Lighting device
By designing lens and fixing components in the lighting device and adjusting the relative distance between the lenses, the problem of optical path coupling under different light source types is solved, enabling fast and zero-cost optical path switching and improving the uniformity of lighting and energy utilization.
Patent Information
- Application Number
- CN202520667871.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-10
- Publication Date
- 2026-02-27
- Estimated Expiration
- 2035-04-10
AI Technical Summary
Existing lighting systems struggle to achieve efficient optical path coupling under different light source types, resulting in uneven brightness and resolution, which fails to meet the needs of various applications.
By designing an illumination device including a lens assembly and a fixing assembly, and utilizing the first lens, filter, second lens and third lens in the lens assembly, and by adjusting the relative distance in the fixing assembly, the numerical aperture of the incident light source can be magnified, adapting to different light source types and quickly switching the illumination light path.
It enables rapid and cost-free switching of lighting optical paths to meet different application needs under different light source conditions, improving the uniformity of lighting and energy utilization, and satisfying the lighting needs of various light source types.
Smart Images
Figure CN223953925U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of semiconductor detection, in particular to a lighting device. BACKGROUND
[0002] In the field of industrial imaging, lighting is a key component of imaging, and is an important factor affecting the quality of human eye observation, defect detection and size measurement results. The correct lighting requirement is to not reduce the brightness and resolution, and to not have light spots and unevenness during lighting. The following indicators are required to be achieved by lighting system designers: 1. Brightness is strong; 2. Suitable spectral characteristics; 3. The size and shape of the light-emitting part are appropriate; 4. Thermal radiation should not be too large; 5. Light source is stable; 6. Good economy.
[0003] Especially the first three, which need to be considered in various imaging lighting applications. However, there are many factors that affect the indicators of the lighting system, and the most important one is the type of light source. The type of light source determines the area of the light source, the light intensity angle distribution, the waveband, the power and the like. For different types of light sources, the designer needs to design the light path coupling of the light source, so as to obtain a lighting scheme that meets the final use requirements from the initial light source. Among them, the final use requirements include the size of the illumination area, the uniformity requirement and the energy requirement and the like. SUMMARY
[0004] Therefore, the purpose of the present application is to provide a lighting device, which can switch the incident light angle of the light source end by switching the incident NA size of the coupling light path according to different light source sizes and light source light angles.
[0005] In a first aspect, the embodiment of the present application provides a lighting device, comprising a light source, further comprising a lens assembly and a fixing assembly for placing the lens assembly, the lens assembly is sequentially provided with a first lens, a filter, a second lens and a third lens along a light propagation path and forms a coupling light path, and amplifies the incident numerical aperture of the light source; the fixing assembly is composed of a plurality of fixing units, and the plurality of fixing units are sequentially connected based on the light propagation path, each fixing unit respectively places the first lens, the filter, the second lens and the third lens, and the relative distance between the filter and the second lens is adjusted through the corresponding fixing unit, and the relative distance between the third lens and the second lens is adjusted through the corresponding fixing unit; the adjustment distance is determined according to the amplification multiple of the incident numerical aperture of the light source.
[0006] In some specific implementation manners, the fixing assembly comprises a first unit, a second unit, a third unit and a fourth unit, the adjustment of the distance between the filter and the second lens is realized by adjusting the relative distance between the second unit and the third unit, and the adjustment of the distance between the third lens and the second lens is realized by adjusting the relative distance between the fourth unit and the third unit.
[0007] In some specific implementation manners, the second unit and the fourth unit are sleeved on the third unit, and the movable connection structure is formed by threads.
[0008] In some specific implementation manners, the fixing assembly further comprises two adjusting knobs connected with the second unit and the fourth unit respectively, and the adjusting knobs are sleeved on the third unit and form a movable connection structure with the third unit by threads; the second unit and the fourth unit are sleeved on the third unit, and the relative positions between the second unit and the third unit and between the fourth unit and the third unit are changed by the adjusting knobs.
