the target luminance value, An appearance inspection apparatus for adjusting the ratio value is proposed.

In the solution of this task, one of several concepts described in the following detailed description is provided. The subject matter of the present invention is not intended to identify the core or essential technology of the claimed subject matter, but merely one of the claimed subject matter is described, each of which is specifically set forth in the following detailed description.

According to the embodiment of the present invention, in the apparatus for visual inspection of the vision measurement and inspection system, the calibration for the optical system can be automatically performed so as to be suitable for the product, so that the time required for the calibration can be shortened, It is possible to resolve the disadvantage and, when the measured value by color does not converge to the target value, the measured value for each color can be converged to the target value through rebalancing for the correlation factor of the optical system.

1 is a block diagram of a visual inspection apparatus according to an embodiment of the present invention.
2 is an example of an optical system control apparatus according to an embodiment of the present invention.
3 is a flow chart illustrating an example of an optical system automatic calibration method of the visual inspection apparatus according to an embodiment of the present invention.
4 is a flow chart showing another example of an optical system automatic calibration method of the visual inspection apparatus according to an embodiment of the present invention.
5 is a flowchart illustrating an example of a camera gain adjustment step according to an embodiment of the present invention.
6 is a flowchart illustrating an example of an illumination value adjustment step according to an exemplary embodiment of the present invention.
7 is a conceptual diagram of convergence in an illumination value adjustment step according to an embodiment of the present invention.

It should be understood that the present invention is not limited to the embodiments described and that various changes may be made without departing from the spirit and scope of the present invention.

In addition, in each embodiment of the present invention, the structure, shape, and numerical values described as an example are merely examples for helping understanding of the technical matters of the present invention, so that the spirit and scope of the present invention are not limited thereto. It should be understood that various changes may be made without departing from the spirit of the invention. The embodiments of the present invention may be combined with one another to form various new embodiments.

In the drawings referred to in the present invention, components having substantially the same configuration and function as those of the present invention will be denoted by the same reference numerals.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

1 is a block diagram of a visual inspection apparatus according to an embodiment of the present invention.

1, an appearance inspection apparatus 100 according to an embodiment of the present invention includes an illumination device 110, a camera device 120, and an optical system controller 120 for inspecting the appearance of a product 1 to be inspected. (130).

Here, in the case where the product 1 to be inspected is a polyhedron, a plurality of visual inspection apparatuses 100 may be required to inspect each surface.

The lighting device 110 can illuminate the product to be inspected. The illumination device 110 can illuminate using a preset illumination value.

Here, the illumination value of the illumination device 110 may be set in advance as an illumination value necessary for visual inspection of the inspection target product 1. [ Alternatively, the illumination value of the illumination device 110 may be set through an illumination value adjustment process by the optical system controller 130 as an appropriate illumination value for each channel before adjusting the camera gain.

The optical system controller 130 can find and set an illumination value for each color.

The camera device 120 may capture the inspection target product and provide a video signal.

The optical system controller 130 can acquire an image from a video signal of the camera device 120. For example, the optical system controller 130 may divide the pre-set region of interest into the respective colors and measure the luminance values of the respective colors. The measured luminance value may be a measured average luminance value obtained by averaging luminance values of a plurality of pixels of the ROI.

Here, the hue may be red (Red), green (Green), and blue (Blue).

Then, the optical system controller 130 adjusts and sets the white balance ratio value of each color in which the measured luminance value of each color obtained from the image converges on the target luminance value while adjusting the white balance ratio value of each color .

If the measurement luminance value of the corresponding color does not converge to the target luminance value, the optical system controller 130 balances the camera gain and then re-balances the measured luminance value of the corresponding color to the target luminance value, The balance ratio value can be adjusted. Here, the camera gain rebalancing will be described below with reference to the following equations (1), (2) and (3).

Meanwhile, the optical system controller 130 may adjust and set the illumination value of the illumination device 110 before adjusting and setting the white balance ratio value for each color related to the camera gain.

2 is an example of an optical system control apparatus according to an embodiment of the present invention.

