US 7294802 B2
A keypad is provided for a computing device. The keypad includes one or more lighting devices or mechanisms for illuminating a plurality of keys structures. In an embodiment, the plurality of key structures are formed from a milky material.
1. A keypad for a computing device, the keypad comprising:
a plurality of light sources;
a plurality of key structures provided over the plurality of light sources so as to be illuminated by the plurality of light sources; and
a first polarization layer provided between the plurality of light sources and the plurality of key structures to distribute light generated from the plurality of lights sources.
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the first polarization layer creates at least one apparent light source for each of the plurality of light sources, wherein a position of the at least one apparent light source is adjacent to a position of a corresponding light source of the plurality of light sources along the first direction; and
the second polarization layer creates at least one apparent light source for (i) each of the plurality of light sources and (ii) each of the apparent light sources created by the first polarization layer.
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17. A keypad for a computing device, the keypad comprising:
a plurality of key structures;
a first lighting component that emits light substantially uniformly over a region that underlies the plurality of key structures, wherein the first lighting component corresponds to a board on which an electroluminescent layer is provided; and
one or more second lighting components that emit light at discrete locations.
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Embodiments of the invention relate to key structures and keypads for computing devices. In particular, embodiments of the invention relate to lighting and usability features for key structures and keypads on computing devices.
Keypads are important aspects of computing devices. With regard to small form-factor keypads in particular, the keypads tend to establish the overall form-factor of a computing device. The keypad is often a very visible and highly used component of such computing devices.
Messaging devices, in particular, have need for QWERTY style keyboards. Such keyboards are often operated by the user using thumbs. Key size, visibility, and sensation are important characteristics for consideration in the design of small form-factor keyboards. One further consideration is usability of such features in darkened environment. Many users typically need to see some or all keys of a keyboard when thumb typing on a small form factor keyboard, as such devices have closely spaced keys that may require visual coordination.
Numerous embodiments are described in this application for enhancing lighting and usability of key structures and keypads of computing devices. It is contemplated that the various features described by this application may be combined in any one of numerous ways.
According to an embodiment, a key structure is provided for a computing device. The key structure is formed from a milky material.
In another embodiment, a keypad is provided for a computing device. The keypad includes one or more lighting devices or mechanisms for illuminating a plurality of keys structures. In an embodiment, the plurality of key structures are formed from a milky material.
One or more embodiments described herein provide a keypad for a computing device. In an embodiment, a plurality of key structures comprise the keypad, and each of the key structures may be referenced by a top end that includes a surface for receiving user-contact and a bottom end that is opposite to the top end. A plurality of discrete light sources may provided underneath the plurality of key structures, so that the plurality of light sources illuminate each of the key structures from the bottom end. A partially opaque material provided between the top of each key structure in the plurality of key structures and the plurality of discrete light sources to cause light generated by the plurality of light sources to be transmissive through each key structure.
A keypad is any multi-key assembly. A keyboard is an implementation of a keypad.
As used herein, something is “milky” if it is opal with creamy body color that dominates the diffracted color. In one embodiment, a resin, key structure or other item is milky if it contains white colored resin, meaning resin having at least some visibly detectable white or off-white material. A material is white if the material contains all the colors of the spectrum.
Diffusion of Bright Light Underlying a Keypad
One or more embodiments described herein provide mechanisms for diffusing bright light provided within a housing of a computing device for purpose of illuminating the device's keypad or keyboard. In particular, some light sources, such as provided by white Light Emitting Diodes (LEDs) emit light that is bright and discrete. The brightness of such lights make their use desirable. But, absent some intervening design for handling the discreteness and brightness of the emitted light, the use of such light sources can result in a keypad being unevenly lit from underneath. In such cases, shadows or cold spots may form on regions that are further away from light sources, while bright or hot spots form on region closes to light sources. Furthermore, factors other than the positioning of light sources may result in the formation of hot and cold spots from the use of discrete light sources 120. Examples of such other key structure features include shading, colorization, use of different materials or surface materials to form some key structures and not others, and different ornamentations provided on key structures on the keypad.
One or more embodiments described herein include keypad design implementations and mechanisms for diffusing and distributing light emitted from LEDs and other bright and discrete light sources.
