Optical sensor device

Abstract

According to one embodiment, an optical sensor device (110) is provided for determining at least one characteristic of the surface of an object (180) located within a measurement range, the sensor device (110) is an illumination assembly (120) having one or more light sources (121, 121-k) configured to emit light toward the measurement range via a focusing optical assembly, wherein the emitted light covers a predetermined wavelength range, and the one or more light sources are configured to form one or more emission region patterns of a predetermined lateral shape; and a first optical assembly (140) configured to disperse the light emitted from the illumination assembly (120) in the longitudinal direction, wherein the light across the predetermined wavelength range in each of the one or more emission region patterns is focused to respective focal length ranges constituting corresponding sub-candidate distance ranges within the measurement range; and the light emitted from the illumination assembly (120) is transmitted toward the first optical assembly (140). The optical sensor assembly (160) includes a beam splitter (130) configured to fold light reflected from the surface of an object (180) and received through a first optical assembly; a second optical assembly (150) configured to receive the foldable light over a predetermined wavelength range, disperse the received light over the predetermined wavelength range laterally, and focus the light over the predetermined wavelength range to a predetermined distance; an optical sensor assembly (160) having a sensor surface positioned at a predetermined distance to receive the laterally dispersed light over the predetermined wavelength range, wherein the light generated from one or more light emission region patterns is received in one or more corresponding sub-position ranges along the axis (y') on the sensor surface; and a detector assembly (170) configured to determine at least one characteristic of the surface of an object (180) based on the laterally dispersed light received over the one or more sub-position ranges along the axis (y') on the sensor surface.

Description

Technical Field

[0001] Non-limiting examples and embodiments of the present invention relate to an optical sensor device that can be used, for example, to measure one or more surface characteristics of an object, such as the distance to the surface of an object located within the measurement range of the sensor device and / or the optical characteristics of the surface of the object.

Background Art

[0002] Optical displacement sensors suitable for measuring the distance to an object under investigation and / or the shape of the object under investigation, known in the art, apply various optical designs and techniques, and the most suitable one may depend at least in part on the requirements and intended uses of the measuring instrument utilizing the optical displacement sensor. Nevertheless, for example, the reliability and accuracy of the measurement results, a relatively simple design, and a small size are typically general requirements to ensure its use across a wide range of different applications, while promoting the improvement of the accuracy and reliability of the measurement without substantially increasing the size and / or complexity of the optical design, and / or promoting the provision of accurate and reliable measurement results without compromising while enabling a smaller and / or simplified optical design. Any improvement in the design of an optical displacement sensor is highly desirable.

Summary of the Invention

[0003] One object of the present invention is to provide an optical sensor device that enables measurement with high accuracy and reliability while presenting a relatively simple design and a relatively small physical size. A further object of the present invention is to provide an optical measuring device that utilizes such an optical sensor device.

[0004] According to one embodiment, an optical sensor device is provided for determining at least one characteristic of the surface of an object located within a measurement range, the sensor device comprising: an illumination assembly having one or more light sources configured to emit light toward the measurement range via a focusing optical assembly, wherein the emitted light covers a predetermined wavelength range, and the one or more light sources are configured to form one or more emission region patterns of a predetermined lateral shape; a first optical assembly configured to disperse the light emitted from the illumination assembly in the longitudinal direction, wherein the light from each of the one or more emission region patterns across the predetermined wavelength range is focused to respective focal length ranges constituting corresponding sub-candidate distance ranges within the measurement range; and a first optical assembly that transmits the light emitted from the illumination assembly toward the first optical assembly, The present invention comprises: a beam splitter configured to fold light reflected from the surface of an object and received through a first optical assembly; a second optical assembly configured to receive the foldable light over a predetermined wavelength range, disperse the received light over the predetermined wavelength range laterally, and focus the laterally dispersed light over the predetermined wavelength range to a predetermined distance; an optical sensor assembly having a sensor surface positioned at a predetermined distance to receive the laterally dispersed light over the predetermined wavelength range, wherein light generated from one or more light emission region patterns is received in one or more corresponding sub-position ranges along the axis on the sensor surface; and a detector assembly configured to determine at least one characteristic of the surface of an object based on the laterally dispersed light received in the one or more sub-position ranges along the axis on the sensor surface.

[0005] According to another embodiment, an optical measuring device is provided for determining the surface properties of an object positioned within a measurement range, the measuring device comprising the aforementioned optical sensor device configured to determine at least one property of the surface of the object, and a mechanism for changing the relative position between the sensor device and the object, the measuring device being configured to move the object to a plurality of positions relative to the sensor device according to a predetermined movement pattern, to operate the sensor device to determine at least one property of the surface of the object at each of the plurality of positions, and to determine the surface properties of the object based on the at least one property of the surface of the object determined at each of the plurality of positions.

[0006] The exemplary embodiments of the invention presented in this patent application should not be construed as limiting the applicability of the appended claims. The verb “to have” and its derivatives are used in this patent application as an open constraint, which does not exclude the existence of features not described. Features described in the following descriptions of some embodiments may be provided in combinations other than those expressly described, unless otherwise expressly stated.

[0007] Some features of the present invention are described in the appended claims. However, aspects of the present invention, both in terms of its configuration and how it operates, along with its further objectives and advantages, will be best understood from the following description of some embodiments when read in conjunction with the appended drawings. [Brief explanation of the drawing]

[0008] Embodiments of the present invention are shown in the accompanying drawings as examples, not as limitations. [Figure 1] A schematic diagram of an optical sensor device following one example is shown. [Figure 2] A schematic diagram of an optical sensor device following one example is shown. [Figure 3A] This diagram schematically illustrates some aspects of distance measurement according to one example. [Figure 3B] This diagram schematically illustrates some aspects of distance measurement according to one example. [Modes for carrying out the invention]

[0009] Figures 1 and 2 show some elements of the optical sensor device 110 according to each example. Each figure in Figures 1 and 2 provides a schematic cross-sectional view of each element of the optical sensor device 110, while some elements are represented as blocks. In this regard, Figures 1 and 2 show the optical sensor device 110 having an illumination assembly 120, a beam splitter 130, a first optical assembly 140, a second optical assembly 150, a light sensor assembly 160, and a detector assembly 170. Hereafter, for the sake of brevity and clarity, the optical sensor device 110 will mainly be referred to as the sensor device 110.

[0010] Note that the schematic diagrams of some elements of the optical sensor device 110 provided in Figures 1 and 2 are not intended to accurately show the positions of these elements relative to each other, their respective sizes relative to each other, or their actual appearance. Rather, Figures 1 and 2 serve to illustrate at least some of the characteristics useful in describing specific aspects relating to the configuration and operation of the sensor device 110 in accordance with this disclosure.

[0011] Figures 1 and 2 each include x, y, and z directions that define a conceptual coordinate system that facilitates the explanation of the spatial relationships between elements of the sensor device 110 shown in Figures 1 and 2, as well as the operational characteristics of some of the elements shown in Figures 1 and 2. In this regard, in the explanation of the specific characteristics of the illumination assembly 120 and the first optical assembly 140, the plane defined by the x and y directions may be considered the transverse direction, and the z direction may be considered the vertical direction.

[0012] The sensor device 110 may be applicable to determine at least one characteristic of the surface of an object 180 (temporarily) positioned within the measurement range of the sensor device 110, based on light reflected from the surface of the object 180 brought into the measurement range. Examples of such characteristics measured via the operation of the sensor device 110 include the distance to the surface of the object 180 and / or the optical properties of the surface of the object 180, the optical properties may include, for example, the reflectance of the surface of the object 180. Various features relating to the configuration and operation of the sensor device 110 will be described below in relation to using the sensor device 110 to determine the distance to the surface of an object 180 (temporarily) positioned within its measurement range (i.e., using the sensor device 110 as an optical displacement sensor), but further examples of the applicability of the sensor device 110 will be provided later in this specification.

