JP6444945B2 - Optical inspection system - Google Patents

Description

  The present invention relates to optical systems, and more particularly to optical inspection systems and optical imaging systems.

  Recently, due to device miniaturization, various automatic high precision inspection devices have been developed to inspect various micro components or even various samples of micro components. In these inspection apparatuses, information on the inspection sample is obtained by detecting light reflected by the inspection sample. In that configuration, how to arrange the light source and the photoelectric element on the optical path of the inspection apparatus is a very serious problem.

  Some inspection devices have a splitter to align the optical path of light propagating from the light source with the optical path of light received by the photoelectric element so that the reflected light is effectively received by the photoelectric element. It's okay. However, the arrangement of the splitter can often reduce the light intensity and significantly increase the consumption of light energy. In addition, in bringing together (combining) the light paths of multiple lights, the light source is often placed directly on the optical axis, so that the dice of the light emitting diodes in the light source can be reduced in the inspection process. May produce an image that forms a ghost spot.

  In another device, the light source may be placed in front of the inspection device to illuminate the test sample from close, and if the light source blocks the reflected light of the sample, the light source is placed off the optical axis. May be. However, such a configuration produces significant oblique illumination from the light source, and the reflected light can be outside the light receiving range of the photoelectric element, thus making it impossible to inspect the sample.

  In some embodiments of the present invention, the light source module includes an aperture and is configured to be positioned proximate to the position of the aperture stop of the optical inspection device to reflect from the inspection sample. There is provided an optical inspection system capable of bringing a light source as close as possible to the optical axis of the optical inspection system without being affected by light. Through its configuration (arrangement), the light source module provides almost vertical incident light and the reflected light is directed into the light receiving range of the photoelectric element. The problem of energy consumption due to the placement of the splitter is solved and the resulting ghost spots from the light source placed directly on the optical axis are prevented. In addition, when the surface of the test sample is not sufficiently flat, compared to normal incident light, almost normal incident light helps to be directed (entered) into the light receiving range of the photoelectric element, which means that Useful for inspection of optical inspection systems.

  In some embodiments of the present invention, an optical imaging system is provided in which the light source is configured with an aperture to provide substantially normal incident light. The light source can be imaged onto the object through the lens. If the surface of the object sample is not sufficiently flat, the recognition pattern formed by the almost normal incident light is useful for better recognition (identification) than the recognition pattern formed by the normal incident light.

  According to some embodiments of the invention, the optical inspection system comprises a lens module, a light source module, and a photoelectric element. The lens module includes a first lens component and a second lens component. The first lens component is disposed between the second lens component and the object side, and the first lens component and the second lens component have a common optical axis. The light source module is disposed between the first lens component and the second lens component and has an opening through which the optical axis passes. The light source module is configured to emit light through the first lens component toward the object side. The photoelectric element is disposed on the side opposite to the object side of the lens module. The photoelectric element is configured to receive object light coming from the object side through the openings of the lens module and the light source module.

  According to some embodiments of the invention, the optical imaging system includes a lens module and a light source module. The lens module is disposed between the object and the light detection side and has an optical axis. The light source module is disposed between the lens module and the light detection side. The light source module includes an opening, the optical axis of the lens module passes through the opening, and the light source module forms an image on the object through the lens module so that the object reflects the image to the light detection side.

  It should be understood that the foregoing general description and the following detailed description are by way of example and are intended to explain the invention as claimed in greater detail. .

The invention may be more fully understood by the following detailed description of embodiments with reference to the following drawings.
1 is a schematic diagram of an optical inspection system according to an embodiment of the present invention. It is a top view of the light source module of the optical inspection system of FIG. 1A. It is sectional drawing of the light source module of the optical inspection system of FIG. 1B. It is sectional drawing of the light source module of the optical inspection system by another embodiment of this invention. It is a top view of the light source module of the optical inspection system by another embodiment of this invention. It is a schematic diagram which shows the action | operation of the light source module of the optical inspection system of FIG. 2A. It is a top view of the light source module of the optical inspection system by another embodiment of this invention. It is a schematic diagram of the optical inspection system by another embodiment of this invention. It is a schematic diagram of the optical inspection system by another embodiment of this invention. It is a schematic diagram of the light source module of the optical inspection system by another embodiment of this invention. It is a schematic diagram of the optical inspection system by another embodiment of this invention. It is a schematic diagram of the optical inspection system by another embodiment of this invention. It is a schematic diagram of the optical inspection system by another embodiment of this invention. FIG. 3 is a schematic diagram of an optical imaging system according to another embodiment of the present invention. FIG. 3 is a schematic diagram of an optical imaging system according to another embodiment of the present invention.

