Apparatus and method for transporting an optical device

Abstract

An apparatus (300) for transporting an optical device (310) is provided. The apparatus (300) includes a contactless suspension system (320) defining a transportation path for the optical device (310). The optical device has two major surfaces. The apparatus (300) includes a first side support (330) arranged to contact a first side portion (316) of the optical device (310) extending between the two major surfaces. The apparatus (300) includes a second side support (340) arranged to contact a second side portion (318) of the optical device (310) extending between the two major surfaces. A position of at least one of the first side support (330) and the second side support (340) is adjustable to adjust a first distance (350) between the first side support (330) and the second side support (340). The first side support (330) and the second side support (340) are movable in a transportation direction (390) defined by the transportation path.

Description

APPARATUS AND METHOD FOR TRANSPORTING AN OPTICAL DEVICEFIELD

[0001] Embodiments described herein relate to apparatuses and methods for transporting optical devices, more specifically optical devices for augmented reality applications, such as waveguide combiners.BACKGROUND

[0002] Virtual reality is generally considered to be a computer-generated simulated environment in which a user has an apparent physical presence. A virtual reality experience can be generated in 3D and viewed with a head-mounted display (HMD) such as glasses or other wearable display devices that have near-eye display panels as lenses for displaying a virtual reality environment that replaces an actual environment.

[0003] Augmented reality, however, enables an experience in which a user can still see through the display lenses of the glasses or other HMD device to view the surrounding environment, yet also see images of virtual objects that are generated for display and appear as part of the environment. Augmented reality can include any type of input, such as audio and haptic inputs, as well as virtual images, graphics, and video that enhances or augments the environment that the user experiences. As an emerging technology, augmented reality is accompanied by many challenges and design constraints.

[0004] In order to allow for a computer-generated virtual image to be combined with a real-world image of the environment so as to provide an augmented reality experience, optical combiners may be used. Such optical combiners may involve waveguides that include a substrate having a plurality of optical structures formed thereon. Since the optical structures are small (e.g. nano-sized), fragile structures that are easily damaged or contaminated, the handling of waveguides may be challenging. For example, a fast, automated processing of waveguides can be difficult, thus affecting the overall rate of productivity in the manufacture of display devices for augmented reality applications.

[0005] In light of the above, there is a need for improved systems and methods for handling optical devices such as waveguides for augmented reality applications.SUMMARY

[0006] According to an embodiment, an apparatus for transporting an optical device is provided. The apparatus includes a contactless suspension system defining a transportation path for the optical device. The optical device has two major surfaces. The apparatus includes a first side support arranged to contact a first side portion of the optical device extending between the two major surfaces. The apparatus includes a second side support arranged to contact a second side portion of the optical device extending between the two major surfaces. A position of at least one of the first side support and the second side support is adjustable to adjust a first distance between the first side support and the second side support. The first side support and the second side support are movable in a transportation direction defined by the transportation path.

[0007] According to a further embodiment, an apparatus for transporting an optical device is provided. The apparatus includes a contactless suspension system defining a transportation path. The apparatus includes a first side support and a second side support defining an optical device containment region. The first side support and the second side support are spaced apart from each other at an adjustable first distance defining an adjustable dimension of the optical device containment region. The first side support and the second side support are movable in a transportation direction defined by the transportation path.

[0008] According to a further embodiment, a method for transporting an optical device is provided. The method includes providing the optical device in a suspended state using a contactless suspension system, the optical device having two major surfaces. The method includes transporting the optical device along a transportation path defined by the contactless suspension system. The method includes moving a first side support and a second side support together with the optical device in a transportation direction defined by the transportation path. The first side support is arranged to contact a first side portion of the optical device extending between the two major surfaces and the second side support is arranged to contact a second side portion of the optical device extending between the two major surfaces. A position of at least one of the first side support and the second side support is adjustable to adjust a first distance between the first side support and the second side support.

[0009] Embodiments are also directed to apparatuses for carrying out the disclosed methods and include apparatus parts for performing each described method aspect. These method aspects may be performed by way of hardware components, a computer programmed by appropriate software, by any combination of the two or in any other manner. Furthermore, embodiments according to the disclosure are also directed to methods for operating the described apparatus. The methods for operating the described apparatus include method aspects for carrying out every function of the apparatus.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments. The accompanying drawings relate to embodiments of the disclosure and are described in the following:FIGs. l(a)-(b) show an example of a waveguide;FIG. 2 shows a waveguide stack including several waveguides;FIG. 3 shows an apparatus for transporting optical devices according to embodiments described herein;FIGs. 4-5 shows an apparatus for transporting optical devices according to embodiments described herein, wherein the optical device is provided at an inclination angle;FIGs. 6(a)-(b) illustrate the notion of an adjustable first distance between a first side support and a second side support of an apparatus according to embodiments described herein;FIG. 7 shows an apparatus for transporting optical devices according to embodiments described herein, wherein the optical device is provided in a horizontal orientation; andFIGs. 8-9 show an apparatus for transporting optical devices according to embodiments described herein.DETAILED DESCRIPTION

[0011] Reference will now be made in detail to the various embodiments of the disclosure, one or more examples of which are illustrated in the figures. Within the following description of the drawings, the same reference numbers refer to same components. Generally, only the differences with respect to individual embodiments are described. Each example is provided by way of explanation of the disclosure and is not meant as a limitation of the disclosure. Further, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield yet a further embodiment. It is intended that the description includes such modifications and variations.

