Patent Description:
Electronic devices such as cellular telephones, handheld computers, and portable music players often include housings with glass members. For example, a device with a display may have a glass cover that serves as a protective layer. In some devices, a rear housing surface may be formed from a layer of glass.

To ensure satisfactory robustness, it is generally desirable to form device housing structures such as cover glass layers and housing surfaces from structures that are sufficiently strong to prevent damage during accidental impact events. For example, it is generally desirable to form portable devices that are subject to drop events from structures that are able to withstand the forces involved in a typical drop event without incurring excessive damage.

Glass strength and device aesthetics can sometimes be enhanced by using sufficiently thick glass layers. However, the size and weight of a device should not be excessive. If care is not taken, modifications that are made to ensure that a device has glass structures that are sufficiently strong, will make the device heavy and bulky.

It would therefore be desirable to be able to provide improved glass structures for electronic devices.

The invention is defined by the independent claim.

An electronic device may have a glass housing structures. The glass housing structures may be used to cover a display and other internal electronic device components. The glass housing structures may cover a front face of an electronic device and, if desired, may cover additional device surfaces.

The glass housing structure may have multiple glass pieces that are joined using a glass fusing process. A peripheral glass member may be fused along the edge of a planar glass member to enhance the thickness of the edge. A rounded edge feature may be formed by machining the thickened edge. Raised fused glass features may surround openings in the planar glass member. Raised support structure ribs may be formed by fusing glass structures to the planar glass member.

Multiple planar glass members may be fused together to form a five-sided box in which electronic components may be mounted. Display structures and other internal components may be slid into place between opposing glass sides of the box.

Opaque masking material and colored glass may be used to create portions of the glass housing structures that hide internal device components from view.

Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments.

Electronic devices such as computers, handheld devices, computer monitors, televisions, cellular telephones, media players, and other equipment may have displays and other components that are covered with glass structures. The glass structures, which may sometimes be referred to as glass housing structures, may be used to provide a protective transparent covering for a display or other optical component, may be used to form a housing sidewall, may be used to form other housing structures such as a rear housing wall or other housing structures, may be used to form raised features such as raised ribs that serve as support structures for a sheet of glass or other glass structures, or may otherwise be used in forming structures in an electronic device.

An example of an electronic device that may have glass housing structures is shown in <FIG>. In the example of <FIG>, electronic device <NUM> has a stand such as stand <NUM> on which main unit <NUM> has been mounted. Main unit <NUM> may include a display such as display <NUM> and a rear housing such as rear housing <NUM> (as an example). Device <NUM> may be a monitor, a monitor with an integrated computer, a television, or other electronic equipment.

Housing <NUM> may be formed from metal, plastic, glass, ceramic, carbon-fiber composite material or other fiber-based composite materials, other materials, or combinations of these materials. Display <NUM> may be covered with glass structures <NUM>. Glass structures <NUM> may serve as a glass front housing structure for device <NUM>. Glass structures <NUM> may be transparent so that display <NUM> may be viewed by a user of device <NUM> through glass structures <NUM>. Display <NUM> may include display structures with image pixels formed from light-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells, electrowetting pixels, electrophoretic pixels, liquid crystal display (LCD) components, or other suitable image pixel structures. Touch sensor electrodes may be included in display <NUM> to provide display <NUM> with touch sensing capabilities (e.g., display <NUM> may be a touch screen) or display <NUM> may be touch insensitive.

In the illustrative example of <FIG>, device <NUM> is a portable device such as a tablet computer, gaming device, navigation device, etc. Display <NUM> may be mounted in housing <NUM>. Display <NUM> may be covered with a display cover layer formed from glass structures <NUM>. Openings may be formed in glass structures <NUM> to accommodate components such as button <NUM>.

