Optical detection device

Abstract

The invention relates to an optical detection device, which is used for detecting a to-be-detected object placed at a test station, and comprises a first coaxial light source which comprises a first light-emitting part and a first light splitting part; the first light-emitting part is used for emitting a first illumination light beam towards a first side surface of a to-be-detected object along a first direction; the first light splitting part is arranged in a light emitting path of the first light emitting part; the first high-brightness light source is arranged on one side of the first coaxial light source and used for emitting a first light supplementing beam, and the first light supplementing beam is projected to the second side face of the to-be-measured object in the direction opposite to the first direction; the light path turning unit and the first light splitting part are arranged in a spaced mode in the second direction, and the second direction and the first direction intersect and are not coplanar. The imaging unit is arranged on one side of the first coaxial light source; the optical detection device provided by the invention is high in detection sensitivity, reduces the risk of missing report and false report, and improves the accuracy and reliability of detection.

Description

Technical Field

[0001] This application relates to the field of detection technology, and in particular to an optical detection device. Background Technology

[0002] With the development of precision manufacturing technology, non-contact, high-precision, and high-efficiency optical inspection of microscopic defects on the sides of workpieces has become the key to improving product yield and process stability.

[0003] Currently, the industry commonly uses a vertical top-down inspection method combined with oblique illumination, which involves using a top-down camera and a side light source to image the side. However, this method has low sensitivity, is prone to missed detections and false alarms, has low reliability, and limited detection capabilities. In addition, there is a detection method using a fixed folded optical path, but this method struggles to guarantee a sufficient imaging signal-to-noise ratio, making it difficult to improve detection accuracy. Summary of the Invention

[0004] Therefore, it is necessary to provide an optical detection device to address the aforementioned problems of low detection sensitivity and limited detection capability.

[0005] An optical inspection device is used to inspect an object placed at a testing station, the optical inspection device comprising:

[0006] The first coaxial light source includes a first light-emitting element and a first beam splitter; the first light-emitting element is used to emit a first illumination beam toward a first side of the object under test along a first direction; the first beam splitter is disposed in the light output path of the first light-emitting element.

[0007] A first high-brightness light source is disposed on one side of the first coaxial light source and is used to emit a first supplementary light beam. The first supplementary light beam is projected onto the second side of the object to be tested in a direction opposite to the first direction.

[0008] The optical path deflection unit is disposed at a distance from the first beam splitter along the second direction, wherein the second direction intersects the first direction but is not coplanar;

[0009] An imaging unit is disposed on one side of the first coaxial light source;

[0010] The first illumination beam is reflected by the first side to form a first imaging beam. The first imaging beam is then incident on the optical path deflection unit after passing through the first beam splitter. The optical path deflection unit deflects the first imaging beam and guides it to the imaging unit.

[0011] In one embodiment, the optical detection device further includes a second coaxial light source, a second high-brightness light source, and a first folding element; the second coaxial light source is disposed on the side of the first coaxial light source away from the imaging unit; the second coaxial light source includes a second light-emitting element and a second beam splitter, the second light-emitting element being used to emit a second illumination beam toward the third side of the object under test along a third direction; the second beam splitter is disposed in the light output path of the second light-emitting element; the second high-brightness light source is disposed at a distance from the second coaxial light source and is used to emit a second supplementary light beam, the second supplementary light beam being projected toward the fourth side of the object under test along a direction opposite to the third direction;

[0012] The first deflecting element is disposed at a distance from the second beam splitter along the second direction. The reflective surface of the first deflecting element faces the imaging unit. The second direction intersects with the third direction but is not coplanar. The second illumination beam is reflected by the third side to form a second imaging beam. The second imaging beam is incident on the first deflecting element after passing through the second beam splitter. The first deflecting element reflects the second imaging beam to the imaging unit.

[0013] In one embodiment, the third direction is perpendicular to the first direction.

[0014] In one embodiment, the optical path deflection unit includes a second deflection element and a third deflection element. The second deflection element is disposed at a distance from the first beam splitter and is used to receive and reflect the first imaging beam. The third deflection element is disposed on the reflected optical path of the second deflection element, and the reflecting surface of the third deflection element faces the imaging unit and is used to reflect the first imaging beam to the imaging unit.

