Surface shape recognition apparatus

A surface shape recognition apparatus comprising:

• a plurality of sensor electrodes formed on an interlevel insulator on a substrate and insulated from each other;
• a passivation film formed on said interlevel insulator to cover an upper surface and side surface of each of said sensor electrodes, said passivation film being formed from a dielectric material;
• a capacitance detection circuit for, when a target recognition object comes into contact with a surface of said passivation film, detecting an electrostatic capacitance formed between said sensor electrode and a surface of said target recognition object opposing said sensor electrode, each of said sensor electrodes is formed into a size with which a plurality of sensor electrodes are covered with a contact surface of said target recognition object in contact with the surface of said passivation film,
• said capacitance detection circuit is formed under said interlevel insulator on said substrate, said capacitance detection circuit comprises a signal generation circuit connected to said sensor electrode to generate a signal corresponding to the electrostatic capacitance, a signal amplification circuit for amplifying a signal generated at a connection portion between said sensor electrode and said signal generation circuit, and an output circuit for converting the signal from said signal amplification circuit into a desired signal and outputting the desired signal, and
• said static electricity avoiding means is included in an input to said signal amplification circuit connected to said sensor electrode, and
• said ground electrode is connected to a reference electrode to which a predetermined potential is applied outside a region where said sensor electrodes are laid out, said ground electrode partially forms one surface together with said passivation film;
• and
• static electricity avoiding means for passing static electricity on the surface of said passivation film, said static electricity avoiding means including a ground electrode formed into a matrix shape, said static electricity avoiding means comprises
• a ground electrode formed on said interlevel insulator to be insulated from said sensor electrodes and partially forming one surface together with said passivation film, and
• a static electricity protection element inserted between said capacitance detection circuit and said sensor electrode,
• wherein said plurality of sensor electrodes are arranged at centers of cells of said ground electrode formed into the matrix shape.

A surface shape recognition apparatus comprising:

• a plurality of sensor electrodes formed on an interlevel insulator on a substrate and insulated from each other, each of said sensor electrodes is formed into a size with which a plurality of sensor electrodes are covered with a contact surface of said target recognition object in contact with the surface of said passivation film,
• said capacitance detection circuit is formed under said interlevel insulator on said substrate, and
• said ground electrode is connected to a reference electrode to which a predetermined potential is applied outside a region where said sensor electrodes are laid out;
• a passivation film formed on said interlevel insulator to cover an upper surface and side surface of each of said sensor electrodes, said passivation film being formed from a dielectric material;
• a capacitance detection circuit for, when a target recognition object comes into contact with a surface of said passivation film, detecting an electrostatic capacitance formed between said sensor electrode and a surface of said target recognition object opposing said sensor electrode, and
• static electricity avoiding means for passing static electricity on the surface of said passivation film, said static electricity avoiding means including a ground electrode formed into a matrix shape, said ground electrode partially forms one surface together with said passivation film, wherein said static electricity avoiding means comprises
• a ground electrode formed on said interlevel insulator to be insulated from said sensor electrodes and partially forming one surface together with said passivation film, and
• a static electricity protection element inserted between said capacitance detection circuit and said sensor electrode,
• wherein said plurality of sensor electrodes are arranged at centers of cells of said ground electrode formed into the matrix shape and said capacitance detection circuit comprises a signal generation circuit connected to said sensor electrode to generate a signal corresponding to the electrostatic capacitance and an output circuit for receiving a signal generated at a connection portion between said sensor electrode and said signal generation circuit, converting the signal into a desired signal, and outputting the desired signal, and
• said static electricity avoiding means is provided as a static electricity protection element between said sensor electrode and said output circuit.