An adjustment fixture based on effective focal length of lens

Abstract

The adjustment jig based on the effective focal length of the lens proposed by the present invention always maintains the distance between the lens and the lighting area as the working distance L of the lens during the process of adjusting the lighting effect. Therefore, the light spot obtained in the lighting area is always the sharpest light spot, maintaining a good lighting effect, making it convenient to observe the same defect from different angles, avoiding missed detection of product defects, and improving product yield. Moreover, the adjustment jig provided by the present invention can be conveniently optimized to a standard module when used in large quantities, which can ensure the same lighting effect, is beneficial to ensure the consistency of camera image acquisition, and thus ensure the stability of the equipment.

Description

Technical Field

[0001] Used in semiconductor, panel industry, or other industries for high-precision defect measurement and detection, especially in the field of visual engineering lighting. Background Art

[0002] In the field of high-precision defect measurement and detection, light sources and lenses are usually used for lighting. Take the plano-convex cylindrical lens as an example. The plano-convex cylindrical lens forms a linear image and is used in situations where the size of the light beam only needs to be controlled in one direction. The light source used with the plano-convex cylindrical lens is a linear light source.

[0003] In order to determine the relative position of the illuminated area, it is necessary to measure the working distance of the linear light source after it passes through the lens. Figure 1 As shown, P″ is the principal point of the plano-convex cylindrical lens, and EFL is the effective focal length. The linear light source is placed at point A (point A is the focus of the plano-convex cylindrical lens), and the light passing through the plano-convex cylindrical lens will form a light spot on the white board at point B, and the width of the light spot is d. By changing the distance between the white board and the surface of the plano-convex cylindrical lens, when the edge sharpness of the light spot is the largest, the working distance L of the plano-convex cylindrical lens can be determined.

[0004] In the prior art, once the working distance L is determined, the light source, lens, and lighting area (i.e. Figure 1 The position of the whiteboard in the image is fixed, the lighting effect is single and lacks choice. Summary of the invention

[0005] The purpose of the present invention is to provide a fixture that can easily adjust a suitable lighting effect, so as to adjust the angle at which light reaches the lighting area while keeping the lens working at the working distance L. Furthermore, the lighting area of ​​the light source can be rotated or moved while keeping the lens working at the working distance. Furthermore, especially when it is used in large quantities, because scales are added at corresponding positions, the man-hours for debugging the lighting effect can be effectively reduced.

[0006] The embodiment of the present invention provides an adjustment fixture based on the effective focal length of a lens, the fixture comprising:

[0007] Light source assembly 1 and pitch adjustment frame 2.

[0008] The light source assembly 1 comprises a light source and a lens. The working distance of the lens is L.

[0009] The pitch adjustment frame 2 includes a left side plate 3 , a right side plate 4 , a connecting rod 5 and a pitch adjustment bracket 6 .

[0010] The left side plate 3 and the right side plate 4 are installed opposite to each other, and vertically support the pitch adjustment frame 2. The left side plate 3 and the right side plate 4 each have an arc-shaped groove at a corresponding position.

[0011] The connecting rods 5 have N pieces and are used to connect the left side plate 3 and the right side plate 4 so that the pitch adjustment frame 2 remains stable. N≥1.

[0012] The pitch adjustment bracket 6 comprises an adjustment bracket 7, a moving component 8 and a locking device 9. The two ends of the adjustment bracket 7 are respectively provided with a moving component 8. The moving component 8 can move along the arc-shaped groove.

[0013] The radius of curvature of the arc-shaped groove coincides with the axis of the lens. In the direction of the axis, the distance from the center arc of the arc-shaped groove to the front end of the lens is L', and the distance from the front end of the lens to the center of the arc of the arc-shaped groove is the working distance L of the lens. Then the radius of curvature of the arc-shaped groove is R c =L+L′.

[0014] The locking device 9 is used to fix the relative position of the moving component 8 and the arc-shaped groove, that is, to fix the angle of the pitch adjustment bracket 6 relative to the horizontal plane.

