Method and device for detecting optical composite element

Abstract

The invention relates to a method and a device for detecting optical properties of an optical composite component. Wherein the composite component comprises a plurality of transparent elements connected to one another and a reflective layer, the transparent elements and the reflective layer being arranged in such a way that light coupled in at the coupling-in section is split into a plurality of first partial beams by means of the plurality of transparent elements in a first section of the composite component, the first partial beam is conducted along different paths in the composite element, and wherein the first partial beam is partially reflected a plurality of times in the second section likewise by means of a plurality of transparent elements such that a plurality of second partial beams are emitted laterally as a result of the partial reflection, and wherein the second partial beams are detected by means of a detector, and determining a quality indicator for the plurality of second partial beams from the signal of the detector, and wherein the plurality of second partial beams are preferably selected according to an aggregation rule, a quality indicator is determined from the signal of said second partial beams such that the quality indicator can be assigned to a particular part of the composite component.

Description

Technical Field

[0001] This invention generally relates to the manufacture of optical composite elements having multiple optical elements joined together, wherein light is conducted and deflected by reflection. In particular, this invention relates to the inspection of the optical quality of such optical composite elements. Background Technology

[0002] For so-called "augmented reality" applications, special glasses are used that project additional information into the user's field of vision through optical devices. This information is typically input via a projector into the glasses lenses, conducted along the lenses via light transmission, and then coupled out again, making it visible to the observer. Different optical elements are arranged within the glasses lenses to couple the input, conduct the light, and couple the output.

[0003] For example, such spectacle lenses are known from EP 1 562 066 B1, US 2023 / 0314689 A1, and WO 2021 / 001841 A1. These spectacle lenses, constructed as image light conductors, can be manufactured by joining multiple optical components having reflective, and especially partially reflective, layers. These layers split image information, for example, input via a projector, into multiple partial beams, which are then conducted in the light conductor and distributedly coupled back out, allowing the observer to detect image information in addition to images of the surrounding environment. Not only the geometric accuracy of the individual components, but also, particularly, the construction of the reflective layers and the mutual orientation of the components, can affect the optical performance of the light conductor in terms of image quality. For example, the modulation transfer function (MTF) can be adversely affected by the skewed orientation and surface quality of the individual components and layers, leading to a reduction in image sharpness. Here, it is desirable not only to determine the quality factor, such as the MTF, but also, in the case of a poor quality factor, to determine which parts of the optical composite assembly are responsible. This is the object of the present invention. Summary of the Invention

[0004] To address this task, a method is provided for detecting the optical performance of an optical composite assembly, wherein the composite assembly includes multiple interconnected transparent elements and a reflective layer. The transparent elements and reflective layer are arranged such that light coupled into the composite assembly at a coupling input segment is split into multiple first beams by the multiple transparent elements in a first segment of the composite assembly. These first beams propagate along different paths within the composite element. Furthermore, in a second segment, these beams are also partially reflected multiple times by the multiple transparent elements, resulting in multiple second beams emitted laterally due to the partial reflections. The second part of the beam was detected using a detector, and The signal from the detector is used to determine, and in particular to calculate, quality indicators for multiple second-part beams, and wherein... Preferably, multiple second-part beams are selected according to the polymerization rule, and quality indicators are calculated from the signals of the second-part beams, so that the quality indicators can be assigned to specific parts of the composite component.

[0005] The corresponding apparatus for performing the method includes a support for the composite component and a light source, the light source being arranged relative to the support such that light coupled into the composite element at the coupling input section of the light source is split into multiple first partial beams in the first segment of the composite component using multiple transparent elements. These first partial beams are propagated along different paths in the composite element, and wherein these partial beams are also partially reflected multiple times in the second segment using multiple transparent elements (8), such that multiple second partial beams are emitted from the sides due to partial reflection. - Includes a detector for detecting the second part of the beam, and – An evaluation agency, wherein the evaluation agency is configured to… - A quality index is calculated from the signal of the detector for a plurality of second-part beams, and for this purpose, a plurality of second-part beams are selected in particular according to a convergence rule, and the quality index is determined from the signal of the second-part beams, such that the quality index can be assigned to a specific part of the composite component.

[0006] Such a portion can be a region or segment of a composite component. Particularly preferably, the selection of the second portion of the beam is even made so that a quality index can be assigned to a completely specific element of the composite component. In particular, such an element can be a specific reflective layer. Therefore, in improvements to the method and apparatus, it is specified that, in order to determine the quality index, the second portion of the beam is selected such that the light from the selected portion of the beam is reflected on a specific reflective layer. This reflection can also involve the first portion of the beam, from which the second portion of the beam is generated.

