CN106448519B - display device - Google Patents

Abstract

A display device includes a display panel, including a plurality of pixel units and a plurality of test pads. The test pad is coupled to the pixel unit to provide a test signal to the pixel unit. The pixel unit is divided into a plurality of first sub-pixels, a plurality of second sub-pixels and a plurality of third sub-pixels according to the display color. Three sub-pixels displaying different colors constitute a pixel, and the first sub-pixel is coupled to a first test pad, the second sub-pixel is coupled to a second test pad, and the third sub-pixel is coupled to a third test pad and a fourth test pad, wherein a portion of the third sub-pixels are coupled to the third test pad, and another portion of the third sub-pixels are coupled to the fourth test pad.

Description

Display device

technical field

The invention relates to a display device, in particular to a display device capable of avoiding voltage offset generated by a common voltage.

Background technique

An Organic Light Emitting Diode (OLED for short) display that uses organic compounds as lighting materials for lighting is a type of flat panel display. The advantages of OLED displays are small size, light weight, wide viewing angle, high contrast and high speed.

Active Matrix Organic light emitting diode (AMOLED) displays have recently become the next generation of emerging flat panel displays. Compared with Active Matrix Liquid Crystal Displays (AMLCD for short), AMOLED displays have considerable advantages, such as higher contrast, wider viewing angles, thinner modules without backlight, lower power consumption and lower low cost.

Whether it is for traditional liquid crystal displays, OLED displays, or for recently developed AMLCD, AMOLED displays, or other types of displays, there may be color shift problems caused by poor circuit design.

Therefore, in order to avoid the occurrence of the color shift problem, a novel display device design is needed, which avoids the voltage shift caused by the common voltage through a novel circuit configuration, so that the display device does not have the color shift problem.

Contents of the invention

The invention discloses a display device, which includes a display panel, including a plurality of pixel units and a plurality of test pads, and the test pads are coupled to the pixel units for providing test signals to the pixel units. The pixel unit is divided into a plurality of first sub-pixels, a plurality of second sub-pixels and a plurality of third sub-pixels according to the display color, and wherein three sub-pixels displaying different colors constitute a pixel, and wherein the first sub-pixel is coupled connected to a first test pad, the second sub-pixel is coupled to a second test pad, and the third sub-pixel is coupled to a third test pad and a fourth test pad, wherein a part of the third sub-pixels is coupled to the third test pad, and another part of the third sub-pixels is coupled to the fourth test pad.

The invention discloses another display device, which includes a display panel, including a plurality of pixel units and a plurality of test pads, and the test pads are coupled to the pixel units for providing test signals to the pixel units. Wherein the pixel unit is divided into a plurality of first sub-pixels, a plurality of second sub-pixels and a plurality of third sub-pixels according to the display color, and wherein three sub-pixels displaying different colors constitute a pixel, and wherein the test pad, the first A sub-pixel receives a first test signal with a first polarity, a second sub-pixel receives a second test signal with a second polarity, and a third sub-pixel receives a third test signal with the first polarity A test signal and a fourth test signal with a second polarity, wherein a part of the third sub-pixels receives the third test signal, and another part of the third sub-pixels receives the fourth test signal.

Description of drawings

FIG. 1 is a block diagram showing a display device according to an embodiment of the invention.

FIG. 2 is a circuit diagram showing an example of a pixel unit according to an embodiment of the present invention.

Figure 3 shows an example of a test pad design.

FIG. 4 is a schematic diagram of an example of a common voltage offset.

FIG. 5 shows an example of a test pad design according to an embodiment of the present invention.

FIG. 6 is a schematic diagram showing the common voltage and the equivalent common voltage according to an embodiment of the present invention.

【Symbol Description】

100～display device;

101, 301, 501～display panels;

102～input unit;

110～gate drive circuit;

120～data drive circuit;

130～pixel matrix;

140～control chip;

200～pixel unit;

303, 503～Visible area;

B_pad, BE_pad, BO_pad, R_pad, G_pad～test pad;

B_pad(+), BE_pad(-), BO_pad(+), R_pad(+), G_pad(-)～test pad voltage polarity;

Cnk～LCD capacitance;

D1, D2, D3, D4, D5, Dn, DN ~ data line;

Equal_VCOM～equivalent voltage;

Gk～gate line;

P1, P2, PM～pixel;

SP1, SP2, SP3～sub-pixel;

Tnk ~ transistor;

VCOM～common voltage;

Vg～pressure difference.

