Optical system fabrication

Abstract

A method of manufacturing an optically transmissive sheet is described. The method includes molding an optically transmissive sheet into a laminate, wherein the optically transmissive sheet is adapted to occur total internal reflection at a first face and a second face of the optically transmissive sheet. The method further includes forming one or more light absorbing layer regions on the first face, the second face, or both of the optically transmissive sheet, wherein the one or more light absorbing layer regions are formed during the molding process. A method of manufacturing an optical element for a touch screen device and a method of manufacturing a touch screen device are also described, as well as an optical translucent sheet, an optical element for a touch screen device and a touch screen device.

Description

Technical Field

[0001] This invention relates to an optical system and a method of manufacturing the same, and more particularly to an optical system and method of manufacturing the same suitable for touch devices. Embodiments of this optical system are particularly suitable for controllers of electronic human-machine interfaces (HDIs), such as automotive center consoles, washing machine panels, handheld game controllers, or other suitable intelligent controllers (HDIs). Background Technology

[0002] Currently, in typical optical touchscreens, light enters from a light-emitting diode (LED) emitter through the outer edge of the panel. While this may be convenient, it can lead to inefficient optical illumination in certain touch areas. For example, when using such a system for a control interface, a certain level of complexity in the optical system is desirable, potentially involving irregular shapes and intricate functions. This can result in considerable manufacturing difficulties.

[0003] The purpose of this invention is to address one or more drawbacks associated with the prior art and to provide a touchscreen that improves in terms of cost and reliability. Summary of the Invention

[0004] In a first aspect, the present invention provides a method for manufacturing an optically transparent sheet, the method comprising: molding the optically transparent sheet into a laminate, wherein the optically transparent sheet is adapted to undergo total internal reflection at a first surface and a second surface of the optically transparent sheet; and forming one or more light-absorbing layer regions on the first surface, the second surface, or both of the optically transparent sheet, wherein the one or more light-absorbing layer regions are formed during the molding process.

[0005] Using this method, optical transducers with precisely selected optical properties can be manufactured. These transducers can be molded with additional features, such as ramps and recesses, which allow for optimization of specific light paths through the transducer, while other light paths can be blocked by light-absorbing layers.

[0006] In this embodiment, the light-absorbing layer region can be formed by in-mold labeling. If so, the coating region may include a first region that absorbs light in the near-infrared region. These coating regions may also include a second region that absorbs light in the visible region. The optical translucent sheet may be an acrylic sheet.

[0007] In a second aspect, the present invention provides a method for manufacturing an optical element for a touchscreen device, the method comprising: forming an optically transparent sheet by the method of the first aspect; and laminating the optically transparent sheet together with an intermediate optical layer and another optically transparent sheet, wherein the intermediate optical layer has a lower refractive index than the optically transparent sheet.

[0008] Using this method, optical elements with desired optical properties can be constructed very efficiently, especially when using acrylic materials for optical lenses.

[0009] In this embodiment, the optical element can be formed by two-shot molding.

[0010] In a third aspect, the present invention provides a method for manufacturing an optical element for a touchscreen device, the method comprising: forming an optically transparent sheet suitable for total internal reflection at a first and a second surface of an optically transparent sheet, the optically transparent sheet having one or more light-absorbing layer regions formed on the first surface, the second surface, or both of the optically transparent sheet; and laminating the optically transparent sheet together with an intermediate optical layer and a further optically transparent sheet, wherein the intermediate optical layer has a lower refractive index than the optically transparent sheet.

[0011] Using this type of method, the desired optical properties can be provided even when using materials for optical transmission layers, such as glass, instead of having to use acrylic materials.

[0012] An intermediate optical layer can then provide optical bonding between the optical lenses. This intermediate optical layer may include fluorinated ethylene propylene.

[0013] In a fourth aspect, a method for manufacturing a touchscreen device is provided, the method comprising: manufacturing a light-transmitting sheet as a top plate using the method of the first aspect; mounting the top plate in a touchscreen device having a plurality of light sources mounted in an associated manner such that light from the plurality of light sources is transmitted within the top plate by total internal reflection; mounting a substrate relative to the top plate such that if an external subject touches a first surface of the top plate, light is coupled from a second surface of the top plate through the first surface of the substrate into the substrate; and mounting one or more detectors associated with the substrate for detecting the light transmitted within the substrate.

[0014] Using this type of method, touchscreen devices with optimized optical properties for optical transmission top plates can be manufactured.

[0015] In one type of embodiment, the top plate and the base plate can be mounted with an air gap between them. This air gap can be provided by a foam mask separator.

[0016] In another type of embodiment, the optical translucent sheet can be manufactured by a second or third method, wherein the substrate is the additional optical translucent sheet.

[0017] Using this type of method, the touch screen device can be equipped with optical elements that are integrally formed, including both the top plate and the substrate, allowing for a particularly simple and efficient manufacturing process for the device with a reduced number of manufacturing steps.

[0018] Here, the substrate can be mounted above the display, which is configured to emit light from the touchscreen device through a top plate.

[0019] In this embodiment, the light-absorbing layer can absorb light emitted by a light source and is suitable for masking the light source. If so, the masking of the light source can substantially limit the propagation of light from the light source through the top plate, such that essentially only light directed for total internal reflection at the surface of the top plate can propagate. The light source can emit light, and the light-absorbing layer region absorbs light in the near-infrared range. Some or all of the light-absorbing region can transmit light substantially in the visible spectrum.

[0020] In this embodiment, the substrate is a weak absorber of light emitted from the plurality of light sources. This can be achieved by chemically doping the substrate with a weakly absorbing material.

[0021] In one embodiment, the top plate extends beyond the substrate, and the one or more light sources are mounted in the region of the top plate extending beyond the substrate. This top plate can be manufactured to taper gradually from a thicker region where the one or more light sources are mounted to a thinner region where the top plate is disposed on the substrate. Here, the one or more light sources can be mounted in one or more recesses in a second surface of the top plate and configured to transmit light through the walls of the recess where the light source is located into the top plate. Such recesses can be linearly extending recesses, with multiple light sources mounted in a linear array within the recesses. In some embodiments, such linearly extending recesses and linear arrays can extend along a straight line, and in some embodiments, they can extend along a curve. Alternatively, one or more recesses can be formed for each of the one or more light sources, each recess having one or more refractive input surfaces such that light from the light source is coupled into the body of the top plate through the one or more refractive input surfaces.

[0022] The substrate can be mounted to prevent light emitted from the substrate and not received by the one or more detectors from entering the top plate.

[0023] In another aspect, the present invention provides an optical translucent sheet manufactured by the method of the first aspect.

[0024] In another aspect, the present invention provides an optical element for a touchscreen device, which is formed of an optically transparent sheet laminated together with an intermediate optical layer and a further optically transparent sheet, wherein the intermediate optical layer has a lower refractive index than the optically transparent sheet. This optical element can be manufactured by methods of the second or third aspect.

[0025] In another aspect, the present invention provides a touch screen device manufactured by a method of a fourth aspect.

[0026] In addition to the principal aspects of the invention as described above, embodiments of the invention also illustrate the following secondary aspects. The principal aspects of the invention as described above can be combined with the following secondary aspects or individual features of the following secondary aspects to provide other aspects of the invention.

[0027] In one aspect, a touch device is provided, comprising: a top plate having a plurality of light sources associated therewith, such that light from the plurality of light sources is transmitted within the top plate via total internal reflection; and a substrate having one or more detectors associated therewith for detecting light transmitted within the substrate. The top plate and the substrate are configured such that if an external subject touches a first surface of the top plate, light is coupled from a second surface of the top plate through the first surface of the substrate into the substrate. The plurality of light sources are disposed within linearly extending recesses in the second surface of the top plate, such that light from the plurality of light sources is coupled into the top plate through the walls of the recesses. The plurality of light sources form a linear array within the linearly extending recesses.

[0028] The top plate has recesses extending linearly along its second surface, effectively forming grooves within the second surface. This allows for the installation of a light source, enabling light to easily and directly penetrate the body of the top plate. This allows light to enter the top plate uniformly and extremely efficiently.

[0029] A linearly extending recess can extend as a straight line, or it can be curved. Similarly, a linear array of light sources can be a straight line or a curve.

[0030] The wall of the recess can form an angle with the plane of the top plate, so that the second surface of the wall and the top plate form an obtuse angle within the top plate.

[0031] The mounting of the light source relative to the refractive surface or the wall of each refractive surface can increase the evanescent field intensity of the refracted light while confining the light within the top plate through total internal reflection.

[0032] The wall of the concave part can have a lens.

[0033] Each light source can be mounted at an angle to the plane of the top plate, such that the light emitted from the light source is mainly tilted toward the first surface.

[0034] Each of the plurality of light sources can be mounted such that the light emitted from the light source is primarily angled toward the wall of the recess.

[0035] The mounting of the light source at an angle relative to the wall of the recess in this manner can be used to increase or otherwise adjust the evanescent field intensity, thereby maximizing or regulating the device's responsiveness to touch.

[0036] The top plate may also include a width-reducing section in which the distance between the first surface and the second surface is substantially constant, but less than the distance between the first surface and the second surface at the recess.

[0037] While some embodiments have a top plate of substantially uniform thickness but do not include recesses, other arrangements are possible and can provide the possibility of enhancing control over total internal reflection light.

[0038] The top plate may also include a sloping section in which the distance between a first surface and a second surface of the top plate decreases, and the sloping section is located between a recess and a width-reducing section.

[0039] The slope section can taper linearly. The slope section can also taper non-linearly.

[0040] The area of ​​the first surface can be masked to prevent total internal reflection of light from the plurality of light sources in the trench.

[0041] The first surface can be masked for the section located on the recess and extending beyond the recess, thereby limiting the angular range of incident light reflected at the first surface from the plurality of light sources.

[0042] Masking can be provided by a light-absorbing layer provided on or at the first surface.

[0043] The area that can be masked in the recess between the light source and the first surface.

[0044] Masking can be provided by a light-absorbing layer provided on or at the surface of the recess.

[0045] Masking can be provided by light-absorbing elements that are mounted together with the light source.

[0046] The masking of the recessed area is used to direct light from the light source to the opening in the top plate.

[0047] The top plate may have a linear protrusion extending away from the first surface on the second surface, wherein the linear extension of the linear protrusion is substantially parallel to the linear extension of the groove. The linear protrusion may have a rectangular or fan-shaped cross-section perpendicular to its linear extent.

[0048] In some embodiments, an air gap may exist between the top plate and the substrate. In other embodiments, an optically transmissive material layer may exist between the top plate and the substrate.

[0049] Multiple light sources can be spaced apart to create a substantially uniform light distribution within the main body of the top panel. Each of the multiple light sources can be a light-emitting diode (LED). Each LED can emit near-infrared light.

[0050] In another aspect, a touch device is provided, comprising: a top plate having one or more light sources associated therewith, such that light from the one or more light sources is transmitted within the top plate via total internal reflection; and a substrate having one or more detectors associated therewith for detecting light transmitted within the substrate. The top plate and the substrate are configured such that if an external body contacts a first surface of the top plate, light is coupled from a second surface of the top plate through the first surface of the substrate into the substrate. Each of the one or more light sources is disposed in a recess within the top plate for the light source, wherein the recess has one or more refractive input surfaces, such that light from the light source is coupled into the body of the top plate through the one or more refractive input surfaces.

[0051] For one or more light sources, the recess may have a central refractive input surface and two side refractive surfaces symmetrically arranged around and adjacent to the central refractive input surface.

[0052] The central refractive input surface may have a different curvature than the side refractive surfaces. In some embodiments, the central refractive input surface may have a conical curvature. In some embodiments, the central refractive input surface may have an elliptical curvature.

[0053] The refractive input surface or the wall of each refractive input surface can form an angle with the plane of the top plate, such that the refractive input surface and the second surface of the top plate form an obtuse angle within the top plate.

[0054] The mounting of the light source relative to the refractive surface or the wall of each refractive surface can increase the evanescent field intensity of the refracted light, while confining the light within the top plate through total internal reflection.

[0055] The refractive input surface or the wall of each refractive input surface may have a lens.

[0056] The light source, or each light source, can be mounted at an angle to the plane of the top plate, such that the light emitted from the light source is mainly tilted toward the first surface.

[0057] Each light source can be mounted such that the light emitted from the light source is primarily angled toward at least one refractive input surface.

[0058] The mounting of the light source at an angle relative to the wall of the recess in this manner can be used to increase or otherwise adjust the evanescent field intensity, thereby maximizing or regulating the device's responsiveness to touch.

[0059] The top plate may also include a width-reducing section in which the distance between the first and second surfaces is substantially constant, but less than the distance between the first and second surfaces at the recess. The top plate may also include a ramp section in which the distance between the first and second surfaces of the top plate decreases, the ramp section being located between the recess and the width-reducing section.

[0060] The slope section can taper linearly. The slope section can also taper non-linearly.

[0061] In some embodiments, an air gap may exist between the top plate and the substrate. In other embodiments, an optically transmissive material layer may exist between the top plate and the substrate.

[0062] A region of the first surface can be masked to prevent total internal reflection of light from each light source in the recess. Masking can be provided for the section of the first surface located on and extending beyond the recess to limit the angular range of incident light reflected at the first surface from the plurality of light sources. Masking can be provided by a light-absorbing layer provided on or at the first surface.

[0063] The touch device may include multiple light sources. The mask may extend over two or more of the multiple light sources.

[0064] The masking can define an effective area of ​​the top plate, wherein the plurality of light sources illuminate the effective area of ​​the top plate.

[0065] The plurality of light sources can be arranged around the perimeter of the effective area. The perimeter of the effective area can be rectangular or elliptical.

[0066] The first surface of the top plate in the effective area may not be planar.

[0067] The multiple light sources can be spaced apart to form a substantially uniform light distribution in the effective area of ​​the top plate.

[0068] The area between the light source and the first surface of each recess can be masked. Masking can be provided by a light-absorbing layer provided on or at the surface of the recess.

[0069] The masking can also be provided by a light-absorbing element mounted together with the light source.

[0070] The masking of the recessed area can define an opening for emitting light from a light source into the top plate.

[0071] Each of the one or more light sources may be a light-emitting diode (LED). Each of the one or more LEDs may emit near-infrared light. In another aspect, a touch device is provided, comprising: a top plate having one or more light sources associated therewith, such that light from the plurality of light sources is transmitted within the top plate in a manner of total internal reflection; and a substrate having one or more detectors associated therewith for detecting light transmitted within the substrate. The top plate and the substrate are configured such that if an external subject touches a first surface of the top plate, light is coupled from a second surface of the top plate through the first surface of the substrate into the substrate. One or more regions of the first surface, the second surface, or both are provided with a layer that suppresses internal reflection at that region of the surface, thereby providing optical separation between a portion of the top plate and another portion of the top plate.

[0072] The layer may be an absorption layer.

[0073] The top plate can be formed by molding, and the layer can be formed by secondary molding or in-mold labeling.

[0074] The layer can separate at least one active area from the other areas of the first surface, wherein each active area is isolated from any other optical activity in the top plate. The active area can provide single touch device functionality.

[0075] The functionality of a touch device may include one of the following: a dial, a slider, a button, a trigger, and a touch screen.

[0076] Each of the multiple light sources is disposed within a recess in the top plate for that light source. The recess may have one or more refractive input surfaces, such that light from the light source is coupled into the body of the top plate through the one or more refractive input surfaces.

[0077] The refractive input surface or the wall of each refractive input surface can form an angle with the plane of the top plate, such that the refractive input surface and the second surface of the top plate form an obtuse angle within the top plate.

[0078] The refractive input surface or the wall of each refractive input surface may have a lens.

[0079] Each light source can be mounted at an angle to the plane of the top plate, such that the light emitted from the light source is mainly tilted toward the first surface.

[0080] Each light source can be mounted such that the light emitted from the light source is primarily angled toward at least one refractive input surface.

[0081] The multiple light sources can be arranged around the perimeter of the effective area. The perimeter of the effective area can be rectangular or elliptical.

[0082] The first surface of the top plate in the effective area does not have to be planar.

[0083] The multiple light sources can be spaced apart to form a substantially uniform light distribution within the effective area of ​​the top plate. Multiple effective areas can exist, separated by this layer.

[0084] Two of the plurality of effective regions may have different touch device functionalities. Two of the plurality of effective regions may have different optical properties. Two of the plurality of effective regions may be light sources of different properties. Two of the plurality of effective regions may be associated with regions of the substrate having different optical properties.