[0007] In the context of this disclosure, the partial beams need not be clear, linear rays, such as those produced by a laser. In the context of this disclosure, these partial beams can also be ray beams. This is, for example, the case when these partial beams transmit image information.

[0008] For the purposes of this disclosure, optical composite components, particularly glass elements, are considered to be transparent elements. However, plastic elements, such as those made of PMMA or polycarbonate, and plastics, such as those commonly used in eyeglass lenses, are also considered. Attached Figure Description

[0009] The invention will now be described in detail with reference to, but not limited to, the accompanying drawings. The same reference numerals denote the same or similar elements herein.

[0010] It shows that: Figure 1 An optical composite component is shown in a device for detecting the optical performance of the composite component.

[0011] Figure 2 An optical composite component is shown, along with a chart comparing several quality metrics.

[0012] Figure 3 A cross-section through the optical composite component is shown.

[0013] Figure 4 It shows according to Figure 3 The beam path for each first part of the beam in the composite component.

[0014] Figure 5 The location of the emission point of the second part of the beam on the second segment is shown.

[0015] Figure 6 A corresponding simulation is shown with the partially removed reflective layer in the first segment.

[0016] Figure 7 A corresponding simulation with a partially removed reflective layer is shown in the second segment.

[0017] Figure 8 The corresponding simulation is shown on a composite element without a mixer segment.

[0018] Figure 9 The corresponding simulation is shown on a composite element with a mixer segment and a characteristic ray emission point, which is relative to the presence of the mixer segment. Figure 7 Add to.

[0019] Figure 10 A crosshair is shown as image information used to determine the modulation transfer function and the arrangement of measurement points.

[0020] Figure 11 A side view of the composite assembly and the camera serving as a detector, as well as the beam path of the second beam section, are shown.

[0021] Figure 12 The values ​​of the modulation transfer function for different colors in two mutually perpendicular directions are shown.

[0022] Figure 13 The values ​​of the modulation transfer function at different measurement points in two mutually perpendicular directions are shown.

[0023] Figures 14 to 16 A contour plot of the modulation transfer function is shown. Detailed Implementation

[0024] Figure 1 An optical composite component 1 is shown, which is particularly suitable as a spectacle lens or screen for augmented reality applications. The composite component 1 is used to study optical quality in a device 2 for detecting the optical performance or optical quality of the composite component 1.

[0025] The composite component 1 consists of a plurality of interconnected transparent elements 8. Typically, and not limited to the example shown, glass elements are preferred as the transparent elements 8. The function of the composite component is also based on the fact that the image information to be displayed to the user is separated into multiple distinct partial beams in the direction of the user's eye and spatially distributed. In particular, a reflective layer 9 is provided for this separation. In a preferred design, the surfaces of the transparent elements 8 are coated with the reflective layer 9. The transparent elements 8 are connected to each other at these coated surfaces, especially by adhesive. In this way, a reflective layer 9 extending within the composite component 1 is obtained. For clarity, the adhesive layer... Figure 1 Not shown in the image.

[0026] Light, especially light used in the composite component 1 in the form of an image signal, is coupled into the composite component 1 via the coupling input section 40. In a particularly preferred embodiment, a projector 70 for projecting an image may be provided as the light source 7 in order to couple the input image signal, not limited to this example.

[0027] According to one embodiment, a coupling input mirror 43, preferably inclined relative to the side 11 of the composite component 1, is provided in the coupling input section 40. This coupling input mirror can also be constructed as a reflective layer 9. In this way, light, especially image information, can be incident in a direction perpendicular to the side 11 and then deflected along the side 11 within the composite component 1. The incident primary rays 40 are divided into a plurality of first partial beams 41 in the first segment 3 of the composite component 1. Deflection of light also occurs during separation on the partially reflective reflective layer 9, which is inclined relative to the primary rays 40, causing the first partial beams 41 to be guided along different paths within the composite element 1. In particular, these first partial beams 41 can also extend parallel to each other and spaced apart, as in… Figure 1As in the example. In the second segment 5, the reflective layer 9 is tilted toward the side 11 of the composite element 1, such that light is partially reflected and emitted from the side 11. Accordingly, the first partial beam 41 is partially reflected multiple times on the reflective layer 9 in the second segment 5, such that due to partial reflection, multiple second partial beams 42 are emitted from the side 11 in a spatially distributed manner on the side 11. For clarity, only one of the first partial beams 41 is shown for the second partial beam 42. To understand the figures, it should be noted that when viewed from above the side 11, the second partial beam 42 itself extends substantially along the line of sight and therefore does not extend in the plane of the figure as shown. The same applies to the primary ray 40 between the light source 7 and the coupling input mirror 43. For better illustration, a quasi-perspective view of these rays is chosen so that the rays are visible in the drawing plane.

