Apparatus and method for driving mobile display device

Abstract

A mobile display device driving apparatus and method which can reduce power consumption are disclosed. The driving apparatus includes a liquid crystal panel having a plurality of liquid crystal cells each formed in sub-pixel areas of four colors, a battery charged with a voltage, a power saving mode signal generator that detects the remaining power of the battery and generates a power saving mode signal based on the detected power to set a power saving mode of the liquid crystal panel. A controller sets a gain value in response to the power saving mode signal, converts external three-color input data into four-color data based on the set gain value and generates a dimming signal in response to the power saving mode signal. A panel driver displays an image based on the four-color data on the liquid crystal panel. An inverter generates a lamp drive voltage based on the dimming signal, and a backlight unit generates light in response to the lamp drive voltage and irradiates the generated light to the liquid crystal panel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like referenced numerals designate corresponding parts throughout the different views.

FIG. 1 is a block diagram schematically showing the configuration of an apparatus that drives a mobile display device.

FIG. 2 is a schematic block diagram of a power saving mode signal generator in FIG. 1.

FIG. 3 is a schematic block diagram of a controller in FIG. 1.

FIG. 4 is a block diagram of a data converter in FIG. 3.

FIG. 5 is a schematic block diagram of a dimming signal generator in FIG. 3.

FIG. 6 is a graph showing an example dimming curve for extraction of a first dimming value in a dimming value extractor in FIG. 5.

FIG. 7 a is a graph showing a second example dimming curve for the extraction of the first dimming value in the dimming value extractor in FIG. 5.

FIG. 7 b is a graph showing another example dimming curve for the extraction of the first dimming value in the dimming value extractor in FIG. 5.

FIG. 8 is a block diagram showing an example data converter in FIG. 3.

FIG. 9 is a block diagram showing another example data converter in FIG. 3.

FIG. 10 is a block diagram showing an example data converter in FIG. 3.

FIG. 11 is a block diagram schematically showing the configuration of an apparatus that drives a mobile display device.

Claims

1. An apparatus that drives a mobile display device, comprising: a liquid crystal panel including a plurality of liquid crystal cells each formed in sub-pixel areas of four colors;a battery coupled with the mobile display device and charged with a voltage;a power saving mode signal generator coupled with the battery and operable to detect a remaining power of the battery and to generate a power saving mode signal based on the detected power to set a power saving mode of the liquid crystal panel;a controller operable to: set a gain value in response to the power saving mode signal; to convert external three-color input data into four-color data based on the set gain value; and to generate a dimming signal based on the power saving mode signal;a panel driver coupled with the liquid crystal panel and operable to display an image corresponding to the four-color data on the liquid crystal panel;an inverter coupled with the controller and operable to generate a lamp drive voltage in response to the dimming signal; anda backlight unit coupled with the inverter and operable to generate a light signal in response to the lamp drive voltage and to irradiate the generated light to the liquid crystal panel.

2. The apparatus of claim 1, wherein the power saving mode signal generator comprises: a battery power detector operable to generate a detect signal based on the remaining power of the battery; anda comparator operable to generate the power saving mode signal based on the detect signal, the power saving mode signal assuming a high state when the detect signal is higher than or equal to a reference signal and a low state when the detect signal is lower than the reference signal.

3. The apparatus of claim 2, wherein the controller comprises: a driver control signal generator operable to generate control signals that control the panel driver using external input synchronous signals;a data converter operable to set the gain value based on the power saving mode signal and to convert the external three-color input data into the four-color data based on the set gain value; anda dimming signal generator that generates the dimming signal using white data of the four-color data and the power saving mode signal.

4. The apparatus of claim 3, wherein the data converter comprises: a gain value setter operable to set the gain value to a range of about 1 to 2 when the power saving mode signal assumes the high state and to a rational number greater than or equal to about two when the power saving mode signal assumes the low state;a data amplifier operable to multiply each of the external three-color input data by the gain value to generate three-color amplified data;a white data extractor operable to extract the white data from the three-color amplified data; anda subtracter operable to subtract the white data from each of the three-color amplified data to generate three-color data,wherein the four-color data includes the three-color data from the subtracter and the white data.

