JPH03237486A - Active matrix panel and its driving method - Google Patents

Abstract

PURPOSE:To prevent the generation of a positional dislocation of display by dividing the scanning time of each row into two parts, individually scanning two thin film transistors (TRs) corresponding to each picture element at each divided time and supplying the same display data to the two TRs. CONSTITUTION:Two thin film TRs TijA, TijB corresponding to one picture element Pij are connected to respectively independent gate bus lines Gia, Gib. If a picture element generating abnormality on a display exists at the time of supplying display data from a data bus line DBj by successively scanning all gate bus lines, the defective thin film TR can be specified from the gate bus line line at the time of generating the abnormality. Since the same display data are supplied to the two thin film TRs TijA, TijB corresponding to each picture element Pij in this constitution, the display data of adjacent picture elements are not supplied even when one TR is disconnected. Thereby, the positional dislocation of displayed contents is not caused.

Description

[Detailed Description of the Invention] [Summary] An active matrix panel with a redundant configuration that does not cause display misalignment and a driving method thereof, regarding an active matrix panel and its driving method that enable defect relief in an active matrix panel. In order to provide the Arranged between two adjacent data bus lines, and diagonally among four intersections between two gate bus lines corresponding to each pixel and two data bus lines adjacent with the pixel in between. Two thin film transistors corresponding to each pixel are connected to each of the two intersection points at the position, and when driving the actimeter matrix panel, the scanning time of each row is divided into two, and the On one side and the other side, two thin film transistors corresponding to each pixel in the row are separately scanned, and the same display data is supplied to the two i''i film transistors.

[Industrial application field]

The present invention relates to an active matrix panel that makes it possible to repair defects in the active matrix panel and a method for driving the same.

In recent years, active matrix liquid crystal display devices with excellent image quality have begun to appear, and in the future, larger panels with larger display capacities are desired. However, as panels become larger and display capacity increases, the probability of defects in the thin film transistor (TPT), which is a switching element, increases in the panel, and the problem of lower yields due to this becomes more serious. . Therefore, in order to increase the size of the channel, there is a strong demand for the practical use of a method for repairing defective TPT.

[Conventional technology]

As a conventional method for relieving defects in active matrix panels, there is a method in which a redundant circuit configuration is provided in which two TPTs are provided for one pixel, and when a defective TPT is detected, it is separated to create a defect-free panel.

However, although the above conventional methods can correct defects,
There is a problem in that the display position may shift. This problem will be explained with reference to FIG.

In the figure, SB, SBZ, SB:l are scan path lines, DBI, DB2. DB:l is the data bus line, E+, E2. E 3. E a
is the pixel electrode. Each pixel electrode E +, E2. E
3. E a is arranged between two adjacent scan path lines, and two driving thin film transistors T A and T 8 are provided corresponding to each pixel electrode.

One of these two thin film transistors TA and TI (TA in the figure) is attached to the scan path line whose scanning order is the front (upper side in the figure), and the other (T11 in the figure) is located at the rear (lower side in the figure).
connected to the scan path line. Therefore, in each scan path line, the thin film transistor TB of the pixel at the front in the scanning order and the thin film transistor TA at the pixel at the back
is connected.

Next, referring to FIG. 4 (al), the operation of the conventional circuit with the redundant configuration described above will be explained by taking as an example the display of the pixel electrode E when a scanning voltage is applied to the scan hash line SB2.

When a scanning voltage is applied to the scanning line SB2,
The thin film transistor (upper thin film transistor) TA connected to the pixel electrode E4 is turned on, and display data supplied from the data bus line DB2 is written. At this time, the thin film transistor T connected to the pixel electrode Ez is also turned on, and the same display data is written to the pixel electrode E2.

Next, when a scanning voltage is applied to the scan path line SB3, the thin film transistor Tw of the pixel electrode E4 is turned on, and the display data supplied from the data bus line DB2 at that time is written.

This display data is then converted to the scan path line S B z
is retained until it is selected. That is, the content displayed by each pixel electrode is the display data supplied when the scan path line below each pixel electrode was selected.

Next, suppose that since the thin film transistor T above the pixel electrode E4 was a defective element, it was separated and driven only by the thin film transistor T, as shown in (b).

In this case, the display data written to the pixel electrode E4 is the data supplied from the data bus line D Bz when the scan path line 5Bff is selected, and is the same as the normal display data described in (al) There is no difference.

However, if the lower thin film transistor '1'8 is a defective element (as shown in C1), it will be separated and driven only by the thin film transistor TA.In this case, the scan path line SB .

The display data supplied when is selected is written,
Is displayed. However, this data is the data that should be written to the pixel electrodes F, . . . , and the data that is originally supplied when the scan line SB is selected should be written to the pixel electrode E.

In this way, in the conventional redundant configuration, not only does the display position shift depending on the position of the defective TPT, but also the defect 'I
It was also difficult to specify the position of ``F'F.

