Lens centering module and method thereof, scanning device

Abstract

The present invention provides a lens centering module and a centering method thereof, and a scanning device. The lens centering module includes a lens and a pair of adjustment blocks. The lens has two end surfaces and a first center line passing through each of the end surfaces. The pair of adjustment blocks are disposed on a platform, each of the adjustment blocks has a recess, an extended bevel protruding from both sides of the recess, and a second center line passing through the recess. Each of the recesses faces each of the end surfaces, and each of the extended bevels abuts an edge of each of the end surfaces, so that the first center line and the second center line are disposed in a same plane, thereby eliminating or minimizing the focal length deviation without using a focal length testing instrument.

Description

Technical Field

[0001] This invention relates to a lens module; more specifically, to a lens centering module and centering method thereof, and a scanning device. Background Technology

[0002] The self-focusing gradient index rod lens (GRIN) used in commercially available linear image sensors refers to an optical lens in which the refractive index of the material changes continuously along a certain direction. Gradient index lenses possess collimation, focusing, divergence, coupling, and imaging properties, and can effectively reduce monochromatic aberrations, including spherical aberration, aberrations, distortion, field curvature, and astigmatism. Their compact, cylindrical shape also makes them easier to use in various miniature optical systems. Gradient index lenses are essential basic components in passive optical communication devices and are widely used in integrated optics fields such as miniature optical systems, collimators, lasers, optical switches, medical optical instruments, optical copiers, fax machines, and scanners.

[0003] Lenses are mainly classified into two categories based on their material: glass and plastic. Plastic lenses are easy to mold, lightweight, low-cost, and widely used. However, due to inherent drawbacks of plastics, such as thermal expansion, water absorption, poor resistance to organic solvents, narrow optical coefficient range, and susceptibility to temperature changes, they still cannot replace glass lenses in optical products. Optical glass, due to its excellent light transmission properties and characteristics regarding thermal expansion and refractive index, still dominates in high-end products. With the development of precision optical systems, the application of gradient refractive index glass is becoming increasingly widespread, and optical systems are placing higher demands on the refractive index distribution and quality of gradient refractive index glass. Figure 1 The diagram shows an embodiment of a conventional refractive index distribution lens. The aperture angle θ is the maximum angle between the light ray incident on one end of the optical axis of the refractive index distribution lens GRIN and the optical axis. F1 is the image plane, and F2 is the object plane of the light-receiving component. L1 is the length of the refractive index distribution lens GRIN. L2 is the image distance between the image plane F1 and the refractive index distribution lens GRIN, and L3 is the object distance between the object plane F2 and the refractive index distribution lens GRIN, wherein the object distance L3 is equal to the image distance L1.

[0004] Generally, a refractive index distribution lens (GRIN) is placed between the image sensor chip (e.g., at the camera plane F1) and the object to be scanned (e.g., at the object-image plane F2), where R is the field of view radius of the refractive index distribution lens GRIN, and the aperture angle θ of the refractive index distribution lens GRIN is, for example, 3–6°, and can be determined according to...Figure 1 The method described in the embodiment determines. Due to assembly and material production tolerance, the refractive index distribution lens GRIN of the final product fails to be placed in the middle design position, thereby causing deviation of the best focal length. However, to solve the above-mentioned problem, a general solution is to use a focal length testing instrument and then use a lens position adjusting mechanism (such as a screw and a gasket) to adjust the refractive index distribution lens GRIN to the middle position. SUMMARY

[0005] One object of the present application is to provide a lens centering module and a lens centering method. The lens centering module includes a pair of adjusting blocks with symmetric grooves to hold a lens so that the center lines of the two ends of the lens are aligned with the center lines of the adjusting blocks, thereby achieving no or minimal deviation of the focal length.

[0006] To achieve the above object, the present application provides a lens centering module disposed on a platform, which includes a lens and a pair of adjusting blocks. The lens has two end surfaces and a first center line passing through each of the end surfaces. The pair of adjusting blocks are disposed on the platform, and each of the adjusting blocks has a groove, an extended bevel protruding from both sides of the groove, and a second center line passing through the groove. Each of the grooves faces each of the end surfaces, and each of the extended bevels abuts the edge of each of the end surfaces so that the first center line is aligned with the second center line.