As shown by
In an embodiment, each key structures 110 includes an actuation member 115 that extends from its bottom end 116. In one implementation, the actuation members 115 are unitarily or integrally formed with the corresponding key structures 110. In another implementation, carrier 112 and key structures 110 are separately formed and combined, and actuation members 115 are unitarily or integrally formed from the carrier 112. In still another embodiment, the actuation members 115 have their own separate carrier and are separately formed from the key structures 110.
Each actuation member 115 may travel inward with compression or insertion of the corresponding key structure 110 to actuate a corresponding one of the electrical contact elements 130. Actuation of anyone of the electrical contact elements 130 triggers a signal that is received and processed by a processor 150 of the computing device. The signal generated from the triggering of any particular key is recognized by the processor 150 as having a value (e.g. alphabet or number value). The electrical contact elements 130 may be provided on a printed circuit board 132, or electrically interconnected substrate (e.g. flex circuit and substrate). In one implementation, the light sources 122 may be provided on a separate sheet. 124 that overlays the printed circuit board 132.
In an embodiment, light sources 122 are LEDs, although other types of light sources can be used. The LEDs provide a benefit of providing bright light for their relative size. In a configuration shown by
Accordingly, stack 102 includes components or elements to diffuse or distribute light emitted from light sources 122. The light sources 120 may illuminate individual key structures 110 from their respective bottom end 116. The result is that illumination is provided from a top end 118 of each respective key structure 120. The top end 118 of each individual key structure 110 may be the surface that receives user contact. The top end 118 of each key structure 110 may also display markings, shading, colorization, and/or printed matter. As such, the top end 118 of each key structure 110 corresponds to the surface from which the desired illumination effect is to take place.
In an embodiment, diffusive or light-distributive material is provided with or between the key structures 110 and the light sources 122. Such material may enable individual key structures 110 to be illuminated while at the same time diffusing light emitted from the individual light sources. One result achieved is that a keypad (or desired regions thereof) is illuminated substantially uniformly through diffusion of light from the discrete and bright light sources 122. Such a uniformly lit keypad may be well lit from underneath, without distracting hot or cold spots in the lighting. Accordingly, an embodiment provides that individual key structures 110 of a keypad have the following characteristics: (i) partially transmissive to light so that light entering the bottom end 116 of the key structures is partially carried through that structure; (ii) diffusive or distributive of light, so that some light used to illuminate each key structure 110 is diffused within and/or underneath the key structure 110.
In an embodiment shown by
One embodiment provides for milky layer 208 to be formed of a thin silicon rubber material. The layer 208 may provide a cushion or dampening effect for the actuation members 215 translating into the corresponding contact elements 230, while at the same time forming a diffusion layer for light emitted from light sources 222.
As shown by
As an alternative or addition to diffusing light emitted from light sources underlying a keypad, one or more embodiments of the invention contemplate distributing light from light sources. A difference between diffusion of light and distribution of light sources is that light from a source is diffused when it is made less discrete and more spread out, while light from a discrete source is maintained relatively discrete but distributed to more places in discrete form.
In order for any polarization material to be effective, an implementation provides that each polarization material is provided a gap distance 456 from a light source (actual or apparent) that is to be distributed. For example, in one implementation, the suitable gap distance 456 is millimeters. When two or more polarization materials are used in the stack 402, each material may need to have a thickness separation (e.g. 2-4 millimeters).
With regard to embodiments described in
Additionally, three or more layers of polarization materials may be used, depending on design implementation. It should be noted that while use of polarization material described with
Combination Lighting Layer
As described above, discrete light sources such as LEDs provide the benefit of brightness, which in turn provide better visibility and aesthetics of a key structure to a user. However, as also described, discrete light sources also provide shading, or hot/cold spots, unless the light emitted from such sources is treated in some manner. An alternative to LEDs and other forms of discrete light sources is a light source that emits light uniformly and evenly across a region that encompasses an entire keypad, or at least portions of the keypad on which lighting is desired. This type of lighting may be referred to as a lighting panel. A specific example of this kind of light source is an electroluminescent (EL) panel. While panel lighting has the benefit of providing uniform and distributed lighting, such lighting does not typically provide the same brightness as LEDs, at least not unless the amperage and size of the panel lighting is increased to be significantly greater than what would be required if only LEDs were to be employed.