Detailed ways

In order to make the above and other objects, features and advantages of the present invention more comprehensible, preferred embodiments are specifically cited below and described in detail with accompanying drawings.

FIG. 1 is a block diagram showing a display device according to an embodiment of the invention. As shown in the figure, the display device 100 may include a display panel 101 , a data driving circuit 120 and a control chip 140 , wherein the display panel 101 includes a gate driving circuit 110 and a pixel matrix 130 . The gate driving circuit 110 is used for generating a plurality of gate driving signals to drive a plurality of pixels of the pixel matrix 130 . The data driving circuit 120 is used for generating a plurality of data driving signals to provide image data to a plurality of pixels of the pixel matrix 130 . The control chip 140 is used to generate a plurality of timing signals, including a clock signal, a reset signal, a start pulse, and the like.

In addition, the display device 100 may further include an input unit 102 . The input unit 102 is used for receiving image signals to control the display panel 101 to display images. According to the embodiment of the present invention, the display device 100 can be applied in an electronic device, wherein the electronic device has various implementations, including: a mobile phone, a digital camera, a personal digital assistant, a mobile computer, a desktop A computer, a television, a monitor for a car, a portable disc player, or any device including an image display function.

According to an embodiment of the present invention, the gate drive circuit 110 may be designed as a gate drive circuit for unilateral drive and disposed on one side of the pixel matrix 130, or may be designed as a gate drive circuit for double-side drive, And they are arranged on both sides of the pixel matrix 130 , and the present invention is not limited to any one implementation. In addition, although in FIG. 1 , the gate driving circuit 110 is disposed outside the pixel matrix 130 , the present invention is not limited thereto. In other embodiments of the present invention, the gate driving circuit 110 may also be disposed on the pixel matrix 130 . Likewise, although in FIG. 1 , the gate driving circuit 110 is disposed on the display panel 101 , the present invention is not limited thereto. In other embodiments of the present invention, the gate driving circuit 110 may not be disposed on the display panel 101 .

According to an embodiment of the present invention, the pixel matrix 130 may include a plurality of pixel units, and each pixel unit is connected to a set of interleaved gate lines and data lines.

FIG. 2 is a circuit diagram showing an example of a pixel unit according to an embodiment of the present invention. According to an embodiment of the present invention, the pixel unit 200 shown in FIG. 2 may be one of the plurality of pixel units in the pixel matrix 130 . The pixel unit 200 can be coupled to the nth data line Dn and the kth gate line Gk of the display panel 101 , where n and k are positive integers. The pixel unit 200 may include a transistor Tnk and a liquid crystal capacitor Cnk coupled to a common voltage VCOM.

For a color display, a pixel unit can correspond to a single sub-pixel (sub-pixel), for example, red (represented by R), blue (represented by B) or green sub-pixel (represented by G), and one group of RGB The sub-pixels (corresponding to the pixel unit described in the embodiments of the present invention) can form a single pixel.

Generally speaking, the display panel includes a visible (Active Area, AA) area and a frame area (Frame Area). Several test pads may be provided in the border area to test whether each pixel (including sub-pixels) in the visible area can be successfully lit, so as to select a faulty display panel.

For display devices used in small-sized electronic devices (eg, the above-mentioned mobile phones, digital cameras, personal digital assistants, etc.), the number of test pads must also be limited due to the limited size of the frame area. However, the display device may have a problem of color shift due to this.

Figure 3 shows an example of a test pad design. As shown in the figure, the display panel 301 can be provided with three test pads R_pad, G_pad and B_pad, which are respectively used to couple to the data lines D1, D2 . When the transistor coupled to the test pad is turned on, the test signal can be transmitted to each pixel unit by providing the test pads R_pad, G_pad and B_pad.

