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 a measurement zone in the vertical direction where the refracted light beams according to wavelengths are focused; and an image sensor that detects color information of the light beams refracted according to wavelengths that are focused and reflected at a position corresponding to the height on the surface of the measurement object, and the optical system includes a focus adjustment unit configured to change the measurement zone by vertically changing the position where the refracted light beams according to wavelengths are focused.

Description

[Technical Field]

[0001] The present disclosure relates to a three-dimensional shape inspection device and a three-dimensional shape inspection method. [Background technology]

[0002] Confocal microscopy (or confocal laser scanning microscopy, CLSM) is a type of microscope that uses a pinhole to remove out-of-focus light, eliminating interference from light outside the focal area and achieving high resolution and accuracy. It is used in fields such as life science, semiconductors, and materials science.

[0003] Among confocal microscopes, chromatic confocal microscopy is known for using chromatic aberration to perform 3D inspection of an object. Chromatic confocal microscopy refracts white light emitted from a light source at different refractive indices for different wavelengths and irradiates the refracted light onto the surface of the object. The refracted light is focused on the surface of the object and reflected, which is then transmitted through a pinhole. The wavelength of the transmitted light is detected using a spectrometer. Chromatic confocal microscopes perform 3D inspections by storing a table of focal length information for the optical system corresponding to the wavelength of the focused light and measuring the height of the object based on the wavelength of the detected light. Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional chromatic confocal microscopes perform 3D inspection by irradiating light emitted from a light source at only one point on the surface of an object to be measured and detecting the reflected light, and are limited to a point scan method or a very short line scan method, resulting in a very slow inspection speed. The embodiments of the present disclosure solve the problems of the conventional technology.

[0005] Furthermore, in conventional chromatic confocal microscopes, the axial resolution depends on the maximum inspection height, so as the maximum inspection height increases, the axial resolution also increases (i.e., the axial resolution deteriorates), resulting in a problem of degraded performance of the device. The embodiments of the present disclosure solve the problems of the conventional technology.

[0006] Furthermore, since a phosphor is a substance that absorbs light or electromagnetic waves of a specific wavelength and emits light of a different wavelength, conventional chromatic confocal microscopes have been known to inaccurately measure the height corresponding to the detected wavelength when the object being measured contains a phosphor. One embodiment of the present disclosure solves this problem in the prior art. [Means for solving the problem]

[0007] One aspect of the present disclosure provides an embodiment of a 3D shape inspection apparatus. The 3D shape inspection apparatus according to a representative 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 a 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 to form a vertical measurement zone where the refracted light beams according to wavelengths are focused, and an image sensor configured to detect color information of the light beams refracted according to wavelengths that are focused and reflected at a position corresponding to a height on the surface of the measurement object, and the optical system includes a focus adjustment unit configured to change the measurement zone by vertically changing the position where the refracted light beams according to wavelengths are focused.

[0008] In one embodiment, the light irradiation unit may be configured to irradiate the plurality of lights having a plurality of focal points in a horizontal direction perpendicular to a vertical direction downward onto the surface of the object to be measured.

[0009] In one embodiment, the focus adjustment unit may include a variable lens that refracts each of the modulated lights, and may be configured to be able to change the measurement section in the vertical direction by adjusting the curvature of the variable lens.

[0010] In one embodiment, the variable lens may include a liquid lens whose curvature changes based on a current applied to the focus adjustment unit.

[0011] In one embodiment, the focus adjustment unit may be configured to select one of a plurality of measurement sections by vertically changing the position where the refracted light for each wavelength is focused.

[0012] In one embodiment, any one of the plurality of measurement sections may be configured to be different from any other of the plurality of measurement sections.

[0013] In one embodiment, the spatial light modulator may include a plurality of digital micromirror devices arranged in an array and configured to reflect and thereby modulate light received from the light source.

[0014] In one embodiment, the image sensor is configured to detect color information of the plurality of lights that are focused and reflected on the surface of the object to be measured, and based on the color information of the plurality of lights detected by the image sensor, the respective heights above the surface of the object to which the plurality of lights are reflected can be measured.

[0015] In one embodiment, the color information may include RGB information of light focused and reflected on the surface of the measurement object.

[0016] In one embodiment, the image sensor may be configured to acquire wavelength information of light focused and reflected on the surface of the measurement object based on the RGB information.

[0017] In one embodiment, the image sensor may include one of a color camera, a multi-spectral camera, or a mono camera with a bandpass filter.

[0018] In one embodiment, the light source may include one of an LED, a halogen lamp, or a xenon lamp.

[0019] In an embodiment, the three-dimensional shape inspection apparatus may further include a control unit that measures the height of the surface of the measurement object based on color information detected by the image sensor.

[0020] In one embodiment, the three-dimensional shape inspection apparatus may further include an external light source configured to irradiate light onto the surface of the measurement object.

[0021] In one embodiment, the image sensor may be configured to acquire wavelength information of light emitted from an external light source that is reflected by the surface of the measurement object.

[0022] In one embodiment, the 3D shape inspection apparatus may further include a control unit configured to control the focus adjustment unit to change the measurement area when the wavelength of light detected by the image sensor is a second wavelength different from the first wavelength when the external light source irradiates light having a first wavelength.

[0023] In one embodiment, the control unit may be configured to control the focus adjustment unit to change the measurement section so that the wavelength of light focused at a position corresponding to the height above the surface of the measurement object does not include wavelengths between the first wavelength and the second wavelength.

[0024] Another aspect of the present disclosure provides an embodiment of a three-dimensional shape inspection apparatus. The three-dimensional shape inspection apparatus according to a representative embodiment includes: a light source; 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 a 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 to form a vertical measurement zone where the refracted light beams according to wavelengths are focused; an image sensor that detects color information of light beams that are focused and reflected at a position corresponding to a height above the surface of the measurement object, among the refracted light beams according to wavelengths; and a focus adjustment unit configured to change the measurement zone by vertically moving the optical system to vertically change the position where the refracted light beams according to wavelengths are focused.

[0025] Another aspect of the present disclosure provides an embodiment of a 3D shape inspection method. The 3D shape inspection method according to a representative embodiment includes: a light modulation step of modulating light received from a light source to irradiate a surface of a measurement object with a plurality of light beams having a plurality of foci; a light irradiation step of irradiating the modulated light beams downward to form a measurement section in an up-down direction where the refracted light beams for each wavelength are focused by refracting the light beams with different refractive indices according to a plurality of wavelengths using chromatic aberration; a focus adjustment step of changing the measurement section by vertically changing the position where the refracted light beams for each wavelength are focused; an information acquisition step of detecting color information of light beams that are focused and reflected at a position corresponding to a height on the surface of the measurement object, among the light beams refracted for each wavelength in the measurement section; and a height measurement step of measuring the height of the surface of the measurement object based on the detected color information.