[0015] In one embodiment, the third folding element and the first folding element are arranged sequentially at intervals along the optical axis of the imaging unit; in the direction perpendicular to the optical axis of the imaging unit, the third folding element and the first folding element are arranged offset from each other.

[0016] In one embodiment, the first coaxial light source further includes a first diffuser disposed between the first light-emitting element and the first beam splitter; the second coaxial light source further includes a second diffuser disposed between the second light-emitting element and the second beam splitter.

[0017] In one embodiment, the first coaxial light source further includes a first heat sink, which is thermally connected to the side of the first light-emitting element opposite to the first beam splitter; the second coaxial light source further includes a second heat sink, which is thermally connected to the side of the second light-emitting element opposite to the second beam splitter.

[0018] In one embodiment, the first coaxial light source further includes a first blocking member disposed between the first beam splitter and the optical path deflection unit. The first blocking member is located at the end of the first beam splitter closer to the object under test and is used to block stray light.

[0019] The second coaxial light source further includes a second blocking member disposed between the second beam splitter and the first deflection element. The second blocking member is located at the end of the second beam splitter closer to the object under test and is used to block stray light.

[0020] In one embodiment, the optical detection device further includes a mounting housing and a fourth deflecting element; the first high-brightness light source and the second high-brightness light source are arranged side by side in the mounting housing; the fourth deflecting element is disposed in the mounting housing and located outside the light outlet of the first high-brightness light source, for reflecting the first supplementary light beam to the second side; the light outlet of the second high-brightness light source faces the second coaxial light source.

[0021] In one embodiment, along the second direction, the orthographic projection of the mounting housing at least partially covers the imaging unit.

[0022] The aforementioned optical inspection device includes a first coaxial light source, a first high-brightness light source, an optical path folding unit, and an imaging unit. The first coaxial light source includes a first light-emitting element and a first beam splitter. The first beam splitter is disposed in the light-emitting optical path of the first light-emitting element. When the first light-emitting element emits a first illumination beam toward a first side of the object under test, the first illumination beam is reflected by the first side to form a first imaging beam, which is then incident on the first beam splitter. The first beam splitter, as the entrance to the imaging optical path, ensures that the reflected light from the defect features of the first side is efficiently collected through this shortest optical path. This helps to improve the imaging sensitivity and detail resolution of micro-defects on the side, thereby effectively reducing the risk of missed and false alarms and improving the accuracy and reliability of the inspection. In addition, by providing sufficient initial light intensity through the first high-brightness light source, the light energy attenuation of the subsequent fixed folding optical path is compensated, enabling the optical inspection device of this application to ensure that the optical signal has a sufficient signal-to-noise ratio. While achieving high-density integration, it also improves the detection accuracy. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of an optical detection device according to an embodiment of this application;

[0024] Figure 2 This is a schematic diagram of the structure of a first coaxial light source, a second coaxial light source, and an optical path folding unit according to an embodiment of this application.

[0025] Figure 3 This is a top view schematic diagram of an optical detection device according to an embodiment of this application;

[0026] Figure 4 This is a partial structural schematic diagram of an optical detection device according to an embodiment of this application.

[0027] Reference numerals: 10, First coaxial light source; 11, First light-emitting element; 12, First beam splitter; 13, First diffuser; 14, First heat sink; 15, First shield; 16, First housing; 20, Complementary light unit; 21, First high-brightness light source; 22, Fourth folding element; 23, Second high-brightness light source; 24, Support; 25, Mounting housing; 30, Optical path folding unit; 31, Second folding element; 32, Third folding element; 40, Second coaxial light source; 41, Second light-emitting element; 42, Second beam splitter; 43, Second diffuser; 44, Second heat sink; 45, Second shield; 46, Second housing; 50, First folding element; 60, Imaging unit; 100, Object under test. Detailed Implementation

[0028] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0029] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0030] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0031] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0032] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0033] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0034] As mentioned in the background section, with the development of advanced manufacturing technologies such as semiconductors, the detection of microscopic defects (such as chipping, cracks, contamination, and residues) on the edges and sides of workpieces such as wafers is a key factor affecting chip yield.

