File:Science and Invention Television 1928.jpg
預覽大小：800 × 445 像素。 其他解析度：320 × 178 像素 | 640 × 356 像素 | 1,138 × 633 像素。
原始檔案 （1,138 × 633 像素，檔案大小：217 KB，MIME 類型：image/jpeg）
摘要
| 描述 |
English: A woman watching an early homemade experimental mechanical television receiver in 1928, from Hugo Gernsback's magazine Science and Invention. During the 1920s some radio stations began broadcasting experimental television programs, which could be viewed by mechanical "televisor" receivers like this one. The video signal from the receiver (left) is applied to a neon lamp in the viewer (right). In front of the lamp a metal disk with holes rotates, creating the scan lines of the image. This created a dim monochrome orange image 1.5 inches (4 cm) square with 48 scan lines at 7.5 frames per second, visible within the viewing cone, which the woman is watching. These mechanical-scan television technologies never achieved images of sufficiently high quality to catch on with the public, and were superseded by electronic scan television broadcasts in the 1930s. Page scans of the above article How to build the S&I Television Receiver on Commons:
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| 日期 | November 1928. This page scanned August 2008. |
| 來源 | Science and Invention magazine, November 1928, Volume 16, Number 7, cover, published by Experimenter Publishing Co., New York, NY. This page was scanned by User:Swtpc6800 on an Epson Perfection 1240U at 300 dpi with half-tone de-screening enabled and stored as TIFF. The image was cropped and touched up in Adobe Photo Elements 5.0. This copy saved as a 150 dpi JPG. |
| 作者 | 未知 |
| 授權許可 (重用此檔案) |
This 1928 issue of Science and Invention would have the copyright renewed in 1955. Online page scans of the Catalog of Copyright Entries, published by the US Copyright Office can be found here. http://onlinebooks.library.upenn.edu/cce/ The search of the Renewals for Periodicals for 1954, 1955 and 1956 show no renewal entries for Science and Invention. Therefore the copyright on the magazine was not renewed and it is in the public domain. Science and Invention ceased publication with the August 1931 issue. A search of the copyright renewal records from 1951 to 1959 shows no entries for Science and Invention. All issues are in the public domain. |
| 其他版本 | Image:Science and Invention Nov 1928 pg618.png |
授權條款
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本作品在美國屬於公有領域，是因為該作品是在1929與1963年之間出版，沒有在該作品增加著作權聲明，且沒有進行著作權更新。除非此作品之作者已經過世一段時間，並達到公有領域所要求的條件，這類美國作品在其他不適用較短期限法則的國家或地區屬於有著作權狀態，如加拿大（作者過世後70年）、中國大陸（作者過世後50年，港澳除外）、德國（作者過世後70年）、墨西哥（作者過世後100年）、瑞士（作者過世後70年）與其他已簽署個別協議的國家。更多資訊請參考Commons:Hirtle chart。
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 公有領域作品必須在美國以及來源國沒有版權問題，才能上傳至維基共享資源。如果此作品不是美國作品，這個文件必須要有一個額外的版權標記顯示此文件在來源國的版權狀態。
注意：此標籤不應用於錄音作品。 |
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| 日期/時間 | 縮圖 | 尺寸 | 用戶 | 備註 | |
|---|---|---|---|---|---|
| 目前 | 2008年8月9日 (六) 17:45 | | 1,138 × 633（217 KB） | Swtpc6800 | A slight adjustment of the rheostats and the picture come in clearly. This photo shows the complete television receiver connected to an ordinary radio set. The picture is seen in the cone. == Summary == {{Information | Description= A slight adjustment |
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