Apparatus and associated method for determining distance, surface thickness, and optical properties of an object - Patents.com

Abstract

Described herein is an apparatus for determining the position and / or optical properties of an object (2). The apparatus includes at least one output element (4.1) for providing light, an illumination optical system (11) for directing light from the output element toward an object, a light sensor (8), and an imaging optical system (13) for focusing light from the object onto the light sensor. The apparatus is configured to determine the position and / or optical properties of the object (2) from a local maximum in the light intensity distribution detected by the light sensor (8), the local maximum being the result of light collected from the intersection of an object point (2.1) with one of the coincident focal points or focal regions formed by the illumination optical system (11) and the imaging optical system (13). The apparatus can be used to determine intensity values ​​for light reflected from the object point (2.1) having at least two different wavelengths. Also described herein is a method for determining the position and / or optical properties of an object (2).

Description

[Technical field]

[0001] In general, the present disclosure relates to optical measurement and imaging. More particularly, but not exclusively, the present disclosure relates to determining the position and optical properties of an object. [Background technology]

[0002] Non-contact photoelectron measuring instruments provide non-destructive and relatively high speed measurements of surface geometry and surface characteristics. To perceive depth information to measure distance and orientation of objects and surfaces, a variety of different techniques exist, such as confocal, structured light or laser triangulation, white light interferometry, fringe projection, or focal depth imaging techniques. Triangulation instruments are widely used to add depth information to various types of industrial machine vision systems due to their relative simplicity and ease of use. In triangulation-based devices, a laser beam or LED is typically projected onto the object to be measured, and the reflected light from the object point is detected by an optical sensor at an imaging angle that depends on the distance between the light source and the object point.

[0003] The imaging angle, the baseline between the light source and the photosensor, and the angle of the light projected from the light source define a triangular shape from which depth information and surface shape can be extracted. It is also common to extract the detected light intensity, which provides information about the optical properties of important materials, such as the surface reflectance.

[0004] A known problem with current triangulation devices is that the measurement speed is limited to the frame rate of the optical sensor.

[0005] A known problem with current laser triangulation systems is that speckle noise, which is seen as an interference pattern on the optical sensor due to coherent illumination light, is unavoidable, hindering the extraction of surface position and surface optical properties.

[0006] Additionally, another known problem with current laser triangulation machines is that they are limited to only being able to use small numerical aperture optics, severely limiting their ability to profile shiny, sloped surfaces. Summary of the Invention

[0007] It is an object of the present invention to at least alleviate one or more problems associated with existing solutions in the context of determining the surface position and surface optical properties of a measured object. In particular, it is an object of the present invention to provide a measuring device for measuring the surface position and surface optical properties, which allows for an improved measurement speed. Furthermore, it is an object of the present invention to provide such a measuring device, which is also suitable for measuring the surface position and surface optical properties of shiny and inclined surfaces. Furthermore, it is an object of the present invention to simplify the arrangement of the measuring device. It is a further object of the present invention to provide an apparatus and a method, which allows for the simultaneous determination of the surface position and at least one property of the surface selected from the group consisting of reflectance, reflectance, transmittance and transmittance with light of one or more different wavelengths.

[0008] The following presents a simplified summary to provide a basic understanding of some concepts of the invention as a prelude to a more detailed description of exemplary and non-limiting embodiments of the invention.

[0009] The object of the invention can be achieved by means of the features of the independent claims.

[0010] According to one aspect of the present invention, a novel apparatus for determining a position and / or optical properties of an object is provided. The device according to the invention comprises: - a point or line output element for supplying light; - an illumination optical system for directing light from the output element to an object; a light sensor for detecting a light intensity value; - an imaging optical system for collecting light from an object onto an optical sensor; Includes.

[0011] The illumination optics is configured to focus light from the position point of the output element to a plurality of illumination focal points or focal regions located at different distances from the illumination optics along an illumination coordinate axis related to a chief ray of the illumination optics for the position point of the output element, where the chief ray is mutual for the plurality of illumination focal points or focal regions focused from the position point of the output element, and where each of the illumination focal points or focal regions along the same illumination coordinate axis differs from each other at least in dominant wavelength or shape and / or is formed with a different optical aperture of the illumination optics.

[0012] The imaging optics associates a corresponding chief ray of the imaging optics from each of the position points of the light sensor to the corresponding position point of the light sensor. Imaging A plurality of imaging optical systems are arranged at different distances from the imaging optical system along a coordinate axis. Imaging The optical sensor is configured to form a focal point or focal region, and the corresponding chief rays are formed from corresponding position points of the optical sensor. Imaging Mutual and same in terms of focus Imaging Along the coordinate axis Imaging Each of the focal points or focal regions differs from the others at least in dominant wavelength or shape and / or is focused at a different optical aperture of the imaging optics.

[0013] The illumination optical system and the imaging optical system are configured such that each of the various illumination focal points or focal regions from the plurality of illumination focal points or focal regions along the same illumination coordinate axis has a different focal point or focal region. Imaging Located along the coordinate axis Imaging and forming a plurality of coincident focal points or focal regions so as to coincide with the focal points or focal regions, where the orientation of the illumination coordinate axis is: Imaging Further, the illumination optics and the imaging optics are configured to form a plurality of coincident focal points or focal regions, each of which is an illumination focal point and an imaging optic that are associated with a common dominant wavelength or shape. Imaging It consists of a focal point or focal region and / or is formed by the correlated optical aperture of the illumination optics and the imaging optics.

[0014] the apparatus being configured to determine positions and / or optical properties of object points of said object from local maxima of the light intensity distribution detected by the light sensor; - the positions of the object points are determined from the positions of local maxima, and / or The optical properties of the object point are determined from the intensity or wavelength of the local maximum, which is the result of light collected from the intersection of the object point with one of the corresponding focal points or focal regions.

[0015] According to the invention there is also provided a new method for determining the position and / or optical properties of an object. The method according to the invention comprises: - providing optical illumination and optical detection of objects from different directions, Light is focused from a location point of the output element to a plurality of illumination focal points or focal regions located at different distances from the illumination optics along an illumination coordinate axis related to a chief ray of the illumination optics for the location point of the output element, where the chief ray is mutual for the plurality of illumination focal points or focal regions focused from the location point of the output element, and where each of the illumination focal points or focal regions along the same illumination coordinate axis differs from each other at least in dominant wavelength or shape and / or is formed with a different optical aperture of the illumination optics, and Related to the corresponding chief rays of the imaging optics for the corresponding position points of the optical sensor Imaging A number of different distances from the imaging optics along a coordinate axis Imaging A focal point or focal region is formed from each of the position points of the optical sensors, where corresponding chief rays are formed from a plurality of position points of the optical sensors. Imaging Mutually and identically related to focal points or focal areas Imaging Along the coordinate axis Imaging each of the focal points or focal regions differing from one another at least in dominant wavelength or shape and / or being focused at a different optical aperture of the imaging optics; forming a plurality of coincident focal points such that each of the various focal points from a plurality of illumination focal points or focal regions along an illumination coordinate axis coincides with a focal point or focal region located along a different illumination coordinate axis, the orientation of the illumination coordinate axis being such that Imaging Unlike the orientation of the coordinate axes, each of the coincident focal points or focal regions is an illumination focal point and a focal region associated with a common dominant wavelength or shape. Imaging comprising a focal point or focal region and / or formed by correlated optical apertures of the illumination optics and the imaging optics; - detecting by a light sensor intensity values ​​of light collected from the object by the imaging optics; determining the position and / or optical properties of the object point such that the position of the object point is determined from the position of a local maximum of the detected light intensity distribution and / or the optical properties of the object point are determined from the intensity or wavelength of a local maximum of the detected light intensity distribution, where the local maximum is the result of light collected from an intersection with one of the focal points or focal regions coinciding with the object point; Includes.

[0016] According to the present invention there is also provided the use of an apparatus for determining a thickness between a first surface and a second surface of an object, wherein said object is at least partially transparent or translucent to light directed at the object.

[0017] The present invention provides advantages over the prior art, for example, the present invention: -Lighting and Imaging By increasing the numerical aperture, it is possible to measure glossy and inclined surfaces. -Lighting and Imaging The use of high numerical aperture optics in makes it possible to maintain a large depth of field and, as a result, to ensure a large depth (Z direction) measurement range. -Enables intensive measurement of objects by making full use of the measurement space, -Several surface features can be measured simultaneously in one image frame, improving measurement speed. - It is possible to provide non-coherent light irradiation and to focus the light on the optical sensor without speckle noise; It is possible to determine the position of object points accurately, regardless of the diffuse reflectance or gloss of the object; -The same type of optical system is used for lighting and Imaging It is possible to use it for.

[0018] Various exemplary and non-limiting embodiments are described in the accompanying dependent claims. The features recited in the claims are freely combinable with each other, unless expressly stated otherwise.

[0019] As used herein, "plurality" means a quantity of two or more. Further, it is to be understood that throughout this specification the use of "a" or "an" i.e. the singular does not exclude the plural.

[0020] As used herein, the word "axis" means an imaginary line, and the word "axis" is the plural of "axis."

[0021] In this specification, the verbs "comprise" and "include" are used as open qualifiers that do not exclude or require the presence of unrecited features.

[0022] The novel features which are believed to be characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its structure and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of certain illustrative embodiments when read in connection with the accompanying drawings.

[0023] As will be appreciated by those skilled in the art, the considerations presented above with respect to various embodiments of the multi-layer structure may be flexibly applied, mutatis mutandis, to embodiments of the associated manufacturing methods, and vice versa.

[0024] The embodiments in the following detailed description are given as examples only, and those skilled in the art can implement the basic idea of ​​the present invention in ways other than those described herein. Most of the embodiments can be realized in various combinations with other embodiments. Although a particular embodiment or embodiments may be referred to in several places in this specification, this does not mean that the reference is directed only to one described embodiment or that the described characteristics can be used only in one described embodiment. In this way, individual features of several embodiments can be combined to provide new inventive embodiments. [Brief description of the drawings]

[0025] The invention will now be described in more detail with reference to the accompanying drawings.

[0026] [Figure 1a] FIG. 1a illustrates diagrammatically an embodiment of an apparatus for determining the position and / or optical properties of an object. [Figure 1b] FIG. 1b shows an exemplary intensity distribution diagram according to FIG. 1a. [Figure 2a-2c] 2a, 2b and 2c show schematic diagrams of different optical aberrations utilized in embodiments. [Diagram 3] FIG. 3 illustrates a schematic of an embodiment of an apparatus for determining the position and / or optical properties of an object. [Figure 4a-4b] Figures 4a and 4b show the spectral content. [Figure 5a] FIG. 5a illustrates diagrammatically an embodiment of an apparatus for determining the position and / or optical properties of an object. [Fig. 5b1-5b2] 5b1, 5b2 show exemplary intensity distribution diagrams according to FIG. 5a. [Figure 6a] FIG. 6a illustrates diagrammatically an embodiment of an apparatus for determining the position and / or optical properties of an object. [Figure 6b] FIG. 6b shows an exemplary intensity distribution diagram according to FIG. 6a. [Figures 7a-7c]7a, 7b and 7c show an example of simultaneous measurement of the surface shape of an object determined according to the present invention. [Figure 8] FIG. 8 is a flow diagram disclosing one embodiment of a method for determining the position and / or optical properties of an object. [Figure 9] 9 and 10 show diagrammatically a further modification of the device according to the present invention. [Figure 10] 9 and 10 show diagrammatically a further modification of the device according to the present invention. [Figure 11] 11 and 12 show diagrammatically a further modification of the device according to the present invention. [Figure 12] 11 and 12 show diagrammatically a further modification of the device according to the present invention. [Figure 13] 13 and 14 show an embodiment in which the interval between adjacent output elements is adjusted. [Figure 14] 13 and 14 show an embodiment in which the interval between adjacent output elements is adjusted. [Figure 15] FIG. 15 shows one embodiment of scanning an object. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] In the following, several embodiments of the present invention are disclosed. In the described embodiments, illumination of an object surface and Imaging In this way, the image of the projected illumination source or illumination source and Imaging A virtual measurement space can be created by matching the image of the optical sensor of the optical system with a number of coincident focal points (measurement lines and / or measurement points of coincident focal points or focal areas) common to both optical systems. When the object to be measured intersects the virtual measurement space, one or more coincident focal points or focal areas of the virtual measurement space intersect the object at a specific object point. The strong reflection originating from the intersection of this object point with the coincident focal point or focal area is indicated by the optical sensor and converted into a surface position of the measured object.