[0013] The distance to the surface of an object 180 positioned within the measurement range of the sensor device 110 can be measured as the distance between a selected reference plane and the position of the object 180 on its surface within the measurement range of the sensor device 110. Therefore, the distance from the reference plane to the position of the object 180 on its surface is a longitudinal measure and can also be referred to as a displacement relative to the reference plane. The reference plane can have any longitudinal position that remains stationary with respect to the measurement range, and can have the longitudinal positions of each element of the sensor device 110, such as the longitudinal position of an element of a measuring instrument or measuring system using the sensor device 110, or, for example, the longitudinal position of the first optical assembly 140. The measurement range covers a range of candidate distances from the reference plane, but the position and depth of the measurement range depend on the respective characteristics of at least the illumination assembly 120 and the first optical assembly 140. The concepts of the measurement range and candidate distances within the measurement range will be explained in more detail in the following description of the sensor device 110 according to the examples in Figures 1 and 2.

[0014] The illumination assembly 120 shown in the respective examples in Figures 1 and 2 comprises one or more light sources 121, 121-k and a focusing lens assembly 122, the optical axis of the focusing lens assembly 122 being aligned with axis A as shown in the respective figures in Figures 1 and 2. The one or more light sources 121, 121-k are configured to emit light covering a predetermined wavelength range, and the light sources 121, 121-k are configured to form one or more light-emitting region patterns of a predetermined spatial shape, and the light emitted from the one or more light sources 121, 121-k can be transmitted through the focusing lens assembly 122 toward the measurement range. In this regard, wavelengths within the predetermined wavelength range are considered in the measurement performed via the operation of the sensor device 110. In one example, the wavelengths transmitted by the light emitted from the illumination assembly 120 may be limited to only the predetermined wavelength range, but in another example, the light emitted from the illumination assembly 120 may also include wavelengths outside the predetermined range. Some of the further features of one or more light sources 121, 121-k will be described below after the description of specific embodiments of the elements of the sensor device 110 shown in the respective examples in Figures 1 and 2.

[0015] In the example in Figure 1, the illumination assembly 120 has a single light source 121 positioned on axis A, thereby resulting in the emission of light from a single light-emitting region pattern of a predetermined spatial shape. As an example, the single light source 121 may be positioned on the focal plane of a focusing lens assembly 122, thereby causing the illumination assembly 120 to transmit collimated or substantially collimated light toward the measurement range. As an example, the lateral shape of the light-emitting region pattern of the single light source 121 may have points, which can be provided, for example, by guiding light through a pinhole positioned, for example, on axis A, on the focal plane of the focusing lens assembly 122. As another example, the lateral shape of the light-emitting region pattern of the single light source 121 may have lines, which can be provided, for example, by guiding light through a slit extending laterally (e.g., in the x-direction) on the focal plane of the focusing lens assembly 122, intersecting, for example, on axis A.

[0016] The example in Figure 2 shows three light sources 121-1, 121-2, and 121-3, which serve as examples that can be generalized to two or more light sources 121-k positioned at their respective locations relative to axis A and to the focal plane of the focusing lens assembly 122, each configured to emit light covering the same predetermined wavelength range (as described above for a single light source 121). In this regard, each of the two or more light sources 121-k preferably has a lateral position (i.e., position relative to axis A) different from the lateral position of each of the other light sources 121-k, and a longitudinal position (e.g., position relative to the focal plane of the focusing lens assembly 122) different from the longitudinal position of each of the other light sources 121-k, in order to focus the respective projections of the emission region patterns therefrom to different lateral and longitudinal positions within the measurement range. Thus, the light emitted from the illumination assembly 120 is not completely collimated. The respective offsets from axis A and from the focal plane are typically fractions of the focal length of the focusing lens assembly 122. The relationship between the positions of the two or more light sources 121-k and their focusing within the measurement range will be described in more detail below. In a particular example, the two or more light sources 121-k may be arranged at equal intervals along an axis on a (conceptual) plane having a non-zero inclination angle with respect to the focal plane of the focusing lens assembly 122, such that the arrangement of the two or more light sources 121-k is centered with respect to axis A.

[0017] Similar to the single light source 121 in the example of Figure 1, in the example of Figure 2, the lateral shape of each light emission area pattern of two or more light sources 121-k may, for example, have points or lines. Consider the example in which two or more light sources 121-k are arranged along an axis on a (conceptual) plane having a non-zero inclination angle with respect to the focal plane of the focusing lens assembly 122, each light emission area pattern may be provided, for example, by guiding light through a (one-dimensional) pinhole array or slit array having a desired number of pinholes or slits at desired intervals, which is arranged at a non-zero inclination angle with respect to the focal plane such that the lines of pinholes or slits in the array are centered with respect to axis A. The number of light emission area patterns and their spacing may be selected such that the lateral spacing and spread of their projections onto the surface of object 180, and consequently the lateral and longitudinal distribution of the measurement subrange resulting therefrom, yield a desired depth and lateral size of the measurement range (this will be explained below). In non-restrictive examples, the diameter of a point of light or the width of a linear beam of light can be in the range of 5 to 30 micrometers (μm), and / or the spacing between points or lines of light can be in the range of 350 to 1000 μm, for example, 500 μm.

[0018] The positions of the two or more light sources 121-k can be selected such that, taking into account the distance between the illumination assembly 120 and the first optical assembly 140, and the lateral size of the first optical assembly 140, the light from the two or more light-emitting region patterns is focused by the first optical assembly 140 to separate lateral positions from each other, and therefore the light from each of the two or more light-emitting region patterns is projected onto the surface of the object 180, positioned within the measurement range, as separate light intensity patterns that are laterally separated from other light intensity patterns projected onto the surface of the object 180. In view of the non-limiting examples relating to the lateral shape of the light-emitting region patterns described above, for each wavelength, the first optical assembly 140 can focus the light emitted from the illumination assembly 120 into sets of points or sets of lines that are substantially equally spaced laterally (e.g., in the y-direction).

[0019] The focusing lens assembly 122 schematically shown in Figures 1 and 2 functions as an example of a focusing optical assembly, and in other examples, the focusing lens assembly 122 may be replaced by a focusing mirror assembly or by a focusing optical assembly having one or more lenses and one or more mirrors. Such a modification of the optical configuration resulting in the use of a focusing optical assembly other than the focusing lens assembly 122 may require repositioning one or more light sources 121 relative to the focusing optical assembly in accordance with the modification in order to provide the functions assigned to the second optical assembly 150 and the photosensor assembly 160 in the sensor device 110 according to the present disclosure.

[0020] The first optical assembly 140 can be positioned along axis A so as to receive the light emitted from the illumination assembly 120, and is configured to disperse the light emitted from the illumination assembly 120 in the longitudinal direction such that light over a predetermined wavelength range from each of the one or more light-emitting region patterns is focused into respective focal length ranges that constitute corresponding one or more sub-candidate distance ranges within the measurement range. Due to its role in focusing the light emitted from the illumination assembly 120, the first optical assembly 140 may also be referred to as the focusing assembly. Here and generally in the present disclosure, the expression 'over a predetermined wavelength range' is applied to refer to wavelengths over the entire predetermined wavelength range, i.e., wavelengths covered by the predetermined wavelength range.

