TWI813330B - LED pulse width modulation driving method, display driver chip, display device and information processing device - Google Patents

LED pulse width modulation driving method, display driver chip, display device and information processing device Download PDF

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TWI813330B
TWI813330B TW111121688A TW111121688A TWI813330B TW I813330 B TWI813330 B TW I813330B TW 111121688 A TW111121688 A TW 111121688A TW 111121688 A TW111121688 A TW 111121688A TW I813330 B TWI813330 B TW I813330B
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pulse width
width modulation
led
pulse
duty cycle
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TW202349365A (en
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李東
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大陸商集璞（上海）科技有限公司
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Abstract

一種LED脈寬調變驅動方法，其包括：在一顯示週期之多個分組期間各依一供應電壓之一電壓值調變一脈衝高度及一脈寬調變占空比，並依調變後之該脈衝高度及該脈寬調變占空比產生一脈衝電壓，其中，調變後之該脈衝高度係與該電壓值成正比且調變後之該脈寬調變占空比係與該電壓值成反比；以及以該些脈衝電壓驅動一電流源電路以為一LED單元提供該顯示週期內之該些分組期間的導通電流。An LED pulse width modulation driving method, which includes: modulating a pulse height and a pulse width modulation duty cycle according to a voltage value of a supply voltage during multiple group periods of a display cycle, and modulating the pulse width according to the voltage value after modulation. The pulse height and the pulse width modulation duty cycle generate a pulse voltage, wherein the modulated pulse height is proportional to the voltage value and the modulated pulse width modulation duty cycle is proportional to the The voltage value is inversely proportional; and the pulse voltages are used to drive a current source circuit to provide an LED unit with conduction current during the group periods in the display cycle.

Description

LED脈寬調變驅動方法、顯示驅動晶片、顯示裝置及資訊處理裝置LED pulse width modulation driving method, display driver chip, display device and information processing device

本發明係有關於LED驅動方法，特別是關於一種可適應供應電壓波動的LED脈寬調變驅動方法。The present invention relates to an LED driving method, and in particular to an LED pulse width modulation driving method that can adapt to supply voltage fluctuations.

請參照圖1，其繪示一現有的LED驅動電路。如圖1所示，一LED驅動電路10係用以為一LED單元20提供一導通電流I LED，其中，LED單元20係耦接於一供應電壓V LED及LED驅動電路10之間，且LED驅動電路10與LED單元20之連接點具有一電壓V SW。 Please refer to Figure 1, which illustrates an existing LED driving circuit. As shown in Figure 1, an LED driving circuit 10 is used to provide an on-current I LED for an LED unit 20, wherein the LED unit 20 is coupled between a supply voltage V LED and the LED driving circuit 10, and the LED driving The connection point between the circuit 10 and the LED unit 20 has a voltage V SW .

詳細而言，LED驅動電路10具有一數位類比轉換單元11、一放大器12、一反相器13、一第一開關14、一第二開關15、一NMOS電晶體16及一電阻17，其中，數位類比轉換單元11係用以依一輸入資料D IN產生一類比電壓；放大器12、NMOS電晶體16及電阻17係用以依該類比電壓產生該導通電流I LED；以及反相器13、第一開關14及第二開關15係用以依一脈寬調變信號PWM之控制決定該導通電流I LED的持續時間，其中，當脈寬調變信號PWM為高電位時，LED驅動電路10提供該導通電流I LED，當脈寬調變信號PWM為低電位時，LED驅動電路10停止提供該導通電流I LED。 In detail, the LED driving circuit 10 has a digital-to-analog conversion unit 11, an amplifier 12, an inverter 13, a first switch 14, a second switch 15, an NMOS transistor 16 and a resistor 17, wherein, The digital-to-analog conversion unit 11 is used to generate an analog voltage according to an input data D IN ; the amplifier 12, the NMOS transistor 16 and the resistor 17 are used to generate the on-current I LED according to the analog voltage; and the inverter 13, A switch 14 and a second switch 15 are used to determine the duration of the on-current I LED according to the control of a pulse width modulation signal PWM. When the pulse width modulation signal PWM is at a high level, the LED driving circuit 10 provides When the pulse width modulation signal PWM is at a low level, the LED driving circuit 10 stops providing the conduction current I LED .

請參照圖2，其繪示圖1之LED驅動電路之一工作波形圖。如圖2所示，當該導通電流I LED依脈寬調變信號PWM之控制呈現方波變動時，其會對電源（一般為DC-DC電源）產生一個週期性的擾動，導致供應電壓V LED呈現低幅度的振盪。 Please refer to FIG. 2 , which illustrates an operating waveform diagram of the LED driving circuit of FIG. 1 . As shown in Figure 2, when the on-current I LED changes in a square wave according to the control of the pulse width modulation signal PWM, it will produce a periodic disturbance in the power supply (usually a DC-DC power supply), causing the supply voltage V The LED exhibits low amplitude oscillation.

