CN206271397U - A kind of OLED pixel circuit and display device - Google Patents

Abstract

The utility model provides an OLED pixel circuit and a display device, which relate to the field of display technology and can prevent a short-circuited sub-pixel from affecting the display of its surrounding sub-pixels. The OLED pixel circuit includes: a driving module, a light emitting module, and a short circuit protection module; Under the control of the scanning signal input terminal, the data signal input terminal, and the first voltage terminal, the light-emitting module is driven to emit light; the light-emitting module is also connected to the second voltage terminal for the connection between the driving module and the second voltage terminal. Under control, to emit light; the short-circuit protection module is connected to the driving module and the light-emitting module, and is used to control the driving module to turn off when a short-circuit occurs in the light-emitting module.

Description

A kind of OLED pixel circuit and display device

technical field

The utility model relates to the field of display technology, in particular to an OLED pixel circuit and a display device.

Background technique

With the rapid development of multimedia technology, OLED (Organic Light-Emitting Diode, organic light-emitting diode) has become a display due to its advantages such as self-illumination, high contrast, wide color gamut, simple preparation process, low power consumption, and easy realization of flexible display. An important light-emitting element in a device.

Among them, especially the AM-OLED (Active Matrix/Organic Light Emitting Diode, Active Matrix Organic Light Emitting Diode) display panel has no viewing angle limitation, low manufacturing cost, high response speed, low power consumption, wide operating temperature range, light weight, It can be used for DC drive of portable machines and has become a research hotspot with the advantages of miniaturization and thinning of hardware equipment.

As shown in Figure 1, in the pixel structure of the AM-OLED display panel, a group of transistors and a first capacitor are integrated in each sub-pixel, and the OLED in the sub-pixel is controlled by driving and controlling the transistor and the first capacitor. The current is controlled to drive the OLED to emit light.

However, since the film layers between the anode and cathode of the OLED are relatively thin, and there are foreign objects in the film layer, or the process of digging holes and climbing slopes is not well controlled, the film layer will be further thinned, making the anode and cathode of the OLED The resistance between them is small and a short circuit occurs, so that the voltage of the V2 terminal connected to the cathode increases. The V2 terminal between each sub-pixel is conductive, so the voltage of the V2 terminal of the short-circuited sub-pixel increases, which easily causes the voltage of the V2 terminal of its surrounding sub-pixels to also increase, thereby affecting the OLED cathode and anode in the surrounding sub-pixels. The pressure difference between them will affect the display of surrounding sub-pixels.

Utility model content

Embodiments of the present invention provide an OLED pixel circuit and a display device, which can prevent a short-circuited sub-pixel from affecting the display of its surrounding sub-pixels.

In order to achieve the above object, the embodiments of the present utility model adopt the following technical solutions:

In the first aspect, an OLED pixel circuit is provided, including a driving module, a light emitting module, and a short circuit protection module; the driving module is respectively connected to a scanning signal input terminal, a data signal input terminal, a first voltage terminal and the light emitting module, It is used to drive the light-emitting module to emit light under the control of the scan signal input terminal, the data signal input terminal, and the first voltage terminal; Under the control of the second voltage terminal, it emits light; the short-circuit protection module is connected to the driving module and the light-emitting module, and is used to control the driving module to turn off when a short-circuit occurs in the light-emitting module.

Preferably, the drive module includes a first transistor, a first capacitor and a second transistor; the gate of the first transistor is connected to the scan signal input terminal, the first pole is connected to the data signal input terminal, and the second pole is connected to the input terminal of the data signal. connected to the gate of the second transistor; the first pole of the second transistor is connected to the first voltage terminal, and the second pole is connected to the light emitting module; the first terminal of the first capacitor is connected to the first The second terminal of the transistor is connected to the first terminal of the second transistor; wherein, the second transistor is an N-type transistor.

Preferably, the drive module includes a first transistor, a first capacitor and a second transistor; the gate of the first transistor is connected to the scan signal input terminal, the first pole is connected to the data signal input terminal, and the second pole is connected to the input terminal of the data signal. connected to the gate of the second transistor; the first pole of the second transistor is connected to the first voltage terminal, and the second pole is connected to the light emitting module; the first terminal of the first capacitor is connected to the first The second terminal of the transistor is connected to the second terminal of the second transistor; wherein, the second transistor is an N-type transistor.