Embodiments of the invention contemplate that a given keypad or keyboard design has some key structures that need bright lighting and other key structures that are adequately lit with panel lighting. Accordingly,
The key structures 514 may be arranged to provide one or more colored keys, keys with surface ornamentations and darkened appearances, and keys formed from different types of material. For example, in a small form-factor QWERTY keyboard, one embodiment provides for a shaded or colorized set of key structures 514, designated by a region 515, for purpose of indicating keys that have both numeric and alphabet values. Another implementation provides for the keypad to include specialized keys 518 that are colored are formed from more opaque material, such as application keys (for quick launching applications) or navigation keys (set for navigation by default).
In one embodiment, lighting layer 520 may include white LEDs 522 that form discrete light sources distributed on a substrate 525 containing an EL panel 526. The LEDs are positioned strategically to conserve energy while lighting key structures that require the most light. In the example shown, the key structures that require the most light are the application keys 518, as they are colorized (e.g. red, green and blue). As such,
Key Structure/Actuation Member Shaping
As shown, actuation members are elongated elements that travel in response to deflection or inward movement of corresponding key structures. The actuation members are used to convert key presses into switching events for electrical switches that underlie key structures. Typically, actuation members are cylindrical or even rectangular and extend downward from a bottom surface of a key structure.
In the context of lighting, the edged nature of actuation members are not conducive. The edges of actuation members reflect or divert light from the light sources, while better illumination results would result if such light was absorbed into the key structures and illuminated.
According to an embodiment, a shape of actuation member 620 is conical, with exterior surface of the actuation member extending to or near the boundary of the key body 605. In the example provided, the key body is symmetrical and round, creating the cone shape. In other implementations, the key body 605 may be non-round (e.g. square or rectangular) or irregular in shape (trapezoidal). In such alternative implementations, the exterior surface of the actuation member 620 may conform to the shape or irregularity of the key body. For example, a square key body may result in a pyramid shaped actuation member 620, while an irregular shaped key body 605 may result in an uneven conical or tapered actuation member 620.
Embodiments shown with
To enhance usability of a keyboard, it is desirable to lessen the restriction of movement of individual key structures when such structures are deflected and/or pushed inward by the user.
It should be noted that darkened and/or colored keys fair worst with light leakage. Light emitting from dark keys is more distracting to a user. Many factors, including key shape and distance to the proximate light sources, need to be considered in forming slits around on darkened keys of a keyboard.
Alternative embodiments may use strips or sections to form the key structure layer of a keyboard stack. Sectioning an otherwise monolithic keyboard into segments reduces the amount of tension that surrounds individual keys as a result of the weight and presence of other key structures formed on a common carrier. For example, in a QWERTY keyboard, each row of key structures may be provided on a separate strip, and the stripped sections may be combined in assembly to form the keyboard. Alternatively, multiple key structures may be formed on “L” or “C” shaped sections, which are then intertwined at assembly to form the monolithic keyboard. While sectioning keyboards for assembly can reduce tension on the carrier and thus enhance usability, the gaps caused by the sectioning also produce light leakage. As such, a balance between the number of sections and the amount of tolerable light leakage may be struck, based on the particular implementation.
One or more embodiments may implement a dampening layer in connection with use of actuation members traveling into contact members. Embodiments described in this section may be implemented independently of other embodiments provided with this application. For example, a dampening layer, such as described with
In an embodiment, the dampening layer 850 is provided over the electrical contacts 830 (
An overall thickness t of the dampening layer may be thin, of the order of less than one millimeter. In one embodiment, the thickness t of the dampening layer is less than 0.5 millimeter. In one specific implementation, the thickness t of the dampening layer is about (within 90%) of 0.25 millimeters. As mentioned, a suitable material for the dampening layer is silicon rubber. In such an implementation, the lighting sources 845 may correspond to light pipes or white LEDs.
Although illustrative embodiments of the invention have been described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments. As such, many modifications and variations will be apparent to practitioners skilled in this art. Accordingly, it is intended that the scope of the invention be defined by the following claims and their equivalents. Furthermore, it is contemplated that a particular feature described either individually or as part of an embodiment can be combined with other individually described features, or parts of other embodiments, even if the other features and embodiments make no mentioned of the particular feature. This, the absence of describing combinations should not preclude the inventor from claiming rights to such combinations.