An image display apparatus comprising: a plurality of pixels which are configured to display an image, wherein each pixel comprises a driving transistor and an OLED pixel element; a first power source which is configured to apply a voltage to each OLED pixel element in the plurality of pixels by means of an emitter-base connection of a first transistor while the collector of the first transistor is connected in parallel to a resistance adjusting the driving voltage of the first transistor; a counter which is configured to output counter signals; a ramp generator operating according to the same clock as the counter and configured to generate a ramp signal; a second power source connected to the cathode of each OLED pixel element in the plurality of pixels and configured to apply a ramp waveform to each OLED pixel element synchronized with the ramp signal generated by the ramp generator; an amplifier connected to the collector of the first transistor and configured to output a trigger signal that appears in the collector of the first transistor when the current flows through the OLED pixel element to which the first power supply is connected and that is being scanned; a data driver which is configured to output a counter value according to the counter signal when the trigger signal is generated wherein the counter value represents the time elapsed since the sweep of the second power source started; and a buffer which is configured to store the counter value; wherein in each pixel, the driving transistor and the OLED pixel element are connected in series in the current path between the first and the second power sources. a plurality of pixels which are configured to display an image, wherein each pixel comprises a driving transistor and an OLED pixel element; a first power source which is configured to apply a voltage to each OLED pixel element in the plurality of pixels by means of an emitter-base connection of a first transistor while the collector of the first transistor is connected in parallel to a resistance adjusting the driving voltage of the first transistor; a counter which is configured to output counter signals; a ramp generator operating according to the same clock as the counter and configured to generate a ramp signal; a second power source connected to the cathode of each OLED pixel element in the plurality of pixels and configured to apply a ramp waveform to each OLED pixel element synchronized with the ramp signal generated by the ramp generator; an amplifier connected to the collector of the first transistor and configured to output a trigger signal that appears in the collector of the first transistor when the current flows through the OLED pixel element to which the first power supply is connected and that is being scanned; a data driver which is configured to output a counter value according to the counter signal when the trigger signal is generated wherein the counter value represents the time elapsed since the sweep of the second power source started; and a buffer which is configured to store the counter value; wherein in each pixel, the driving transistor and the OLED pixel element are connected in series in the current path between the first and the second power sources.