Touch screen panel with surface friction modification

Abstract

Embodiments allow for forming a friction-modified touch-sensitive surface on a touch screen panel. In particular, the touch-sensitive surface is enhanced with two friction-modifying materials that are interspersed with each other as a monolayer according to a predetermined pattern on the surface of the touch screen panel. In one embodiment, the refractive indices of the materials differ from each other by more than 0.10. In another embodiment, the materials have a dynamic coefficient of friction that is within one range or the other of 0.01 and 0.05, respectively, measured relative to printed paper that has a dynamic coefficient of friction of 0.17 by itself. In another embodiment, the materials have a water contact angle that is greater than 90 degrees and an oil contact angle that is greater than 30 degrees, the oil contact angle being measured with n-hexadecane.

Description

Background Technology

[0001] Until relatively recently, keyboards and mice were the most common input devices used with computing devices such as PCs. Even touchscreen smartphones typically accepted text input via a virtual keyboard displayed on the touchscreen. However, more recently, pen-based input has become more popular on touchscreen devices.

[0002] The high-resolution, wide color gamut displays common in some touchscreen devices (such as the Microsoft® Surface® tablet) enable sophisticated digital drawing applications that provide accurate simulations of artistic drawing and painting (i.e., the strokes of a pen, pencil, brush, etc.), especially when used with a stylus or digital pen. Summary of the Invention

[0003] This disclosure is provided to introduce, in a simplified form, a selection of concepts also described in the detailed description. This disclosure is not intended to identify key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

[0004] This document describes a touchscreen panel, a touchscreen computing device, and a method for forming a friction-modified touch-sensitive surface on the touchscreen. In one example aspect, the outer touch-sensitive surface of the touchscreen panel is reinforced with a friction-modified material. In an embodiment, first and second friction-modified materials are dispersed as monolayers on the surface of the touchscreen panel according to a predetermined pattern.

[0005] On the other hand, the first and second friction-modifying materials are selected such that one of the friction-modifying materials is relatively more amorphous than the other. In one embodiment, the first and second friction-modifying materials are selected to have substantially different refractive indices, wherein the difference in refractive indices is greater than 0.10. In another embodiment, the first and second friction-modifying materials are selected to have a coefficient of kinetic friction in one or more of the ranges between 0.01 and 0.05 or between 0.06 and 0.1, respectively, said coefficient of kinetic friction being measured relative to a printing paper having a coefficient of kinetic friction of 0.17. In another embodiment, the first and second friction-modifying materials have a water contact angle greater than 90 degrees and an oil contact angle greater than 30 degrees, the oil contact angle being measured using n-hexadecane.

[0006] In another aspect, the first and second friction modification materials are dispersed to each other according to a predetermined pattern, the predetermined pattern including: a Penrose tiling pattern; a white noise pattern; a blue noise pattern; or a plurality of sub-patterns, each sub-pattern being adjacent to at least one other sub-pattern, wherein the transition between adjacent sub-patterns is substantially undetectable.

[0007] Other features and advantages of the examples, as well as their structures and operations, are described in detail below with reference to the accompanying drawings. Note that the ideas and techniques are not limited to the specific embodiments described herein. These examples are presented herein for illustrative purposes only. Additional examples will be apparent to those skilled in the art based on the teachings contained herein. Attached Figure Description

[0008] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate various embodiments of the present application and, together with the specification, further serve to explain the principles of the embodiments and allow those skilled in the art to implement and use these embodiments.

[0009] Figure 1 A touchscreen computing device including a touchscreen panel and a stylus suitable for use with the computing device are described according to one embodiment.

[0010] Figure 2 A schematic elevation view of the display layer and touch sensor layer of a touch screen panel according to one embodiment is depicted.

[0011] Figure 3 An example graph depicts the changing coefficient of kinetic friction between the stylus and the paper as the stylus moves across the paper, according to one embodiment.

[0012] Figure 4a The original words “dart” and “kite” are depicted in the Penrose tile according to one embodiment.

[0013] Figure 4b A description of a method according to an embodiment is provided. Figure 4a The Penrose pattern is generated from kites and darts.

[0014] Figure 4c Depicting according to one embodiment, Figure 4b A magnified view of the Penrose pattern.

[0015] Figure 5a and 5b A graph depicting a white noise pattern according to one embodiment and a typical white noise radial power spectrum are shown.

[0016] Figure 6a A blue noise tiling pattern according to one embodiment is depicted.

[0017] Figure 6b The generation according to one embodiment is described Figure 6a The blue noise pattern is a 3x3 matrix of blue noise tiles.

[0018] Figure 6c A graph depicting a typical radial power spectrum of a blue noise pattern according to one embodiment is provided.

[0019] Figure 7 A flowchart depicts an example method for manufacturing a friction-modified touchscreen panel according to one embodiment.

[0020] Figures 8a-8e A schematic side elevation view depicts the layer-by-layer manufacturing steps of a touchscreen panel with surface friction modification according to one embodiment.