由於該導通電流I LED在每個週期(T OFF+T ON)都一樣，因此LED單元20之兩端間的壓差會保持固定，亦即，LED單元20之底端電壓V SW會在脈寬調變信號PWM之各個高電位期間隨著供應電壓V LED變動。 Since the on-current I LED is the same in every cycle (T OFF + T ON ), the voltage difference between the two ends of the LED unit 20 will remain fixed. That is, the bottom voltage V SW of the LED unit 20 will change at the pulse rate. Each high potential period of the wide modulation signal PWM changes with the supply voltage V LED .

在一般應用中，LED單元20之底端電壓V SW在脈寬調變信號PWM之高電位期間會被設定在一較低的電位，例如300mV，以降低LED驅動電路10的功耗。然而，當供應電壓V LED的變動幅度較大時，LED單元20之底端電壓V SW就有可能落到300mV以下而使LED驅動電路10無法正常提供該導通電流I LED。要解決此問題，一般的作法是將設定的電壓提到較高位置，如400mV。然而，此安排卻會使LED驅動電路10的功耗增加並使工作溫度上升。 In general applications, the bottom voltage V SW of the LED unit 20 is set to a lower potential, such as 300 mV, during the high potential period of the pulse width modulation signal PWM to reduce the power consumption of the LED driving circuit 10 . However, when the supply voltage V LED fluctuates greatly, the bottom voltage V SW of the LED unit 20 may fall below 300 mV, causing the LED driving circuit 10 to be unable to provide the conduction current I LED normally. To solve this problem, the general approach is to raise the set voltage to a higher position, such as 400mV. However, this arrangement will increase the power consumption of the LED driving circuit 10 and increase the operating temperature.

為解決上述的問題，本領域亟需一新穎的LED脈寬調變驅動方法。In order to solve the above problems, a novel LED pulse width modulation driving method is urgently needed in this field.

本發明之主要目的在於揭露一種LED脈寬調變驅動方法，其可在一預定之顯示週期內依一供應電壓之準位變化調變各分組期間之一對應脈衝電流之脈衝高度及脈衝寬度，以確保一電流源電路在該供應電壓位於最低準位時仍可正常操作，及一LED單元在該顯示週期之平均亮度維持不變，以及優化能量使用效率並從而降低一驅動晶片的工作溫度。The main purpose of the present invention is to disclose an LED pulse width modulation driving method, which can modulate the pulse height and pulse width of a corresponding pulse current in each group period according to the level change of a supply voltage within a predetermined display period. This is to ensure that a current source circuit can still operate normally when the supply voltage is at the lowest level, and the average brightness of an LED unit during the display period remains unchanged, as well as optimizing energy usage efficiency and thereby reducing the operating temperature of a driver chip.

本發明之另一目的在於揭露一種顯示驅動晶片，其可藉由上述的LED脈寬調變驅動方法確保其內部之所述電流源電路在該供應電壓位於最低準位時仍可正常操作，及使一LED單元在該顯示週期之平均亮度維持不變，同時優化能量使用效率並降低其工作溫度。Another object of the present invention is to disclose a display driver chip that can ensure that the current source circuit inside the chip can still operate normally when the supply voltage is at the lowest level through the above-mentioned LED pulse width modulation driving method, and The average brightness of an LED unit during the display period is maintained unchanged, while optimizing energy efficiency and reducing its operating temperature.

本發明之另一目的在於揭露一種顯示裝置，其可藉由上述的顯示驅動晶片確保其顯示畫面不受該供應電壓之準位波動的影響，同時優化能量使用效率並降低其工作溫度。Another object of the present invention is to disclose a display device that can use the above-mentioned display driver chip to ensure that its display image is not affected by fluctuations in the supply voltage level, while optimizing energy efficiency and reducing its operating temperature.

本發明之又一目的在於揭露一種資訊處理裝置，其可藉由上述的顯示裝置確保其顯示畫面不受該供應電壓之準位波動的影響，同時優化能量使用效率並降低其工作溫度。Another object of the present invention is to disclose an information processing device that can use the above-mentioned display device to ensure that its display screen is not affected by fluctuations in the level of the supply voltage, while optimizing energy efficiency and reducing its operating temperature.

為達前述目的，一種LED脈寬調變驅動方法乃被提出，其係利用一控制電路實現且其包括： 在一顯示週期之多個分組期間各依一供應電壓之一電壓值調變一脈衝高度及一脈寬調變占空比，並依調變後之該脈衝高度及該脈寬調變占空比產生一脈衝電壓，其中，調變後之該脈衝高度係與該電壓值成正比且調變後之該脈寬調變占空比係與該電壓值成反比；以及 以該些脈衝電壓驅動一電流源電路以為一LED單元提供該顯示週期內之該些分組期間的導通電流。 In order to achieve the aforementioned purpose, an LED pulse width modulation driving method is proposed, which is implemented using a control circuit and includes: During multiple groups of a display period, a pulse height and a pulse width are modulated according to a voltage value of a supply voltage, and a duty cycle is modulated according to the modulated pulse height and the pulse width. The ratio generates a pulse voltage, wherein the modulated pulse height is proportional to the voltage value and the modulated pulse width modulation duty cycle is inversely proportional to the voltage value; and The pulse voltages are used to drive a current source circuit to provide an LED unit with conduction current during the group periods in the display cycle.

