WO2019080306A1 - Système d'affichage et procédé de commande de courant associé - Google Patents

Système d'affichage et procédé de commande de courant associé

Info

Publication number
WO2019080306A1
WO2019080306A1 PCT/CN2017/116294 CN2017116294W WO2019080306A1 WO 2019080306 A1 WO2019080306 A1 WO 2019080306A1 CN 2017116294 W CN2017116294 W CN 2017116294W WO 2019080306 A1 WO2019080306 A1 WO 2019080306A1
Authority
WO
WIPO (PCT)
Prior art keywords
current
light source
electrical parameter
illuminating light
digital
Prior art date
Application number
PCT/CN2017/116294
Other languages
English (en)
Chinese (zh)
Inventor
单剑锋
Original Assignee
惠科股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 惠科股份有限公司 filed Critical 惠科股份有限公司
Publication of WO2019080306A1 publication Critical patent/WO2019080306A1/fr

Links

Classifications

    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/3406—Control of illumination source

Definitions

  • the present application relates to the field of liquid crystal display technologies, and in particular, to a display system and a current driving method thereof.
  • liquid crystal display (LCD) components are used in various applications such as a note-writing computer, a mobile phone, a personal digital assistant, a car dashboard, and the like.
  • the illuminating source is located in the LCD module, such as behind a liquid crystal layer, to facilitate viewing of the image and to produce an optimum illuminating effect.
  • the illuminating light source can be a fluorescent lamp, an electroluminescent component, a light emitting diode (LED), a gaseous discharge lamp, or the like.
  • the general control circuit provides a rectified current to the illuminating source.
  • the illuminating light source module 104 may be located behind the light modulator in the LCD assembly.
  • the illuminating light source module 104 includes a series of light emitting diodes (LEDs).
  • An LED current control integrated circuit (also referred to as a controller) 102 controls the drive current of the light source module 104.
  • the output DRV of the controller 102 is coupled to the base of the transistor 108 via an RC filter 106.
  • the collector of transistor 108 is coupled to power supply unit Vcc via connector load resistor 110.
  • the emitter of transistor 108 is grounded.
  • the collector of transistor 108 is further coupled to illuminating light source module 104 via diode 112.
  • the output of the illuminating light source module 104 is grounded via a bias resistor 114.
  • the output of the light source module 104 is also coupled to the terminal FB of the controller 102.
  • Capacitor 116 grounds power supply unit Vcc.
  • Another capacitor 118 grounds diode 112.
  • the bias resistor 114 determines a drive current value that can flow through the illuminating light source module 104.
  • Controller 102 outputs a fixed enable signal to the base of transistor 108 via RC filter 106.
  • Transistor 108 provides a predetermined drive current to illuminating light source module 104.
  • the drive current through the illumination source module 104 cannot be adjusted.
  • the LED brightness of the illuminating light source module 104 is proportional to the driving current flowing through the illuminating light source module 104. Long-term use of the circuit components may cause unpredictable changes in the drive current of the illuminating light source module 104.
  • the present application provides a display system for controlling a working drive current of a light source in a liquid crystal display system according to different use conditions and a current driving method thereof.
  • an embodiment of the present application provides a display system, including: a display device having at least one illuminating light source; and a current controller connecting the at least one illuminating light source, the current controller comprising: Calculating a total lighting time of the at least one illuminating light source; storing means for connecting the meter, configured to store a plurality of digital reference values respectively corresponding to different total lighting turns, wherein each digital reference The value corresponds to a predetermined driving current of the at least one illuminating light source; the digital-to-analog converter is connected to the storage device and the digital reference value for converting the total lighting time of the at least one illuminating light source into a first electrical parameter; a comparator connected to the digital-to-analog converter and configured to compare the first electrical parameter with a second electrical parameter corresponding to a working drive current of the at least one illuminating light source, and generate a driving bias current; and a current regulator, Connecting the comparator and adjusting a working drive current of the
  • an embodiment of the present application provides a current driving method for a display system, including: calculating a meter corresponding to a total lighting time of the at least one light source, and converting the at least one light
  • the total lighting time of the light source is a digital reference value, wherein the digital reference value corresponds to a predetermined driving current of the at least one illuminating light source; converting the digital reference value into a first electrical parameter; and measuring the work corresponding to the at least one illuminating light source a second electrical parameter of the driving current; comparing the first electrical parameter with the second electrical parameter, and generating a driving bias current according to the comparison result; and adjusting the operation of the at least one illuminating light source according to the driving bias current Drive current.
  • an embodiment of the present disclosure provides a display system, including: a display device having at least one illuminating light source; and a current controller connecting the at least one illuminating light source, wherein the current controller comprises: an environment a light sensor that senses ambient brightness in front of the display device; a storage device coupled to the ambient light sensor, configured to store a plurality of digital reference values respectively corresponding to different ambient brightness, wherein each digital reference value Corresponding to a predetermined driving current of the at least one illuminating light source; a digital to analog converter connected to The storage device and the digital reference value for converting the ambient brightness in front of the display device into a first electrical parameter; a comparator connected to the digital-to-analog converter and configured to compare the first electrical parameter with the corresponding a second electrical parameter of the operating drive current of the at least one illuminating light source, and generating a driving bias current; and a current regulator connected to the comparator and adjusting a working driving current of the at least one illuminating light source
  • an embodiment of the present application provides a current driving method for a display system, including: calculating an ambient light sensor corresponding to an ambient brightness in front of a display device, and converting the ambient brightness to a digital reference value,
  • the digital reference value corresponds to a predetermined driving current of the at least one illuminating light source; converting the digital reference value into a first electrical parameter; measuring a second electrical parameter corresponding to the working driving current of the at least one illuminating light source; comparing the first An electrical parameter and the second electrical parameter, and generating a driving bias current according to the comparison result; and adjusting a working driving current of the at least one illuminating light source according to the driving bias current.
  • an embodiment of the present application provides a display system, including: a display device having at least one illuminating light source; and a current controller connecting the at least one illuminating light source, wherein the current controller includes
  • a working temperature sensor sensing an operating temperature of the at least one illuminating light source
  • a storage device coupled to the operating temperature sensor, configured to store a plurality of digital reference values respectively corresponding to different operating temperatures, wherein each The digital reference value corresponds to a predetermined driving current of the at least one illuminating light source
  • the digital-to-analog converter is connected to the storage device and the digital reference value for converting the operating temperature of the at least one illuminating light source into a first electrical parameter
  • a current regulator connected The comparator and adjusting a working drive current of the at least one illuminating light source according to a driving bias current, wherein the driving bias current corresponds to a difference between the first electrical parameter and the second electrical parameter.
  • an embodiment of the present application provides a current driving method for a display system, including: calculating a working temperature sensor corresponding to an operating temperature of the at least one illuminating light source, and converting the working temperature to a number a reference value, wherein the digital reference value corresponds to a predetermined driving current of the at least one illuminating light source; converting the digital reference value into a first electrical parameter; measuring a second electrical parameter corresponding to the working driving current of the at least one illuminating light source; The first electrical parameter and the second electrical parameter are generated according to a comparison result Driving a bias current; and adjusting a working drive current of the at least one illuminating light source according to the driving bias current.
