Membrane switch
AssigneeSharp Kabushiki Kaisha
InventorMasazumi Tabuchi
Life of this patent
Estimating the term…
Abstract
In a switch apparatus having a membrane structure, when it is detected that a conductive pattern comes into contact with both of two conductive patterns, it is judged that a normal ON operation is performed, and an ON signal is output. When the conductive pattern comes into contact with only one of the two conductive patterns, it is judged that a failure such as a short-circuit due to peeling occurs, and an alarm signal is output. The switch apparatus has a self-detecting function, so that it reliably detects an unstable condition of a failure such as a short-circuit due to peeling.
Claims19
A switch apparatus having a membrane structure and comprising an operating portion, said switch apparatus being able to be activated when said operating portion is operated,
- said switch apparatus further comprises:
- at least three conducting members, said conducting members being electrically insulated from each other when said operating portion is not operated, conducting members of at least one combination of said conducting members being electrically connected with each other when said operating portion is operated;
- means for separately detecting when a first of said conducting members is electrically connected with a second of said conducting members and when said second conducting member is electrically connected with a third of said conducting members;
- and
- output means for outputting an ON signal when said means for detecting has detected that at least one of said first and second or said second and third conducting members are electrically connected together.
A switch apparatus having a membrane structure and comprising an operating portion, said switch apparatus being able to be activated when said operating portion is operated,
- said switch apparatus further comprises:
- at least three conducting members, said conducting members being electrically insulated from each other when said operating portion is not operated, conducting members of at least one combination of said conducting members being electrically connected with each other when said operating portion is operated;
- means for separately detecting when a first of said conducting members is electrically connected with a second of said conducting members and when said second conducting member is electrically connected with a third of said conducting members;
- output means for outputting an ON signal in the case where conducting members of a first predetermined combination of said conducting members are electrically connected with each other;
- and
- alarm means for outputting an alarm signal in the case where conducting members of a second predetermined combination of said conducting members are electrically connected with each other for a predetermined period of time.
A switch apparatus having a membrane structure and comprising an operating portion, said switch apparatus being able to be activated when said operating portion is operated,
- said switch apparatus further comprises:
- at least three conducting members, said conducting members being electrically insulated from each other when said operating portion is not operated, at least one combination of said conducting members being electrically connected when said operating portion is operated;
- means for separately detecting when a first of said conducting members is electrically connected with a second of said conducting members and when said second conducting member is electrically connected with a third of said conducting members;
- output means for outputting an ON signal when a first predetermined combination of said conducting members is electrically connected for a first predetermined period of time;
- and
- alarm means for outputting an alarm signal when a second predetermined combination of said conducting members is electrically connected for a second predetermined period of time.
A switch apparatus having a membrane structure and comprising an operating portion, said switch apparatus being able to be activated when said operating portion is operated,
- said switch apparatus further comprises:
- at least three conducting members, said conducting members being electrically insulated from each other when said operating portion is not operated, conducting members of at least one combination of said conducting members being electrically connected with each other when said operating portion is operated;
- means for separately detecting when a first of said conducting members is electrically connected with a second of said conducting members and when said second conducting member is electrically connected with a third of said conducting members;
- output means for outputting an ON signal when said first and second conducting members are electrically connected and said second and third conducting members are electrically connected and when said means for detecting has detected that at least one of said first and second or said second and third conducting members are electrically connected together.
Dependencies are inferred from the claim text.