[0035] Currently, the inspection method typically employs a vertical top-down view combined with oblique illumination. This method has limitations: vertical top-down viewing results in shallow depth of field and blurred images from steep sidewalls; it is also susceptible to interference when facing workpieces with highly reflective surfaces, such as wafers, leading to low defect contrast and signal-to-noise ratio. Another inspection method, which uses optical path folding, suffers from signal attenuation due to unavoidable beam splitting losses and multiple reflections, making it difficult to guarantee a sufficient imaging signal-to-noise ratio and thus affecting inspection accuracy.

[0036] To address the aforementioned problems, this application provides an optical detection device. Please refer to [link / reference]. Figure 1 and Figure 2 , Figure 1 A schematic diagram of the optical detection device according to one embodiment of this application is shown. Figure 2 A schematic diagram of the structure of a first coaxial light source 10, a second coaxial light source 40, and an optical path reversal unit 30 in one embodiment of this application is shown. An optical detection device provided in one embodiment of this application is used to detect a test object 100 placed at a test station. The optical detection device includes: a first coaxial light source 10, a supplementary light unit 20, an optical path reversal unit 30, and an imaging unit 60. The first coaxial light source 10 includes a first light-emitting element 11 and a first beam splitter 12. The first light-emitting element 11 emits a first illumination beam along a first direction X toward a first side of the test object 100. The first beam splitter 12 is disposed in the light-emitting path of the first light-emitting element 11. The supplementary light unit 20 includes a first high-brightness light source 21, which is disposed on one side of the first coaxial light source 10 and is used to emit a first supplementary light beam. The first supplementary light beam is projected onto a second side of the test object 100 in a direction opposite to the first direction X, and the second side is disposed opposite to the first side. The optical path deflection unit 30 is spaced apart from the first beam splitter 12 along the second direction Z, and the second direction Z intersects the first direction X but is not coplanar. The imaging unit 60 is disposed on one side of the first coaxial light source 10.

[0037] The first illumination beam is reflected by the first side to form the first imaging beam. The first imaging beam is incident on the optical path deflection unit 30 after passing through the first beam splitter 12. The optical path deflection unit 30 deflects the first imaging beam and guides it to the imaging unit 60.

[0038] Understandably, when the first illumination beam is reflected by the first side to form the first imaging beam and is incident on the first beam splitter 12, the first beam splitter 12 directly serves as the entrance to the imaging optical path. This ensures that the illumination and imaging optical paths highly overlap and have the shortest path, guaranteeing that the signal light reflected from the first side can be collected most efficiently. This improves the imaging sensitivity and detail resolution of microscopic defects on the side, enhancing the ability to identify minor scratches, contamination, and other defects, effectively reducing the risk of missed and false alarms, thereby improving the accuracy and reliability of detection. Simultaneously, the first high-brightness light source 21 provides initial light intensity redundancy to compensate for the inherent light loss in the subsequent fixed folding optical path, obtaining a high signal-to-noise ratio imaging signal. This allows the optical detection device of this application to achieve high-density integration while also improving detection accuracy.

[0039] In some embodiments, the second direction Z is perpendicular to the first direction X, and the second direction Z is vertical. It can be understood that the second direction Z and the first direction X only need to intersect but not be coplanar; the specific angle can be adjusted according to the spatial layout and is not limited to perpendicularity.

[0040] In some embodiments, the optical detection device further includes a second coaxial light source 40, a second high-brightness light source 23, and a first refracting element 50; the second coaxial light source 40 is disposed on the side of the first coaxial light source 10 away from the imaging unit 60; the second coaxial light source 40 includes a second light-emitting element 41 and a second beam splitter 42, the second light-emitting element 41 being used to emit a second illumination beam along a third direction Y toward the third side surface of the object under test 100; the second beam splitter 42 is disposed in the light output path of the second light-emitting element 41. The second high-brightness light source 23 and the second coaxial light source 40 are disposed at intervals relative to each other, and are used to emit a second supplementary light beam; the second supplementary light beam is projected onto the fourth side surface of the object under test 100 along a direction opposite to the third direction Y, the fourth side surface being disposed opposite to the third side surface. The first refracting element 50 is disposed at intervals relative to the second beam splitter 42 along a second direction Z, the reflective surface of the first refracting element 50 facing the imaging unit 60, the second direction Z intersecting the third direction Y but not coplanar.