[0009] In some specific implementation manners, the adjusting knobs are connected with the second unit and the third unit respectively by a plurality of connecting rods.
[0010] In some specific implementation manners, the first lens is an asymmetric double convex lens, and the curvature of the convex surface at the light entrance is smaller than the curvature of the convex surface at the light exit.
[0011] In some specific implementation manners, the filter is a plane cylindrical lens.
[0012] In some specific implementation manners, the second lens is a plane convex lens, and the convex surface is located at the light exit surface.
[0013] In some specific implementation manners, the third lens is a plane convex lens, and the convex surface is located at the light entrance surface.
[0014] In some specific implementation manners, the magnification is 2-7 times.
[0015] The embodiment of the present application has the following beneficial effects: the embodiment of the present application provides a lighting device, a lens assembly and a fixing assembly are arranged, the lens assembly comprises a first lens, a filter, a second lens and a third lens, the fixing assembly comprises a first unit, a second unit, a third unit and a fourth unit for placing the lenses respectively, and the adjustment of the vertical aperture magnification of the light source in the lighting device is realized by adjusting the distance between the second unit and the third unit and the distance between the fourth unit and the third unit, which can be applied to various types of light sources, and only the working distance of the lens needs to be changed, so that different lighting light paths under different application requirements can be quickly and zero-cost switched.
[0016] Other features and advantages of the present disclosure will be set forth in the descriptions that follow, and in part will be apparent from the description, or can be learned by practice of the present disclosure as hereinafter more fully described, or can be learned by practice of the present disclosure.
[0017] In order to make the above objectives, features and advantages of the present disclosure more obvious and comprehensible, the following preferred embodiments are specifically described below, and the accompanying drawings are referred to for a detailed description. BRIEF DESCRIPTION OF DRAWINGS
[0018] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.
[0019] Figure 1 The schematic diagram of the illumination light path structure provided by the embodiment of the present application is shown in the figure.
[0020] Figure 2 The sectional view of the illumination device provided by the embodiment of the present application is shown in the figure.
[0021] Figure 3 The schematic diagram of the overall structure of the illumination device provided by the embodiment of the present application is shown in the figure.
[0022] 10-lens assembly; 20-fixing assembly;
[0023] 11-light source light entrance surface; 12-first lens; 13-filter; 14-second lens; 15-third lens; 16-light exit surface; 21-first unit; 22-second unit; 23-third unit; 24-fourth unit; 25-adjusting knob; 26-thread; 27-screw. DETAILED DESCRIPTION
[0024] In order to make the objectives, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the present application will be described clearly and completely below in combination with the drawings. Obviously, the described embodiments are some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0025] The illumination device provided in the embodiments of the present application is applied to semiconductor optical detection, wherein the semiconductor products are wafer products, including patterned wafers and non-patterned wafers. In other embodiments, the illumination device can also be applied to other precision component products. The illumination device is used to project an illumination light beam on the surface of the product, and an image acquisition device acquires a surface image of the product based on the illumination light beam, and analyzes the image to determine whether the surface of the product has visible defects, damages or other undesirable features.
[0026] Alternatively, the measurement device in the embodiments can also be used in a dark field / bright field defect detection scenario. The illumination device projects an illumination light beam on the surface of the product, and a sensor acquires scattered light / reflected light of the surface of the product and determines whether the surface of the product has defects and the type of the defects according to the distribution characteristics of the scattered light / reflected light.
[0027] For the detection scenario, the illumination system is a key system, and the requirements for the illumination system cannot reduce the brightness and resolution, and there cannot be light spots and unevenness during illumination. Moreover, there are many factors that affect the system indicators of the illumination system, and the most important factor is the type of light source. The type of light source determines the light emitting surface, light intensity angle distribution, waveband and power of the light source. For different types of light sources, the light path coupling design of the light source is required during the design of the illumination system, so as to obtain an illumination scheme that meets the final use requirements from the initial light source.