2, the optical system controller 130 may include an image acquisition unit 131, a brightness value measurement unit 132, and a white balance ratio value setting unit 133.

The image acquisition unit 131 may acquire an image from the image signal from the camera device 120. [ For example, the image acquisition unit 131 may convert an analog image signal into a digital image signal, and extract the image from the digital image signal.

The brightness value measuring unit 132 may measure a brightness value for each color using the image from the image obtaining unit 131 to provide a measured brightness value.

The white balance ratio value setting unit 133 adjusts the white balance ratio value of each color in a direction in which the measured brightness value converges to a predetermined target brightness value, and when the measured brightness value converges to the target brightness value The white balance ratio value of each color at that time is set and even if the white balance ratio value is adjusted to the upper limit value or the lower limit value, if the measured luminance value of the corresponding color does not converge to the target luminance value, The white balance ratio value of the corresponding color can be adjusted in a direction in which the measured luminance value of the corresponding color converges on the target luminance value.

Hereinafter, an optical system automatic calibration method of the visual inspection apparatus will be described with reference to Figs. 3 to 6. Fig. In the present application, the description of the visual inspection apparatus and the description of the optical system automatic calibration method of the visual inspection apparatus can be supplemented and applied to each other, unless otherwise specified.

3 is a flow chart illustrating an example of an optical system automatic calibration method of the visual inspection apparatus according to an embodiment of the present invention.

A method of automatically calibrating an optical system of a visual inspection apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG.

Hereinafter, the description of the optical system auto-calibration method of the visual inspection apparatus can be applied to the operation description with reference to FIGS. 1 and 2. Accordingly, in the explanation of the optical system automatic calibration method of the visual inspection apparatus, The detailed description may be omitted.

Referring to FIG. 3, an optical system automatic calibration method of the visual inspection apparatus includes an illumination device 110 for illuminating a product to be inspected, a camera device 120 for photographing the product to be inspected, and an optical system controller 130 S220, S230, S240 and S250 in order to inspect the appearance of the product to be inspected (1 in Fig. 1) by the method of the appearance inspection apparatus.

In step S210, the optical system controller 130 can acquire an image from a video signal from the camera device 120. [

In step S220, the optical system controller 130 may measure the luminance value of each color from the image, and provide the measured luminance value for each color. For example, the luminance value of the hue may be a red luminance value, a green luminance value, and a blue luminance value.

In step S230, the optical system controller 130 may adjust the white balance ratio value of the corresponding color, and determine whether the measured luminance value of the corresponding color converges to a predetermined target luminance value. Here, the color white balance ratio value may be a red color white balance ratio value, a green color white balance ratio value, and a blue color white balance ratio value.

In step S240, the optical system controller 130 adjusts the white balance ratio value of each color in the direction in which the measured luminance value converges to the target luminance value, and adjusts the white balance ratio value to the upper limit value or the lower limit value The white balance ratio value of the corresponding color in the direction in which the measured luminance value of the corresponding color converges to the target luminance value is obtained Lt; / RTI >

In step S250, when the measured brightness value is converged to the target brightness value by the optical system controller 130, the white balance ratio value of each color at that time may be set.

4 is a flow chart showing another example of an optical system automatic calibration method of the visual inspection apparatus according to an embodiment of the present invention.

Referring to FIG. 4, the method for automatically calibrating an optical system of the visual inspection apparatus according to an exemplary embodiment of the present invention may include steps S100 (illumination value adjustment step) and step S200 (camera gain adjustment step).

In step S100, the illumination value of the illumination device 110 may be adjusted by the optical system controller 130, and a description thereof will be described with reference to FIG.

3 and 5, the camera gain may be adjusted, and the description thereof will be further described with reference to FIG. 5 in addition to the description with reference to FIG.

5 is a flowchart illustrating an example of a camera gain adjustment step according to an embodiment of the present invention.

1 to 5, when the measured luminance value of the corresponding color is larger than the target luminance value (refer to S241 in FIG. 5), the optical system controller 130 converges the measured luminance value of the corresponding color to the target luminance value The white balance ratio value of the corresponding color can be reduced.

