Element which is provided with a section for position determination, and measurement method

Abstract

A method for measuring the position of a target surface (203, 1203) which has position-determining sections (101A, 101B, 101C, 101D; 1101A, 1101B) provided thereon, wherein a diffuse reflectance of the target surface is 0.1% or less and a diffuse reflectance of the position-determining sections (101A, 101B, 101C, 101D; 1101A, 1101B) is 5% or more, and wherein the target surface (203; 1203) is a surface of an element (200; 1200) which is provided with a first plane (201; 1201) and a second plane which forms an angle between 15° and 75° to the first plane (201; 1201), wherein the target surface (203; 1203) is the second plane is and the element (200; 1200) is provided with at least three sections for determining position (101A, 101B, 101C, 101D; 1101A, 1101B) at the second level, wherein the sections for determining position (101A, 101B, 101C, 101D;1101 A, 1101B) are arranged such that a distance between the position detection sections (101A, 101B, 101C, 101D; 1101A, 1101B) is sufficiently large to locate the second plane, the method comprising the steps: ; Illuminate (S2010) the target surface (203; 1203) with parallel light perpendicular to the first plane (201; 1201); Determining (S2020) the positions of boundary lines of the majority of sections for position determination (101A, 101B, 101C, 101D; 1101A, 1101B) starting from a survey of the target area (203; 1203), and Determine (S2030) the position of the target area (203; 1203) from the positions of the boundary lines of the majority of sections for determining the position (101A, 101B, 101C, 101D; 1101A, 1101B).

Description

Field of invention

[0001] The present invention relates to an element which is provided with a section for determining position and a measuring method. Description of the related technology

[0002] For example, with an element provided with a prism face, the angle formed by the prism face with another surface through which a light ray passes must be determined with high accuracy. Accordingly, the angle formed by the prism face with the other surface through which the light ray passes must be measured with high precision. When measuring an angle formed by two surfaces of an element, the conventional method is to cut the element in a suitable plane and measure the angle formed by the two surfaces at the section. However, the conventional measuring method has the following problems: First, cutting an element is very time-consuming. Second, deformation of the element caused by cutting and a burr created by the cutting process prevent a highly accurate measurement of the angle.Thirdly, the measured values ​​vary depending on the selected section. Therefore, it is difficult to measure the angle formed by the two surfaces with high accuracy using conventional measuring methods.

[0003] On the other hand, conventional methods for aligning two elements by using a position marker corresponding to a position detection section have been developed (Patent Document 1 and Patent Document 2). However, no method for measuring an angle formed by two faces of an element by using position detection sections has been developed, nor has an element been developed that is configured such that an angle formed by two faces of the element can be measured using the position detection sections. Documents relating to the technology patent documents Patent document 1: JP 2008 - 216 905 A Patent document 2: JP 2014 - 137 410 A

[0004] DE 10 2007 032 471 A1 discloses a method for determining the position of a camera system relative to an object, wherein the object is arranged outside the field of view of the camera system, by means of at least one mirror, wherein the position parameters of the mirror are known and / or can be determined by at least three mirror markers arranged on the mirror, wherein the object is reflected at least partially by the mirror into the camera system, an imaging function is established which describes the mapping of an object point into the image memory of the camera system, wherein the unknown quantities of the imaging function are determined by means of numerical solution approaches and the position between the camera system and the object is determined from this.

[0005] US 2013 / 0194569 A1 discloses a substrate inspection method comprising: measuring a substrate on which a target is formed, generating a plane equation of the substrate, and capturing a region of the target formed on the substrate. Subsequently, taking into account the height of the target, a region of the target is transformed into a substrate plane using the plane equation. The target is then inspected against a region of the target transformed into a substrate plane by the plane equation and a region of the target against reference data. Therefore, an offset value of a target is determined according to an inclined position of the substrate, and any distortion of the measurement data is compensated for by using the offset value.

[0006] US Patent 2007 / 0058904A1 discloses a method for the high-precision alignment of a surface-emitting laser and a lens in an optical module, in which the optical coupling between a surface-emitting laser and other optical devices, such as an optical fiber, is achieved via lenses, as well as a structure for providing the method. A lens element is prepared in which the lenses are arranged at a depth t1 from a reference plane and an alignment mark is provided at a depth t2 (t1 < t2). The alignment of the lens and the surface-emitting laser, which are mounted on the circuit board for a photonic device, is then performed. Explanation of the invention; Problem to be solved by the invention

[0007] In general, there is a need for a method to measure the position (e.g., coordinates) of a surface or an angle formed by two surfaces of an element by using sections (e.g., areas, such as regions of a surface) to determine the position, and for an element that is set up so that an angle formed by two surfaces of the element can be measured by using sections to determine the position. Means to solve the problem