[0028] The illumination device provided in the embodiments of the present application mainly controls the light path coupling based on different types of light sources, and the function is to magnify the light emitting surface of the initial light source and project a magnified uniform illumination spot at the illumination end. The technical means adopted is to switch the light entering NA size of the coupling light path according to different light source sizes and light emitting angles of the light source, so as to freely switch the light angle allowed to enter the light source end, and according to the change of the light path, the relative position of the lens in the light path is adjusted to realize the adjustment of the light path.
[0029] Specifically, referring to Figure 1 the illumination light path structure diagram in the illumination device provided in the embodiments, the lens assembly of the illumination device is composed of a plurality of lenses in Figure 1 , and in the embodiments, the lens assembly is packaged and connected by a fixing assembly to form the final illumination device. In the embodiments, the illumination device is finally configured in the form of a lens barrel in the detection system and placed in a corresponding angle posture.
[0030] Generally, the illumination device in the detection system is usually placed facing the surface of the object to be detected and forms a certain angle with the surface of the object to be detected, so as to form an incident light beam with a certain angle on the surface of the object to be detected, and the reflected light beam is received by the sensor at the rear end through the reflection of the surface of the object to be detected.
[0031] In the lens assembly 10 in the embodiment, the light propagation path based on the light entrance surface 11 of the light source sequentially includes a first lens 12, a filter 13, a second lens 14, and a third lens 15 to finally form an light exit surface 16, form a coupling light path through the lens assembly, and amplify the incident numerical aperture (NA) of the light source. The lens assembly forms a critical illumination amplification system, the incident end of the light source is between 1-2 times the focal length of the lens assembly, and the exit end of the lens assembly forms an inverted image with amplification. The amplification factor is 2-7 times.
[0032] In the embodiment, the light exit surface of the lens assembly can be directly illuminated, i.e., the incident light is projected onto the surface of the object to be detected. However, in other embodiments, the entrance pupil surface of a subsequent optical functional device, such as the entrance pupil surface of a uniform light system, can be accessed. This will not be described in detail in the embodiment.
[0033] Specifically, for the above lens assembly, the first lens is an asymmetric double convex lens in the embodiment, the curvature of the convex surface at the light entrance is smaller than the curvature of the convex surface at the light exit. The filter is a plane cylindrical lens, the second lens is a plane convex lens with the convex surface at the light exit, and the third lens is a plane convex lens with the convex surface at the light entrance.
[0034] In the above lens assembly, the optical specifications can be referred to Table 1.
[0035] Table 1. Optical specification table of lens assembly
[0036]
[0037] The lens assembly in the embodiment should be able to allow the implementation of different optical requirements, wherein the optical requirements are specifically different NA requirements under different light source scenarios, specifically different NA variable ranges and NA amplification factor adjustments.
[0038] Specifically, the adjustment of the relative position relationship between the lens assemblies in the embodiment mainly adjusts the relative distance between the filter and the second lens, the relative distance between the third lens and the filter, and the relative distance between the third lens and the second lens.
[0039] In the embodiment, embodiments 1 and 2 are provided to explain the above relative distance adjustment.
[0040] Embodiment 1
[0041] The design requirement of the illumination device for this embodiment is that the light source incident NA is 0.7, the exit NA is 0.286, and the NA magnification is 3.3. The light collection half angle is 44.4°, which covers more than 90% of the total emission energy of the light source, so the design basis of the optical path structure is the energy size requirement of the illuminated surface. According to the initial light intensity angle distribution curve of the light source, a larger range is intercepted for collection, thereby reducing the energy loss of the light source.
[0042] The magnification of the illumination device for this embodiment is 3.3 times, and the magnification is based on the diameter of the exit surface, that is, the size of the illuminated surface. If the exit surface is connected to a subsequent optical system, the size of the exit surface is determined according to the entrance pupil diameter of the entrance pupil surface of the subsequent optical system. In order to achieve the optical requirements of the above-mentioned illumination device, the distance between the filter and the second lens is adjusted in this embodiment, and the distance between the second lens and the third lens is adjusted.
[0043] The adjustment results of the distance are shown in Table 2.