[0028] Using the method and apparatus 2 according to this disclosure, the optical qualities of these second beams 42 can now be investigated. Furthermore, it can be determined, in particular, which region or even which specific element in the composite assembly 1 causes a possible degradation in image quality. Evaluation is performed using a detector 12, which is arranged such that it can detect the second beams 42. Specifically, a camera 120 is configured as the detector 12. An evaluation mechanism 15 is connected to the detector 12 or the camera 120, and is configured to calculate quality indices for the plurality of second beams 42 from the signals of the detector 12, and for this purpose, in particular, selects the plurality of second beams 42 according to aggregation rules, and determines the quality indices from the signals of the second beams, such that the quality indices can be assigned to specific portions of the composite assembly 1. The plurality of beams 42 can be detected individually and sequentially, for example, by repositioning the detector 12 with appropriate mechanisms for detecting additional second beams 42. Alternatively or additionally, the detector 12 can also detect the plurality of second beams 42 simultaneously.

[0029] Generally, but particularly for embodiments where a projector 70 is used as the light source and a camera 120 is used for the detector 12, it is advantageous for accurate measurement that the exit pupil of the light source 7, preferably the projector 70, is smaller than the entrance pupil of the detector 12, especially the camera 120. In this way, the departure point of the second beam 42 and thus its optical path can be well defined and reliably detected. Preferably, the entrance pupil is at least twice as large.

[0030] The calculation of the quality index generally includes the sum of the signals forming detector 12, and in particular, the formation of an average value. For example, a quality index can be measured for each second portion of the selected set of beams 42. Then, an average quality index can be determined from the individual values.

[0031] If the signal of a specific second beam 42 is evaluated without considering the other second beams 42, this can also be understood as a simple weighted analysis of the second beams 42 using weights 0 and 1. However, additional weighting can generally be performed within the set of second beams 42 selected according to the aggregation rule for determining quality indicators. Therefore, in addition to selection, the aggregation rule can include one or more weights with weights different from 1. Thus, without being limited to the specific embodiment, improvements to the method and the corresponding apparatus specify that the signals of the second beams 42 are weighted to determine quality indicators. For example, this improvement is meaningful when a particular second beam 42 is more strongly affected by the optical performance of a portion of the composite element 1 than other beams.

[0032] If backtracking Figure 1 The ray path of the second partial beam 42, as illustrated in the example, shows that all partial beams 42 are reflected on the same reflective layer 9 in the first segment 3 because the second partial beams 42 are separated from the single first partial beam 41 reflected on that reflective layer. Therefore, the quality index derived from the signals of these second partial beams 42 is affected by this single reflective layer 9. Thus, generally, and not limited to this particular example, preferred improvements to the method and the correspondingly configured apparatus 2 for evaluation specify that the second partial beam 42 used to determine the quality index is selected such that the light of the selected partial beam 42 is reflected on a specific reflective layer 9. However, the light of the partial beam 42 also passes through multiple other optical elements along its path from the coupled input of the primary ray to the coupled output on the side 11. However, when examining the quality index of different sets of partial beams 42, the influence of a specific portion of the composite component 1 on the quality index can be extracted particularly well. Therefore, in general, improvements to the method and the corresponding apparatus 2 specify that the quality index is compared with at least one other quality index, which is determined by different sets of the second beam 42. Figure 2 An example of this is shown. Figure 2 The right side shows something similar to Figure 1 Composite element 1. The beam paths of all first and second part beams 41, 42 to primary beam 40 are shown here.

