WO2008078143A1 - A keypad assembly - Google Patents

A keypad assembly Download PDF

Info

Publication number
WO2008078143A1
WO2008078143A1 PCT/IB2006/004179 IB2006004179W WO2008078143A1 WO 2008078143 A1 WO2008078143 A1 WO 2008078143A1 IB 2006004179 W IB2006004179 W IB 2006004179W WO 2008078143 A1 WO2008078143 A1 WO 2008078143A1
Authority
WO
WIPO (PCT)
Prior art keywords
light guide
sheet light
keypad assembly
silicone sheet
domes
Prior art date
Application number
PCT/IB2006/004179
Other languages
French (fr)
Inventor
Olivier Bruandet
Original Assignee
Nokia Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nokia Corporation filed Critical Nokia Corporation
Priority to PCT/IB2006/004179 priority Critical patent/WO2008078143A1/en
Publication of WO2008078143A1 publication Critical patent/WO2008078143A1/en

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/0058—Means for improving the coupling-out of light from the light guide varying in density, size, shape or depth along the light guide
    • G02B6/006—Means for improving the coupling-out of light from the light guide varying in density, size, shape or depth along the light guide to produce indicia, symbols, texts or the like
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H13/00—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch
    • H01H13/70—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a plurality of operating members associated with different sets of contacts, e.g. keyboard
    • H01H13/88—Processes specially adapted for manufacture of rectilinearly movable switches having a plurality of operating members associated with different sets of contacts, e.g. keyboards
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/0035—Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it
    • G02B6/0036—2-D arrangement of prisms, protrusions, indentations or roughened surfaces
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/0035—Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it
    • G02B6/004—Scattering dots or dot-like elements, e.g. microbeads, scattering particles, nanoparticles
    • G02B6/0043—Scattering dots or dot-like elements, e.g. microbeads, scattering particles, nanoparticles provided on the surface of the light guide
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2205/00—Movable contacts
    • H01H2205/016—Separate bridge contact
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2205/00—Movable contacts
    • H01H2205/016—Separate bridge contact
    • H01H2205/024—Means to facilitate positioning
    • H01H2205/026—Adhesive sheet
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2205/00—Movable contacts
    • H01H2205/016—Separate bridge contact
    • H01H2205/024—Means to facilitate positioning
    • H01H2205/03—Apertured plate
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2209/00—Layers
    • H01H2209/046—Properties of the spacer
    • H01H2209/06—Properties of the spacer transparent
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2219/00—Legends
    • H01H2219/036—Light emitting elements
    • H01H2219/044—Edge lighting of layer
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2219/00—Legends
    • H01H2219/036—Light emitting elements
    • H01H2219/048—Constituting key
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2219/00—Legends
    • H01H2219/054—Optical elements
    • H01H2219/062—Light conductor
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2227/00—Dimensions; Characteristics
    • H01H2227/036—Minimise height
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/02—Constructional features of telephone sets
    • H04M1/22—Illumination; Arrangements for improving the visibility of characters on dials
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/02—Constructional features of telephone sets
    • H04M1/23—Construction or mounting of dials or of equivalent devices; Means for facilitating the use thereof

Abstract

A keypad assembly comprising: a key mat; a silicone sheet light guide; and switching domes directly fixed to the silicone light guide.