The second conventional example shown in FIG. In the pixel, one thin film transistor TA is connected to the scan bus line SB, and the data bus line DB+, and the other thin film transistor Tl
l is scan bus line SB2 and data bus line D
Connect to Bz.

In this redundant configuration, the combination of scan bus lines and data bus lines for driving thin film transistors is different for each thin film transistor, so defect T
If PT exists, it is easy to locate it.

In this conventional example, the data displayed on normal pixels is supplied via the thin film transistor Tll, so the thin film transistor T is a flame transistor, as shown in FIG. Even so, the display position will not shift because the data supplied from the thin film transistor T is displayed as in the normal case. However, as shown in the same figure (C1), if the other thin film transistor TB is a defective element, the data supplied from the thin film transistor TA, that is, the data that should be written to C3, is displayed. The position will shift.

[Problem to be solved by the invention]

As described above, in the conventional redundant configuration, even if defects could be corrected, the problem of pixel position shift could not be avoided. This problem occurs because two thin film transistors are connected at each intersection of the scan bus line and the data bus line, and two thin film transistors for driving each pixel are connected to different data buses. Display data is supplied from the line.

The object of the invention is to provide an active matrix panel with a redundant configuration that does not cause display displacement, and a method for driving the same.

[Means to solve the problem]

An uninvented configuration will be explained with reference to FIG.

As shown in the figure, the present invention arranges a plurality of pixels Pij in a matrix with two thin film transistors Tija and TijB corresponding to each other, and a first and a second thin film transistor corresponding to each row.
Two gate bus lines Gia and G1b are arranged, each pixel Pij is arranged between two adjacent data bus lines DBj and DBj+1, and each pixel Pi
Two gate bus lines Gia and Gib corresponding to j and two data bus lines DBj adjacent to each other with the pixel in between.
Two thin film transistors TijA and TijB corresponding to each pixel were connected to each of the two diagonally located intersections among the four intersections between and DBj+1.

Thin film transistors for driving adjacent pixels are connected to the diagonal positions of this set, except for the gate bus lines at both ends.

When driving the active matrix panel having the above configuration, the scanning time for each row is divided into two, and in one and the other, the two thin film transistors TijA and TijB+ corresponding to each pixel in the row are separately scanned, and
The two thin film transistors T! The same display data is supplied to L and Tjjs.

[For production]

In the above configuration, the two thin film transistors TijA and TijB corresponding to one pixel Pij are connected to separate gate pass lines Gia and Gib, respectively. Therefore, when all the gate pass lines are sequentially scanned and display data is supplied from the data bus line, if there is a pixel that exhibits an abnormality in display, the defective thin film transistor can be identified from the gate pass line at which the abnormality occurred.

Furthermore, if the panel with the above configuration is driven as described above, two thin film transistors TijA and Tij corresponding to each pixel Pij
Since the same display data is supplied to both ijB, even if one thin film transistor is disconnected, the display data of the adjacent pixel will not be supplied, and therefore the position of the displayed content will shift. There isn't.

In addition, in the above scanning, (1) the scanning time is divided into two, and in each row, the gate pass line at the front in the scan order (this is referred to as the first gate bus line Gia) is scanned in the first half, and the gate bus line at the rear in the second half is scanned. line (this is connected to the second gate bus line G
By scanning (referred to as ib), that is, by performing double-speed scanning, driving can be performed at the same scanning period as in the conventional method.

Furthermore, since the panel configured as described above allows the location of defective elements to be easily identified, the operation of all thin film transistors is inspected in advance and defective elements are separated before connection to an external circuit. Thereafter, by connecting to an external circuit and performing the above-described driving, defect-free display can be performed without causing any displacement of the displayed content.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

In this embodiment, as shown in FIG. 1, two thin film transistors TijA and TijB are provided for each pixel Pij. On the other hand, as a scan path line, 2
Installed wooden gate bus lines Gia and Gib,
A pixel electrode Eij of each pixel Pij is arranged between two adjacent data bus lines DBj and DBj+1.

Two gate pass lines G i corresponding to each pixel Pij above
In this embodiment, a and G ib are arranged adjacent to each other with each pixel Pij in between. These two tree gate bus lines Gia,
It is assumed that G ib is scanned in this order.

Among the four intersections with the two gate bus lines Gia and G+b arranged corresponding to each pixel Pij, the intersection between the gate pass line Gia in the previous scanning order and the data bus line DBj in the previous digit position A thin film transistor TijA was connected to the intersection, and another thin film transistor TijB was connected to the intersection at a diagonal position.

The two thin film transistors TijA and Tijm scan independently within one scanning time as shown in the figure, and in synchronization with this scanning, display data is supplied to the thin film transistor Tij^ from the data bus line DBj, and to TijB from the DBj+1. do. In other words, double speed scanning is performed.

FIG. 2 is a block diagram of essential parts showing a circuit configuration for driving this embodiment.