Preferably, the light emitting module includes an OLED, an anode of the OLED is connected to the driving module, and a cathode is connected to the second voltage terminal.

Preferably, the short circuit protection module includes a third transistor and a second capacitor; the gate and first pole of the third transistor are connected to the light emitting module and the driving module, and the second pole is connected to the second The first terminal of the capacitor; the second terminal of the second capacitor is connected to the driving module; wherein, the third transistor is a P-type transistor.

Further preferably, the driving module includes a first transistor, a first capacitor, and a second transistor; the light emitting module includes an OLED; the gate and the first electrode of the third transistor are respectively connected to the second transistor of the second transistor. The electrode is connected to the anode of the OLED; the second terminal of the second capacitor is connected to the second electrode of the first transistor and the gate of the second transistor.

Preferably, the short-circuit protection module includes a fourth transistor and a second capacitor; the gate of the fourth transistor is connected to both the light-emitting module and the driving module, and the first pole is connected to the light-emitting module and the second capacitor. Both voltage terminals are connected, and the second pole is connected to the first terminal of the second capacitor; the second terminal of the second capacitor is connected to the driving module; wherein, the fourth transistor is a P-type transistor.

Further preferably, the driving module includes a first transistor, a first capacitor, and a second transistor; the light emitting module includes an OLED; the gate of the fourth transistor is connected to the second pole of the second transistor and the OLED The anodes of both are connected, and the first pole is connected with the cathode of the OLED and the second voltage terminal; the second terminal of the second capacitor is connected with the second pole of the first transistor and the second transistor of the second transistor. Both gates are connected.

Preferably, the first transistor is an N-type transistor.

In a second aspect, a display device is provided, comprising the OLED pixel circuit described in the first aspect.

The embodiment of the present invention provides an OLED pixel circuit and a display device. By adding a short-circuit protection module to the OLED pixel circuit, and when the light-emitting module of the sub-pixel emits light normally, the short-circuit protection module is turned off; and when the light-emitting module of the sub-pixel After the short circuit, the short circuit protection module is turned on, and the drive module is controlled to be turned off, so that the signals of the first voltage terminal and the input terminal of the data line number cannot be output to the light emitting module. In this way, even if the light emitting module is short circuited, the second The signal at the voltage terminal will not increase, but will still maintain its original signal strength, thereby preventing the normal display of its surrounding sub-pixels from being affected by a short circuit in a certain sub-pixel.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are only some embodiments of the utility model, and those skilled in the art can also obtain other drawings based on these drawings without creative work.

FIG. 1 is a schematic structural diagram of an OLED pixel circuit provided in the prior art;

Fig. 2 is a schematic structural diagram of an OLED pixel circuit provided by an embodiment of the present invention;

Fig. 3 is a kind of specific structural schematic diagram 1 of each module in Fig. 2;

Fig. 4 is a kind of specific structural schematic diagram II of each module in Fig. 2;

Fig. 5 is a kind of specific structural schematic diagram three of each module in Fig. 2;

FIG. 6 is a schematic diagram 4 of a specific structure of each module in FIG. 2 .

reference sign

10-drive module; 20-light-emitting module; 30-short-circuit protection module; GATE-scanning signal input terminal; DATA-data signal input terminal; V1-first voltage terminal; V2-second voltage terminal; C1-first capacitor; C2-the second capacitor; T1-the first transistor; T2-the second transistor; T3-the third transistor.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. example. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

The embodiment of the present invention provides an OLED pixel circuit, as shown in FIG. 2 , including a driving module 10 , a light emitting module 20 , and a short circuit protection module 30 .

The driving module 10 is respectively connected to the scanning signal input terminal GATE, the data signal input terminal DATA, the first voltage terminal V1 and the light emitting module 20, for the scanning signal input terminal GATE, the data signal input terminal DATA, and the first voltage terminal V1. Under control, the light emitting module 20 is driven to emit light.

The light emitting module 20 is also connected to the second voltage terminal V2 for emitting light under the control of the driving module 10 and the second voltage terminal V2.

