Method and apparatus for slicing multi-layer glass element

Abstract

The present application provides a method of manufacturing a blank of a light guide optical element (1) from a composite glass stack (3) comprising a plurality of glass sheets (5) bonded together and a light reflecting layer (7) disposed therebetween, the method comprising cutting slices (9) from the composite glass stack (3) along parallel cutting planes (11). Aligning the composite glass stack (3) with the cutting plane (11) comprises:-adjusting the inclination angle of the plane (16) with the cutting plane (11) with an autocollimator (22); and-adjusting the position of the stack (3) in a direction inclined, preferably perpendicular, cutting plane (11). The composite glass stack (3) is fixed to a holder (23) in its alignment direction and cut into a blank forming the light guide optical element (1).

Description

Technical Field

[0001] The present invention generally relates to the technical field of manufacturing glass-based optical components. In particular, the present invention relates to precision cutting of glass slices to obtain optical components. Background Art

[0002] In some applications, it is necessary to use optical components with complex structures. Such complex optical components can include a large number of stacked glass layers with intermediate functional optical layers, such as light reflecting and / or polarizing layers. These components can be used as waveguide elements, for example, to provide near-eye displays. For such applications, the structuring of the optical element is used to expand a small image to a large field of view. The optical element can then be worn as a transparent screen or eyeglass lens, which displays images from a small side-mounted screen superimposed with the ambient image seen through the lens. In order to correctly guide and superimpose the projected and superimposed images with the ambient image seen by the wearer of such a near-eye display, the layers of the stacked layers should be positioned and oriented with high precision relative to their surfaces or interfaces. The method for manufacturing these optical elements (also called light-guiding optical elements) is described in WO 2021 / 240515 A1. In general, the method is based on stacking and bonding together a plurality of coated transparent plates to form an optical block, which is then sliced ​​at predetermined intervals to form a plurality of light-guiding optical elements. However, the separation of the light-guiding optical element from the optical block is particularly important, since the individual layers within the stack should be precisely oriented, since the direction and position of the separation plane relative to the optical block defines the orientation of the individual layers within the separation element. It is therefore an object of the invention to increase the precision of the separation of slices from a multilayer block. This object is solved by the subject matter of the independent claim. Advantageous developments of the invention are defined in the dependent claims. Summary of the invention

[0003] Therefore, a method and apparatus for manufacturing a light-guiding optical element blank from a composite glass laminate is provided herein, wherein the composite glass laminate comprises a plurality of glass sheets bonded together, and a light-reflecting layer disposed between the glass sheets. The method comprises cutting slices from the composite glass laminate along parallel cutting planes. The method further comprises aligning the composite glass laminate with the cutting planes so that the light-reflecting layer has a defined orientation relative to the sides of the slice after cutting. Advantageously, the alignment is performed before cutting. The composite glass laminate has a plane with a defined orientation relative to the light-reflecting layer within the composite glass laminate so that when the cutting plane extends along the plane parallel to the composite glass laminate, the light-reflecting layer within the slice is oriented correctly. The alignment of the composite glass laminate with the cutting plane comprises: - adjusting the tilt angle of the plane of the composite glass stack relative to the cutting plane using an autocollimator; and - adjusting the position of the composite glass laminate obliquely, preferably perpendicularly to the direction of the cutting plane.

[0004] The composite glass laminate is held fixed on a retaining frame along its alignment direction and cut into the slices. These slices form blanks for the light-guiding optical element. Depending on the structure of the blanks, these blanks can be directly processed into light-guiding optical elements or combined with other slices. In the latter case, the blanks are intermediate products for producing light-guiding optical elements. For example, the slices can be used to produce another composite glass laminate. Then, the glass laminate can be sliced ​​again using the method described herein to produce blanks to be used for producing light-guiding optical elements.

[0005] Preferably, the slices are cut from the composite glass laminate using a wire saw having a large number of parallel sections of one or more cutting wires. In this case, the longitudinal direction of the cutting wire and the advancing direction of the composite glass laminate relative to the movement of the cutting wire cross the cutting plane.

[0006] The light reflecting layer described herein may be, in particular, a semi-reflective layer, ie, a layer that reflects a certain proportion of incident light according to parameters of the light (eg, inclination angle, polarization or wavelength). BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The present invention will be described in more detail below with reference to the accompanying drawings.

[0008] Figure 1 A perspective view of a composite glass stack is shown.

[0009] Figure 2 A front view of a composite glass stack is shown.

[0010] Figure 3 Shows from Figure 2 Slices cut from the composite glass stack shown.

[0011] Figure 4 A device for slicing a composite glass stack is shown, the device having a device for aligning the composite glass stack with a cutting plane.

[0012] Figure 5 Schematic diagrams showing various misalignments of the light reflecting layer compared to a properly aligned light reflecting layer.

[0013] Figure 6 Shown are sketches of two autocollimator displays before and after alignment of the composite glass stack.

[0014] Figure 7A sketch of a display of a camera for adjusting the lateral position of a composite glass stack is shown.

[0015] Figure 8 A test composite glass stack is shown.

[0016] Fig. 9 A device for measuring the tilt angle offline is shown.

[0017] Fig.10 A coarse adjustment step of the tilt angle is shown.

[0018] Fig.11 A coarse adjustment of the azimuthal tilt angle is shown.