[0026] In one embodiment, the focus adjusting step may include selecting one of a plurality of measurement sections by vertically changing the position where the light refracted according to the wavelength is focused, and the information acquiring step and the height measuring step may be performed based on color information of light that is focused and reflected at a position corresponding to the height on the surface of the object to be measured, among the light refracted according to the wavelength in one of the measurement sections.

[0027] In one embodiment, the 3D shape inspection method may further include an external light source irradiation step of irradiating light onto the surface of the measurement object, wherein the information acquisition step includes an external light source wavelength detection step of acquiring wavelength information of light emitted from the external light source and reflected from the surface of the measurement object, and the focus adjustment step may include a step of changing the measurement section when the wavelength of light detected in the external light source wavelength detection step is a second wavelength different from the first wavelength when light having a first wavelength is irradiated in the external light source irradiation step. [Effects of the Invention]

[0028] According to an embodiment of the present disclosure, it is possible to inspect a large area of ​​an object in 3D at a faster speed using a spatial light modulator and an image sensor that detects color information of light.

[0029] According to the embodiment of the present disclosure, by dividing the maximum inspectable area into a plurality of steps and inspecting the area, it is possible to reduce the axial resolution and improve the performance of the apparatus.

[0030] According to an embodiment of the present disclosure, even when the measurement object contains a fluorescent material, accurate 3D inspection can be performed by changing the measurement section. [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 10 is a schematic diagram showing a driving method of a three-dimensional shape inspection device according to a comparative example of the present disclosure. [Figure 2]2 is a graph showing that light emitted from the light source of FIG. 1 is refracted at different refractive indices according to wavelength in an optical system, forming measurement sections in the up and down directions. [Figure 3] 2 is a schematic diagram illustrating how light emitted from a light source in FIG. 1 is refracted at different refractive indices according to wavelength in an optical system, forming measurement zones in the vertical direction. [Figure 4] 1 is an overall perspective view of a three-dimensional shape inspection device according to an embodiment of the present disclosure. [Figure 5] FIG. 5 is a cross-sectional view taken along the line A1-A1′ in FIG. [Figure 6] FIG. 1 is a schematic diagram illustrating a digital micromirror device utilized in one embodiment of the present disclosure. [Figure 7] FIG. 1 is a schematic diagram illustrating a charge-coupled device (CCD) utilized in one embodiment of the present disclosure. [Figure 8] FIG. 2 is a schematic diagram illustrating a process in which a three-charge coupled device according to an embodiment of the present disclosure acquires RGB information of light. [Figure 9] FIG. 9 is a conceptual diagram showing a process of converting the RGB information acquired in FIG. 8 into an HSV coordinate system. [Figure 10] 1 is a schematic diagram illustrating an operation of a three-dimensional shape inspection device according to an embodiment of the present disclosure. [Figure 11] FIG. 2 is a perspective view showing a focus adjustment unit according to an embodiment of the present disclosure. [Figure 12] FIG. 12 is a cross-sectional view taken along line S1-S1' in FIG. [Figure 13] FIG. 1 is a conceptual diagram illustrating how a liquid lens operates according to one embodiment of the present disclosure. [Figure 14] 10 is a graph illustrating an example of selecting and inspecting one measurement section from among a plurality of measurement sections according to an embodiment of the present disclosure. [Figure 15] 6 is a cross-sectional view showing an embodiment in which the three-dimensional shape inspection apparatus shown in FIG. 5 further includes an external light source. [Figure 16] 10 is a graph illustrating a method of operation of a three-dimensional shape inspection device when a measurement object includes a fluorescent material, according to an embodiment of the present disclosure. [Figure 17]1 is a flowchart showing the flow of an embodiment of a three-dimensional shape inspection method according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0032] The examples of the present disclosure are provided for the purpose of explaining the technical concept of the present disclosure, and the scope of the rights of the present disclosure is not limited to the examples presented below or the specific descriptions of these examples.

[0033] Unless otherwise specified, all technical and scientific terms used in this disclosure have the meanings commonly understood by those of ordinary skill in the art to which this disclosure belongs. All terms used in this disclosure have been selected for the purpose of more clearly describing this disclosure, and are not selected to limit the scope of rights related to this disclosure.

[0034] As used in this disclosure, terms such as "including," "comprising," "having," and the like should be understood as open-ended terms that include the possibility of including other embodiments, unless otherwise specified in the phrase or sentence in which the term is included.

[0035] In this disclosure, the singular terms "a," "an," and "the" may include the plural meaning unless otherwise specified, and this also applies to the singular terms recited in the claims.

[0036] The terms "first", "second", etc. used in this disclosure are used to distinguish between multiple elements, and do not limit the order or importance of the elements.

[0037] The term "module" as used in this disclosure refers to software or hardware components such as a field-programmable gate array (FPGA) or an application-specific integrated circuit (ASIC). However, a "module" is not limited to hardware and software, and may be configured to reside on an addressable storage medium or to implement one or more processors. Thus, by way of example, a "module" includes components such as software components, object-oriented software components, class components, and task components, as well as processors, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. Additionally, the functionality provided within components and "modules" may be combined into fewer components and "modules" or further separated into additional components and "modules."

[0038] As used in this document, the phrase "based on" is used to describe one or more factors that influence the decision, act of judgment, or behavior described in the phrase or sentence containing the phrase, and does not exclude additional factors that influence that decision, act of judgment, or behavior.

[0039] In this disclosure, when a component is referred to as being "coupled" or "connected" to another component, it should be understood that the component is directly coupled or connected to the other component, or is coupled or connected through yet another component.

[0040] Directional terms such as "below" and "down" used in this disclosure refer to the direction in which the measurement object is positioned relative to the 3D shape inspection device in the attached drawings, and directional terms such as "up" and "above" refer to the opposite direction. However, this is merely for the purpose of explanation to make this disclosure clearer, and the definition of each direction may change depending on the reference point.

[0041] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In the accompanying drawings, identical or corresponding components are designated by the same reference numerals. Furthermore, in the following description of the embodiments, duplicated descriptions of identical or corresponding components may be omitted. However, omission of a description of a component does not mean that the component is not included in any of the embodiments.

[0042] Fig. 1 is a schematic diagram showing a driving method of a three-dimensional shape inspection device according to a comparative example of the present disclosure. Fig. 2 is a graph showing that light emitted from the light source of Fig. 1 is refracted by different refractive indices according to wavelength in the optical system, thereby forming vertical measurement zones. Fig. 3 is a schematic diagram showing how light emitted from the light source of Fig. 1 is refracted by different refractive indices according to wavelength in the optical system, thereby forming vertical measurement zones.

