A list of a few, borrowed from someone else:
Wells, transparent flat panel display, 1936
http://www.technovelgy.com/ct/content.asp?Bnum=1286
Boucher, micro-books, 1943
http://www.technovelgy.com/ct/content.asp?Bnum=250
Asimov, the tele-book, 1951
http://www.technovelgy.com/ct/content.asp?Bnum=1802
Heinlein, the reading plate, 1954
http://www.technovelgy.com/ct/content.asp?Bnum=601
Stanislav Lem, the "opton," -- it's an ebook -- 1961
http://www.technovelgy.com/ct/content.asp?Bnum=1024
1965, Philip K. Dick, "batery-powered 3D comic book"
http://www.technovelgy.com/ct/content.asp?Bnum=1108