US5164697A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Input keyboard for an electronic appliance in entertainment electronics
Assignee: Nokia Deutschland GmbH
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Filing: 1991-04-03
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Granted: 1992-11-17
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Expires: 2011-04-03
Abstract
Abstract An input keyboard (1) contains a switching device (3) for pushbuttons (22) wherein the contact linings (11.1, 11.2) on a printed circuit board (10) are bridged by a countercontact (16) operated by the pushbutton (22). The countercontact (16) consists of a carbonized plastic foil (14) and an electrically conducting layer (17) on the side facing away from the contact linings. By virtue of this arrangement there comes into being a bridging resistance between the bridged conductor strips (12.1, 12.2) that depends on the operating pressure (P) applied to the pushbutton, this resistance being then used to cause a control circuit arrangement (6) to generate a control command (Bf) for setting a particular function and an adjustment command (Bw) for setting a particular value or adjustment rate.
Inventors
- 👤 Richard Kramer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:53
CPC Classifications
H; H01; H01H; H01H13/00; H01H13/70; H01H13/702; H01H2215/00; H01H2215/004; H01H2239/00; H01H2239/078
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
299 words
An input keyboard for an electronic appliance in entertainment electronics with pushbuttons guided at right angles to the keyboard cover plate (23) and an insulating printed circuit board carrying, in positions correlated with the pushbuttons, contact linings that are to be electrically connected, and with switching devices situated between the pushbuttons and the insulating printed circuit board, where each of the switching devices is correlated with one of the pushbuttons and contains a countercontact that, whenever the pushbutton correlated with the switching device is in its depressed position, will provide a large area of electrical connection between the correlated contact linings, wherein the countercontact (16) contains a carbonized plastic foil (14) of high electrical resistance that bears against an insulating edge (26) arranged between the printed circuit board (10) and the plastic foil and surrounding the area of the contact linings (11.1, 11.2) correlated with the pushbutton (22), the plastic foil having a certain, though very small electrical conductivity and a thickness (d) that is very small as compared with the distance (a) between the contact linings correlated with the appropriate pushbutton that are to be electrically connected, on the side of the carbonized carbon foil facing away from the contact linings there is arranged an electrically conducting layer (17) having an electrical conductivity that is very great as compared with the electrical conductivity of the carbonized plastic foil, and the contact linings (11.1, 11.2) correlated with a given pushbutton are connected to a control circuit arrangement (6) for converting bridging resistance (Rk) of the switching device (3) into a control command (Bf, Bw) that determines both a control or adjustment function and a control or adjustment variable, the bridging resistance depending on the pressure (P) that the depressed pushbutton (22) exerts on the countercontact (16) of that pushbutton.
Claim 2
Dependent Claim
299 words
An input keyboard for an electronic appliance in entertainment electronics with pushbuttons guided at right angles to the keyboard cover plate (23) and an insulating printed circuit board carrying, in positions correlated with the pushbuttons, contact linings that are to be electrically connected, and with switching devices situated between the pushbuttons and the insulating printed circuit board, where each of the switching devices is correlated with one of the pushbuttons and contains a countercontact that, whenever the pushbutton correlated with the switching device is in its depressed position, will provide a large area of electrical connection between the correlated contact linings, wherein the countercontact (16) contains a carbonized plastic foil (14) of high electrical resistance that bears against an insulating edge (26) arranged between the printed circuit board (10) and the plastic foil and surrounding the area of the contact linings (11.1, 11.2) correlated with the pushbutton (22), the plastic foil having a certain, though very small electrical conductivity and a thickness (d) that is very small as compared with the distance (a) between the contact linings correlated with the appropriate pushbutton that are to be electrically connected, on the side of the carbonized carbon foil facing away from the contact linings there is arranged an electrically conducting layer (17) having an electrical conductivity that is very great as compared with the electrical conductivity of the carbonized plastic foil, and the contact linings (11.1, 11.2) correlated with a given pushbutton are connected to a control circuit arrangement (6) for converting bridging resistance (Rk) of the switching device (3) into a control command (Bf, Bw) that determines both a control or adjustment function and a control or adjustment variable, the bridging resistance depending on the pressure (P) that the depressed pushbutton (22) exerts on the countercontact (16) of that pushbutton.
Claim 3
Dependent Claim
44 words
An input keyboard in accordance with claim 1, wherein a spring element (20) is arranged between the bottom (27) of a pushbutton (22) and the countercontact (16) of that pushbutton to ensure a uniform pressure distribution over the contact surface (18) of the countercontact.