The test pad R_pad is coupled to the data lines coupled to the red sub-pixels for providing test signals to test the red sub-pixels, and the test pad G_pad is coupled to the data lines coupled to the green sub-pixels for providing test signals To test the green sub-pixel, the test pad B_pad is coupled to the data lines coupled to the blue sub-pixel to provide a test signal to test the blue sub-pixel, wherein three sub-pixels displaying different colors can constitute a pixel, For example, pixels P1, P2...PM.

The positive and negative symbols marked under each test pad represent the voltage polarity of the test signal provided to these test pads relative to the common voltage VCOM, where the positive sign indicates that the voltage difference of the test signal relative to the common voltage VCOM is positive and negative. The sign indicates that the voltage difference of the test signal relative to the common voltage VCOM is negative.

However, such an arrangement cannot achieve polarity balance, so that when the transistor coupled to the test pad is turned on, the level of the common voltage VCOM will have a coupling effect due to the supply of the test signal, resulting in a voltage offset.

FIG. 4 is a schematic diagram of an example of a common voltage offset, in which the test pad receiving the voltage pulse and its voltage polarity are marked under each voltage pulse. As shown in the figure, since the number of data lines receiving the positive polarity test signal is more than that of the negative polarity test signal, the level of the original common voltage VCOM is shifted to the level of the equivalent voltage Equal_VCOM due to the coupling effect. In this way, due to the relatively large voltage difference Vg between the equivalent voltage Equal_VCOM and the test signal supplied by the green test pad G_pad, the color displayed on the display panel is greenish.

In order to solve the above-mentioned color shift problem caused by unbalanced polarity, a new test pad configuration design will be introduced below to achieve polarity balance.

According to an embodiment of the present invention, the plurality of pixel units included in the display panel can be divided into three sub-pixels according to the displayed colors, including a plurality of first sub-pixels, a plurality of second sub-pixels and a plurality of third sub-pixels Pixels, such as, but not limited to, the above-mentioned red, blue and green sub-pixels. Three of the sub-pixels displaying different colors can form a pixel.

In addition, the display panel may include a plurality of test pads coupled to the pixel units for providing test signals to the pixel units. In an embodiment of the present invention, in order to achieve polarity balance, the number of test pads is configured as an even number.

According to an embodiment of the present invention, one of the three sub-pixels displaying different colors is selected and divided into two parts, which respectively receive test signals of different polarities. More specifically, according to an embodiment of the present invention, one of the three sub-pixels displaying different colors is selected, divided into two parts, respectively coupled to different test pads, and through these test pads Provide test signals with different polarities.

For example, in one embodiment of the present invention, the first sub-pixel is coupled to a first test pad, the second sub-pixel is coupled to a second test pad, and the third sub-pixel is coupled to a third The test pad and a fourth test pad, wherein a number of third sub-pixels coupled to the third test pad is equal or nearly equal to a number of third sub-pixels coupled to the fourth test pad. For example, the third sub-pixel can be equally divided into two parts, one part is coupled to the third test pad, and the other part is coupled to the fourth test pad.

According to an embodiment of the present invention, the third sub-pixels constituting the odd pixels may be designed to be coupled to the third test pad, and the third sub-pixels constituting the even pixels may be designed to be coupled to the fourth test pad. The odd-numbered pixels and the even-numbered pixels can be defined according to the numbers of the data lines they are connected to, or according to the pixel positions or pixel numbers of each pixel in the visible area.

In an embodiment of the present invention, a voltage of a test signal coupled to the first test pad and a voltage of a test signal coupled to the second test pad have different polarities with respect to the common voltage VCOM, and the third test A voltage of the test signal coupled to the pad and a voltage of the test signal coupled to the fourth test pad have different polarities with respect to the common voltage VCOM, thus achieving polarity balance.

For example, a first subpixel receives a first test signal with a first polarity through a test pad, a second subpixel receives a second test signal with a second polarity through a test pad, and a third subpixel receives a test signal with a second polarity through a test pad. A third test signal with a first polarity and a fourth test signal with a second polarity.