5. The apparatus of claim 3, wherein the data converter comprises: a gain value setter operable to set the gain value to a range of about 1 to 2 when the power saving mode signal assumes the high state and to a rational number greater than or equal to about two when the power saving mode signal assumes the low state;a first gamma corrector operable to gamma correct the three-color input data to generate linearized primary three-color data;a brightness/color separator operable to separate the primary three-color data into a brightness component and color components;a brightness amplifier operable to multiply the separated brightness component by the gain value to generate an amplified brightness component;a mixer operable to mix the amplified brightness component and the separated color components to generate secondary three-color data; anda second gamma corrector operable to gamma correct the secondary three-color data to generate three-color data and to gamma correct the amplified brightness component to generate the white data,wherein the four-color data includes the three-color data and the white data.

6. The apparatus of claim 3, wherein the data converter comprises: a gain value setter operable to set the gain value to a range of about 1 to 2 when the power saving mode signal assumes the high state and to a rational number greater than or equal to about two when the power saving mode signal assumes the low state;a data amplifier operable to multiply each of the external three-color input data by the gain value to generate three-color amplified data;a white data extractor operable to extract the white data from the three-color amplified data;a subtracter operable to subtract the white data from each of the three-color amplified data to generate three-color data; anda selector operable to selectively output the three-color data based on the power saving mode signal,wherein the four-color data includes the three-color data from the subtracter and the white data.

7. The apparatus of claim 6, wherein the selector supplies the three-color data to the panel driver when the power saving mode signal assumes the high state and does not supply the three-color data to the panel driver when the power saving mode signal assumes the low state.

8. The apparatus of claim 7, wherein a black and white image based on the white data is displayed on the liquid crystal panel when the liquid crystal panel is in a power saving mode corresponding to the power saving mode signal of the low state.

9. The apparatus of claim 3, wherein the data converter comprises: a gain value setter operable to set the gain value to a range of about 1 to 2 when the power saving mode signal assumes the high state and to a rational number greater than or equal to about two when the power saving mode signal assumes the low state;a first gamma corrector operable to gamma correct the three-color input data to generate linearized primary three-color data;a brightness/color separator operable to separate the primary three-color data into a brightness component and color components;a brightness amplifier operable to multiply the separated brightness component by the gain value to generate an amplified brightness component;a mixer operable to mix the amplified brightness component and the separated color components to generate secondary three-color data;a selector operable to selectively output the secondary three-color data based on the power saving mode signal; anda second gamma corrector operable to gamma correct the secondary three-color data from the selector to generate three-color data and to gamma correct the amplified brightness component to generate the white data,wherein the four-color data includes the three-color data and the white data.

10. The apparatus of claim 9, wherein the selector supplies the three-color data to the second gamma corrector when the power saving mode signal assumes the high state and does not supply the three-color data to the second gamma corrector when the power saving mode signal assumes the low state.

11. The apparatus of claim 10, wherein a black and white image based on the white data is displayed on the liquid crystal panel when the liquid crystal panel is in the power saving mode corresponding to the power saving mode signal of the low state.

12. The apparatus of claim 3, wherein the dimming signal generator comprises: a dimming value extractor operable to extract a first dimming value signal corresponding to the white data from a set dimming curve;a second dimming value signal fixed or arbitrarily set by a user that reduces power consumption of the backlight unit; anda selector operable to select the first dimming value signal as the dimming signal and to supply the selected first dimming value signal to the inverter, when the power saving mode signal assumes the high state, and operable to select the second dimming value signal as the dimming signal and operable to supply the selected second dimming value signal to the inverter, when the power saving mode signal assumes the low state.

13. The apparatus of claim 12, wherein the dimming curve has any one of a linear curve shape, a quadratic curve shape or a diagonal shape set between a minimum dimming value and a maximum dimming value.