[0021] The features and advantages of the various embodiments will become more apparent from the following detailed description when the same reference numerals are used to identify corresponding elements in the accompanying drawings. In the drawings, the same reference numerals generally indicate equivalent, functionally similar, and / or structurally similar elements. The first appearance of an element in a drawing is indicated by the leftmost digit of the corresponding reference numeral(s). Detailed Implementation

[0022] I. Introduction

[0023] This specification and accompanying drawings disclose one or more embodiments including various features of the invention. The scope of the invention is not limited to the disclosed embodiments. The disclosed embodiments are merely illustrative of the invention, and modified versions of the disclosed embodiments are also covered by the invention. The various embodiments of the invention are defined by the appended claims.

[0024] References to "an embodiment," "an example embodiment," "an exemplary embodiment," etc., in the specification indicate that the described embodiment may include a particular feature, structure, or characteristic; however, each embodiment need not necessarily include that particular feature, structure, or characteristic. Furthermore, these phrases do not necessarily refer to the same embodiment. Additionally, when a particular feature, structure, or characteristic is described in connection with an embodiment, whether explicitly described or not, implementing that feature, structure, or characteristic in conjunction with other embodiments is considered to be within the knowledge of those skilled in the art.

[0025] In this discussion, unless otherwise stated, adjectives such as substantially and approximately denote conditions or relational characteristics that modify one or more features of embodiments of this disclosure should be understood to mean that the condition or characteristic is limited to a tolerance of operation of the embodiment that is acceptable for the application to which the embodiment is intended.

[0026] Several exemplary embodiments are described below. It should be noted that any section / subsection headings provided herein are not intended to be limiting. Various embodiments are described in this document, and embodiments of any type may be included under any section / subsection. Furthermore, the embodiments disclosed in any section / subsection may be combined in any way with any other embodiments described in the same section / subsection and / or different sections / subsections.

[0027] II. Example Implementation

[0028] As mentioned above, modern high-resolution, wide-color-gamut displays enable applications on touchscreen devices to accurately simulate pen and / or pencil strokes. While such simulated strokes may be visually very realistic, unfortunately, the physical feel associated with drawing such strokes on a touchscreen device using a digital pen or stylus is not as satisfying as with traditional pencils and paper.

[0029] The feeling of writing with a pencil or pen on paper is unique, and this feeling cannot be replicated by gliding a rigid pen tip across the perfectly smooth glass of a touchscreen panel. Touchscreen panels with smooth touch surfaces can make it difficult to create or control fine strokes with a stylus because the glass surface of a typical touchscreen panel has too little friction. Furthermore, the lack of friction between the stylus tip and the touchscreen surface makes it difficult for users to maintain awareness of the stylus tip's position without actively looking at it.

[0030] Therefore, this document describes embodiments of touchscreen panels including a friction-modified surface that imparts a relatively rough feel, such as paper, when touched by a user with a suitable stylus or digital pen. Touchscreen panels can be used in any type of computing device that requires a display and receives input from a user. Such devices can include, for example, mobile devices (e.g., smartphones, tablets, PDAs, etc.), laptops and notebook computers, and many other types of computing devices. For example, consider… Figure 1 The illustration depicts a touchscreen computing device 102 including a touchscreen panel 108 and a stylus 104 adapted for use with the computing device 102, according to one embodiment. The stylus 104 includes a stylus tip 106, which will be discussed in further detail below.

[0031] Touchscreen panels, such as touchscreen panel 108, typically include a digitizer for detecting touch input from a finger or digital pen. Figure 1 (Not shown in the image). Digitizers can operate in various ways. For example, digitizers in the touchscreen panels of mobile devices such as smartphones and tablets typically operate in a capacitive multi-touch mode using capacitive sensors. One such sensor is called a "mutual capacitance" sensor, which is typically formed as a matrix comprising a transparent conductive material, such as indium tin oxide. For example, consider... Figure 2The diagram depicts a schematic side elevation view 200 of an LCD display layer 204 and a touch sensor layer 218, according to an embodiment, suitable for receiving friction-modified surfaces in a touchscreen panel. The LCD display layer 204 includes a backlight layer 206, a glass layer 208, a TFT layer 210, an LCD layer 212, an RGB filter layer 214, and a glass layer 216. The touch sensor layer 218 includes an indium tin oxide (“ITO”) layer 220, an insulating layer 222, another ITO layer 224, a polarizer layer 226, and a top glass layer 202. These layers of the schematic side elevation view 200 are described below.

[0032] like Figure 2 The LCD display layer 204 shown in schematic diagram 200 is an example layer found in conventional liquid crystal thin-film transistor displays. The LCD display is a transmissive medium, thereby selectively reducing or blocking light from a constantly on light source on a per-pixel basis. LCD display layer 204 includes a backlight 206, which includes a constantly on white light source. Glass layers 208 and 216 surround the remaining layers. TFTs 210 include thin-film transistor arrays arranged in a matrix across the display, one TFT per pixel. Each TFT acts as a control valve to drive the liquid crystal cell corresponding to that pixel. When no voltage is applied to the liquid crystal cell, the liquid crystal molecules align parallel to the surface of the display, thus blocking light transmission. Conversely, when a voltage is applied through the TFT, the liquid crystal cell can become fully or partially transparent. By changing the voltage applied by each TFT, the intensity of light from the backlight 206 can be changed at each discrete location. Since the backlight 206 is a white light source, the LCD display also includes an RGB filter 214 disposed above LCD layer 212. RGB filter 214 is a matrix of red, green, and blue filters covering the LCD matrix, and renders the light transmitted at each location as one of these colors. Although Figure 2 As not shown in the diagram, the LCD display layer 204 may also include polarizer layers above and below the LCD layer 212.