According to an embodiment of the present invention, the first polarity and the second polarity are voltage polarities relative to the common voltage VCOM, and the first polarity and the second polarity are opposite.

FIG. 5 shows an example of a test pad design according to an embodiment of the present invention. As shown in the figure, the display panel 501 can be provided with four test pads R_pad, G_pad, BO_pad and BE_pad, which are respectively used to couple to the data lines D1, D2...DN in the visible area 503. When the test pads are coupled After the transistor is turned on, the test signal can be transmitted to each pixel unit by providing test pads R_pad, G_pad, BO_pad and BE_pad.

The test pad R_pad can be coupled to the red sub-pixel, for example, sub-pixel SP1, the test pad G_pad can be coupled to the green sub-pixel, for example, sub-pixel SP2, and the test pad BO_pad can be coupled to constitute odd pixels, for example, pixel P1, The blue sub-pixel, for example, sub-pixel SP3, and the test pad BE_pad can be coupled to the blue sub-pixel, for example, sub-pixel SP3 constituting an even-numbered pixel, for example, pixel P2, wherein three sub-pixels displaying different colors A pixel, eg, pixels P1 , P2 . . . PM may be constituted.

The positive and negative symbols marked under each test pad represent the voltage polarity of the test signal provided to these test pads relative to the common voltage VCOM, where the positive sign indicates that the voltage difference of the test signal relative to the common voltage VCOM is positive and negative. The sign indicates that the voltage difference of the test signal relative to the common voltage VCOM is negative.

As shown in the figure, since the voltage polarities of the test signals received by the sub-pixels are balanced, that is, the numbers of positive polarity and negative polarity are equal or nearly equal, the level of the common voltage VCOM will not produce voltage deviation. shifting problem.

6 is a schematic diagram showing common voltages and equivalent common voltages according to an embodiment of the present invention, wherein the test pads receiving the voltage pulses and their voltage polarities are marked under each voltage pulse. In this embodiment, the voltage polarity of the test signal provided to the test pad R_pad is positive (marked as R_pad(+)), and the voltage polarity of the test signal provided to the test pad G_pad is negative (marked as G_pad(-) ), the voltage polarity of the test signal provided to the test pad BO_pad is positive (marked as BO_pad(+)), and the voltage polarity of the test signal provided to the test pad BE_pad is negative (marked as BE_pad(-)).

As shown in the figure, after the above test pads and voltage polarity configuration, the level of the equivalent voltage Equal_VCOM and the level of the original common voltage VCOM can still be kept equal or nearly equal, so there will be no problem of voltage offset.

It should be noted that the examples introduced above are only used to illustrate the concept of the present invention, but not to limit the scope of the present invention. For example, the test signal voltage polarities provided to each test pad can also be designed as R_pad(-), G_pad(+), BO_pad(-) and BE_pad(+).

In addition, the practicable manner of the present invention is not limited to dividing the test pad coupled to the blue sub-pixel into two test pads as described above. Based on the same concept, in the embodiment of the present invention, the test pad can also be designed to include RO_pad, RE_pad, G_pad and B_pad, wherein a part of the red sub-pixel is coupled to the test pad RO_pad, and another part of the red sub-pixel is coupled to to test pad RE_pad. The test signal voltage polarity provided to each test pad can be designed as RO_pad(+), RE_pad(-), G_pad(+) and B_pad(-), or it can be RO_pad(-), RE_pad(+), G_pad(-) and B_pad(+).

Similarly, based on the same concept, in the embodiment of the present invention, the test pad can also be designed to include R_pad, GO_pad, GE_pad and B_pad, wherein a part of the green sub-pixels is coupled to the test pad GO_pad, and the other part of the green sub-pixels The pixels are coupled to the test pad GE_pad. The test signal voltage polarity provided to each test pad can be designed as R_pad(+), GO_pad(-), GE_pad(+) and B_pad(-), or it can be R_pad(-), GO_pad(+), GE_pad(-) and B_pad(+).

