PORTABLE ELECTRONIC DEVICE HAVING A WATERPROOF KEYPAD

• US 20120020045A1
• Filed: 07/21/2010
• Published: 01/26/2012
• Est. Priority Date: 07/21/2010
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Research In Motion Limited (Blackberry Limited)
• Inventors: Tanase, Silviu
• Granted Patent: US 8,446,264 B2
• Time in Patent Office: Days
• US Class Current: 361/807
• CPC Class Codes: G06F 3/0234 using switches operable in different directions
• CPC Class Codes: H01H 13/85 characterised by tactile feedback features
• CPC Class Codes: H01H 13/86 characterised by the casing, e.g. sealed casings or casings reducible in size
• CPC Class Codes: H01H 2215/052 piezoelectric
• CPC Class Codes: H01H 2223/003 Membrane embracing all keys
• CPC Class Codes: H01H 2239/006 Containing a capacitive switch or usable as such
• CPC Class Codes: H01H 9/04 Dustproof, splashproof, drip-proof, waterproof, or flameproof casings
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 17/9625 using a force resistance transducer
• CPC Class Codes: H03K 2217/960785 with illumination
• CPC Class Codes: H04M 1/18 Telephone sets specially adapted for use in ships, mines, or other places exposed to adverse environment H04M1/19 takes precedence
• CPC Class Codes: H04M 1/23 Construction or mounting of dials or of equivalent devices; Means for facilitating the use thereof by improving visibility H04M1/22

Abstract

A portable electronic device having a waterproof keypad and a keypad assembly for the waterproof keypad are described. In one embodiment, the keypad assembly comprises: an embossed keypad having a top and bottom surface, the embossed keypad having a plurality of embossed keys on the top surface; a capacitive sensor layer located below the bottom surface of the embossed keypad; and an actuator located below the capacitive sensor layer moveable between a first position in an unactuated state to a second position in an actuated state.

Claims

1. A keypad assembly, comprising:

an embossed keypad having a top and a bottom surface, the embossed keypad having a plurality of embossed keys on the top surface;

a capacitive sensor layer located below the bottom surface of the embossed keypad; and

an actuator located below the capacitive sensor layer and moveable between a first position in an unactuated state to a second position in an actuated state.

2. The keypad assembly of claim 1, wherein the embossed keypad comprises a flexible sheet, wherein the embossed keys are over-molded on the top surface of the flexible sheet.

3. The keypad assembly of claim 1, wherein the capacitive sensor layer comprises a capacitive sheet including a number of capacitive plate electrodes configured to detect the presence of an object near to or touching an embossed key in the embossed keypad.

4. The keypad assembly of claim 3, wherein each capacitive plate electrode includes a capacitive plate pair deposited on opposite sides of a substrate.

5. The keypad assembly of claim 4, wherein spaces are provided between capacitive plate pairs in the capacitive sensor layer, the spaces corresponding to spaces between embossed keys in the embossed keypad.

6. The keypad assembly of claim 1, further comprising a stiffener located between the capacitive sensor layer and the actuator.

7. The keypad assembly of claim 1, wherein the actuator comprises a piezoelectric assembly comprising at least one piezoelectric element, the movement from the first position to the second position being caused by modulation of the charge of the piezoelectric element, thereby providing tactile feedback.

8. The keypad assembly of claim 7, wherein the piezoelectric element moves from the first position to the second position in response to expansion of the piezoelectric element caused by a decrease in a charge of the piezoelectric element, and the piezoelectric element moves from the second position to the first position in response to contraction of the piezoelectric element caused by an increase in the charge of the piezoelectric element.

9. The keypad assembly of claim 1, wherein the embossed keypad and capacitive sensor layer are formed of a substantially transparent material, the keypad assembly further comprising a light guide assembly located immediately below the capacitive sensor layer for illuminating at least a portion of the embossed keys with light provided by a light source.

10. The keypad assembly of claim 1, wherein the embossed keypad is formed from a transparent polyethylene terephthalate (PET) and the capacitive sensor layer is formed from patterned indium-tin oxide (ITO) or comprises an array of transparent capacitive sensors.

11. The keypad assembly of claim 9, wherein the light guide assembly comprises:

a light emitting diode (LED); and

a light diffuser positioned opposite the LED and having a light incident surface which receives light from the LED when activated, and at least one light emitting surface, wherein the light diffuser is configured to direct the received light towards at least one of the embossed keys to illuminate it.

12. A portable electronic device, comprising:

a housing having a front face and defining an aperture in the front face, the aperture in the front face opening into an internal cavity defined by the housing;

a processor received within the housing;

a keypad assembly, comprising an embossed keypad having a top and a bottom surface, the embossed keypad having a plurality of embossed keys on the top surface;

a capacitive sensor layer located below the bottom surface of the embossed keypad; and

an actuator located below the capacitive sensor layer and moveable between a first position in an unactuated state to a second position in an actuated state;

wherein the capacitive sensor layer of the keypad assembly is connected to the processor, the capacitive sensor layer transmitting input signals to the processor when an object is detected near to or touching an embossed key in the embossed keypad; and

a gasket located around a perimeter of a keypad area of the embossed keypad and between the embossed keypad and an inner surface of the internal cavity of the housing, the gasket sealing the key assembly to the front face of the housing.

13. The portable electronic device of claim 12, wherein the actuator is resiliently biased against the capacitive sensor layer to permit movement of the embossed keypad and capacitive sensor layer between a rest position and an actuated position relative to the housing.

14. The portable electronic device of claim 12, wherein the capacitive sensor layer comprises a capacitive sheet including a number of capacitive plate electrodes configured to detect the presence of an object near to or touching an embossed key in the embossed keypad;

wherein the processor is configured to;

map capacitive plate pairs in the capacitive sensor layer to embossed keys of the embossed keypad,

determine a location of a capacitive plate pair which experiences a change in capacitance exceeding a threshold capacitance change caused by the presence of an object near to or touching the embossed keypad in accordance with a mapping of the capacitive plate pairs to embossed key in the embossed keypad,

determine a particular key in the embossed keys of the embossed keypad in accordance with the determined location, and

generate an output in accordance with the determined key.

15. The portable electronic device of claim 12, wherein the processor is configured to move the actuator between the first position to the second position in response to the detection of the presence of an object near to or touching an embossed key in the embossed keypad.

16. The portable electronic device of claim 12, further comprising:

a force sensor located below the key assembly and connected to the processor, the force sensor configured to measure forces applied to the keypad assembly;

wherein the processor is configured to move the actuator between the first position to the second position in response to the detection of a force by the force sensor which exceeds a threshold level.

17. The portable electronic device of claim 12, wherein the inner surface of the internal cavity of the housing defines a channel in which the gasket is received.

18. The portable electronic device of claim 12, further comprising a display screen exposed by the housing and connected to the processor.

19. A method comprising:

determining a location of a capacitive plate pair which experiences a change in capacitance exceeding a threshold capacitance change caused by the presence of an object near to or touching an embossed keypad of a keypad assembly, the embossed keypad having a plurality of embossed keys on a top surface thereof;

determining a particular key in the embossed keys of the embossed keypad in accordance with the determined location; and

generating an output in accordance with the determined key.

20. The method of claim 19, further comprising:

moving an actuator located below the capacitive plate pair between a first position in an unactuated state to a second position in an actuated state in response to the detection of the presence of an object near to or touching an embossed key in the embossed keypad.