<FIG> is a perspective view of electronic device <NUM> in a configuration in which the electronic device housing has been formed from glass structures <NUM> that surround internal device components. End face <NUM>' of device <NUM> may also be formed from glass (as an example) and may include openings for audio jack <NUM>, switch <NUM>, and digital connector port <NUM> (as examples). Display <NUM> may be used to display images on one or more sides of device <NUM>. The portion of glass structures <NUM> of <FIG> that overlap display <NUM> may be transparent, so that the images displayed by display <NUM> may be visible by a user of device <NUM> through glass structures <NUM>. The rear surface of glass structures <NUM> may be transparent or may be colored (as examples).

In the illustrative example of <FIG>, device <NUM> has been provided with upper and lower glass layers <NUM>. Housing structure <NUM> (e.g., a layer of glass, ceramic, plastic, fiber-based composite, other material, or combination of these materials) may optionally be interposed between upper and lower glass structures <NUM>. Structures <NUM> and optional structure <NUM> may form a housing for device <NUM>. Display <NUM> may be mounted behind upper glass layer <NUM> (e.g., on the front face of device <NUM>). Openings in glass structures <NUM> may be used to accommodate buttons such as button <NUM> and other components (e.g., a speaker aligned with speaker port <NUM>).

The illustrative device configurations of <FIG>, <FIG>, <FIG>, and <FIG> are merely illustrative. Any suitable electronic equipment may be provided with glass housing structures, if desired.

<FIG> is a cross-sectional side view of electronic device <NUM> in a configuration in which glass housing structure <NUM> has been used to form a cover glass layer over display structures <NUM>. Display structures <NUM> may be used to form display <NUM>.

Display structures <NUM> may include a number of layers of material. These layers may include, for example, layers of glass, layers of plastic, and layers of adhesive. A liquid crystal display may have layers of polarizer, light diffusing elements, light guides for backlight structures, and a liquid crystal layer. An organic light-emitting diode (OLED) display may have organic materials that are used in producing light. An array of circuit components such as a thin-film transistor (TFT) array may be used to drive the image pixels in a display. This array of circuitry may be formed on a substrate material such as glass or polymer. The substrate layer on which the thin-film transistors and/or other circuitry for the display are formed may sometimes referred to as a TFT substrate or transistor substrate.

Glass housing structures <NUM> may be mounted to housing structures <NUM> (e.g., housing structures formed from metal, glass, plastic, fiber-based composites, etc.).

Internal components may be mounted within the housing of electronic device <NUM>. For example, device <NUM> may include a printed circuit such as printed circuit <NUM>. Printed circuit <NUM> may be a rigid printed circuit board (e.g., a fiberglass-filled epoxy board), a flexible printed circuit ("flex circuit") formed from a flexible sheet of polyimide or other polymer layer, or may formed using other dielectric substrate materials. Components <NUM> such as switches, connectors, discrete circuit elements such as capacitors, resistors, and inductors, integrated circuits, and other electronic devices may be mounted to substrate <NUM>. Display structures <NUM> may be coupled to circuitry on substrates such as substrate <NUM> using communications path <NUM> (e.g., a flex circuit cable or other suitable path).

To help maximize the interior volume in device <NUM> and reduce the size and weight of glass structures <NUM>, center portion <NUM> of glass structures <NUM> may have a thickness T1 that is smaller than edge thickness T2. The smaller size of thickness T1 may create a recessed portion <NUM>. Recess <NUM> in center portion <NUM> may have a rectangular shape or other suitable shape and may be configured to receive internal components in device <NUM> such as display structures <NUM>. The larger size of edge thickness T2 relative to center thickness T1 may help strengthen glass structure <NUM> along its periphery to prevent damage in the event of an impact event. The larger size of the edges of glass structures <NUM> may also improve device aesthetics.

