Reducing Platen Acoustical Noise
Original Publication Date: 1988-Dec-01
Included in the Prior Art Database: 2005-Feb-15
One of the sources of acoustical noise in a typewriter or printer results from the vibration of the platen when impacted by a key and which vibration may be amplified by bodies in contact with the platen. The platen vibrates, as a beam mounted at two ends, in various bending nodes, with frequencies characteristic of the bending nodes, e.g., the 1st, 2nd, 3rd, 4th, 5th, etc., bending nodes. The noise associated with the first node in most typewriters and printers is low enough in frequency and amplitude not to be of concern, and the 4th and higher nodes are high enough in frequency also not to be of concern. The third node can be effectively controlled by design of the impacting mechanism. However, the second node is of primary concern.