[0019] Fig.12 An alignment device is shown. DETAILED DESCRIPTION

[0020] Figure 1 and Figure 2 A perspective view of a composite glass laminate and a front view of one side of the composite glass laminate are shown. Figure 1 As shown in the perspective view of FIG. 1 , the composite glass laminate 3 includes a plurality of light reflecting layers 7 facing parallel to the side surface 17 of the composite glass laminate 3. In general, without being limited to the illustrated embodiment, the light reflecting layers 7 are spaced apart from each other at a certain distance along their normal direction or perpendicular to their surface. Figure 2 As shown, the composite glass laminate 3 includes a large number of glass sheets 5 bonded together by bonding layers 6. These bonding layers 6 can be optical bonding layers or adhesive layers. Generally speaking, the thickness of the bonding layer 6 can be preferably in the range of 0.5 μm to 6 μm, more preferably in the range of 0.75 μm to 5 μm, further preferably 1 μm to 4 μm, and especially 1 μm to 3 μm.

[0021] Light reflecting layers 7 are arranged between the glass sheets 5. Preferably, these light reflecting layers 7 are produced by depositing a layer material on one of the faces of the glass sheets 5. Figure 2The intended cutting planes 11 are also shown in dashed lines. Preferably, the distances between the cutting planes 11 are selected to match the distances between the light reflecting layers 7, so that in the slices generated by cutting along the cutting planes 11, the light reflecting layers 7 are arranged at equal distances from the sides of the slices. In a preferred embodiment, the composite glass laminate 3 is cut so that the light reflecting layers 7 in the slices are arranged centrally between the sides of the slices. Therefore, without being limited to the specific embodiment shown, the composite glass laminate 3 comprises a plurality of light reflecting layers 7 oriented parallel to the sides 17 of the composite glass laminate 3, wherein the step of adjusting the position of the composite glass laminate 3 in a direction perpendicular to the cutting planes 11 comprises adjusting the position of the composite glass laminate 3 so that the light reflecting layer 7 is arranged centrally in the slice 9 in a direction perpendicular to the sides of the slice. For example, an optical element with a centered light reflecting layer used as a hybrid layer is known from US2022 / 0091413 A1.

[0022] In the example shown, the glass sheets 5 have the same thickness. However, in a preferred embodiment, the thickness of the outer glass sheets 50 forming the side 17 of the composite glass laminate 3 may be different from the thickness of the glass sheets 5 sandwiched between these outer glass sheets 50. Further preferably, the thickness of the outer glass sheets 50 forming the side 17 is greater than the thickness of the inner glass sheets 5 sandwiched between the outer glass sheets 5, 50. In one example, the thickness of the outer glass sheet 50 is 5 mm, and the thickness of the inner glass sheet 5 is 1.55 mm. In general, without being limited to a specific example, the thickness of the inner glass sheet 5 may be in the range of 1 mm to 3 mm. In addition, without being limited to a specific example, the composite glass laminate 3 may have at least 10, preferably 10 to 60, more preferably 20 to 50 inner glass sheets 5 sandwiched between the outer glass sheets 50. Therefore, according to a modification of the method, at least 9, preferably 9 to 59, more preferably 19 to 49 slices may be cut from the composite glass laminate 3, which slices form a blank for a light-guiding optical element.

[0023] In one example, the glass sheet 5 is made of N-BK7 glass. The dimensions of the composite glass laminate are 70×70×70 mm. 3 , with a dimensional tolerance of + / - 0.3 mm. The side surfaces 17 formed by the side surfaces of the outer glass sheet 50 may be a D151 ground surface or finer, in particular, these sides may be polished. The top and bottom sides may have a slightly lower surface quality, for example, may be ground surfaces. The edges may be chamfered to a maximum of 0.5 mm.

[0024] Figure 3 Shows that from Figure 1 , Figure 2A slice 9 cut from a composite glass laminate is shown. The slice 9 has side surfaces 13, 15 formed by cutting the composite glass laminate 3 along a cutting plane 11. As mentioned above, the light reflecting layer 7 is preferably arranged centrally between the side surfaces 13, 15.

[0025] According to one embodiment, the slice 9 can form a light-guiding optical element 1, for example, after cutting the slice 9 along a predefined contour and / or after finishing the side surfaces 13, 15. Therefore, according to one embodiment, a method for producing a light-guiding optical element 1 is provided, comprising: generating a slice 9 from a composite glass stack 3 using the method described herein, polishing the side surfaces 13, 15 of the slice 9, and cutting the slice 9 along a predefined contour to obtain the light-guiding optical element 1. In another embodiment, the slice 9 is an intermediate product of the light-guiding optical element 1, wherein the slice 9 is again stacked with other slices, which are usually of different structure, to form another composite glass stack, which can then be sliced ​​again using the method disclosed herein.

[0026] In contrast, in a preferred embodiment, the position of the composite glass laminate 3 relative to the cutting plane 11 is adjusted so that the position deviation of the light reflecting layer 7 relative to a reference position within a slice 9 cut from the composite glass laminate 3 is less than 0.2 mm, preferably less than 0.1 mm. As mentioned above, preferably, the reference position is the center position of the slice 9 between its side faces 13, 15. Therefore, if the light reflecting layer 7 is located at the center of the slice, the difference in distance between the light reflecting layer 7 and the side faces 13, 15 of the slice after slicing and polishing is less than 0.2 mm, or even less than 0.18 mm.

