1. A two-terminal current controller for controlling a first current passing through a load, wherein:
during a rising period of a rectified alternative-current (AC) voltage when a voltage established across the load does not exceed a first voltage, the two-terminal current controller operates in a first mode;
during the rising period when the voltage established across the load exceeds the first voltage but does not exceed a second voltage, the two-terminal current controller operates in a second mode; and
during the rising period when the voltage established across the load exceeds the second voltage, the two-terminal current controller operates in a third mode;
during the rising period when the voltage established across the load drops to a third voltage smaller than the second voltage after exceeding the second voltage, the two-terminal current controller is configured to:
operate in the second mode when a difference between the second and third voltages exceeds a first hysteresis band; and
operate in the third mode when a difference between the second and third voltages does not exceed the first hysteresis band; and
the two-terminal current controller includes:
a current limiting unit configured to:
conduct a second current associated with the rectified AC voltage, regulate the second current according to the voltage established across the load and maintain the first current at zero when the two-terminal current controller operates in the first mode;
conduct the second current, maintain the second current at a predetermined value larger than zero and maintain the first current at zero when the two-terminal current controller operates in the second mode; and
switch off when the two-terminal current controller operates in the third mode; and
an adjusting unit configured to adjust the predetermined value and the second voltage.
2. The two-terminal current controller of claim 1, wherein when the voltage established across the two-terminal current controller becomes smaller than a fourth voltage but is larger than the first voltage during a falling period of the rectified AC voltage, the two-terminal current controller operates in the second mode for maintaining the first current at substantially zero and setting the second current to the predetermined value, and the fourth voltage is larger than the second voltage.
3. The two-terminal current controller of claim 2, wherein when the voltage established across the two-terminal current controller becomes larger than a fifth voltage which is larger than the fourth voltage after becoming smaller than the fourth voltage during the falling period of the rectified AC voltage, the two-terminal current controller is configure to:
operate in the third mode when a difference between the fourth and fifth voltages exceeds a second hysteresis band; and
operate in the second mode when a difference between the fourth and fifth voltages does not exceed the second hysteresis band.
4. The two-terminal current controller of claim 3, wherein the current limiting unit comprises:
a first switch configured to conduct the second current according to a control signal;
a band-gap reference voltage generator configured to provide a band-gap reference voltage;
a first voltage-dividing circuit configured to provide a first reference voltage and a second reference voltage by voltage-dividing the band-gap reference voltage;
a second voltage-dividing circuit configured to provide a sixth voltage and a seventh voltage by voltage-dividing the rectified AC voltage;
a current-detecting circuit coupled in series to the first switch and configured to detect the second current and provide a corresponding feedback voltage;
a voltage edge-detecting circuit configured to determine whether the rectified AC voltage is during the rising period or the falling period;
a comparator configured to provide the control signal according to a relationship between the first reference voltage and the feedback voltage, the second voltage, the fourth voltage and a determining result of the voltage edge-detecting circuit;
a first hysteresis comparator configured to provide the fourth voltage according to a relationship between the second reference voltage and the sixth voltage; and
a second hysteresis comparator configured to provide the second voltage according to a relationship between the second reference voltage and the seventh voltage.
5. The two-terminal current controller of claim 4, wherein the adjusting unit includes:
a resistor coupled in parallel with the first voltage-dividing circuit for adjusting the first reference voltage and the second reference voltage.
6. The two-terminal current controller of claim 4, wherein the adjusting unit includes:
a resistor; and
a fuse coupled in parallel with the resistor for coupling the resistor in parallel with the first voltage-dividing circuit when burned, thereby adjusting the first reference voltage and the second reference voltage.
7. The two-terminal current controller of claim 4, wherein the adjusting unit includes:
a resistor; and
a fuse coupled in series to the resistor for coupling the resistor in parallel with the first voltage-dividing circuit when unburned, thereby adjusting the first reference voltage and the second reference voltage.
8. The two-terminal current controller of claim 4 wherein the current-detecting circuit comprises:
a resistor coupled to the first switch for providing the feedback voltage according to the second current; and
a second switch coupled in parallel to the resistor for adjusting an effective impedance of the resistor.
