TWI738331B - OLED display driving circuit and OLED display using it - Google Patents

Abstract

An OLED display driving circuit for driving an OLED pixel array, wherein the OLED pixel array includes a plurality of OLED sub-pixel units, and the OLED display driving circuit has: a basic pulse number setting unit for storing a basic pulse number; A first correction pulse number setting unit for storing a first correction pulse number, wherein the first correction pulse number corresponds to an operating temperature of the OLED pixel array, and it is a positive integer or a negative integer ; A summing unit for summing the basic pulse times and the first modified pulse times to generate a total pulse times; a finite pulse generating unit for generating a pulse signal according to the total pulse times, and the pulse signal has a corresponding A number of pulses; and a voltage control unit for generating a corresponding voltage difference according to the corresponding number of pulses of the pulse signal and an input voltage to bias the OLED pixel array.

Description

OLED display driving circuit and OLED display using it

The present invention relates to an OLED display driving circuit, in particular to a driving circuit that can compensate for the temperature effect of the brightness of the OLED display.

Please refer to FIG. 1, which shows a circuit diagram of a sub-pixel unit of a conventional OLED display. As shown in FIG. 1, a sub-pixel unit 10 includes a first N-type thin film transistor 11, a pixel capacitor 12, a second N-type thin film transistor 13 and an OLED element 14, wherein the second N-type thin film transistor The crystal 13 and the OLED element 14 are connected in series between a fixed supply voltage V _DD and a fixed reference voltage V _SS .

，

為電子的移動率，

為單位面積的氧化層電容，W為通道寬度，L為通道長 度，V _GS為第二N型薄膜電晶體13的閘極和源極的電壓差，V _th為一閾值電壓，

為通道長度調變參數，以及V _DS為第二N型薄膜電晶體13的汲極和源極的電壓差。 In operation, a column driving circuit (not shown in the figure) will cause a scan signal V _{SCAN to} assume a high potential to turn on the first N-type thin film transistor 11, so that a row driving circuit (not shown in the figure) one of the data signals to provide a voltage V _dATA can be stored on pixel capacitor 12 is determined second N-type channel thin film transistor 13 is the current I _D by the voltage, so that the channel current I _D by driving the OLED element OLED element 14 14 presents a brightness corresponding to the voltage of the data signal V _{DATA, where}

,

Is the mobility of electrons,

Is the oxide layer capacitance per unit area, W is the channel width, L is the channel length, V _GS is the voltage difference between the gate and source of the second N-type thin film transistor 13, V _th is a threshold voltage,

Is the channel length modulation parameter, and V _DS is the voltage difference between the drain and the source of the second N-type thin film transistor 13.

However, since the current-voltage characteristics of the OLED element 14 drift with temperature changes _{, if the voltage of the data signal V DATA} output by the row driving circuit is fixed, if the forward bias voltage of the OLED element 14 changes due to temperature changes , the second N-type thin film transistor V _GS 13 (equal to the data signal V _dATA voltage and the voltage difference between the OLED element 14 of the forward bias voltage) will change, resulting in changes in the channel current I _D is generated, so that the OLED element 14 with The temperature change produces a display difference.

In addition, due to the limitation of the manufacturing process, different batches of OLED displays may also have display differences due to the specification variation of thin film transistors and OLED components.

In order to solve the above problems, a novel OLED display driving circuit is urgently needed in the art.

The main purpose of the present invention is to provide an OLED display driving circuit, which can generate a corresponding voltage difference with a pulse number and an input voltage to bias each OLED sub-pixel unit of an OLED pixel array, and according to operating temperature or manufacturing batch The number of pulses is determined to adjust the corresponding voltage difference, so as to compensate for the deviation of the electrical characteristics of each OLED sub-pixel unit of the OLED pixel array, thereby effectively eliminating the display difference of the OLED pixel array.

