| Number | Date | Country | Kind |
|---|---|---|---|
| 2010-023281 | Sep 2010 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 2052797 | Read | Sep 1936 | A |
| 3794326 | Bialek | Feb 1974 | A |
| 4066078 | Berg | Jan 1978 | A |
| 4161174 | Mercuri | Jul 1979 | A |
| 4237886 | Sakurada et al. | Dec 1980 | A |
| 4306685 | Coffee | Dec 1981 | A |
| 4326720 | Erlich | Apr 1982 | A |
| 4861039 | Phillips et al. | Aug 1989 | A |
| 5024227 | Schmid | Jun 1991 | A |
| 5052617 | Colclough et al. | Oct 1991 | A |
| 5332229 | Fielder et al. | Jul 1994 | A |
| 7346380 | Axelgaard et al. | Mar 2008 | B2 |
| 7567420 | Kobayashi et al. | Jul 2009 | B2 |
| 7874503 | Imahori et al. | Jan 2011 | B2 |
| 8015724 | Imahori et al. | Sep 2011 | B2 |
| 8109452 | Akisada et al. | Feb 2012 | B2 |
| 8191805 | Nakada et al. | Jun 2012 | B2 |
| 8209990 | Nakada et al. | Jul 2012 | B2 |
| 8292202 | Hirai | Oct 2012 | B2 |
| 20060064892 | Matsui et al. | Mar 2006 | A1 |
| 20060202067 | Mitsui et al. | Sep 2006 | A1 |
| 20090289132 | Watanabe et al. | Nov 2009 | A1 |
| 20100187338 | Yano et al. | Jul 2010 | A1 |
| 20100243765 | Uegaki et al. | Sep 2010 | A1 |
| 20110006139 | Masuda | Jan 2011 | A1 |
| 20110101134 | Yano et al. | May 2011 | A1 |
| 20120067986 | Kobayashi et al. | Mar 2012 | A1 |
| 20120160940 | Omori et al. | Jun 2012 | A1 |