[0043] The operation of the three-dimensional shape inspection device 50 according to the comparative example will be described below with reference to FIGS.

[0044] The three-dimensional shape inspection apparatus 50 can irradiate light onto the surface of the measurement object 20 by transmitting light emitted from a light source 52 through a beam splitter 54. The light source 52 may be configured to emit light having multiple wavelengths. The measurement object 20 may include various inspected objects, such as cells, metal and non-metal materials, and semiconductor substrates used in fields such as life science, semiconductors, and materials science. The measurement object 20 may also include a transparent body or other material, and may include a mirror surface (C4 bump, μ bump, die, etc.) of a semiconductor or the like.

[0045] The light transmitted through the beam splitter 54 may be refracted by the optical system 56. The optical system 56 may be configured to refract incident light at different refractive indices according to wavelengths using chromatic aberration. The optical system 56 may be configured to focus light using chromatic aberration so that light with longer wavelengths is focused farther from the optical system 56 and light with shorter wavelengths is focused closer to the optical system 56. For example, referring to FIG. 1 , the manner in which light having multiple wavelengths is refracted by the optical system 56 at different refractive indices is shown, with light having the shortest wavelength λ1 of the multiple wavelengths being focused closest to the optical system 56 and light having the longest wavelength λn of the multiple wavelengths being focused farthest from the optical system 56. Among the light refracted according to wavelength, there may be light having a height-corresponding wavelength λm that is focused at a position corresponding to the height on the surface of the measurement object 20. The height-corresponding wavelength λm may have a value between the shortest wavelength λ1 and the longest wavelength λn.

[0046] The light refracted according to the plurality of wavelengths may be configured to be reflected on the surface of the measurement object 20 and reflected from the beam splitter 54. The beam splitter 54 can reflect the light having the plurality of wavelengths reflected on the surface of the measurement object 20 toward the pinhole 58. The beam splitter 54, the optical system 56, and the pinhole 58 may be configured to transmit only light having a height-corresponding wavelength λ m, which is focused and reflected at a position corresponding to the height on the surface of the measurement object 20, among the light having the plurality of wavelengths. A spectrometer 60 may be formed on the light path passing through the pinhole 58. The spectrometer 60 may be configured to detect the light as a spectrum according to wavelength and to detect intensity information according to the wavelength of the light.

[0047] The three-dimensional shape inspection device 50 may be configured to measure the height of the measurement object 20 by detecting wavelength components of light focused on the surface of the measurement object 20 using a spectrometer 60. 3D inspection may be performed to inspect the three-dimensional shape of the measurement object 20 by moving the three-dimensional shape inspection device 50 or the measurement object 20 horizontally during inspection. The three-dimensional shape inspection device 50 of the comparative example is limited to a very slow inspection speed because it is only capable of a point scan method or a very small line scan method in which light emitted from a light source 52 irradiates only one point on the surface of the measurement object to perform 3D inspection. The inspection speed of the point scan method of the three-dimensional shape inspection device 50 of the comparative example is less than 1 mm2.

[0048] The axial resolution of the three-dimensional shape inspection device 50 according to the comparative example will be described with reference to FIGS.

[0049] The axial resolution of the three-dimensional shape inspection device 50 satisfies the following formula 1.

[0050] [Formula 1] JPEG2025533775000002.jpg992

[0051] The axial resolution (Axial Res) is proportional to the measurement range (ΔMeasurement Range) and the spectral resolution (Spectral Res), and inversely proportional to the difference (Δλ) between the maximum and minimum wavelengths of the light source 52 used for inspection. The proportionality constant (k) in Equation 1 is a constant determined during the design process of the inspection environment or inspection device. The resolution described herein is the shortest distance at which two closely spaced points can be distinguished, and the smaller this value, the better the performance of the inspection device. For example, as shown in FIGS. 2 and 3, the measurement range (ΔMeasurement Range) is the distance between the point where light with the shortest wavelength λ1 is focused and the point where light with the longest wavelength λn is focused. The wavelength difference (Δλ) is the difference between the shortest wavelength λ1 and the longest wavelength λn, and the measurement range (ΔMeasurement Range) is Z1.

[0052] The 3D shape inspection apparatus 50 according to the comparative example described above can measure the height of a measurement object when the measurement object is positioned at a position where light is focused, and therefore the inspection range of the measurement object may be changed according to the measurement range (ΔMeasurement Range). That is, the measurement range may refer to the maximum inspection height of the 3D shape inspection apparatus 50. The 3D shape inspection apparatus 50 according to the comparative example has a problem in that as the measurement range increases, i.e., as the maximum inspection height increases, the axial resolution also increases.

[0053] In contrast, a 3D shape inspection device and a 3D shape inspection method according to an embodiment of the present disclosure, which will be described below with reference to Figures 4 to 17, have the advantage of enabling high-speed, large-area 3D inspection of a measurement object using a spatial light modulator and an image sensor that detects color information of light. Also, in one embodiment, a focus adjustment unit is used to divide the maximum inspectable area into multiple steps for inspection, thereby improving axial resolution.

[0054] Fig. 4 is an overall perspective view of a three-dimensional shape inspection device according to an embodiment of the present disclosure, and Fig. 5 is a cross-sectional view taken along line A1-A1' in Fig. 4.

[0055] 4 and 5, the three-dimensional shape inspection apparatus 10 may be configured to inspect the three-dimensional shape of the measurement object 20. The three-dimensional shape inspection apparatus 10 may be configured to inspect the shape of the measurement object 20 by irradiating light onto the measurement object 20 and detecting information about the reflected light. The three-dimensional shape of the measurement object 20 can be inspected by detecting the positions and heights of multiple surfaces of the measurement object 20 while moving the three-dimensional shape inspection apparatus 10 or the measurement object 20. For convenience of explanation, FIG. 5 shows the three-dimensional shape inspection apparatus 10 and the measurement object 20 positioned in one location, but the present disclosure is not limited thereto, and the three-dimensional shape inspection apparatus 10 and the measurement object 20 may be moved vertically or horizontally for inspection.

[0056] The three-dimensional shape inspection device 10 may include a light irradiation unit 100, an optical system, and an image sensor 400.

[0057] The light irradiating unit 100 may be configured to irradiate light onto the surface of the measurement object 20. The light irradiating unit 100 may be configured to irradiate light in a downward direction where the measurement object 20 is located.

[0058] The light irradiation unit 100 may include a light source (not shown) and a spatial light modulator 110. The light source may be a white light source having multiple wavelengths. The light source may include any one of an LED, a halogen lamp, or a xenon lamp. The light source may include a sunlike LED. The present disclosure is not limited thereto, and any light source capable of emitting light having multiple wavelengths may be used in the present disclosure.