The short-circuit protection module 30 is connected to the driving module 10 and the light-emitting module 20 , and is used to control the driving module 10 to shut down when the light-emitting module 20 is short-circuited.

The embodiment of the present invention provides an OLED pixel circuit. By adding a short-circuit protection module 30 to the OLED pixel circuit, and when the light-emitting module 20 of the sub-pixel emits light normally, the short-circuit protection module 30 is turned off; and when the light-emitting module 20 of the sub-pixel After a short circuit occurs, the short circuit protection module 30 is turned on and controls the drive module 10 to be turned off, so that the signals of the first voltage terminal V1 and the data line number input terminal DATA cannot be output to the light emitting module 20. In this way, even if the light emitting module 20 is short circuited , the signal of the second voltage terminal V2 connected to the light-emitting module 20 will not increase, but still maintains its original signal strength, thereby preventing a sub-pixel from being short-circuited and affecting the normal display of its surrounding sub-pixels.

The specific structure of each module in FIG. 2 will be described in detail below in conjunction with specific embodiments.

Embodiment one

Embodiment 1 provides an OLED pixel circuit. As shown in FIG. 3 , a driving module 10 includes a first transistor T1 , a first capacitor C1 and a second transistor T2 .

The gate of the first transistor T1 is connected to the scan signal input terminal GATE, the first pole is connected to the data signal input terminal DATA, and the second pole is connected to the gate of the second transistor T2.

The first pole of the second transistor T2 is connected to the first voltage terminal V1 , and the second pole is connected to the light emitting module 20 .

A first end of the first capacitor C1 is connected to the second pole of the first transistor T1, and a second end is connected to the first pole of the second transistor T2.

Alternatively, as shown in FIG. 4 , the first terminal of the first capacitor C1 is connected to the second pole of the first transistor T1 , and the second terminal is connected to the second pole of the second transistor T2 .

The light emitting module 20 includes an OLED, an anode of the OLED is connected to the driving module 10, and a cathode is connected to the second voltage terminal V2.

The short-circuit protection module 30 includes a third transistor T3 and a second capacitor C2. The gate and first pole of the third transistor T3 are both connected to the light emitting module 20 and the driving module 10, and the second pole is connected to the first end of the second capacitor C2.

A second end of the second capacitor is connected to the driving module 10 .

Wherein, the second transistor T2 is an N-type transistor; the third transistor T3 is a P-type transistor.

More specifically, the first pole of the second transistor T2 is connected to the first voltage terminal V1, and the second pole is connected to the anode of the OLED.

As shown in Figure 3, the first terminal of the first capacitor C1 is connected to the second pole of the first transistor T1 and the gate of the second transistor T2, and the second terminal is connected to the first pole of the second transistor T2 and the first voltage Both terminals V1 are connected.

Or, as shown in FIG. 4, the first end of the first capacitor C1 is connected to the second pole of the first transistor T1 and the gate of the second transistor T2, and the second end is connected to the second pole of the second transistor T2 and the OLED The anodes are connected.

The gate of the third transistor T3 is connected to the second pole of the second transistor T2 and the anode of the OLED; the first pole is connected to the second pole of the second transistor T2 and the anode of the OLED; the second pole is connected to the second capacitor C2 The first end connection.

The second end of the second capacitor C2 is connected to both the second pole of the first transistor T1 and the gate of the second transistor T2.

It should be noted that, first, the first transistor T1 may be an N-type transistor or a P-type transistor. The preferred first transistor T1 in the embodiment of the present invention is an N-type transistor. In FIG. 3 and FIG. 4 , the first transistor T1 is an N-type transistor for example.

Second, the transistor provided by the embodiment of the utility model can be an enhancement transistor or a depletion transistor; the first pole of the transistor provided by the embodiment of the utility model can be a source, and the second pole can be a drain. Alternatively, the first pole of the transistor may be the drain, and the second pole may be the source, which is not limited in the present invention, and can be reasonably selected according to the type of the transistor.

Thirdly, in the implementation of the utility model, the first voltage terminal V1 constantly outputs a high level, and the second voltage terminal V2 constantly outputs a low level for example.

