TW201201627A - LED display device capable of balancing its current and method thereof - Google Patents

Abstract

A method for balancing current of LED display device is provided. The LED display device includes a plurality of LED module, a storage unit, a MCU (Microprogrammed Control Unit), the storage unit stores a standard voltage. The method includes steps: starting correcting function; controlling each of the plurality of LED module at work state in sequence; returning a feedback voltage indicating work current of one LED module to the MCU; comparing the feedback voltage with the standard voltage; adjusting the work current of the LED module according to the compare result if the feedback voltage is not equal to the standard voltage.

Description

201201627 VI. Description of the Invention: [Technical Jaw Field of the Invention] [0001] The present invention relates to an LED display device, and more particularly to an LED display device capable of controlling current equalization and a control method thereof. [Prior Art] [0002] A light source that is energy-saving and environmentally friendly has been used for many illumination devices and display devices. Generally, for a led display device, multiple LED tubes are often required. When the LED lamps are driven and displayed, the material of each LED tube is often slightly different, resulting in the flow of each LED lamp. The current is not _, the LED light (four) brightness is also different, which causes the display of the uneven sentence. Therefore, it is necessary to provide an LED lamp driving device and method to solve the above problems. [Summary of the Invention]

Controllable LED

In view of the above, there is provided an LED lamp driving device and current balancing in a square lamp. [0005] 099121059 A (10) display capable of controlling current equalization, including a sacred module, a storage unit, a micro processing unit 'several__, _ voltage generation module. The reduction unit - a plurality of letters __, a feedback end, a positive trigger module, and a current correction module. The fine unit has a standard voltage value. Shout the voltage generation module and connect to the feedback terminal. Each of the control switches is connected in series with the -LED module between the voltage terminal and the feedback voltage generating module, and the plurality of control switches are also respectively connected to the plurality of signal outputs. The correction trigger module is used to generate a correction trigger signal; the current correction module is connected to (4) the correction trigger (4), and controls 0992037 Form No. A0101 Page 4 / 17 pages 201201627 The right dry signal output sequentially outputs a pulse width modulation The signal is connected to the corresponding connected control switch, so that the LED module is in the working state in turn, and the feedback voltage generating module sequentially generates a feedback voltage to the feedback end and transmits it to the current correction module; after receiving the feedback voltage, the current correction module will The feedback voltage is compared with a standard voltage value in the storage unit. When not in agreement, the current correction module adjusts the pulse width modulation signal output by the corresponding signal output terminal according to the comparison result of the feedback voltage and the standard voltage value, thereby adjusting the LED. The current in the module. 〇[〇〇〇6] A method for controlling current equalization of an LED display device, the LED display device comprising a plurality of LED modules, a storage grass element, and a micro processing unit, wherein the storage unit stores a standard voltage value; the control LED display device The method for setting the current equalization includes the steps of: starting the correction function; sequentially controlling each Led module to be in working state when the LED display device performs the startup or shutdown operation; feeding back the operating current of the LED module in the form of the feedback voltage The micro-processing unit • compares the feedback voltage with the standard voltage value in the memory cell; when the .ii. return voltage is different from the standard voltage value, the LED touch is adjusted according to the comparison result of the feedback voltage and the standard Q voltage value. The working current of the group. [0007] The LED display device and control method for controlling current equalization of the present invention can periodically automatically correct the current of each LED module to equalize the current flowing through the plurality of LED modules to make the LED display device 1Lighting sentence [Embodiment] [0008] Please refer to FIG. 1 , which is a circuit diagram of an LED display device 1 capable of controlling current equalization. The LED display device 1 includes a micro processing unit 1〇, a plurality of LED modules Lb Ln (n>= 2) 'several control switches K1~Kn (n>= 2) and a 099121059 form number A0101 0992037156-0 201201627 feedback voltage The module 20 is generated. The micro processing unit 1 includes a plurality of signal rounds PWM1~PWMn and a feedback end FB. Wherein, each LED module is connected in series with a control switch between the voltage terminal Vcc and the feedback voltage generating module 2〇. The signal output terminals PWM1 to PWMn are respectively connected with the control switch jmn__ for outputting the pulse width modulation signal. Controlling the on and off of the corresponding control switch, thereby controlling the LED module to work or not. The feedback voltage generating module 20 is connected to the feedback end FB for generating a feedback voltage to the feedback end FB when the LED module is in operation, and the feedback voltage is a reflection of the actual working current of the LED module. The LED display device 1 further includes a memory unit 〇 for storing a standard voltage value. The standard voltage value is a reflection of the standard operating current of the LED modules L1 LLn. The micro processing unit 10 further includes a calibration trigger module 〇1 and a current correction module 102. The calibration trigger module 101 is configured to generate a correction trigger signal to