[0012] Embodiments described herein involve optical devices. A device may be considered an optical device if the optical properties of the device are relevant for the method or apparatus in which the device is used. At least a portion of an optical device can be made of a transparent material, such as glass or plastic. Some optical devices may be configured to change the properties, e.g. the propagation direction, of light. For example, an optical device may include optical structures for changing the propagation direction of light. Other optical devices may be unstructured and allow light to pass therethrough substantially unaltered. An optical device as described herein may be an optical device for use in augmented reality applications. An optical device can also be called an optical element. Examples of optical devices include waveguides and transparent cover elements, such as cover glasses, as described herein.

[0013] An optical device as described herein, such as a waveguide or a transparent cover element, can be a thin piece of material. An optical device can be a plate element, including a plate element having a flat surface or a plate element having a curved surface. An optical device can have a first major surface and a second major surface opposite the first major surface. An optical device may be a substantially two-dimensional device, wherein a thickness of the optical device between the first major surface and the second major surface can be much smaller (e.g. 1 % or less) than a dimension, such as a length or width, of the first or second major surface. For example, the thickness of an optical device may be 1 mm or less, 500 pm or less, or 300 pm or less.

[0014] Figs. l(a)-(b) show an exemplary waveguide 10. As shown in Fig. 1(a), the waveguide 10 may include a substrate 110, which may be a thin piece of transparent material, such as glass or plastic. At least one grating structure, such as a grating structure 112 and a grating structure 114, may be disposed on the substrate 110. The waveguide 10 may include an input coupling region 102 defined by the grating structure 112. The waveguide 10 may include an output coupling region 104 defined by the grating structure 114. Light, in particular light corresponding to a virtual, computer-generated image, may be coupled into the waveguide 10 at the input coupling region 102. The light may propagate through the waveguide 10 until the light reaches the output coupling region 104. At the output coupling region 104, the light may exit the waveguide 10. Further, also at the output coupling region 104, light from the external, real -world surroundings may be transmitted through the waveguide 10 (as shown by the dashed line), allowing the user to see a combination of a virtual image and a real -world image. The waveguide 10 may be a waveguide combiner for providing an augmented reality experience to a user.

[0015] Fig. 1(b) shows a grating structure 120 of a waveguide 10 in more detail. The grating structure 120 may be the grating structure 112 or the grating structure 114 shown in Fig. 1(a), and may accordingly serve to provide an input coupling region or an output coupling region of the waveguide 10. The grating structure 120 may be formed on a major surface 12 of the substrate 110. The grating structure 120 may include a plurality of optical structures 122. The optical structures 122 may be configured to change a propagation direction of light incident on the grating structure 120. The optical structures 122 may have dimensions, e.g. width and / or height, that lie in the sub-micron and even nanometer range. The optical structures may be arranged adjacent to each other with a gap in between. As shown in Fig. 1(b), the optical structures 122 may be shaped, for example, as slanted fins.

[0016] The disclosure is not limited to the exemplary waveguide 10 shown in Figs. 1(a)- (b) and applies likewise to other waveguides. For example, a waveguide may have more than two grating structures (e.g. the waveguide may have one or more intermediate regions defined by further grating structures), the arrangement and shape of the optical structures 122 may be different from the example shown in Fig. 1(b), the waveguide may have grating structures disposed on both sides of the waveguide, and so on.

[0017] An optical device as described herein may be a waveguide. The waveguide may include a substrate. The waveguide may include a plurality of optical structures formed on the substrate. The optical structures may have sub-micro-dimensions, e.g. nano-sized dimensions. The plurality of optical structures may form one or more grating structures on the substrate. A waveguide can be a waveguide combiner. A waveguide combiner may be configured for combining a virtual computer-generated image with a real-world image of a surrounding environment. A waveguide may be an augmented reality waveguide combiner.

[0018] In an optical system, such as an augmented reality device, several waveguides may be stacked on top of each other to form a waveguide stack. For example, each waveguide in the waveguide stack may be configured for manipulating light in a respective wavelength range, which is beneficial for providing color images.

[0019] Fig. 2 shows an example of a waveguide stack 200. The waveguide stack 200 may include a cover glass 202a (bottom cover glass), a waveguide 10a, a waveguide 10b, a waveguide 10c and a cover glass 202b (top cover glass) stacked in this order. An adhesive 204a may be disposed between the cover glass 202a and the waveguide 10a. Adhesives 204b, 204c and 204d may be disposed between waveguides 10a and 10b, between waveguides 10b and 10c, and between waveguide 10c and cover glass 202b, respectively. Each of the waveguides lOa-c may be a waveguide as described herein, such as a waveguide 10 shown in Figs. l(a)-(b).

[0020] A cover glass, such as cover glasses 202a-b, may a protective glass. A cover glass may shield a surface of a waveguide adjacent to the cover glass, for example to prevent a grating formed on said surface from being contacted or contaminated. It may be the case that a cover glass has no optical structures, such as a grating.

[0021] An adhesive, such as adhesives 204a-d, may be configured to attach adjacent optical devices of a waveguide stack to each other. For example, adhesive 204a may be configured to attach cover glass 202a to waveguide 10a. An adhesive may be a pressure sensitive adhesive (PSA). An adhesive may be a pre-formed adhesive, such as a pre-formed PSA. An adhesive may have an elongated shape. For example, an adhesive may be an adhesive tape. An adhesive may function as a spacer providing a gap, particularly an air gap,between adjacent optical devices of the waveguide stack. Due to the adhesive, it may be the case that said adjacent optical devices do not contact each other.

[0022] The waveguide stack 200 shown in Fig. 2 includes a total of three waveguides. The disclosure is not limited thereto. A waveguide stack may include 1 or more, 2 or more, or 3 or more waveguides. For example, a waveguide stack may include a total of 2 waveguides stacked between a cover glass 202a and a cover glass 202b. In another example, a waveguide stack may include a single waveguide and a single cover glass.