[0085] The touch device may also include an absorbent layer on part or all of the periphery of the top panel.

[0086] Each of the one or more light sources may be a light-emitting diode (LED).

[0087] In another aspect, a packaged light-emitting diode is provided, comprising a light-emitting diode die and a cylindrical lens directly mounted on the light-emitting surface of the light-emitting diode die, wherein the light emitted by the cylindrical lens has a narrow angular distribution along a first axis and a wide angular distribution along a second axis orthogonal to the first axis.

[0088] The cylindrical lens can be formed as a substantially oblate spheroidal lens truncated within a body having two first truncated portions and one second truncated portion. The two first truncated portions can be perpendicular to the axis of the oblate spheroid and equidistant from the longest semi-diameter of the oblate spheroid, and can be parallel to the two axes of the oblate spheroid and parallel to each other. The second truncated portion can be parallel to another axis of the oblate spheroid and perpendicular to the two first truncated portions. The light-emitting diode die can be adjacent to the second truncated portion.

[0089] Cylindrical lenses can be oblate spheroids.

[0090] A cylindrical lens can be formed as an aspherical lens within a modified ellipsoid having two first truncated portions and one second truncated portion. The two first truncated portions can be perpendicular to the axis of the modified ellipsoid and equidistant from the longest radius of the modified ellipsoid, and can be parallel to the two axes of the ellipsoid and parallel to each other. The second truncated portion can be parallel to the other axis of the ellipsoid and perpendicular to the two first truncated portions.

[0091] The LED die can be adjacent to the second cut-off portion. The ellipsoid can be modified to have a greater curvature than an ellipsoid in the direction perpendicular to the light-emitting surface of the LED die, and a smaller curvature than an ellipsoid in the direction parallel to the light-emitting surface of the LED die.

[0092] The length of the light-emitting surface of the two first cut-off portions perpendicular to the bare die of the light-emitting diode can be greater than half the length of the light-emitting surface of the lens body perpendicular to the bare die of the light-emitting diode.

[0093] In another aspect, a touch device is provided, comprising: a top plate having one or more light sources associated therewith, such that light from the one or more light sources is transmitted within the top plate via total internal reflection; and a substrate having one or more detectors associated therewith for detecting light transmitted within the substrate. The top plate and the substrate are configured such that if an external subject touches a first surface of the top plate, light is coupled from a second surface of the top plate through the first surface of the substrate into the substrate. Each of the one or more light sources is disposed within a recess in the top plate for the light source, wherein the recess has a refractive input surface such that light from the light source is coupled into the body of the top plate through the refractive input surface, and wherein each of the one or more light sources is a light-emitting diode packaged as described in the preceding paragraph.

[0094] The mounting of each of the one or more light sources relative to the refractive input surface allows the combination of the shapes of the lens and the refractive input surface of the light source to diffuse light substantially uniformly in the plane of the top plate.

[0095] The refractive input surface or the wall of each refractive input surface can form an angle with the plane of the top plate, such that the refractive input surface and the second surface of the top plate form an obtuse angle within the top plate.

[0096] Each light source can be mounted at an angle to the plane of the top plate, such that the light emitted from the light source or each light source is mainly tilted toward the first surface.

[0097] Each light source can be mounted such that the light emitted from the light source is angled toward the refractive input surface.

[0098] The methods, features, and aspects described above can be used individually or in combination. A feature of one aspect can be applied, alone or in appropriate combination, to a feature of another aspect. Attached Figure Description

[0099] To facilitate a better understanding of the invention, preferred, non-limiting embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 This is a schematic cross-sectional view of a touchscreen device; Figure 2 The touchscreen device is shown integrated into the driver's cab of the vehicle; Figure 3 It is a cross-sectional view of the portion of the light guide that incorporates a light source located in a recess on the lower side of the light guide; Figure 4 It is a cross-sectional view of the portion of another light guide that incorporates a light source located in a recess on the lower side of the light guide; Figure 5 It is a perspective view of a portion of a light guide combined with a trench injection optic geometry, including a ramp section; Figure 6 It is a perspective view of another light guide combined with the geometry of a grooved injection optical device and having a constant thickness; Figure 7 This is a perspective view of the portion of the light guide that incorporates a pocket injection optic. Figure 8a This shows the range of light angles extending beyond the critical angle at the boundary between the acrylic material and air; Figure 8b This shows the range of light angles extending beyond the critical angle at the boundary between the acrylic material and the FEP. Figure 9 A cross-sectional view of the portion of the light guide that has a light source located in a recess on the lower side of the light guide; Figure 10 It is a cross-sectional view of another light guide combined with a light source in a recess on the lower side of the light guide, wherein an absorption mask is disposed on the upper surface of the light guide; Figure 11 It is a perspective side view of a portion of a light guide combined with a recess for receiving a light source in use, wherein the recess has a front wall with a lens. Figure 12a To illustrate the graph of light loss from the light guide, where light enters the light guide from a light source located in a recess on the lower side of the light guide, and the power density of the light coupled into and within the light guide, all for different tilt angles of the front wall of the recess; Figure 12b It is a cross-sectional view of the portion of the light guide that has a light source disposed in a recess on the lower side of the light guide, wherein the front wall of the recess is not inclined. Figure 12c A cross-sectional view of the portion of the light guide that has a light source disposed in a recess on the lower side of the light guide, wherein the front wall of the recess has a 50° tilt angle. Figure 13a To illustrate the light loss from the light guide, where light enters the light guide from a light source located in a recess on the lower side of the light guide, the graph also shows the light coupled into the light guide and the power density in the light guide, all for different tilt angles of the front wall of the recess; Figure 13bIt is a cross-sectional view of the portion of the light guide that has a light source disposed in a recess on the lower side of the light guide, wherein the front wall of the light source cavity is not inclined and the light source is not inclined; Figure 13c It is a cross-sectional view of the portion of the light guide that incorporates a light source located in a recess on the lower side of the light guide, wherein the front wall of the light source cavity has a 30° tilt angle, and the central axis of the light source is approximately perpendicular to the front wall of the recess. Figure 14 It is a perspective side view of a portion of a light guide combined with a recess for receiving a light source in use, wherein the light guide includes an extruded section or groove adjacent to the front wall of the recess. Figure 15 It is a perspective side view of another light guide combined with a recessed portion for receiving a light source in use, wherein the light guide includes a non-linear ramp section; Figure 16 This illustrates a touchscreen device that combines a slider, a crosshair (D-pad), and a raised rectangular screen. Figure 17a It is a schematic perspective view of a portion of a grooved injection optics device with a straight, linearly extending front wall; Figure 17b It is a schematic perspective view of a portion of a grooved injection optics device with a curved, linearly extending front wall; Figure 18a It is a schematic perspective view of a pocket-type optical device, in which the height and slope of the front wall of the recess vary with its length; Figure 18b This is a schematic perspective view of a pocket-type optics device incorporated in a light guide with a ramp section; Figure 19 It is a schematic perspective view of a light guide incorporating multiple pocket-type optical devices, and includes an absorption mask layer on its upper surface; Figure 20 It is a top view of a light guide incorporating pocket-type optical devices; Figure 21a It is a side view of the portion of the light guide that has a light source set in a recess on the lower side of the light guide; Figure 21b Shown from Figure 21a The intensity distribution of the light source output of the device; Figure 21c Shown from Figure 21a The intensity distribution of light from the light source within the optical guide; Figure 22a The horizontal and vertical intensity distributions of light from a wide-angle surface-mount LED are shown. Figure 22bThe horizontal and vertical intensity distributions of light from a narrow-angle surface-mount LED are shown. Figure 23a This is a perspective view of an LED device incorporating a circular lens; Figure 23b Shown from Figure 23a The horizontal and vertical intensity distribution of light from the device; Figure 24a This is a perspective view of a superelliptical LED package incorporating a cylindrical lens; Figure 24b Shown from Figure 24a The horizontal and vertical intensity distribution of light from the device; Figure 24c yes Figure 24a A plan view of an LED package; Figure 25a It is a combination of optical waveguides Figure 24a A side view of a portion of the LED package; Figure 25b It is a combination of optical waveguides Figure 24a A perspective view of a portion of the LED package; Figure 25c Showing separately from Figure 24a The intensity distribution of the output of the LED package; Figure 25d Shown from Figure 25b The intensity distribution of light from the light source within the optical guide; Figure 26 A graph showing the relationship between the uniformity of light intensity distribution in the light guide and the distance from the pocket-type optical device in the z-direction; Figure 27 It is a graph showing the light power from the LED and how the horizontal and vertical beam half-angles of the LED vary for different LED chip sizes; Figure 28 It is a perspective view of a light guide with a curved profile and sixteen pocket-type optics. Figure 29a is Figure 28 Another perspective view of the light guide, showing the light distribution within it; Figure 29b is a perspective view of a curved light guide incorporating twelve pocket-type optical elements, and shows the light distribution in the light guide; Figure 29c It is a perspective view of a curved light guide incorporating eight pocket-type optics, and shows the light distribution in the light guide; Figure 29d Figures 29a to 29b show different angular positions around the central axis C of the optical guide. Figure 29c A graph showing the uniformity of optical power density in the sidewalls of each light guide; Figure 30 It is a perspective view of a light guide with a rectangular outline and thirty-two pocket-type optical devices. Figure 31a for Figure 30 Another perspective view of the light guide, showing the light distribution within it; Figure 31b It is a perspective view of a rectangular light guide incorporating twenty-six pocket-type optical elements, and shows the light distribution in the light guide; Figure 31c It is a perspective view of a rectangular light guide incorporating twenty pocket-type optical elements, and shows the light distribution in the light guide; Figure 31d It is shown Figures 31a to 31c A graph showing the uniformity of optical power density along the x-axis for each optical guide; Figure 32 It is a perspective view of a curved light guide that combines an effective area and an ineffective area; Figure 33 It is a perspective view of a flat light guide that includes multiple effective regions separated by ineffective regions defined by an absorption mask layer; Figure 34a It is a cross-sectional side view of a curved light guide that combines an incident optical device at either end and an absorber on the end face; Figure 34b It is a cross-sectional side view of a curved light guide that combines an incident optical device at either end and an absorber along the end wall. Figure 35a It is a cross-sectional side view of a curved light guide incorporating incident optics at either end, and shows stray light reflected from one of the incident optics. Figure 35b It is a cross-sectional side view of a curved light guide that incorporates an incident optical device disposed at either end and an absorber extending on one of the incident optical devices. Figure 36 This is a cross-sectional side view of the composite material portion of the touch device; Figure 37 This is a cross-sectional side view of a portion of another touch device made of composite material; Figure 38 This is a cross-sectional side view of a portion of another touch device made of laminated material; Figure 39 This is a cross-sectional side view of a portion of another touch device made of laminated material; Figure 40 A curved optical guide is shown, along with the radius of curvature and thickness of the optical guide used to calculate the turntable angle curvature ratio. Figure 41aThis illustrates a pocket-type optics device that provides a narrow light distribution; Figure 41b A pocket-type optics device is shown that provides a wide light distribution in a curved light guide; Figure 42a Another example of an HE-LED package incorporating an aspherical lens is shown; Figure 42b Shown from Figure 42a The horizontal and vertical intensity distribution of light from the device; Figure 42c yes Figure 42a A plan view of the HE-LED package; Figure 43 This shows an intermediate layer formed by multiple sublayers, used as the middle layer in a laminated material. Detailed Implementation

[0100] Optical touch light guides, primarily marketed as whiteboard upgrades and using flat light guides, are known. However, the market is moving in new directions, requiring the introduction of thin, continuous 3D curved upper layers to provide a single, free-flowing shape (without any mechanical components breaking through the surface), thus allowing for a more refined and aesthetically pleasing style. Security is also a key factor, necessitating the addition of geometric notches or grooves on the top surface of the upper layer to: (a) assist in finger positioning or guidance, and (b) allow users to identify relevant portions of the touchscreen simply by touch, without having to look at where their fingers are (i.e., “keeping your eyes on the road”).

[0101] According to the present invention, an optical touch controller for an electronic human-machine interface (HDI) 8 is described.

[0102] The device of the present invention can utilize, for example, touchscreen technology developed by the applicant and described in WO2015 / 155508. In the method taught in WO2015 / 155508, suppressed total internal reflection is used in conjunction with a lossy substrate 18. The processing device can then determine the location of a touch using the transmission loss between light entering the substrate unit 18 and one or more detectors 20 associated with the substrate 18. This lossy substrate 18 can be a weak absorber of light emitted from a relevant light source and can be chemically doped with a weakly absorbing material for this purpose.

[0103] refer to Figure 1 It illustrates the method taught in WO2015 / 155508, whereby HDI 8 includes a three-layer optical laminate over one or more displays. Figure 1(Not shown in the image). Light is coupled to the top plate or upper layer 10 of the laminate via total internal reflection and contained within the upper light guide 10 until a touch of the first or upper surface 23 of the upper layer 10 causes a small percentage of the light contained in the upper layer 10 to be emitted from the second or lower surface 25 of the upper layer 10 through the middle layer 14 (air or a low-refractive-index material) toward and through the first or upper surface 26 of the lower laminate 18 (i.e., substrate 18), where the light can be detected and the finger press position on the upper surface 23 can be determined. The lower laminate 18 is doped, and the light is dispersed in the lower laminate 18, so that the finger press position can be calculated based on the light detected at the photodetector 20. Multiple photodetectors 20 may be present and arranged around the lower laminate 18, which can be arranged to most effectively detect the finger press position of the geometry of the HDI 8.

[0104] It has now been discovered that a particularly efficient HDI 8 can be developed by achieving a uniform light distribution in the upper layer 10 of the light guide through the use of a novel method of light injection. New methods and apparatus are described for injecting light into the upper layer 10 of the light guide and for shaping the distribution of the injected light for the benefit of improved touch response. A method for manufacturing a laminated structure suitable for mass production is also described. The novel 3D light guide geometry described requires a new way to couple or “inject” light into the top plate 10, which minimizes light loss at geometric features (e.g., at curved portions of the top plate 10) and enables efficient use of available light, effectively distributing it to where it is most needed. Furthermore, the new light guide can be easily manufactured (e.g., using injection molding technology) and can use surface mount device (SMD) components to minimize the form factor and simplify construction.

[0105] By directing light into the top plate 10, which is closer to the geometry where the light is most needed, the light does not travel a greater distance than necessary before reaching the effective touch detection area on the upper surface 23 of the top plate 10, which is capable of detecting touch on the touchscreen. This solves the inefficiency associated with edge-injection of light in the light guide. Furthermore, the incident light does not become scattered before it is "used," i.e., within the effective touch detection area of ​​the touchscreen 8. An important aspect of efficiency is ensuring that all light traveling within the light guide is "useful" light—that is, light traveling on the appropriate trajectory so that the touch detection process operates as expected. Light that is useless in this way may not contribute to the signal but may contribute to noise; therefore, preventing stray light propagation may be more important than simply maximizing the amount of light entering the top plate 10 to achieve the optimal signal-to-noise ratio.

[0106] Reference Figure 3 This illustrates a device for directing light from the light source 12 into the light guide 10. For example, Figure 3 The arrangement can be incorporated as such Figure 1 The top plate 10 of the touch detection system 8.

[0107] In this example, the light guide 10 consists of a constant thickness t L The curved plate is defined, with its thickness limited to the distance between the upper surface 23 and the lower surface 25 of the light guide 10. The light guide 10 can be planar or various other three-dimensional (3D) shapes. Unlike conventional systems where light is coupled into the light guide 10 through its edges, in... Figure 3 In the example, light is coupled into the light guide 10 at the point where it is inserted from the edge of the light guide 10 (although the coupling point is not limited to this point in the light guide 10). In this way, light is coupled into the light guide 10 at a point closer to the beginning of the geometry that requires light, that is, closer to the effective area of ​​the light guide 10 where the light is used for touch detection.

[0108] like Figure 3 As shown, the light guide 10 includes a cavity or recess 30 for receiving and surrounding a light source 12, which in this example is an LED. The cavity 30 is defined in the second or lower surface 25 of the light guide 10 at the lower side of the light guide 10 and extends partially through the thickness t of the light guide 10. L This is to avoid penetrating the upper surface 23 of the light guide 10. In this way, the cavity 30 extends from the lower surface 25 of the light guide 10 toward the upper surface 23 of the light guide 10 and terminates below the upper surface 23, such that the top surface 32 of the cavity 30 is located between the upper surface 23 and the lower surface 25 of the light guide 10. The portion of the light guide between the top surface 32 and the upper surface 23 defines the top 34 of the cavity 30. In other words, the portion of the light guide 10 above the cavity 30 defines the top 34 of the cavity 30 (see details). Figure 4 ).