[0028] As used herein, reflection refers to specular and diffuse reflection, where specular refers to reflection from smooth surfaces and diffuse refers to reflection from rough surfaces, and reflection refers to scattering, refraction, and reflection of radiation from within the object being measured.

[0029] The geometric shape of the illumination output element providing light, or at least a part thereof, is advantageously projected via an illumination optical system to intersect with an object point, which can be for example a point from the surface of the object to be measured, and this image is monitored in imaging, where the light reflected from the object is collected via an imaging optical system on a light sensor. In the light intensity distribution detected by the light sensor, a local intensity maximum is provided at a point corresponding to the intersection of the object point with the image of the projected light source shape and the position point of the light sensor shape. The position of the object point is determined from the location of the local intensity maximum of the light distribution defined by the light sensor, and the optical properties of the object point are determined from the intensity or wavelength of the local intensity maximum.

[0030] In this specification, the position or location of a local maximum of the intensity distribution refers to the position on the light sensor 8 where the intensity value of the detected light is a local maximum.

[0031] If the object being measured (e.g., the target) consists of multiple surfaces that are partially light-transmitting and partially light-reflecting, such as a plastic film or a glass plate, the method creates separate local intensity maxima from each of these surfaces, and the thickness of the film or plate can be defined based on the difference in the positions of these intensity maxima, if the refractive indices of the materials involved in the measurement and the measurement geometry are known. The measurement geometry depends on the illumination angle and Imaging It includes an angle and the shape of the object 2 to be measured with respect to the angle.

[0032] In some cases it is also possible to determine the position of an object point on a sub-surface of the object relative to the light directed at the object, i.e. on the internal structure of the object, which depends on the optical properties of the object (such as transparency or translucency).

[0033] In the various figures, the same or corresponding parts are indicated by the same reference numerals and, in most cases, duplicate textual descriptions are omitted.

[0034] 1a shows an apparatus according to an embodiment 100. The apparatus comprises one point-like output element 4.1 (i.e. an output element formed as a point) for providing light, illumination optics 11 directing the light from the output element 4.1 towards an object 2 to be measured, a light sensor 8 for detecting light intensity values, and imaging optics 13 for collecting the light from the object 2 on the light sensor 8.

[0035] Optical illumination means and optical Imaging Both of the means are arranged such that the illumination optics 11 includes one or more output elements 4.1 to collect different points from the illumination, and the imaging optics 13 includes a light sensor 8. Imaging The illumination optics 11 are configured to form both focal points or focal regions into the virtual measurement space such that different points from the regions are focused in a known manner at different positions on the virtual measurement space. Each focal point or focal region formed by the illumination optics 11 from the location point of illumination (i.e., output element) differs from the others in at least dominant wavelength or shape and / or is formed with a different optical aperture of the illumination optics 11. Correspondingly, Imaging Each focal point or focal region formed by the imaging optics 13 from a location point of the region (i.e., the light sensor) differs from the others in at least dominant wavelength or shape and / or is formed with a different optical aperture of the imaging optics 13. At each coincident focal point or focal region, the illumination focal points or illumination focal regions (i.e., the focal points or focal regions formed by the illumination optics 11) have the same common dominant wavelength or shape. Imaging Focus point or Imaging The coincident focal points or regions are formed to coincide (overlap) with the focal regions (i.e., the focal points or regions formed by the imaging optics 13). Additionally or alternatively, the focal points or regions are formed by correlated optical apertures of the illumination optics 11 and the imaging optics 13. That is, each coincident focal point or region is formed by illumination and imaging optics 13 associated with a common dominant wavelength or shape. ImagingA focal point or focal area is formed by the correlated optical apertures of the illumination optics 11 and the imaging optics 13. Thereby, it is possible to form a plurality of coincident focal points or focal areas (i.e. common focal points or focal areas) where each coincident focal point or focal area is associated with a common dominant wavelength of the formed focal points or focal areas and / or where the coincident optical apertures of the illumination optics 11 and the imaging optics 13 are formed. If an object point on the surface of the object 2 to be measured coincides with any of the coincident focal points or focal areas of the virtual measurement space thus formed, the reflection arising therefrom will be very strong compared to the reflected light from other object points on the surface of the object 2. By the imaging optics 13, the light reflected on the surface of the object 2 is directed to the light sensor 8, which detects the position of the local intensity maximum of the propagated light and forms data of the position and intensity of the detected light into an electrical signal. The light sensor 8 can be, for example, a CCD, a CMOS matrix, a Position Sensitive Detector (PSD), etc. The device determines from the electrical signal a reflection maximum representative of the surface shape of the object 2 by means of processing means (not shown in FIG. 1 a), by which the measured position of the object point of the object 2 is determined. Alternatively or additionally, the optical property of the object point can be determined from the intensity maximum of the corresponding signal of the maximum reflection corresponding to the intensity value of the corresponding local intensity maximum or the wavelength of the local intensity maximum.

[0036] In various embodiments, output element 4.1 may generally include or consist of an LED or laser-based light source for illuminating and providing light.

[0037] In various embodiments, each output element may advantageously include a separate light source and a separate slit or pinhole through which light (ie, illumination) from the separate light sources passes.

[0038] The light (ie, optical radiation) provided by the output element may be electromagnetic radiation having a wavelength range from ultraviolet (wavelength ca. 50 nm) to infrared (wavelength ca. 1 mm).

[0039] The light provided may be white light (ie, containing all visible wavelengths) or may be light containing one wavelength or many different wavelengths.

[0040] In various embodiments, the light provided may be either coherent or non-coherent light.

[0041] The illumination optical system 11 and the imaging optical system 13 may include a lens or optical components such as a lens, a mirror, etc. Furthermore, the illumination optical system 11 and the imaging optical system 13 may be the same or different.

[0042] In the device of the embodiment 100, longitudinal chromatic aberration is utilized in the illumination optical system 11 and the imaging optical system 13. Due to longitudinal chromatic aberration, the wavelengths λ1(4.1), λ2(4.1), λ3(4.1), λ4(4.1), λ5(4.1), λ6(4.1), λ7(4.1), λ8(4.1), λ9(4.1), λ10(4.1), λ11(4.1), λ12(4.1), λ13(4.1), λ14(4.1), λ15(4.1), λ16(4.1), λ17(4.1), λ18(4.1), λ19(4.1), λ21(4.1), λ22(4.1), λ23(4.1), λ24(4.1), λ25(4. m (4.1) with different illumination focal points and wavelengths λ1(8), λ2(8), λ3(8), λ4(8), λ m (8) optical sensor 8 end points P1(8) and P n (8) Different positions from different points Imaging The focal points form said optics at different distances in the direction of the corresponding chief rays, see Fig. 1a. This is also shown in Fig. 2a, with a larger enlargement of the illumination optics 11. The illumination focal points formed from the position point P1 (4.1) of the output element 4.1 are along the same illumination coordinate axis A1 (4.1). The chief ray F1 (4.1) is reciprocal to the illumination focal points formed from the position point P1 (4.1) of the output element 4.1 and located at different wavelengths and different distances from the illumination optics 11. Thus, the same position point P1 (8) → P n (8) Imaging The focal point is the corresponding position point P1(8) → P n The chief ray of the imaging optical system 13 for (8) is the same as F1(8) → F n (8) and the same Imaging Coordinate axis A1(8) → A n In FIG. 1a along (8), the position point P of the optical sensor 8 x (8) Imaging Chief ray F at the focal pointx (8) and related Imaging Axis A x (8), and the position point P y (8) Imaging Chief ray F at the focal point y (8) and related Imaging Axis A y (8) is shown.

[0043] In this specification, we refer to a set of different objects as “first object” → “last object”, and P1(8) → P n (8) determines the limit positions P1(8) and P n (8), where n can be any integer greater than 1.

[0044] The point-like output element 4.1 of the device in embodiment 100 may advantageously be an LED-based light source emitting white light.

[0045] In the embodiment 100, by adjusting the distance of the output element 4.1 from the illumination optical system 11, the displacement of the output element 4.1 from the optical axis of the illumination optical system 11, the distance of the optical sensor 8 from the imaging optical system 13, and the inclination of the optical sensor 8 from the optical axis of the imaging optical system 13, the optical system is able to change the illumination focal point of the position point P1(4.1) of the output element 4.1 and the different position point P1(8)→P n (8) Imaging In each coincident focal point, one illumination focal point of the position point P1 (4.1) is aligned with one position point P1 (8) → P n (8) Imaging In other words, the coincident focal points are associated with a dominant wavelength common to the coincident focal points. Furthermore, in order to measure different positions of the intersecting object 2, each of the illumination focal points of the position point P1 (4.1) of the output element 4.1 forming the coincident focal points is associated with a different dominant wavelength. Imaging Coordinate axis A1(8) → A n Position point P1(8) of optical sensor 8 along (8) → P n (8) Such ImagingA matching focal point is formed to match the focal point. Imaging Coordinate axis A1(8) → A n (8) and their axes Imaging The focal point is a different position point P1(8) → P n (8). Thus, there are advantageously a number of (various) coincident focal points formed from various illumination focal points of the position point P1 (4.1) of the output element 4.1, each of which has a different Imaging Coordinate axis A1(8) → A n Position point P1 of the optical sensor 8 located along (8) → P n (8) Imaging It can be aligned with the focal point.

[0046] In the embodiment 100, chromatic aberration in the vertical direction (axial direction) occurs due to the lens or lenses of the illumination optical system 11 and the imaging optical system 13. As a result, in the embodiment 100, in the virtual measurement space below the surface of the object 2, the red end component λ m (4.1),λ m (8) is focused, and correspondingly, above the object 2, the blue end components of light λ1(4.1), λ1(8) are focused. Imaging The blue ends of the spectrum, λ1(4.1) and λ1(8), are both in focus at the top of the virtual measurement space. Therefore, at the bottom of the measurement space (below the object 2 at height h1 in Figure 1a), the red end of the spectrum, λ m (4.1),λ m (8) is in focus. The height of the surface of the object 2 influences which components of the spectrum of the light directed at the object are reflected from the object. The color of the spectral components is not important in this embodiment, since the light signal reflected from the object 2 is advantageously detected by a black-white line or matrix light sensor 8 or a camera. However, wavelength information of this reflected light may also be utilized, as described later in this specification.

[0047] In the example of FIG. 1a, two different cases of heights h0 and h1 of the surface of the object 2 are illustrated. These surface layers scatter light. The intersection of the focal point coincident with the object 2 is illustrated from both heights shown. When the surface is at surface height h0, the object point 2.1 coincides with the coincidence point A1(S)A1 of wavelength λ2. y (R). This intersection is the P of the light sensor 8. y (R) are shown by the position points. When the surface is at surface height h1, the object point 2.2 coincides with the wavelength λ4 at the coincident point A1(S)A x (R). This intersection is the P of the light sensor 8. x Indicated by the location point (R).

[0048] FIG. 1b shows an example of a signal according to the embodiment of FIG. 1a received from a light sensor 8 of the device. FIG. 1b shows the intensity of light incident on the light sensor 8 as a function of the position of the location point of the light sensor 8. The local maximum signal h0(2.1) is detected by the object point 2.1 at height h0 of the object 2 (i.e. the focal point A1(4.1)A1 coincides with the object point 2.1). y Another local maximum signal h1 (2.2) is due to reflection from object point 2.2 at height h1 of object 2 (i.e., focal point A1 (4.1) A1 coincides with object point 2.2). x (8)) Advantageously, the position of the received local maximum signal is calibrated to correspond to a position according to the coordinate system 199.

[0049] In this device, the position of the local maximum received by the light sensor 8 and the position of the output element illuminated by the reflected light from the intersection of the focal points coinciding with the object point are calibrated to correspond to the position of the object 2 based on triangulation.

[0050] In this embodiment 100, lighting and Imaging Both are shown at symmetric angles with respect to the surface of the object 2. However, the invention is not limited to such a symmetric measurement situation and it is possible to vary the illumination and Imaging The angles of the lights can be different. ImagingAlthough the angle between varies, nevertheless, at each coincident focal point that defines the measurement space, there is a common dominant wavelength associated with each illumination focal point. Imaging A coincident focal point can be formed so that the focal points are coincident.

