Backlit key assembly having a reduced thickness
AssigneeResearch In Motion Limited
InventorsChao Chen, Jana Lynn Papke, Dietmar Frank Wennemer
Life of this patent
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Abstract
A backlit key assembly having a reduced thickness for an electronic device, and an electronic device having such a backlit key assembly are provided. The key assembly utilizes a local sink (recess) in a backing plate of the key assembly to lower the light source (e.g. LED) and flexible printed circuit board relative to the backing plate. The key assembly described herein provides a suitable leading space for the light source while permitting the overall thickness of the key assembly to be reduced compared with conventional backlit key designs.
Claims24
A key assembly for use in an electronic device, comprising:
- a backing plate having a top surface which defines at least one recess;
- a key subassembly located above the top surface of the backing plate, including:
- a dome sheet having a number of dome switches on one side thereof;
- a flexible member formed of a light transmissive material having opposed first and second sides, the flexible member having a plurality of key stems located on the first side and a plurality of actuators located on the second side opposite the key stems and adjacent to the dome switches for actuating them;
- at least one keycap having a light transmitting portion attached to at least one of the key stems;
- and
- a flexible printed circuit board (PCB) received within the recess of the backing plate and connected to the dome sheet;
- a light emitting diode (LED) connected to the PCB;
- and
- a light diffuser positioned opposite the LED having a light incident surface and at least one light emitting surface, wherein the light diffuser is configured to receive light from the LED when activated and direct the light towards the flexible member to illuminate it, wherein the illuminated flexible member emits at least a portion of the light received from the light diffuser through the light transmitting portion of the keycap to illuminate it.
An electronic device, comprising:
- a controller;
- a key assembly, comprising;
- a backing plate having a top surface which defines at least one recess;
- a key subassembly located above the top surface of the backing plate, including:
- a dome sheet having a number of dome switches on one side thereof;
- a flexible member formed of a light transmissive material having opposed first and second sides, the flexible member having a plurality of key stems located on the first side and a plurality of actuators located on the second side opposite the key stems and adjacent to the dome switches for actuating them;
- at least one keycap having a light transmitting portion attached to at least one of the key stems;
- and
- a flexible printed circuit board (PCB) received within the recess of the backing plate and connected to the dome sheet;
- a light emitting diode (LED) connected to the PCB;
- and
- a light diffuser positioned opposite the LED having a light incident surface and at least one light emitting surface, wherein the light diffuser is configured to receive light from the LED when activated and direct the light towards the flexible member to illuminate it, wherein the illuminated flexible member emits at least a portion of the light received from the light diffuser through the light transmitting portion of the keycap to illuminate it;
- wherein the controller being configured for receiving input signals in response to the actuation of the dome switches and for recognizing corresponding inputs in response to the received input signals.
Dependencies are inferred from the claim text.