[0033] The second beam 42, emitted perpendicular to the plane of the diagram, is symbolically represented by dots. In this example, the primary ray 40 is divided into eleven first beams 41 in the first segment 3. Therefore, as in Figure 1As in the example, each of the second partial beams 42 generated by a specific first partial beam 41 is reflected in the first segment 3 at a specific facet or a specific reflective layer 9. The quality index can also be affected by other elements in the beam path. However, this can be shown through comparison. For this purpose, a bar chart with quality indices for the set of second partial beams 42 respectively applied to the first partial beam 41 is shown on the left. Thus, each bar represents a row of quality indices for the resulting matrix arrangement of the second partial beams 42. Therefore, the aggregation rule used in selecting the partial beams 42 in this example is embodied in selecting the second partial beams 42 separated from the same first partial beam 41 respectively. In this example, all twelve such second partial beams 42 can be selected. A subset can also be considered, such as using only every third partial beam 42. The comparison now shows that, for example, the reflection at the reflective layer 9 closest to the coupling input mirror 43 can be assigned a higher quality index compared to the third and fourth reflective layers 9 in this direction. The first quality index here is higher than the average value plotted by the dashed line, while the reflections on the third and fourth reflective layers yield sub-average quality indices. Therefore, through this evaluation, elements with poor optical performance can be identified. If a systemic effect is observed here, then if necessary, the optical performance can be reversed and improved by adapting the manufacturing method for composite element 1.

[0034] from Figure 2 It can also be seen that the effect of the reflective layer 9 of the second segment 5 on the optical performance of the composite element 1 can be studied in a similar manner. In this example, all the second partial beams 42 in the matrix distribution of the second partial beams 42 are reflected on the same reflective layer 9 of the second segment 5. In this case, the second partial beams 42 in each column of the matrix distribution of the second partial beams 42 can be selected, which correspondingly represents another aggregation rule. However, the aggregation rule here can be slightly more complex, because the first partial beam 41 may also cause two second partial beams 42 by two reflections on the same reflective layer 9 in the second segment 5. However, the accurate aggregation rule can be obtained, for example, by simulation. The quality indicators thus obtained can then be studied by comparison, similar to those already described with the aid of bar charts.

[0035] Generally, not limited to specific examples and types of quality indicators, in improvements to the method and apparatus, quality indicators can also be determined by at least two previously measured quality indicators. Another quality indicator determined by two or more quality indicators can be referred to as a higher-level quality indicator. For example, such a higher-level quality indicator can be the difference, quotient, sum, or product of previously determined quality indicators. The average value of the quality indicators of the second portion of the beam 42 has already been mentioned above; these second portion beams are respectively divided from the first portion of the beam 41. Figure 2 In the charts, the dispersion of each quality indicator Q can also be measured or calculated as another higher-level quality indicator.

[0036] With the help of Figure 1 and Figure 2 This explains how the quality of each reflective layer 9 in the first segment 3 and the second segment 5 can be inferred by selecting and evaluating the signal of a specific second-part beam. However, such a composite optical assembly 1 often also includes other optical components. Therefore, a partially reflective reflective layer 9, placed horizontally or extending parallel to the side 11, can be provided. Such a reflective layer can be used to separate the first-part beam, thereby guiding the separated rays along different paths in the second segment 5. This can thus homogenize brightness fluctuations. Figure 3 The optical composite assembly 1 is shown in cross-section. The composite assembly 1 is typically a disk shape with parallel sides 11, 13. Unlike the one shown, the composite assembly 1 may also have a slight arch. Between the first segment 3 and the second segment 5 (whose reflective layer 9 is oriented at an angle to the sides 11, 13), a mixer segment 14 with a reflective layer 9 arranged parallel to the sides 11, 13 is arranged.

[0037] Figure 4 The beam path for a single first partial beam 41 in this composite assembly 1 is schematically shown. As can be seen, the first partial beam 41 is split into two partial beams 410 and 411 on the reflective layer 9 of the mixer segment 14, and then from these two partial beams are further separated into second partial beams 42 on the reflective layer 9 of the second segment 5 and emitted from the side 11. If the reflective layer 9 is omitted in the mixer segment, the partial beam 410 is missing. Accordingly, all the second partial beams 42 emanating from that partial beam 410 can also be eliminated. Thus, these second partial beams 42 emanating from the partial beam 410 contain information about the optical quality of the mixer segment 14 and its reflective layer 9. However, in this case, the aggregation rules for selecting the second partial beams are more complex than the selection rules for the reflective layers 9 of the first and second segments 3 and 5. Figure 4In the example, the second portion of the beam 42 to be selected is drawn with solid lines for illustration, and the portion of the beam 42 not to be considered is drawn with dashed lines. It should be noted that the spatial position of the second portion of the beam 42 and the corresponding convergence rule also depend on the path of the first portion of the beam 41, which in turn depends on the path of the primary beam. For this purpose, the illustration is merely exemplary. However, generally, not limited to the example shown, improvements to the method and the correspondingly arranged apparatus 2 specify that the optical composite element 1 has a mixer segment 14 arranged in the ray direction before the second segment 3, preferably between the first segment 3 and the second segment 5, the interior of which has a partially reflective surface 9 parallel to the side surface 11, wherein, for determining quality indicators, the second portion of the beam 42 is selected such that it originates from the portion of the beam 410 reflected on the reflective surface 9.