[0021] One or more sub-candidate distance ranges resulting from the wavelength-dependent focusing characteristics of the first optical assembly 140 define the measurement range of the sensor device 110, and they also set the range of distances measurable via the operation of the sensor device 110. Thus, since one of the candidate distances can be identified as representing the longitudinal position of the surface of the object 180 (temporarily) positioned within the measurement range, it is referred to as a 'candidate distance'. Therefore, in a scenario where the longitudinal position of the first optical assembly 140 functions as a reference plane for representing the measurement distance, the candidate distance found to represent the longitudinal position of the surface of the object 180 also directly indicates the distance measured via the operation of the sensor device 110 (i.e., the displacement of the surface of the object 180 with respect to the reference plane). However, in a scenario where the reference plane is offset from the longitudinal position of the first optical assembly 140, the distance measured via the operation of the sensor device 110 can be obtained as the sum of the offset between the reference plane and the longitudinal position of the first optical assembly 140 and the candidate distance found to represent the longitudinal position of the surface of the object 180.

[0022] The first optical assembly 140 further functions as part of a condenser optical system, and the light reflected from the surface of an object 180 (temporarily) brought into the measurement range passes through the first optical assembly 140 so as to return toward the beam splitter 130. The beam splitter 130 bends the reflected light toward the second optical assembly 150. After the second optical assembly 150 introduces lateral dispersion into the received bent light, the resulting laterally dispersed light is passed through for reception on the sensor surface of the optical sensor assembly 160. As a result, a predetermined wavelength range transmitted therein is distributed along the axis y' on the sensor surface. The transmission of the light reflected from the surface of the object 180 through the second optical assembly 150 and its reception on the sensor surface of the optical sensor assembly 160 will be described in more detail below.

[0023] According to an example, the first optical assembly 140 shown in each of the examples of FIGS. 1 and 2 has a first focusing lens assembly 141 having an optical axis aligned with the axis A. The first focusing lens assembly 141 is configured to introduce a predetermined amount of longitudinal chromatic dispersion that results in focusing different wavelengths included in the light received from the illumination assembly 120 on the opposite side of the first focusing lens assembly 141 at different wavelength-dependent (different) distances from the first focusing lens assembly 141. The characteristics of the first focusing lens assembly 141 can be selected to provide a desired amount of longitudinal dispersion, and the applicable amount of longitudinal dispersion can depend, for example, on a predetermined wavelength range of the light from one or more light-emitting region patterns of one or more light sources 121, 121-k, and / or the desired depth and position of the measurement range created by the first optical assembly 140. Longitudinal chromatic dispersion may also be referred to as longitudinal chromatic aberration.

[0024] Given such focusing characteristics for light from a single light-emitting region pattern in the example of Figure 1, the longitudinal chromatic dispersion introduced by the first optical assembly 140 results in different wavelengths of light from the single light-emitting region pattern being focused to different focal lengths from the first optical assembly 140, such that shorter wavelengths are focused to a shorter distance from the first optical assembly 140 than longer wavelengths. In the framework of the example of Figure 1, the range of focal lengths from the focal length of the shortest wavelength in a given wavelength range to the focal length of the longest wavelength in a given wavelength range defines a single sub-candidate distance range, and consequently also defines the available measurement range of the sensor device 110.

[0025] To further illustrate the scenario of a single light-emitting region pattern, when determining the distance to a position on the surface of an object 180 (temporarily) brought into the measurement range using a sensor device 110 according to the example in Figure 1, the light emitted from the single light-emitting region pattern is projected onto the surface of the object 180 at a measurement position (lateral) aligned with axis A, and reflected from the surface of the object 180. In this regard, the characteristics of the reflected light differ at different wavelengths depending on the longitudinal position of the surface of the object 180 within the measurement range. Wavelengths focused at candidate distances that coincide with the surface of the object 180 will reflect a sharp image of the single light-emitting region pattern, while wavelengths focused at other candidate distances that do not coincide with the surface of the object 180 will reflect a blurry image of the single light-emitting region pattern. In this regard, the degree of blurriness increases as the difference between the candidate distance to which a given wavelength is focused and the surface of the object 180 increases. As a result, reflected light of wavelengths focused on the surface of object 180 is received at the sensor surface of the photosensor assembly 160 with a higher intensity than the respective intensities of wavelengths not focused on the surface of object 180, and the received light intensity decreases as the distance between the position on the surface of object 180 and the focal length of each non-focused wavelength increases.

[0026] Accordingly, in the example of Figure 1, where light from a single emission region pattern originating from a single light source 121 positioned on axis A is applied to create a single measurement subrange that also functions as the (overall) measurement range, the longitudinal position and depth of the measurement range of the sensor device 110 depend at least on the amount of longitudinal chromatic dispersion introduced by the first optical assembly 140 and a predetermined wavelength range considered in the measurement. In this regard, the single measurement subrange provides a unique mapping between wavelengths within the predetermined wavelength range and corresponding candidate distances. As an example of considering the above-described characteristics having an effect on measurement depth applicable within the framework of the example of Figure 1, the design of the sensor device 110 may be based on calculations and / or simulations that proceed from defining a desired depth of the measurement range and selecting a predetermined wavelength range and / or focusing characteristics of the first optical assembly 140 to be considered in the measurement so that the desired depth of the measurement range is obtained.

[0027] Next, referring to a scenario according to the example in Figure 2, in which light from two or more (separate) light-emitting region patterns is emitted from the illumination assembly 120 and received by the first optical assembly 140, the manner in which a predetermined wavelength range is focused from the first optical assembly 140 to a corresponding distance range so as to define a range of candidate distances, and the manner in which reflected light of wavelengths focused to a candidate distance coinciding with the surface of object 180 is received at a relatively high intensity (compared to reflections of other wavelengths) on the sensor surface of the sensor assembly 160, follows the logic described above with separately necessary modifications for the light from each of the two or more light-emitting region patterns. In particular, in the framework of the sensor device 110 according to the example in Figure 2, the first optical assembly 140 is configured to disperse the light received from the illumination assembly 120 in the longitudinal direction, so that light across a predetermined wavelength range from each of the two or more light-emitting region patterns is focused from the first optical assembly 140 to a corresponding distance range at each lateral measurement position, thereby defining each sub-candidate distance range. The resulting two or more sub-candidate distance ranges function as two or more measurement sub-ranges located at each (lateral) measurement position, and together these two or more measurement sub-ranges define the (overall) measurement range of the sensor device 110.

[0028] Therefore, in the example in Figure 2, the two or more measurement subranges are spatially distributed at different positions in the lateral direction, and these positions can be referred to as (lateral) measurement positions or (lateral) measurement points corresponding to the lateral position of the light emission area pattern of the light source 121-k from which each measurement subrange originates. Furthermore, the two or more measurement subranges are also spatially distributed at different positions in the vertical direction, depending on the vertical position (relative to the focal plane of the focusing optical assembly of the illumination assembly 120) of the light emission area pattern of the light source 121-k from which each measurement subrange originates.

[0029] In a non-limiting example, two or more measurement subranges may be distributed within the measurement range as described below: - Considering the lateral distribution of the measurement subranges, the light emitted from the light source 121-k positioned on axis A creates each measurement subrange along axis A, the light emitted from the light source 121-k positioned on the first side of axis A creates each measurement subrange at a lateral position on the second side of axis A (opposite the first side of axis A), and the light emitted from the light source 121-k positioned on the second side of axis A creates each measurement subrange at a lateral position on the first side of axis A. - Considering the vertical distribution of the measurement subranges, the light from the light source 121-k positioned 'behind' the focal plane of the focusing optical assembly in the illumination assembly 120 (with respect to the distance to the first optical assembly 140) will produce measurement subranges that are closer to the first optical assembly 140 than the measurement subranges produced by the light source positioned on the focal plane of the focusing optical assembly, and the light from the light source 121-k positioned 'in front' the focal plane of the focusing optical assembly will produce measurement subranges that are further from the first optical assembly 140 than the measurement subranges produced by the light source positioned on the focal plane of the focusing optical assembly. - The respective emission region patterns of the light source 121-k, which are offset laterally from axis A, result in the first optical assembly 140 focusing different wavelengths at different distances from axis A, and the focal offset from axis A increases with the distance of the emission region from axis A. Thus, the resulting measurement subrange is defined by a focal range that is slightly tilted with respect to axis A, thereby causing a 'drift' in each (lateral) measurement position that moves away from axis A as the distance of the emission region from axis A increases.

