Patent Description:
The invention relates to a light guide-based deadfront article for a display, and more particularly to vehicle interior systems including a light guide-based deadfront article for a display.

In various applications involving displays, it is desirable to have a display surface or functional surface having a deadfront appearance. In general, a deadfront appearance is a way of hiding a display or functional surface such that there is a seamless transition between a display and a non-display area, or between the deadfronted area of an article and non-deadfronted area or other surface. For example, in a typical display having a glass or plastic cover surface, it is possible to see the edge of the display (or the transition from display area to non-display area) even when the display is turned off. However, it is often desirable from an aesthetic or design standpoint to have a deadfronted appearance such that, when the display is off, the display and non-display areas present as indistinguishable from each other and the cover surface presents a unified appearance. One application where a deadfront appearance is desirable is in automotive interiors, including in-vehicle displays or touch interfaces, as well as other applications in consumer mobile or home electronics, including mobile devices and home appliances. However, it is difficult to achieve both a good deadfront appearance and, when a display is on, a high-quality display.

Referring generally to the figures, vehicle interior systems may include a variety of different curved surfaces that are designed to be transparent, such as curved display surfaces, and the present disclosure provides articles and methods for forming these curved surfaces from a glass material. Forming curved vehicle surfaces from a glass material may provide a number of advantages compared to the typical curved plastic panels that are conventionally found in vehicle interiors. For example, glass is typically considered to provide enhanced functionality and user experience for many curved cover material applications, such as display applications and touch screen applications, compared to plastic cover materials.

Further, it is considered desirable in many applications to equip displays, and particularly displays for vehicle interior systems, with a deadfront structure. In general, a deadfront is a structure used in a display that blocks visibility of display components, icons, graphics, etc. when the display is off, but allows display components to be easily viewed when the display is on. In addition, a deadfront layer on a display or other glass vehicle system component can be used to match the color or pattern of the glass component to adjacent non-glass components to eliminate the visibility of transitions from the glass article to the non-glass article. For example, a display with a glass deadfront having a wood grain pattern or a leather pattern can be used to match the appearance of the display with surrounding wood or leather components of a vehicle interior system (e.g., a wood or leather dashboard) in which the display is mounted.

<FIG> shows a vehicle interior <NUM> that includes three different vehicle interior systems <NUM>, <NUM>, <NUM>, according to an exemplary embodiment. Vehicle interior system <NUM> includes a center console base <NUM> with a curved surface <NUM> including a display, shown as curved display <NUM>. Vehicle interior system <NUM> includes a dashboard base <NUM> with a curved surface <NUM> including a display, shown curved display <NUM>. The dashboard base <NUM> typically includes an instrument panel <NUM> which may also include a curved display. Vehicle interior system <NUM> includes a dashboard steering wheel base <NUM> with a curved surface <NUM> and a display, shown as a curved display <NUM>. In one or more embodiments, the vehicle interior system may include a base that is an arm rest, a pillar, a seat back, a floor board, a headrest, a door panel, or any portion of the interior of a vehicle that includes a curved surface.

The embodiments of the deadfront articles described herein can be used in any or all of vehicle interior systems <NUM>, <NUM> and <NUM>. While <FIG> shows an automobile interior, the various embodiments of the vehicle interior system may be incorporated into any type of vehicle such as trains, automobiles (e.g., cars, trucks, buses and the like), seacraft (boats, ships, submarines, and the like), and aircraft (e.g., drones, airplanes, jets, helicopters and the like), including both human-piloted vehicles, semi-autonomous vehicles and fully autonomous vehicles. Further, while the description herein relates primarily to the use of the deadfront embodiments used in vehicle displays, it should be understood that various deadfront embodiments discussed herein may be used in any type of display application.

Referring to <FIG>, a deadfront <NUM> for a vehicle display, such as displays <NUM>, <NUM> and/or <NUM>, is shown and described. <FIG> shows the appearance of deadfront <NUM> when a light source of the associated display is inactive, and <FIG> shows the appearance of deadfront <NUM> when a light source of the associated display is active. As shown in <FIG>, with the light source activated, a plurality of graphics or icons <NUM> are visible on the display. When the light source is inactivated, icons <NUM> disappear, and deadfront <NUM> presents a surface showing a desired pattern (e.g., a leather grain pattern in <FIG>) that is unbroken by icons <NUM>.

As will be discussed in more detail below, deadfront article <NUM> provides this differential icon display by utilizing one or more colored layers located between an outer glass layer and a light source. The optical properties of the colored layer are designed such that when the light source is turned off the borders of the icons or other display structures beneath the colored layer are not visible, but when the light source is on, icons <NUM> are visible. In various embodiments, the deadfront articles discussed herein are designed to provide a high quality deadfront, including high contrast icons with the light source on, combined with high contrast deadfront appearance when the light is off. Further, Applicant provides these various deadfront articles in a manner suitable for cold forming to curved shapes, including complex curved shapes, as discussed below.

Referring to <FIG>, a deadfront article <NUM> for a display is shown according to an exemplary embodiment. Deadfront article <NUM> includes a cover layer or structure, shown as cover glass stack <NUM>, a light guide layer, shown as glass light guide layer <NUM>, a reflector <NUM> and a light extraction layer <NUM>. In general, cover glass stack <NUM> includes an outer surface <NUM>, an inner surface <NUM>, a glass layer <NUM> and an ink layer <NUM>.

Glass layer <NUM> is located between outer surface <NUM> and inner surface <NUM>, and ink layer <NUM> is located between inner surface <NUM> and glass layer <NUM>. In one embodiment, ink layer <NUM> is a single layer of light transmitting ink or pigment applied to glass layer <NUM> to provide the deadfront functionality discussed herein. In various embodiments, such as shown in <FIG>, ink layer <NUM> may include two or more layers of ink or pigment material that each have different characteristics that provide different functionality to deadfront article <NUM>. In a specific embodiment, ink layer <NUM> includes a first layer <NUM> of light transmitting ink or pigment and a second layer <NUM> of light transmitting ink or pigment.

