| 发明名称 |
SWIVEL STANDARD FOR PORTABLE PROJECTION SCREEN |
| 摘要 |
A standard for a portable projection screen providing for improved image focus and picture clarity over the whole of the screen by easy and convenient swivel adjustment of the screen about the stand axis without lifting the standard base off the floor.
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| 申请公布号 |
US3696856(A) |
申请公布日期 |
1972.10.10 |
| 申请号 |
USD3696856 |
申请日期 |
1970.12.21 |
| 申请人 |
DA-LITE SCREEN CO. INC. |
发明人 |
FRED S. POTTER |
| 分类号 |
G03B21/58;(IPC1-7):G03B21/56 |
主分类号 |
G03B21/58 |
| 代理机构 |
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