initiate a correction function, wherein the calibration trigger module 101 can periodically generate the correction trigger signal according to a system default or a user-set correction period. For example, the trigger signal is corrected every other week or a difference. In other embodiments, the calibration trigger module (8) generates a correction trigger signal according to (10) a period in which the display device 1 is turned on and off. For example, each time the LED display device 1 is turned on or off, the calibration trigger module 101 generates the Correct the trigger signal. In other embodiments, the (10) display device 1 may further include a correction function key (not shown) through which the user can generate a control command to trigger the calibration trigger module 1 to generate the correction trigger signal. . The current correction module U2 receives the correction trigger signal and then 'sequentially controls the LED module to be in the state of the state, that is, the current correction module 1G2 controls the signal wheel to output the end pwMn output - the pulse width adjustment 099121059 form number A0101 page 0992037156- 0 201201627 The signal is sent to the corresponding control switch Κ1~Κη' so that the LED module Lb Ln is in the working state in turn. The feedback voltage generating module 2 〇 sequentially generates a feedback voltage reflecting the operating current of the LED module in the working state. To the feedback terminal FB, and transmitted to the current correction module 102. In the present embodiment, the current correction module 1〇2 controls only one signal output terminal to output a pulse width modulation signal, and other signal output terminals. The pulse width modulation signal is not output. Therefore, at the same time, only one LED module is in the working state, and the other LED modules are in the inoperative state. After receiving the feedback voltage, the current correcting module 1〇2 compares the feedback voltage with the standard voltage value in the storage unit 30. When not, the corresponding signal is adjusted according to the comparison result of the feedback voltage and the standard voltage value. The pulse width modulation signal outputted at the output terminal adjusts the operating current of the LED module. [0010] In the present embodiment, the pulse width modulation signal initially outputted by the signal output terminals PWM1 to PWMn is used to control the current of the LED modules L1 to Ln to be a standard current value 'caused by the unevenness of the material of the LED module. The actual current of the LED modules is not the standard current value _:; the 'current correction module 102 adjusts the pulse width modulation signal outputted by the signal output terminal according to the result of the tp voltage and the standard voltage value tb, if the feedback voltage Higher than the standard voltage value, the actual current value of the Led module is higher than the standard current value, thereby adjusting the pulse width modulation signal outputted from the signal output terminal, and controlling the operating current of the LED module to be lowered until the LED module is The actual current is adjusted to match the standard current value. Conversely, if the feedback voltage is lower than the standard voltage value, the actual current value of the LED module is lower than the standard current value, thereby adjusting the pulse width modulation signal outputted by the signal output terminal, and controlling the operating current of the LED module to be increased until The actual current of the LED module is adjusted to be consistent with the standard current value. 099121059 Form No. A0101 0992037156-0 201201627 [0013] [0013] The current correction module 102 adjusts the pulse width modulation signal outputted by the corresponding signal output terminal to adjust the duty ratio of the pulse width modulation signal due to the pulse width The duty ratio of the modulated signal is different, and the time for conducting the intercepting of the control switch is different, so that the current flowing through the LED module is also changed accordingly. Among them, the larger the duty ratio of the pulse width modulation signal outputted from the signal output terminal, the longer the control switch conduction time is. The operating current of the LED module is larger. In the present embodiment, the LED modules Lb Ln each include a plurality of LED tubes D' connected in series. In FIG. 1, the number of the LED tubes D is two. In other embodiments, the LED tubes D are The number can be any number of three or four. The right dry control switches K1~.Κη include a control terminal (not labeled), a first conductive terminal (not labeled), and a second conductive terminal (not labeled), the plurality of control switches Κ1~Κη The control terminals are respectively connected to the signal output terminals PWM1 to PWMn, and the first conductive terminals are respectively connected to the LED modules L1 to Ln. The feedback voltage generating module 20 is a grounding resistor Rs, and one end of the grounding resistor RS away from the grounding point is connected with the feedback end FB to form a connecting node T, and the connecting node τ is simultaneously connected with the second conducting ends of the plurality of control switches K1 to Kn. connection. In this embodiment, the plurality of control switches KlnKn are ΝρΝ transistors Q1Qn, and the control terminal, the first-side conduction terminal and the second conduction terminal respectively correspond to the base, the emitter and the collector of the _triode. When the correction trigger module 1G1 generates a correction trigger signal when the calibration period comes or presses the correction function key, the current correction module 1〇2 receives the correction trigger signal and then sequentially passes the signal output terminal p~PWMn. The output-pulse width modulation signal is sent to the corresponding control switches n~Kn such that the (10) board group LI Ln is in the Guard state. (10) module currently in the state of protection, control switch receiving the pulse width modulation (4), and grounding resistance 099121059 Form No. A0101 Page 8 of 17 0992037156-0 201201627