In various embodiments, first layer <NUM> is coupled to, attached to or bonded to an inner surface of glass layer <NUM>, and may be applied via processes such as inkjet printing. First layer <NUM> may be formed from an ink material, a pigment material or any suitable layer that provides both light transmission and light blocking as discussed herein. In general, first layer <NUM> is a layer with differential light transmission properties that acts to block the visibility of aspects of the display below first layer <NUM> when a light source is inactive, but when the light source is active, first layer <NUM> provides sufficient light transmission to allow various display components, graphics, etc. to be viewed through first layer <NUM>. In a specific embodiment, the transmission of the first layer <NUM> is between <NUM>% and <NUM>% for light having wavelengths of <NUM> -<NUM>.

In addition to blocking visibility of display components/icons while the display light source is inactive, a user viewing deadfront article <NUM> from outside of outer surface <NUM> is able to see first layer <NUM>. Thus, first layer <NUM> may be formed to provide a desired pattern or appearance to the display incorporating deadfront article <NUM> while also eliminating the visibility of various display components while the light source is inactive. In various embodiments, first layer <NUM> is formed, colored, applied, etc. in a manner that provides a desired appearance to the display incorporating deadfront article <NUM>. In various embodiments, first layer <NUM> provides one or more of the following appearances: a wood-grain design, a leather-grain design, a fabric design, a brushed metal design, a graphic design, and a logo. In other embodiments, first layer <NUM> may provide a solid colored appearance, such as a flat consistent black appearance.

Second layer <NUM> is located below first layer <NUM> and may be applied or printed onto the lower surface of first layer <NUM>. In the embodiment shown, second layer <NUM> is an image enhancing layer of light transmitting ink or pigment located between the first layer <NUM> and light extraction layer <NUM>. In a specific embodiment, layer <NUM> is formed from a white colored, light transmitting material that increases contrast of various portions of deadfront article <NUM>, such as the graphics of the display (discussed below) or a pattern, design, logo, etc. provided by layer <NUM>.

Deadfront article <NUM> is equipped with a glass light guide layer <NUM> and a light extraction layer <NUM> located on a surface of glass light guide layer <NUM>. In general, in this arrangement glass light guide layer <NUM> and light extraction layer <NUM> act together to form graphics, shown as graphics <NUM>, <NUM> and <NUM> in <FIG>, when a display light source is activated.

In specific embodiments, glass light guide layer <NUM> is a sheet of glass material having inner and outer major surfaces, and in the embodiment shown in <FIG>, light extraction layer <NUM> is located on the outer major surface of light guide layer <NUM>. Light extraction layer <NUM> is printed or applied to the surface of light guide layer <NUM> in a pattern corresponding to one or more display graphics, such as graphics <NUM>, <NUM> and <NUM> in <FIG>.

<FIG> shows a display <NUM> equipped with deadfront article <NUM>. As shown in <FIG>, display <NUM> is equipped with one or more light sources, shown as white light sources <NUM>, <NUM> and <NUM> and colored light sources <NUM>, <NUM> and <NUM>. In various embodiments, light sources <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and/or <NUM> are LED light sources. In various embodiments, light sources <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and/or <NUM> may be monochrome or multi-colored.

In general, the light sources are optically coupled to glass light guide layer <NUM> such that light from the light source(s) is carried within glass light guide layer <NUM> via total internal reflection. Light extraction layer <NUM> acts to extract out light from the glass light guide layer <NUM> in the shape of the graphics <NUM>, <NUM> and <NUM>, and because of the light transmission characteristics of ink layer <NUM>, the shape of the extracted light is visible through cover glass stack <NUM> from outside of the display. This arrangement allows the user to view graphics <NUM>, <NUM> and <NUM>, when the light source(s) are activated. When the light source(s) are inactive, ink layer <NUM> provides the blocking function discussed herein and blocks the visibility of light extraction layer <NUM>.

As can be seen from this description, the function of deadfront article <NUM> to provide visibility of graphics <NUM>, <NUM> and <NUM> when the light sources are activated and to block visibility of display components, such as light extraction pattern that forms graphics <NUM>, <NUM>, and <NUM>, stems from a balance of the light transmission properties of the various layers and materials that make up deadfront article <NUM>. In general, light extraction layer <NUM> is formed from an ink material having an opacity, and the opacity of this ink material is less than a threshold that is related to a transmissivity of light through the cover glass stack <NUM>.

In specific embodiments, the transmissivity of light through cover glass stack <NUM> is greater than <NUM>% and the opacity of the ink material of light extraction layer <NUM> is less than <NUM>%. In other specific embodiments, the transmissivity of light through cover glass stack <NUM> is between <NUM>% and <NUM>% and the opacity of the ink material of light extraction layer <NUM> is less than <NUM>%. In other specific embodiments, the transmissivity of light through cover glass stack <NUM> is about <NUM>% and the opacity of the ink material of light extraction layer <NUM> is about <NUM>%. In other specific embodiments, the transmissivity of light through cover glass stack <NUM> is about <NUM>% and the opacity of the ink material of light extraction layer <NUM> is about <NUM>%.

In specific embodiments, the ink material of light extraction layer <NUM> is a white ink material having an average thickness in a range of <NUM> to <NUM>. In some such embodiments, the light extraction patterns of light extraction layer <NUM> are made of a white ink that has a reflectance that is substantially the same as the reflectance of the reflector <NUM>. In various embodiments, light extraction layer <NUM> may be visible or non-visible to the eye.

In various embodiments, light extraction layer <NUM> is formed from clear ink material having an opacity that is nearly <NUM>%. In this embodiment, light extraction patterns are invisible when the backlight is off, and they are visible when the backlight is on. In another embodiment, light extraction layer <NUM> is located on the bottom or inner surface of light guide layer <NUM> and light confining features are located on the top surface of light guide layer <NUM>. In this embodiment, a first section of the graphics can be made visible in one color and a second section of the graphics can be made visible in a different color.