[0051] In the embodiment 100, the output element 4.1 is on the optical axis of the illumination optics 11. However, the position of the illumination and output element 4.1 is not limited to this position, and the output element 4.1 can also be located in other positions, as will be seen in further embodiments.

[0052] In embodiment 100, the spectrum of light provided by output element 4.1 need not be continuous, but may for example comprise a sequence of different wavelengths or a sequence of discontinuous light in different ways.

[0053] Turning to the second embodiment 200, various features of embodiment 200 are generally believed to be similar to those of embodiment 100 and will not be repeated here to avoid unnecessary redundancy.

[0054] However, the embodiment 200 differs from the embodiment 100 in that the lens or lenses of the illumination optics 11 and the imaging optics 13 are provided with spherical aberration. In that case, the optics may have different illumination focal points θ1(4.1)→θ m (4.1) and Imaging Focal point θ1(8)→θ m (8). The rays propagating through the central optical system have a focal point θ 1 that is closer to the center than the rays propagating around the outer edge of the lens. 1→m (4.1),θ 1-m (8) Move away.

[0055] This is done by dividing the output element 4.1 into two different numerical apertures θ1(4.1) and θ mAn illumination optics 11 having (4.1) is illustrated in FIG. 2b. An exemplary lens of the illumination optics 11 is configured to form a number of different illumination focal points from a location point P1 (4.1) that are located at different distances from the illumination optics 11 along the illumination coordinate axis A1 (4.1) at different numerical apertures of the lens or lenses of the illumination optics 11. Thus, the imaging optics 13 includes the same property. Also, Imaging In this case, if spherical aberration is provided, the imaging optical system 13 will move from the position point P1(8) of the optical sensor (8) to P n (8) From each of them: Imaging Coordinate axis A1(8) → A n A plurality of different imaging optical systems are arranged along the optical axis (8) at different distances from the imaging optical system (13). Imaging The focal points are configured to be formed by different numerical apertures of the lenses or lenses of the imaging optics 13. In this embodiment, measurements can be realized either at one wavelength, at various wavelengths or at white light.

[0056] In the embodiment 200, the measurement is based on the spherical aberration of a lens or lenses, or generally of optical components, of the illumination optics 11 and the imaging optics 13. The coincident focal points can be arranged similarly as illustrated in the example of FIG. 1a for the embodiment 100. Thereby, in the virtual measurement space below the surface of the object 2, the component θ formed at the smallest angular aperture of the lens or lenses of said optics is m (4.1),θ m (8), and correspondingly, the components θ1(4.1), θ1(8) formed by the lens or the maximum angular aperture of the lens of the optical system are focused above the object 2. Now, when using spherical aberration, at each coincident focal position, one illumination focal point of the position point P1(4.1) of the output element 4.1 and one position point P1(8) → P of the optical sensor 8 are focused on the object 2. n (8) Imaging Since the positions of the focal points are the same (i.e., coincident), these coincident focal points θ 1→m (4.1) and θ 1→m (8) is formed by the correlated (equal) optical apertures of the illumination optics (11) and imaging optics (13) that produce a local maximum on the photosensor 8 when this coincident focal point intersects with the object 2.

[0057] The third embodiment 300 differs from embodiment 200 in that the lens or lenses of the illumination optical system 11 and the imaging optical system 13 are provided with astigmatism. In this case, the optical system is adapted to have different focal regions φ1(4.1)→φ, so that at different distances from the optical system, the focal point from a certain position appears intermediate between a line or an ellipse rather than a point. m (4.1) and φ1(8) → φ m (8). Due to astigmatism, the tangential and sagittal rays are refracted in different optical systems, and the two rays intersect with the corresponding principal rays at corresponding position points at different focal regions in the area of ​​the illumination optical system 11 or the imaging optical system 13. These tangential and sagittal rays are focused Imaging No point is obtained, but rather a continuous series of elongated convergences ranging from linear to elliptical depending on the distance from the optical system.

[0058] This is a case where, for the illumination optical system 11, three illumination focal regions φ1(4.1), φ2(4.2), and φ3(4.3) are formed from a position point P1(4.1) of the output element 4.1 by different optical apertures of the illumination optical system 11. n (4.1) and φ m (4.1) is shown in Fig. 2c. Therefore, the imaging optics 13 includes the same property.

[0059] In embodiment 300, the measurement is based on the astigmatism of the lenses or lenses of the illumination optics 11 and the imaging optics 13. The coincident focal points can be arranged in a similar manner as illustrated in the example of FIG. 1a for embodiment 100. This allows the illumination and Imaging The most elliptical illumination and Imaging focal region φ m (4.1),φ m (8) is located in the virtual measurement space below the surface of the object 2, and the most linear focal area φ m (4.1),φ m(8) is focused on the object 2. Now, when astigmatism is utilized, in each of the corresponding focal regions, one illumination focal region φ of the position point P1(4.1) of the output element 4.1 is 1→m (4.1) is the position point P1(8) → P n (8) Imaging Focal area φ 1→m (8) is formed with the correlated optical apertures of the illumination optics 11 and the imaging optics 13. In this embodiment, measurements can be achieved with either one wavelength, various wavelengths, or white light.

[0060] 3 shows a measurement arrangement according to an embodiment 400. This embodiment differs from the previous embodiments in that it includes two linear output elements, designated by reference numbers 4.1 and 4.2, and a matrix light sensor, designated by reference number 8b. In the matrix light sensor 8b, the position point K1 (8b) → K n (8b) and P1(8b) → P n Since the intensities of reflected light from the object 2 in two different directions, i.e., (8b), can be measured, a rectangular coordinate system (i.e., an orthogonal coordinate system) can be formed from said position points of the optical sensor 8b. The illumination optical system 11 and the imaging optical system 13 can include any optical aberrations in the manner described above. Thus, different components of light from the position point P1(4.1)→Pn(4.1) of the output element 4.1 and the position point P1(4.2)→Pn(4.2) of the output element 4.2 are focused at different distances from the illumination optical system 11. The imaging optical system 13 can therefore focus the light at position points K1(8b)→K1(8b) at different distances from the imaging optical system 11. n (8b) and P1(8b) → P n (8b) configured to form a focal point or area.

[0061] The illumination optics 11 and the imaging optics 13 are arranged in the manner described above to form coincident focal points or coincident focal regions. Now, if both output elements 4.1 and 4.2 have a linear geometry, it is possible for the illumination optics 11 and the imaging optics 13 to place coincident focal points or focal regions on lines of different depths, the lines being formed from different position points of both output elements and different position points of the light sensor 8b.

[0062] When the illumination optical system 11 and the imaging optical system 13 utilize longitudinal chromatic aberration, the illumination focal points and the dominant wavelengths are common and coincident at different depths in the virtual measurement space. Imaging Correspondingly, when spherical aberration is utilized, there will be lines of coincident focal points at different depths, each of which corresponds to a coincident illumination focal point formed by corresponding correlated (equal) optical apertures in the illumination optics 11 and imaging optics 13. Imaging Correspondingly, if astigmatism is utilized in the illumination optics 11 and imaging optics 13, there will be lines of coincident focal regions at different depths, and each corresponding line of coincident focal regions will have a corresponding illumination focal region and corresponding focal region associated with the same shape. Imaging A focal area of ​​the illumination light source is formed by a focal area of ​​the illumination light source. Imaging The focal regions are formed by corresponding correlated (equal) optical apertures of the illumination optics 11 and the imaging optics 13 .

[0063] In FIG. 3, when the illumination optical system 11 and the imaging optical system 13 utilize longitudinal chromatic aberration, the intersection points of the surface of the object 2 with the lines of coincident focal points denoted as L1a and L1b are illustrated. L1a is the position point P1 (4.1) → P n (4.1) Illumination focal point and position point P1(8b) of optical sensor 8b → P n (8b), K1(8b) → K n (8b) Imaging L2b is the reflection line due to the intersection of the focal point with an object point on the surface located on the line formed by the focal point. n (4.2) Illumination focal point and position point P1(8b) of optical sensor 8b → Pn (8b), K1(8b) → K n (8b) Imaging The reflection line is the intersection of the focal points with an object point on the surface located on the line formed by the focal points. In Figure 3, there is one intersection point from each of L1a and L2b, which coincides with focal point A. z (4.1)A xy (8) and other intersections coincide with focal point A z (4.2)A xy (8) is illustrated separately. z Chief ray F for (4.1) z Illumination coordinate axis A associated with (4.1) z One of the illumination focal points along (4.1) and the position point P of the light sensor 8b x (8b)K y Chief ray F for (8b) xy Associated with (8b) Imaging Coordinate axis A xy In line with (8b) Imaging Matching focal point A from one of the focal points z (4.1)A xy (8) is formed. The position point P of the output element 4.2 is z Chief ray F for (4.2) z Illumination coordinate axis A associated with (4.2) z One of the illumination focal points along (4.2) and the position point P of the optical sensor 8b x (8b)K x Chief ray F for (8b) xx Associated with (8b) Imaging Coordinate axis A XX In line with (8b) Imaging Matching focal point A from one of the focal points z (4.2)A XX As with any other coincident focal points according to this disclosure, each of the multiple coincident focal points of embodiment 300 is a specific coincident illumination focal point and Imaging Each associated with the same wavelength of the focal point.

[0064] Matching focal point A z (4.1)A xyThe surface of object 2 intersects with the output element position P z (4.1) is reflected, and part of the reflected light reaches the position point P of the optical sensor 8b. x (8b)K y (8b) can generate local maxima in the reflection data collected and formed at the focal point A. z (4.2)A xx The surface of object 2 intersects with the output element position P z (4.2) is reflected, and part of the reflected light reaches the position P of the optical sensor 8b. x (8b)K x A local maximum can be generated for the reflectance data collected and formed on photosensor 8b. Similarly, other intersections of L1a and L1b also generate local maxima as shown by the corresponding lines on photosensor 8b.

[0065] In various embodiments, the device comprises a plurality of linear or point-like output elements 4.1→4.n or a combination thereof.

[0066] In an embodiment including various output elements, the illumination optics 11 may include position points P1→P for each of the output elements 4.1→4.n. n Each light is aligned along the corresponding illumination coordinate axis A1→A n Each of these axes corresponds to a corresponding position point P1→P of a corresponding output element 4.1→4.n. n The corresponding chief ray F1→F of the illumination optical system 11 n The corresponding chief ray F1→F n are mutually related to a plurality of illumination focal points or focal regions collected from corresponding position points P1→Pn of corresponding output elements 4.1→4.n. n The same corresponding illumination coordinate axis A1→A nEach of the illumination focal points or focal regions along the line differs from one another at least in dominant wavelength or shape and / or is formed using a different optical aperture of the illumination optics 11.

[0067] Furthermore, the illumination optics 11 and the imaging optics 13 are configured to form a plurality of coincident focal points or focal regions, the same corresponding illumination coordinate axis A1→A for each of the output elements 4.1→4.n. n Each of the various focal points or focal regions from the plurality of illumination focal points or focal regions along Imaging Positioned along the coordinate axis A1(8) → An(8) Imaging The illumination coordinate axis A1 → A2 for each of the output elements 4.1 → 4.n coincides with a corresponding focal point or focal area with the focal point or focal area. n The direction of Imaging Coordinate axis A1(8) → A n Different from the direction of (8).

[0068] In various embodiments, the longitudinal chromatic aberration is determined by the position points P1 to P2 of the output elements 4.1 to 4.n. n The light from each of these is reflected by the corresponding illumination coordinate axis A1 → A n , which are utilized by the illumination optics 11 to focus illumination at a plurality of illumination focal points located at different distances from the illumination optics 11 along the position points P1→P n The corresponding chief ray F1→F of the illumination optical system 11 n By relating it to the same lighting coordinate axis A1 → A n Each illumination focal point along the line is different in dominant wavelength. Correspondingly, the position point P1(8) → P n From each of (8), the corresponding position point P1(8) → P n (8), the corresponding chief ray F1(8) → F n (8) Corresponding correspondence to Imaging Coordinate axis A1(8) → A n (8) along the imaging optical system 13 at different distances. Imaging The imaging optical system 13 is provided with longitudinal chromatic aberration so as to form a focal point. ImagingCoordinate axis A1(8) → A n (8) so that each focal point along the line is at a different dominant wavelength.

