Patent ID: 11955068
Assignee: BOE TECHNOLOGY GROUP CO., LTD.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 12:
13. A gamma driving voltage generating circuit, comprising:
a gamma standard high voltage generating circuit;
a gamma standard low voltage generating circuit;
a gamma driving voltage element electrically coupled between an output terminal of a selecting element of the gamma standard high voltage generating circuit and an output terminal of a selecting element of the gamma standard low voltage generating circuit, and configured to generate a gamma driving voltage according to a gamma standard high voltage and a gamma standard low voltage; wherein
the gamma standard high voltage generating circuit and/or the gamma standard low voltage generating circuit is a gamma standard voltage generating circuit, the gamma standard voltage generating circuit comprises a constant voltage element configured to output a constant voltage;
a following voltage element electrically coupled to a driving voltage terminal and configured to output a following voltage changing with a driving voltage of the driving voltage terminal; a selecting element electrically coupled to an output terminal of the constant voltage element and an output terminal of the following voltage element, and configured to output the following voltage or the constant voltage as an output voltage at an output terminal thereof, the output voltage is a gamma standard voltage for generating gamma driving voltages at gray levels by performing voltage divisions thereon; a comparison element electrically coupled to the output terminal of the selecting element, and configured to control the selecting element to output the following voltage in response to that the output voltage meets a preset standard, and control the selecting element to output the constant voltage in response to that the output voltage does not meet the preset standard, wherein the preset standard is one of: i) the output voltage is lower than a threshold voltage, or,ii) the output voltage is higher than the threshold voltage; and the constant voltage is one of i) higher than or equal to the threshold voltage; or ii) lower than or equal to the threshold voltage, respectively; the following voltage element comprises an offset voltage component configured to output a preset offset voltage, and a voltage adding component electrically coupled to an output terminal of the offset voltage component and the driving voltage terminal and configured to add the offset voltage to the driving voltage and output an added voltage as the following voltage; the selecting element comprises a multiplexer comprising a control terminal and two input terminals, the two input terminals are respectively electrically coupled to the output terminal of the constant voltage element and the output terminal of the following voltage element, the control terminal of the multiplexer is electrically coupled to the comparison element, and the multiplexer is configured to enable corresponding one of the input terminals thereof to be electrically coupled with the output terminal thereof according to a signal at the control terminal thereof; the comparison element comprises a threshold voltage component configured to output a preset threshold voltage, wherein the preset standard is that the output voltage is lower than the threshold voltage, or that the output voltage is higher than the threshold voltage; a comparison component electrically coupled to the output terminal of the selecting element and an output terminal of the threshold voltage component, and configured to control the selecting element to output the following voltage or the constant voltage according to a relationship between the output voltage and the threshold voltage; the comparison component comprises a comparator having two input terminals electrically coupled to the output terminal of the selecting element and the output terminal of the threshold voltage component, respectively, and configured to compare the output voltage with the threshold voltage to output a comparison result signal; and a controller electrically coupled to an output terminal of the comparator and the control terminal of the selecting element, and configured to control the selecting element to output the following voltage or the constant voltage according to the comparison result signal from the output terminal of the comparator, and wherein
in the gamma standard high voltage generating circuit, the comparison element is configured to control the selecting element to output the following voltage in response to that the output voltage is lower than a preset threshold voltage and control the selecting element to output the constant voltage in response to that the output voltage is higher than or equal to the preset threshold voltage, and the following voltage is higher than the driving voltage, the constant voltage is higher than or equal to the threshold voltage, and the output voltage is a gamma standard high voltage; and
in the gamma standard low voltage generating circuit, the comparison element is configured to control the selecting element to output the following voltage in response to that the output voltage is higher than a preset threshold voltage and control the selecting element to output the constant voltage in response to that the output voltage is lower than or equal to the preset threshold voltage; and the following voltage is lower than the driving voltage, the constant voltage is lower than or equal to the threshold voltage, and the output voltage is a gamma standard low voltage.