To achieve the above objective, an OLED display driving circuit is proposed, which is used to drive an OLED pixel array, wherein the OLED pixel array includes a plurality of OLED sub-pixel units, and the OLED display driving circuit has:

A basic pulse frequency setting unit for storing a basic pulse frequency;

A first correction pulse number setting unit for storing a first correction pulse number, wherein the first correction pulse number corresponds to an operating temperature of the OLED pixel array, and it is a positive integer or a negative integer ；

A summation unit for summing the number of basic pulses and the number of first modified pulses to generate a total number of pulses;

A finite pulse generating unit for generating a pulse signal according to the total number of pulses, the pulse signal having a corresponding number of pulses; and

A voltage control unit is used for generating a corresponding voltage difference according to the corresponding number of pulses of the pulse signal and an input voltage to bias the OLED pixel array.

In order to achieve the above objective, the present invention further provides an OLED display driving circuit, which is used to drive an OLED pixel array, wherein the OLED pixel array includes a plurality of OLED sub-pixel units, and the OLED display driving circuit has:

A basic pulse frequency setting unit for storing a basic pulse frequency;

A second correction pulse number setting unit for storing a second correction pulse number, wherein the second correction pulse number corresponds to a batch information of the OLED pixel array, and it is a positive integer or a negative Integer

A summation unit for summing the number of basic pulses and the number of second modified pulses to generate a total number of pulses;

A finite pulse generating unit for generating a pulse signal according to the total number of pulses, the pulse signal having a corresponding number of pulses; and

A voltage control unit is used for generating a corresponding voltage difference according to the corresponding number of pulses of the pulse signal and an input voltage to bias the OLED pixel array.

In order to achieve the above objective, the present invention further provides an OLED display driving circuit, which is used to drive an OLED pixel array, wherein the OLED pixel array includes a plurality of OLED sub-pixel units, and the OLED display driving circuit has:

A basic pulse frequency setting unit for storing a basic pulse frequency;

A first correction pulse number setting unit for storing a first correction pulse number, wherein the first correction pulse number corresponds to an operating temperature of the OLED pixel array, and it is a positive integer or a negative integer ；

A second correction pulse number setting unit for storing a second correction pulse number, wherein the second correction pulse number corresponds to a batch information of the OLED pixel array, and it is a positive integer or a negative Integer

A summation unit for summing the number of basic pulses, the number of first modified pulses, and the number of second modified pulses to generate a total number of pulses;

A finite pulse generating unit for generating a pulse signal according to the total number of pulses, the pulse signal having a corresponding number of pulses; and

A voltage control unit is used for generating a corresponding voltage difference according to the corresponding number of pulses of the pulse signal and an input voltage to bias the OLED pixel array.

In one embodiment, the corresponding voltage difference is determined by the difference between a supply voltage and a reference ground voltage, and the corresponding voltage difference is determined by fixing the reference ground voltage and changing the supply voltage, or fixing the supply Voltage and change the reference ground voltage, or change the supply voltage and the reference ground voltage at the same time.

In an embodiment, the OLED sub-pixel unit has:

A first N-type thin film transistor, the gate of which is coupled to a scan signal output by a row of drive circuits, and the drain is coupled to a data signal output from the row of drive circuits;

A pixel capacitor, coupled between the source of the first N-type thin film transistor and a reference ground;

A second N-type thin film transistor, the gate of which is coupled to the source of the first N-type thin film transistor, and the drain is coupled to the supply voltage; and

An OLED device is coupled between the source of the second N-type thin film transistor and the reference ground voltage.

In an embodiment, the OLED sub-pixel unit has:

An N-type thin film transistor, the gate of which is coupled to a scan signal output by a column of drive circuits, and the drain is coupled to a data signal output from a row of drive circuits;

A pixel capacitor, coupled between the source of the N-type thin film transistor and the supply voltage;

A P-type thin film transistor, the gate of which is coupled to the source of the N-type thin film transistor, and the source is coupled to the supply voltage; and

An OLED device is coupled between the drain of the P-type thin film transistor and the reference ground voltage.