  • an embodiment of the present application provides a display system, including: a display device having at least one illuminating light source; and a current controller connecting the at least one illuminating light source, the current controller comprising: a light sensor that senses an ambient brightness in front of the display device; a working temperature sensor that senses an operating temperature of the at least one light source; a storage device that connects the ambient light sensor and the operating temperature The sensor is configured to store a plurality of digital reference values respectively corresponding to different ambient brightnesses and different operating temperatures, wherein each digital reference value corresponds to a predetermined driving current of the at least one light source; the digital to analog converter is connected to the The storage device and the digital reference value for converting the ambient brightness in front of the display device and the operating temperature of the at least one illuminating light source into a first electrical parameter; a comparator connected to the digital-to-analog converter and used for comparing Determining a first electrical parameter and a second electrical parameter corresponding to a working drive current
  • an embodiment of the present application provides a display system, including: a display device having at least one illuminating light source; and a current controller connecting the at least one illuminating light source, the current controller comprising: a storage device configured to store a plurality of first digital reference values respectively corresponding to different usage conditions, wherein each first digital reference value corresponds to a predetermined driving current of the at least one illuminating light source; a first digital to analog converter, connected The first storage device and the first digital reference value for converting the use condition into a first electrical parameter; the light sensor sensing the brightness of the at least one light source; the second storage device, connecting the a photo sensor, configured to store a second digital reference value, wherein the second digital reference value corresponds to a working drive current of the at least one illuminating light source; and a second digital to analog converter coupled to the second storage device And converting the second digital reference value into a second electrical parameter; a comparator connected to the first digital to analog converter and the second digital to analog
  • an embodiment of the present application provides a current driving method of a display system, including: a digital reference value is a first electrical parameter, wherein the first digital reference value corresponds to a predetermined driving current of the at least one illuminating light source; sensing a photo sensor corresponding to the brightness of the at least one illuminating light source, and converting the at least The brightness of an illuminating light source is a second digital reference value, wherein the second digital reference value corresponds to a working driving current of the at least one illuminating light source; converting the second digital reference value into a second electrical parameter; comparing the first electrical quantity a parameter and the second electrical parameter, and generating a driving bias current according to the comparison result; and adjusting a working driving current of the at least one illuminating light source according to the driving bias current.
  • the present application pre-stores a plurality of digital reference values by the storage device, so that each digital reference value corresponds to different usage conditions, thereby selecting a corresponding digital reference value as the adjusted working drive current according to different usage conditions.
  • the second electrical parameter of the present application in addition to the direct measurement of the driving current, can also be achieved by directly setting the light sensor to obtain the corresponding working drive current to avoid the same current. The brightness difference caused by the total lighting temperature or the different working temperatures.
  • FIG. 1 is a schematic diagram of a conventional current regulator for an illuminating light source.
  • FIG. 2 is a schematic diagram of a controller for providing a light source to adjust a working drive current by using a voltage comparator according to an embodiment of the present application.
  • FIG. 3 is a schematic diagram of a controller for providing a light source to adjust a working drive current by using a current comparator according to an embodiment of the present application.
  • FIG. 4 is a flow chart showing the steps of adjusting the working drive current flowing through the illuminating light source in an embodiment of the present application.
  • FIG. 5 is a schematic diagram of a controller for providing a light source to adjust a working drive current by using a voltage comparator according to another embodiment of the present application.
  • FIG. 6 is a diagram of a method for providing a light source to adjust a working drive power by using a current comparator according to another embodiment of the present application. Schematic diagram of the flow controller.
  • FIG. 7 is a flow chart showing the steps of adjusting the working drive current flowing through the illuminating light source in another embodiment of the present application.
  • FIG. 8 is a schematic diagram of a controller for providing a light source to adjust a working drive current by using a voltage comparator according to another embodiment of the present application.
  • FIG. 9 is a schematic diagram of a controller for providing a light source to adjust a working drive current by using a current comparator according to another embodiment of the present application.
  • FIG. 10 is a flow chart showing the steps of adjusting the working drive current flowing through the illuminating light source in another embodiment of the present application.
  • FIG. 11 is a schematic diagram of a controller for providing a light source to adjust a working drive current using a voltage comparator according to another embodiment of the present application.
  • FIG. 12 is a schematic diagram of a controller for providing a light source to adjust a working drive current using a current comparator according to another embodiment of the present application.
  • FIG. 13 is a flow chart showing the steps of adjusting the working drive current flowing through the illuminating light source in another embodiment of the present application.
  • a display system includes: a display device and a current controller 260.
  • the display device is a liquid crystal display device having at least one illuminating light source 214, and the at least one illuminating light source 214 includes a plurality of serially connected LEDs 242 ( L)-(n), LED 242 (l)-(n) may be connected in series, in parallel, or in series and in parallel, and the light source 214 may include a backlight source for the LCD system, for example for small LED backlight source for LCD system, LED backlight source can include various LEDs, such as white LED, color LED and organic LED (OLED).
  • LED backlight source can include various LEDs, such as white LED, color LED and organic LED (OLED).
  • the current controller 260 is connected to at least one illuminating light source 214, and the current controller 260 includes: a counter 221, a storage device 220, a digital to analog converter 222, a comparator 235, and a current regulator 212.
  • the meter 221 calculates the total lighting time of the at least one illuminating light source 214. For example, the calculation of the total lighting time can be initiated by the meter 221 by the driving signal DRV.
  • the storage device 220, the connection meter 2 21, is configured to store a plurality of digital reference values 226 corresponding to different total lighting hours, wherein each number
  • the word reference 226 corresponds to a predetermined drive current of at least one of the illumination sources 214, and the digital reference can be derived from the desired operating conditions of the emulated illumination source 214.
  • the preferred drive current value corresponding to the desired brightness of the illuminating source 214 may be derived from the operating conditions that simulate the desired brightness of the illuminating source 214, and then The preferred driving current value can be converted into a digital reference value by using an analog-to-digital converter and stored in the storage device 220. Since the illuminable component will have a light fading phenomenon depending on the total lighting time, that is, the total lighting time is The illuminating light source of 100 ⁇ and 5000 ⁇ in total illumination is different at the same working drive current.
  • the predetermined driving current of the illuminating light source 214 can be set to be proportional to the total lighting time of the illuminating light source 214, that is, the longer the total lighting time of the illuminating light source 214 is, the larger the predetermined driving current is. Increase the working drive current to compensate for the light decay phenomenon.
  • the digital-to-analog converter 222 is connected to the storage device 220 and the digital reference value 226 for converting the total lighting time of the at least one illuminating light source 214 into a first electrical parameter, for example, the digital-to-analog converter 222.
  • the digital reference value 226 is converted into an analog signal and converted into an analog signal to the voltage reference unit 230.
  • the voltage reference unit 230 is used to generate a reference voltage signal (first electrical parameter) corresponding to the analog signal.
