CN203300191U - Active matrix organic light-emitting diode (AMOLED) pixel unit circuit and display panel - Google Patents

Abstract

The embodiment of the utility model provides an active matrix organic light-emitting diode (AMOLED) pixel unit circuit and a display panel, and the embodiment is used for integrating a touch screen circuit into an AMOLED pixel unit circuit and making an AMOLED display panel provided with a touch screen function. The AMOLED pixel unit circuit comprises a driving module which is used for amplifying an induction signal produced by a touch induction module, outputting the induction signal via an induction signal output module and driving a light-emitting module, a light-emitting control module which is used for controlling the light-emitting module to emit light, a threshold compensation module which is used for compensating a threshold voltage for the driving module, the touch induction module which is used for producing the induction signal and outputting the induction signal to the driving module, and the induction signal output module which is used for outputting the induction signal amplified by the driving module.

Description

Active matrix organic light emitting diode AMOLED pixel unit circuit and display panel

Technical Field

The utility model relates to a show technical field, especially relate to an active matrix organic light emitting diode pixel unit circuit to and display panel.

Background

The technology of integrating a Touch Screen in a TSP Cell in a liquid crystal box is to manufacture an inductor Sensor and a driving circuit thereof of the Touch Screen (TSP) on an Array substrate by using an Array process. The TSP Sensor is integrated in a Liquid Crystal Display (LCD) panel of a Liquid Crystal Display (LCD) panel, so that the product is light and thin, the functions are diversified, and the reliability of the touch screen is effectively improved.

Fig. 1(a) and 1(b) illustrate a basic photo-sensing type TSP in Cell circuit in the prior art, and in fig. 1(a), a Sensor senses light using a photodiode D1 and generates an electric leakage to detect a touch signal. In fig. 1(b), the Sensor senses illumination by using a sensing capacitor C2, and detects a touch signal by means of sensing capacitive coupling and capacitance change. A Thin-Film Transistor (TFT) T1 is used as an amplifying Transistor for amplifying the voltage change after the D1 detects the touch signal, so as to enhance the output driving capability of the TSP in Cell circuit, and provide the external TSP reading circuit to correctly read the detection result.

Compared with the traditional liquid crystal panel, the Active Matrix/Organic Light Emitting Diode (AMOLED) has the characteristics of high reaction speed, high contrast ratio, wide viewing angle and the like. The pixels of the AMOLED are driven to emit light by means of the related driving circuits on the Array substrate, and fig. 2 is an embodiment of a pixel unit circuit of the AMOLED.

If the TSP in Cell circuit shown in fig. 1(a) or fig. 1(b) is simply integrated into the AMOLED pixel Cell circuit shown in fig. 2, 3 TFTs and 1 capacitor are added in addition to the existing 5 TFTs and 2 capacitors, and 3 control signals are added in addition to 3 control signals and 2 power sources to the control signal lines, there will be insufficient space in the AMOLED pixel to add these TFTs and signal lines. Therefore, the prior art cannot integrate the TSP in Cell circuit in the AMOLED pixel Cell circuit.

SUMMERY OF THE UTILITY MODEL

The embodiment of the utility model provides an active matrix organic light emitting diode pixel cell circuit to and display panel for the realization is integrated the touch-sensitive screen circuit in AMOLED pixel cell circuit, and the preparation has the AMOLED display panel of touch-sensitive screen function.

The embodiment of the utility model provides an active matrix organic light emitting diode AMOLED pixel unit circuit, including light emitting module, drive module, threshold value compensation module, light emitting control module, touch-sensitive module and sensing signal output module; wherein,

the driving module is used for amplifying the sensing signal generated by the touch sensing module, outputting the sensing signal through the sensing signal output module and driving the light emitting module;

the light emitting control module is used for controlling the light emitting module to emit light;

the threshold compensation module is used for performing threshold voltage compensation on the driving module;

the touch sensing module is used for generating a sensing signal and outputting the sensing signal to the driving module;

and the sensing signal output module is used for outputting the sensing signal amplified by the driving module.

An embodiment of the utility model provides a display panel includes AMOLED pixel unit circuit.

According to the above technical scheme, the utility model discloses newly-increased less circuit element in current AMOLED pixel Cell circuit through sharing data line, circuit element and control signal etc. has realized integrated TSP in Cell circuit in AMOLED pixel Cell circuit.

Drawings

FIGS. 1(a) and 1(b) are schematic diagrams of a touch screen circuit in the prior art;

FIG. 2 is a circuit schematic diagram of an AMOLED pixel cell in the prior art;

fig. 3 is a schematic circuit diagram of an AMOLED pixel unit according to an embodiment of the present invention;

fig. 4 is a schematic circuit diagram of an AMOLED pixel unit according to another embodiment of the present invention;

fig. 5 is a timing diagram of control signals of an AMOLED pixel unit circuit according to an embodiment of the present invention;

fig. 6 is a graph showing the relationship between the level of the control signal of the AMOLED pixel unit circuit according to the embodiment of the present invention.

