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File:Science and Invention Television 1928.jpg

原始文件 （1,138 × 633像素，文件大小：217 KB，MIME类型：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television technologies never achieved images of sufficiently high quality to catch on with the public, and were superseded by electronic scan television broadcasts in the 1930s.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:

The page numbers were on an annual basis, not per issue. This issue had pages 577 to 672. The magazine is 8.5 by 11.5 inches.
日期 November 1928. This page scanned August 2008.
来源 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Unknown author
授权
(二次使用本文件)		 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

许可协议

Public domain
本作品属于公有领域，因为其是于1929~1963年之间在美国出版，且无论其是否具有著作权声明，它并未进行著作权更新。更多信息请参考Commons:Hirtle chart/zh及著作权更新日志。请注意该作品在其他对美国作品不适用较短期限法则的司法管辖区仍然受著作权保护（基于作者的逝世日期），如加拿大（作者过世后70年）、中国大陆（作者过世后50年，不包括香港和澳门）、德国（作者过世后70年）、墨西哥（作者过世后100年）、瑞士（作者过世后70年）及其他有本地条约的国家。

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Public domain
这个作品在美利坚合众国属于公有领域，因为它首次发布早于1929年1月1日，或于该日期之前在美国著作权局登记。
公有领域作品必须在美国以及来源国没有版权问题，才能上传至维基共享资源。如果此作品不是美国作品，这个文件必须要有一个额外的版权标记显示此文件在来源国的版权状态。
注意：此标签不应用于录音作品。PD-1923美国公有领域//commons.wikimedia.org/wiki/File:Science_and_Invention_Television_1928.jpg

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当前2008年8月9日 (六) 17:452008年8月9日 (六) 17:45版本的缩略图1,138 × 633（217 KB）Swtpc6800A 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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