[0023] Further, instead of cover glasses, transparent cover elements made of materials other than glass may be used in a waveguide stack. Throughout the present disclosure, a cover glass may be replaced by a transparent cover element.

[0024] A waveguide stack may be formed. Forming the waveguide stack may include placing a cover glass 202a on a support, placing an adhesive 204a on the cover glass 202a, placing a waveguide 10a on the adhesive 204a, placing an adhesive 204b on the waveguide 10a, and so on, in this order.

[0025] According to embodiments described herein, an optical device, such as a waveguide, is transported without contacting the two major surfaces of the optical device. The optical structures on the major surfaces, such as grating structures of a waveguide, are not touched during transportation, ensuring that the optical structures are not damaged or contaminated. The optical device may be transported by side contact only, i.e., by contacting only one or more side surfaces of the optical device. Further, embodiments described herein allow optical devices having different dimensions to be transported by a single apparatus. This is particularly beneficial since optical devices, such as waveguides for augmented reality applications, may come in a variety of different shapes and sizes. The apparatus according to embodiments described herein is configured for universal transportation of optical devices, i.e. is capable of handling optical devices having different dimensions, in a controlled and reliable manner without contacting the major surfaces of the optical devices.

[0026] Fig. 3 shows an apparatus 300 for transporting an optical device 310 according to embodiments described herein.

[0027] According to an embodiment, an apparatus 300 for transporting an optical device 310 is provided. The apparatus 300 includes a contactless suspension system 320 defining a transportation path for the optical device 310. The optical device has two major surfaces, such as a first major surface 312 and a second major surface 314. The apparatus 300 includes a first side support 330 arranged to contact a first side portion 316 of the optical device 310 extending between the two major surfaces. The apparatus 300 includes a second side support 340 arranged to contact a second side portion 318 of the optical device 310 extending between the two major surfaces. A position of at least one of the first side support 330 and the second side support 340 is adjustable to adjust a first distance 350 between the first side support 330 and the second side support 340. The first side support 330 and the second side support 340 are movable in a transportation direction 390 defined by the transportation path.

[0028] The apparatus 300 according to embodiments described herein may be part of a tool for processing waveguides, in particular a tool for manufacturing waveguide stacks.

[0029] The optical device 310 may be a waveguide, a transparent cover element such as a cover glass, or another optical device. According to embodiments, the optical device 310 may be a waveguide including a substrate and a plurality of optical structures formed thereon. The plurality of optical structures may form a grating.

[0030] The optical device 310 may include a first major surface 312 and a second major surface 314 opposite the first major surface 312. The total area of the optical device 310 may be defined by the area of the first major surface 312 or the area of the second major surface 314. The first major surface 312 and the second major surface 314 may have substantially the same area.

[0031] The optical device 310 may have one or more side surfaces, also called edge surfaces, between the first major surface 312 and the second major surface 314. A side surface of the optical device 310 may be a thin surface extending between the first major surface 312 and the second major surface 314. A side surface may have an area which is, for example, 10% or less of the area of the first major surface or the area of the second major surface. A side portion of the optical device, such as the first side portion 316 or the second side portion 318, or any other side portion described herein, can be understood as a portion of a side surface of the optical device 310. A side portion extends between the first majorsurface 312 and the second major surface 314. A side portion is not part of a major surface of the optical device 310. A side portion may have a dimension, e.g. a length or width, corresponding to a thickness of the optical device 310 between the first major surface 312 and the second major surface 314. Where the optical device 310 is a waveguide, the first side portion 316 and the second side portion 318 of the optical device 310 may be first and second side portions, respectively, of a substrate of the waveguide.

[0032] The first side portion 316 and the second side portion 318 can be part of two different side surfaces of the optical device or can be part of a same surface of the optical device.

[0033] In some embodiments, the first side portion 316 and the second side portion 318 may be disposed on opposite sides of the optical device 310, as illustrated in Fig. 3. In other embodiments, different from Fig. 3, the first side portion 316 and the second side portion 318 may be disposed on a same side of the optical device 310.

[0034] A side support of the apparatus 300, such as the first side support 330, the second side support 340 or any other side support described herein, may be configured for contacting an optical device only at a side surface of the optical device. It may be the case that the side support does not contact the two major surfaces of the optical device.

[0035] The contactless suspension system 320, also called contactless levitation system, is configured for contactlessly suspending the optical device 310. The term “contactlessly suspending” can be understood in the sense that the optical device is provided in a suspended state, or floating state, wherein the contactless suspension system 320 does not include a mechanical support carrying the weight of the optical device 310 by means of contact between the mechanical support and the optical device 310. While the optical device 310 is contactlessly suspended by the contactless suspension system 320, it may be the case that there is no contact between the optical device 310 and the contactless suspension system 320. The contactless suspension system 320 may exert a contactless action on the optical device 310 that holds the optical device 310 at a predetermined distance from the contactless suspension system 320. The predetermined distance may be adjustable by controlling a magnitude of a contactless force exerted by the contactless suspension system 320 on theoptical device 310. A contactless suspension system 320 may, for example, include an ultrasonic vibration generator, as described below.

[0036] The fact that the optical device 310 is contactlessly acted upon by the contactless suspension system 320 does not exclude portions of the optical device 310 from being contacted by other parts of the apparatus 300. For example, the first side support 330 and the second side support 340 may contact side portions of the optical device 310. Yet, according to embodiments described herein, the apparatus 300 is configured fortransporting the optical device 310 by side contact only, that is to say, by contacting only one or more side surfaces of the optical device 310. According to embodiments, the apparatus 300 may be configured to transport the optical device 310 without contacting the two major surfaces of the optical device 310.

