Optical position detection device and method

Abstract

The present application discloses an optical position detection device and method, the device comprising: a light source; a first reflector, which can make the incident light beam from the light source incident on the surface to be measured of the workpiece at a certain inclination angle; a lateral offset magnifying lens group, which can make the reflected light beam of the surface to be measured laterally offset and amplify it before incident on the detector; and a detector. The detection device and method of the present invention adopt an independent optical path and an oblique incidence method, which can avoid the spatial position occupied by other optical paths, and the device is simple, reliable and low-cost. It is also highly accurate and can magnify the position change of the workpiece surface by 50 to 100 times, and can achieve sub-micron position detection.

Description

Technical Field

[0001] The present application relates to the field of optical processing technology, and in particular to an optical position detection device and method. Background Art

[0002] Optical position detection methods have the advantages of non-contact, high precision and fast response, and are widely used in fields such as positioning control and product morphology detection.

[0003] There are many existing optical position detection methods: confocal method (also known as conjugate focus method, more common in laser confocal microscopes), triangulation method (widely used in current commercial laser displacement sensors), interference method (such as dual-frequency laser interferometer), astigmatism method (the servo focusing of the optical drive adopts this method, which is also used in precision optical processing, such as patent 201010170978.4), etc.

[0004] In special cases, the above methods are difficult to meet the needs. For example, if another optical path has occupied the position directly above the workpiece to be measured, the optical path position has been occupied and the technical solution cannot be implemented. Summary of the invention

[0005] The object of the present invention is to provide an optical position detection device and method to overcome the deficiencies in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present application discloses an optical position detection device, comprising:

[0008] light source;

[0009] A first reflector can make an incident light beam from a light source incident on a surface to be measured of a workpiece at a certain inclination angle;

[0010] The lateral displacement magnifying lens group can laterally displace and amplify the reflected light beam of the surface to be measured before it is incident on the detector;

[0011] detector.

[0012] Preferably, in the above optical position detection device, a processing space is defined, and the processing space is located vertically above the surface to be measured of the workpiece.

[0013] The light source, the first reflector, the lateral offset magnifying lens group and the detector are all located outside the processing space.

[0014] Preferably, in the above optical position detection device, the light source and the first reflector are located on one side of the processing space.

[0015] The laterally offset magnifying lens group and the detector are located on the other side of the processing space.

[0016] Preferably, in the above-mentioned optical position detection device, the lateral displacement magnifying lens group includes a prism, and the prism can perform lateral displacement and magnification on the reflected light beam of the surface to be measured.

[0017] Preferably, in the above optical position detection device, the reflected light beam from the surface to be measured enters from one A surface of the prism and is emitted from the B surface of the prism.

[0018] The A surface is parallel to the surface to be measured.

[0019] Preferably, in the above-mentioned optical position detection device, the prism can horizontally shift and magnify the incoming reflected light beam by 8 times.

[0020] Preferably, in the above optical position detection device, the lateral displacement magnifying lens group includes a beam expander lens group, and the beam expander lens group is arranged between the detector and the prism.

[0021] The beam expander lens group can laterally shift and amplify the reflected light beam of the surface to be measured.

[0022] Preferably, in the above-mentioned optical position detection device, the beam expander lens group can perform a lateral shift and amplify the incoming reflected light beam by 5 to 20 times.

[0023] Preferably, in the above optical position detection device, a second reflector is provided between the beam expander lens group and the prism.

[0024] The beam expander lens group and the second reflector are sequentially arranged directly below the detector.

[0025] Correspondingly, the present application also discloses an optical position detection method, providing the optical detection device,

[0026] The optical detection device has an independent detection light path.

[0027] The incident light path is incident obliquely from one side of the processing space, and is emitted obliquely from the other side of the processing space.

[0028] Compared with the prior art, the advantages of the present invention are: the detection device and method of the present invention adopt an independent optical path and an oblique incidence mode, which can avoid the space occupied by other optical paths, and the device is simple and reliable, low cost. It has high precision and can magnify the position change of the workpiece surface by 50 to 100 times, and can achieve sub-micron position detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 Shown is a schematic structural diagram of an optical position detection device in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0033] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] Combination Figure 1 As shown, in one embodiment of the present application, an optical position detection device is provided, which uses optical means to detect whether the roughness or position fluctuation of the surface of the workpiece 10 meets the processing requirements.

[0035] First, a processing space 20 is defined, which is located vertically above the surface of the workpiece to be measured. More preferably, the space vertically above the entire surface of the workpiece 10 to be processed is the processing space 20. The processing space can be provided with other optical paths 30, such as laser cutting optical paths, semiconductor lithography optical paths, etc.

[0036] The optical position detection device is an optical path independent of the optical path 30 and dedicated to detecting the surface position of the workpiece 30. Due to its independence, it can be used in conjunction with different optical devices without modifying the original optical device or borrowing the original optical elements of the optical device.

