Method and apparatus for enhancing keycap legend visibility in low light conditions

Techniques and apparatus to provide improved visibility to user input devices, such as keys, are disclosed. In low light conditions, keys can be difficult to distinguish. For example, often keys have legends on them to visually distinguish them from one another, but in low light conditions it can be difficult for users to visually distinguish the different keys. The legends can be textual and/or graphic. Hence, according to one embodiment, light from a nearby display device can be used to provide illumination to the user input devices (e.g., keys). More particularly, in one embodiment, some light from the nearby display device can be directed towards and reflected from the user input devices (e.g., keys) to enhance visibility of the keys or the legends thereon.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to illumination of keys for electronic devices and, more particularly, to illumination of keys for electronic devices using reflected light.

2. Description of the Related Art

Computing devices, such as notebook computers, mobile phones, netbook computers, e-readers and others, commonly provide one or more keys for user selection. The keys are often provided in a keyboard or keypad. In order for user to see and visually distinguish between the keys, the keys include legends. For example, a given key might be for the character “a”, the number “1” or a symbol “#”. Providing the legends in a color that has a high contrast to a base color of the keys can be helpful to visibility. In some cases, these computer systems can provide backlighting to the keys. The backlighting provides illumination to the keys so that a user can visually distinguish between the keys. Such illumination is particularly useful when the computing devices are used in low light conditions.

Unfortunately, however, providing backlighting requires additional circuitry and optical components. Backlighting when active also consumes power and thus renders the computing device less power efficient. Accordingly, there is a continuing need to provide alternative ways to provide illumination of keys for low light conditions.

SUMMARY

The invention pertains to techniques and apparatus to provide improved visibility to user input devices, such as keys. In low light conditions, keys can be difficult to distinguish. For example, often keys have legends on them to visually distinguish them from one another, but in low light conditions it can be difficult for users to visually distinguish the different keys. The legends can be textual and/or graphic. Hence, according to one embodiment, light from a nearby display device can be used to provide illumination to the user input devices (e.g., keys). More particularly, in one embodiment, some light from the nearby display device can be directed towards and reflected from the user input devices (e.g., keys) to enhance visibility of the keys or the legends thereon. As discussed below, the user input devices (e.g., key) can be configured to enhance reflection of light and thereby improve visibility of the keys or the legends thereon.

The invention can be implemented in numerous ways, including as a method, system, device, or apparatus. Several embodiments of the invention are discussed below.

According to one embodiment, a computing device can include a display for presenting displayed data, and at least one key configured to facilitate user input to the computing device. The at least one key includes a key structure, a reflective layer disposed adjacent the key structure, and a diffusion layer disposed over the reflective layer.

According to another embodiment, a method for illuminating keys of a portable computing device can use light from a display associated with the portable computing device. More particularly, the method can include receiving, at the keys, at least a portion of light emitted from the display and directed toward the keys; reflecting a portion of the light emitted from the display and directed toward the keys; diffusing the reflected portion of the light; and providing the diffused, reflected light to a user position.

According to still another embodiment, a non-backlit key of an electronic device can include a top surface, a reflective layer disposed proximate the top surface and representing a legend, and a diffusion layer disposed over the reflective layer. The diffusion layer operates to diffuse light reflected from the reflective layer in a controlled manner such that the legend of the non-backlit key is more visible in low light conditions.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The invention pertains to techniques and apparatus to provide improved visibility to user input devices, such as keys. In low light conditions, keys can be difficult to distinguish. For example, often keys have legends on them to visually distinguish them from one another, but in low light conditions it can be difficult for users to visually distinguish the different keys. The legends can be textual and/or graphic. Hence, according to one embodiment, light from a nearby display device can be used to provide illumination to the user input devices (e.g., keys). More particularly, in one embodiment, some light from the nearby display device can be directed towards and reflected from the user input devices (e.g., keys) to enhance visibility of the keys or the legends thereon. As discussed below, the user input devices (e.g., key) can be configured to enhance reflection of light and thereby improve visibility of the keys or the legends thereon.

Embodiments of the invention are discussed below with reference toFIGS. 1-5D. However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes as the invention extends beyond these limited embodiments. The illustrations provided in these figures are not necessarily drawn to scale; instead, the illustrations are presented in a manner to facilitate presentation.

