Touch sensing device

Abstract

The present application relates to a touch sensing device comprising: a panel having a touch surface; a first set of emitters, a set of photodetectors, and a processing component. The touch surface is curved in a concave shape on a first axis. The touch sensing device also includes a frame assembly including a first frame member including a first portion and a second portion, a second frame member including a first portion and a second portion, and a seal. The second frame member is disposed on top of the first frame member such that the perimeter of the panel is disposed between the second portion of each of the first frame member and the second frame member. A seal is disposed between the second portion of the second frame member and the plate. The frame assembly is arranged to apply a controlled force along the perimeter of the plate such that the curvature of the plate is controlled. The touch surface is curved into a concave shape on a second axis perpendicular to the first axis.

Description

[0001] This application is a divisional application of a PCT application filed on December 7, 2017, with application number 201780076351.2 (international application number PCT / SE2017 / 051233), entitled “IMPROVED TOUCH DEVICE”, which has entered the Chinese national phase. Technical Field

[0002] The present invention relates generally to the field of optical touch sensitive systems. More specifically, the present invention relates to bending plates and assemblies for holding a plate of a system, such as a glass plate, relative to a panel so that the curvature of the plate is controlled. The present invention also relates to methods of assembling a plate of an optical touch sensitive system with a panel, such as a display panel, in such a manner that the curvature is controlled. Background Art

[0003] In a class of touch sensitive panels commonly referred to as above surface optical touch systems and known, for example, by US4459476, a plurality of optical emitters and optical receivers are arranged around the periphery of the touch surface to create a grid of intersecting optical paths above the touch surface. Each optical path extends between a corresponding pair of emitter / receivers. An object contacting the touch surface will block some of the optical paths. Based on the identity of the receiver that detects the blocked optical paths, the processor can determine the cut-off position between the blocked optical paths. This type of system can only detect the position of one object (single touch detection). In addition, the required number of emitters and receivers, and the resulting cost and complexity, increase rapidly with the surface area and / or spatial resolution of the touch panel.

[0004] In a variation such as that shown in WO2006 / 095320, each optical emitter emits a light beam that diverges across the touch surface, and each light beam is detected by one or more optical receivers positioned around the periphery of the touch surface.

[0005] These systems typically direct light to traverse the touch surface at heights up to 5 mm.

[0006] Other above-surface optical touch systems use tomographic touch imaging to sense touch, such as described in WO2016 / 130074. Such systems allow light to be directed closer to the touch surface, which in turn allows for significantly improved accuracy and requires a lower beam. The light is typically directed above the plate at a height of about 1 mm.

[0007] Typically, the touch surface is a glass plate. In systems where light is directed closer to the touch surface, intra-plate distortion can have a disproportionately large effect on the light signal. Therefore, the use of a glass plate in previously known above-surface optical touch systems is unsuitable when light is passed closer to the plate because the accuracy of the system is compromised by intra-plate distortion.

[0008] Additionally, frames used to assemble boards and panels (such as LCD panels) for optical touch systems can introduce distortion in the form of uncontrolled warping, which introduces twists or bends in the board, even though the board is normally flat. Uncontrolled warping can even block light from passing through the board. This is due to the uncontrolled twisting of the frame when it is attached to the panel.

[0009] Although not described with respect to touch systems, methods of minimizing glass warping are known from the window industry and display panel industry. Such solutions include pre-bending the glass to control the warping. However, such solutions are not suitable / inadequate for touch sensitive systems because they generally require bulky frames at the edges of the glass and / or pressure points closer to the center of the panel where pressure can be applied to control the shape of the glass. These solutions are not suitable for situations where extremely small / lightweight border bezels are required and where there cannot be any support other than the border to touch the glass. In addition, pre-bent glass is expensive and fragile during transportation.

[0010] Therefore, an improved frame assembly for holding the plates of an optical touch sensitive system relative to the panel would be advantageous, particularly allowing for improved accuracy, increased compactness, cost effectiveness and / or controlled curvature would be advantageous. In addition, there is a need in the art for a touch panel having a beneficial shape that helps to transfer as much light from the emitter as possible to the detector. Summary of the invention

[0011] Therefore, the present embodiments preferably seek to mitigate, alleviate or eliminate one or more defects, shortcomings or problems in the art, such as those identified above, either individually or in any combination, by providing a component, an assembly method and a set of frame components according to the present application.

[0012] A first embodiment of the present invention describes a component for maintaining and controlling the curvature of a panel for an optical touch-sensitive system, comprising: a first frame component extending in a first plane and configured to extend at least partially around a panel; at least one second frame component extending in a second plane and forming a support portion for the panel; and at least one spacer component at least partially positioned between the support portion and the first frame component, the spacer component configured to control the curvature of the first frame component; and wherein the at least one second frame component is configured to engage the panel at the support portion and be connected to the first frame component, and wherein the shape and / or position of the second frame is controlled by the curvature of the first frame component through the spacer component to control the curvature of the panel.

[0013] A second embodiment of the present invention describes a method for assembling panels and plates for an optical touch-sensitive system, comprising: providing a first frame component that extends in a first plane and is configured to extend at least partially around the panel; providing at least one second frame component that forms a support portion for the plate; supporting the plate by the support portion; connecting the second frame component to the first frame component so that the support portion extends at least partially in a second plane that is substantially opposite to at least a portion of the first frame component and separated from the first plane; and controlling the curvature of the first frame component by a spacing component connected to the first frame component, thereby tilting the support portion to control the curvature of the plate.

[0014] A third embodiment of the present invention describes a set of frame components for assembling panels and plates for a touch-sensitive system, comprising: a first frame component extending in a first plane; at least one second frame component forming a support portion for the plate and connectable to the first frame component; and a spacing component adjustably connectable to the first frame component; wherein at least a portion of the support portion can be tilted relative to the first frame component via the spacing component so as to extend in the curved second plane.

[0015] Some embodiments of the present invention provide for controlling the curvature of a plate for an optical touch sensitive system so that no bending occurs when the plate is assembled with a panel. This can prevent deformation in the plate from affecting the light signal transmitted through the plate, which in turn allows the system to have improved accuracy and a lower light beam. Additionally or alternatively, an embodiment provides curvature control so that the field of view of a detector receiving light from a light emitter of a touch sensitive system is increased compared to a substantially flat plate. Furthermore, the improved field of view provides improved accuracy of the touch sensitive system and allows for a better light beam. Furthermore, an embodiment provides a component that is curvature controllable while being compact. Moreover, the curvature can be controlled without contacting the center of the plate.

[0016] A fourth embodiment of the present invention describes a touch sensing device, comprising a touch surface; a group of emitters arranged around the touch surface to emit a first light beam to pass through the touch surface; a group of light detectors arranged around the touch surface to receive light from the first group of emitters, wherein each light detector is arranged to receive light from more than one emitter; and a processing unit configured to determine a position of an object on the touch surface based on output signals of the group of light detectors, wherein the touch surface is curved on a first axis according to a first parabola.

