JP3290602B2 - Liquid crystal display device inspection method and liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is related to method of inspecting an active matrix liquid crystal display device.

[0002]

2. Description of the Related Art In recent years, a liquid crystal display device has attracted attention as a display device for displaying characters and information because of its size and low power consumption. Among them, an active matrix type liquid crystal display device in which a switching element typified by a TFT (thin film transistor) is connected to each pixel electrode in order to quickly display a moving image and display a moving image clearly has attracted attention.

Active matrix type liquid crystal display devices include those in which pixel electrodes for displaying red, green, and blue are arranged in a delta arrangement and those in which they are arranged in a stripe arrangement. FIGS. 12 and 13 show a liquid crystal display device in which pixel electrodes are arranged in a delta arrangement.
Shown in

A pixel electrode 11R for displaying red, a pixel electrode 11G for displaying green, and a pixel electrode 11B for displaying blue.
Are arranged in a delta arrangement, and a gate wiring 12 and a source wiring 13 are arranged by sewing between the pixel electrodes 11.
At the intersection of the gate line 12 and the source line 13, a TFT
Switching element 1 represented by (thin film transistor)
The pixel electrode 11 and the source line 13 are electrically connected / disconnected by the potential applied to the gate line 12.

The pixel electrode 11 of the same color is connected to one of the gate lines 12.
The pixel electrodes 11 of the same color, which are arranged in the same column for each wiring and are adjacently arranged via the gate wiring 12, are shifted by 1.5 pixels.

In this delta arrangement, two pixel electrodes 11 of different colors are connected to one source line 13 via a switching element 14 for each pixel. 15a is a drive circuit for applying a drive potential to the gate line 12, 15b is a drive circuit for applying a drive potential to the source line 13, 15c
Is a drive circuit for applying a drive potential to the counter electrode 17, and the drive circuits 15a, 15b and 15c are arranged outside the screen.

FIG. 13A is a sectional view taken along the line AA 'of FIG. 12, and FIG. 13B is a sectional view taken along the line BB' of FIG. The pixel electrode 11 faces the counter electrode 17 with the liquid crystal 16 interposed therebetween, and displays characters and information by changing the ratio of transmitted light according to the potential difference between the pixel electrode 11 and the counter electrode 17.

FIG. 14 shows a state of an inspection step before completion of a liquid crystal display device in which pixel electrodes are arranged in stripes.

[0009]

In order to produce a liquid crystal display device with a high yield, conventionally, driving circuits 15a and 15
Before forming b and 15c, a defect inspection is performed to apply a potential to all the gate lines 12, the source lines 13 and the counter electrode 17 to display white, black, red, green and blue screens.

In this defect inspection, a probe is mainly used to connect the inspection circuit to the gate wiring 12 and the source wiring 13. However, if the liquid crystal display device becomes small and high definition, it becomes difficult or impossible to make the probe. Become.

In a liquid crystal display device in which the pixel electrodes 11 are arranged in a stripe arrangement, one inspection wiring G connected to all the gate wirings 12 as shown in FIG. Three inspection lines S1, S2, S3 connecting all the source lines 13 for each of red, green, and blue
And a single inspection wiring C connected to the counter electrode 17, a total of five inspection wirings 18 are added, and the inspection wiring 18 and the inspection circuit are connected and inspected. A simple inspection configuration in which cutting is performed is adopted.

However, in this configuration, the switching element 1
4 must always be inspected in a conductive state, and a failure due to conduction / interruption of the switching element 14 cannot be detected.

Further, when the pixel electrode 11 is used in a liquid crystal display device arranged in a delta arrangement, one source line 1
Since the two-color pixel electrodes 11 are connected to 3, the display cannot be performed in red, green, and blue, and the inspection detection rate is reduced.

According to the present invention, a defect inspection can be performed without using a probe, and even when pixel electrodes are arranged in a delta arrangement, red, green, and blue can be displayed, and the inspection detection rate can be improved. It is an object to realize a liquid crystal display device.

Another object of the present invention is to realize a liquid crystal display device capable of detecting a defect caused by a switching element when pixel electrodes are arranged in a stripe array.

[0016]

According to the inspection method for a liquid crystal display device of the present invention, two inspection wirings are added to the gate wiring, and one of the two inspection wirings is alternately provided for each gate wiring. The present invention is characterized in that the inspection is performed by alternately applying a potential for electrically connecting the switching element to the two inspection wirings.