Fourth, after the third transistor T3 is turned on, the second voltage terminal V2 pulls down the high voltage signal input from the data signal input terminal DATA to the second capacitor C2 through the third transistor T3, so as to avoid the high voltage signal input from the data signal input terminal DATA The voltage signal is output to the anode of the OLED.

Above, as shown in Figure 3 and Figure 4, when the scan signal input terminal GATE inputs the scan signal, the first transistor T1 is turned on, the data signal input terminal DATA inputs the data signal, and is output to the gate of the second transistor T2 after passing through the first transistor T1 pole, and charge the first capacitor C1 at the same time. The second transistor T2 is a P-type transistor. Under the control of the high voltage signal, the second transistor T2 is turned on, and the high voltage signal of the first voltage terminal V1 is output to the anode of the OLED through the second transistor T2, while the low voltage signal of the second voltage terminal V2 The voltage signal is output to the cathode of the OLED to drive the OLED to emit light. Wherein, the third transistor T3 is an N-type transistor, which is turned on after the gate receives a low voltage signal, and under normal display conditions, the anode of the OLED outputs a high voltage signal to the gate of the third transistor T3, and the third transistor T3 is turned off.

When the anode and cathode of the OLED are short-circuited, the potential on the anode decreases. At this time, the anode outputs a low-voltage signal to the gate of the third transistor T3, which controls the opening of the third transistor T3, and the low-voltage signal on the anode passes through the third transistor T3. The output is to the gate of the second transistor T2, and under the control of the low voltage signal, the second transistor T2 is turned off. The high-voltage signal of the first voltage terminal V1 stops outputting to the anode, and the second voltage terminal V2 pulls down the high-voltage signal input from the data signal input terminal DATA to the second capacitor C2 through the third transistor T3, so that the data signal input terminal DATA The high voltage signal cannot be output to the anode.

Based on this, after a short circuit occurs between the anode and the cathode of the OLED, the low potential on the cathode will not rise due to neutralization with the high potential on the anode, and thus will not affect the signal on the second voltage terminal V2.

Embodiment two

Embodiment 2 provides an OLED pixel circuit. As shown in FIG. 5 , the driving module 10 includes a first transistor T1 , a first capacitor C1 and a second transistor T2 .

The gate of the first transistor T1 is connected to the scan signal input terminal GATE, the first pole is connected to the data signal input terminal DATA, and the second pole is connected to the gate of the second transistor T2.

The first pole of the second transistor T2 is connected to the first voltage terminal V1 , and the second pole is connected to the light emitting module 20 .

A first end of the first capacitor C1 is connected to the second pole of the first transistor T1, and a second end is connected to the first pole of the second transistor T2.

Alternatively, as shown in FIG. 6 , the first end of the first capacitor C1 is connected to the second pole of the first transistor T1 , and the second end is connected to the second pole of the second transistor T2 .

The light emitting module 20 includes an OLED, an anode of the OLED is connected to the driving module 10, and a cathode is connected to the second voltage terminal V2.

The short circuit protection module 30 includes a fourth transistor T4 and a second capacitor; the gate of the fourth transistor T4 is connected to the light emitting module 20 and the driving module 10, the first pole is connected to the light emitting module 20 and the second voltage terminal V2, and the second pole is connected to the light emitting module 20 and the second voltage terminal V2. The pole is connected to the first terminal of the second capacitor C2.

A second terminal of the second capacitor C2 is connected to the driving module 20 .

Wherein, the second transistor T2 is an N-type transistor; the fourth transistor T4 is a P-type transistor.

More specifically, the first pole of the second transistor T2 is connected to the first voltage terminal V1, and the second pole is connected to the anode of the OLED.

As shown in Figure 5, the first terminal of the first capacitor C1 is connected to the second pole of the first transistor T1 and the gate of the second transistor T2, and the second terminal is connected to the first pole of the second transistor T2 and the first voltage Both terminals V1 are connected.

Or, as shown in FIG. 6, the first end of the first capacitor C1 is connected to the second pole of the first transistor T1 and the gate of the second transistor T2, and the second end is connected to the second pole of the second transistor T2 and the OLED The anodes are connected.