[0033] Touch sensor layer 218 is placed on top of LCD display layer 204. As described above, the mutual capacitance sensor can be formed as a matrix comprising a transparent conductive material (e.g., indium tin oxide). Touching the surface of the touchscreen panel with a finger or other conductive object causes a change in the charge storage capacity of capacitor nodes (i.e., the overlay layer) near the touch (and thus a change in capacitance). Each capacitive node is associated with one or more pixels directly below the touch point on the display. The capacitance change of the capacitor nodes can be detected to determine the touch position of a finger or conductive object on the touch-sensitive display. The capacitance change can be detected by rapidly sampling each node using any of the various techniques known in the art. Mutual capacitance detection allows for multi-touch operation, where multiple touch objects (e.g., fingers) can be tracked simultaneously.

[0034] Above the ITO layer 224, the touchscreen panel may include a polarizer layer 226, which operates alone or in combination with other anti-reflective layers (not shown) to reduce screen reflections. The polarizer layer 226 is used to polarize light entering the display from outside the device, such that when the polarized light is reflected away from the inner layers, the polarizer layer 226 prevents the light from leaving the display.

[0035] The touch sensor layer 218 also includes a top glass layer 202, which typically forms the outermost layer of the touchscreen panel. In conventional touchscreen panels using capacitive touch, projected capacitive touch, or some other touch technologies, the outermost surface on which or on which the touch-sensitive surface is formed is typically made of glass, plastic (including polycarbonate, PET, acrylic, etc.), or other similar materials. The component having this outermost glass, plastic, or other similar material is typically referred to as a "cover lens," but may sometimes be called a "top glass" or "top cover." For cover lenses made of glass (such as ion-strengthened glass), the thickness can range from about 0.3 mm to about 0.6 mm for smartphone applications, and from 0.3 mm to 1.0 mm for large displays. For cover lenses made of acrylic materials (such as polymethyl methacrylate), the thickness can range from about 1.0 mm to higher for smartphone applications.

[0036] It should be understood that while the embodiments described herein can be expressed using capacitive touch sensors and / or TFT LCD displays, the embodiments can be implemented using any suitable touch panel technology, including transparent touch technologies (such as capacitive touch and projected capacitive touch (including in-cell, on-lens sensors, on-cell, and other variations) and even some forms of resistive touch technology). The underlying display can be of any type, including any type of transmissive display, such as LCD, emitting displays (such as LED, micro-LED, and / or OLED), and reflective displays based on, for example, electronic paper.

[0037] Within certain limitations, digitizers, including those using mutual capacitance sensors, can be used to accept touch input from any object capable of causing a change in capacitance within the sensor; perhaps the most familiar example is a user's finger. Another example includes what is commonly referred to as a passive stylus. Passive styluses typically consist of a relatively large, flexible, and blunt tip that is internally electrically connected to a shaft that is conductive within the stylus itself. When held, the stylus essentially becomes an electrical extension of the hand, thus acting as an artificial finger that can be used as a pen. One problem with this type of stylus is the limitation on how small the tip can be constructed and expected to function properly on a touch-sensitive device. If the tip is too small, it may not be able to change the capacitance at the sensor node to be read correctly (i.e., the input may appear as noise and be filtered out). Large, flexible tips can provide all the precision needed for simple navigation of menus on a device or webpage. However, such tips are generally not precise enough for artistic drawing or many other uses. It is also difficult or impossible to see the point of contact of the stylus on the touch-sensitive surface, leading to further inaccuracies. To address these and other drawbacks of passive styluses, other types of digital pens have been created.

[0038] One type of digital pen operates in a mode commonly referred to as "reflective capacitance." As described above, the act of touching a capacitively based digitizer causes a change in the charge stored in the digitizer's capacitor nodes at the point of contact. However, the same action also causes a change in the charge stored at, for example, the tip electrode of the digital pen. Reflective capacitance digital pens are used to detect and measure changes in induced current or voltage at the tip electrode and then amplify that change in response. The result is an additional change in capacitance at the capacitor nodes due to this amplification, and thus the digitizer detects a much stronger touch signal. Because of this amplification, it is possible to produce digital pens with much smaller and more rigid tips, which can provide higher spatial resolution to the digitizer.

[0039] Another type of digital pen operates similarly to a reflective capacitive digital pen, but may include the ability to transmit information directly to the touch-sensitive device itself, and may also include specially designed tip electrode features designed to work with the matching digitizer design. This type of digital pen is often referred to as an "active digital pen." Such active digital pens and their matching digitizers can have the excellent spatial resolution desired, for example, by graphic designers and artists. Furthermore, the ability to establish one-way communication from the digital pen to the digitizer or bidirectional communication between them allows the digitizer to collect additional information and provide it to a host application running, for example, on the corresponding touch-sensitive device.