[0027] The central position of the light-reflecting layer 7 within the slice is only one of several parameters for the correct orientation. Of particular importance is the inclination of the light-reflecting layer 7 relative to a reference plane. Such a reference plane may in particular be a side surface 13, 15 of the slice 9. According to a preferred embodiment, the orientation of the composite glass laminate 3 relative to the cutting plane 11 is adjusted by means of an autocollimator so that the inclination angle of the light-reflecting layer 7 of the slice 9 cut from the composite glass laminate 3 is less than 15 arc seconds, or less than 0.004166 degrees, respectively.

[0028] Adjustment and slicing are described in detail below. Figure 4 A schematic diagram of a cutting device 2 for cutting slices from a composite glass laminate 3 is shown. The cutting device 2 comprises a wire saw 21 having a plurality of parallel segments 180 of one or more cutting wires 18. For example, a single cutting wire 18 can be guided in a zigzag manner around spaced bearings. In this way, adjacent parallel segments 180 of the cutting wire 18 advance in opposite directions, such as Figure 4 As shown by the two arrows in .

[0029] The composite glass laminate 3 is held by a holding frame 23 , and is cut by moving the composite glass laminate 3 relative to the cutting wire 18 .

[0030] The composite glass laminate 3 is aligned using an alignment device 10. In this embodiment example, the alignment device 10 comprises three stacked workbenches 32, 33, 34, preferably micro-workbenches, wherein two workbenches 32, 33 adjust the tilt angles α, β in non-parallel planes, in particular in vertical planes. Figure 4 As can be seen in FIG. 1 , the tilt angle β is the azimuth angle of rotation about the axis in the cutting direction. Another workbench 34 is provided for linear displacement in a direction tilted relative to the cutting plane 11, preferably in a direction perpendicular to the cutting plane 11. A cutting plane 11 of one of the parallel segments 180 is indicated by a dotted line. Thus, in general, without being limited to the specific example shown, the alignment device 10 comprises stacked workbenches 32, 33, 34, wherein: - the table 32 is arranged to adjust or manipulate the azimuth angle of rotation of the composite glass stack around an axis along the cutting direction; the table 33 is arranged to adjust or manipulate the angle of rotation of the composite glass laminate 3 about an axis inclined (preferably perpendicular) relative to the cutting plane 11, and The table 34 is arranged to adjust or manipulate the position of the composite glass laminate 3 along a direction inclined (preferably perpendicular) relative to the cutting plane (11).

[0031] Thus, the method for manufacturing a blank according to the present embodiment comprises fixing the composite glass stack 3 on a holder 23 movable by stacked work tables 32 , 33 , 34 ; - using one of the work tables 32 to adjust or manipulate the azimuth angle of rotation of the composite glass stack 3 about an axis along the cutting direction; - using one of the work tables 33 to adjust or manipulate the angle of rotation of the composite glass laminate 3 about an axis inclined (preferably perpendicular) to the cutting plane 11; and - Using one of the work tables 34 to adjust or manipulate the position of the composite glass laminate 3 in a direction oblique to the cutting plane 11 (preferably perpendicular).

[0032] In contrast to the described embodiment, the worktable can be provided for the combined adjustment of two parameters, for example for the adjustment of two tilt angles α, β. In this case, only two worktables are required.

[0033] The composite glass laminate 3 is cut into slices forming blanks of light-guiding optical elements by moving the holder 23 with the fixed composite glass laminate 3 relative to one or more cutting lines 18, preferably using a large work table or pusher 35. Preferably, the cutting is performed by moving the holder 23 with the fixed composite glass laminate 3 downwards.

[0034] In a preferred embodiment, Figure 4 As shown in the example of , the composite glass laminate 3 is bonded to a sacrificial substrate or plate 27 fixed to a holder. The cutting process thus comprises cutting completely through the composite glass laminate 3 and further partially into the sacrificial plate 27. After cutting, the bond between the sacrificial plate 27 and the composite glass laminate 3 is released or released, respectively, so that the slice 9 is separated from the sacrificial plate 27. Preferably, for this purpose, the composite glass laminate is bonded to the sacrificial plate 27 by a releasable cement, in particular a UV releasable cement or a thermally releasable cement.

[0035] In one Figure 4 In an embodiment also realized in the example of , the autocollimator 22 is arranged in a fixed relationship with the cutting device 2, in particular the wire saw 21. In this way, the tilt angle of the composite glass stack 3 can be aligned online in the cutting device.

[0036] Furthermore, in general, the step of adjusting the position of the composite glass laminate 3 so that the light reflecting layer 7 is centered in the slice 9 in a direction perpendicular to the side surfaces 13, 15 preferably includes monitoring the position of at least one light reflecting layer 7 by means of a camera 24. In one embodiment, as also in Figure 4 As shown in the example of , the camera 24 is also arranged in a fixed relationship with the cutting device 2, in particular the wire saw 21, so that the position of the composite glass laminate 3 can be adjusted online (in particular using the workbench 34). In the exemplary embodiment, the camera 24 is arranged in the advancing direction along the composite glass laminate 3. However, the camera 24 can also be placed in a position for observing in the longitudinal direction of the parallel segments 180 along one or more cutting lines 18. It has been proven that the position adjustment of the composite glass laminate 3 in a direction inclined, preferably perpendicular, to the cutting plane 11 by the image control captured by the camera 24 is very precise, so that after slicing and polishing, the absolute value of the distance difference between the light reflecting layer 7 and the sides 13, 15 of the slice 9 is less than 0.18 mm. This feature can also be achieved by other embodiments disclosed herein. Preferably, also as Figure 4 As shown in the example of FIG. 2 , the camera 24 is arranged to image at least one light emitting layer 7 along the edge. This allows for an exact positioning of the composite glass stack 3 .