[0007] In one embodiment, before the first center line is aligned with the second center line, the method further includes moving the pair of adjusting blocks toward the center of the lens so that the second center line of the pair of adjusting blocks approaches the first center line of the lens.

[0008] In one embodiment, when the first center line is aligned with the second center line, the method further includes disposing adhesive between each of the grooves and each of the end surfaces so that the pair of adjusting blocks are fixedly connected to the lens.

[0009] In one embodiment, the pair of adjusting blocks are made of plastic, metal, glass, or a combination thereof, and the lens is a transparent cylinder made of glass, quartz, or crystal.

[0010] In one embodiment, an included angle is further included between each of the extended bevels and the second center line, and the included angle ranges from 0 to 90 degrees.

[0011] The present application also provides a lens centering method for a lens centering module disposed on a platform, which includes the following steps:

[0012] providing a lens having two end surfaces and a first center line passing through each of the end surfaces;

[0013] The lens centering module includes a pair of adjustment blocks, each of which has a recess, an extended bevel protruding from both sides of the recess, and a second center line passing through the recess, each of the recesses faces each of the end surfaces, and each of the extended bevels abuts the edge of each of the end surfaces; and

[0014] The pair of adjustment blocks are moved toward the center of the lens, so that the first center line is aligned with the second center line.

[0015] In an embodiment, in the step of moving the pair of adjustment blocks toward the center of the lens, a force is applied to the pair of adjustment blocks, so that the second center line of the pair of adjustment blocks approaches a straight line with the first center line of the lens.

[0016] In an embodiment, after the step of aligning the first center line with the second center line, an adhesive is applied between each of the recesses and each of the end surfaces, so that the pair of adjustment blocks are fixedly connected with the lens.

[0017] In an embodiment, the lens centering module is disposed in a housing, so that a first distance between the first center line and a plane of an object to be scanned is equal to a second distance between the second center line and an image sensing chip.

[0018] In an embodiment, an included angle between each of the extended bevels and the second center line ranges from 0 to 90 degrees.

[0019] Further, the present application provides a scanning device, which includes the lens centering module as claimed in any one of items 1 to 5, the scanning device includes a housing and an image sensing module, which is disposed in the housing corresponding to the lens centering module and includes a circuit board and an image sensing chip disposed on the circuit board.

[0020] In an embodiment, a first distance between the first center line and a plane of an object to be scanned is equal to a second distance between the second center line and an image sensing chip.

[0021] The lens centering module of the present application has a simple structure, and is easy to assemble and maintain. Specifically, the lens centering module of the present embodiment can quickly align and fix the first / second center line of the lens and the pair of adjustment blocks by limiting and adjusting the distance between the lens and the pair of adjustment blocks, and thus is easy to assemble and maintain. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to make the above content of the present application more obvious and easy to understand, the following preferred embodiments are described in detail below with reference to the accompanying drawings:

[0023] Figure 1This is a schematic diagram of an example of an existing refractive index distribution lens;

[0024] Figure 2 This is a schematic diagram of the first embodiment of the lens centering module of the present invention;

[0025] Figure 3 This is a schematic diagram of a second embodiment of the lens centering module of the present invention;

[0026] Figure 4 This is a schematic diagram of a third embodiment of the lens centering module of the present invention;

[0027] Figure 5 This is a schematic diagram of the fourth embodiment of the lens centering module of the present invention;

[0028] Figure 6 This is a schematic diagram of the first embodiment of the adjustment block of the lens centering module of the present invention;

[0029] Figure 7 This is a schematic diagram of a second embodiment of the adjustment block of the lens centering module of the present invention; and

[0030] Figure 8 This is a flowchart of the centering method of the lens centering module of the present invention. Detailed Implementation

[0031] Please refer to the above figures, where the same component symbols represent the same or similar components. The principles of the present invention are illustrated by way of example in a suitable environment. The following description is based on the specific embodiments of the invention illustrated, and should not be construed as limiting the invention to other specific embodiments not detailed herein.