  Reference will now be made in detail to embodiments of the invention, examples of which are illustrated in the following figures. Wherever possible, the same reference numbers will be used in the drawings and the description to refer to the same or like parts.

  FIG. 1A is a schematic diagram of an optical inspection system 100 according to one embodiment of the present invention. The optical inspection system 100 includes a lens module 110, a light source module 120, and a photoelectric element 130. The lens module 110 includes a first lens component 112 and a second lens component 114. The first lens component 112 is disposed between the second lens component 114 and the object side 200, and the first lens component 112 and the second lens component 114 have a common optical axis O1. The light source module 120 is disposed between the first lens component 112 and the second lens component 114, and has an opening 122 through which the optical axis O1 passes. The light source module 120 is configured to emit light SL through the first lens component 112 toward the object side 200. The photoelectric element 130 is disposed on the side opposite to the object side 200 of the lens module 110. The photoelectric element 130 is configured to receive the object light OL from the object side 200 through the opening 122 of the lens module 110 and the light source module 120.

  The optical inspection system 100 includes an aperture stop that limits the diameter of the beam that passes through the lens module 110, and the aperture stop is positioned proximate to the position in the optical inspection system 100 where the beam has the smallest diameter. . In this embodiment, the first lens component 112 and the second lens component 114 are confocal, thus forming a confocal system. The aperture stop is disposed close to the confocal position of the first lens component 112 and the second lens component 114. In one or more embodiments of the present invention, the light source module 120 is positioned adjacent to the position of the aperture stop of the optical inspection system 100.

  In various embodiments of the present invention, the light source module 120 may be disposed at a position of the aperture stop with a distance tolerance (tolerance), which is a range in which the placement error is acceptable for an application. Distance. The distance tolerance may be a few millimeters, but is not limited thereto. In some embodiments, if the light source module 120 is disposed between the aperture stop and the first lens component 112, the distance LA between the aperture stop and the front side of the first lens component 112. It is preferable to install the light source module 120 away from the aperture stop within a distance of less than 25%. In some other embodiments, if the light source module 120 is disposed between the aperture stop and the second lens component 114, between the aperture stop and the rear side of the second lens component 114. It is preferable to install the light source module 120 away from the aperture stop up to a distance of less than 25% of the distance LB. That is, the light source module 120 may be disposed with a tolerance of + 25% of the distance LA and −25% of the distance LB with respect to the aperture stop of the optical inspection system 100 (the front side is represented by + and the rear side is represented by −).

  In some embodiments, the narrowest portion of the opening 122 of the light source module 120 is an aperture stop. In other words, the hole of the light source module 120 may be the aperture of the optical inspection system 100. Here, as an example, a telescope system may be mentioned, but it should not limit the scope of the present invention. The light source module 120 may be placed in close proximity to the aperture stop position of other systems, and the light source module 120 provides both the path size limitation and illumination functions.

  When inspecting an inspection sample on the object side 200, the light source module emits light SL to the object side 200, the light SL passes through the first lens component 112 and reaches the inspection sample on the object side 200, and the inspection sample. Reflects light SL, which is hereinafter referred to as object light OL. The object light OL is sent (propagated) to the photoelectric element 130 through the first lens component 112, the opening 122 of the light source module 120, and the second lens component 114. Information on the topography (fine structure) of the surface of the inspection sample may be imaged on the photoelectric element 130 by the lens module 110, whereby the photoelectric element 130 acquires information on the inspection sample.

Specifically, in an embodiment of the present invention, the positions of the inspection sample (located on the object side 200), the lens module 110, the photoelectric element 130, and the internal elements of the lens module 110 satisfy the imaging formula. be able to. Here, for example, a thin lens is assumed. The lens module 110 is a thin lens having a focal length of f. In order to connect the images, the arrangement of the test sample and the photoelectric element 130 satisfies the following thin lens formula:
u ⁻¹ + v ⁻¹ = f ⁻¹
Here, u is the distance between the test sample and the thin lens, and v is the distance between the photoelectric element 130 and the thin lens. In practical applications involving consideration of certain lens thicknesses and lens group thicknesses, this thin lens formula does not limit the various embodiments of the present invention.