[0015] The light source assembly 1 is fixedly connected to the adjustment bracket 7 and can change position as the moving component 8 moves in the arc-shaped groove, thereby achieving adjustment of the projection direction of the light source.

[0016] In some embodiments, the present invention provides an adjustment fixture based on the effective focal length of a lens:

[0017] The moving member 8 is a cam follower member 8'.

[0018] In some embodiments, the present invention provides an adjustment fixture based on the effective focal length of a lens:

[0019] The moving component 8 is an arc-shaped slider 8 ″, and the arc-shaped slider 8 ″ is customized according to the circular arc groove.

[0020] In some embodiments, the present invention provides an adjustment fixture based on the effective focal length of a lens:

[0021] The arc-shaped groove is marked with scale.

[0022] In some embodiments, the present invention provides an adjustment fixture based on the effective focal length of a lens, the fixture further comprising:

[0023] The moving part 8 is provided with a pointer.

[0024] In some embodiments, the present invention provides an adjustment fixture based on the effective focal length of a lens, the fixture further comprising:

[0025] Z-axis rotation axis, Z-axis rotation connector.

[0026] The Z-axis rotation axis is used as a rotation axis to realize rotation in the Z direction, and to achieve position fixation after adjusting the rotation angle.

[0027] The Z-direction rotating connector is used to connect the Z-direction rotating axis and the pitch adjusting frame 2 , and drives the pitch adjusting frame 2 to rotate and fix around the Z-direction rotating axis.

[0028] In some embodiments, the present invention provides an adjustment fixture based on the effective focal length of a lens, the fixture further comprising:

[0029] The X-direction moving component 8 is used to drive the pitch adjustment frame 2 to move along the X-direction.

[0030] In some embodiments, the present invention provides an adjustment fixture based on the effective focal length of a lens:

[0031] The light source is a linear light source, and the lens is a plano-convex cylindrical lens.

[0032] In some embodiments, the present invention provides an adjustment fixture based on the effective focal length of a lens:

[0033] The light source is a point light source, and the lens is a circular lens.

[0034] The beneficial effects of the present invention are:

[0035] The adjustment jig based on the effective focal length of the lens proposed by the present invention always maintains the distance between the lens and the lighting area as the working distance L of the lens during the process of adjusting the lighting effect. Therefore, the light spot obtained in the lighting area is always the sharpest light spot, maintaining a good lighting effect, making it convenient to observe the same defect from different angles, avoiding missed detection of product defects, and improving product yield. Moreover, the adjustment jig provided by the present invention can be conveniently optimized to a standard module when used in large quantities, which can ensure the same lighting effect, is beneficial to ensure the consistency of camera image acquisition, and thus ensure the stability of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or prior art descriptions. However, those skilled in the art should understand that the drawings described below are only some examples of the present application and do not limit its scope.

[0037] Figure 1 Schematic diagram of the lens working principle.

[0038] Figure 2It is a structural schematic diagram of a specific embodiment of the adjustment fixture based on the effective focal length of the lens of the present invention.

[0039] Figure 3 The diagram is a connection diagram of a light source assembly and a pitch adjustment bracket of a specific embodiment of an adjustment fixture based on the effective focal length of a lens of the present invention.

[0040] Figure 4 The figure is a schematic diagram of the side plates and connecting rods of a specific embodiment of the adjustment fixture based on the effective focal length of the lens of the present invention.

[0041] Figure 5 It is a schematic diagram of a cam follower component of a specific embodiment of an adjustment fixture based on the effective focal length of a lens of the present invention.

[0042] Figure 6 It is a schematic diagram of an arc-shaped slider according to a specific embodiment of the adjustment fixture based on the effective focal length of a lens of the present invention.

[0043] Figure 7 The figure is a schematic diagram of the working principle of a specific embodiment of the adjustment fixture based on the effective focal length of the lens of the present invention.

[0044] Figure 8 The figure is a schematic diagram of the working principle of a specific embodiment of the adjustment fixture based on the effective focal length of the lens of the present invention. DETAILED DESCRIPTION

[0045] The technical scheme in the embodiment of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiment of the present application. It should be understood by those skilled in the art that the described embodiment is a part of the embodiment of the present invention, rather than all the embodiments. Based on the embodiment in the present application, those skilled in the art can make any appropriate modifications or variations to obtain all other embodiments.