[0032] like Figures 2 to 4 The diagram shows schematic representations of the first to third embodiments of the lens centering module of the present invention. The present invention provides a lens centering module 100, disposed on a platform 101. The platform 101 can be any worktable with a plane, and is not limited in this embodiment. Figures 2 to 4 In the illustrated embodiment, the lens centering module 100 includes a lens 110 and a pair of adjustment blocks 120.

[0033] Lens 110 has two end faces 112 and a first center line 114 passing through each end face 112. A pair of adjustment blocks 120 are disposed on the platform 101. Each adjustment block 120 has a groove 122, an extending inclined edge 124 protruding from both sides of the groove 122, and a second center line 126 passing through the groove 122. Each groove 122 faces each end face 112, and each extending inclined edge 124 abuts against the edge of each end face 112, so that the first center line 114 and the second center line 126 are flush.

[0034] In this embodiment, the lens 110 is preferably a transparent cylinder and made of glass, quartz, crystal or other suitable material. The pair of adjustment blocks 120 are made of plastic, metal, glass or a combination thereof, which is adjusted according to the material of the lens 110 (or the object to be adjusted) and is not limited. Therefore, the lens centering module 100 of this embodiment no longer needs to be matched with a focal length test instrument, or is adjusted by inserting components such as screws and shims into the lens position adjustment mechanism to adjust its position in the center, so as to obtain no or minimal focal length deviation.

[0035] As shown in Figure 3 , before the first center line 114 is arranged flush with the second center line 126, the pair of adjustment blocks 120 is also moved towards the center of the lens 110, so that the second center line 126 of the pair of adjustment blocks 120 approaches the first center line 114 of the lens 110. In other words, a force F is applied to the pair of adjustment blocks 120, so that the second center line 126 of the pair of adjustment blocks 120 approaches the first center line 114 of the lens 110 until the second center line 126 is flush with the first center line 114.

[0036] Please refer to Figure 6 and Figure 7 for the first and second embodiments of the adjustment blocks of the lens centering module. An included angle θ is also included between each extension bevel 124 and the second center line 126, and the angle θ ranges from 0 to 90 degrees. By clamping the lens 110 with the pair of adjustment blocks 120, the lens 110 is self-adapted and balanced according to the symmetric bevels, shapes or angles θ of the ends of the extension bevels 124 of the pair of adjustment blocks 120 during clamping, so that the symmetric opening shape of the groove 122 is consistent with the first center line 114 of the lens 110. Further, when the angle θ of each adjustment block 120 is larger, the diameter of the clamped lens 110 is relatively smaller; when the angle θ of each adjustment block 120 is larger, the diameter of the clamped lens 110 is relatively larger. The angle θ of the groove 122 of each adjustment block 120 and the material can be adjusted according to the size and material of the lens 110 to be matched, which can be changed as needed.

[0037] In the embodiment shown in Figure 4 , when the first center line 114 is arranged flush with the second center line 126, an adhesive 130 is also arranged between each groove 122 and each end surface 112 to connect and fix the pair of adjustment blocks 120 and the lens 110. The material of the adhesive 130 is, for example, epoxy, silicone or other suitable adhesive, which is not limited.

[0038] Please refer to Figure 5 Fig. 4 shows a fourth embodiment of the lens centering module of the present application. When the lens centering module 100 is fixed, the distance between the first center line 114 / second center line 126 and the edges of the adjustment blocks 120 is the same. For example, as shown in Fig. 4, the first center line 114 / second center line 126 is parallel to the edges of the adjustment blocks 120. Figure 5 For example, as shown in Fig. 5, the lens centering module 100 is placed in the casing 210 of the scanning device 200 to perform a scanning detection operation. Specifically, when the lens centering module 100 is placed in the casing 210, the upper and lower sides of the lens centering module 100 are the scanning object plane 220 and the image sensing module 230, respectively. The image sensing module 230 further includes a circuit board 232 and an image sensing chip 234 disposed on the circuit board 232. The first distance D1 between the first center line 114 and the scanning object plane 220 is equal to the second distance D2 between the second center line 126 and the image sensing chip 234. In other words, the scanning device 200 has a fixed depth of field range / focus distance alignment, which reduces the need for additional adjustment of other components in the prior art.