Glass structures <NUM> may have a rectangular periphery (e.g., glass structures <NUM> may be formed from structures such as a planar sheet having a rectangular outline when viewed from above) and center portion <NUM> may form a rectangular recess within center of glass structures <NUM>. In this type of configuration, thickened edge portions <NUM> may form a rectangular ring that runs around the periphery of glass structure <NUM>. If desired, glass structure <NUM> may have other shapes (e.g., oval, circular, square, shapes with curved edges and/or straight edges, etc.). The thickened edge portions of glass structures <NUM> may also be provided along only part of the edges of glass structures <NUM>, rather than the entire periphery of glass structures <NUM>.

Housing structures such as structures <NUM> and <NUM> may be joined using interposed layers of adhesive, using fasteners, using interlocking engagement features such as snaps, or using other suitable attachment mechanisms.

In the illustrative example of <FIG>, glass structures <NUM> (e.g., the upper portion of the device housing) may have a planar exterior surface <NUM> and lower housing <NUM> (e.g., metal, glass, plastic, ceramic, fiber-based composites, etc.) may be have a curved exterior surface <NUM>. A display or other structures may be mounted under the recessed portion of glass structures <NUM>. Internal components <NUM> may be mounted in the interior of the device.

<FIG> is an example in which device <NUM> has been provide with two substantially similar glass housing structures <NUM>. Structures <NUM> may, as an example, have rectangular shapes with thinner (recessed) center regions <NUM> and thickened edges <NUM>. One or more displays and other internal components may be provided in device <NUM> of <FIG>.

As shown in <FIG>, device <NUM> may have a housing member such as housing sidewall structure <NUM> that is interposed between upper and lower glass housing structures <NUM>. Structure <NUM> may be formed from metal, glass, ceramic, plastic, fiber-based composite material, other materials, or a combination of these materials. Upper and lower glass housing structures <NUM> in <FIG> may have recessed portions (e.g., rectangular recesses), as described in connection with <FIG>. Display structures and other internal device components may be received within the recesses of structures <NUM> of <FIG>.

Device structures such as glass structures <NUM> may be formed from multiple pieces of glass that are fused together. Glass structures may, for example, be heated to an elevated temperature (e.g., about <NUM>° C. ) that is above the glass fusion temperature and that is below the glass working temperature. Using a metal die or other glass fusing tool, the heated glass pieces may be pressed together. Glass structures that are fused together using this type of approach may have invisible or barely visible joint lines (i.e., the fused glass joints that are formed when fusing a first glass member to a second glass member may be invisible or barely visible to the naked eye).

Illustrative operations and equipment involved in forming glass structures <NUM> with recessed portion are shown in <FIG>.

Initially, a portion of glass structures <NUM> such as planar glass member 20A may be formed and polished using polishing tool <NUM>. For example, both upper surface <NUM> and lower surface <NUM> of glass structures 20A may be polished using tool <NUM>. Polishing tool <NUM> may be used to perform mechanical and/or chemical polishing processes. Glass structures 20A may be formed from a glass sheet with a rectangular shape, a shape with curved edges, a shape with straight edges, or a shape with a combination of curved and straight edges.

Following polishing operations with tool <NUM>, additional glass structures may be fused to glass structures 20A using heated press (fusing tool) <NUM>. In particular, upper press member <NUM> may be moved downwards in direction <NUM> while lower press member <NUM> is moved upwards in direction <NUM> to press glass structures 20A and glass structures 20B together. During pressing, the temperature of glass structures 20A and 20B may be maintained at an elevated temperature of about <NUM>. (e.g., a temperature above the fusion temperature of the glass and below the working temperature of the glass). This forms glass fusion bond <NUM> between structures 20A and 20B and fuses structures 20A and 20B together to form glass structures <NUM>.

Glass structures 20B may, for example, be a peripheral glass member having the shape of a rectangular ring that runs around the periphery of a rectangular version of glass structure 20A or may be a glass member that runs around part of the periphery of glass structure 20A (as examples). The glass structures that are formed by fusing structures 20B to structures 20A may have an edge thickness T2 and a thinner central region of thickness T1, as described in connection with <FIG> (as an example). If desired, glass structures 20A and/or 20B may have other shapes (e.g., to form additional glass thickness around an opening in glass structure 20A, to form ribs or other supporting structures on glass structures 20A, to form a peripheral thickened edge portion around a non-rectangular piece of glass, etc.).