)만큼 증가시키고, 이 경우 카메라 장치의 이득 변경값(ㅿG) 및 다른 색상의 화이트 밸런스 비율값 각각의 변경값(

,

)을 상기 수학식1에 따라 조정하는 카메라 이득 리밸런싱을 수행할 수 있다 (도 5의 S242 참조).
For example, when the measurement luminance value of the corresponding color is greater than the target luminance value, the optical system controller 130 determines that the white balance ratio value of the corresponding color is the minimum value and the measured luminance value of the corresponding color does not converge to the target luminance value , The white balance ratio value of the corresponding color is set to a predetermined change value (

), And in this case, the gain change value (G) of the camera apparatus and the change value of each of the white balance ratio values of the other colors

,

) According to Equation (1) above (see S242 in FIG. 5).

Bcolor1, Bcolor2, and Bcolor3 are white balance ratio values of any one of red, green, and blue, and Bcolor1, Bcolor2, and Bcolor3 are white balance ratio values of any one of red, . And A is a constant, for example, 20 / 0.0359.

5), the optical system controller 130 sets the white balance ratio of the corresponding color so that the measured luminance value of the corresponding color converges to the target luminance value (step S241 in FIG. 5) Value can be increased.

)만큼 감소시키고, 이 경우 카메라 장치의 이득 변경값(ㅿG) 및 다른 색상의 화이트 밸런스 비율값 각각의 변경값(

,

)을 하기 수학식1에 따라 조정할 수 있다(도 5의 S243 참조).
For example, when the measured luminance value of the corresponding color is smaller than the target luminance value, the optical system controller 130 determines that the measured luminance value of the corresponding color does not converge to the target luminance value at the maximum value , The white balance ratio value of the corresponding color is set to a predetermined change value (

), And in this case, the gain change value (? G) of the camera apparatus and the change value (? G) of the white balance ratio value of each color

,

) Can be adjusted according to the following equation (1) (see S243 in FIG. 5).

)만큼 증가시키고, 이 경우 카메라 장치의 이득 변경값(ㅿG) 및 녹색 및 청색의 화이트 밸런스 비율값 각각의 변경값(

,

)을 하기 수학식2에 따라 조정하는 카메라 이득 리밸런싱을 수행할 수 있다(도 5의 S243 참조).Referring to FIG. 5, when the measured luminance value of red is larger than the target luminance value, the optical system controller 130 determines that the red white balance ratio value Bred is the minimum value and the measured luminance value of red converges to the target luminance value. , The red white balance ratio value (Bred) is set to a predetermined change value (

). In this case, the gain change value (? G) of the camera apparatus and the change value (? G) of each of the green and blue white balance ratio values

,

) Can be performed according to the following equation (2) (see S243 in FIG. 5).

)만큼 감소시키고, 이 경우 카메라 장치의 이득 변경값(ㅿG) 및 녹색 및 청색의 화이트 밸런스 비율값 각각의 변경값(

,

)을 하기 수학식2에 따라 조정할 수 있다(도 5의 S243 참조).
Alternatively, when the measured luminance value of red is smaller than the target luminance value, the optical system controller 130 may set the red luminance value to the target luminance value if the measured white luminance value of red does not converge to the target luminance value The white balance ratio value (Bred) is set to a predetermined change value (

), And in this case, the gain change value (? G) of the camera apparatus and the change value (? G) of each of the green and blue white balance ratio values

,

) Can be adjusted according to the following equation (2) (see S243 in FIG. 5).

Bred, Bgreen, and Bblue are white balance ratio values of red, green, and blue, and Bred, Bgreen, and Bblue are changed values of white balance ratio values of red, green, and blue. And A is a constant, for example, 20 / 0.0359.

)만큼 증가시킨다.Referring to Equation (2), when the measured brightness value of red is larger than the target brightness value, the optical system controller 130 must reduce the red white balance ratio value Bred, and the red white balance ratio value When the measured luminance value of red does not converge to the target luminance value even at the minimum value of the red white balance ratio value Bred so that the red white balance ratio value Bred can be further reduced, (

).