[0046] The embodiment of the present invention provides an adjustment fixture based on the effective focal length of a lens, the fixture comprising:

[0047] Light source assembly 1 and pitch adjustment frame 2.

[0048] The light source assembly 1 comprises a light source and a lens. The working distance of the lens is L.

[0049] The pitch adjustment frame 2 includes a left side plate 3 , a right side plate 4 , a connecting rod 5 and a pitch adjustment bracket 6 .

[0050] The left side plate 3 and the right side plate 4 are installed opposite to each other, and vertically support the pitch adjustment frame 2. The left side plate 3 and the right side plate 4 each have an arc-shaped groove at a corresponding position.

[0051] The connecting rods 5 have N pieces and are used to connect the left side plate 3 and the right side plate 4 so that the pitch adjustment frame 2 remains stable. N≥1.

[0052] The pitch adjustment bracket 6 comprises an adjustment bracket 7, a moving component 8 and a locking device 9. The two ends of the adjustment bracket 7 are respectively provided with a moving component 8. The moving component 8 can move along the arc-shaped groove.

[0053] The radius of curvature of the arc-shaped groove coincides with the axis of the lens. In the direction of the axis, the distance from the center arc of the arc-shaped groove to the front end of the lens is L', and the distance from the front end of the lens to the center of the arc of the arc-shaped groove is the working distance L of the lens. Then the radius of curvature of the arc-shaped groove is R c =L+L′.

[0054] The locking device 9 is used to fix the relative position of the moving component 8 and the arc-shaped groove, that is, to fix the angle of the pitch adjustment bracket 6 relative to the horizontal plane.

[0055] The light source assembly 1 is fixedly connected to the adjustment bracket 7 and can change position as the moving component 8 moves in the arc-shaped groove, thereby achieving adjustment of the projection direction of the light source.

[0056] In this embodiment, if Figure 2 As shown, the fixture includes the light source assembly 1 and the pitch adjustment frame 2. The light source assembly 1 includes the light source and the lens. Figure 1 As shown, the light point of the light source is located at the focus of the lens. Point light or line light, at the focus, will become parallel light after passing through the lens, forming a relatively uniform area (the light spot is the sharpest) at a certain distance (working distance). After measuring the working distance, the fixture of this embodiment can maintain the distance between the lens and the lighting area at the working distance. In addition, the amount of light irradiated onto the surface of the object to be measured by the lens should be able to meet the measurement or detection requirements. The light source and the lens can be used in combination to achieve a lighting effect within the technical field involved in the present invention. The light source and the lens can be connected together to form a module, or they can be independent of each other. However, if Figure 3 As shown, the light source and the lens should maintain a stable relative position with the pitch adjustment bracket 6, that is, the light source assembly 1 and the pitch adjustment bracket 6 should constitute a rigid body, and change their positions together with the movement of the movable component 8 in the arc-shaped groove to achieve the adjustment of the projection direction of the light source.

[0057] like Figure 4As shown, it is the fixed part of the pitch adjustment frame 2. The left side plate 3 and the right side plate 4 of the pitch adjustment frame 2 can be connected by the connecting rod 5 to form a stable whole, or can be an integrated structure, such as a U-shaped structure. In this case, it can be considered that there is an integrated connecting rod 5 between the left side plate 3 and the right side plate 4. The connecting rod 5 can be one or more, can be as narrow as a stick or as wide as a board, can be straight or curved, and can connect the left side plate 3 and the right side plate 4 into a stable whole.

[0058] like Figure 3 As shown, the pitch adjustment bracket 6 is a movable component that can rotate, including the adjustment bracket 7, the moving component 8 and the locking device 9. The adjustment bracket 7 can drive the light source assembly 1 to rotate. The shape, size, etc. of the adjustment bracket 7 can be determined according to the needs of the light source and the lens, and it only needs to be able to stably install the light source assembly 1 and drive the light source assembly 1 to rotate. The rotation is driven by the movement of the moving component 8 in the circular arc groove. The curvature of the circular arc groove is equal everywhere, that is, the arc of the circular arc groove is a part of a specific circle. The moving component 8 can be a cam follower component 8', a slider, etc., such as Figure 5 and Figure 6 It can also be a gear rolling on the arc-shaped rack, which can move in the circular arc groove. The pitch adjustment bracket 6 and the pitch adjustment frame 2 form a moving pair through the moving component 8 and the left side plate 3 and the right side plate 4.