[0037] The optical device 310 may be transported in the transportation direction 390 while being in a suspended state provided by the contactless suspension system 320. The contactless suspension system 320 may be a stationary system. It may be the case that the contactless suspension system 320 remains in a fixed position during transportation of the optical device 310.

[0038] The optical device 310 that is being transported may be disposed between the first side support 330 and the second side support 340. The first side support 330 may be disposed behind the optical device 310 that is moving in the transportation direction 390, as shown in Fig. 3. The second side support 340 may be disposed in front of the optical device 310 that is moving in the transportation direction 390, as also shown in Fig. 3. The terms “in front of’ and “behind” are defined with respect to the movement of the optical device 310 in the transportation direction 390.

[0039] According to embodiments, the first side support 330 and the second side support 340 may be arranged for containing the optical device 310 inside an optical device containment region. The adjustable first distance 350 between the first side support 330 and the second side support 340 may define an adjustable dimension of the optical device containment region. The optical device containment region may be disposed at least partially between the first side support 330 and the second side support 340. An advantage of the firstside support 330 and the second side support 340 is that stability is provided for the optical device that is being transported.

[0040] The first side support 330 and the second side support 340 may move in the transportation direction 390 together with the optical device 310. The first side support 330 and the second side support 340 may be arranged for limiting a movement of the optical device 310 in a horizontal direction during transportation of the optical device 310. The first side support 330 and the second side support 340, which are spaced apart from each other by the first distance 350, may define an optical device containment region. The first distance 350 may define a dimension, e.g. a length, of the optical device containment region. As the first side support 330 and the second side support 340 move in the transportation direction 390, the optical device containment region moves in the transportation direction 390 together with the first side support 330 and the second side support 340. The first side support 330 and the second side support 340 may prevent the optical device 310 from moving out of the optical device containment region during transportation of the optical device 310. The optical device 310 may be contained inside the optical device containment region.

[0041] For example, in Fig. 3, the optical device 310 is transported in the transportation direction 390. During such transportation, the optical device 310, being in a suspended state resulting from the action of the contactless suspension system 320, may float slightly towards the left and / or towards the right. The first side support 330 may limit a movement of the optical device 310 towards the left, and the second side support 340 may limit a movement of the optical device 310 towards the right. For example, if the optical device 310 moves to the left, the first side portion 316 of the optical device 310 will collide with the first side support 330, and the optical device 310 is prevented from continuing to move to the left. Likewise, if the optical device 310 moves to the right, the second side portion 318 of the optical device 310 will collide with the second side support 340. The optical device 310 in the suspended state may swing back and forth between the first side support 330 and the second side support 340. Yet, the optical device 310 is contained within the region between the first side support 330 and the second side support 340, i.e. the optical device containment region. In other configurations, the first side support 330 and the second side support 340 may be arranged tightly against the optical device 310 to maintain contact with the optical device 310 at all times, so that a left / right floating movement of the optical device310 is not even possible. In such a case, the optical device 310 may be held in a fixed position between the first side support 330 and the second side support 340 during transportation. A stable transportation of the optical device is provided.

[0042] According to embodiments, the first distance 350 may be a distance in the transportation direction 390. The first distance 350 is an adjustable distance. The first distance 350 may be adjusted, particularly increased or decreased, by changing a position of the first side support 330 and / or a position of the second side support 340 with respect to the transportation direction 390. The first side support 330 and the second side support 340 may be moved closer together or farther apart to adjust the first distance 350.

[0043] According to embodiments, the apparatus 300 may include an actuator system including one or more actuators for changing a position of at least one of the first side support 330 and the second side support 340 to adjust the first distance 350. For example, the one or more actuators may include one or more motors.

[0044] According to embodiments, the first distance 350 may be adjustable to allow optical devices with different dimensions to be transported by the apparatus 300. The first distance 350 may be adjusted depending on a dimension of the optical device. The first distance 350 shown in Fig. 3 is an example of a first distance suitable for containing an optical device 310 having a first dimension, e.g. a first length, with respect to the transportation direction 390. The first distance 350 may be adjusted to accommodate another optical device having a second dimension different from the first dimension.

[0045] Adjusting the first distance 350 may result in an adjustment of a size of the optical device containment region. In other words, the size of the optical device containment region may be increased or decreased by adjusting the first distance 350.

[0046] Fig. 4 shows an apparatus 300 for transporting an optical device 310 according to embodiments described herein.

[0047] The apparatus 300 according to embodiments described herein includes a contactless suspension system 320 for contactlessly suspending the optical device 310. According to embodiments, the contactless suspension system 320 may include an ultrasonic vibration generator. The ultrasonic vibration generator may be configured to provideultrasonic vibrations. The ultrasonic vibration generator may provide a contactless repulsive force acting on the optical device 310.

[0048] The ultrasonic vibration generator may include a sonotrode 414. The sonotrode 414 may be mounted to a body portion 402 of the apparatus 300. The sonotrode 414 may be configured for providing ultrasonic vibrations. The ultrasonic vibrations may result in a repulsive contactless force pushing the optical device 310 upward. The ultrasonic vibration generator may include a resonating element 412, such as a resonating plate (also called vibrating plate), that may be connected to the sonotrode 414. The resonating element 412 may have one or more flat portions arranged for facing the optical device 310. The resonating element 412 may be configured for transmitting the ultrasonic vibrations created by the sonotrode 414 to an optical device receiving area of the apparatus 300.

[0049] The contactless suspension system 320 may act on the optical device 310 from below the optical device 310. The sonotrode 414 and / or the resonating element 412 may be disposed below an optical device receiving area of the apparatus 300. The repulsive force provided by the ultrasonic vibration generator may be an upward force.