Suitable light extraction features can include a roughed surface on the glass sheet, produced either by roughening a surface of the glass sheet directly, or by coating the sheet with a suitable coating, for example a diffusion film. Light extraction features in some embodiments can be obtained, for example, by printing reflective (e.g., white dots) with a suitable ink, such as a UV-curable ink and drying and/or curing the ink. In some embodiments, combinations of the foregoing extraction features may be used.

In some embodiments, cover glass structure <NUM> has a light transmittance level less than <NUM>%. In such embodiments, when a light source of the display is inactive, ink layer <NUM> is visible from outside of cover glass structure <NUM> and also blocks the visibility of the light extraction layer <NUM> from outside of cover glass structure <NUM>. In a specific embodiment, a total level of light transmission through all layers of the cover glass stack <NUM> is between <NUM>%-<NUM>% for light having wavelengths from <NUM> to <NUM>.

As shown best in <FIG>, in some embodiments, glass light guide layer <NUM> is formed from a glass material that has an average thickness that is less than an average thickness of cover glass layer <NUM>. In some embodiments, glass light guide layer <NUM> and cover glass layer <NUM> are formed from the same glass material as each other. In some other embodiments, glass light guide layer <NUM> is formed from a first glass material, and cover glass layer <NUM> is formed from a second glass material different from the first glass material. In some embodiments, an air gap may be located between glass light guide layer <NUM> and cover structure <NUM> facilitating the light guide properties of layer <NUM>. In other embodiments, light guide layer <NUM> is made from a non-glass material, such as a polymer material. In a specific non-glass embodiment, light guide layer <NUM> is formed from a poly(methyl methacrylate) (PMMA).

Referring to <FIG>, glass light guide layer <NUM> is located between reflector <NUM> and cover glass stack <NUM>. In general, reflector <NUM> is a layer of reflective material that reflects light extracted from the backside of light guide layer <NUM> back into light guide layer <NUM> toward cover glass stack <NUM>. In some embodiments, reflector <NUM> acts to increase light intensity available to display information and increases the overall display brightness of light from light guide layer <NUM> through cover structure <NUM>.

By utilizing the glass light guide based as a light source for generating graphics <NUM>, <NUM> and <NUM> as discussed above, Applicant believes that display <NUM> may provide a variety of advantages. In one exemplary embodiment (as shown best in <FIG>), light guide layer <NUM> is formed from a sheet of glass material that includes an edge surface <NUM> that extends between the outer perimeters of the inner and outer major surfaces of the light guide layer <NUM>. In such embodiments, as shown schematically in <FIG>, the light source(s) are optically coupled to edge surface <NUM>. This arrangement allows the light source(s) of display <NUM> to be located in any of a variety of positions, eliminating the need for the light source(s) to be located in a stacked arrangement with deadfront article <NUM>. Thus, by providing light guide layer <NUM>, which is thin compared to many typical display stacks, like LED display stacks, the arrangement of deadfront article <NUM> allows for a thinner display, which may be particularly suited for location of displays on some vehicular or automotive structures that do not have sufficient depth to support a conventional display.

In some embodiments, the width and length dimensions of glass light guide layer <NUM> are substantially the same as the width and length dimensions of cover glass layer <NUM> such that glass light guide layer <NUM> provides a single light guide structure coextensive with the entire width and length of deadfront article <NUM>. In other embodiments, glass light guide layer <NUM> has a width and/or length dimension that is less than the corresponding dimension of cover glass layer <NUM>. In such embodiments, the glass light guide layer <NUM> may illuminate a sub-region of deadfront article <NUM>.

In some such specific embodiments, deadfront article <NUM> may include multiple glass light guide layers <NUM> each illuminating a different spatially distinct region of deadfront article <NUM>, represented by the different dashed line sections in <FIG>. In some such embodiments, upper light guide region <NUM> is optically coupled to light source <NUM> having a first color (e.g., a blue color), central light guide region <NUM> is optically coupled to light source <NUM> having a second color (e.g., a yellow color), lower light guide region <NUM> is optically coupled to light source <NUM> having a third color (e.g., a red color). This arrangement allows each of the different spatially distinct light guide regions to be illuminated with a distinct color, allowing a wider range of information to be conveyed via display <NUM>.

It should be understood that the glass materials or layers of deadfront article <NUM>, such as glass layer <NUM> and glass light guide layer <NUM> may be formed from any of the glass materials discussed herein. Further, deadfront article <NUM> may be shaped to a curved shape via any of the shaping processes discussed herein. In various embodiments, cover structure <NUM> may include a functional surface layer <NUM>, which may include at least one of a glare reduction coating, an anti-glare coating, a scratch resistance coating, an anti-reflection coating, a half-mirror coating, or easy-to-clean coating. Display <NUM> may also be equipped with touch sensor functionality.

A light guide plate was formed from Corning's trademarked Willow glass with a thickness of <NUM>. Light extraction patterns, corresponding to the desired graphics, were printed on the light guide plate with UVink LH-<NUM> White ink available from Mimaki Global, using the Mimaki UJF7151 plus printer. The white ink was about <NUM> thick. Different levels of the opacity of the white ink were used.

When the opacity of the white ink was higher than a threshold, the light extraction patterns were visible even when the backlight was off. When the opacity of the white ink was lower than a threshold, the light extraction patterns were invisible when the backlight was off. The threshold of the acceptable opacity varies with the transmission of the cover stack <NUM>. When the transmission of cover stack <NUM> was near <NUM>%, the threshold of the acceptable opacity of the white ink of light extraction layer <NUM> was about <NUM>%. When the transmission of cover stack <NUM> was about <NUM>%, the threshold of the acceptable opacity of the white ink of light extraction layer <NUM> was about <NUM>%. Further, when the white ink of light extraction layer <NUM> has opacity greater than the threshold, and the reflectance of the reflector <NUM> is substantially the same as the reflectance of the white ink of light extraction layer <NUM>, the light extraction patterns are invisible when the backlight is off, and the light extraction patterns are visible when the backlight is on.