[0038] To selectively detect the second portion of the beam 42, one embodiment of the device typically includes a moving mechanism 18 that allows the detector 12 and the optical composite assembly 1 to move relative to each other, positioning the detector 12 at a specific measurement position relative to the optical composite assembly 1, particularly to grid the side 11 at a predetermined measurement position. In this example, the detector 12 is mounted on the moving mechanism 18 so that the moving mechanism can move while the composite assembly 1 remains fixed. Movement with the opposite configuration or combination of moving composite elements 1 is also possible. For evaluating the image signal, generally and not limited to this example, it is also preferred that the detector 12 includes a camera 120.

[0039] The accompanying figures below graphically illustrate the simulation-generated aggregation rules for reflections at the various reflective surfaces 9 in the first and second segments 3, 5 and the mixer segment 14, as discussed above.

[0040] Figure 5 The emission point of the second portion of the beam 42 is brightly shown over an area of ​​12 mm x 12 mm in the second segment 5. (As shown from...) Figure 2 As can be seen in the schematic diagram, a series of emission points for the second beam 42, separated from the first beam 41, are derived. The first beam 41, as described, is formed on specific, sequentially arranged reflective layers 9 within the first segment 3. The basic beam 41... Figure 5 The figures are shown in 41-3 to 41-8.

[0041] Figure 6 The same simulation is shown, where the reflective layer is partially removed in the first segment 3. Only the reflective layers marked 41-3 and 41-8 are retained. Accordingly, two rows of emission points for the second partial beam 42 are generated.

[0042] Figure 7 Based on this composite element, all reflective layers 9 exist in the first segment, but the two reflective layers 9 of the second segment exist only at the edges of the image field. As already explained, the second portion of the beam 42, which also exists and needs to be selected according to the corresponding aggregation rules, does not necessarily need to be arranged precisely according to the columns of the matrix-shaped grid. Rather, the beam path generates a slight shift in the emission point in the x-direction and also generates multiple second portion beams 42 from the first portion of the beam 41. In any case, the pattern shown for the primary rays incident according to the simulation can be used as an aggregation rule to check the optical quality of the corresponding reflective layers 9 of the second segment 5.

[0043] Figure 8 A corresponding simulation is shown on the composite element 1 without the mixer segment 14 or its reflective surface extending parallel to the side 11. As can be seen, with Figure 5 Compared to the simulation of the composite element 1 with mixer segment 14, the second portion of the beam 42, which extends diagonally, is missing. When in Figure 4 The effect can be easily observed when a schematic beam path is observed. Figure 9 The corresponding simulation of the composite element with mixer segment 14 is shown, i.e., with Figure 5 The same simulation is used here. However, a circle around the beam emission point is used to represent the same... Figure 8 Compared to the added second-section beams, these labeled second-section beams correspond to a convergence rule to detect the optical quality of the mixer segments according to quality indicators. Similar to... Figure 2 Such relative comparisons can be made by measuring quality indicators. Figure 8 The second part of the beam, visible in the image, is then transmitted. Here, by... Figure 8 and Figure 9 The higher-level quality indices determined by the quality index of the set of partial beams shown can also be particularly convincing in describing the quality of the reflective layer in mixer segment 14. For example, the modulation transfer function can be correlated with a subset of the second partial beam 42 that is transmitted and reflected on reflective layer 9.

[0044] Several quality indicators exist, which can be determined using the method described and the apparatus 2 constructed according to this method. In particular, the following quality indicators are especially advantageous for evaluating product quality: - The modulation transfer function in at least one image direction, optionally depending on color. - Compare, especially the proportions of the modulation transfer function for two different image orientations. - Angular deviation of the direction of the second part of the beam 42 - Transmission efficiency, especially, also depends on color. - Color coordinate offset, - Dispersion in the emitted second portion of the beam 42 - Polarization of the second part of the beam 42.