[0017] It should be emphasized that when the term "include / comprises" is used in this specification, it is used to limit the existence of the described features, integers, steps or components, but does not exclude the existence or addition of one or more other features, integers, steps, components or combinations thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] These and other aspects, features and advantages that can be achieved by the embodiments of the present invention will become clear and apparent through the following description of the embodiments of the present invention and with reference to the accompanying drawings, in which:

[0019] Figure 1 is a top view of the first frame member showing cross-sectional axes AA and BB;

[0020] Figure 2a-2d is a cross-sectional view of an embodiment of an assembly;

[0021] Figure 3a is a diagram showing the assembly having the second frame member relative to the first frame member and holding the panel in a flat plane Figure 1 A schematic diagram of the cross-sectional axis BB;

[0022] Figure 3b is a diagram showing the assembly having the second frame member relative to the first frame member and holding the panel in a flat plane Figure 1 A schematic diagram of the cross-sectional axis AA;

[0023] Figure 3c is a diagram showing the assembly having the second frame member curved relative to the first frame member and holding the panel in a concave curved plane Figure 1 Schematic diagram of the cross-sectional axis BB (cross section);

[0024] Figure 3d is a diagram showing the assembly having the second frame member curved relative to the first frame member and holding the panel in a concave curved plane Figure 1Schematic diagram of the cross-sectional axis AA (cross section);

[0025] Figure 4a is a perspective view of a first frame member;

[0026] Figure 4b is a schematic diagram of the panel being in a convex shape and the frame of the first frame member being in a concave shape including the plate 2 also being controlled to be in a concave shape;

[0027] Figure 4c is a side view showing screws 116a and 116b;

[0028] Figure 5a-5h are side and perspective views of an embodiment of an assembly including a screw device for configuring a frame shape; and

[0029] Figure 6 is a schematic cross-section of a first orientation of an embodiment of an assembly;

[0030] Figure 7 is a schematic side view of another embodiment for providing the curvature of the plate 2;

[0031] Figure 8 Shows Figure 5a-5g isometric view of a variation of an embodiment of;

[0032] Fig. 9 is a schematic diagram showing a top view of an optical touch system and corresponding detection lines;

[0033] Fig.10a An isometric view of a flat touch surface of an optical touch system is shown;

[0034] Fig.10b shows a cross-sectional view of an optical touch system having a flat touch surface;

[0035] Fig.11a An isometric view of a touch surface of an optical touch system having a curved profile on the x-axis is shown;

[0036] Fig.11b A cross-sectional view along the x-axis of an optical touch system having a touch surface with a curved profile on the x-axis is shown;

[0037] Fig.11c A cross-sectional view along the x-axis of an optical touch system having a touch surface with a curved profile on the x-axis is shown;

[0038] Fig.11d Examples of the types of warping that a touch panel may exhibit are shown.

[0039] Fig.12a A top view of a touch surface of an optical touch system is shown;

[0040] Figure 12b An isometric view of a touch surface of an optical touch system having a curved profile on an x-axis and a curved profile on a y-axis is shown;

[0041] Fig.12c A cross-sectional view along the x-axis of an optical touch system having a curved profile on the x-axis and a touch surface on the y-axis is shown;

[0042] Fig.12d A cross-sectional view along the y-axis of an optical touch system having a curved profile on the x-axis and a touch surface on the y-axis is shown;

[0043] Fig.13a shows a cross-sectional depiction of light rays emitted from a point at an edge of a curved touch surface and propagating across the curved touch surface to be received by a detector at an opposite edge of the touch surface;

[0044] Fig.13b a graph showing light rays emitted from a point at an edge of a curved touch surface and received by a detector at an opposite edge of the touch surface relative to the angle of the emitter light rays;

[0045] Fig.14a shows a cross-sectional rendering of light rays emitted from a point at an edge of a curved touch surface and propagating across the curved touch surface to be received by a detector at an opposite edge of the touch surface;

[0046] Fig.14b a graph showing light rays emitted from a point at an edge of a curved touch surface and received by a detector at an opposite edge of the touch surface relative to the angle of the emitter light rays;

[0047] Fig.15a A cross-sectional rendering showing light rays emitted from a point at an edge of a curved touch surface and propagating across the curved touch surface to be received by a detector at an opposite edge of the touch surface;

[0048] Fig.15b a graph showing light rays emitted from a point at an edge of a curved touch surface and received by a detector at an opposite edge of the touch surface relative to the angle of the emitter light rays;

[0049] Fig.16a A cross-sectional rendering showing light rays emitted from a point at an edge of a curved touch surface and propagating across the curved touch surface to be received by a detector at an opposite edge of the touch surface;

[0050] Fig.16ba graph showing light rays emitted from a point at an edge of a curved touch surface and received by a detector at an opposite edge of the touch surface relative to the angle of the emitter light rays;

[0051] Fig.17a A cross-sectional rendering showing light rays emitted from a point at an edge of a curved touch surface and propagating across the curved touch surface to be received by a detector at an opposite edge of the touch surface;

[0052] Fig.17b a graph showing light rays emitted from a point at an edge of a curved touch surface and received by a detector at an opposite edge of the touch surface relative to the angle of the emitter light rays;

[0053] Fig.18a shows the curvature of the real touch surface along the x-axis relative to the parabolic curved surface;

[0054] Fig.18b shows the deviation between the real touch surface and the parabolic surface along the x-axis;

[0055] Fig.19a shows the curvature of the real touch surface along the x-axis relative to the parabolic curved surface;

[0056] Fig.19b shows the deviation between the real touch surface and the parabolic surface along the x-axis;

[0057] Fig.20a A top view showing displacement contours of a touch surface according to an embodiment;

[0058] Fig.20b Shown according to Fig.20a a curvature of the touch surface along the x-axis of an embodiment of the present invention;

[0059] Fig.20c Shown according to Fig.20a a curvature of the touch surface along the y-axis of an embodiment;

[0060] Fig.20d Shown according to Fig.20a a curvature of the touch surface along a diagonal of an embodiment;

[0061] Fig.21a A top view showing displacement contours of a touch surface according to another embodiment;

[0062] Figure 21b Shown according to Fig.21a a curvature of the touch surface along the x-axis of an embodiment of

[0063] Fig.21c Shown according to Fig.21a a curvature of the touch surface along the y-axis of an embodiment of

[0064] Fig.21d Shown according to Fig.21a The curvature of the touch surface of an embodiment is along a diagonal. DETAILED DESCRIPTION

[0065] Specific embodiments of the present invention will now be described with reference to the accompanying drawings. However, the present invention may be implemented in many different forms and should not be considered limited to the embodiments set forth herein; rather, these embodiments are provided to make the disclosure thorough and complete and to fully convey the scope of the present invention to those skilled in the art. The terms used in the detailed description of the embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same numbers represent the same components.

[0066] In an optical touch-sensitive system, a plate 2 of the system, such as a glass plate, can be arranged opposite a panel 1, such as an LCD panel or an additional frame. Plate 2 is usually substantially flat. After integration, the periphery of plate 2 is a matter of concern: all four faces / edges of plate 2 must be flat or slightly concave when viewed from the touch surface (i.e. the side of plate 2 on which the light passes). One aspect of this is to ensure that the mechanical parts holding or supporting the periphery of plate 2 have no convex bends / convexities. Sometimes, holding plate 2 involves several parts (back cover, brackets, edge covers, screw bosses). The stiffer the components of the assembly, the more they will dictate the final shape of plate 2.

[0067] In prior art solutions, the frame holding the panel 2 at the edge / perimeter may introduce some distortion to the panel (corners will not fit perfectly on a flat surface). Distortion may create bulges / convexities along the panel diagonals and should be minimized or avoided. Distortion tolerance depends on e.g. glass specifications, product, size, integrated glass perimeter shape and how the VESA mount is attached.

[0068] Figure 1 Embodiments of frame assemblies 100, 200 are shown that prevent convexity along the board, such as along board edges and / or diagonals. Some embodiments avoid convexity and may even create concavity to further improve the touch system. Frame 109 is formed by first frame member 102. Connecting members 112 and spacing members 116 are described in the following embodiments.

[0069] According to some embodiments of the present invention, the assembly 100, 200 configured to hold or support the plate 2 and the panel 1 applies a controlled force to the plate 2, thereby controlling the curvature of the plate 2. Figure 2a-2c and Figure 3a-3dIn the embodiment shown, this force applies a torque to the support portions 101a, 101b for the plate 2. Figure 4a-4c In the embodiment of the present invention, the force is substantially straight and perpendicular to the plate 2. Figure 2a-2c , 3a-3d, 4a-4c and 5a-5g. However, these embodiments can be combined to provide more embodiments.

[0070] Figure 2a-2d An embodiment is shown in which the frame assembly 100 includes a first frame member 102 and at least one second frame member 103a, 103b. The first frame member 102 can form a rear support frame extending at least partially on the back side of the panel 1. The second frame members 103a, 103b can form a holder or bracket. In addition, the second frame members 103a, 103b can extend along at least a portion of the periphery of the plate 2 and / or the panel 1. Separate second frame members 103a, 103b can extend at least partially along the periphery of different sides of the plate 2 and / or the panel 1. For example, two second frame members 103a, 103b can extend along the opposite periphery of the plate 2 and / or the panel 1. Alternatively, four second frame members 103a, 103b can extend along the periphery of the plate 2 and / or the panel 1, i.e., each extending along each side of the rectangular plate 2 and / or the panel 1.