Referring to <FIG>, various sizes, shapes, curvatures, glass materials, etc. for a glass-based deadfront along with various processes for forming a curved glass-based deadfront are shown and described. It should be understood, that while <FIG>-<NUM> are described in the context of a simplified curved deadfront structure <NUM> for ease of explanation, deadfront structure <NUM> may be any of the deadfront article embodiments discussed herein.

As shown in <FIG>, in one or more embodiments, deadfront article <NUM> includes a curved outer glass layer <NUM> having at least a first radius of curvature, R1, and in various embodiments, curved outer glass layer <NUM> is a complex curved sheet of glass material having at least one additional radius of curvature. In various embodiments, R1 is in a range from about <NUM> to about <NUM>.

Curved deadfront article <NUM> includes a deadfront colored layer <NUM> (e.g., the ink/pigment layer(s), as discussed above) located along an inner, major surface of curved outer glass layer <NUM>. In general, deadfront colored layer <NUM> is printed, colored, shaped, etc. to provide a wood-grain design, a leather-grain design, a fabric design, a brushed metal design, a graphic design, a solid color and/or a logo. Curved deadfront article <NUM> also may include any of the additional layers <NUM> (e.g., high optical density layers, light guide layers, reflector layers, display module(s), display stack layers, light sources, etc.) as discussed above or that otherwise may be associated with a display or vehicle interior system as discussed herein.

As will be discussed in more detail below, in various embodiments, curved deadfront article <NUM> including glass layer <NUM> and colored layer <NUM> may be cold-formed together to a curved shape, as shown in <FIG>. In some embodiments, curved deadfront article <NUM> including glass layer <NUM>, colored layer <NUM> and additional layers <NUM> may be cold-formed together to a curved shape, such as that shown in <FIG>. In other embodiments, glass layer <NUM> may be formed to a curved shape, and then layers <NUM> and <NUM> are applied following curve formation.

Referring to <FIG>, outer glass layer <NUM> is shown prior to being formed to the curved shape shown in <FIG>. In general, Applicant believes that the articles and processes discussed herein provide high quality deadfront structures utilizing glass of sizes, shapes, compositions, strengths, etc. not previously provided.

As shown in <FIG>, outer glass layer <NUM> includes a first major surface <NUM> and a second major surface <NUM> opposite first major surface <NUM>. An edge surface or minor surface <NUM> connects the first major surface <NUM> and the second major surface <NUM>. Outer glass layer <NUM> has a thickness (t) that is substantially constant and is defined as a distance between the first major surface <NUM> and the second major surface <NUM>. In some embodiments, the thickness (t) as used herein refers to the maximum thickness of the outer glass layer <NUM>. Outer glass layer <NUM> includes a width (W) defined as a first maximum dimension of one of the first or second major surfaces orthogonal to the thickness (t), and outer glass layer <NUM> also includes a length (L) defined as a second maximum dimension of one of the first or second surfaces orthogonal to both the thickness and the width. In other embodiments, the dimensions discussed herein are average dimensions.

In one or more embodiments, outer glass layer <NUM> has a thickness (t) that is in a range from <NUM> to <NUM>. In various embodiments, outer glass layer <NUM> has a thickness (t) that is about <NUM> or less. For example, the thickness may be in a range from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, or from about <NUM> to about <NUM>.

In one or more embodiments, outer glass layer <NUM> has a width (W) in a range from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, or from about <NUM> to about <NUM>.

In one or more embodiments, outer glass layer <NUM> has a length (L) in a range from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, or from about <NUM> to about <NUM>.

As shown in <FIG>, outer glass layer <NUM> is shaped to a curved shaping having at least one radius of curvature, shown as R1. In various embodiments, outer glass layer <NUM> may be shaped to the curved shape via any suitable process, including cold-forming and hot-forming.

In specific embodiments, outer glass layer <NUM> is shaped to the curved shape shown in <FIG>, either alone, or following attachment of layers <NUM> and <NUM>, via a cold-forming process. As used herein, the terms "cold-bent," "cold-bending," "cold-formed" or "cold-forming" refers to curving the glass deadfront at a cold-form temperature which is less than the softening point of the glass (as described herein). A feature of a cold-formed glass layer is an asymmetric surface compressive between the first major surface <NUM> and the second major surface <NUM>. In some embodiments, prior to the cold-forming process or being cold-formed, the respective compressive stresses in the first major surface <NUM> and the second major surface <NUM> are substantially equal.

In some such embodiments in which outer glass layer <NUM> is unstrengthened, the first major surface <NUM> and the second major surface <NUM> exhibit no appreciable compressive stress, prior to cold-forming. In some such embodiments in which outer glass layer <NUM> is strengthened (as described herein), the first major surface <NUM> and the second major surface <NUM> exhibit substantially equal compressive stress with respect to one another, prior to cold-forming. In one or more embodiments, after cold-forming (shown, for example, in <FIG>) the compressive stress on the second major surface <NUM> (e.g., the concave surface following bending) increases (i.e., the compressive stress on the second major surface <NUM> is greater after cold-forming than before cold-forming).

Without being bound by theory, the cold-forming process increases the compressive stress of the glass article being shaped to compensate for tensile stresses imparted during bending and/or forming operations. In one or more embodiments, the cold-forming process causes the second major surface <NUM> to experience compressive stresses, while the first major surface <NUM> (e.g., the convex surface following bending) experiences tensile stresses. The tensile stress experienced by surface <NUM> following bending results in a net decrease in surface compressive stress, such that the compressive stress in surface <NUM> of a strengthened glass sheet following bending is less than the compressive stress in surface <NUM> when the glass sheet is flat.

Further, when a strengthened glass sheet is utilized for outer glass layer <NUM>, the first major surface and the second major surface (<NUM>, <NUM>) are already under compressive stress, and thus first major surface <NUM> can experience greater tensile stress during bending without risking fracture. This allows for the strengthened embodiments of outer glass layer <NUM> to conform to more tightly curved surfaces (e.g., shaped to have smaller R1 values).