[0069] In those embodiments in which a matrix light sensor is used, each Imaging The coordinate axes, principal rays and position points may be related to the coordinate system of the position points of the light sensor 8b as described for embodiment 400.

[0070] If the illumination optical system 11 and the imaging optical system 13 are provided with longitudinal chromatic aberration, the respective focal points that coincide will be the illumination focal points associated with a common dominant wavelength. Imaging It consists of a focal point.

[0071] In various embodiments, the spherical aberration is calculated by the position points P1 →P n The light from each of the output elements 4.1 → 4.n is directed to the corresponding position points P1 → P n The corresponding chief ray F1→F of the illumination optical system 11 n The corresponding illumination coordinate axis A1→A n A plurality of light sources are positioned at different distances from the illumination optical system 11 along the Imaging The same illumination coordinate axis A1→A n Each illumination focal point along the axis is formed at a different optical aperture of the illumination optical system 11. Correspondingly, the position point P1(8)→P n From each of (8), the corresponding position point P1(8) → P n (8), the corresponding chief ray F1(8) → F n (8) Corresponding correspondence to Imaging Coordinate axis A1(8) → A n A plurality of imaging optical systems 13 are arranged at different distances along the optical axis (8). Imaging The imaging optical system 13 is provided with spherical aberration to form the focal point, so that the same Imaging Coordinate axis A1(8) → A n Each focal point along (8) is formed at a different optical aperture of the imaging optics 13.

[0072] When the illumination optics 11 and the imaging optics 13 are provided with spherical aberration, the respective simultaneous focal positions are formed at the associated optical apertures of the illumination optics 11 and the imaging optics 13 .

[0073] In various embodiments, the astigmatism is determined by the position points P1→P n The light from each of the output elements 4.1 → 4.n is directed to the position points P1 → P n The corresponding chief ray F1→F of the illumination optical system 11 n The illumination optical system 11 is provided to focus the light onto a plurality of illumination focal regions of different shapes positioned at different distances from the illumination optical system 11 along corresponding illumination coordinate axes A1→An associated with the same illumination coordinate axis A1→A. n Each illumination focal region along the axis is formed at a different optical aperture of the illumination optics 11. Correspondingly, the astigmatism is n (8), the corresponding position point P1(8) → P n (8), the corresponding chief ray F1(8) → F n (8) Corresponding correspondence to Imaging Coordinate axis A1(8)>A n (8) along the imaging optical system 13 at different distances. Imaging The same is provided in the imaging optical system 13 to form the focal region. Imaging Coordinate axis A1(8) → A n Each focal region along (8) is formed at a different optical aperture of the imaging optics 13.

[0074] When the illumination optics 11 and the imaging optics 13 are provided with astigmatism, each of the coincident focal regions consists of an illumination focal region and an imaging focal region associated with a common shape and formed by correlated optical apertures of the illumination optics 11 and the imaging optics 13.

[0075] 4a and 4b are examples of the spectral content of collected light, showing the intensity (I) of collected light as a function of wavelength (λ) when utilizing longitudinal chromatic aberration in the illumination optics 11 and imaging optics 13. FIG. 4b is an example of a spectrum from the location of the photosensor 8 collecting reflected light occurring at the intersection of the object 2 with one of the focal points coincident with the focal point. The spectrum of FIG. 4b shows the intensity (I) of collected light at a particular wavelength λ. p There is a very clear maximum at , which indicates that a particular wavelength of light is reflected from the intersection of the focal points coinciding with object 2, and information about the optical properties of object 2 is revealed. On the other hand, the wavelength λ of which the measured light of the intersection is mainly composed p The intensity of is strongly attenuated in the spectrum of light collected from a location point on the light sensor 8 if that location point is close to a location point on the light sensor 8 that collects light from the intersection. The spectrum of light collected from such a location point will have a wavelength λ that is mainly concentrated at the maximum in the spectrum of the reflected light from the intersection, as shown in FIG. 4a. p There is a very clear attenuation at the location.

[0076] In measuring optical properties, the intensity of a local maximum at a certain object point of the measured object is determined. The intensity of the local maximum is proportional to the reflectance of the object point at which the local maximum was determined. Furthermore, if the target point is on the object surface, determining the intensity of the local maximum can provide information about the reflectance of the surface.

[0077] If the illumination optics 11 and imaging optics 13 make use of longitudinal chromatic aberration, it is possible to calibrate the wavelength of the local maximum associated with the position of the coincident focal point in the measurement space, so that by measuring the position of the object, such as the surface height, one can obtain information about the reflectance of the object at a particular known wavelength from that position. Furthermore, if the device contains different output elements, there are different measurement geometries, which allow the object to be measured simultaneously using a variety of wavelengths.

[0078] Figure 5a shows an embodiment 500 including two point-like output elements, indicated with reference numbers 4.1 and 4.2. The embodiment 500 further exploits longitudinal chromatic aberration in the illumination optics 11 and imaging optics 13, whereby a number of coincident focal points are formed at different heights, each of which consists of an illumination focal point and an imaging focal point associated with a common dominant wavelength as described above. Figure 5a shows an illumination focal point formed from two position points P1 (4.1) and P1 (4.2) of the output element and two position points P1 (4.3) and P1 (4.4) of the optical sensor 8 with five different wavelengths λ1 to λ5 at a depth in the z direction. w (8) and P q (8) Imaging The illumination focal points and the Imaging Four different coincident foci consisting of parts of the focal point, namely, A1(4.2)A q (8) for λ1, A1(4.1)A q (8) is λ2, A1(4.2)A w (8) for λ2 and A1(4.1)A W (8) is illustrated as λ4.

[0079] FIG. 5a shows two different possible surface heights h a and b The height of the surface of the object 2 is h a h a The one coincident focal point that intersects at is one of the illumination focal points formed from the position point P1 (4.1) of the output element 4.1 and the position point P w (8) and one of the illumination focal points formed from A1(4.1)A q (8). a Another coincident focal point intersecting at is one of the illumination focal points formed by the position point P1 (4.2) of the output element 4.2 and the position point P of the optical sensor 8. w (8) Imaging A1(4.2)A consists of one of the focal points w (8). Each of these intersections gives rise to a local maximum in the intensity distribution as shown in FIG. 5b1. w (8) The local maximum value ha (2.2a) is the focal point A1 (4.1) A that coincides with the object point 2.1a q (8). Correspondingly, the position point P on the sensor 8 is q (8) The local maximum value h a (2.1a) is the focal point A1 (4.2) A that coincides with the object point 2.2a w This is the result of the intersection of (8).

[0080] The surface height of object 2 is h b When the focal point A1(4.1)A coincides with the object point 2.1b, w The intersection of the surface and the virtual measurement space occurs at position (8). This intersection is the same position point P of the optical sensor 8 as shown in FIG. w (8), the focal point A1 (4.2) A w (8). To determine the location of the intersection, and thus the location of the object point, the apparatus of embodiment 500 is configured to resolve from which location point of the output element, either 4.1 or 4.2 in this example, the light collected from the reflection of the intersection point originates. Because the local maximum of the reflected light from the intersection with one of the focal points coincident with object 2 is primarily of one dominant wavelength, the apparatus can determine from which output element (either 4.1 or 4.2 in this example) the light of the local maximum originates by determining the wavelength of the local maximum. This can be done by resolving the different location points P1 → P of output elements 4.1 → 4.n. n For each position of the coincident focal point associated with a certain wavelength λ 1→m Thus, in the embodiment of FIG. 5a, the position point P w The local maximum value corresponding to (8) corresponds uniquely to the position point P1 (4.2) of the output element 4.2. Therefore, the position point P w The local maximum corresponding to (8) corresponds uniquely to the position point P1 (4.1) of the output element 4.1.

[0081] In one embodiment, the light sensor 8 is an RGB camera so that the wavelength of the local maximum can be determined.

[0082] In an embodiment comprising two or more output elements 4.1→4.n and exploiting the longitudinal chromatic aberration of the illumination optics 11 and the imaging optics 13, the device is configured to determine the wavelength of a local maximum of the light intensity distribution detected by the light sensor 8 and to identify from which output element 4.1→4.n the light of the local maximum is provided to determine the position of the intersecting object point 2.1. The light sensor 8 may be an RGB camera configured to determine the wavelength of the local maximum.

[0083] In various embodiments, the light sensor 8 may be a CCD or CMOS sensor, or the like.

[0084] Also, the measuring device, Imaging It is also called a measuring device, triangulation device, or optical device.

[0085] The output elements of the device may also be called illumination elements or light source elements.

[0086] The distribution of coincident focus positions defines a measurement space for determining the positions of object points 2.1 of the object 2 to be measured.

[0087] In an embodiment, the positions of object points of the object (2) to be measured are determined for at least one of the x, y or z coordinates of an xyz coordinate system associated with the distribution of coincident focal points.

[0088] Fig. 6a shows an embodiment 600 of the thickness measurement of an object 2d that is at least partially transparent or translucent for light directed at the object (2). The object 2d comprises two surfaces, between which is the thickness D of the object at a certain position. In the example of Fig. 6a, the first surface is denoted as 2f and the second surface as 2s. The embodiment 600 can be used with any optical aberration in the illumination optics 11 and the imaging optics 13, and the intersection position of the object 2d is measured in the manner described above.

[0089] Fig. 6b shows an example of a signal according to the embodiment of Fig. 6a received from the optical sensor 8 of the device. 2f (2.1s) is the reflection from object point 2.1f on upper surface 2f (i.e., focal point A1 (4.1) A1 coincides with object point 2.1f). b (8)). Another local maximum signal h 2s (2.1f) is the object point 2.1s on the lower surface (i.e., the focal point A1 (4.1) A coincides with the object point 2.1s). a The thickness D of the object at the positions of these object points 2.1f, 2.1s can be determined from the distance D' of the local maximum if the refractive index of the measured object and the measured geometry are known.

[0090] In one embodiment, the thickness between a first surface (2f) and a second surface (2s) of the object (2), which is at least partially transparent or translucent to light directed towards the object (2), is determined from the position difference between a local maximum of the intensity distribution of the detected light on the light sensor 8 resulting from the first surface (2f) and a local maximum of the intensity distribution of the detected light on the light sensor 8 resulting from the second surface (2s).

[0091] FIG. 7a shows an example of the intensity distribution on a matrix camera type sensor 8 when measuring the surface of an object 2c to be measured according to the invention. Areas of high illumination are shown as bright areas. In FIG. 7a, a single Imaging Each of these horizontal regions in the frame that are brighter than the background is the result of a simultaneous intersection of the surface with a different line containing different coincident focal points that are measured in the manner described above. This exemplary measurement consists of the illumination of 27 linear output elements. In Fig. 7a, the discontinuities in the lines are due to the variation in surface shape depending on the object 2c being measured. The 27 lines are each measured simultaneously from a different surface portion of 2c. In Fig. 7b, the 27 lines are measured simultaneously from a different surface portion of 2c. Imaging The areas are indicated by dashed lines. Figure 7c shows a schematic side view of object 2c illustrating the measured surface shape.

[0092] FIG. 8 shows a flowchart of a method according to an exemplary and non-limiting embodiment 800 . The method comprises the steps of: Step 802: Providing optical illumination and optical detection of an object from different directions; Step 804: Detecting light reflected from an object; Step 806: determining the position of the object point; and - Step 808: determining optical properties.

[0093] At 802, light is focused from each of the location points of each of the output elements onto illumination focal points or focal regions located at different distances from the illumination optics along corresponding illumination coordinate axes associated with corresponding chief rays of the illumination optics for the corresponding location points of the corresponding output elements. The corresponding chief rays are mutual for the multiple illumination focal points or focal regions focused from the corresponding location points of the corresponding output elements. Each of the illumination focal points or focal regions along the same corresponding illumination coordinate axis for the corresponding location points of the corresponding output elements differ from each other at least in dominant wavelength or shape and / or are formed with different optical apertures of the illumination optics.