[0071] like Figure 4a-4c As shown, the panel 1 may be held between the first frame member 102 and the second frame member 103a, 103b. The plate 2 may be supported or held on a first side of a portion of the second frame member 103a, 103b forming the support portion 101a, 101b. The panel 1 may be held or supported by a second side of the support portion 101a, 101b forming the support portion of the panel 1. An adhesive member 104, such as an adhesive tape, may be arranged between the support portion 101a, 101b and the plate 2. A pad 105 may be arranged between the support portion 101a, 101b and the panel 1.

[0072] In one embodiment, components 102, 103 (shown in the figures as comprising components 103a and 103b) are formed from a single piece.

[0073] The second frame parts 103 a , 103 b may be connected to the first frame part 102 .

[0074] exist Figure 2a-2c and Figure 3a-3d In the embodiment of the present invention, the second frame parts 103a, 103b are connected to the first frame part 102 by at least one connecting member 106a, 106b (such as screws, welding points / pieces, rivets, etc.). Therefore, the second frame parts 103a, 103b can be rigidly connected to the first frame part 102.

[0075] The first frame member 102 may include flanges 107a, 107b extending around the periphery of the first frame member 102. Similarly, the second frame members 103a, 103b may include flanges 108a, 108b. When assembled, the flanges 107a, 107b of the first frame member 102 may be arranged to abut against the flanges 108a, 108b of the second frame members 103a, 103b. The flanges 107a, 107b of the first frame member 102 may be held together with the flanges 108a, 108b of the second frame members 103a, 103b by connecting members 106a, 106b.

[0076] The first frame member 102 may form a frame 109 extending in a first plane (in Figure 1 1 ). The frame 109 is configured to extend at least partially around the first side of the panel 1. The first side of the panel 1 may be the rear side of the panel 1. In some embodiments, the frame 109 has a width such as 3-10 cm. The frame 109 may extend from an edge of the first side toward the center of the first side of the panel 1. Thus, the frame 109 may be rectangular and made of a single piece of material.

[0077] like Figure 3a and 3b As shown, the assembly 100 may include at least one support area 110a, 110b for supporting the back cover 111. The support area 110a, 110b may extend in a plane substantially parallel to the first plane in which the frame 109 extends. The support area 110a, 110b may be located further away from the support portion 101a, 101b of the second frame member 103a, 103b than the frame 109, so that the frame 109 and the back cover 111 are spaced apart. In the embodiment shown, the support area 110a, 110b is arranged between the flange 107a, 107b and the frame 109 of the first frame member 102. The back cover 111 may be connected to the support area 110a, 110b, for example by a connecting member such as a screw.

[0078] In other embodiments, the support area 110a, 110b is provided by a flange 108a, 108b of the second frame part 103a, 103b. The flange 107a, 107b of the first frame part 102 may be connected to the second frame part 103a, 103b between the flange 108a, 108b of the second frame part 103a, 103b and the support portion 101a, 101b.

[0079] The second frame members 103a, 103b may form the support portions 101a, 101b. For example, the second frame members 103a, 103b may form an elongated member, the cross-section of which is at least partially L-shaped. When assembled, the second frame members 103a, 103b may extend along the periphery of the panel 1 and wrap around the periphery of the panel so that the support portions 101a, 101b extend at least partially in a second plane that is generally opposite to the frame 109 and spaced apart from the first plane. The second frame members 103a, 103b are thereby configured to extend at least partially on a second side of the panel 1, for example on a front side of the panel 1.

[0080] In some embodiments, the second frame member 103a, 103b has a first portion and a second portion. The first portion can be arranged at a certain angle relative to the second portion. The second portion can form the support portion 101a, 101b and be configured to extend in a second plane opposite to the frame 109. The first portion can extend between the second portion and the first frame member 102. Moreover, the first portion can extend along the edge or side surface of the panel 2 when assembled. The first frame member 102 can be connected to the first portion of the second frame member 103a, 103b. The first portion can be substantially perpendicular to the second portion.

[0081] like Figure 3a-3d As shown, the first frame part 102 can be connected to the first part of the second frame part 103a, 103b so that they are fixed relative to each other. In addition, the second frame part 103 can be tilted relative to the first frame part 102. The force applied to the first frame part 102 is transmitted to the second frame part 103, so that the support parts 101a, 101b are tilted toward the first frame part 102. Therefore, the torque can control the inclination of the second part of the second frame part 103a, 103b, that is, the support parts 101a, 101b of the support plate 2, relative to the first frame part 102. Figure 3c and 3d In some embodiments, the inclination angles of the support portions 101a, 101b are controlled to be neutral, that is, the inclination angles of the support portions 101a, 101b are controlled to be substantially parallel to the panel 1 and / or the panel 2 is controlled to be in a plane, as shown in FIG. Figure 3a and 3b In other embodiments, the inclination angles of the support portions 101a, 101b are controlled to be negative relative to the contact surface, that is, the inclination angles of the support portions 101a, 101b are controlled so that the free ends of the support portions 101a, 101b are inclined toward the frame 109, as shown in FIG. Figure 3c and 3das shown. In the latter case, the plate 2 is given a slightly concave shape, i.e. in the direction from the touch surface of the plate 2 towards the panel 1. In each of these cases, the curvature is controlled so that the field of view of the detector for receiving light from the light emitter of the touch sensitive system is improved, because a convex curvature of the plate is avoided. Likewise, the improved field of view provides improved accuracy of the touch sensitive system as well as allowing a lower light beam. Furthermore, since the support portions 101a, 101b only need to extend a short distance on the plate 2 at the periphery, the assembly becomes compact while the curvature is controllable. Moreover, the curvature can be controlled without contacting the center of the plate. When concavity is applied / imposed, the sensitivity of the system can be further improved.

[0082] Figure 2a-2d and Figure 3a-3d An embodiment of a connecting member 112 for connecting the first frame member 102 to the panel is shown. A plurality of connecting members 112 (e.g., members 112a, 112b, and 112c shown in triplicate) may be arranged around the frame 109, for example at each corner of the frame 109, as shown in FIG. Figure 4a As shown by the circles in the figure. Each connecting member may include a set of screws 112a, 112b, 112c, 113a, 113b. Each screw may be arranged in a hole in the frame 109, which may be a threaded hole. Each connecting member may include at least two screws 112a, 112b, 112c, 113a, 113b. At least one screw 112a, 113a may be arranged to displace the frame 109 away from the panel 1, for example by means of threads in the frame 109 and by pushing the panel 1. Figure 2d At least one further screw 112b, 112c, 113b may be arranged to displace the frame 109 towards the panel 1, for example by means of a thread in the panel and a hole in the frame 109, which is also shown in FIG. Figure 2d Indicated by arrows.

[0083] Figure 2a The embodiment shows that each connecting member includes at least three screws 112a, 112b, 112c. The three screws 112a, 112b, 112c are arranged closer to the center of the first frame member 102, that is, the three screws 112a, 112b, 112c are closer to the center of the first frame member 102 than to the periphery of the supporting parts 101a, 101b. Figure 2a The imaginary extension 114a, 114b, 114c of the longitudinal axis of each screw 112a, 112b, 112c would pass outside the bearing portions 101a, 101b when viewed in the cross section shown in. In the embodiment shown, the first screw 112a is arranged between the second screw 112b and the third screw 112c. Figure 2aOnly one set of screws is shown as an example. However, the screw sets may be arranged anywhere around the frame 109 to connect the first frame part 102 to the panel 1 .