In various embodiments, the thickness of outer glass layer <NUM> is tailored to allow outer glass layer <NUM> to be more flexible to achieve the desired radius of curvature. Moreover, a thinner outer glass layer <NUM> may deform more readily, which could potentially compensate for shape mismatches and gaps that may be created by the shape of a support or frame (as discussed below). In one or more embodiments, a thin and strengthened outer glass layer <NUM> exhibits greater flexibility especially during cold-forming. The greater flexibility of the glass articles discussed herein may allow for consistent bend formation without heating.

In various embodiments, outer glass layer <NUM> (and consequently deadfront <NUM>) may have a compound curve including a major radius and a cross curvature. A complexly curved cold-formed outer glass layer <NUM> may have a distinct radius of curvature in two independent directions. According to one or more embodiments, the complexly curved cold-formed outer glass layer <NUM> may thus be characterized as having "cross curvature," where the cold-formed outer glass layer <NUM> is curved along an axis (i.e., a first axis) that is parallel to a given dimension and also curved along an axis (i.e., a second axis) that is perpendicular to the same dimension. The curvature of the cold-formed outer glass layer <NUM> can be even more complex when a significant minimum radius is combined with a significant cross curvature, and/or depth of bend.

Referring to <FIG>, display assembly <NUM> is shown according to an exemplary embodiment. In the embodiment shown, display assembly <NUM> includes frame <NUM> supporting (either directly or indirectly) both a light source, shown as a display module <NUM>, and deadfront structure <NUM>. As shown in <FIG>, deadfront structure <NUM> and display module <NUM> are coupled to frame <NUM>, and display module <NUM> is positioned to allow a user to view light, images, etc. generated by display module <NUM> through deadfront structure <NUM>. In various embodiments, frame <NUM> may be formed from a variety of materials such as plastic (PC/ABS, etc.), metals (Al-alloys, Mg-alloys, Fe-alloys, etc.). Various processes such as casting, machining, stamping, injection molding, etc. may be utilized to form the curved shape of frame <NUM>. While <FIG> shows a light source in the form of a display module, it should be understood that display assembly <NUM> may include any of the light sources discussed herein for producing graphics, icons, images, displays, etc. through any of the dead front embodiments discussed herein. Further, while frame <NUM> is shown as a frame associated with a display assembly, frame <NUM> may be any support or frame structure associated with a vehicle interior system.

In various embodiments, the systems described herein allow for formation of deadfront structure <NUM> to conform to a wide variety of curved shapes that frame <NUM> may have. As shown in <FIG>, frame <NUM> has a support surface <NUM> that has a curved shape, and deadfront structure <NUM> is shaped to match the curved shape of support surface <NUM>. As will be understood, deadfront structure <NUM> may be shaped into a wide variety of shapes to conform to a desired frame shape of a display assembly <NUM>, which in turn may be shaped to fit the shape of a portion of a vehicle interior system, as discussed herein.

In one or more embodiments, deadfront structure <NUM> (and specifically outer glass layer <NUM>) is shaped to have a first radius of curvature, R1, of about <NUM> or greater. For example, R1 may be in a range from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, or from about <NUM> to about <NUM>.

In one or more embodiments, support surface <NUM> has a second radius of curvature of about <NUM> or greater. For example, the second radius of curvature of support surface <NUM> may be in a range from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, or from about <NUM> to about <NUM>.

In one or more embodiments, deadfront structure <NUM> is cold-formed to exhibit a first radius curvature, R1, that is within <NUM>% (e.g., about <NUM>% or less, about <NUM>% or less, about <NUM>% or less, about <NUM>% or less, about <NUM>% or less, or about <NUM>% or less) of the second radius of curvature of support surface <NUM> of frame <NUM>. For example, support surface <NUM> of frame <NUM> exhibits a radius of curvature of <NUM>, deadfront structure <NUM> is cold-formed to have a radius of curvature in a range from about <NUM> to about <NUM>.

In one or more embodiments, first major surface <NUM> and/or second major surface <NUM> of glass layer <NUM> includes a surface treatment or a functional coating. The surface treatment may cover at least a portion of first major surface <NUM> and/or second major surface <NUM>. Exemplary surface treatments include at least one of a glare reduction coating, an anti-glare coating, a scratch resistance coating, an anti-reflection coating, a half-mirror coating, or easy-to-clean coating.

The various glass layer(s) of the deadfront structures discussed herein, such as outer glass layer <NUM>, may be formed from any suitable glass composition including soda lime glass, aluminosilicate glass, borosilicate glass, boroaluminosilicate glass, alkali-containing aluminosilicate glass, alkali-containing borosilicate glass, and alkali-containing boroaluminosilicate glass.

Unless otherwise specified, the glass compositions disclosed herein are described in mole percent (mol%) as analyzed on an oxide basis.

In one or more embodiments, the glass composition may include SiO<NUM> in an amount in a range from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, or from about <NUM> mol% to about <NUM> mol%, and all ranges and sub-ranges therebetween.

In one or more embodiments, the glass composition includes Al<NUM>O<NUM> in an amount greater than about <NUM> mol%, or greater than about <NUM> mol%. In one or more embodiments, the glass composition includes Al<NUM>O<NUM> in a range from greater than about <NUM> mol% to about <NUM> mol%, from greater than about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, or from about <NUM> mol% to about <NUM> mol%, and all ranges and sub-ranges therebetween. In one or more embodiments, the upper limit of Al<NUM>O<NUM> may be about <NUM> mol%, <NUM> mol%, <NUM> mol%, <NUM> mol%, or <NUM> mol%.