The gate of the fourth transistor T4 is connected to the second pole of the second transistor T2 and the anode of the OLED; the first pole is connected to the second voltage terminal V2 and the cathode of the OLED; the second pole is connected to the first electrode of the second capacitor C2 end.

The second end of the second capacitor C2 is connected to both the second pole of the first transistor T1 and the gate of the second transistor T2.

Above, as shown in FIG. 5 and FIG. 6, when the scanning signal input terminal GATE inputs the scanning signal, the first transistor T1 is turned on, and the data signal input terminal DATA inputs the data signal, which is output to the gate of the second transistor T2 after passing through the first transistor T1. pole, and charge the first capacitor C1 at the same time. The second transistor T2 is a P-type transistor. Under the control of the high voltage signal, the second transistor T2 is turned on, and the high voltage signal of the first voltage terminal V1 is output to the anode of the OLED through the second transistor T2, while the low voltage signal of the second voltage terminal V2 The voltage signal is output to the cathode of the OLED to drive the OLED to emit light. Wherein, the fourth transistor T4 is an N-type transistor, which is turned on after receiving a low-voltage signal at the gate. Under normal display conditions, the anode of the OLED outputs a high-voltage signal to the gate of the fourth transistor T4, and the fourth transistor T4 is turned off.

When the anode and cathode of the OLED are short-circuited, the potential on the anode decreases, and at this time, the anode outputs a low-voltage signal to the gate of the fourth transistor T4 to control the opening of the fourth transistor T4, and the low-voltage signal on the second voltage terminal V2 passes through The fourth transistor T4 outputs to the gate of the second transistor T2, and under the control of the low voltage signal, the second transistor T2 is turned off. The high-voltage signal of the first voltage terminal V1 stops outputting to the anode, and the second voltage terminal V2 pulls down the high-voltage signal input from the data signal input terminal DATA to the second capacitor C2 through the third transistor T3, so that the data signal input terminal DATA The high voltage signal cannot be output to the anode.

An embodiment of the present invention also provides a display device, including any OLED pixel circuit described above. It has the same structure and beneficial effect as the OLED pixel circuit provided by the foregoing embodiments. Since the foregoing embodiments have described the structure and beneficial effects of the OLED pixel circuit in detail, details will not be repeated here.

The embodiment of the present utility model also provides a driving method of the above-mentioned OLED pixel circuit, and the driving method includes:

The scanning signal input terminal GATE inputs the scanning signal, the data signal input terminal DATA inputs the data signal, and the driving module 10 drives the light emitting module 20 to emit light.

If the light-emitting module 20 is short-circuited, the short-circuit protection module 30 controls the driving module 10 to shut down.

Specifically, as shown in FIG. 3 and FIG. 4 , the scanning signal input terminal GATE inputs a scanning signal to control the first transistor T1 to turn on; the data signal input terminal DATA inputs a data signal to control the second transistor T2 to turn on to drive the OLED to emit light.

If the OLED emits light normally, the signal output from the first voltage terminal V1 to the anode via the second transistor T2 controls the third transistor T3 to be turned off.

If the OLED is short-circuited, the signal applied to the anode by the second voltage terminal V2 controls the third transistor T3 to be turned on, and the signal applied to the anode by the second voltage terminal V2 controls the second transistor T2 to be turned off.

Alternatively, as shown in FIG. 5 and FIG. 6 , if the OLED emits light normally, the signal output from the first voltage terminal V1 to the anode via the second transistor T2 controls the fourth transistor T4 to be turned off.

If the OLED is short-circuited, the signal applied to the anode by the second voltage terminal V2 controls the fourth transistor T4 to turn on, and the signal on the second voltage terminal V2 directly controls the second transistor T2 to turn off.

The embodiment of the present invention provides a driving method for an OLED pixel circuit. By adding a short-circuit protection module 30 to the OLED pixel circuit, and when the light-emitting module 20 of the sub-pixel emits light normally, the short-circuit protection module 30 is turned off; and when the sub-pixel After the light-emitting module 20 is short-circuited, the short-circuit protection module 30 is turned on, and controls the drive module 10 to turn off, so that the signals of the first voltage terminal V1 and the data line number input terminal DATA cannot be output to the light-emitting module 20, so that even if the light-emitting module 20 is short-circuited, the signal of the second voltage terminal V2 connected to the light-emitting module 20 will not increase, but still maintains its original signal strength, thereby preventing a sub-pixel from being short-circuited and affecting its surrounding sub-pixels. normal display.