[0008] According to the present invention, a method for measuring a target surface as defined in claim 1 and an element as defined in claim 4 are provided. Exemplary embodiments according to the invention are defined in the dependent claims. A method according to a first aspect of the present disclosure is a method for measuring the position of a target surface or target plane (e.g., a surface; for example, a plane whose position or inclination is to be measured; hereinafter referred to as: target surface), which is provided, for example, with sections for determining the position, wherein a diffuse reflection or a reflectance of a diffuse reflection (hereinafter referred to as: reflection) of the target surface is (e.g., approximately) 0.1% or less, and a diffuse reflection or a reflectance of a diffuse reflection (hereinafter referred to as: reflection) of the sections for determining the position (e.g.,The deviation is approximately 5% or more, and the target surface is configured such that a normal to a tangent plane at any point on the target surface where each of the position detection sections is installed forms an arbitrarily selectable angle between approximately 15° and approximately 75° to a specific direction (e.g., an illumination or irradiation direction). The method may, for example, comprise the following steps: illuminating (e.g., irradiating) the target surface with parallel light (e.g., collimated light, which has parallel light rays) in the specified direction; determining the positions of boundary lines of the plurality of position detection sections from an image or recording (hereinafter referred to as "recording") of the target surface; and determining the position of the target surface by the positions of the boundary lines of the plurality of position detection sections.

[0009] In the procedure according to the present aspect, for example, the position of the target surface can be measured with high accuracy by precisely determining the positions of the boundary lines of the majority of sections for position determination.

[0010] In a method according to the first embodiment of the first aspect of the present disclosure, the target surface is a surface of an element (e.g., an object to be measured) which is provided with a first plane or surface (hereinafter referred to as: plane) and a second plane or surface (hereinafter referred to as: plane) which forms an angle of (e.g., approximately) 15° to (e.g., approximately) 75° with the first plane, wherein the target surface is the second plane, and wherein the element is provided with at least three sections (e.g., areas) for position detection on the second plane, the sections for position detection being arranged such that the distance between the sections for position detection is sufficiently large to enable the localization (e.g., detection) of the second plane. In the step of illuminating the target surface, the second plane is illuminated with parallel light which is (e.g., at least substantially) perpendicular to the first plane.

[0011] In the method according to the present disclosure, the position of the second plane can be measured with high accuracy by precisely determining the positions of the boundary lines of the at least three sections for position determination.

[0012] A method according to a second embodiment of the first aspect of the present disclosure may, for example, further include the step of determining an angle between the first plane and the second plane using the position(s) (e.g. coordinates) of the second plane.

[0013] In the method according to the present embodiment, the angle between the first plane and the second plane can be measured with high accuracy using the position(s) (e.g., coordinates in three spatial directions) of the second plane. In other words, in the method according to the present disclosure, it is not necessary to cut (e.g., slice) the element through a plane (e.g., along a plane) to measure the angle. Accordingly, problems do not arise when cutting the element, the accuracy of the measurement is not impaired due to deformation of the element caused by cutting or by burrs generated by cutting, and measured values ​​do not vary depending on a selected section (e.g., of two sections created during cutting).

[0014] In a method according to the third embodiment of the third aspect of the present disclosure, the position of each of the boundary lines of the at least three sections can be obtained for position determination using a plurality of pixels (e.g. picture points) of the recording.

[0015] According to the present disclosure, the position of each of the boundary lines can be obtained from the at least three sections for position determination using a plurality of pixels of the recording, and therefore the accuracy of the measurement can be further increased.

[0016] An element according to the second aspect of this disclosure can, for example, be an element having a first plane and a second plane, the second plane having an angle between (e.g., approximately) 15° and (e.g., approximately) 75° to the first plane. The second plane can, for example, be provided with at least three sections (e.g., regions of the plane) for position detection, the positions of which can be arranged such that the distance between them is sufficiently large to allow the second plane to be located (e.g., detected). A diffuse reflection of the second plane can be (e.g., approximately) 0.1% or less, and a diffuse reflection of the positions of which can be (e.g., approximately) 5% or more.

[0017] In the case of the element as described above, the position of the second plane relative to the first plane can be determined by locating the boundary lines of at least three sections used for position determination. Therefore, the angle formed by the first and second planes can be measured with high accuracy. In other words, if the angle formed by the first and second planes is measured in the element as described above, the element does not need to be cut by a plane to measure the angle. Consequently, many problems associated with cutting the element are avoided, the accuracy of the measurement is not degraded due to deformation of the element caused by cutting or burrs produced by the cutting process, and measured values ​​do not vary depending on the selected section (e.g., of the element).

[0018] In an element according to the first embodiment of the second aspect of the present disclosure, the at least three sections for determining position can be arranged, for example, at the periphery (e.g., an edge) of the second plane.