[0030] In view of the above, since each of the two or more light sources 121-k emits light that transmits the same predetermined wavelength range, each of the two or more measurement subranges created based on the position of each light source's respective emission area pattern of the two or more light sources 121-k provides a different mapping between the predetermined wavelength range and the corresponding sub-candidate distance range at each (lateral) measurement position. In particular, the first light source of the two or more light sources 121-k located farther from the focusing optical assembly of the illumination assembly 120 creates a measurement subrange that covers a shorter candidate distance than another measurement subrange created by the second light source of the two or more light sources 121-k located closer to the focusing optical assembly, thereby providing a different mapping between the corresponding sub-candidate distance range and the predetermined wavelength range in each measurement subrange created by the light from the respective emission area patterns of the first and second light sources 121-k.

[0031] Considering the two or more measurement subranges resulting from the use of two or more light sources 121-k, as exemplified in Figure 2 which includes three light sources 121-1, 121-2, and 121-3, the relationship between the respective positions of the three light sources 121-1, 121-2, and 121-3 and the measurement subranges created based on the light from their respective emission region patterns can be described as follows: - The light source 121-2 can be positioned on axis A at the focal plane of the condensing lens assembly 122, and as a result, the longitudinal dispersion generated by the first optical assembly 140 will focus a predetermined wavelength range transmitted by the emission region pattern generated from the light source 121-2 into a second measurement sub-range located on axis A that covers a second sub-candidate distance range. - The light source 121-1 can be positioned 'behind' the focal plane of the condensing lens assembly 122 on the first side of axis A, and as a result, the longitudinal dispersion generated by the first optical assembly 140 will focus a predetermined wavelength range transmitted by the emission area pattern of the light source 121-1 into a first measurement subrange located at a (lateral) measurement position on the second side of axis A, in a range of longitudinal positions closer to the first optical assembly 140 than a second measurement subrange created based on the emission area pattern of the light source 121-2, thereby the first measurement subrange will cover a first sub-candidate distance range that includes candidate distances shorter than the candidate distances of the second sub-candidate distance range. - The light source 121-3 can be positioned 'in front' of the focal plane of the focusing lens assembly 122 on the second side of axis A, and as a result, the longitudinal dispersion generated by the first optical assembly 140 will focus a predetermined wavelength range transmitted by the emission area pattern of the light source 121-3 into a third measurement subrange located at a (lateral) measurement position on the first side of axis A, in a longitudinal position further from the first optical assembly 140 than the second measurement subrange created based on the emission area pattern of the light source 121-2, thereby the third measurement subrange will cover a third sub-candidate distance range that is longer than the candidate distance of the second sub-candidate distance range.

[0032] Accordingly, in the example of Figure 2, where two or more light sources 121-k, each positioned at different distances from the focusing optical assembly and at different distances from axis A, each have two or more emission region patterns that together create separate measurement subranges that define the (overall) measurement range, the longitudinal position and depth of the measurement range depend at least on the amount of longitudinal chromatic dispersion introduced by the first optical assembly 140, the respective positions of the two or more light sources 121-k relative to the focusing optical assembly, and a predetermined range of wavelengths to be considered in the measurement. These characteristics of the sensor device 110 may be selected to ensure that the resulting two or more measurement subranges exhibit partial longitudinal overlap with each other, thereby covering the (overall) measurement range without gaps. As an example, the design of the sensor device 110 may involve at least partially experimental steps, starting with defining a desired depth of the measurement range, followed by selecting the respective positions of the two or more light sources 121-k, selecting a predetermined wavelength range to be emitted from the two or more light sources 121-k, and / or selecting the focusing characteristics of the first optical assembly 140 so that the desired depth of the measurement range is obtained.

[0033] The beam splitter 130 is positioned along axis A between the illumination assembly 120 and the first optical assembly 140, and is configured to transmit light emitted from the illumination assembly 120 toward the first optical assembly 140, and to bend light reflected from the surface of the object 180 (temporarily) brought into the measurement range for transmission along axis B. The beam splitter 130 can receive reflected light along axis A through the first optical assembly 140, which results in the light reflected from the surface of the object 180 being converted back from a longitudinal color 'dispersion domain' to a 'non-dispersion domain' with respect to further reflection from the beam splitter 130 toward the second optical assembly 150 along axis B. Thus, light originating from the illumination assembly 120 is guided along axis A through the first optical assembly 140 toward the object 180, and light reflected from the object 180 is collected along axis A through the first optical assembly 140, thereby providing a coaxial measurement configuration.

[0034] The beam splitter 130 may have an applicable beam splitter known in the art, configured to transmit a first portion of the light directed thereto and reflect a second portion of the light directed thereto in both directions. In this regard, the first and second portions of the light typically total 100%, however, in beam splitter implementations that rely on a reflective coating deposited on an optical substrate, for example, a small amount of light may be absorbed by the coating. As an example, the first and second portions may each be substantially 50%, thereby providing the beam splitter 130 as a 50 / 50 beam splitter.

[0035] The second optical assembly 150 is configured to receive light from the beam splitter 130 over a predetermined wavelength range along axis B, disperse the received light over the predetermined wavelength range laterally, and focus the laterally dispersed light over the predetermined wavelength range to a predetermined (focal) distance for reception by the photosensor assembly 160. Thus, the light received by the second optical assembly 150 can be transmitted as a whole through the second optical assembly 150 and further to the photosensor assembly 160. The lateral dispersion introduced in the second optical subassembly 150 results in the transmission of light over the predetermined wavelength range in a laterally dispersed form along axis C toward the photosensor assembly 160, such that different wavelengths within the predetermined wavelength range are focused at different lateral positions at the focal distance. It should be noted in this regard that, in the context of describing the characteristics of the light bent by the beam splitter 130 and the laterally dispersed light, the concept of laterality is different from that applied in the description of the illumination assembly 120 and the first optical assembly 140. In particular, in the context of describing the properties of light bent by the beam splitter 130, the transverse direction has a direction that crosses axis B (for example, substantially perpendicular to it), whereas in the context of describing the properties of light dispersed in the transverse direction, the transverse direction has a direction that crosses axis C (for example, substantially perpendicular to it).

[0036] In the respective examples of Figures 1 and 2, the second optical assembly 150 comprises a dispersion prism 151 and a second focusing lens assembly 152, wherein the dispersion prism 151 is configured to receive light over a predetermined wavelength range and introduce a predetermined amount of lateral chromatic dispersion into the light it receives from the beam splitter 130, and the second focusing lens assembly 152 is configured to focus the laterally dispersed light to a predetermined (focal) distance. The properties of the dispersion prism 151 can be selected to provide a desired amount of lateral dispersion, and the applicable amount of lateral dispersion may depend, for example, on a predetermined wavelength range considered in the measurement and / or the depth of the measurement range created by the first optical assembly 140.

