JP7070867B2 - Visual inspection equipment and its optical system automatic calibration method - Google Patents

Description

The present invention relates to a visual inspection apparatus applicable to a vision measurement and inspection system and an optical system automatic calibration method thereof.

Typically, a vision measurement and inspection system is equipment that measures or inspects a target product using vision optical systems. Examples of products to be inspected include various electronic components such as passive elements, ISMs (Image Sensor Modules), and substrates.

Such a vision measurement and inspection system may include a plurality of products and a plurality of visual inspection devices for inspecting the inspection surface of each product. The plurality of visual inspection devices can acquire an image of the passive element by using the set lighting and the camera, and can determine the appearance defect of the product based on the acquired image. Here, when the product to be inspected is used in a state where a defect has occurred, a fatal loss can be caused, so that an appearance inspection process is required as one of the production processes of the product to be inspected.

Here, the passive element, which is a product to be inspected, is an element that consumes, stores, and releases electric power supplied from the outside. Examples of the passive element include MLCC (Multi Layer Ceramic Capacitor) and BLCC (Boundary Layer Ceramic Capacitor). ), VLC (Vertically Laminated Capacitor), EMC (Electro Magnetic Capacitor) and the like.

However, the reflectance of multiple visual inspection devices may differ significantly from product to product, and the image quality may differ significantly depending on the settings of the vision optical system, and the measurement and inspection performance depends on the image quality. obtain.

In order to perform efficient inspection using multiple visual inspection devices, it is necessary to obtain images of uniform quality for each product, and for that purpose, before measuring and inspecting the product, make it suitable for the relevant product. It is necessary to properly adjust and set the optical system.

The conventional optical system adjustment method is a method in which a worker manually adjusts one by one in the field depending on the experience value of the worker.

Such manual adjustment has a problem that the reliability of the inspection is lowered because the deviation may occur for each worker and the accuracy of the inspection is inferior.

Further, there is a problem that it takes a lot of time to manually adjust the optical system for each of the plurality of visual inspection devices one by one.

In particular, when there are many types of products to be inspected, the conventional adjustment method has different reflectances for each product type, model, and capacity, so even if the maximum amount of illumination is used, the target (taget). It may be smaller than the value, or the measured value may not converge to the target value even if the amount of light of the illumination is used to the minimum. In this case, in the conventional method, it is considered that the adjustment of the corresponding camera has failed, and further manual adjustment is required. This has the problem that it often becomes necessary to manually further adjust the optical system for the product.

On the other hand, conventionally, a calibration method of an optical system in a vision measurement and inspection system has been proposed, but an appropriate alternative for the case where the white balance ratio value for each hue does not temporarily converge to the target value has not been proposed. Is.

Japanese Unexamined Patent Publication No. 2001-249804

In one embodiment of the present invention, the visual inspection device of the vision measurement and inspection system can automatically calibrate the optical system, and when the measured luminance value for each hue does not converge to the target luminance value, the camera gain is set. Provided is an visual inspection apparatus and an optical system automatic calibration method thereof so that the measured luminance value for each hue converges to a target luminance value by rebalancing.

According to one embodiment of the present invention, an optical device for illuminating the product to be inspected, a camera device for photographing the product to be inspected and providing an image signal, and an image obtained from the image signal of the camera device are obtained and each hue is obtained. Includes an optical system control device that adjusts and sets the white balance ratio value of each hue in which the measured luminance value of each hue obtained from the above image converges to the target luminance value while adjusting the white balance ratio value of the above. If the measured luminance value of the corresponding hue does not converge to the target luminance value, the optical system control device rebalances the camera gain and then white of the corresponding hue so that the measured luminance value of the corresponding hue further converges to the target luminance value. A visual inspection device that adjusts the balance ratio value is proposed.

According to one embodiment of the present invention, in the visual inspection device of the vision measurement and inspection system, the optical system can be automatically calibrated to suit the product, so that the time required for calibration can be shortened. In addition to eliminating the drawbacks of manual calibration, if the measured value for each hue does not converge to the target value, the measured value for each hue may converge to the target value due to rebalancing with respect to the correlation factors of the optical system. There is an effect that can be done.