在一實施例中，在該顯示週期內之該些分組期間中之調變後的所述脈衝高度及所述脈寬調變占空比之積的和等於預設的所述脈衝高度及所述脈寬調變占空比之積的和。In one embodiment, the sum of the products of the modulated pulse height and the pulse width modulation duty cycle in the grouping periods within the display period is equal to the preset pulse height and the Describes the sum of the products of pulse width modulation duty cycles.

在一實施例中，該LED單元係由多個LED燈串中擇一者。In one embodiment, the LED unit is selected from a plurality of LED light strings.

為達前述目的，本發明進一步提出一種顯示驅動晶片，其具有一控制電路以執行一LED脈寬調變驅動程序，該程序包括： 在一顯示週期之多個分組期間各依一供應電壓之一電壓值調變一脈衝高度及一脈寬調變占空比，並依調變後之該脈衝高度及該脈寬調變占空比產生一脈衝電壓，其中，調變後之該脈衝高度係與該電壓值成正比且調變後之該脈寬調變占空比係與該電壓值成反比；以及 以該些脈衝電壓驅動一電流源電路以為一LED單元提供該顯示週期內之該些分組期間的導通電流。 To achieve the aforementioned objectives, the present invention further proposes a display driver chip, which has a control circuit to execute an LED pulse width modulation driving program, which program includes: During multiple groups of a display period, a pulse height and a pulse width are modulated according to a voltage value of a supply voltage, and a duty cycle is modulated according to the modulated pulse height and the pulse width. The ratio generates a pulse voltage, wherein the modulated pulse height is proportional to the voltage value and the modulated pulse width modulation duty cycle is inversely proportional to the voltage value; and The pulse voltages are used to drive a current source circuit to provide an LED unit with conduction current during the group periods in the display cycle.

在一實施例中，在該顯示週期內之該些分組期間中之調變後的所述脈衝高度及所述脈寬調變占空比之積的和等於預設的所述脈衝高度及所述脈寬調變占空比之積的和。In one embodiment, the sum of the products of the modulated pulse height and the pulse width modulation duty cycle in the grouping periods within the display period is equal to the preset pulse height and the Describes the sum of the products of pulse width modulation duty cycles.

在一實施例中，該LED單元係由多個LED燈串中擇一者。In one embodiment, the LED unit is selected from a plurality of LED light strings.

為達前述目的，本發明進一步提出一種顯示裝置，其具有一LED模組及用以驅動該LED模組之一顯示驅動晶片，該顯示驅動晶片具有一控制電路以執行一LED脈寬調變驅動程序，該程序包括： 在一顯示週期之多個分組期間各依一供應電壓之一電壓值調變一脈衝高度及一脈寬調變占空比，並依調變後之該脈衝高度及該脈寬調變占空比產生一脈衝電壓，其中，調變後之該脈衝高度係與該電壓值成正比且調變後之該脈寬調變占空比係與該電壓值成反比；以及 以該些脈衝電壓驅動一電流源電路以為該LED模組之一LED單元提供該顯示週期內之該些分組期間的導通電流。 To achieve the above object, the present invention further proposes a display device, which has an LED module and a display driver chip for driving the LED module. The display driver chip has a control circuit to perform an LED pulse width modulation drive. program, which includes: During multiple groups of a display period, a pulse height and a pulse width are modulated according to a voltage value of a supply voltage, and a duty cycle is modulated according to the modulated pulse height and the pulse width. The ratio generates a pulse voltage, wherein the modulated pulse height is proportional to the voltage value and the modulated pulse width modulation duty cycle is inversely proportional to the voltage value; and The pulse voltages are used to drive a current source circuit to provide an on-current for one of the LED units of the LED module during the group periods in the display cycle.

在一實施例中，在該顯示週期內之該些分組期間中之調變後的所述脈衝高度及所述脈寬調變占空比之積的和等於預設的所述脈衝高度及所述脈寬調變占空比之積的和。In one embodiment, the sum of the products of the modulated pulse height and the pulse width modulation duty cycle in the grouping periods within the display period is equal to the preset pulse height and the Describes the sum of the products of pulse width modulation duty cycles.

在可能的實施例中，該LED模組可為一次毫米發光二極體模組、一微發光二極體模組或一量子點發光二極體模組。In a possible embodiment, the LED module may be a sub-millimeter LED module, a micro LED module or a quantum dot LED module.

為達前述目的，本發明進一步提出一種資訊處理裝置，一中央處理單元及如前述之顯示裝置，其中，該中央處理單元係用以與該顯示裝置通信。To achieve the above object, the present invention further provides an information processing device, a central processing unit and the aforementioned display device, wherein the central processing unit is used to communicate with the display device.