  • the voltage reference unit 230 is shown as a separate unit, however, voltage reference unit 230 can be combined into a digital to analog converter 222, for example, digital to analog converter 222 can be used to convert digital reference value 226 to a first electrical parameter.
  • the comparator 235 is a voltage comparator 235, and is electrically connected to the digital-to-analog converter 222 through the voltage reference unit 230, and is configured to compare the first electrical parameter (eg, the reference voltage value) with the second working operating current of the corresponding illuminating source 214.
  • the first electrical parameter eg, the reference voltage value
  • the current regulator 212 includes a metal oxide semiconductor (MOS) transistor 240 for adjusting the operating drive current of the light source 214, the gate terminal and the voltage of the MOS transistor 240.
  • the comparator 235 is connected, and receives the driving signal DRV, and the source terminal of the MOS transistor 240 is grounded.
  • the drain terminal of the MOS transistor 240 is further connected to the light source 214 via the diode D.
  • the diode D is also grounded via the bypass capacitor C, and the diode D is used for protection.
  • Illumination source 214 avoids controller 260 failure and is used for unwanted high frequency current steering Flow through the bypass capacitor C to ground.
  • the current controller further includes a detector 216 coupled to the illumination source 214 and Used to measure the second electrical parameter (such as: feedback voltage value).
  • the detector 216 is coupled to the illumination source 214.
  • the detector 216 includes a detector resistor Rs for determining the voltage FB corresponding to the operating drive current flowing through the illumination source 214, the detector resistor Rs and the input of the voltage comparator 235.
  • the terminal is connected, the voltage comparator 23 5 receives the voltage FB and compares it with the first electrical parameter (eg, the reference voltage value) from the voltage reference unit 230, and generates the drive signal DRV of the gate terminal of the MOS transistor 240, the drive signal DRV.
  • the first electrical parameter eg, the reference voltage value
  • the gate terminal of the MOS transistor 240 is driven according to the difference between the voltage F B and the reference voltage value, and the MOS transistor 240 adjusts the operating driving current of the illuminating light source 214 according to the driving signal DRV.
  • the total lighting time of the illuminating light source 214 is 5000.
  • the predetermined driving current is 5A
  • the first electrical parameter (reference voltage value) is 120V
  • the operating drive current of the illuminating light source 214 is reduced to 3A and the second electrical parameter (voltage FB) due to the long time between lighting periods.
  • the difference between the voltage FB and the reference voltage value produces a relatively strong drive signal DRV, causing the operating drive current of the illuminating source 214 to increase, as in the case, such as Work driving current flowing through the light source 214 is too large, the voltage comparator 235 generates a drive signal DRV is relatively weak, causing the work light source driving current 214 is reduced.
  • the meter 221 can be set in the current controller 260 to calculate the total lighting time, the current controller 26
  • a display system includes: a display device and a current controller 260.
  • the display device is a liquid crystal display device having at least one illuminating light source 214, and the at least one illuminating light source 214 includes a plurality of serially connected LEDs 242 ( L)-(n), LED 242 (l)-(n) may be connected in series, in parallel, or in series and in parallel, and the light source 214 may include a backlight source for the LCD system, for example for small LED backlight source for LCD system, LED backlight source can include various LEDs, such as white LED, color LED and organic LED (OLED).
  • LED backlight source can include various LEDs, such as white LED, color LED and organic LED (OLED).
  • the current controller 260 is connected to at least one illuminating light source 214, and the current controller 260 includes: a counter 221, a storage device 220, a digital to analog converter 222, a comparator 235, and a current regulator 212.
  • the meter 221 calculates the total lighting time of the at least one illuminating light source 214. For example, the calculation of the total lighting time can be initiated by the meter 221 by the driving signal DRV.
  • the storage device 220 is configured to store a plurality of digital reference values 226 corresponding to different total lighting levels, wherein each digital reference value 226 corresponds to a predetermined driving current of the at least one illumination source 214, the number
  • the reference value can be derived from the operating conditions required to simulate the illumination source 214. For example, if the brightness of the illuminating light source 214 flows through the illuminating light
  • the drive current of the source 214 is proportional, and the preferred drive current value corresponding to the desired brightness of the illuminating source 214 can be derived from the operating conditions of the desired brightness of the illuminating source 214, and then the preferred drive current value can be utilized with an analog to digital converter.
  • the illuminable component Converted into a digital reference value and stored in the storage device 220, since the illuminable component will have a light decay phenomenon depending on the total lighting time, that is, the total lighting time between 100 hours and the total lighting time is 5000 hours.
  • the illuminating light source emits different brightness under the same working drive current. Generally, the brightness of the total illuminating time of 500 ⁇ is less than the brightness of 100 ⁇ between the total lighting times. Therefore, the predetermined driving current of the illuminating light source 214 can be set to be proportional to the total lighting time of the illuminating light source 214, that is, the longer the total lighting time of the illuminating light source 214 is, the larger the predetermined driving current is. Increase the working drive current to compensate for the light decay phenomenon.
  • the digital-to-analog converter 222 is connected to the storage device 220 and the digital reference value 226 for converting the total lighting time of the at least one illuminating light source 214 into a first electrical parameter, for example, the digital-to-analog converter 222.
  • the digital reference value 226 is converted into an analog signal and converted into an analog signal to the current reference unit 232.
  • the current reference unit 232 is used to generate a reference current signal (first electrical parameter) corresponding to the analog signal.
  • the current reference unit 232 is shown as a separate unit, however, current reference unit 232 can be combined into a digital to analog converter 222, for example, digital to analog converter 222 can be used to convert digital reference value 226 to a first electrical parameter.
  • the comparator 237 is a current comparator 237, and is electrically connected to the digital-to-analog converter 222 through the current reference unit 232, and is configured to compare the first electrical parameter (eg, the reference current value) with the second working operating current of the corresponding illuminating source 214.
  • the first electrical parameter eg, the reference current value
  • the current regulator 212 includes a metal oxide semiconductor (MOS) transistor 240 for adjusting the operating drive current of the light source 214, the gate terminal and current of the MOS transistor 240.
  • the comparator 237 is connected and receives the driving signal DRV, and the source terminal of the MOS transistor 240 is grounded.
  • the drain terminal of the MOS transistor 240 is further connected to the illuminating light source 214 via the diode D.
  • the diode D is also grounded via the bypass capacitor C, and the diode D is used for protection.
  • Illumination source 214 avoids controller 260 failure and is used for unwanted high frequency current steering Flow through the bypass capacitor C to ground.
  • the current controller further includes a detector 216 coupled to the illumination source 214 and configured to measure a second electrical parameter (eg, a feedback current value).
  • the detector 216 is coupled to the illumination source 214, and the detector 216 includes a sense resistor Rs and a pair of MOS transistors 252a and 252b.
  • MOS transistors 252a and 252b The gate terminal is grounded, and the drain terminal of the MOS transistor 252b is connected to the gate terminal.
  • the drain terminal of the MOS transistor 252a is connected to the current comparator 237.
