Patent Application
20100013754
1. Technical Field
The present disclosure relates to a liquid crystal display (LCD) device.
2. Description of Related Art
Generally, an LCD device includes a plurality of scanning lines, a plurality of data lines and a plurality of thin-film transistors (TFTs). Source electrodes and gate electrodes of the TFTs are connected to the data lines and the gate lines, respectively. When one of the data line is broken, no signal is fed to the broken line, resulting in deterioration in the quality of displayed images. The broken line should be repaired. Another LCD device including a repair line for restoring the broken line is provided accordingly. Two terminals of the broken line are connected through the repair line. An upper part of the broken line still can receive a data signal. A lower part of the broken line receives the data signal through the repair line.
Normally, data lines are very thin, exhibiting essential resistance accordingly. The data signal transmitted through the data line experiences a delay. On the contrary, the repair line is comparatively wide, so essential resistance thereof is almost zero, and data signals transmitted through the repair line experience almost no delay. However, when a break point occurs on a latter half of the data line, delay time of the data signal of the lower part of the broken line is less than that corresponding to positions of the other data lines. Therefore, brightness of pixels below the break point is different from that of other pixels in the same row. Display performance of the LCD device is thus likely to be affected.
What is needed, therefore, is an LCD device which can overcome the described limitations.
Reference will now be made to the drawings to describe preferred and exemplary embodiments of the invention in detail.
The first repair line 23 intersects and is disposed on a first side of the data line 202. The second repair line 24 intersects and is disposed on a second side of the data line 202. The first side of the data line 202 is adjacent to the data driver 21, and the second side of the data line 202 is distant from the data driver 21. Further, the two repair lines 23, 24 are disposed beyond the display area 20 to avoid generation of capacitance with other metal lines.
When the data line 202 experiences a break point, the pixel units 201 below the break point cannot receive the data signals via the broken data line 202. An intersection of the broken data line 202 and the first repair line 23 is defined as a first crossing point 205. An intersection of the broken data line 202 and the second repair line 24 is defined as a second crossing point 206. In order to repair the broken data line 202, the broken data line 202 and the first repair line 23 may be shorted at the first crossing point 205 by a laser, and the broken data line 202 and the second repair line 24 may be shorted at the second crossing point 206 by the laser. As a result, data signals are sent from the data driver 21 to pixel units 201 above the break point via the broken data line 202, and to the remaining pixel units 201 below the break point via the first repair line 23, the amplifier 25, the delay circuit 27, the second repair line 24 and the broken data line 202.
The delay circuit 27 includes an adjustable resistor 270 and a capacitor 271. The adjustable resistor 270 is connected to the second repair line 24, and is grounded via the capacitor 271. The control circuit 26 adjusts a resistance of the adjustable resistor 270 according to a position of each pixel unit 201 corresponding to the broken data line 202. Thereby, a delay time of the delay circuit 27 can be adjusted. A plurality of points on the data line 202 is defined. A longitudinal coordinate of each point corresponds to a position of each pixel unit 201.
Referring to
A parameter N denotes a distance between the first crossing point 205 and the second crossing point 206. A parameter R1 denotes a resistance of one data line 202. A parameter R2 denotes a resistance from the first crossing point 205 to the amplifier 25 of the first repair line 23. A parameter R3 denotes a resistance from the delay circuit 27 to the second crossing point 206 of the second repair line 24. The first crossing point 205 of the data line 202 is regarded as a coordinate origin. If a longitudinal coordinate of the break point is a parameter Y and a longitudinal coordinate of an arbitrary point G of the data line is a parameter Y1, a compensation resistance for the arbitrary point G is denoted as a parameter VR.
Y1 exceeding Y and Y exceeding N/2 or Y1 exceeding N/2 and Y being less than N/2 can be expressed by the formula:
(Y1/N)×R1=R2+VR+R3+(N−Y1)×R1/N (1)
Because the first repair line 23 and the second repair line 24 are comparatively wide, R2 and R3 can be discounted. As a result, formula (1) can be further expressed as:
(Y1/N)×R1=VR+N−Y1)×R1/N (2)
According to formula (2), the compensation resistance VR can be expressed as:
VR=(Y1−N/2)×R1/(N/2) (3)
A method for adjusting the resistance of the adjustable resistor 270 is described as follows. Longitudinal coordinate Y of the break point and the longitudinal coordinate Y1 of points G corresponding to pixel units 202 are determined. When Y1 exceeds Y and Y exceeds N/2 or Y1 exceeds N/2 and Y is less than N/2, the microprocessor 260 locates a corresponding compensation resistance VR in look-up table 261 according to a longitudinal coordinate Y1 of each point G, and adjusts the resistance of the adjustable resistor 270 to VR. When Y1 is less than Y or Y1 is less than N/2, the microprocessor 260 adjusts the resistance of the adjustable resistor 270 to zero.
LCD device 2 further includes the delay circuit 27 and the control circuit 26. Under control of the control circuit 26, the delay circuit 27 delays the data signal transmitted through the first repair line 23 and the second repair line 24 according to the position of each pixel unit 201 of the broken data line 202. Thus, the delay of the data signal of the lower part of the broken data line 202 nearly equals the delay of the data signal of corresponding positions of the other data lines 202. Brightness of pixel units 201 below the break point equals those of other pixel units 201 in the same rows. Display performance of the LCD device is thus maintained.
It is to be further understood that even though numerous characteristics and advantages of preferred and exemplary embodiments have been set out in the foregoing description, together with details of structures and functions associated with the embodiments, the disclosure is illustrative only, and changes may be made in detail (including in matters of arrangement of parts) within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 200810141627.3 | Jul 2008 | CN | national |
