FreshPatents.com Logo
stats FreshPatents Stats
1 views for this patent on FreshPatents.com
2011: 1 views
Updated: April 14 2014
newTOP 200 Companies filing patents this week


    Free Services  

  • MONITOR KEYWORDS
  • Enter keywords & we'll notify you when a new patent matches your request (weekly update).

  • ORGANIZER
  • Save & organize patents so you can view them later.

  • RSS rss
  • Create custom RSS feeds. Track keywords without receiving email.

  • ARCHIVE
  • View the last few months of your Keyword emails.

  • COMPANY DIRECTORY
  • Patents sorted by company.

AdPromo(14K)

Follow us on Twitter
twitter icon@FreshPatents

Panel for liquid crystal display device

last patentdownload pdfimage previewnext patent


Title: Panel for liquid crystal display device.
Abstract: A panel of a liquid crystal display panel with a plurality of pixels is disclosed, wherein each pixel comprises one switch, one pixel electrode and one floating line. The switch comprises a gate, a source, and two drains. The pixel electrode can be electrically connected to the switch through the drain. Besides, each floating conductive line and two drains of the same switch are crossed but electrically disconnected. Hence, the design of the dual drain (or dual source) illustrated above and the combined the technique of laser welding can be used to repair the source-drain leakage of the substrate of the liquid crystal display device. ...


Inventors: Wen-Yi SHYU, Chun-Chang Chiu, Liang-Neng Chien
USPTO Applicaton #: #20110074662 - Class: 345 87 (USPTO) - 03/31/11 - Class 345 


view organizer monitor keywords


The Patent Description & Claims data below is from USPTO Patent Application 20110074662, Panel for liquid crystal display device.

last patentpdficondownload pdfimage previewnext patent

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a panel or a substrate of a liquid crystal display device and, more particularly, to a panel or a substrate of an active matrix liquid crystal display device and the repairing method of the same.

2. Description of Related Art

The improvement of the yield of the process for manufacturing a panel of a liquid crystal display device (LCD) is very important. For improving the yield, it is necessary to repeatedly inspect in all the steps of the manufacturing process for screening out the unqualified products. However, particles exist inside and/or outside the apparatuses for manufacturing processes. The particles usually result in defects on the substrate for the liquid crystal display devices. For example, as a particle 90 falls on the surface of the switch 21 of the substrate 1 (see FIG. 1), the particle 90 results in shorting between the data line (source line) 35 and the drain 36. This shorting causes source-drain leakage and will further make the liquid crystal display device generate dark dots or bright dots (i.e. point defects) as the display device displays.

Since dumping the liquid crystal display device with point defects directly costs money, the manufacturers of LCD devices do many efforts on improving the manufacturing process and environment for manufacturing. For example, the LCD makers increase the frequency for cleaning the environment, enhancing the monitoring for the cleanness of the manufacturing environment, and improving the maintenance of the manufacturing apparatuses. On the other hand, the LCD manufacturers also develop method for repairing the LCD panel or the substrate of the LCD devices for saving costs. The yield can be improved effectively if the defected LCD device or the substrate of the LCD device can be well repaired. Of course, the cost can be reduced when the defected LCD device or the substrate of the LCD device can be well repaired.

The conventional method for repairing the defects on the LCD is shown in FIG. 1. A particle 90 falls on the surface of a switch (thin film transistor) 21 of a normally black liquid crystal display device and further results in a TFT defect such as source-drain leakage or TFT weak. When a voltage is applied on the LCD, a bright dot (i.e. a point defect) generates. The conventional method for repairing the defects illustrated above is achieved by welding the capacitor conductive lines 47 and the capacitor top lead 471 together and further cutting the drain 36, wherein the capacitor top lead 471 contact the pixel electrode 52 through contact holes 45, and the pixel electrode 52 electrically connected to the switch 21 through the drain 36. The cross of FIG. 1 marks 500 is the position of cutting. After repairing, the repaired pixel of the LCD acts as a permanent dark dots. Since human eyes are not sensitive to the dark dots, the consumer can also accept the LCDs with limited dark dots. Even though the tolerance value for the dark dots is higher than that of the bright dots, the permanent dark dots are not actually recovered through the conventional repairing method. In other words, the permanent dark dots are still abnormal pixels.

