`  == CD4 - Shibata stylus ==  The description of the Shibata stylus is incorrect - the article states ``the Shibata stylus greatly reduced the contact area of the stylus on the walls of the record groove`` but it is in fact the opposite: the Shibata stylus had a larger contact area, which reduced wear because the tracking force was distributed over a wider area.  Originally stylus tips were spherical, which resulted in a very small contact area (theoretically a single point but in practice a small area due to deformation of the vinyl under the stylus pressure).  Elliptical stylii were then introduced which increased the contact area, reducing wear and increasing fidelity; and the Shibata stylus (also known as hyper-elliptical or line contact) was an extension of this development. The article is correct to point out that the Shibata stylus could give improved playback from a disc already worn by a spherical stylus, since it would maintain contact with un-worn parts of the groove wall.   auntiephos`