[0040] For any type of digital pen (and other types of pens), it is possible to use a small, rigid nib and control the nib's hardness and frictional properties. When used with such styluses, embodiments can provide the user with paper-like feedback when drawing or writing on a touchscreen panel that includes a friction-modified surface. By modifying the surface friction of the touchscreen to approximate the friction between the paper and the pen tip as the pen tip moves across it, embodiments provide this paper-like feel on touchscreen panel devices. For example, consider... Figure 3 The example curve 300 depicts the changing coefficient of kinetic friction (“COF”) between the stylus and the paper as the stylus moves across the paper. As shown in curve 300, the frictional variation between the pen tip and the paper, with an average COF of approximately 0.30, occurs at various points above or below this value when the pen tip moves 40 mm across the paper. Such variations in the coefficient of friction are typically due to variations in the surface roughness of the paper itself.

[0041] Notice, Figure 3 The graph 300 is merely exemplary and used to illustrate how friction can vary on the surface of real paper, but should not be construed as a requirement of any embodiment. For example, depending on the properties of the selected friction-modifying material, the attributes of the predetermined pattern, and / or the properties of the stylus used for tactile input, the embodiments may have a surface average COF higher or lower than 0.30. In other words, the embodiments are intended to replicate the variable surface friction of pen-paper interaction, rather than replicating any particular average COF.

[0042] Paper roughness typically ranges from 1µ to 5µ in average roughness (RA), resulting from the paper's fiber content, where fiber diameters are 10-50µ and fiber spacing is 10-200µ. While the surface roughness of a touchscreen panel can be modified to resemble that of paper, modifying the surface to add vertical undulations between 10-50µ in height will render the transparent overlay lens surface matte, which cannot reproduce full grayscale contrast or full-screen resolution. Furthermore, surface perturbations (e.g., peaks and valleys) will create microscopic "microlenses" that tend to distort the displayed image and produce color flicker and other problems. Therefore, various embodiments form a friction-modified surface on the touchscreen panel that approximates the variable friction of paper by dispersing two different friction-modifying materials onto the surface of the touchscreen panel, wherein the materials are selected to have different frictional properties and deposited as a monolayer.

[0043] Various friction-modifying materials can be employed in the embodiments. For example, modern touchscreen panels are sometimes coated with polymer layers to reduce contaminant buildup or enhance the device's cleanability (i.e., to have a high water contact angle). Such coatings may include, for example, long-chain polymers with siloxane groups at one end and fluorine groups at the other. The siloxane groups react with hydroxyl groups on the glass surface to form very strong and stable covalent Si-O bonds. It has been observed that the structure of such polymer molecules determines the nanoscale roughness of the coated surface. Specifically, compounds with a more glassy / amorphous long-chain molecular structure (e.g., DaikinOptool UD509) will provide a more lubricated surface compared to compounds with more crystalline short-chain molecules (e.g., DaikinOptool UD120). In the embodiments, the "smooth" amorphous compound dispersed on the surface of the touchscreen panel along with the more crystalline compound will not only increase the apparent friction between the screen surface and the stylus tip but also vary it across the entire surface. The resulting friction, achieved through a modified surface, will cause the stylus tip to encounter either greater or less friction as it moves across different types of materials.

[0044] The polymer compounds applicable to the various embodiments disclosed herein have the following characteristics: for crystalline materials, the coefficient of kinetic friction (“COF”) is between 0.06 and 0.10; and for amorphous materials, the kinetic COF is between 0.01 and 0.05. As will be understood by those skilled in the art, the kinetic COF is defined between two materials and is therefore not a property of a particular material. Rather, the coefficient of kinetic friction is an empirical measurement of a “system property,” where the measured COF depends on the two materials in contact with each other. For the kinetic COF range specified above, such COFs were measured between each polymer compound and a paper sample, wherein the paper sample has a kinetic COF of approximately 0.17 compared to another sample of the same paper.

[0045] In addition to the COFs described above applicable to the compounds of each embodiment, such compounds may be selected that have the following additional properties: a water contact angle >90 degrees (for cleanliness); and an oil contact angle greater than 30 degrees as measured with n-hexadecane (for fingerprint resistance). Ideally, the compounds will also exhibit resistance to skin moisturizers, petrolatum containing 6.5% α-hydroxyl, perfumes, artificial sweat, coffee, cola, ketchup, and / or isopropanol.

[0046] Note that, unlike previous attempts to produce touchscreen panels with surface friction modification, it is not necessary to match the bulk refractive index of each of the crystalline and amorphous friction modification compounds because, in each embodiment, each compound is adhered as a monolayer to the outer surface of the touchscreen panel. In addition to being able to use friction modification materials with substantially different refractive indices, depositing such materials as monolayers makes the material pattern invisible and does not produce any scattering. Furthermore, the surface haze of the embodiments shows almost no increase compared to unpatterned surfaces (i.e., haze measurements of the manufactured embodiments using a Gardner haze meter show haze <0.15%).

[0047] Having described the compounds suitable for use in the various embodiments, this specification now turns to how the embodiments control the dispersion of the friction modification materials among themselves on the surface of the touchscreen panel. Of course, there are many ways to disperse two compounds among themselves. The embodiments described herein, and those discussed in further detail below, use predetermined patterns to mask portions of the touchscreen panel, thereby allowing the friction modification materials to be patterned onto the surface of the panel.