9. The two-terminal current controller of claim 4, wherein:
during the falling period when the voltage established across the load does not exceed the first voltage, the first switch is configured to regulate the second current according to the control signal; and
during the falling period when the voltage established across the load exceeds the first voltage but does not exceed the fourth voltage, the first switch is configured to maintain the second current at the predetermined value according to the control signal and maintain the first current at zero.
10. The two-terminal current controller of claim 9, wherein the two-terminal current controller is configured to regulate the second current according to the voltage established across the load, so that a relationship between the voltage established across the load and the second current matches a characteristic when the first switch operates in a specific operational region.
11. The two-terminal current controller of claim 1, wherein the current limiting unit comprises:
a first switch configured to conduct the second current according to a control signal;
a band-gap reference voltage generator configured to provide a band-gap reference voltage;
a first voltage-dividing circuit configured to provide a first reference voltage and a second reference voltage by voltage-dividing the band-gap reference voltage;
a second voltage-dividing circuit configured to provide a fourth voltage by voltage-dividing the rectified AC voltage;
a current-detecting circuit coupled in series to the first switch and configured to detect the second current and provide a corresponding feedback voltage;
a voltage edge-detecting circuit configured to determine whether the rectified AC voltage is during the rising period or the falling period;
a first comparator configured to provide the control signal according to a relationship between the first reference voltage and the feedback voltage, the second voltage, the third voltage and a determining result of the voltage edge-detecting circuit; and
a second hysteresis comparator configured to provide the second voltage according to a relationship between the second reference voltage and the fourth voltage.
12. The two-terminal current controller of claim 11, wherein the adjusting unit includes:
a resistor; and
a fuse coupled in parallel with the resistor for coupling the resistor in parallel with the first voltage-dividing circuit when burned, thereby adjusting the first reference voltage and the second reference voltage.
13. The two-terminal current controller of claim 11, wherein the adjusting unit includes:
a resistor; and
a fuse coupled in series to the resistor for coupling the resistor in parallel with the first voltage-dividing circuit when unburned, thereby adjusting the first reference voltage and the second reference voltage.
14. The two-terminal current controller of claim 11 wherein the current-detecting circuit comprises:
a resistor coupled to the first switch for providing the feedback voltage according to the second current; and
a second switch coupled in parallel to the resistor for adjusting an effective impedance of the resistor.
15. The two-terminal current controller of claim 11, wherein:
during the rising period when the voltage established across the load does not exceed the first voltage, the switch is configured to regulate the second current according to the control signal; and
during the rising period when the voltage established across the load exceeds the first voltage, the switch is configured to maintain the second current at the predetermined value according to the control signal.
16. The two-terminal current controller of claim 1, wherein a barrier voltage for turning on the two-terminal current controller is smaller than a barrier voltage for turning on the load.
17. A light-emitting diode (LED) lighting device with overvoltage protection, comprising:
a first luminescent device for providing light according to a first current;
a second luminescent device coupled in series to the first luminescent device for providing light according to a second current;
a first impedance device for limiting the first current or the second current within a first predetermined range when a voltage established across the first luminescent device and the second luminescent device exceeds a first predetermined value;
a first two-terminal current controller coupled in parallel to the first luminescent device and in series to the second luminescent device and configured to regulate the second current according to a voltage established across the two-terminal current controller, wherein:
during a rising period of a rectified AC voltage when the voltage established across the two-terminal current controller does not exceed a first voltage, the first two-terminal current controller operates in a first mode;
during the rising period when the voltage established across the two-terminal current controller exceeds the first voltage but does not exceed a second voltage, the first two-terminal current controller operates in a second mode;
during the rising period when the voltage established across the two-terminal current controller exceeds the second voltage, the first two-terminal current controller operates in a third mode; and
the first two-terminal current controller includes:
a current limiting unit configured to:
conduct a third current associated with the rectified AC voltage, regulate the third current according to the voltage established across the first luminescent device and maintain the first current at zero when the first two-terminal current controller operates in the first mode;
conduct the third current, maintain the third current at a second predetermined value larger than zero and maintain the first current at zero when the first two-terminal current controller operates in the second mode; and
switch off for equalizing the first current and the second current when the first two-terminal current controller operates in the third mode; and
an adjusting unit configured to adjust the second predetermined value and the second voltage.