In addition, the defects caused by other factors decrease greatly since the process for manufacturing LCDs improves a lot in recent years. Hence, the point defects resulted from source-drain leakage become major defects relatively. Moreover, the tolerable requirement for the point defects becomes strict as the size of the LCD increases. Therefore, it is desirable to provide an improved method to mitigate the aforementioned problems of the source-drain leakage.

SUMMARY

OF THE INVENTION

The present invention provides a panel of the liquid crystal display device. The substrate of the panel includes a plurality of pixels. Each pixel comprises: a switch, a pixel electrode, and a floating conductive line. The switch includes a gate, a source, and two drains. The pixel electrode is electrically connected to the switch by the assistance of the drain. The floating conductive line crosses the two drains without electrical connection. Hence, when source-drain leakage generates, the switch can be repaired by cutting the drains, and selectively welding the drain, and the floating conductive line. For example, when a particle falls on the location between the drain and the source, TFT source-drain leakage may happen because the short between the source and the drain generates.

Moreover, in the present invention, the source of the switch refers to the branch of the data line, which extends to overlap the switch. The source of the switch is connected to the data line.

In this kind of condition, the pixel with defects can be repaired into a normal pixel for displaying if the circuit of the defected pixel has the dual drain circuit of the pixel of the present invention. The repairing steps of the method of the present invention can be of following steps: (A) providing a substrate of a liquid crystal display device having a plurality of pixels, wherein each pixel includes: a switch having a gate, a source, and two drains; a pixel electrode; and a floating conductive line; wherein the pixel electrode electrically connects to the switch through the drain, and the floating conductive line crosses the two drains without electrical connection; (B) cutting one of the two drains, wherein the location of the cut on the drain is not between “the crossed position of the drain and the floating conductive line” and “the switch”; and (C) checking the pixel through charging the source and the gate on the substrate.

If the repaired pixel displays normally, the repairing is completed and can be stopped. In contrary, if the laser-repaired pixel doesn\'t display normally, it means that perhaps the particle falls on the uncut drain. In this situation, the defected pixel can be subsequently repaired by the following steps: (D) cutting the uncut drain, wherein the location of the cut on the conductive line is between “the crossed position of the drain and the floating conductive line” and “the switch”; and; (E) welding the two drains and the floating conductive line together to make the two drains electrically connected to the floating conductive line.

Hence, if the defect of a pixel is TFT source-drain leakage or TFT weak, the defect can be repaired through the laser-welding of the connection of dual drain and the floating conductive line design of the substrate of the present invention.

In addition, the present invention also provides a substrate having dual-source circuit in the TFT area. The substrate includes a plurality of pixels. Each pixel comprises: a switch, a pixel electrode, and a floating conductive line. The switch includes a gate, two sources, and a drain. The pixel electrode is electrically connected to the switch by the assistance of the drain. The floating conductive line crosses the two sources without electrical connection.

In this invention, the source refers to the branch of the data line, which extends to overlap the switch. The source of the switch is connected to the data line.

Likewise, the pixel with TFT source-drain leakage defect (or TFT weak) can be repaired into a normal pixel for displaying if the circuit of the defected pixel has the dual source circuit of the pixel of the present invention. The repairing steps of the method of the present invention can be a method of following steps: (A) providing a substrate of a liquid crystal display device having a plurality of pixels, wherein each pixel includes: a switch having a gate, a drain, and two sources; a pixel electrode; and a floating conductive line; wherein the pixel electrode electrically connects to the switch through the drain, and the floating conductive line crosses the two sources without electrical connection; (B) cutting one of the two source s, wherein the location of the cut on the source is not between “the crossed position of the source and the floating conductive line” and “the switch”; and (C) checking the pixel through charging the source and the gate on the substrate.