[0048] Of course, many patterns are possible, but not all patterns are suitable. More specifically, a suitable pattern should not have any long sequence that might manifest as an unnatural tactile response in the stylus. For example, consider a simple pattern in which a friction-modifying compound is deposited on the entire surface in a checkerboard pattern. While such a surface would have alternating areas of relatively high or low friction, a stylus drawing on such a surface would suffer an unpleasant 'click' sound when the stylus tip interacts with the overly regular pattern. Therefore, the embodiments employ predetermined patterns that do not have a long sequence, such as, for example, Penrose tiling. Reference will now be made to... Figures 4a-4c Describe Penrose tiling.

[0049] Penrose tiling is a type of non-periodic tiling in which the tiling covers a surface in polygonal or other shapes, and the pattern lacks translational symmetry (i.e., moving any tiling a finite distance without rotation will not produce the same tiling). Although Penrose tiling can have reflective and rotational symmetry, it is precisely because of the lack of translational symmetry that Penrose tiling is suitable for use in various embodiments. This is true because moving a stylus along a straight line on a Penrose tiling surface will not cause the stylus to trace a repeating pattern.

[0050] Penrose tiling has many variations that use different tile shapes. Figure 4a The original words “dart” and “kite” are depicted in Penrose tile according to one embodiment. Figure 4aIncludes Kite 402 and Dart 404. Instances of Kite and Dart can be tiled according to certain matching rules, where such tiling can expand outwards indefinitely. Figure 4b A description of a method according to an embodiment is provided. Figure 4a The Penrose pattern generated by kite 402 and dart 404. Due to its difficulty in discernment... Figure 4b The Penrose tiling structure, Figure 4c Depicting Figure 4b An enlarged view of the Penrose pattern, showing details. Alternatives to the Penrose tiling are available for each embodiment.

[0051] For example, Figure 5a and 5b A graph 506 depicts a white noise pattern 504 according to one embodiment and a typical white noise radial power spectrum. The pixels of the white noise image are independent random variables with a uniform probability distribution. Such a white noise image can be created by generating random numbers between 0 and 255 for each pixel, where the resulting numbers correspond to the 8-bit grayscale of that pixel. The white noise pattern 504 can be created from such a white noise image by applying a thresholding operation to render pixels as black or white. The white noise pattern 504 can then be used to pattern the deposition of two friction-modified materials, where each material corresponds to a black or white pixel in the white noise pattern 502.

[0052] Figure 5b Graph 506 illustrates a typical radial power spectrum of white noise. Consistent with the fact that the pixels of a white noise image are random variables with a uniform distribution, the power is essentially uniformly distributed across the entire spectrum. The power present at lower frequencies corresponds to larger “blocky” regions (i.e., aggregates) of the pattern, and such regions can cause unnatural variations in surface friction felt by the stylus. In this case, the embodiments could instead employ alternative patterns with little or no low-frequency energy.

[0053] For example, Figures 6a-6c Blue noise tiles 602, including a 3x3 tiled blue noise pattern 604 comprising the blue noise tiles 602, and a typical blue noise radial power spectrum 606 are depicted according to various embodiments. Blue noise prevents the formation of aggregates in the pattern, and blue noise patterns such as blue noise pattern 604 may be suitable for use in the various embodiments. The absence of aggregates is partly due to the absence of low-frequency components, as shown in the blue noise radial power spectrum 606.

[0054] The blue noise pattern 604 can be generated in a variety of ways known in the art. For example, combining a 50% grayscale base image with a small amount of white noise and running the resulting image through an error diffusion algorithm (e.g., Jarvis Judice and Ninke) can generate an image that substantially includes blue noise. Various alternative schemes for generating blue noise images are known in the art, but may be computationally intensive in some cases. Therefore, it may be desirable to construct a larger blue noise image using a pre-computed blue noise tile (such as, for example, blue noise tile 602) and by forming an NxN matrix of blue noise tile 602. For example, blue noise pattern 604 is a 3x3 matrix of blue noise tile 602. Although blue noise tile 602 is reused, it can be seen that blue noise pattern 604 has few or no discernible repeating patterns.

[0055] Therefore, the embodiments do not require patterning the entire touchscreen panel surface with a single monolithic pattern. Instead, tiling can be used, as long as care is taken to avoid repeating structures appearing and becoming noticeable when used with a stylus. In other words, the transition points between one tile and another should not be so abrupt that the user can detect such a transition when the stylus tip passes over it. Similarly, tiling does not require using only a single blue noise tiling pattern, such as blue noise tiling 602. Instead, any number of tilings can be combined with each other to create a blue noise pattern (or other noise patterns, such as white noise patterns) similar to blue noise pattern 604.

[0056] Having described suitable compounds and mask patterns above, this specification now turns to a description of methods for manufacturing friction-modified touchscreen panels. For example, Figure 7 A flowchart 700 depicts an example method for manufacturing a friction-modified touchscreen panel according to one embodiment. Figures 8a-8e A schematic side elevation view depicting the layer-by-layer manufacturing steps of surface friction modification for a touchscreen panel, where each step corresponds to... Figure 7 This is a step from flowchart 700. Therefore, refer to... Figures 8a to 8e To describe Figure 7 Flowchart 700.