18. The LED lighting device of claim 17, wherein when the voltage established across the first two-terminal current controller is larger than the first voltage and does not exceed a third voltage during a falling period of the rectified AC voltage, the first two-terminal current controller is turned on for maintaining the first current at substantially zero and setting the second current and the third current to the second predetermined value, and the third voltage is larger than the second voltage.
19. The LED lighting device of claim 18, wherein the current limiting unit comprises:
a first switch configured to conduct the third current according to a control signal;
a band-gap reference voltage generator configured to provide a band-gap reference voltage;
a first voltage-dividing circuit configured to provide a first reference voltage and a second reference voltage by voltage-dividing the band-gap reference voltage;
a second voltage-dividing circuit configured to provide a fourth voltage and a fifth voltage by voltage-dividing the rectified AC voltage;
a current-detecting circuit coupled in series to the switch and configured to detect the third current and provide a corresponding feedback voltage;
a voltage edge-detecting circuit configured to determine whether the rectified AC voltage is during the rising period or the falling period;
a first comparator configured to provide the control signal according to a relationship between the first reference voltage and the feedback voltage, the second voltage, the third voltage and a determining result of the voltage edge-detecting circuit;
a second comparator configured to provide the second voltage according to a relationship between the second reference voltage and the fourth voltage; and
a third comparator configured to provide the third voltage according to a relationship between the second reference voltage and the fifth voltage.
20. The LED lighting device of claim 19, wherein the adjusting unit includes:
a resistor coupled in parallel with the first voltage-dividing circuit for adjusting the first reference voltage and the second reference voltage.
21. The LED lighting device of claim 19, wherein the adjusting unit includes:
a resistor; and
a fuse coupled in parallel with the resistor for coupling the resistor in parallel with the first voltage-dividing circuit when burned, thereby adjusting the first reference voltage and the second reference voltage.
22. The LED lighting device of claim 19, wherein the adjusting unit includes:
a resistor; and
a fuse coupled in series to the resistor for coupling the resistor in parallel with the first voltage-dividing circuit when unburned, thereby adjusting the first reference voltage and the second reference voltage.
23. The LED lighting device of claim 19, wherein the current-detecting circuit comprises:
a resistor coupled to the first switch for providing the feedback voltage according to the third current; and
a second switch coupled in parallel to the resistor for adjusting an effective impedance of the resistor.
24. The LED lighting device of claim 19, wherein:
during the falling period when the voltage established across the first two-terminal current controller does not exceed the first voltage, the first switch is configured to regulate the third current according to the control signal; and
during the falling period when the voltage established across the first two-terminal current controller exceeds the first voltage but does not exceed the third voltage, the first switch is configured to maintain the third current at the second predetermined value according to the control signal and maintain the first current at zero.
25. The LED lighting device of claim 24, wherein the first two-terminal current controller is configured to regulate the third current according to the voltage established across the first luminescent device, so that a relationship between the voltage established across the first luminescent device and the second current matches a characteristic when the first switch operates in a specific operational region.
26. The LED lighting device of claim 17, wherein the current limiting unit comprises:
a first switch configured to conduct the third current according to a control signal;
a band-gap reference voltage generator configured to provide a band-gap reference voltage;
a first voltage-dividing circuit configured to provide a first reference voltage and a second reference voltage by voltage-dividing the band-gap reference voltage;
a second voltage-dividing circuit configured to provide a third voltage by voltage-dividing the rectified AC voltage;
a current-detecting circuit coupled in series to the first switch and configured to detect the third current and provide a corresponding feedback voltage;
a voltage edge-detecting circuit configured to determine whether the rectified AC voltage is during the rising period or the falling period;
a first comparator configured to provide the control signal according to a relationship between the first reference voltage and the feedback voltage, the second voltage and a determining result of the voltage edge-detecting circuit; and
a second comparator configured to provide the second voltage according to a relationship between the second reference voltage and the third voltage.
