Current drive circuit and drive method thereof, and electroluminescent display apparatus using the circuit

A current drive apparatus which operates a plurality of loads by applying a current thereto, the current drive apparatus comprising:

• a plurality of output terminal groups each including a predetermined number of output terminals to which the loads are respectively connected;
• a single current generation circuit which outputs an operating current having a predetermined current value;
• a plurality of current storage circuit groups each including a predetermined number of current storage circuits which are respectively connected to the predetermined number of output terminals of a respective one of the plurality of output terminal groups, and which sequentially fetch and hold the operating current, and simultaneously output a drive current based on the operating current to the predetermined number of output terminals;
• and
• a plurality of input current storage circuits which are provided between the current generation circuit and the plurality of current storage circuit groups, respectively, and which sequentially fetch and hold the operating current output from the current generation circuit, and sequentially supply the held operating current to the plurality of current storage circuit groups, respectively, such that each of the input current storage circuits supplies the operating current to the predetermined number of current storage circuits of a respective one of the current storage circuit groups in parallel.

A current drive apparatus which operates a plurality of loads by applying a current thereto, the current drive apparatus comprising:

• a plurality of output terminal groups each including a predetermined number of output terminals to which the loads are respectively connected;
• a single reference current generation circuit which generates and outputs a plurality of reference currents having different current values;
• a plurality of reference current storage circuits which are provided for the plurality of output terminal groups, respectively, and which fetch and hold the reference currents, and output a plurality of gradation reference currents based on the reference currents;
• a plurality of current generation circuits which are provided for the plurality of reference current storage circuits, respectively, and each of which selects any of the respective gradation reference currents in accordance with an input signal, and generates gradation currents;
• and
• a plurality of current storage circuit groups each including current storage circuits which are respectively provided for the predetermined number of output terminals of a respective one of the plurality of output terminal groups, and which sequentially fetch and hold the respective gradation currents, and simultaneously output drive currents based on the gradation currents to the respective output terminals.

A drive method of a current drive apparatus which operates a plurality of loads connected to a plurality of output terminals by applying to a current thereto, the drive method comprising:

• generating an operating current having a predetermined current value by using a single current generation circuit, and outputting the operating current to a plurality of current storage circuits;
• sequentially fetching and holding the operating current in the current storage circuits;
• and
• simultaneously outputting a drive current based on the operating current held in the current storage circuits to the respective output terminals,
• wherein the plurality of current storage circuits are provided as a plurality of current storage circuit groups each including a predetermined number of current storage circuits, and before the step of holding the operating current output from the current generation circuit in the plurality of current storage circuits, (i) a step of sequentially fetching and holding the operating current in a plurality of input current storage circuits respectively provided for the plurality of current storage circuit groups and (ii) a step of sequentially supplying the operating current held in each of the input current storage circuits to the predetermined number of current storage circuits of a respective one of the current storage circuit groups, are performed in parallel.

A display apparatus comprising:

• a display panel having a plurality of scanning lines arranged in a row direction, a plurality of signal lines arranged in a column direction, and a plurality of display pixels each arranged in a vicinity of an intersection of the respective scanning lines and signal lines and having an optical element;
• a signal drive circuit comprising:
• (i) a single current generation circuit which generates and outputs an operating current having a current value based on a display signal;
• (ii) a plurality of current storage circuit groups each including a predetermined number of current storage circuits which are provided in accordance with respective signal lines, and which sequentially fetch the operating current output from the current generation circuit, and simultaneously output a drive current based on the operating current to the signal lines;
• and
• (iii) a plurality of input current storage circuits which are provided between the current generation circuit and the plurality of current storage circuit groups, respectively, and which sequentially fetch and hold the operating current output from the current generation circuit, and each of which sequentially supplies the held operating current to the predetermined number of current storage circuits of a respective one of the plurality of current storage circuit groups;
• and
• a scanning drive circuit which outputs to each of the plurality of the scanning lines a scanning signal used to sequentially select the display pixel connected to the scanning line.

A display apparatus comprising:

• a display panel comprising:
• a plurality of scanning line groups each including a predetermined number of scanning lines arranged in a row direction;
• a plurality of signal lines arranged in a column direction;
• and
• a plurality of display pixels each arranged in a vicinity of an intersection of the respective scanning lines and signal lines having an optical element;
• a signal drive circuit comprising:
• (i) a single reference current generation circuit which generates and outputs a plurality of reference currents having different current values;
• (ii) a plurality of reference current storage circuits which are respectively provided for the plurality of signal line groups, and which fetch and hold the respective reference currents and output a plurality of gradation reference currents based on the respective reference currents;
• (iii) a plurality of current generation circuits each of which selects any of the respective gradation reference currents in accordance with a display signal, and generates and outputs gradation currents;
• and
• (iv) a plurality of current storage circuits which are provided for the predetermined number of signal lines of a respective one of the signal line groups, and which sequentially fetch and hold the gradation currents output from the gradation current generation circuit, and simultaneously output drive currents based on the gradation currents to the predetermined number of signal lines;
• and
• a scanning drive circuit which outputs to the respective scanning lines a scanning signal used to sequentially select the display pixels connected to the scanning lines.