Detection device capable of rapidly switching focal length

Abstract

The invention relates to a detection device capable of quickly switching focal length, comprising a light emitting unit which continuously emits initial light beams with different colors; wherein the emergent points of the initial light beams with different colors are different; a rotating unit rotating the light emitting unit to change a color of a selected light beam formed by the light emitting unit passing through the rotating unit; the focusing unit is used for focusing the selected light beam to obtain a focused light beam, so that the focused light beam irradiates the surface of the measured object to form an information light beam; and the camera receives the information light beam and detects to obtain a surface image of the detected object. By adopting the detection device capable of rapidly switching the focal length, the detection light source can be rapidly switched under the condition of low cost, and good detection precision is kept.

Description

Technical Field

[0001] The present invention relates to the field of optical imaging detection, and in particular to a detection device for rapidly switching focal length. Background Art

[0002] As society develops and industrialization becomes increasingly prevalent, lens testing for surveillance, security, aerial photography, drones, lithography, semiconductors, and wafers is becoming increasingly common in both industrial development and daily life. Consequently, the requirements for semiconductor and wafer testing accuracy and efficiency are becoming increasingly stringent. Therefore, when inspecting different objects, it is necessary to quickly switch the focus of the inspection device to achieve sufficient inspection accuracy.

[0003] Existing detection devices change the focal length by changing the focal position of the focusing lens in the detection device. This includes methods such as mechanically displacing the focusing lens or the entire detection device and using a focusing lens made of liquid crystal. However, these detection devices either sacrifice accuracy for detection cost or sacrifice cost for detection accuracy, resulting in unsatisfactory actual detection results. Summary of the Invention

[0004] Based on this, an object of the present invention is to provide a detection device with fast focal length switching, which can achieve fast switching of detection light sources at low cost and maintain good detection accuracy.

[0005] A detection device for rapidly switching focal length, comprising:

[0006] The light-emitting unit continuously emits initial light beams of different colors; wherein the emission points of the initial light beams of different colors are different;

[0007] A rotating unit, which rotates the light-emitting unit to change the color of a selected light beam formed by the light-emitting unit passing through the rotating unit;

[0008] A focusing unit focuses the selected light beam to obtain a focused light beam, so that the focused light beam is irradiated on the surface of the object to be measured to form an information light beam;

[0009] The camera receives the information beam and detects the surface image of the object being measured.

[0010] Compared with the prior art, the present invention can conveniently and quickly switch light sources of different colors for detection, while maintaining stability when switching light sources, thereby ensuring detection accuracy.

[0011] Furthermore, the rotating unit includes an outer disk and an inner disk with the same center; the outer disk is rotatable, the light-emitting unit is arranged on the outer disk and rotates along with the outer disk, and the irradiation point of the initial light beam on the inner disk forms a circular rotating path; the inner disk is provided with a through hole, and the circular rotating path passes through the through hole of the inner disk, and when the irradiation point of the initial light beam coincides with the through hole, the rotating unit emits the initial light beam to form a selected light beam.

[0012] Furthermore, the rotating unit includes at least one handle; the outer disk is rotated by the handle to rotate the light-emitting unit, thereby changing the initial light beam coincident with the through hole to change the color of the selected light beam.

[0013] Furthermore, the focusing unit focuses the selected light beams of different colors to obtain focused light beams with different emitting directions, so that each focused light beam is focused at a different position.

[0014] Furthermore, different light sources are switched to photograph the same object to obtain images of the surface of the object at various heights, thereby achieving multi-dimensional detection.

[0015] Furthermore, different light sources are switched to shoot different objects to obtain images of the surface of the objects at different heights to achieve multi-layer detection.

[0016] Furthermore, the camera can switch different performances for detection according to information light beams of different colors.

[0017] Furthermore, the light emitting unit includes light sources of three colors: RGB.

[0018] Furthermore, there are three handles, and each handle corresponds to a certain color.

[0019] Furthermore, it also includes a connecting rod, which is arranged between the rotating unit and the focusing unit and connected to the inner disk to fixedly connect the rotating unit and the focusing unit so that the selected light beam emitted by them can normally enter the spectroscope.

[0020] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the principle adopted by the detection device for rapidly switching focal length of the present invention.

[0022] Figure 2 Schematic diagram of the structure of the detection device for rapid focal length switching of the present invention.

[0023] Figure 3 This is a front structural schematic diagram of the rotating unit in the detection device for rapidly switching focal length of the present invention.