[0039] The present application further provides a centering method of a lens centering module. Please refer to Figure 8 Fig. 6 shows a flowchart of the centering method of the lens centering module of the present application. The lens centering module 100 is disposed on a platform 101. The centering method includes the following steps: step S10, providing a lens 110 having two end surfaces 112 and a first center line 114 passing through the end surfaces 112. Step S20, providing a pair of adjustment blocks 120 each having a groove 122, an extended bevel 124 protruding from both sides of the groove 122, and a second center line 126 passing through the groove 122. The grooves 122 face the end surfaces 112 and the extended bevels 124 abut the edges of the end surfaces 112. Step S30, moving the pair of adjustment blocks 120 toward the center of the lens 110 so that the first center line 114 is parallel to the second center line 126.

[0040] In steps S10 and S20, the lens 110 is preferably a transparent cylinder and made of glass, quartz, crystal or other suitable material. The material of the pair of adjustment blocks 120 is plastic, metal, glass or a combination thereof, which is adjusted according to the material of the lens 110 (or the object to be adjusted) and is not limited. In step S30, a force F is further applied to the pair of adjustment blocks 120 to make the second center line 126 of the pair of adjustment blocks 120 and the first center line 114 of the lens 110 approach a straight line. In other words, before the first center line 114 and the second center line 126 are aligned, the pair of adjustment blocks 120 is further moved towards the center of the lens 110 to make the second center line 126 of the pair of adjustment blocks 120 and the first center line 114 of the lens 110 approach a straight line until the second center line 126 and the first center line 114 are completely aligned.

[0041] After the step of aligning the first center line 114 and the second center line 126, an adhesive 130 is further applied between each groove 122 and each end surface 112 to connect and fix the pair of adjustment blocks 120 and the lens 110. The material of the adhesive 130 is, for example, epoxy, silicone or other suitable adhesive, and is not limited. Therefore, the embodiment holds the lens 110 by the pair of adjustment blocks 120, and in the process of holding, the lens 110 is self-adapted in position and balanced according to the symmetrically beveled edges 124 of the pair of adjustment blocks 120, the shape or angle θ, etc., and finally makes the symmetrically open shape of the grooves 122 consistent with the first center line 114 of the lens 110.

[0042] In the embodiment, the lens centering module 100 is further arranged in a housing 210 to make a first distance D1 between the first center line 114 and a scanning object plane 220 equal to a second distance D2 between the second center line 126 and an image sensing chip 234. Figure 5 Specifically, taking the scanning device 200 as an example, the lens centering module 100 is placed in the housing 210 of the scanning device 200 to perform scanning detection. When the lens centering module 100 is placed in the housing 210, the upper and lower / opposite sides of the lens centering module 100 are respectively the scanning object plane 220 and the image sensing module 230. The image sensing module 230 further includes a circuit board 232 and the image sensing chip 234 disposed on the circuit board 232, so that the first distance D1 between the first center line 114 and the scanning object plane 220 is equal to the second distance D2 between the second center line 126 and the image sensing chip 234. In other words, the scanning device 200 has a fixed depth of field range / same focal length alignment, which reduces the need for additional adjustment by other components in the prior art.

[0043] An angle θ is also included between each extension bevel 124 and the second center line 126, and the angle θ ranges from 0 to 90 degrees. When the angle θ of each adjustment block 120 is larger, the diameter of the clamped lens 110 is relatively smaller; when the angle θ of each adjustment block 120 is larger, the diameter of the clamped lens 110 is relatively larger. The angle θ of each adjustment block 120 groove 122 and the material can be adjusted according to the size and material of the lens 110 to be matched, and changed as needed.