Because lower surface <NUM> of glass structures 20A was polished by tool <NUM>, this surface may remain polished following fusion of glass structures 20B to glass structures 20A.

Following formation of glass structures <NUM> using glass fusing tool <NUM>, glass structures <NUM> may be strengthened. For example, glass structures <NUM> may be strengthened using chemical strengthening tool <NUM>. Chemical strengthening tool <NUM> may be used to immerse glass structures <NUM> in a bath containing potassium nitrate (as an example). Glass structures <NUM> may be free of glass frit at fusion joints <NUM>, which may promote compatibility with chemical strengthening treatments. Heat-based tempering operations may also be performed to strengthen glass structures <NUM>, if desired.

Following strengthening of glass structures <NUM> with chemical strengthening tool <NUM>, glass structures <NUM> may have polished upper surface <NUM>, polished lower surface <NUM>, recessed central region <NUM> of thickness T1, and thickened edge regions <NUM> of thickness T2 (T2>T1). Glass structures <NUM> may then be assembled into device <NUM>. For example, glass structures <NUM> may be attached to additional glass structures (using glass fusing, using adhesive, using fasteners, using mating engagement structures, etc.) and/or non-glass housing structures.

As shown in <FIG>, for example, glass structures <NUM> may be mounted to housing structures <NUM>. Because of the use of the glass fusing process of <FIG> to join glass structures 20B to glass structures 20A, fusion joint <NUM> between structures 20A and 20B may be invisible or nearly invisible to the naked eye of the user of device <NUM>, thereby enhancing device aesthetics. The enhanced thickness T2 of the edge portion of glass structures <NUM> (in the example of <FIG>) may help improve the resistance of glass structures <NUM> to damage due to an impact event.

If desired, glass structures 20B may be fused to glass structures 20A in other patterns. For example, glass structures 20B that have the shape of strengthening support ribs may be fused across the center of the surface of glass structures 20A, as shown in <FIG>. Strengthening features formed from structures 20B may have the shape of a cross (as shown in the example of <FIG>), may have a T shape, may have a central arm with multiple branches, or may have any other suitable pattern. The strengthening structure pattern formed by glass structures 20B on structures 20A of <FIG> is merely illustrative.

<FIG> is an interior perspective view of illustrative glass structures <NUM> that have been provided with openings such as button opening <NUM> (e.g., for button <NUM> of <FIG>) and speaker port opening <NUM> (e.g., for speaker port <NUM> of <FIG>). As shown in <FIG>, glass structures 20B may be used to locally thicken glass structures 20A in the vicinity of one or more openings in glass structures 20A. Glass structures 20B may, for example, form raised rings or other raised structures that surround openings <NUM> and <NUM> to provided additional structural support for glass structures 20A in the vicinity of openings <NUM> and <NUM>.

<FIG> is an illustrative cross-sectional side view of device <NUM> in a configuration in which glass structures <NUM> have been provided with external features by fusing glass structures 20B to exterior surface <NUM> of glass structures 20A. In the example of <FIG>, glass structures 20B have been used to create a raised feature such as a circular ring on the surface of glass structures 20A that surrounds button <NUM>. Light source <NUM> may optionally be used to provide illumination for the raised ring formed by structures 20B. If desired, raised features may be formed elsewhere on surface <NUM> of glass structures 20A (e.g., surrounding speaker port <NUM>, in a particular location on a touch screen, around the rectangular peripheral edge of display <NUM> and device <NUM>, etc.).

Glass structures <NUM> may be formed from clear glass, glass with a colored tint (e.g., a blue tint, red tint, green tint, etc.), black glass, gray glass, or glass of other colors. As shown in <FIG>, glass structures 20A and 20B may be formed from glass of different colors. For example, glass structures 20A may be formed from clear glass and glass structures 20B may be formed from black glass or non-clear glass of another color. The amount of color in structures 20B may be sufficient to render structures 20B dark or opaque in appearance or may allow structures 20B to remain transparent. The use of a color for structures 20B that is not clear may help hide interior device components from view through the edge of structures <NUM>.

