Key signal entering device for thin electronic apparatus

A thin small electronic apparatus comprising:

• a display device;
• a circuit board;
• an anisotropically conductive sheet connected with said display device and said circuit board;
• and
• key actuating means provided on said anisotropically conductive sheet, wherein a key signal is generated in said circuit board by electric conduction of said anisotropically conductive sheet upon application of a pressure on said key actuating means, a drive signal for said display device being transmitted from said circuit board through said anisotropically conductive sheet.

A key signal entering device for a thin electronic apparatus, comprising:

• an anisotropically conductive sheet;
• a first flexible sheet having a first electrode and disposed on said anisotropically conductive sheet;
• and
• a second flexible sheet having a second electrode and disposed under said anisotropically conductive sheet in such a manner that said first and second electrodes are positioned in a mutually facing relationship, whereby in response to application of pressure on said electrodes by a key actuation said anisotropically conductive sheet achieves a change in the conductive area in the thickness direction thereof in a portion contacting said electrodes to form an electric connection therebetween, thereby generating a key signal.

An electronic calculator, comprising:

• a power source;
• a display device;
• an arithmetic unit;
• a keyboard;
• and
• an anisotropically conductive sheet provided in said keyboard, wherein said anisotropically conductive sheet is flexible at least in a portion thereof corresponding to said keyboard.