[0094] Further, at 802, a corresponding chief ray of the imaging optics is associated from each of the location points of the light sensor to the corresponding location point of the light sensor. Imaging Several different points are positioned at different distances from the imaging optics along the coordinate axis. Imaging A focal point or focal region is formed. Corresponding chief rays are formed from corresponding position points of the light sensor. Imaging It is mutual with respect to the focal point. Imaging Along the coordinate axis Imaging Focus point or Imaging Each of the regions differs from the others in at least dominant wavelength or shape and / or is focused at a different optical aperture of the imaging optics.

[0095] Further, at 802, each of the various focal points or focal regions from the plurality of illumination focal points or focal regions along the same corresponding illumination coordinate axis for each of the output elements is adjusted to a different focal point or focal region. Imaging Positioned along a coordinate axis ImagingA plurality of coincident focal points or focal regions are formed so as to coincide with the focal point or focal region. The illumination coordinate axis of each output element is oriented as follows: Imaging Each of the coincident focal points or focal regions is an illumination focal point and a focal region associated with a common dominant wavelength or shape. Imaging It consists of a focal point or focal region and / or is formed by the correlated optical aperture of the illumination optics and the imaging optics.

[0096] At 804, intensity values ​​of light collected from the object by the imaging optics are detected.

[0097] In 806, the position of the object point is determined from the position of the local maximum of the intensity distribution of the detected light.

[0098] At 808, an optical property of the object point is determined from the intensity or wavelength of a local maximum in the intensity distribution of the detected light.

[0099] Steps 806 and 808 are optional steps that may accomplish either 806 or 808, or alternatively, both 806 and 808.

[0100] It will be apparent to one skilled in the art that the measurement process may be looped back to step 802, thereby creating a continuous measurement process.

[0101] A method according to an embodiment includes determining a thickness between a first surface and a second surface of an object that is at least partially transparent or translucent to light directed at the object from a position difference between an object point on the first surface of the object and an object point on the second surface of the object.

[0102] In the method according to the embodiment, the illumination optics utilizes longitudinal chromatic aberration to focus each of the illumination focal points along the same corresponding illumination coordinate axis for corresponding position points of corresponding output elements that differ from each other at least in the dominant wavelength. Imaging Along the coordinate axis, ImagingEach focal point or focal region is brought into focus.

[0103] In a method according to an embodiment, the method includes a step in which the illumination optics focuses each of the illumination focal points along the same corresponding illumination coordinate axis for corresponding position points of corresponding output elements at different optical apertures of the illumination optics by using spherical aberration. Further, the imaging optics focuses each of the illumination focal points along the same corresponding illumination coordinate axis for corresponding position points of corresponding output elements at different optical apertures of the imaging optics by using spherical aberration. Imaging Along each coordinate axis Imaging Focus on the focal point.

[0104] In a method according to an embodiment, the method includes a step in which the illumination optics focuses respective illumination focal regions along the same corresponding illumination coordinate axis for corresponding position points of corresponding output elements having different shapes by using astigmatism. Further, the imaging optics focuses respective illumination focal regions along the same corresponding illumination coordinate axis for corresponding position points of corresponding output elements having different shapes by using astigmatism. Imaging Along the coordinate axis Imaging Each of the focal regions is brought into focus.

[0105] In a method according to an embodiment, the method comprises arranging a photosensor substantially perpendicular to an optical axis of the imaging optics and arranging a plurality of output elements in a plane, said plane forming an oblique angle with respect to the optical axis of the illumination optics, and preferably said plurality of output elements comprising a plurality of linear output elements.

[0106] Figures 9 and 10 show a further embodiment 900. In this embodiment, the device includes two or more output elements. In Figure 9, the device 900 includes five output elements 4.1 → 4.5, but the number of output elements may vary depending on the application. Furthermore, the output elements can be linear or point output elements or a combination thereof, as described elsewhere in this specification. If the output elements 4.1 → 4.5 are linear output elements, they extend in the x-direction in the coordinate system 199 of the device.

[0107] The output elements are arranged in alignment with one another on a plane 5. In this embodiment 900, the plane 5 containing said two or more output elements is arranged at an oblique angle α with respect to the optical axis 11' of the illumination optics 11. The light sensor 8, which can be either a line sensor or a matrix sensor depending on the application, is arranged at a substantially perpendicular angle β with respect to the optical axis 13' of the imaging optics 13, as shown in Figure 9. If the light sensor 8 is a line sensor, it is advantageously arranged in the YZ-plane, as shown in Figure 9.

[0108] By providing longitudinal chromatic aberration to the illumination optical system 11 and the imaging optical system 13, the illumination focal point and the position point of each output element 4.1 → 4.5 are the same as in the previous embodiment. Imaging Focal points and their illumination focal points and Imaging A coincident focal point formed from the focal points is provided. Alternatively, forming focal points and areas with spherical aberration or astigmatism, or any combination of the three, can also be used in the apparatus 900.

[0109] In the device 900 of FIG. 9, the angle β is used to determine the angle formed by the different position points P1(8)→P8(n) of the optical sensor 8. Imaging The focal points are arranged on a set of focal planes FP8 (λ1→λm) that are inclined at an angle of γ with respect to the Y direction of the coordinate system 199. The illumination focal points formed from the different position points of each output element 4.1→4.5 and a certain one having the same wavelength are arranged on the same focal plane FP8 (λ1→λm). Imaging By tilting the plane 5 at an angle β so that the focal point coincides with the focal point, Imaging A coincident focal point between the focal points of the output elements is formed (i.e., coincident) such that the illumination focal point of each output element is at least partially at a different height (i.e., at a different Z coordinate) compared to the coincident focal points associated with the other output elements. ImagingA coincident focal point is formed so as to coincide with the focal point. This is shown in FIG. 9, where a series of coincident focal points related to illumination focal points along the same illumination axis (principal ray) formed from one position point from each output element 4.1, 4.2, 4.3, 4.4, and 4.5 are illustrated as lines and are denoted S4.1(λ1→m), S4.2(λ1→m), S4.3(λ1→m), S4.4(λ1→m), S4.5(λ1→m). These coincident focal point lines are at least partially arranged at different heights in the Z direction. An illumination focal point lying between the focal plane FP8(λ1) of the shortest wavelength λ1 and the focal plane FP8(λm) of the longest wavelength λm is Imaging A coincidence point is formed from the focal points. As a result, a distribution of a plurality of coincident focal points is formed between the focal planes FP8(λ1) and FP8(λm), with FP8(λ1) being the focal plane closest to the imaging optics 13 and FP8(λm) being the focal plane furthest from the imaging optics 13, respectively. In the distribution of coincident focal positions, there are spatially separated lines S4.1(λ1→m), S4.2(λ1→m), S4.3(λ1→m), S4.4(λ1→m), and S4.5(λ1→m) of coincident focal positions associated with the different output elements 4.1, 4.2, 4.3, 4.4, and 4.5, respectively. Each of these lines contributes to the total depth of field of coincident focal points in the Z direction. This means that the total usable Z range of the measurement space defined by the coincident focal points is larger than if there was only one output element 4.1 or if all lines of coincident focal points associated with different output elements were arranged to have similar Z coordinates.

[0110] FIG. 10 shows a magnified view of the measurement space of FIG. 9. In FIG. 10, the total Z range of the measurement space of the device 900 is depicted as Ztot. The coincident focal point with the highest Z coordinate is located on the line S4.5 (λ1→m) and has the dominant wavelength λ1. The lowest coincident focal point (i.e., has the lowest Z coordinate) of the measurement space of the device 900 of FIG. 9 and FIG. 10, respectively, is located on the line S4.1 (λ1→m) with the dominant wavelength λm. ΔZ(4.1), ΔZ(4.2), ΔZ(4.3), ΔZ(4.4), and ΔZ(4.5) respectively indicate the measurement (sub) range in the Z direction defined by the coincident focal points on the lines of the coincident focal points S4.1 (λ1→m), S4.2 (λ1→m), S4.3 (λ1→m), S4.4 (λ1→m), and S4.5 (λ1→m). These measurement (sub)ranges may overlap in the Z direction as shown, so that Ztot for device 900 consists of these (sub)ranges.

[0111] 9 and 10 also illustrate an object 2 having a plane. In the figures, there are two intersections between the surface of the object 2 and coincident focal points with different Y coordinates and different dominant wavelengths. One intersection occurs with the coincident focal point of A1(4.2)Aq(8) on the line S4.2(λ1→m). A1(4.2)Aq(8) is a coincident focal point where the illumination focal point A1(4.2) formed from the position point P1(4.2) of the output element 4.2 and the illumination focal point Aq(8) formed from the position point Pq(8) of the light sensor 8 coincide. Another intersection shown in FIG. 9 and FIG. 10 occurs at the coincident focal position of A1(4.1)Aw(8) on the line S4.1(λ1→m), respectively. A1(4.1)Aw(8) is a coincident focal point obtained by matching the illumination focal point A1(4.1) formed from the position point P1(4.1) of the output element 4.1 with the illumination focal point Aq(8) formed from the position point Pq(8) of the optical sensor 8.

[0112] As in other embodiments of the present disclosure, in the apparatus 900 each output element 4.1→4.n is separately calibrated such that each position of the coincident focal point associated with a different position point P1→Pn of the output element 4.1→4.n corresponds to a certain wavelength λ1→m and a certain position point on the light sensor 8.

[0113] In the device 900, the focal point of coincidence between the focal plane FP8(λ1) of the shortest wavelength λ1 and the focal plane FP8(λm) of the longest wavelength λm is limited. The limiting of the coincidence between these focal planes can be done in various ways. For example, a (bandpass) filter can be placed in front of the output elements 4.1→4.n to limit the light emitted therefrom. Alternatively or additionally, a (bandpass) filter can be placed in front of the light sensor 8 to limit the light detected there. Alternatively, the output elements 4.1→4.n can be configured to emit only at wavelengths that are in a limited range from λ1 to λm.

[0114] Since the total Z measurement range of the device 900 consists of sub-ranges associated with the individual output elements, the total Z measurement range can be controlled by the number of output elements 4.1→4.n.

[0115] Also, by adjusting the spacing of adjacent output elements, it is possible for the coincident focal points to cover the entire Z range of the measurement space, and further, it is possible to adjust the spacing of adjacent output elements such that there are at least two different coincident focal points for each height position (i.e., Z coordinate) in the measurement space.

[0116] There are various advantages that may be realized with the apparatus 900. One advantage is that the imaging optics 13 can be simplified and the detected light is arranged to reach the sensor surface at a substantially right angle, Imaging It is also possible to improve the quality of the

[0117] Another advantage is that the illumination and imaging optical system can form a coincident focal point even if the numerical aperture is relatively large. This allows measurement of glossy or inclined surfaces. In addition, with a general laser triangulation 3D sensor that irradiates the object to be measured with a parallel light source laser light, all the light is already focused on the glossy surface that is visually inclined. Imaging 3D measurements of tilted glossy surfaces are not possible as they fall outside the aperture.

[0118] Another advantage is that the overall Z measurement range of the device can be increased without increasing the longitudinal chromatic aberration of the imaging and illumination optics, since the measurement range can be increased by increasing the number of output elements. As a result, the Z measurement range of the device can be increased when the output elements (i.e., light sources) are configured to emit light in a narrow wavelength band. For example, the longitudinal chromatic aberration of the imaging optics can be as short as 200 μm to provide a measurement Z range of, say, 4 mm.

[0119] For example, the output elements of a device can be configured to emit only blue light, and thus the longitudinal chromatic aberration of the optics of such a device can be tuned for those blue wavelengths.

[0120] Alternatively or additionally to longitudinal chromatic aberration, spherical aberration and / or astigmatism can be used in the optical system of the device 900 as described herein. In these cases, the device can be realized similarly to the embodiment of Fig. 9, Fig. 10, which uses longitudinal chromatic aberration to form a measurement space defined by a distribution of coincident focal points. The coincident focal points when using spherical aberration, and the coincident focal areas when using astigmatism, can be formed as described herein above. Furthermore, the limitation of the coincident focal points or areas between the lowest and highest focal planes of the optical sensor 8 can be done by limiting the optical aperture of the optical system and / or by the design of the optical system, as will be understood by those skilled in the art.

[0121] As with other embodiments of the present disclosure utilizing spherical or astigmatism, each output element 4.1 → 4.n of the apparatus can be separately calibrated such that each position of a coincident focal point or area associated with different position points P1 → Pn of the output elements 4.1 → 4.n is calibrated to correspond to a certain correlated optical aperture of the illumination optics and imaging optics and a certain position point on the optical sensor 8.