[0059] The light irradiator 100 may include a light irradiator case 150 that introduces light L from the light source into the three-dimensional shape inspection device 10. The light irradiator case 150 may have a space formed therein and be configured to receive light L from the light source. The internal space of the light irradiator case 150 may be a stop on the path along which light L from the light source is irradiated to the measurement object 20. The light irradiator case 150 may have a hole formed therein and include a light receiver 152 that protrudes to the outside. The light L from the light source may be received inside the three-dimensional shape inspection device 10 through the light receiver 152.

[0060] The spatial light modulator 110 may be configured to modulate the light L received from the light source. The spatial light modulator 110 may include any device that can change the amplitude or phase information of incident light depending on the position. The spatial light modulator 110 may be a device that controls the spatial distribution of light, thereby forming a light image in three-dimensional space.

[0061] The spatial light modulator 110 may be configured to modulate light received from the light source so that the light has multiple focal points. The light irradiation unit 100 may be configured to irradiate a plurality of light beams having multiple focal points onto the surface of the measurement object 20. Although FIGS. 4 and 5 show that a single light beam having a single focal point is irradiated onto the surface of the measurement object 20, this is for convenience of explanation, and a plurality of digital micromirror devices (DMDs), which are an example of a spatial light modulator described below in conjunction with FIG. 6, may be used to irradiate a plurality of light beams having multiple focal points onto the surface of the measurement object 20.

[0062] The optical system can refract light according to multiple wavelengths using chromatic aberration. The optical system can refract light according to multiple wavelengths with different refractive indices. The optical system can refract each light modulated by the spatial light modulator 110. The optical system can be configured to refract light having multiple wavelengths with different refractive indices to form a measurement zone in which the refracted light according to wavelength is focused. The measurement zone can be formed in the vertical direction. Although FIGS. 4 and 5 show that a single light having a single focus is irradiated onto the surface of the measurement object 20, as shown in FIGS. 2 and 3, the modulated light can form a vertical measurement zone by using the optical system to refract light L received from a light source with different refractive indices according to multiple wavelengths.

[0063] The optical system may include multiple lenses 211, 212, 213, 214, 215, and 241. The lenses may include any optical device that focuses or diverges light by refracting the light it receives. The lenses may include a variable-curvature lens 241, whose curvature is adjustable.

[0064] The three-dimensional shape inspection apparatus 10 may include a reflecting unit 220 that reflects light and changes the travel path of the light. The reflecting unit 220 may include an optical device configured to reflect the received light so that the light is transmitted to another path.

[0065] The three-dimensional shape inspection apparatus 10 may include an optical splitter 230 that reflects a portion of the light and transmits the other portion of the light, thereby splitting the travel path of the light into two paths. The optical splitter 230 may include an optical device that transmits a portion of the received light and reflects the other portion.

[0066] The image sensor 400 can detect color information of light. The image sensor 400 can detect light reflected by the measurement object 20. The image sensor 400 can detect light that is focused and reflected at a position corresponding to the height on the surface of the measurement object 20, among light that is refracted according to wavelength and reflected by the measurement object 20. The image sensor 400 may be configured to detect color information of a plurality of light beams that are focused and reflected on the surface of the measurement object 20.

[0067] In one embodiment, the three-dimensional shape inspection apparatus 10 may include a control unit that measures the height of the surface of the measurement object 20. The control unit may include a computer that stores programs and / or information. The control unit may be configured to measure the height of the measurement object 20 based on color information detected by the image sensor 400. The height of the measurement object 20 from which the multiple lights are reflected can be measured based on the color information of the multiple lights detected by the image sensor 400. The image sensor 400 can measure each height on the surface of the measurement object 20 from which the multiple lights are reflected. The image sensor 400 of the three-dimensional shape inspection apparatus 10 of the present disclosure can measure the heights on multiple surfaces of the measurement object 20 at once, thereby enabling high-speed large-area inspection of the measurement object.

[0068] 6 is a schematic diagram showing a digital micromirror device used in an embodiment of the present disclosure. With reference to FIG. 6, a digital micromirror device (hereinafter referred to as DMD) will be described as an example of a spatial light modulator 110 according to an embodiment of the present disclosure.

[0069] The spatial light modulator 110 may include a digital micromirror device (DMD) using digital light processing (DLP) technology. The digital micromirror device (DMD) may include multiple DMDs arranged in an array. The digital micromirror device (DMD) may be a micro-sized mirror fabricated using a micro-electromechanical system (MEMS). That is, each of the multiple digital micromirror devices (DMDs) can function as a pixel. The digital micromirror devices (DMDs) in FIG. 6 form an array with 18 rows and 19 columns, but the numbers of rows and columns that make up the array are exemplary, and any other number of rows and columns may be used.

[0070] The DMD may have electrodes at its bottom to receive electrical signals from the outside and a reflecting mirror at its top to reflect light. An electrical signal is applied to the electrodes at the bottom of the DMD to adjust the angle of the reflecting mirror, so that the reflected light is either reflected by an external projection lens (not shown) and emitted, or reflected by a light-absorbing plate (not shown) and absorbed instead of being emitted. Adjusting the electrodes at the bottom of the DMD can control the on / off state of the light from each DMD. The spatial light modulator 110 can adjust each pixel of the DMD to an on / off state, so that it can modulate light L received from a light source into light having a desired shape and form. In FIG. 6, the digital micromirror devices in 4n+1 rows and 4n+1 columns of the array are shown to be in the on state (n is an integer greater than or equal to 0), but the present disclosure is not limited to this, and the digital micromirror devices of individual array elements can be arbitrarily adjusted to the on / off state.

[0071] 4 to 6, the light irradiation unit 100 may be configured to irradiate a plurality of lights downward in a horizontal direction perpendicular to the up-down direction onto the surface of the measurement object 20. Each of the plurality of digital micromirror devices (DMDs) may be adjusted to an on / off state, and light reflected by a digital micromirror device (DMD) in an on-state may be emitted toward the measurement object 20. Therefore, the plurality of lights emitted and modulated from each of the plurality of digital micromirror devices (DMDs) may be configured to have a plurality of focal points. The three-dimensional shape inspection apparatus 10 according to an embodiment of the present disclosure may be configured to irradiate a plurality of lights having a plurality of focal points onto the surface of the measurement object 20.

[0072] Fig. 7 is a schematic diagram showing a charge-coupled device (CCD) used in one embodiment of the present disclosure. Fig. 8 is a schematic diagram showing a process in which a three-charge-coupled device according to one embodiment of the present disclosure acquires RGB information of light. Fig. 9 is a conceptual diagram showing a process in which the RGB information acquired in Fig. 8 is converted into an HSV coordinate system.

