3D shape inspection device and 3D shape inspection method

Abstract

A three-dimensional shape inspection device according to a disclosed embodiment includes a light source and a spatial light modulator configured to modulate light received from the light source, and a light irradiation unit configured to irradiate a plurality of light beams having a plurality of foci downward onto the surface of a measurement object; an optical system configured to refract each of the modulated light beams with different refractive indices according to a plurality of wavelengths using chromatic aberration, thereby forming an upward and downward measurement section in which the refracted light according to wavelength is focused; an optical splitter configured to transmit a portion of the light reflected by the measurement object and to reflect another portion of the light reflected by the measurement object; a first detection unit that detects information regarding the wavelength of the light transmitted through the optical splitter; and a second detection unit that detects information regarding the wavelength of the light reflected from the optical splitter, and the filter detection unit, which is either the first detection unit or the second detection unit, is equipped with a filter unit that blocks light of a specific wavelength or above and is configured to detect information regarding light of a wavelength below the specific wavelength.

Claims

[Claim 1] A light irradiation unit comprising a light source and a spatial light modulator configured to modulate the light received from the light source, configured to irradiate the surface of an object to be measured with multiple beams of light having multiple focal points downwards, An optical system configured to form a vertical measurement section in which the light refracted at each wavelength is focused by refracting each of the modulated lights at different refractive indices for each wavelength using chromatic aberration, An optical splitter configured to transmit some of the light reflected from the object to be measured, and to reflect the other part of the light reflected from the object to be measured, A first detection unit that detects information regarding the wavelength of light transmitted through the optical splitter, It includes a second detection unit that detects information regarding the wavelength of light reflected from the optical splitter, The system includes a control unit that measures the height of the base of the object to be measured and the height of a transparent object placed on the base based on the information detected by the first detection unit and the information detected by the second detection unit, A three-dimensional shape inspection device in which a filter detection unit, which is either the first detection unit or the second detection unit, is configured to detect information of light below a specific wavelength by including a filter unit that blocks light of a specific wavelength or higher. [Claim 2] The three-dimensional shape inspection apparatus according to claim 1, wherein the filter detection unit is configured to detect light intensity information. [Claim 3] The system further includes a focus adjustment unit configured to change the measurement interval by changing the position at which the light refracted according to the wavelength is focused in the vertical direction, The three-dimensional shape inspection apparatus according to claim 2, wherein the control unit is configured to control the focus adjustment unit to change the measurement interval when the light intensity information is determined to be below a predetermined first specific intensity. [Claim 4] The control unit, The three-dimensional shape inspection apparatus according to claim 3, wherein when the light intensity information is determined to be below a predetermined first specific intensity, the focus adjustment unit is controlled to change the measurement section so that shorter wavelength light is reflected by the object to be measured. [Claim 5] The system further includes a focus adjustment unit configured to change the measurement interval by changing the position at which the light refracted according to the wavelength is focused in the vertical direction, The three-dimensional shape inspection apparatus according to claim 2, wherein the control unit is configured to control the focus adjustment unit to change the measurement interval when the light intensity information is determined to be equal to or greater than a predetermined second specific intensity. [Claim 6] The control unit, The three-dimensional shape inspection apparatus according to claim 5, wherein when the light intensity information is determined to be equal to or greater than a predetermined second specific intensity, the focus adjustment unit is controlled to change the measurement section so that longer wavelength light is reflected by the object to be measured. [Claim 7] The system further includes a focus adjustment unit configured to change the measurement interval by changing the position at which the light refracted according to the wavelength is focused in the vertical direction, The control unit controls the focus adjustment unit to change the measurement interval when the light intensity information meets a predetermined standard. The three-dimensional shape inspection apparatus according to claim 2, wherein the first detection unit and the second detection unit are configured to detect information regarding the wavelength of light again when the measurement interval has been changed. [Claim 8] The control unit, (i) In the first state before changing the measurement interval, the system is configured to acquire first information detected by the no-filter detection unit among the first and second detection units, which is not the filter detection unit, and to acquire second information detected by the filter detection unit. (ii) In the second state, after changing the measurement interval, the system is configured to acquire the third information detected by the no-filter detection unit and the fourth information detected by the filter detection unit. (iii) The three-dimensional