[0084] exist Figure 2b In the embodiment shown, each set of screws comprises only two screws 113a, 113b. The first screw 113a is arranged opposite to the supporting parts 101a, 101b, i.e. Figure 2b When viewed in the cross section shown, the imaginary extension 115a of the longitudinal axis of the first screw 113a passes through the support portion 101b, for example through its center. The second screw 113b of the two screws is arranged closer to the center of the first frame part 102, i.e. the second screw 113b is closer to the center of the first frame part 102 than to the periphery of the support portions 101a, 101b. Figure 2b When viewed in the cross section shown, an imaginary extension 115b of the longitudinal axis of the first screw 113b would pass outside the support portion 101b.

[0085] like Figure 2d As shown, the first screw 112a is arranged to displace the frame 109 away from the panel 1. This can be achieved by means of a threaded hole 112i in the frame 102, the first screw engaging the threaded hole 112i when the head of the screw abuts the panel 1. The second screw 112b is arranged to displace the frame 109 towards the panel, closer to the panel 1. This can be achieved by means of a threaded hole 112f in the panel 1, the second screw 112b engaging the threaded hole 112f when the head of the second screw 112b abuts the surface of the frame. By using the screws 112a and / or 112b, a force can be applied to the frame 102 and / or the panel 2 to control the bending or rotation of the frame / panel.

[0086] exist Figure 2b In the embodiment of FIG. 1 , since the first screw 113 b is aligned on the support parts 101 a , 101 b , only two screws are needed to control the bending or rotation of the frame.

[0087] exist Figure 2a-2b In the embodiment, only one set of screws is shown. However, the screw set can be arranged at any position around the frame 109 to support the plate 2 and the panel 1.

[0088] Figure 2c Shows Figure 2a and Figure 2b A combination of embodiments, i.e. sets of screws with two as well as three screws, may be arranged around the frame 109. Thus, flexibility is provided.

[0089] like Figure 2a-2cAs shown in FIGS. 3c and 3d , each set of screws 112a, 112b, 112c, 113a, 113b can apply force to the frame 109. Therefore, the curvature of the frame 109 can be controlled to apply a torsion force or torque to the second frame parts 103a, 103b, so that the support parts 101a, 101b are tilted, and the curvature of the plate is thereby controlled. Figure 3a In the assembly shown, a net force is applied so that the frame is generally flat and parallel to the panel 1. Figure 3c and 3d In the assembly shown, a net force is provided to the frame 109 away from the support portions 101a, 101b, which will cause the frame 109 to be slightly concave when viewed from the contact surface of the panel 2. Therefore, a torque will be provided at the second frame members 103a, 103b, which will cause the support portions 101a, 101b to tilt along the edge or perimeter of the panel 2. Therefore, by controlling the curvature of the first frame member 102, the curvature of the panel can be controlled. When viewed from the touch surface of the panel 2, the panel 2 may become concave or inward.

[0090] Figure 4a-4c , Figure 5a-5g An embodiment is shown in which a selectable alternative or additional control over the shape of the frame 109 may be introduced. Figure 4a As shown, the connecting member 112 may be arranged at a corner of the frame 109. The connecting member 112 may include the Figure 2a-2c and 3a-3d as described in a set of screws 112a, 112b, 112c, 113a, 113b. The connecting member 112 can be arranged to pull the panel 1 towards the frame 109. This can be done with or without tilting the support portions 101a, 101b as described above. At least one spacing member 116 (wherein the spacing member 116 can include screws 112 and independent spacing members) can be arranged along the periphery of the frame 109 between the two connecting members 112. The spacing member 116 is arranged in the assembly to apply a force to the frame 109 away from the panel 1. Therefore, the force applied by the spacing member 112 can be transmitted to the second frame member 103a, 103b, so that the support members 101a, 101b tilt as described above, thereby controlling the curvature of the panel 2.

[0091] like Figure 4bAs shown, the general shape of the frame 109 will be concave (i.e., concave or inwardly concave), while the general shape of the panel 1 can be convex (i.e., convex or protruding). Depending on its rigidity, the panel can also be maintained as a generally flat surface. The resulting shape of the plate 2 will be concave. Therefore, each side of the frame 109 can be controlled to follow a curved trajectory. The curvature can be adjusted by controlling the force applied by each spacing member and / or by controlling the number of spacing members 116 along each side of the frame 109. As a result, the support portions 101a, 101b, at least at the free ends 101a, 101b of the support portions, can also follow a curved trajectory. Therefore, at least a portion of the support portions 101a, 101b can extend in a curved plane.

[0092] When the second frame members 103a, 103b are detached or connected only to the first frame member 102, they may have a relaxed state. In the relaxed state, the support portions 101a, 101b extend in a substantially flat plane. The second frame members 103a, 103b may be transferred from the relaxed state to a stressed flexed state or stressed state (or deflected state) by, for example, a connecting member 112 and a spacing member 116. The inclination at the opposite ends of the support members 101a, 101b where the connecting member 112 is provided may be less than the inclination between the ends where the spacing member 116 is provided. As a result, the second frame members 103a, 103b may be transferred to a flexed or stressed state. In the flexed or stressed state, the support portions 101a, 101b extend in a curved plane (i.e., a curved surface) along their length. The curved surface may form a parabolic concave curve along at least a portion of the length of the support portion 101a, 101b in a cross section taken along the support portion 101a, 101b (such as at the free end or end of the support portion 101a, 101b). The combination of the connecting assembly 112 and the spacing member 116 may form a screw device combination that can maintain the second frame member 103a, 103b in a flexed or stressed state when assembled with the first frame member 102.

[0093] The spacing member 116 may be provided by a single screw that engages with threads in the frame 109 while its end engages or abuts a surface on the panel 1. Optionally, the panel 1 includes a threaded hole into which the spacing member 116 may be screwed. The screwing of the spacing member 116 causes the frame 109 to move toward the panel 1. Alternatively, the spacing member 116 may include a spacing member, such as a gasket, a spacer, etc. Figure 3a and 3b as well as Figure 4cIn the embodiment, two spacers 116a, 116b are shown for illustration purposes, and they can form different embodiments. In other embodiments, a single spacer 116a, 116b can be used. The head of the spacer 116a, 116b can be abutted against the back cover 111, and the spacer 116a, 116b can be connected to the frame 109, wherein the frame 109 can be pulled toward the back cover 111. As a result, the frame 109 becomes concave. In some embodiments, the spacer 116a does not abut or engage the panel 1, wherein the panel 1 can be unaffected by the force applied to the frame 109. In other embodiments, the spacer 116b is long enough so that the top end of the spacer 116b abuts against the surface of the panel 1. This adds further control over the shape of the panel 2.

[0094] In some embodiments, the frame assembly 100 includes a plurality of spacing members 116 that are spaced apart from the corners of the frame 109. One or more spacing members 116 may be disposed along each perimeter or side of the frame. If a single spacing member 116 is disposed along each side, it is preferably centered between the corners of the frame 109.

[0095] Each spacing member 116 may comprise a screw of a predetermined length. This means that the screw can be fully accommodated in place so that the head and the tip abut the corresponding surface, thereby obtaining a predetermined curvature of the plate 2. The degree of curvature can be adjusted by one or more spacing members arranged between the head and the surface with which the head engages. It is particularly useful if multiple spacing members 116 are provided along a single side or have different lengths on different sides. The more padding provided, the less force is applied to the frame 109. Alternatively, if Figure 5h As shown, the predetermined height difference may be produced by other methods, for example, by milling the frame to a predetermined height, to allow for a more continuous support structure.

[0096] Figure 5a-5h An embodiment of an assembly 200 is shown that may incorporate the first frame member 102 described above. Figure 5a-5h The embodiment shown in FIG. 1 is shown inverted relative to the previously shown embodiment, with the plate 2 at the top.