With the above-mentioned test pad design and voltage polarity configuration, the level of the equivalent voltage Equal_VCOM can be kept equal or nearly equal to the level of the original common voltage VCOM, so the problem of voltage offset will not occur. In addition, this design is especially applicable to the display devices of small-sized electronic devices (such as the above-mentioned mobile phones, digital cameras, personal digital assistants, etc.), effectively solving the traditional color shift problem caused by the polarity imbalance caused by the limitation of frame size .

The use of the ordinal numerals "first", "second", "third" and the like to modify elements in the claims does not in itself imply any priority, order of precedence, order of priority among elements, or method performance The order of the steps of the above is used only as a label to distinguish between different elements with the same name (with different ordinal numbers).

Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Those skilled in the art may make some changes and modifications without departing from the spirit and scope of the present invention, so the protection scope of the present invention The scope defined by the appended claims shall prevail.

Claims (7)

1. a kind of display equipment, comprising:

Display pannel includes multiple pixel units and multiple testing cushions, and the testing cushion is coupled to the pixel unit, is used To provide test signal to the pixel unit,

Wherein the pixel unit is multiple first sub-pixels, multiple second sub-pixels and multiple thirds according to display hue distinguishes Sub-pixel, and wherein the sub-pixel of three display different colors constitutes pixel, and

Wherein first sub-pixel is both coupled to the first testing cushion, second sub-pixel is both coupled to the second testing cushion, and And the third sub-pixel is coupled to third testing cushion and the 4th testing cushion, the third sub-pixel of a portion is coupled to The third sub-pixel of the third testing cushion, another part is coupled to the 4th testing cushion, wherein the first testing cushion institute coupling The voltage of the test signal connect has from the voltage for the test signal that second testing cushion is coupled relative to common voltage different Polarity, and the test that the voltage for the test signal that wherein the third testing cushion is coupled and the 4th testing cushion are coupled is believed Number voltage relative to common voltage have different polarity.

2. display equipment as described in claim 1, wherein being coupled to the number of the third sub-pixel of the third testing cushion It measures equal with the quantity of the third sub-pixel of the 4th testing cushion is coupled to.

3. display equipment as described in claim 1, wherein the third sub-pixel for constituting odd pixel be coupled to this Three testing cushions, and the third sub-pixel for constituting even pixel is coupled to the 4th testing cushion.

4. a kind of display equipment, comprising:

Display pannel includes multiple pixel units and multiple testing cushions, and the testing cushion is coupled to the pixel unit, is used To provide test signal to the pixel unit,

Wherein the pixel unit is multiple first sub-pixels, multiple second sub-pixels and multiple thirds according to display hue distinguishes Sub-pixel, and wherein the sub-pixel of three display different colors constitutes pixel, and

Wherein by the testing cushion, first sub-pixel, which receives, has the first polar first test signal, described second Sub-pixel, which receives, has the second polar second test signal, and the third sub-pixel receive have this first polar the Three test signals and there is the second polar 4th test signal, the third sub-pixel of a portion receive this Three test signals, the third sub-pixel of another part receive the 4th test signal, wherein first polarity and this second Polarity is the polarity of voltage relative to common voltage, and first polarity is opposite with second polarity.

5. display equipment as claimed in claim 4, wherein first sub-pixel is both coupled to the first testing cushion, to logical It crosses first testing cushion and receives the first test signal, second sub-pixel is both coupled to the second testing cushion, to by being somebody's turn to do Second testing cushion receives the second test signal, and receives the third sub-pixel coupling of the part of third test signal Be connected to third testing cushion, and receive the 4th test signal the another part the third sub-pixel be coupled to the 4th survey Examination pad, to receive third test signal by the third testing cushion respectively and receive the 4th by the 4th testing cushion Test signal.

6. display equipment as claimed in claim 5, wherein being coupled to the number of the third sub-pixel of the third testing cushion It measures equal with the quantity of the third sub-pixel of the 4th testing cushion is coupled to.

7. display equipment as claimed in claim 5, wherein the third sub-pixel for constituting odd pixel be coupled to this Three testing cushions, and the third sub-pixel for constituting even pixel is coupled to the 4th testing cushion.