The liquid crystal panel l of this embodiment has 200 scanning lines, therefore the number of gate bus lines is 400, and the number of pixels on the l line is 320. Therefore, the number of data bus lines is 3.
There were 21 pieces.

The above 400 gate pass lines are sequentially scanned by a scan driver 2, and display data is supplied from a data driver 3.

In this embodiment, each pixel has two thin films]・transistor T
The display data supplied via ijA and Tijm are the same. However, the data bus line that supplies the display data is different when the thin film transistor TijA is selected and when the thin film transistor TijB is selected.

Therefore, when the gate bus line Gia is selected, display data is set from the beginning of the data driver 3, and when Gib is selected, the same display data is set from the second digit.

In order to perform double-speed scanning in this way, the same display data is
line memory 4 to set it in the data driver 3.
is provided to hold the above display data.

The timing generation circuit 5 generates a data clock, a scan clock 1-day latch signal, and a start pulse, and controls the above-mentioned operations of the scan driver 2 and data driver 3 using these signals.

FIG. 3 is a timing diagram showing the operation of this embodiment.

As shown in the figure, a scan start pulse is sent out in synchronization with the vertical synchronization signal, and based on this, 400 scan clocks are output per frame. Every time this scan clock is output, the gate pass line G
ia is sequentially scanned from the beginning.

A horizontal synchronization signal is output in synchronization with the vertical synchronization signal. The interval between two consecutive horizontal synchronizing signals is one scanning time, and in this embodiment, this one scanning time is divided into two, and one film transistor T i J A is divided into two in the first half, and the other one is divided into two in the second half. The film transistor TijB is scanned.

In the first half of the scanning time for each line, the contents of the line memory 4 are transferred to the data driver 3 using 320 data clocks, and are stored within 320 bits from the beginning. This data is written as display data to each pixel via the thin film transistor TijB.

In the latter half of each scanning time, the contents of the line memory 4 are
The data is transferred to the data driver 3 using 321 data clocks and stored between the 2nd bit and the 321st bit. This data is written to each pixel via the thin film transistor Tijs.

Repeat this operation for every 200 lines to make one screen (
1 frame) is completed.

In this embodiment, each intersection of 200 gate pass lines Gia and Gib and 321 data bus lines DBij corresponds to only one thin film transistor, and one intersection corresponds to two or more thin film transistors. There's nothing to do. Therefore, if a display abnormality occurs during the operation described in j.2, the defective thin film transistor can be identified from its position and tie name.

Even after detecting a defective transistor and separating the defective transistor in this manner, no pixel shift occurs in the panel of this embodiment. In other words, at any pixel,
Two thin film transistors T! Since the same data is supplied through C and TijB1, even if one of them is removed as a defective transistor, normal display data will be supplied from the remaining transistor, and the display data of the adjacent pixel will be supplied as before. It will not be done.

〔Effect of the invention〕

As explained above, according to the present invention, the yield of active matrix panels can be improved by the redundant diagram B configuration, and the problem of pixel misalignment after repairing defects in thin film transistors can be eliminated, and thin film transistors can be manufactured at low cost and with excellent display quality. A matrix type liquid crystal display device can be realized.

In the figure, 1 is an active matrix liquid crystal panel, 2 is a scan driver, 3 is a data driver, 4 is a line memory, 5 is a timing generation circuit, Pij is a pixel, and Ei
j is a pixel electrode, TijB1 and TijB are three-film transistors provided corresponding to each pixel, GiaGib is a gate pass line, and DBj is a data bus line.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a configuration diagram of the present invention, Fig. 2 is a drive circuit configuration diagram of the present invention, Fig. 3 is a drive timing diagram of the present invention, and Figs. 4 and 5 are conventional diagrams. FIG. 2 is a diagram illustrating problems in the redundant configuration of 1st run-f-Time flat leaf PFI/I course α Ming exit 1st figure 41pH1R4t+ i-i p, q-\leia, 1,4 shi 11 ring 5'Iz; 7-rrg Fig. 3 DB+ B2 B3 Conventional ＾／'、'lCollection Katsuko-'s Figure 4

Claims (2)

[Claims] (1) Two thin film transistors (Tij_A,
A plurality of pixels (Pij) associated with Tij_B) are arranged in a matrix, and two gate bus lines (Gia, Gib), first and second, are provided corresponding to each row, and each pixel Pij is It is arranged between two adjacent data bus lines (DBj and PBj+1), and each pixel (P
ij) Two gate bus lines (Gia, Gib)
) and two adjacent data bus lines (
One of the two thin film transistors (Tij_A, Tij_B) corresponding to each pixel is connected to each of the two diagonally located intersections among the four intersections of DBj and DBj+1). active matrix panel. (2) When driving the active matrix panel, the scanning time for each row is divided into two, and on one side and the other side, two thin film transistors (
Tij_A, Tij_B) are scanned separately, and the two thin film transistors (Tij_A, Tij_B) are scanned separately.
2. The method of driving an active matrix panel according to claim 1, further comprising supplying the same display data to the display panel B).