[0097] like Figure 5a and Figure 5bAs shown, the frame assembly 200 may include a first frame member 202 and a second frame member 203. The first frame member 202 and the second frame member 203 may be elongated members, each having a support portion 201a, 201b. The first frame member 202 and the second frame member 203 may, for example, have an L-shaped cross-section. The first portion of each of the first frame member 202 and the second frame member 203 may be configured to extend along an edge of the panel 1. The second portion of each of the first frame member 202 and the second assembly 203 forms the support portion 201a, 201b, and may be configured to extend a short distance, such as 1-3 cm, from the periphery of the panel 2 above the surface of the panel 2 when assembled. In addition, the second frame member 203 may be arranged on top of the first frame member 202, and such that when assembled, the periphery of the panel 2 is arranged between the second portion of each frame member 202, 203. Therefore, each support portion 201a, 201b can support or engage the opposing surface of the panel 2, just as Figure 5g shown.

[0098] In some embodiments, such as Figure 5c-5d As shown, a gasket 205 (e.g., gaskets 205a, 205b, 205c, 205d, 205e) is arranged between the first frame member 202 and the second frame member 203. The gasket 205 can be, for example, arranged on the support portion 201a of the first frame member 202. Moreover, the seal 204a can be arranged on the support portion 201b of the second frame member 203.

[0099] The pad 205 may have a varying thickness along its length, i.e., along the length of the first frame member 202. This configuration is to achieve the desired curved shape of the periphery of the panel 2 when pinned between the first frame member 202 and the second frame member 203, as shown in FIG. Figure 5f-5g As shown. For example, the liner 205 has opposite ends and can be thinner between the opposite ends than at the ends. This configuration is to obtain a predetermined peripheral concavity of the panel 2. The liner is sufficiently rigid so that its ends are thicker even when compressed. The ends of the liner 205 can be about 1.5-2.0 mm and thinner by about 1 mm in the center.

[0100] In some embodiments, the pad 205 has multiple parts along its length. The thickness of each part may be different. For example, the first part 205a of the pad is arranged at one end thereof, and the second part 205b of the pad is arranged at the other end thereof. The first part 205a and the second part 205b may have a first thickness, which may be equal at each part. At least the third part 205c of the pad is arranged between the first part 205a and the second part 205b. The third part 205c has a second thickness. The first thickness is thicker than the second thickness. For example, the thickness difference is about 0.5-2mm, preferably about 1.0mm. The thickness difference can vary according to the length of the pad 205 and the edge of the plate 2 to be concave. In some embodiments, the fourth and fifth parts 205d, 205e can be arranged between the first and second parts 205a, 205b and the third part 205c, respectively. The fourth part 205d and the fifth part 205e can further control the shape of the concave curve provided by the device / component 200. The length of each of the first portion 205a and the second portion 205b can be approximately 2-20% of the total length of the cushion 205. The length of the third portion can be approximately 60-96% of the total length of the cushion 205. The length of each of the fourth and fifth portions 205d, 205e can be approximately 10-20% of the total length of the cushion 205. In some embodiments, the total length of the fourth and fifth portions 205d, 205e is shorter than the length of the third portion 205c, and the total length of the first portion 205a and the second portion 205a is shorter than the total length of the fourth portion 205d and the fifth portion 205e. This provides a parabolic concave curve along the length of the frame assembly 200.

[0101] like Figure 5e As shown, the distance between the support portion 201a of the first frame part 202 and the support portion 201b of the second frame part 203 may be discontinuous in the assembled state.

[0102] In order to maintain the concave surface of the panel 2, the first frame member 202 and the second frame member 203 can be held together so that the distance between the support portions 201a, 201b is maintained in the assembled state. The first frame member 202 has a first hole 217a and a second hole 217b, which are arranged at opposite ends of the first frame member 202, such as at the second portion of the first frame member 202. The first hole 217a and the second hole 217b are arranged in a first plane. The third hole 217c is arranged between the first hole 217a and the second hole, for example, centered between the first hole 217a and the second hole 217b. The third hole 217c is arranged on a plane different from the first plane. The distance or offset between the plane in which the first and second holes 217a, 217b are arranged and the plane in which the third hole 217c is arranged can be substantially the same as the thickness difference between the first and second portions 205a, 205b and the third portion 205c, i.e., about 0.5-2 mm. In some embodiments, the first hole 217 a and the second hole 217 b are centered along the length of the first frame member 202 in each of the first and second portions 205 a , 205 b .

[0103] Similarly, the second frame member 203 may include a first hole 218a and a second hole 218b arranged at opposite ends of the second frame member 203. The third hole 218c may be arranged between the first hole 218a and the second hole 218b of the second frame member 203. The first hole 218a, the second hole 218b and the third hole of the second frame member 203 are arranged substantially in the same plane when the second frame member 203 is disconnected from the first frame member 202. The second frame member 203 may be harder or weaker than the first frame member 202 and may be turned so that each hole 218a, 218b, 218c of the second frame member 203 is aligned with the hole 217a, 217b, 217c of the first frame member 202. Therefore, the support portion 201b of the second frame member 203 may be turned so that it extends in a plane that is curved in the assembled state of the frame assembly 200. Screws 219a, 219b, 219c can be inserted through the aligned holes 217a, 217b, 217c; 218a, 218b, 218c and can directly engage the panel or engage the threaded holes in the panel 1, which will keep the frame parts 202, 203 in the assembled state. Other relative arrangements of holes 217a, 217b, 217c; 218a, 218b, 218c are foreseeable, wherein the central holes 217c, 218c of each frame part 202, 203 are not aligned in the relaxed state of the second frame part 203, but are aligned in the flexed or stressed state of the second frame part 203.

[0104] In some embodiments, the first frame member 202 forms a frame side and the second frame member 203 forms an edge cover. Figure 4a-4c To be used together with the frame 109 discussed above, the frame side can replace Figure 4a-4c Thus, the frame side comprises a support portion 201 a having a support surface substantially opposite the frame 109 and configured to support a pad 205 .

[0105] like Figure 6 As shown, a member (eg, a seal 204a ) may be provided between the support portion 201a and the plate 2 . Figure 6 The forces and torques generated when a force 220 is applied to the second frame member 203a are shown. A second force 221 is applied to the support portion 201. Therefore, a net torque 222 is generated, which is counterclockwise in the arrangement shown. The plate 2 will follow a curved trajectory, as shown by the dashed line 223.

[0106] exist Figure 7 In the embodiment shown, an alternative arrangement for defining the curvature of the panel 2 is provided. In this embodiment, a support block 301 is arranged to support the glass panel 2. The support block 301 has a surface portion which includes a tapered edge at an angle to the second frame member 103A. The panel 2 is pressed against the top surface of the support block 301 by pressure 201b from the first frame member 102 and the seal 204a. The pressure 201b causes the panel 2 to follow the contour of the top surface of the support block 301, and the panel 2 is forced into a bending plane at an angle to the plane of the second frame member 103A. The final path of the panel 2 is shown by the curvature path 310. The tapered surface portion 303 is at an angle of between 0.5 degrees and 3 degrees to the second frame member 103A.

[0107] exist Figure 8 In the embodiment shown, there is provided Figure 5a-5g . In this embodiment, the second frame member 203 has been modified so that the portion 410 has been removed from the edge portion 203c of the second frame member 203. This reduces the force required to bend the second frame member 203 in a manner that causes the panel 2 to bend. The portion 410 may be removed by a milling process, a carving or a cutting process, or the second frame member 203 may be formed without the portion 410 by a molding process or the like. The portion 410 preferably reduces the depth of the second frame member 203 at the narrowest point by between 5-20%.

[0108] The frame components of embodiments of the assembly may be made from sheet metal and given the desired design, thickness and / or made from different materials in order to obtain the forces, shapes, torques, etc. discussed above.

[0109] Embodiments include methods for assembling a panel 1 and a plate 2 for an optical touch sensing system. The method may include setting / providing a frame component according to embodiments presented herein. The method further includes connecting a first frame component to a second frame component; supporting the plate on a support portion of the assembly; and connecting at least one of the first frame component and the second frame component to the panel such that the support portion extends in a flat or curved plane. Moreover, the method includes connecting the second frame component to the first frame component such that the support portion extends at least partially in a second plane opposite to at least a portion of the first frame component and is spaced apart from the first plane. The curvature of the first frame component can be controlled by a spacing component connected to the first frame component, and thereby the support portion can be tilted to control the curvature of the plate.