[0109] Cavity 30 includes Figure 3 The front surface 36 and rear surface 38 and the side surface shown are shown. Figure 3(Not shown in the diagram). As it moves in the direction from the lower surface 25 to the upper surface 23, the front surface 36 and the rear surface 38 tilt toward each other. In this way, the width of the cavity 30 gradually decreases, such that the width of the cavity 30 between its front surface 36 and rear surface or wall 38 decreases as it moves away from the lower surface 25 toward the upper surface 23 of the light guide 10. It should be noted that the rear surface 38 only needs to be tilted to produce the draft angle for injection molding. Now, particularly considering the light-coupled end of the cavity 30, the front wall 36 forms an angle with the plane of the light guide or top plate 10 in the region where the light source cavity 30 is coupled, such that the front wall 36 and the second or lower surface 25 of the top plate 10 form an obtuse angle within the top plate 10 to form a refractive input surface. In this example, the side surface tilts inward from the lower surface 25 to the upper surface 23, but this can vary in other examples. For example, the side surface may extend vertically between the upper surface 23 and the lower surface 25, but is typically provided with a ramp to enable injection molding. It should be understood that the shape of cavity 30 may vary in other examples.

[0110] When the light source is 12, Figure 3 When arranged in cavity 30, the light-emitting area 40 of light source 12 (from which light emitted from light source 12 is emitted) faces the front surface 36 of cavity 30. In this manner, light emitted from light source 12 enters light guide 10 through the front surface 36 of cavity 30 (which serves as the light coupling surface or wall of cavity 30). In this embodiment, absorbers 42 in the form of light-absorbing layers are provided on the top surface 32 and rear surface 38 of light source cavity 30 to block light emitted from light source 12 from leaving light source cavity 30 through its upper or rear surfaces 32, 38. In this way, absorbers 42 prevent unwanted stray light that cannot reach the effective touch detection area of ​​light guide 10 from emitting from above, behind, or to the side of light source 12. This advantageously removes stray light that may interfere with the touch detection system. In this example, absorbers 42 are also provided below the lower surface 25 of light guide 10, adjacent to light source cavity 30, to prevent light reflection from light source 12 in this area. In this way, light that does not meet the critical angle standard for total internal reflection can be blocked and cannot be transmitted in the light guide 10.

[0111] exist Figure 3 In one example, the light guide 10 includes a cavity 30 configured to surround a single light source 12. However, it should be understood that in other examples, the light guide 10 may include multiple cavities 30, each of which may be configured to surround one or more light sources 12. Furthermore, in some examples, the light guide 10 may include a single cavity 30 configured to surround multiple light sources 12.

[0112] Therefore, as described above, at least one cavity 30 is cut out in the lower side of the light guide 10, which is large enough to accommodate a single light emitter 12 or multiple light emitters 12. The size and dimensions of the light source 12 determine the size and dimensions of the cavity 30 required to accommodate the light source 12, and the cavity is provided with clearance tolerances conforming to good mechanical design specifications. For mass-produced optical components, injection molding is the manufacturing method of choice. This requires a minimum top thickness t on the light source 12 (in this example, the light source is in the form of an LED). R It can be reliably molded, otherwise this could result in a "sunk" in the upper surface 23 of the light guide 10 above the LED, which is functionally and aesthetically unacceptable. Top thickness t R The thickness of the top 34 of the cavity 30 is defined as the distance between the top surface 32 of the cavity 30 and the upper surface 23 of the light guide. Figure 3 In the embodiment, with the LED height h L In contrast, using a relatively thicker light guide section allows the top 34 of cavity 30 to have sufficient thickness t. R To accommodate the LED 12 without causing a sinking in the upper surface 23 of the light guide 10 above the LED 12.

[0113] Figure 4 Another embodiment of a device for directing light from a light source 12 into a light guide 10 for a touch optics system is shown. In this example, the light guide 10 includes a relatively thick first segment 46 and a relatively thin second segment 48 (i.e., a segment with a reduced width). The first segment 46 is thicker than the second segment 48. In other words, the distance between the first surface 23 and the second surface 25 of the light guide 10 is greater in the first segment 46 than in the second segment 48. A light source cavity 30 is disposed in the first, relatively thick segment 46 of the light guide 10. A ramp segment 50 of the light guide 10, extending in a direction away from the front wall 36 of the recess 30, reduces the distance between the first surface 23 and the second surface 25, combining the first segment 46 (i.e., the thicker cavity segment) with the second segment 48 (i.e., the thinner light guide segment).

[0114] and Figure 3 The light source cavity 30 is similar. Figure 4 The light source cavity 30 of the device is defined in the lower surface 25 of the light guide 10 and extends partially through the thickness of the light guide 10. The cavity 30 terminates at a top surface 32 located between the upper surface 23 and the lower surface 25 of the light guide 10, and the portion of the light guide 10 between the top surface 32 and the upper surface 23 defines the top 34 of the cavity 30. The cavity 30 includes... Figure 4 The front surface 36 and rear surface 38, as well as the side surface (in) shown in the figure, are also shown in the figure. Figure 4(Not shown in the image). When moving in the direction from the lower surface 25 to the upper surface 23, the front surface 36 and the rear surface 38 tilt toward each other. Therefore... Figure 4 The cavity 30 gradually decreases in width, such that the width of the cavity 30 between its front surface 36 and rear surface 38 decreases as it moves away from the lower surface 25 of the light guide 10 toward the upper surface 23 of the light guide 10. However, this gradual decrease... Figure 4 In the device, it is not as good as in Figure 3 This is evident in the example. In this example, the side surface slopes inward from the lower surface 25 to the upper surface 23, but this can vary in other examples. It should also be generally understood that the shape of the cavity 30 can vary in other examples.

[0115] Similar to again Figure 3 The arrangement, set up in Figure 4 The light-emitting region 40 of the light source 12 in cavity 30 faces the front surface 36 of cavity 30, such that the front surface 36 of cavity 30 acts as an optical coupling surface. The optical coupling surface 36 defines the refractive input surface of the light guide 10, at which light from the light source 12 is refracted into the light guide 10. An absorber 42 is disposed on the top surface 32 and below the lower surface 25 of the light guide 10, adjacent to the light source cavity 30, for reasons already discussed... Figure 3 The reasons described are similar.

[0116] Turn now Figure 5 It has already been similar to Figure 4 The light source cavity 30 shown is integrated into the light guide 10, which has a curved geometry, but the size of the light source cavity is designed to surround multiple light sources 12 (for clarity, in...). Figure 5 (Only one light source is marked in the image) instead of a single light source 12. Figure 5 The optical guide 10 is bent in two dimensions, especially in the y and z dimensions, such as... Figure 5 As specified in the text. Figure 5 The optical guide 10 is extruded symmetrically about the x-axis, as... Figure 5 As specified in the text.

[0117] Light emitted from light source 12 passes through refractive input surface 36 and through ramp section 50 of light guide 10, where it is confined within light guide 10 by total internal reflection. The array of light sources 12 is spaced along the length of linearly extending recess 30 to form a linear array within recess 30, thereby creating a substantially uniform light distribution within the body of light guide or top plate 10.

[0118] The optical coupling surface 36 through which light enters the optical guide 10 and the ramp optical guide section 50 are configured to take into account the spatial and angular characteristics of the light source 12, and specifically configured as follows: a) Maximize the optical incident efficiency from the one or more light sources 12 to the light guide 10. This can be achieved, for example, by providing optical polishing on the optical coupling surface 36; b) Eliminate or minimize optical losses, particularly in the vertical plane, by ensuring that light does not fall outside the critical angle range at the upper surface 23 and / or lower surface 25 of the light guide 10 (i.e., the angle of incidence of light rays hitting the upper / lower surface 23 / 25 relative to the surface normal of the upper / lower surface 23 / 25 does not fall below the relevant critical angle defined relative to the surface normal). c) The touch sensitivity of the system incorporating the light guide 10 as described above is maximized by controlling the average angle of incidence (relative to the surface normal) of the light at the upper surface 23 of the light guide. Specifically, the incident optics are configured such that the average angle of incidence of the light emitted from the light source 12 and reaching the upper surface 23 and lower surface 25 of the light guide 10 is closer to the critical angle. The angle of incidence α of the light incident on the upper / lower surfaces 23 / 25 is defined relative to the surface normal of the upper / lower surfaces 23 / 25, which is common in the art and is fully and clearly stated in [the relevant section]. Figure 1 As shown in the diagram, the depth of the evanescent field, i.e., the penetration of the evanescent field, increases as the incident angle of light undergoing total internal reflection at the boundary approaches the critical angle. Therefore, arranging the incident optics such that the light undergoing total internal reflection in the light guide 10 propagates as close as possible to the critical angle increases the depth of the evanescent field, which in turn improves the touch sensitivity of such a system utilizing suppressed total internal reflection during touch detection. It should be understood that the angle between the incident light from the light source 12 and the upper / lower surfaces 23 / 25 of the light guide 10 can change as the light passes through the light guide 10 via total internal reflection, especially if the light guide 10 is curved. For example, if the angle α at which light strikes the upper / lower surfaces 23 / 25 of the light guide 10 decreases to fall below the critical angle, and thus below the angle threshold for total internal reflection, light will be lost from the light guide 10. With this in mind, the range of vertical angles of the incident light coupled to the light guide 10 can be selected to balance the benefits of the increased evanescent field depth with the light loss that occurs when the incident angle α of the light falls below the critical angle. Considering these points, it should be understood that the mounting of the light source 12 relative to the wall of the refractive surface or each refractive surface 36 can be arranged to refract the light, thereby increasing the evanescent field intensity, while confining the light within the top plate 10 by total internal reflection.

[0119] d) Specifically, light is propagated in a horizontal plane to optimize the uniformity of light power density at the upper surface 23 of the light guide 10, thereby improving the uniformity of touch response in the touch-sensitive area of ​​the system.

[0120] e) Generate an optical cavity shape that is large enough to accommodate one or more light-emitting packages 12 depending on the application, but small enough to minimize the distance between the back side of the optical cavity 30 (i.e., the rear surface 38 of the light source cavity 30) and the starting point of the effective area of ​​the touch surface.

[0121] f) Improve the ease of manufacturing the shape of the optical cavity.

[0122] exist Figure 5 and 6 In this embodiment, cavity 30 defines a linearly extending recess in top plate 10 for receiving a plurality of light sources 12, and is referred to as a "groove entrance optic" (TIO) 52. In other embodiments, cavity 30 is dimensioned and arranged to surround a single light source 12, such as Figure 7 As shown, and referred to as a "pocket-injection optics" (PIO) 74. Other variations are possible. Figure 5 and Figure 6 In this embodiment, the linearly extending recess extends across the light guide 10 in a straight line; however, it should be noted that this may differ in other embodiments. For example, in other embodiments, the linearly extending recess may extend along a curved path. In some variations, the cavity 30 may extend across the top plate 10, for example along a conical or aspherical path, along a path defined by a spline curve, or along any other path consisting of one or more segments, not all of which are listed herein but will be apparent to those skilled in the art.

[0123] It should be understood that one or more grooved injection optics 52 may be combined with one or more pocket injection optics 74 within the same top plate 10, and / or more generally within the same touch device or system.

[0124] Typically, for a flat light guide 10 with upper and lower flat surfaces 23 and 25 extending parallel to each other, once light is coupled or “injected” into the light guide 10, the light is confined within the light guide 10, as long as the angle between the reflected light and the surface normal remains equal to or greater than the critical angle determined by the refractive index of the material of the light guide 10. Figure 8a and Figure 8b The path of a light ray propagating in an acrylic light guide 10 and reaching the lower surface 25 of the light guide 10 at a critical angle is shown. Figure 8a In the middle, the lower surface 25 defines the interface between the acrylic material of the light guide 10 and the air gap, which defines the intermediate layer 14 between the light guide 10 and the substrate 18, such that the critical angle at the interface is approximately 42°. Figure 8b In this process, a fluorinated polymer and fluorinated ethylene propylene (FEP) material layer is provided between the top plate 10 and the substrate 18 to define the intermediate layer 14, such that the critical angle at the interface is approximately 64°.

[0125] However, for light guides 10 with more complex surface profiles, including, for example, 3D recesses or domes, additional requirements must be met to minimize light loss during propagation through the light guide 10. When using a light source 12 with a relatively small divergence angle, the general rule for minimizing light loss from the light guide 10 is that any light guide curvature should follow a ratio of bending radius to light guide thickness greater than 5:1. That is, referring to... Figure 40 The radius of curvature Rc of the optical guide 10 in a given region and the thickness t of the optical guide 10 in that given region p The ratio should exceed 5 / 1. This ratio can be called the turntable angle curvature ratio Kd, such that Kd = Rc / tp > 5 / 1.

[0126] This rule is generally effective when using a light source 12 that emits light with a relatively small angular divergence. However, for a light source 12 with a large light divergence angle, at least a portion of the light from the light source 12 falls below the relevant critical angle and the likelihood of light loss in the light guide 10 increases, especially if the light guide 10 bends rapidly and continuously in opposite directions, for example, if the geometric profile of the light guide 10 undergoes an “S” deviation.

[0127] In devices utilizing optical touch detection, light loss from the system, particularly from the light guide 10, is highly undesirable. Escaped light, i.e., light lost from the light guide 10, may be reflected back into the system by the user, causing the system to erroneously detect a touch. For example, even if the user's hand does not touch the upper surface 23 of the light guide 10, a user's hand near the light guide 10 may reflect escaped light back into the system, resulting in false touch detection. Furthermore, escaped light reflected back into the system may reduce the accuracy of the finger pressure position determined by the system and may also reduce the overall pressure response. As will be explained below, this can be addressed by limiting the angular range of the light rays coupled from the light source 12 into the light guide 10, ensuring that substantially all light rays propagating in the light guide 10 remain above the critical angle throughout their propagation within the light guide 10 and do not escape from the light guide 10 by falling below the critical angle.

[0128] Turn to Figure 5 and Figure 6 Now we will consider in more detail the simplified optical geometry of the grooved injection optics 52.

[0129] The geometry of a grooved incident optics device is essentially a 2D design in a vertical plane, i.e., the yz plane, which protrudes along the x-axis.

[0130] Instead of determining the ideal shape of the 3D geometry of the grooved injection optics 52 or the pocket injection optics (discussed in more detail later) all at once, the problem can be simplified into vertical and horizontal profiles. The next section discusses how the horizontal and vertical profiles can be designed and optimized independently of each other, and then combined to achieve the complete 3D geometry of the grooved injection optics 52.

[0131] It can be recognized that the optical performance in the vertical plane is not entirely independent of the geometry in the horizontal plane (or vice versa), and full 3D optimization can further improve the optical performance of the grooved injection optics 52. However, considering the vertical and horizontal profiles separately enables a simplified optimization process, which results in good coupling performance of the grooved injection optics 52.

[0132] First, turn to the vertical profile of the grooved injection optics 52 in the yz plane. The key requirements for optimizing the design geometry of the grooved injection optics 52 in the vertical plane are: i. Maximize the optical coupling efficiency entering the optical guide 10; ii. Maximize the optical power density (or evanescent field) at the top surface 23 of the light guide 10; iii. To minimize light loss in the light guide 10 (primarily caused by losses from the upper surface 23 and lower surface 25 of the light guide). It should be noted that light lost from the system via the top 34 of the light guide 10 and the rear wall 38 of the cavity 30, or light reaching the printed circuit board (PCB) 54 below the light source 12, is not included in the following analysis; and iv. Minimize the distance between the rear wall 38 of the trench injection optics 52 and the effective area of ​​the light guide 10 (i.e., the area where the system of the light guide 10 can detect touch on the upper surface 23 of the light guide 10).

[0133] Several factors (primarily related to the numerical aperture of the optical system and the refractive index of the light guide material) can be used to control or limit the range of light angles propagating within the light guide 10, thereby minimizing light loss.

[0134] The size of the light source 12 that emits light into the light guide 10 is a key factor, and several suitable light sources are available on the market that are ideal for this application. LED 12 is suitable due to its small size, fast response, and wavelength range. However, it should be understood that the principles described herein apply to any suitable light source 12, and the invention is not limited to the use of LED 12.