[0041] The second illumination beam is reflected by the third side to form a second imaging beam. This second imaging beam is then incident on the first deflecting element 50 after passing through the second beam splitter 42. The first deflecting element 50 reflects the second imaging beam to the imaging unit 60. The optical detection device provided in this application can simultaneously or sequentially image two adjacent sides of the object under test 100 without moving the object 100, thus improving detection coverage and efficiency. Furthermore, the second imaging beam is guided to the imaging unit 60 through the first deflecting element 50, achieving a high degree of integration and acquisition of dual-path optical signals. This eliminates the need for multiple imaging units 60, helping to reduce costs, space requirements, and data processing complexity.

[0042] In some embodiments, the second direction Z is perpendicular to the third direction Y, and the second direction Z is vertical. It can be understood that the second direction Z and the third direction Y only need to satisfy a relationship of intersecting but not coplanar; the specific angle can be adjusted according to the spatial layout and is not limited to perpendicularity.

[0043] In some embodiments, the illumination intensity of the first high-brightness light source 21 and the second high-brightness light source 23 is not less than 10,000 Klus (kilolux).

[0044] In some embodiments, the independently controllable first coaxial light source 10, second coaxial light source 40, first high-brightness light source 21 and second high-brightness light source 23 can be flexibly combined and controlled by programming to enable the optical detection device to conveniently switch and realize various optical detection modes such as bright field, dark field, low-angle illumination, backlight, etc.

[0045] Please refer to the following: Figure 3 , Figure 3 A top view schematic diagram of an optical detection device according to one embodiment of this application is shown. In some embodiments, the third direction Y is perpendicular to the first direction X, which helps to improve the detection coverage.

[0046] In some embodiments, the optical path folding unit 30 includes a second folding element 31 and a third folding element 32; the second folding element 31 is disposed at a distance from the first beam splitter 12 and is used to receive and reflect the first imaging beam; the third folding element 32 is disposed on the reflected optical path of the second folding element 31, and the reflecting surface of the third folding element 32 faces the imaging unit 60, and is used to reflect the first imaging beam to the imaging unit 60. This optical path folding achieves a more compact structure for the optical detection device.

[0047] Please refer to the following: Figure 4 , Figure 4 A partial structural schematic diagram of an optical detection device according to one embodiment of this application is shown. In some embodiments, along the optical axis of the imaging unit 60, the third folding element 32 and the first folding element 50 are arranged alternately; in the direction perpendicular to the optical axis of the imaging unit 60, the third folding element 32 and the first folding element 50 are staggered. By staggering their arrangement along the optical axis of the imaging unit 60 and layering them vertically, two non-interfering folding paths are planned in physical space for the first imaging beam and the second imaging beam, allowing the first imaging beam and the second imaging beam to converge into the same imaging unit 60, making the structure of the optical detection device more compact.

[0048] In some embodiments, the first coaxial light source 10 further includes a first diffuser 13 disposed between the first light-emitting element 11 and the first beam splitter 12 for homogenizing the first illumination beam. The second coaxial light source 40 further includes a second diffuser 43 disposed between the second light-emitting element 41 and the second beam splitter 42 for homogenizing the second illumination beam.

[0049] In some embodiments, the first coaxial light source 10 further includes a first heat sink 14, which is thermally connected to the side of the first light-emitting element 11 away from the first beam splitter 12; the second coaxial light source 40 further includes a second heat sink 44, which is thermally connected to the side of the second light-emitting element 41 away from the second beam splitter 42.

[0050] In some embodiments, the first heat sink 14 is disposed on the side of the first light-emitting element 11 away from the first beam splitter, and at least a portion of the first heat sink 14 is in contact with the first light-emitting element 11 to achieve efficient heat conduction. The second heat sink 44 is disposed on the side of the second light-emitting element 41 away from the second beam splitter, and at least a portion of the second heat sink 44 is in contact with the second light-emitting element 41 to achieve efficient heat conduction. By providing the first heat sink 14 and the second heat sink 44, the brightness stability and service life of the first coaxial light source 10 and the second coaxial light source 40 during long-term operation can be guaranteed.