Detailed Description

The embodiment of the utility model provides an active matrix organic light emitting diode pixel cell circuit to and display panel for the realization is integrated the touch-sensitive screen circuit in AMOLED pixel cell circuit, and the preparation has the AMOLED display panel of touch-sensitive screen function.

Referring to fig. 3, an embodiment of the present invention provides an active matrix organic light emitting diode AMOLED pixel unit circuit, which includes a light emitting module 13, a driving module 11, a threshold compensation module 14, a light emitting control module 12, a touch sensing module 15, and a sensing signal output module 16; wherein,

the driving module 11 is configured to amplify the sensing signal generated by the touch sensing module 15 and output the amplified sensing signal through the sensing signal output module 16, and drive the light emitting module 13;

a light emitting control module 12 for controlling the light emitting module 13 to emit light;

a threshold compensation module 14, configured to perform threshold voltage compensation on the driving module 14;

the touch sensing module 15 is used for generating a sensing signal and outputting the sensing signal to the driving module 14;

and the sensing signal output module 16 is configured to output the sensing signal amplified by the driving module 14.

Preferably, the driving module 11 includes a first transistor T1 having a gate connected to the first node P1 of the circuit and two terminals connected to the second node P2 and the third node P3 of the circuit, respectively.

Preferably, the lighting control module 12 includes a second transistor T2, a fifth transistor T5 and a sixth transistor T6, wherein the gate of the second transistor T2 is connected to the second signal control line (corresponding to the second signal CR2 — n) of the current stage AMOLED pixel unit circuit, and the other two electrodes are respectively connected to the low voltage level signal line (corresponding to the low voltage level signal VSS) and the second node P2 of the circuit; the gate of the fifth transistor T5 is connected to the first signal control line (corresponding to the first signal CR1 — n) of the current stage AMOLED pixel unit circuit, and the other two electrodes are connected to the third node P3 and the POWER line (corresponding to the POWER supply) of the circuit, respectively; the gate of the sixth transistor T6 is connected to the second signal control line (corresponding to the second signal CR2 — n) of the current stage AMOLED pixel unit circuit, and the other two electrodes are connected to the third node P3 and the light emitting module 13, respectively.

Preferably, the light emitting module 13 includes a first light emitting diode D1, one end of which is connected to the sixth transistor T6, and the other end of which is connected to a POWER line (corresponding POWER).

Preferably, the threshold compensation module 14 includes a fourth transistor T4 and a first capacitor C1;

the gate of the fourth transistor T4 is connected to a third signal control line (corresponding to the third signal CR3 — n) of the current-stage AMOLED pixel unit circuit, and the other two electrodes are respectively connected to the third node P3 and the first node P1; the first capacitor C1 is connected between the first node P1 and the low voltage level signal line (corresponding to the low voltage level signal VSS).

Preferably, the touch sensing module 15 includes a seventh transistor T7 and a second light emitting diode D2; wherein a gate of the seventh transistor T7 is connected to a first signal control line (corresponding to the first signal CR1 — n) of the current-stage AMOLED pixel unit circuit, and two other electrodes are respectively connected to the second light emitting diode D2 and the first node P1; one end of the second light emitting diode D2 is connected to the seventh transistor T7, and the other end is connected to the low voltage level signal line (corresponding to the low voltage level signal VSS); or,

referring to fig. 4, the touch sensing module 15 includes a seventh transistor T7 and a sensing capacitor C2; the gate of the seventh transistor T7 is connected to the first signal control line (corresponding to the first signal CR1 — n) of the current stage AMOLED pixel unit circuit, and the other two electrodes are connected to the sensing capacitor C2 and the first node P1, respectively. The sensing capacitor C2 has one end connected to the seventh transistor T7 and the other end required to be in contact with the outside, e.g., a human body, and changes the voltage of the first capacitor C1 by means of the sensing capacitive coupling and the capacitance change.

When the seventh transistor T7 is turned on, the sensing element D2 or C2 can generate a sensing current and input the sensing current into the first transistor T1, and the sensing current is amplified by the first transistor T1 and output to the DATA line (corresponding to the DATA signals DATA _ OLED & TSP) through the sensing signal output module 16.

The touch sensing module 15 also shares the capacitor C1 as a storage capacitor, and shares a power line, which alternately inputs the required levels for the tspin cell circuit and the AMOLED circuit to operate.

In the present invention, there are two embodiments of the sensing element, the first embodiment is shown in fig. 3, and the sensing element is a photodiode; in a second embodiment, as shown in fig. 4, the sensing element is a sensing capacitor.