According to the present invention, even when the pixel electrodes are arranged in a delta arrangement, red / green / blue display is possible, and a simple inspection is possible. In addition, when the pixel electrodes are arranged in a stripe arrangement, a defect caused by the switching element can be detected.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 is for red, green,
Pixel that displays only one of the three blue colors
A plurality of electrodes, and the three colors and the pixel electrode
A display color of each of the pixel electrodes
However, only the same pixel electrode is electrically connected via the switching element.
Mat having a plurality of source lines connected to the
In the liquid crystal display device of the Rix system, the red, green, blue
Three source-side inspection wires for each of the three colors
All source lines with the same pixel electrode color for each inspection line
Connected to each other, and the gate lines are alternately connected to each other.
Gate side inspection wiring and one connected to the opposite electrode
Remove the inspection electrode group consisting of the counter electrode side inspection wiring
It is a liquid crystal display device provided as possible.

According to the second aspect of the present invention, three colors of red, green and blue are provided.
Multiple pixel electrodes that display only one of the colors
Several, and the three colors and the pixel electrodes are arranged in a delta arrangement.
And two of the three colors displayed on each of the pixel electrodes.
Only pixel electrodes of colors are electrically connected via switching elements.
Active matrices with multiple source lines connected
In the liquid crystal display device of the matrix type, the red, green and blue
A combination of three colors consisting of a combination of two of the three colors
The source side inspection wiring has three source side inspection wirings for each alignment.
The combination of two colors of the pixel electrode is the same for each inspection wiring
All source lines are connected, and gate lines alternate every other line
Two gate-side inspection wires connected to the
Inspection electrode consisting of one continuous counter electrode side inspection wiring
Groups, is a liquid crystal display device which is provided to be except that Installing.

The invention according to claim 3 is the invention according to claim 1 or claim
Item 2. In the liquid crystal display device according to item 2, two gate side inspections
A potential to electrically conduct the switching element to each wiring
Is applied alternately, and after inspection, source side inspection wiring
And the source wiring, and the gate side inspection wiring and the front.
Connection with the gate wiring, and the counter electrode side inspection wiring and
Necessary for normal operation of the liquid crystal display device in connection with the counter electrode.
Inspection of liquid crystal display devices to open unnecessary electrical connections
Is the way.

According to a fourth aspect of the present invention, there is provided the liquid according to the first aspect.
In the inspection method for a liquid crystal display device, a liquid crystal display device which performs an inspection by setting a period in which a switching element is in a conductive state to 以下 or less of a period in which a potential is alternately applied to two gate-side inspection lines.
This is a method of inspecting the position.

The invention according to claim 5 is the invention according to claim 3 or claim
Terms in 4 testing method of the liquid crystal display device according, the liquid crystal display instrumentation for the switching frequency of the switching elements to alternately conduct the two gate side inspection line in the above 24Hz inspect
This is a method of inspecting the position.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
It will be described based on. FIG. 1 shows a liquid crystal display device in which pixel electrodes are arranged in a delta arrangement, and includes six inspection lines S1, S2, S
3, G1, G2, and C are formed on the glass substrate on which the pixel electrode 11 is formed by being drawn out of the display range.

The inspection wiring G1 is connected to all the gate wirings 12 in the odd-numbered columns, such as the first column, the third column, and the fifth column arranged along the gate wiring 12. I have. The inspection lines G2 are connected to all the gate lines 12 in the even-numbered columns, such as the second column, the fourth column, the sixth column,... Arranged along the gate lines 12.

The inspection wiring S1 is connected to all the source wirings 13 to which the pixel electrodes 11 for displaying red and green are connected via the switching elements 14 among the source wirings 13.

The inspection wiring S2 is connected to all the source wirings 13 to which the pixel electrodes 11 for displaying green and blue are connected via the switching elements 14 among the source wirings 13.

The inspection wiring S3 is connected to all the source wirings 13 to which the pixel electrodes 11 for displaying blue and red are connected via the switching elements 14 among the source wirings 13.