FIG. 1is a side view of an electronic device100according to one embodiment. The electronic device100is, for example, a mobile computing device (e.g., a laptop computer, a notebook computer or a netbook computer), a mobile communication device (e.g., a mobile phone) or a digital media playback device (e.g., a DVD player). The electronic device100includes a base portion102and a top portion104. The base portion102houses at least one printed circuit board together with various electrical components that interoperate to provide an electronic device (e.g., computing device) for either general purposes or specific purposes. The base portion102also supports a user input region106. For example, the user input region106can include a keyboard or keypad having a plurality of keys. The top portion104can contain a display device108. When operating, the display device108produces light for illumination of text or graphics being presented on the display device108. While most of the light from the display device108is typically emitted normal to the surface of the display device108, a portion of the light can also be directed towards the base portion102. The portion of the light that from the display device108that is directed towards the base portion102can be reflected from one or more of the keys (e.g., key tops or key caps) of the user input region106(e.g., keyboard). The reflected light112can be directed towards the eyes114of a user on the computing device100. Consequently, the reflected light112facilitates the user in recognizing legends provided on the keys in the user input region106(e.g., keyboard) in low light conditions.

FIG. 2Ais a conceptual diagram of an optical arrangement200illustrating one embodiment. The optical arrangement200can, for example, be used with an electronic device. The optical arrangement200includes a light source202. The light source202produces light that can be utilized to illuminate not only a display device but also keys within a key region204. The light source202is, for example, provided by a backlight of a LCD display screen. The key region204includes a plurality of keys that can be similarly constructed so as to facilitate illumination in low light conditions. In particular, the keys within the key region204include key caps206. A key cap is considered to be an upper portion or top of a key.

A key cap206can be modified to facilitate illumination. In particular, according to one embodiment, applied to the top of each of the key caps206is a reflective layer208and a diffusion layer210. The reflective layer208can operate to reflect at least a portion of the light212from the light source202that is incident on the key region204. The incident light212impinges on the keys caps206in the key region204, and passes through the diffusion layer210and is then partially reflected by the reflective layer208to provide reflected light214directed towards the eyes216of a user.

The diffusion layer210operates to diffuse (or scatter) the reflected light214so that the illumination on the key caps206is diffused so that any images depicted by the light source202are diffused and thus the illumination of the key caps206provides general illumination as opposed to a direct reflection of images being depicted by the light source202. For example, if the light source202were part of a display device, and if the display device were to present an image of a mountain on its display with illumination from the light source202, then the diffusion layer210would diffuse the reflected light214so that the mountain would not be recognizable from the reflected light214being viewed by the user.

FIG. 2Bis a flow diagram of a key illumination process250according to one embodiment. The key illumination process250is, for example, performed by an electronic device (e.g., computing device) having a light source and a key region with one or more keys. For example, the key illumination process250can be performed by the electronic device providing the optical arrangement200illustrated inFIG. 2A.

The key illumination process250can receive252light emitted from a light source (e.g., display) at one or more keys. A portion of the light received at the one or more keys can be reflected254. The reflected portion of the light received at the one or more keys can then be diffused256. Thereafter, the diffused, reflected light can be provided258to a user position. As a result, the one or more keys are able to be illuminated using light originating from a light source. The light source can be a display device of a portable computer. As such, the key illumination process250makes uses of an existing light source (e.g., display device) and thus does not require a dedicated light source. The reflection of the light from the one or more keys is due to reflective material provided on the one or more keys. In one implementation, the one or more keys can have key caps as described above with reference toFIG. 2A. Various suitable structures or arrangements for keys or key caps are detailed below.

FIG. 3is a side view of a reflective key300according to one embodiment. In this embodiment, the reflective key300can include a key structure302, a reflective layer304provided on the top surface of the key structure302, and a diffusion layer306provided over the reflective layer304. For durability, it is advantageous to keep the reflective layer304and the diffusion layer306relatively thin. The thickness of the reflective layer304depends upon implementation. However, in one example, the reflective layer304can have a thickness of about 1-15 micrometers. The thickness of the diffusion layer306also depends upon implementation. However, in one example, the diffusion layer306can have a thickness of about 8-30 micrometers. The reflective layer304illustrated inFIG. 3can be patterned directly or indirectly so that an appropriate legend is provided on the key structure302.

The reflective layer304and the diffusion layer306can be provided in various different ways. In one embodiment, either or both of the reflective layer304and the diffusion layer306can be applied by being sprayed on. The sprayed on solution for the reflective layer304can be ink or paint based and include reflective material, such as small pieces of aluminum, silver or compounds (or alloys) thereof. The sprayed on solution for the diffusion layer306can also be ink or paint based. In another embodiment, the reflective layer can be applied by a silkscreen process. The diffusion layer306can be provided by a variety of materials. One suitable material for the diffusion layer306is acrylic paint.

FIGS. 4A and 4Billustrate exemplary top surfaces of key caps according to different embodiments. InFIG. 4A, a key cap400includes a top surface402. The top surface402of the key cap400illustrates a reflective legend404. The reflective legend404is formed from a reflective material, such as the reflective layer304illustrated inFIG. 3. In the example shown inFIG. 4A, the reflective legend404shown inFIG. 4Ahas an “O” shape. A diffusion layer406can be provided on the top surface402over the reflective legend404. The diffusion layer406typically covers at least the reflective legend404but also may cover the entire top surface402of the key cap400.