[0037] As described above, the second optical assembly 150 and the dispersion prism 151 within it can receive the light bent by the beam splitter 130 substantially entirely, and the light received by the second optical assembly 150 and the dispersion prism 151 within it is similarly substantially entirely present in the laterally dispersed light provided as the output of the second optical assembly 150 for light reception at the sensor surface of the light sensor assembly 160 (described in more detail below). In other words, the second optical assembly 150 is configured to transmit the light received from the beam splitter 130 substantially entirely for light reception at the sensor surface of the sensor assembly 160. Thus, while receiver optics typically applied in known solutions involve spatial filtering by focusing the light they receive into a receiver pinhole or receiver slit, which results in only focused wavelengths of the received light passing through while substantially blocking out-of-focus wavelengths, the second optical assembly 150 does not apply filtering to the light that passes through it. The omission of such spatial filtering in the second optical assembly 150 allows for a simplified and more affordable construction of the optical configuration applied to the sensor device 110 and facilitates simple adjustment of the relative positions and / or orientations of the elements of the sensor device 110.

[0038] The dispersion prism 151 schematically shown in Figures 1 and 2 functions as an example of a dispersion optical component, but in other examples, the dispersion prism 151 may be replaced by other dispersion optical components or by a configuration of two or more optical components that provide a desired amount of lateral dispersion to the light received therein. Non-limiting examples of such other dispersion optical components include transmission diffraction gratings and reflection diffraction gratings. The use of dispersion optical components other than the dispersion prism 151 may require repositioning the second focusing lens assembly 152 (or other focusing optical component or assembly) and / or the photosensor assembly 160 in accordance with such modification in order to provide the functions assigned to the second optical assembly 150 and the photosensor assembly 160 in the sensor device 110 according to this disclosure.

[0039] The second focusing lens assembly 152 schematically shown in Figures 1 and 2 functions as an example of a focusing optical component or assembly, but in other examples, the second focusing lens assembly 152 may be replaced by other focusing optical assemblies, such as a focusing mirror assembly or a focusing optical assembly having one or more lenses and one or more mirrors. The use of a focusing optical assembly other than the second focusing lens assembly 152 may require repositioning the dispersion prism 151 (or other dispersion optical component) and / or the optical sensor assembly 160 in accordance with the modification in order to provide the functions assigned to the second optical assembly 150 and the optical sensor assembly 160 in the sensor device 110 according to the present disclosure.

[0040] In a further example, the dispersion optical component and the focusing optical component, shown as the dispersion prism 151 and the second focusing lens assembly 152, respectively, in the examples of Figures 1 and 2, may be replaced by a single optical component or assembly that provides a desired amount of lateral dispersion and performs focusing.

[0041] The optical sensor assembly 160 is positioned at a predetermined (focal) distance from the second optical assembly 150 and has a sensor surface that receives laterally dispersed light from the second optical assembly 150 along axis C. As described above, light over a predetermined wavelength range transmitted in the bent light provided as input to the second optical assembly 150 and in the laterally dispersed light output from the second optical assembly 150 is received by the sensor surface. In this regard, one or more light intensity patterns in the laterally dispersed light are spaced apart from each other, as are their projections onto the surface of object 180, and this spacing is maintained in their projections onto the sensor surface. In particular, due to the lateral dispersion introduced by the second optical assembly 150, the sensor surface receives light from one or more light emission region patterns in one or more corresponding sub-position ranges along axis y' on the sensor surface. Conversely, each of the one or more sub-position ranges along axis y' on the sensor surface maps to a predetermined wavelength range transmitted in one of the one or more light emission region patterns. In one example, axis y' on the sensor surface is aligned with the direction of lateral dispersion generated by the operation of the second optical assembly 150, in other words, axis y' is substantially parallel to the direction of lateral dispersion, ensuring that each light from one or more light-emitting region patterns is received in a laterally dispersed form in separate and non-overlapping sub-position ranges along axis y'. In another example, axis y' may have a non-zero angle with the direction of lateral dispersion generated in the second optical assembly 150, and the angle between axis y' and the direction of lateral dispersion is selected so that each light from one or more light-emitting region patterns is received in separate sub-position ranges along non-overlapping axes y' on the sensor surface.

[0042] As described above, (in the scenario following the example in Figure 2) the light from each of the one or more light emission area patterns of the illumination assembly 120 results in the creation of a respective measurement subrange, and the mapping from a given wavelength range to a corresponding sub-candidate distance range differs from that of other measurement subranges. Therefore, the applicable mapping between a given wavelength range and the corresponding sub-candidate distance range within the measurement range differs for each sub-position range along axis y' on the sensor surface. In other words, for each of the one or more sub-position ranges along axis y' on the sensor surface (receiving laterally dispersed light from each of the one or more light emission area patterns), there exists a respective predetermined mapping from the given sub-position range along axis y' on the sensor surface to the corresponding sub-candidate distance range within the measurement range, and this mapping depends on the spatial arrangement of the optical components of the sensor device 110.

[0043] In the example of Figure 1, which utilizes a single luminescence pattern for measurement, the laterally dispersed light from the single luminescence pattern is received on the sensor surface within a single sub-position range along axis y', while the distance to the surface of object 180 at the location of a single (lateral) measurement position can be determined based on the intensity of the light received on the sensor surface as a function of the position across a single sub-position range along axis y' on the sensor surface. Each position within the single sub-position range along axis y' maps to a corresponding wavelength in a predetermined wavelength range via a predetermined mapping, and each wavelength in the predetermined wavelength range maps to a corresponding candidate distance within the measurement range. As described above, a single wavelength of the longitudinally dispersed light from the single luminescence pattern, focused by the first optical assembly 140 to a candidate distance coinciding with the surface of object 180 at the location of a single (lateral) measurement position, provides a sharp image of the luminescence pattern on the sensor surface, while other wavelengths not focused to this candidate distance do not provide a sharp image of the luminescence pattern on the sensor surface. Therefore, the sensor surface position within a single sub-position range along axis y' on the sensor surface, where the light transmitted from a single light emission region pattern receives the highest intensity, maps to a candidate distance that coincides with the position on the surface of object 180 at the location of a single (lateral) measurement position, and thus determines the distance to the surface of object 180. In this regard, at least the following scenarios can be considered: - There is no (local) intensity maximum that constitutes a peak in the light intensity across a single sub-position range along axis y', which suggests that the surface of object 180 is not within the measurement range. - There is a (local) intensity maximum that constitutes a peak in light intensity across a single sub-position range along axis y', which suggests the presence of a surface of object 180 within the measurement range at a candidate distance that maps (via the corresponding wavelength) to the location of the intensity maximum within a single sub-range along axis y'.

[0044] In the example of Figure 2, which utilizes two or more light emission patterns for measurement, the light from each of the two or more light emission patterns is received on the sensor surface within each of two or more sub-position ranges along axis y', while the distance to the surface of object 180 at each (lateral) measurement position can be determined based on the intensity of the light received on the sensor surface as a function of the position across each of the two or more sub-position ranges along axis y' on the sensor surface. In each of the two or more sub-position ranges along axis y', each position is mapped to a corresponding wavelength in a predetermined wavelength range via a predetermined mapping related to the respective sub-position range, and each wavelength in the predetermined wavelength range is mapped to a corresponding candidate distance within the respective measurement sub-range via a predetermined mapping related to the respective measurement sub-range. As described above, the wavelengths of vertically dispersed light generated from each of the two or more light emission region patterns, which are focused by the first optical assembly 140 to candidate distances that coincide with the surface of object 180 at each (lateral) measurement position, provide a sharp image of the reflected light, resulting in the sensor surface receiving reflected light with higher intensity compared to other wavelengths that are focused to candidate distances that do not coincide with the surface of object 180. Therefore, the sensor surface positions across two or more sub-position ranges along axis y' on the sensor surface that receive the light transmitted by the light generated from the two or more light emission region patterns with the highest intensity map to (one or more) candidate positions that coincide with the positions on the surface of object 180 at each of the two or more (lateral) measurement positions, and thus determine the respective distances to the surface of object 180 at each (lateral) measurement position. In this regard, at least the following scenarios can be considered: - There are no (local) intensity maximums constituting a peak in light intensity across two or more sub-position ranges along axis y', which suggests that the surface of object 180 is not within the measurement range. - There is a single (local) intensity maximum that constitutes a peak at one of two or more sub-position ranges along axis y', which suggests the presence of the surface of object 180 within the measurement range at each (lateral) measurement position at a candidate distance that maps (via the corresponding wavelength) to the location of the single local intensity maximum within each of the two or more sub-position ranges along axis y'. - There are two or more local intensity maximums that constitute each peak at one light intensity in each of two or more sub-position ranges along axis y', which suggests the presence of the surface of object 180 within the measurement range at each of two or more (lateral) measurement positions at each candidate distance that maps (via the corresponding wavelength) to each of the two or more local intensity maximums within each of the two or more sub-position ranges along axis y'.