[0110] Fig. 9 A top plan view of an example of a touch sensitive device 99 is shown. Emitters 30a are distributed around the periphery of the touch pad 10 to propagate light through the touch surface 20. Detectors 30b are distributed around the periphery of the touch surface 20 to receive a portion of the propagated light. Light from each emitter 30a will propagate to a plurality of different detectors 30b on a plurality of optical paths 50.

[0111] The above embodiments describe methods for achieving control of panel shape and curvature. The following embodiments describe ideal shapes for achieving improved touch sensor system performance. The optical path 50 can be conceptually represented as a "detection line" extending across the touch surface 20 between a pair of emitters 30a and detectors 30b. As shown in the top plan view, the emitters 30a and detectors 30b together define a grid of detection lines 50 ("detection grid") on the touch surface 20. The spacing of the intersections in the detection grid defines the spatial resolution of the touch sensitive device 99, that is, the smallest object that can be detected on the touch surface 20. The width of the detection line is a function of the width of the emitter and the corresponding detector. A wide detector that detects light from a wide emitter provides a wide detection line with a wider surface coverage range, and minimizing the space between the detection lines does not provide any touch coverage. The disadvantage of a wide detection line may be a reduced ability to distinguish different objects and a lower signal-to-noise ratio.

[0112] As used herein, the emitter 30a can be any type of device capable of emitting radiation in the desired wavelength range, such as a diode laser, a VCSEL (vertical cavity surface emitting laser), an LED (light emitting diode), an incandescent lamp, a halogen lamp, etc. The emitter 30a can also be formed by the end of an optical fiber. The emitter 30a can generate light in any wavelength range. The following examples assume that the light occurs in the infrared region (IR), that is, at a wavelength above about 750nm. Similarly, the detector 30b can be any device capable of converting light (in the same wavelength range) into an electrical signal, such as a photodetector, a CCD device, a CMOS device, etc.

[0113] The detectors 30b collectively provide an output signal, which is received and sampled by the signal processor 130. The output signal includes a plurality of sub-signals also referred to as "projection signals," each of which represents the energy of light from one of the light emitters 30a received by one of the light detectors 30b. Depending on the implementation, the signal processor 130 may need to process the output signals to separate the individual projection signals. The projection signals represent the received energy, intensity, or power of the light received by the detectors 30b on each detection line 50. Whenever an object partially or completely blocks a detection line 50, the received energy on that detection line is reduced or "attenuated."

[0114] The signal processor 130 may be configured to process the projection signal in order to determine properties of the touch object, such as position (e.g., position in an x,y coordinate system), shape, or area. The determination may involve, for example, straight-forward triangulation based on attenuation detection lines as disclosed in US7432893 and WO2010 / 015408, or more advanced processing to reconstruct a distribution of attenuation values ​​(referred to as an "attenuation pattern" for simplicity) across the touch surface 20, where each attenuation value represents a local degree of light attenuation. The attenuation pattern may be further processed by the signal processor 130 or by a separate device (not shown) to determine the position, shape, or area of ​​the touch object. The attenuation pattern may be generated, for example, based on the projection signal values ​​by any available algorithm for image reconstruction, including tomographic reconstruction methods such as filtered back-projection, FFT-based algorithms, ART (algebraic reconstruction technique), SART (simultaneous algebraic reconstruction technique), etc. Optionally, the attenuation pattern may be generated by adjusting one or more basis functions and / or by statistical methods such as Bayesian inversion. Examples of such reconstruction functions designed for touch determination can be found in WO2009 / 077962, WO2011 / 049511, WO2011 / 139213, WO2012 / 050510 and WO2013 / 062471, all of which are incorporated herein by reference.

[0115] In the example shown, the device 99 also includes a controller 120 that is connected to selectively control the activation of the emitter 30a and possibly the readout of data from the detector 30b. Depending on the implementation, the emitter 30a and / or the detector 30b may be activated sequentially or simultaneously, for example as disclosed in US8581884. The signal processor 130 and the controller 120 may be configured as separate units, or they may be integrated into a single unit. Either or both of the signal processor 130 and the controller 120 may be implemented at least in part by software executed by the processing unit 140.

[0116] Fig.10a A generally flat rectangular touch panel 10 according to the prior art is shown. In this example, the touch panel is made of glass, plastic or any other material such as PMMA (Poly(methyl methacrylate)). Fig.10a Two axes are defined in the touch panel 10. The x-axis is defined as an axis parallel to and equidistant from the long side pair of the rectangle and extending along the flat surface of the touch surface. The y-axis is defined as an axis parallel to and equidistant from the short side pair of the rectangle and extending along the flat surface of the touch surface. At least a portion of the top surface of the touch panel 10 includes the touch surface 20.

[0117] Fig.10b An example of a touch device according to the prior art is shown. Fig.10b The touch device is shown in cross section, where the cross section extends along the x-axis of the plate 10. Light is emitted by the emitter 30a, passes through the transmissive plate 10 and through the touch surface 20 and is reflected by the reflector surface 80 of the edge reflector 70 to propagate in a plane generally parallel to the touch surface 20. The light will then continue until it is diverted by the reflector surface 80 of the edge reflector 70 located at the opposite edge of the transmissive plate 10, where the light will be diverted to pass downward through the transmissive plate 10 and onto the detector 30b. In the case where an object is applied to the touch surface 20, some of the light above the touch surface 20 is blocked. This blocking is detected by the touch device and used to determine the presence, size and / or shape of the object. The emitter and detector can be arranged in many other configurations so that light from the emitter is transferred to the touch surface and from the touch surface to the detector. Other known arrangements are to arrange the emitter and detector above the touch surface and directly transmit and receive light without using a reflective surface. The light can also be transmitted to the touch surface by a waveguide, an optical cable or other optical member.

[0118] Fig.11a Shows something like Fig.10a1, but in which the touch pad 10 is curved. In this embodiment, the pad remains generally flat in the direction of the y-axis, but is curved in a concave direction relative to the x-axis. In this embodiment, the x-axis is defined as an axis extending parallel to and equidistant from a pair of long sides of a rectangle. The vertex of the parabola or parabola of the touch surface is the point where the touch surface is farthest from the edge of the touch pad. When the x-axis is at the height of the edge of the touch pad, the distance of the touch surface from the x-axis can be used to measure the curvature of the pad. Fig.11b Shows Fig.11a FIG. 1 is a cross-sectional view of the touch panel 10 along the x-axis.

[0119] Fig.11c An exemplary embodiment of a curved touch panel 10 is shown. The touch panel 10 has a width of 1900 mm along the x-axis and a height of 1070 mm along the y-axis. In this exemplary embodiment, the glass is shaped so that the touch surface follows a parabolic curve relative to the x-axis. The midpoint O of the touch surface 20 is the midpoint between the center of the touch surface and the x-axis. The curvature of the touch surface 20 is parabolic, and the maximum distance a between the touch surface and the x-axis is located at the center point O of the touch surface.

[0120] Fig.11d The maximum allowable concave distance a and the maximum allowable convexity b are shown. The maximum allowable convexity b can be an important consideration because a generally convex portion of the touch surface can cause light between the emitter and the detector to be blocked and cause the touch signal to be significantly lost. In this embodiment, the maximum allowable convexity b is a negative value.

[0121] In one embodiment, the range of distance a for vertically oriented touch pads is limited to improve yield and performance of the touch system. The range depends on the size of the touch system. The minimum value is needed to ensure that non-parabolic deviations in glass shape and convexity during integration do not result in a convex integrated touch surface. The maximum value is needed to ensure that the light field height of the final touch system remains reasonably low to enable better contact detection and lift-off detection of a touching object. Preferably, distance a ranges from 0-2.5 mm.

[0122] For the concave glass in this embodiment, the maximum distance a is positive. The curvature of the touch surface can therefore be modeled as:

[0123] F(x)=-a+cx 2

[0124] In this example embodiment, Fig.11c The maximum distance a between the 1900 mm long cross section of the touch surface and the x-axis is 2.0 mm. Therefore, the ideal parabolic curve of the touch surface 20 can be:

[0125] F(x)=5.5*10 -6 *x 2 -2.0

[0126] where F(x) is the distance between the x-axis and the touch surface at position x, where F(x) is zero at the midpoint of the edge, where the x-axis intersects the perimeter.