14. An apparatus that drives a mobile display device, comprising: a liquid crystal panel coupled with the mobile display device and including a plurality of liquid crystal cells each formed in sub-pixel areas of four colors;an optical sensor coupled with the mobile display device and operable to detect an amount of ambient light;a power saving mode signal generator coupled with the optical sensor and operable to generate a power saving mode signal based on the ambient light amount detected by the optical sensor to set a power saving mode of the liquid crystal panel;a controller coupled with the power saving mode signal generator and operable to: set a gain value in response to the power saving mode signal; to convert external three-color input data into four-color data based on the set gain value; and to generate a dimming signal based on the power saving mode signal;a panel driver coupled with the liquid crystal panel and operable to display an image based on the four-color data of the liquid crystal panel;an inverter coupled with the controller and operable to generate a lamp drive voltage in response to the dimming signal; anda backlight unit coupled with the inverter and operable to generate light in response to the lamp drive voltage and irradiate the generated light to the liquid crystal panel.

15. The apparatus of claim 14, wherein the power saving mode signal assumes a high state when the ambient light amount is greater than or equal to about a level of a reference signal and a low state when the ambient light amount is smaller than about the level of the reference signal.

16. The apparatus of claim 15, wherein the controller comprises: a driver control signal generator operable to generate control signals that control the panel driver using external input synchronous signals;a data converter operable to set the gain value based on the power saving mode signal and to convert the external three-color input data into the four-color data based on the set gain value; anda dimming signal generator that generates the dimming signal using white data of the four-color data and the power saving mode signal.

17. The apparatus of claim 16, wherein the data converter comprises: a gain value setter operable to set the gain value to a range of about 1 to 2 when the power saving mode signal assumes the high state and to a rational number greater than or equal to about two when the power saving mode signal assumes the low state;a data amplifier operable to multiply each of the external three-color input data by the gain value to generate three-color amplified data;a white data extractor operable to extract the white data from the three-color amplified data; anda subtracter operable to subtract the white data from each of the three-color amplified data to generate three-color data,wherein the four-color data includes the three-color data from the subtracter and the white data.

18. The apparatus of claim 16, wherein the data converter comprises: a gain value setter operable to set the gain value to a range of about 1 to 2 when the power saving mode signal assumes the high state and to a rational number greater than or equal to about two when the power saving mode signal assumes the low state;a first gamma corrector operable to gamma correct the three-color input data to generate linearized primary three-color data;a brightness/color separator operable to separate the primary three-color data into a brightness component and color components;a brightness amplifier operable to multiply the separated brightness component by the gain value to generate an amplified brightness component;a mixer operable to mix the amplified brightness component and the separated color components to generate secondary three-color data; anda second gamma corrector operable to gamma correct the secondary three-color data to generate three-color data and to gamma correct the amplified brightness component to generate the white data,wherein the four-color data includes the three-color data and the white data.

19. The apparatus of claim 16, wherein the data converter comprises: a gain value setter operable to set the gain value to a range of about 1 to 2 when the power saving mode signal assumes the high state and to a rational number greater than or equal to about two when the power saving mode signal assumes the low state;a data amplifier operable to multiply each of the external three-color input data by the gain value to generate three-color amplified data;a white data extractor operable to extract the white data from the three-color amplified data;a subtracter operable to subtract the white data from each of the three-color amplified data to generate three-color data; anda selector operable to selectively output the three-color data based on the power saving mode signal,wherein the four-color data includes the three-color data from the subtracter and the white data.

20. The apparatus of claim 19, wherein the selector supplies the three-color data to the panel driver when the power saving mode signal assumes the high state and does not supply the three-color data to the panel driver when the power saving mode signal assumes the low state.

21. The apparatus of claim 20, wherein a black and white image based on the white data is displayed on the liquid crystal panel when the liquid crystal panel is in a power saving mode related to the power saving mode signal of the low state.

