Means and circuit to shorten the optical response time of liquid crystal displays
First Claim
Patent Images
1. An active matrix liquid crystal display having a plurality of picture elements arranged in rows and columns comprising:
- a first substrate and a second substrate opposing the first substrate defining a cell gap between said first and second substrates having a liquid crystal layer disposed there between, at least one of the first substrate or the second substrate being transparent,a plurality of pixel control circuits at each intersection of rows and columns,each of the pixel control circuits comprising;
a first transistor,a plurality of video signal voltage lines lying in columns of the display and carrying an enlarged voltage(Va), the enlarged voltage being larger than a desired voltage(Vd) needed for a desired grey scale in each pixel, anda plurality of scan lines connected to a first gate line of the first transistor, each row allowing for the enlarged voltage rather than the desired voltage needed for the desired grey scale of each pixel and allowing the enlarged voltage to work as a boosting voltage accelerating the transition into a desired grey scale, to charge the pixels, andthe pixel control circuits able to change the enlarged voltage into the desired voltage needed for the desired grey scale, thereby ending the effect of the boosting voltage within a frame time allocated for a time-sequential writing of the enlarged voltage larger than needed for the desired grey scale into all rows of the display; and
the plurality of column and row lines occupied with an addressing voltage of the rows with the enlarged voltage being larger than the desired voltage needed for the desired grey scale, the plurality of column and row lines not being available for changing to the desired voltage needed for the desired grey scale, andapplying the enlarged voltage, the enlarged voltage being larger than the desired voltage required for a desired grey scale in the pixels and accelerating the transition into the desired grey scale and changing the enlarged voltage into the desired voltage needed for a given grey scale,the plurality of pixel control circuits further comprising;
a first capacitor directly connected to a drain of a second transistor and a liquid crystal pixel and a second capacitor, the first capacitor being parallel to the second transistor, the first capacitor directly connected in series to the second capacitor, the series connected first capacitor and second capacitor being placed in parallel to the liquid crystal pixel,the second transistor having a short between the drain and gate, a source of the second transistor directly connected between the series connected first capacitor and second capacitor, the first capacitor and second capacitor being charged to the boosting voltage, the short between the drain and gate of the second transistor creating, a resistance to eliminate the need for a second gate line, a discharging of the first capacitor and an e-function which decays rapidly over time.
0 Assignments
0 Petitions
Accused Products
Abstract
An active matrix liquid crystal display is addressed by a voltage larger than the voltage needed for the desired grey shades. A special control circuit is added to each pixel in the display in order to generate a decaying e-function as a boosting voltage for an accelerated transition into the desired grey scale. After the completed decay of this: e-function the driving voltage needed for the desired grey scale is provided by the control circuit.
31 Citations
4 Claims
-
1. An active matrix liquid crystal display having a plurality of picture elements arranged in rows and columns comprising:
-
a first substrate and a second substrate opposing the first substrate defining a cell gap between said first and second substrates having a liquid crystal layer disposed there between, at least one of the first substrate or the second substrate being transparent, a plurality of pixel control circuits at each intersection of rows and columns, each of the pixel control circuits comprising; a first transistor, a plurality of video signal voltage lines lying in columns of the display and carrying an enlarged voltage(Va), the enlarged voltage being larger than a desired voltage(Vd) needed for a desired grey scale in each pixel, and a plurality of scan lines connected to a first gate line of the first transistor, each row allowing for the enlarged voltage rather than the desired voltage needed for the desired grey scale of each pixel and allowing the enlarged voltage to work as a boosting voltage accelerating the transition into a desired grey scale, to charge the pixels, and the pixel control circuits able to change the enlarged voltage into the desired voltage needed for the desired grey scale, thereby ending the effect of the boosting voltage within a frame time allocated for a time-sequential writing of the enlarged voltage larger than needed for the desired grey scale into all rows of the display; and the plurality of column and row lines occupied with an addressing voltage of the rows with the enlarged voltage being larger than the desired voltage needed for the desired grey scale, the plurality of column and row lines not being available for changing to the desired voltage needed for the desired grey scale, and applying the enlarged voltage, the enlarged voltage being larger than the desired voltage required for a desired grey scale in the pixels and accelerating the transition into the desired grey scale and changing the enlarged voltage into the desired voltage needed for a given grey scale, the plurality of pixel control circuits further comprising; a first capacitor directly connected to a drain of a second transistor and a liquid crystal pixel and a second capacitor, the first capacitor being parallel to the second transistor, the first capacitor directly connected in series to the second capacitor, the series connected first capacitor and second capacitor being placed in parallel to the liquid crystal pixel, the second transistor having a short between the drain and gate, a source of the second transistor directly connected between the series connected first capacitor and second capacitor, the first capacitor and second capacitor being charged to the boosting voltage, the short between the drain and gate of the second transistor creating, a resistance to eliminate the need for a second gate line, a discharging of the first capacitor and an e-function which decays rapidly over time. - View Dependent Claims (2, 3)
-
-
4. An active matrix liquid crystal display having a plurality of picture elements arranged in rows and columns comprising:
-
a first substrate and a second opposing substrate defining a cell gap between said first and second substrates having a liquid crystal layer disposed there between, the two substrates having at least one of the substrates being transparent, a plurality of pixels circuits at each intersection of rows and columns, each of the pixel circuits comprising; a first transistor, a plurality of video signal voltage lines lying in columns of the display and carrying an enlarged voltage (Va) larger than a desired voltage (Vd) needed for a desired grey scale in each pixel, and a plurality of scan lines connected to a first gate line of the first transistor, each row allowing for the enlarged voltage rather than the desired voltage needed for the desired grey scale of each pixel and allowing the enlarged voltage to work as a boosting voltage accelerating the transition into a desired grey scale, to charge the pixels, and a pixel control circuit able to change the enlarged voltage into the desired voltage needed for the desired grey scale, thereby ending the effect of the boosting voltage within a frame time allocated for a time-sequential writing of the enlarged voltage larger than needed for the desired grey scale into all rows of the display; and the plurality of column and row lines occupied with an addressing voltage of the rows with the enlarged voltage being larger than the desired voltage needed for the desired grey scale, the plurality of column and row lines not being available for changing to the desired voltage needed for the desired grey scale, and applying the enlarged voltage, the enlarged voltage being larger than the desired voltage required for a desired grey scale in the pixels accelerating the transition into the desired grey scale and changing the enlarged voltage into the desired voltage needed for a given grey scale, the pixel control circuits further comprising; a first capacitor, and a second transistor, wherein the second transistor is parallel to the first capacitor and the first capacitor being connected directly across a source and a drain of the second transistor, a second capacitor connected directly between the source and a gate of the second transistor, the second capacitor being charged together with a parasitic capacitance generated between the gate and drain of the first transistor thereby lowering the potential at the gate of the second transistor resulting in a slower discharge and shaping a decaying e-function into a slow decay and becoming faster over time as the decay enhances the boosting effect of the decaying e-function thereby providing more torque to the liquid crystal.
-
Specification