WO2001084586A1

WO2001084586A1 - Short locate decision method for plasma display pannel electrode

Info

Publication number: WO2001084586A1
Application number: PCT/KR2000/000446
Authority: WO
Inventors: Tae Wook Park
Original assignee: Tae Wook Park
Priority date: 2000-04-28
Filing date: 2000-05-10
Publication date: 2001-11-08
Also published as: KR100380762B1; KR20010104456A; AU2000246182A1

Abstract

The method of determining a shorted position of a plasma display panel electrode is disclosed. The method measures resistances of opposite ends of each electrode with first end shorted with a short bar, and second end of each electrode coming into contact with a probe. Further, the measured resistances are stored, and are compared with a reference value, in addition to compared with each other. Thereby, the present invention can determine whether the electrodes are shorted, and determine a shorted position using an equation. Accordingly, the present invention detects a shorted position of fine electrodes, thus promptly repairing the shorted electrodes and improving the productivity. In the present invention, a short bar comes into contact with opposite ends of fine electrodes and a probe comes into contact with the electrodes. The present invention determines whether the electrodes are shorted and detects the shorted position, in response to the resistance detected sequentially.

Description

SHORT LOCATE DECISION METHOD FOR PLASMA DISPLAY PANNEL ELECTRODE

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates in general to an apparatus and method for testing short circuits of a Plasma Display Panel (hereinafter, referred to as "PDP") electrode, and more particularly to a method of determining a shorted position of a plasma display panel electrode, in order to test short circuits of a plurality of fine electrodes used as scanning lines of the plasma display panel.

Description of the Prior Art

As well known to those skilled in the art, a plasma display panel (PDP) includes a plurality of electrodes for horizontal and vertical scanning. In this regard, the short circuit of each horizontal and vertical scanning electrode causes the defect of image pixels. Therefore, the horizontal and vertical scanning electrodes should be tested, and only PDP without defects should be selectively inputted to following processes. If an accurate test for short circuits of such electrodes is not carried out, following high cost processes are performed to produce only a defective PDP, thereby causing a significant economic loss.

According to the prior art, a probe is used for testing the short circuits of the PDP electrodes. Specifically, adjacent two electrodes of the PDP are tested with the probe while changing its position on two adjacent electrodes sequentially in order to measure the resistances of the electrodes. Then, the user determines that the short circuit is detected if current flows between the adjacent electrodes. In this case, the conventional short test method using the prove is problematic in that it complicates the testing process due to the change of the probe position sequentially for testing the short between electrodes,

Further, the conventional short test method is problematic in that the user cannot find a shorted position, and so if it is determined that the short is detected, a separate shorted position searching device is required to find the position by searching from one side of the shorted electrode to the other side is searched, thereby consuming much time and costs in searching and correcting the shorted electrode.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a method of determining a shorted position of PDP electrodes while determining whether or not a short circuit is detected in a plurality of fine electrodes, such that the shorted position are promptly and exactly detected, and are promptly repaired, thereby improving the productivity.

In accordance with the present invention, the above and other objects can be accomplished by the provision of a method of determining a shorted position of plasma display panel electrodes, comprising the steps of a) bring a short bar into contact with first ends of the PDP electrodes, sequentially bring a probe into contact with second ends of the electrodes, measuring a resistance (Rl) between a probe position(X) and a short bar position Y as Rl = Ra + {Rb x (Rd + Re) / (Rb + Rd +Re)}, and converting the resistance(Rl) into a digital value, prior to being stored; b) measuring a resistance(R2) between a probe position(X') and the position(Y) as R-2 = Re + {(Re + Rb) x Rd / (Rb+ Rd+ Re)}, and converting the resistance(R2) into a digital value, prior to being stored; c) contacting the short bar with the second ends of the electrodes, sequentially contacting the probe with the first ends of the electrodes, measuring a resistance(R3) between a short bar position(T) and a probe position(U) as R3 = {Ra x (Re + Re) / (Ra + Re + Re)} + Rb, and converting the resistance(R3) into a digital value, prior to being stored; d) measuring a resistance(R4) between the position(T) and a probe position(U') as R4 = {(Ra + Re) x Re / (Ra +Re + Re)} + Rd, and converting the resistance(R4) into a digital value, prior to being stored; e) determining whether or not the resistance value(Rl) is smaller than a resistance value(Z), wherein Z is set as an actual resistance value between normal electrodes, and is larger than a value(Z/2); f)determining whether or not the resistance value(R2) is smaller than the resistance value (Z), and is larger than the value(Z/2); g) determining whether or not the resistances(Rl) and (R2) are the same if all conditions at steps e) and f) are satisfied; and h) determining whether or not the resistances(R3) and (R4) are the same, thus determining whether or not the short circuit is detected in the electrodes based on determination results of steps e), f), g) and h).

Preferably, the present invention measure resistances of opposite ends of each electrode by making a first end of each electrode shorted with a short bar and a second end come into contact with a probe. Further, the measured resistances are stored, and are compared with a reference value, in addition to compared with each other. Thereby, the present invention can determine whether the electrodes are shorted, and determine a shorted position using an equation. Accordingly, the present invention detects a shorted position of fine electrodes, thus promptly repairing the shorted electrodes and improving the productivity.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: Figs. 1 to 4 are views showing a measurement of resistances of fine PDP electrodes according to the present invention; and

Figs. 5 is a flowchart of a method of determining a shorted position of fine PDP electrodes.

DETAILED DESCRIPTION OF THE PREFERRED

EMBODIMENTS

Figs. 1 to 4 are views showing the process of determining the shorted position of fine electrodes by measuring resistances of the fine electrodes according to the present invention. For ease of description, the end of each electrode on the left-hand side of the drawings will be referred to as the left end of the electrode and the opposite end on the right-hand side of the drawings will be referred to as the right end.