22. The apparatus of claim 16, wherein the data converter comprises: a gain value setter operable to set the gain value to a range of about 1 to 2 when the power saving mode signal assumes the high state and to a rational number greater than or equal to about two when the power saving mode signal assumes the low state;a first gamma corrector operable to gamma correct the three-color input data to generate linearized primary three-color data;a brightness/color separator operable to separate the primary three-color data into a brightness component and color components;a brightness amplifier operable to multiply the separated brightness component by the gain value to generate an amplified brightness component;a mixer operable to mix the amplified brightness component and the separated color components to generate secondary three-color data;a selector operable to selectively output the secondary three-color data in response to the power saving mode signal; anda second gamma corrector operable to gamma correct the secondary three-color data from the selector to generate three-color data and to gamma correct the amplified brightness component to generate the white data,wherein the four-color data includes the three-color data and the white data.

23. The apparatus of claim 22, wherein the selector supplies the three-color data to the second gamma corrector when the power saving mode signal assumes the high state and does not supply the three-color data to the second gamma corrector when the power saving mode signal assumes the low state.

24. The apparatus of claim 23, wherein a black and white image based on the white data is displayed on the liquid crystal panel when the liquid crystal panel is in the power saving mode corresponding to the power saving mode signal of the low state.

25. The apparatus of claim 16, wherein the dimming signal generator comprises: a dimming value extractor operable to extract a first dimming value signal based on the white data from a set dimming curve;a second dimming value signal fixed or arbitrarily set by a user to reduce power consumption of the backlight unit; anda selector operable to select the first dimming value signal as the dimming signal and to supply the selected first dimming value signal to the inverter, when the power saving mode signal assumes the high state, and operable to select the second dimming value signal as the dimming signal and supply the selected second dimming value signal to the inverter, when the power saving mode signal assumes the low state.

26. The apparatus of claim 25, wherein the dimming curve has any one of a linear curve shape, a quadratic curve shape or a diagonal shape set between about a minimum dimming value and about a maximum dimming value.

27. A method that drives a mobile display device, the display device including a liquid crystal panel including a plurality of liquid crystal cells each formed in sub-pixel areas of four colors, the method comprising: detecting remaining power of a battery charged with a voltage and generating a power saving mode signal based on the detected power to set a power saving mode of the liquid crystal panel;setting a gain value based on the power saving mode signal, converting external three-color input data into four-color data based on the set gain value and generating a dimming signal in response to the power saving mode signal;driving a backlight unit based on a lamp drive voltage corresponding to the dimming signal to irradiate light to the liquid crystal panel; andsupplying image signals based on the four-color data to the liquid crystal panel to display a corresponding image on the liquid crystal panel.

28. The method of claim 27, wherein detecting the remaining power comprises: generating a detect signal based on the remaining power of the battery; andgenerating the power saving mode signal based on the detect signal, the power saving mode signal assuming a high state when the detect signal is higher than or equal to a reference signal and a low state when the detect signal is lower than the reference signal.

29. The method according to claim 28, wherein setting the gain value comprises: generating control signals for control of a panel driver using external input synchronous signals;setting the gain value based on the power saving mode signal and converting the external three-color input data into the four-color data based on the set gain value; andgenerating the dimming signal using white data of the four-color data and the power saving mode signal.

30. The method of claim 29, wherein converting the external three-color input data into the four-color data comprises: setting the gain value to a range of about 1 to 2 when the power saving mode signal assumes the high state and to a rational number greater than or equal to about two when the power saving mode signal assumes the low state;multiplying each of the external three-color input data by the gain value to generate three-color amplified data;extracting the white data from the three-color amplified data; andsubtracting the white data from each of the three-color amplified data to generate three-color data,wherein the four-color data includes the three-color data and the white data.

31. The method of claim 29, wherein converting the external three-color input data into the four-color data comprises: setting the gain value to a range of about 1 to 2 when the power saving mode signal assumes the high state and to a rational number greater than or equal to about two when the power saving mode signal assumes the low state;gamma correcting the three-color input data to generate linearized primary three-color data;separating the primary three-color data into a brightness component and color components;multiplying the separated brightness component by the gain value to generate an amplified brightness component;mixing the amplified brightness component and the separated color components to generate secondary three-color data; andgamma correcting the secondary three-color data to generate three-color data and gamma correcting the amplified brightness component to generate the white data,wherein the four-color data includes the three-color data and the white data.