Preferably, the sensing signal output module 16 includes a third transistor T3, a gate of which is connected to the second signal control line (corresponding to the second signal CR2_ n) of the current stage AMOLED pixel unit circuit, and two poles of which are respectively connected to the DATA line (corresponding to the DATA signals DATA _ OLED & TSP) and the second node P2.

Preferably, the anode of the second light emitting diode D2 is connected to the low voltage level signal line (corresponding to the low voltage level signal VSS), and the cathode is connected to the seventh transistor T7.

Preferably, the cathode of the first light emitting diode D1 is connected to the sixth transistor T6, and the anode is connected to a power line.

Preferably, the first transistor T1, the second transistor T2, the fourth transistor T4, the fifth transistor T5 and the sixth transistor T6 are N-type thin film transistors TFT, and the third transistor T3 is a P-type TFT.

The value of the third control signal VSS in the present invention remains unchanged, and specifically can be the cut-off level of the N-type TFT.

The working principle of the circuit provided by the embodiment of the present invention is described below with reference to fig. 3, 5 and 6.

As shown in fig. 5, the timing sequence of the control signal of the circuit provided by the embodiment of the present invention includes six stages: an initial Init phase, a Photo sensing phase, a Read phase, a Charge phase, a Write phase, and an Organic Light Emitting Diode (OLED) phase. V in FIG. 5_DATAIs the DATA line DATA _ OLED&The gray scale voltage of TSP has a value range of [ V_DL，V_DH]The D1 brightness is different for different gray scale voltages. The magnitude relation of the level values of the respective signals shown in FIG. 5 is shown in FIG. 6, VSS<V_DL＜V_DH<VINI<The values of the levels of VDD are preset, and the specific values can be set according to actual needs. The following describes each stage.

An Init stage: the turning on of T5 turns off the OLED D1, turns on T7, and turns on the photodiode D2, which is TSP Sensor, to the gate of the amplifying transistor T1. C1 acts as a TSP amplifying TFT T1 storage capacitor. T4 is turned on and POWER level is V_INIInitializing the TSP in cell circuit, i.e. initializing the gate storage capacitor precharge value of the amplifying transistor T1 to an initial level V_INITo ensure that the following stage T1 operates in a saturated amplification state.

Photo stage: t4 is turned off, and the photodiode D2 detects the touch state of the Panel. When Panel is touched by a finger, an external light source cannot irradiate the photodiode D2, light receiving of D2 is less, light-induced leakage current is small, and level change of C1 voltage in a PHOTO stage due to electric leakage is small; when the Panel is not touched by a finger, an external light source can irradiate the photodiode D2, the photodiode D2 receives light, a large PHOTO-induced leakage current is generated, and the voltage at the phase C1 of PHOTO generates a large level change due to the leakage current. Therefore, if touched, the gate voltage of T1 changes little from the initial voltage; if not touched, the gate voltage of T1 changes greatly from the initial voltage.

After the Photo phase begins, the pixel in the upper row is driven by CR2_ n-1 to be in the Write phase, the DATA _ OLED & TSP inputs the DATA level at T1 of the pixel in the upper row, and the level of the Photo phase CR2_ n jumps to the low level after the Write phase of the pixel in the upper row is finished because the pixels in multiple rows share the DATA _ OLED & TSP.

And (4) READ stage: the PHOTO phase results are stored on C1. At this time, T3 is turned on, DATA _ OLED & TSP is used as a readout line for the output voltage of the TSP in cell circuit at this time, and the amplifying transistor T1 amplifies the gate voltage thereof to output to the readout line to the peripheral TSP readout circuit.

The above 3 stages are the TSP in Cell circuit work, can respond to external touch and output induction signals. The circuit then enters the AMOLED circuit operating phase.

And a Charge stage: t4 and T5 are turned on, the storage capacitor C1 is charged, and the gate level of T1 is V_INIT1 may be viewed as a diode and enter saturation.

Write stage: t2, T5, T6 are turned off, and T3 and T4 are turned on, at which time the DATA _ OLED&TSP as AMOLED DATA signal input, DATA _ OLED&TSP input V_DATAVoltage, node P2, T1 source level is V_DATAGate source voltage V of T1 transistor_GSInitially at V_INI-V_DATA. C1 starts to discharge through T1, T3 and T4, and the grid level of T1 gradually decreases until the grid-source voltage V is reached_GSReaches a threshold voltage V_TH. At this time, the T1 tube enters subthreshold conduction, the T1 tube is cut off, and the C1 stops discharging through the T1 tube. Due to the voltage holding effect of C1, and the other end V of C1_SSAt this time, the gate level of T1 is V_TH+V_DATA。

An OLED stage: t3, T4 and T5 are turned off, T2 and T6 are turned on, and the OLED starts to emit light. The source electrode of the T1 is connected with VSS through the T2 conduction, namely the grid source voltage V of the driving tube T1_GS=V_DATA+V_TH-V_SS

The current flowing through the OLED at this time is:

$I_{T1}=\frac{k}{2}\&CenterDot;{[V_{\mathrm{TH}}+V_{\mathrm{DATA}}-V_{\mathrm{TH}}-V_{\mathrm{SS}}]}^2=\frac{k}{2}\&CenterDot;{(V_{\mathrm{DATA}}-V_{\mathrm{SS}})}^2$

wherein k is a constant, V_DATAHas a value range of V_DLTo V_DH。

The embodiment of the utility model provides a display panel is still provided, include AMOLED pixel unit circuit.

