US4736076A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Capacitance switching device for keyboard
Assignee: Brother Industries Ltd
•
Filing: 1987-03-18
•
Granted: 1988-04-05
•
Expires: 2007-03-18
Abstract
Abstract Disclosed is a capacitance keyboard switching device comprising a fixed electrode formed on one surface of a first insulating film, a movable electrode formed on one surface of a second insulating film, a spacer interposed between the first and second insulating films and provided with a switching opening formed through the spacer for allowing the fixed and movable electrodes to come close to and separate from each other with one of the first and second insulating films interposed between the fixed and movable electrodes, a movable electrode depressing member provided with a depressing portion for depressing the movable electrode to cause the movable electrode to come close to the fixed electrode through the one insulating film, in order to keep the movable electrode flat when the movable electrode is depressed toward the fixed electrode, the depressing portion is provided with a surface area selected to be larger than a surface area of the movable electrode so that the surface area of the depressing member completely covers the surface area of the movable electrode when the depressing portion depresses the movable electrode, or the second insulating film is provided with slots formed therein.
Inventors
- 👤 Isao Mochizuki
- 👤 Mitsumasa Kako
- 👤 Yoshihisa Masuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:38
CPC Classifications
H; H01; H01H; H01H13/00; H01H13/70; H01H13/702; H01H13/703; H01H2203/00; H01H2203/056; H01H2211/00; H01H2211/006; H01H2211/02; H01H2215/00; H01H2215/004; H01H2215/006; H01H2221/00; H01H2221/036; H01H2221/042; H01H2221/058; H01H2227/00; H01H2227/022; H01H2233/00; H01H2233/01; H01H2233/02; H01H2233/022; H01H2239/00; H01H2239/006
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
178 words
A capacitance keyboard switching device comprising: a fixed electrode formed on one surface of a first insulating film stationarily mounted on a support; a movable electrode formed on one surface of a second insulating film; a spacer interposed between said first and second insulating films and provided with a switching opening formed through said spacer for allowing said fixed and movable electrodes to come close to each other with one of said first and second insulating films interposed between said fixed and movable electrodes to separate the electrodes from each other; a movable electrode depressing member provided with a depressing portion for depressing said movable electrode to cause said movable electrode to come close to said fixed electrode with said one insulating film interposed between said fixed and movable electrodes, said depressing portion having a surface area larger than the surface area of said movable electrode so that the surface area of said depressing member completely covers the surface area of said movable electrode to thereby cause the entire movable electrode to uniformally move toward said fixed electrode.
Claim 2
Dependent Claim
178 words
A capacitance keyboard switching device comprising: a fixed electrode formed on one surface of a first insulating film stationarily mounted on a support; a movable electrode formed on one surface of a second insulating film; a spacer interposed between said first and second insulating films and provided with a switching opening formed through said spacer for allowing said fixed and movable electrodes to come close to each other with one of said first and second insulating films interposed between said fixed and movable electrodes to separate the electrodes from each other; a movable electrode depressing member provided with a depressing portion for depressing said movable electrode to cause said movable electrode to come close to said fixed electrode with said one insulating film interposed between said fixed and movable electrodes, said depressing portion having a surface area larger than the surface area of said movable electrode so that the surface area of said depressing member completely covers the surface area of said movable electrode to thereby cause the entire movable electrode to uniformally move toward said fixed electrode.
Claim 3
Dependent Claim
46 words
A capacitance keyboard switching device according to claim 1, in which said movable electrode depressing member is shaped like a reversed cup and said depressing portion is formed at a top thereof, and a thin conical portion is formed integrally with and below said depressing portion.
Claim 4
Dependent Claim
23 words
A capacitance keyboard switching device according to claim 2, in which said depressing portion has a through hole formed at a center thereof.
Claim 5
Dependent Claim
19 words
A capacitance keyboard switching device according to claim 2, in which said depressing portion has a concave lower surface.
Claim 6
Dependent Claim
32 words
A capacitance keyboard switching device according to claim 2, in which said depressing portion has a recess in a lower surface thereof to form an annular rim portion on said lower surface.
Claim 7
Dependent Claim
111 words
A capacitance keyboard switching device comprising: a fixed electrode formed on one surface of a first insulating film stationarily mounted on a support; a movable electrode formed on one surface of a second insulating film; a spacer means interposed between said first and second insulating films and provided with a switching opening for allowing said fixed and movable electrodes to come close to and separate from each other with one of said first and second insulating films interposed between said fixed and movable electrodes; and slot means formed in said second insulating film disposed around said movable electrode to weaken said second film and thereby facilitate movement of said movable electrode.
Claim 8
Dependent Claim
111 words
A capacitance keyboard switching device comprising: a fixed electrode formed on one surface of a first insulating film stationarily mounted on a support; a movable electrode formed on one surface of a second insulating film; a spacer means interposed between said first and second insulating films and provided with a switching opening for allowing said fixed and movable electrodes to come close to and separate from each other with one of said first and second insulating films interposed between said fixed and movable electrodes; and slot means formed in said second insulating film disposed around said movable electrode to weaken said second film and thereby facilitate movement of said movable electrode.
Claim 9
Dependent Claim
176 words
A capacitance keyboard switching device according to claim 6, in which said second insulating film is disposed above said first insulating film and said fixed and movable electrodes are formed on respective lower surfaces of said first and second insulating films, and in which said device further comprises a reverse cup-shaped movable electrode pressing member including a top portion, a thin conical portion formed integrally with and below said top portion, and a depressing portion for depressing said second insulating film, said conical portion being positioned on an upper surface of said second insulating film, said top portion being made to abut at its upper surface on a lower surface of a key, so that when said key is manually depressed said depressing portion is lowered together with said top portion to thereby depress said second insulating film to cause said movable electrode to come into contact with said first insulating film to thereby form a capacitance between said movable electrode and said fixed electrode with said first insulating film interposed there between as a dielectric.
Claim 10
Dependent Claim
47 words
A capacitance keyboard switching device according to claim 7, in which said depressing portion is constituted by a sponge material and an insulating layer attached on a lower surface of said sponge material, and bonded onto a lower surface of said top portion through an adhering layer.
Claim 11
Dependent Claim
36 words
A capacitance keyboard switching device according to claim 7, in which a protrusion is formed on the upper surface of said top portion and inserted into a hole formed in the lower surface of said key.
References Cited (Backward Citations)
US30435A
Cited
US3696908A
Cited
US3750149A
Cited
USRE30435E
Cited
US4066855A
Cited
US4066855B1
Cited
US4376239A
Cited
JPS60117512A
Cited
US4659879A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-04-05 | 1991-10-05 | 1992-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-05 | 1995-10-05 | 1996-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-05 | 1999-10-05 | 2000-04-05 | $7700.00 | Window Closed / Lapsed |