The inspection wiring C is connected to the counter electrode 17. Next, in the liquid crystal display device of the present invention, white, black,
FIGS. 2 to 6 show test signal waveforms when performing red, green, and blue display, respectively. Inspection wirings G1, G2, S1, S2
The signal waveforms applied to S3 and C are Vg1 and Vg, respectively.
2, Vs1, Vs2, Vs3, and VC. In order to make the switching element 14 fully electrically conductive / interrupted, V
The signal potentials applied to g1 and Vg2 are Von and Voff
And The potential applied to the counter electrode 17 is defined as Vc.

The pixel electrodes 11A, 11B, 11C, 11
The potential difference between D, 11E, 11F and the counter electrode 17, that is, the liquid crystal voltage applied to the liquid crystal 16 is represented by V11A, V11B,
V11C, V11D, V11E, and V11F.

In this liquid crystal display device, the pixel electrode 1
The liquid crystal displays red, green, and blue when the potential difference between the counter electrode 1 and the counter electrode 17 is small, and displays black when the potential difference is large. Until the pixel electrode 11 and the counter electrode 1
7 is maintained.

The pixel electrode 11A in the case where a test signal waveform shown in FIGS. 2-6 and indicia pressure, 11B, 11C, 11D, 11
E, 11F, liquid crystal voltage waveforms V11A, V11B,
V11C, V11D, V11E, V11F, the relationship between the display color of each pixel electrode, and the display color of the entire screen,
7 to 11 respectively.

As described above, the number of inspection wirings 18 connected to the gate wiring 12 is two, G1 and G2.
By alternately applying the Von potential applied to the two inspection lines G1 and G2, white, black, red, green, and blue can be displayed, and it can be seen that a simple inspection can be realized.

The period τb during which the Von potential is applied is Von
It is necessary to set the potential to not more than の of the period τa for alternately applying the potential to the two inspection wirings G1 and G2. The gate waveforms VG1 and VG2 applied to the gate line 12 are delayed due to the resistance and capacitance of the test lines G1 and G2 and the gate line 12. If the time for applying the Von potential is too long, a delay occurs in a waveform that changes from Von to Voff, so that the switching element 14 cannot be electrically cut off, and a failure due to the switching element 14 may not be detected.

Therefore, the period for applying the Von potential is Vo
It is necessary to secure a sufficient time for shutting off the switching element 14 by setting the n potential to 以下 or less of a period in which the n potential is alternately applied to the two inspection wirings G1 and G2.

The cycle of the potential for applying the Von potential to the two inspection wirings must be 24 Hz or more at which flicker is not recognized by human eyes. Further, even if the number of test lines is increased to two, the gate waveforms VG1 and VG2 applied to the odd-numbered gate lines 12 and the even-numbered gate lines connected to the two test lines are made the same, and the odd-numbered and even-numbered gate lines are set. The liquid crystal voltages at the pixel electrodes connected to the gate lines are made equal. That is, in FIG.
1A = V11F "" V11B = V11C ""
In order to set V11D = V11E ″, of the two inspection wirings connected to the gate wiring, the gate wiring is connected to one inspection wiring and intersected with the other inspection wiring. It is necessary to make the resistance and the capacitance generated in the test wirings the same.

After the inspection is completed, a part of the pattern is blown by irradiating a laser beam along a dashed line T shown in FIG. 1 to open an electrical connection pattern between the inspection wiring, the source wiring, the gate wiring, and the counter electrode. And finished into a product. Alternatively, in the case of the liquid crystal display device to be inspected before the drive circuits 15a, 15b, and 15c are formed, the drive circuits 15a,
15b and 15c are formed and finished into a product.

In the above embodiment, a part of the pattern is blown by irradiating a laser beam to open the electrical connection pattern between the inspection wiring and the source wiring, the gate wiring, and the counter electrode. A part of the substrate is cut and separated at the position of the cutting part T, and the inspection wiring and the source wiring are separated.
The electrical connection pattern between the gate wiring and the counter electrode can be opened.

In the above embodiment, the liquid crystal display device in which the pixel electrodes are arranged in a delta arrangement has been described as an example. However, the present invention is also effective for a liquid crystal display device in which the pixel electrodes 11 are arranged in a stripe arrangement. The number of test wirings 18 connected to the gate wiring 12 is reduced to two, and the Von potential applied to the two test wirings G1 and G2 is alternately applied to detect a defect caused by conduction / interruption of the switching element 14. can do.