Claim 4
Dependent Claim
27 words
An input keyboard in accordance with claim 2, wherein the spring element (20) is made of a plastic material having an elastic springing back characteristic against compression.
Claim 5
Dependent Claim
35 words
An input keyboard in accordance with claim 1 wherein the spring element (20) correlated with a pushbutton (22) is fixed to the bottom (27) of the pushbutton to constitute a component of the said pushbutton.
Claim 6
Dependent Claim
28 words
An input keyboard in accordance with claim 4, wherein the electrically conducting layer (17) is applied as a terminal layer to the bottom (27) of the pushbutton (22).
Claim 7
Dependent Claim
48 words
An input keyboard in accordance with claim 1, wherein the electrically conducting layer (17) is applied to the side of the carbonized plastic foil (14) facing away from the contact linings (11.1, 11.2) of a switching device (3) at least in the area of the said contact linings.
Claim 8
Dependent Claim
18 words
An input keyboard in accordance with claim 1, wherein the electrically conducting layer (17) is a graphite layer.
Claim 9
Dependent Claim
42 words
An input keyboard in accordance with claim 1, characterized in that the contact linings (11.1, 11.2) correlated with a pushbutton (22) consist of a graphite layer that is applied to the appropriate conductor surfaces (12.1, 12.2) of the printed circuit board (10).
Claim 10
Dependent Claim
67 words
An input keyboard in accordance with claim 1, characterized in that the insulating edge that provides a bearing for the carbonized plastic foil (14) is the edge (26) of a cutout (25) in a thin insulating plate (13) arranged between the printed circuit board (10) and the carbonized plastic foil, the said cutout surrounding the area of the contact linings (11.1, 11.2) correlated with the pushbutton (22).
Claim 11
Dependent Claim
35 words
An input keyboard in accordance with claim 2, wherein the spring element (20) correlated with a pushbutton (22) is fixed to the bottom (27) of the pushbutton to constitute a component of the said pushbutton.
Claim 12
Dependent Claim
35 words
An input keyboard in accordance with claim 3, wherein the spring element (20) correlated with a pushbutton (22) is fixed to the bottom (27) of the pushbutton to constitute a component of the said pushbutton.
Claim 13
Dependent Claim
28 words
An input keyboard in accordance with claim 10, wherein the electrically conducting layer (17) is applied as a terminal layer to the bottom (27) of the pushbutton (22).
Claim 14
Dependent Claim
28 words
An input keyboard in accordance with claim 11, wherein the electrically conducting layer (17) is applied as a terminal layer to the bottom (27) of the pushbutton (22).
Claim 15
Dependent Claim
48 words
An input keyboard in accordance with claim 2, wherein the electrically conducting layer (17) is applied to the side of the carbonized plastic foil (14) facing away from the contact linings (11.1, 11.2) of a switching device (3) at least in the area of the said contact linings.
Claim 16
Dependent Claim
48 words
An input keyboard in accordance with claim 3, wherein the electrically conducting layer (17) is applied to the side of the carbonized plastic foil (14) facing away from the contact linings (11.1, 11.2) of a switching device (3) at least in the area of the said contact linings.
Claim 17
Dependent Claim
18 words
An input keyboard in accordance with claim 2, wherein the electrically conducting layer (17) is a graphite layer.
Claim 18
Dependent Claim
18 words
An input keyboard in accordance with claim 3, wherein the electrically conducting layer (17) is a graphite layer.
Claim 19
Dependent Claim
40 words
An input keyboard in accordance with claim 2, wherein the contact linings (11.1, 11.2) correlated with a pushbutton (22) consist of a graphite layer that is applied to the appropriate conductor surfaces (12.1, 12.2) of the printed circuit board (10).
Claim 20
Dependent Claim
40 words
An input keyboard in accordance with claim 3, wherein the contact linings (11.1, 11.2) correlated with a pushbutton (22) consist of a graphite layer that is applied to the appropriate conductor surfaces (12.1, 12.2) of the printed circuit board (10).
Claim 21
Dependent Claim
65 words
An input keyboard in accordance with claim 2, wherein the insulating edge that provides a bearing for the carbonized plastic foil (14) is the edge (26) of a cutout (25) in a thin insulating plate (13) arranged between the printed circuit board (10) and the carbonized plastic foil, the said cutout surrounding the area of the contact linings (11.1, 11.2) correlated with the pushbutton (22).
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-11-17 | 1996-05-18 | 1996-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-17 | 2000-05-18 | 2000-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-11-17 | 2004-05-18 | 2004-11-17 | $7700.00 | Window Closed / Lapsed |