[0050] By the combination of the repulsive upward contactless force provided by the ultrasonic vibration generator and the downward action of gravity on the optical device 310 (i.e. the weight of the optical device 310), a contactless suspension of the optical device 310 can be provided. Due to the upward repulsive contactless force provided by the ultrasonic vibration generator, an air cushion is created, preventing the optical device, that is forced downwards by the action of gravity, from contacting the resonating element 412. The optical device 310 may be maintained in a floating state without there being contact between the optical device 310 and the contactless suspension system. The vertical position of the suspended optical device (e.g. the distance between the optical device and the resonating element 412) can be adjusted by controlling the magnitude of the repulsive contactless force exerted by the ultrasonic vibration generator, particularly by controlling the magnitude of the ultrasonic vibrations generated by the sonotrode 414.

[0051] The contactless suspension system 320 may include one or more sonotrodes similar to sonotrode 414 and one or more resonating elements similar to resonating element 412 in different possible amounts and configurations. For example, the contactless suspensionsystem 320 may include a single sonotrode connected to a single resonating element, may include a single sonotrode connected to multiple resonating elements, or may include multiple sonotrodes connected to multiple respective resonating elements.

[0052] Fig. 4 shows the transportation direction 390 extending into the drawing plane. With respect to the transportation direction 390, the first side support 330 is disposed behind the optical device 310. The second side support 340 is disposed in front of the optical device 310. The first side support 330 may face a first side of the optical device 310. The second side support 340 may face a second side of the optical device 310. The first side support 330 and the second side support 340 may project substantially vertically, in particular upward. The first side support 330 and the second side support 340 may project in a direction perpendicular to at least one major surface of the optical device and / or a direction perpendicular to the optical device receiving area of the apparatus 300. The first side support 330 and the second side support 340 may be disposed above the resonating element 412, e.g. above a center region of the resonating element 412. As shown in Fig. 4, the first side support 330 and the second side support 340 may be disposed in a recess between two portions 412a and 412b of the resonating element 412. In other embodiments, instead of a single resonating element 412 as shown in Fig. 4, the apparatus 300 may include a first resonating element and a second resonating element that are spaced apart from each other, wherein the first side support 330 and the second side support 340 are disposed between the first resonating element and the second resonating element.

[0053] The first side support 330 and the second side support 340 may be decoupled from the contactless suspension system, in particular from the ultrasonic vibration generator. Accordingly, ultrasonic vibrations generated by the sonotrode 414 are not transmitted to the first side support 330 or the second side support 340.

[0054] According to embodiments, the contactless suspension system 320 may be arranged for providing the optical device 310 at an inclination angle 420 with respect to a horizontal plane. For example, the resonating element 412 may be tilted to provide the inclination angle 420. The inclination angle 420, which may also be called a tilting angle, may be 15 degrees or less, 10 degrees or less, or 5 degrees or less. For example, the inclination angle 420 may be about 2-5 degrees.

[0055] According to embodiments, the apparatus 300 may include a third side support 450 arranged for contacting a third side portion 452 of the optical device 310. The third side portion 452 may extend between the two major surfaces of the optical device 310. The third side support 450 may be arranged to support the third side portion 452 of the optical device 310 that is being provided at the inclination angle 420. The third side support 450 may be adjacent to an optical device receiving area of the apparatus 300, i.e. adjacent to the suspended optical device 310. Due to the tilted orientation of the suspended optical device 310, gravity acting on the optical device 310 causes the optical device 310 to move downwards along the tilted plane of the optical device 310. While the optical device 310 is provided at the inclination angle 420, gravity acting on the optical device 310 may cause the third side portion 452 of the optical device 310 to abut against the third side support 450. The optical device 310 may be held at the inclination angle 420 by a combination of the contactless suspension system 320 acting contactlessly on the optical device 310 and the third side support 450 supporting the third side portion 452 of the optical device 310.

[0056] An inclined optical device 310 that abuts against the third side support 450 has the advantage that the suspended optical device 310 has a well-defined, known (or easily determinable) position. Since gravity pushes the optical device 310 continuously against the third side support 450, the position of the third side portion 452 is stationary and can be easily determined (e.g. using a camera), which may be very helpful in any application where the position of the optical device 310 shall be precisely controlled.

[0057] Fig. 5 shows a top view of the apparatus 300 of Fig. 4.

[0058] As illustrated in Fig, 5, the first side support 330 may be arranged for contacting the optical device 310 at a first side of the optical device 310. The second side support 340 may be arranged for contacting the optical device 310 at a second side of the optical device 310. The third side support 450 may be arranged for contacting the optical device 310 at a third side of the optical device 310. The first side may be opposite the second side. The third side may extend from the first side to the second side. The first side portion 316, the second side portion 318 and the third side portion 452 may be disposed on the first side, the second side and the third side, respectively, of the optical device 310.

[0059] According to embodiments, the third side support 450 may be movable in the transportation direction 390. The third side support 450 may be a conveyor belt, or may be at least a portion of a conveyor belt. The conveyor belt may be an endless conveyor belt. The conveyor belt may extend in the transport direction 390. The conveyor belt may be configured for transporting the optical device 310 in the transport direction 390 while the optical device 310 is held in a suspended state by the contactless suspension system.

[0060] The third side support 450, particularly a conveyor belt, may be arranged laterally with respect to an optical device receiving area of the apparatus 300. The conveyor belt may have a contact surface for contacting the third side portion 452 of the optical device 310. The contact surface may be a vertical surface.