[0135] To ensure reasonable optical coupling efficiency of the light entering the light guide 10, the size of the light source 12 is typically chosen to be less than one-quarter of the thickness of the light guide. Furthermore, depending on the application, the light source 12 can be selected with a wide or narrow angle light distribution, correspondingly focusing or diffusing the light distribution. As previously stated, the objective here is to maximize the useful optical coupling entering the light guide 10, rather than simply maximizing all optical coupling (including light from angles that do not generate a signal but produce noise). This invention primarily relates to the use of a narrow-angle light source 12, but the described techniques are equally applicable to wide-angle light sources 12.

[0136] Increasing the distance between the light-emitting area 40 of LED 12 (i.e., the LED tip 40) and the refractive input surface 36 (see related description below for a fixed aperture width) narrows the range of vertical angles of light rays coupled (or “injected”) into the light guide 10 through the refractive input surface 36. Reference Figure 9 The distance between the LED tip 40 and the refractive input surface 36 is determined by z. LED This indicates that the angular range of the light rays coupled to the light guide 10 in the vertical or z-axis direction is determined by... This indicates that reducing the range of vertical angle rays... The optical coupling efficiency is reduced because light outside the vertical angle range is not coupled into the optical guide 10. However, reducing the vertical angle range... The benefit is that this reduces the likelihood of light being lost from the light guide 10 during its passage through the light guide 10, especially in the light guide 10 which has a curvature that defines the radius of a sharp bend in the vertical dimension.

[0137] Another way to limit the angular range of light coupled into the light guide 10 is by using an aperture 56. The aperture 56 can be defined using an absorption mask 58 applied to the top surface 32 and along the base 60 of the cavity 30. The material of the absorption mask 58 is chosen to absorb light within a wavelength range emitted by one or more associated light sources 12 disposed in the cavity 30. In embodiments of the invention, the light source 12 disposed in the cavity 30 may emit light in the near-infrared wavelength range, and the absorption mask 58 may accordingly absorb light in the near-infrared wavelength range. In some examples, the absorption mask 58 may be black paint. As discussed further below, one approach that can be taken is to mask only light within the "working" range for detection without masking other light, allowing such other light to be used for other purposes; for example, the masking may only work for infrared light while transmitting visible light.

[0138] It should be noted that, although in Figure 9 An absorption mask 58 is applied to the top surface 32 of the cavity 30 and along the base 60 of the cavity 30 to define an orifice 56. However, in other examples, the orifice 56 can be defined by applying the absorption mask 58 to other suitable surfaces. For example, as... Figure 10 As shown, an absorption mask 58 can be applied to the upper surface 23 of the light guide 10, rather than to the top surface 32 of the cavity 30, to define the upper edge of the aperture 56. The absorption mask 58 applied to the upper surface 23 of the light guide 10 extends far enough along the upper surface 23 to intercept light that has already passed through the top 34 of the cavity, but not far enough to intercept light that will undergo total internal reflection from the top surface 23. Figure 10 As shown, for this purpose, the absorption mask 58 extends along the upper surface 23 over the entire length Lc of the cavity 30 and terminates at a position off-center from the cavity 30 within the ramp section 50 of the light guide 10. This provides masking for the section of the first surface 23 located above the light source cavity 30 and extending beyond the cavity 30, limiting the range of angles at which light from the plurality of light sources 12 is reflected at the first surface 23 of the light guide 10. The use of in-mold labeling (IML) or secondary molding to obtain the light guide 10 with the absorption mask 58 (e.g., the absorption mask described) will then be explained.

[0139] The angles and two-dimensional (2D) shapes of one or more optical surfaces of the light guide input cavity wall 36 used for refracting (i.e. bending) light can also be configured to control or limit the range of light angles propagating within the light guide 10. For example, Figure 11 An example of a light source cavity 30 is shown having an optical coupling wall 36 shaped to define a symmetrical lens, such that the optical coupling wall 36 has a convex curvature. In other words, in this example, the front wall 36 of the light source cavity 30 is a lens. The symmetrical lens is tilted or angled relative to the vertical axis y, such that the optical coupling wall 36 is tilted inward toward the light source 12 from the lower surface 25 to the upper surface 23. The symmetrical lens shape is added to the input wall 36 at a sufficient angle to refract the input surface 36 so that this geometry can be manufactured by injection molding. Figure 11 The lens helps to reduce the angular range of light entering the light guide 10, and especially the vertical angular range. .

[0140] If the light guide is used as a top plate 10 in conjunction with a middle or intermediate layer 14 made of a material such as fluoropolymer (FEP) rather than air, Figure 1 In the system, it is preferable to further limit the angular range of the light rays entering the light guide 10 from the light source 12, especially the vertical angular range. The refractive index of FEP (i.e., 1.344) is higher than that of air (i.e., 1.0), meaning that the range of angles exceeding the critical angle at the boundary between the light guide or top plate 10 and the intermediate layer 14, and thus undergoing total internal reflection, decreases from approximately 48° (when the light guide 10 is made of acrylic and the intermediate layer 14 is air) to 26° (when the light guide 10 is made of acrylic and the intermediate layer 14 is FEP). This is in Figure 8a and Figure 8b As shown in the diagram, they indicate that they fall within the middle layer of air 14 ( Figure 8a ) and FEP middle layer 14 ( Figure 8b The system's critical angle range is the range of light rays within its angular range. Therefore, it should be understood that, compared to systems utilizing air as the middle layer 14, systems utilizing the FEP middle layer 14 (e.g., Figure 1 In systems that utilize light from one or more light sources into the light guide 10, the vertical angle range of the light rays is more restricted so that virtually all incident light falls within the angle range that allows total internal reflection at the boundary between the light guide 10 and the intermediate layer 14. Therefore, a more restricted angle range is required in systems that use, for example, an FEP instead of air as the intermediate layer 14.

[0141] It is also important to manage the light directed downwards from the light source towards the PCB 54 on which the light source 12 is mounted, because if the light is not absorbed, a small portion may reflect off the PCB surface and generate unwanted stray light in the system.

[0142] With these factors understood, Figure 12 shows how to increase the utilization of, for example Figure 6 The average ray angle in the light guide 10 of the grooved incident optics 52 shown is designed to maximize the evanescent field and, consequently, the touch sensitivity, but not to make the end of the angle range too close to the critical angle, which would result in high optical loss of the light guide 10.

[0143] refer to Figure 12a Curve 62 represents the light loss from the system (y-axis) for different tilt angles of the optical coupling surface (x-axis). (See reference...) Figure 12b and Figure 12c The tilt angle is defined as the tilt angle of the optical coupling surface relative to the vertical axis y. When the optical coupling surface extends vertically, as... Figure 12b As shown, the tilt angle is defined as 0°. When the optical coupling surface is tilted to extend at an angle relative to the vertical direction, the tilt angle is non-zero, as shown below. Figure 12c As shown, the optical coupling surface of the photoguide has a 50° tilt angle. It should be noted that... Figure 12c In the middle, the light source 12 is installed such that the light emitted from the light source 12 is mainly tilted towards the front wall 36 of the recess 30.

[0144] like Figure 12a As shown, the light lost from the upper and lower surfaces of the light guide at a tilt angle of 50° ( Figure 12c The lower angle is at 0° of inclination ( Figure 12bThe angle of incidence is greater at the bottom. This is because increasing the tilt angle of the optical coupling surface from 0° to 50° reduces the angle of incidence of light from the light source reaching the optical coupling surface, where the angle of incidence is defined as the angle between the light ray and the surface normal of the optical coupling surface. Compared to a device using a 0° tilt angle, in a device using a 50° tilt angle, the deflection of the light ray due to refraction when passing through the optical coupling surface is increased, thus reducing the angle of incidence of the light ray relative to the surface normals at the upper and lower surfaces of the light guide. In this way, the possibility that at least some light ray falls below the critical angle and is lost from the system increases.

[0145] Curve 64 represents the amount of light coupled to the light guide 10 (y-axis) in microwatts (μW) for different tilt angles (x-axis), and shows that the optical power coupled to the plate 10 increases with the increase of the tilt angle.

[0146] Curve 66 represents the power density at the upper surface 23 of the light guide 10 for different tilt angles. Curve 66 shows that increasing the tilt angle increases the power density at the upper surface. The higher power density at the upper surface of the light guide indicates a stronger evanescent field, which in turn allows for better touch sensitivity in such systems utilizing suppressed total internal reflection in touch detection mechanisms.

[0147] Understanding the above text about Figures 12a to 12c The description of how the parameters change with the tilt angle allows for the selection of an appropriate tilt angle for the optical coupling surface 36 in order to balance the advantages of a stronger evanescent field and better contact sensitivity at higher tilt angles with the disadvantage of increased system losses at higher tilt angles.

[0148] refer to Figures 13a to 13c In another embodiment, touch sensitivity can be further increased not only by angulating the trench wall corners (i.e., the tilt angle of the light coupling surface 36), but also by rotating the LED orientation in the yz plane, although this does make manufacturing more complex. (See reference) Figure 13c The light source 12 emits light symmetrically around its central axis C and is mounted at an angle to the plane of the top plate 10, such that its central axis C is tilted towards the first surface 23 of the top plate 10. Therefore, the light emitted from the light source is primarily tilted towards the first surface 23. Furthermore, the light source 12 is mounted such that its central axis C is perpendicular to the front wall 36 of the light source cavity 30. It should be noted that in other examples, the light source 12 may be mounted such that its central axis C is slightly deviated from the axis perpendicular to the front wall 36 of the light source cavity 30.

[0149] Reference Figure 14 In another embodiment, an extruded section 68 is added to the lower leading edge of the wedge 50 or groove to help "capture" any unwanted stray light from the bottom edge 70, avoiding sharp edges and providing support for the light guide 10. The extruded section 68 defines a linear protrusion extending away from the first surface 23 on the second surface 25 of the light guide 10. Figure 14 As shown, the linear extension of the linear protrusion 68 is substantially parallel to the linear extension of the light source cavity 30. In this example, the linear protrusion 68 has a rectangular cross-section perpendicular to its linear range. In other embodiments, the shape of the protrusion 68 can vary. For example, the linear protrusion 68 may have a fan-shaped or similar cross-section perpendicular to its linear range. It should be understood that... Figure 14 The ramp of the optical guide 10 is linear, meaning the distance between the first surface 23 and the second surface 25 of the optical guide 10 decreases linearly in the ramp section 50 of this example. (Refer to...) Figure 15 In another embodiment, the ramp of the light guide 10 is not linear, but is reduced using a faceted or other continuous nonlinear function (e.g., curved, asymmetric, spline-curved) or a combination of appropriate functions. In other words, in Figure 15 In one embodiment, the distance between the first surface 23 and the second surface 25 of the optical guide 10 decreases non-linearly in the ramp section 50.

[0150] The key requirements or techniques for optimizing the design geometry of trench-in-the-plane optical devices are as follows: i. A defined optical power density (or evanescent field) target is achieved across the top surface 23 of the optical guide 10; ii. Achieve a defined uniformity target for optical power density (typically having μW / mm²) across the entire effective area of ​​the touch surface 23 of the light guide 10. 2 (Units). As previously mentioned, the effective area of ​​the light guide 10 is the area on the touch surface 23 that the system can detect a touch. For example, for a touchscreen, the effective area can be a wide, roughly rectangular area. For a finger sliding groove, i.e., a portion of the upper surface 23 of the light guide that includes one or more grooves serving as a finger guide, the effective area can be an elongated, narrow region 72, such as... Figure 16 As shown. A uniform optical power density within the effective region of the light guide 10 is beneficial because it improves the uniformity of touch response over the effective region; iii. Achieve the uniformity target of light power density over the effective area of ​​the touch surface 23 using a minimum amount of light source 12; iv. To achieve the uniformity target of optical power density across the effective area of ​​the touch surface 23 at the shortest possible distance from one or more light sources 12; v. Minimize the distance between the back surface 38 of the trench injection optics 52 (i.e., the rear surface 38 of the light source cavity 30) and the effective area of ​​the light guide 10.

[0151] The optical geometry of the grooved injection optical device 52 is beneficial to improving the light distribution across the upper light guide surface 23.

[0152] In using such Figure 5 or Figure 6 In the light guide 10 of the grooved injection optical device 52 shown, the horizontal light distribution on the top surface 23 of the 2D curved geometry of the light guide 10 mainly originates from the LED light distribution and the layout of the light source array, that is, the arrangement of the light source 12 disposed in the cavity 30 of the grooved injection optical device 52.

[0153] The light source array layout refers to the spacing and orientation of the light sources 12 within the light source cavity 30. The trajectory of the LED output can also be altered by adjusting the geometry of the light source cavity 30, particularly the shape of the light coupling surface 36. (Refer to...) Figure 17a An embodiment of a trench-injection optics device 52 having a flat planar optical coupling surface 36 is shown. (See reference...) Figure 17b An embodiment of a grooved incident optics device 52 with a curved optical coupling surface 36 is shown. Specifically, Figure 17a In one embodiment, the optical coupling surface 36 is bent relative to the x-direction to define the bend in the xz plane.

[0154] Generally, the farther the LED array is from the touch geometry, the better the uniformity of light from the light guide 10 of the light source 12 will be. In other words, the uniformity of light in the light guide 10 improves with increasing distance from the light source 12 of the trench-injection optics 52, so that the uniformity of light in the effective area improves with increasing distance between the effective area and the light source 12.

[0155] However, in many applications, for aesthetic reasons or due to space considerations / constraints in the final touchscreen product, it is advantageous for the effective area to be closer, and in some cases as close as possible, to the light source 12 of the light guide 10. Ideally, the separation of the array from the geometry should be minimized, and the spacing between adjacent light sources 12 should be maximized to satisfy uniformity objectives.

[0156] In this embodiment, masking is used, i.e., an absorbing mask layer 58 or element is used to absorb light to absorb light reaching the upper surface 23 or lower surface 25 of the light guide 10. In other words, the area of ​​the first surface or upper surface 23 and / or the second surface or lower surface 25 can be masked to prevent total internal reflection of light from the plurality of light sources 12 in the trench or recess 36 within the light guide 10.

[0157] Mask layers 58 or elements can be arranged to control, for example, the position of the upper surface 23, where light is allowed to be reflected from the upper surface 23. This, in turn, allows light to be emitted at an angle from the light source 12 so that the optical fibers do not undergo total internal reflection from the upper surface 23 but are instead absorbed, thereby controlling light leakage from the upper surface 23 of the light guide 10. Since the intensity distribution of the light source can vary with angle in the xz plane, the mask edges can also vary with angle in the xz plane accordingly.

[0158] In embodiments where lensing is not used to couple light emitted from light source 12 into light guide 10, the method of the trench-in optics 52 described above allows for flexibility in the placement of the light source components. This is because, in this case, the precise position and orientation of each light source 12 within the cavity 30 is less critical compared to the case where light from light source 12 propagates through a lens before entering light guide 10.

[0159] Therefore, when lensing is not used, the impact of variations in the placement of light source components (e.g., due to assembly tolerances) on the optical performance (e.g., irradiance distribution or optical efficiency) of the array of trench-incident optics 52 can be reduced.

[0160] A method for directing light into a light guide 10 using a pocket-injection optics (PIO) 74 will now be described.

[0161] For example, in Figure 7 Figure 18 Figure 19 and Figure 20 An example of a pocket-type optics 74 is shown.

[0162] The pocket-type optics 74 employs a fully 3D geometry to control the horizontal and vertical angular distribution of light from the light source 12. To this end, the 3D shape of the light source cavity 30, where the light source 12 is located, is designed to control the angular distribution of light coupled to and traveling within the light guide 10. This optical design of the pocket-type optics 74 controls the light distribution in the vertical direction (y-axis) in a manner similar to that of the trench-type optics 52, and provides additional control over the intensity distribution in the horizontal direction (x-axis). This can be used to address differences in the vertical intensity distribution with angle and to influence the convergence or divergence of light distribution on the surface 23 of the effective region of the light guide 10.

[0163] First, consider the vertical profile of the pocket-type optics 74 in the yz plane. The key requirements for optimizing the design geometry of the pocket-type optics in the vertical plane are the same as those for the groove-type optics 52. For clarity and completeness, these requirements will be repeated below: i. Maximize the optical coupling efficiency entering the optical guide 10; ii. Maximize the optical power density (or evanescent field) at the top surface 23 of the light guide 10; iii. To minimize light loss in the light guide 10 (primarily caused by losses from the upper surface 23 and lower surface 25 of the light guide). It should be noted that light lost from the system via the top 34 of the light guide 10 and the rear wall 38 of the cavity 30, or light reaching the printed circuit board (PCB) 54 below the light source 12, is not included in the following analysis; and iv. Minimize the distance between the rear wall 38 of the trench injection optics 52 and the effective area of ​​the light guide 10 (i.e., the area where the system of the light guide 10 can detect touch on the upper surface 23 of the light guide 10).