)만큼 증가시킬 때, 상기 수학식 2를 이용하면 카메라 장치의 이득 변경값(ㅿG) 및 녹색 및 청색의 화이트 밸런스 비율값 각각의 변경값(

,

)을 조정하는 카메라 이득 리밸런싱을 수행할 수 있다(도 5의 S243 참조).
For example, the optical system controller 130 may change the red white balance ratio value Bred to the change value (red) in a state in which the output power (yred, ygreen, yblue)

, The gain change value (? G) of the camera apparatus and the change value (? G) of each of the green and blue white balance ratio values

,

(See S243 in FIG. 5).

Where xred, xgreen, and xblue are the input powers of red, green, and blue, G is the gain of the camera device, and Bred, Bgreen, and Blue are the output powers of red, green, and blue, Bblue is the white balance ratio value of red, green and blue. And B is a constant, for example 0.0359.

Referring to Equation (3), the output power (yred, ygreen, yblue) of each color is a function of the input power (xred, xgreen, xblue) and the gain (G) of the camera apparatus.

)만큼 감소시킨다.If the measured brightness value of red is smaller than the target brightness value, the optical system controller 130 may increase the red white balance ratio value Bred, When the measured luminance value of red does not converge to the target luminance value at the maximum value, the red white balance ratio value Bred is set to a predetermined change value (

).

)만큼 감소시킬 때, 상기 수학식 2를 이용하면 카메라 장치의 이득 변경값(ㅿG) 및 녹색 및 청색의 화이트 밸런스 비율값 각각의 변경값(

,

)을 조정할 수 있다(도 5의 S243 참조).
For example, the optical system controller 130 may change the red white balance ratio value Bred to the change value (Yred, ygreen, yblue) while maintaining the output power (yred,

), The gain change value (G) of the camera apparatus and the change value (? G) of each of the green and blue white balance ratio values

,

(See S243 in Fig. 5).

,

,

) 및 카메라 장치의 이득 변경값(ㅿG)은 서로 상관 관계를 가지고, 수학식 2 및 3을 만족하는 조합의 값들을 갖는다.For example, referring to equations (2) and (3), the camera gain rebalancing will be described with reference to the change value of the white balance ratio value Bred of red, green,

,

,

) And the gain change value (G) of the camera device have correlation values with each other and have values of the combination satisfying the expressions (2) and (3).

)만큼 증가시키고, 적색의 화이트 밸런스 비율값(Bred)을 상기 변경값(

)만큼 증가시킬 때, 상기 수학식 2를 이용하면 카메라 장치의 이득 변경값(ㅿG) 및 녹색 및 청색의 화이트 밸런스 비율값 각각의 변경값(

,

)을 결정할 수 있다.In the process of adjusting the white balance ratio value of red so that the measured luminance value of red converges to the target luminance value at the preset combination value, the measured white luminance value of red is changed from the minimum value to the target luminance value The red white balance ratio value Bred is set to a preset change value Bred so that the red white balance ratio value Bred can be further reduced,

), And the red white balance ratio value Bred is increased by the change value (

, The gain change value (? G) of the camera apparatus and the change value (? G) of each of the green and blue white balance ratio values

,

Can be determined.

)만큼 감소시키고, 적색의 화이트 밸런스 비율값(Bred)을 상기 변경값(

)만큼 감소시킬 때, 상기 수학식 2를 이용하면 카메라 장치의 이득 변경값(ㅿG) 및 녹색 및 청색의 화이트 밸런스 비율값 각각의 변경값(

,

)을 결정할 수 있으며, 이러한 과정이 카메라 이득 리밸런싱이다.In the process of adjusting the white balance ratio value of red so that the measured luminance value of red converges to the target luminance value, when the measured white luminance value of red does not converge to the target luminance value at the maximum value , The red white balance ratio value (Bred) is set to a predetermined change value (Bred) so that the red white balance ratio value (Bred)

), And the red white balance ratio value Bred is decreased by the change value (

), The gain change value (G) of the camera apparatus and the change value (? G) of each of the green and blue white balance ratio values

,

), And this process is camera gain rebalancing.