To achieve the above objective, the present invention further provides an OLED display, which has an OLED pixel array and an OLED display driving circuit for driving the OLED pixel array, wherein the OLED pixel array includes a plurality of OLED sub-pixel units, and the OLED pixel array The display drive circuit has:

A basic pulse frequency setting unit for storing a basic pulse frequency;

A first correction pulse number setting unit for storing a first correction pulse number, wherein the first correction pulse number corresponds to an operating temperature of the OLED pixel array, and it is a positive integer or a negative integer ；

A summation unit for summing the number of basic pulses and the number of first modified pulses to generate a total number of pulses;

A finite pulse generating unit for generating a pulse signal according to the total number of pulses, the pulse signal having a corresponding number of pulses; and

A voltage control unit is used for generating a corresponding voltage difference according to the corresponding number of pulses of the pulse signal and an input voltage to bias the OLED pixel array.

To achieve the above objective, the present invention further provides an OLED display, which has an OLED pixel array and an OLED display driving circuit for driving the OLED pixel array, wherein the OLED pixel array includes a plurality of OLED sub-pixel units, and the OLED pixel array The display drive circuit has:

A basic pulse frequency setting unit for storing a basic pulse frequency;

A second correction pulse number setting unit for storing a second correction pulse number, wherein the second correction pulse number corresponds to a batch information of the OLED pixel array, and it is a positive integer or a negative Integer

A summation unit for summing the number of basic pulses and the number of second modified pulses to generate a total number of pulses;

A finite pulse generating unit for generating a pulse signal according to the total number of pulses, the pulse signal having a corresponding number of pulses; and

A voltage control unit is used for generating a corresponding voltage difference according to the corresponding number of pulses of the pulse signal and an input voltage to bias the OLED pixel array.

To achieve the above objective, the present invention further provides an OLED display, which has an OLED pixel array and an OLED display driving circuit for driving the OLED pixel array, wherein the OLED pixel array includes a plurality of OLED sub-pixel units, and the OLED pixel array The display drive circuit has:

A basic pulse frequency setting unit for storing a basic pulse frequency;

A first correction pulse number setting unit for storing a first correction pulse number, wherein the first correction pulse number corresponds to an operating temperature of the OLED pixel array, and it is a positive integer or a negative integer ；

A second correction pulse number setting unit for storing a second correction pulse number, wherein the second correction pulse number corresponds to a batch information of the OLED pixel array, and it is a positive integer or a negative Integer

A summation unit for summing the number of basic pulses, the number of first modified pulses, and the number of second modified pulses to generate a total number of pulses;

A finite pulse generating unit for generating a pulse signal according to the total number of pulses, the pulse signal having a corresponding number of pulses; and

A voltage control unit is used for generating a corresponding voltage difference according to the corresponding number of pulses of the pulse signal and an input voltage to bias the OLED pixel array.

In one embodiment, the corresponding voltage difference is determined by the difference between a supply voltage and a reference ground voltage, and the corresponding voltage difference is determined by fixing the reference ground voltage and changing the supply voltage, or fixing the supply Voltage and change the reference ground voltage, or change the supply voltage and the reference ground voltage at the same time.

In order to enable your reviewer to further understand the structure, features, purpose, and advantages of the present invention, the drawings and detailed descriptions of preferred specific embodiments are attached as follows.

The principle of the present invention is: a finite pulse generating unit is used to generate a corresponding number of pulses according to a temporary content, and a voltage control unit is used to generate a corresponding voltage difference according to the corresponding number of pulses and an input voltage to bias an OLED Each OLED sub-pixel unit of the pixel array, and the temporary storage content is determined according to the operating temperature or manufacturing batch to adjust the corresponding voltage difference to compensate for the deviation of the electrical characteristics of each OLED sub-pixel unit of the OLED pixel array, thereby Effectively eliminate the display difference of the OLED pixel array.

Please refer to FIG. 2, which shows a circuit diagram of an embodiment of an OLED display using the OLED display driving circuit of the present invention. As shown in FIG. 2, an OLED display 100 includes an OLED display driving circuit and an OLED pixel array 200. The OLED display driving circuit includes a basic pulse frequency setting unit 111, a first modified pulse frequency setting unit 112, and an OLED pixel array 200. The second pulse frequency setting unit 113, a sum unit 120, a finite pulse generation unit 130, and a voltage control unit 140; and the OLED pixel array 200 includes a plurality of OLED sub-pixel units.