If the repaired pixel displays normally, the repairing is completed and can be stopped. In contrary, if the laser-repaired pixel doesn\'t display normally, it means that perhaps the particle falls on the uncut source. In this situation, the defected pixel can be subsequently repaired by the following steps: (D) cutting the uncut source, wherein the location of the cut on the source is between “the crossed position of the source and the floating conductive line” and “the switch”; and (E) welding the two sources and the floating conductive line together to make the two sources electrically connect to the floating conductive line.

The sources (or the drains) of the present invention can be cut with any cutting steps. Preferably, the source s (or the drains) are cut by laser. The laser of the present invention can be any laser. Preferably, the laser of the present invention is YAG laser, ruby laser, or CO2 laser. The sources (or the drains) and the floating conductive line of the present invention can be welded with any laser. Preferably, the sources (or the drains) and the floating conductive line of the present invention are welded by YAG laser, ruby laser, or CO2 laser.

In addition, each pixel of the substrate of the liquid crystal display device can further include a gate conductive line that is electrically connected to the gate. Each pixel of the substrate of the liquid crystal display device can optionally further include capacitor conductive line that is electrically connected to the drain, and the drain can be electrically connected to the pixel electrode through the capacitor conductive line, and the drain can electrically connected with the pixel electrode through the capacitor conductive line. The capacitor conductive line can be in any form. Preferably, the capacitor conductive line includes a top capacitor lead, and a bottom capacitor lead, wherein the top capacitor lead overlaps the bottom capacitor lead without electrical connection. In addition, the top capacitor lead can have at least one contact hole for electrically connecting the pixel electrode and the top capacitor lead. The pixel electrode of the substrate of the present invention can be made of any conductive material. Preferably, the pixel electrode of the substrate of the present invention is made of transparent conductive materials. More preferably, the pixel electrode is made of indium tin oxide or indium zirconium oxide (IZO). The floating conductive line can be made of any conductive material. Preferably, the floating conductive line and the gate conductive line are made of the same material.

Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of the TFT switch of the substrate of a prior art.

FIG. 2 is a top view of the TFT switch of the substrate of the first embodiment of the present invention.

FIG. 3 is a top view of the TFT switch of the substrate of the embodiments of the present invention.



Download full PDF for full patent description/claims.

Advertise on FreshPatents.com - Rates & Info


You can also Monitor Keywords and Search for tracking patents relating to this Panel for liquid crystal display device patent application.
###
monitor keywords



Keyword Monitor How KEYWORD MONITOR works... a FREE service from FreshPatents
1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored.
3. Each week you receive an email with patent applications related to your keywords.  
Start now! - Receive info on patent apps like Panel for liquid crystal display device or other areas of interest.
###


Previous Patent Application:
Display device and electronic equipment using the same
Next Patent Application:
Array substrate and manufacturing method thereof
Industry Class:
Computer graphics processing, operator interface processing, and selective visual display systems
Thank you for viewing the Panel for liquid crystal display device patent info.
- - - Apple patents, Boeing patents, Google patents, IBM patents, Jabil patents, Coca Cola patents, Motorola patents

Results in 0.52981 seconds


Other interesting Freshpatents.com categories:
Qualcomm , Schering-Plough , Schlumberger , Texas Instruments , -g2-0.2054
     SHARE
  
           

FreshNews promo


stats Patent Info
Application #
US 20110074662 A1
Publish Date
03/31/2011
Document #
12961105
File Date
12/06/2010
USPTO Class
345 87
Other USPTO Classes
International Class
09G3/36
Drawings
5


Laser Welding


Follow us on Twitter
twitter icon@FreshPatents