[0024] Figure 4 It is a side structural schematic diagram of the rotating unit in the detection device for rapid focal length switching of the present invention. DETAILED DESCRIPTION

[0025] The present invention has carefully analyzed the existing detection device and found that the reason for its unsatisfactory detection effect is that the structure changed when changing the focal length is in the middle of the optical path system, making it difficult to ensure the stability of detection efficiency and accuracy. Figure 1 The present invention understands that light beams of different wavelengths have different refractive indices and different focusing distances after passing through the focusing lens, so it considers switching light sources of different colors to change the focusing focal length of the detection device. However, since the detection object is constantly replaced during the detection of the assembly line, the light source being detected is constantly reused, and it is impossible to repeatedly turn the corresponding light source on and off, and merge different light sources located in different optical paths into the same optical path through a reflector. Repeated turning on and off will cause damage to the light source. For this reason, the present invention attempts to use a rotation method to switch the light source, and move the mechanical displacement error outside the optical path system without changing the original optical path, so as to achieve rapid switching of focal length at low cost and high precision.

[0026] Based on this, see Figure 2 The present invention designs a detection device for rapidly switching focal length, which includes a light emitting unit 10, a rotating unit 20, a spectroscopic unit 30, a focusing unit 40, a connecting rod (not shown) and a camera 50.

[0027] The light-emitting unit 10 includes multiple light sources with different wavelengths to continuously provide initial light beams of multiple colors. The different colored light beams are not emitted from the same location on the light-emitting unit 10, but rather lie on a circular trajectory. In this embodiment, three LEDs (red, green, and blue) are used as light sources, enabling comprehensive inspection of the object under test with minimal number of passes.

[0028] Combine Figure 3 and Figure 4 , Figure 3 The front structure of the rotating unit 20 is shown. Figure 4The side structure of the rotating unit 20 is shown. The rotating unit 20 comprises a cocentric inner disk 21 and outer disk 22, and a handle 23. The inner disk 21 is connected to the outer disk 22 by a bearing. The outer disk 22 is rotatable, and when the outer disk 22 rotates, the inner disk 21 does not rotate with it. The light-emitting unit 10 is mounted on the outer disk 22 and rotates with it. The light points of multiple light sources are always illuminated on the inner disk 21. When the light-emitting unit 10 rotates with the outer disk 22, the light points of the multiple light sources form a circular rotation path. The inner disk 21 is provided with a through hole. The circular rotation path formed by the light points of the multiple light sources passes through the through hole of the inner disk 21. Whenever the light point of a light source coincides with the through hole, the rotating unit 20 emits an initial light beam of the corresponding color of the light source to form a selected light beam. Specifically, the center of the inner disk 21 is point A, which is the location of the through hole of the inner disk 21, while the center of the outer disk 22 is point B. There is a certain offset between the two. Therefore, the through hole of the inner disk 21 is not located at the center of the rotation path of the light-emitting unit 10, but is located on the rotation path of the light-emitting position of the light-emitting unit 10, so that light sources of different colors can be switched through the through hole of the inner disk 21 when the light-emitting unit 10 rotates.

[0029] The handle 23 is connected to the outer disk 22. When the color of the light source needs to be changed, it can be achieved manually or automatically by rotating the handle 23. It is understandable that the number of handles 23 is not limited. Regardless of whether the number of handles 23 is greater or less than the number of LEDs in the light-emitting unit 10, a light source of a corresponding color can be obtained by rotating each handle 23 according to the arc angle divided by the number of LEDs as a gear. Preferably, the same number of handles 23 as the number of LEDs is used. In this case, each handle 23 can correspond to a light source of a certain color, making the adjustment process intuitive and quick.

[0030] It should be noted that, in order to facilitate observation and distinction, Figure 4 The beam angle difference is designed for the selective light beams of different colors so that the separation of each light beam can be distinguished. In fact, the selective light beams of different colors have the same path when they are emitted, and there is no beam angle difference. Therefore, the selective light beams are emitted from the same position when they exit the rotating unit 20, but the final focusing position is different due to the different refractive indices of each light beam.

[0031] The light splitting unit 30 is a beam splitter, which is disposed in the propagation direction of the selected light beam and reflects the selected light beam to obtain an integrated light beam.

[0032] The focusing unit 40 is positioned in the propagation direction of the integrated light beam and focuses the integrated light beam to produce a focused light beam, which is then irradiated onto the surface of the object being measured. Integrated light beams of different colors have different wavelengths and, therefore, different refractive indices. After being refracted by the focusing unit 40, the resulting focused light beams have different emission directions. Specifically, focused light beams with shorter wavelengths have greater refractive indices, resulting in larger emission angles and shorter focusing distances, such as the blue light in an RGB light source.