[0073] In one embodiment referring to FIG. 7, the image sensor may include a charge coupled device (hereinafter referred to as a CCD). A charge coupled device (CCD) refers to a sensor that converts light into electric charges to obtain light information. A charge coupled device (CCD) is composed of a pixel-shaped chip and has a photodiode inside that generates electrons according to the amount of photons. Therefore, light intensity information can be obtained by measuring and reconstructing the amount of electrons or current.

[0074] The charge-coupled device (CCD) may include a plurality of charge-coupled devices (CCDs) arranged in an array format. Each of the charge-coupled devices (CCDs) can serve as a pixel. The plurality of charge-coupled devices (CCDs) may be configured to detect color information of the plurality of lights reflected when modulated light having a plurality of focal points is focused on the surface of the measurement object 20. Based on the color information of the plurality of lights detected by the charge-coupled device (CCD), the respective heights above the surface of the measurement object 20 at which the plurality of lights are reflected can be measured.

[0075] The charge coupled device (CCD) may be a 1-charge coupled device (1CCD) consisting of one charge coupled device, or a 3-charge coupled device (3CCD) having three separate charge coupled devices.

[0076] For example, referring to Figure 8, a 3-charge coupled device (3CCD) may include three separated charge coupled devices, 3CCD-R, 3CCD-G, and 3CCD-B. Each of the three separated charge coupled devices, 3CCD-R, 3CCD-G, and 3CCD-B, is located on the path of light separated into R, G, and B components by prisms A, B, and C, and can detect the R, G, and B components of light. The 3-charge coupled device (3CCD) detects the R, G, and B components separated by prisms A, B, and C with each charge coupled device, providing higher color reproducibility and image quality than a 1-charge coupled device (1CCD) system.

[0077] In another embodiment (not shown), the image sensor 400 may include a complementary metal oxide semiconductor (CMOS). The CMOS may be configured to include a plurality of pixels. Light reaching each pixel may be focused on a photodiode to generate electrons, and the generated electrons may be converted into a voltage to detect light information.

[0078] The image sensor 400 may include any one of a color camera, a multi-spectral camera, or a mono camera with a bandpass filter, but the image sensor 400 of the present disclosure is not limited thereto and includes any device capable of detecting RGB information of light.

[0079] The color information of the light detected by the image sensor 400 may include RGB information. For example, the color information of the light detected by a 3-charge coupled device (3CCD) of the image sensor 400 may include RGB information. The RGB information may be RGB information of light that is refracted according to wavelength and focused and reflected at a position corresponding to the height on the surface of the measurement target 20.

[0080] The image sensor 400 may be configured to obtain light wavelength information based on the detected RGB information.

[0081] In one embodiment not shown, a lookup table is created in which wavelength information corresponding to RGB information is tabulated in advance, so that the RGB information detected by the image sensor 400 can be converted into light wavelength information.

[0082] In another embodiment referring to FIG. 9 , the image sensor 400 may be configured to convert RGB information into another coordinate system to acquire wavelength information of light focused and reflected on the surface of the measurement target 20. The other coordinate system may be an HSV coordinate system or a CIE XYZ coordinate system. For example, the RGB information detected by the image sensor 400 may be converted into the HSV coordinate system using the following Equations 2, 3, and 4 to acquire wavelength information of light using the HSV information. H is a value representing hue and has values ​​from 0° to 360°, where 0° and 360° may represent red hue. S is a value representing saturation, where 100% represents the darkest state, and 0% represents an achromatic color of the same brightness. V is a value representing brightness, where white is 100% and black is 0%. Since the wavelength information of a light source according to the H value of the light source is a predetermined value (for example, when H is 0° or 360°, the wavelength of red light is 625 to 740 nm), the wavelength information of the light source can be detected by the H value obtained by HSV coordinate system transformation.

[0083] [Formula 2] JPEG2025533775000003.jpg1543 JPEG2025533775000004.jpg1969

[0084] [Formula 3] JPEG2025533775000005.jpg1473

[0085] [Formula 4] JPEG2025533775000006.jpg1331

[0086] Furthermore, in a CIE chromaticity diagram obtained by converting RGB information into the CIE XYZ coordinate system, the dominant wavelength, which is the wavelength of the monochromatic light closest to the chromaticity coordinate of the light source, may be detected. The HSV coordinate system and the CIE XYZ coordinate system described above are merely examples for explaining the present disclosure, and any coordinate system capable of obtaining wavelength information of light may be used.

[0087] 10 is a schematic diagram showing the operation of a three-dimensional shape inspection device according to an embodiment of the present disclosure. The inspection method of the three-dimensional shape inspection device 10 of the present disclosure will be described below with reference to FIGS. 4, 5, and 10.

[0088] The spatial light modulator 110 modulates light L received from the light source and irradiates the light onto the surface of the measurement object 20. An optical system for transmitting light may be arranged on a path from the spatial light modulator 110 until the light is irradiated onto the measurement object 20. For example, the optical system may include multiple lenses 211, 212, 214, and 241 arranged on the path. An optical splitter 230 may be arranged on a path from the spatial light modulator 110 until the light is irradiated onto the measurement object 20. The optical splitter 230 can form an optical path from the spatial light modulator 110 to the measurement object 20 by reflecting the received light. The optical system may include a lens 242 located before the light is irradiated onto the measurement object 20. The lens 242 may be composed of multiple lenses. The lens 242 may be an objective lens.

[0089] Light reflected on the surface of the measurement object 20 is configured to be transmitted to the image sensor 400. An optical system for transmitting the light reflected on the measurement object 20 to the image sensor 400 may be disposed on a path from the measurement object 20 to the image sensor 400. For example, the optical system may include a plurality of lenses 241, 214, 212, and 215 disposed on the path. An optical splitter 230 may be disposed on a path from the measurement object 20 to the image sensor 400. The optical splitter 230 transmits the received light to form an optical path from the measurement object 20 to the image sensor 400. The image sensor 400 can measure the height of the measurement object 20 by detecting color information of light that is focused and reflected at a position corresponding to the height on the surface of the measurement object 20, among light refracted according to wavelength. The optical path formed so that the light L emitted from the light source can be reflected by the measurement object 20 and transmitted to the image sensor 400 is not limited to this, and any optical path can be formed by arranging a lens, a reflecting unit 220, and an optical splitter 230.

[0090] The 3D shape inspection device 10 may include a focus adjustment unit configured to change the measurement area by vertically changing the position where light refracted by the optical system according to wavelength is focused. For example, the focus adjustment unit may be embodied as a means for changing the position of the optical system according to the embodiments described below, or may be embodied as a means constituting a part of the optical system and capable of changing the position where light is focused.

