1. A pixel driver circuit for driving an OLED pixel in an active matrix OLED display, comprising:
a switch having an input, an output and a control input which is coupled to a row select line of the display;
a current driver TFT transistor having a gate coupled to the output of the switch, a drain coupled to the pixel, and a source coupled to a voltage source;
a capacitor having an electrode coupled to the voltage source, and another electrode coupled to the current driver TFT transistor gate; and
a toggle element, the toggle element having an output coupled to the input of the first switch and including a first input and a second input, the first input which may be coupled to a data voltage and the second input which may be coupled to a reverse voltage, the toggle element capable of alternating between inputs over a refresh period of the display.
2. A method for controlling a voltage controlled current driving TFT in an active matrix OLED display, the OLED display providing updated pixel data to each pixel of the display over a refresh period, the method comprising:
providing a data signal to the gate of the current driving TFT during a first portion of the refresh period; and
providing a reverse data signal to the gate of the current driving TFT during a second portion of the refresh period, the reverse data signal reverse biasing the TFT to reduce the effects of threshold drift.
3. The method of claim 2, wherein the reverse data signal is derived from the data signal provided to the gate of the TFT during the first portion of the refresh period.
4. The method of claim 2, wherein all pixels of the display receive corresponding data signals during a first portion of the refresh period, which is prior to a second portion of the refresh period during which the pixels receive the reverse data signals.
5. A method for providing data to pixel drivers in an active matrix OLED display employing voltage controlled TFT current drivers, the display including row control lines activating select rows of the display and column data lines to provide data to pixels in selected rows, the method comprising:
(a) activating a row of the display by transmitting a corresponding control signal to the row control line for the row;
(b) providing data signals to the column data lines of the display in accordance with the display pixel data for the row;
(c) repeating steps (a) and (b) until data is provided to all rows of the display;
(d) activating a row of the display by transmitting a corresponding control signal to the row control line of the row;
(e) providing reverse data signals to the column data lines of the display, the reverse data determined by reference to the data signal levels provided to the rows of the display; and
(f) repeating steps (d) and (e) until reverse data is provided to all rows of the display.
6. The method of claim 5, wherein the reverse data signal is derived from each pixel data signal provided in step (b).
7. A method for providing data to pixel drivers in an active matrix OLED display employing voltage controlled TFT current drivers, the display including a row control line activating each row of the display and column data lines to provide data to columns of the display, the method comprising:
(a) activating a first row of the display by transmitting a corresponding control signal to the row control line for the first row;
(b) providing data signals to the column data lines of the display in accordance with the display pixel data for the first row;
(c) activating a second row of the display by transmitting a corresponding control signal to the row control line of the second row;
(d) providing reverse data signals to the column data lines of the display in accordance with the reverse data for the second row;
(e) repeating steps (a)-(d) until each row of the display is provided a data signal and is provided a reverse data signal.
8. The method of claim 7, wherein the second row is determined by the formula:
Row(Current rowN2)Mod N; 1RowN
Where N is the number of rows in the display.
9. The method of claim 7, wherein the reverse data signals provided to a row are derived from the data signals provided to each pixel in the row.
10. The method of claim 7, wherein the reverse data signals are a predetermined level signal uniformly provided to all rows of the display.
11. A pixel driving circuit, comprising:
a current switch having a control input, a current input, and a current output;
a memory element coupled to the current output of the switch to receive data current from the switch;
a current driving transistor, the current driving transistor having a gate coupled to the output of the memory element, and having an output coupled to a pixel; and
a toggle switch having a first input coupled to a data source and having a second input coupled to a reverse data source and having an output coupled to the current input of the current switch.
12. An OLED active matrix display, comprising:
a plurality of pixel elements arranged as a matrix, said matrix arrangement including pixel rows and pixel columns;
a plurality of row control lines for selectively activating a row of pixel elements so as to update pixel data in said pixel elements;
a plurality of column control lines for providing data to activate each pixel elements in a selected row;
a plurality of selection means, each selection means selecting between at least a first input and a second input to provide an output, each selection means output operatively coupled to one of said plurality of column control lines;
means for providing pixel data, said means for providing pixel data coupled to said first input of each of said plurality of selection means; and
means for providing reverse pixel data, said means for providing reverse pixel data coupled to said second input of each of said plurality of selection means.
13. The display of claim 12, wherein the pixel elements are TFT based current driving circuits.
14. The display of claim 12, wherein each pixel element includes a plurality of OLED display elements.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A spreading head harness for headphones or a head set, comprising a first and a second harness member each with a substantially arc-shaped curvature and a first and a second connection member for receiving headphone ear pieces, each harness member comprising:
a first and a second end area;
a flexible spring region for elastic widening and contraction of the harness member having a longitudinal axis;
said first and second end areas being twisted relative to the spring region around the longitudinal axis of the spring region and bent relative to the arc-shaped curvature for generating a mechanical tension in the harness member;
wherein the first end areas of the first and second harness member are connected to the first connection member;
wherein the second end areas of the first and second harness member are connected to the second connection member;
wherein in a first operating position the first and second harness member extend substantially parallel to each other;
wherein in a second operating position, when the connection members are pulled away from each other and the flexible spring region of the first and second harness member are widened, the first and second harness member are spread from each other due to a mechanical tension in the end areas of the first and second harness member.
2. The harness according to claim 1, wherein the flexible spring region is fashioned in its entirety from spring steel.
3. The harness according to claim 1, wherein the end areas are twisted in opposite directions relative to the spring region.
4. The harness according to claim 1, wherein the end areas are twisted relative to the spring region by an angle (\u03b1) greater than 0\xb0 and less than 45\xb0.
5. The harness according to claim 1, wherein the end areas are bent inward relative to the curvature.
6. The harness according to claim 1, wherein the end areas are bent relative to the curvature by an angle (\u03b2) greater than 0\xb0 and less than 20\xb0.
7. The harness according to claim 1, wherein the partial harness is constructed in such a way that a cable is guided from one end area to the other end area through the partial harness.
8. The harness according to claim 1, wherein the partial harness has a sheathing for guiding a cable from one end area to the other end area through the sheathing.
9. The harness according to claim 1, wherein the connection member comprises:
holding members at which the end areas of the harness member can be mounted;
said holding members being designed for twisting of the end areas around the longitudinal axis relative to the spring regions, bending of the end areas relative to the curvature, and for generation of a mechanical tension in the harness member when the end areas are mounted to the holding areas; and
said end areas being twisted relative to the spring region when mounted to the holding members.
10. Headphones or a headset with a spreading head harness according to claim 1 and with at least one headphone ear piece, wherein at least one holder for the at least one headphone ear piece is arranged at the end areas of the harness member andor connection members.