[0122] In an embodiment, the optical sensor 8 is a line scan camera or a matrix camera arranged substantially perpendicular to the optical axis 13 of the imaging optical system 13, and the multiple output elements 4.1 → 4.n are arranged on a plane 5 which forms an oblique angle with the optical axis 11' of the illumination optical system 11.

[0123] To obtain the surface shape or topography of the measured object, it is necessary to scan the object through the measurement space of the device. The surface shape can then be created as a reconstruction of the position measurements (e.g. height and Z coordinate) of the individual object points of the object 2. If a 3D measurement of the object is desired, the device advantageously comprises at least one linear element 4.1→4.5. The design of the device, which concerns how many and what type of output elements of 4.1→4.5 it comprises, depends on the application. Relevant for obtaining surface measurements is that the design of the output elements 4.1→4.5 of the device is such that all object points to be measured intersect with at least one coincident focal point or area.

[0124] Scanning measurements can be realized by moving (i.e. scanning) the object to be measured through a measurement space defined by coincident focal points or regions of the device. In such scanning, the object can be moved, for example, by a linear actuator or a conveyor. Alternatively, the object can be held in place when the scan is actually performed, by moving the device, for example on a rail or with the help of any other kind of moving mechanism or means, such that a target point on the surface of the object intersects at least one coincident focal point of the device.

[0125] The predetermined scan path and Z measurement sub-range of the apparatus can be adjusted so that each surface point of the object being measured passes through at least one coincident focal point, regardless of the Z position of the object point within the Z measurement range.

[0126] In an embodiment of the method in which the coincident focal points are formed utilizing the longitudinal chromatic aberration of the illumination optical system 11 and the imaging optical system 13, the method includes a step of moving the object 2 relative to the apparatus so that the object point 2.1 intersects with at least one coincident focal point, each of the at least one coincident focal point having a common dominant wavelength.

[0127] In an embodiment of the method in which the coincident focal points are formed utilizing the spherical aberration of the illumination optical system 11 and the imaging optical system 13, the method includes a step of moving the object 2 relative to the apparatus so that the object point 2.1 intersects with at least one coincident focal point, each of the at least one coincident focal point being formed at a correlated optical aperture of the illumination optical system 11 and the imaging optical system 13.

[0128] In an embodiment of the method in which the coincident focal points are formed using the spherical aberration of the illumination optics 11 and the imaging optics 13, the method comprises the steps of moving the object 2 relative to the apparatus such that the object point 2.1 intersects with at least one coincident focal region, each of the at least one coincident focal region being associated with an illumination focal region and a common shape. Imaging It consists of a focal region, which is formed by the relative optical apertures of the illumination optics 11 and the imaging optics 13 .

[0129] In Fig. 11, an example of determining intensity values ​​of light reflected from a point on an object 2 at different wavelengths is shown. The device 1000 in the figure corresponds to the device 900, and therefore the same or corresponding parts are indicated with the same reference numerals and duplicate text description is omitted. However, determining intensity values ​​of light reflected from a point on an object 2 at different wavelengths is not limited to the device 900. In fact, the same is possible in other embodiments of the present disclosure, for example the devices 400 or 500.

[0130] Determining the intensity values ​​of light reflected from a point on the object 2 at several different wavelengths with the device according to the invention can be done if the device comprises two or more output elements and if the coincident focal points are formed by exploiting the longitudinal chromatic aberration of the illumination optics 11 and the imaging optics 13. That is to say, there are several coincident focal points formed from two or more output elements. The coincident focal points are distributed such that there are lines of coincident focal points that are spatially separated from one another, each associated with a certain position point 4.1 → 4.5 of a certain output element. Furthermore, at the coincident focal points of each line, the coincident focal points are arranged in order of increasing wavelength with different distances from the illumination optics 11 and different heights (i.e. Z coordinates).

[0131] Fig. 11 illustrates the scanning of an object 2 through a measurement space defined by coincident focal points of the device 1000. In the figure, reference numerals t1, t2 and t3 indicate different time instances of intersection of the same object point o with different coincident focal points of the measurement space. The scanning direction is indicated by a long arrow from left to right above the movement path of the object 2. The path is indicated by a dashed line and labelled 1010.

[0132] When determining the intensity values ​​of the reflected light from an object point of the object 2 at multiple different wavelengths, the object point is scanned in the measurement space to intersect with different coincident focal points, each having a different dominant wavelength, and associated with a different output element compared to other intersecting coincident focal points. In Fig. 11, the scanning is realized such that the object point intersects with the coincident focal point of S4.3 (λ1 → m) at a first time instance t1, with the coincident focal point of S4.2 (λ1 → m) at a second time instance t2, and with the coincident focal point of S4.1 (λ1 → m) at a third time instance t3. The light reflected from each of these three intersection points is detected at different positions with corresponding intensities on the light sensor 8. In the figure, the positions of the detected light on the light sensor 8 are denoted Im(t1), Im(t2), and Im(t3), respectively.

[0133] As described herein, the light reflected from the intersection of the object point with the coincident focal point produces a local intensity maximum, the position of which on the light sensor 8 allows the position of the object point to be determined. The processor (not shown) of the device can also be configured to determine the wavelength of the reflected light from the intersection point corresponding to the emitted light to said coincident focal point involved in the intersection point. This can be determined based on the position of the local maximum and on information about which output element 4.1 → 4.5 provides the light of the local maximum. It is thus configured to determine the intensity value and the corresponding wavelength of the reflected light from an object point intersecting a coincident focal point. The information about which output element 4.1 → 4.5 provides the light of the local maximum can be obtained when the object 2 is moved through the measurement space in a predetermined path, whereby the coordinates of the moving object point or the scanning direction object are known at different time instances. This can for example be encoded in the means for realizing the scanning of the object 2.

[0134] Alternatively, the output elements emitting light associated with the intersecting coincident focal points can be implemented to be switched on and off in synchronism with the scanning of the object in order to know from which information the output elements 4.1→4.5 are providing the light of the local maximum.

[0135] As described herein, an apparatus using longitudinal chromatic aberration in its illumination 11 and imaging optics 13 to form coincident focal points can be calibrated such that each position of the coincident focal points associated with different position points P1→Pn of the individual output elements 4.1→4.n corresponds to a certain wavelength λ1→m and a certain position point on the light sensor 8. Based on such a calibration and on information about the position of the local maximum on the light sensor 8 and information about which output element 4.1→4.n provides the light of the local maximum, it is therefore possible to determine the wavelength of the local maximum.

[0136] In Fig. 12, a schematic diagram of the wavelength distributions of light delivered to different crossed coincident focal points at time instances t1, t2 and t3 is shown. The maximum intensities of these distributions correspond to the dominant wavelengths of the crossed coincident focal points at time instances t1, t2 and t3. Fig. 12 therefore shows that the local maxima detected for light at positions Im(t1), Im(t2) and Im(t3) of the light sensor 8 have different wavelengths.

[0137] As a result, it is advantageously possible to determine intensity values ​​of reflected light from a surface point having a number of different wavelengths in the same time it takes to acquire the surface profile of the object in a scanning measurement. Furthermore, it is advantageously possible to increase the number of determined intensity values ​​of different wavelengths for reflected light from an object point by increasing the number of coincident focal points to be intersected with that object point, which can be achieved by increasing the number of output elements.

[0138] A further advantage is that when the same surface point is measured with multiple wavelengths, the resolution of the acquired surface profile measurements is also improved, since the uncertainty due to noise is reduced compared to measurements where each measured object point intersects a single coincident focal point.

[0139] The method according to the embodiment comprises a step of determining intensity values ​​for light reflected from an object point 2.1 having at least two different wavelengths, which step comprises the following steps: - obtaining values ​​of the intensity of the detected light on the light sensor 8 at a plurality of different time instances, including at least a first and a second time instance; - moving an object 2 relative to the device between each two time instances along a predetermined path, whereby an object point 2.1 intersects with at least two coincident focal points, each of the at least two coincident focal points having a different dominant wavelength and associated with a different output element 4.1→4.n compared to the other at least two coincident focal points intersecting with the object point 2.1; - determining the positions and respective intensity values ​​of local maxima of the acquired intensity values ​​of the detected light; - determining intensity values ​​for reflected light from an object point 2.1 having at least two different wavelengths based on the determined positions and respective intensity values ​​of the local maxima and on information from which output element 4.1 → 4.n the light of the local maximum is supplied.

[0140] In Figures 5a, 5b1 and 5b2 and herein it has been demonstrated that when adjacent output elements 4.1 → 4.n are spaced sufficiently close to each other, the local intensity maxima of the detected light supplied from different output elements 4.1 → 4.n adjacent to them can be positioned at the same position on the light sensor 8.

[0141] If adjacent output elements 4.1 → 4.n are sufficiently spaced from each other, the local intensity maxima (i.e. peaks) of the detected light provided by these different adjacent output elements 4.1 → 4.n cannot overlap at all on the light sensor 8. In this case, the calibration of the device is clearly realized and for each local intensity maximum on the light sensor 8 there is only one, known output element 4.1 → 4.n from which the light of the local intensity maximum can be provided. Such a case is illustrated in FIG. 13, where there are three spatially separated lines S4.1(λ1 → m), S4.2(λ1 → m) and S4.3(λ1 → m) of coincident focal points associated with the three output elements 4.1, 4.2, 4.3 (these three output elements and the illumination optics 11 are not shown in the figure). Due to the sufficient spacing between 4.1, 4.2, and 4.3, the coincident focal points S4.1(λ1→m), S4.2(λ1→m), and S4.3(λ1→m) associated with these three output elements are far apart from each other in the measurement space, and the measurement areas of these lines, A, B, and C in the figure, are projected via the imaging optics 13 onto separate, non-overlapping areas A', B', and C', respectively, on the light sensor 8. Imaging As this case is shown in the figure, ImagingIf the regions do not overlap each other, there will be only one output element 4.1 → 4.n from which light of the local intensity maximum can be provided. The spacing of adjacent output elements 4.1 → 4.n must be designed to provide a maximum light intensity on the light sensor. Imaging There are separate regions of Imaging It is possible for each of these regions to uniquely correspond to only one output element 4.1→4.n.

[0142] Compared to the design shown in FIG. 13, one way to arrange adjacent output elements 4.1→4.n more densely is to use an RGB sensor as the light sensor 8. In FIG. 14, a measurement space consisting of 10 spatially separated lines of coincident focal points is illustrated. 1401 depicts the direction in which light from the 10 output elements 4.1→4.10 is provided to each line of coincident focal points. The figure depicts a line of coincident focal points S4.n(λ1→m) with wavelength λm and a line of its one coincident focal point CFP(λm). 1402 depicts the direction of the RGB sensor (output elements 4.1→4.10, illumination optics 11, imaging optics 13 not shown). The blue, green and red bands depict the wavelength bands of the focal plane of the RGB sensor 8. The three separate bands of the focal plane of this RGB sensor 8 are located in three separate areas on the sensor. Imaging That is, it is possible to closely space the coincident focal points of three adjacent lines such that there are coincident focal points from each of the three adjacent lines having the same location on the light sensor 8. Thus, the same focal points at a certain location on the light sensor 8 can be used. Imaging There may be one corresponding focal point in each of the red, green and blue focal plane bands associated with the focal point, and the local intensity maximum of each of the channels on that location may be clearly identified by calibration as corresponding to a certain output element 4.1→4.n.

[0143] In Fig. 15, the scanning of an object 2 through a measurement space defined by nine different lines of coincident focal points (i.e. there are coincident focal points associated with nine different output elements 4.1 → 4.n) of an embodiment 1500 of the device is shown. Note that for convenience, the output elements 4.1 → 4.n, the illumination optics 11 and imaging optics 13, and the light sensor 8 are not shown. The figure shows that an object point of the object 2 intersects with the coincident focal points in a certain order in a predetermined path 1010 shown by a dashed line intersecting with five coincident focal point lines at five different time instances t1, t2, t3, t4, and t5. It is important to note that the Z-range of the measurement space is adjusted so that each object point (surface point) of the object 2 intersects with the same number of different lines of coincident focal points associated with the different output elements 4.1 → 4.n. In the figure, the Z-range is adjusted so that the number of different lines of coincident focal points intersecting with the object point is five.

