Display device and display device driving method

A display device comprising:

• a scanning line group including a scanning line of a first row and a scanning line of a second row;
• a signal line group including a signal line of a first column which flows a first designation current and a signal line of a second column which flows a second designation current;
• an optical element group including a first optical element which is connected to the scanning line of the first row and emits light in accordance with a current value of a first driving current supplied thereto, and a second optical element which is connected to the scanning line of the second row and emits light in accordance with a current value of a second driving current supplied thereto;
• a pixel circuit group including a first pixel circuit which is connected to the first optical element and supplies the first driving current, the current value of which is equal to a current value of the first designation current, which is supplied thereto, and a second pixel circuit which is connected to the second optical element and supplies the second driving current, the current value of which is equal to a current value of the second designation current, which is supplied thereto;
• and
• a power supply which applies a designation current reference voltage to both the first pixel circuit and the second pixel circuit within a selection period, and which applies a driving current reference voltage to both the first pixel circuit and the second pixel circuit within a non-selection period so that the first pixel circuit supplies the first driving current to the first optical element and the second pixel circuit supplies the second driving current to the second optical element;
• wherein the optical elements have respective first electrodes connected to the power supply through the pixel circuits corresponding thereto and a second electrode to which a reference voltage is applied;
• and
• wherein the power supply selectively outputs the driving current reference voltage and the designation current reference voltage to supply the first and second designation currents, and the driving current reference voltage is not less than the reference voltage applied to the second electrode of the optical elements, and the designation current reference voltage is not more than the reference voltage applied to the second electrode of the optical elements.

A display device driving method comprising:

• supplying a first designation current to a first driving transistor within a first selection period to store charges corresponding to a current value of the first designation current between a gate and a source of the first driving transistor;
• supplying a second designation current to a second driving transistor within a second selection period to store charges corresponding to a current value of the second designation current between a gate and a source of the second driving transistor;
• and
• from an end of the first selection period until a beginning of the second selection period, (i) outputting a driving current reference voltage to the first driving transistor and a first optical element which is connected in series with the first driving transistor, and (ii) outputting the driving current reference voltage to the second driving transistor and a second optical element which is connected in series with the second driving transistor;
• and
• applying a designation current reference voltage to both the first driving transistor and the second driving transistor in the first selection period and the second selection period;
• wherein the driving current reference voltage is a voltage at which a source-drain voltage of the first driving transistor and a source-drain voltage of the second driving transistor are set in a saturated state.

A display device driving method comprising:

• supplying a first designation current to a first driving transistor within a first selection period to store charges corresponding to a current value of the first designation current between a gate and a source of the first driving transistor;
• supplying a second designation current to a second driving transistor within a second selection period after supplying the first designation current to store charges corresponding to a current value of the second designation current between a gate and a source of the second driving transistor;
• and
• after supplying the second designation current, outputting a driving current reference voltage to the first driving transistor and a first optical element which is connected in series with the first driving transistor, and outputting the driving current reference voltage to the second driving transistor and a second optical element which is connected in series with the second driving transistor;
• applying a designation current reference voltage to both the first driving transistor and the second driving transistor in the first selection period and the second selection period;
• wherein the driving current reference voltage is a voltage at which a source-drain voltage of the first driving transistor and a source-drain voltage of the second driving transistor are set in a saturated state.