Object of the Day

Laser for Sony Discman

March 8

This small laser comes from a model D-5 Sony Discman, the company’s first commercially available personal CD player. Compact discs and players were developed as a collaboration between Sony and Philips in the late 70s and early 80s. The first public presentation of the technology took place on this day in 1979, and its impact on the music industry and ubiquity can still be seen 40 years later. 

Laser for Compact Disc Player

As scientists and engineers came to better understand lasers, they developed a multitude of uses for this light source. The development of Compact Discs (CDs) and Digital Video Discs (DVDs) revolutionized the audio and video recording industries. Lasers are essential in making and playing both types of discs. Scientists refer to laser light as "highly coherent," meaning that the photons stay tightly focused rather than spreading out like the light from a flashlight. Coherent light can be focused on a very small spot. The pits on CDs and DVDs are microscopic.
This is the laser assembly from a Sony model D-5 "Discman" portable CD player. Donated in 1985, it shows how small lasers had become only 25 years after their invention. This object also shows the dramatic decrease in the amount of power needed to operate a laser. The power supply for Theodore Maiman's 1960 ruby laser is about 6 feet tall by 2 feet square and weights about 500 pounds. By contrast, the Sony "Discman" weighed less than 1 pound and operated on AA batteries.
Currently not on view
Data Source
National Museum of American History
Sony Corporation
date made
Credit Line
from Sony Consumer Products Company
Physical Description
metal (overall material)
plastic (overall material)
overall: 1.5 cm x 8.8 cm x 12 cm; 9/16 in x 3 7/16 in x 4 3/4 in
Object Name
laser assembly
Other Terms
laser assembly; Lasers and Masers
Bottom of laser assembly for Sony 'Discman' CD player