[0045] Some of these quality indicators, such as transmission efficiency, can also be determined using non-imaging measurement methods. For example, lasers can be considered as the light source and simple detectors, such as photodiodes. Polarization can also be considered using non-imaging measurements. The polarization of light is affected by reflection on the reflective layer 9. Furthermore, measurements such as... Figure 1 and Figure 3 The example shown is a λ / 2 plate 16. This λ / 2 plate rotates the polarization direction of light, thereby achieving effective reflection on the reflective layer 9 in the second segment 5. The plate is very thin, and the tolerances can cause correspondingly strong fluctuations in the polarization state. Another effect is possible birefringence in the transparent element 8.

[0046] However, the preferred option is, for example, Figure 1 As already mentioned, a projector 70 is generally used to couple the input primary beam 40, which contains image information and is evaluated by means of a detector 12 in the form of a camera 120. To determine the modulation transfer function for the second beam 42, an image can be coupled to one or more test structures, such as crosshairs, dots, or circles, and the corresponding image in the second beam 42 is detected by the camera 120. These images can be evaluated, in terms of their sharpness, in two different image directions, approximately perpendicular to the branches of the crosshairs in the case of the crosshairs, in order to determine the modulation transfer function. Such a crosshair 15 with two spatial directions y, x is shown in... Figure 10 Partial image (a) and partial image (b) show the area on the second segment 5 with nine measurement points XP1–XP9 for other embodiments. The measurement points are located in a square area of ​​approximately 17 x 17 mm.

[0047] Each measurement point represents the emission point of the second portion of the beam 42. In the example below, the emission points or spatial arrangement of the second portion of the beam 42 are not explicitly chosen such that the image signal is isolated from the influence of a specific element, such as a specific reflective layer, and can be assigned to said specific element. Instead, the measurement points, or the detected second portion of the beam, are chosen such that they are centered relative to the user's eye. Nevertheless, these measurement locations can provide information about the quality of a specific area of ​​the composite component 1, so that quality indicators can be assigned to a specific part of the composite component 1. Therefore, the optical path for measurement point XP3 and the second portion of the beam emitted there is the shortest, and the optical path for measurement point XP7 is the longest, because the first segment 3 is arranged to the right of the section shown and the coupling input of the primary ray is from the upper right near measurement point XP3.

[0048] Such as using Figure 4 As described, the second portion of the beam 42 emanating from measurement points XP1–XP9 can be detected by moving the detector 12, preferably the camera 120, past the measurement position via a suitable moving mechanism 18, or by scanning the side 11. Furthermore, according to an alternative or additional embodiment, rapid measurement can also be performed by having all measurement points XP1–XP9, or the second portion of the beam emanating from there, be detected together in the camera 120. For this purpose, the cameras 120 are arranged at a large interval, so that… Figure 11 As shown, the camera lens 121 detects and images part of the beam 42. Lens 121 can, in particular, be constructed as a telescope. The side view corresponds to the view from left to right. Figure 10 The line-of-sight direction of the arrangement of measurement points XP1–XP9 shown in the illustration. Therefore, the three measurement points and their second portion of the beam 42 overlap in the illustration. Of course, this arrangement for simultaneously detecting multiple portions of the beam is not limited to this specific example. It is also possible to simultaneously detect all portions of the beam. Figure 5 The partial beams 42 shown are all possible as long as the entire shown area can be imaged simultaneously. Therefore, not limited to a specific example, in one embodiment, the detector 12 includes a camera 120 arranged at a certain distance from the side 11 of the composite assembly 1, such that multiple partial beams 42 are simultaneously detected by the camera 120, wherein these second partial beams 42 are emitted from the side 11 at a distance of at least 10 mm, preferably at least 15 mm. If multiple second partial beams 42 are detected simultaneously, as in... Figure 11 As shown, a projector can also be used to couple the input of the corresponding test image, which contains multiple test structures, such as crosshairs. For Figure 10The example of partial image (b) shows that an image with nine crosshairs 15 can be coupled into the input in a 3 x 3 matrix arrangement, the crosshairs then visible at the corresponding measurement positions XP1–XP9.