[0037] In order to adjust the inclination or respectively adjust the inclination angles α, β, the autocollimator 22 can monitor the inclination of one of the inner surfaces of the composite glass laminate 3, such as the inclination of one of the light emitting layers 7. In this case, the autocollimator is advantageously arranged to monitor the inclination angle of the light emitting layer 7 closest to the autocollimator 22. In another embodiment, it is also Figure 4 In the example of , the plane 16 of the composite glass laminate 3 having a defined orientation relative to the light reflecting layer 7 is a side surface 17 of the composite glass laminate 3. For this embodiment, i.e., generally, the orientation of the side surface of the composite glass laminate 3 is advantageously adjusted if at least the side surface 17 monitored by the autocollimator 22 has a polished surface quality. For example, the side surface 17 can be a polished surface.

[0038] Figure 5 Various misalignments of the light reflecting layer 7 in the slice 9 due to improper alignment of the composite glass laminate 3 before slicing are shown. In case (a), the tilt angle α is greater than 15 arc seconds. In case (b), the tilt angle β exceeds 10 arc seconds. Case (c) shows a misalignment, in which the difference z1-z2 in the distance between the layer 7 and the side faces 13, 15 exceeds 0.18 mm. Of course, a defective slice 9 may have more than one such misalignment. Case (d) shows a proper alignment, in which all the constraints shown in the partial images (a) to (c) are met. Further, after polishing the slice 9, for example, for a slice with a thickness of 1.2 mm, the thickness tolerance of the slice 9 can be limited to a maximum of 0.05 mm.

[0039] Figure 6 Two pictures (a) and (b) of the autocollimator 22 display are shown. Picture (a) shows the display of the autocollimator 22 before the composite glass laminate 3 is aligned. The tilt angles α1, β1 are shown as mutually perpendicular straight lines and are offset from the center of the display due to the misalignment. As shown, the center can be marked with a crosshair. The autocollimator is also aligned with the cutting plane 11, so adjusting the tilt angle of the plane 16 of the composite glass laminate 3 relative to the cutting plane 11 by using the autocollimator 22 includes adjusting the orientation of the composite glass laminate 3 so that the straight lines representing the tilt angles α, β are centered, or intersect in the center of the display, thereby also matching the crosshairs. Figure 6 Picture (b) shows this state.

[0040] Figure 7 It further shows Figure 4The camera 24 is shown showing a picture of a display screen for adjusting the lateral position of the composite glass stack. The camera 24 images the light reflective layer 7 along the edge and across the arrangement of parallel segments 180 of one or more cutting lines. In order to adjust the position of the composite glass 3 in a direction oblique (preferably perpendicular) to the cutting plane 11 (as in the embodiment discussed here, this is the position of the light reflective layer 7 at the center of the slice 9), the position of the composite glass stack 3 is adjusted so that the light reflective layer 7 is centered between the faces 180 in the image. In the example shown, it is necessary to adjust the position of the composite glass stack 3 so that the light reflective layer 7 is slightly moved to the right in the image shown.

[0041] In order to provide the composite glass laminate 3 with a suitable orientation relative to the cutting plane 11, the orientation of the autocollimator 22 relative to the holder 23 is advantageously also aligned and / or corrected according to a preferred refinement. According to this refinement, the orientation of the autocollimator 22 relative to the cutting plane 11 is adjusted, the method comprising: using the autocollimator 22 to adjust the tilt angle of the plane 16 of the composite glass laminate 30 to be tested relative to the cutting plane 11; cutting the composite glass laminate 30 into slices 9; placing one of the sides 13, 15 of one of the slices (preferably the outermost slice 9, in particular the slice 9 comprising the side of the composite glass laminate 30 facing the autocollimator) on the reference surface 25; measuring the tilt angle of the plane 16, preferably measuring the tilt angle of the side 15, 13 opposite to the side 13, 15 placed on the reference surface 25; and correcting the orientation of the autocollimator 22 relative to the cutting plane 11. Similarly, the position and orientation of the camera 24 can be corrected.

[0042] For the purpose of initial adjustment, it is not necessary to use a fully equipped composite glazing laminate 3 having a large number of light reflecting layers 7. Instead, a dummy or test composite glazing laminate may be used. Figure 8 An example of such a test composite glass stack 30 is shown. For adjusting the settings of the autocollimator 22 and / or the camera 24, a single pane with a light-reflecting layer 7 is sufficient. Figure 8 In the example of FIG. 1 , the composite glass stack 30 for testing includes three simulated glass sheets 37 and one hybrid glass sheet 36 sandwiched between two of the stacked simulated glass sheets 37. For alignment purposes, the hybrid glass sheet 36 may have a light reflecting layer (not shown). In one example, the thickness of the simulated glass sheet 37 (i.e., the distance between the sides 13, 15) is about 20 mm, and the thickness of the hybrid glass sheet is about 6 mm.