It is a block diagram of the visual inspection apparatus according to one Embodiment of this invention. This is an example of an optical system control device according to an embodiment of the present invention. It is a flowchart which shows an example of the optical system automatic calibration method of the visual inspection apparatus by one Embodiment of this invention. It is a flowchart which shows the other example of the optical system automatic calibration method of the optical system automatic calibration apparatus by one Embodiment of this invention. It is a flowchart which shows an example of the camera gain adjustment stage by one Embodiment of this invention. It is a flowchart which shows an example of the illumination value adjustment stage by one Embodiment of this invention. It is a conceptual diagram of convergence in the illumination value adjustment stage by one Embodiment of this invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, embodiments of the invention can be transformed into various other embodiments, and the scope of the invention is not limited to the embodiments described below. Also, embodiments of the invention are provided to more fully explain the invention to those with average knowledge in the art. Therefore, the shape and size of the elements in the drawings may be exaggerated for a clearer explanation.

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

Referring to FIG. 1, the visual inspection device 100 according to an embodiment of the present invention includes a lighting device 110, a camera device 120, and an optical system control device 130 for inspecting the appearance of the product 1 to be inspected. ..

Here, when the product 1 to be inspected is a polyhedron, a plurality of visual inspection devices 100 may be required to inspect each surface.

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

Here, the lighting value of the lighting device 110 can be set in advance to the lighting value required for the appearance inspection of the product 1 to be inspected. Alternatively, the illumination value of the illumination device 110 can be set to an appropriate illumination value for each channel and each hue by an illumination value adjustment process by the optical system control device 130 before adjusting the camera gain.

The optical system control device 130 can check and set the illumination value for each hue.

The camera device 120 can photograph the product to be inspected and provide a video signal.

The optical system control device 130 can acquire an image from the image signal of the camera device 120. As an example, the optical system control device 130 can measure the luminance value for each hue with respect to a preset region of interest separately for each hue from the acquired image. The measured luminance value can be a measured average luminance value obtained by averaging the luminance values of a plurality of pixels in the region of interest.

Here, the hue can be red, green, and blue.

Next, the optical system control device 130 adjusts the white balance ratio value of each hue in which the measured luminance value of each hue obtained from the image converges to the target luminance value while adjusting the white balance ratio value of each hue. And can be set.

Further, the optical system control device 130 corresponds so that if the measured luminance value of the corresponding hue does not converge to the target luminance value, the measured luminance value of the corresponding hue further converges to the target luminance value after rebalancing the camera gain. The white balance ratio value of hue can be adjusted. Here, the rebalancing of the camera gain will be described later with reference to the following equations 1, 2 and 3.

On the other hand, the optical system control device 130 can adjust and set the illumination value of the illumination device 110 before adjusting and setting the white balance ratio value for each hue related to the camera gain.

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

Referring to FIG. 2, the optical system control device 130 can include an image acquisition unit 131, a luminance value measurement unit 132, and a white balance ratio value setting unit 133.

The video acquisition unit 131 can acquire video from the video signal from the camera device 120. As an example, the video acquisition unit 131 can convert an analog video signal into a digital video signal and extract video from the digital video signal.

The luminance value measuring unit 132 can measure the luminance value of each hue using the image from the image acquiring unit 131 and provide the measured luminance value.

The white balance ratio value setting unit 133 adjusts the white balance ratio value of each hue so that the measured luminance value converges to the preset target luminance value, and when the measured luminance value converges to the target luminance value. , Even if the white balance ratio value of each hue at that time is set and the above white balance ratio value is adjusted to the upper limit value or the lower limit value, if the measured brightness value of the corresponding hue does not converge to the target brightness value, the camera gain is increased. After rebalancing, the white balance ratio value of the corresponding hue can be further adjusted so that the measured luminance value of the corresponding hue converges to the target luminance value.

Next, a method of automatically calibrating the optical system of the visual inspection apparatus will be described with reference to FIGS. 3 to 6. The description of the visual inspection device and the method for automatically calibrating the optical system of the visual inspection device in the present specification can be applied complementarily to each other unless there are special circumstances.

FIG. 3 is a flowchart showing an example of an optical system automatic calibration method for an visual inspection apparatus according to an embodiment of the present invention.

A method for automatically calibrating the optical system of the visual inspection apparatus according to the embodiment of the present invention will be described with reference to FIGS. 3 to 6.

The operation described with reference to FIGS. 1 and 2 can be applied to the description of the method for automatically calibrating the optical system of the visual inspection apparatus described later. Thereby, in the description of the optical system automatic calibration method of the visual inspection apparatus, duplicate detailed description can be omitted as much as possible.

