Patent ID: 8587573
Filing Date: 2013-11-19
Classification: G09G

Abstract:
1. A driving circuit for driving a display panel, the driving circuit comprising: m (m being a natural number of 2 or more) output terminals connected to the display panel; m+1 output circuit blocks, provided for each separate one of the output terminals, which include (i) output circuits for outputting output signals for driving the display panel and (ii) output buffers, constituted by operational amplifiers, which buffer the output signals outputted from the output circuits and then output the output signals to the output terminals, respectively, the (m+1)th one of the output circuit blocks being a spare output circuit block including (i) a spare output circuit capable of outputting an output signal for driving the display panel and (ii) a spare output buffer, constituted by an operational amplifier, which is capable of buffering the output signal outputted from the spare output circuit and then outputting the output signal to the plurality of output terminals; a control circuit for controlling switching of the driving circuit between normal operation and self-detection repairing operation, for causing input signals to be inputted into the plurality of output circuits during the normal operation, and for causing a first test input signal to be inputted into the plurality of output circuits and a second test input signal to be inputted into the spare output circuit during the self-detection repairing operation; and a self-repairing circuit for, after having been switched by the control circuit to the self-detection repairing operation, self-repairing the driving circuit if the driving circuit is defective, the self-repairing circuit including, a comparing circuit for comparing the output signals outputted from the output circuits with the output signal outputted from the spare output circuit; a decision circuit for determining, in accordance with a result of comparison made by the comparing circuit, whether any of the output circuits is defective or not; a connection switching circuit for, when the decision circuit has determined all the output circuits to be good, connecting the hth (h being a natural number of m or less) output circuit to the hth output terminal, and for, when the decision circuit has determined the ith (i being a natural number of m or less) output circuit to be defective, connecting the jth (j being a natural number of i−1 or less) output circuit to the jth output terminal and connecting the (k+1)th (k being a natural number of i or more to m or less) output circuit to the kth output terminal; and a selecting circuit for, when the decision circuit has determined all the output circuits to be good, selecting the hth output circuit as an output circuit for loading that one of the input signals which corresponds to the hth output terminal, and for, when the decision circuit has determined the ith output circuit to be defective, selecting the jth output circuit as an output circuit for loading that one of the input signals which corresponds to the jth output terminal and selecting the (k+1)th output circuit as an output circuit for loading that one of the input signals which corresponds to the kth output terminal, the comparing circuit being constituted by the operational amplifiers of the output circuit blocks, the operational amplifiers of the output circuit blocks being controlled by switching control of the control circuit so that (i) the operational amplifiers switch to serving as the output buffers during the normal operation by receiving the output signals from the output circuits through positive input terminals and having their outputs negatively fed back through negative input terminals and (ii) the operational amplifiers switch to serving as the comparing circuit during the self-detection repairing operation by receiving the output signals from the output circuits through the positive input terminals and receiving the output signal from the spare output circuit through the negative input terminals.