Akai ¼-inch video tape was an analogue open reel video tape format introduced in 1969. It used helical-scanning and initially only recorded in black and white (a colour video recorder using the tape, the Akai VTS-150, was introduced in 1974).
The first machine to use the format was the Akai VTS-100, a portable video tape recorder with a detachable video monitor and a video camera. An optional RF modulator was available for playback through a standard television set.
Video resolution was 200 lines, and the system was aimed at the consumer market. One advantage over other domestic video tape recorders that used ½-inch wide tape (such as the EIAJ-1 ½-inch format) was that tape for the Akai system was much cheaper. A number of different companies produced tape for the Akai format.
Most of the tape was on plastic 5-inch reels with cine spindle hubs but the VT-700, a stationary video tape recorder introduced by Akai in the early 1970s, could accommodate 10.5-inch NAB hub reels of ¼-inch video tape as well.
Tapes recorded on the later colour VTS-150 are not compatible with tapes recorded on black and white models due to differences in tape speed.