Bias circuit and method for operating the same
AssigneeLG Electronics Inc.
InventorU Hyun Kim
Life of this patent
Estimating the term…
Abstract
A bias circuit and a method for operating the same minimizes a picture distortion. The bias circuit includes a main capacitor and a plurality of sub capacitors for compensating picture distortion, a controller provides control signals having different duty cycles, and a plurality of switches receiving each of the switch control signals and changing each link (or path) between the main capacitor and the sub capacitors in accordance with the received switch control signals.
Claims28
A bias circuit for a display device to prevent and/or compensate a picture distortion, comprising:
- a controller that generates a plurality of control signals and each of the plurality of first control signals having a different duty cycle, and includes a plurality of comparators to output the plurality of first control signals, each comparator having a first input and a second input, wherein the first inputs of the plurality of comparators receive a same first signal and each of the second inputs of the plurality of comparators receives a second signal, and wherein the second signal input into each comparator has a different DC component which determines the duty cycle of a respective one of the first control signals;
- and
- a compensation circuit having a plurality of first switches, at least one main capacitor and a plurality of sub capacitors, a corresponding first switch provided between the main capacitor and a corresponding sub capacitor,
- wherein the plurality of first switches determine at least one of whether the main capacitor is coupled to the plurality of sub capacitors or whether the plurality of sub capacitors are coupled to each other, based on the plurality of first control signals.
A bias circuit for a display device, comprising:
- a controller that generates a plurality of first control signals and each of the plurality of first control signals having a different duty cycle, and includes a plurality of comparators to output the plurality of first control signals, each comparator having a first input and a second input, wherein the first inputs of the plurality of comparators receive a same first signal and each of the second inputs of the plurality of comparators receives a second signal, wherein the second signal input into each comparator has a different DC component which determines the duty cycle of a respective one of the first control signals;
- and
- a compensation circuit responsive to the plurality of control signals, wherein a duty cycle of a corresponding first control signal determines which portion of a picture is compensated for distortion, and comprises a plurality of first switches, at least one main capacitor and a plurality of sub-capacitors, a corresponding first switch provided between the main capacitor and a corresponding sub-capacitor, wherein the plurality of first switches determines at least one of whether the main capacitor is coupled to the plurality of sub-capacitors or whether the plurality of sub-capacitors are coupled to each other, based on the plurality of first control signals, and includes a plurality of comparators to output the plurality of first control signals.
The bias circuit of claim hi 14, wherein the corresponding first control signal is provided directly to a corresponding first switch.
A method of driving a bias circuit, comprising:
- generating switch control signals each having a different duty cycle, wherein the switch control signals are generated with different duty cycles by generating a first parabolic signal that is synchronized with a horizontal synchronizing signal, generating second parabolic signals each having a DC voltage of a different voltage level applied thereto, and generating the switch control signals each having a different duty cycle in accordance with the first and second parabolic signals;
- providing the switch control signal to a plurality of switches;
- and
- providing a combined capacitance value of a main capacitor and a plurality of sub capacitors, which are connected to each switch, in accordance with the switch control signals.
Dependencies are inferred from the claim text.