WO2001080275A1

WO2001080275A1 - Short and break tester probe for plasma display pannel

Info

Publication number: WO2001080275A1
Application number: PCT/KR2000/000445
Authority: WO
Inventors: Tae Wook Park
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-04-03
Filing date: 2000-05-10
Publication date: 2001-10-25
Anticipated expiration: 2002-10-03
Also published as: CN1353858A; AU4783900A; KR100350513B1; KR20010094032A; JP2003531387A

Abstract

Disclosed herein is a probe apparatus for testing for short circuits and breakages of the electrodes of a plasma display panel. The probe apparatus includes a probe (3) for being brought into contact with an electrode (2) while being rotated by a motor (1). A tip (4) is formed on one end of the probe (3). A support frame (6) supports center portions of the probe (3) and the motor (1), the support frame (6) being provided with a bearing for allowing the probe to be rotated. The probe apparatus may further include a coupler (7) for connecting the motor (1) to the probe (3), said coupler (7) being provided with an opening (8) in a side of the coupler (7), and rotation detecting means for detecting the number of rotations by emitting and receiving infrared rays on both sides of the opening (8).

Description

SHORT AND BREAK TESTER PROBE FOR PLASMA DISPLAY PA NEL

Technical Field

The present invention relates generally to a probe apparatus for testing for short circuits and breakages of the electrodes of a Plasma Display Panel (hereinafter, referred to as "PDP"), and more particularly to a probe apparatus for testing for short circuits and breakages of a plurality of minute electrodes used as the scanning lines of a PDP.

Background Art

As well known to those skilled in the art, a PDP includes a plurality of electrodes for horizontal and vertical scanning. Accordingly, the short circuit or breakage of each horizontal or vertical scanning electrode causes the defect of a picture element, so the horizontal and vertical electrodes of the PDP should be tested and only PDPs without defects should be input to subsequent processes.

If an accurate test for short circuits and breakages of electrodes is not carried out, subsequent high cost processes are performed to produce a defective PDP, thereby incurring a massive economic loss.

The width of each electrode is merely 80j-t.ii and the interval between

neighboring electrodes is 150 m, so a conventional probe apparatus for testing

for short circuits and breakages of the minute electrodes should have a superhigh precision in which an error in the positioning of its probe (which will be brought

into contact with both sides of each electrode) should be within ±lO m.

Accordingly, the excessive fabricating costs of the probe apparatus are incurred. As a result, the price of the probe apparatus is high and the maintenance costs of the probe apparatus are also high, so there occurs the problem that the manufacturing costs of the PDP are excessively increased.

In addition, each electrode of a PDP is merely 80 zm, so the tip of the

conventional probe should be pointed. Accordingly, in the process of repeated measurement, the tip of the conventional probe is easily worn, so there occur the inconvenience of frequently replacing the probe with a new one and the economic burden of the excessive replacement costs. Additionally, the electrode itself is damaged by the pointed tip of the probe, so the defect rate of PDPs is increased.

Disclosure of the Invention

Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a probe for testing for short circuits and breakages of the electrodes of a plasma display panel, which does not require a test equipment to be fabricated with an ultrahigh degree of precision, which does not need the frequent replacement of the probe, and which has no risk of the damaging the electrodes. In order to accomplish the above object, the present invention provides a probe apparatus for testing for short circuits and breakages of the electrodes of a PDP that employs a rolling probe instead of a conventional probe having a pointed tip. In accordance with the present invention, a value of resistance between one side of each electrode in rolling contact with a probe and the other side of the electrode is calculated by a microprocessor and it is determined whether the electrode is shorted or broken on the basis of the calculated result. Therefore, very precise test results can be obtained, problems concerning the wear and damage of the probe or electrode are eliminated, and the fabricating costs of the probe apparatus are reserved due to no need for superhigh precision technology.

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:

Fig. 1 is a perspective view showing the entire appearance of a probe in accordance with the present invention;

Fig. 2 is a longitudinal cross section showing the entire construction and operation of the probe of the present invention; Fig. 3 is a diagram showing the tip of the probe of the present invention;

Fig. 4 is a graph illustrating a sampling process in accordance with the present invention; and Fig. 5 is a diagram showing a limitation in the specifications of the tip of the probe.

1: motor 2: electrode

3: probe 4: tip

5: bearing 6: support frame

7: coupler 8: opening

9: rotation detecting means

Best Mode for Carrying Out the Invention

The probe apparatus of the present invention is described in detail with reference to accompanying drawings, hereinafter.