在可能的實施例中，所述之資訊處理裝置可為一智慧型手機、一可攜式電腦、一車載電腦、一穿戴式電子裝置或一廣告看板。In possible embodiments, the information processing device may be a smart phone, a portable computer, a vehicle-mounted computer, a wearable electronic device or an advertising billboard.

為使　貴審查委員能進一步瞭解本發明之結構、特徵及其目的，茲附以圖式及較佳具體實施例之詳細說明如後。In order to enable the review committee to further understand the structure, characteristics and purpose of the present invention, drawings and detailed descriptions of preferred embodiments are attached as follows.

請參照圖3，其繪示本發明之顯示裝置之一實施例的方塊圖。如圖3所示，一顯示裝置100具有一LED模組110及用以驅動該LED模組110之一顯示驅動晶片120，其中，LED模組110具有m個LED單元111，m為大於1之正整數，該些LED單元111之電流輸入端各經由一開關112耦接至一供應電壓V LED，電流輸出端耦接一共同節點，該些開關112係由m個開關信號SW 1至SW m控制；顯示驅動晶片120具有一控制電路以執行一LED脈寬調變驅動程序，該控制電路具有一數位類比轉換單元121、一放大器122、一反相器123、一占空比調整單元124、一第一開關125、一第二開關126、一第一NMOS電晶體127、一第二NMOS電晶體128及一電阻129，其中，數位類比轉換單元121係用以依一脈衝高度資料D IN＜1:m＞產生一類比電壓，其中脈衝高度資料D IN＜1:m＞係與開關信號SW 1至SW m對應；放大器122、第一NMOS電晶體127、第二NMOS電晶體128及電阻129係用以依該類比電壓產生一導通電流I LED，其中，第一NMOS電晶體127之通道耦接該共同節點且該共同節點具有一電壓V SW；占空比調整單元124係用以依一脈寬調變占空比資料PWMI＜1:m＞產生一輸出脈寬調變信號PWMO＜1:m＞，其中脈寬調變占空比資料PWMI＜1:m＞係與開關信號SW 1至SW m對應；以及反相器123、第一開關125及第二開關126係用以依輸出脈寬調變信號PWMO＜1:m＞之控制決定該導通電流I LED的持續時間，其中，當輸出脈寬調變信號PWMO＜1:m＞為高電位時，該控制電路提供該導通電流I LED，當輸出脈寬調變信號PWMO＜1:m＞為低電位時，該控制電路停止提供該導通電流I LED。另外，LED模110可為一次毫米發光二極體模組、一微發光二極體模組或一量子點發光二極體模組。 Please refer to FIG. 3 , which illustrates a block diagram of a display device according to an embodiment of the present invention. As shown in FIG. 3 , a display device 100 has an LED module 110 and a display driver chip 120 for driving the LED module 110 . The LED module 110 has m LED units 111 , and m is greater than 1. Positive integer, the current input terminals of the LED units 111 are each coupled to a supply voltage V LED through a switch 112, and the current output terminals are coupled to a common node. The switches 112 are composed of m switching signals SW 1 to SW m Control; the display driver chip 120 has a control circuit to execute an LED pulse width modulation driving program. The control circuit has a digital-to-analog conversion unit 121, an amplifier 122, an inverter 123, and a duty cycle adjustment unit 124. A first switch 125, a second switch 126, a first NMOS transistor 127, a second NMOS transistor 128 and a resistor 129, in which the digital-to-analog conversion unit 121 is used according to a pulse height data D IN <1:m> generates an analog voltage, in which the pulse height data D IN <1:m> corresponds to the switching signals SW 1 to SW m ; the amplifier 122, the first NMOS transistor 127, the second NMOS transistor 128 and the resistor 129 It is used to generate an on-current I LED according to the analog voltage, wherein the channel of the first NMOS transistor 127 is coupled to the common node and the common node has a voltage V SW ; the duty cycle adjustment unit 124 is used according to a The pulse width modulation duty cycle data PWMI＜1:m＞ generates an output pulse width modulation signal PWMO＜1:m＞, where the pulse width modulation duty cycle data PWMI＜1:m＞ is related to the switching signal SW 1 corresponding to SW m ; and the inverter 123, the first switch 125 and the second switch 126 are used to determine the duration of the on-current I LED according to the control of the output pulse width modulation signal PWMO<1:m>, where, When the output pulse width modulation signal PWMO＜1:m＞is at high potential, the control circuit provides the conduction current I LED . When the output pulse width modulation signal PWMO＜1:m＞is at low potential, the control circuit stops. Provides the conduction current I LED . In addition, the LED module 110 may be a sub-millimeter LED module, a micro LED module or a quantum dot LED module.