[0164] All the factors discussed above for the grooved-in-light optics 52 (primarily related to the numerical aperture of the optical system and the refractive index of the light guide material) also apply to the pocket-in-light optics 74, and will not be repeated for the sake of brevity. Here, only the main additional factors that can be used to control or limit the range of perpendicular light angles propagating within the light guide 10 are highlighted, thereby optimizing the aforementioned key requirements.

[0165] The angle, shape, and taper of the refractive input surface 36 (also known as the optical coupling surface 36 of the light source cavity 30) can be used to control the range of perpendicular angles of light propagating within the light guide 10. As discussed with respect to the trench-type incident optics 52, the depth of the evanescent field, i.e., the penetration of the evanescent field, increases as the angle of incidence of light undergoing total internal reflection at the boundary between two regions of different refractive index materials approaches the critical angle. Therefore, configuring the incident optics 52, 73 such that light propagates in the light guide 10 at an angle as close as possible to the critical angle increases the depth of the evanescent field, which in turn improves the touch sensitivity of such a system utilizing suppressed total internal reflection during touch detection.

[0166] Such as about Figure 12b and Figure 12c As discussed, by ensuring that light from the light source 12 within the light guide 10 propagates as close to the critical angle as possible, increasing the angle of the optical coupling surface 36 relative to the vertical (y) axis (i.e., the slope or tilt angle of the refractive input surface 36) can be used to increase the evanescent field at the upper surface 23 of the light guide 10. Similarly, the inclusion of a ramp section 50 in the light guide 10 (between the thicker section 46 and the thinner section 48 comprising the light source cavity 30) can be used to increase the evanescent field at the upper surface 23 of the light guide 10, and the taper of the ramp section 50, or some combination thereof, can also be adjusted. However, in the pocket-type optics 74, these parameters can be varied in the rearwardly extending side of the optical coupling surface 36 toward the rear of the light source cavity 30, for example, to compensate for variations in the light source intensity distribution.

[0167] Figure 18a It shows that it can be combined, for example, with, such as Figure 1 An embodiment of the pocket-type optics 74 in the top plate 10 of the touch detection system.

[0168] and Figure 5 and Figure 6 The arrangement of the grooved incident optical device 52 is similar. Figure 18aThe pocket-type optics 74 includes a cavity or recess 30 in the lower side of the light guide defined by the top plate 10. The cavity 30 has an optical coupling surface 36, which serves as a refractive input surface for coupling light from the light source 12 disposed in the cavity 30 into the body of the top plate 10.

[0169] exist Figure 18a In this embodiment, the refractive input surface 36 defines a curved path between a first end 76 and a second end 78, and defines a curved length between the first end 76 and the second end 78. The refractive input surface 36 extends from the first end 76 to the second end 78 around the light source 12 so as to partially surround the light source 12. The front side of the light source 12 defines a light-emitting region 40 of the light source, which faces the refractive input surface 36 of the cavity 30. In use, light is emitted from the light-emitting region 40 of the light source 12 and passes through the refractive input surface 36 into the body of the top plate 10, where the light undergoes total internal reflection.

[0170] Still refer to Figure 18a The height of the refractive input surface 36, i.e., the distance between the upper edge 80 and the lower edge 82 of the refractive input surface 36, varies along the curved path between the first end 76 and the second end 78 of the refractive input surface 36. Specifically, in Figure 18a In one embodiment, the height of the refractive input surface 36 increases from a minimum height at the first end 76 and the second end 78 to a maximum height at the center position between the first end 76 and the second end 78 along the length of the refractive input surface 36.

[0171] exist Figure 18a In this arrangement, the tilt angle or slope of the refractive input surface 36 also varies along the curved path between the first end 76 and the second end 78 of the refractive input surface 36. Specifically, the tilt angle of the refractive input surface 36 increases from the first end 76 along the curved length of the refractive input surface 36 to the center position. Similarly, the refractive input surface 36 increases from the second end 78 along the curved length of the refractive input surface 36 to the center position.

[0172] In other examples, the height and tilt angle of the refractive input surface 36, as well as the variation in the height and tilt angle of the refractive input surface 36 between the first end 76 and the second end 78, may differ from those of other examples. Figure 18a The arrangement of the refractive input surface 36. In some examples, the height and tilt angle of the refractive input surface 36 may be constant over the entire bending length of the refractive input surface 36. For example, the parameters defining the shape and arrangement of the refractive input surface 36 may vary depending on the parameters of the associated light source 12.

[0173] Figure 18b Showing the integration in the top plate 10 Figure 18a The pocket-type optics 74 has a sloping section 50 between the thicker section 46 of the combined light source cavity 30 and the thinner section 48 of the top plate 10. Figure 18b In the example, the lower surface 25 of the top plate 10 surrounding the light source cavity 30 slopes upward toward the upper surface 23 of the top plate 10 from the thicker section 46 to the thinner section 48, defining a ramp section 50 of the top plate 10. Figure 18b In this embodiment, the slope of the lower surface 25 near the center of the bending length of the refractive input surface 36 is greater than the slope at the first end 76 and the second end 78 of the refractive input surface 36. In this way, the taper of the top plate 10 is greater in front of the light source 12, especially at the light-emitting area 40 of the light source 12, than at the side of the light source 12.

[0174] Now back Figure 7 The pocket-type optics 74 of this embodiment includes a light source cavity or recess 30 having a plurality of refractive input surfaces 36. The pocket-type geometry has the same basic control over the vertical light distribution as the groove-type optics 52, but with additional control over the horizontal intensity distribution. This can be used to address differences in the vertical intensity distribution with angle, as well as the convergence or divergence of light distribution on the surface of the effective area where a touch can be detected. It should be recognized that different touch geometries may require pocket-type optics 74 with narrow or wide light distributions.

[0175] Figure 41a A pocket-type optics 74 is shown that provides a narrow light distribution. Figure 41a The pocket-type optics 74 includes a single refractive input surface 36 with a convex curvature in the xz plane. Light emitted from the light source 12 (in [the xz plane]) passes through the refractive input surface 36. Figure 41a The middle part is represented by multiple light rays 79. For clarity, in Figure 41a The horizontal distribution of the light (only two rays are marked in the image) is shaped by the refractive input surface 36 to provide a narrow distribution of light in the light guide 10. This narrow light distribution is suitable, for example, in elongated, narrow effective regions, such as those used in applications such as... Figure 16 The effective area of ​​slider 72 shown.

[0176] Figure 41b A pocket-type optics 74 is shown, which provides a wide light distribution. Figure 41b The pocket-type optics 74 has a similar Figure 7 The similar configuration shown has three refractive input surfaces 36, which are used to filter light from the light source 12 (by... Figure 41b The multiple rays 79 (represented by only two rays for clarity) are horizontally shaped to provide a broad light distribution in the light guide 10. This broad light distribution can be suitable, for example, for applications such as... Figure 28 The turntable device shown.

[0177] Figure 7Examples include a first side refractive input surface 84, a second side refractive input surface 86, and a central refractive input surface 88. The light source 12 is disposed in the recess 30 such that light is coupled into the body of the top plate 10 through the refractive input surface 36. The light source cavity 30 is disposed in a relatively thick first section 46 of the light guide 10. A ramp section or wedge 50 of the light guide 10 connects the first section 46 to a thinner (or narrower) second section 48 of the light guide 10, and is located between the recess 30 and the narrower section 48. In the narrower section 48, the distance between the first surface 23 and the second surface 25 is substantially constant, but smaller than the distance between the first surface 23 and the second surface 25 at the recess 30.

[0178] The first side refractive input surface 84 extends along a curved path between its first end 90 and second end 92. When the light source 12 is used in the cavity 30, the first end 90 of the first side refractive input surface 84 is positioned on the first side 94 of the light source 12. The central refractive input surface 88 extends along a curved path between its first end 96 and second end 98, and combines with the first side refractive input surface 84 and the second side refractive input surface 86. The second side refractive input surface 86 extends along a curved path between its first end 100 and second end 102. When the light source 12 is used in the cavity 30, the second end 102 of the second side refractive input surface 86 is positioned on the second side 104 of the light source 12. The central refractive input surface 88 is located directly in front of the front of the light source 12, such that the light-emitting area 40 of the light source 12 faces the central refractive input surface 88.

[0179] In this example, two side refractive surfaces 84 and 86 are symmetrically arranged around and adjacent to the central refractive input surface 88. (The sentence appears to be incomplete and requires further context.) Figure 7 The lieutenant general understands that in this example, the central refractive input surface 88 has a different curvature than the side refractive surfaces 84 and 86.

[0180] In this manner, light emitted from the light source 12 is coupled into the body of the top plate 10 via the central refractive input surface 88 in a direction generally in front of the light source 12, and light emitted from the light source 12 is coupled into the top plate 10 via the first side refractive input surface 84 and the second side refractive input surface 86 in a generally lateral direction. The arrangement of the side refractive input surfaces 84, 86 or the wings extending from the central refractive input surface 88 provides better control over the intensity distribution of light from the light source 12 in the light guide 10.

[0181] Refraction input surfaces 84, 86, 88, for example, with Figure 12c and Figure 15The light guide 10 is inclined inward toward the light source 12 from the lower surface 25 to the upper surface 23. In other words, the walls of the refractive input surfaces each form an angle with the plane of the top plate 10, such that the refractive input surfaces 84, 86, 88 form an obtuse angle with the second surface 25 of the top plate 10 within the top plate 10.

[0182] Such as about Figure 12c The tilted input surfaces 84, 86, and 88 discussed herein allow control over the range of vertical angles of light propagating in the light guide 10, and can in particular be used to push the angle of light toward a critical angle to improve evanescent field penetration at the upper surface 23 of the light guide 10 and improve touch sensitivity.

[0183] The curvature along the lengths of the refractive input surfaces 84, 86, and 88 provides control over the horizontal diffusion of light in the xz plane of the light guide 10. Different geometries, particularly the different horizontal curvatures of the first side refractive input surface 84, the second side refractive input surface 86, and the central refractive input surface 88 in the xz plane, allow for enhanced control over the horizontal distribution of light from the light source 12 within the light guide 10.

[0184] exist Figure 7 and Figure 20 In the example, the curvature of the central refractive input surface 88 defines an approximately elliptical shape in the horizontal or xz plane of the light guide 10. Specifically, the central refractive input surface 88 defines a semi-ellipse in the horizontal plane, wherein the horizontal distance in the x-axis between the first end 96 and the second end 98 of the central refractive input surface 88 defines the minor axis of the ellipse. The central refractive input surface 88 is configured to diffuse light emitted from the light source 12 and incident on the central refractive input surface 88 in the horizontal (xz) plane of the light guide.

[0185] The curvature of the first refractive input surface 84 and the second refractive input surface 86 in the horizontal plane is selected so that the light rays are redirected to reach these appropriate portions. Figure 7 and Figure 20 In the embodiments, the first refractive input surface 84 and the second refractive input surface 86 are configured to restrict the horizontal diffusion of light reaching these portions in the light guide 10, such as Figure 20 As shown.

[0186] It should be noted that in other embodiments, the curvature of the refractive input surfaces 84, 86, 88 may vary. For example, one or more of the refractive input surfaces 84, 86, 88 may have a conical curvature or a defined spline curve. Figure 19 The top plate 10 is shown to incorporate two pocket-type optics 74, which have the same characteristics as... Figure 7The optical device has a similar shape, and it is shown that an absorption mask layer 58 can be disposed on the upper surface 23 of the light guide 10 to prevent stray light from the light source 12 from escaping from the light guide 10, similar to... Figure 3 , Figure 4 and Figure 10 Mask 58. As mentioned before, such as Figure 19 The masking shown is used to control light leakage from the light guide 10, and specifically blocks light rays that fall below the critical angle in the masked area and therefore would directly pass through and exit the upper surface 23 of the light guide 10. Figure 19 In this embodiment, the leading edge 106 of the mask 58 terminates before the first total internal reflection ray reaches the upper surface 23 of the light guide and defines the starting point of the effective region of the light guide 10 in which a touch on the upper surface 23 of the light guide 10 can be detected. In other words, essentially all light from the light source 12 that reaches the masked area of ​​the upper surface 23 of the light guide 10 falls below the critical angle and would escape from the light guide 10 without the mask 58. Therefore, the mask 58 does not absorb the "useful" light that would undergo total internal reflection at the upper surface 23 without the mask 58. As previously mentioned, one possibility is to mask only the light within the "working" range for detection, without masking other light, allowing other light to be used for other purposes; for example, the masking could operate only on infrared light, while visible light is transmitted.

[0187] exist Figure 19 In the example, mask 58 is shown extending over both pocket-in optics 74. It should be understood that in some examples, mask 58 may be disposed over all pocket-in optics 74 of the light guide 10, or only over a portion of the pocket-in optics 74 of the light guide 10. Furthermore, in some examples, mask may extend only partially over some or all of the pocket-in optics 74 of the light guide 10. The key requirements or techniques for optimizing the design geometry of pocket-in optics in the horizontal (xz) plane are the same as those discussed regarding the trench-in optics 52, as follows: i. A defined optical power density (or evanescent field) target is achieved across the top surface 23 of the optical guide 10; ii. Implement the entire effective area across touch surface 23 (which can be a wide rectangular area for a screen, but a long, narrow area for a finger slider recess, see [reference]). Figure 16 Optical power density (μW / mm) 2 The uniformity target is defined by ) iii. Achieve the uniformity objective using the minimum amount of source 12; iv. Achieve the uniformity target at the shortest possible distance from one or more light sources 12; v. Minimize the distance between the back surface 38 of the pocket-type optics 74 and the effective area.

[0188] However, the horizontal profile control in the 3D geometry of the pocket-type optics 74 allows for direct control of the horizontal intensity distribution from the light source 12 using key control parameters.

[0189] The pocket-type optics 74 uses a single or multiple refractive input surface optical profiles to diffuse or collimate light distribution to suit the desired application. Figure 20 Show Figure 7 , Figure 19 and Figure 20 The geometry of the multiple refractive input surfaces has three distinct parts (first side refractive input surface 84, second side refractive input surface 86, and central refractive input surface 88), which have different geometric profiles and are combined in the top plate 10 of the touch screen that requires a wide light distribution.

[0190] Figure 21a Show Figure 20 The pocket-type optics 74 are shown, and light from the light source 12 propagates in the light guide 10 to provide a wide intensity distribution in the horizontal (xz) plane in the effective area of ​​the light guide 10.

[0191] Figure 21b The image shows the refractive input surfaces 84, 86, 88 before passing through the pocket-type optics 74. Figure 21a The arrangement of the light source 12 results in a narrow horizontal intensity distribution of output. Figure 21c This diagram illustrates the intensity distribution of light from the light source 12 within the light guide 10, after passing through the refractive input surfaces 84, 86, and 88 of the pocket-type optics 74, within the effective region of the light guide 10, located in a thinner region 48. (See diagram from...) Figure 21c The lieutenant general understands that the refractive input surfaces 84, 86, and 88 broaden the horizontal intensity distribution of light from the light source 12, in order to... Figure 21c The horizontal plane shown provides a wide intensity distribution. Therefore, Figure 21c Shown by using Figure 21a The pocket-type optics 74 produces a wide intensity distribution in the horizontal (xz) plane of the light guide 10.

[0192] It should be understood that other geometries can be used for one or more refractive input surfaces of the pocket-type optics 74 to provide different horizontal light distributions as needed or desired to match the touch geometry for a specific touchscreen application.

[0193] The shape of the refractive input walls (i.e., one or more refractive input surfaces) of the pocket-type optics 74 advantageously provides direct control over the xz intensity distribution in the light guide 10, and enables the array of pocket-type optics 74 to provide improved uniformity, especially when close to the light source 12. When compared to an equivalent array of trench-type optics 52, the array of pocket-type optics 74, which provides predetermined horizontal and vertical shaping of light from its associated light source 12, offers improved uniformity and control over the horizontal intensity distribution. Generally, the improved angular light distribution fineness achieved using the pocket-type optics 74 allows for the same uniformity to be achieved with fewer light sources 12.