[0019] According to the present embodiment, the position of the second plane can be determined with high accuracy by the at least three position detection sections, which are arranged, for example, at the periphery of the second plane, and therefore the angle formed by the first plane and the second plane can be measured with high accuracy.

[0020] An element according to the second embodiment of the second aspect of the present disclosure may, for example, be provided with four sections for determining position.

[0021] In an element according to the third embodiment of the second aspect of the present disclosure, each of at least three position markers can correspond to a (e.g., respective) individual section for determining the position (e.g., the section for determining the position is represented by a position marker).

[0022] An element according to the fourth embodiment of the second aspect of the present disclosure can, for example, be an element according to the third embodiment, wherein the length of a boundary line of each position marker can be (e.g., approximately) between 0.1 mm and (e.g., approximately) 3 mm, and the length of each position marker in the direction of the boundary line can be equal to the length of the boundary line.

[0023] According to the present embodiment, for example, a sufficient number of measuring points can be arranged along the boundary line, wherein each measuring point can have a size that corresponds to the size of a single pixel (e.g., picture point).

[0024] An element according to the fifth embodiment of the second aspect of the present disclosure may, for example, be provided with at least two position markers, which have at least one position marker corresponding to a plurality of sections for determining the position (e.g., two or more sections for determining the position may be provided in one position marker).

[0025] For example, an element according to the sixth embodiment of the second aspect of the present disclosure can be used for optical applications.

[0026] An element according to the seventh embodiment of the second aspect of the present disclosure may, for example, be an element according to the sixth embodiment, wherein at least one of the first plane and the second plane may be a plane of a prism (e.g., a plane on which a prism is arranged), a plane for arranging a lens, or a plane for installing an optical fiber. Brief description of the drawings Fig. 1 shows an element according to an embodiment of the present invention, Fig. Figure 2 is a flowchart illustrating how the angle between the first plane and the second plane is determined using four position markers. Fig. Figure 3 is a flowchart illustrating how the X, Y, and Z coordinates of four position markers are determined. Fig.Figure 4 shows a cross-section of the element, where the cross-section is shown in the direction of the maximum angle of inclination of the second plane and perpendicular to the first plane (e.g. in the plane of the angle between the first and the second plane). Fig. Figure 5 shows a cross-section of the element, wherein the cross-section is shown in the direction of the maximum angle of inclination of the second plane and perpendicular to the first plane (e.g. in the plane of the angle between the first and second planes) and wherein paths of light rays illuminating a position marker are shown. Fig. Figure 6 shows an enlarged view of a position marker. Fig. 7A to 7C show reflected light on the surface, which, for example, creates a diffuse reflection. Fig.Figure 8 shows a cross-section in the direction of the maximum angle of inclination of the second plane (e.g., in the plane of the angle between the first and second planes), which is provided with a position marker that has a surface which produces a diffuse reflection. Fig. Figures 9A to 9C show how an angle formed by two planes of an element is measured using a conventional method. Fig. Figure 10 shows an element provided with position markers on a surface provided with a plurality of grooves for arranging optical fibers, and Fig. 11A and Fig. Figure 11B shows an element according to a further embodiment of the present invention. Detailed description

[0027] The Fig.Figure 1 shows an element according to an embodiment of the present invention. The element (e.g., a receptacle for optical devices, such as a prism, a lens, etc.) according to the embodiment is an optical element 200, which is provided with a surface (e.g., a surface) that is equipped with lenses and a prism surface. The optical element 200 is provided with a reference plane or reference surface (hereinafter referred to as: reference plane) 201, a plane or surface (hereinafter referred to as: plane) 205 which is perpendicular to the reference plane 201, and a plane or surface (hereinafter referred to as: plane) 203 which forms an angle (an acute angle) with the reference plane 201. The plane 203 is a plane or surface of a prism. The reference plane 201 is provided with a plurality of lenses 301 which are arranged in a straight line.Furthermore, the plane 205 is provided with a plurality of lenses 301, which are arranged in a straight line. Light rays traveling in a direction perpendicular to the reference plane 201 and entering the plurality of lenses 301, which are arranged in a straight line on the reference plane 201, are reflected by the plane 203 in the optical element 200 and reach the plurality of lenses 305, which are arranged in a straight line on the plane 205. Therefore, the optical element 200 is configured such that light rays traveling in a direction perpendicular to the reference plane 201 and entering the plurality of lenses 301, which are arranged in a straight line on the reference plane 201, exit the optical element 200 after passing through the lenses 301 and the lenses 305. Level 203 is provided with four position markers 101A, 101B, 101C and 101D.Each of the four position markers 101A, 101B, 101C, and 101D is a surface that causes a diffuse reflection formed on plane 203. Generally, position markers of an optical element are installed outside the area (e.g., at the periphery of plane 203) that is used as an optical surface on a surface of the optical element.