  • the gate bias of 252b is changed such that the current flowing through the drain terminal of MOS transistor 252a changes.
  • current comparator 237 detects that the current flowing through MOS transistor 252b is different from the reference current value
  • current comparator 237 is A driving signal DRV corresponding to the difference is generated, and the driving signal DRV adjusts a driving current of the current regulator 212.
  • the predetermined driving current is 5A
  • the first electrical parameter is (Reference current value) is 5A
  • the working drive current of the illuminating light source 214 is reduced to 3A
  • the second electrical parameter is 3A
  • the difference between the current and the reference current value is relatively strong.
  • the drive signal DRV causes the operating drive current of the illuminating source 214 to increase. Similarly, if the operating drive current flowing through the illuminating source 214 is too large, the current comparator 237 generates a relatively weak drive. The dynamic signal DRV causes the operating drive current of the illuminating light source 214 to decrease.
  • the meter 221 can be set in the current controller 260 to calculate the total lighting time, and the current controller 26 0 automatically selects the corresponding digital reference value 226 according to the total lighting time, and accordingly increases the work. Drive current to compensate for light decay.
  • step 410 a meter corresponding to the total lighting time of the illuminating light source is calculated, and the total lighting time of the illuminating light source is converted to a digital reference value, wherein the digital reference value corresponds to a predetermined driving current of the illuminating light source.
  • step 420 then converting the digital reference value to a first electrical parameter (voltage or current).
  • Step 430 Measure a second electrical parameter (voltage or current) corresponding to the working drive current of the illuminating light source.
  • Step 440 comparing the first electrical parameter with the second electrical parameter.
  • step 450 it is determined whether there is a difference between the measured first electrical parameter and the second electrical parameter. If there is a difference, step 460 is executed to generate a driving bias current according to the comparison result to adjust the working driving current of the illuminating light source, and steps 430 to 460 are repeatedly performed until there is no difference between the first electrical parameter and the second electrical parameter. , then it ends.
  • a display system includes: a display device and a current controller 260.
  • the display device is a liquid crystal display device having at least one illuminating light source 214, and the at least one illuminating light source 214 includes a plurality of serially connected LEDs 242 ( l)-(n) , LED 242 (l)-(n) can be connected in series, in parallel, or in series and in parallel.
  • the illuminating light source 214 may include a backlight source for an LCD system, such as an LED backlight source for a small LCD system, and the LED backlight source may include various LEDs such as white LEDs, color LEDs, and organic LEDs (OLEDs).
  • the current controller 260 is connected to at least one illuminating light source 214, and the current controller 260 includes: an ambient light sensor 223, a storage device 220, a digital to analog converter 222, a comparator 235, and a current regulator 212.
  • the ambient light sensor 223 senses the ambient brightness in front of the display device.
  • the storage device 2 20 is connected to the ambient light sensor 223, and configured to store a plurality of digital reference values 226 corresponding to different ambient brightnesses, wherein each of the digital reference values 226 corresponds to a predetermined driving current of the at least one light source 214, the digital reference The value can be derived from the desired operating conditions of the simulated illumination source 214.
  • the preferred drive current value corresponding to the desired brightness of the illuminating source 214 can be derived from the operating conditions that simulate the desired brightness of the illuminating source 214, and then The preferred driving current value can be converted into a digital reference value by using the analog-to-digital converter and stored in the storage device 220. Since the human eye needs a relatively high backlight in a relatively bright environment, the content on the display device can be clearly seen. In a darker environment, too high a backlight can cause discomfort or even damage to the eyes, which in turn requires lower backlighting.
  • the digital reference 226 performs different degrees of control of the working drive current for different ambient brightness. Therefore, the predetermined driving current of the illuminating light source 214 can be set to be proportional to the ambient brightness, that is, the brighter the ambient brightness, the larger the predetermined driving current is to increase the working driving current to generate a higher backlight.
  • the digital-to-analog converter 222 is connected to the storage device 220 and the digital reference value 226 for converting the ambient brightness in front of the display device into a first electrical parameter.
  • the digital-to-analog converter 222 first converts the digital reference value 226 into an analog signal and The analog signal is forwarded to the voltage reference unit 230, and the voltage reference unit 260 is used to generate a reference voltage signal (first electrical parameter) corresponding to the analog signal.
  • the voltage reference unit 230 is displayed as a separate unit, however, the voltage Reference unit 230 can be combined into a digital to analog converter 222, for example, digital to analog converter 222 can be used to convert digital reference value 226 to a first electrical parameter.
  • the comparator 235 is a voltage comparator 235, and is electrically connected to the digital-to-analog converter 222 through the voltage reference unit 230, and is configured to compare the first electrical parameter (eg, the reference voltage value) with the second working operating current of the corresponding illuminating source 214.
  • the first electrical parameter eg, the reference voltage value
  • the current regulator 212 includes a metal oxide semiconductor (MOS) transistor 240, and the MOS transistor 240 is used to adjust the operating drive of the light source 214.
  • MOS metal oxide semiconductor
  • the current terminal, the gate terminal of the MOS transistor 240 is connected to the voltage comparator 235, and receives the driving signal DR V, and the source terminal of the MOS transistor 240 is grounded, and the drain terminal of the MOS transistor 240 is further connected to the light source 214 via the diode D, and the diode D is further
  • the bypass capacitor C is grounded, and the diode D is used to protect the illuminating light source 214 from the failure of the controller 260, and to drain the bypass capacitor C to ground with an undesired high frequency current.
  • the current controller further includes a detector 216 coupled to the illumination source 214 and configured to measure a second electrical parameter (eg, a feedback voltage value).
  • the detector 216 is coupled to the illumination source 214.
  • the detector 216 includes a detector resistor Rs for determining the voltage FB corresponding to the operating drive current flowing through the illumination source 214, the detector resistor Rs and the input of the voltage comparator 235.
  • the terminal is connected, the voltage comparator 23 5 receives the voltage FB and compares it with the first electrical parameter (eg, the reference voltage value) from the voltage reference unit 230, and generates the drive signal DRV of the gate terminal of the MOS transistor 240, the drive signal DRV.
  • the first electrical parameter eg, the reference voltage value
  • the gate terminal of the MOS transistor 240 is driven according to the difference between the voltage F B and the reference voltage value, and the MOS transistor 240 adjusts the working driving current of the illuminating light source 214 according to the driving signal DRV, for example, the ambient brightness in front of the display device is 200 nits, then predetermined
  • the driving current is 5A
  • the first electrical parameter (reference voltage value) is 120V
  • the working driving current of the xenon light source 214 is only 3A
  • the second electrical parameter (voltage FB) is 100V
  • the voltage FB and the reference voltage value are The difference between the two produces a relatively strong drive signal DRV, causing the operating drive current of the illuminating source 214 to increase to produce a higher backlight.
  • the voltage comparator 235 If the light source 214 flows through the work of the drive current is too large, the voltage comparator 235 generates a drive signal DRV is relatively weak, causing the work light source driving current 214 is reduced.