該LED脈寬調變驅動程序包括： (一)接收一脈衝高度資料D IN＜1:m＞及一脈寬調變占空比資料PWMI＜1:m＞； (二)在一顯示週期之多個分組期間各依供應電壓V LED之一電壓值調變脈衝高度資料D IN＜1:m＞及脈寬調變占空比資料PWMI＜1:m＞，並依調變後之脈衝高度及脈寬調變占空比產生一脈衝電壓，其中，調變後之脈衝高度係與供應電壓V LED之電壓值成正比且調變後之脈寬調變占空比係與供應電壓V LED之電壓值成反比；以及 (三)以該些脈衝電壓驅動第二NMOS電晶體128之閘極以為一LED單元111提供該顯示週期內之該些分組期間的導通電流。 The LED pulse width modulation driver includes: (1) Receive a pulse height data D IN <1:m> and a pulse width modulation duty cycle data PWMI <1:m>; (2) During a display period During multiple grouping periods, the pulse height data D IN <1:m> and the pulse width modulation duty cycle data PWMI <1:m> are modulated according to a voltage value of the supply voltage V LED , and the pulse height after modulation is And the pulse width modulation duty cycle generates a pulse voltage, where the modulated pulse height is proportional to the voltage value of the supply voltage V LED and the modulated pulse width modulation duty cycle is proportional to the supply voltage V LED is inversely proportional to the voltage value; and (3) driving the gate of the second NMOS transistor 128 with the pulse voltages to provide an LED unit 111 with an on-current during the group periods in the display cycle.

請參照圖4，其繪示圖3之顯示裝置100之顯示驅動晶片120之一工作波形圖。如圖4所示，一顯示週期分成6個分組期間(T OFF+T ON)，驅動晶片120在該些分組期間內係以與供應電壓V LED成正比的方式調整導通電流I LED之峰值，及與供應電壓V LED成反比的方式調整脈寬調變占空比(T ON/(T OFF+T ON))。依此，本發明即可使該共同節點之電壓V SW的谷值變化量極小化，從而在供應電壓V LED處於低谷時使該控制電路仍有足夠的偏壓以正常提供導通電流I LED。 Please refer to FIG. 4 , which illustrates an operating waveform diagram of the display driver chip 120 of the display device 100 of FIG. 3 . As shown in Figure 4, a display cycle is divided into six group periods (T OFF + T ON ). During these group periods, the driver chip 120 adjusts the peak value of the on-current I LED in proportion to the supply voltage V LED . And adjust the pulse width modulation duty cycle (T ON /(T OFF +T ON )) in inverse proportion to the supply voltage V LED . Accordingly, the present invention can minimize the valley variation of the voltage V SW of the common node, so that when the supply voltage V LED is at a low valley, the control circuit still has enough bias voltage to normally provide the conduction current I LED .

另外，本發明之每一個LED單元111的導通電流I LED都是以一顯示週期(如常用的幀週期等)內的平均值對應一顯示效果，亦即，只要在一顯示週期內的平均電流相等，就可認為顯示效果相等。因此，假設在供應電壓V LED處於低谷時將導通電流I LED乘上1/A，並將脈寬調變占空比乘上A，A為大於1的正實數，則在一顯示週期內的平均電流就可維持不變。 In addition, the conduction current ILED of each LED unit 111 of the present invention corresponds to a display effect based on the average value within a display period (such as a common frame period, etc.), that is, as long as the average current within a display period If they are equal, the display effects can be considered to be equal. Therefore, assuming that when the supply voltage V LED is at a low valley, the on-current I LED is multiplied by 1/A, and the pulse width modulation duty cycle is multiplied by A. A is a positive real number greater than 1, then within one display period The average current can remain unchanged.

由上述的說明可知，本發明揭露了一種LED脈寬調變驅動方法。請參照圖5，其繪示本發明之LED脈寬調變驅動方法之一實施例之流程圖，該方法係利用一控制電路實現。如圖5所示，該方法包括：在一顯示週期之多個分組期間各依一供應電壓之一電壓值調變一脈衝高度及一脈寬調變占空比，並依調變後之該脈衝高度及該脈寬調變占空比產生一脈衝電壓，其中，調變後之該脈衝高度係與該電壓值成正比且調變後之該脈寬調變占空比係與該電壓值成反比(步驟a)；以及以該些脈衝電壓驅動一電流源電路以為一LED單元提供該顯示週期內之該些分組期間的導通電流(步驟b)。As can be seen from the above description, the present invention discloses an LED pulse width modulation driving method. Please refer to FIG. 5 , which illustrates a flow chart of an embodiment of the LED pulse width modulation driving method of the present invention. The method is implemented using a control circuit. As shown in Figure 5, the method includes: modulating a pulse height and a pulse width according to a voltage value of a supply voltage during multiple groups of a display period, and modulating the duty cycle according to the modulated value. The pulse height and the pulse width modulation duty cycle generate a pulse voltage, wherein the modulated pulse height is proportional to the voltage value and the modulated pulse width modulation duty cycle is proportional to the voltage value. Inversely proportional (step a); and driving a current source circuit with the pulse voltages to provide an LED unit with conduction current during the group periods in the display cycle (step b).