[0028] The four position markers 101A, 101B, 101C, and 101D are used to measure the angle formed by plane 203 with reference plane 201. Reference plane 201 corresponds to a first plane, and plane 203 corresponds to a second plane. The angle formed by the first and second planes is greater than 0° and less than 90°.

[0029] The Fig.Figure 2 is a flowchart illustrating how the angle between the first plane and the second plane is determined using the four position markers.

[0030] In step S1010 of the Fig. 2. The X, Y, and Z coordinates of the four position markers are determined. An X-axis and a Y-axis, which are arranged perpendicular to each other, are determined in the first plane (reference plane) 201. A Z-axis is determined so that it is perpendicular to the reference plane 201. How the X, Y, and Z coordinates of the four position markers are determined is described in detail below. In general, a section (e.g., area) for determining the X, Y, and Z coordinates is referred to as a section for determining the position. In the present embodiment, the four position markers constitute four sections (e.g., areas) for determining the position.

[0031] In step S1020 of the Fig.2. The position of the second plane is determined based on the X, Y, and Z coordinates of the four position markers. The position of the second plane can be determined using a least squares method with four sets of X, Y, and Z coordinates.

[0032] In general, the position of a plane can be determined if the number of sections for determining the position is three or more.

[0033] The four position markers 101A, 101B, 101C, and 101D are arranged such that the distance between them is sufficiently large to locate the position of the second plane using the four sets of X, Y, and Z coordinates. The four position markers can be placed at the periphery (e.g., the edge) of the second plane.

[0034] In step S1030 of the Fig.Step 2 will yield the angle formed by the first plane 201 and the second plane 203. The first plane 201 is contained within the XY plane, and the position of the second plane 203 was determined in step S1020. Therefore, the angle between the two planes can be obtained.

[0035] Furthermore, according to steps S1010 and S1020, the Fig. 2. The position of a plane can generally be determined by using position markers.

[0036] The following describes how the X, Y, and Z coordinates of the four position markers are determined. An example procedure is described in which an image measurement system (e.g., an image measurement system; for example, a system that takes images / recordings of a plane in order to measure it) is used.

[0037] The Fig. Figure 3 is a flowchart illustrating how the X, Y, and Z coordinates of the four position markers are determined.

[0038] In step S2010 of the Fig. 3. Using the recording measuring system, an image of the second plane 203 is taken from the direction which is perpendicular to the first plane (the reference plane) 201.

[0039] In step S2020 of the Fig.3. The X and Y coordinates of the boundaries (e.g., boundary lines) of the four position markers are determined using the obtained image by the following procedure: An arbitrary pixel (e.g., an image or raster point) in the image is defined as the origin of the coordinate system. The pixels in the image that correspond to the boundaries of the four position markers 101A, 101B, 101C, and 101D are identified. The X coordinates of the boundaries of the position markers are determined based on the position of the origin pixel in the X-axis direction and the positions of the pixels in the X-axis direction that correspond to the boundaries of the position markers. The Y coordinates of the boundaries of the position markers are determined based on the position of the origin pixel in the Y-axis direction and the positions of the pixels in the Y-axis direction that correspond to the boundaries of the position markers.The positions of the boundaries, i.e., the edges of the position markers, are determined by differences in pixel density (e.g., pixel color and / or distribution) in the image. Accordingly, it is important that the boundaries of the position markers are clearly depicted in the image. The accuracy of a measurement using an image is limited by the pixel size of the sensor in a measurement system. For example, when an image is taken through a microscope, the accuracy corresponding to the pixel size is approximately 0.5 µm.

[0040] In step S2030 of the Fig.3. The Z-coordinates of the position marker boundaries are determined. These Z-coordinates can be determined using the autofocus function of the measuring device. Alternatively, they can be determined using a non-contact distance sensor such as a laser.

[0041] The Fig.Figure 4 shows a cross-section of element 200, oriented in the direction of the maximum angle of inclination of the second plane 203 and perpendicular to the first plane 201. The circularly highlighted section shows an enlarged view of the cross-section oriented in the direction of the maximum angle of inclination of the second plane 203 and perpendicular to the first plane 201 near the position marker 101A. A line AX is a straight line passing through the boundary between the position marker 101A and the second plane 203 and is perpendicular to the first plane 201. The boundary line between the surface of the position marker 101A and the second plane 203 is shown in the Fig. The cross-section shown in section 4 is perpendicular and parallel to the first plane 201 and is represented by point A.

