Data entry keyboard

• US 4,701,579 A
• Filed: 05/28/1986
• Issued: 10/20/1987
• Est. Priority Date: 05/29/1985
• Status: Expired due to Term

• Current Assignee: Brother Kogyo Kabushiki Kaisha
• Original Assignee: Brother Kogyo Kabushiki Kaisha
• Inventors: Yamakawa, Kiyoshi, Minaminaka, Kazuyoshi, Kurachi, Hisao, Ito, Takeo
• Primary Examiner(s): Scott, J. R.
• Application Number:
  US06/868,426
• Time in Patent Office: 510 Days
• Field of Search: 200/5 A, 200/86 R, 200/159 B
• US Class Current: 200/5.00A
• CPC Class Codes: H01H 13/702 with contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches
• CPC Class Codes: H01H 13/703 characterised by spacers between contact carrying layers
• CPC Class Codes: H01H 13/785 characterised by the material of the contacts, e.g. conductive polymers
• CPC Class Codes: H01H 2201/03 Composite
• CPC Class Codes: H01H 2203/05 to avoid damage by deformation of layers
• CPC Class Codes: H01H 2207/044 Resist layer
• CPC Class Codes: H01H 2211/024 Peripheral edge deformable
• CPC Class Codes: H01H 2213/01 with internal pressure of other switch sites
• CPC Class Codes: H01H 2217/03 Concave plane
• CPC Class Codes: H01H 2227/002 Layer thickness

Abstract

Disclosed is a data entry keyboard which has a multitude of depressible keys which are selectively depressed for the entry of predetermined data. In the keyboard, an insulating member is sandwiched between a first substrate having stationary electrodes and a flexible second substrate having movable electrodes. The stationary and movable electrodes face one another through apertures formed in the insulating member. Upper and lower marginal surface portions of the insulating member, including the respective peripheral edges of the apertures, are kept parallel to the first and second substrates corresponding thereto by a plurality of protuberances on the substrates so that voids with a predetermined width are left between the marginal surface portions and the individual substrates. The movable electrodes of the second substrate are electrically fixed, in the form of a cantilever each, to the extreme end portions of branch conductor strips which diverge from a main conductor strip at right angles thereto. When one of the keys is depressed, the second substrate is deformed to narrow the corresponding void, thus bringing the corresponding movable and stationary electrodes into contact with each other.

Claims

1. A data engry keyboard having a multitude of depressible keys which are selectively depressed for the entry of predetermined data, comprising:

a first substrate including stationary electrodes corresponding individually to the keys;

a flexible second substrate deformable by the depression of the keys and including movable electrodes corresponding individually to the stationary electrodes and conductor means electrically connected to the individual movable electrodes, each said conductor means being formed of an elongated main conductor strip and branch conductor strips extending from the main conductor strip and connected, at one end portion thereof, to their corresponding movable electrodes in the form of a cantilever;

an insulating member interposed between the first and second substrates and having a multitude of apertures in alignment with the stationary and movable electrodes, each said aperture having a peripheral edge provided with a first predetermined diameter, said insulating member including first ring-shaped marginal surface portions corresponding to the first substrate and second ring-shaped marginal surface portions corresponding to the second substrate, both said first and second ring-shaped marginal surface portions surrounding the respective peripheral edges of the apertures;

first spacer means located radially outside the peripheral edge of said aperture along a first circle provided with a second predetermined diameter larger than said first diameter so as to define a first void of a predetermined width between the second substrate and the second marginal surface

second spacer means located radially outside the peripheral edge of said aperture along a second circle provided with said second predetermined diameter so as to define a second void of a predetermined width between the first substrate and the first marginal surface portion, whereby said insulating member is supported at the peripheral edge portion of the aperture by said first and second spacer means in the form of a cantilever.

2. The data entry keyboard according to claim 1 wherein said first spacer means includes a plurality of first protuberances which are formed on the second substrate and arranged at given angular intervals along said first circle, and

said second spacer means includes a plurality of second protuberances which are formed on the first substrate and arranged so that said second protuberances correspond to face said first protuberances respectively.

3. The data entry keyboard according to claim 2 wherein said first protuberances are three in number and arranged at angular intervals of 90 degrees.

4. The data entry keyboard according to claim 1, wheein said branch conductor strips extend substantially at right angles to the main conductor strip and parallel to one another.