[0043] Fig. 9A device for determining the adjustment of the autocollimator 22 is shown. After the composite glass laminate 3 or preferably the test composite glass laminate 30 has been cut into slices 9, one of the slices 9 is placed on a reference surface 25, for example on a support 26. The support 26 can be, for example, a granite plate. The inclination angles α1, β1 of the side 13 opposite the side 15 located on the reference surface 25 are then measured. For this purpose, an outermost cut slice 9 is used, so that the side 17 of the composite glass laminate 3 forms the side 13 of the slice 9. This is advantageous because this side may already have a polished surface quality, while the other side may have a higher roughness due to the cutting process. The side 13 thus forms a plane 16, the inclination of which is measured relative to the cutting plane 11. Alternatively, an inner slice 9 can be used, and the inclination angle in this case can be determined based on the inclination angle of the light reflecting layer 7 in the slice. Preferably, the inclination angle is determined again using the autocollimator 22. The autocollimator 22 can be removed from the cutting device 2 and mounted to Fig. 9 In any case, the orientation of the autocollimator relative to the reference surface 25 is calibrated so that the measured tilt angles α1, β1 can be used to correct the adjustment of the autocollimator 22 of the alignment device 10. Thus, the correction of the position and orientation of the autocollimator is determined in the offline measurement. Typically, the outer slice 9 used for the tilt angle measurement is different from the inner slice 9. After processing a conventional composite glass laminate 3, typically only the inner slice has the same Figure 3 The structure shown in FIG. 1 is such that the outer slice 9 cannot be used as a blank for the light-guiding optical element 1. Figure 2 As can be seen, this is evident because the outer slice does not contain the light reflecting layer 7 .

[0044] Generally speaking, in normal operation of the cutting device 2, the tilt angle can also be controlled at least once between processing two composite glass laminates 3, i.e. between the cutting steps of two laminates. In particular, after cutting the composite glass laminate 3, the orientation tilt of the slice 9 can be determined offline, as described above, i.e. by placing the slice 9 on the reference surface 25. Advantageously, the tilt angles of a large number of slices 9 can be measured and an average tilt angle can be determined from these tilt angles to increase the accuracy. Fig. 9As shown, in the case of misalignment, unlike the outer slice 9, the inner slice 9 generally has parallel side faces 13, 15. Therefore, in this case, the inclination of the inner surface, in particular the inclination of the light-reflecting layer 7, is used for measurement. Therefore, in a modified version, the method comprises: cutting the first composite glass laminate 3 to form the slice 9, and subsequently cutting the second composite glass laminate 3, wherein one of the side faces 13, 15 of a large number of slices 9 cut from the first composite glass laminate is placed on a reference surface 25, and the inclination angle of the inner surface of the slice 9, in particular the light-reflecting layer 7, relative to the reference surface 25 is measured, and an average inclination angle is determined, and wherein the orientation of the autocollimator 22 is corrected based on the average inclination angle, and the second composite glass laminate 3 is cut using its inclination angle relative to the cutting plane 11, which is adjusted using the autocollimator 22 and in the direction corrected therefrom. In addition to the direction, these steps can also be performed in particular with a test composite glass laminate 30.

[0045] Of course, if Fig. 9 As shown, this embodiment can also be combined with measuring the inclination angle of the outer slice (especially measuring the inclination angle of one of the side surfaces 13 and 15). Therefore, the preferred process flow is as follows. 1. Use the dial gauge or Precitec sensor to roughly set β (measured on polished glass). 2. Use at least one camera 24 to roughly set α (align the line plane 180 so that it is parallel to the top surface of the composite glass laminate 3), 3. Align the autocollimator 22: Copy the vertical and horizontal lines on the autocollimator. 4. Slice the composite glass laminate 30 for testing, 5. As reference Fig. 9 As described above, the tilt angles α1 and β1 of the first slice or outer slice 9 of the composite glass laminate 30 for testing are measured offline, 6. Install the composite glass laminate 3 on the holder 23 and adjust the inclination angles α and β on the workbenches 32 and 33. 7. As reference Fig. 9 As described, the orientation of the autocollimator is corrected using the tilt angles α1 and β1 determined by offline measurement, 8. Use workbenches 32 and 33 to fine-tune the inclination angles α and β. 9. Use workbench 34 to fine-tune z. 10. Slice the composite glass laminate 3, 11. Offline measurement of α and β of all slices and determination of the average tilt angle and 12. Install the next composite glass layer 3 and adjust α and β on the workbench 32, 33. 13. Utilize Fig. 9 The average tilt angle is determined by offline measurement. and Correct the direction of the autocollimator, 14. Fine-tune the inclination angles α and β on the workbenches 32 and 33. 15. Fine-tune z on workbench 34, and 16. Slice the composite glass laminate 3.