Referring to FIG. 3, the optical system automatic calibration method of the visual inspection device includes a lighting device 110 for illuminating the product to be inspected, a camera device 120 for photographing the product to be inspected, and an optical system control device 130. A method performed by a visual inspection apparatus, which includes S210, S220, S230, S240, and S250 for inspecting the appearance of a product to be inspected (1 in FIG. 1). ..

At the S210 stage, the optical system control device 130 can acquire an image from the image signal from the camera device 120.

In the step S220, the optical system control device 130 measures the luminance value of each hue from the video, and can provide the measured luminance value for each hue. As an example, the hue luminance value can be a red luminance value, a green luminance value, and a blue luminance value.

In the step S230, the optical system control device 130 may determine whether the measured luminance value of the hue is converged to the preset target luminance value while adjusting the white balance ratio value of the hue. can. Here, the white balance ratio value of the hue can be a red white balance ratio value, a green white balance ratio value, and a blue white balance ratio value.

In the S240 step, the optical system control device 130 adjusts the white balance ratio value of each hue so that the measured luminance value converges to the target luminance value, and the white balance ratio value reaches the upper limit value or the lower limit value. Even when adjusted, if the measured luminance value of the corresponding hue does not converge to the target luminance value, the measured luminance value of the corresponding hue is further converged to the target luminance value after the camera gain is rebalanced. The white balance ratio value of can be adjusted.

In the S250 step, when the measured luminance value is converged to the target luminance value by the optical system control device 130, the white balance ratio value of each hue at that time can be set.

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

Referring to FIG. 4, the optical system automatic calibration method of the visual inspection apparatus according to the embodiment of the present invention can include S100 step (illumination value adjustment step) and S200 step (camera gain adjustment step). ..

In the S100 stage, the illumination value of the illumination device 110 can be adjusted by the optical system control device 130, and the description thereof will be described later with reference to FIG.

In the S200 stage, as shown in FIGS. 3 and 5, the camera gain can be adjusted, and the description thereof will be described later with reference to FIG. 5 in addition to the explanation with reference to FIG. do.

FIG. 5 is a flowchart showing an example of a camera gain adjustment stage according to an embodiment of the present invention.

Referring to FIGS. 1 to 5, in the optical system control device 130, when the measured luminance value of the corresponding hue is larger than the target luminance value (see S241 of FIG. 5), the measured luminance value of the corresponding hue is the target luminance. The white balance ratio value of the corresponding hue can be reduced so as to converge to the value.

For example, in the optical system control device 130, when the measured luminance value of the corresponding hue is larger than the target luminance value, the measured luminance value of the corresponding hue converges to the target luminance value when the white balance ratio value of the corresponding hue is the minimum value. Otherwise, the white balance ratio value of the corresponding hue is increased by a preset change value (ΔBcolor1), and in this case, the gain change value (ΔG) of the camera device and the white balance ratio value of other hues are changed respectively. (ΔBcolor2, ΔBcolor3) can be adjusted by the following equation 1 to perform camera gain rebalancing (see S242 in FIG. 5).

In the above formula 1, Bcolor1, Bcolor2, and Bcolor3 are white balance ratio values of any one of red, green, and blue, respectively, and ΔBcolor1, ΔBcolor2, and ΔBcolor3 are white balance ratios of any one of red, green, and blue. The changed value of the value. Further, A is a constant and can be 20 / 0.0359 as an example.

Further, the optical system control device 130 corresponds to the case where the measured luminance value of the corresponding hue is smaller than the target luminance value (see S241 in FIG. 5) so that the measured luminance value of the corresponding hue converges to the target luminance value. The white balance ratio value of hue can be increased.

For example, in the optical system control device 130, when the measured luminance value of the corresponding hue is smaller than the target luminance value, the measured luminance value of the corresponding hue converges to the target luminance value when the white balance ratio value of the corresponding hue is the maximum value. Otherwise, the white balance ratio value of the corresponding hue is reduced by a preset change value (ΔBcolor1), and in this case, the gain change value (ΔG) of the camera device and the white balance ratio value of other hues are changed respectively. (ΔBcolor2, ΔBcolor3) can be adjusted by the above equation 1 (see S243 in FIG. 5).

Referring to FIG. 5, in the optical system control device 130, when the measured luminance value of red is larger than the target luminance value, the measured luminance value of red is the target when the white balance ratio value (Bred) of red is the minimum value. If it does not converge to the luminance value, the red white balance ratio value (Bred) is increased by a preset change value (ΔBred), and in this case, the gain change value (ΔG) of the camera device and the green and blue white balance ratios. The camera gain can be rebalanced by adjusting each change value (ΔBgreen, ΔBblue) by the following equation 2 (see S243 in FIG. 5).