In one or more embodiments, glass layer(s) herein are described as an aluminosilicate glass article or including an aluminosilicate glass composition. In such embodiments, the glass composition or article formed therefrom includes SiO<NUM> and Al<NUM>O<NUM> and is not a soda lime silicate glass. In this regard, the glass composition or article formed therefrom includes Al<NUM>O<NUM> in an amount of about <NUM> mol% or greater, <NUM> mol% or greater, <NUM> mol% or greater, about <NUM> mol% or greater, about <NUM> mol% or greater.

In one or more embodiments, the glass composition comprises B<NUM>O<NUM> (e.g., about <NUM> mol% or greater). In one or more embodiments, the glass composition comprises B<NUM>O<NUM> in an amount in a range from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, and all ranges and sub-ranges therebetween. In one or more embodiments, the glass composition is substantially free of B<NUM>O<NUM>.

As used herein, the phrase "substantially free" with respect to the components of the composition means that the component is not actively or intentionally added to the composition during initial batching, but may be present as an impurity in an amount less than about <NUM> mol%.

In one or more embodiments, the glass composition optionally comprises P<NUM>O<NUM> (e.g., about <NUM> mol% or greater). In one or more embodiments, the glass composition comprises a non-zero amount of P<NUM>O<NUM> up to and including <NUM> mol%, <NUM> mol%, <NUM> mol%, or <NUM> mol%. In one or more embodiments, the glass composition is substantially free of P<NUM>O<NUM>.

In one or more embodiments, the glass composition may include a total amount of R<NUM>O (which is the total amount of alkali metal oxide such as Li<NUM>O, Na<NUM>O, K<NUM>O, Rb<NUM>O, and Cs<NUM>O) that is greater than or equal to about <NUM> mol%, greater than or equal to about <NUM> mol%, or greater than or equal to about <NUM> mol%. In some embodiments, the glass composition includes a total amount of R<NUM>O in a range from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, or from <NUM> mol% to about <NUM> mol%, and all ranges and sub-ranges therebetween. In one or more embodiments, the glass composition may be substantially free of Rb<NUM>O, Cs<NUM>O or both Rb<NUM>O and Cs<NUM>O. In one or more embodiments, the R<NUM>O may include the total amount of Li<NUM>O, Na<NUM>O and K<NUM>O only. In one or more embodiments, the glass composition may comprise at least one alkali metal oxide selected from Li<NUM>O, Na<NUM>O and K<NUM>O, wherein the alkali metal oxide is present in an amount greater than about <NUM> mol% or greater.

In one or more embodiments, the glass composition comprises Na<NUM>O in an amount greater than or equal to about <NUM> mol%, greater than or equal to about <NUM> mol%, or greater than or equal to about <NUM> mol%. In one or more embodiments, the composition includes Na<NUM>O in a range from about from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, or from <NUM> mol% to about <NUM> mol%, and all ranges and sub-ranges therebetween.

In one or more embodiments, the glass composition includes less than about <NUM> mol% K<NUM>O, less than about <NUM> mol% K<NUM>O, or less than about <NUM> mol% K<NUM>O. In some instances, the glass composition may include K<NUM>O in an amount in a range from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, or from about <NUM> mol% to about <NUM> mol%, and all ranges and sub-ranges therebetween. In one or more embodiments, the glass composition may be substantially free of K<NUM>O.

In one or more embodiments, the glass composition is substantially free of Li<NUM>O.

In one or more embodiments, the amount of Na<NUM>O in the composition may be greater than the amount of Li<NUM>O. In some instances, the amount of Na<NUM>O may be greater than the combined amount of Li<NUM>O and K<NUM>O. In one or more alternative embodiments, the amount of Li<NUM>O in the composition may be greater than the amount of Na<NUM>O or the combined amount of Na<NUM>O and K<NUM>O.

In one or more embodiments, the glass composition may include a total amount of RO (which is the total amount of alkaline earth metal oxide such as CaO, MgO, BaO, ZnO and SrO) in a range from about <NUM> mol% to about <NUM> mol%. In some embodiments, the glass composition includes a non-zero amount of RO up to about <NUM> mol%. In one or more embodiments, the glass composition comprises RO in an amount from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, and all ranges and sub-ranges therebetween.

In one or more embodiments, the glass composition includes CaO in an amount less than about <NUM> mol%, less than about <NUM> mol%, or less than about <NUM> mol%. In one or more embodiments, the glass composition is substantially free of CaO.

In some embodiments, the glass composition comprises MgO in an amount from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, or from about <NUM> mol% to about <NUM> mol%, and all ranges and sub-ranges therebetween.

In one or more embodiments, the glass composition comprises ZrO<NUM> in an amount equal to or less than about <NUM> mol%, less than about <NUM> mol%, less than about <NUM> mol%, less than about <NUM> mol%, less than about <NUM> mol%, less than about <NUM> mol%. In one or more embodiments, the glass composition comprises ZrO<NUM> in a range from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, or from about <NUM> mol% to about <NUM> mol%, and all ranges and sub-ranges therebetween.

In one or more embodiments, the glass composition comprises SnO<NUM> in an amount equal to or less than about <NUM> mol%, less than about <NUM> mol%, less than about <NUM> mol%, less than about <NUM> mol%, less than about <NUM> mol%, less than about <NUM> mol%. In one or more embodiments, the glass composition comprises SnO2 in a range from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, or from about <NUM> mol% to about <NUM> mol%, and all ranges and sub-ranges therebetween.

In one or more embodiments, the glass composition may include an oxide that imparts a color or tint to the glass articles. In some embodiments, the glass composition includes an oxide that prevents discoloration of the glass article when the glass article is exposed to ultraviolet radiation. Examples of such oxides include, without limitation oxides of: Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ce, W, and Mo.

In one or more embodiments, the glass composition includes Fe expressed as Fe<NUM>O<NUM>, wherein Fe is present in an amount up to (and including) about <NUM> mol%. In some embodiments, the glass composition is substantially free of Fe. In one or more embodiments, the glass composition comprises Fe<NUM>O<NUM> in an amount equal to or less than about <NUM> mol%, less than about <NUM> mol%, less than about <NUM> mol%, less than about <NUM> mol%, less than about <NUM> mol%, less than about <NUM> mol%. In one or more embodiments, the glass composition comprises Fe<NUM>O<NUM> in a range from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, from about <NUM> mol% to about <NUM> mol%, or from about <NUM> mol% to about <NUM> mol%, and all ranges and sub-ranges therebetween.