[0144] In the figure, the distance or spacing between adjacent lines of coincident focal points is depicted with reference character D, which in this embodiment is adjusted to be the same for each line of coincident focal points. That is, the output elements in this embodiment are equally spaced from each other. It should be noted that the distance between adjacent output elements of the device does not have to be the same, but can be varied depending on the application.

[0145] If how far the object must be moved in a given path 1010 in the scanning direction between two successive time instances is known, and the corresponding spacing D of adjacent lines of coincident focal points is known (i.e., the distance between the output elements is known), then the period of time dT between two successive time instances tn-1 and tn (i.e., dT=tn-tn-1) is also known.

[0146] At a first time instance t1, the object point of the object 2 intersects with the corresponding focal point of one line of the corresponding focal point S4.n (λ1→m). This intersection causes a local intensity maximum at a certain position (e.g. XY position) of the light sensor 8. Since the trajectory of the object is known, due to a predefined path 1010, the physical object point of the object causes another local intensity maximum on a new position (e.g. new XY position) of the light sensor at a second time instance t2=t1+dT1, which new position can be calculated from the previous position. This procedure can be repeated again and again at new time instances t1+dT1+dT2+dT3... until the same object point has moved through the entire measurement space. Once the object 2 has passed through the entire measurement space, no further signals (i.e. intensity maxima) are detected. In this example, five local intensity maxima are detected at five different time instances t1→t5, since there are five intersections of the object point with the corresponding focal point of the different lines of the five corresponding focal points. Each output element 4.1 → 4.n associated with these intersections can then be identified by fitting these measurement intersections to an appropriate set of five corresponding output elements providing the light of successive local intensity maxima detected on the light sensor 8. The surface height above the position of the object point can be determined from the calibration based on the position of the local intensity maximum on the light sensor 8 and information from which output element the light that caused said local intensity maximum was provided. The wavelength of said local maximum can be determined based on the position of said local intensity maximum on the light sensor 8 and information from which output element the light that caused said local intensity maximum was provided. This allows the position of the object point to be determined by the number of times that a line of coincident focal points is crossed, among other characteristics such as the wavelength and intensity of a certain local intensity maximum, thus improving the determination of the height (i.e. Z coordinate) of the object point, etc. In this example, the height of the object point is determined five times.

[0147] As described herein, the spacing between a set of output elements 4.1→4.n may be different from the spacing between other adjacent output elements in the device. This difference in spacing between adjacent output elements 4.1→4.n may be utilized in identifying which output element provided the light of a local maximum. For example, in the device of the embodiment of FIG. 15, if the adjacent output elements have a single dissimilar spacing, it is not problematic to have a local intensity maximum, for example, at the first time instance t1, due to the low reflectance of the object surface at the corresponding wavelength. In this case, four local intensity maxima are determined at time instances t4→t5, and the dissimilarity of the spacing of the adjacent output elements 4.1→4.n allows the missing local intensity maximum to be identified as being the first or last in the order of detected local intensity maxima. If a local intensity maximum is missing between the first and last local intensity maximum (i.e., if the reflectance of the object surface is low at the corresponding wavelength), the location of the missing local intensity maximum may be determined based on the determined duration between successive time instances and the total time between the first and last time instances.

[0148] In an embodiment, at least one spacing between adjacent output elements 4.1→4.n is different from other spacings between adjacent linear output elements 4.1→4.n.

[0149] The invention has been described above with reference to the aforementioned embodiments and several advantages of the invention have been demonstrated.

[0150] The present disclosure is not limited to the above-described embodiment, and the concept of the present invention can be applied in many ways within the scope of the claims.

[0151] The features recited in the corresponding claims are freely combinable with one another, unless expressly stated otherwise.

Claims

1. 1. An apparatus for determining the position and / or optical properties of an object (2), comprising: A point or line output element (4.1) for supplying light; an illumination optical system (11) for directing light from said output element (4.1) to said object (2); a light sensor (8) for detecting a light intensity value; an imaging optical system (13) for collecting light from the object (2) onto the light sensor (8); Including, the optical property relates to the transmission or reflection of light through the object (2); the illumination optical system (11) is configured to focus light from a position point (P1(4.1)) of the output element (4.1) into a plurality of illumination focal points or illumination focal regions located at different distances from the illumination optical system (11) along an illumination coordinate axis (A1(4.1)) associated with a chief ray (F1(4.1)) of the illumination optical system (11) relative to the position point (P1(4.1)) of the output element (4.1), wherein the chief ray (F1(4.1)) is mutually shared by the plurality of illumination focal points or illumination focal regions focused from the position point (P1(4.1)) of the output element (4.1), and each of the plurality of illumination focal points or illumination focal regions along the illumination coordinate axis (A1(4.1)) differs from each other at least in dominant wavelength or shape and / or is formed by a different optical aperture of the illumination optical system (11), the imaging optical system (13) is configured to form a plurality of imaging focal points or imaging focal regions positioned at different distances from the imaging optical system (13) along an imaging coordinate axis (A1(8)→An(8)) associated with a corresponding chief ray (F1(8)→Fn(8)) of the imaging optical system (13) from each of the position points (P1(8)→Pn(8)) of the optical sensor (8) to a corresponding position point (P1(8)→Pn(8)) of the optical sensor (8); wherein the corresponding chief rays (F1(8)→Fn(8)) are mutually shared by the plurality of imaging focal points or imaging focal areas formed from corresponding position points (P1(8)→Pn(8)) of the optical sensor (8), and each of the plurality of imaging focal points or imaging focal areas along the imaging coordinate axis (A1(8)→An(8)) differs from each other at least in dominant wavelength or shape and / or is formed by different optical apertures of the imaging optical system (13); the illumination optical system (11) and the imaging optical system (13) are configured such that various focal points or focal areas from the plurality of illumination focal points or illumination focal areas along the illumination coordinate axis (A1(4.1)) each form a plurality of coincident focal points or coincident focal areas with imaging focal points or imaging focal areas located along a different imaging coordinate axis (A1(8) → An(8)); The direction of the illumination coordinate axis (A1(4.1)) is different from the directions of the multiple imaging coordinate axes (A1(8) → An(8)), the plurality of coincident focal points or coincident focal regions each consisting of an illumination focal point and an imaging focal point associated with a common dominant wavelength or shape, or an illumination focal region and an imaging focal region associated with the common dominant wavelength or shape, and / or formed by correlated optical apertures of the illumination optics (11) and the imaging optics (13); The device determines the position and / or optical properties of an object point (2.1) of the object (2) from a local maximum of light intensity values ​​detected by the light sensor (8), Determining the position of the object point (2.1) from the position on the light sensor (8) that corresponds to the local maximum, and / or determining the optical property of the object point (2.1) from the intensity or wavelength of the light corresponding to the local maximum, 11. An apparatus according to claim 10, wherein the local maximum is obtained from the light collected from an intersection of the object point (2.1) with one of the plurality of coincident focus points or coincident focus regions.

2. 2. The device according to claim 1, wherein the device comprises a plurality of linear or point output elements (4.1 -> 4.n) or a combination thereof.

3. the illumination optical system (11) is configured to focus light from each of the position points (P1 → Pn) for each of the plurality of linear or point-like output elements (4.1 → 4.n) onto a plurality of illumination focal points or illumination focal areas positioned at different distances from the illumination optical system (11) along corresponding illumination coordinate axes (A1 → An) associated with corresponding chief rays (F1 → Fn) of the illumination optical system (11) for corresponding position points (P1 → Pn) of corresponding output elements (4.1 → 4.n); 3. The apparatus according to claim 2, wherein the corresponding chief rays (F1 → Fn) are mutually shared by the plurality of illumination focal points or illumination focal areas focused from the corresponding position points (P1 → Pn) of the corresponding output elements (4.1 → 4.n), and each of the plurality of illumination focal points or illumination focal areas along the corresponding illumination coordinate axes (A1 → An) for the corresponding position points (P1 → Pn) of the corresponding output elements (4.1 → 4.n) differ from each other at least in the dominant wavelength or shape and / or are formed with different optical apertures of the illumination optics (11).

4. 4. The device according to claim 3, wherein the illumination optical system (11) and the imaging optical system (13) are configured to form a plurality of coincident focal points or focal areas such that for each of the plurality of linear or point-like output elements (4.1 → 4.n), each of the various focal points or focal areas from the plurality of illumination focal points or illumination focal areas along the corresponding illumination coordinate axes (A1 → An) coincides at the coincident focal point or coincident focal area with an imaging focal point or imaging focal area positioned along a different imaging coordinate axis (A1(8) → An(8)), and wherein a direction of the plurality of illumination coordinate axes (A1 → An) for each of the plurality of linear or point-like output elements (4.1 → 4.n) is different from a direction of the plurality of imaging coordinate axes (A1(8) → An(8)).

5. a longitudinal chromatic aberration is provided in the illumination optical system (11) for focusing light from each of the position points (P1→Pn) for each of the plurality of linear or point-like output elements (4.1→4.n) to a plurality of illumination focal points located at different distances from the illumination optical system (11) along the corresponding illumination coordinate axis (A1→An) associated with the corresponding chief ray (F1→Fn) of the illumination optical system (11) for the corresponding position point (P1→Pn) of the corresponding output element (4.1→4.n), such that each of the illumination focal points along the illumination coordinate axis (A1→An) differ in the dominant wavelength; and 5. The apparatus according to claim 3, wherein longitudinal chromatic aberration is provided in the imaging optical system (13) to form a plurality of imaging focal points located at different distances from the imaging optical system (13) along the imaging coordinate axis (A1(8) → An(8)) associated with the corresponding chief ray (F1(8) → Fn(8)) of the imaging optical system (13) to the corresponding position point (P1(8) → Pn(8)) of the optical sensor (8), such that each of the plurality of imaging focal points along the imaging coordinate axis (A1(8) → An(8)) has a different dominant wavelength.

6. a spherical aberration is provided in the illumination optical system (11) to focus light from each of the position points (P1 → Pn) for each of the plurality of linear or point-like output elements (4.1 → 4.n) to a plurality of imaging focal points located at different distances from the illumination optical system (11) along the corresponding illumination coordinate axis (A1 → An) associated with the corresponding chief ray (F1 → Fn) of the illumination optical system (11) for the corresponding position point (P1 → Pn) of the corresponding output element (4.1 → 4.n), whereby each of the illumination focal points along the illumination coordinate axis (A1 → An) is formed with a different optical aperture of the illumination optical system (11); and 6. The apparatus according to claim 3, wherein a spherical aberration is provided in the imaging optical system (13) to form a plurality of imaging focal points located at different distances from the imaging optical system (13) along the imaging coordinate axis (A1(8) → An(8)) associated with the corresponding chief ray (F1(8) → Fn(8)) of the imaging optical system (13) to the corresponding position point (P1(8) → Pn(8)) of the optical sensor (8), such that each of the focal points along the imaging coordinate axis (A1(8) → An(8)) is formed at a different optical aperture of the imaging optical system (13).

7. an astigmatism is provided in the illumination optical system (11) for focusing light from each of the position points (P1→Pn) for each of the plurality of linear or point-like output elements (4.1→4.n) onto a plurality of illumination focal areas having different shapes positioned at different distances from the illumination optical system (11) along the corresponding illumination coordinate axis (A1→An) associated with the corresponding chief ray (F1→Fn) of the illumination optical system (11) for the corresponding position point (P1→Pn) of the corresponding output element (4.1→4.n), whereby each of the illumination focal areas along the illumination coordinate axis (A1→An) is formed with a different optical aperture of the illumination optical system (11); 7. The apparatus according to claim 3, wherein astigmatism is provided in the imaging optics (13) to form a plurality of illumination focal regions located at different distances from the imaging optics (13) along the imaging coordinate axis (A1(8) → An(8)) associated with the corresponding chief ray (F1(8) → Fn(8)) of the imaging optics (13) to the corresponding position point (P1(8) → Pn(8)) of the optical sensor (8), such that each of the focal regions along the imaging coordinate axis (A1(8) → An(8)) is formed at the different optical aperture of the imaging optics (13).

8. 6. The apparatus of claim 5, wherein when the illumination optical system (11) and the imaging optical system (13) are provided with longitudinal chromatic aberration, the plurality of coincident focal points each comprise an illumination focal point and an imaging focal point associated with the common dominant wavelength.