The basic pulse number setting unit 111 can be a register for storing a basic pulse number.

The first correction pulse number setting unit 112 can be a register for storing a first correction pulse number, wherein the first correction pulse number corresponds to an operating temperature of the OLED display 100, and it can be It is a positive or negative integer.

The second correction pulse number setting unit 113 can be a register for storing a second correction pulse number, wherein the second correction pulse number corresponds to a batch of information of the OLED display 100, and Can be a positive integer or a negative integer.

The summation unit 120 is used for summing the basic pulse number, the first modified pulse number, and the second modified pulse number to generate a total pulse number.

The finite pulse generating unit 130 is used to generate a pulse signal OUT _P according to the total number of pulses, which has a corresponding number of pulses.

The voltage control unit 140 is used to generate a corresponding voltage difference V _OUT (=V _DD -V _SS ) according to the corresponding number of pulses of the _{pulse signal OUT P and an input voltage V IN} to bias the OLED pixel array 200 Each OLED sub-pixel unit. In a possible embodiment, the corresponding voltage difference V _OUT can be determined by fixing V _SS and changing V _DD , or by fixing V _DD and changing V _SS , or by changing V _DD and V _SS at the same time.

In actual operation, the OLED display 100 can determine the number of first correction pulses based on a measured operating temperature, and/or determine the number of second correction pulses based on the information of its manufacturing batch to determine the total The number of pulses is adjusted so as to adjust the corresponding voltage difference V _OUT to compensate for the deviation of the electrical characteristics of each OLED sub-pixel unit of the OLED pixel array 200, thereby effectively eliminating the display difference of the OLED pixel array 200.

Please refer to FIG. 3a, which shows a circuit diagram of an embodiment of the OLED sub-pixel unit of the OLED pixel array 200 of FIG. 2. As shown in FIG. 3a, a sub-pixel unit 201 includes a first N-type thin film transistor 201a, a pixel capacitor 201b, a second N-type thin film transistor 201c, and an OLED element 201d. The first N-type thin film transistor 201d _{The gate of the crystal 201a is coupled to a scan signal V SCAN} output by a column drive circuit (not shown in the figure), and the drain is coupled to a _{data signal V DATA} output from a row drive circuit (not shown in the figure) , And the source is coupled to the pixel capacitor 201b; the pixel capacitor 201b is coupled between the source of the first N-type thin film transistor 201a and a reference ground; the gate of the second N-type thin film transistor 201c It is coupled to the source of the first N-type thin film transistor 201a, the drain is _{coupled to V DD} , and the source is coupled to the anode of the OLED element 201d; and the OLED element 201d is coupled to the second N-type Between the source of the thin film transistor 201c and V _SS.

In the actual operation of the OLED sub-pixel unit 201 of FIG. 3a, if its electrical characteristics are changed due to changes in operating temperature and/or manufacturing batch differences, the OLED display driving circuit of the present invention will adaptively adjust the V _DD and V _SS pressure, so that the second N-type thin film transistor 201c of the channel current I _D remains unchanged, so as to avoid generating pixel array of OLED display differences.

Please refer to FIG. 3b, which shows a circuit diagram of another embodiment of the OLED sub-pixel unit of the OLED pixel array 200 of FIG. 2. As shown in FIG. 3b, a sub-pixel unit 202 includes an N-type thin-film transistor 202a, a pixel capacitor 202b, a P-type thin-film transistor 202c, and an OLED element 202d. The gate electrode of the N-type thin-film transistor 202a _{It is coupled with a scan signal V SCAN} output by a column drive circuit (not shown in the figure) _{, the drain is coupled with a data signal V DATA} output by a row drive circuit (not shown in the figure), and the source is Coupled with the pixel capacitor 202b; the pixel capacitor 202b is coupled _{between the source of the N-type thin film transistor 202a and V DD} ; the gate of the P-type thin film transistor 202c is coupled to the source of the N-type thin film transistor 202a The source is _{coupled to V DD} , and the drain is coupled to the anode of the OLED element 202d; and the OLED element 202d is coupled between _{the drain of the P-type thin film transistor 202c and V SS.}

In the actual operation of the OLED sub-pixel unit 202 of FIG. 3b, if its electrical characteristics change due to changes in operating temperature and/or manufacturing batch differences, the OLED display driving circuit of the present invention will adaptively adjust the V _DD and V _SS pressure, so that the P-type channel thin film transistor 202c of the current I _D remains unchanged, so as to avoid generating pixel array of OLED display differences.