Unlike this, in the optical system control device 130, when the measured luminance value of red is smaller than the target luminance value, the measured luminance value of red converges to the target luminance value when the white balance ratio value of red is the maximum value. Otherwise, the red white balance ratio value (Bred) is reduced by a preset change value (ΔBred), and in this case, the gain change value (ΔG) of the camera device and the green and blue white balance ratio values, respectively. The changed value (ΔBgreen, ΔBblue) can be adjusted by the following equation 2 (see S243 in FIG. 5).

In the above formula 2, Red, Bgreen and Bblue are red, green and blue white balance ratio values, and ΔBred, ΔBgreen and ΔBblue are red, green and blue white balance ratio values. Further, A is a constant and can be 20 / 0.0359 as an example.

Referring to the above equation 2, the optical system control device 130 must reduce the red white balance ratio value (Bred) when the measured luminance value of red is larger than the target luminance value, but the red white balance ratio. If the measured luminance value of red does not converge to the target luminance value even when the value (Bred) is the minimum value, the red white balance ratio value (Bred) can be further reduced. The balance ratio value (Bred) is increased by a preset change value (ΔBred).

For example, in the optical system control device 130, the red white balance ratio value (Bred) is changed only by the change value (ΔBred) while the output power (yred, ygreen, yblue) is maintained as in the following formula 3. When increasing, the above equation 2 is used to rebalance the camera gain by adjusting the gain change value (ΔG) of the camera device and the respective change values (ΔBgreen, ΔBblue) of the green and blue white balance ratio values. (See S243 in FIG. 5).

In Equation 3, yred, ygreen and yblue are red, green and blue output powers, xred, xgreen and xblue are red, green and blue input powers, G is the gain of the camera device, and Bred, Bgreen and Bblue are red, green and blue white balance ratio values. Further, B is a constant and can be 0.0359 as an example.

With reference to the above equation 3, the output power (yred, ygreen, yblue) for each hue is a function of the input power (xred, xgreen, xblue) and the gain (G) of the camera device.

On the other hand, referring to the above equation 2, the optical system control device 130 must increase the red white balance ratio value (Bred) when the measured luminance value of red is smaller than the target luminance value. If the measured luminance value of red does not converge to the target luminance value when the white balance ratio value of red is the maximum value, the white balance ratio value (Bred) of red is reduced by a preset change value (ΔBred). Let me.

For example, in the optical system control device 130, the red white balance ratio value (Bred) is changed to the changed value (ΔBred) while the output power (yred, ygreen, yblue) is maintained as in the formula 3. By using the above equation 2, it is possible to adjust the gain change value (ΔG) of the camera device and the respective change values (ΔBgreen, ΔBblue) of the green and blue white balance ratio values (FIG. 5). See S243).

On the other hand, the rebalancing of the camera gain will be described. For example, referring to Equations 2 and 3, the red, green, and blue white balance ratio value (Bred) change values (ΔBred, ΔBgreen, ΔBblue) and the gain change value (ΔG) of the camera device have a correlation with each other. And has a combination value that satisfies equations 2 and 3.

In the process of adjusting the red white balance ratio value so that the red measured luminance value converges to the target luminance value in the preset combination value, the red color is red when the red white balance ratio value is the minimum value. The red white balance ratio value (Bred) is set to a preset change value (ΔBred) so that the red white balance ratio value (Bred) can be further reduced when the measured luminance value does not converge to the target luminance value. ), And the red white balance ratio value (Bred) is increased by the above change value (ΔBred). When the above equation 2 is used, the gain change value (ΔG) of the camera device and the green and blue white balance ratios are used. Each change value (ΔBgreen, ΔBblue) of the value can be determined.

Further, in the process of adjusting the red white balance ratio value so that the red measured luminance value converges to the target luminance value, the red measured luminance value is the target luminance value when the red white balance ratio value is the maximum value. The red white balance ratio value (Bred) is reduced by a preset change value (ΔBred) so that the red white balance ratio value (Bred) can be further increased when it does not converge to the red color. When the above equation 2 is used when the white balance ratio value (Bred) is decreased by the above change value (ΔBred), the gain change value (ΔG) of the camera device and the respective change values (green and blue white balance ratio values) ( ΔBgreen, ΔBblue) can be determined. Such a process is camera gain rebalancing.

