When were CD's invented?

Answer 1

1970 At Philips, Compaan and Pete Kramer complete a glass disc prototype and determine that a laser will be needed to read the information.

1977 Mitsubishi, Hitachi & Sony show digital audio disc prototypes at the Tokyo Audio Fair.
JVC Develops Digital Audio Process

Enteresting note:
1854 George Boole publishes "An Investigation Into the Laws of Thought." A book that contained, among other things, theories that were later used to build digital circuits.

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In 1979 Philips and Sony set up a joint task force of engineers to design the new digital audio disc. Prominent members of the task force were Joop Sinjou, Kees Immink and Toshi tada Doi. After a year of experimentation and discussion, the taskforce produced the "Red Book", the Compact Disc standard. Philips contributed the general manufacturing process, based on video LaserDisc technology. Philips also contributed the Eight-to-Fourteen Modulation, EFM, which offers both a long playing time and a high resilience against disc handling damage such as scratches and fingerprints, while Sony contributed the error-correction method, CIRC. The Compact Disc Story[1], told by a former member of the taskforce, gives background information on the many technical decisions made, including the choice of the sampling frequency, playing time, and disc diameter. According to Philips, the Compact Disc was thus "invented collectively by a large group of people working as a team[2]."

http://en.wikipedia.org/wiki/Compact_disc

Answer 2

They were invented by James T. Russell in the 60's. The rights to the patent were bought in the early 80's to make a push towards commercial availability.

Answer 3

i think in the late 1980's to early 1990's