Inspection device and method of inspecting inspection target using the same
An inspection device includes an imaging unit which captures an inspection target and outputs image data corresponding to the inspection target, a data extraction unit which receives the image data and extracts inspection data corresponding to an inspection area of the inspection target from the image data, a setting unit which sets a threshold value based on a grayscale value of comparative data compared with the inspection data, and an inspection unit which determines whether the inspection target is defective based on the threshold value.
1 . An inspection device for inspecting an inspection target, the inspection device comprising:
an imaging circuit which captures the inspection target and outputs image data corresponding to the inspection target;
a data extraction circuit which receives the image data and extracts inspection data corresponding to an inspection area of the inspection target from the image data;
a setting circuit which sets a threshold value based on a grayscale value of comparative data compared with the inspection data in a manner in which the threshold value increases as the grayscale value of the comparative data increases and the threshold value decreases as the grayscale value of the comparative data decreases; and
an inspection circuit which determines that the inspection target is defective in a state in which a difference between the inspection data and the comparative data exceeds the threshold value,
wherein the grayscale value range of the comparative data is classified into a plurality of sections,
wherein the threshold value has a linear relationship with the grayscale value of the comparative data in each of the plurality of sections, and
wherein a slope in a section corresponding to higher grayscale value is greater than a slope in a section corresponding to lower grayscale value.
2 . The inspection device of claim 1 , wherein the plurality of sections comprise a first section, a second section, and a third section, and
the grayscale value of the comparative data has a range comprising the first section, the second section, and the third section.
3 . The inspection device of claim 2 , wherein the setting circuit sets the grayscale value of the comparative data and the threshold value such that an increase amount of the grayscale value of the comparative data is directly proportional to an increase amount of the threshold value in each of the first section, the second section, and the third section.
4 . The inspection device of claim 3 , wherein a relationship between the increase amount of the grayscale value of the comparative data and the increase amount of the threshold value in the first section is defined as a first proportional value,
a relationship between the increase amount of the grayscale value of the comparative data and the increase amount of the threshold value in the second section is defined as a second proportional value,
a relationship between the increase amount of the grayscale value of the comparative data and the increase amount of the threshold value in the third section is defined as a third proportional value,
the third proportional value is set greater than the second proportional value by the setting circuit, and
the second proportional value is set greater than the first proportional value by the setting circuit.
5 . The inspection device of claim 3 , wherein the setting circuit sets the threshold value to which a first correction value is applied in the first section, sets the threshold value to which a second correction value is applied in the second section, and sets the threshold value to which a third correction value is applied in the third section.
6 . The inspection device of claim 1 , wherein a reference grayscale value is defined in a range of the grayscale value of the comparative data, and
the inspection circuit does not determine whether the inspection target is defective in a section where the grayscale value is greater than the reference grayscale value.
7 . The inspection device of claim 1 , wherein the inspection area comprises a first inspection area and a second inspection area,
the data extraction circuit extracts first inspection data corresponding to the first inspection area and second inspection data corresponding to the second inspection area, and
the inspection circuit determines whether the first and second inspection data are defective based on different threshold values from each other.
8 . The inspection device of claim 1 , wherein the comparative data correspond to a comparative area from the image data to be compared with the inspection area.
9 . The inspection device of claim 1 , wherein the inspection target comprises a plurality of cells.
10 . The inspection device of claim 8 , wherein the inspection target comprises a plurality of layers, and the inspection area and the comparative area are defined in a same layer.
11 . The inspection device of claim 1 , further comprising:
a light source which irradiates a light; and
an optical member which controls a path of the light to direct toward the inspection target.