Description

TITLE
A keypad assembly
FIELD OF THE INVENTION
Embodiments of the present invention relate to a keypad assembly. In particular, they relate to a low-profile keypad assembly.
BACKGROUND TO THE INVENTION
One form of current keypad assembly comprises a key mat, an underlying rigid light guide, a layer of white PET and switching key domes. Such keypad assemblies may be too thick.
It would be desirable to create lower-profile keypad assemblies.
One form of current low-profile keypad assembly comprises an electroluminescent (EL) layer between a key mat and switching key domes. A disadvantage of this assembly is that the EL layer requires special drivers and does not provide good tactile feedback to a user actuating the key mat.
It would therefore be desirable to provide another form of lower-profile keypad assembly.
BRIEF DESCRIPTION OF THE INVENTION
According to some embodiments of the invention there is provided a keypad assembly comprising: a key mat; a silicone sheet light guide; and switching domes directly fixed to the silicone sheet light guide. According to some embodiments of the invention there is provided a switching sheet assembly comprising: a silicone sheet light guide; and switching domes directly fixed to the silicone sheet light guide.
According to some embodiments of the invention there is provided a keypad assembly comprising: a key mat; a flexible sheet light guide; and switching domes directly fixed to the flexible sheet light guide.
The use of a flexible light guide to which the domes are directly connected produces a low profile keypad arrangement 10 with good tactile feedback.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention reference will now be made by way of example only to the accompanying drawings in which:
Figure 1 schematically illustrates a keypad assembly comprising: a key mat; a silicone sheet light guide; and switching domes directly fixed to the silicone sheet light guide; and
Figures 2A and 2B illustrate how a switch sheet assembly may be created.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
Figure 1 schematically illustrates an apparatus 1 comprising a printed wiring board 40 and a keypad assembly 2.
The keypad assembly 2 comprises: a key mat 10; a silicone sheet light guide 20; and switching domes 30 directly fixed to the silicone sheet light guide 20.
In more detail, Figure 1 schematically illustrates a key mat 10 that is suitable for use in an electronic device such as a mobile cellular telephone, a personal digital assistant, a computer or similar. The key mat 10 comprises a plurality of keys 12 connected to a resilient web 14. The underside of each key has a protrusion 13 that extends downwards towards a dome 30. The resilient web 14 is supported in places by a metal frame 16. The metal frame 16 has a plurality of apertures 17 that are in register with the protrusions 13 and also underlying domes 30.
The silicone sheet light guide 20 is a sheet of silicone rubber that extends underneath the key mat 10 and is used to channels lights to the keys 12 of the key mat 10.
Light is input to the silicone sheet light guide 20 by a light source 28, such as a light emitting diode (LED) attached to the printed wiring board 40. Light is output from the silicone sheet light guide 20 via output portions 22 that are directly underneath the keys 12 on an upper surface 21 A of the silicone sheet light guide 20. The output portions 22 typically comprise modifications to the surface of the silicone sheet light guide 20 that enable light trapped within the light guide 20 by total internal reflection to be emitted. The output portions 22 may for example be abraded areas, printed areas or similar.
The silicone sheet light guide 20 is not attached to the key mat 10 and is separable from the key mat 10. However, the silicone sheet light guide is attached by adhesive 27 to a metal frame 24. The metal frame 24 supports the silicone sheet light guide 20. The metal frame 24 has apertures 25 that are positioned underneath and in register with the protruding portions 13 of the keys 12. The apertures 25 expose portions of an underside 21 B of the silicone sheet light guide 20 to which the domes 30 are fixedly attached, directly without an intervening layer. The domes may, for example, be attached by adhesive or glue. The metal frame 24 also provides air gaps to the interior of the metal domes 30 and an upper reflective surface that reflects light towards the key mat 10.
The metal frame 24 may be attached to the printed wiring board (PWB) 30 by adhesive 26. The metal domes 30 make contact with circuitry on the printed wiring board 40 and overlie switching elements 42. When the metal dome 30 is depressed, it resiliently deforms to make physical contact with switching element 42 and complete an electric circuit.
In use, the user actuates a key 12 by pressing it downwards. The resilient web 14 deforms enabling the downward protrusion 13 to travel downwards and deform the combination of silicone sheet light guide 20 and dome 30. Deformation of the dome 30 results in the dome 30 making electrical contact with the switch element 42 on a printed wiring board (PWB) 40.
Figures 2A and 2B illustrate how a switch sheet assembly 50 may be created.
An array of metal domes 30 are fixedly connected to the underside of a silicone sheet light guide 20. A metal frame 24, which has apertures 25, is placed in register with the domes 30 using guides 51 and is attached to the silicone sheet light guide 20 using adhesive 27. Adhesive 26 may be applied to the underside of the metal frame 24 so that the switching sheet assembly
50 can be attached to a printed wiring board 40.
The assembled switching sheet assembly 50 is illustrated in Figure 2B.
It will be appreciated that the switching sheet assembly 50 illustrated in Figures 2A and 2B is particularly useful for a QWERTY keyboard.
The use of a flexible light guide to which the domes are directly connected produces a low profile keypad arrangement 10.
Although embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the invention as claimed. Whilst endeavoring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.
I/we claim:

Claims

1. A keypad assembly comprising: a key mat; a silicone sheet light guide; and switching domes directly fixed to the silicone sheet light guide.
2. A keypad assembly as claimed in claim 1 wherein the key mat comprises a plurality of keys and the silicone sheet light guide comprises output portions underlying the keys of the key mat.
3. A keypad assembly as claimed in claim 1 wherein the surface of the silicone sheet light guide is adapted at the output portions to enable light to be emitted towards the keys.
4. A keypad assembly as claimed in claim 1 , 2 or 3, further comprising a printed wiring board (PWB) which in combination with the switching domes forms switches for actuation via the key mat.
5. A keypad assembly as claimed in claim 4, wherein the silicone sheet light guide underlies the key mat, the switching domes underlie the silicone sheet light guide and the PWB underlies the switching domes.
6. A keypad assembly as claimed in claim 4 or 5 further comprising a rigid frame between the silicone sheet light guide and the PWB that has openings to enable the domes to contact the PWB.
7. A keypad assembly as claimed in claim 6, wherein the rigid frame provides air passage to the domes.
8. A keypad assembly as claimed in claim 6, wherein the rigid frame has an upper surface, presented towards the key mat, of reflective material.
9. A switching sheet assembly comprising: a silicone sheet light guide; and switching domes directly fixed to the silicone sheet light guide.
10. A keypad assembly comprising: a key mat; a flexible sheet light guide; and switching domes directly fixed to the flexible sheet light guide.
11. An apparatus comprising the keypad assembly of any one of claims 1 to 8 and 10.
PCT/IB2006/004179 2006-12-22 2006-12-22 A keypad assembly WO2008078143A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/IB2006/004179 WO2008078143A1 (en) 2006-12-22 2006-12-22 A keypad assembly