To sum up, the embodiment of the utility model provides a through the chronogenesis and the level value of redesign each working signal, newly-increased less circuit element in current AMOLED pixel unit circuit, through sharing data line, circuit element and control signal etc. realized integrating TSP in Cell circuit in AMOLED pixel unit circuit.

It will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims and their equivalents, the present invention is also intended to include such modifications and variations.

Claims (11)

1. An active matrix organic light emitting diode AMOLED pixel cell circuit, comprising: the device comprises a light emitting module, a driving module, a threshold value compensation module, a light emitting control module, a touch sensing module and a sensing signal output module; wherein,

the driving module is used for amplifying the sensing signal generated by the touch sensing module, outputting the sensing signal through the sensing signal output module and driving the light emitting module;

the light emitting control module is used for controlling the light emitting module to emit light;

the threshold compensation module is used for performing threshold voltage compensation on the driving module;

the touch sensing module is used for generating a sensing signal and outputting the sensing signal to the driving module;

and the sensing signal output module is used for outputting the sensing signal amplified by the driving module.

2. The circuit of claim 1, wherein the driving module comprises a first transistor, a gate of the first transistor is connected to a first node of the circuit, and two other electrodes of the first transistor are respectively connected to a second node and a third node of the circuit, wherein the first node is a connection point between the driving module and the threshold compensation module, the second node is a common connection point between the driving module and the light emission control module and the sensing signal output module, and the third node is a common connection point between the driving module and the light emission control module and the threshold compensation module.

3. The circuit according to claim 2, wherein the light emission control module comprises a second transistor, a fifth transistor and a sixth transistor, wherein the gate of the second transistor is connected to the second signal control line of the current-stage AMOLED pixel unit circuit, and the other two electrodes are respectively connected to the low voltage level signal line and the second node of the circuit; the grid electrode of the fifth transistor is connected with a first signal control line of the current-stage AMOLED pixel unit circuit, and the other two electrodes are respectively connected with a third node and a power line of the circuit; the grid electrode of the sixth transistor is connected with the second signal control line of the pixel unit circuit of the AMOLED at the current stage, and the other two electrodes are respectively connected with the third node and the light emitting module.

4. The circuit of claim 3, wherein the light emitting module comprises a first light emitting diode having one end connected to the sixth transistor and the other end connected to a power line.

5. The circuit of claim 4, wherein the threshold compensation module comprises a fourth transistor and a first capacitor;

the grid electrode of the fourth transistor is connected with a third signal control line of the current-stage AMOLED pixel unit circuit, and the other two electrodes are respectively connected with the third node and the first node; the first capacitor is connected between the first node and the low voltage level signal line.

6. The circuit of claim 5, wherein the touch sensing module comprises a seventh transistor and a second light emitting diode; the grid electrode of the seventh transistor is connected with a first signal control line of the current-stage AMOLED pixel unit circuit, and the other two electrodes are respectively connected with the second light-emitting diode and the first node; one end of the second light emitting diode is connected with the seventh transistor, and the other end of the second light emitting diode is connected with the low-voltage level signal line; or,

the touch sensing module comprises a seventh transistor and a sensing capacitor; the grid electrode of the seventh transistor is connected with a first signal control line of the pixel unit circuit of the AMOLED at the current stage, and the other two electrodes are respectively connected with the sensing capacitor and the first node; the sensing capacitor.

7. The circuit of claim 6, wherein the sensing signal output module comprises a third transistor, a gate of which is connected to the second signal control line of the current-stage AMOLED pixel unit circuit, and two other poles of which are respectively connected to the data line and the second node.

8. The circuit of claim 6, wherein the anode of the second light emitting diode is connected to the low voltage level signal line and the cathode is connected to a seventh transistor.

9. The circuit of claim 4, wherein the cathode of the first light emitting diode is connected to the sixth transistor and the anode is connected to a power line.

10. The circuit according to any one of claims 2 to 9, wherein the first transistor, the second transistor, the fourth transistor, the fifth transistor, and the sixth transistor are N-type thin film transistors, TFTs, and the third transistor is a P-type TFT.

11. A display panel comprising an active matrix organic light emitting diode AMOLED pixel cell circuit as claimed in any one of claims 1 to 10.

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