Key sheet

• US 20070125629A1
• Filed: 11/17/2006
• Published: 06/07/2007
• Est. Priority Date: 11/18/2005
• Status: Active Grant

• Current Assignee: Polymatech Company Limited
• Original Assignee: Polymatech Company Limited
• Inventors: Senzui, Akira
• Granted Patent: US 7,358,454 B2
• Time in Patent Office: Days
• US Class Current: 200/5.A
• CPC Class Codes: H01H 13/704 characterised by the layers, e.g. by their material or structure H01H13/703 takes precedence
• CPC Class Codes: H01H 2217/004 Larger or different actuating area
• CPC Class Codes: H01H 2221/058 to avoid tilting or skewing of contact area or actuator
• CPC Class Codes: H01H 2223/0345 with keys positioned directly next to each other without an intermediate bezel or frame

Abstract

Provided is a stable key sheet in which, even if a key top is operated so as to be shifted sidewise, no excessive change, such as great tottering of the key top or overlapping of key tops each other, is caused. A key sheet including: a key top having a fixation protrusion protruding from a center of a bottom surface; and a base sheet to which the fixation protrusion is fixed, further includes a stopper plate having an opening through which the fixation protrusion of the key top is passed and whose edge faces a side of the fixation protrusion, in which, at a time of sidewise movement of the key top, the stopper plate abuts the key top to regulate the sidewise movement of the key top.

Claims

1. A key sheet, comprising:

a key top having a surface portion exposed through an operational opening formed in a casing of an apparatus, and a fixation protrusion protruding from a center of a bottom surface of the surface portion; and

a base sheet which is formed of a rubber-like elastic material and which is equipped with a movable membrane, to which the fixation protrusion is fixed and which float-supports the key top to allow displacement of the key top through depression, and a support leg placed on a board,

further comprising a stopper plate having an opening through which the fixation protrusion of the key top is passed and whose edge faces a side of the fixation protrusion, wherein, at a time of sidewise movement of the key top, the stopper plate abuts the key top to regulate the sidewise movement of the key top.

2. A key sheet according to claim 1, wherein, at the time of sidewise movement of the key top, the fixation protrusion abuts the opening edge of the stopper plate.

3. A key sheet according to claim 1, wherein the stopper plate is equipped with a threshold protrusion protruding from a surface of the stopper plate to a position beside the key top and regulating sidewise movement of the key top.

4. A key sheet according to claim 1, wherein, at a time of depressing operation on the key top, the movable membrane of the base sheet is separated from the stopper plate.

5. A key sheet according to claim 1, wherein the opening of the stopper plate is larger than the fixation protrusion and smaller than the key top.

6. A key sheet according to claim 1, wherein the stopper plate is placed on the base sheet without being fixed to the base sheet.

7. A key sheet according to claim 1, wherein both the stopper plate and the base sheet have mounting holes to be fit-engaged with positioning protrusions provided on the casing of the apparatus.

8. A key sheet according to claim 1, wherein a light shield layer is provided on a surface of the base sheet.

9. A key sheet according to claim 1, wherein a surface of the base sheet is level.

10. A key sheet according to claim 1, wherein the stopper plate is fixed to the support leg of the base sheet.

11. A key sheet according to claim 10, wherein both the stopper plate and the base sheet have mounting holes to be fit-engaged with positioning protrusions provided on the casing of the apparatus.

12. A key sheet according to claim 10, wherein a light shield layer is provided on the surface of the base sheet.

13. A key sheet according to claim 10, wherein the surface of the base sheet is level.

14. A key sheet, comprising:

a key top exposed through an operational opening (101b) formed in a casing of an apparatus; and

a base sheet which is formed of a rubber-like elastic material and which is equipped with a fixation protrusion protruding from a surface and fixed to the key top, a movable membrane float-supporting the key top to allow displacement of the key top through depression, and a support leg placed on a board,

further comprising a stopper plate having an opening through which the fixation protrusion of the base sheet is passed and whose edge faces a side of the fixation protrusion, wherein, at a time of sidewise movement of the key top, the stopper plate abuts the fixation protrusion to regulate the sidewise movement of the key top.

15. A key sheet according to claim 14, wherein, at the time of sidewise movement of the key top, the fixation protrusion abuts the opening edge of the stopper plate.

16. A key sheet according to claim 14, wherein the stopper plate is equipped with a threshold protrusion protruding from a surface of the stopper plate to a position beside the key top and regulating sidewise movement of the key top.

17. A key sheet according to claim 14, wherein at a time of depressing operation on the key top, the movable membrane of the base sheet is separated from the stopper plate.

18. A key sheet according to claim 14, wherein the opening of the stopper plate is larger than the fixation protrusion and smaller than the key top.

19. A key sheet according to claim 14, wherein the stopper plate is placed on the base sheet without being fixed to the base sheet.

20. A key sheet according to claim 14, wherein both the stopper plate and the base sheet have mounting holes to be fit-engaged with positioning protrusions provided on the casing of the apparatus.

21. A key sheet according to claim 14, wherein the light shield layer is provided on a surface of the base sheet.

22. A key sheet according to claim 14, wherein the stopper plate is fixed to the support leg of the base sheet.

23. A key sheet according to claim 22, wherein both the stopper plate and the base sheet have mounting holes to be fit-engaged with positioning protrusions provided on the casing of the apparatus.

24. A key sheet according to claim 22, wherein the light shield layer is provided on the surface of the base sheet.