  • the ambient light sensor 223 can be disposed in the current controller 260 to sense the ambient brightness in front of the display device, and the current controller 260 automatically selects a corresponding digital reference value 226 according to the ambient brightness, and adjusts the work drive accordingly. Current.
  • a display system includes: a display device and a current controller 260.
  • the display device is a liquid crystal display device having at least one illuminating light source 214, and the at least one illuminating light source 214 includes a plurality of serially connected LEDs 242 ( L)-(n), LED 242 (l)-(n) may be connected in series, in parallel, or in series and in parallel, and the light source 214 may include a backlight source for the LCD system, for example for small LED backlight source for LCD system, LED backlight source can include various LEDs, such as white LED, color LED and organic LED (OLED).
  • LED backlight source can include various LEDs, such as white LED, color LED and organic LED (OLED).
  • the current controller 260 is connected to at least one illuminating light source 214, and the current controller 260 includes: an ambient light sensor 223, a storage device 220, a digital to analog converter 222, and a comparator 235. And a current regulator 212.
  • the ambient light sensor 223 senses the ambient brightness in front of the display device.
  • the storage device 2 20 is connected to the ambient light sensor 223, and configured to store a plurality of digital reference values 226 corresponding to different ambient brightnesses, wherein each of the digital reference values 226 corresponds to a predetermined driving current of the at least one light source 214, the digital reference The value can be derived from the desired operating conditions of the simulated illumination source 214.
  • the preferred drive current value corresponding to the desired brightness of the illuminating source 214 can be derived from the operating conditions that simulate the desired brightness of the illuminating source 214, and then The preferred driving current value can be converted into a digital reference value by using the analog-to-digital converter and stored in the storage device 220. Since the human eye needs a relatively high backlight in a relatively bright environment, the content on the display device can be clearly seen. In a darker environment, too high a backlight can cause discomfort or even damage to the eyes, which in turn requires lower backlighting.
  • the digital reference 226 performs different degrees of control of the working drive current for different ambient brightness. Therefore, the predetermined driving current of the illuminating light source 214 can be set to be proportional to the ambient brightness, that is, the brighter the ambient brightness, the larger the predetermined driving current is to increase the working driving current to generate a higher backlight.
  • the digital-to-analog converter 222 is connected to the storage device 220 and the digital reference value 226 for converting the ambient brightness in front of the display device into a first electrical parameter.
  • the digital-to-analog converter 222 first converts the digital reference value 226 into an analog signal and The analog signal is forwarded to the current reference unit 232, and the current reference unit 232 is used to generate a reference current signal (first electrical parameter) corresponding to the analog signal.
  • the current reference unit 232 is shown as a separate unit, however, the current Reference unit 232 can be combined into a digital to analog converter 222, for example, digital to analog converter 222 can be used to convert digital reference value 226 to a first electrical parameter.
  • the comparator 237 is a current comparator 237, and is electrically connected to the digital-to-analog converter 222 through the current reference unit 232, and is configured to compare the first electrical parameter (eg, the reference current value) with the second working operating current of the corresponding illuminating source 214.
  • the first electrical parameter eg, the reference current value
  • the current regulator 212 includes a metal oxide semiconductor (MOS) transistor 240 for adjusting the operating drive current of the light source 214, the gate terminal and current of the MOS transistor 240.
  • the comparator 237 is connected, and receives the driving signal DR V, and the source terminal of the MOS transistor 240 is grounded.
  • the drain terminal of the MOS transistor 240 is further connected to the illuminating light source 214 via the diode D.
  • the current controller further includes a detector 216 coupled to the illumination source 214 and configured to measure a second electrical parameter (eg, a feedback current value).
  • the detector 216 is coupled to the illumination source 214, and the detector 216 includes a sense resistor Rs and a pair of MOS transistors 252a and 252b.
  • the gate terminals of the MOS transistors 252a and 252b are grounded, and the drain terminal of the MOS transistor 252b is connected to the gate terminal.
  • the drain terminal of the MOS transistor 252a is connected to the current comparator 237.
  • the driving current flowing through the illuminating light source 214 is changed, the voltage FB across the detector resistor Rs is also changed, and the change of the voltage FB causes the MOS transistor 252a.
  • the gate bias of 252b is changed such that the current flowing through the drain terminal of MOS transistor 252a changes.
  • current comparator 237 detects that the current flowing through MOS transistor 252b is different from the reference current value, current comparator 237 is A driving signal DRV corresponding to the difference is generated, and the driving signal DRV adjusts a driving current of the current regulator 212.
  • the predetermined driving current is 5 A
  • the first electrical parameter (reference current value) 5A but the working driving current of the illuminating light source 214 is only 3A
  • the second electrical parameter is 3A
  • the difference between the current and the reference current value generates a relatively strong driving signal DRV, resulting in the operation of the illuminating light source 214.
  • the drive current is increased to produce a higher backlight.
  • the current comparator 237 is relatively weak.
  • the drive signal DRV causes the operating drive current of the illuminating light source 214 to decrease.
  • the ambient light sensor 223 can be disposed in the current controller 260 to sense the ambient brightness in front of the display device, and the current controller 260 automatically selects the corresponding digital reference value 226 according to the ambient brightness, and adjusts the work accordingly. Drive current.
  • step 411 an ambient light sensor corresponding to the ambient brightness in front of the display device is sensed, and the ambient brightness is converted into a digital reference value, wherein the digital reference value corresponds to a predetermined driving current of the light source.
  • step 421 then converting the digital reference value to a first electrical parameter (voltage or current).
  • step 431 Measure a second electrical parameter (voltage or current) corresponding to the working drive current of the illuminating light source.
  • Step 441 Compare the first electrical parameter with the second electrical parameter.
  • step 451 it is determined whether there is a difference between the measured first electrical parameter and the second electrical parameter. If there is a difference, step 461 is executed to generate a driving bias current according to the comparison result to adjust the working driving current of the illuminating light source, and steps 431 to 461 are repeatedly performed until there is no difference between the first electrical parameter and the second electrical parameter. , then it ends.
  • the display system includes: a display device and a current controller 260.
  • the display device is a liquid crystal display device having at least one illuminating light source 214, and the at least one illuminating light source 214 includes a plurality of serially connected LEDs 242(l)- (n), the LEDs 242 (1)-(n) may be connected in series, in parallel, or in series and in parallel, and the illumination source 214 may include a backlight source for the LCD system, such as for a small LCD system.
  • LED backlight source, LED backlight source can include various LEDs, such as white LED, color LED and organic LED (OLED).
  • the current controller 260 is connected to at least one illuminating light source 214, and the current controller 260 includes: an operating temperature sensor 224, a storage device 220, a digital to analog converter 222, a comparator 235, and a current regulator 212.
  • the operating temperature sensor 224 senses the operating temperature of the illuminating light source 214.
  • the storage device 220 is connected to the operating temperature sensor 224 and configured to store a plurality of digital reference values 226 respectively corresponding to different operating temperatures, wherein each of the digital reference values 226 corresponds to a predetermined driving current of the at least one illuminating source 214, and the digital reference value It can be derived from the operating conditions required to simulate the illumination source 214.