  On the other hand, in the embodiment of the present invention in which the light source module 120 including the opening 122 is disposed, the optical path of the light SL emitted from the light source module 120 is coupled to the optical path of the object light OL received by the photoelectric element 130. (Combined), which means that the central part of each beam substantially coincides with each other. The optical inspection system 100 does not incur significant energy consumption caused by the use of a splitter, and multiple ghost spots caused by a light source placed directly on the optical axis O1 can be prevented. On the other hand, by placing the light source module 120 close to the position of the aperture stop of the optical inspection system 100, the light source module 120 does not affect the object light OL, or interfere with the object light OL. It can be as close as possible to the optical axis O1 of the inspection system 100 so that the light source module 120 can provide incident light substantially perpendicular to the object side 200 (eg, propagation of light SL through the first lens component 112). The angle between the direction and the optical axis O1 is in the range of ± 0.1 ° to ± 10 °, in the range of ± 0.1 ° to ± 5 °, in the range of ± 0.1 ° to ± 3 °, etc. ). In some embodiments, light passing through the first lens component 112 may exclude normal incident light (ie, the angle between the light propagation direction of the light and the optical axis O1 is 0). Here, for the optical inspection system (camera) of F / 8, the angle may be less than ± 3 °.

  In some embodiments of the present invention, the light source module 120 is annular and may be referred to as the annular light source module 120, but it is not intended to limit the various embodiments of the present invention. The light source module 120 may have another shape including the opening 122 inside, such as a square, an ellipse, or a triangle. Alternatively, the light source module 120 may be composed of a plurality of separated or divided light source components (portions).

  FIG. 1B is a top view of the light source module 120 of the optical inspection system 100 of FIG. 1A. 1C is a cross-sectional view of the light source module 120 of the optical inspection system 100 of FIG. 1B. Reference is now made to both FIG. 1B and FIG. 1C. In one or more embodiments, the light source module 120 includes a plurality of light sources 124 and a carrier 126. The plurality of light sources 124 emit light toward the object side 200 (see FIG. 1A), the carrier 126 is configured to hold the plurality of light sources 124 in the carrier, and the carrier 126 is an opening of the light source module 120. 122 and has an opening 126a through which the optical axis O1 (see FIG. 1A) passes.

  In the present embodiment, the carrier 126 of the light source module 120 includes a recess (recess) 126 b disposed on at least one side (surface) of the opening 126 a of the carrier 126. The opening of the recess 126b is opposed to the object side 200 (see FIG. 1A), and at least a part thereof is disposed in the recess 126b so that the plurality of light sources 124 emit light toward the object side 200 (see FIG. 1A). Is done. Here, the plurality of light sources 124 may be formed on the bottom surface 126 c and the side wall 126 d of the carrier 126. In another embodiment, due to manufacturing difficulties, the plurality of light sources 124 may be disposed on the bottom surface 126c of the carrier 126 and not disposed on the sidewall 126d. In this embodiment, the recess 126b surrounds the opening 126a of the carrier 126 so that the plurality of light sources 124 similarly surrounds the opening 126a.

  In some embodiments, the light source module 120 may include a reflective layer 127 disposed between the carrier 126 and the plurality of light sources 124. Here, the reflective layer 127 may be disposed in the recess 126b, and constitutes a reflective cup for increasing the light output. In some embodiments, the recess 126b comprises a sloped sidewall. The inclined sidewall helps the reflective layer 127 to reflect light, while the inclined sidewall forms the narrowest portion of the opening 126a to determine the position of the aperture stop of the optical inspection system 100. For example, the narrowest portion is adjacent to the object side 200 of FIG. 1A.

  In addition, the light source module 120 may further include an optical film 128 such as, for example, a diffuser film or a Fresnel lens film. The optical film is between the plurality of light sources 124 and the object side 200 to improve the distribution uniformity of the light emitted from the plurality of light sources 124.

  Here, the plurality of light sources 124 may be a plurality of halogen lamps, a plurality of light emitting diodes, a plurality of organic light emitting diodes, or other plurality of illumination elements. The carrier 126 has good rigidity (rigidity) to hold the plurality of light sources 124 and their circuits, and the carrier 126 may be glass, plastic, metal, or the like. In some implementations, the carrier 126 may block light coming from the object side 200 (see FIG. 1A) and the carrier 126 has a low transmission at the spectral wavelength used by the optical inspection system. The material of the reflective layer 127 is, for example, silver, aluminum, copper, barium sulfate, titanium oxide, or other material having high reflectivity, and is 80 at the spectral wavelength of light used in the optical inspection system. % Reflectivity. The material of the optical film 128 may be polyester acrylate. The photoelectric element may be a charge coupled device (CCD) or other photosensitive element.

  In some embodiments of the present invention, the light source 124 may be a visible light source or an invisible light source. According to the spectrum of the light source, the materials of the reflective layer 127, the optical film 128, the first lens component 112, and the second lens component 114 are correspondingly adjusted. For example, in the region from visible light to infrared, silver has high reflectivity, but for wavelengths in the range of less than 340 nanometers silver has low reflectivity. Aluminum has a high reflectance in the range from ultraviolet to infrared. When the plurality of light sources 124 are visible light sources, the material of the reflective layer 127 may include more silver so as to reflect visible light. On the other hand, when the plurality of light sources 124 are ultraviolet light sources, the material of the reflective layer 127 may contain more aluminum so as to reflect the ultraviolet light.