27. The LED lighting device of claim 26, wherein the adjusting unit includes:
a resistor coupled in parallel with the first voltage-dividing circuit for adjusting the first reference voltage and the second reference voltage.
28. The LED lighting device of claim 26, wherein the adjusting unit includes:
a resistor; and
a fuse coupled in parallel with the resistor for coupling the resistor in parallel with the first voltage-dividing circuit when burned, thereby adjusting the first reference voltage and the second reference voltage.
29. The LED lighting device of claim 26, wherein the adjusting unit includes:
a resistor; and
a fuse coupled in series to the resistor for coupling the resistor in parallel with the first voltage-dividing circuit when unburned, thereby adjusting the first reference voltage and the second reference voltage.
30. The LED lighting device of claim 26, wherein the current-detecting circuit comprises:
a resistor coupled to the first switch for providing the feedback voltage according to the third current; and
a second switch coupled in parallel to the resistor for adjusting an effective impedance of the resistor.
31. The LED lighting device of claim 26, wherein:
during the rising period when the voltage established across the first two-terminal current controller does not exceed the first voltage, the first switch is configured to regulate the third current according to the control signal; and
during the rising period when the voltage established across the first two-terminal current controller exceeds the first voltage, the first switch is configured to maintain the third current at the second predetermined value according to the control signal.
32. The LED lighting device of claim 17, wherein a barrier voltage for turning on the two-terminal current controller is smaller than a barrier voltage for turning on the first luminescent device.
33. The LED lighting device of claim 17, wherein each luminescent device includes a plurality of LEDs coupled in series.
34. The LED lighting device of claim 17, wherein the first impedance device includes a resistor, capacitor, a constant current source integrated circuit, or a constant current sink integrated circuit.
35. The LED lighting device of claim 17, wherein the first impedance device is coupled in series to the first luminescent device and the second luminescent device.
36. The LED lighting device of claim 35 wherein the first two-terminal current controller is coupled in parallel to the serially-coupled first luminescent device and the first impedance device.
37. The LED lighting device of claim 35, further comprising:
a second two-terminal current controller coupled in series to the first two-terminal current controller and the second luminescent device and configured to regulate the second current according to a voltage established across the second two-terminal current controller, wherein the first impedance device is coupled in parallel to the second two-terminal current controller.
38. The LED lighting device of claim 17, further comprising:
a third luminescent device coupled in series to the first luminescent device and the second luminescent device for providing light according to a fourth current;
a second two-terminal current controller coupled in parallel to the third luminescent device and in series to the first two-terminal current controller and the second luminescent device and configured to regulate the second current according to a voltage established across the second two-terminal current controller;
a second impedance device for limiting the fourth current within a second predetermined range when a voltage established across the first to third luminescent devices exceeds a third predetermined value, wherein:
the first impedance device is coupled in parallel to the first two-terminal current controller and coupled in series to the first luminescent device; and
the second impedance device is coupled in parallel to the second two-terminal current controller and coupled in series to the second luminescent device.
39. The LED lighting device of claim 35, wherein the first impedance device comprises:
a second two-terminal current controller coupled in series to the first two-terminal current controller and configured to regulate the second current according to a voltage established across the second two-terminal current controller.
40. The LED lighting device of claim 17, further comprising:
a third luminescent device coupled in series to the first luminescent device and the second luminescent device for providing light according to a fourth current;
a second two-terminal current controller coupled in parallel to the third luminescent device and in series to the first two-terminal current controller and the fourth luminescent device and configured to regulate the second current according to a voltage established across the second two-terminal current controller;
wherein the first impedance device comprises a third two-terminal current controller coupled in series to the first two-terminal current controller and the second two-terminal current controller, and configured to regulate the fourth current according to a voltage established across the third two-terminal current controller.