As shown in <FIG>, internal device structures may also be hidden from view by providing structures 20B with a layer of opaque masking material <NUM>. Material <NUM> may be black ink, white ink, colored ink, or other opaque substances (as an example).

<FIG> shows how opaque masking material <NUM> may be formed on the inner edges of glass structures 20B. This may allow surfaces <NUM> of structures 20B to remain uncovered so that surfaces <NUM> may be attached to device structures using adhesive (as an example).

<FIG> is a cross-sectional side view of glass structures <NUM> in a configuration in which glass structures 20A and glass structures 20B have both been formed from non-clear glass (e.g., black glass, gray glass, blue glass, green glass, other colored glass, etc.).

In the <FIG> example, glass structures <NUM> have been provided with a layer of opaque masking material <NUM> (e.g., black ink, white ink, colored ink, or other opaque substance) that covers lower surface <NUM> of glass structures 20A and lower surfaces <NUM> of glass structures 20B.

Illustrative operations involved in forming glass structures <NUM> with a recessed portion and curved features such as rounded edges are shown in <FIG>.

As shown in <FIG>, a portion of glass structures <NUM> such as polished planar glass member 20A may be fused with glass structures 20B by moving structures 20A in direction <NUM> while moving structures 20B in direction <NUM> while applying heat in fusing tool (heated press) <NUM>.

After fusing structures 20A and 20B together using tool <NUM>, tool <NUM> (e.g., a machining tool, grinding tool, polishing tool and/or other equipment for machining and polishing structures <NUM>) may be used in removing excess glass along curved surfaces <NUM> and <NUM>, thereby rounding the edges of glass structures <NUM>.

Glass strengthening equipment such as chemical strengthening tool <NUM> may be used to strengthen glass structures <NUM> following formation of curved surfaces <NUM> and <NUM>.

If desired, display structures <NUM> (<FIG>) may be laminated to glass structures <NUM> using lamination tool <NUM>. For example, display <NUM> may be laminated to lower planar polished surface <NUM> and curved interior surface <NUM> of glass structures <NUM> using adhesive. Display structures <NUM> may be formed using a substrate that is sufficiently flexible to allow display structures <NUM> to conform to the curved shape of surface <NUM>. Display structures <NUM> may be for example, flexible structures for a flexible liquid crystal display, flexible electrowetting display structures, flexible electrophoretic display structures, or flexible organic light-emitting diode display structures (as examples).

As shown in <FIG>, glass structures 20B may be provided with angled (beveled) inner edge surface <NUM>. Surface <NUM> may be coated with an optional opaque masking material such as layer <NUM>. The non-zero angle that is made by surface <NUM> with respect to surface normal <NUM> of planar lower surface <NUM> of planar glass member 20A may help improve the strength of glass structures <NUM>.

In the <FIG> configuration, the inner edge of glass structures 20B has been provided with a planar surface (i.e., surface <NUM> is flat). An illustrative arrangement in which the inner edge of glass structures 20B has been provided with a curved surface (curved surface <NUM>) is shown in <FIG>.

<FIG> shows how glass structures <NUM> may be formed from extruded glass structures such as extruded hollow-rod-shaped glass structure 20C and associated cap structures such as end cap glass structure 20D. Glass structures 20C and 20D may be formed using glass extruding and machining tools such as tools <NUM>. Fusing tool <NUM> may be used to fuse structures 20C and 20D together. If desired, electronic component may be housed within the interior of extruded glass structures 20D. Fused caps 20C may be used to enclose these internal components within the interior of device <NUM>.