The above is only a specific embodiment of the present utility model, but the scope of protection of the present utility model is not limited thereto. Anyone familiar with the technical field can easily think of changes or changes within the technical scope disclosed by the utility model Replacement should be covered within the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be based on the protection scope of the claims.

Claims (10)

1. An OLED pixel circuit, characterized in that, comprises a drive module, a light emitting module, and a short circuit protection module; The driving module is connected to the scanning signal input terminal, the data signal input terminal, the first voltage terminal and the light-emitting module respectively, and is used to connect the scanning signal input terminal, the data signal input terminal, and the first voltage terminal. Under the control of the terminal, drive the light-emitting module to emit light; The light-emitting module is also connected to a second voltage terminal for emitting light under the control of the driving module and the second voltage terminal; The short-circuit protection module is connected to the driving module and the light-emitting module, and is used to control the driving module to shut down when a short-circuit occurs in the light-emitting module. 2. The OLED pixel circuit according to claim 1, wherein the driving module comprises a first transistor, a first capacitor and a second transistor; The gate of the first transistor is connected to the scan signal input terminal, the first pole is connected to the data signal input terminal, and the second pole is connected to the gate of the second transistor; The first pole of the second transistor is connected to the first voltage terminal, and the second pole is connected to the light emitting module; The first end of the first capacitor is connected to the second pole of the first transistor, and the second end is connected to the first pole of the second transistor; Wherein, the second transistor is an N-type transistor. 3. The OLED pixel circuit according to claim 1, wherein the driving module comprises a first transistor, a first capacitor and a second transistor; The gate of the first transistor is connected to the scan signal input terminal, the first pole is connected to the data signal input terminal, and the second pole is connected to the gate of the second transistor; The first pole of the second transistor is connected to the first voltage terminal, and the second pole is connected to the light emitting module; The first end of the first capacitor is connected to the second pole of the first transistor, and the second end is connected to the second pole of the second transistor; Wherein, the second transistor is an N-type transistor. 4. The OLED pixel circuit according to claim 1, wherein the light emitting module comprises an OLED, an anode of the OLED is connected to the driving module, and a cathode is connected to the second voltage terminal. 5. The OLED pixel circuit according to claim 1, wherein the short circuit protection module comprises a third transistor and a second capacitor; Both the gate and the first pole of the third transistor are connected to the light emitting module and the driving module, and the second pole is connected to the first end of the second capacitor; The second end of the second capacitor is connected to the driving module; Wherein, the third transistor is a P-type transistor. 6. The OLED pixel circuit according to claim 5, wherein the driving module comprises a first transistor, a first capacitor and a second transistor; the light emitting module comprises an OLED; The gate and the first pole of the third transistor are respectively connected to the second pole of the second transistor and the anode of the OLED; The second end of the second capacitor is connected to both the second pole of the first transistor and the gate of the second transistor. 7. The OLED pixel circuit according to claim 1, wherein the short circuit protection module comprises a fourth transistor and a second capacitor; The gate of the fourth transistor is connected to both the light emitting module and the driving module, the first pole is connected to both the light emitting module and the second voltage terminal, and the second pole is connected to the first electrode of the second capacitor. one end; The second end of the second capacitor is connected to the driving module; Wherein, the fourth transistor is a P-type transistor. 8. The OLED pixel circuit according to claim 7, wherein the driving module comprises a first transistor, a first capacitor and a second transistor; the light emitting module comprises an OLED; The gate of the fourth transistor is connected to the second pole of the second transistor and the anode of the OLED, and the first pole is connected to the cathode of the OLED and the second voltage terminal; The second end of the second capacitor is connected to both the second pole of the first transistor and the gate of the second transistor. 9. The OLED pixel circuit according to any one of claims 2, 3, 6 or 8, wherein the first transistor is an N-type transistor. 10. A display device, comprising the OLED pixel circuit according to any one of claims 1-9.