  In addition, the first lens component 112 and the second lens component 114 are required to substantially not absorb the light emitted from the plurality of light sources 124 and are also emitted from the plurality of light sources 124. It is required that the material properties of the first lens component 112 and the second lens component 114 are not easily impaired by light (for example, separation of the adhesive portion by infrared radiation or UV degradation).

  FIG. 1D is a cross-sectional view of a light source module 120 of an optical inspection system 100 according to another embodiment of the present invention. This embodiment is similar to the embodiment of FIG. 1C, but in this embodiment, the carrier 126 of the light source module 120 does not include the recess 126b, and a plurality of light sources 124 face the object side 200. It is different in that it is arranged directly on the side (surface) of 126.

  As described above, the light source module 120 may include a reflective layer 127 disposed between the carrier 126 and the plurality of light sources 124 to improve the output light.

  Other details of this embodiment are substantially the same as those shown in the embodiment of FIG. 1C and will not be described again here. In actual application, the structure of the light source module 120 may be designed based on the spatial requirements (necessity) of the optical inspection system 100, and the structure shown in the figure does not limit the scope of the present invention. .

  FIG. 2A is a top view of the light source module 120 of the optical inspection system 100 according to another embodiment of the present invention. In one or more embodiments of the present invention, the plurality of light sources 124 are annularly disposed on the carrier 126 so as to expose the openings 126a of the carrier 126. In some embodiments, the plurality of light sources 124 may be turned on (on) or turned off (off) by a single control system. In some embodiments, different portions of the plurality of light sources 124 may be turned on or off by a plurality of control systems, respectively, and different portions of the plurality of light sources 124 may have different emission angles. Hereinafter, a method for controlling the plurality of light sources 124 of the light source module 120 by the plurality of control systems will be described.

  Specifically, in the present embodiment, the first portion P1 due to the plurality of light sources 124a is annularly arranged adjacent to the opening 126a of the carrier 126, and the second portion P2 due to the plurality of light sources 124b is The carrier 126 is annularly arranged away from the opening 126a. The first portion P1 formed by the plurality of light sources 124a and the second portion P2 formed by the plurality of light sources 124b have different emission angles. For example, for the object side 200 (see FIG. 1A), the light provided by the first portion P1 from the plurality of light sources 124a is more vertical than the light provided by the second portion P2 from the plurality of light sources 124b. Incident.

  FIG. 2B is a schematic diagram illustrating the operation of the light source module 120 of the optical inspection system of FIG. 2A. Here, in order to display clearly, only the photoelectric element 130 and the object on the object side are drawn, and the lens module related to the light source module of the optical inspection system is omitted. Reference is now made to FIGS. 2A and 2B. When an object is inspected, first, a first portion P1 by a plurality of light sources 124a provides light SL1 to the object, and then a second portion P2 by a plurality of light sources 124b provides light SL2 to the object. The object receives light SL1 and SL2 having different emission angles in order.

  In some embodiments, the first portion P1 due to the plurality of light sources 124a and the second portion P2 due to the plurality of light sources 124b may simultaneously provide the light SL1 and SL2. With this configuration, the smoother surface area RA may reflect the light SL1 and SL2 to the photoelectric element 130, and the less smooth surface area RB may reflect only the light SL2 to the photoelectric element 130. At this time, the plurality of light sources 124a and the plurality of light sources 124b may be configured to provide light having different wavelengths in order to improve recognition (identification). For example, the plurality of light sources 124a are blue light sources, the plurality of light sources 124b are red light sources, the surface region RA indicates purple (mixed blue and red), and the surface region RB indicates red. With multiple light sources 124a and 124b having different emission angles, the surface of the object may be inspected layer by layer to obtain detailed information about the surface topography of the object.

  Here, the light SL1 is drawn substantially vertically to show that the light SL1 is more parallel to the optical axis than the light SL2. However, in an actual configuration, the light SL1 is not completely vertical. FIG. 2B is drawn only to illustrate the concept and design of embodiments of the present invention, and the angle of light, the surface of the object, or other details shown in the figures are within the scope of the present invention. It is not limited.

  FIG. 2C is a top view of the light source module 120 of the optical inspection system according to another embodiment of the present invention. This embodiment is similar to the embodiment of FIG. 2A, but in this embodiment, the plurality of light sources 124 includes a first portion P1, a second portion P2, a third portion P3, and a fourth portion. It differs in that it includes P4. When the object is inspected, the first portion P1 and the fourth portion P4 may be controlled to irradiate at the same time, so that the illumination patterns of the plurality of light sources 124 are not completely symmetric, or the second The portion P2 and the third portion P3 may be controlled to irradiate simultaneously.