[0091] The focus adjusting unit may change a position where light refracted according to wavelength is focused. The focus adjusting unit may change the position where light is focused in an up-down direction. The focus adjusting unit may be configured to change a measurement section where light refracted according to wavelength is focused. The focus adjusting unit may change a position where the shortest wavelength among light refracted according to wavelength is focused in an up-down direction. The focus adjusting unit may change a position where the longest wavelength among light refracted according to wavelength is focused in an up-down direction. The focus adjusting unit may change a position where light having a wavelength between the shortest wavelength and the longest wavelength among light refracted according to wavelength is focused in an up-down direction.

[0092] In one embodiment not shown, the focus adjustment unit can be operated by a mechanical means for adjusting the position of the optical system to change the measurement zone. The focus adjustment unit may be configured to be able to change the measurement zone by moving the optical system vertically.

[0093] 10 to 13, the focus adjustment unit 240 can form part of the optical system. The following description will be given based on the embodiment shown in FIGS.

[0094] 10 , the optical system may include a focus adjustment unit 240. In the present disclosure, the focus adjustment unit 240 is disposed on the optical path immediately before the measurement object 20 is irradiated, but the present disclosure is not limited to this, and the focus adjustment unit 240 may be disposed at any point on the optical path from the light source to the image sensor 400.

[0095] The focus adjustment unit 240 can be operated by electronic means, such as applying a current to change the measurement area.

[0096] Fig. 11 is a perspective view showing a focus adjustment unit according to an embodiment of the present disclosure. Fig. 12 is a cross-sectional view taken along line S1-S1' in Fig. 11. Fig. 13 is a conceptual diagram showing how a liquid lens according to an embodiment of the present disclosure operates.

[0097] 10 to 13, the focus adjustment unit 240 may include a variable lens 241 that refracts each light beam modulated by the spatial light modulator 110. The focus adjustment unit 240 may be configured to adjust the curvature of the variable lens 241. In general, as the curvature of the variable lens 241 increases, the focal length, which is the distance from the variable lens to the point where light is focused, may decrease. The focus adjustment unit 240 may adjust the thickness C of the variable lens 241 by adjusting the curvature of the variable lens 241. In general, as the curvature of the variable lens 241 increases, the thickness C of the variable lens 241 may also increase.

[0098] The curvature of the variable lens 241 may be adjusted based on a current applied to the focus adjustment unit 240. The curvature of the variable lens 241 can be adjusted by adjusting the current applied to the focus adjustment unit 240. The focus adjustment unit 240 may be configured to adjust the curvature of the variable lens 241 to change the measurement section in which refracted light of each wavelength is focused in the vertical direction.

[0099] The variable lens 241 may include a liquid lens 260 whose curvature is variable. The curvature of the liquid lens 260 may change in response to an applied current. The curvature of the liquid lens 260 may be adjusted by adjusting the applied current. For example, the curvature of the liquid lens 260 may be increased by adjusting the current applied to the liquid lens 260, thereby increasing the thickness of the liquid lens (C1->C2) (see FIG. 13). As the curvature and thickness of the liquid lens 260 increase, the focal length of the liquid lens 260 may decrease, and the measurement section may be shifted vertically by the decreased focal length (see FIG. 13).

[0100] FIG. 14 is a graph for explaining how to select and inspect one measurement section from among a plurality of measurement sections according to an embodiment of the present disclosure.

[0101] The focus adjustment unit 240 may be configured to select one of a plurality of measurement zones by changing the position where refracted light is focused for each wavelength. The focus adjustment unit 240 may be configured to select one of a plurality of measurement zones in the vertical direction by changing the position where light is focused in the vertical direction. For example, the focus adjustment unit 240 may select one of a first measurement zone (0 to Z3), a second measurement zone (Z1 to Z2), and a third measurement zone (Z2 to Z3) to perform an inspection. Compared to the comparative example shown in FIGS. 1 to 3, the present disclosure can measure the measurement zone (0 to Z1) by dividing it into multiple measurement zones, thereby reducing the measurement zone range (ΔMeasurement Range) in Equation 1 and reducing the axial resolution (i.e., the axial resolution can be reduced by three times for the same maximum inspectable height Z1). While FIG. 14 shows three measurement zones, this is for convenience of explanation, and the present disclosure is not limited thereto. Inspection can be performed by dividing the measurement zone into one or more measurement zones.

[0102] In one embodiment, any one of the plurality of measurement sections may be configured to be different from any other of the plurality of measurement sections. Any one of the measurement sections may be configured to have a different vertical level from any other of the measurement sections. The level of any part of any one of the measurement sections may be configured to be the same as the level of any part of any other of the measurement sections (i.e., there may be at least one section in different measurement sections having the same level). The level of all sections of any one of the measurement sections may be configured to be different from the level of all other sections. While FIG. 14 illustrates an example in which the level of all sections of any one of the measurement sections is configured to be different from the level of all other sections, the present disclosure is not limited thereto.

[0103] Fig. 15 is a cross-sectional view showing an embodiment in which the three-dimensional shape inspection apparatus shown in Fig. 5 further includes an external light source. Fig. 16 is a graph for explaining a method of operating the three-dimensional shape inspection apparatus when the measurement object includes a fluorescent material according to an embodiment of the present disclosure.

[0104] With reference to FIGS. 15 and 16, a method of operation of the three-dimensional shape inspection device of the present disclosure when the measurement object contains a fluorescent material will be described.

[0105] Fluorescent materials are materials that absorb light or electromagnetic waves with specific wavelengths and emit light with other wavelengths. When a measurement object contains fluorescent materials, it is necessary to check whether the wavelength of the reflected and detected light is a wavelength reflected by the measurement object without fluorescent materials or a wavelength emitted by excitation from the fluorescent materials. In addition, when inspecting with a 3D shape inspection device, it is necessary to adjust the measurement area so that light with specific wavelengths is not focused and reflected on the surface of the measurement object.

[0106] 15 , the three-dimensional shape inspection apparatus 10 may include an external light source 600 configured to irradiate light onto the surface of the measurement object 20. The external light source 600 may be configured to irradiate light having a single wavelength onto the surface of the measurement object 20. The external light source 600 may be configured to irradiate the surface of the measurement object 20 with light having a single wavelength, and then increase or decrease the wavelength of the light having the single wavelength and further irradiate light, thereby irradiating light of multiple wavelengths onto the surface of the measurement object 20. The image sensor 400 may be configured to acquire wavelength information of the light emitted from the external light source 600 that is reflected by the surface of the measurement object 20.

[0107] 16 , when an external light source 600 irradiates a measurement object 20 with light having a first wavelength λ1, and the wavelength of light reflected by the measurement object 20 and detected by the image sensor 400 is a second wavelength λ2 different from the first wavelength λ1, the control unit may confirm the presence of a phosphor in the measurement object 20. The control unit may be configured to control the focus adjustment unit 240 to change the measurement range when the wavelength of light reflected from the measurement object 20 and detected by the image sensor 400 is the second wavelength λ2 when the external light source 600 irradiates the measurement object 20 with light having the first wavelength λ1. The control unit may control the focus adjustment unit 240 to prevent the image sensor 400, which detects light reflected from the measurement object, from detecting light excited by a phosphor included in the measurement object.