[0059] like Figure 7 , which is a schematic diagram of the principle of the light source assembly 1 rotating along the circular arc groove. The working distance L of the lens should be a known value. Figure 7 In the view shown, with point C at the front end of the lens 10 as the base point, point O on the lens axis that is located in front of the lens 10 at the working distance L is the point where the sharpest light spot can be obtained, that is, the center position of the center arc of the circular arc groove. The radius of curvature of the circular arc groove coincides with the axis of the lens 10. The distance from the center arc of the circular arc groove to the base point in the direction of the axis is L′. The value of L′ can be set independently according to the light source assembly 1, and can be larger or smaller. In principle, it is appropriate to facilitate assembly and debugging. Because of the above-mentioned setting, the radius of curvature R of the circular arc groove c=L+L′. That is to say, the distance from the base point to the sharpest light spot (the light spot of the convex lens is circular, and the light spot of the plano-convex cylindrical lens is an elongated rectangle) is equal to the working distance L of the lens, and the light source (point light source or linear light source), the lens 10 (convex lens or plano-convex cylindrical lens), the base point and the center line of the working distance are located on the same axis. Therefore, when the movable component 8 moves in the circular arc groove, the moving trajectory of the base point and the center arc line of the circular arc groove form concentric circular arcs, that is, the center of the center arc line of the circular arc groove is always the center of the moving trajectory of the base point, that is, the distance from the center of the circle to the base point is always the working distance L of the lens, and therefore it is always the point where the sharpest light spot can be obtained. Therefore, the technical solution of the present invention achieves the adjustment of the projection direction of the light source, that is, the change of the pitch angle, while still maintaining a good lighting effect.

[0060] It should be further pointed out that Figure 7 The example shows the case where L' is located on the extension line of L. There is also a case where L' and part of L overlap, such as Figure 8 At this time, L' should be taken as a negative value in the calculation, that is, the curvature radius R of the arc groove c =L+L' is a value L' smaller than the working distance L of the lens. This method has the advantages of saving space and avoiding interference with other components in a limited space.

[0061] The locking device 9 is used to fix the relative position of the moving part 8 and the arc-shaped groove, that is, to fix the angle of the pitch adjustment bracket 6 relative to the horizontal plane, which ensures that the projection direction of the light source can be maintained after adjustment. The locking device 9 can be implemented in a variety of ways. For example, when the position of the moving part 8 is adjusted by rolling the gear on the arc-shaped rack, after adjusting the angle, the gear is locked, the arc-shaped rack can be fixed, and then the position of the light source assembly 1 is fixed; when the adjustment bracket 7 is tightened by the spring, the adjustment screw is used to support the adjustment bracket 7, and the angle of the adjustment bracket 7 can be adjusted and fixed by adjusting the screw forward or reverse; a number of threaded holes are processed around the arc-shaped groove, and after adjusting the angle, the moving part 8 is supported by the screw, which can also achieve the fixation of the adjustment bracket 7. There are too many such schemes to list, and most of the schemes that can achieve position fixation in the prior art are applicable, so they will not be repeated. However, it should be further pointed out that the technical solution of the present invention does not involve the drive of the movable component 8, because the manual or electric driving methods used in the prior art are all applicable. At this time, if the driving component has a locking function and uses the locking function to achieve the position fixing effect achieved by the technical solution of the present invention, then the device that realizes the locking function should still belong to the locking device 9 referred to in the technical solution of the present invention.

[0062] In the process of product defect inspection or measurement, the same defect will appear differently in the image when the light source is at different angles, which will affect the image processing and may cause missed detection to some extent. The technical solution of this embodiment can avoid missed detection of product defects by adjusting the light source with higher precision.