在步驟a中，在該顯示週期內之該些分組期間中之調變後的所述脈衝高度及所述脈寬調變占空比之積的和可等於預設的所述脈衝高度及所述脈寬調變占空比之積的和，依此，即可使一顯示週期內的平均電流相等以產生等效的顯示效果。In step a, the sum of the products of the modulated pulse height and the pulse width modulation duty cycle in the grouping periods within the display period may be equal to the preset pulse height and the pulse width modulation duty cycle. The sum of the products of the pulse width modulation duty cycles can be used to equalize the average current within a display period to produce an equivalent display effect.

在步驟b中，該LED單元可由多個LED燈串中擇一。In step b, the LED unit may be selected from a plurality of LED light strings.

另外，依上述的說明，本發明進一步提出一種資訊處理裝置。請參照圖6，其繪示本發明之資訊處理裝置之一實施例的方塊圖。如圖6所示，一資訊處理裝置200具有一中央處理單元210及一顯示裝置220，其中，顯示裝置220係由圖3所示之顯示裝置100實現，且中央處理單元210係用以與顯示裝置220通信。另外，資訊處理裝置200可為一智慧型手機、一可攜式電腦、一車載電腦、一穿戴式電子裝置或一廣告看板。In addition, according to the above description, the present invention further provides an information processing device. Please refer to FIG. 6 , which illustrates a block diagram of an embodiment of the information processing device of the present invention. As shown in FIG. 6 , an information processing device 200 has a central processing unit 210 and a display device 220 . The display device 220 is implemented by the display device 100 shown in FIG. 3 , and the central processing unit 210 is used to communicate with the display device 220 . Device 220 communicates. In addition, the information processing device 200 can be a smart phone, a portable computer, a vehicle-mounted computer, a wearable electronic device or an advertising billboard.

藉由前述所揭露的設計，本發明乃具有以下的優點： 一、本發明之LED脈寬調變驅動方法可在一預定之顯示週期內依一供應電壓之準位變化調變各分組期間之一對應脈衝電流之脈衝高度及脈衝寬度，以確保一電流源電路在該供應電壓位於最低準位時仍可正常操作，及一LED單元在該顯示週期之平均亮度維持不變，以及優化能量使用效率並從而降低一驅動晶片的工作溫度。 二、本發明之顯示驅動晶片可藉由上述的LED脈寬調變驅動方法確保其內部之所述電流源電路在該供應電壓位於最低準位時仍可正常操作，及使一LED單元在該顯示週期之平均亮度維持不變，同時優化能量使用效率並降低其工作溫度。 三、本發明之顯示裝置可藉由上述的顯示驅動晶片確保其顯示畫面不受該供應電壓之準位波動的影響，同時優化能量使用效率並降低其工作溫度。 四、本發明之資訊處理裝置可藉由上述的顯示裝置確保其顯示畫面不受該供應電壓之準位波動的影響，同時優化能量使用效率並降低其工作溫度。 Through the design disclosed above, the present invention has the following advantages: 1. The LED pulse width modulation driving method of the present invention can modulate the pulse height and pulse width of the corresponding pulse current in each group period according to the level change of a supply voltage within a predetermined display period to ensure a current source The circuit can still operate normally when the supply voltage is at the lowest level, and the average brightness of an LED unit during the display cycle remains unchanged, optimizing energy usage efficiency and thereby reducing the operating temperature of a driver chip. 2. The display driver chip of the present invention can use the above-mentioned LED pulse width modulation driving method to ensure that the current source circuit inside the chip can still operate normally when the supply voltage is at the lowest level, and enable an LED unit to operate normally when the supply voltage is at the lowest level. The average brightness of the display cycle remains unchanged, while optimizing energy efficiency and reducing its operating temperature. 3. The display device of the present invention can use the above-mentioned display driver chip to ensure that the display screen is not affected by the fluctuation of the supply voltage level, while optimizing the energy usage efficiency and reducing the operating temperature. 4. The information processing device of the present invention can use the above-mentioned display device to ensure that its display screen is not affected by fluctuations in the level of the supply voltage, while optimizing energy usage efficiency and reducing its operating temperature.

本案所揭示者，乃較佳實施例，舉凡局部之變更或修飾而源於本案之技術思想而為熟習該項技藝之人所易於推知者，俱不脫本案之專利權範疇。What is disclosed in this case is a preferred embodiment. Any partial changes or modifications derived from the technical ideas of this case and easily inferred by those familiar with the art will not deviate from the scope of the patent rights of this case.

綜上所陳，本案無論目的、手段與功效，皆顯示其迥異於習知技術，且其首先發明合於實用，確實符合發明之專利要件，懇請　貴審查委員明察，並早日賜予專利俾嘉惠社會，是為至禱。To sum up, regardless of the purpose, means and effects of this case, it shows that it is completely different from the conventional technology, and that the invention is practical first, and indeed meets the patent requirements for inventions. I sincerely ask the review committee to take a clear look and grant the patent as soon as possible for your benefit. Society is a prayer for the Supreme Being.