As illustrated in Figs. 1 and 2, the probe apparatus of the present invention is comprised of a probe 3 for being brought into contact with an electrode 2 while being rotated by a motor 1, a tip 4 formed on one end of the probe 3, a support frame 6 for supporting the center portions of the probe 3 and the motor 1, the support frame 6 being provided with a bearing for allowing the probe to be rotated, a coupler 7 for connecting the motor 1 to the probe 3, the coupler 7 being provided with an opening 8 in a side of the coupler 7, and rotation detecting means for detecting the number of rotations by emitting and receiving infrared rays on both sides of the opening 8.

In the probe apparatus of the present invention, first of all, an electric source is applied to the motor 1, so the probe 3 is rotated. Additionally, the support frame 6 itself can be considered as an electrode.

In addition, as depicted in Fig. 2, the tip 4 of the probe 3 is slantingly brought into contact with an electrode 2. Accordingly, though the tip 4 of the probe 3 is brought into point contact with the electrode 2, the degree of damage caused to the electrode 2 is considerably reduced in comparison with a conventional probe apparatus in which upper and lower probes come in contact with the electrode 2, under the condition that the rolling speed "a" at which the tip 4 of the probe 3 rolls on the electrode 2 while being in rolling contact with the electrode 2 is synchronized with the moving speed "b" of the electrodes 2. Additionally, as shown in Fig. 3, while the tip 4 of the probe 3 rolls over one- sides of multiple electrodes 2, current flows through the probe 3, one side of each electrode 2 and the other side of the electrode 2. In this case, since the value of voltage applied to the electrode 2 through the probe 3 is kept constant, the calculation of the value of resistance is made on the basis of the variation of current. Such variation of current is converted to a digital value through an analog/digital converter, and this digital value is calculated and sensed by the variation of the value of resistance by a microprocessor. If the variation of the value of resistance deviates from a predetermined range of allowable variations, the electrode 2 is determined to be shorted or broken. That is, it can be determined whether the electrode 2 is shorted or broken by comparing the variation between the values of resistance at one and the other ends of the electrode 2 with the values of the predetermined range.

The value of resistance actually measured by the probe 3, as shown in Fig. 4, is kept intermediate at the moment when the tip 4 is situated at the center of the electrode 4 and stably in contact with the electrode 4. The value of resistance is relatively large at the moments of initial and final contact. Thereafter, the tip 4 comes in contact with two electrodes 2, so the two electrodes 2 seem to be shorted therebetween. These processes are repeated. As a result, the microprocessor undergoes a sampling period between the initial contact period and the final contact period, and disregards input values during the initial and final contact periods and the period for which the tip 4 of the probe 3 is in simultaneous contact with two electrodes.

Meanwhile, for the probe apparatus of the present invention, it suffices that the diameter of the tip 4 of the probe 3 is greater than the height of the electrode 2. Additionally, the measurement is impossible if the tip 4, as shown in Fig. 5, comes in contact with three electrodes 2, so the diameter of the tip 4 should be smaller than the minimum diameter that would allow the electrode 2 to come into contact with three electrodes 2. In accordance with the present invention, the number of rotations of the probe 3 can be detected by the rotation detecting means 9. The motor 1 can be controlled by the microprocessor on the basis of the detected number of rotations.

In addition, in the probe apparatus of the present invention, an air-rotated fan can be employed instead of the motor 1. In such a case, a solenoid valve for controlling the supply of air should be operated by the rotation detecting means 9.

Industrial Applicability In the probe apparatus of the present invention, the value of resistance is measured by the rolling of the tip 4 of the probe 3, so the driving structure of the probe 3 is considerably simplified as compared with a conventional one in which the short circuits and breakages of a plurality of horizontal and vertical scanning lines are tested for while shape probes continuously and vertically slide along both sides of the electrode 2. Accordingly, the fabricating costs of the probe apparatus can be greatly reduced. In consequence, the entire fabricating costs of a PDP can be considerably lowered. Additionally, in accordance with the present invention, the value of resistance is measured by the rolling of the tip 4 of the probe 3 on the electrode 2,so the wear of the electrode 2 and the probe 3 does not occur, thereby considerably reducing the frequency of breakdown and the maintenance costs of the probe apparatus.

Claims

1. A probe apparatus for testing for short circuits and breakages of the electrodes of a plasma display panel, comprising a probe 3 for being brought into contact with an electrode 2 while being rotated by a motor 1; a tip 4 formed on one end of the probe 3; and a support frame 6 for supporting center portions of the probe 3 and the motor 1, the support frame 6 being provided with a bearing for allowing the probe to be rotated.

2. The probe apparatus according to claim 1, further comprising a coupler 7 for connecting the motor 1 to the probe 3, said coupler 7 being provided with an opening 8 in a side of the coupler 7, and rotation detecting means for detecting the number of rotations by emitting and receiving infrared rays on both sides of the opening 8.