shape inspection apparatus according to claim 7, configured to measure the height of the base of the object to be measured and the height of a transparent body placed on the base based on the first information, the second information, the third information, and the fourth information. [Claim 9] When the working distance is defined as a value proportional to the average distance from the optical system to the position where the light refracted for each wavelength is focused, The control unit, The three-dimensional shape inspection apparatus according to claim 8, configured to measure the refractive index of the transparent body based on the working distance in the first state, the working distance in the second state, the first information, and the third information. [Claim 10] The optical system has a unique focus shift value for each wavelength due to chromatic aberration. When the working distance is defined as a value proportional to the average distance from the optical system to the position where the light refracted for each wavelength is focused, The control unit, The three-dimensional shape inspection apparatus according to claim 8, configured to measure a refractive index which is the value obtained by subtracting the working distance in the second state from the working distance in the first state, and dividing that value by the value obtained by subtracting the first focus shift value corresponding to the first information from the third focus shift value corresponding to the third information. [Claim 11] The control unit, A three-dimensional shape inspection apparatus according to claim 10, configured to measure the height of the base of the object to be measured and the height of a transparent body placed on the base, based on the first information, the second information, the third information, the fourth information, and the refractive index. [Claim 12] The focus adjustment unit includes a variable lens configured to change the measurement interval based on the applied current, The three-dimensional shape inspection apparatus according to claim 10, wherein the larger the applied current, the larger the value obtained by subtracting the working distance in the second state from the working distance in the first state. [Claim 13] The three-dimensional shape inspection apparatus according to claim 1, wherein the filter detection unit is the second detection unit. [Claim 14] The aforementioned spatial light modulator is The three-dimensional shape inspection apparatus according to claim 1, comprising a plurality of digital micromirror devices configured to modulate light received from the light source by reflecting it, and arranged in an array format. [Claim 15] The three-dimensional shape inspection apparatus according to claim 1, wherein the first detection unit and the second detection unit are configured to detect color information of light that has been focused and reflected from the light refracted according to the wavelengths at a position corresponding to the height of the base of the object to be measured or the height of a transparent body placed on the base. [Claim 16] The three-dimensional shape inspection apparatus according to claim 1, wherein the light irradiation unit is configured to irradiate the surface of the object to be measured with a plurality of lights having a plurality of focal points in a horizontal direction perpendicular to the vertical direction, in a downward direction. [Claim 17] A light modulation step in which light received from a light source is modulated so that multiple beams of light with multiple focal points are irradiated onto the surface of the object to be measured, A light irradiation step in which each of the modulated lights is refracted by chromatic aberration at different refractive indices for multiple wavelengths, thereby irradiating downwards to form a measurement section in the vertical direction where the light refracted for each wavelength is focused, A light path formation step in which a light splitter transmits some of the light reflected from the object to be measured and reflects the other part of the light reflected from the object to be measured, A first detection step in which information regarding the wavelength of light transmitted in the light path formation step is detected, A second detection step involves detecting information regarding the wavelength of the light reflected in the aforementioned optical path formation step, The process includes the step of measuring the height of the base of the object to be measured and the height of the transparent object placed on the base, based on the information detected in the first detection step and the information detected in the second detection step. A three-dimensional shape inspection method comprising a filter detection step in which either the first detection step or the second detection step blocks light of a specific wavelength or higher and detects information of light of a wavelength lower than the specific wavelength. [Claim 18] The aforementioned filter detection step is configured to detect light intensity information, The method for inspecting a three-dimensional shape according to claim 17, further comprising a focus adjustment step in which the measurement interval is changed by changing the position in the vertical direction of the position where the light refracted according to the wavelength is focused, when the light intensity information is determined to be below a predetermined first specific intensity or above a predetermined second specific intensity. [Claim 19] The aforementioned filter detection step is configured to detect light intensity information, If the light intensity information meets a predetermined standard, the method further includes a focus adjustment step to change the measurement interval by changing the position in the vertical direction where the light refracted for each wavelength is focused, The three-dimensional shape inspection method according to claim 17, wherein the first detection step and the second detection step are performed again with the measurement interval changed.

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