Rs forms a current loop and thus ground resistance. The one end away from the grounding point, that is, the connecting node T generates a voltage, that is, the feedback voltage, and the feedback terminal FB receives the feedback voltage and transmits it to the current correcting module 102. After receiving the feedback voltage, the current correcting module 102 'sends the feedback voltage and stores The standard voltage values in the unit 30 are compared. When they are inconsistent, the pulse width modulation signal outputted by the corresponding signal wheel output is adjusted according to the comparison result of the feedback voltage and the standard voltage value, thereby adjusting the LED module currently in the working state. Current in. [0014] For example, when the current correction module 102 rotates a pulse width modulation signal to the control switch K2 (NPN transistor Q2) such that the control switch K2 is turned on, the branch of the LED module L2 is turned on, and the LED module L2 and The grounding resistor Rs forms a current loop, and the voltage terminal Vcc provides a current to the current loop, which is the operating current of the LED module L2, and the operating current flows through the grounding resistor rs such that the ground end of the grounding resistor Rs is connected. The node T has a voltage which is a feedback voltage reflecting the operating current of the LED module L2. After receiving the feedback voltage, the current correction module 102 compares the feedback voltage with the standard voltage value in the storage unit 〇30. When not, the corresponding signal output terminal is adjusted according to the comparison result of the feedback voltage and the standard voltage value. The pulse width modulation signal is output to adjust the current in the LED module currently in operation. [0015] Please refer to FIG. 2 ' is a flow chart of a method for controlling current balancing of the LED display device 1 according to the present invention. First, the correction trigger module 101 generates a correction trigger signal upon a trigger period or when the user presses the correction function key, and activates the correction function (S201). After receiving the correction trigger signal, the current correction module 1〇2 sequentially controls the operation of the LED modules L1 LLn, that is, the current correction module 1 〇 2 099121059 Form No. A0101 Page 9 / Total π page 0992037156-0 201201627 Control signal The output PWM PWM PWMn respectively outputs a pulse width modulation signal to the control switches K1 to Kn, and turns on the branch where the LED module L1 is located, so that the LED module Lb Ln is in the working state (S202). The feedback voltage generating module 20 sequentially feeds the operating currents of the LED modules L1 L Ln to the feedback end FB of the micro processing unit 10, that is, the feedback voltage generating module 20 sequentially generates an operating current of the LED module that is in the working state. The voltage is fed back to the feedback terminal fb (S203). The current correcting module 102 compares the feedback voltage with a standard voltage value in the storage unit 30 to determine whether the feedback voltage matches the standard voltage value in the storage unit (S204). When the current correcting module 1〇2 determines that the feedback voltage is inconsistent with the standard voltage value, 'the operating current of the LED module is adjusted according to the comparison result of the feedback voltage and the standard voltage value, that is, the electrocution is only * the positive module 102 is in the feedback voltage When the value is less than the standard voltage value, the duty ratio of the pulse width modulation signal outputted from the corresponding output terminal is increased, thereby increasing the operating current of the LEJ) module, and the current correction module 1〇2 is at a feedback voltage greater than the standard voltage. When the value is set, the duty ratio of the pulse width modulation signal outputted from the corresponding signal output terminal is lowered to reduce the operating current of the LED mode (s2〇5). [0016] Thus, the LED display device and the control method for controlling current equalization of the present invention can automatically correct the current of each LED module periodically, thereby equalizing the current flowing through the LED modules L1 to Ln, so that The led display device 1 emits light uniformly. BRIEF DESCRIPTION OF THE DRAWINGS [FIG. 1] FIG. 1 is a circuit diagram of an LED display device capable of controlling current equalization in a first embodiment of the present invention. 2 is a flow chart of a method for controlling current balancing of an LED display device in a first embodiment of the present invention. 099121059 Form No. A0101 Page 10/Total 17 Pages 201201627 [Description of Main Component Symbols] [0019] LED Display Device: 1 [0020] Micro Processing Unit: 10 [0021] LED Module: LI, L2~Ln [0022] Control Switch: ΚΙ, K2~Kn [0023] Feedback voltage generation module: 20 [0024] Signal output: PWM1, PWM2~PWMn [0025] Storage unit: 30 [0026] Correction trigger module·· 101 [0027] Current Correction module: 102