In this way, the above has completely and clearly explained the technical solution of the present invention; and, from the above, it can be known that the present invention has the following advantages:

The OLED display driving circuit of the present invention can generate a corresponding voltage difference with a pulse number and an input voltage to bias each OLED sub-pixel unit of an OLED pixel array, and the pulse number can be adjusted according to the operating temperature or manufacturing batch. The corresponding voltage difference is used to compensate the deviation of the electrical characteristics of each OLED sub-pixel unit of the OLED pixel array, thereby effectively eliminating the display difference of the OLED pixel array.

It must be emphasized that the foregoing disclosures in this case are preferred embodiments, and any partial changes or modifications that are derived from the technical ideas of this case and are easily inferred by those who are familiar with the art will not deviate from the patent of this case. Right category.

In summary, regardless of the purpose, means and effects of this case, it is shown that it is very different from the conventional technology, and its first invention is practical, and it does meet the patent requirements of the invention. I implore the examiner to check it out and grant the patent as soon as possible. Society is for the best prayer.

10: Sub-pixel unit 11: The first N-type thin film transistor 12: pixel capacitance 13: The second N-type thin film transistor 14: OLED components 100: OLED display 111: Basic pulse frequency setting unit 112: The first correction pulse number setting unit 113: The second pulse number setting unit 120: Sum unit 130: Finite pulse generation unit 140: Voltage control unit 200: OLED pixel array 201: sub-pixel unit 201a: The first N-type thin film transistor 201b: pixel capacitance 201c: The second N-type thin film transistor 201d: OLED component 202: sub-pixel unit 202a: N-type thin film transistor 202b: pixel capacitance 202c: P-type thin film transistor 202d: OLED component

FIG. 1 shows a circuit diagram of a sub-pixel unit of a conventional OLED display. FIG. 2 shows a circuit diagram of an embodiment of an OLED display using the OLED display driving circuit of the present invention. FIG. 3a is a circuit diagram of an embodiment of the OLED sub-pixel unit of the OLED pixel array of FIG. 2. FIG. FIG. 3b is a circuit diagram of another embodiment of the OLED sub-pixel unit of the OLED pixel array of FIG. 2. FIG.

100: OLED display

111: Basic pulse frequency setting unit

112: The first correction pulse number setting unit

113: The second pulse number setting unit

120: Sum unit

130: Finite pulse generation unit

140: Voltage control unit

200: OLED pixel array

Claims (8)