  As described above, each portion of the plurality of light sources 124 may have a different emission angle and light color, and layer-by-layer inspection may be achieved.

  Here, the configurations depicted in FIGS. 2A and 2C do not limit the scope of the present invention, and there may be multiple style designs for the array of multiple light sources 124 in practical applications. For example, the plurality of light sources 124 may be arranged in a plurality of shapes other than an annular shape, but still include a plurality of portions for layer-by-layer inspection.

  FIG. 3A is a schematic diagram of an optical inspection system 100 according to another embodiment of the present invention. This embodiment is similar to the embodiment of FIG. 1A, but differs in that the light source module 120 includes at least one light source 124 and a reflector (mirror) 129. The light source 124 is configured to emit light. The reflecting mirror 129 is configured to reflect light coming from the light source 124 toward the object side 200, and the reflecting mirror 129 includes an opening 129a through which the optical axis O1 passes (through) so as to form an opening of the light source module 120. .

  In this embodiment, the reflecting mirror 129 is a plane reflecting mirror. The flat reflector includes a plurality of reflective layers having high reflectivity, and the material of the flat reflector includes silver, aluminum, copper, barium sulfide, titanium oxide, or high reflectivity for reflecting light. Other substances may be used. The plurality of reflective layers may have a flat surface. Further, the surface roughness (arithmetic mean deviation; Ra) of the reflecting mirror 129 is configured to be less than a certain roughness, and the reflecting mirror 129 having such roughness is a perfect reflecting mirror or light. It may be regarded as a plane reflector that can achieve scattering. In some embodiments, a certain roughness may be set based on the optical inspection system 100. For example, the roughness may be less than about 1.6 micrometers (μm). Of course, a certain roughness value does not limit the scope of the present invention. In other embodiments, the roughness can be any value between 1 μm and 1.6 μm.

  In this embodiment, the light propagation direction of the light from the light source 124 and the direction perpendicular to the plane reflecting mirror (reflecting mirror 129) form an angle therebetween, and the angle is the direction perpendicular to the plane reflecting mirror (reflecting mirror 129). And substantially equal to the angle between the optical axis O1. For example, the angle is about 45 °, but it does not limit the scope of the present invention, and in practical applications the angle is determined based on the spatial arrangement (configuration) of the optical inspection system 100. It's okay.

  When the inspection sample on the object side 200 is inspected, the plurality of light sources 124 provide light SL to the object side 200 through reflection by the reflecting mirror 129. The light SL is propagated (sent) through the first lens component 112 to the inspection sample on the object side 200. After being reflected by the test sample, the object light OL is sent to the photoelectric element 130 through the first lens component 112, the opening 129 a of the reflector 129 of the light source module 120, and the second lens component 114. In addition, the photoelectric element 130 acquires information on the inspection sample. Other details of this embodiment are similar to those of the embodiment of FIG. 1A, and therefore description thereof will not be repeated here.

  FIG. 3B is a schematic diagram of an optical inspection system 100 according to another embodiment of the present invention. This embodiment is similar to the embodiment of FIG. 3A, except that the reflector 129 includes two planar reflectors, the number of light sources 124 is two, and the two planar reflectors are Arranged on opposite sides of the optical axis O1 to form an opening 129a as a whole.

  As described above, in the present embodiment, the light propagation direction of light from each of the plurality (two) of light sources and each of the plurality (two) of planar reflecting mirrors (reflecting mirrors 129) The angle is substantially equal to the angle between the direction perpendicular to the planar reflecting mirror (reflecting mirror 129) and the optical axis O1. Other details of this embodiment are similar to those of the previous embodiments and will not be repeated here.

  In addition to the arrangement (configuration) shown in FIGS. 3A and 3B, it should be understood that the reflector 129 and the light source 124 may be designed in other ways. FIG. 3C is a schematic diagram of a light source module 120 of an optical inspection system according to another embodiment of the present invention. In the structural arrangement of the light source module 120, the reflecting mirror 129 has a rough reflecting surface 129b on the side of the reflecting mirror 129 facing the object side. In other words, the reflecting mirror 129 may not be the planar reflecting mirror described so far. Light coming from the light source 124 is sent to the surface 129b, and the surface 129b reflects light diffusely (diffusely) to the object side so as to form a more uniform intensity distribution of the light. Compared to the planar reflectors exemplified so far, the reflector 129 of this embodiment has a higher ability to dissipate light. Specifically, in this embodiment, the arithmetic mean deviation (Ra) of the surface 129b of the reflector 129 may be larger than a certain roughness as exemplified previously, for example, 1.6 μm.