Referring to Fig. 1, in order to measure resistance between adjacent fine electrodes, a short bar is brought into contact with right ends of a plurality of fine electrodes, while the right ends of the electrodes are shorted. On the other hand, a probe comes into contact with the left ends of the fine electrodes sequentially. Providing that the second and third electrodes are shorted due to a process error, the resistance between the second and third electrodes is measured as follows. First, a resistance Rl between a probe position X on the left end of the second electrode and a position Y of the short bar is expressed as Rl = Ra + {Rb x (Rd + Re) / (Rb + Rd + Re), and the analog resistance Rl is converted into a digital value, prior to being stored at step 1.

Next, as shown in Fig. 2, if the probe is moved to the position X', a resistance R2 between a probe position X' on the left end of the third electrode and the position Y is measured as R2 = Re + {(Re + Rb) x Rd / (Rb + Rd + Re)}, and then the analog resistance R2 is converted into a digital value, prior to being stored at step 2.

Further, as shown in Fig. 3, the short bar is alternatively moved to the left ends of the fine electrodes in drawings, and the probe comes into contact with the right ends of the fine electrodes sequentially. At this time, a resistance R3 between a position T of the short bar and a probe position U on the right end of the second electrode is measured as R3 = {Ra x (Re + Re) / (Ra + Re + Re)} + Rb, and then the analog resistance R3 is converted into a digital value, prior to being stored at step 3.

Next, as shown in Fig. 4, if the probe is moved to the position U', a resistance R4 between the position T and a probe position U' on the right end of the third electrode is measured as R4 = {(Ra + Re) x Re / (Ra + Re + Re)} + Rd, and then the analog resistance R4 is converted into a digital value, prior to being stored at step 4. Thereafter, it is determined whether or not the resistance value Rl of Fig. 1 obtained according to the above process is smaller than Z, which is set as an actual resistance value between normal electrodes, and is larger than Z/2 at step 5. Then, it is determined whether or not the resistance value R2 is smaller than Z, and is larger than Z/2 at step 6. At steps 5 and 6, if all conditions are satisfied, it is determined whether or not the resistances Rl and R2 are the same at step 7. Further, it is determined whether or not the resistances R3 and R4 are the same at step 8.

In this case, if above conditions are satisfied, it is determined that a short circuit is detected between adjacent electrodes. The state of the short circuit can be shown with an LED (Light Emitting Diode) or LCD (Liquid Crystal Display) panel. Further, the shorted position can be determined according to an equation as {((x-0.5) 2) 1 }, wherein x is a value of each of the resistances of each Rl , R2, or R3, R4 divided by the resistance value Z. In the equation, "1 " is an entire length of each electrode, and a resistance Re between the shorted electrodes is

regarded as "0"[Ω].

Due to various causes, an error may be occurred in the determination of the shorted position, and typically, the error range should be within 5%.

The error range within 5% allows an electrode tester so called a visual sensor to promptly detect the shorted position, thus enabling a prompt repair and significantly improving the PDP productivity.

The present invention repeats the above process to determine whether the fine electrodes are shorted, in addition to determination of a shorted position thereof. As apparent from the above description, the present invention provides a method of determining a shorted position of PDP electrodes, which has advantage that it can determine whether fine electrodes are shorted in addition to determination of a shorted position, thus enabling a prompt repair of the shorted electrodes and considerably improving productivity of PDP electrodes. Further, the present invention has an economic effect of minimizing an operation time of a visual sensor, thereby saving the maintenance costs of the PDP.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims:

1. A method of determining a shorted position of plasma display panel electrodes, comprising the steps of: a) bring a short bar into contact with first ends of the PDP electrodes, sequentially bring a probe into contact with second ends of the electrodes, measuring a resistance(Rl) between a probe position(X) and a short bar position(Y) as Rl = Ra + {Rb x (Rd + Re) / (Rb + Rd + Re), and converting the resistance(Rl) into a digital value, prior to being stored; b) measuring a resistance(R2) between a probe position(X') and the position(Y) as R2 = Re + {(Re + Rb) x Rd / (Rb + Rd + Re)}, and converting the resistance(R2) into a digital value, prior to being stored; c) contacting the short bar with the second ends of the electrodes, sequentially contacting the probe with the first ends of the electrodes, measuring a resistance(R3) between a short bar position(T) and a probe position(U) as R3 = {Ra x (Re + Re) / (Ra + Re + Re)} + Rb, and converting the resistance(R3) into a digital value, prior to being stored; d) measuring a resistance(R4) between the position(T) and a probe position(U') as R4 = {(Ra + Re) x Re / (Ra + Re + Re)} + Rd, and converting the resistance(R4) into a digital value, prior to being stored; e) determining whether or not the resistance value(Rl) is smaller than a resistance value(Z), wherein Z is set as an actual resistance value between normal electrodes, and is larger than a value(Z/2); f) determining whether or not the resistance value(R2) is smaller than the resistance value (Z), and is larger than the vaιue(Z/2); g) determining whether or not the resistances(Rl) and (R2) are the same if all conditions at steps e) and f) are satisfied; and h) determining whether or not the resistances(R3) and (R4) are the same, thus determining whether or not the short circuit is detected in the electrodes based on determination results of steps e), f), g) and h).

2. The method as set forth in Claim 1, wherein a shorted position of the electrodes is determined according to an equation as {((x-0.5) 2) 1 }, wherein x is a value of each of the resistances (Rl, R2) or (R3, R4) divided by the resistance value (Z).