[0046] refer to Fig.10 , describes a rough arrangement of a first composite glass laminate 3 to be sliced ​​(i.e., according to step 1 of the above process flow), which first composite glass laminate 3 to be sliced ​​can be a composite glass laminate 30 for testing. Fig.10 In the figure, only a holder 23 is schematically shown, which holds a sacrificial plate 27 on which the composite glass laminate 3 is attached. A rough adjustment or pre-adjustment of the tilt angle about the rotation axis tilted to the moving direction of cutting the composite glass laminate 3 is performed by measuring the positions of points on the face of the composite glass laminate 3 along the path of the composite glass laminate 3 in the moving direction during the cutting operation, and adjusting the orientation of the composite glass laminate 3 based on the measurement results, in particular, adjusting the orientation so that the positions have equal values ​​in the direction perpendicular to the face. This trajectory direction is parallel to the cutting plane 11. Fig.10 The picture (a) shows the composite glass laminate 3 in a first position, Fig.10 The picture (b) of FIG. 1 shows a composite glass laminate 3 in a second position, wherein the second position is offset from the first position along the path or along the direction of movement. The arrow in the picture (a) indicates the direction of movement. The position in the illustrated embodiment is measured using a measuring instrument 40. If the tilt angle is zero, the position values ​​of the measuring instrument are equal relative to the two positions. Preferably, the measurement is performed on the side 17 extending parallel to the cutting plane 11. Another position- or distance-sensitive sensor, such as an optical sensor or a capacitive sensor, can be used instead of or in addition to the measuring instrument.

[0047] Fig.11 Another pre-adjustment step corresponding to step 2 of the above process flow is shown. The pre-adjustment can adjust the azimuth tilt angle, the rotation axis of which is along the cutting movement direction. Fig.11As can be seen in the figure, for at least two points on the surface 17 spaced apart in the longitudinal direction along the line 18, at least one camera 24 is used to measure the distance from the surface 17 to the cutting line 18 or a segment 180 thereof. Advantageously, points close to the edge of the surface 17 are selected to minimize measurement errors. The orientation of the composite glass laminate 3 is then adjusted so that the distances a, b are equal, or, more generally, their difference is minimized. In the example, two cameras 24 are used. Alternatively, the composite glass laminate 3 can be moved in a direction parallel to the cutting line 18 and the distances recorded sequentially. Alternatively, a single camera with a sufficiently large field of view is used so that the spaced apart points are within the field of view. According to Fig.11 , it is obvious that the distance is measured only in one direction perpendicular to the surface.

[0048] exist Figure 4 In the exemplary embodiment shown, an alignment device including a table 32, 33, 34, an autocollimator 22 and a camera 24 is arranged in the cutting device 2 or forms part of the cutting device 2, respectively. According to another embodiment, the alignment of the composite glass laminate 3 is performed outside the cutting device 2. This can advantageously avoid the components of the alignment device from being affected by dust generated by the cutting device. The example described below is based on such an embodiment, wherein the holder 23 has a defined orientation relative to the cutting plane 11 when the holder 23 is inserted and fixed in the cutting device 2, and wherein the composite glass laminate 3 is aligned with the holder 23 when the holder 23 is detached from the cutting device 2 and fixed on the alignment device 10, wherein the composite glass laminate 3 is aligned with the holder 23 as monitored by the autocollimator 22 and fixed to the holder 23 in the aligned orientation, and wherein the holder 23 with the composite glass laminate 3 attached is inserted and fastened to the cutting device 2, whereby the composite glass laminate 3 has a defined orientation relative to the cutting plane due to its defined orientation relative to the holder 23. Then, the cutting operation can be started and the slice 9 can be cut with high precision. Fig.12 An alignment device 10 suitable for this embodiment is shown. For example, the alignment device 10 may include a base plate on which tools for alignment are mounted. These tools include a base 47 for adjusting the position and orientation of the composite glass stack 3 and the autocollimator 22. Preferably, a camera 24 is also mounted on the alignment device 10 to monitor the lateral position of the composite glass stack 3 relative to the cutting plane 11. Figure 4 As shown in the exemplary embodiment of FIG. 4 , the side surface 17 of the composite glass layer 3 can be used as a plane 16 which has a defined orientation relative to the cutting plane 11 of the cutting device 2 .

[0049] The holder 23 for the composite glass laminate 3 is mounted on the fixture 42. If the position and orientation of the autocollimator 22 and the camera 24 are properly calibrated, the autocollimator 22 and the camera 24 have a defined alignment relationship with the holder 23, so that, with respect to the cutting operation, the holder 23 will be fixed in the cutting device 2 and also have a defined alignment relationship with respect to the cutting plane 11. In order to fix the composite glass laminate 3 on the holder 23 in an aligned position and orientation, the base 47 can be used to move and / or rotate the composite glass laminate 3, while the inclination angle and lateral position of the composite glass laminate 3 are monitored using the autocollimator 22 and the camera 24. In the embodiment shown, similar to Figure 4 In the embodiment of the present invention, the base 47 is moved using the work tables 32, 33, 34. However, other adjustment tools may be used alternatively or additionally. For example, a manual universal joint, preferably a micrometer screw, may be used to operate the base.

[0050] When alignment is achieved, the composite glass laminate 3 is fixed to the holder 23. In order to fasten the composite glass laminate 3 to the holder 23, preferably an adhesive 44 is used. For example, the alignment process can be performed during the curing of the adhesive 44, while the adhesive 44 is still soft.

[0051] As in Figure 4 In the embodiment of FIG. 2 , the composite glass stack 3 is preferably not fixed directly to the holder 23 , but to a sacrificial plate 27 , and the sacrificial plate 27 is then fixed to the holder 23 .

[0052] In particular, according to Fig.12 The embodiment relies on the calibration of the alignment device 10. Therefore, reference Figures 9 to 11 The described embodiments include using Fig. 9 , determining the average tilt angle of a large number of cut slices 9, and appropriately correcting the orientation of the autocollimator, which can also be used according to Fig.12 In an embodiment with offline alignment. However, the Fig. 9 The additional device for offline measurement of the tilt angle is shown in FIG. Fig.12 The alignment device 10 shown performs the calibration.