32. The method of claim 29, wherein converting the external three-color input data into the four-color data comprises: setting the gain value to a range of about 1 to 2 when the power saving mode signal assumes the high state and to a rational number greater than or equal to about two when the power saving mode signal assumes the low state;multiplying each of the external three-color input data by the gain value to generate three-color amplified data;extracting the white data from the three-color amplified data;subtracting the white data from each of the three-color amplified data to generate three-color data; andselectively outputting the three-color data in response to the power saving mode signal using a selector,wherein the four-color data includes the three-color data and the white data.

33. The method of claim 32, further comprising outputting, by the selector, the three-color data when the power saving mode signal assumes the high state and not outputting the three-color data when the power saving mode signal assumes the low state.

34. The method of claim 33, further comprising displaying a black and white image based on the white data on the liquid crystal panel when the liquid crystal panel is in the power saving mode corresponding to the power saving mode signal of the low state.

35. The method of claim 29, wherein converting the external three-color input data into the four-color data comprises: setting the gain value to a range of about 1 to 2 when the power saving mode signal assumes the high state and to a rational number greater than or equal to about two when the power saving mode signal assumes the low state;gamma correcting the three-color input data using a first gamma corrector to generate linearized primary three-color data;separating the primary three-color data into a brightness component and color components;multiplying the separated brightness component by the gain value to generate an amplified brightness component;mixing the amplified brightness component and the separated color components to generate secondary three-color data;selectively outputting the secondary three-color data in response to the power saving mode signal using a selector; andgamma correcting the secondary three-color data from the selector using a second gamma corrector to generate three-color data and gamma correcting the amplified brightness component using the second gamma corrector to generate the white data,wherein the four-color data includes the three-color data and the white data.

36. The method of claim 35, further comprising supplying, by the selector, three-color data to the second gamma corrector when the power saving mode signal assumes the high state and not supplying the three-color data to the second gamma corrector when the power saving mode signal assumes the low state.

37. The method of claim 36, further comprising displaying a black and white image based on the white data on the liquid crystal panel when the liquid crystal panel is in the power saving mode corresponding to the power saving mode signal of the low state.

38. The method of claim 29, wherein generating the dimming signal comprises: extracting a first dimming value corresponding to the white data from a set dimming curve;supplying a second dimming value fixed or arbitrarily set by a user to reduce power consumption of the backlight unit; andoutputting the first dimming value as the dimming signal when the power saving mode signal assumes the high state and the second dimming value as the dimming signal when the power saving mode signal assumes the low state.

39. The method of claim 38, wherein the dimming curve comprises any one of a linear curve shape, a quadratic curve shape or a diagonal shape set between about a minimum dimming value and about a maximum dimming value.

40. A method that drives a mobile display device, the display device including a liquid crystal panel including a plurality of liquid crystal cells each formed in sub-pixel areas of four colors, the method comprising: detecting an amount of ambient light and generating a power saving mode signal based on the detected ambient light amount to set a power saving mode of the liquid crystal panel;setting a gain value based on the power saving mode signal, converting external three-color input data into four-color data based on the set gain value and generating a dimming signal based on the power saving mode signal;driving a backlight unit based on a lamp drive voltage corresponding to the dimming signal to irradiate light to the liquid crystal panel; andsupplying image signals based on the four-color data to the liquid crystal panel to display a corresponding image on the liquid crystal panel.

41. The method of claim 40, wherein detecting the amount of ambient light comprises setting the power saving mode signal to a high state when the ambient light amount is greater than or equal to about a level of a reference signal and setting the power saving mode signal to about a low state when the ambient light amount is smaller than about the level of the reference signal.