[0057] Figure 7 Flowchart 700 begins at step 702. In step 702, a first friction-modifying material layer is deposited on the outer surface. For example, and referring to... Figure 8a A uniform layer 802a of the first friction-modifying material is deposited on the entire top glass 202 (i.e., the outer surface) of, for example, the touchscreen panel 108 of the computing device 102. As described above, the first friction-modifying material may comprise a relatively amorphous compound or a relatively more crystalline compound.

[0058] Flowchart 700 continues to step 704. In step 704, a mask layer is deposited on the first friction-modified material layer according to a predetermined pattern. For example, and referring to... Figure 8b The mask layer 804 is deposited on top of the first friction-modified material of layer 802a and is used to protect the portions of layer 802a from subsequent processing steps (i.e., in a manner similar to integrated circuit manufacturing).

[0059] Flowchart 700 continues to step 706. In step 706, the first friction modification material is removed from the unmasked area of ​​the outer surface. (See reference) Figure 8b and 8c , Figure 8b The portions of layer 802a that are visible from above through a window in the mask can be removed, for example, by plasma etching, to produce a result such as Figure 8c The etched layer 802b is shown. After etching, the window in the mask layer 804 extends downwards and through the first friction-modified material of layer 802a all the way to the top glass layer 202.

[0060] Flowchart 700 continues to step 708. In step 708, a second friction-modifying material layer is deposited on the outer surface. (See reference) Figure 8d Layer 806 includes a second friction-modifying material, wherein the material has the following properties: Figure 8a The initial deposition, as shown and described in step 702 of flowchart 700 above, is a complementary friction profile of a first friction-modifying material for layer 802a. That is, if the initial layer 802a has a more amorphous compound, a more crystalline compound is used to deposit layer 806, and vice versa. During the deposition of layer 806, a second friction-modifying material extends downward through the mask layer 804 and through a window in the etched layer 802b to contact and bond to the top glass layer 202. Following the deposition of layer 806, the bottom layer (layer 802c) of this stack comprises a patterned combination of the first and second friction-modifying materials.

[0061] Flowchart 700 ends at step 710. In step 710, the mask layer is removed. For example, refer to... Figure 8d and 8e The mask layer 804 and any remaining amount of the second friction-modifying material above layer 802c (i.e., at layer 806) are removed, resulting in a top glass layer 202. The first and second friction-modifying materials are dispersed on the top glass layer according to the predetermined mask pattern employed. As described above, the first and second friction-modifying materials are selected such that each material represents one or more ranges of an acceptable kinetic COF relative to the paper, which has a kinetic COF of approximately 0.17 when measured relative to itself. Note that... Figure 7 The manufacturing process of flowchart 700 (and such as...) Figures 8a-8e The described process is only a single example of a process for manufacturing a touchscreen panel with surface friction modification, and other process steps and techniques may be substituted in the various embodiments.

[0062] In one embodiment, the first and second friction-modifying materials are selected to have a coefficient of kinetic friction in one or more of the ranges between 0.01 and 0.05 or between 0.06 and 0.1, respectively, the coefficient of kinetic friction being measured relative to a printing paper having a coefficient of kinetic friction of 0.17.

[0063] For example, one such process may include a peel-off screen printing process. As mentioned above, such a process can be achieved by first patterning the top glass with adhesive according to a predetermined pattern (e.g., as shown in the image). Figure 2 The process is performed on the top glass (202) shown. Next, a first friction modification material layer can be placed on top of the adhesive layer, which acts as a mask. The voids in the adhesive layer allow the first friction modification layer to contact the glass surface and bond to it at these locations. Next, the adhesive can be dissolved with a solvent, and any excess friction modification material can be mechanically removed, leaving only the firmly bonded material. At this point, a top glass with a first friction modification material patterned according to a predetermined pattern will be visible, with voids in the first friction modification material extending downwards to the glass surface. Next, a second friction modification material can be deposited, which can penetrate through the voids in the second friction modification material all the way down to the top of the glass and thus bond to it. Finally, excess and loosely bonded second friction modification material can be removed, exposing the first friction modification material and leaving the first and second friction modification materials scattered on the surface of the touchscreen panel.

[0064] In another embodiment, dry film lithography can be used to manufacture touchscreens with surface friction modification. Such process steps can be performed in the following general manner:

[0065] Use a dry film photoresist (such as DuPont Riston EM213) to laminate the top glass.

[0066] A photomask with a predetermined pattern is used to cover the laminated top glass, exposing the unmasked photoresist to ultraviolet light.

[0067] Unexposed photoresist was removed by development with 1.0 wt% sodium carbonate at room temperature. The top glass was then patterned with a polymerized photoresist mask, including openings down to the top glass.

[0068] A first friction-modifying material layer is sprayed on, allowing the material to penetrate downwards into and bond with the exposed top glass.

[0069] The UV-exposed / polymerized photoresist is dissolved using, for example, 1.5% by weight of sodium hydroxide, and excess and loosely bonded first friction modification material is removed. The top glass is now patterned with the first friction modification material (including the voids extending down to the top glass).

[0070] A second friction-modifying material is sprayed on, allowing it to penetrate downwards to the exposed top and bond with it.

[0071] Excessive and loosely bonded second friction modification material is removed, leaving the first and second friction modification materials scattered on the surface of the touchscreen panel.