10:LED驅動電路10:LED drive circuit

11:數位類比轉換單元11: Digital to analog conversion unit

12:放大器12:Amplifier

13:反相器13:Inverter

14:第一開關14:First switch

15:第二開關15:Second switch

16:NMOS電晶體16:NMOS transistor

17:電阻17: Resistor

20:LED單元20:LED unit

100:顯示裝置100:Display device

110:LED模組110:LED module

111:LED單元111:LED unit

112:開關112: switch

120:顯示驅動晶片120:Display driver chip

121:數位類比轉換單元121: Digital to analog conversion unit

122:放大器122:Amplifier

123:反相器123:Inverter

124:占空比調整單元124:Duty cycle adjustment unit

125:第一開關125:First switch

126:第二開關126:Second switch

127:第一NMOS電晶體127:The first NMOS transistor

128:第二NMOS電晶體128: Second NMOS transistor

129:電阻129: Resistor

200:資訊處理裝置200:Information processing device

210:中央處理單元210:Central processing unit

220:顯示裝置220:Display device

步驟a:在一顯示週期之多個分組期間各依一供應電壓之一電壓值調變一脈衝高度及一脈寬調變占空比，並依調變後之該脈衝高度及該脈寬調變占空比產生一脈衝電壓，其中，調變後之該脈衝高度係與該電壓值成正比且調變後之該脈寬調變占空比係與該電壓值成反比Step a: Modulate a pulse height and a pulse width according to a voltage value of a supply voltage during multiple groups of a display period, and modulate the duty cycle according to the modulated pulse height and pulse width. The variable duty cycle generates a pulse voltage, wherein the modulated pulse height is proportional to the voltage value and the modulated pulse width modulation duty cycle is inversely proportional to the voltage value.

步驟b:以該些脈衝電壓驅動一電流源電路以為一LED單元提供該顯示週期內之該些分組期間的導通電流Step b: driving a current source circuit with the pulse voltages to provide an LED unit with conduction current during the group periods in the display cycle

圖1繪示一現有的LED驅動電路。 圖2繪示圖1之LED驅動電路之一工作波形圖。 圖3繪示本發明之顯示裝置之一實施例的方塊圖。 圖4繪示圖3之顯示裝置之顯示驅動晶片之一工作波形圖。 圖5繪示本發明之LED脈寬調變驅動方法之一實施例之流程圖。 圖6繪示本發明之資訊處理裝置之一實施例的方塊圖。 Figure 1 illustrates a conventional LED driving circuit. FIG. 2 illustrates an operating waveform diagram of the LED driving circuit of FIG. 1 . FIG. 3 is a block diagram of a display device according to an embodiment of the present invention. FIG. 4 shows an operating waveform diagram of the display driver chip of the display device of FIG. 3 . FIG. 5 shows a flow chart of an embodiment of the LED pulse width modulation driving method of the present invention. FIG. 6 is a block diagram of an embodiment of the information processing device of the present invention.

步驟a:在一顯示週期之多個分組期間各依一供應電壓之一電壓值調變一脈衝高度及一脈寬調變占空比，並依調變後之該脈衝高度及該脈寬調變占空比產生一脈衝電壓，其中，調變後之該脈衝高度係與該電壓值成正比且調變後之該脈寬調變占空比係與該電壓值成反比 Step a: Modulate a pulse height and a pulse width according to a voltage value of a supply voltage during multiple groups of a display period, and modulate the duty cycle according to the modulated pulse height and pulse width. The variable duty cycle generates a pulse voltage, wherein the modulated pulse height is proportional to the voltage value and the modulated pulse width modulation duty cycle is inversely proportional to the voltage value.

步驟b:以該些脈衝電壓驅動一電流源電路以為一LED單元提供該顯示週期內之該些分組期間的導通電流 Step b: driving a current source circuit with the pulse voltages to provide an LED unit with conduction current during the group periods in the display cycle

Claims (8)

