Liquid crystal display controller
View Patent ↗The present invention provides a liquid crystal display controller device and method which provides for a full and/or partial display with good display quality and/or low power consumption based on the scanning period for an active scan line being dependent upon a number of reference clock pulses. Some embodiments of the present invention include one or more of the following features: keeping the frequency substantially constant for different numbers of active scan lines, allowing change of the frequency due to characteristics of the LCD, displaying gradation with near linear effective voltage characteristics, displaying graduation data with lower power, or displaying a partial or full screen in a mobile device, for example, a cell phone.
1. A module comprising:
a display panel; and
a display control device capable of adjusting a frame frequency of the display panel, the display control device comprising:
an interface which receives display data from an external device to be coupled to the display module;
a memory which stores the display data;
a register capable of storing from the external device a division ratio, a number of a second clock signal per a scanning period, and a number of active lines of the display panel;
a signal generator which divides a first clock signal by the division ratio to generate the second clock signal, and which generates a signal having the frame frequency based on the second clock signal, the number of the second clock signal per the scanning period and the number of active lines of the display panel stored in the register;
a voltage generator which generates a plurality of driving voltage signals, and
a data line driver which converts the display data into one of the plurality of driving voltage signals generated by the voltage generator to be provided to the display panel according to the frame frequency.
2. A module according to the claim 1 ,
wherein the display control device further comprises:
a clock generator which provides the first clock signal using an oscillator.
3. A module according to the claim 1 ,
wherein the signal generator generates a signal synchronized with the scanning period based on the second clock signal and the stored number of the second clock signal per the scanning period, and
wherein the display control device further comprises:
a scanning line driver which provides a selecting voltage to scan the active lines on the display panel according to the scanning period.
4. A module comprising:
a display panel on which a plurality of data lines and a plurality of scanning lines are arranged in a matrix;
a display controller coupled to the display panel, the display controller comprising:
a first generator configured to generate an original clock signal;
a memory configured to store display data received from an external processor to be coupled to the display controller;
a register configured to set a division ratio of the original clock signal, a number of clock of a reference clock signal per a scanning period and a number of active lines of the display panel, all of which can be changed by the external processor;
a second generator configured to divide the original clock signal by the division ratio to generate the reference clock and to generate a signal having a frame period based on the division ratio of the original clock signal, the number of clocks of a reference clock signal per a scanning period and the number of active lines of the display panel;
a data line driver configured to convert the display data from the memory into a driving voltage to be provided to the display panel; and
a scanning line driver for providing a selecting voltage to scan the active lines in the scanning lines of the display panel according to the scanning period.
5. A module according to the claim 4 ,
wherein the display controller is one chip.
6. A cellular phone comprising:
a processor;
a display panel; and
a display control device coupled to the processor and the display panel and capable of adjusting a frame frequency of the display panel, the display control device comprising:
an interface which receives display data from the processor;
a memory which stores the display data;
a register capable of storing from the processor a division ratio, a number of a second clock signal per a scanning period, and a number of active lines of the display panel;
a signal generator which divides the first clock signal by the division ratio to generate the second clock signal, and which generates a signal having the frame frequency based on the second clock signal, the number of the second clock signal per the scanning period and the number of active lines of the display panel stored in the register;
a voltage generator which generates a plurality of driving voltage signals, and
a data line driver which converts the display data into one of the plurality of driving voltage signals generated by the voltage generator to be provided to the display panel according to the frame frequency.
7. A cellular phone according to the claim 6 , wherein the display control device further comprises:
a clock generator which provides the first clock signal using an oscillator.
8. A cellular phone according to the claim 6 ,
wherein the signal generator generates a signal synchronized with the scanning period based on the second clock signal and the stored number of the second clock signal per the scanning period, and
wherein the display control device further comprises:
a scanning line driver which provides a selecting voltage to scan the active lines on the display panel according to the scanning period.
9. A cellular phone comprising:
a processor;
a display panel on which a plurality of data lines and a plurality of scanning lines are arranged in a matrix;
a display controller coupled to the processor and the display panel, the display controller comprising:
a first generator for generating an original clock signal;
a memory for storing display data received from the processor to the display controller;
a register for setting a division ratio of the original clock signal, a number of clock of a reference clock signal per a scanning period and a number of active lines of the display panel, all of which can be changed by the processor;
a second generator for dividing the original clock signal by the division ratio to generate the reference clock and to generate a signal having a frame period based on the division ratio of the original clock signal, the number of clocks of a reference clock signal per a scanning period and the number of active lines of the display panel;
a data line driver for converting the display data from the memory into a driving voltage to be provided to the display panel; and
a scanning line driver for providing a selecting voltage to scan the active lines in the scanning lines of the display panel according to the scanning period.
