The Toshiba T100, the company's first laptop computer, shipped in 1982 with an LCD screen of 80x25 text resolution: http://oldcomputers.net/toshiba-t100.html
Was this the first computer ever to have an LCD screen as opposed to line display, i.e. capable of displaying more than one line of text? It is the first one I have been able to find (though there are several earlier examples of LCD line displays, of course, depending on where you draw the distinction between a computer and a calculator).
Edit: As Raffzahn observed, I misread that page. 80x25 is only if you connect the machine to a CRT monitor; the LCD is considerably smaller.
Okay then, to clarify the question and for the sake of definiteness, let's say: what was the first computer ever to have an LCD screen capable of at least 40x25 text? That being the typical minimum standard for microcomputers around that time.