[0044] Table 2. Relative distance adjustment table one
[0045]
[0046] In this embodiment, the determination of the numerical value of the above-mentioned relative distance adjustment can be calculated according to the optical simulation software, which will not be described in detail in this embodiment.
[0047] Embodiment 2
[0048] The difference between this embodiment and embodiment 1 is that the type of light source changes, which causes the change of the corresponding incident NA. In this embodiment, the NA value of the light source incident end changes from 0.7 in embodiment 1 to 0.3, and the light collection half angle is 17.5° and the full angle is 35°. In this embodiment, the corresponding magnification is determined according to the size of the illuminated surface or the size of the entrance pupil surface of the subsequent optical system, and the relative distance between the filter and the second lens and the relative distance between the third lens and the third lens are adjusted to achieve the optical requirements. Specifically, the distance adjustment under this scenario is shown in Table 3.
[0049] Table 3. Relative distance adjustment table two
[0050]
[0051] In summary, according to the lens assembly described in Embodiment 1 and Embodiment 2, the lens assembly in the present embodiment can realize the design of the coupled light path under different light source types and illumination area sizes by adjusting the relative distance between the lenses, without repeating the design and manufacture of the light path and lenses. It is worth noting that the light source types in the present embodiment can be halogen lamps, xenon lamps, LEDs, etc.; the variable magnification range is 2-7 times, that is, under one structure, only the working distance of the two lenses needs to be changed, and different illumination light paths under different application requirements can be quickly and zero-cost switched. The light path is suitable for most large field illumination application scenarios under microscopic imaging. Moreover, the light path structure in the present embodiment couples a filter, which can meet different waveband illumination requirements, including but not limited to ultraviolet light, visible light, infrared light, etc. The light path structure in the present embodiment can selectively receive the light emitting angle of the light source in the range of 0-106° (corresponding to the NA range of 0-0.8). The advantage of the light path is that it can improve the uniformity of the illumination surface after coupling, and can also maximize the energy of the illumination surface.
[0052] The relative distance adjustment of the lens assembly in the present embodiment is realized based on the fixed assembly, and the cooperation relationship between the fixed assembly and the lens assembly can be referred to Figure 2 .
[0053] Referring to Figure 2 , the fixed assembly includes a plurality of fixed units, and each lens in the lens assembly is arranged in a corresponding fixed unit. The plurality of fixed units form a cylindrical structure to form a complete illumination device. The fixed assembly includes a first unit 21, a second unit 22, a third unit 23, and a fourth unit 24. The four units correspond to the first lens, the filter, the second lens, and the third lens in the lens assembly, respectively.
[0054] As described above, the adjustment of the relative position relationship between the lens assemblies in the present embodiment mainly adjusts the relative distance between the filter and the second lens, the relative distance between the third lens and the filter, and the relative distance between the third lens and the second lens. It can be understood that the adjustment object is the filter and the third lens. Therefore, in the present embodiment, the fixed units in the fixed assembly arranged between the filter and the third lens should be movable, that is, the second unit and the fourth unit are movable, and are movable relative to the third unit.
[0055] Specifically, in one implementation manner, the second unit and the fourth unit are sleeved on the third unit, and an active connection structure is formed at the connection position by setting threads. The second unit and the fourth unit can be rotated by an external force, so that the filter and the third lens arranged in the units can move relative to the second lens in the third unit.
[0056] Further, in another embodiment, in order to ensure the stability and controllability of the connection of the second unit, the third unit and the fourth unit during rotation, an adjusting knob 25 is arranged on the two ends of the third unit close to the second unit and the fourth unit. The adjusting knob is arranged on the third unit and is arranged in threaded connection with the outer thread of the third unit through a thread 26, so as to form a movable connection structure. In addition, the adjusting knob is connected with the second unit and the fourth unit through a connecting rod, and is used for limiting the adjusting knob. Specifically, in this embodiment, the connecting rod is a screw 27, and a base connected with the screw is arranged on the second unit and the fourth unit respectively, so as to connect the second unit and the fourth unit with the third unit through the screw respectively.
