Patent ID: 8203518

Claim:
A display device, comprising: a board; and a level shift circuit which includes a thin film transistor having a polycrystalline semiconductor layer, and is formed on the board, wherein the level shift circuit includes: a plurality of source-input level shift circuits; and a selection circuit, wherein each of the plurality of source-input level shift circuits includes: a plurality of unit level shift circuits having drain resistors different in value from one another; and a first level shift circuit and a second level shift circuit which are provided so as to correspond to each of the plurality of unit level shift circuits, wherein the first level shift circuit includes: a drain resistor which is equal in value to the drain resistor of corresponding one of the plurality of unit level shift circuits; and a source terminal to which an input signal which is in a high level is input, wherein the second level shift circuit includes: a drain resistor which is equal in value to the drain resistor of the corresponding one of the plurality of unit level shift circuits; and a source terminal to which an input signal which is in a low level is input, and wherein the selection circuit selects an output from one of the plurality of unit level shift circuits based on whether an output from the corresponding first level shift circuit and an output from the corresponding second level shift circuit are in the high level or the low level.