The rebalancing of the camera gain has been described by taking the case of red as an example, but the same principle can be applied to green and blue.

As described above, the green color can be adjusted using the following formula 4 and the blue color can be adjusted using the following formula 5 by the same method as the adjustment process for red color.

FIG. 6 is a flowchart showing an example of the illumination value adjustment stage according to the embodiment of the present invention, and FIG. 7 is a conceptual diagram of convergence in the illumination value adjustment stage according to the embodiment of the present invention.

Referring to FIGS. 6 and 7, the step (S100) for adjusting the illumination value can include an S110 step, an S120 step, an S130 step, an S140 step, and an S150 step.

At the S110 stage, the optical system control device 130 can acquire an image from the image signal from the camera device 120.

In the step S120, the optical system control device 130 measures the luminance value of each hue from the image, and can provide the measured brightness value for each hue.

In the step S130, the optical system control device 130 can determine whether the measured brightness value of the corresponding hue is converged to the preset target brightness value while adjusting the illumination value of the corresponding hue.

In the step S140, if the measured brightness value is not converged to the target brightness value by the optical system control device 130, the illumination value of each hue is adjusted to proceed to the step of acquiring the image.

Then, in the S150 step, when the measured brightness value is converged to the target brightness value by the optical system control device 130, the illumination value of each hue at that time can be set.

As shown in FIG. 7, by going through the illumination value adjustment process of the illumination device as described above, the illumination value at which the measured brightness value for each hue with respect to the illumination device is converged to the target brightness value is investigated and set. can do.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited to this, and various modifications and modifications are made within the scope of the technical idea of the present invention described in the claims. It is clear to those with ordinary knowledge in the art that this is possible.

100 Visual inspection device 110 Lighting device 120 Camera device 130 Optical system control device 131 Image acquisition unit 132 Luminance value measurement unit 133 White balance ratio value setting unit

Claims (14)

Lighting equipment that illuminates the product to be inspected,
A camera device that captures the product to be inspected and provides a video signal,
The white balance ratio value of each hue in which the measured luminance value of each hue obtained from the image converges to the target luminance value while acquiring the image from the video signal of the camera device and adjusting the white balance ratio value of each hue. Including optical system control device, which adjusts and sets
The optical system control device is
If the measured luminance value of the corresponding hue does not converge to the target luminance value, after rebalancing the camera gain, the white balance ratio value of the corresponding hue is further adjusted so that the measured luminance value of the corresponding hue converges to the target luminance value. Visual inspection equipment. The optical system control device is
A video acquisition unit that acquires video from the video signal from the camera device,
A luminance value measuring unit that measures the luminance value of each hue from the image and provides the measured luminance value,
The white balance ratio value of each hue is adjusted so that the measured luminance value converges to the preset target luminance value, and when the measured luminance value converges to the target luminance value, the white balance ratio value of each hue at that time. If the measured luminance value of the corresponding hue does not converge to the target luminance value even when the white balance ratio value is adjusted to the upper limit value or the lower limit value, the camera gain is rebalanced and then the corresponding hue is measured. The visual inspection apparatus according to claim 1, further comprising a white balance ratio value setting unit that adjusts the white balance ratio value of the corresponding hue so that the luminance value converges to the target luminance value. The optical system control device is
The white balance ratio value of the corresponding hue is reduced so that the measured luminance value of the corresponding hue converges to the target luminance value when the measured luminance value of the corresponding hue is larger than the target luminance value, according to claim 1 or 2. Visual inspection equipment. The optical system control device is
If the measured luminance value of the corresponding hue is larger than the target luminance value, and the measured luminance value of the corresponding hue does not converge to the target luminance value when the white balance ratio value of the corresponding hue is the minimum value, the white balance ratio value of the corresponding hue Is increased by the preset change value ΔBcolor1, and in this case, the change values ΔBcolor2 and ΔBcolor3 of the gain change value ΔG of the camera device and the white balance ratio value of other hues are expressed by the following equations.

The visual inspection apparatus according to claim 3, wherein the camera gain adjusted by the above rebalancing is performed. The optical system control device is
If the measured luminance value of the corresponding hue is smaller than the target luminance value, the white balance ratio value of the corresponding hue is increased so that the measured luminance value of the corresponding hue converges to the target luminance value, which is one of claims 1 to 4. The visual inspection device according to paragraph 1. The optical system control device is
If the measured luminance value of the corresponding hue is smaller than the target luminance value, and the measured luminance value of the corresponding hue does not converge to the target luminance value when the white balance ratio value of the corresponding hue is the maximum value, the white balance ratio value of the corresponding hue Is reduced by the preset change value ΔBcolor1, and in this case, the change values ΔBcolor2 and ΔBcolor3 of the gain change value ΔG of the camera device and the white balance ratio value of other hues are expressed by the following equations.