[0049] Figure 12 The values ​​of the modulation transfer function (MTF) for different colors in two mutually perpendicular directions are shown. Partial image (a) shows the values ​​corresponding to... Figure 10 The partial image (a) shows the value 1 / 2Ny_ROIV for the y-direction, and the partial image (b) shows the value 1 / 2Ny_ROIH for the x-direction. A portion of the beam from the central measurement point XP5 is evaluated. The measurements 1 / 2Ny_ROIV and 1 / 2Ny_ROIH are measures of the sharpness of the crosshairs 15 used for imaging, expressed as multiples of the half-Nyquist frequency of the human eye. Specifically, these values ​​represent the percentage contrast of a pattern with 10 lines per degree of visual angle. The MTF for blue, green, red, and white is evaluated corresponding to the abbreviations B, G, R, and W. Figure 12 As shown, resolution, or MTF, is almost independent of color for both spatial directions, as all values ​​lie near the average value plotted by dashed lines. However, the MTF values ​​differ significantly between the vertical direction (partial image (a)) and the horizontal direction (partial image (b)), with better sharpness achieved in the vertical direction. For the following example of the spatial distribution of MTF, only green is evaluated.

[0050] Figure 13 Monocular analysis of values ​​1 / 2Ny_ROIV (partial image (a), y-direction) and 1 / 2Ny_ROIH (partial image (b), x-direction) is shown. For both directions, a slight decrease in resolution is observed within the measurement points across all rows. Therefore, the highest resolution is observed within the row at measurement points XP3, XP6, and XP9, located to the right of the ray entering the second segment 5, and the lowest at the furthest measurement points XP1, XP4, and XP7. While the measurement points may not be assigned to specific reflective layers, they demonstrate the influence of the reflective layer 9 of the second segment 5 as part of the composite element 1. In other words, the measured values ​​can be assigned to quality indicators, and in particular, to the reduction in the number of reflective layers 9 in the middle.

[0051] Using these measurements 1 / 2Ny_ROIV and 1 / 2Ny_ROIH, contour maps of the MTF for the measurement area can also be created, such as in... Figure 10 As shown in part of image (b). Figure 14 The MTF profile is shown, particularly the value 1 / 2Ny_ROIH (i.e., resolution in the x-direction) for composite element 1 with good optical resolution. To understand these figures, note that... Figure 14The spatial orientation indicated in the following diagrams is relative to... Figure 10 In some images (b), the orientation is reversed. Measurement point XP3 is located in the lower left of the contour plot, not the upper right. Measurements are plotted to the left of the contour line.

[0052] Here, using the contour with a 1 / 2Ny_ROIH value of 31, we can also see the optimal resolution in the region of measurement location XP3, specifically in the lower left. Interestingly, a slight minimum occurs in the middle of this region when the 1 / 2Ny_ROIH value is 23. Therefore, as in Figure 13 The continuous reduction in resolution in the example is not mandatory.

[0053] Figure 15 Another example of this contour plot is shown. Here, the highest resolution value is located in the upper left corner, which is... Figure 10 The partial image (b) corresponds to the region surrounding the measurement point XP9. Regarding MTF, the optical quality can still be assessed as good. However, the profile curves indicate a slight degradation in the first segment 3, or a slight degradation in one or more reflective layers 9 within that segment. Specifically, a quality index of 1 / 2Ny_ROIH with a slightly degraded value of 18 can be assigned to the portion of the first segment 3 approximately near the coupling input segment 4.

[0054] at last, Figure 16 A profile with the difference in MTF values ​​is shown. In summary, over a large area, the low resolution stems from a relatively low value of 10 / 2Ny_ROIH. Such composite elements can be eliminated by using correspondingly set minimum requirements.

[0055] Although the present invention has been described with reference to preferred embodiments, it is not limited thereto and can be modified in various ways.

[0056] List of reference numerals 1 Optical composite components 2. Apparatus for detecting the optical performance of optical composite component 1 3. First segment 4. Coupled input section 5. Second Section 6 supports 7. Light source 8 Transparent Components 9. Reflective layer 11, 13 1 side view 12 detectors 14 Mixer Segments 15 Crosshairs 16 λ / 2 plate 18. Mobile mechanism 40 Primary rays 41 First part of the beam 42 Second part of the beam 43 Coupled Input Mirror 70 Projector 120 camera 121 lenses 410, 411 are partial beams generated in mixer segment 14.