<FIG> shows how internal electronic device components <NUM> may be inserted into glass structures 20E and, if desired, may be covered with fused end cap 20F. Structures 20E may be formed by fusing together five glass members to form a five-sided box with a lower face that is open to receive components <NUM>. The five-sided box may be formed from a first pair of opposing planar structures (e.g., front and rear sheets of glass), a second pair of opposing planar structures (e.g., opposing left and right sheets or strips of glass), and a fifth planar sheet (or strip) of glass such as end cap layer 20F that have been fused together using fused joints. An air gap may be formed between opposing glass walls in box-shaped glass structures 20E. Ribs or other strengthening structures such as structures 20B of <FIG> may be formed on one, two, three, four, or more than four of the surfaces of the five-sided box-shaped glass structures 20E of <FIG>.

Components <NUM> may be inserted into the interior of structures 20E (e.g., in the gap formed between the opposing front and rear sheets and between the opposing right and left sheets of glass). Components <NUM> may include, for example, display structures <NUM> for forming display <NUM> and other components (see, e.g., components <NUM> of <FIG>). Glass structures 20E may be formed from sheets of glass that are fused together using fusing equipment such as fusing tool <NUM> (<FIG> and <FIG>). Glass structures 20F may be attached to glass structures 20E using glass fusing techniques, using adhesive, or using other attachment mechanisms.

<FIG> is a side view of glass structures 20E showing how internal components <NUM> may be slid into the interior of glass structure 20E in direction <NUM> through end face opening <NUM> in glass structures 20E. If desired, machining techniques such as the curved edge machining techniques described in connection with <FIG> may be used in creating curved surfaces on glass structures 20E (see, e.g., rounded edge surfaces <NUM> of glass structures <NUM> of device <NUM> in <FIG>).

As shown in <FIG>, edge <NUM> of glass structures <NUM> may be provided with a roughened surface that helps to scatter and diffuse light. Device <NUM> may be provided with a light-emitting diode or other internal light source <NUM>. Light source <NUM> may produce light <NUM> that strikes roughened edge surface <NUM> of glass structures <NUM>. Light <NUM> may illuminate the exposed exterior edge of light structures <NUM>. Some or all of the peripheral edge portions of glass structures <NUM> may be illuminated in this way.

<FIG> is a flow chart of illustrative steps that may be used in forming glass structures <NUM>.

At step <NUM>, glass structures such as glass structures 20A and 20B may be polished using polishing equipment <NUM>.

At step <NUM>, fusing equipment <NUM> may be used to fuse two or more glass structures together. For example, glass structures 20A and 20B may be fused together to form glass structures <NUM> or the five sides of the five-sided-box glass structures of <FIG> and <FIG> may be fused together.

If desired, additional machining and polishing operations may be formed at step <NUM>. For example, a thickened edge portion (of thickness T2) of glass structures <NUM> may be machined and polished to form a rounded edge for glass structures <NUM>, as shown in <FIG>. If desired, machining operations to form a rounded edge structure on glass structures <NUM> may be performed during the operations of step <NUM> (e.g., using machining and polishing equipment).

At step <NUM>, glass structures <NUM> may be strengthened using heat and/or chemical treatment. For example, glass structures <NUM> may be strengthened by applying a chemical bath to glass structures <NUM> using chemical strengthening tool <NUM>.

Claim 1:
A portable electronic device (<NUM>) comprising:
a glass housing structure comprising:
a front glass sheet (<NUM>) defining a front exterior surface (<NUM>) of the portable electronic device (<NUM>);
a rear glass sheet (<NUM>) defining a rear exterior surface of the portable electronic device (<NUM>); and
a glass sidewall structure (<NUM>) positioned between the front and rear glass sheets, fused to the front glass sheet, and defining at least a portion of a side exterior surface of the portable electronic device (<NUM>), the front glass sheet and the glass sidewall structure defining a curved surface having a curved exterior profile that extends from the front exterior surface (<NUM>) to the side exterior surface; and
a display (<NUM>) positioned within the glass housing structure.