[0045] In the above scenario, a scenario in which the presence of the surface of object 180 is detected based on a single (local) maximum intensity value may occur, for example, when measuring a substantially opaque surface that is substantially flat, substantially aligned with the measurement range, or has only a slight inclination with respect to the measurement range, while a scenario in which the presence of the surface of object 180 is detected based on two or more local maximum intensity values ​​may occur, for example, when measuring a substantially flat surface with a large inclination with respect to the measurement range, or when measuring a non-flat surface regardless of its orientation with respect to the measurement range.

[0046] The optical sensor assembly 160 can be embodied as a line sensor or a pixel sensor, as known in the art. In a non-limiting example, the sensor assembly 160 may have an image sensor, such as a charge-coupled device (CCD) sensor or a complementary metal-oxide-semiconductor (CMOS) sensor.

[0047] The detector assembly 170 is configured to determine the distance to the surface of object 180 based on one or more local intensity maximums of light dispersed laterally across one or more sub-position ranges along axis y' on the sensor surface. As described above, the presence of the surface of object 180 within the measurement range may be detectable based on one or more (local) intensity maximums of light dispersed laterally across one or more sub-position ranges along axis y'. In particular, the distance to the surface of object 180 may be determined based on one or more candidate distances that map to one or more locations, respectively, of the local intensity maximums of light dispersed laterally along axis y' on the sensor surface. As an example of this, the detector assembly 170 may be configured to determine the distance by the following procedure, which includes identifying the location of one or more local intensity maximums across one or more sub-position ranges along axis (y') on the sensor surface, and for each of the one or more identified locations, performing the following: - Within that, identify each sub-position range along axis y' in which each specified position exists, - From each predetermined mapping between each sub-position range along axis y' and the corresponding sub-candidate distance range, select a predetermined mapping related to each identified sub-position range, and then, - A selected predetermined mapping is applied to identify candidate distances corresponding to the (relative) position of each identified position within the identified sub-position range, thereby determining the distance to the surface of object 180 at each (lateral) measurement position.

[0048] As described above, in the example of Figure 1, which results in guiding laterally dispersed light from a single emission region pattern to a single sub-position range along axis y', the applicable mapping between the sub-position range along axis y' and the corresponding sub-candidate distance range is the same regardless of the position along axis y' (in other words, the identification of the sub-position range along axis y' in which the maximum intensity is located is implicit). In the example of Figure 2, which results in guiding laterally dispersed light from two or more emission region patterns to two or more sub-position ranges along axis y', the distance determination may involve first identifying the sub-position range along axis y' in which the maximum intensity is located, and then determining candidate distances through the application of each mapping related to the identified sub-position range along axis y'.

[0049] The detector assembly 170 can be embodied as a device having a processor and memory, the memory being configured to store computer program code that implements the operation of the detector assembly 170 in accordance with this disclosure when executed by the processor.

[0050] Figure 3A schematically shows the mapping between sub-position ranges along axis y' on the sensor surface, following a non-restrictive example within the framework of the example in Figure 1. In this regard, Figure 3A shows a single measurement sub-range Z at a single (lateral) measurement position (left figure). m This scenario involves the use of a single light source 121 that provides a single emission region pattern to create. Due to the lateral dispersion introduced in the second optical assembly 150, a given wavelength range of the laterally dispersed light corresponds to a subposition range y' along axis y' on the sensor surface. mIt is distributed over (center figure). As mentioned above, a sharp image of reflected light at wavelengths focused to candidate distances that coincide with the surface of object 180 results in the sensor surface receiving reflected light at a relatively high intensity compared to the received light intensity at wavelengths focused to candidate distances that do not coincide with the surface of the object, and the intensity of light received by the sensor surface gradually decreases as the distance between the non-coincident candidate distance and the surface of object 180 increases. Therefore, the sub-position range y' along axis y' on the sensor surface m The light intensity as a function of position over a single sub-position range y' maps to a candidate distance that coincides with the surface of object 180 at a single (lateral) measurement position. m At this position, it can be represented as a curve showing the (local) maximum intensity value that constitutes the peak in light intensity along axis y' (right-hand figure).

[0051] Figure 3B schematically shows the mapping between sub-position ranges along axis y' on the sensor surface, following a non-restrictive example within the framework of the example in Figure 2. In this regard, Figure 3B shows the three measurement sub-ranges Z at each of the three (lateral) measurement positions (left side of the figure). 1、 Z 2、 This scenario involves the use of three light sources 121-1, 121-2, and 121-3, each providing three emission region patterns to create Z3. Lateral dispersion introduced in the second optical assembly 150 allows for the measurement of the subrange Z. 1、 Z 2、 The predetermined wavelength range transmitted by the light from each of the three emission region patterns reflected from Z3 is distributed across the respective sub-position ranges y'1, y'2, and y'3 along axis y' on the sensor surface (center figure). In the example in Figure 3B, the light intensity as a function of position within each of the sub-position ranges y'1, y'2, and y'3 can be a piecewise curve across each of the sub-position ranges y'1, y'2, and y'3, which shows a (local) intensity maximum that constitutes a peak in light intensity at a position within sub-position range y'2 that maps to a candidate distance that coincides with the surface of object 180 at each of the three (lateral) measurement positions (right figure).

[0052] In one example, one or more light sources 121, 121-k are configured to emit light with substantially uniform radiant power over a predetermined wavelength range, ensuring that the radiant power of each reflection from one or more emission region patterns from the surface of an object 180 (temporarily) positioned within the measurement range is substantially independent of wavelengths within that range, thereby enabling the determination of the distance to the object 180 within the measurement range via a direct comparison of the respective light intensities over one or more sub-position ranges along axis y' on the sensor surface. In another example, the radiant power of the emitted light may vary over a predetermined wavelength range, but in such an approach, the detector assembly 170 is configured to take into account the wavelength dependence of the radiant power of the light transmitted by one or more emission region patterns originating from the illumination assembly 120 when determining the maximum intensity over one or more sub-position ranges along axis y' on the sensor surface, in order to ensure accurate determination of the sensor surface position corresponding to a candidate distance coinciding with the surface of the object 180 positioned therein.

[0053] Considering the applicable predetermined wavelength ranges in the examples of Figures 1 and 2, in the example of Figure 1, a relatively wide wavelength range is required to ensure a measurement range of sufficient depth for the intended operation and purpose of the sensor device 110. As a non-limiting example, in the example of Figure 1, the predetermined wavelength range can span a band with a width of 10–150 nm, covering a selected subrange of visible wavelengths (i.e., approximately 400–700 nm). The use of a single light source 121 may be advantageous because it allows for a relatively simple design regarding the configuration of the optical components of the sensor device 110, by requiring only consideration of the reflection of light from a single emission area pattern from a single measurement subrange. Furthermore, the single light source 121 can be positioned on the focal plane of the focusing optical assembly of the illumination assembly 120, thereby emitting a single emission area pattern as substantially collimated light that is also substantially collimated when received by the dispersive optical component of the second optical assembly 150, thereby ensuring sharp focusing of laterally dispersed light on the sensor surface.