[0061] In operation, the third side support 450, particularly a conveyor belt, may move in the transport direction 390. While the optical device 310 is held in a suspended state using the contactless suspension system, particularly in a tilted orientation, the third side portion 452 of the optical device 310 may be supported by the third side support 450. Static friction between the third side portion 452 of the optical device 310 and the third side support 450 supporting said third side portion 452 may result in a movement of the optical device 310 in the transport direction 390. The optical device 310 may be transported by the apparatus 300 due to friction between the optical device and the moving third side support 450. During transportation, the major surfaces of the optical device 310 are not contacted.

[0062] The first side support 330 and / or the second side support 340 may be movable in the transportation direction 390. According to embodiments, the first side support 330 and the second side support 340 may be connected to or be part of a conveyor system including one or more conveyers. A movement of the conveyor system in the transportation direction 390 may cause a movement of the first side support 330 and the second side support 340 in the transportation direction 390.

[0063] The first side support 330 may be connected to, or be part of, a first conveyor 530, e.g. a belt conveyor, of the conveyor system. The first conveyor 530 may be movable in the transportation direction 390 to move the first side support 330 in the transportation direction 390. The second side support 340 may be connected to, or be part of, a second conveyor 540, e.g. a belt conveyor, of the conveyor system. The second conveyor 540 may be movable inthe transportation direction 390 to move the second side support 340 in the transportation direction 390. The first conveyor 530 and / or the second conveyor 540 may be movable at a same speed as the third side support 450, which may correspond to a transportation speed of the optical device 310.

[0064] The first conveyor 530 and the second conveyor 540 may be movable relative to each other to adjust the first distance 350 between the first side support 330 and the second side support 340. The first conveyor 530 and the second conveyor 540 may be individually driven by a first drive actuator and a second drive actuator, respectively. By controlling the first drive actuator and / or the second drive actuator, the first distance 350 can be adjusted. The first distance 350 may be set to a target value, e.g. depending on a dimension of the optical device 310 that is to be transported. After the first distance 350 has been set to the target value, the first conveyor 530 and the second conveyor 540 may move together in the transportation direction 390, so that the first distance 350 remains substantially constant during transportation of the optical device 310.

[0065] During operation, the first side support 330, the second side support 340 and the third side support 450 may move in the transportation direction 390, e.g. at a substantially same speed. The optical device 310 is in a suspended state during transportation due to the action of the contactless suspension system on the optical device 310. The third side portion 452 of the optical device 310 may be supported by the third side support 450, particularly in light of the tilted orientation of the optical device 310. The third side support 450, e.g. a conveyor belt, may move in the transportation direction 390. The optical device 310 may move together with the third side support 450 in the transportation direction 390 due to friction between the third side support 450 and the third side portion 452 of the optical device 310. The first side support 330 and the second side support 340 may move together with the optical device in the transportation direction 390. During transportation, it may happen that the optical device 310, at least temporarily, loses contact with the third side support 450, and / or that the optical device 310 starts swinging left and right, e.g. if the side of the optical device 310 which is supported by the third side support 450 is curved (as shown in Fig. 5). In such a case, the first side support 330 and the second side support 340 can ensure that any movement of the optical device 310 is contained within the optical device containment region defined by the first side support 330 and the second side support 340. The opticaldevice 310 is only contacted at one or more side surfaces of the optical device 310. The two major surfaces are not contacted.

[0066] As shown in Fig. 5, the apparatus 300 may include a plurality of first side supports 330 and a plurality of second side supports 340. Each first side support 330 may be connected to, or be part of, the first conveyor 530. Each second side support 340 may be connected to, or be part of, the second conveyor 540. A first distance, and a corresponding optical device containment region, may be defined between any first side support 330 and consecutive second side support 340. The apparatus 300 may be configured for transporting a plurality of optical devices, wherein each optical device is contained inside a respective optical device containment region.

[0067] Figs. 6(a)-(b) illustrate that the first distance 350 is adjustable. The optical device 310a shown in Fig. 6(a) has a larger dimension with respect to the transportation direction 390 than the optical device 310b shown in Fig. 6(b). In light thereof, the first distance 350 between the first side support 330 and the second side support 340 in Fig. 6(a) is larger than the first distance 350 in Fig. (b). In both Fig. 6(a) and 6(b), the optical device is contained within a corresponding waveguide containment region that is tailored to the size of the optical device in question. By having an adjustable first distance 350, both the optical device 310a and the optical device 310b, i.e. optical devices with different dimensions, can be transported by the same apparatus.

[0068] Fig. 7 shows an apparatus 300 for transporting an optical device 310 according to embodiments described herein.

[0069] According to embodiments, the apparatus 300 may include a fourth side support 750 arranged to contact a fourth side portion 752 of the optical device 310. The third side portion 452 and the fourth side portion 752 may be disposed on opposite sides of the optical device 310, as shown in Fig. 7. The third side support 450 and the fourth side support 750 may face each other and / or may be disposed on opposite sides of an optical device receiving area of the apparatus 300. The fourth side support 750 may be spaced apart from the third side support 450 with respect to a transversal direction 755. The transversal direction 755 may be substantially perpendicular (including deviations of, e.g., up to 15 degrees) to thetransportation direction 390. The waveguide containment region may be between the third side support 450 and the fourth side support 750.

[0070] The fourth side support 750 may be designed and function similarly to the third side support 450. The fourth side support 750 may be movable in the transportation direction 390. The fourth side support 750 may be a conveyor belt, which may have a vertically oriented contact surface for contacting the fourth side portion 752 of the optical device 310. The third side support 450 and the fourth side support 750 may move in the transportation direction 390 at a substantially same speed, which may correspond to a speed of transportation of the optical device 310.