[0194] Another advantage of the pocket-type approach is that the available optical power from the light source 12 can be used more efficiently (and with less electrical power consumption) because the light is distributed to where it is needed, i.e., the effective area of ​​the light guide 10, and is not wasted in areas of the light guide 10 where it is not needed.

[0195] Due to its compact size, the pocket-type optics 74 also allows for greater flexibility in positioning the light source 12, which provides more space for other optical or mechanical features or electrical components or assemblies.

[0196] Furthermore, if a light source 12 fails in the array of pocket-in-the-light optics 74, the combined light distribution is less affected compared to the array of trench-in-the-light optics 52, because all pocket-in-the-light optics 74 can have the same light distribution. Similarly, any inherent differences in LEDs within the array of pocket-in-the-light optics 74 are less significant. For example, if the optical output of one light source 12 differs significantly from the optical output of an adjacent light source 12 in the array of pocket-in-the-light optics 74, the impact on the light distribution can be smaller when compared to a similar scenario in a trench-in-the-light optics 52 with an array of light sources 12.

[0197] In some cases, it may be desirable to provide a combination of groove-in-light optics 52 and pocket-in-light optics 74 in a single device. For example, separate “effective areas” that mask each other can be provided for the device, effectively creating multiple devices or sub-devices, and different optics types can be used for each device to suit the overall function of the relevant effective area. For other device types, it may be desirable to use both groove-in-light optics 52 and pocket-in-light optics 74 to provide efficient light transmission throughout the entire device, which is particularly applicable when the shape of the effective area is complex.

[0198] Those skilled in the art will understand that the placement of the light source 12 relative to one or more refractive input surfaces 36, 84, 86, 88 will affect the shaping provided by one or more refractive input surfaces 36, 84, 86, 88 of the pocket-type optics 74, and this should therefore be taken into account when positioning the light source 12 within the light source cavity 30. In the field of optical components, the use of the trench-type or pocket-type optics 52 or 74 structures discussed above, when used with surface-mount (SMD) type light sources such as LEDs, offers specific key advantages. The smaller the light source package, the smaller the volume of the light source cavity 30 required in the underside of the light guide 10, and the less intrusive the light source 12 and associated cavity 30 are to other functional elements in the assembly. However, it has been found that the light distribution from some LEDs 12 is not ideal and may lead to lower efficiency and uniformity.

[0199] Applications of light sources 12 (particularly LEDs) for touchscreens can generally be divided into two groups related to their angular distribution of light intensity. LEDs 12 with a wide angular range in the horizontal direction and a narrow angular range in the vertical direction are best suited for applications with a wide area to be illuminated, such as screen, dome, or turntable geometries. In these cases, the intensity distribution should have “soft” edges so that any overlap with adjacent pocket-type optics 74 produces a uniform irradiance distribution.

[0200] LED 12 with narrow angular ranges in both the horizontal and vertical directions is best suited for applications with narrow areas to be illuminated, such as for slider and trigger geometries. In these cases, a “hard edge” intensity distribution of LED 12 is acceptable because the geometry is typically illuminated by at least one pocket-type optic 74 at each end of the geometry, and there is no need for overlapping light distributions of adjacent LEDs 12.

[0201] It should be noted that the forward direction of the intensity distribution is along the z-axis (if using...). Figure 5 The coordinate system is aligned (within the coordinate system), and the intensity distribution is symmetric about the yz and xz planes.

[0202] For example, SMD LEDs currently available on the market that are suitable for use in pocket-sized optics are typically divided into two groups.

[0203] Reference Figure 22a Wide-angle SMD LEDs have a wide "bat wing" shaped intensity distribution in both the horizontal (xz) and vertical (xy) planes.

[0204] Figure 22aThe wide, gently sloping "soft edge" of the horizontal profile provides a good starting point for achieving reasonable uniformity in the horizontal plane, and can be further improved when combined with a pocket-type optics 74 having an appropriate horizontal lens profile (i.e., appropriate geometry in the xz plane for proper horizontal beam shaping) on ​​the refractive input surfaces 36, 84, 86, 88.

[0205] However, in Figure 22a Even with a suitable horizontal profile having one or more refractive input surfaces 36, 84, 86, 88, the wide distribution in the vertical profile cannot be well matched with the numerical aperture of the pocket-injection optics 74. This results in poor optical coupling efficiency entering the light guide 10, which incorporates the pocket-injection optics 74 and the LED light source 12.

[0206] Reference Figure 22b and Figure 23b Narrow-angle SMD LEDs have a narrow intensity distribution in both the horizontal (xz) and vertical (xy) planes. (See reference...) Figure 23a This type of LED uses a circular lens that focuses a portion of the light from the LED chip. Light missed from this focusing effect produces a "halo" of large-angle rays around a central narrow cone. By appropriately adjusting the distance of LED 12 from one or more refractive input surfaces 36, 84, 86, 88, the narrow cone rays from LED 12 can be matched to the numerical aperture of the pocket-entry optics 74 in the vertical plane. In the horizontal plane, the narrow cone rays can be diffused using a conical profile on the pocket-entry optics 74, which has been shown to give the desired light distribution in the light guide 10. However, the halo emitted through the sidewalls 108 of LED 12 results in poor optical coupling efficiency and causes stray light management problems in the assembly.

[0207] Considering the above, Figure 24a The design of a superelliptical LED package (HE-LED) 109 is shown. Package 109 can be used, for example, in conjunction with a pocket-type optics geometry that does not have optical power, such that the refractive input surface 36 does not have a lensing effect on light received from the light source 12, referred to as 0%-PIO. Package 109 can also be used in conjunction with other incident optical geometry (e.g., a geometry with optical power) such that light from the light source 12 enters the front wall 36 through which the light guide 10 passes, providing a lensing effect. For example, the front wall 36 can be configured to provide a lensing effect in the horizontal dimension, the vertical dimension, or both, to provide an improvement in the horizontal and / or vertical light distribution in the light guide 10 as needed.

[0208] Figure 24aThe packaged light-emitting diode 109 includes a bare LED die or chip 110 and a lens 112. The lens 112 is in the form of a cylindrical lens, which significantly improves the optical coupling efficiency between the light source 12 and the light guide 10, as well as the uniformity of light in the light guide 10. The light emitted through the cylindrical lens 112 has a narrow-angle distribution along a first axis and a wide-angle distribution along a second axis orthogonal to the first axis. In this way, Figure 24a The packaged LED 109 is ideally suited for touchscreen applications.

[0209] like Figure 24a As shown, in this example, the cylindrical lens 112 is formed as a substantially oblate ellipsoidal lens 112a truncated within a body having two first truncated portions 114 and one second truncated portion 116. The two first truncated portions 114 are perpendicular to the axis A of the oblate ellipsoid and equidistant from its longest radius. The second truncated portion 116 is parallel to the axis A of the oblate ellipsoid and perpendicular to the two first truncated portions 114. In other examples, the shape of the lens 112 may be similar to... Figure 24a The difference is, for example, that it is a defined oblate spheroid.

[0210] Figure 24a The LED chip 110 of the package 109 is positioned on its support substrate in relation to... Figure 23a The arrangement of LED chips 110 (in) Figure 24a (Not visible in the middle) at the same location on its substantially identical support substrate 118, and Figure 24a Lens 112a is directly mounted on the light-emitting surface of the bare die of the light-emitting diode. It should be understood that... Figure 24a The bare die of the light-emitting diode in package 109 is close to the second cut-off portion 116.

[0211] Figure 42a Another example of the HE-LED package 109 is shown. (e.g.) Figure 24a Example, Figure 42a The package 109 includes a bare LED die or chip (not shown) and a cylindrical lens 112. Figure 42a The LED chip in package 109 is positioned on its support substrate 118 in relation to Figure 23a The LED chips 110 are arranged in the same position on their supporting substrate 118. However, in Figure 42aIn the example, the cylindrical lens 112 takes the form of a truncated aspherical lens 112b. Specifically, the cylindrical lens 112b is formed as an aspherical lens within a modified ellipsoid having two first truncated portions 114 and one second truncated portion 116. The two first truncated portions 114 are perpendicular to the axis A of the modified ellipsoid and are equidistant from the longest radius of the modified ellipsoid. The first two truncated portions 114 are parallel to two axes of the ellipsoid and are parallel to each other. The second truncated portion 116 is parallel to the other axis A of the ellipsoid and perpendicular to the two first truncated portions 114. Figure 42a The lens geometry is achieved by sweeping a horizontal spline path across a vertical axis. variable It is generated from the radius. For example, from... Figure 42a It can be understood that lens 112b has greater curvature at the center (i.e., at the short first radius of curvature R1) and less curvature on the sides and toward the sides (i.e., at the long second radius of curvature R2). In this example, because the lens surface is farther away on the sides than at the center, less power is needed on average to roughly collimate the diverging light.

[0212] Figure 24b and Figure 42b Showing from Figure 24a and Figure 42a The intensity distribution of light in the horizontal (xz) and vertical (xy) planes of the package 109. From Figure 24b and Figure 42b Understandable. Figure 42a The package 109 using the aspherical lens 112b provides a higher performance than... Figure 24a The package 109 using the flattened ellipsoidal lens 112a has a narrower horizontal light distribution. Therefore, it should be understood that the choice of lens 112 can affect the angular distribution of light from the package 109.

[0213] Figure 25a and Figure 25b Show Figure 24a HE-LED package 109 and similar Figure 18a The combination of the geometry of the pocket-type optics 74. Figure 25c The HE-LED lens 112 is shown to capture the full wavelength of light from the LED die, which forms an arc of approximately 180° with the die in the horizontal plane, thus improving optical coupling efficiency. Figure 25d The image shows the intensity distribution of light from the light source 12 within the light guide 10 in the effective region 48 of the thinner region of the light guide 10. This more efficient capture of available light from the LED die results in less stray light being suppressed and processed in the system.

[0214] Figure 26 Showing with, for example Figure 7Compared to the previous arrangement, the "soft edge" and smoother HE-LED intensity distribution significantly reduced the distance from the pocket-type optics 74 in the forward or z-direction to achieve the 10% uniformity target (by...). Figure 26 (Indicated by line 119 in the diagram). In other words, using the HE-LED package 109 allows for a more uniform light intensity distribution at the pocket-type optics 74, closer to the light guide 10. Figure 7 In the arrangement of the unused HE-LED package 109, the intensity distribution is discontinuous, and a greater length is required to traverse the light guide 10 before achieving the same light intensity uniformity.

[0215] Figure 27 This demonstrates how the optical power of an HE-LED can be scalable by increasing the LED die size along the horizontal axis without adversely affecting the 109 angular distribution characteristics of the HE-LED.

[0216] It has been shown how light can be transmitted into the light guide 10, for example... Figure 1 The top plate 10 of the device is described below. Next, the management of light in the light guide 10 will be discussed. In particular, how to skillfully manage light in the light guide 10 to control the locations that light can or cannot reach will be discussed.

[0217] One method for managing light in the light guide 10 is to use a distribution pattern of light incident "dots" to create an effective luminous area, or active area, for the touchscreen.

[0218] Another approach is to use light-absorbing features (such as paint, overmolding, in-mold labeling (IML)) to limit the angular range of light rays or isolate optical geometry and control those ineffective areas, i.e., to provide optical ineffective areas.

[0219] Considering the first approach, an "effective region" can be created by placing one or more pocket-type optics 74 in a pattern around a given light guide geometry. In different embodiments, the pocket-type optics 74 can be combined in different patterns or array configurations (e.g., squares, rectangles, circles, and many other variations) to efficiently and uniformly distribute light across the effective region. For example, refer to... Figure 16 A first effective area 120 can be created using a circular array of wide-angle pocket-type optics 74a to illuminate the cross-key (i.e., cross-key) geometry. A second effective area 122 can be created near the same light guide 10 using a pair of narrow-angle pocket-type optics 74b positioned at either end of the touch area defining a single slider geometry.

[0220] The key factors for optimizing patterned light distribution in the effective region are: • The inherent intensity distribution of pocket-type optics (which can be fixed); • Pattern for arranging the pocket-type optics 74; • The spacing of the pocket-type optics 74 in the pattern; and • Orientation of the pocket-type optical device 74.

[0221] The same optical target (as described above) is applied to the effective area; that is: • Maximize the optical power efficiency delivered to the effective region; • Optimize optical uniformity as close as possible to the target percentage range; • Minimize the distance from the pocket-type optics 74 to the edge of the touch-sensitive area (i.e., to the area where target uniformity is achieved); • By using a minimum number of pocket-type optics 74, more space can be left for other components in the assembly, and power consumption can be minimized.

[0222] An example of creating an effective area using a multi-pocket injection optics 74 layout geometry will now be discussed.

[0223] Figure 28 The geometry of a circular 3D "rotary" light guide is shown, which utilizes multiple pocket-type optics 74 (for clarity, in...). Figure 28 (Only one of them is marked in the text) Couples light into the light guide 10. Figure 28 The turntable light guide 10 has a curved profile, and this turntable light guide can form with... Figure 1 A similar double-slab arrangement for the top slab.

[0224] Figure 28 The light guide 10 has an upper wall 124, a side wall 126, and a lower wall 128. The upper wall 124 defines a central region of the light guide 10, which is substantially planar and generally circular in plan view. The side wall 126 extends downward and radially outward from the circumferential edge 130 of the upper wall 124 to the lower wall 128.

[0225] Light is emitted from multiple light source cavities 30 (for clarity, in...) Figure 28 Only one of them is marked in the image. (Multiple light sources 12 in the image) Figure 28 (Only one of them is shown in the image) is incident into the light guide 10. Each light source 12 is located at the circumferential edge portion 132 of the light guide 10 and undergoes total internal reflection in the light guide 10.

[0226] In this example, the light guide 10 includes sixteen light source cavities 30, each receiving and surrounding a single light source 12. It should be understood that in other examples, more or fewer light sources 12 and associated light source cavities 30 are possible.

[0227] Each light source cavity 30 in this example utilizes Figure 7 The geometry of the pocket-type optics 74 is shown. Figure 7 In this arrangement, each light source cavity 30 is defined by a recess in the lower side of the light guide 10 and is disposed within the thicker section 46 of the light guide 10. A ramp section 50 of the light guide 10 combines the thicker section 46 of the light guide 10, including the light source cavity 30, with a thinner section 48 of the light guide 10. In this manner, the sidewall 126 and upper wall 124 of the light guide 10 define the thinner section 48 of the light guide 10, and the lower wall 128 defines the thicker section 46 and the ramp section 50 of the light guide 10.

[0228] Light sources 12 and associated light source cavities 30 are spaced apart at equal intervals around the circumferential edge portion 132 of the light guide 10. Each light source 12 is arranged to face inward toward the central axis C of the light guide 10, such that each light source 12 emits light toward the central axis C.

[0229] Figure 28 The arrangement provides a touch detection area 134, i.e., an effective area or region, for the light guide 10 when it is combined with a suitable touch detection arrangement (e.g., similar to...). Figure 1 In a double-plate arrangement, touch on the light guide 10 can be detected. Figure 28 In the example, the touch detection area 134 is defined by the sidewalls 126 and upper wall 124 of the light guide 10 in this embodiment. However, in other embodiments, the effective area 134 may also surround at least a portion of the lower wall 128 of the light guide 10. Regardless, the light source 12 of the light guide 10 is positioned around the perimeter 136 of the effective area or region 134, which in this example defines a circle in a plan view. In other examples, the shape of the perimeter 136 may vary and may define an ellipse, rectangle, or square in a plan view; these are merely a few non-limiting examples. The light sources 12 are spaced apart to form a substantially uniform light distribution in the effective area 134 of the top plate 10. Figures 29a to 29b Figure 29d Shown in having with Figure 28 The uniformity of light within the similarly arranged turntable light guide 10. Specifically, Figure 29a shows... Figure 28 The light guide 10 includes sixteen light sources 12 (not visible in Figure 29a), and Figure 29b shows the connection with... Figure 28 The light guide is similar to the light guide 10, but includes twelve instead of sixteen equally spaced light sources 12, and Figure 29c Showing with Figure 28 A similar light guide 10, but comprising eight instead of sixteen equally spaced light sources 12. (See Figures 29a to...) Figure 29cIn the diagram, the brighter and darker portions of the light guide 10 represent the irradiance within the light guide 10, with the brighter portions representing higher irradiance and the darker portions representing lower irradiance. (See Figure 29a to...) Figure 29c As can be understood, the light irradiance within the light guide 10 is generally non-uniform within the lower wall 128 of the light guide 10, which includes alternating bright and dark areas (related to the spacing between the light sources 12).