10. A cellular phone according to the claim 9 ,
wherein the display controller is one chip.
11. A module comprising:
a display panel having scanning lines and data lines; and
a display control device capable of adjusting a frame frequency of the display panel, the display control device comprising:
an interface which receives display data from an external device to be coupled to the display module;
a memory which stores the display data;
a register configured to store from the external device a number of a first clock signal per a scanning period, and a number of active lines which corresponds to selected ones of the scanning lines of the display panel to be driven;
a signal generator which generates a signal having the frame frequency based on the first clock signal, a division ratio, the number of the first clock signal per the scanning period and the number of active lines of the display panel stored in the register;
a voltage generator which generates a plurality of driving voltage signals, and
a data line driver which converts the display data into one of the plurality of driving voltage signals generated by the voltage generator to be provided to the data lines of the display panel according to the frame frequency.
12. A module according to the claim 11 ,
wherein the display control device further comprises:
a clock generator which provides an original clock signal using an oscillator,
wherein the register further stores the division ratio which is written from the external device, and
wherein the signal generator divides the original clock signal by the division ratio to generate the first clock signal.
13. A module according to the claim 11 ,
wherein the signal generator generates a signal synchronized with the scanning period based on the first clock signal and the stored number of the first clock signal per the scanning period, and
wherein the display control device further comprises:
a scanning line driver which provides a selecting voltage to scan the active lines on the display panel according to the scanning period.
14. A module comprising:
a display panel on which a plurality of data lines and a plurality of scanning lines are arranged in a matrix;
a display controller coupled to the display panel, the display controller comprising:
a memory configured to store display data received from an external processor to be coupled to the display controller;
a register configured to set a number of clock of a reference clock signal per a scanning period and a number of active lines which corresponds to selected ones of the scanning lines of the display panel, all of which can be changed by the external processor;
a generator configured to generate a signal having a frame period based on a division ratio, the number of clocks of the reference clock signal per a scanning period and the number of active lines of the display panel; and
a data line driver configured to convert the display data from the memory into a driving voltage to be provided to the plurality of data lines of the display panel; and
a scanning line driver configured to provide a selecting voltage to scan the active lines in the plurality of scanning lines of the display panel according to the scanning period.
15. A module according to the claim 14 ,
wherein the display controller is one chip.
16. A cellular phone comprising:
an external device;
a display panel; and
a display control device coupled to the external device and the display panel and capable of adjusting a frame frequency of the display panel, the display control device comprising:
an interface which receives display data from the external device;
a memory which stores the display data;
a register configured to store from the external device a number of a first clock signal per a scanning period, and a number of active lines which corresponds to selected ones of the scanning lines of the display panel;
a signal generator which generates a signal having the frame frequency based on a division ratio, the number of the first clock signal per the scanning period and the number of active lines of the display panel stored in the register;
a voltage generator which generates a plurality of driving voltage signals, and
a data line driver which converts the display data into one of the plurality of driving voltage signals generated by the voltage generator to be provided to data lines of the display panel according to the frame frequency.
17. A cellular phone according to the claim 16 ,
wherein the display control device further comprises:
a clock generator which provides an original clock signal using an oscillator,
wherein the register further stores the division ratio which is written from the external device, and
wherein the signal generator divides the original clock signal by the division ratio to generate the first clock signal.
18. A cellular phone according to the claim 16 ,
wherein the signal generator generates a signal synchronized with the scanning period based on the first clock signal and the stored number of the first clock signal per the scanning period, and
wherein the display control device further comprises:
a scanning line driver which provides a selecting voltage to scan the active lines on the display panel according to the scanning period.
19. A cellular phone comprising:
a processor;
a display panel on which a plurality of data lines and a plurality of scanning lines are arranged in a matrix;
a display controller coupled to the processor and the display panel, the display controller comprising:
a memory for storing display data received from the processor to the display controller;
a register for setting a number of clock of a reference clock signal per a scanning period and a number of active lines which corresponds to selected ones of the plurality of scanning lines of the display panel, all of which can be changed by the processor;
a generator for generating a signal having a frame period based on a division ratio, the number of clocks of the reference clock signal per a scanning period and the number of active lines of the display panel;
a data line driver for converting the display data from the memory into a driving voltage to be provided to the display panel; and
a scanning line driver for providing a selecting voltage to scan the active lines in the scanning lines of the display panel according to the scanning period.
20. A cellular phone according to the claim 19 ,
wherein the display controller is one chip.