[0042] The Fig.Figure 5 shows a cross-section of element 200, oriented along the direction of the maximum inclination angle of the second plane 203 and perpendicular to the first plane 201, and shows light rays illuminating the position marker. The circularly highlighted section shows an enlarged view of the cross-section oriented along the direction of the maximum inclination angle of the second plane 203 and perpendicular to the first plane 201 near the position marker 101A. The circularly highlighted section shows light rays illuminating the position marker. When a photograph parallel to the first plane 201 is taken with the recording measuring system, the second plane 203 is illuminated by light traveling in the direction perpendicular to the first plane 201.Position marker 101A is a surface that produces diffuse reflection. Therefore, in the direction of the light path perpendicular to the first plane 201, a portion of the light L1 reaching position marker 101A near the boundary between position marker 101A and the second plane 203 is reflected in the direction perpendicular to the first plane 201 and travels towards the recording measurement system. Conversely, the second plane 203 is at an angle to the first plane 201 and does not produce diffuse reflection. Therefore, in the direction of the light path perpendicular to the first plane 201, the light L2 reaching the second plane 203 is not reflected towards the recording measurement system. Consequently, in a photograph taken with the recording measurement system, the position of the boundary between position marker 101A and the second plane 203 is clearly shown.

[0043] In the description above, an X-axis and a Y-axis, which are perpendicular to each other, are determined in the first plane (reference plane) 201. The second plane 203 is illuminated by light traveling in a direction perpendicular to the first plane 201, and an image of the second plane 203 is taken from the same direction perpendicular to the first plane (reference plane) 201. Generally, an X-axis and a Y-axis, which are perpendicular to each other, can be determined in a virtual plane that is perpendicular to the direction in which the parallel light is emitted / travels. In this case, the first plane is not needed as the reference plane.

[0044] The Fig. Figure 6 shows an enlarged view of position marker 101D. As shown in the Fig.As shown in Figure 6, the boundary line between position marker 101D and the second plane 203 is parallel to the first plane 201. This means that the Z-coordinate of any point on the boundary line is a fixed value (e.g., all points on the boundary line have the same Z-coordinate). Furthermore, the length of the boundary line is such that it has five or more measurement points, which are represented as black dots. The size of a measurement point corresponds to the size of a pixel of the imaging system. For example, the length of the boundary line is in the range of 0.1 mm to 3.0 mm. Although the above description and the Fig. Since the description regarding position marker 101D is discussed in section 6, it is also applicable to the other position markers.

[0045] According to the embodiment of the present invention, the position of a boundary line, represented by a plurality of pixels, can be clearly displayed in a recording of a measurement system, allowing the X and Y coordinates of the boundary line to be easily captured. Furthermore, with a plurality of measurement points corresponding to a plurality of pixels, a plurality of sets of X, Y, and Z coordinates are determined, and the average of the X coordinates, an average of the Y coordinates, and an average of the Z coordinates are each defined as the X, Y, and Z coordinates of the position markers. Therefore, it can be expected that deviations in the measured values ​​will be reduced by using the plurality of sets of X, Y, and Z coordinates.

[0046] The area that produces diffuse reflection is described below.

[0047] The Fig.Figures 7A to 7C show the reflection of light from a surface, which, for example, creates a diffuse reflection. Fig. Figure 7A shows incident light (e.g., ambient light) and light produced by diffuse reflection. Fig. Figure 7B shows incident light (e.g., ambient light) and light produced by a directed (e.g., specular) reflection. Fig. Figure 7C shows incident light (e.g., ambient light), light caused by diffuse reflection, and light caused by specular reflection. In general, a surface that produces diffuse reflection exhibits the characteristics of Fig. 7A or the Fig. 7C.

[0048] The luminous flux quantity or intensity (hereinafter referred to simply as intensity) caused by diffuse reflection from a surface (e.g., a surface) that generates diffuse reflection is estimated below. The total quantity or intensity E D The luminous flux of diffuse (diffusely reflected) light is represented by the following equation. ED=E0−ET−ES−EA

[0049] E0 represents the amount or strength (hereinafter referred to simply as: strength) of the luminous flux of the incident light, E T represents the amount or intensity (hereinafter referred to simply as intensity) of the luminous flux of the transmitted light, E S represents an amount or strength (hereinafter referred to as strength) of the luminous flux produced by directed reflection and E AIlluminance represents the amount or intensity (hereinafter referred to simply as intensity) of the luminous flux of the absorbed light. The luminous flux intensities (e.g., illuminance) described above apply to a unit area (e.g., a predetermined region) of the surface that produces the diffuse reflection, and the unit is lux. 1 lux is equal to 1 lumen per square meter. 2 . E0 corresponds to the amount or strength of the illuminance of the surface that produces the diffuse reflection.