[0230] Figure 29d Figures 29a to 29b show different angular positions around the central axis C of the optical guide 10. Figure 29c The uniformity of optical power density in the sidewalls 126 of each optical guide 10. Figure 29d In the diagram, curve 138 represents the optical guide arrangement in Figure 29a, curve 140 represents the optical guide arrangement in Figure 29b, and curve 142 represents... Figure 29c The optical guide arrangement. Lines 144 and 146 represent the upper and lower limits, within which the optical power density falls within a range of plus or minus 10%. Taking this into consideration, from... Figure 29d It will be recognized that the arrangements of Figures 29a and 29b provide + / - 10% uniformity of light power density within the sidewall 126, while using fewer light sources 12 for illumination. Figure 29c The arrangement of the elements does not fall within the uniformity range at any location across the sidewall 126.

[0231] Turn now Figure 30 Using multiple pocket-type optics 74 (in) Figure 30 Another example of creating an effective area (marking only one of them) is this time in a rectangular flat light guide plate 10. With Figure 28 The same as the optical guide 10. Figure 30 Optical guides can be combined with the utilization Figure 1 The basic technology is based on the double-plate layout.

[0232] Figure 30 The light guide 10 is a substantially flat plate with a rectangular shape in the plan view, defined by two long side edges 150 combined with two short side edges 148. In this example, the short side edges 148 of the light guide 10 have a length of 150 mm, and in this example, the long side edges 150 of the light guide 10 have a length of 210 mm; however, it should be understood that these dimensions may vary in other examples.

[0233] Figure 30 The optical guide 10 includes, for example, Figure 7 Multiple pocket-type optical devices 74 are shown. The light source cavity 30 of the pocket-type optical devices 74 is arranged along the edge portions 154, 156 of the light guide 10. Figure 30In this example, the light guide 10 includes six light source cavities 30 along each short-side edge portion 154 of the light guide 10, and ten light source cavities 30 along each long-side edge portion 156 of the light guide 10. Therefore, in this example, the light guide 10 includes thirty-two light source cavities 30, and thirty-two associated light sources 12 (i.e., thirty-two pocket-entry optics 74) disposed in the light source cavities 30 during use. It should be understood that in other examples, the light guide 10 may include more or fewer pocket-entry optics 74.

[0234] like Figure 7 The arrangement is such that each pocket-type optic 74 is disposed in the thicker section 46 of the light guide 10. A ramp section 50 of the light guide 10 connects the thicker section 46 to a thinner section 48 of the light guide 10. In this example, the thinner section 48 of the light guide 10 defines a central region with a rectangular shape in the plan view of the light guide 10. The thinner section 48 defines an effective area or region 134 of the light guide 10, wherein a touch on the light guide 10 can be detected when the light guide 10 is coupled to a suitable touch detection device, such as a [missing information - likely a device for detecting touches]. Figure 1 A similar dual-plate device.

[0235] Figures 31a to 31d Showing with Figure 30 The uniformity of light within a similarly arranged rectangular light guide 10. Specifically, Figure 31a Show Figure 30 The light guide 10 includes thirty-two pocket-type optics 74 (in Figure 31a (Not visible in the middle) Figure 31b Showing with Figure 30 A similar light guide 10, but it includes twenty-six pocket-type incident optics 74, and Figure 31c Showing with Figure 30 A similar light guide 10, but it includes twenty pocket-type optics 74. (See Figures 29a to 29b). Figure 29c similar, Figures 31a to 31c The brighter and darker portions of the light guide 10 represent the intensity distribution of light within the light guide 10, where the brighter portions represent higher intensity and the darker portions represent lower intensity.

[0236] Figure 31d Shown in Figures 31a to 31c In each optical guide, the optical power density is along the central axis, especially... Figure 30 The uniformity on the x-axis is shown. Lines 158 and 160 represent the upper and lower limits, within which the optical power density falls within a range of plus or minus 10%. Figure 31d In the middle, curve 159 represents Figure 31a The optical guide arrangement, represented by curve 161. Figure 31b The optical guide arrangement, and curve 163 indicates Figure 31c The optical guide arrangement. Taking this into consideration, from... Figure 31d This is understandable. Figures 31a to 31c The arrangement of all elements provides a + / -10% uniformity of optical power density within the central region of the optical guide 10.

[0237] The concept of an optically invalid region will now be described in more detail. An optically invalid region can be formed by using a light-absorbing element, a light-absorbing layer, or a light-absorbing coating 58 on the light guide 10. The light-absorbing layer or element 58 can be used to isolate a separate optical geometry in a region of the light guide 10. The light-absorbing layer or element 58 can be additionally or alternatively used to prevent light from one region of the light guide 10 from interfering with light from another region of the light guide 10, thereby avoiding undesirable light leakage from the light guide 10. Typically, a layer or coating 58 disposed on a region of the first surface 23, the second surface 25, or one or more of both of the light guide 10 can be used to suppress internal reflections at that region of the respective surfaces 23, 25 to provide optical separation between a portion of the top plate 10 and another portion of the top plate 10.

[0238] Reference Figure 32 The image shows a light guide 10 having two optically active regions 162 separated by an optically inactive region 164. Figure 32 The light guide 10 couples light into a first effective region 162a using a first grooved incident optics 52a, and couples light into a second effective region 162b using a second grooved incident optics 52b. The first effective region 162a defines a wedge-shaped geometry with upward and downward sloping portions 166. The second effective region 162b defines a slider geometry. It should be understood that in other examples, the light guide 10 may incorporate more or fewer effective regions 162, and the effective regions 162 may define other geometries, such as a turntable. Furthermore, light-incident geometries can be used to illuminate the effective regions 162 of the light guide 10, such as other grooved incident optics 52 geometries or pocket incident optics 74 geometries. Additionally, light sources 12 with different properties can be used to illuminate different effective regions 162 of the light guide 10.

[0239] Light enters the first effective region 162a with a narrow vertical angle range to minimize loss. However, after passing through the wedge geometry of the first effective region 162a, the angle range of the light incident from the first grooved incident optics 52a can be widened. In, for example... Figure 32In the light guide 10 shown without the ineffective region 164, if light from the first trench incident optics 52a is allowed to continue into the second effective region 162b after passing through the first effective region 162a and through the slider geometry in the second effective region 162b, the angular range of the incident light can be further widened, such that some light rays may fall below the critical angle limit (i.e., outside the angular range of total internal reflection at one of these surfaces 23, 25) at the upper surface 23 or lower surface 25 of the light guide 10 and be lost from the light guide 10. Figure 32 As shown, a light absorption band 168 is added to the underside of the light guide 10 between the first effective region 162a and the second effective region 162b, creating an invalid region 164 that isolates the first effective region 162a from the second effective region 162b.

[0240] Turn now Figure 33 Another example of the light guide 10 uses a single absorption invalid region 170 to isolate multiple effective regions 172. An absorption mask layer 174 with multiple openings is provided on the upper surface 23 of the light guide 10 to define multiple effective regions 172 of the light guide 10. Specifically, the effective regions 172 of the light guide 10 in which touch detection can be performed are defined in the openings 176 of the absorption mask layer 174.

[0241] Mask layer 174 may include, for example, black paint or any other suitable opaque paint or material. In some examples, mask layer 174 may be formed by overmolding or using an IML. As previously described, mask layer 174 may be opaque to “working” light but transparent to other light, such as visible light if the device is configured to operate in the infrared.

[0242] Ineffective regions can be controlled or prevented using various light absorption methods, i.e., the loss of light incident from the light guide 10. Table 1 below summarizes the advantages and disadvantages of three known light absorption methods (i.e., using paint, secondary molding, or IML).

[0243] · Table 1. Different absorption methods used for regional isolation

[0244] An example of using zone isolation will now be described.

[0245] Figure 34a and Figure 34b An example of end-area isolation in a symmetrical light guide 10 is shown, wherein an absorbing coating 178 is provided on part or all of the periphery of the top plate 10. A first trench injection optic 52A is positioned toward or near a first end 180 of the light guide 10, and a second trench injection optic 52b is positioned at the opposite second end 182 of the light guide 10.

[0246] exist Figure 34a In this arrangement, an absorber is provided on the end face of the light guide 10 to prevent light from escaping from the light guide 10 through the end face. In this example, an absorber 178 is provided on the second end face 184 at the second end 182 of the light guide 10, and absorbs the light entering the light guide 10 from the first incident optical device 52a at the first end 180 of the light guide 10, and prevents the light from leaving the light guide 10 through the second end face 184. In some examples, an absorber 178 may be provided on the first end face 186 at the first end 180 of the light guide 10 to prevent light from escaping from the light guide 10 through the first end face 186, particularly to prevent light from escaping from the second trench incident optical device 52b.

[0247] exist Figure 34b In this arrangement, an absorber 178 is provided along a portion of the end wall of the light guide 10 to prevent light from escaping from the light guide 10 through the end wall. In this example, an absorber 178 is provided on the upper surface 23 of the light guide 10 along the second end wall portion 188 at the second end 182 of the light guide 10, such that light incident from the first incident optical device 52a into the light guide 10 is absorbed and blocked, preventing it from leaving the light guide 10 through the second end wall portion 188 and preventing the light from continuing to travel in the light guide 10. In some examples, an absorber 178 may be provided on the first end wall portion 190 at the first end 180 of the light guide 10 to prevent light from escaping from the light guide 10 through the first end wall portion 190, particularly preventing light from escaping from the second trench incident optical device 52b, and preventing it from continuing to travel in the light guide 10. Although in Figure 34b In the arrangement, the absorber 178 is disposed on the upper surface 23 of the light guide 10, but it should be noted that in some examples, the absorber 178 may be additionally or alternatively disposed on the lower surface 25 of the light guide 10.

[0248] In some examples, the absorber 178 may be disposed on the end face and end wall portions as needed.

[0249] In this way, light traveling from one end of the light guide 10 to the other end is absorbed at one or more end faces and / or end walls to prevent the light from escaping from the light guide 10 as stray light.

[0250] like Figure 35a As shown, light from the first trench incident optics 52a can pass through the light guide 10 and be reflected upwards by total internal reflection, exiting the input wall (i.e., the optical coupling wall 36) of the second trench incident optics 52b. This light reflected at the optical coupling wall 36 of the second trench incident optics may escape from the light guide 10 as stray light through the upper surface 23 of the light guide 10. Figure 35bA light guide 10 is shown, wherein an absorber 178 is disposed on the upper surface 23 of the light guide 10 to absorb and block the escape of stray light reflected from the optical coupling surface 36. For this purpose, the absorber 178 extends above and across the second entrance optics 52b and its optical coupling wall 36. It should be noted that in some examples, the absorber 178 may additionally or alternatively be disposed on the lower surface 25 of the light guide for this purpose. For example, an absorber 178 disposed on the lower surface 25 of the light guide 10, extending forward from the second trench entrance optics 52b (i.e., away from the second end 182 of the light guide 10 and toward the center of the light guide), can absorb light from the first entrance optics 52a before it can reach the second trench entrance optics 52b. Similarly, this is also true for an absorber 178 extending forward from the second trench entrance optics 52b on the upper surface 23 of the light guide 10.

[0251] As mentioned earlier, the role of absorbers can be more complex because different properties may be required at different wavelengths. In some cases, the absorbers discussed above, for example in the separation effective region, can absorb at the operating wavelength but transmit at other wavelengths. This allows devices configured for infrared detection to use "masking" areas in the visible light region for separating the effective region; for example, through these separation areas, the display behind the touchscreen can be seen.

[0252] In some examples, absorbers can be used for aesthetic masking of subsurface optics and components of the light guide 10 to improve the aesthetics of the arrangement or simplify the appearance of the device to the user. In this regard, it is useful to add an opaque tint to the light guide 10, which absorbs at visible wavelengths but transmits at near-infrared (NIR) wavelengths used by the light source 12 (e.g., LED light source 12), in an arrangement opposite to that just discussed, where opacity exists at the operating wavelength rather than the visible wavelength. This opacity tint can be used, for example, to conceal the trench-in optics 52 or pocket-in optics 74 or any other components beneath the light guide 10 from the user's perspective, while allowing NIR light from one or more light sources 12 to propagate unaffected within the light guide 10 without absorption.

[0253] As described above, the light guide 10 can be combined with, for example, Figure 1 The three-layer optical laminate is used to provide a touch device 8, and the three-layer optical laminate can be positioned above the display to form the touch device 8.

[0254] In this arrangement, the laminated upper layer 10 and lower layer 18 can be referred to as the transmitting (Tx) and receiving (Rx) layers, respectively. The upper layer 10 and lower layer 18 are separated by a middle layer 14, which may comprise air or an optical material (referred to as a cladding) having a lower refractive index than the upper layer 10 and lower layer 18. When the middle layer 14 comprises an optical material, the optical material defines an optical transmission material layer.

[0255] The grooved-in-place optics 52 and pocket-in-place optics 74 structures already discussed can be prototyped using a combination of standard acrylic machine polishing or vacuum casting techniques, which are better suited for small-batch manufacturing. However, the use of grooved or pocket-in-place optics 52, 74 in the upper transmission layer 10 of such a system enables new construction methods that allow for medium to large-batch manufacturing. For example, injection molding techniques can be used to produce laminated structures that combine some or all of the following optical elements and features: light entry, effective and ineffective areas, light detection, decorative effects, and display elements. This offers the following key advantages: minimal form factor, lower part number, ease of assembly, improved transmission, aesthetics, and ultimately lower overall manufacturing and assembly costs. All of these can be designed using surface-mount electronic components, again minimizing the form factor and simplifying assembly.

[0256] As already discussed, various methods can be employed in the light guide 10 to absorb unwanted light, such as preventing this light from escaping through the top 34 of the grooved or pocket-type optical cavity 52, 74 (see, for example, see...). Figure 10 and Figure 19 ), or prevent light from passing through from one effective zone to another (e.g., see Figures 32 to 3 5). This scheme using masking technology allows the area of ​​the light guide 10, particularly the area of ​​the first surface 23 of the light guide 10, to be isolated from any other optical activity in the light guide 10.

[0257] For example, a varnish with an appropriate absorption spectrum that matches one or more light sources 12 can be used to block light reaching different surfaces and regions of the light guide 10. However, the varnish used for this purpose involves a secondary process. In this secondary process, the application of the varnish may not always be precisely controlled, and the application of the varnish is not cost-effective for large-volume production.

[0258] Secondary molding or in-mold labeling (IML) / in-mold decoration (IMD) processes allow for the absorption of ink placed in the mold as a thin secondary layer, and both offer attractive alternatives to the above. These manufacturing techniques allow for the creation of areas on a touch surface (i.e., the upper surface of the top plate or light guide), which can be combined with an absorption mask to (a) conceal components or features below the top plate 10 in view, (b) optically isolate one area from another, or (c) provide a decorative effect, as well as combinations of these effects (a) to (c). Once the molding process is set up, this manufacturing method provides a solution for the mass production of large volumes of upper or transmissive layers 10 with precise and effective stray light control.

[0259] IML (as opposed to secondary molding) offers significant advantages, enabling attractive decorative effects that can make surfaces appear as many different materials (e.g., fabric, carbon fiber, or leather). Typically, the LEDs 12 used for the groove and pocket-mounted optics 52, 74 emit in the near-infrared (NIR) region of the spectrum. Inks used in the IML can be selected to absorb light in the visible spectrum (i.e., 400-800 nm) and be used to create the decorative effect. The same inks are chosen such that they do not absorb NIR light from the LEDs 12 and do not interfere with the touch detection process. The embodiments described in detail herein outline the use of acrylic materials (e.g., poly(methyl methacrylate) or PMMA) sheets; however, it should be noted that other types of three-layer systems can be used, for example, a glass layer can be used as a substitute for the acrylic layer. However, the manufacturing techniques discussed herein are particularly suitable for acrylic top and bottom layers.

[0260] Table 2 shows a comparison of absorber mask manufacturing processes or IML / IMD using two-stage injection molding: Table 2. Comparison of absorption mask manufacturing processes using two-stage injection molding or IML / IMD

[0261] Regarding the overall wall section thickness range in Table 2, it should be noted that these values ​​are those considered good practices for standard mass production.

