Backlighted key for a keypad of an electronic device

• US 7,582,839 B2
• Filed: 02/28/2007
• Issued: 09/01/2009
• Est. Priority Date: 02/28/2007
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Kyowski, Timothy, Ng, Albert, Pang, Suzanne Man
• Primary Examiner(s): Enad; Elvin G
• Assistant Examiner(s): Anglo; Lheiren Mae A
• Application Number:
  US11/679,981
• Publication Number:
  US 20080202907A1
• Time in Patent Office: 916 Days
• Field of Search: 200310-317
• US Class Current: 200/310
• CPC Class Codes: H01H 13/83 characterised by legends, e.g. Braille, liquid crystal displays, light emitting or optical elements
• CPC Class Codes: H01H 2219/028 Printed information
• CPC Class Codes: H01H 2219/056 Diffuser; Uneven surface
• CPC Class Codes: H01H 2219/062 Light conductor
• CPC Class Codes: H01H 2231/022 Telephone handset
• CPC Class Codes: H04M 1/22 Illumination; Arrangements for improving the visibility of characters on dials
• 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

The invention relates to a key plunger for a key of an electronic device. The plunger comprises: a stalk made of a transparent material allowing light to pass through; a plinth connected to the top of the stalk; and a body section connected to the top of the plinth made of a translucent, light-diffusing material. The body section is shaped to fit snugly within an interior of a cap for the key. The plunger is made from a two-shot moulding process for forming the stalk and the section. The plunger may be part of a key assembly that also has a key cap shaped to snugly fit over the plunger and a backlight to light an interior of the cap.

Claims

1. A key plunger for a key of an electronic device, comprising:

a stalk made of a first material allowing light to pass through;

a plinth connected to the top of said stalk; and

a body section connected to the top of said plinth, said body section made of a second, material and shaped to fit snugly within an interior of a cap for said key and to extend horizontally about said stalk,

wherein

said second material is a translucent, light-diffusing material;

said first material allows more light to pass therethrough than said second material;

either a two-shot moulding process or a welding process is used to form said key plunger;

in said key plunger, said second material disperses light from a source located below said body section which enters said body section into a region in said body section immediately over said stalk to brighten a first shadow region associated with said region in said body section; and

said transparent material transmits light passing through said stalk from said source to brighten a second shadow region located on a side of said stalk which is opposite to said source.

2. The key plunger as claimed in claim 1, wherein said transparent material comprises a clear polycarbonate or resin.

3. The key plunger as claimed in claim 2, wherein:

said plinth

is made of said first material; and

is formed with said stalk when said two-shot moulding process is used; and

said stalk is solid.

4. The key plunger as claimed in claim 2, wherein:

said plinth

is made of said second material; and

is formed with said body section when said two-shot moulding process is used; and

said stalk is solid.

5. The key plunger as claimed in claim 2, wherein said second material in said body section comprises a coloured polycarbonate or resin and disperses light within said body about said region to further reduce said shadow in said shadow area.

6. A key assembly for a key of a keypad of an electronic device, comprising:

a key plunger having

a stalk made of a first material allowing light to pass through;

a plinth connected to the top of said stalk; and

a body section connected to the top of said plinth, said body section made of a second material and shaped to fit snugly within an interior of a cap for said key and to extend horizontally about said stalk;

a key cap shaped to fit over said key plunger; and

a backlight to illuminate an interior of said key cap, said backlight located underneath said key plunger and to a side of said stalk,

wherein

said second material is translucent and light-diffusing;

said first material allows more light to pass therethrough than said second material;

either a two-shot moulding process or a welding process is used to form said key plunger; and

in said key plunger, said second material allows light transmitted from said backlight which enters said body section from underneath said body section and from said side of said stalk to be dispersed into a region in said body section immediately over said stalk to brighten a first shadow region associated with said region in said body section and said first material allows transmission of light passing through said stalk from said backlight to brighten a second shadow region located on a second side opposite of said side of said stalk.

7. The key assembly for a key of a keypad of an electronic device as claimed in claim 6, wherein said first material comprises a clear polycarbonate or resin.

8. The key assembly for a key as claimed in claim 7, wherein:

said plinth

is made of said first material; and

is formed with said stalk when said two-shot moulding process is used; and

said stalk is solid.

9. The key assembly for a key as claimed in claim 7, wherein a first layer of paint providing an outline of a character associated with said key is applied to the top of said key cap.

10. The key assembly for a key as claimed in claim 9, wherein a character is etched in said first layer of paint.

11. The key assembly for a key as claimed in claim 10, wherein a second layer of transparent paint is provided between said cap and said first layer of paint.

12. The key assembly for a key of a keypad of an electronic device as claimed in claim 7, wherein said plinth:

is made of said second material; and

is formed with said body section when said two-shot moulding process is used.

13. The key assembly for a key of a keypad of an electronic device as claimed in claim 7, wherein said second material in body section comprises a coloured polycarbonate or resin and disperses light from said backlight within said body about said region to further reduce said shadow in said shadow area.

14. The key assembly for a key of a keypad of an electronic device as claimed in claim 7, wherein said key plunger is utilized in a “

return”

key in said keypad.

15. The key assembly for a key of a keypad of an electronic device as claimed in claim 7, wherein said key plunger is utilized in a “

function”

key in said keypad.

16. The key assembly for a key of a keypad of an electronic device as claimed in claim 6, wherein an air gap is provided between said key plunger and said key cap when said key cap is mounted over said key plunger.

17. A key assembly for a key of a keypad of an electronic device, comprising:

a key plunger having;

a stalk made of first material allowing light to pass through; and

a body section connected to the top of said stalk, said body section made of a second material and shaped to fit snugly within an interior of a cap for said key and to extend horizontally about said stalk;

a key cap shaped to fit over said key plunger; and

a backlight to illuminate an interior of said key cap, said backlight located underneath said key plunger and to a side of said stalk,

wherein

said second material is translucent and light-diffusing;

said first material allows more light to pass therethrough than said second material;

either a two-shot moulding process is used to separately form said stalk and said body section or a welding process is used to bond said stalk to said body; and

after said key plunger is formed, said second material allows light transmitted from a said backlight which enters said body section from underneath said body section and from said side of said stalk to be dispersed into a region in said body section immediately over said stalk to brighten a first shadow region associated with said region in said body section and said first material allows transmission of light passing through said stalk from said backlight to brighten a second shadow region located on a second side opposite of said side of said stalk.

18. The key assembly for a key as claimed in claim 17, wherein a first layer of paint providing an outline of a character associated with said key is applied to the top of said key cap and said stalk is solid.

19. The key assembly for a key of a keypad of an electronic device as claimed in claim 17, wherein a character associated with said key is etched in a first layer of paint applied to the top of said key cap and said stalk is solid.

20. The key assembly for a key of a keypad of an electronic device as claimed in claim 19, wherein a second layer of transparent paint is provided between said top of said key cap and said first layer of paint.

21. The key assembly for a key of a keypad of an electronic device as claimed in claim 17, wherein an air gap is provided between said key plunger and said key cap when said key cap is mounted over said key plunger.