An OLED display driving circuit for driving an OLED pixel array, wherein the OLED pixel array includes a plurality of OLED sub-pixel units, and the OLED display driving circuit has: a basic pulse number setting unit for storing a basic pulse number; A second correction pulse number setting unit for storing a second correction pulse number, wherein the second correction pulse number corresponds to a batch information of the OLED pixel array, and it is one of the batch information The value range includes positive integers and negative integers; a sum unit for summing the basic pulse number and the second modified pulse number to generate a total pulse number; a finite pulse generating unit for generating a pulse number according to the total pulse number A pulse signal, the pulse signal having a corresponding number of pulses; and a voltage control unit for generating a corresponding voltage difference according to the corresponding number of pulses of the pulse signal and an input voltage to bias the OLED pixel array . An OLED display driving circuit for driving an OLED pixel array, wherein the OLED pixel array includes a plurality of OLED sub-pixel units, and the OLED display driving circuit has: a basic pulse number setting unit for storing a basic pulse number; A first correction pulse number setting unit for storing a first correction pulse number, wherein the first correction pulse number corresponds to an operating temperature of the OLED pixel array and is within a range of the operating temperature Contains positive integers and negative integers; a second correction pulse number setting unit for storing a second correction pulse number, wherein the second correction pulse number corresponds to a batch information of the OLED pixel array, and A value range of the batch information includes positive integers and negative integers; a sum unit for summing the basic pulse number, the first modified pulse number, and the second modified pulse number to generate a total pulse number; A finite pulse generating unit for generating a pulse signal according to the total number of pulses, the pulse signal having a corresponding number of pulses; and a voltage regulating unit for generating a pulse signal according to the corresponding number of pulses and a The input voltage generates a corresponding voltage difference to bias the OLED pixel array. The OLED display driving circuit described in any one of the first to second items of the patent application, wherein the corresponding voltage difference is determined by the difference between a supply voltage and a reference ground voltage, and the corresponding voltage difference is determined The method is to fix the reference ground voltage and change the supply voltage, or fix the supply voltage and change the reference ground voltage, or change the supply voltage and the reference ground voltage at the same time. According to the OLED display driving circuit described in claim 3, the OLED sub-pixel unit has: a first N-type thin film transistor, the gate of which is coupled with a scan signal output by a column driving circuit, The drain is coupled to a data signal output by a row of driving circuit; a pixel capacitor is coupled between the source of the first N-type thin film transistor and a reference ground; and a second N-type thin film transistor, which The gate is coupled to the source of the first N-type thin film transistor, and the drain is coupled to the supply voltage; and an OLED device is coupled to the source of the second N-type thin film transistor And the reference ground voltage. According to the OLED display driving circuit described in claim 3, the OLED sub-pixel unit has: an N-type thin film transistor, the gate of which is coupled with a scan signal output by a column of driving circuits, and the drain It is coupled to a data signal output by a row of driving circuit; a pixel capacitor is coupled between the source of the N-type thin film transistor and the supply voltage; a P-type thin film transistor whose gate is connected to the N The source of the P-type thin film transistor is coupled to the supply voltage; and an OLED device is coupled between the drain of the P-type thin film transistor and the reference ground voltage. An OLED display having an OLED pixel array and an OLED display driving circuit for driving the OLED pixel array, wherein the OLED pixel array includes a plurality of OLED sub-pixel units, and the OLED display driving circuit has: a basic pulse number The setting unit is used to store a basic pulse number; a second correction pulse number setting unit is used to store a second correction pulse number, wherein the second correction pulse number corresponds to a batch information of the OLED pixel array Corresponding, and it includes positive integers and negative integers in a value range of the batch information; a sum unit for summing the basic pulse number and the second modified pulse number to generate a total pulse number; a finite pulse generation Unit for generating a pulse signal according to the total number of pulses, the pulse signal having a corresponding number of pulses; and a voltage control unit for generating a pulse signal according to the corresponding number of pulses and an input voltage of the pulse signal The corresponding voltage difference biases the OLED pixel array. An OLED display having an OLED pixel array and an OLED display driving circuit for driving the OLED pixel array, wherein the OLED pixel array includes a plurality of OLED sub-pixel units, and the OLED display driving circuit has: a basic pulse number The setting unit is used to store a basic pulse number; a first correction pulse number setting unit is used to store a first correction pulse number, wherein the first correction pulse number corresponds to an operating temperature of the OLED pixel array , And it includes a positive integer and a negative integer within a range of the operating temperature; a second correction pulse number setting unit for storing a second correction pulse number, wherein the second correction pulse number is related to the OLED pixel One of the arrays corresponds to the batch information, and it includes positive integers and negative integers within a numerical range of the batch information; a sum unit for summing the basic pulse number, the first modified pulse number, and the second Modifying the number of pulses to generate a total number of pulses; a finite pulse generating unit for generating a pulse signal according to the total number of pulses, the pulse signal having a corresponding number of pulses; and A voltage control unit is used for generating a corresponding voltage difference according to the corresponding number of pulses of the pulse signal and an input voltage to bias the OLED pixel array. For the OLED display described in any one of items 6 to 7 of the scope of patent application, the corresponding voltage difference is determined by the difference between a supply voltage and a reference ground voltage, and the corresponding voltage difference is determined by Fix the reference ground voltage and change the supply voltage, or fix the supply voltage and change the reference ground voltage, or change the supply voltage and the reference ground voltage at the same time.

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