| 摘要 |
<p>Method and means for supporting an optical read or write head to maintain a constant spacing between the head and a moving information storage medium. A major drawback in the prior art head assemblies incorporating pheumatic forcing pistons concerns the chattering, or lateral and axial vibrations, of the lens assembly relative to the housing due to the turbulent airflow in the passageway leading from the annular chamber to the atmosphere. The present invention provides a lens assembly/housing arrangement in which substantial axial support for the lens assembly within the housing is obtainable simultaneously with eliminating the turbulent air flow by increasing the axial width verses gap width ratio. Basically, the invention involves an annular pressure chamber provided between air journal bearings at each end of the housing. Air pressure in the annular chamber is regulated to provide a stable but variable biasing force on the inner lens assembly relative to the housing in a direction opposite that of a relatively fixed opposing biasing force.</p> |