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/IB2006/004179 WO2008078143A1 (en) 2006-12-22 2006-12-22 A keypad assembly

Publications (1)

Publication Number Publication Date
WO2008078143A1 true WO2008078143A1 (en) 2008-07-03

Family

ID=39562144

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2006/004179 WO2008078143A1 (en) 2006-12-22 2006-12-22 A keypad assembly

Country Status (1)

Country Link
WO (1) WO2008078143A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9259884B2 (en) 2013-05-16 2016-02-16 Blackberry Limited Method and apparatus pertaining to reversed thermoformed film
US9348426B2 (en) 2013-05-16 2016-05-24 Blackberry Limited Method and apparatus pertaining to web-coupled keyboard keys

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0500330A2 (en) * 1991-02-21 1992-08-26 Nec Corporation Flat keyboard switch
WO2005117047A1 (en) * 2004-05-28 2005-12-08 Sunarrow Ltd. Key unit with casing
WO2005120025A1 (en) * 2004-06-04 2005-12-15 Hanwool Information Tech. Co., Ltd. El sheet and dome keypad using the same
EP1724801A1 (en) * 2005-05-19 2006-11-22 Samsung Electronics Co.,Ltd. Keypad assembly for a portable terminal

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0500330A2 (en) * 1991-02-21 1992-08-26 Nec Corporation Flat keyboard switch
WO2005117047A1 (en) * 2004-05-28 2005-12-08 Sunarrow Ltd. Key unit with casing
EP1768146A1 (en) * 2004-05-28 2007-03-28 Sunarrow Ltd. Key unit with casing
WO2005120025A1 (en) * 2004-06-04 2005-12-15 Hanwool Information Tech. Co., Ltd. El sheet and dome keypad using the same
EP1724801A1 (en) * 2005-05-19 2006-11-22 Samsung Electronics Co.,Ltd. Keypad assembly for a portable terminal

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9259884B2 (en) 2013-05-16 2016-02-16 Blackberry Limited Method and apparatus pertaining to reversed thermoformed film
US9348426B2 (en) 2013-05-16 2016-05-24 Blackberry Limited Method and apparatus pertaining to web-coupled keyboard keys

Similar Documents

Publication Publication Date Title
US8050019B2 (en) Keypad with water and dust protection
JP2012512596A (en) Light diffusion actuator film (LDAF) keypad module
US20080073186A1 (en) Thin Key Sheet and Thin Key Unit Incorporating the Thin Key Sheet
US20060283698A1 (en) Illuminating membrane switch and illuminating keypad using the same
US6861600B1 (en) Integrated switch and backlight assembly
US7181007B2 (en) Flat-profile keypad assembly and label
US9384918B2 (en) Illuminated keyboard
US8085246B2 (en) Keypad panel assembly having laterally-illuminated keypad surface
US7718910B2 (en) Movable contact assembly and switch using the same
US20080277253A1 (en) Thin Key Sheet
JP5023971B2 (en) Movable contact with light guiding function and input device using the same
WO2008078143A1 (en) A keypad assembly
CA2476778C (en) Printed circuit board for a mobile device
KR101518066B1 (en) Flexible printed circuit board, input module and mobile apparatus
EP2270824B1 (en) Keypad with Water and Dust Protection
KR100689391B1 (en) Keypad assembly
JP2007194092A (en) Membrane sheet and switching device
KR20060120302A (en) Key pad assembly
KR101331945B1 (en) Key input device and mobile terminal having it
JP2010129502A (en) Movable contact element, and switch using the same
JP2008159346A (en) Portable electronic equipment
US20080036003A1 (en) Backlighted membrane switch
JP2001176353A (en) Key switch
KR20080037974A (en) Keypad assembly
JP2009295525A (en) Illuminating structure of light guide layer

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 06849518

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 06849518

Country of ref document: EP

Kind code of ref document: A1