Claims

1. A method for detecting the optical performance of an optical composite assembly (1), wherein the composite assembly (1) comprises a plurality of transparent elements (8) interconnected with each other and a reflective layer (9), wherein the transparent elements (8) and the reflective layer (9) are arranged such that light coupled into the composite assembly (1) at a coupling input segment (4) is split into a plurality of first partial beams (41) in a first segment (3) of the composite assembly (1) by means of the plurality of transparent elements (8), the first partial beams being propagated along different paths in the composite assembly (1), and wherein, The first beam (41) is also partially reflected multiple times in the second segment (5) by multiple transparent elements (8), so that multiple second beams (42) are emitted from the side (11) due to partial reflection, among which - The second beam (42) is detected using a detector (12), and - The quality index of multiple second-part beams (42) is determined by the signal from the detector (12), and wherein - Preferably, a plurality of second-part beams (42) are selected according to the aggregation rule, and the quality index is determined from the signal of the second-part beams, so that the quality index can be assigned to a specific part of the component (1).

2. The method according to the preceding claims, characterized in that, In order to determine the quality index, a second portion of the beam (42) is selected such that the light from these selected portions of the beam (42) is reflected on a specific reflective layer (9).

3. The method according to any one of the preceding claims, characterized in that, The quality index is compared with at least one other quality index, which is determined by different sets of the second beam (42).

4. The method according to any one of the preceding claims, characterized in that, A higher-level quality indicator is determined by using at least two previously determined quality indicators.

5. The method according to any one of the preceding claims, characterized in that, The optical composite element (1) has a mixer segment (14) arranged between the first segment (3) and the second segment (5), the mixer segment having a partially reflective reflective surface (9) parallel to the side (11) and located inside the composite element (1), wherein, in order to determine the quality index, a second partial beam (42) is selected that originates from a partial beam (410) reflected on the reflective surface (9).

6. The method according to any one of the preceding claims, characterized in that, At least one of the following quality indicators was measured: - A modulation transfer function in at least one image direction, preferably dependent on color. - Compare, especially the proportions of the modulation transfer functions for two different image orientations. - Angular deviation of the direction of the second part of the beam (42) - Transmission efficiency, especially, also depends on color. - Color coordinate offset, - Dispersion in the emitted second part of the beam (42), - Polarization of the second part of the beam (42), Preferably, in order to determine the modulation transfer function for the second partial beam (42), an image having one or more test structures is coupled into the input, and the image in the second partial beam (42) is detected by a camera (120), and the sharpness of the image is evaluated in two different image directions.

7. The method according to any one of the preceding claims, characterized in that, The signal of the second beam (42) is weighted to determine the quality index.

8. An apparatus (2) for performing the method according to any one of the preceding claims, comprising a support (6) for a composite component (1) and a light source (7), the light source being arranged relative to the support (6) such that light coupled into the composite component (1) at a coupling input segment (4) is split into a plurality of first partial beams (41) in a first segment (3) of the composite component (1) by means of a plurality of transparent elements (8), the first partial beams being propagated along different paths in the composite component (1), and wherein, The first beam (41) is also partially reflected multiple times in the second segment (5) by multiple transparent elements (8), so that multiple second beams (42) are emitted from the side (11) due to partial reflection, wherein the device (2) - Includes a detector (12) for detecting the second portion of the beam (42), and - An assessment agency (15), wherein the assessment agency (15) is configured to: - A quality index is calculated from the signal of the detector (12) for a plurality of second part beams (42), and for this purpose, a plurality of second part beams (42) are selected in particular according to a aggregation rule, and the quality index is determined from the signal of the second part beams, such that the quality index can be assigned to a specific part of the composite component (1).

9. The apparatus (2) according to claim 8, characterized in that, The light source (7) includes a projector (70) for transmitting images.

10. The apparatus (2) according to any one of claims 8-9, wherein, The detector (12) includes a camera (90).

11. The apparatus (2) according to any one of claims 8-10, characterized in that, The exit pupil of the light source (7), preferably the projector (70), is smaller than the entrance pupil of the detector (12), preferably the camera (120).

12. The apparatus (2) according to any one of claims 8-11, characterized in that... The moving mechanism (18) enables the detector (12) and the optical composite assembly (1) to move relative to each other so as to position the detector (12) relative to the optical composite assembly (1) at a specific measurement position.

13. The apparatus (2) according to any one of claims 8-12, wherein, The detector (12) includes a camera (120) arranged at a distance from the side (11) of the composite component (1) such that multiple partial beams (42) are simultaneously detected by the camera (120), wherein the second partial beam (42) is emitted on the side (11) at a distance of at least 10 mm, preferably at least 15 mm.

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