Just recently? The industry has been thinking about it[1][2][3][4] since before most of us were born.

[1] https://patents.google.com/patent/US3576576A/en

[2] https://patents.google.com/patent/US3611388A/en

[3] https://patents.google.com/patent/US3971029A/en

[4] https://patents.google.com/patent/US4095228A/en