[0072] III. Additional Example Implementations

[0073] This document provides a touchscreen panel including a friction-modified touch-sensitive surface. The friction-modified touch-sensitive surface includes: an outer surface of the touchscreen panel, the outer surface including a touch-sensitive area; a first friction-modifying material; and a second friction-modifying material, wherein the first and second friction-modifying materials are dispersed among each other as monolayers on the outer surface according to a predetermined pattern, and wherein the first friction-modifying material is relatively more amorphous than the second friction-modifying material.

[0074] In one embodiment of the aforementioned touchscreen panel, the difference in refractive index between the first friction-modifying material and the second friction-modifying material is greater than 0.10.

[0075] In another embodiment of the aforementioned touchscreen panel, the first friction-modifying material has a coefficient of kinetic friction between 0.01 and 0.05, and the second friction-modifying material has a coefficient of kinetic friction between 0.06 and 0.10, wherein the coefficients of kinetic friction of the first and second friction-modifying materials are measured relative to a printed paper having a coefficient of kinetic friction of 0.17.

[0076] In one embodiment of the aforementioned touchscreen panel, the first and second friction-modifying materials have a water contact angle greater than 90 degrees.

[0077] In one embodiment of the aforementioned touchscreen panel, the first and second friction-modifying materials have an oil contact angle greater than 60 degrees, which is measured using n-hexadecane.

[0078] In another embodiment of the aforementioned touchscreen panel, the predetermined pattern includes: a Penrose tiling pattern; a white noise pattern; a blue noise pattern; or a plurality of sub-patterns, each sub-pattern being adjacent to at least one other sub-pattern, wherein the transition between adjacent sub-patterns is substantially undetectable.

[0079] In another embodiment of the aforementioned touchscreen panel, the predetermined pattern has a feature size greater than 200 micrometers.

[0080] This article provides a method for forming a friction-modified touch-sensitive surface on the outer surface of a touchscreen panel. The method includes: depositing a first friction-modifying material layer on the outer surface; depositing a mask layer on the first friction-modifying material layer according to a predetermined pattern; removing the first friction-modifying material from an unmasked area of ​​the outer surface; depositing a second friction-modifying material layer on the outer surface; and removing the mask layer, wherein the first and second friction-modifying materials are selected to have a coefficient of kinetic friction in one or more of a range between 0.01 and 0.05 or between 0.06 and 0.1, respectively, the coefficient of kinetic friction being measured relative to printed paper having a coefficient of kinetic friction of 0.17.

[0081] In one embodiment of the aforementioned method, the first friction-modified material is relatively more amorphous than the second friction-modified material.

[0082] In another embodiment of the aforementioned method, the difference in refractive index between the first friction-modifying material and the second friction-modifying material is greater than 0.1.

[0083] In one embodiment of the aforementioned method, the first and second friction-modifying materials have a water contact angle greater than 90 degrees.

[0084] In one embodiment of the aforementioned method, the first and second friction-modifying materials have an oil contact angle greater than 30 degrees, which is measured using n-hexadecane.

[0085] In another embodiment of the aforementioned method, the predetermined pattern includes: a Penrose tiling pattern; a white noise pattern; a blue noise pattern; or a plurality of sub-patterns, each sub-pattern being adjacent to at least one other sub-pattern, wherein the transition between adjacent sub-patterns is substantially undetectable.

[0086] In another embodiment of the aforementioned method, the first and second friction-modified material layers are deposited as monolayers.

[0087] This document provides a touchscreen computing device. The touchscreen computing device includes: a processor; a touchscreen panel coupled to the processor and including a friction-enhanced touch-sensitive surface, the friction-enhanced touch-sensitive surface including: an outer surface of the touchscreen panel including a touch-sensitive area; a first friction-modifying material; and a second friction-modifying material, wherein the first and second friction-modifying materials are dispersed as monolayers on the outer surface according to a predetermined pattern, and wherein the first friction-modifying material is relatively more amorphous than the second friction-modifying material.

[0088] In one embodiment of the aforementioned touchscreen computing device, the difference in refractive index between the first friction-modifying material and the second friction-modifying material is greater than 0.10.

[0089] In another embodiment of the aforementioned touchscreen computing device, the first friction-modifying material has a coefficient of kinetic friction between 0.01 and 0.05, and the second friction-modifying material has a coefficient of kinetic friction between 0.06 and 0.10, wherein the coefficients of kinetic friction of the first and second friction-modifying materials are measured relative to a printed paper having a coefficient of kinetic friction of 0.17.

[0090] In one embodiment of the aforementioned touchscreen computing device, the first and second friction-modifying materials have a water contact angle greater than 90 degrees.

[0091] In one embodiment of the aforementioned touchscreen computing device, the first and second friction-modifying materials have an oil contact angle greater than 30 degrees, which is measured using n-hexadecane.

[0092] In another embodiment of the aforementioned touchscreen computing device, the predetermined pattern includes: a Penrose tiling pattern; a white noise pattern; a blue noise pattern; or a plurality of sub-patterns, each sub-pattern being adjacent to at least one other sub-pattern, wherein the transition between adjacent sub-patterns is substantially undetectable.