  Various configurations of the reflector 129 have been provided in the previous description. Although a top view of the reflector 129 has not been shown so far, those skilled in the art will appreciate that the reflector 129 may be other shapes, such as a circle, square, ellipse, or triangle with an opening therein. It should be noted that you get. The reflector may be a completely continuous structure. Alternatively, the reflecting mirror 129 may be composed of a plurality of separated or divided reflecting parts (portions). The details of the reflector 129 shown in the figures do not limit the scope of the invention.

  FIG. 4A is a schematic diagram of an optical inspection system 100 according to another embodiment of the present invention. This embodiment is similar to the embodiment of FIG. 1A, but this embodiment is different in that the first lens component and the second lens component constitute a double Gauss lens as a whole. Here, the light source module 120 is disposed close to the position of the aperture stop of the double Gauss lens. Specifically, the narrowest part of the opening 122 of the light source module 120 is an aperture stop. A double Gauss lens is a type of lens group that is substantially symmetric with respect to the aperture stop, with a negative lens (divergent lens) surrounding the aperture stop and a positive lens (convergence lens) and meniscus lens around it. (External), the positive lens and the meniscus lens are arranged at an appropriate distance.

  In other words, in this embodiment, the first lens component 112 and the second lens component 114 are substantially similar to each other, each including a negative lens, a positive lens, and a meniscus lens, The first lens component 112 and the second lens component 114 are arranged symmetrically about the narrowest portion of the opening 122 of the light source module 120.

  Other details of this embodiment are similar to those of the embodiment of FIG. 1A and will not be repeated here.

  FIG. 4B is a schematic diagram of an optical inspection system 100 according to another embodiment of the present invention. This embodiment is similar to the embodiment of FIG. 1A, except that the first lens component and the second lens component form a cook triplet as a whole. Here, the light source module 120 is a cook triplet aperture stop.

  Specifically, the first lens component 112 includes a convex lens and a concave lens, and the second lens component 114 includes a convex lens. The convex lens of the first lens component 112 and the convex lens of the second lens component 114 are arranged before and after the concave lens of the first lens component 112, respectively, and a predetermined distance from the concave lens of the first lens component 112 And form a substantially symmetric design. The light source module 120 is disposed adjacent to the position of the aperture stop, and thus is disposed between the concave lens of the first lens component 112 and the convex lens of the second lens component 114.

  Other details of this embodiment are similar to those of the embodiment of FIG. 1A and will not be repeated here.

  FIG. 4C is a schematic diagram of an optical inspection system 100 according to another embodiment of the present invention. This embodiment is similar to the embodiment of FIG. 1A, but differs in that the first lens component and the second lens component constitute a tesser as a whole. The light source module 120 is disposed adjacent to the position of the aperture stop of the tessel.

  Specifically, the first lens component 112 includes a convex lens and a concave lens, and the second lens component 114 includes a compound lens. The convex lens of the first lens component 112 and the compound lens of the second lens component 114 are arranged before and after the concave lens of the first lens component 112, and a predetermined distance from the concave lens of the first lens component 112. Retained. The light source module 120 serves as an aperture stop disposed between the concave lens of the first lens component 112 and the compound lens of the second lens component 114.

  Other details of this embodiment are similar to those of the embodiment of FIG. 1A and will not be repeated here.

  FIG. 5A is a schematic diagram of an optical imaging system 300 according to another embodiment of the present invention. The optical imaging system 300 includes a lens module 310 and a light source module 320. The lens module 310 is disposed between the object 400 and the light detection side 500 and has an optical axis O2. The light source module 320 is disposed between the lens module 310 and the light detection side 500. The light source module 320 includes an opening 322, and the optical axis O <b> 2 of the lens module 310 passes through the opening 322. The light source module 320 is configured to form an image on the object 400 through the lens module 310 such that the object 400 reflects the image to the light detection side 500.

  In this embodiment, the light source module 320 includes at least one light source 324, at least one reflector, and at least one light source lens component 328. The reflecting mirror 326 is configured to reflect the light emitted from the light source 324, the light PL propagates toward the object 400, and the reflecting mirror 326 forms the opening 322 of the light source module 320. It has an opening 326a through which the optical axis O2 passes. Here, like the reflecting mirror (see FIG. 3A) shown in the previous embodiment, the reflecting mirror 326 is a plane reflecting mirror, and the light propagation direction of light from the light source 324 and the direction perpendicular to the plane reflecting mirror are An angle is formed between them, and the angle is substantially equal to an angle between the direction perpendicular to the planar reflector and the optical axis O2. The light source lens component 328 is disposed between the light source 324 and the reflector 326, and the light source lens component 328 is configured to help the light emitted from the light source 324 form an image on the object 400.

