Power supply method for liquid crystal display

Claim 1

A power supply for a liquid crystal display, comprising: DC power source means for delivering a source voltage larger than the driving voltage for driving said display, said power source means having first and second reference terminals; voltage regulator means coupled to said power source means for receiving said source voltage and in response thereto supplying a regulated output voltage having a negative temperature characteristic, said regulated output voltage corresponding to the driving voltage of said display, said voltage regulator means including first and second output terminals for outputting said regulated voltage, logic circuit means coupled intermediate said first and second output terminals and said liquid crystal display for receiving said regulated output voltage and in response thereto selectively driving said liquid crystal display; a transistor coupled in series between said second reference terminal and said second output terminal; said voltage regulator means including constant-current circuit means coupled intermediate said first reference terminal and said transistor, and a plurality of series-connected forward biased diode means coupled between said first reference terminal and said transistor, each of said diode means having the same forward voltage and negative temperature characteristic, said constant-current circuit supplying said forward current to said plurality of series-connected diode means, said regulated output voltage being substantially determined by multiplying the forward voltage of one of said diode means by the number of said diode means, said negative temperature characteristic of said regulated output voltage being substantially determined by multiplying the negative temperature characteristic of said forward voltage of one of said diode means by the number of diode means.