Patent ID: 8026889

Claim:
A drive circuit of a display device, comprising: a gradation voltage generation circuit which generates a plurality of gradation voltages based on a voltage supplied from a voltage source; a gradation voltage selection circuit which selects a gradation voltage from among the plurality of gradation voltages generated by the gradation voltage generation circuit in response to an inputted image signal, and which outputs the selected gradation voltage as the analog signal voltage; an output circuit, which amplifies and outputs the analog signal voltage, wherein, in a test mode, the gradation voltage generation circuit, the gradation voltage selection circuit and the output circuit are disconnectable from one another; a first switch circuit provided between the gradation voltage selection circuit and the output circuit; and a second switch circuit provided between the gradation voltage generation circuit and the gradation voltage selection circuit, wherein the first switch circuit includes: a first test switch, which disconnects the gradation voltage selection circuit from the output circuit in the test mode; a second test switch which connects, in the test mode, the gradation voltage selection circuit to a first tester connection terminal; and a third test switch which connects, in the test mode, the output circuit to a second tester connection terminal.