In this embodiment, the light emitted from the light source 324 may comprise a pattern. Alternatively, several shielding sheets with a plurality of openings with special patterns (such as slits or square holes) were emitted from the light source 324 after passing through the shielding sheets. It may be placed in front of the uniform light source 324 so that the light comprises a pattern. In one or more embodiments, the pattern of the light source 324 is coupled onto the object 400 by adjusting the placement of the light source 324, the light source lens component 328, the lens module 310, and the object 400 to meet the imaging formula. May be imaged. For a clearer illustration, a thin lens is taken here as an example. Consider (think) the light source lens component 328 and the lens module 310 to be thin lenses having a focal length f. For imaging, the arrangement of light source (s) 324, light source lens component 328, lens module 310, and object 400 satisfy the following formula for a thin lens:
u ⁻¹ + v ⁻¹ = f ⁻¹
Here, u is the distance between the light source 324 and the thin lens, and v is the distance between the object 400 and the thin lens. In practical applications, certain lens thicknesses and lens group thicknesses are considered, and the thin lens formula is not a limitation of various embodiments of the present invention.

  Through that arrangement, the light source module 320 may form an image on the object 400. Due to the configuration of the reflecting mirror 326 of the light source module 320 having the opening 326a, the light source module 320 can provide almost perpendicular incident light PL. In some embodiments, the light PL provided by the light source module 320 excludes normal incident light. In some cases where the surface of the object 400 is not sufficiently flat, the recognition pattern formed by the nearly normal incident light may be reflected more vertically than the recognition pattern formed by the normal incident light. The recognition pattern formed by the almost normal incident light is more useful for subsequent recognition (identification).

  Here, the object 400 reflects the image to the light detection side 500 through the opening 322. Specifically, the photoelectric element illustrated in the previous embodiment may be disposed on the light detection side 500. The photoelectric element is disposed on the optical axis O2 in order to receive an image from the object 400. As shown in the embodiment of FIG. 1A, the arrangement of the object 400, the photoelectric element, other lenses, and the lens module 310 satisfies the imaging formula, and the image reflected by the object 400 is on the photoelectric element. There may be other lenses between the photoelectric element and the lens module 310 so that an image can be formed. However, the photoelectric element is not limited to being arranged on the optical axis, and the photoelectric element may detect the image on the object 400 from the side surface instead of detecting the image through the opening 322. Should be understood. In practical applications, the optical imaging system 300 may not include a photoelectric element, and the user may observe the image on the object 400 directly from the side with the naked eye.

  Although only one planar reflector is shown in the figure, it is not so limited in practical applications. In some embodiments, as previously shown, the reflector 326 includes two planar reflectors, the number of light sources 324 is two, and the (two) planar reflectors have an optical axis O2. Are arranged on opposite sides of each other to form an opening (of the reflecting mirror) as a whole. The light propagation direction of the light from each of the plurality of light sources 324 and the direction perpendicular to each of the plurality of planar reflecting mirrors form an angle therebetween, and the angle is perpendicular to the above-described planar reflecting mirror and the optical axis O2. Is substantially equal to the angle between. Alternatively, the reflector 326 may comprise a rough surface (ie, the arithmetic mean deviation is greater than 1.6 μm) so that the light is diffusely reflected back to the object 400.

  In this embodiment, the light source lens component 328 may be a doublet lens, as shown in the figure, and the light source lens component 328 is composed of a concave lens and a convex lens, but the configuration shown in the figure is that of the present invention. It does not limit the range. In addition, the light source module 320 of the present embodiment may include various designs, and those with related designs may be referred to the light source module 120 of the previous embodiments, the details of which are here Then don't repeat.

  FIG. 5B is a schematic diagram of an optical imaging system 300 according to another embodiment of the present invention. This embodiment is similar to the embodiment of FIG. 5A, except that the light source module 320 includes a plurality of light sources and carriers.

  In this embodiment, the light emitted from the light source module 320 may be designed to convey image information, and the lens module 310 converts the light into an image on the object 400. Here, the configuration of the lens module 310 is merely schematically shown, and the configuration shown in the drawing does not limit the scope of the present invention.

  For the structure of the light source module 320, reference may be made to the light source module 120 shown in the previous embodiment of FIGS. 1B-1D. Similarly, the plurality of light sources emit light toward the object, the carrier is configured to hold the plurality of light sources, and the carrier has one opening through which the optical axis passes so as to form an opening of the light source module. Have In some embodiments, the plurality of light sources are arranged in a ring on the carrier to expose the carrier opening. Before the light source module, there may be several optical films with openings, for example a diffuse film or a Fresnel lens film. The plurality of optical films may improve the uniformity of light distribution from the light source, or may cooperate with the lens module 310 as a plurality of practical lenses of the imaging system.

