Cathode ray tube optical filter device with cursor pointing function

A crt optical filter device to be installed on a computer monitor of a computer and capable of controlling movement of a cursor on a screen of the computer monitor, said crt optical filter device comprising:

• a first transparent plastic sheet having an inner surface formed with a transparent first conductive circuit layer and a pair of first conductors;
• a transparent glass panel having an outer surface disposed adjacent to said inner surface of said first transparent plastic sheet and an inner surface to be disposed adjacent to the screen of the computer monitor, said outer surface of said glass panel being provided with a transparent second conductive circuit layer, a pair of second conductors, and a grounded static conductor;
• one of said inner surface of said first transparent plastic sheet and said outer surface of said glass panel being further provided with a plurality of spacers which are made of an insulative material and which space apart said first and second conductive circuit layers;
• and
• an interface card connected electrically to said first and second conductors and to be connected electrically to the computer, said interface card receiving analog X and Y signals that correspond to a selected part of said first transparent plastic sheet from said first and second conductors when a portion of said first conductive circuit layer contacts and connects electrically with a portion of said second conductive circuit layer due to application of pressure on said selected part of said first transparent plastic sheet, said interface card processing said analog X and Y signals into corresponding digital signals for controlling the computer to move the cursor on the screen of the computer monitor so as to coincide with said selected part of said first transparent plastic sheet and for controlling the computer to accomplish predetermined functions.