[0071] A second distance 760 between the third side support 450 and the fourth side support 750 may be adjustable. The second distance 760 may be a distance with respect to a transversal direction 755. At least one of the third side support 450 and the fourth side support 750 may be movable in the transversal direction 755 to adjust the second distance 760. The third side support 450 and / or the fourth side support 750 may be connected to an actuator system including one or more actuators, e.g. motors, for moving at least one of the third side support 450 and the fourth side support 750 in the transversal direction 755. The adjustable second distance 760 may define an adjustable dimension, e.g. an adjustable width, of the optical device containment region with respect to the transversal direction 755. The second distance 760 may be adjusted depending on a dimension of the optical device 310 with respect to the transversal direction 755.

[0072] According to embodiments, the optical device 310 may be provided in a suspended state in a horizontal orientation of the optical device 310. At least one of the two major surfaces of the optical device 310 may be horizonal during transportation of the optical device 310. That is to say, different from e.g. the apparatus 300 shown in Figs. 4-5, it may be the case that there is no inclination angle 420.

[0073] In operation, the first side support 330, the second side support 340, the third side support 450 and the fourth side support 750 may move in the transportation direction 390, e.g. at a substantially same speed. The optical device 310 that is provided in a suspended state by the contactless suspension system 320 may have a horizontal orientation, i.e. it may be the case that there is no inclination angle 420. In the absence of an inclination angle, theoptical device 310 is not forced downwards by the action of gravity to abut against the third side support 450, providing a difference with respect to the operation of the apparatus 300 of Figs. 4-5. The provision of a fourth side support 750, in addition to the first side support 330, the second side support 340 and the third side support 450, ensures that the horizontally oriented optical device 310 is contained within the corresponding waveguide containment region. The first side support 330 in combination with the second side support 340 may limit a movement of the optical device in the transportation direction 390. The third side support 450 in combination with the fourth side support 750 may limit a movement of the optical device in the transversal direction 755. The optical device 310 is transported by side contact only.

[0074] Figs. 8-9 show an apparatus 300 for transporting an optical device 310 according to embodiments described herein.

[0075] The apparatus 300 includes a contactless suspension system including at least one sonotrode 414 and a resonating element 412, which may function analogously to the contactless suspension system described above. The contactless suspension system may be arranged to provide a plurality of optical devices 310 in a suspended state at an inclination angle.

[0076] The apparatus 300 may include a plurality of stationary side supports 850 adjacent to the contactless suspension system. The stationary side supports 850 may be configured for supporting optical devices 310 by side contact only. Each stationary side support 850 may support a respective optical device 310 at a side surface 852 of the optical device 310. Gravity acting on the optical device 310, which is provided in a suspended state at an inclination angle, may cause the side surface 852 to abut against the stationary side support 850. Each stationary side support 850 may remain in a fixed position, i.e. does not move together with the optical device 310 that is being transported by the apparatus 300. Each stationary side support 850 may be decoupled from the resonating element 412, so that the ultrasonic vibrations generated by the sonotrode 414 are not transmitted to the stationary side support 850. For example, a stationary side support 850 may be mounted to a basis structure (to which also the guide rail 820 may be mounted). The basis structure may be decoupled from the ultrasonic vibration generator.

[0077] As illustrated in Fig. 8, each stationary side support 850 may have two support portions on opposite ends of the stationary side support 850 for contacting two respective portions of the side surface 852 of an optical device 310. A distance between the two support portions may be adjustable to accommodate optical devices having different dimensions.

[0078] The plurality of stationary side supports 850 may be arranged at spaced-apart locations alongside the contactless suspension system, as shown in Fig. 8. The plurality of stationary side supports 850 may correspond to different locations for holding an optical device 310. An optical device 310 may be moved from one such location to the next, thereby achieving a transportation of the optical device 310 in the transportation direction 390.

[0079] The apparatus 300 may include a transfer system for transferring an optical device 310 from one stationary side support 850 to a subsequent stationary side support 850. The transfer system may include a first side support 330 and a second side support 340. Both the first side support 330 and the second side support 340 may be arranged for contacting the side surface 852, i.e. a same side surface, of the optical device 310. In this embodiment, the first side portion 316 (contacted by the first side support 330) and the second side portion 318 (contacted by the second side support 340) of the optical device 310 are disposed on a same side of the optical device 310. The first side portion 316 and the second side portion 318 are both part of the side surface 852, as illustrated in more detail in Fig. 9.

[0080] As was also the case in embodiments described above, a position of at least one of the first side support 330 and the second side support 340 may be adjustable to adjust a first distance 350 between the first side support 330 and the second side support 340. For example, the second side support 340 may be connected to one or more actuators, e.g. one or more motors, for changing the position of the second side support 340 relative to the first side support 330. By having an adjustable first distance 350, optical devices of different dimensions, in particular different lengths of the side surface 852, can be transported by the apparatus 300.

[0081] The first side support 330 and the second side support 340 may be mounted to a basis 830 that is movable on a guide rail 820 extending in the transportation direction 390. The first side support 330 and the second side support 340 may be movable in the transportation direction 390 along the guide rail 820. The first side support 330 and thesecond side support 340 may further be movable in a transversal direction 755, e.g. by one or more motors.

[0082] In operation, the first distance 350 may be set to a suitable value depending on a dimension of the optical device 310. The first side support 330 and the second side support 340 may be moved in the transversal direction 755 to engage the side surface 852 of an optical device 310. By moving in the transversal direction 755, the first side support 330 and the second side support 340 may push the optical device 310 away from the stationary side support 850 that is holding the optical device 310, so that the stationary side support 850 no longer contacts the side surface 852. At this point, the side surface 852 may only be supported by the first side support 330 and the second side support 340. The first side support 330 and the second side support 340 supporting the optical device 310 may then move in the transportation direction 390 (e.g. to the right) to the subsequent stationary side support 850. The first side support 330 and the second side support 340 may be retracted with respect to the transversal direction 755 to position the side surface 852 of the optical device 310 against said subsequent stationary side support 850. Accordingly, the optical device 310 has been transported from one stationary side support 850 to the subsequent stationary side support 850 by the transfer system. After the optical device 310 has been transferred from the first side support 330 and the second side support 340 to the subsequent stationary side support 850, the first side support 330 and the second side support 340 may move backwards with respect to the transportation direction 390 to the initial position of the first side support 330 and the second side support 340.