[0093] IV. Conclusion

[0094] Although various embodiments of the disclosed subject matter have been described above, it should be understood that they are presented by way of example only and not as limiting. Those skilled in the art will understand that various modifications in form and detail may be made without departing from the spirit and scope of the embodiments as defined in the appended claims. Accordingly, the scope of the disclosed subject matter should not be limited to any of the exemplary embodiments described above, but should be defined only by the following claims and their equivalents.

Claims

1. A touchscreen panel including a friction-modified touch-sensitive surface, said friction-modified touch-sensitive surface comprising: The outer surface of the touch screen panel includes a touch-sensitive area; First friction modification material; as well as A second friction-modifying material, wherein the first friction-modifying material and the second friction-modifying material are distributed on the outer surface as monolayers according to a predetermined pattern, and wherein the first friction-modifying material is relatively more amorphous than the second friction-modifying material.

2. The touchscreen panel according to claim 1, characterized in that, The difference in refractive index between the first friction-modifying material and the second friction-modifying material is greater than 0.

10.

3. The touchscreen panel according to claim 2, characterized in that, The first friction-modifying material has a coefficient of kinetic friction between 0.01 and 0.05, and the second friction-modifying material has a coefficient of kinetic friction between 0.06 and 0.10, wherein the coefficients of kinetic friction of the first and second friction-modifying materials are measured relative to a printing paper having a coefficient of kinetic friction of 0.

17.

4. The touchscreen panel according to claim 1, characterized in that, The first friction modification material and the second friction modification material have a water contact angle greater than 90 degrees.

5. The touchscreen panel according to claim 1, characterized in that, The first friction modification material and the second friction modification material have an oil contact angle greater than 30 degrees, which is measured using n-hexadecane.

6. The touchscreen panel according to claim 1, characterized in that, The predetermined pattern includes: Penrose tiling pattern; White noise pattern; Blue noise pattern; or multiple sub-patterns, each of which is adjacent to at least one other sub-pattern, wherein the transition between adjacent sub-patterns is substantially undetectable.

7. The touchscreen panel according to claim 6, characterized in that, The predetermined pattern has a feature size greater than 200 micrometers.

8. A method for forming a friction-modified touch-sensitive surface on the outer surface of a touchscreen panel, comprising: A first friction-modifying material layer is deposited on the outer surface; A mask layer is deposited on the first friction-modified material layer according to a predetermined pattern; Remove the first friction-modifying material from the unmasked area of ​​the outer surface; A second friction-modifying material layer is deposited on the outer surface, wherein the first friction-modifying material is relatively more amorphous than the second friction-modifying material; as well as Remove the mask layer; The first friction-modifying material and the second friction-modifying material are selected to have a coefficient of kinetic friction in one or more of the ranges between 0.01 and 0.05 or between 0.06 and 0.1, respectively, the coefficient of kinetic friction being measured relative to a printing paper having a coefficient of kinetic friction of 0.

17.

9. The method according to claim 8, characterized in that, The difference in refractive index between the first friction-modifying material and the second friction-modifying material is greater than 0.

1.

10. The method according to claim 8, characterized in that, The first friction modification material and the second friction modification material have a water contact angle greater than 90 degrees.

11. The method according to claim 8, characterized in that, The first friction modification material and the second friction modification material have an oil contact angle greater than 30 degrees, which is measured using n-hexadecane.

12. The method according to claim 8, characterized in that, The predetermined pattern includes: Penrose tiling pattern; White noise pattern; Blue noise pattern; or multiple sub-patterns, each of which is adjacent to at least one other sub-pattern, wherein the transition between adjacent sub-patterns is substantially undetectable.

13. The method according to claim 8, characterized in that, The first and second friction-modifying materials are deposited as a monolayer.

14. A touchscreen computing device, comprising: processor; A touchscreen panel coupled to the processor and including a friction-enhanced touch-sensitive surface, the friction-enhanced touch-sensitive surface comprising: The outer surface of the touch screen panel includes a touch-sensitive area; First friction modification material; and A second friction-modifying material, wherein the first friction-modifying material and the second friction-modifying material are distributed on the outer surface as monolayers according to a predetermined pattern, and wherein the first friction-modifying material is relatively more amorphous than the second friction-modifying material.

15. The touchscreen computing device according to claim 14, characterized in that, The difference in refractive index between the first friction-modifying material and the second friction-modifying material is greater than 0.

1.

16. The touchscreen computing device according to claim 15, characterized in that, The first friction-modifying material has a coefficient of kinetic friction between 0.01 and 0.05, and the second friction-modifying material has a coefficient of kinetic friction between 0.06 and 0.1, wherein the coefficients of kinetic friction of the first and second friction-modifying materials are measured relative to a printing paper having a coefficient of kinetic friction of 0.

17.

17. The touchscreen computing device according to claim 14, characterized in that, The first friction modification material and the second friction modification material have a water contact angle greater than 90 degrees.

18. The touchscreen computing device according to claim 14, characterized in that, The first friction modification material and the second friction modification material have an oil contact angle greater than 30 degrees, which is measured using n-hexadecane.

19. The touchscreen computing device according to claim 14, characterized in that, The predetermined pattern includes: Penrose tile pattern; White noise pattern; Blue noise pattern; or Multiple sub-patterns, each of which is adjacent to at least one other sub-pattern, wherein the transition between adjacent sub-patterns is substantially undetectable.

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