[0108] The control unit may be configured to control the focus adjustment unit 240 to change the measurement range so that the wavelength of light focused at a position corresponding to the height on the surface of the measurement object 20 does not include wavelengths between the first wavelength λ1 and the second wavelength λ2. If the wavelength of light focused at a position corresponding to the height on the surface of the measurement object 20 includes wavelengths between the first wavelength λ1 and the second wavelength λ2, the height corresponding to the wavelength detected by the image sensor 400 during the inspection process may be inaccurate. The measurement range may be changed to a range of a third wavelength λ3 and a fourth wavelength λ4, which does not include wavelengths between the first wavelength λ1 and the second wavelength λ2 (see FIG. 16 ). In FIG. 16 , the first wavelength λ1 and the second wavelength λ2 are shown to be approximately 450 nm to 500 nm, and the third wavelength λ3 and the fourth wavelength λ4 are shown to be approximately 570 nm to 620 nm, but the present disclosure is not limited thereto.

[0109] FIG. 17 is a flowchart showing the flow of an embodiment of a three-dimensional shape inspection method according to the present disclosure.

[0110] Referring to Figures 4, 5, and 17, the 3D shape inspection method (S10) may include a white light irradiation step (S101), a DLP multiple pattern irradiation step (S102), a measurement object irradiation step (S103), and a reflection step (S104) of a wavelength signal corresponding to the height of the measurement object.

[0111] The white light irradiation step (S101) is a step of irradiating light L from a light source to irradiate the surface of the measurement object 20 with light. The DLP multiple pattern irradiation step (S102) may be a step of modulating the light received in the white light irradiation step (S101). The DLP multiple pattern irradiation step (S102) may be configured to modulate the light L received from the light source so as to irradiate the surface of the measurement object 20 with a plurality of lights having a plurality of focal points. In the DLP multiple pattern irradiation step (S102), light modulation may be performed by the spatial light modulator 110. The DLP multiple pattern irradiation step (S102) may correspond to a light modulation step.

[0112] The measurement object irradiating step (S103) may be configured to refract each of the lights modulated in the DLP multiple pattern irradiating step (S102) with different refractive indices for each of a plurality of wavelengths due to chromatic aberration, and irradiate the light downward to form a measurement zone in the vertical direction where the refracted light for each wavelength is focused. The modulated light in the measurement object irradiating step (S103) may form the measurement zone through an optical system. The measurement object irradiating step (S103) may correspond to the light irradiating step.

[0113] The step of reflecting a wavelength signal corresponding to the height of the measurement object (S104) may be a step of reflecting focused light at a position corresponding to the height on the surface of the measurement object 20, among the light refracted according to wavelength irradiated onto the measurement object in the step of irradiating the measurement object (S103).

[0114] The 3D shape inspection method (S10) may include an information acquisition step of detecting color information of light that is focused and reflected at a position corresponding to the height on the surface of the measurement object 20, among light refracted by wavelength in the measurement section.

[0115] The information acquisition step may include an image acquisition step (S105), an RGB information acquisition step (S106), a coordinate system conversion step (S107), and a wavelength information confirmation step (S108).

[0116] The image acquiring step (S105) may be a step of receiving an image or information of light reflected from the light focused at a position corresponding to the height on the surface of the measurement object 20. The image acquiring step (S105) may be configured to receive the light reflected from the measurement object 20 using the image sensor 400. The RGB information acquiring step (S106) may be a step of acquiring RGB information of the light received in the image acquiring step (S105). The RGB information acquiring step (S106) may be configured to acquire the RGB information of the light using a 3CCD (3CCD) of the image sensor 400.

[0117] The coordinate system conversion step (S107) may include converting the RGB information acquired in the RGB information acquisition step (S106) into another coordinate system (e.g., HSV coordinate system or CIE XYZ coordinate system). The wavelength information confirmation step (S108) may include confirming wavelength information of light based on the information acquired in the coordinate system conversion step (S107). As described above, the wavelength information confirmation step (S108) may confirm wavelength information of light using an H value in the HSV coordinate system or dominant wavelength information in the CIE XYZ coordinate system.

[0118] The 3D shape inspection method (S10) may include a measurement object height confirmation step (S109) of measuring the height of the surface of the measurement object based on the color information detected in the information acquisition step. In the measurement object height confirmation step (S109), the height of the measurement object can be measured by detecting color information of light that is focused and reflected at a position corresponding to the height on the surface of the measurement object 20, among light refracted according to wavelength. The measurement object height confirmation step (S109) may correspond to the height measurement step.

[0119] The three-dimensional shape inspection method (S10) may include a 3D inspection proceeding step (S110) after the measurement object height confirmation step. The 3D inspection proceeding step may include at least one of the above-described steps (S101 to S109), and these steps (S101 to S109) may be performed multiple times to perform inspection on multiple surfaces of the measurement object 20.

[0120] The 3D shape inspection method (S10) may include a focus adjustment step of changing a measurement area by vertically changing a position where refracted light for each wavelength is focused. The focus adjustment step may be a step of changing the measurement area by the focus adjustment unit 240. The focus adjustment step may be performed before the white light irradiation step (S101) or before the white light irradiation step in the 3D inspection proceeding step (S110) which is performed at least once, so that the focus adjustment step may be performed multiple times.

[0121] The focus adjusting step may include a measurement section selecting step of selecting one of the plurality of measurement sections by vertically changing a position where light refracted according to wavelength is focused. The measurement section selecting step may be configured to vertically select one of the plurality of measurement sections by vertically changing a position where light is focused using the focus adjusting unit 240. The information acquiring step and the height measuring step may be performed based on color information of light that is focused and reflected at a position corresponding to a height on the surface of the measurement object, among light refracted according to wavelength in one of the measurement sections selected in the measurement section selecting step. The measurement section selecting step may be performed before the white light irradiating step (S101) or before the white light irradiating step in the 3D inspection proceeding step (S110) that is performed at least once, so that the measurement section selecting step may be performed multiple times.

[0122] The 3D shape inspection method (S10) may further include an external light source irradiating step of irradiating light onto a surface of the measurement object. The information acquiring step may include an external light source wavelength detecting step of acquiring wavelength information of light reflected from the surface of the measurement object in the external light source irradiating step. The external light source irradiating step and the external light source wavelength detecting step may be performed before the white light irradiating step (S101) or before the white light irradiating step in the 3D inspection proceeding step (S110) which is performed at least once, so that the external light source irradiating step and the external light source wavelength detecting step may be performed multiple times.