9. 7. The apparatus of claim 6, wherein when the illumination optical system (11) and the imaging optical system (13) are provided with spherical aberration, each of the coincident focal points is formed at the correlated optical apertures of the illumination optical system (11) and the imaging optical system (13).

10. 8. The apparatus of claim 7, wherein when the illumination optical system (11) and the imaging optical system (13) are provided with astigmatism, each of the coincident focal regions consists of an illumination focal region and an imaging focal region associated with a common shape and formed by the correlated optical apertures of the illumination optical system (11) and the imaging optical system (13).

11. 6. The device according to claim 5, wherein when the device comprises two or more output elements (4.1 → 4.n), the device is configured to determine the wavelength of the local maximum of the intensity values ​​of the light detected by the light sensor (8) in order to distinguish from which output element (4.1 → 4.n) the light of the local maximum is provided in order to determine the position of the object point (2.1) at the intersection.

12. 12. Apparatus according to any one of claims 2 to 11, wherein the optical sensor (8) is a line scan camera, a matrix camera, an RGB camera or a position sensitive detector (PSD).

13. 12. The apparatus according to claim 11, wherein the light sensor (8) is an RGB camera configured to determine the wavelength of the local maximum.

14. The device according to any one of claims 2 to 13, wherein the determination of the position of the object point (2.1) is based on triangulation.

15. Apparatus according to any one of claims 2 to 14, wherein the distribution of coincident focal points defines a measurement space for determining positions of object points (2.1) of the object (2) to be measured.

16. 16. The apparatus according to claim 2, wherein when measuring an object (2) that is at least partially transparent or translucent to the light directed towards the object (2), the apparatus is configured to determine a thickness between the first surface (2f) and the second surface (2s) of the object (2) that is at least partially transparent or translucent to the light directed towards the object (2) from a position difference between the local maximum of the intensity values ​​of the detected light on the light sensor (8) resulting from a first surface (2f) and the local maximum of the intensity values ​​of the detected light on the light sensor (8) resulting from a second surface (2s).

17. 17. The device according to claim 2, wherein the optical sensor (8) is a line scan camera or a matrix camera arranged perpendicular to the optical axis (13') of the imaging optical system (13), and the plurality of linear or point-shaped output elements (4.1 → 4.n) are arranged on a plane (5), where the plane (5) forms an oblique angle with respect to the optical axis (11') of the illumination optical system (11).

18. The device according to any one of claims 2 to 17, wherein at least one spacing between adjacent output elements (4.1 → 4.n) among the plurality of linear or dot-like output elements (4.1 → 4.n) is different from other spacings between the adjacent output elements (4.1 → 4.n).

19. A method for determining the position and / or optical properties of an object (2) using an apparatus, comprising: The apparatus comprises: A point or line output element (4.1) for supplying light; an illumination optical system (11) for directing light from said output element (4.1) to said object (2); a light sensor (8) for detecting a light intensity value; an imaging optical system (13) for collecting light from the object (2) onto the light sensor (8); Including, the optical property relates to the transmission or reflection of light through the object (2); The method comprises: Providing optical illumination and optical detection from different directions to the object (2), focusing light from a position point (P1(4.1)) of the output element (4.1) on a plurality of illumination focal points or illumination focal areas located at different distances from the illumination optical system (11) along an illumination coordinate axis (A1(4.1)) associated with a chief ray (F1(4.1)) of the illumination optical system (11) relative to the position point (P1(4.1)) of the output element (4.1), where the chief ray (F1(4.1)) is mutually shared by the plurality of illumination focal points or illumination focal areas focused from the position point (P1(4.1)) of the output element (4.1), and each of the plurality of illumination focal points or illumination focal areas along the illumination coordinate axis (A1(4.1)) differs from each other at least in dominant wavelength or shape and / or is formed by a different optical aperture of the illumination optical system (11); and A plurality of imaging focal points or imaging focal regions positioned at different distances from the imaging optical system (13) along an imaging coordinate axis (A1(8) → An(8)) associated with a corresponding chief ray (F1(8) → Fn(8)) of the imaging optical system (13) to a corresponding position point (P1(8) → Pn(8)) of the optical sensor (8) are formed from each of the corresponding position points (P1(8) → Pn(8)) of the optical sensor (8), and the corresponding chief ray (F 1(8)→Fn(8)) are mutually shared by the plurality of imaging focal points or imaging focal regions formed from corresponding position points (P1(8)→Pn(8)) of the optical sensor (8), and each of the plurality of imaging focal points or imaging focal regions along the imaging coordinate axes (A1(8)→An(8)) differ from each other in at least dominant wavelength or shape and / or are focused with different optical apertures of the imaging optics (13); forming a plurality of coincident focal points or coincident focal regions, each of which corresponds to an imaging focal point or focal region located along a different imaging coordinate axis (A1(8)→An(8)), the direction of which is different from the directions of the imaging coordinate axes (A1(8)→An(8)); and each of which is made up of an illumination focal point and an imaging focal point associated with a common dominant wavelength or shape, or an illumination focal region and an imaging focal region associated with the common dominant wavelength or shape, and / or which is formed by a correlated optical aperture of the illumination optical system (11) and the imaging optical system (13); detecting, by the light sensor (8), intensity values ​​of light collected from the object (2) by the imaging optics (13); determining the position and / or optical properties of an object point (2.1) of the object (2), where the position of the object point (2.1) is determined from a position on the light sensor (8) corresponding to a local maximum of the light intensity values ​​and / or the optical properties of the object point (2.1) are determined from the light intensity or wavelength corresponding to said local maximum, where said local maximum is obtained from the light collected from an intersection of the object point (2.1) with one of the plurality of coincident focus points or coincident focus regions; A method comprising:

20. The method further comprises: focusing light from each of the position points (P1→Pn) of each of a plurality of output elements (4.1→4.n) onto illumination focal points or illumination focal areas located at different distances from the illumination optical system (11) along corresponding illumination coordinate axes (A1→An) associated with corresponding chief rays (F1→Fn) of the illumination optical system (11) for corresponding position points (P1→Pn) of corresponding output elements (4.1→4.n), where the corresponding chief rays (F1→Fn) correspond to the corresponding output focal points (P1→Pn) of the corresponding output elements (4.1→4.n), each of the illumination focal points or illumination focal areas shared by each other and focused from the corresponding location points (P1->Pn) of the corresponding output elements (4.1->4.n) along the corresponding illumination coordinate axes (A1->An) to the corresponding location points (P1->Pn) of the corresponding output elements (4.1->4.n) differs from each other at least in dominant wavelength or shape and / or is formed with a different optical aperture of the illumination optics (11); forming a plurality of coincident focal points or coincident focal areas, each of which for each of the output elements (4.1→4.n) differs from an imaging focal point or imaging focal area located along a different imaging coordinate axis (A1(8)→An(8)), with the direction of the plurality of illumination coordinate axes (A1→An) for each of the output elements (4.1→4.n) being different from the direction of the imaging coordinate axis (A1(8)→An(8)); 20. The method of claim 19, comprising:

21. The method further comprises:

21. The method according to claim 20, comprising determining a thickness between the first surface (2f) and the second surface (2s) of the object (2), which is at least partially transparent or semi-transparent to light directed towards the object (2), from a position difference between the local maximum of the intensity values ​​of the detected light on the light sensor (8) resulting from a first surface (2f) and the local maximum of the intensity values ​​of the detected light on the light sensor (8) resulting from a second surface (2s).

22. the illumination optical system (11) focuses the corresponding position points (P1→Pn) of the corresponding output elements (4.1→4.n) having at least different dominant wavelengths on each of the plurality of illumination focal points or illumination focal areas along the corresponding illumination coordinate axes (A1→An) by using longitudinal chromatic aberration; The method according to any one of claims 20 to 21, wherein the imaging optical system (13) focuses the light on each of the plurality of imaging focal points or imaging focal regions along the imaging coordinate axes (A1(8) → An(8)) where at least the dominant wavelengths are different from each other by using longitudinal chromatic aberration.

23. the illumination optical system (11) focuses the corresponding position points (P1→Pn) of the corresponding output elements (4.1→4.n) having different optical apertures of the illumination optical system (11) along the corresponding illumination coordinate axes (A1→An) by using spherical aberration, 23. The method according to any one of claims 20 to 22, wherein the imaging optical system (13) focuses on each of the plurality of imaging focal points along the imaging coordinate axis (A1(8) → An(8)) with different optical apertures of the imaging optical system (13) by using spherical aberration.

24. the illumination optical system (11) uses astigmatism to focus the corresponding position points (P1→Pn) of the corresponding output elements (4.1→4.n) having different shapes on each of the illumination focal regions along the corresponding illumination coordinate axes (A1→An); 24. The method according to claim 20, wherein the imaging optics (13) focuses each of the imaging focal regions along the imaging coordinate axes (A1(8)→An(8)) that are different in shape by using astigmatism.

25. The method comprises: Positioning the optical sensor (8) perpendicular to the optical axis (13') of the imaging optical system (13); The method according to any one of claims 20 to 24, comprising the step of arranging the plurality of output elements (4.1 → 4.n) on a plane (5), the plane (5) forming an oblique angle with respect to an optical axis (11') of the illumination optical system (11), the plurality of output elements (4.1 → 4.n) consisting of a plurality of linear output elements (4.1 → 4.n).

26. The method comprises at least one of the following steps: moving the object (2) relative to the device such that the object point (2.1) intersects with at least one coincident focal point, where each of the at least one coincident focal point has the same common dominant wavelength; moving the object (2) relative to the apparatus such that the object point (2.1) intersects with at least one coincident focal point, each of the at least one coincident focal point being formed at the correlated optical apertures of the illumination optics (11) and the imaging optics (13); or moving the object (2) relative to the apparatus such that the object point (2.1) intersects with at least one coincident focal point, each of the at least one coincident focal area consisting of an illumination focal area and an imaging focal area associated with the common shape and formed by the correlated optical apertures of the illumination optics (11) and the imaging optics (13); The method according to any one of claims 20 to 24, comprising:

27. The method comprises at least one of the following steps: moving the object (2) relative to the device such that the object point (2.1) intersects with a certain number of coincident focal points, each of the certain number of coincident focal points having a different dominant wavelength when the number of intersecting coincident focal points is two or more; moving the object (2) relative to the device such that the object point (2.1) intersects with a certain number of coincident focal points, where when the number of intersecting coincident focal points is two or more, each of the certain number of coincident focal points is formed with a different correlated optical aperture of the illumination optics (11) and the imaging optics (13); or moving the object (2) relative to the apparatus such that the object point (2.1) intersects with a certain number of coincident focal regions, each of which consists of an illumination focal region and an imaging focal region associated with a common shape and formed with the correlated optical apertures of the illumination optics (11) and the imaging optics (13), where each coincident focal region has a different shape and is formed with a different correlated optical aperture of the illumination optics (11) and the imaging optics (13) when the number of coincident focal regions intersecting with the object point (2.1) is two or more; 26. The method of claim 25, comprising:

28. obtaining intensity values ​​of the detected light on the light sensor (8) at a plurality of different time instances including at least a first and a second time instance; - moving an object (2) relative to the device between each two time instances along a predetermined path, whereby the object point (2.1) intersects with at least two coincident focal points, each of the at least two coincident focal points having a different dominant wavelength and associated with a different output element (4.1→4.n) compared to the other at least two coincident focal points intersecting with the object point (2.1); determining locations and respective intensity values ​​for local maxima of the acquired intensity of the detected light; determining intensity values ​​of the light reflected from said object point (2.1) having at least two different wavelengths based on the determined locations and respective intensity values ​​of said local maxima and on information from which output element (4.1 → 4.n) the light of said local maxima is provided; The method of any one of claims 20 to 27, further comprising:

29. 29. The method according to any one of claims 20 to 28, further comprising arranging at least one spacing between adjacent output elements (4.1 → 4.n) of the plurality of output elements (4.1 → 4.n) differently than other spacings between the adjacent output elements (4.1 → 4.n).

30. Use of the device according to any one of claims 1 to 18 for determining a thickness between a first surface (2f) and a second surface (2s) of an object (2), said object (2) being at least partially transparent or translucent to the light directed towards said object (2).

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