Patent ID: 7700886

Claim:
A rubber key device for an apparatus having a case, comprising: a key top member having an operation face, which is exposed to outside through an opening formed on the case, multiple depression areas to be depressed by a user, the multiple depression areas being defined on the operation face and arranged along a periphery of the operation face; multiple rubber keys arranged below the key top member, top faces of the multiple rubber keys facing a back surface of the key top member at positions corresponding to the multiple operation areas, respectively; a click feel generating mechanism provided to each rubber key and configured to generate a click feel in response to depression of each rubber key by a certain degree; and a load transmitting mechanism provided between the back surface of the key top member and the top face of each of the multiple rubber keys, wherein, when one of the multiple depression areas is depressed by the user, the key top member rotates about a fulcrum at an opposing end of the key top member with respect to the depressed depression area, the rubber key corresponding to the depressed depression area being depressed by the back surface of the key top member at a position corresponding to the depressed depression area with the load transmitting mechanism provided therebetween, the load transmitting mechanism transmitting the load caused by the depression of the depression area to the top face of the corresponding one of the multiple rubber keys such that the load is transmitted to only a substantially central portion of the top face of the corresponding one of the multiple rubber keys regardless of the depression amount of the depression, area, wherein the load transmitting mechanism includes a step defined by an upper face and a lower face, the upper face being closer than the lower face to the back surface of the top key member, the step being located at substantially the center of the top face of each of the multiple rubber keys, the upper face being arranged on a central portion of the multiple rubber keys, the lower face being arranged on a side opposing to the central portion and an outer side of the rubber key on which the step is formed, wherein a condition α<β is satisfied, where α represents a rotation angle at which the key top member is rotated about the fulcrum as one of the multiple depression areas is depressed and the corresponding rubber key is depressed, and β represents an angle formed between a plane of the back surface of the key top member before being rotated and a plane contacting both an edge of the upper face at the step and an outer end, which is an end opposite to the end at which the step is formed, of the lower face, and, wherein each of the upper face and the lower face is semicircular shape viewed in a direction perpendicular to the upper face, a linear side of the semicircular upper face meeting a linear side of the semicircular lower face at the step.