[0127] Fig.12a and 12b Shows something like Fig.11a , but wherein the trackpad 10 is curved in two axes. Fig.12a A top plan view of the touch panel 10 is shown, and Figure 12b An isometric view is shown. In this embodiment, the touch pad is curved in a concave direction relative to the x-axis and is also curved in a concave direction relative to the y-axis. Fig.11a As with the embodiment shown, the x-axis is defined as an axis extending parallel to and equidistant from a pair of long sides of a rectangle and passing through a center point O on the touch surface. Thus, the curvature of the pad can be measured by the distance from the touch surface to the x-axis. Similarly, the y-axis is defined as an axis extending parallel to and equidistant from a pair of short sides of a rectangle and passing through a center point O on the touch surface. Thus, the curvature of the touch pad along this axis can be measured by the distance from the touch surface to the y-axis.

[0128] Fig.12c and Fig.12d Shown along Fig.12a and Figure 12b 1 and 2. The corresponding cross-sectional views of the x-axis and y-axis of the touch panel 10 of FIG. 1. In an exemplary embodiment of a curved touch panel 10, the touch panel 10 has a width of 1900 mm along the x-axis and a height of 1070 mm along the y-axis. In this exemplary embodiment, the glass is formed so that the touch surface follows a parabolic curve relative to the x-axis. The midpoint O of the touch surface 20 is the center of the touch surface and parallel to the midpoint of the x-axis. The curvature of the touch surface 20 is parabolic, and the maximum distance a between the touch surface and the x-axis is located at the center point O. For the concave glass in this embodiment, the maximum distance a is a positive value. The curvature of the touch surface can therefore be simulated as:

[0129] z(x,y)=-a+b*x 2 +c*x 2 y 2 +d*y 2

[0130] Where z is the distance between the plane defined by the x-axis and the y-axis and the touch surface, and x and y are coordinates in the plane of the glass.

[0131] In an example embodiment with a flat perimeter around the plate and a maximum distance of 2.0 mm measured at y=0 (i.e. the middle of the plate) and along the x-direction:

[0132] z(x,y)=-2+5.56e-06*x 2 -4.74e-11*x 2 y2+1.7e-05*y 2

[0133] In another exemplary embodiment having a concave perimeter around the plate with a maximum distance of 2.0 mm measured at y=0 (short to short of the screen) and along the x direction and a maximum distance of 1.5 mm measured at x=0 (long to long of the screen) and along the y direction, wherein the top and bottom edges have a maximum distance of 1.0 mm and the left and right edges have a maximum distance of 0.5 mm:

[0134] z(x,y)=-2.5+5.56e-06*x 2 -2.37e-11*x 2 *y 2 +1.28e-05*y 2

[0135] Fig.13a A cross-sectional view of light propagating across an example embodiment of a curved touch panel 10 along the x-axis is shown. The touch surface has a curved profile on the x-axis. In the cross-sectional view, the propagation path of light from a point light source 1310 is shown. Dashed line 1320 represents the propagation path of light emitted from the point light source 1310 that is not received by the detector surface 1340. Solid line 1330 shows the propagation path of light emitted from the point light source 1310 that is received by the detector surface 1340. As shown, part of the light is lost above the detector, part is lost below the detector, and part of the light is received at the detector surface. A person looking from the emission point to the mirror image of the detector (reflected in the touch surface) will perceive the detector size to be 2.2 times the actual detector. This magnification effect is the effect of using an off-axis parabolic mirror. In the specific case of a touch system, this results in a 2.2 times detection signal enhancement / amplification compared to a flat touch surface. This amplification applies only to the signal and is not important for ambient light received by the detector. In a preferred embodiment, the detectors and emitters of the touch system are 3 mm or less above the touch surface (directly or indirectly) and the length of the detection line is in the range of 100 to 2500 mm, with an angle of incidence very close to 90 degrees. Therefore, adding incident light, dirt or anti-glare coatings on the touch surface has no real effect on the reflection, so it is effectively a mirror.

[0136] Fig.13b Provides the emission light from the point light source 1310 relative to the Fig.13a 13. The z-coordinate range of the detector surface is represented by the vertical axis. The light emitted by the point light source 1310 received at the z-coordinate within the range is received by the detector.

[0137] Fig.14a Shows Fig.13a 14. In the cross-sectional view, the propagation path of the light from the second point light source 1410 is shown. In this example, the detection signal enhancement is about 3.3. Fig.14b shows the relative position of the second point light source 1410 Fig.13b The corresponding diagram of .

[0138] Fig.15a Shows Fig.13a In the cross-sectional view, the propagation path of the light from the third point light source 1510 is shown. Fig.15b The third point light source 1510 is shown Fig.13b In this example, the detection signal enhancement is about 3.03.

[0139] Fig.16a Shows Fig.13a In the cross-sectional view, the propagation path of the light from the fourth point light source 1610 is shown. Fig.16b The fourth point light source 1610 is shown Fig.13b In this example, the detection signal enhancement is about 2.71.

[0140] Fig.17a Shows Fig.13a In the cross-sectional view, the propagation path of the light from the fifth point light source 1710 is shown. Fig.17b The fifth point light source 1710 is shown Fig.13b In this example, the detection signal enhancement is about 2.19.

[0141] Figures 13a-17b Different emitter locations illustrate that different portions of the touch surface are utilized. The portion of the touch surface used as a reflector will depend on the actual shape of the glass and the location and size of the emitter and detector aperture surfaces 1340.

[0142] However, the touch pad 10 cannot be perfectly manufactured, positioned or maintained in shape. Therefore, some deviation can be expected between the curve followed by the touch surface and the ideal parabolic curve.

[0143] Fig.18a A graph showing a mathematically defined parabolic curve and a real-world parabolic touch surface. Fig.18aIn an exemplary embodiment of the invention, the curved touch panel 10 has a width of 1900 mm along the x-axis and a height of 1070 mm along the y-axis (wherein the x-axis and the y-axis are defined as Fig.12a , as defined in the embodiment shown in 4b). In this example embodiment, the glass is shaped so that the touch surface follows a parabolic curve 1810 relative to the x-axis. The maximum distance a between the touch surface and the x-axis is 10 mm. The mathematically defined parabolic curve is defined as 1820. The curve graph shows the deviation between the mathematically defined parabola represented by the dotted line 1820 and the real touch surface 1810. In this context, the real touch surface is asymmetrically curved / warped. Fig.10b Shown is a short to short mid section of thermally tempered glass with a diagonal of 2180mm, a 16:9 ratio, just at or below the maximum limit of recessed distance <6mm and a |parabola deviation| <0.5mm.

[0144] The parabolic fit of touch surface 1810 has an s-shaped trace (residue). This asymmetrical curvature may be the result of problems with the transfer rollers or uneven temperature distribution during the rapid cooling phase of the tempering process during manufacturing.

[0145] Fig.18b shows the mathematically defined parabolic curve and Fig.18a A graph of the deviation between real-world parabolic touch surfaces.

[0146] The following table defines a preferred set of constraints on the touch surface shape to achieve an optimal touch surface shape.

[0147] The term "bend / warp" defines the distance between the touch surface and a corresponding axis intersecting the center point O in the z-axis direction.

[0148]

[0149] Fig.18a The convexity b is shown. Fig.18b A parabolic deviation is shown.

[0150] Fig.19a shows the mathematical definition of the parabolic curve and Fig.18a Another graph of a similar glass, but where Fig.19a Glass is out of scope for touch system production and is not recommended. Fig.19a One reason for the large concavity shown may be that during the quenching process during manufacturing, the tempering process was run with too large a difference between the bottom and top cooling parameters. The mathematically defined parabolic curve is defined as 1920. The graph shows the deviation between the mathematically defined parabolic curve and the actual touch surface 1910.