41. The LED lighting device of claim 17 further comprising a power supply circuit configured to provide the rectified AC voltage for driving the first luminescent device and the second luminescent device.
42. The LED lighting device of claim 41 wherein the power supply circuit includes an AC-AC voltage converter.
43. The LED lighting device of claim 17, wherein the first luminescent device, the second luminescent device, the first impedance device, the first two-terminal current controller and the adjusting unit are disposed on a same circuit board.
44. The LED lighting device of claim 17, further comprising:
a silicon-controlled rectifier coupled in parallel to the first luminescent device and configured to:
conduct a fourth current when a voltage established across the first luminescent device exceeds a break-over voltage; or
switch off when the voltage established across the first luminescent device does not exceed the break-over voltage.
45. The LED lighting device of claim 44, wherein the first luminescent device, the second luminescent device, the first impedance device, the first two-terminal current controller, the adjusting unit and the silicon-controlled rectifier are disposed on a same circuit board.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A liquid crystal display comprising:
a first substrate including a plurality of pixels arranged in m columns by n rows;
n data lines disposed on the first substrate;
m gate lines arranged substantially parallel to the data lines;
n data distribution lines arranged to cross the m gate lines and electrically connected to the data lines, respectively;
source driving chips disposed on a first portion of the first substrate; and
a gate driver disposed on a second portion of the first substrate, which is opposite to the first portion of the first substrate,
wherein each of the data distribution lines is electrically connected to a subset of the pixels arranged in a corresponding row, each of the gate lines is connected to a subgroup of the pixels arranged in a corresponding column, the source driving chips apply data signals to the pixels through the data lines and the data distribution lines, and the gate driver applies gate signals to the pixels through the gate lines.
2. The liquid crystal display of claim 1, wherein the gate driver comprises m amorphous silicon gate circuits each of which applies a gate signal to a corresponding subgroup of the pixels through a corresponding gate line of the gate lines.
3. The liquid crystal display of claim 2, wherein the amorphous silicon gate circuits are disposed on a lower portion of the first substrate.
4. The liquid crystal display of claim 1, wherein each of the pixels comprises a thin film transistor and a pixel electrode, and each of the data distribution lines is electrically connected to source electrodes of thin film transistors of a corresponding subset of the pixels arranged in the corresponding row.
5. The liquid crystal display of claim 4, wherein each of the gate lines is connected to gate electrodes of thin film transistors of a corresponding subgroup of the pixels arranged in the corresponding column.
6. The liquid crystal display of claim 1, wherein the source driving chips are disposed on an upper portion of the first substrate, the gate driver is disposed on a lower portion of the first substrate, and a distance between a left edge of the first substrate and a pixel of the plurality of pixels is less than or equal to 1mm.
7. The liquid crystal display of claim 2, wherein the first substrate comprises:
a first base substrate on which the data lines and the gate lines are disposed such that the data lines are spaced apart from the gate lines;
a gate insulating layer disposed on the first base substrate to cover the data lines and the gate lines; and
column spacers disposed on the gate insulating layer, each of the column spacers overlapping a corresponding data line of the data lines and overlapping a corresponding gate line of the gate lines.
8. The liquid crystal display of claim 7, wherein the data lines comprises a same metal material as the gate lines.
9. The liquid crystal display of claim 7, further comprising:
a second substrate facing the first substrate; and
a liquid crystal layer disposed between the first substrate and the second substrate and including liquid crystal molecules, where the column spacer has a dielectric constant lower than a dielectric constant of the liquid crystal molecules.
10. The liquid crystal display of claim 7, wherein the column spacer comprises an epoxy-based acrylic resin.
11. The liquid crystal display of claim 7, wherein each of the data lines is spaced apart from a corresponding gate line of the gate lines by a distance equal to or greater than four micrometers.