Where the glass composition includes TiO<NUM>, TiO<NUM> may be present in an amount of about <NUM> mol% or less, about <NUM> mol% or less, about <NUM> mol% or less or about <NUM> mol% or less. In one or more embodiments, the glass composition may be substantially free of TiO<NUM>.

An exemplary glass composition includes SiO<NUM> in an amount in a range from about <NUM> mol% to about <NUM> mol%, Al<NUM>O<NUM> in an amount in a range from about <NUM> mol% to about <NUM> mol%, Na<NUM>O in an amount in a range from about <NUM> mol% to about <NUM> mol%, K<NUM>O in an amount in a range of about <NUM> mol% to about <NUM> mol%, and MgO in an amount in a range from about <NUM>. <NUM> mol% to about <NUM> mol%. Optionally, SnO<NUM> may be included in the amounts otherwise disclosed herein.

In one or more embodiments, outer glass layer <NUM> or other glass layer of any of the deadfront article embodiments discussed herein may be formed from a strengthened glass sheet or article. In one or more embodiments, the glass articles used to form the layer(s) of the deadfront structures discussed herein may be strengthened to include compressive stress that extends from a surface to a depth of compression (DOC). The compressive stress regions are balanced by a central portion exhibiting a tensile stress. At the DOC, the stress crosses from a positive (compressive) stress to a negative (tensile) stress.

In one or more embodiments, the glass articles used to form the layer(s) of the deadfront structures discussed herein may be strengthened mechanically by utilizing a mismatch of the coefficient of thermal expansion between portions of the glass to create a compressive stress region and a central region exhibiting a tensile stress. In some embodiments, the glass article may be strengthened thermally by heating the glass to a temperature above the glass transition point and then rapidly quenching.

In one or more embodiments, the glass articles used to form the layer(s) of the deadfront structures discussed herein may be chemically strengthening by ion exchange. In the ion exchange process, ions at or near the surface of the glass article are replaced by - or exchanged with - larger ions having the same valence or oxidation state. In those embodiments in which the glass article comprises an alkali aluminosilicate glass, ions in the surface layer of the article and the larger ions are monovalent alkali metal cations, such as Li+, Na+, K+, Rb+, and Cs+. Alternatively, monovalent cations in the surface layer may be replaced with monovalent cations other than alkali metal cations, such as Ag+ or the like. In such embodiments, the monovalent ions (or cations) exchanged into the glass article generate a stress.

Ion exchange processes are typically carried out by immersing a glass article in a molten salt bath (or two or more molten salt baths) containing the larger ions to be exchanged with the smaller ions in the glass article. It should be noted that aqueous salt baths may also be utilized. In addition, the composition of the bath(s) may include more than one type of larger ion (e.g., Na+ and K+) or a single larger ion. It will be appreciated by those skilled in the art that parameters for the ion exchange process, including, but not limited to, bath composition and temperature, immersion time, the number of immersions of the glass article in a salt bath (or baths), use of multiple salt baths, additional steps such as annealing, washing, and the like, are generally determined by the composition of the glass layer(s) of a deadfront structure (including the structure of the article and any crystalline phases present) and the desired DOC and CS of the glass layer(s) of a deadfront structure that results from strengthening.

Exemplary molten bath composition may include nitrates, sulfates, and chlorides of the larger alkali metal ion. Typical nitrates include KNO<NUM>, NaNO<NUM>, LiNO<NUM>, NaSO<NUM> and combinations thereof. The temperature of the molten salt bath typically is in a range from about <NUM> up to about <NUM>, while immersion times range from about <NUM> minutes up to about <NUM> hours depending on the glass thickness, bath temperature and glass (or monovalent ion) diffusivity. However, temperatures and immersion times different from those described above may also be used.

In one or more embodiments, the glass articles used to form the layer(s) of the deadfront structures may be immersed in a molten salt bath of <NUM>% NaNO<NUM>, <NUM>% KNO<NUM>, or a combination of NaNO<NUM> and KNO<NUM> having a temperature from about <NUM> to about <NUM>. In some embodiments, the glass layer(s) of a deadfront structure may be immersed in a molten mixed salt bath including from about <NUM>% to about <NUM>% KNO<NUM> and from about <NUM>% to about <NUM>% NaNO<NUM>. In one or more embodiments, the glass article may be immersed in a second bath, after immersion in a first bath. The first and second baths may have different compositions and/or temperatures from one another. The immersion times in the first and second baths may vary. For example, immersion in the first bath may be longer than the immersion in the second bath.

In one or more embodiments, the glass articles used to form the layer(s) of the deadfront structures may be immersed in a molten, mixed salt bath including NaNO<NUM> and KNO<NUM> (e.g., <NUM>%/<NUM>%, <NUM>%/<NUM>%, <NUM>%/<NUM>%) having a temperature less than about <NUM> (e.g., about <NUM> or about <NUM>). for less than about <NUM> hours, or even about <NUM> hours or less.

Ion exchange conditions can be tailored to provide a "spike" or to increase the slope of the stress profile at or near the surface of the resulting glass layer(s) of a deadfront structure. The spike may result in a greater surface CS value. This spike can be achieved by single bath or multiple baths, with the bath(s) having a single composition or mixed composition, due to the unique properties of the glass compositions used in the glass layer(s) of a deadfront structure described herein.

In one or more embodiments, where more than one monovalent ion is exchanged into the glass articles used to form the layer(s) of the deadfront structures, the different monovalent ions may exchange to different depths within the glass layer (and generate different magnitudes stresses within the glass article at different depths). The resulting relative depths of the stress-generating ions can be determined and cause different characteristics of the stress profile.