[0063] When used in large quantities, the technical solution of this embodiment can be optimized into a standard module, which can ensure the same lighting effect, is beneficial to ensure the consistency of camera image acquisition, and further ensures the stability of the equipment.

[0064] In some embodiments, the present invention provides an adjustment fixture based on the effective focal length of a lens:

[0065] The moving member 8 is a cam follower member 8'.

[0066] In this embodiment, if Figure 5 As shown, the moving component 8 is the cam follower component 8'. The cam follower component 8' is provided with two cam followers to simulate the two end points of the arc, which can slide in the arc-shaped groove to achieve the adjustment of the pitch angle.

[0067] In some embodiments, the present invention provides an adjustment fixture based on the effective focal length of a lens:

[0068] The moving component 8 is an arc-shaped slider 8 ″, and the arc-shaped slider 8 ″ is customized according to the circular arc groove.

[0069] In this embodiment, if Figure 6 As shown, the sliding component is an arc-shaped slider 8". The arc-shaped slider 8" (negative tolerance) is customized to match the arc-shaped arc-shaped grooves (positive tolerance) on the left and right side plates 4. The arc-shaped slider 8" slides in the arc-shaped groove to ensure that the center of the circle remains unchanged, thereby effectively achieving the adjustment of the pitch angle.

[0070] In some embodiments, the present invention provides an adjustment fixture based on the effective focal length of a lens:

[0071] The arc-shaped groove is marked with scale.

[0072] In this embodiment, if Figure 5 and Figure 6 As shown, the arc-shaped groove is marked with scales to facilitate positioning during the adjustment process, so as to find the best position and fix it at the best position.

[0073] In some embodiments, the present invention provides an adjustment fixture based on the effective focal length of a lens, the fixture further comprising:

[0074] The moving part 8 is provided with a pointer.

[0075] In this embodiment, a pointer is provided on the moving component 8, which can accurately point to the scale marked on the arc-shaped groove, making it easy to read.

[0076] In some embodiments, the present invention provides an adjustment fixture based on the effective focal length of a lens, the fixture further comprising:

[0077] Z-axis rotation axis, Z-axis rotation connector.

[0078] The Z-axis rotation axis is used as a rotation axis to realize rotation in the Z direction, and to achieve position fixation after adjusting the rotation angle.

[0079] The Z-direction rotating connector is used to connect the Z-direction rotating axis and the pitch adjusting frame 2 , and drives the pitch adjusting frame 2 to rotate and fix around the Z-direction rotating axis.

[0080] In this embodiment, the pitch adjustment frame 2 rotates as a whole with the Z direction as the rotation axis, which does not affect the adjustment function of the adjustment bracket 7. Although the position of the light spot of the light source on the surface of the object to be measured has changed, the light spot is always the sharpest light spot, and the relationship between the points in the cross-sectional view remains unchanged. The Z-axis of rotation can be connected to a motor and fixed in position through the locking function of the motor, or it can be manually adjusted and fixed in position through conventional methods such as screws, which will not be described here.

[0081] In some embodiments, the present invention provides an adjustment fixture based on the effective focal length of a lens, the fixture further comprising:

[0082] The X-direction moving component 8 is used to drive the pitch adjustment frame 2 to move along the X-direction.

[0083] In this embodiment, the forward and backward movement of the pitch adjustment frame 2 in the X direction is an integral movement, which does not affect the adjustment function of the adjustment bracket 7. Although the position of the light spot of the light source on the surface to be detected has changed, the light spot is always the sharpest light spot, and the relationship between the points in the cross-sectional view remains unchanged. The movement in the X direction can be achieved by sliding along the track, or by screws and slides, or by being driven by other carriers that can move in the X direction, and can be achieved by a variety of existing technologies. The X-moving component 8 refers to the component that realizes the movement in the X direction.

[0084] In some embodiments, the present invention provides an adjustment fixture based on the effective focal length of a lens:

[0085] The light source is a linear light source, and the lens is a plano-convex cylindrical lens.