42. The method according to claim 41, wherein setting the gain value comprises: generating control signals that control a panel driver using external input synchronous signals;setting the gain value based on the power saving mode signal and converting the external three-color input data into the four-color data based on the set gain value; andgenerating the dimming signal using white data of the four-color data and the power saving mode signal.

43. The method of claim 42, wherein converting the external three-color input data into the four-color data comprises: setting the gain value to a range of about 1 to 2 when the power saving mode signal assumes the high state and to a rational number greater than or equal to about two when the power saving mode signal assumes the low state;multiplying each of the external three-color input data by the gain value to generate three-color amplified data;extracting the white data from the three-color amplified data; andsubtracting the white data from each of the three-color amplified data to generate three-color data,wherein the four-color data includes the three-color data and the white data.

44. The method of claim 42, wherein converting the external three-color input data into the four-color data comprises: setting the gain value to a range of about 1 to 2 when the power saving mode signal assumes the high state and to a rational number greater than or equal to about two when the power saving mode signal assumes the low state;gamma correcting the three-color input data to generate linearized primary three-color data;separating the primary three-color data into a brightness component and color components;multiplying the separated brightness component by the gain value to generate an amplified brightness component;mixing the amplified brightness component and the separated color components to generate secondary three-color data; andgamma correcting the secondary three-color data to generate three-color data and gamma correcting the amplified brightness component to generate the white data,wherein the four-color data includes the three-color data and the white data.

45. The method of claim 42, wherein converting the external three-color input data into the four-color data comprises: setting the gain value to a range of about 1 to 2 when the power saving mode signal assumes the high state and to a rational number greater than or equal to about two when the power saving mode signal assumes the low state;multiplying each of the external three-color input data by the gain value to generate three-color amplified data;extracting the white data from the three-color amplified data;subtracting the white data from each of the three-color amplified data to generate three-color data; andselectively outputting the three-color data in response to the power saving mode signal using a selector,wherein the four-color data includes the three-color data and the white data.

46. The method of claim 45, further comprising outputting, by the selector, the three-color data when the power saving mode signal assumes the high state and not outputting the three-color data when the power saving mode signal assumes the low state.

47. The method of claim 46, further comprising displaying a black and white image based on the white data on the liquid crystal panel when the liquid crystal panel is in the power saving mode corresponding to the power saving mode signal of the low state.

48. The method of claim 42, wherein converting the external three-color input data into the four-color data comprises: setting the gain value to a range of about 1 to 2 when the power saving mode signal assumes the high state and to a rational number greater than or equal to about two when the power saving mode signal assumes the low state;gamma correcting the three-color input data using a first gamma corrector to generate linearized primary three-color data;separating the primary three-color data into a brightness component and color components;multiplying the separated brightness component by the gain value to generate an amplified brightness component;mixing the amplified brightness component and the separated color components to generate secondary three-color data;selectively outputting the secondary three-color data in response to the power saving mode signal using a selector; andgamma correcting the secondary three-color data from the selector using a second gamma corrector to generate three-color data and gamma correcting the amplified brightness component using the second gamma corrector to generate the white data,wherein the four-color data includes the three-color data and the white data.

49. The method of claim 48, further comprising supplying, by the selector, the three-color data to the second gamma corrector when the power saving mode signal assumes the high state and not supplying the three-color data to the second gamma corrector when the power saving mode signal assumes the low state.

50. The method of claim 49, further comprising displaying a black and white image based on the white data on the liquid crystal panel when the liquid crystal panel is in the power saving mode corresponding to the power saving mode signal of the low state.

51. The method of claim 42, wherein generating the dimming signal comprises: extracting a first dimming value corresponding to the white data from a set dimming curve;supplying a second dimming value fixed or arbitrarily set by a user to reduce power consumption of the backlight unit; andoutputting the first dimming value as the dimming signal when the power saving mode signal assumes the high state and the second dimming value as the dimming signal when the power saving mode signal assumes the low state.

52. The method according to claim 51, wherein the dimming curve comprises any one of a linear curve shape, a quadratic curve shape or a diagonal shape set between about a minimum dimming value and about a maximum dimming value.