Although red has been described for the camera gain rebalancing, it can be applied to the same principle for green and blue.

As described above, in the same manner as the adjustment process for red, green can be adjusted using the following equation (4), and blue can also be adjusted using the following equation (5).

FIG. 6 is a flow chart illustrating an example of an illumination value adjustment step according to an embodiment of the present invention, and FIG. 7 is a conceptual diagram of convergence in an illumination value adjustment step according to an embodiment of the present invention.

6 and 7, step S100 of adjusting the illumination value may include step S110, step S120, step S130, step S140, and step S150.

In step S110, the optical system controller 130 can acquire an image from a video signal from the camera device 120. [

In step S120, the optical system controller 130 may measure the luminance value of each color from the image, and provide the measured brightness value for each color.

In step S130, the optical system controller 130 may adjust the corresponding color and determine whether the measured brightness of the corresponding color is converged to a predetermined target brightness value.

In step S140, if the measured brightness value is not converged to the target brightness value by the optical system controller 130, the illumination value of each color is adjusted to proceed to acquire the image.

In step S150, when the measured brightness value converges to the target brightness value, the optical system controller 130 may set an illumination value of each color.

Through the illumination value adjustment process of the illumination device, as shown in FIG. 7, it is possible to find and set the illumination value converging the measured brightness value for each color to the target brightness value.

100: Appearance inspection device
110: Lighting device
120: camera device
130: Optical system control device
131:
132: luminance value measuring unit
133: White balance ratio value setting unit

Claims (14)

A lighting device for illuminating a product to be inspected;
A camera device for photographing the inspection target product and providing a video signal; And
And adjusting and setting a white balance ratio value of each color in which a measured luminance value of each color obtained from the image converges on a target luminance value while adjusting a white balance ratio value of each color, An optical system control device; Lt; / RTI >
The optical system controller
If the measurement luminance value of the corresponding color does not converge to the target luminance value, the camera gain rebalance is performed, and then the white balance ratio value of the corresponding color is adjusted so that the measured luminance value of the corresponding color converges to the target luminance value
Appearance inspection device.
The optical system control apparatus according to claim 1,
An image acquisition unit for acquiring an image from a video signal from the camera device;
A luminance value measuring unit for measuring a luminance value for each color from the image and providing a measured luminance value; And
A white balance ratio value of each color is adjusted in a direction in which the measured luminance value converges to a predetermined target luminance value, and when the measured luminance value converges to the target luminance value, a white balance ratio value of each color is set , If the measured luminance value of the corresponding color does not converge to the target luminance value even if the white balance ratio value is adjusted to the upper limit value or the lower limit value, the measured luminance value of the corresponding color is again adjusted to the target luminance value A white balance ratio value setting unit for adjusting a white balance ratio value of the corresponding color in a converging direction;
And a visual inspection device.
The optical system control apparatus according to claim 1,
When the measured luminance value of the corresponding color is larger than the target luminance value, the white balance ratio value of the corresponding color is decreased so that the measured luminance value of the corresponding color converges to the target luminance value
Appearance inspection device.
The optical system control apparatus according to claim 3,
If the measured luminance value of the corresponding color is larger than the target luminance value, if the measured white balance ratio value of the corresponding color does not converge to the target luminance value from the minimum value, the white balance ratio value of the corresponding color is changed value

In this case, the gain change value G of the camera apparatus and the change value of each of the white balance ratio values of the other colors

,

Is expressed by the following equation
[Mathematical Expression]

Perform camera gain rebalancing according to
Appearance inspection device.
The optical system control apparatus according to claim 1,
When the measured luminance value of the corresponding color is smaller than the target luminance value, the white balance ratio value of the corresponding color is increased so that the measured luminance value of the corresponding color converges to the target luminance value
Appearance inspection device.
6. The apparatus according to claim 5, wherein the optical system controller
If the measured luminance value of the corresponding color is smaller than the target luminance value and if the measured white luminance value of the corresponding color does not converge to the target luminance value at the maximum value, Change value