[0054] In the example in Figure 2, the use of multiple light sources 121-k allows for a relatively narrow wavelength range to create multiple measurement subranges for different candidate distances within the measurement range. As a non-limiting example, in the example in Figure 2, a given wavelength range can span a bandwidth of 10–50 nm, such as 25 nm, and can cover a pre-selected subrange of visible wavelengths, such as selected from a subrange of 420–480 nm. In another non-limiting example, a given wavelength range could cover a 25 nm bandwidth from 425 nm to 450 nm (i.e., violet and / or blue light). In this regard, the use of any relatively narrow bandwidth facilitates the provision of substantially uniform radiant power across the applied wavelength range, while the use of the violet-blue spectrum is advantageous in that light-emitting diodes (LEDs) that provide relatively high radiant power in this wavelength range are readily available for use as two or more light sources 121-k. The multiple measurement subranges resulting from the application of multiple light sources 121-k may introduce some additional complexity when fine-tuning the configuration of the optical components of the sensor device 110, but it allows for the provision of an increased measurement depth measurement range using the relatively narrow bandwidth of light emitted from the illumination assembly 120.

[0055] The use of a relatively narrow bandwidth offers further advantages in terms of simplified and / or more affordable optical design, through the use of simpler optical components and / or less expensive glass materials, compared to designs using a relatively wide bandwidth. Another further advantage of the relatively narrow bandwidth arises from the operation of the second optical assembly 150, where, as previously mentioned, using two or more light sources 121-k to provide light from two or more emission region patterns results in the illumination assembly 120 emitting light that is not fully collimated and the dispersion optical component of the second optical assembly 150 receiving such light. However, the relatively narrow bandwidth nevertheless ensures that the laterally dispersed light on the sensor surface is focused sharp enough to allow detection of local intensity maximums along axis y' on the sensor surface.

[0056] The sensor device 110 described above may be employed as a component of a measuring instrument or measuring system applicable to measuring one or more aspects or characteristics of the surface shape of an object 180 by operating the sensor device 110 to measure the distance to a plurality of positions on the surface of an object 180, thereby capturing data that can describe the shape of the surface of the object 180. As an example, the measuring instrument or measuring system may have mechanisms for moving the object 180 to a plurality of different measuring positions relative to the sensor device 110 according to a predetermined movement pattern, and for operating the sensor device 110 to measure the distance to the surface of the object 180 at the plurality of different measuring positions. In another example, the measuring instrument or measuring system may have mechanisms for moving the sensor device 110 to a plurality of different measuring positions relative to the object 180 according to a predetermined movement pattern, and for operating the sensor device 110 to measure the distance to the surface of the object 180 at the plurality of different measuring positions.

[0057] Accordingly, a measuring instrument or measuring system may be applied to scan a region on the surface of object 180 and derive a three-dimensional (3D) map of the shape of the surface of object 180 using the measured distances obtained during the scanning process. In this regard, the movement pattern can define step-by-step movement through a plurality of positions covering the region to be scanned via scanning parameters that define the step size, step direction, and predetermined timing between consecutive steps for scanning, and the measuring instrument or measuring system can derive the 3D map based on the scanning parameters and knowledge of the respective distances measured at the plurality of positions. The measuring instrument or measuring system may further apply knowledge of the lateral and longitudinal positions of one or more measurement subranges and the light intensity across one or more sub-position ranges along axis y' on the sensor surface captured via the operation of the detection unit 170 in deriving the 3D map. The movement pattern is preferably designed to ensure that the respective distance to the surface of object 180 is measured at least once at each of the plurality of positions, in view of the lateral distribution of one or more measurement subranges of the sensor device 110. As an example related to this, in a scenario where the measurement depends on multiple measurement subranges at each lateral measurement position, the movement pattern may include scanning steps with a sufficiently small step size in the y-direction to ensure that all desired measurement points on the surface of object 180 in the y-direction are covered.

[0058] In the above, the operation of the sensor device 110 and its application as part of a measuring device or measuring system have been described implicitly by referring to the measurement of the distance to a single surface of an object 180 (temporarily) positioned within the measurement range, which in practice implies the measurement of the distance to the outer surface of the object 180 (i.e., the surface of the object 180 facing the first optical subassembly 140). However, exemplary modifications of the sensor device 110 according to the examples in Figures 1 and 2 may be applied to determine the distances to the outer surface and the other surface, respectively, provided that the material of the object 180 between the outer surface and another surface beneath the outer surface (e.g., an embedded surface) is transparent to light in a predetermined wavelength range applied to the measurement by the sensor device 110. This may, for example, allow for the determination of the thickness of a (transparent) coating layer provided as the outermost layer on the surface of the object 180, or the determination of the thickness of a (transparent) film provided as the object 180 for measurement via the operation of the sensor device 110.

[0059] The optical configuration of the sensor device 110, including the illumination assembly 120, beam splitter 130, first optical assembly 140, second optical assembly 150, and sensor assembly 160, is therefore applicable to such measurements of the respective distances to the two surfaces of object 180, while the (possible) presence of another surface embedded beneath the outer surface can be taken into account in the operation of the detector assembly 170. In this regard, both the outer surface and the other surface of object 180 yield respective peaks in the light intensity on the sensor surface corresponding to the respective candidate distances that coincide with these two surfaces of object 180 at the respective (lateral) measurement positions, and these may appear as the respective local intensity maximums in the laterally dispersed light captured on the sensor surface of the sensor assembly 160.

[0060] In a scenario following the example in Figure 1, where a single emission region pattern is applied, the respective maximum intensity values ​​originating from the outer surface and another surface of object 180 can appear as respective local maximum intensity values ​​within a single sub-position range along axis y', thereby making them easily recognizable as reflections originating from two different surfaces of object 180, even if there is no significant difference in the magnitude of each of these two local maximum intensity values. Thus, the respective candidate distances corresponding to the respective positions of these two local maximum intensity values ​​can be found based on their respective positions within a single sub-position range through the use of the (one or more) mappings described above, with the shorter of the two distances implicitly relating to the outer surface of object 180 and the longer of the two distances relating to the other surface of object 180. In a scenario following the example in Figure 2, where two or more emission region patterns are applied, the respective maximum intensity values ​​originating from the outer surface and another surface of object 180 can appear as respective local maximum intensity values ​​within the same sub-position range along axis y', or in different sub-position ranges along axis y'. Therefore, similar to the scenario using a single emission region pattern, in this scenario as well, the respective candidate distances corresponding to the respective locations of these two local intensity maximums can be found based on their respective locations within the respective sub-position ranges of two or more sub-position ranges along axis y', through the use of the respective (one or more) mappings described above.

[0061] A variation of the sensor device 110 configured to measure the respective distances to two surfaces of object 180 can be applied as an element of a measuring device or measuring system, as described above, with the necessary modifications. In particular, the use of such a variation of the sensor device 110 may enable, for example, the measurement of the thickness of a coating provided as the outermost layer of object 180 or the thickness of a film provided as object 180, via the derivation of a 3D map of the type described above, based on the respective distances to the outer layer and other layers of object 180 at multiple measurement positions.