[0262] Referring again to Figures 8A and 8B, replacing the intermediate air layer 14 in the three-layer system, which includes an upper and lower acrylic layer, with a layer of higher refractive index material reduces the critical ray angle at the boundary (i.e., the angle between the light ray and the surface boundary changes from approximately 48° to 26°). Therefore, replacing the intermediate air layer with a middle layer of higher refractive index requires a more limited angular range in the light guide 10 so that virtually all light undergoes total internal reflection at the boundary.

[0263] However, compared to using a 1 mm air gap, using a cladding layer in a 3-layer laminate advantageously reduces the overall laminate thickness. To provide this advantage while maintaining the widest possible angular range where light undergoes total internal reflection at the boundaries between the upper and lower layers and the cladding layer, the cladding material is chosen to be a low-refractive-index material with a refractive index as close as possible to that of air. In some examples, the cladding layer can take the form of an intermediate FEP layer, but other materials are also possible.

[0264] Replacing the air gap with a low-refractive-index intermediate layer reduces Fresnel reflections at the boundary between the upper (transmitting) layer and the intermediate layer, and at the boundary between the lower (receiving) layer 18 and the intermediate layer 14. This improves the overall transmittance and transparency of the laminate. Furthermore, replacing the air gap in the laminated structure with a low-refractive-index intermediate layer enhances the robustness of the manufactured components.

[0265] The disadvantage of replacing the air gap with a low-refractive-index middle layer 14 is the reduced evanescent field intensity due to the shallower average light reflection angle. Furthermore, the laminate using a low-refractive-index middle layer 14 instead of air provides lower optical coupling efficiency due to the need to reduce the angular range of total internal reflection.

[0266] We will now discuss manufacturing examples that demonstrate how a low-refractive-index intermediate layer can be combined with secondary molding or in-mold marking.

[0267] Figure 36 A touch device formed of composite material 192 is shown. Composite material 192 includes an upper (transmitting) layer 10 in the form of an optically transparent sheet, which defines the touch surface 23 of the device. Composite material 192 also includes a lower (receiving) layer 18 in the form of a separate optically transparent sheet, and a middle layer 14 defined by an air gap between the upper layer 10 and the lower layer 18. The upper layer 10 includes a trench-in optics 52, which includes an array of light sources 12 disposed in a light source cavity 30 of the trench-in optics 52. Figure 36 Only one of them can be seen in the image. It should be understood that, in addition to or in place of the grooved incident optics 52, other optical devices can be used... Figure 36 The arrangement incorporates one or more pocket-type optics 74.

[0268] In this example, the light source 12 is an LED operating in the near-infrared (NIR) region of the spectrum. The device includes a single printed circuit board (PCB) 54 on which the light source 12 is mounted, and an upper layer 10 and a lower layer 18 are held on either side of the PCB 54 using a mechanical frame or retainer 194. An ethylene vinyl acetate (EVA) foam pad 196 is inserted between the upper layer 10 and the lower layer 18 to create or provide an air gap 14 and hold them apart from each other. In this way, the lower layer or substrate 18 is mounted relative to the upper layer or top plate 10 such that if an external body contacts the first surface 23 of the top plate 10, light is coupled from the second surface 25 of the top plate 10 through the first or upper surface of the substrate 10 into the substrate 10. Another EVA pad 198 is inserted between the lower layer 18 and the display 200 and also forms a partial composite material 192 to create an air gap 202 and hold the lower layer 18 and the display 200 apart from each other.

[0269] An acetate film is added to the contact points of the upper or lower layers (i.e., the contact areas between the upper layer 10 and other components, and between the lower layer 18 and other components) to prevent the upper layer 10 and lower layer 18 from "wetting" and causing constrained light leakage. The upper layer 10 is injection molded together with the IML in the insert tool to allow border, graphic, or texture effects to be added to a portion of the upper surface 23 of the upper layer 10 without completely covering the display 200 below. Furthermore, a thin layer of material 204 is printed on the underside of the IML film 203, which is transparent to light in the near-infrared region of the spectrum but absorbs light in the visible region of the spectrum. In this way, the LED 12 under layer 204 is masked from being seen by the user, while still allowing total internal reflection of the NIR light emitted by the LED 12 from the upper surface 23 of the upper layer 10. Similar to... Figure 3 The arrangement includes separate opaque layer portions 206, i.e., light-absorbing elements, disposed on the upper surface 32 and rear surface 38 of the light source cavity 30 between the first surface of the light source 12 and the light guide 10, defining... Figure 36 The light source aperture 56 in the arrangement limits the angular range of light emitted by the LED 12 coupled to the upper light guide 10.

[0270] Alternative mask arrangements are possible. In an alternative mask arrangement (not shown), the [mask element] can be omitted. Figure 36 In the arrangement, an opaque near-infrared absorbing coating 206 is disposed above the light source in cavity 30, and the light source aperture 56 may alternatively be defined by an upper surface IML film arrangement. Specifically, a portion of the upper surface IML film arrangement above cavity 30 can absorb in the near-infrared region of the spectrum to simulate... Figure 36 The absorbent coating 206 is arranged in a specific configuration. In this case, the upper surface IML film arrangement remains as before. Figure 36 The visible absorption of decorative effects in the arrangement.

[0271] A sensor in the form of a photodetector 20 is positioned as needed at the edge of the lower layer 18 to detect light coupled from the upper layer 10 to the lower layer 18 in response to a touch on the upper surface 23 of the upper layer 10.

[0272] Figure 37 Another composite material device 192 using a single PCB 54 is shown (i.e., similar to...). Figure 36 ). Figure 37 The device includes an additional IML membrane 208, which provides with Figure 36 This has a similar function to the layer that limits the light source aperture 56. Therefore, Figure 37 The arrangement does not include the opaque layer portion 206 disposed on the top surface 32 and rear surface 38 of the light source cavity 30, because an additional IML film 208 replaces this element. In particular, the additional IML film 208 has an opaque layer 210, which is used to limit the angular range of light coupled from the LED 12 to the upper layer 10. This provides a single, laminated upper optical component to improve ease of assembly.

[0273] Similar to about Figure 36 Regarding the discussion, alternative mask devices (not shown) can also be used here. For example, one possible alternative mask device could omit the additional IML film 208 and use a different upper surface IML film device configured to absorb the near-infrared region in a suitable area above the light source 12 to define the light source aperture 56. In this case, the upper surface IML film arrangement can still be maintained as previously described. Figure 36 The visible absorption of decorative effects in the arrangement.

[0274] Figure 38 A touch device formed by a laminate 212 is shown. The laminate 212 includes an upper layer 10 defining an optical transmittance, a lower layer 18 defining another optical transmittance, and an intermediate optical layer 14 in the form of a low-refractive-index intermediate layer between the upper layer 10 and the lower layer 18. In this example, the low-refractive-index intermediate layer 14 is a single low-refractive-index optical adhesive layer that provides optical bonding between the optical transmittances 10 and 18. In other examples, the intermediate layer may take different suitable forms. For example, in some examples, the intermediate layer may be formed by stacking sublayers.

[0275] Figure 43 An example of a middle layer 14a formed by stacking sublayers is shown. Middle layer 14a includes an upper optically clear adhesive film layer and a lower optically clear adhesive film layer 213, respectively bonded and adhered to the upper layer 10 and the lower layer 18. Middle layer 14a also includes two polycarbonate layers 215 and a central low-refractive-index adhesive layer 217. Figure 43In the example, the upper adhesive layer and the lower adhesive layer 213 each have a thickness of 0.25 mm, the polycarbonate layer 215 each has a thickness of 0.1 mm, and the central low-refractive-index adhesive layer 217 has a thickness of approximately 5 μm. In other examples, the materials and forms of the sublayers can be different, and in particular, the number and thickness of the stacked sublayers can vary.

[0276] Back Figure 38 The laminate 212 also includes a display 200 positioned below the lower layer 18, and an additional low-refractive-index layer 214 disposed between the lower layer 18 and the display 200. Figure 36 and Figure 37 The layout is the same. Figure 38 The device comprises a single PCB 54.

[0277] It should be understood that, with Figure 36 and Figure 37 Compared to the previous arrangement, the air layers between the upper layer 10 and the lower layer 18, and between the lower layer 18 and the display 200, have been replaced by low-refractive-index layers 14 and 214. The low-refractive-index layers 14 and 214 are optically bonded to the upper layer 10 and the lower layer 18 via optical bonding layers. This increases manufacturing complexity but provides individual, laminated optical components for simpler assembly.

[0278] As in Figure 36 In the arrangement, separate opaque layer portions 206 are positioned at the upper and rear positions within the light source cavity 30. Figure 38 The light source aperture 56 in the arrangement limits the angular range of light emitted by the LED 12 coupled to the upper light guide 10. As previously mentioned, in embodiments, the opaque layer portion 206 may be opaque only in the "operating" near-infrared range and may actually be transparent in part or all of the visible spectrum. Similarly, as in... Figure 36 In this arrangement, a thin layer of material 204, which is transparent to light in the near-infrared region of the spectrum but absorbs light in the visible region of the spectrum, is printed onto the underside of an IML film 203. Layer 204 is formed during the lamination process. Figure 38 The device also includes an absorption structure 218, which is arranged to block light that is not intended to undergo total internal reflection and continue to propagate in the light guide 10.

[0279] It should be understood that Figure 38 The upper layer 10 of the arrangement has a ramp wedge-shaped portion 50 between the thicker portion 46 of the light guide 10 including the grooved injection optics 52 and the thinner portion 48 of the light guide 10 defining the effective area of ​​the light guide 10 that can detect touch.

[0280] Figure 39 The use of laminate 212 (similar to) is shown. Figure 38 Another touch device formed by laminating (the laminate). Figure 39 Many features of the device and Figure 38 The layout features are the same, so for simplicity, they will not be described further. And... Figure 38 Compared to the previous arrangement, Figure 39 The arrangement includes an additional IML film 220 on the lower surface of the upper layer 10, which is positioned to extend across the rear surface 38 and the upper surface 32 of the light source cavity 30, providing and defining Figure 38 The individual opaque layer portion 206 of the light source aperture 56 in the upper layer 10 functions similarly. An additional IML film 220 is used to control the angular range of light coupled from the LED 12 into the upper layer 10. Note, as in... Figure 36 In the arrangement, a thin layer of material 204, which is transparent to light in the near-infrared region of the spectrum but absorbs light in the visible region of the spectrum, is printed onto... Figure 39 The IML membrane 203 is placed on the lower side of the laminate. Layer 204 is formed during the molding process of the laminate.

[0281] It should be noted that alternative mask arrangements are possible. In one such alternative mask arrangement (not shown), the additional IML 220 above the LED 12 can be omitted, and different upper surface IML film arrangements configured to absorb the near-infrared region in a suitable area above the light source 12 to define the light source aperture 56 can be used. In this case, the upper surface IML film arrangement can still maintain the visible absorption decorative effect, as previously described.

[0282] As can be understood from the above discussion, by combining the fabrication elements for light injection, light distribution, and light isolation into a laminated structure, they can be assembled together using injection molding technology. One or more light-absorbing layers can be replaced with in-mold labeling (IML), and the air gap between the upper and lower layers can be replaced with a low-refractive-index layer such as a FEP.

[0283] Those skilled in the art will understand that the invention can be modified to take many alternative forms described herein without departing from the scope of the appended claims.

Claims

1. A method for manufacturing an optical translucent sheet, the method comprising: The optically translucent sheet is formed into a laminate, wherein the optically translucent sheet is suitable for total internal reflection at the first and second surfaces of the optically translucent sheet; as well as One or more light-absorbing layer regions are formed on the first surface, the second surface, or both the first surface and the second surface of the optical transparent sheet, wherein the one or more light-absorbing layer regions are formed during the molding process.

2. The method according to claim 1, wherein the light absorption layer region is formed by in-mold labeling.

3. The method of claim 2, wherein the coating region includes a first region that absorbs light in the near-infrared region.

4. The method of claim 3, wherein the coated region includes a second region that absorbs light in the visible region.

5. The method according to any one of claims 1 to 4, wherein the optical translucent sheet is an acrylic sheet.

6. A method for manufacturing an optical element for a touchscreen device, the method comprising: An optically transparent sheet is formed by the method of any one of claims 1 to 5; The optical translucent sheet is laminated together with an intermediate optical layer and another optical translucent sheet, wherein the intermediate optical layer has a lower refractive index than the optical translucent sheet.

7. The method of claim 6, wherein the optical element is formed by secondary molding.

8. A method for manufacturing an optical element for a touchscreen device, the method comprising: An optically transparent sheet suitable for total internal reflection at a first and second surface of the optically transparent sheet is formed, the optically transparent sheet having one or more light-absorbing layer regions formed on the first surface, the second surface, or both the first surface and the second surface of the optically transparent sheet; as well as The optical translucent sheet is laminated together with an intermediate optical layer and another optical translucent sheet, wherein the intermediate optical layer has a lower refractive index than the optical translucent sheet.

9. The method according to any one of claims 6 to 8, wherein the intermediate optical layer provides optical bonding between the optically transparent sheets.

10. The method according to any one of claims 6 to 9, wherein the intermediate optical layer comprises fluorinated ethylene propylene.

11. A method of manufacturing a touchscreen device, the method comprising: An optically transparent sheet is manufactured as a top plate according to any one of claims 1 to 5, and the top plate is installed in the touch screen device, wherein a plurality of light sources are installed in association such that light from the plurality of light sources is transmitted within the top plate in a manner of total internal reflection; as well as A substrate is mounted relative to the top plate such that if an external body contacts a first surface of the top plate, light is coupled from a second surface of the top plate through the first surface of the substrate into the substrate, and one or more detectors are mounted in association with the substrate for detecting light transmitted within the substrate.

12. The method of claim 11, wherein the top plate and the substrate are mounted to have an air gap between the top plate and the substrate.

13. The method of claim 12, wherein the air gap is provided by a foam mask separator.

14. The method of claim 11, wherein the optical translucent sheet is manufactured by the method of any one of claims 6 to 10, wherein the substrate is the additional optical translucent sheet.

15. The method according to any one of claims 11 to 14, wherein, The substrate is mounted above the display, which is configured to emit light from the touchscreen device through the top plate.

16. The method according to any one of claims 11 to 15, wherein the light-absorbing layer absorbs light emitted by the light source and is adapted to mask the light source.

17. The method of claim 16, wherein the masking of the light source substantially restricts the propagation of light from the light source through the top plate, such that light directed for total internal reflection can propagate substantially only at the surface of the top plate.

18. The method according to claim 16 or 17, wherein the light source emits near-infrared light and the light-absorbing layer region absorbs near-infrared light.

19. The method of claim 18, wherein a portion or all of the light absorption region is substantially transmissive in the visible spectrum.

20. The method according to any one of claims 11 to 19, wherein the substrate is a weak absorber of light emitted from the plurality of light sources.

21. The method of claim 20, wherein the substrate is chemically doped with a weakly absorbing material.

22. The method according to any one of claims 11 to 21, wherein the top plate extends beyond the substrate, and wherein one or more light sources are mounted in the region of the top plate extending beyond the substrate.

23. The method of claim 22, wherein the top plate is manufactured to gradually taper from a thicker region where the one or more light sources are mounted to a thinner region over the substrate.

24. The method according to claim 22 or 23, wherein, The one or more light sources are mounted in one or more recesses in the second surface of the top plate and configured to transmit light into the top plate through the walls of the recesses, the light sources being located in the recesses.

25. The method of claim 24, wherein the recess is a linearly extending recess, and a plurality of light sources are mounted in the recess in a linear array.

26. The method of claim 25, wherein the linearly extending recess and the linear array extend along a straight line.

27. The method of claim 25, wherein the linearly extending recess and the linear array extend along a curve.

28. The method according to claim 24, wherein, One or more recesses are formed for each of the one or more light sources, wherein each recess has one or more refractive input surfaces such that light from the light source is coupled into the body of the top plate through the one or more refractive input surfaces.

29. The method according to any one of claims 22 to 28, wherein, The substrate is mounted to prevent light emitted from the substrate and not received by the one or more detectors from entering the top plate.

30. An optical translucent sheet manufactured by any one of claims 1 to 5.

31. An optical element for a touchscreen device, comprising an optically transparent sheet laminated together with an intermediate optical layer and a further optically transparent sheet, wherein the intermediate optical layer has a lower refractive index than the optically transparent sheet.

32. The optical element according to claim 31, manufactured by any one of claims 6 to 10.

33. A touch screen device manufactured by any one of claims 11 to 29.

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