PIANO-STYLE KEYPAD EMPLOYING A LIGHT GUIDE

• US 20080018606A1
• Filed: 07/18/2006
• Published: 01/24/2008
• Est. Priority Date: 07/18/2006
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Research In Motion Limited (Blackberry Limited)
• Inventors: Chen, Chao
• Granted Patent: US 7,825,899 B2
• Time in Patent Office: Days
• US Class Current: 345/169
• CPC Class Codes: G06F 3/0202 Constructional details or processes of manufacture of the input device

Abstract

An improved piano-style keypad comprises a light guide and a key sheet, with the light guide retaining the key sheet on a substrate, such as a printed circuit board of a handheld electronic device. The keypad is advantageously configured to enable key caps of the keypad to be adhered to key bodies of the keypad in a fashion that provides long-term reliability while still providing keys that can readily actuated and that provide tactile feedback that is desirable to the user.

Claims

1. A keypad for a handheld electronic device that comprises a light source, the keypad comprising:

a key sheet comprising a base and a number of key bodies, at least some of the key bodies each being disposed on the base and being movable between an unactuated position and an actuated position, the key body in the actuated position being structured to complete a circuit of the handheld electronic device, at least a portion of the key sheet being translucent; and

a light guide comprising a frame and a number of supports, at least a portion of the frame being disposed adjacent at least a portion of the base, at least some of the supports each engaging the base, at least a portion of the light guide being translucent and being structured to transmit light between the light source and the key sheet.

2. The keypad of claim 1 wherein the key sheet comprises a number of receptacles, at least some of the supports each being received in a receptacle.

3. The keypad of claim 2 wherein the receptacles are holes formed in the base, and wherein the supports are pegs that protrude from the frame and that are received in the holes.

4. The keypad of claim 3 wherein at least some of the pegs each have an interference fit with a hole.

5. The keypad of claim 1 wherein the base comprises a web and a leg network, the leg network protruding from the web and being structured to engage a substrate of the handheld electronic device, a portion of the web peripheral to a particular key body being movable between an undeflected position and a deflected position, the portion of the web being in the undeflected position when the particular key body is in the unactuated position, the portion of the web being in the deflected position when the particular key body is in the actuated position.

6. The keypad of claim 5 wherein the leg network comprises a plurality of braces structured to engage the substrate, the braces being structured to resist movement of a portion of the web peripheral to one key body toward its undeflected position when a portion of the web peripheral to an adjacent key body moves toward its deflected position.

7. The keypad of claim 6 wherein at least some of the braces each have a hole formed therein, and wherein the supports are pegs that protrude from the frame and that are received in the holes, at least some of the key bodies being movable along a direction between the unactuated and actuated positions, and wherein the pegs protrude along the direction from the frame, the pegs resisting movement of the braces transverse to the direction.

8. The keypad of claim 1 wherein the key sheet further comprises a number of key caps, at least some of the key caps each being adhered to a key body.

9. The keypad of claim 8 wherein the frame has a number of openings formed therein, at least some of the key bodies each being disposed within an opening.

10. The keypad of claim 8 wherein at least a portion of the frame is disposed between the base and the key caps.

11. A keypad for a handheld electronic device that comprises a light source, the keypad comprising:

a key sheet comprising a base a number of key bodies, and a number of key caps, at least some of the key bodies each being disposed on the base and being movable between an unactuated position and an actuated position, the key body in the actuated position being structured to complete a circuit of the handheld electronic device, at least some of the key caps each being adhered to a key body, at least a portion of the key sheet being translucent; and

a light guide, at least a portion of the light guide overlying at least a portion of the base, at least a portion of the light guide being translucent and being structured to transmit light between the light source and the key sheet.

12. The keypad of claim 11 wherein the light guide has a number of openings formed therein, at least some of the key bodies each being disposed within an opening.

13. The keypad of claim 12 wherein the light guide comprises a frame and a number of supports, the openings being formed in the frame, at least a portion of the frame being disposed between the base and the key caps.

14. The keypad of claim 11 wherein the base comprises a web and a leg network, the leg network protruding from the web and being structured to engage a substrate of the handheld electronic device, a portion of the web peripheral to a particular key body being movable between an undeflected position and a deflected position, the portion of the web being in the undeflected position when the particular key body is in the unactuated position, the portion of the web being in the deflected position when the particular key body is in the actuated position.

15. The keypad of claim 14 wherein at least a portion of the web is disposed between the leg network and at least a portion of the light guide.

16. The keypad of claim 15 wherein the portion of the web peripheral to the particular key body extends between the particular key body and at least a portion of the leg network.

17. The keypad of claim 16 wherein the portion of the web that is movable between the undeflected and deflected positions has at least about 0.6 millimeters between the particular key body and the at least portion of the leg network.

18. The keypad of claim 17 wherein the key bodies each have a mounting surface, at least some of the key caps each being adhered to the mounting surface of a key body, each mounting surface having an area of at least about fifteen square millimeters.

19. The keypad of claim 17 wherein the mounting surfaces are substantially planar.

20. A keypad for a handheld electronic device that comprises a light source, the keypad comprising:

a substrate;

a light guide comprising a frame and a number of retention members, at least some of the retention members each being engaged with the substrate;

a key sheet comprising a base and a number of key bodies, at least some of the key bodies each being disposed on the base and being movable between an unactuated position and an actuated position, the key body in the actuated position being structured to complete a circuit of the handheld electronic device, at least a portion of the key sheet being disposed between at least a portion of the light guide and at least a portion of the substrate, at least a portion of the key sheet being translucent; and

at least a portion of the light guide being translucent and being structured to transmit light between the light source and the key sheet.

21. The keypad of claim 20 wherein at least some of the retention members each comprise a latch that is engaged with the substrate.

22. The keypad of claim 20 wherein the light guide further comprises a number of supports engaged with the key sheet, the retention members and the supports extending away from the frame in a common direction.

23. The keypad of claim 22 wherein the base has a number of holes formed therein, and wherein the supports are pins received in the holes, the pins resisting movement of the base in a direction transverse to the common direction.

24. The keypad of claim 20 wherein the key sheet further comprises a number of key caps, at least some of the key caps each being adhered to a key body.

25. The keypad of claim 24 wherein the frame has a number of openings formed therein, at least some of the key bodies each being disposed within an opening.

26. The keypad of claim 24 wherein at least a portion of the frame is disposed between the base and the key caps.