  • the preferred drive current value corresponding to the desired brightness of the illuminating source 214 may be derived from the operating conditions that simulate the desired brightness of the illuminating source 214, and then The preferred driving current value can be converted into a digital reference value by using an analog-to-digital converter and stored in the storage device 220. Since the illuminating light source 214 is driven at the same temperature and at the same temperature, the illuminating source 2 14 will be different. Brightness, the higher the operating temperature of the illuminating light source 214, the brighter the brightness, and therefore the operating drive current needs to be reduced.
  • the digital reference 226 performs different degrees of control of the working drive current for different operating temperatures. Therefore, the predetermined driving current of the illuminating light source 214 can be set to be inversely proportional to the operating temperature, that is, the higher the operating temperature, the smaller the predetermined driving current to reduce the operating driving current.
  • the digital-to-analog converter 222 is connected to the storage device 220 and the digital reference value 226 for converting the operating temperature of the illuminating light source 214 into a first electrical parameter.
  • the digital-to-analog converter 222 first converts the digital reference value 226 into an analog signal and The analog signal is forwarded to the voltage reference unit 230, and the voltage reference unit 230 is used to generate a reference voltage signal (first electrical parameter) corresponding to the analog signal.
  • the voltage reference unit 230 is displayed as a separate unit, however, the voltage reference Units 230 can be combined into a digital to analog converter 222, for example, digital to analog converter 222 can be used to convert digital reference value 226 to a first electrical parameter.
  • the comparator 235 is a voltage comparator 235, and is electrically connected to the digital-to-analog converter 222 through the voltage reference unit 230, and is configured to compare the first electrical parameter (eg, the reference voltage value) with the second working operating current of the corresponding illuminating source 214. Electrical parameters (such as: feedback voltage value), and generate a drive signal DRV corresponding to the difference between the two input voltages (such as: drive bias current) And the current regulator 212 is connected to the comparator 235 and adjusts the working drive current of the at least one illuminating source 214 according to the driving bias current.
  • the current regulator 212 includes a metal oxide semiconductor (MOS) transistor 240, the MOS transistor.
  • MOS metal oxide semiconductor
  • the gate terminal of the MOS transistor 240 is connected to the voltage comparator 235, and receives the driving signal DRV, and the source terminal of the MOS transistor 240 is grounded, and the drain terminal of the MOS transistor 240 is further diode-passed.
  • D is connected to the illuminating light source 214, and the diode D is also grounded via the bypass capacitor C.
  • the diode D is used to protect the illuminating light source 214 from the failure of the controller 260, and is used to drain the bypass capacitor C to ground with an undesired high frequency current.
  • the current controller further includes a detector 216 coupled to the illumination source 214 and configured to measure a second electrical parameter (eg, a feedback voltage value).
  • the detector 216 is coupled to the illumination source 214.
  • the detector 216 includes a detector resistor Rs for determining the voltage FB corresponding to the operating drive current flowing through the illumination source 214, the detector resistor Rs and the input of the voltage comparator 235.
  • the terminal is connected, the voltage comparator 23 5 receives the voltage FB and compares it with the first electrical parameter (eg, the reference voltage value) from the voltage reference unit 230, and generates the drive signal DRV of the gate terminal of the MOS transistor 240, the drive signal DRV.
  • the first electrical parameter eg, the reference voltage value
  • the gate terminal of the MOS transistor 240 is driven according to the difference between the voltage F B and the reference voltage value, and the MOS transistor 240 adjusts the operating driving current of the illuminating source 214 according to the driving signal DRV.
  • the operating temperature of the illuminating source 214 is 50 degrees.
  • the predetermined driving current is 5A, and the first electrical parameter (reference voltage value) is 120V, but the working driving current of the xenon light source 214 is only 3A, and the second electrical parameter (voltage FB) is 100V, then the voltage FB and the reference voltage value are The difference between the two produces a relatively strong drive signal DRV, causing the operating drive current of the illuminating source 214 to increase to produce a higher brightness, as in the case, if By operation of the drive current of light source 214 is too large, the voltage comparator 235 generates a drive signal DRV is relatively weak, causing the work light source driving current 214 is reduced.
  • the operating temperature sensor 224 can be set in the current controller 260 to sense the operating temperature of the illuminating light source 214, and the current controller 260 automatically selects the corresponding digital reference value 226 according to the operating temperature, and adjusts the working drive accordingly. Current.
  • a display system includes: a display device and a current controller 260.
  • the display device is a liquid crystal display device having at least one illuminating light source 214, and the at least one illuminating light source 214 includes a plurality of serially connected LEDs 242 ( L)-(n), LED 242 (l)-(n) may be connected in series, in parallel, or in series and in parallel, and the light source 214 may include a backlight source for the LCD system, for example for small LCD system LED backlight source, LED backlight source can include various LEDs, such as white LED, color LED and organic LED (OLED).
  • LED backlight source can include various LEDs, such as white LED, color LED and organic LED (OLED).
  • the current controller 260 is connected to at least one illuminating light source 214, and the current controller 260 includes: an operating temperature sensor 224, a storage device 220, a digital to analog converter 222, a comparator 235, and a current regulator 212.
  • the operating temperature sensor 224 senses the operating temperature of the illuminating light source 214.
  • the storage device 220 is connected to the operating temperature sensor 224 and configured to store a plurality of digital reference values 226 respectively corresponding to different operating temperatures, wherein each of the digital reference values 226 corresponds to a predetermined driving current of the at least one illuminating source 214, and the digital reference value It can be derived from the operating conditions required to simulate the illumination source 214.
  • the preferred drive current value corresponding to the desired brightness of the illuminating source 214 may be derived from the operating conditions that simulate the desired brightness of the illuminating source 214, and then The preferred driving current value can be converted into a digital reference value by using an analog-to-digital converter and stored in the storage device 220. Since the illuminating light source 214 is driven at the same temperature and at the same temperature, the illuminating source 2 14 will be different. Brightness, the higher the operating temperature of the illuminating light source 214, the brighter the brightness, and therefore the operating drive current needs to be reduced.
  • the digital reference 226 performs different degrees of control of the working drive current for different operating temperatures. Therefore, the predetermined driving current of the illuminating light source 214 can be set to be inversely proportional to the operating temperature, that is, the higher the operating temperature, the smaller the predetermined driving current to reduce the operating driving current.
  • the digital-to-analog converter 222 is connected to the storage device 220 and the digital reference value 226 for converting the operating temperature of the illuminating light source 214 into a first electrical parameter.
  • the digital-to-analog converter 222 first converts the digital reference value 226 into an analog signal and The analog signal is forwarded to the current reference unit 232, and the current reference unit 232 is configured to generate a reference current signal (first electrical parameter) corresponding to the analog signal.
  • the current reference unit 232 is shown as a separate unit, however, the current reference Unit 232 can be combined into a digital to analog converter 222, for example, digital to analog converter 222 can be used to convert digital reference value 226 to a first electrical parameter.
