&lt;Summagraphics Corp> said thepatent infringement suit filed by Lockheed Corp's &lt;LK> Sanders
Rogers Associates unit is invalid.
    Summagraphics said it will seek an injunction to stop
Sanders from continuing with its suit.
    The company said prior to Sanders filing a patent for an
electromagnetic digitizing apparatus, it was working with
technology that was patented and subsequently reflected in the
Rogers patent.
 Reuter