[0039]

As described above, according to the present invention, red, green,
Even if pixel electrodes for displaying blue are arranged in a delta arrangement, and two pixel electrodes of two colors are connected to one source wiring via a switching element, two inspection wirings are added to the gate wiring, and the switching element is formed. A liquid crystal display device that can perform red, green, and blue display in the same manner as a liquid crystal display device in which pixel electrodes are arranged in a stripe array by alternately applying a potential to be electrically conducted, and can perform a simple inspection. Can be realized.

When pixel electrodes for displaying red, green, and blue are arranged in a stripe arrangement, there is an advantage that a defect caused by conduction / interruption of the switching element can be detected.

[Brief description of the drawings]

FIG. 1 is a plan view of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a test signal waveform diagram in the case of white display.

FIG. 3 is a test signal waveform diagram in the case of black display.

FIG. 4 is a test signal waveform diagram in the case of red display.

FIG. 5 is a test signal waveform diagram for a green display.

FIG. 6 is a test signal waveform diagram in the case of blue display.

FIG. 7 is a liquid crystal voltage waveform diagram for each pixel in the case of white display.

FIG. 8 is a liquid crystal voltage waveform diagram for each pixel in the case of black display.

FIG. 9 is a liquid crystal voltage waveform diagram for each pixel in the case of red display.

FIG. 10 is a liquid crystal voltage waveform diagram for each pixel in the case of green display.

FIG. 11 is a liquid crystal voltage waveform diagram for each pixel in the case of blue display.

FIG. 12 is a plan view of a conventional liquid crystal display device in which pixel electrodes are arranged in a delta arrangement.

FIG. 13 is a sectional view of the conventional example.

FIG. 14 is a plan view of a conventional liquid crystal display device in which pixel electrodes are arranged in stripes.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Pixel electrode 12 Gate wiring 13 Source wiring 14 Switching element 15a, 15b, 15c Driving circuit 16 Liquid crystal 17 Counter electrode 18 Test wiring T Cutting part

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01M 11/00-11/02 G01R 31/00 G01R 31/24-31/25 G02F 1/13-1 / 133 G02F 1/137

Claims (5)

(57) [Claims] 1. One of three colors of red, green and blue
A plurality of pixel electrodes for displaying only the three colors,
The pixel electrodes are arranged in a stripe array, and the pixel electrodes
Only pixel electrodes with the same display color among the poles are switched on
Source wirings that are electrically connected via
Active matrix liquid crystal display device
There are three source-side inspection wires for each of the three colors red, green, and blue.
The display color of the pixel electrode is the same for each of the source side inspection wirings.
One source line is connected, and one gate line
Two gate-side inspection wirings connected alternately for each
It consists of one counter electrode side inspection wiring connected to the electrode
A liquid crystal display device in which a test electrode group is provided so as to be removable. 2. Any one of three colors of red, green and blue
A plurality of pixel electrodes for displaying only the three colors,
The pixel electrodes are arranged in a delta arrangement, and each of the pixel electrodes is
Only two pixel electrodes out of the three displayed colors are switched.
Source wiring that is electrically connected through the
Active matrix type liquid crystal display device having plural lines
In the above, a combination of two of the three colors of red, green and blue
Source-side inspection wires for each of the three different color combinations
The color of the display of the pixel electrode for each of the source side inspection wirings.
All of the source lines having the same combination are connected, and two gate-side inspection lines are connected alternately for each gate line, and one counter electrode-side inspection line is connected to the counter electrode. A liquid crystal display device in which a test electrode group is provided so as to be removable. 3. The liquid crystal display device according to claim 1 or 2.
Inspection of a switching element on each of the two gate-side inspection wires
Inspection is performed by alternately applying a potential for electrical conduction, and after the inspection, the connection between the source-side inspection wiring and the source wiring is performed.
And connection between the gate-side inspection wiring and the gate wiring.
And the connection between the counter electrode side inspection wiring and the counter electrode.
Electrical connections that are not required for normal operation of the LCD
Inspection method of liquid crystal display device to open. 4. The switching element according to claim 1, wherein said switching element is in a conductive state for 2 hours.
Of the period in which the potential is alternately applied to the gate-side inspection wires
4. The inspection method for a liquid crystal display device according to claim 3, wherein the inspection is performed at a ratio of not more than / 2. 5. The inspection method for a liquid crystal display device according to claim 3, wherein the switching frequency of the switching element which is alternately conducted to the two gate-side inspection wirings is set to 24 Hz or more.