发明名称 |
Picture-in-picture television receiver |
摘要 |
A picture-in-picture television receiver is disclosed in which a television picture to be inset is compressed at a compression rate of 1/n and inset as a small-picture in part of a main television picture or large picture, and a single field memory for small-picture reproduction is provided therein in or from which a video signal can be randomly read and written line by line as a unit. In the single field memory is stored the small-picture video signal line by line by the application of a writing clock in which case the time taken in the writing is less than 1/(n+1) of a horizontal period. Then, from the memory is read the stored small-picture information by the application of a reading clock of n times the frequency of the writing clock during the time that writing is not performed, and supplied to be inset in the main television picture. A small-capacity buffer memory is provided at the prestage or following stage of the field memory to prevent the read/write timing overlap in the field memory irrespective of whether the small-picture and the main television picture are synchronized or not in the transmission systems. Thus, the capacity of the field memory essential for the small-picture is about a half of the conventional one.
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申请公布号 |
US4249213(A) |
申请公布日期 |
1981.02.03 |
申请号 |
US19790074761 |
申请日期 |
1979.09.11 |
申请人 |
HITACHI, LTD. |
发明人 |
IMAIDE, TAKUYA;KUROYANAGI, TOMOMITSU;MASUDA, MICHIO |
分类号 |
H04N5/45;(IPC1-7):H04N5/22 |
主分类号 |
H04N5/45 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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