# US 2012/0073941 A1 · Backlighting apparatus for a keypad assembly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2012/0073941 A1 - Document ID: US20120073941A1 - Status: Published application - Kind: A1 - Application number: 12/889,594 - Filed: 2010-09-24 - Published: 2012-03-29 - Earliest claimed: 2010-09-24 - Assignees: Research In Motion Limited - Inventors: Chao Chen - Web page: https://patentgrep.com/patent/US20120073941A1 ## CPC - H01H 13/023: {Light-emitting indicators (for multi-layer switches H01H13/83)} - H01H 11/00: Apparatus or processes specially adapted for the manufacture of electric switches (processes specially adapted for manufacture of rectilinearly movable switches having a plurality of operating members associated with different sets of contacts, e.g. keyboards, H01H13/88) - H01H 13/83: characterised by legends, e.g. Braille, liquid crystal displays, light emitting or optical elements - H01H 2215/004: Collapsible dome or bubble - H01H 2219/06: Reflector - H01H 2219/062: Light conductor - Y10T 29/49105: Switch making - H01H: ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES (contact cables H01B7/10; electrolytic self-interrupters H01G9/18; emergency protective circuit arrangements H02H; switching by electronic means without contact-making H03K17/00) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A keypad assembly including a dome configured to operatively engage a switch sensor; a dome overlay guide operatively coupled by to the dome; a key corresponding to the dome and configured to operatively engage the dome; and a light emitting source, configured to emit light. The dome overlay guide is configured to receive the light emitted by the light emitting source and direct the received light toward the keys. ## Claims ### Claim 1 A keypad assembly comprising: a) a dome configured to operatively engage a switch sensor; b) a dome overlay guide operatively coupled to the dome; c) a key corresponding to the dome, and configured to operatively engage the dome; d) a light emitting source configured to emit light; and e) wherein the dome overlay guide is configured to receive the emitted light and direct the received light toward the key. ### Claim 2 (depends on 1) The keypad assembly of claim 1, wherein the dome overlay guide comprises a light guide film. ### Claim 3 (depends on 1) The keypad assembly of claim 1, further comprising a reflector layer configured to reflect light escaping the dome overlay guide. ### Claim 4 (depends on 3) The keypad assembly of claim 3, wherein the reflector layer is configured to reflect the escaping light toward the key. ### Claim 5 (depends on 3) The keypad assembly of claim 3, wherein the dome overlay guide is between the reflector layer and the key. ### Claim 6 (depends on 1) The keypad assembly of claim 1, wherein the operative coupling comprises an adhesive. ### Claim 7 (depends on 1) The keypad assembly of claim 1, further comprising a deflection web configured to seat the key, wherein the deflection web is between the key and the dome overlay guide. ### Claim 8 (depends on 1) The keypad assembly of claim 1, wherein the light emitting source comprises a side firing light emitting diode. ### Claim 9 (depends on 1) The keypad assembly of claim 1, comprising a plurality of keys, and a plurality of corresponding domes. ### Claim 10 (depends on 1) A mobile device comprising the keypad assembly of claim 1. ### Claim 11 A keypad assembly comprising: a) a dome configured to operatively engage a switch sensor; b) a dome overlay guide operatively coupled to the dome; c) a key corresponding to the dome, and configured to operatively engage the dome; d) a deflection web configured to seat the key; e) a side firing light emitting source configured to emit light; f) wherein the dome overlay guide is configured to receive the emitted light, and direct the received light toward the key; and g) wherein an actuator is adjacent to a portion of an upper surface of the dome overlay guide. ### Claim 12 (depends on 11) The keypad assembly of claim 11, wherein the dome overlay guide comprises a light guide film. ### Claim 13 (depends on 11) The keypad assembly of claim 11, further comprising a reflector layer configured to reflect light escaping the dome overlay guide. ### Claim 14 (depends on 13) The keypad assembly of claim 13, wherein the reflector layer is configured to reflect the escaping light toward the key. ### Claim 15 (depends on 13) The keypad assembly of claim 13, further comprising a printed circuit board, wherein the reflector layer is positioned between the printed circuit board and the dome overlay guide. ### Claim 16 (depends on 13) The keypad assembly of claim 13, wherein the dome overlay guide is adhered to the reflector layer. ### Claim 17 (depends on 16) The keypad assembly of claim 16, wherein the dome overlay guide comprises at least one cavity configured to emit the received light in a direction toward the key. ### Claim 18 (depends on 11) The keypad assembly of claim 11, wherein the side firing light emitting source comprises a light emitting diode. ### Claim 19 A method for providing backlighting for a keypad assembly, the keypad assembly comprising a printed circuit board having a switch sensor, a key corresponding to the switch sensor, a light emitting source configured to emit light, the method comprising: a) providing a dome corresponding to the switch sensor; b) adhering a light guide film to the dome; and c) securing the light guide film within the keypad assembly, wherein the light guide film is configured to receive the emitted light, and wherein the dome is configured to operatively engage the switch sensor. ### Claim 20 (depends on 19) The method of claim 19, further comprising adhering a reflector layer to the light guide film.