[0050] Table 1 shows the ratios of the luminous flux intensities to the corresponding components of equation (1), including the magnitude E0 of the incident luminous flux, for a plane without diffuse structure and for surfaces that produce diffuse reflection, provided with various types of diffuse structure (e.g., diffusely reflecting structures). The ratio of the magnitude of the diffuse luminous flux to the magnitude E0 of the incident luminous flux, i.e., the diffuse reflection, should preferably be 5.0% or more. If an element is manufactured, for example, by injection molding, a diffuse structure can be formed on a (e.g., injection molding) mold by etching, electrical discharge machining (EDM), spark erosion (EDM), or the like, so that the diffuse structure is transferred to a surface of the element. Table 1 Type of diffuse structure E D E0 E T E S E A Plane without diffuse structure 0,0 % 100,0 % 94,2 % 5,8 % 0,0 % Structure produced by etching 16,7 % 100,0 % 83,3 % 0,0 % 0,0 % Structure produced by electrical erosion 7,9 % 100,0 % 92,1 % 0,0 % 0,0 % Structure created by sandblasting 50,0 % 100,0 % 50,0 % 0,0 % 0,0 % White leaf (perfect diffuse reflection) 96,0 % 100,0 % 0,0 % 0,0 % 4,0 %

[0051] The intensity of the light in the direction with an angle Θ0 with respect to a normal (perpendicular) to the surface that produces the diffuse reflection, that is, a luminance, is represented by the following equation. LR=EDcosΘ02π

[0052] The unit of luminance is candela per m². 2 Candela is the unit of luminous intensity, which represents the luminous flux per solid angle, and corresponds to lumens per steradian. Accordingly, the unit of luminance is also lux per steradian.

[0053] When an angle of incidence (of the light) L1 is applied to the position mark 101A in the Fig. Since 5 is represented by Θ0, the luminance in the direction L1 can be obtained by equation (2).

[0054] Table 2 shows values ​​of L R, which are obtained by equation (2) for numerous values ​​of the angle of incidence and for surfaces that produce diffuse reflection and which are provided with numerous types of diffuse (e.g., diffusely reflecting) structures. The values ​​L R are given as relative values, which are obtained by substituting the values ​​of E D (The unit is %) of Table 1 in (the parameter) E D of equation (2). The “angle of incidence” in Table 2 means Θ0 in equation (2). Table 2 angle of incidence Type of diffuse structure 45° 15° 30° 60° 75° Plane without diffuse structure 0,00 % 0,00 % 0,00 % 0,00 % 0,00 % Structure produced by etching 1,88 % 2,57 % 2,30 % 1,33 % 0,69 % Structure produced by electrical erosion 0,89 % 1,21 % 1,09 % 0,63 % 0,33 % Structure created by sandblasting 5,63 % 7,69 % 6,89 % 3,98 % 2,06 % White leaf (perfect diffuse reflection) 10,80 % 14,76 % 13,23 % 7,64 % 3,95 %

[0055] Table 2 specifies the minimum relative luminance value for the structure produced by electroerosion at an angle of incidence of 75°. The minimum relative luminance value is 0.33%. Assuming a typical case where the illuminance (e.g., the intensity of the luminous flux directed onto it) of the surface producing the diffuse reflection is 50,000 lux at an angle of incidence of 0° (perpendicular incidence), the luminance in the case described above is 165 lux per steradian, which can be easily detected by a CCD or CMOS detector. On the other hand, in the general case, the diffuse reflection of a surface on which a position marker is located, such as the second plane 203, is 0.1% or less.Accordingly, a position marker which has the surface that produces a diffuse reflection can be detected using diffuse reflection light.

[0056] Table 3 shows typical depth (roughness) values ​​for numerous types of diffuse structures. The depth of any type of diffuse (e.g., diffusely reflecting) structure is less than 1 µm. Table 3 Type of diffuse structure Typical depth value Structure produced by etching 0,56 µm Structure produced by electrical erosion 0,80 µm Structure created by sandblasting 0,04 µm White sheet (perfect diffuse reflection) Size of a molecular structure

[0057] The influence of the roughness of a surface that generates diffuse reflection on the accuracy of measuring an angle of plane 203 is described below. Sufficient accuracy for measuring an angle is 0.3° or less.

[0058] The Fig.Figure 8 shows a cross-section running in the direction of the maximum angle of inclination of the second plane 203 (e.g., intersecting the second plane 203 perpendicularly), which is provided with a position marker having a surface for generating diffuse reflection. It is assumed that the angle formed by plane 203 with plane 201 is measured using points A and B on plane 203. The length of the position marker, which has a surface generating diffuse reflection in the direction of the maximum angle of inclination, is represented as p. The distance between point A and point B is represented as s. A difference between the coordinate of point A and the coordinate of point B in the vertical direction, i.e., in the direction perpendicular to plane 201, is represented as z. Furthermore, it is assumed that a depth of the diffuse structure is represented as d.The angle α1 of the plane 203 with respect to the plane 201 is represented by the following equation. arcsin(zs)=α1

