Key switch device and portable electronic device having the same

A key switch device for switching a signal as a key top is pressed down, comprising:

• first and second link members which are cross-linked with each other to act like scissors;
• the key top having receiver portions formed in an underside thereof for movably or pivotably receiving upper shaft pairs each formed at upper ends of each of the first and second link members;
• a support plate disposed under the key top;
• a membrane member disposed on the support plate under the key top and having a contact point;
• an elastic switch shaped as a conical frustum, and when pressed down by the key top, contacting by a portion thereof the contact point in the membrane member;
• and
• a mounting member separate from the support plate, the mounting member including fixing portions for movably or pivotably fixing lower shaft pairs each formed at lower ends of the each link member, fastening portions fixedly fastened with the support plate, and means for maintaining the elastic switch in position, wherein the maintaining means has a central opening for supporting a lower outer periphery of the elastic switch.

A portable electronic device comprising:

• a CPU, a storage unit for storing a plurality of programs, a board mounted with a plurality of components for processing operations according to the programs, a keyboard including a plurality of key switch devices each for switching a signal as a key top is pressed down, a liquid crystal display unit and a power supply, wherein each of the keyboard includes
• first and second link members which are cross-linked with each other to act like scissors;
• the key top having receiver portions formed in an underside thereof for movably or pivotably receiving upper shaft pairs each formed at upper ends of each of the first and second link members;
• a support plate disposed under the key top and having a plurality of through holes in predetermined positions;
• a membrane member disposed on the support plate under the key top, the membrane member having a contact point for contacting an elastic switch as the elastic switch is pressed down by the key top and openings formed around the through holes in the support plate to expose the through holes;
• and
• a mounting member separate from the support plate, the mounting member including fixing portions for movably or pivotably fixing lower shaft pairs each formed at lower ends of the each link member and fastening portions fixedly fastened with an underside of the support plate via the through holes in the support plate.

A portable electronic device comprising:

• a CPU, a storage unit for storing a plurality of programs, a board mounted with a plurality of components for processing operations according to the programs, a keyboard including a plurality of key switch devices each for switching a signal as a key top is pressed down, a liquid crystal display unit and a power supply, wherein each of the keyboard includes:
• first and second link members which are cross-linked with each other to act like scissors;
• the key top having receiver portions formed in an underside thereof for movably or pivotably receiving upper shaft pairs each formed at upper ends of each of the first and second link members;
• a support plate disposed under the key top;
• a membrane member disposed on the support plate under the key top and having a contact point;
• an elastic switch shaped as a conical frustum, and when pressed down by the key top, contacting by a portion thereof the contact point in the membrane member;
• and
• a mounting member separate from the support plate, the mounting member including fixing portions for movably or pivotably fixing lower shaft pairs each formed at lower ends of the each link member, fastening portions fixedly fastened with the support plate, and means for maintaining the elastic switch in position, wherein the maintaining means has a central opening for supporting a lower outer periphery of the elastic switch.