InFIG. 4B, a key cap400′ is similar to the key cap400ofFIG. 4A. Nevertheless, the key cap400′ includes a top surface402′. The top surface402′ of the key cap400′ illustrates a reflective legend404′. The reflective legend404′ is formed from a reflective material, such as the reflective layer304illustrated inFIG. 3. In the example shown inFIG. 4B, the reflective legend404′ shown inFIG. 4Bcan provide a graphical element, such as a corporate logo. A diffusion layer406′ can be provided on the top surface402′ over the reflective legend404′. The diffusion layer406′ typically covers at least the reflective legend404′ but also may cover the entire top surface402′ of the key cap400′.

FIG. 5Ais a cross-sectional view of a reflective key500according to one embodiment. The reflective key500includes a key502. In one embodiment, the key502can be opaque, such as a particular color (e.g., black). The key502can also includes an inner opening (or hollow portion)504. The reflective key500can include a mirror layer506that is provided for a top surface of the key502. The mirror layer506is provided by a reflective material. The reflective material can be a broad spectrum reflective material. For example, the mirror layer506can be formed of aluminum, silver or compounds (or alloys) thereof. In particular, the mirror layer506can be an ink or paint having aluminum or silver fragments therein. One suitable ink is a mirror effect ink from Seiko Advance Ltd. Of Tokyo, Japan. One suitable paint is a mirror effect paint from PPG Industries, Inc. of Pittsburgh, Pa. In addition, a barrier layer508can be provided over the mirror layer506. The barrier layer508is at least partially if not fully translucent. The barrier508can be clear in color and may also include glass particles other clear materials (e.g., acrylic particles) to provide diffusion. The glass particles can, for example, be fibers or spheres. The thickness of the mirror layer506and the barrier layer508depend upon implementation. However, in one example, the mirror layer506and the barrier layer508can each have a thickness of about 9-12 and 8-11 micrometers, respectively.

Additionally, a patterned layer510can be provided over the barrier layer508. The patterned layer510is typically an opaque layer, for example, black. The patterned layer510can be provided so as to cover at least a portion of the key502so that only select portions of the mirror layer506remain visible. Those portions of the mirror layer506not covered by the patterned layer510yield the desired legend for the key502. The thickness of the patterned layer510also depends upon implementation. However, in one example, the patterned layer510can have a thickness of about 8-15 micrometers, or in a more particular example 9-11 micrometers.

After the patterned layer510has been applied, a protective layer512can be provided over the patterned layer510. The protective layer512can protect the reflective legend that results from the reflective layer506, the diffusion layer508and the patterned layer510. The protective layer512is a thin protective coating. The thickness of the protective layer512depends upon implementation. However, in one example, the protective layer512can have a thickness of about 15-30 micrometers, or in a more particular example 20-22 micrometers. The protective layer512can also provide diffusion, in which case it can include diffusing materials. The protective layer512can be applied by being sprayed on. The sprayed on solution for the protective layer512can be ink or paint based and is typically clear (e.g., clear acrylic paint, clear resin) and may also include the diffusing materials. The gloss level (or diffusion effect) of the protective layer512can be controlled to limit gloss level (e.g., to about 5 gloss units).

The patterned layer510has a pattern that it is formed when the patterned layer510is initially applied, or formed into a layer that is initially applied. In one implementation, a layer is patterned when formed. For example, the layer can be sprayed, silk-screened or deposited (e.g., PVD) on in the desired pattern. In another implementation, the layer can be formed and then be patterned. For example, chemical etching or laser ablation can be used to pattern the layer.

FIG. 5Bis a cross-sectional view of a reflective key550according to another embodiment. The reflective key550includes a key552. In one embodiment, the key552can be at least partially translucent, such as clear. The key552can also include an inner opening (or hollow portion)554.

In this embodiment, a mirror layer556can be provided on the inner, underside portion of the key552. Hence, even though the mirror layer556is provided on the inner, underside portion of the inner opening554, impinging light received via the top of the reflective key550can be reflected from the mirror layer556. The mirror layer556can be provided by a reflective material. For example, mirror layer556can be formed on an ink or paint having quantities of aluminum or silver contained therein.

The reflective key550can also include a diffusion region558. In this embodiment, the diffusion region558can be embedded within or provided by the material of the reflective key550. At the top of the key552, a patterned layer560can be provided to superimpose a pattern for a legend to be provided on the reflective key550.

The patterned layer560is typically an opaque layer, for example, black. The patterned layer560can be provided so as to cover at least a portion of the key552so that only select portions of the mirror layer556remain visible. Those portions of the mirror layer556not covered by the patterned layer560yield the desired legend for the key552.