[0062] In a further example, the operation of the sensor device 110 is generalized to measuring at least one characteristic of the surface of an object 180 (temporarily) positioned within a measurement range, the at least one characteristic of the surface may include the position of one or more surfaces of the object 180 positioned within the measurement range, or one or more optical characteristics of the surface of the object 180 positioned within the measurement range. In this regard, as another exemplary variation of the sensor device 110 according to the examples in Figures 1 and 2, the operation of the detector assembly 170 may include using the light intensity as a function of the position along axis y' on the sensor surface of the sensor assembly 160 directly as an indicator of the reflectance or gloss of the (outer) surface of the object 180 (temporarily) positioned within the measurement range, for example, so that the reflectance or gloss is determined based on the magnitude of one or more local intensity maximums along axis y'. When such a modification of the sensor device 110 is used as an element of the above-described type of measuring device or measuring system for scanning the surface of object 180, it will provide a high-precision two-dimensional (2D) map of the surface of object 180, which will function as a 2D image that is (substantially perfectly) in focus throughout, regardless of changes in the shape of the surface in the longitudinal direction (i.e., in the z-direction along axis A). Such 2D imaging of object 180 can serve as a reconstruction of any text and / or patterns provided on the surface of object 180.

[0063] Referring to the respective examples in Figures 1 and 2, the sensor device 110 described above, and its exemplary variations described above, can be further modified in several ways without departing from the scope of the sensor device 110 according to this disclosure. As an example thereof, the sensor device 110 may include one or more elements not shown in each of Figures 1 and 2, one or more elements shown in each of Figures 1 and 2 may be omitted, and / or one or more elements shown in each of Figures 1 and 2 may be replaced by other elements that can serve the same or substantially similar purpose as the respective elements that function to replace them.

Claims

1. An optical sensor device (110) for determining at least one characteristic of the surface of an object (180) positioned within a measurement range, An illumination assembly (120) having two or more light sources (121, 121-k) positioned at different locations with respect to the optical axis and focal plane of a focusing optical assembly and configured to emit light toward the measurement range through the focusing optical assembly (122), wherein the light emitted from each of the two or more light sources covers the same predetermined wavelength range, and the two or more light sources are configured to form two or more emission region patterns of a predetermined spatial shape, A first optical assembly (140) configured to disperse light emitted from the illumination assembly (120) in the vertical direction, wherein light over a predetermined wavelength range from each of the two or more light emission region patterns is focused to respective focal length ranges constituting two or more corresponding sub-candidate distance ranges within the measurement range at two or more measurement positions distributed at different distances from the optical axis (A) of the first optical assembly (140), A beam splitter (130) is configured to transmit light emitted from the illumination assembly (120) toward the first optical assembly (140) and to bend the light reflected from the surface of the object (180) and received through the first optical assembly (140), A second optical assembly (150) is configured to receive the bent light over a predetermined wavelength range, to disperse the received light over the predetermined wavelength range laterally, and to focus the laterally dispersed light over the predetermined wavelength range to a predetermined distance. A light sensor assembly (160) having a sensor surface positioned at a predetermined distance to receive the laterally dispersed light over the predetermined wavelength range, wherein the light generated from the two or more light emission region patterns is received in two or more corresponding sub-position ranges along the axis (y') on the sensor surface, A detector assembly (170) configured to determine at least one characteristic of the surface of the object (180) based on the intensity of each of the laterally dispersed light received over two or more sub-position ranges along the axis (y') on the sensor surface, An optical sensor device (110) having the following features.

2. The detector assembly (170) is determined based on one or more local intensity maximum values ​​of the laterally dispersed light across two or more sub-position ranges along the axis (y') on the sensor surface. The distance from the object (180) to the surface, The optical properties of the surface of the object (180), An optical sensor device (110) according to claim 1, configured to determine one or more of the following.

3. The optical sensor device (110) according to claim 2, wherein the detector assembly (170) is configured to determine the distance from the surface of the object (180) to one or more of the two or more measurement positions based on two or more candidate distances corresponding to two or more wavelengths corresponding to each of the positions of the two or more local intensity maximum values ​​of light dispersed laterally within each of the two or more sub-position ranges along the axis (y') on the sensor surface.

4. The detector assembly (170) is Identify the location of each of the two or more local intensity maximum values ​​across the two or more sub-position ranges along the axis (y') on the sensor surface, and for each of the identified locations, Each of the aforementioned identified positions is located within a corresponding sub-position range along the axis (y'), From the predetermined mappings between the sub-position range along the axis (y') and the corresponding sub-candidate distance range, a predetermined mapping related to each of the identified sub-position ranges is selected. Applying the selected predetermined mapping, one of the candidate distances corresponding to the relative position of each of the identified positions within the identified sub-position range is identified, thereby determining the distance to the surface of the object (180). An optical sensor device (110) according to claim 2, configured to perform the following.

5. The optical sensor device (110) according to claim 2, wherein the detector assembly (170) is configured to determine the reflectance of the surface of the object (180) based on the magnitude of each of the one or more local intensity maximums of the laterally dispersed light over two or more sub-position ranges along the axis (y') on the sensor surface.

6. The predetermined wavelength range extends across a bandwidth having a width in the range of 10 nanometers to 50 nanometers, and The predetermined wavelength range is between 420 nanometers and 480 nanometers. The optical sensor device (110) according to claim 1, wherein at least one of the following is applied.

7. The optical sensor device (110) according to claim 1, wherein the predetermined spatial shape of the two or more light-emitting region patterns has points or lines.

8. The light emitted from the two or more light sources (121, 121-k) is generated from two or more light-emitting diodes, and The two or more light sources (121, 121-k) are provided by projecting light through a pinhole array or a slit array. The optical sensor device (110) according to claim 1, wherein at least one of the following is applied.

9. The optical sensor device (110) according to claim 1, wherein the first optical assembly (140) has a focusing lens assembly (141) configured to provide a predetermined amount of longitudinal chromatic dispersion.

10. The second optical assembly (150) is A dispersion optical component (151) is configured to receive the bent light over a predetermined wavelength range from the beam splitter (130) and to provide a predetermined amount of lateral color dispersion to the bent light over the predetermined wavelength range, A focusing optical assembly (152) configured to focus the light dispersed laterally over the predetermined wavelength range to the predetermined distance, An optical sensor device (110) according to claim 1, having the above characteristics.

11. The optical sensor device (110) according to claim 1, wherein the second optical assembly (150) is configured to receive the bent light substantially as a whole and to provide the received bent light substantially as a whole as light dispersed laterally for light reception on the sensor surface of the optical sensor assembly (160).

12. The optical sensor device (110) according to claim 1, wherein the optical sensor assembly (160) has an image sensor.

13. An optical measuring device for determining the surface properties of an object (180) positioned within a measurement range, An optical sensor device (110) according to any one of claims 1 to 12, configured to determine at least one characteristic of the surface of the object (180), A mechanism for changing the relative position between the sensor device (110) and the object (180), It has, The measuring device is The object (180) is moved to multiple positions relative to the sensor device (110) according to a predetermined movement pattern. The sensor device (110) is operated to determine at least one characteristic of the surface of the object (180) at the plurality of locations. Based on the at least one characteristic of each of the surfaces of the object (180) determined at the plurality of positions, the surface characteristics of the object (180) are determined. It is configured in such a way. Measuring device.

14. The measuring device according to claim 13, wherein the surface characteristics include the shape of the surface of the object (180), and the sensor device (110) is configured to determine the distance to the surface of the object (180) based on the position of each of the one or more local intensity maximums of the laterally dispersed light over two or more sub-position ranges along the axis (y') on the sensor surface.

15. The measuring device according to claim 13, wherein the surface characteristics include the reflectance of the surface of the object (180), and the sensor device (110) is configured to determine the reflectance of the surface of the object (180) based on the magnitude of each of the one or more local intensity maximums of the laterally dispersed light over the two or more sub-position ranges along the axis (y') on the sensor surface.

Images