CS is measured using those means known in the art, such as by surface stress meter (FSM) using commercially available instruments such as the FSM-<NUM>, manufactured by Orihara Industrial Co. Surface stress measurements rely upon the accurate measurement of the stress optical coefficient (SOC), which is related to the birefringence of the glass. SOC in turn is measured by those methods that are known in the art, such as fiber and four point bend methods, both of which are described in ASTM standard C770-<NUM> (<NUM>), entitled "Standard Test Method for Measurement of Glass Stress-Optical Coefficient", and a bulk cylinder method. As used herein CS may be the "maximum compressive stress" which is the highest compressive stress value measured within the compressive stress layer. In some embodiments, the maximum compressive stress is located at the surface of the glass article. In other embodiments, the maximum compressive stress may occur at a depth below the surface, giving the compressive profile the appearance of a "buried peak.

DOC may be measured by FSM or by a scattered light polariscope (SCALP) (such as the SCALP-<NUM> scattered light polariscope available from Glasstress Ltd. , located in Tallinn Estonia), depending on the strengthening method and conditions. When the glass article is chemically strengthened by an ion exchange treatment, FSM or SCALP may be used depending on which ion is exchanged into the glass article. Where the stress in the glass article is generated by exchanging potassium ions into the glass article, FSM is used to measure DOC. Where the stress is generated by exchanging sodium ions into the glass article, SCALP is used to measure DOC. Where the stress in the glass article is generated by exchanging both potassium and sodium ions into the glass, the DOC is measured by SCALP, since it is believed the exchange depth of sodium indicates the DOC and the exchange depth of potassium ions indicates a change in the magnitude of the compressive stress (but not the change in stress from compressive to tensile); the exchange depth of potassium ions in such glass articles is measured by FSM. Central tension or CT is the maximum tensile stress and is measured by SCALP.

In one or more embodiments, the glass articles used to form the layer(s) of the deadfront structures maybe strengthened to exhibit a DOC that is described a fraction of the thickness t of the glass article (as described herein). For example, in one or more embodiments, the DOC may be equal to or greater than about <NUM>. 05t, equal to or greater than about <NUM>. 1t, equal to or greater than about <NUM>. 11t, equal to or greater than about <NUM>. 12t, equal to or greater than about <NUM>. 13t, equal to or greater than about <NUM>. 14t, equal to or greater than about <NUM>. 15t, equal to or greater than about <NUM>. 16t, equal to or greater than about <NUM>. 17t, equal to or greater than about <NUM>. 18t, equal to or greater than about <NUM>. 19t, equal to or greater than about <NUM>. 2t, equal to or greater than about <NUM>. In some embodiments, The DOC may be in a range from about <NUM>. 08t to about <NUM>. 25t, from about <NUM>. 09t to about <NUM>. 25t, from about <NUM>. 18t to about <NUM>. 25t, from about <NUM>. 11t to about <NUM>. 25t, from about <NUM>. 12t to about <NUM>. 25t, from about <NUM>. 13t to about <NUM>. 25t, from about <NUM>. 14t to about <NUM>. 25t, from about <NUM>. 15t to about <NUM>. 25t, from about <NUM>. 08t to about <NUM>. 24t, from about <NUM>. 08t to about <NUM>. 23t, from about <NUM>. 08t to about <NUM>. 22t, from about <NUM>. 08t to about <NUM>. 21t, from about <NUM>. 08t to about <NUM>. 2t, from about <NUM>. 08t to about <NUM>. 19t, from about <NUM>. 08t to about <NUM>. 18t, from about <NUM>. 08t to about <NUM>. 17t, from about <NUM>. 08t to about <NUM>. 16t, or from about <NUM>. 08t to about <NUM>. In some instances, the DOC may be about <NUM> or less. In one or more embodiments, the DOC may be about <NUM> or greater (e.g., from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, or from about <NUM> to about <NUM>.

In one or more embodiments, the glass articles used to form the layer(s) of the deadfront structures may have a CS (which may be found at the surface or a depth within the glass article) of about <NUM> MPa or greater, <NUM> MPa or greater, <NUM> MPa or greater, about <NUM> MPa or greater, about <NUM> MPa or greater, about <NUM> MPa or greater, about <NUM> MPa or greater, about <NUM> MPa or greater, about <NUM> MPa or greater, about <NUM> MPa or greater, or about <NUM> MPa or greater.

In one or more embodiments, the glass articles used to form the layer(s) of the deadfront structures may have a maximum tensile stress or central tension (CT) of about <NUM> MPa or greater, about <NUM> MPa or greater, about <NUM> MPa or greater, about <NUM> MPa or greater, about <NUM> MPa or greater, about <NUM> MPa or greater, about <NUM> MPa or greater, about <NUM> MPa or greater, about <NUM> MPa or greater, or about <NUM> MPa or greater. In some embodiments, the maximum tensile stress or central tension (CT) may be in a range from about <NUM> MPa to about <NUM> MPa.

Claim 1:
A deadfront article (<NUM>) for a display comprising:
a cover structure (<NUM>) comprising:
an inner surface (<NUM>);
an outer surface opposite the inner surface (<NUM>);
a light guide layer (<NUM>) comprising:
an inner surface; and
an outer surface facing toward the inner surface (<NUM>) of the cover structure (<NUM>); and
a light extraction layer (<NUM>) located on at least one of the inner surface and the outer surface of the light guide layer (<NUM>);
characterized in that:
the cover structure (<NUM>) comprises: a glass layer (<NUM>) located between the inner surface (<NUM>) and the outer surface (<NUM>);
a first layer (<NUM>) of light transmitting ink or pigment located between the inner surface (<NUM>) of the cover structure (<NUM>) and the glass layer (<NUM>); and
at least one of:
the light extraction layer (<NUM>) is a white ink material having an average thickness in a range of .<NUM> to <NUM>, and
the cover structure (<NUM>) comprises a second layer (<NUM>) of light transmitting ink or pigment disposed between the first layer (<NUM>) and the light extraction layer (<NUM>).