  • the comparator 237 is a current comparator 237, and is electrically connected to the digital-to-analog converter 222 through the current reference unit 232, and is configured to compare the first electrical parameter (eg, the reference current value) with the second working operating current of the corresponding illuminating source 214.
  • the first electrical parameter eg, the reference current value
  • the current regulator 212 includes a metal oxide semiconductor (MOS) transistor 240 for adjusting the operating drive current of the light source 214, the gate terminal and current of the MOS transistor 240.
  • the comparator 237 is connected and receives the drive signal DRV, and the MOS transistor 2
  • the source of the MOS transistor 240 is further connected to the illuminating source 214 via the diode D.
  • the diode D is also grounded via the bypass capacitor C.
  • the diode D is used to protect the illuminating source 214 from the failure of the controller 260, and is used for unwanted purposes.
  • the high frequency current is drained through the bypass capacitor C to ground.
  • the current controller further includes a detector 216 coupled to the illumination source 214 and configured to measure a second electrical parameter (eg, a feedback current value).
  • Detector 216 is coupled to illuminating source 214, which includes sense resistor Rs and a pair of MOS transistors 252a and 252b.
  • the gate terminals of the MOS transistors 252a and 252b are grounded, and the drain terminal of the MOS transistor 252b is connected to the gate terminal.
  • the drain terminal of the MOS transistor 252a is connected to the current comparator 237.
  • the predetermined driving current is 5A
  • the first electrical parameter (reference voltage value)
  • the operating drive current of the illuminating light source 214 is only 3A
  • the second electrical parameter (voltage FB) is 100V
  • the difference from the reference voltage value produces a relatively strong drive signal DRV, causing the operating drive current of the illuminating source 214 to increase to produce a higher brightness.
  • the voltage comparator 235 generates a relatively weak drive signal DRV, causing the operating drive current of the illuminating light source 214 to decrease.
  • the operating temperature sensor 224 can be set in the current controller 260 to sense the operating temperature of the illuminating light source 214, and the current controller 260 automatically selects the corresponding digital reference value 226 according to the operating temperature, and adjusts the work accordingly. Drive current.
  • the display system can adjust the working drive current according to the result of the ambient brightness sensing and the working temperature sensing.
  • the display system can include: the ambient light sensor 223 and Operating temperature sensor 224.
  • the ambient light sensor 223 senses the ambient brightness in front of the display device
  • the operating temperature sensor 224 senses the operating temperature of the light source 214
  • the storage device 220 connects the ambient light sensor 22 and the operating temperature sensor 224.
  • the drive current, digital reference value can be derived from the operating conditions required to simulate the illumination source 214. Therefore, the current controller 260 can automatically select a corresponding digital reference value 226 according to the ambient brightness and the operating temperature, and adjust the working drive current accordingly.
  • step 412 a working temperature sensor corresponding to the operating temperature of the illuminating light source is sensed, and the switching operating temperature is a digital reference value, wherein the digital reference value corresponds to a predetermined driving current of the illuminating light source.
  • step 422 and then converting the digital reference value into a first electrical parameter (voltage or current).
  • step 432 Measure a second electrical parameter (voltage or current) corresponding to the working drive current of the illuminating light source. Step 442, comparing the first electrical parameter with the second electrical parameter.
  • step 452 it is determined whether there is a difference between the measured first electrical parameter and the second electrical parameter. If there is a difference, step 462 is performed to generate a driving bias current according to the comparison result to adjust the working driving current of the illuminating light source, and steps 431 to 461 are repeatedly performed until there is no difference between the first electrical parameter and the second electrical parameter. , then it ends.
  • a display system includes: a display device and a current controller 2 60
  • the display device can be a liquid crystal display device having at least one illuminating light source 214, and the at least one illuminating light source 214 can include a plurality of series connected LEDs 242(1)-(n), and the LEDs 242(l)-(n) can be stringed.
  • the illuminating light source 214 may include a backlight source for an LCD system, such as an LED backlight source for a small LCD system, and the LED backlight source may include various LEDs, such as white light. LED, color LED and organic LED (OLED).
  • the current controller 260 is connected to at least one illuminating light source 214, and the current controller 260 includes: a use condition 225, a first storage device 220, a first digital to analog converter 222, a second storage device 253, and a second digital to analog conversion.
  • the device 254, the comparator 235, the photo sensor 251 and the current regulator 212 are examples of the current regulator 212.
  • the use condition 225 can include sensing the operating temperature of the illuminating light source 214, the total lighting time of the illuminating light source 214, and the ambient brightness in front of the display device.
  • the first storage device 220, the connection use condition 225 is configured to store a plurality of first digital reference values 226 respectively corresponding to different usage conditions 225, wherein each of the first digital reference values 226 corresponds to a predetermined driving current of the at least one illumination source 214
  • the first digital reference value 226 can be derived from the desired operating conditions of the simulated illumination source 214.
  • the corresponding illuminating light source 2 The preferred drive current value for the desired brightness may be derived from the operating conditions that simulate the desired brightness of the illumination source 214, and then the preferred drive current value may be converted to a first digital reference value using an analog to digital converter and stored in the first In the storage device 220, since the illuminating light source 214 has different brightness, working drive current, and the like under different use conditions 225, it is necessary to adjust the working drive current of the illuminating light source 214.
  • the first digital reference 226 performs different degrees of control of the working drive current for different usage conditions 225.
  • the first digital-to-analog converter 222 is connected to the first storage device 220 and the first digital reference value 226 for converting the operating temperature of the illuminating light source 214 into a first electrical parameter, for example: the first digital-to-analog converter 222 first
  • a digital reference value 226 is converted into an analog signal and converted to an analog signal to the first voltage reference unit 230.
  • the first voltage reference unit 230 is configured to generate a reference voltage signal (first electrical parameter) corresponding to the analog signal.
  • the first voltage reference unit 230 is shown as a separate unit. However, the first voltage reference unit 230 may be combined into a first digital to analog converter 222.
  • the first digital to analog converter 222 may be configured to use the first digital reference value 226.
  • the photo sensor 251 can sense the brightness of the illuminating light source 214.
  • the second storage device 252 is connected to the photo sensor 251 and configured to store a plurality of second digital reference values 253 respectively corresponding to the brightness of the different illumination sources 214, wherein each of the second digital reference values 253 corresponds to the at least one illumination source 214
  • the operational drive current, the second digital reference 253, can be derived from the desired operating conditions of the simulated illumination source 214.
  • the value of the operating drive current corresponding to the brightness of the illuminating source 214 can be derived from the operating conditions of the emulated illuminating source 214, and then the operating drive current value
  • the analog to digital converter can be converted to a digital reference value 253 and stored in the second storage device 252.
  • the second digital-to-analog converter 254 is connected to the second storage device 252 and the second digital reference value 253 for converting the brightness of the illuminating light source 214 into a second electrical parameter.
  • the second digital-to-analog converter 222 first performs the second
  • the digital reference value 253 is converted into an analog signal and converted to an analog signal to the second voltage reference unit 255.