After the patterned layer560has been applied, a protective layer562can be provided over the patterned layer560. The protective layer562protects the reflective legend that results from the reflective layer556, the diffusion region558and the patterned layer560. The protective layer512is a thin protective coating. The thickness of the protective layer512depends upon implementation. However, in one example, the protective layer512can have a thickness of about 10-30 micrometers. The protective layer512can be applied by being sprayed on. The sprayed on solution for the protective layer512can be ink or paint based and is typically clear (e.g., clear acrylic paint, clear resin).

FIG. 5Cis a cross-sectional view of a reflective key570according to another embodiment. The reflective key570includes a key572. In one embodiment, the key572can be opaque, such as a particular color (e.g., black). The key572can also include mirror elements574. More generally, the mirror elements574can be referred to as reflective elements. The mirror elements574can be formed by patterning a mirror layer or by selectively forming the mirror elements574. The patterning can make use of chemically etching or laser etching/ablation.

In addition, a protective layer576can be provided over the mirror elements574and other portion of the top of the key572. In this embodiment, the protective layer576also serves as a diffusion layer. Diffusion can be provided by limiting the gloss characteristics of the protective layer576. In this embodiment, the protective layer576is at least partially if not fully translucent. The protective layer578can be clear in color and may also include glass fibers to provide additional diffusion. The protective layer576can protect the reflective legend that results from the mirror elements574and the key572.

FIG. 5Dis a cross-sectional view of a reflective key580according to still another embodiment. The reflective key580includes a key582. In one embodiment, the key582can be opaque, such as a particular color (e.g., black). The key582can also include mirror elements584. More generally, the mirror elements584can be referred to as reflective elements. For example, the mirror elements584can be formed of aluminum or silver. In particular, the mirror layer506can be an ink or paint having aluminum or silver fragments therein. The mirror elements584can be formed by patterning a mirror layer or by selectively forming the mirror elements584. The patterning can make use of chemically etching or laser etching/ablation.

In addition, the reflective key580can provide a diffusion layer586over the mirror elements584. The diffusion layer586can be at least partially if not fully translucent. The diffusion layer586can be clear in color and may also include glass fibers to provide additional diffusion. Additionally, a protective layer588can be provided over the diffusion layer586. The protective layer588can protect the reflective legend that results from the mirror elements584, the diffusion layer586and the key582. It should be understood that the diffusion layer586and the protective layer588can be provided as separately deposited layers or a single layer providing both diffusion and protection.

The reflective layer or mirror elements discussed herein can be applied as ink or paint as noted above. Alternatively, the reflective layer or mirror elements can be applied by Physical Vapor Deposition (PVD) if formed of metal, such as silver or aluminum. In such case the thickness of the reflective layer or mirror elements can be as thin as one (1) micrometer or less.

Although the techniques described above primarily concern reflective legends for user input device, such as keys, in other embodiments, the techniques described herein can be use to provide other reflective markings that would advantageously be more visible in low light conditions. In general, the reflective markings, or annotations, provided on products can be textual and/or graphic. The marking can be provided for informational, cosmetic and/or functional reasons. For example, the markings can be used to provide a product (e.g., a product's housing) with certain information. The marking can, for example, be use to label the product with various information. When a marking includes text, the text can provide information concerning the product (e.g., electronic device). For example, the text can include one or more of: name of product, trademark or copyright information, design location, assembly location, model number, serial number, license number, agency approvals, standards compliance, electronic codes, memory of device, and the like. When a marking includes a graphic, the graphic can pertain to a logo, a certification mark, standards mark or an approval mark that is often associated with the product. The marking can be used for advertisements to be provided on products. The markings can also be used for customization (e.g., user customization) of a housing of a product.

Although the embodiments described herein do not require changes to a display device or keys, in some embodiment, it may be useful to alter the physical configuration of the display device or keys. For example, the display device could be altered such that a portion of its emitted light is incident on the keys to be illuminated. Also, for example, the keys could be altered to allow them to more efficiently receive the light emitted from the display device. For instance, the structure for the key could angled toward the display device.

The various aspects, features, embodiments or implementations of the invention described above can be used alone or in various combinations.

Different aspects, embodiments or implementations may, but need not, yield one or more of the following advantages. One advantage is that legends or marking can be made reflective with appropriate diffusion so that the legends or markings can be visible in low light conditions. Another advantage is that backlight is not need needed for keys (e.g., key boards or keypads) if the legends on the keys are made suitably reflective. Here, additional components to support backlighting are not needed and thus electronic device can potentially be made thinner. Still another advantage is that keys can be provided with reflective legends in a manner that renders the legends durable, protected and with reliable adhesion.

The many features and advantages of the present invention are apparent from the written description. Further, since numerous modifications and changes will readily occur to those skilled in the art, the invention should not be limited to the exact construction and operation as illustrated and described. Hence, all suitable modifications and equivalents may be resorted to as falling within the scope of the invention.