[0053] The present disclosure also relates to a device for performing the method described herein. Thus, the device comprises a cutting device 2 and an alignment device 10. The alignment device 10 may be as follows: Figure 4 A portion of the cutting device 2 of the embodiment, or a reference Fig.12 Individual devices as described.

[0054] Thus, without being limited to the specific examples described herein, the apparatus is for manufacturing a blank of a light-guiding optical element 1 from a composite glass laminate 3, the composite glass laminate 3 comprising a plurality of glass sheets 5 bonded together, and a light-reflecting layer 7 disposed between the glass sheets 5, wherein the apparatus comprises a cutting device 2 for cutting a slice 9 from the composite glass laminate 3 along a parallel cutting plane 11, and an alignment device 10 for aligning the composite glass laminate 3 with the cutting plane 11, such that after cutting the light-reflecting layer 7 has a defined orientation relative to the sides 13, 15 of the slice 9, wherein the composite glass laminate 3 has a plane 16 having a defined orientation relative to the light-reflecting layer 7 within the composite glass laminate 3, such that when the cutting plane 11 extends parallel to the plane 16 of the composite glass laminate 3, the light-reflecting layer 7 within the slice 9 has a correct orientation, wherein the apparatus comprises a holder 23 for holding the composite glass laminate 3 in its aligned orientation, and wherein the alignment device 10 comprises: an autocollimator 22 for monitoring the adjustment of the angle of inclination of the plane 16 of the composite glass stack 3 relative to the cutting plane 11 , and - means for adjusting the position of the composite glass laminate 3 in a direction oblique to the cutting plane 11 , preferably perpendicular to the cutting plane 11 .

[0055] It is obvious to those skilled in the art that the various embodiments described herein may be combined within the scope of the claims and are not limited to the specific examples shown in the drawings. Fig.12 The offline adjustment can also be Figure 4 Further, the alignment of a layer 7 extending parallel to the side faces 13, 15 of the slice 9 has been shown. However, the method can also be applied to an obliquely extending light-reflecting layer 7 which has a well-defined angle relative to the side faces 13, 15.

[0056] Reference numerals list

Claims

1. A method for producing a blank of a light-conducting optical element (1) from a composite glass stack (3), wherein: The composite glass laminate (3) comprises a plurality of glass sheets (5) bonded together, wherein a light reflecting layer (7) is arranged between the glass sheets (5), wherein the method comprises cutting slices (9) from the composite glass laminate (3) along parallel cutting planes (11), wherein the method further comprises aligning the composite glass laminate (3) with the cutting planes (11) such that the light reflecting layer (7) has a defined orientation relative to the side surfaces (13, 15) of the slices (9) after cutting; wherein the composite glass laminate (3) has a plane (16) having a defined orientation relative to the light reflecting layer (7) within the composite glass laminate (3), such that when the cutting plane (11) is parallel to the plane (16) of the composite glass laminate (3), the light reflecting layer (7) within the slice (9) has a correct orientation, wherein the alignment of the composite glass laminate (3) with the cutting plane (11) comprises: - using an autocollimator (22) to adjust the inclination angle of the plane (16) of the composite glass laminate (3) relative to the cutting plane (11); and - adjusting the position of the composite glass laminate (3) along a direction inclined relative to the cutting plane (11), preferably a vertical direction; The composite glass stack (3) is fixedly held in its aligned orientation on a holder (23) and cut into slices (9), which form blanks of the light-guiding optical element (1).

2. The method according to claim 1, wherein: The composite glass laminate (3) comprises a plurality of light reflecting layers (7) oriented parallel to the side surfaces (17) of the composite glass laminate (3), and wherein the step of adjusting the position of the composite glass laminate (3) in a direction perpendicular to the cutting plane (11) comprises adjusting the position of the composite glass laminate (3) such that the light reflecting layers (7) are centered within the slice (9) in a direction perpendicular to the side surfaces (13, 15).

3. The method according to any one of the preceding claims, wherein: The plane (16) of the composite glass laminate (3) having a defined orientation relative to the light reflecting layer (7) is a side surface (17) of the composite glass laminate (3).

4. A method according to any one of the preceding claims, wherein: The slices (9) are cut from the composite glass laminate (3) using a wire saw (21) having a plurality of parallel segments (180) of one or more cutting wires (18).

5. A method according to any one of the preceding claims, wherein: The step of adjusting the position of the composite glass stack (3) so that the light reflecting layer (7) is centered in the slice (9) in a direction perpendicular to the side surfaces (13, 15) comprises monitoring the position of at least one light reflecting layer (7) by means of a camera (24).

6. A method according to any one of the preceding claims, wherein: The autocollimator (22) is arranged in a fixed relationship with the cutting device (2), in particular the wire saw (21).

7. A method according to any one of the preceding claims, wherein: The method comprises cutting a first composite glass laminate (3) to form slices (9) and subsequently cutting a second composite glass laminate (3), wherein the plurality of slices (9) cut from the first composite glass laminate and one of their side surfaces (13, 15) are placed on a reference surface (25), and the tilt angles of the inner surfaces of the slices (9), in particular the light reflecting layer (7) relative to the reference surface (25) are measured, and an average tilt angle is determined, and wherein the orientation of the autocollimator (22) is corrected based on the average tilt angle, and the second composite glass laminate (3) is cut with its tilt angle relative to the cutting plane (11) adjusted using the autocollimator (22) in the corrected orientation.