12. The liquid crystal display of claim 2, wherein
the first substrate comprises:
a first base substrate;
a first branch portion branched from a corresponding data line of the data lines in a row direction and disposed on the first base substrate;
a gate insulating layer disposed on the first base substrate to cover the first branch portion;
a second branch portion branched from a corresponding data distribution line of the data distribution lines in a column direction and disposed on the gate insulating layer to be adjacent to the first branch portion;
an inter-insulating layer disposed on the gate insulating layer to cover the second branch portion; and
a bridge electrically connecting the first branch portion and the second branch portion,
a first hole is formed through the gate insulating layer and the inter-insulating layer to expose the first branch portion,
a second hole is formed through the inter-insulating layer to expose the second branch portion, and
the bridge includes portions disposed in the first hole, disposed in the second hole, and disposed on the inter-insulating layer between the first and second holes.
13. The liquid crystal display of claim 1, wherein
the first substrate comprises:
a first base substrate; and
a gate insulating layer, the data lines are disposed on the first base substrate,
the gate insulating layer is disposed on the first base substrate to cover the data lines,
the gate insulating layer includes contact holes that expose the data lines,
the data distribution lines include portions disposed in the contact holes and electrically connected to corresponding data lines of the data lines, respectively.
14. A liquid crystal display comprising:
a first substrate including a plurality of pixels arranged in m columns by n rows;
m data lines disposed on the first substrate;
n gate lines arranged substantially parallel to the data lines;
m data distribution lines arranged to cross the m gate lines and electrically connected to the data lines, respectively;
source driving chips disposed on a first portion of the first substrate; and
gate driving chips disposed on a second portion of the first substrate, which is opposite to the first portion of the first substrate,
wherein each of the data distribution lines is electrically connected to a subset of the pixels among the plurality of pixels arranged in a corresponding column, each of the gate lines is electrically connected to a subgroup of the pixels among the plurality of pixels arranged in a corresponding row, the source driving chips apply data signals to the pixels through the data lines and the data distribution lines, and the gate driving chips apply gate signals to the pixels through the gate lines.
15. The liquid crystal display of claim 14, wherein each of the pixels comprises a thin film transistor and a pixel electrode, and each of the data distribution lines is electrically connected to source electrodes of thin film transistors of a corresponding subset of the pixels arranged in the corresponding column.
16. The liquid crystal display of claim 15, wherein each of the gate lines is connected to gate electrodes of thin film transistors of a corresponding subgroup of the pixels arranged in the corresponding row.
17. The liquid crystal display of claim 14, wherein the source driving chips are disposed on a left portion of the first substrate, the gate driving chips are disposed on a right portion of the first substrate, and a distance between an upper edge of the first substrate and a pixel of the plurality of pixels is less than or equal to 1mm.
18. A liquid crystal display comprising:
a first substrate including a plurality of pixels arranged in m columns by n rows;
n2 data lines disposed on the first substrate;
2 m gate lines arranged substantially parallel to the data lines;
n2 data distribution lines arranged to cross the 2 m gate lines and electrically connected to the data lines, respectively;
source driving chips disposed on a first portion of the first substrate; and
a gate driver disposed on a second portion of the first substrate, which is opposite to the first portion,
wherein each of the data distribution lines is disposed between a subset of the pixels arranged in an odd-numbered row and a subset of the pixels arranged in an even-numbered row and electrically connected to the subsets of the pixels arranged in the odd- and even-numbered rows, each of the gate lines is electrically connected to a subgroup of the pixels arranged in a corresponding column, two gate lines adjacent to each other among the gate lines are respectively disposed at left and right sides of a same subgroup of the pixels arranged in a same column, one gate line of the two adjacent gate lines is electrically connected to odd-numbered pixels arranged in the same column, the other gate line of the two adjacent gate lines is connected to even-numbered pixels arranged in the same column, the source driving chips apply data signals to the pixels through the data lines and the data distribution lines, and the gate driver applies gate signals to the pixels through the gate lines.
19. The liquid crystal display of claim 18, wherein the gate driver comprises 2 m amorphous silicon gate circuits each of which applies a gate signal to corresponding pixels through a corresponding gate line of the gate lines.
20. The liquid crystal display of claim 19, wherein the amorphous silicon gate circuits are mounted on a lower portion of the first substrate.