[0083] The transfer system may include a plurality of pairs of first side supports 330 and second side supports 340, as shown in Fig. 8. Each pair may be arranged to transfer a corresponding optical device from one stationary side support 850 to the next, in the manner described above. Accordingly, a plurality of optical devices 310 may be transported in parallel.

[0084] According to a further embodiment, an apparatus for transporting an optical device is provided. The apparatus includes a contactless suspension system defining a transportation path. The apparatus includes a first side support and a second side support defining an optical device containment region. The first side support and the second side support are spaced apart from each other at an adjustable first distance defining an adjustable dimension of theoptical device containment region. The first side support and the second side support are movable in a transportation direction defined by the transportation path. The apparatus may include any feature or combination of features of an apparatus for transporting an optical device according to embodiments described herein.

[0085] According to a further embodiment, a method for transporting an optical device is provided. The method includes providing the optical device in a suspended state using a contactless suspension system, the optical device having two major surfaces. The method includes transporting the optical device along a transportation path defined by the contactless suspension system. The method includes moving a first side support and a second side support together with the optical device in a transportation direction defined by the transportation path. The first side support is arranged to contact a first side portion of the optical device extending between the two major surfaces and the second side support is arranged to contact a second side portion of the optical device extending between the two major surfaces. A position of at least one of the first side support and the second side support is adjustable to adjust a first distance between the first side support and the second side support. The method may include performing any function or combination of functions of an apparatus for transporting an optical device according to embodiments described herein.

[0086] According to embodiments, the method may include adjusting the first distance based on a dimension of the optical device.

[0087] According to embodiments, the waveguide may be transported without contacting the two major surfaces of the waveguide.

[0088] While the foregoing is directed to embodiments of the disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

CLAIMS1. An apparatus (300) for transporting an optical device (310), comprising: a contactless suspension system (320) defining a transportation path for the optical device, the optical device having two major surfaces (312, 314); a first side support (330) arranged to contact a first side portion (316) of the optical device extending between the two major surfaces; and a second side support (340) arranged to contact a second side portion (318) of the optical device extending between the two major surfaces, wherein a position of at least one of the first side support and the second side support is adjustable to adjust a first distance (350) between the first side support and the second side support, wherein the first side support and the second side support are movable in a transportation direction (390) defined by the transportation path.

2. The apparatus of claim 1, wherein the optical device is a waveguide (10, lOa-c) comprising a substrate (110) and a plurality of optical structures (122) formed thereon.

3. The apparatus of claim 1 or 2, wherein the first distance is adjustable to allow optical devices with different dimensions to be transported by the apparatus.

4. The apparatus of any of the preceding claims, wherein the apparatus is configured to transport the optical device without contacting the two major surfaces of the optical device.

5. The apparatus of any of the preceding claims, wherein the contactless suspensionsystem includes an ultrasonic vibration generator (412, 414).

6. The apparatus of any of the preceding claims, wherein the first distance is a distance in the transportation direction.

7. The apparatus of any of the preceding claims, further comprising an actuator system including one or more actuators for changing a position of at least one of the first side support and the second side support to adjust the first distance.

8. The apparatus of any of the preceding claims, wherein the first side support and the second side support are arranged for containing the optical device inside an optical device containment region, the adjustable first distance between the first side support and the second side support defining an adjustable dimension of the optical device containment region.

9. The apparatus of any of the preceding claims, further comprising a third side support (450) arranged for contacting a third side portion (452) of the optical device extending between the two major surfaces, the third side support being movable in the transportation direction, the first side support, the second side support and the third side support being arranged to contact a first side, a second side and a third side, respectively, of the optical device.

10. The apparatus of any of the preceding claims, wherein the first side support and the second side support are connected to or are part of a conveyor system including one or more conveyers (530, 540).

11. The apparatus of any of the preceding claims, wherein the contactless suspension system is arranged for providing the optical device at an inclination angle (420) with respect to a horizontal plane.

12. An apparatus (300) for transporting an optical device (310), comprising: a contactless suspension system (320) defining a transportation path; and a first side support (330) and a second side support (340) defining an optical device containment region, the first side support and the second side support being spaced apart from each other at an adjustable first distance (350) defining an adjustable dimension of the optical device containment region, the first side support and the second side support being movable in a transportation direction (390) defined by the transportation path.

13. A method for transporting an optical device (310), comprising: providing the optical device in a suspended state using a contactless suspension system (320), the optical device having two major surfaces (312, 314); transporting the optical device along a transportation path defined by the contactless suspension system; and moving a first side support (330) and a second side support (340) together with the optical device in a transportation direction (390) defined by the transportation path, the first side support being arranged to contact a first side portion (316) of the optical device extending between the two major surfaces and the second side support being arranged to contact a second side portion (318) of the optical device extending between the two major surfaces, anda position of at least one of the first side support and the second side support being adjustable to adjust a first distance (350) between the first side support and the second side support.

14. The method of claim 13, further comprising: adjusting the first distance based on a dimension of the optical device.

15. The method of claim 13 or 14, wherein the optical device is transported without contacting the two major surfaces of the optical device.

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