[0123] The focusing step may include changing a measurement section when the wavelength of light detected in the external light source wavelength detecting step is a second wavelength different from the first wavelength when the external light source irradiating step irradiates light having a first wavelength. The focusing step may include changing the measurement section so that the wavelength of light focused at a position corresponding to a height above the surface of the measurement object does not include a wavelength between the first wavelength and the second wavelength different from the first wavelength. The focusing step may be performed after the external light source wavelength detecting step.

[0124] Although the technical idea of ​​the present disclosure has been described above by way of some embodiments and examples shown in the accompanying drawings, it should be understood that various substitutions, modifications, and changes can be made without departing from the technical idea and scope of the present disclosure, which can be understood by those skilled in the art to which the present disclosure pertains. Furthermore, such substitutions, modifications, and changes should be considered to fall within the scope of the appended claims.

Claims

1. a light irradiation unit including a light source and a spatial light modulator configured to modulate light received from the light source, and configured to irradiate a plurality of lights having a plurality of focal points downward onto a surface of the measurement object; an optical system configured to refract each of the modulated lights with different refractive indices according to a plurality of wavelengths due to chromatic aberration, thereby forming measurement zones in an up-down direction in which the refracted lights according to wavelengths are focused; an image sensor that detects color information of light that is focused and reflected at a position corresponding to a height on the surface of the measurement object, among the light refracted according to wavelength; The optical system includes a focus adjustment unit configured to change the measurement area by vertically changing a position where the light refracted according to wavelength is focused.

2. 2. The three-dimensional shape inspection device according to claim 1, wherein the light irradiation unit is configured to irradiate the plurality of lights having a plurality of foci in a horizontal direction perpendicular to a vertical direction downward onto the surface of the measurement object.

3. 2. The three-dimensional shape inspection device according to claim 1, wherein the focus adjustment unit includes a variable lens that refracts each of the modulated lights, and is configured to be able to change the measurement section in the vertical direction by adjusting the curvature of the variable lens.

4. The three-dimensional shape inspection device according to claim 3 , wherein the variable lens includes a liquid lens whose curvature changes based on a current applied to the focus adjustment unit.

5. The focus adjustment unit 2. The three-dimensional shape inspection device according to claim 1, wherein the position where the refracted light for each wavelength is focused is changed in the vertical direction, thereby making it possible to select any one of a plurality of measurement sections.

6. The three-dimensional shape inspection device according to claim 5 , wherein any one of the plurality of measurement sections is configured to be different from any other of the plurality of measurement sections.

7. The spatial light modulator comprises: The three-dimensional shape inspection apparatus according to claim 1 , comprising a plurality of digital micromirror devices arranged in an array, configured to reflect and thereby modulate light received from the light source.

8. The image sensor is configured to detect color information of the plurality of lights focused and reflected on the surface of the measurement object; 2. The three-dimensional shape inspection device according to claim 1, wherein the heights of the reflected lights on the surface of the object are measured based on color information of the lights detected by the image sensor.

9. The three-dimensional shape inspection device according to claim 1 , wherein the color information includes RGB information of light focused and reflected on the surface of the measurement object.

10. The image sensor The three-dimensional shape inspection device according to claim 9 , configured to acquire wavelength information of light focused and reflected on the surface of the measurement object based on the RGB information.

11. The 3D shape inspection apparatus according to claim 1 , wherein the image sensor comprises one of a color camera, a multispectral camera, and a mono camera having a bandpass filter.

12. The three-dimensional shape inspection device according to claim 1 , wherein the light source includes one of an LED, a halogen lamp, and a xenon lamp.

13. The three-dimensional shape inspection device according to claim 1 , further comprising a control unit that measures the height of the surface of the measurement object based on color information detected by the image sensor.

14. further comprising an external light source configured to project light onto the surface of the measurement object; The three-dimensional shape inspection device according to claim 1 , wherein the image sensor is configured to acquire wavelength information of light emitted from an external light source and reflected by the surface of the measurement object.

15. 15. The three-dimensional shape inspection apparatus of claim 14, further comprising: a control unit configured to control the focus adjustment unit to change the measurement range when the wavelength of light detected by the image sensor is a second wavelength different from the first wavelength when the external light source irradiates light having a first wavelength.

16. The control unit 16. The three-dimensional shape inspection device according to claim 15, wherein the focus adjustment unit is controlled to change the measurement section so that the wavelength of light focused at a position corresponding to the height on the surface of the measurement object does not include wavelengths between the first wavelength and the second wavelength.

17. a light irradiation unit including a light source and a spatial light modulator configured to modulate light received from the light source, and configured to irradiate a plurality of lights having a plurality of focal points downward onto a surface of the measurement object; an optical system configured to refract each of the modulated lights with different refractive indices according to a plurality of wavelengths due to chromatic aberration, thereby forming measurement zones in an up-down direction in which the refracted lights according to wavelengths are focused; an image sensor that detects color information of light that is focused and reflected at a position corresponding to a height on the surface of the measurement object, among the light refracted according to wavelength; a focus adjustment unit configured to change the measurement section by vertically changing the position where the light refracted according to the wavelength is focused by vertically moving the optical system.

18. a light modulation step of modulating the light received from the light source so as to irradiate a surface of the measurement object with a plurality of light beams having a plurality of focal points; a light irradiation step of irradiating the modulated light downward to form a measurement section in an up-down direction where the light refracted according to the wavelength is focused by refracting the modulated light with different refractive indices according to the wavelengths due to chromatic aberration; a focus adjusting step of changing the measurement section by vertically changing a position where the light refracted according to the wavelength is focused; an information acquiring step of detecting color information of light reflected from the light refracted by wavelength in the measurement section and focused at a position corresponding to a height on the surface of the measurement object; a height measurement step of measuring a height of the surface of the measurement object based on the detected color information.

19. The focus adjustment step includes: selecting one of a plurality of measurement sections by vertically changing a position where the light refracted by each wavelength is focused, The information acquisition step and the height measurement step include:

20. The 3D shape inspection method of claim 18, wherein the 3D shape inspection is performed based on color information of light that is focused and reflected at a position corresponding to a height on the surface of the measurement object, among light refracted by wavelength in any one measurement section.

20. The method further includes an external light source irradiation step of irradiating light onto the surface of the measurement object, The information acquiring step includes an external light source wavelength detecting step of acquiring wavelength information of light emitted from an external light source and reflected from the surface of the measurement object, The focus adjustment step includes:

20. The three-dimensional shape inspection method of claim 18, further comprising: changing the measurement section when the wavelength of light detected in the external light source wavelength detection step is a second wavelength different from the first wavelength when the external light source irradiation step irradiates light having a first wavelength.

Images