[0151] Fig.19b shows the mathematical definition of the parabola and Fig.19a A plot of the deviation between real-world parabolic touch surfaces. Fig.19a A real-world parabolic touch surface is an example of a symmetric but higher order curvature (e.g., a W shape). Such curvatures can greatly reduce signal enhancement and can be caused by symmetric temperature problems during the manufacturing tempering process (e.g., the center or edge of the glass is too hot).

[0152] Fig.20a An embodiment in which the touch surface forms a parabola is shown. Fig.20a , a top view of the touch surface is shown with contour lines showing the depth of the touch surface relative to a flat plane intersecting the four corners of the touch surface. The digits shown on each contour line represent the depth of the contour line. The x-axis, y-axis, and diagonal axis d are all shown in the figure. The x-axis is defined as an axis extending parallel to and equidistant from a pair of long sides of a rectangle. The y-axis is defined as an axis extending parallel to and equidistant from a pair of short sides of a rectangle. The diagonal axis d is defined as an axis extending diagonally from a corner to an obliquely opposite corner. In this embodiment, the x-axis, y-axis, and diagonal axis d of the touch surface 20 each describe a parabola relative to the depth of the touch surface. In Fig.20b In , the diagonal axis d is shown extending from the lower left corner to the upper right corner. Fig.20a In the exemplary embodiment, the curved touch panel 10 has a width of 1900 mm along the x-axis and a height of 1070 mm along the y-axis.

[0153] Figures 20b-20d Shows Fig.20a Alternative parabolic morphology of the illustrated embodiment. Fig.20b A graph of an ideal parabola of a touch surface below and relative to the x-axis is shown. The deviation from the x-axis (bottom axis) is shown relative to the position along the x-axis (left axis). Fig.20c A graph of an ideal parabola of a touch surface below and relative to the y-axis is shown. The deviation from the x-axis (bottom axis) is shown relative to the position along the y-axis (left axis). Fig.20d A diagram of an ideal parabola of a touch surface below and relative to a diagonal axis is shown. The deviation from the x-axis (bottom axis) is shown relative to the position along the diagonal axis (left axis).

[0154] Figures 20a-20d The illustrated embodiment describes a touch surface that provides a substantial signal enhancement for signals propagating between most emitters and detectors. However, the non-planar perimeter of the touch surface makes the manufacture and assembly of such a system more complicated.

[0155] Fig.21a The touch surface in the embodiment shown forms Fig.20aThe embodiment shown has a selective parabola. Fig.20a Same, Fig.21a A top plan view of the touch surface is provided, wherein contour lines illustrate the depth of the touch surface relative to a flat plane intersecting the four edges of the touch surface 20. The number shown on each contour line represents the depth of the contour line. The x-axis, y-axis, and diagonal axis d are all shown in the figure. The x-axis is defined as an axis extending parallel to and equidistant from a pair of long sides of a rectangle. In this embodiment, the x-axis of the touch surface 20 describes a parabola relative to the depth of the touch surface. The y-axis is defined as an axis extending parallel to and equidistant from a pair of short sides of a rectangle. In this embodiment, the y-axis of the touch surface 20 also describes a parabola relative to the depth of the touch surface. The diagonal axis d is defined as an axis extending diagonally from a corner to a diagonally opposite corner. Figure 21b In , the diagonal axis d is shown extending from the lower left corner to the upper right corner. Figure 21b In an exemplary embodiment of the invention, the curved touch pad 10 has a width of 1900 mm along the x-axis and a height of 1070 mm along the y-axis. The perimeter of the touch surface of this embodiment is flat or nearly flat. In embodiments where the perimeter of the touch surface is flat or nearly flat, the surface below some of the detection lines will not be a perfect parabola. Even with a nearly perfectly integrated glass shape with a bend between 1-2.5 mm, some of the detection lines (a very small portion) will actually have less signal than flat glass. This small disadvantage is offset by a significant overall signal improvement. In addition, with a flat or nearly flat perimeter of the touch surface, the touch system may be easier to manufacture and assemble.

[0156] Figure 21b A graph of an ideal parabola of a touch surface below and relative to the x-axis is shown. The deviation from the x-axis (bottom axis) is shown relative to the position along the x-axis (left axis). Fig.21c A graph of an ideal parabola of a touch surface below and relative to the y-axis is shown. The deviation from the x-axis (bottom axis) is shown relative to the position along the y-axis (left axis). Fig.21d A diagram of an ideal parabola of a touch surface below and relative to a diagonal axis is shown. The deviation from the x-axis (bottom axis) is shown relative to the position along the diagonal axis (left axis).

[0157] It will be apparent that the features and attributes of the specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which fall within the scope of the present disclosure.

[0158] Conditional language used herein, such as "can," "may," "might," "could," "for example," and the like, unless expressly stated otherwise or otherwise understood in the context of use, is generally meant to convey that certain embodiments include, while other embodiments do not include, certain features, components, and / or states. Thus, such conditional language is generally not intended to imply that one or more embodiments require the features, components, and / or states in any case, or that one or more embodiments necessarily include logic for determining whether such features, components, and / or states are included or will operate in any particular embodiment with or without author input or prompting.

[0159] The present invention has been described above with reference to specific embodiments. However, other embodiments than those described above are equally possible within the scope of the present invention. Method steps different from those described above can be provided within the scope of the present invention. Different features and steps of the present invention can be combined into other combinations except those described.

Claims

1. A touch sensing device, comprising: A panel (2) having a touch surface (20); A first group of emitters (30a) arranged around the touch surface (20) to emit a first light beam that can pass through the touch surface (20); a set of light detectors (30b) arranged around the touch surface (20) to receive light from the first set of emitters (30a), wherein each light detector (30b) is arranged to receive light from more than one light emitter (30a); a processing unit configured to determine a position of an object on the touch surface (20) based on output signals of the set of light detectors (30b), wherein the touch surface (20) is curved into a concave shape on a first axis, Characterized in that the touch sensing device further comprises a frame assembly (200), wherein the frame assembly comprises: A first frame member (202) comprising a first portion and a second portion (201a), a second frame member (203) comprising a first portion and a second portion (201b), wherein the second frame member (203) is arranged on top of the first frame member (202) so that the periphery of the panel (2) is arranged between the second portion (201a, 201b) of each of the first frame member (202) and the second frame member (203), and a sealing member (204a) arranged between the second portion (201b) of the second frame member (203) and the plate member (2), wherein the frame assembly (200) is arranged to apply a controlled force along the periphery of the plate (2) so that the curvature of the plate (2) is controlled, The touch surface (20) is curved into a concave shape on a second axis perpendicular to the first axis.

2. The touch sensing device according to claim 1, wherein: The third axis extends along a diagonal of the touch surface (20), the diagonal extending diagonally from one corner of the touch surface (20) to a diagonally opposite corner of the touch surface (20), wherein the first axis, the second axis, and the third axis each describe a parabola relative to the depth of the touch surface (20).

3. A touch sensing device according to any one of the preceding claims, wherein the touch surface (20) is curved on a first axis according to a first parabola.

4. A touch sensing device according to any one of the preceding claims, wherein: The touch surface (20) is curved on a second axis according to a second parabola.

5. A touch sensing device according to any one of the preceding claims, wherein: The touch surface (20) forms a parabola.

6. The touch sensing device according to claim 5, wherein: The parabola is an elliptical parabola.

7. A touch sensing device according to any one of the preceding claims, wherein: Each point of the first axis of the touch surface (20) is within 0.5 mm of a mathematical parabola.

8. The touch sensing device according to claim 7, wherein: The mathematical parabola is based on z(x,y)=a+bx 2 +cx 2 y 2 +dy 2 is defined as , where z is the depth and x and y are the coordinates in the plane of the glass.

9. A touch sensing device according to any one of the preceding claims, wherein: The plate member comprises a glass or plastic sheet.

10. The touch sensing device according to any one of the preceding claims, further comprising a plurality of spacer members (116), wherein the spacer members (116) are arranged to apply force to the frame assembly (200) along the sides of the frame assembly (200) so that the frame assembly (200) follows a curved trajectory.

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