Brightness compensation apparatus and application method thereof
For improving the brightness decay of a display due to its aging, a non-volatile memory such as Flash can be used to store a brightness accumulation value of each point of the display, and each point can be compensated for its brightness accordingly. However, the non-volatile memory suffers from incorrect write-in data or temporary power disconnection, and thus the error will exist all the time to make the display non-even. Hence, the present invention uses a multiple data backups and CRC error detection, plus new/old data comparison to protect data the non-volatile memory from incorrect brightness compensation value so as to uniform the brightness of the display.
1. An brightness compensation apparatus in uniformity, for cooperating with a driver IC to drive a display, comprising:
a volatile memory, for storing a color/brightness accumulation value of each pixel on the display;
a non-volatile memory, for preventing a missing for the color/brightness accumulation value;
a calculating unit, for accumulating the color/brightness accumulation value for the each pixel; and
a detector means, coupled to the calculating unit and the non-volatile memory, for checking the color/brightness accumulation value outputted from the calculating unit with the color/brightness accumulation value stored in the non-volatile memory, wherein if the checking process appears to be correct, the detector means further allows the color/brightness accumulation value outputted from the calculating unit and the color/brightness accumulation value stored in the non-volatile memory are respectively written in the non-volatile memory and the volatile memory so as to uniform a brightness of the display,
wherein the non-volatile memory is divided into a first area and a plurality of second areas, and a capacity of the first area is greater than an average capacity of the plurality of the second areas, and wherein the first area stores a data detecting code for checking if data obtained from the first area are correct; and
wherein the detector means follows an equation of Y−X<K, and wherein Y is a new color brightness accumulation value for being written into the non-volatile memory, X is an original color brightness accumulation value in the non-volatile memory, and K is a maximum difference between two contiguous color brightness accumulation values in a specific time frame.
2. The apparatus as recited in claim 1 , wherein the volatile memory is a dynamic RAM.
3. The apparatus as recited in claim 1 , wherein the volatile memory is a static RAM.
4. The apparatus as recited in claim 1 , wherein the non-volatile memory is a flash memory.
5. The apparatus as recited in claim 1 , wherein the first area is used for further storing a complete data of the color/brightness accumulation or high-bit data of the color/brightness accumulation.
6. The apparatus as recited in claim 1 , wherein the second area is used for storing low-bit data of the color/brightness accumulation.
7. The apparatus as recited in claim 1 , wherein the calculating unit is accumulating the color/brightness accumulation value for the each pixel in two-section format such as high-bit data and low-bit data.
8. The apparatus as recited in claim 6 , wherein each of the second areas further stores a data detecting code for checking if data obtained from the second areas are correct.
9. The apparatus as recited in claim 1 , wherein the non-volatile memory is further divided into an extra third area identical to the first area in their sizes to serve as a backup copy for the first area.
10. The apparatus as recited in claim 1 , wherein the plurality of adjacent second areas can be backup copies for each other.
11. The apparatus as recited in claim 1 , wherein the data detecting code in the first area is a CRC code.
12. The apparatus as recited in claim 8 , wherein the data detecting code in the second areas is a CRC code.
13. An brightness compensation apparatus in uniformity, for cooperating with a driver IC to drive a display, comprising:
a volatile memory, for storing a color/brightness accumulation value of each pixel on the display;
a non-volatile memory, for preventing a missing for the color/brightness accumulation value;
a calculating unit, for accumulating the color/brightness accumulation value for the each pixel; and
a detector means, coupled to the calculating unit and the non-volatile memory, for checking the color/brightness accumulation value outputted from the calculating unit with the color/brightness accumulation value stored in the non-volatile memory, wherein if the checking process appears to be correct, the detector means further allows the color/brightness accumulation value outputted from the calculating unit and the color/brightness accumulation value stored in the non-volatile memory are respectively written in the non-volatile memory and the volatile memory so as to uniform a brightness of the display,
wherein the non-volatile memory is divided into a first area and a plurality of second areas, and a capacity of the first area is greater than an average capacity of the plurality of the second areas, and wherein the first area stores a data detecting code for checking if data obtained from the first area are correct; and
wherein the detector means follows an equation of Y<X; and wherein Y is a new color brightness accumulation value for being written into the non-volatile memory, X is an original color brightness accumulation value in the non-volatile memory.
14. A method for enacting a color/brightness accumulation in unanimity in a writing-in or reading-out process, comprising steps of:
(a) providing a brightness compensation apparatus having a non-volatile memory, said brightness compensation apparatus cooperates with an driver IC to drive a display;
(b) dividing the non-volatile memory in the brightness compensation apparatus into at least a first area and a plurality of second areas 1˜n, where n is an integer greater than zero and the first area is for storing the color/brightness accumulation or high-bit data of the color/brightness accumulation, and the second area 1˜n are for storing low-bit data of the color/brightness accumulation;
(c) writing the color/brightness accumulation or the high-bit data of the color/brightness accumulation in the first area;
(d) writing the low-bit data of the color/brightness accumulation in the second areas;
(e) judging if the display functions properly, if yes, go to s 502 or s 503 ; if no, awaiting the display re-boots;
(f) after the display re-boots, obtaining the low-bit data of the color/brightness accumulation from a last write-in area such as a second area j where j is an integer between 1˜n, and meanwhile obtaining a complete data of the color/brightness accumulation or the high-bit data of the color/brightness accumulation; s 506 :
judging if there exists errors in the low-bit data; and
(g) if any error, obtaining the low-bit data of the color/brightness accumulation from the second area j−1.
15. The method as recited in claim 14 , wherein the step (a) further comprises, dividing the non-volatile memory into an extra third area, where the extra third area serves the purpose for a backup for the first area.
16. The method as recited in claim 15 , further comprising steps of:
(h) judging if there exists errors in the complete data of the color/brightness accumulation or the high-bit data stored in the first area; and
(i) if there does, obtaining the color/brightness accumulation or the high-bit data of the color/brightness accumulation from the third area.
17. The method as recited in claim 14 , wherein the area(s) have a plurality of sectors.
18. The method as recited in claim 17 , wherein each of the sectors has an error detecting code.
19. The method as recited in claim 18 , wherein the error detecting code is a CRC code.
20. The method as recited in claim 14 , wherein there is further included a carry virtual bit in the second areas.
21. The method as recited in claim 14 , wherein the non-volatile memory is a flash memory.