The visual inspection apparatus according to claim 5, which rebalances the camera gain adjusted by. The optical system control device is
Claims 1 to 6 adjust and set the white balance ratio value for each hue related to the illumination value of the lighting device before adjusting and setting the white balance ratio value for each hue related to the camera gain. The visual inspection apparatus according to any one of the above. An optical system automatic calibration method for an visual inspection device including a lighting device for illuminating a product to be inspected, a camera device for photographing the product to be inspected, and an optical system control device.
The stage of acquiring an image from the image signal from the camera device by the optical system control device, and
A step of measuring the luminance value of each hue from the above image and providing the measured luminance value for each hue, and
While adjusting the white balance ratio value of the corresponding hue, the stage of determining whether the measured brightness value of the corresponding hue converges to the preset target brightness value, and
Even when the white balance ratio value of each hue is adjusted so that 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, the measured luminance value of the corresponding hue is the target. If it does not converge to the brightness value, after rebalancing the camera gain, the stage of adjusting the white balance ratio value of the corresponding hue so that the measured brightness value of the corresponding hue converges to the target brightness value, and
A method for automatically calibrating an optical system of an visual inspection apparatus, which comprises a step of setting a white balance ratio value of each hue at that time when the measured luminance value converges to the target luminance value. At the stage of adjusting the white balance ratio value,
The visual inspection according to claim 8, wherein when the measured luminance value of the corresponding hue is larger than the target luminance value, the white balance ratio value of the corresponding hue is reduced so that the measured luminance value of the corresponding hue converges to the target luminance value. How to automatically calibrate the optical system of the device. At the stage of adjusting the white balance ratio value,
If the measured luminance value of the corresponding hue is larger than the target luminance value, and the measured luminance value of the corresponding hue does not converge to the target luminance value when the white balance ratio value of the corresponding hue is the minimum value, the white balance ratio value of the corresponding hue Is increased by the preset change value ΔBcolor1, and in this case, the change values ΔBcolor2 and ΔBcolor3 of the gain change value ΔG of the camera device and the white balance ratio value of other hues are expressed by the following equations.

The method for automatically calibrating an optical system of the visual inspection apparatus according to claim 9, wherein the camera gain adjusted by is rebalanced. At the stage of adjusting the white balance ratio value,
Any of claims 8 to 10, wherein when the measured luminance value of the corresponding hue is smaller than the target luminance value, the white balance ratio value of the corresponding hue is increased so that the measured luminance value of the corresponding hue converges to the target luminance value. The method for automatically calibrating an optical system of the visual inspection apparatus according to item 1. At the stage of adjusting the white balance ratio value,
If the measured luminance value of the corresponding hue is smaller than the target luminance value, and the measured luminance value of the corresponding hue does not converge to the target luminance value when the white balance ratio value of the corresponding hue is the maximum value, the white balance ratio value of the corresponding hue Is reduced by the preset change value ΔBcolor1, and in this case, the change values ΔBcolor2 and ΔBcolor3 of the gain change value ΔG of the camera device and the white balance ratio value of other hues are expressed by the following equations.

The method for automatically calibrating an optical system of the visual inspection apparatus according to claim 11, wherein the camera gain adjusted by the above is rebalanced. The method for automatically calibrating an optical system of an appearance inspection device according to any one of claims 8 to 12, further comprising a step of adjusting a lighting value of the lighting device before the step of acquiring the image. The step of adjusting the lighting value is
The stage of acquiring an image from the image signal from the camera device by the optical system control device, and
The stage of measuring the luminance value of each hue from the above image and providing the measured brightness value for each hue, and
While adjusting the illumination value of the corresponding hue, the stage of determining whether the measured brightness value of the corresponding hue converges to the preset target brightness value, and
If the measured brightness value does not converge to the target brightness value, the stage of adjusting the illumination value of each hue and proceeding to the stage of acquiring the image, and the stage of proceeding to the stage of acquiring the image.
The method for automatically calibrating an optical system of an visual inspection apparatus according to claim 13, comprising a step of setting an illumination value of each hue at that time when the measured brightness value converges to the target brightness value.

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