一種LED脈寬調變驅動方法，其係利用一控制電路實現且其包括：在一顯示週期之多個分組期間各依一供應電壓之一電壓值調變一脈衝高度及一脈寬調變占空比，並依調變後之該脈衝高度及該脈寬調變占空比產生一脈衝電壓，其中，調變後之該脈衝高度係與該電壓值成正比且調變後之該脈寬調變占空比係與該電壓值成反比；以及以該些脈衝電壓驅動一電流源電路以為一LED單元提供該顯示週期內之該些分組期間的導通電流；其中，在該顯示週期內之該些分組期間中之調變後的所述脈衝高度及所述脈寬調變占空比之積的和等於預設的所述脈衝高度及所述脈寬調變占空比之積的和。 An LED pulse width modulation driving method is implemented using a control circuit and includes: modulating a pulse height and a pulse width modulation ratio according to a voltage value of a supply voltage during multiple groups of a display cycle. The duty cycle is adjusted, and a pulse voltage is generated according to the modulated pulse height and the pulse width modulation duty cycle, where the modulated pulse height is proportional to the voltage value and the modulated pulse width The modulation duty cycle is inversely proportional to the voltage value; and the pulse voltages are used to drive a current source circuit to provide an LED unit with conduction currents during the group periods within the display period; wherein, within the display period, The sum of the modulated pulse height and the pulse width modulation duty cycle in the grouping periods is equal to the preset sum of the pulse height and the pulse width modulation duty cycle. . 如申請專利範圍第1項所述之LED脈寬調變驅動方法，其中，該LED單元係由多個LED燈串中擇一者。 For example, in the LED pulse width modulation driving method described in item 1 of the patent application, the LED unit is selected from a plurality of LED light strings. 一種顯示驅動晶片，其具有一控制電路以執行一LED脈寬調變驅動程序，該程序包括：在一顯示週期之多個分組期間各依一供應電壓之一電壓值調變一脈衝高度及一脈寬調變占空比，並依調變後之該脈衝高度及該脈寬調變占空比產生一脈衝電壓，其中，調變後之該脈衝高度係與該電壓值成正比且調變後之該脈寬調變占空比係與該電壓值成反比；以及以該些脈衝電壓驅動一電流源電路以為一LED單元提供該顯示週期內之該些分組期間的導通電流； 其中，在該顯示週期內之該些分組期間中之調變後的所述脈衝高度及所述脈寬調變占空比之積的和等於預設的所述脈衝高度及所述脈寬調變占空比之積的和。 A display driver chip has a control circuit to execute an LED pulse width modulation driving program. The program includes: modulating a pulse height and a voltage value according to a voltage value of a supply voltage during multiple groups of a display cycle. Pulse width modulation duty cycle, and generates a pulse voltage according to the modulated pulse height and the pulse width modulation duty cycle, wherein the modulated pulse height is proportional to the voltage value and modulated The pulse width modulation duty cycle is then inversely proportional to the voltage value; and the pulse voltages are used to drive a current source circuit to provide an LED unit with conduction current during the group periods within the display cycle; Wherein, the sum of the products of the modulated pulse height and the pulse width modulation duty cycle in the group periods within the display period is equal to the preset pulse height and the pulse width modulation The sum of the products of variable duty cycles. 如申請專利範圍第3項所述之顯示驅動晶片，其中，該LED單元係由多個LED燈串中擇一者。 For example, in the display driver chip described in Item 3 of the patent application, the LED unit is selected from a plurality of LED light strings. 一種顯示裝置，其具有一LED模組及用以驅動該LED模組之一顯示驅動晶片，該顯示驅動晶片具有一控制電路以執行一LED脈寬調變驅動程序，該程序包括：在一顯示週期之多個分組期間各依一供應電壓之一電壓值調變一脈衝高度及一脈寬調變占空比，並依調變後之該脈衝高度及該脈寬調變占空比產生一脈衝電壓，其中，調變後之該脈衝高度係與該電壓值成正比且調變後之該脈寬調變占空比係與該電壓值成反比；以及以該些脈衝電壓驅動一電流源電路以為該LED模組之一LED單元提供該顯示週期內之該些分組期間的導通電流；其中，在該顯示週期內之該些分組期間中之調變後的所述脈衝高度及所述脈寬調變占空比之積的和等於預設的所述脈衝高度及所述脈寬調變占空比之積的和。 A display device has an LED module and a display driver chip used to drive the LED module. The display driver chip has a control circuit to execute an LED pulse width modulation driver program. The program includes: a display Each of the plurality of group periods of the cycle modulates a pulse height and a pulse width modulation duty cycle according to a voltage value of a supply voltage, and generates a pulse height and a pulse width modulation duty cycle according to the modulated pulse height and the pulse width modulation duty cycle. Pulse voltage, wherein the modulated pulse height is proportional to the voltage value and the modulated pulse width modulation duty cycle is inversely proportional to the voltage value; and driving a current source with these pulse voltages The circuit provides conduction current for one of the LED units of the LED module during the grouping periods within the display period; wherein the modulated pulse height and the pulse height during the grouping periods within the display period are The sum of the product of the wide modulation duty cycle is equal to the sum of the preset product of the pulse height and the pulse width modulation duty cycle. 如申請專利範圍第5項所述之顯示裝置，其中，該LED模組係一次毫米發光二極體模組、一微發光二極體模組和一量子點發光二極體模組所組成模組所選擇的一種顯示模組。 The display device as described in item 5 of the patent application scope, wherein the LED module is composed of a sub-millimeter light-emitting diode module, a micro-light-emitting diode module and a quantum dot light-emitting diode module. A display module selected by the group. 一種資訊處理裝置，其具有一中央處理單元及如申請專利範圍第5至6項中任一項所述之顯示裝置，其中，該中央處理單元係用以與該顯示裝置通信。 An information processing device having a central processing unit and a display device as described in any one of items 5 to 6 of the patent application, wherein the central processing unit is used to communicate with the display device. 如申請專利範圍第7項所述之資訊處理裝置，其係由一智慧型手機、一可攜式電腦、一車載電腦、一穿戴式電子裝置和一廣告看板所組成群組中所選擇的一種裝置。 The information processing device described in Item 7 of the patent application is one selected from the group consisting of a smart phone, a portable computer, a vehicle-mounted computer, a wearable electronic device and an advertising billboard. device.
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