In this case, the gain change value G of the camera apparatus and the change value of each of the white balance ratio values of the other colors

,

Is expressed by the following equation
[Mathematical Expression]

Perform camera gain rebalancing according to
Appearance inspection device.
The optical system control apparatus according to claim 1,
Adjusting and setting a white balance ratio value for each color related to the illumination value of the illumination device before adjusting and setting the white balance ratio value for each color related to the camera gain
Method of automatic calibration of an optical system of a visual inspection apparatus.
A method for automatically calibrating an optical system of a visual inspection apparatus including an illuminating device for illuminating an inspection target product, a camera device for photographing the inspection target product, and an optical system control device,
Acquiring an image from a video signal from the camera apparatus by the optical system controller;
Measuring a luminance value of each color from the image and providing a measured luminance value for each color;
Determining whether a measured luminance value of a corresponding color converges to a predetermined target luminance value while adjusting a white balance ratio value of the corresponding color;
Even when the white balance ratio value of each color is adjusted in the direction in which the measured luminance value converges to the target luminance value and the white balance ratio value is adjusted to the upper limit value or the lower limit value, Adjusting the white balance ratio value of the color in a direction in which the measured luminance value of the corresponding color converges to the target luminance value after rebalancing the camera gain; And
Setting a white balance ratio value of each color when the measured luminance value converges to the target luminance value;
And an automatic calibration method of the optical system of the visual inspection apparatus.
9. The method of claim 8, wherein adjusting the white balance ratio value comprises:
When the measured luminance value of the corresponding color is larger than the target luminance value, the white balance ratio value of the corresponding color is decreased so that the measured luminance value of the corresponding color converges to the target luminance value
Method of automatic calibration of an optical system of a visual inspection apparatus.
10. The method of claim 9, wherein adjusting the white balance ratio value comprises:
If the measured luminance value of the corresponding color is larger than the target luminance value, if the measured white balance ratio value of the corresponding color does not converge to the target luminance value from the minimum value, the white balance ratio value of the corresponding color is changed value

In this case, the gain change value G of the camera apparatus and the change value of each of the white balance ratio values of the other colors

,

Is expressed by the following equation
[Mathematical Expression]

Perform camera gain rebalancing according to
Method of automatic calibration of an optical system of a visual inspection apparatus.
9. The method of claim 8, wherein adjusting the white balance ratio value comprises:
When the measured luminance value of the corresponding color is smaller than the target luminance value, the white balance ratio value of the corresponding color is increased so that the measured luminance value of the corresponding color converges to the target luminance value
Method of automatic calibration of an optical system of a visual inspection apparatus.
12. The method of claim 11, wherein adjusting the white balance ratio value comprises:
If the measured luminance value of the corresponding color is smaller than the target luminance value and if the measured white luminance value of the corresponding color does not converge to the target luminance value at the maximum value, Change value

In this case, the gain change value G of the camera apparatus and the change value of each of the white balance ratio values of the other colors

,

Is expressed by the following equation
[Mathematical Expression]

Perform camera gain rebalancing according to
Method of automatic calibration of an optical system of a visual inspection apparatus.
9. The method of claim 8,
Adjusting an illumination value of the illumination device prior to acquiring the image; Further comprising
Method of automatic calibration of an optical system of a visual inspection apparatus.
14. The method of claim 13, wherein adjusting the illumination value comprises:
Acquiring an image from a video signal from the camera apparatus by the optical system controller;
Measuring a luminance value of each color from the image and providing a measured luminance value for each color;
Determining whether a measured brightness value of the corresponding color converges to a predetermined target brightness value while adjusting an adjustment of the corresponding color;
If the measured brightness value does not converge to the target brightness value, proceeding to adjusting the illumination value of each color to obtain the image; And
Setting an illumination value of each color when the measured brightness value converges to the target brightness value;
And an automatic calibration method of the optical system of the visual inspection apparatus.

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