[0051] In some embodiments, the first coaxial light source 10 further includes a first blocking member 15 disposed between the first beam splitter 12 and the optical path deflection unit 30; the first blocking member 15 is located at the end of the first beam splitter 12 near the object under test 100, and is used to block stray light. The second coaxial light source 40 further includes a second blocking member 45 disposed between the second beam splitter 42 and the first deflection element 50; the second blocking member 45 is located at the end of the second beam splitter 42 near the object under test 100, and is used to block stray light. By providing the first blocking member 15 and the second blocking member 45, stray light from non-imaging directions can be blocked from entering the imaging optical path, thereby effectively reducing image background noise, making the effective signal generated by side defects more prominent, and improving the contrast and signal-to-noise ratio of the image.

[0052] In some embodiments, the supplementary lighting unit 20 further includes a mounting housing 25 and a fourth deflecting element 22; a first high-brightness light source 21 and a second high-brightness light source 23 are arranged side-by-side within the mounting housing 25. The fourth deflecting element 22 is disposed on the mounting housing 25, located outside the light outlet of the first high-brightness light source 21, and is used to reflect the first supplementary light beam to the second side of the object under test 100. The light outlet of the second high-brightness light source 23 faces the second coaxial light source 40. By encapsulating the first high-brightness light source 21 and the second high-brightness light source 23 with the mounting housing 25, the supplementary lighting unit 20 is modularized, making the structure of the optical detection device more compact.

[0053] In some embodiments, the supplementary lighting unit 20 further includes a bracket 24, which is disposed on the mounting housing 25 and located outside the light outlet of the first high-brightness light source 21. A fourth deflecting element 22 is disposed on the bracket 24, and the reflective surface of the fourth deflecting element 22 faces the second side of the object 100 to be measured.

[0054] In some embodiments, the orthographic projection of the mounting housing 25 along the second direction Z at least partially covers the imaging unit 60, improving space utilization, reducing floor space, and making the structure of the optical detection device more compact.

[0055] In some embodiments, the first coaxial light source 10 further includes a first housing 16 for encapsulating the first light-emitting element 11, the first beam splitter 12, the first diffuser 13, the first heat sink 14, and the first shielding element 15, thereby achieving modularity of the first coaxial light source 10. The second coaxial light source 40 further includes a second housing 46 for encapsulating the second light-emitting element 41, the second beam splitter 42, the second diffuser 43, the second heat sink 44, and the second shielding element 45, thereby achieving modularity of the second coaxial light source 40.

[0056] The optical inspection device provided in this application uses the first beam splitter 12 in the first coaxial light source 10 as the entrance to the imaging optical path and the second beam splitter 42 in the second coaxial light source 40 as the entrance to the imaging optical path. This ensures that the illumination optical path and the imaging optical path are highly overlapped and have the shortest path. Combined with the light source compensation of the first high-brightness light source 21 and the second high-brightness light source 23, it achieves efficient signal collection and high signal-to-noise ratio imaging, thereby significantly improving the imaging sensitivity and detail resolution of microscopic defects on the sides, resulting in high detection accuracy and reliability. In addition, the dual optical signals are folded and converged to the same imaging unit 60, allowing for simultaneous detection of two adjacent sides without moving the object under test 100 or adding an imaging unit 60. This ensures detection performance while improving detection efficiency, detection coverage, and system integration, effectively balancing miniaturization, low cost, and high reliability.

[0057] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An optical inspection device for inspecting an object (100) placed at a test station, characterized in that, The optical detection device includes: The first coaxial light source (10) includes a first light-emitting element (11) and a first beam splitter (12); the first light-emitting element (11) is used to emit a first illumination beam toward a first side of the object to be tested (100) along a first direction; the first beam splitter (12) is disposed in the light-emitting path of the first light-emitting element (11); A first high-brightness light source (21) is disposed on one side of the first coaxial light source (10) and is used to emit a first supplementary light beam. The first supplementary light beam is projected onto the second side of the object to be tested (100) in a direction opposite to the first direction. The optical path deflection unit (30) is arranged at intervals from the first beam splitter (12) along the second direction, wherein the second direction intersects the first direction but is not coplanar; An imaging unit (60) is disposed on one side of the first coaxial light source (10); The first illumination beam is reflected by the first side to form a first imaging beam. The first imaging beam is incident on the optical path deflection unit (30) after passing through the first beam splitter (12). The optical path deflection unit (30) deflects the first imaging beam and guides it to the imaging unit (60).