[0028] Feedback end: FB

[0029] Grounding resistance: Rs

[0030] Connection node: T

[0031] LED tube: D

[0032] NPN Transistor: Ql, Ql~Qn [0033] Start Correction Function: Step S201 [0034] sequentially control each LED module to be in an operating state: Step S202 [0035] The operating current of the LED module is fed back The form is fed back to the micro processing unit: Step S203 [0036] Whether the feedback voltage is consistent with the standard voltage value: Step S204 099121059 Form No. A0101 Page 11 of 17 0992037156-0 201201627 [0037] Adjusting the LED module according to the comparison result Working current. ··Step S205 099121059 Form No. A0101 Page 12 / Total Page 0992037156-0

Claims (1)

201201627 VII. Patent application scope: 1. T-type LED display (four) that can control current equalization, including several _modules. - The good (10) display device also includes a storage unit, which stores a standard voltage value. The micro processing unit comprises: a plurality of signal wheel outputs; and a feedback end; a Q feedback voltage generating module connected to the feedback end; and a plurality of control switches each of which is connected in series with a module. Between the end and the phase-feeding voltage generating group, the plurality of control switches are also respectively connected to the plurality of signal output terminals; and the processing unit further includes a correction triggering module and a current correcting module, and the correcting triggering module is used for generating Correcting the trigger signal; after receiving the correction trigger signal, the current correction module controls a plurality of signal output terminals to sequentially output a pulse width modulation signal to the corresponding connected control switch, so that the LED module is sequentially in the state of the servo state (4) The voltage generation module generates - reflects the feedback current of the operating current of the LED module in the working state to the feedback end, and transmits it to the current positive mode After receiving the voltage, the current correction module compares the feedback voltage with a standard voltage value in the storage unit. When not, the current correction module adjusts the corresponding signal according to a comparison result between the feedback voltage and the standard voltage value. The pulse width modulation signal outputted by the output terminal, thereby adjusting the current in the LED module. 2. The controllable current equalization LED display device according to claim 1, wherein the calibration trigger module is based on the system Default or user-set calibration 099121059 Form No. A0101 Page 13 of 17 0992037156-0 201201627 Positive cycle, the correction trigger signal is generated periodically. 3 · Controllable current equalization as described in claim 2 (10) A display device, wherein the controllable current-balanced LED display device further comprises a correction function key for generating a control command to trigger the correction trigger module to generate the correction trigger signal. 4. As described in claim 1 The LED display device capable of controlling current equalization, wherein the current correction module has a feedback voltage less than a standard voltage value When the corresponding signal output end of the control is turned up, the duty ratio of the pulse width modulation signal is rotated to increase the working current of the corresponding LED module, and the current correction module controls the adjustment when the feedback voltage is greater than the sample voltage value. The duty ratio of the pulse width modulation signal is rotated by the corresponding signal output terminal, thereby reducing the operating current of the corresponding LED module. 5. The LED display device capable of controlling current equalization as described in claim 1 Each of the LED modules includes a plurality of LED tubes connected in series. 6. The LED display device capable of controlling current equalization according to claim 1 of the patent application, wherein each of the control switches includes a control unit; a _' end, a first conductive end and a second conductive end, each control side of the control side is respectively connected to the plurality of signal output ends, and the first guiding end is respectively connected to the plurality of LED modules one by one . 7. The controllable current equalization LED display device according to claim 6, wherein the control switch 岣 is an NPN transistor, and the control terminal, the first conductive terminal and the second conductive terminal respectively correspond to a base of the NPN transistor. , emitter and collector. 8. The controllable current equalization LED display device as described in claim 6 , wherein the feedback dust generating module is a grounding resistor, the grounding resistance is away from one end of the grounding point and the feedback end, and the plurality of control switches The second guide 099121059 Form No. A0101 Page 14 / Total 17 Page 0992037156-0 201201627 The terminals are connected. After receiving the current correction signal, the current correction module controls a signal output to output a pulse width modulation signal to the corresponding control switch. When the LED module connected in series with the control switch is in an active state, the LED module, the control switch, and the grounding resistor form a current loop, so that the grounding resistor generates the feedback voltage from one end of the grounding point. Ο A method for controlling current equalization of an LED display device, the LED display device comprising a plurality of LED modules, a storage unit, and a micro-processing unit, wherein the storage unit τ stores a standard voltage value; and the improvement is that the control LED display device is current-balanced The method comprises the steps of: starting a correction function; . . :: sequentially controlling each LED module to be in a working state; and feeding back the operating current of the LED module to the micro processing unit in the form of a feedback voltage; comparing the feedback voltage with the storage unit Whether the standard voltage value is consistent; when the feedback voltage is inconsistent with the standard voltage value, the operating current of the LED module is adjusted according to the comparison result of the feedback voltage and the standard voltage value. ί Ο Ο Ο Ο Ο 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制 控制A0101 Page 15 of 17 0992037156-0