[0057] Specifically, the adjusting method of the adjusting structure is to loosen the screw, rotate the adjusting knobs on the two sides in the forward direction or the reverse direction, change the relative position of the adjusting knob relative to the third unit, and drive the corresponding second unit or / and fourth unit to change the relative position relative to the third position, so as to change the distance of the filter relative to the second lens or / and the distance of the third lens relative to the second lens.
[0058] In this embodiment, in order to ensure the concentricity of the optical lens, the two screws should be symmetrically arranged, and further, six screws are preferably arranged in a ring shape in this embodiment to increase the stability of the connection and the stability of the horizontal position.
[0059] In this embodiment, the parallelism is ensured by the precise machining of the adjusting knob and the surface of the optical machine fixing part, so that the fixing parts always maintain relative parallelism during the adjusting process, and the inclination does not occur, so as to ensure the concentricity of the optical lenses. Compared with the adjusting mode of the shaft sleeve or the waist hole, the adjusting mode of the preferred embodiment can effectively ensure that the concentricity and perpendicularity of the optical machine structure do not change during the adjusting process. In addition, the thread in this embodiment is an optical fine thread, and the adjusting precision is very high through the optical fine thread, which can reach 1.4um / °.
[0060] In summary, the embodiment of the present application provides a lighting device, which comprises a lens assembly and a fixing assembly. The lens assembly comprises a first lens, a filter, a second lens and a third lens, and the fixing assembly comprises a first unit, a second unit, a third unit and a fourth unit for placing the lenses respectively. The distance between the second unit and the third unit and the distance between the fourth unit and the third unit are adjusted to realize the adjustment of the vertical aperture magnification of the light source in the lighting device, which can be applied to various types of light sources. Only the working distance of the lens needs to be changed, and different lighting light paths under different application requirements can be quickly and zero-cost switched.
[0061] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.
[0062] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.
Claims
1. An illumination device comprising a light source, characterized in that The lens assembly is sequentially provided with a first lens, a filter, a second lens and a third lens along an optical propagation path and forms a coupling light path, and the fixed assembly is composed of a plurality of fixed units which are sequentially connected based on the optical propagation path, each of which is provided with the first lens, the filter, the second lens and the third lens, and the relative distance between the filter and the second lens and the relative distance between the third lens and the second lens are adjusted by the corresponding fixed units, and the adjustment distance is determined according to the magnification of the numerical aperture of the light source.
2. The illumination device of claim 1, wherein The fixed assembly includes a first unit, a second unit, a third unit and a fourth unit, the relative distance between the second unit and the third unit is adjusted to adjust the distance between the filter and the second lens, and the relative distance between the fourth unit and the third unit is adjusted to adjust the distance between the third lens and the second lens.
3. The illumination device of claim 2, wherein, The second unit and the fourth unit are sleeved on the third unit and are movably connected to the third unit by threads.
4. The illumination device of claim 2, wherein, The fixed assembly further includes two adjusting knobs connected to the second unit and the fourth unit respectively, and the adjusting knobs are sleeved on the third unit and are movably connected to the third unit by threads; the second unit and the fourth unit are sleeved on the third unit, and the relative positions between the second unit and the third unit and between the fourth unit and the third unit are changed by the adjusting knobs.
5. The illumination device of claim 4, wherein, The adjusting knobs are connected to the second unit and the third unit by a plurality of connecting rods respectively.
6. The illumination device of claim 1, wherein, The first lens is an asymmetric double convex lens, and the curvature of the convex surface at the light entrance is smaller than that of the convex surface at the light exit.
7. The illumination device of claim 1, wherein The filter is a plane cylindrical lens.
8. The illumination device of claim 1, wherein, The second lens is a plane convex lens, and the convex surface is located at the light exit surface.
9. The illumination device of claim 1, wherein, The third lens is a plane convex lens, and the convex surface is located at the light entrance surface.
10. The illumination device of claim 1, wherein, The magnification is 2-7 times.