8. The method according to any one of the preceding claims, comprising cutting a first composite glass laminate (3) to form slices (9), and subsequently cutting a second composite glass laminate (3), wherein a plurality of slices (9) cut from the first composite glass laminate (3) are placed on a reference surface (25), and the inclination angles of the planes (16) of the slices (9) relative to the reference surface (25) are measured, and an average inclination angle is determined, and wherein, The orientation of the autocollimator (22) is corrected according to the average tilt angle, and the second composite glass laminate (3) is cut with its tilt angle relative to the cutting plane 11 adjusted using the autocollimator in its corrected orientation.

9. A method according to any one of the preceding claims, wherein: The composite glass laminate (3) is combined with a sacrificial plate (27) fixedly held on the retaining frame, and wherein the cutting comprises completely cutting through the composite glass laminate (3) and further partially cutting into the sacrificial plate (27), wherein after cutting, the bond between the sacrificial plate (27) and the composite glass laminate (3) is released, so that the slice (9) is separated from the sacrificial plate (27).

10. A method according to any one of the preceding claims, wherein: The method comprises at least one of the following steps: - adjusting the position of the composite glass laminate (3) relative to the cutting plane (11) so that the position of the light reflecting layer (7) deviates by less than 0.2 mm, preferably less than 0.1 mm, relative to a reference position, preferably a center position, within a slice (9) cut from the composite glass laminate (3); - adjusting the orientation of the composite glass laminate (3) relative to the cutting plane (11) so that the tilt angle of the light reflecting layer (7) of the slice (9) cut from the composite glass laminate (3) is less than 15 arc seconds; - pre-adjusting the inclination angle about an axis of rotation inclined to the direction of movement of the composite glass laminate (3) for cutting, comprising: measuring the positions of points on the face of the composite glass laminate (3) along the path in the direction of movement of the composite glass laminate (3) during the cutting operation, and adjusting the orientation of the composite glass laminate (3), in particular the adjustment direction, according to the measurement results, so that these positions have equal values ​​in a direction perpendicular to the face; as well as - pre-adjustment, wherein at least one camera (24) is used to measure the distance between the face (17) of the composite glass laminate (3) and the cutting wire (18), at least two points on the face (17) being spaced apart in the longitudinal direction of the cutting wire (18), and then the orientation of the composite glass laminate (3) is adjusted so that the distances between the points and the cutting line (18) are equal.

11. A method according to any one of the preceding claims, comprising: - fixing the composite glass stack (3) on a holder (23) movable by means of stacked workbenches (32, 33, 34); - using one of the workbenches (33) to adjust the azimuth angle of rotation of the composite glass stack (3) around an axis along the cutting direction; and One of the work tables (34) is used to adjust or manipulate the position of the composite glass stack (3) in a direction oblique to the cutting plane (11).

12. A method according to any one of the preceding claims, wherein: When the holder (23) is inserted into and fixed in the cutting device (2), the holder (23) has a defined orientation relative to the cutting plane (11), and wherein, when the holder (23) is detached from the cutting device (2) and fixed on the alignment device (10), the composite glass laminate (3) is aligned with the holder (23); as monitored by the autocollimator (22), the composite glass laminate (3) is aligned with the holder (23) and fixed to the holder (23) in an aligned orientation, and wherein the holder (23) with the composite glass laminate (3) attached is inserted into and fastened to the cutting device (2) so that the composite glass laminate (3) has a defined orientation relative to the cutting plane due to its defined orientation relative to the holder (23).

13. A method for manufacturing a light-guiding optical element (1), comprising: Producing a slice (9) from a composite glass stack (3) using a method according to one of the preceding claims; The side surfaces (13, 15) of the slice (9) are polished; and the slice (9) is cut along a predefined contour line to obtain the light-guiding optical element (1).

14. A device for producing a blank of a light-conducting optical element (1) from a composite glass stack (3), wherein: The composite glass laminate (3) comprises a plurality of glass sheets (5) bonded together and a light reflecting layer (7) arranged between the glass sheets (5); the device comprises a cutting device (2) and an alignment device (10), wherein the cutting device (2) is used to cut a slice (9) from the composite glass laminate (3) along a parallel cutting plane (11), and the alignment device (11) is used to align the composite glass laminate (3) with the cutting plane (11) so that the light reflecting layer (7) is aligned with the side surface (11) of the slice (9) after cutting. 13, 15) having a defined orientation, wherein the composite glass laminate (3) has a plane (16) having a defined orientation relative to the light reflecting layer (7) within the composite glass laminate (3), such that when the cutting plane (11) is parallel to the plane (16) of the composite glass laminate (3), the light reflecting layer (7) within the slice (9) has a correct orientation, wherein the device comprises a holder (23) for holding the composite glass laminate (3) in its aligned orientation, and wherein the alignment means comprises: - an autocollimator (22) for monitoring the adjustment of the inclination angle of the plane (16) of the composite glass stack (3) relative to the cutting plane (11), and - means for adjusting the position of the composite glass layer (3) in a direction inclined, preferably perpendicular, relative to the cutting plane (11).

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