[0086] In this embodiment, the light source assembly 1 uses a combination of the linear light source and the plano-convex cylindrical lens. Because the volume of the light source assembly 1 is relatively large, the adjustment bracket 7 should also have enough space to ensure the stability of the light source assembly 1 after installation.

[0087] In some embodiments, the present invention provides an adjustment fixture based on the effective focal length of a lens:

[0088] The light source is a point light source, and the lens is a circular lens.

[0089] In this embodiment, the light source is a point light source, and the lens is a circular lens. The combination of the light source assembly 1 is already available in the market as a finished product, and the entire finished product is called a "point light source". Although the lens is not reflected in the name, the lens is already included. The volume of the light source assembly 1 is relatively small and it is easier to install. Accordingly, the adjustment bracket 7 can also be simpler, and it only needs to ensure the stability of the light source assembly 1 after installation.

Claims

1. An adjustment fixture based on the effective focal length of a lens, characterized in that: The fixtures include: A light source assembly (1) and a pitch adjustment frame (2); The light source assembly (1) comprises a light source and a lens; The working distance of the lens is L; The pitch adjustment frame (2) comprises a left side plate (3), a right side plate (4), a connecting rod (5) and a pitch adjustment bracket (6); The left side plate (3) and the right side plate (4) are installed relative to each other to support the pitch adjustment frame (2) in the vertical direction; The left side plate (3) and the right side plate (4) each have an arc-shaped groove at a corresponding position; The connecting rods (5) are N in number and are used to connect the left side plate (3) and the right side plate (4) so ​​that the pitch adjustment frame (2) remains stable; N≥1； The pitch adjustment bracket (6) comprises an adjustment bracket (7), a moving component (8) and a locking device (9); The two ends of the adjustment bracket (7) are each provided with a moving component (8); The moving component (8) is capable of moving along the arc-shaped groove; The point C at the front end of the lens is taken as the base point; the distance between the center arc of the arc-shaped groove and the front end of the lens in the direction of the lens axis is L′, and the distance from the front end of the lens to the center of the arc of the arc-shaped groove is the working distance L of the lens, then the curvature radius of the arc-shaped groove Rc=L+L′; the light source, the lens, the base point and the center line of the working distance are located on the same axis; the point on the lens axis that is located in front of the lens at the working distance L is the point that can obtain the sharpest light spot; the distance from the center of the circle to the base point is always the working distance L of the lens; The locking device (9) is used to fix the relative position of the moving component (8) and the arc-shaped groove, that is, to fix the angle of the pitch adjustment bracket (6) relative to the horizontal plane; The light source assembly (1) and the adjustment bracket (7) are fixedly connected and can change position as the moving component (8) moves in the arc-shaped groove, thereby achieving adjustment of the projection direction of the light source.

2. The fixture according to claim 1, characterized in that: The moving component (8) is a cam follower component (8').

3. The fixture according to claim 1, characterized in that: The moving component (8) is an arc-shaped slider (8″), and the arc-shaped slider (8″) is customized according to the circular arc groove.

4. The fixture according to claim 1, characterized in that: The arc-shaped groove is marked with scales.

5. The fixture according to claim 4, characterized in that: The fixture also includes: The moving component (8) is provided with a pointer.

6. The fixture according to any one of claims 1 to 5, characterized in that: The fixture also includes: Z-axis rotation axis, Z-axis rotation connector; The Z-axis rotation axis is used as a rotation axis to realize rotation in the Z direction and to achieve position fixation after adjusting the rotation angle; The Z-direction rotating connecting member is used to connect the Z-direction rotating axis and the pitch adjusting frame (2), and drives the pitch adjusting frame (2) to rotate and fix around the Z-direction rotating axis.

7. The fixture according to any one of claims 1 to 5, characterized in that: The fixture also includes: The X-direction moving component (8) is used to drive the pitch adjustment frame (2) to move along the X direction.

8. The fixture according to any one of claims 1 to 5, characterized in that: The light source is a linear light source, and the lens is a plano-convex cylindrical lens.

9. The fixture according to any one of claims 1 to 5, characterized in that: The light source is a point light source, and the lens is a circular lens.

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