  Other details of the invention are similar to those of the embodiment of FIG. 5A and will not be described again here.

  In an embodiment of the present invention, the light source module is configured to include an opening, and is disposed in the vicinity of the position of the aperture stop of the optical inspection apparatus, without being affected by the reflected light from the inspection sample, An optical inspection system is provided that can bring the light source closer to the optical axis of the optical inspection system. Through such a configuration, the light source module provides substantially vertical incident light so that the reflected light is within the light receiving range of the photoelectric element. The problem of energy consumption due to the placement of the splitter is solved and the resulting ghost spots from the light source placed directly on the optical axis are prevented. In addition, in some cases where the surface of the test sample is not sufficiently flat, compared to normal incident light, almost normal incident light helps to be directed into the light receiving range of the photoelectric element, which means that optical inspection Useful for system inspection.

  In an embodiment of the invention, an optical imaging system is provided in which the light source is configured with an aperture and provides nearly vertical light. The light source can be imaged onto the object through the lens. In some cases where the surface of the object sample is not sufficiently flat, recognition patterns formed by near normal incident light are more useful in recognition than recognition patterns formed by normal incident light.

  Although the present invention has been described in considerable detail with reference to certain embodiments thereof, other embodiments are possible. Accordingly, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.

  It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the above, the present invention is intended to cover modifications and variations to the present invention which are provided to be within the scope of the following claims.

100: Optical inspection system, 110: Lens module,
112 ... 1st lens component, 114 ... 2nd lens component,
120 ... light source module, 122 ... opening of the light source module,
124, 124a, 124b ... light source, 126 ... carrier,
126a ... opening of carrier 126b ... concave portion 126c ... bottom surface,
126d ... side wall 127 ... reflective layer 128 ... optical film 129 ... reflector
129a ... opening of the reflecting mirror, 129b ... rough reflecting surface, 130 ... photoelectric element,
200 ... object side, 300 ... optical imaging system, 310 ... lens module,
320 ... light source module, 322 ... opening, 324 ... light source,
326 ... Reflecting mirror, 326a ... Opening of reflecting mirror, 328 ... Light source lens component,
400 ... object, 500 ... light detection side,
LA: the distance between the aperture stop and the front side of the first lens component,
LB: Distance between the aperture stop and the rear surface of the second lens component,
O1, O2 ... optical axis, OL ... object light, P1 ... first part, P2 ... second part,
P3 ... third part, P4 ... fourth part, PL ... light,
SL, SL1, SL2 ... light, RA ... smooth surface area,
RB: Unsmooth surface area.

Claims (5)

An optical inspection system,
A first lens component; and a second lens component, wherein the first lens component is disposed between the second lens component and the object side, and the first lens component A lens module in which the portion and the second lens component have a common optical axis;
Wherein it is disposed between the first lens component and said second lens component, which is configured to emit light toward the object side through the front Symbol first lens component A light source module;
A photoelectric element arranged on the opposite side to the said object side of the lens module,
Have
The first lens component and the second lens component are a confocal system, and the first lens component and the second lens component form a confocal system;
The light source module is disposed proximate to a position of an aperture stop of the confocal system ;
The light source module includes a plurality of light sources that emit light toward the object side through the first lens component, a carrier configured to hold the plurality of light sources, and an optical film. And
The carrier has an opening, a bottom surface surrounding the carrier opening, a first side wall extending from one end of the bottom surface adjacent to the carrier opening to the object, and the bottom surface separated from the carrier opening. A second side wall extending from the other end toward the object,
The first side wall, the bottom surface, and the second side wall form a recess surrounding the opening of the carrier, and the plurality of light sources are at least partially disposed in the recess,
The plurality of light sources are between the optical film and the carrier,
The optical film has an opening, the opening of the carrier and the opening of the optical film are penetrated by the common optical axis, forming the opening of the light source module as a whole,
The optical inspection system , wherein the photoelectric element is configured to receive object light from the object side through an opening of the lens module and the carrier . The optical inspection system according to claim 1 , wherein the plurality of light sources are arranged in a ring shape on the carrier so as to expose an opening of the carrier. The optical inspection system according to claim 1 , wherein the first portion of the plurality of light sources and the second portion of the plurality of light sources have different emission angles. The first portions of the plurality of light sources are arranged in an annular shape near the opening of the carrier, and the second portions of the plurality of light sources are arranged in an annular shape apart from the opening of the carrier. The optical inspection system according to claim 3 . The optical inspection system according to claim 1 , wherein the light source module includes a reflective layer disposed between the carrier and the light source.

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