[0044] In summary, the lens centering module 100 and the centering method thereof, and the scanning device 200, due to the simple structure, quick and convenient assembly of the lens centering module 100, the lens centering module 100 no longer needs to be matched with a focal length test instrument, or the position of the lens in the middle is adjusted by inserting components such as screws and spacers that can micro-adjust the lens position mechanism, so that no or minimal focal length deviation can be achieved. Specifically, the lens centering module 100 of the present embodiment only needs to adjust the position limit between the lens 110 and the pair of adjustment blocks 120 to quickly align and fix the first / second center line 114, 126 of the lens 110 and the pair of adjustment blocks 120, so it is quite simple and convenient to assemble or maintain.

[0045] Although examples of the present application have been described with respect to specific embodiments, they are only examples, and the present application is not limited thereto, and should be interpreted as having the broadest scope within the technical spirit disclosed in the specification. Those skilled in the art can implement the present application in a form not described in the embodiments of the present application by combining or replacing the disclosed embodiments, but it also does not depart from the scope of the present application. In addition, it is obvious that those skilled in the art can change or modify the disclosed embodiments based on the specification, therefore, such changes or modifications fall within the scope of the present application.

Claims

1. A lens centering module, mounted on a platform, characterized in that, include: A lens having two end faces and a first center line passing through each of the end faces; as well as A pair of adjustment blocks are disposed on the platform. Each adjustment block has a groove, an extended inclined edge protruding from both sides of the groove, and a second center line passing through the groove. Each groove faces each end face, and each extended inclined edge abuts the edge of each end face. The pair of adjustment blocks can move toward the center of the lens so that the first center line and the second center line are flush.

2. The lens centering module as described in claim 1, characterized in that, When the first center line and the second center line are flush, the method further includes providing an adhesive between each groove and each end face to connect and fix the pair of adjustment blocks to the lens.

3. The lens centering module as described in claim 1, characterized in that, The adjustment blocks are made of plastic, metal, glass, or a combination thereof, and the lens is a transparent cylinder made of glass, quartz, or crystal.

4. The lens centering module as described in claim 1, characterized in that, Each of the extended hypotenuses and the second centerline also includes an included angle, the angle of which ranges from 0 to 90 degrees.

5. A method for centering a lens centering module, the lens centering module being disposed on a platform, characterized in that, Includes the following steps: A lens is provided having two end faces and a first center line passing through each of the end faces; A pair of adjusting blocks are provided, each having a groove, extending inclined edges protruding from both sides of the groove, and a second centerline passing through the groove, wherein the grooves are positioned facing the end faces and the extending inclined edges abut against the edges of the end faces; and Move the pair of adjustment blocks toward the center of the lens so that the first center line is aligned with the second center line.

6. The centering method of the lens centering module as described in claim 5, characterized in that, The step of moving the pair of adjustment blocks toward the center of the lens further includes applying a force to the pair of adjustment blocks so that the second center line of the pair of adjustment blocks approaches a straight line with the first center line of the lens.

7. The centering method of the lens centering module as described in claim 5, characterized in that, After the step of setting the first center line and the second center line flush, the method further includes applying an adhesive between each groove and each end face to connect and fix the pair of adjustment blocks to the lens.

8. The centering method of the lens centering module as described in claim 5, characterized in that, It also includes placing the lens centering module, which fixes the pair of adjustment blocks to the lens, inside a housing, so that a first distance between the first center line and a plane of the object to be scanned is equal to a second distance between the second center line and an image sensing chip.

9. The centering method of the lens centering module as described in claim 5, characterized in that, Each of the extended hypotenuses and the second centerline also includes an included angle, the angle of which ranges from 0 to 90 degrees.

10. A scanning device comprising the lens centering module according to any one of claims 1 to 4, characterized in that, include: A casing; and An image sensing module is provided in the housing, corresponding to the lens centering module. The image sensing module includes a circuit board and an image sensing chip disposed on the circuit board. The first distance between the first center line and the plane of the object to be scanned is equal to the second distance between the second center line and the image sensing chip.

Images