[0037] In order to avoid interference of the optical position detection device with the original optical equipment, the optical position detection device is arranged outside the processing space, and the incident light path generated by the optical position detection device is incident obliquely from one side of the processing space 20 and emitted obliquely from the other side of the processing space 20.

[0038] In one embodiment, the optical position detection device includes a light source 401, and the light source 401 is used to generate incident light 402 for workpiece surface detection.

[0039] In a preferred embodiment, the light source 401 may be a laser diode, an LED, or a helium-neon laser, etc. The wavelength of the light source is generally greater than 450 nm, and the light emitting power is relatively weak.

[0040] Incident light 402 from light source 401 is preferably emitted downward in a vertical direction.

[0041] The optical position detection device includes a first reflector 403 , which is disposed directly below the light source 401 and can cause the incident light beam from the light source 401 to be incident on the surface to be measured (upper surface) of the workpiece 10 at a certain inclination angle.

[0042] In this technical solution, the light source 401 and the first reflector 403 are arranged on the same side of the processing space 20, and the light source 401 and the first reflector 403 are arranged up and down, which can reduce the occupation of the horizontal space.

[0043] The optical position detection device also includes a transverse offset magnifying lens group, which can laterally offset and magnify the reflected light beam of the surface to be measured before it is incident on the detector 404.

[0044] The laterally offset magnifying lens group and the detector 404 are located on the same side of the processing space and on the opposite side to the light source 401 .

[0045] The lateral offset magnifying lens group includes a prism 405, a second reflecting mirror 406 and a beam expander lens group 407 which are sequentially arranged along the detection light path.

[0046] The prism 405 can laterally shift and amplify the reflected light beam from the surface to be measured.

[0047] In one embodiment, in the prism 405, the reflected light beam from the surface to be measured enters from one A surface of the prism and exits from the B surface of the prism. The A surface is substantially parallel to the surface to be measured, and the angle between the A surface and the B surface is generally 45°.

[0048] Furthermore, the prism 405 can laterally shift and amplify the incoming reflected light beam by about 8 times.

[0049] In this technical solution, the installation space around the workpiece 10 is limited, and the prism 405 is small in size and low in cost while achieving lateral displacement, and can be conveniently arranged near the workpiece to receive reflected light.

[0050] Similarly, in order to avoid occupying the horizontal space, the detector 404, the beam expander lens group 407 and the second reflector 406 are arranged in sequence up and down.

[0051] The second reflector 406 is used to reflect the reflected light from the prism 405 to the beam expander assembly 407 along a vertical direction.

[0052] The beam expander 407 can amplify the lateral displacement of the reflected light beam of the surface to be measured. Specifically, the beam expander can be of Galileo type, Kepler type or other types.

[0053] Furthermore, the beam expander lens group 407 can perform a lateral shift to amplify the incoming reflected light beam by about 5 to 20 times, preferably 8 times.

[0054] Through the two-stage magnification of the prism and the beam expander group, the position change of the workpiece surface can be magnified 50 to 100 times, and sub-micron position detection can be achieved with high accuracy. The typical unit size of the detector 404 is about 5um, and its detection accuracy can be better than 0.1um under the condition of 50 to 100 times geometric magnification.

[0055] In summary, the detection device and method of the present invention adopt an independent light path and an oblique incidence method, which can avoid the space occupied by other light paths, and the device is simple, reliable and low-cost.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An optical position detection device, characterized in that: include: light source; A first reflector can make an incident light beam from a light source incident on a surface to be measured of a workpiece at a certain inclination angle; The lateral displacement magnifying lens group can laterally displace and amplify the reflected light beam of the surface to be measured before it is incident on the detector; detector; The lateral displacement magnifying lens group includes a prism, which can perform lateral displacement magnification on the reflected light beam of the surface to be measured; The reflected light beam from the surface to be measured enters from the A surface of the prism and exits from the B surface of the prism, wherein the A surface is parallel to the surface to be measured; The prism can horizontally shift and magnify the incoming reflected light beam by 8 times; The lateral displacement magnifying lens group includes a beam expander lens group, which is arranged between the detector and the prism, and can perform lateral displacement and magnification on the reflected light beam of the surface to be measured; The beam expander group can horizontally shift and magnify the incoming reflected light beam by 5 to 20 times; A second reflector is arranged between the beam expander group and the prism, and the beam expander group and the second reflector are arranged in sequence directly below the detector.

2. The optical position detection device according to claim 1, characterized in that: Define a processing space, which is located vertically above the surface of the workpiece to be measured. The light source, the first reflector, the lateral offset magnifying lens group and the detector are all located outside the processing space.

3. The optical position detection device according to claim 2, characterized in that: The light source and the first reflector are located on one side of the processing space. The laterally offset magnifying lens group and the detector are located on the other side of the processing space.

4. An optical position detection method, characterized in that: Provide an optical position detection device as claimed in any one of claims 2 to 3, The optical position detection device has an independent detection optical path. The incident light path is incident obliquely from one side of the processing space, and is emitted obliquely from the other side of the processing space.

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