[0059] If the angle α1 is 75°, the following value is obtained. zs=0.9659

[0060] On the other hand, if the diffuse structure is present, a position of the base of the diffuse structure is represented as A', and a value of the angle measured using point A' and point B is represented as α2. The angle α2 should be 74.7° or greater, such that the difference between angles α1 and angle α2 is 0.3° or less. If s is provided as being significantly larger than d, the following relationship holds true with respect to the measured value of angle α2, as shown in the Fig. 8 is shown. arcsin(z−ds)<α2

[0061] Accordingly, α2 is greater than 74.7° if the following relationship holds true. arcsin(z−ds)=74.7°

[0062] In this case, the following value will be obtained. z−ds=0.9646

[0063] Accordingly, assuming that d is 1 µm, the difference between angle α1 and angle α2 can be less than 0.3° if it is ensured that s is 770 µm or more.

[0064] If the angle α1 is 45°, the following value is obtained. zs=0.7071

[0065] Angle α2 should be 44.7° or greater, such that the difference between angle α1 and angle α2 is 0.3° or less. α2 is greater than 44.7° if the following relationship holds. arcsin(z−ds)=44.7°

[0066] In this case, the following value will be obtained. z−ds=0.7034

[0067] Accordingly, assuming that d is 1 µm, the difference between angle α1 and angle α2 can be less than 0.3° if it is ensured that s is 271 µm or more.

[0068] The distance between point A and point B corresponds to a distance between the position markers. Accordingly, if the distance between the position markers is 1 mm or more, angle measurements are not affected by the surface roughness, regardless of the value of angle α1.

[0069] The Fig. Figures 9A to 9C show how an angle formed by two planes of an element is measured using a conventional method. Fig. 9A shows positions where angles are measured. The positions of cross-sections marked with dotted-dashed lines AA and BB are the measurement positions. Fig.Figure 9B shows a cross-section of the element at the dotted-dashed line AA, and if an angle formed by the two planes is measured in this cross-section, the angle is 45°. Fig. Figure 9C shows a cross-section of the element along the dotted-dashed line BB, and when an angle formed by the two planes is measured in this cross-section, the angle is 43.219°. Therefore, in a conventional method where an angle is measured in a cross-section of an element, the angle varies depending on the position (direction) of the measurement. On the other hand, in the method according to the present invention, coordinates of positions of two planes are determined, and therefore the problem of variation described above will not occur.

[0070] Table 4 shows measured angles of a prism plane obtained by a conventional method, in which an angle is measured in a cross-section of an element, and by the method according to the present invention. The numbers "1", "2", and "3" represent the first, second, and third measured values, respectively. The unit of the angle is degrees. A "mean" value in Table 1 represents the mean of the three measured values. The values ​​of "6δ" in Table 1 are obtained by estimating the values ​​δ (standard deviation) of the three measured values ​​and multiplying these values ​​by 6. "CP" represents a process capability index, which is a ratio of the variation to the tolerance range. The values ​​of CP in Table 1 are obtained by dividing the tolerance range by 6δ. Table 4 Tolerance range 1 2 3 mean 6δ CP Present invention 0,6 44,99 45,03 44,92 44,98 0,35 1,72 Related technology 0,6 44,80 44,99 44,75 44,85 0,76 0,79

[0071] In general, it can be determined that deviations in measurement fall sufficiently within the tolerance range if the CP value is 1.33 or higher. Accordingly, it is determined that a tolerance range of 0.6° is achieved, i.e., a measurement accuracy of ± 0.3° can be obtained by the method according to the present invention.

[0072] The Fig. Figure 10 shows an element provided with position markers on a surface that is provided with a plurality of grooves for arranging optical fibers. In the Fig.Figure 10 shows the position markings circled. In general, the present invention can be applied to elements comprising a prism plane, an entrance surface, and an exit surface, on / in which lenses are formed, and an entrance surface and an exit surface that are at an angle to each other, such that a surface with a plurality of grooves for arranging optical fibers is formed, as described in the Fig. 10 is shown, or similar measures are applied.

[0073] In the embodiments described above, a single position marker constitutes a single section for position determination. In general, a single position marker can have multiple sections for position determination.

[0074] The Fig. 11A and Fig. Figure 11B shows an element 1200 according to a further embodiment of the present invention. Fig.11A is a perspective view of element 1200, and the Fig. Figure 11B is a top view of element 1200. Element 1200 is provided with two linear position markers 1101A and 1101B on a plane 1203. Using at least three positions, which have a position on position marker 1101A and a position on position marker 1101B as sections for determining the position, the angle formed by plane 1203 and plane 1201 can be measured.