[0033] The connecting rod is provided between the rotating unit 20 and the focusing unit 40 to securely connect the rotating unit 20 and the focusing unit 40. The connecting rod is connected to the inner disk 21 to provide support for the rotating unit 20 and to secure the rotating unit 20 to ensure that the selected light beam emitted by the rotating unit 20 can normally enter the spectroscope.

[0034] After the focused light beam is irradiated on the surface of the object to be measured, it is reflected to form an information beam. The camera 50 receives the information beam after passing through the spectroscope and obtains an image of the surface of the object to be measured. When the object to be measured has a certain height, by switching different light sources to photograph the same object to be measured and obtaining images of the surface of the object to be measured at various heights, multi-dimensional detection can be achieved. When the object to be measured is translucent, by switching different light sources to photograph different objects to be measured and obtaining images of the surface of the object to be measured at various heights, multi-layer detection can be achieved. In particular, since the color of the light source is constantly switching, the camera 50 located at the end of the optical path system can also be switched according to the corresponding light source color, thereby reducing the performance requirements for the camera 50.

[0035] It can be understood that since the detection device for rapidly switching focal lengths of the present invention is almost unaffected by gravity, in addition to being able to rapidly switch between different focusing platform heights in the vertical direction, it can also rapidly switch between different focusing planes in any direction, and can cope with various irregular surfaces of objects to be measured or fine objects to be measured placed on receiving platforms at different heights.

[0036] The fast focal length switching detection device of the present invention utilizes the principle that light beams of different colors have different refractive indices. By switching light sources of different colors, the focus distance is changed, thereby avoiding mechanical displacement in the optical path system. At the same time, the light sources of different colors are switched by a rotation method, thereby achieving fast switching at a low cost. It has multiple advantages and strong applicability.

[0037] The above-described embodiments merely represent the best modes of carrying out the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that variations and modifications are possible, as would be apparent to those skilled in the art, without departing from the spirit of the present invention, and the present invention is intended to encompass such variations and modifications.

Claims

1. A detection device for rapidly switching focal length, characterized in that: include: The light-emitting unit continuously emits initial light beams of different colors; wherein the emission points of the initial light beams of different colors are different; A rotating unit, which rotates the light-emitting unit to change the color of a selected light beam formed by the light-emitting unit passing through the rotating unit; A focusing unit focuses the selected light beam to obtain a focused light beam, so that the focused light beam is irradiated on the surface of the object to be measured to form an information light beam; The camera receives the information beam and detects the surface image of the object being measured.

2. The device for detecting rapid focal length switching according to claim 1, wherein: The rotating unit includes an outer disk and an inner disk with the same center; the outer disk is rotatable, and the light-emitting unit is arranged on the outer disk and rotates along with the outer disk, and the irradiation point of the initial light beam on the inner disk forms a circular rotating path; the inner disk is provided with a through hole, and the circular rotating path passes through the through hole of the inner disk. When the irradiation point of the initial light beam coincides with the through hole, the rotating unit emits the initial light beam to form a selected light beam.

3. The device for detecting rapid focal length switching according to claim 2, wherein: The rotating unit includes at least one handle; the outer disk is rotated by the handle to rotate the light emitting unit, thereby changing the initial light beam coincident with the through hole to change the color of the selected light beam.

4. The device for detecting rapid focal length switching according to claim 3, wherein: The focusing unit focuses the selected light beams of different colors to obtain focused light beams with different emitting directions, so that each focused light beam is focused at a different position.

5. The device for detecting rapid focal length switching according to claim 4, wherein: Switch different light sources to shoot the same object to obtain images of various heights on the surface of the object to achieve multi-dimensional detection.

6. The device for detecting rapid focal length switching according to claim 4, wherein: Switch different light sources to shoot different objects to be measured, and obtain images of the surface of the object at various heights to achieve multi-layer detection.

7. The device for detecting rapid focal length switching according to claim 5 or 6, characterized in that: The camera can switch different performances for detection according to information light beams of different colors.

8. The device for detecting rapid focal length switching according to claim 7, wherein: The light emitting unit includes light sources of three colors: RGB.

9. The device for detecting rapid focal length switching according to claim 8, wherein: There are three handles, and each handle corresponds to a certain color.

10. The device for detecting rapid focal length switching according to claim 9, wherein: It also includes a connecting rod, which is arranged between the rotating unit and the focusing unit and connected to the inner disk to fix the rotating unit and the focusing unit so that the selected light beam emitted by them can normally enter the spectroscope.

Images