2. The optical detection device according to claim 1, characterized in that, The optical detection device further includes a second coaxial light source (40), a second high-brightness light source (23), and a first folding element (50); the second coaxial light source (40) is disposed on the side of the first coaxial light source (10) away from the imaging unit (60); the second coaxial light source (40) includes a second light-emitting element (41) and a second beam splitter (42), the second light-emitting element (41) is used to emit a second illumination beam toward the third side of the object under test (100) along a third direction; the second beam splitter (42) is disposed in the light output path of the second light-emitting element (41); the second high-brightness light source (23) is disposed at a distance from the second coaxial light source (40) and is used to emit a second supplementary light beam, the second supplementary light beam being projected onto the fourth side of the object under test (100) in a direction opposite to the third direction; The first folding element (50) is disposed at a distance from the second beam splitter (42) along the second direction. The reflective surface of the first folding element (50) faces the imaging unit (60). The second direction intersects with the third direction but is not coplanar. The second illumination beam is reflected by the third side to form a second imaging beam. The second imaging beam is incident on the first folding element (50) after passing through the second beam splitter (42). The first folding element (50) reflects the second imaging beam to the imaging unit (60).

3. The optical detection device according to claim 2, characterized in that, The third direction is perpendicular to the first direction.

4. The optical detection device according to claim 2, characterized in that, The optical path deflection unit (30) includes a second deflection element (31) and a third deflection element (32). The second deflection element (31) is disposed at a distance from the first beam splitter (12) and is used to receive and reflect the first imaging beam. The third deflection element (32) is disposed on the reflected optical path of the second deflection element (31) and the reflecting surface of the third deflection element (32) faces the imaging unit (60) and is used to reflect the first imaging beam to the imaging unit (60).

5. The optical detection device according to claim 4, characterized in that, Along the optical axis of the imaging unit (60), the third folding element (32) and the first folding element (50) are arranged at intervals; in the direction perpendicular to the optical axis of the imaging unit (60), the third folding element (32) and the first folding element (50) are arranged offset from each other.

6. The optical detection device according to claim 2, characterized in that, The first coaxial light source (10) further includes a first diffuser (13), which is disposed between the first light-emitting element (11) and the first beam splitter (12); the second coaxial light source (40) further includes a second diffuser (43), which is disposed between the second light-emitting element (41) and the second beam splitter (42).

7. The optical detection device according to claim 2, characterized in that, The first coaxial light source (10) further includes a first heat sink (14), which is thermally connected to the side of the first light-emitting element (11) away from the first beam splitter (12); the second coaxial light source (40) further includes a second heat sink (44), which is thermally connected to the side of the second light-emitting element (41) away from the second beam splitter (42).

8. The optical detection device according to claim 2, characterized in that, The first coaxial light source (10) further includes a first shielding member (15) disposed between the first beam splitter (12) and the optical path deflection unit (30). The first shielding member (15) is located at one end of the first beam splitter (12) near the object to be tested (100) and is used to block stray light. The second coaxial light source (40) further includes a second blocking member (45) disposed between the second beam splitter (42) and the first deflection element (50). The second blocking member (45) is located at one end of the second beam splitter (42) near the object under test (100) and is used to block stray light.

9. The optical detection device according to claim 2, characterized in that, The optical detection device further includes a mounting housing (25) and a fourth deflecting element (22); the first high-brightness light source (21) and the second high-brightness light source (23) are arranged side by side in the mounting housing (25); the fourth deflecting element (22) is disposed in the mounting housing (25) and located outside the light outlet of the first high-brightness light source (21), and is used to reflect the first supplementary light beam to the second side; the light outlet of the second high-brightness light source (23) faces the second coaxial light source (40).

10. The optical detection device according to claim 9, characterized in that, Along the second direction, the orthographic projection of the mounting housing (25) at least partially covers the imaging unit (60).

Images