[0075] Furthermore, the present invention can generally determine the position of a surface that has a curved (e.g., bent) surface. A surface whose position is to be determined is defined as a surface A. Several sections for determining the position are provided on surface A. Each of the sections for determining the position has a surface that generates diffuse reflection. The diffuse reflection of surface A is (e.g., approximately) 0.1% or less, and the diffuse reflection of the sections for determining the position is (e.g., approximately) 5% or more. When surface A is illuminated by parallel light in (e.g., from) a predetermined direction, light rays in / from the direction of illumination are reflected only if they are reflected by a section that has a tangent plane perpendicular to the direction of illumination.Furthermore, sections for determining position are installed on a section of surface A, to which the normal (perpendicular) forms an angle between 15° and 75° with respect to the predetermined direction (e.g., direction of illumination). Accordingly, if a photograph is taken in the direction of illumination, the coordinates of the boundary lines of the sections for determining position can be determined by the flowchart of the [system / project]. Fig. The three methods shown can be obtained. In many cases, the position of area A can be determined using the coordinates of the boundary lines of the position-finding sections obtained in this way. For example, if area A is spherical, the center of the sphere can be determined as the point that is equidistant from a point on the boundary line of each of the three position-finding sections.

Claims

[1] A method for measuring the position of a target surface (203, 1203) which has position-determining sections (101A, 101B, 101C, 101D; 1101A, 1101B) provided thereon, wherein a diffuse reflectance of the target surface is 0.1% or less and a diffuse reflectance of the position-determining sections (101A, 101B, 101C, 101D; 1101A, 1101B) is 5% or more, and wherein the target surface (203; 1203) is a surface of an element (200; 1200) which is provided with a first plane (201; 1201) and a second plane which forms an angle between 15° and 75° to the first plane (201; 1201), wherein the target surface (203; 1203) the second level is and the element (200; 1200) is provided with at least three sections for determining position (101A, 101B, 101C, 101D; 1101A, 1101B) on the second level, wherein the sections for determining position (101A, 101B, 101C, 101D;1101 A, 1101B) are arranged such that a distance between the positioning sections (101A, 101B, 101C, 101D; 1101A, 1101B) is sufficiently large to locate the second plane, the method comprising the steps:; Illuminate (S2010) the target surface (203; 1203) with parallel light perpendicular to the first plane (201; 1201); Determining (S2020) the positions of boundary lines of the majority of sections for position determination (101A, 101B, 101C, 101D; 1101A, 1101B) starting from a survey of the target area (203; 1203), and Determine (S2030) the position of the target area (203; 1203) from the positions of the boundary lines of the majority of sections for determining the position (101A, 101B, 101C, 101D; 1101A, 1101B). [2] The method according to claim 1, further comprising the step of determining an angle between the first plane (201; 1201) and the second plane (203; 1203) using the positions of the second plane (203; 1203). [3] The method according to any of the preceding claims, wherein the position of each of the boundary lines of the at least three sections for position determination (101A, 101B, 101C, 101D; 1101A, 1101B) is obtained using multiple pixels in the recording. [4] An element (200; 1200) which has a first plane (201; 1201) and a second plane (203; 1203) which has an angle between 15° and 75° to the first plane (201; 1201), wherein the second level (203; 1203) is provided with at least three sections for position detection (101A, 101B, 101C, 101D; 1101A, 1101B) on it, wherein the sections for position detection are arranged such that a distance between the sections for position detection (101A, 101B, 101C, 101D; 1101A, 1101B) is sufficiently large to locate the second level (203; 1203), and where the diffuse reflection of the second plane is 0.1% or less and the diffuse reflection of the sections for position determination is 5% or more. [5] The element (200; 1200) according to claim 4, wherein the at least three position detection sections (101A, 101B, 101C, 101D; 1101A, 1101B) are arranged at the periphery of the second plane (203; 1203). [6] The element (200; 1200) according to claim 4 or 5, which is provided with four sections for position detection (101A, 101B, 101C, 101D; 1101A, 1101B). [7] The element (200; 1200) according to any one of claims 4 to 6, wherein each of at least three position markers corresponds to a single section for position determination. [8] The element (200; 1200) according to claim 7, wherein the length of a boundary line of each of the position markers is between 0.1 mm and 3 mm and the length of each of the position markers in the direction of the boundary line is equal to the length of the boundary line. [9] The element (200; 1200) according to any one of claims 4 to 8, which is provided with at least two position markers, which have at least one position marker corresponding to several position determination sections (101A, 101B, 101C, 101D; 1101A, 1101B). [10] The element (200; 1200) according to any one of claims 4 to 9, which is usable for optical applications. [11] The element (200; 1200) according to claim 10, wherein at least one of the first plane (201; 1201) and the second plane (203; 1203) is a plane of a prism, a plane for arranging a lens or a plane for installing an optical fiber.

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