  • the second voltage reference unit 255 is configured to generate a second electrical parameter corresponding to the analog signal.
  • the second voltage reference unit 255 Displayed as separate units, however, the second voltage reference unit 255 can be combined into a second digital to analog converter 254, for example, the second digital to analog converter 254 can be used to convert the second digital reference value 253 into a second electrical parameter. .
  • the comparator 235 is a voltage comparator 235, is electrically connected to the first digital-to-analog converter 222 through the first voltage reference unit 230, and is electrically connected to the second digital-to-analog converter 254 through the second voltage reference unit 255, and is used for comparison.
  • the first electrical parameter such as: reference voltage value
  • the second electrical parameter such as: feedback voltage value
  • a driving signal DRV for example, a driving bias current
  • the current regulator 212 includes a metal oxide semiconductor (MOS) transistor 240 for adjusting the operating drive current of the illuminating light source 214.
  • MOS metal oxide semiconductor
  • the gate terminal of the MOS transistor 240 is connected to the voltage comparator 235 and receives the driving signal DRV, and the MOS The source terminal of the transistor 240 is grounded.
  • the drain terminal of the MOS transistor 240 is further connected to the illuminating light source 214 via the diode D.
  • the diode D is also grounded via the bypass capacitor C.
  • the diode D is used to protect the illuminating light source 214 from the malfunction of the controller 260, and is not intended to be used.
  • the desired high frequency current is drained through the bypass capacitor C to ground.
  • voltage comparator 235 receives a second electrical parameter (eg, a feedback voltage value) and will compare with a first electrical parameter (eg, a reference voltage value) from first voltage reference unit 230, and The drive signal DRV of the gate terminal of the MOS transistor 240 is generated, the drive signal DRV drives the gate terminal of the MOS transistor 240 according to the difference between the voltage FB and the reference voltage value, and the MOS transistor 240 adjusts the working drive current of the illuminating light source 214 according to the drive signal DRV.
  • the use condition 225 is the ambient brightness in front of the display device.
  • the predetermined drive current is 5 A
  • the first electrical parameter (reference voltage value) is 120 V
  • the neon sensor 251 senses that the brightness of the illuminating light source 214 is 100 nits
  • the working current of the brightness of 100 ns is only 3 A
  • the second electrical parameter (feedback voltage value) is 100 V
  • the difference between the first electrical parameter and the second electrical parameter That is, a relatively strong driving signal DRV is generated, resulting in an illuminating light source.
  • the working drive current of 214 is increased to generate a higher backlight. Similarly, if the brightness of the illuminating light source 214 is too bright and the corresponding working driving current is too large, the voltage comparator 235 generates a relatively weak driving signal DRV, reducing the illuminating source. 214 works to drive current.
  • the use condition 225 can be set in the current controller 260, and the current controller 260 automatically selects the corresponding digital reference value 226 according to the use condition 2 25, and does not measure the working drive current of the illumination source 214, but sets The photo sensor 251 directly senses the brightness of the light to avoid a brightness drop caused by the total lighting time or different operating temperatures at the same current, so that the adjustment of the working drive current is more accurate.
  • a display system includes: a display device and a current controller 260.
  • the display device is a liquid crystal display device having at least one illuminating light source 214, and at least one illuminating light source 214 includes a plurality of serially connected LEDs 242 ( L)-(n), LED 242 (l)-(n) may be connected in series, in parallel, or in series and in parallel, and the light source 214 may include a backlight source for the LCD system, for example for small LCD system LED backlight source, LED backlight source can include various LEDs, such as white LED, color LED and organic LED (OLED).
  • LED backlight source can include various LEDs, such as white LED, color LED and organic LED (OLED).
  • the current controller 260 is connected to at least one illuminating light source 214, and the current controller 260 includes: a use condition 225, a first storage device 220, a first digital to analog converter 222, a second storage device 253, and a second digital to analog conversion.
  • the use condition 225 can include sensing the operating temperature of the illuminating light source 214, the total lighting time of the illuminating light source 214, and the ambient brightness in front of the display device.
  • the first storage device 220 is configured to store a plurality of first digital reference values 226 respectively corresponding to the different use conditions 225, wherein each of the first digital reference values 226 corresponds to a predetermined drive current of the at least one illumination source 214
  • the first digital reference value can be derived from the desired operating conditions of the simulated illumination source 214.
  • the preferred drive current value corresponding to the desired brightness of the illuminating source 214 may be derived from the operating conditions that simulate the desired brightness of the illuminating source 214, and then The preferred drive current value can be converted to the first digital reference value by the analog to digital converter and stored in the first storage device 220. Since the different illumination conditions 225, the illumination source 214 will have different brightness, working drive current, etc. Therefore, it is necessary to adjust the working drive current of the illuminating light source 214.
  • the first digital reference 226 performs different degrees of control of the working drive current for different usage conditions 225.
  • the first digital-to-analog converter 222 is connected to the first storage device 220 and the first digital reference value 226 for converting the operating temperature of the illuminating light source 214 into a first electrical parameter, for example: the first digital-to-analog converter 222 first
  • a digital reference value 226 is converted into an analog signal and converted to an analog signal to the first current reference unit 232.
  • the first current reference unit 232 is configured to generate a reference current signal (first electrical parameter) corresponding to the analog signal, for the sake of explanation.
  • the first current reference unit 232 is shown as a separate unit. However, the first current reference unit 232 can be combined into a first digital-to-analog converter 222.
  • the first digital-to-analog converter 222 can be used to convert the digital reference value 226.
  • the photo sensor 251 can sense the brightness of the illuminating light source 214.
  • the second storage device 252 is connected to the photo sensor 251 and configured to store a plurality of second digital reference values 253 respectively corresponding to the brightness of the different illumination sources 214, wherein each of the second digital reference values 253 corresponds to the at least one illumination source 214
  • the operational drive current, the second digital reference 253, can be derived from the desired operating conditions of the simulated illumination source 214.
  • the value of the operating drive current corresponding to the brightness of the illuminating source 214 can be derived from the operating conditions of the emulated illuminating source 214, and then the operating drive current value
  • the analog to digital converter can be converted to a digital reference value 253 and Stored in the second storage device 252.
  • the second digital-to-analog converter 254 is connected to the second storage device 252 and the second digital reference value 253 for converting the brightness of the illuminating light source 214 into a second electrical parameter.
  • the second digital-to-analog converter 222 first performs the second
  • the digital reference value 253 is converted to an analog signal and converted to an analog signal to a second current reference unit 256, which is used to generate a second electrical parameter corresponding to the analog signal.
  • the second voltage reference unit 256 Displayed as separate units, however, the second voltage reference unit 256 can be combined into a second digital to analog converter 254, for example, the second digital to analog converter 254 can be used to convert the second digital reference value 253 to a second electrical parameter.
  • the comparator 237 is a current comparator 237.
  • the first current reference unit 232 is electrically connected to the first digital-to-analog converter 222 and the second voltage reference unit 256 is electrically connected to the second digital-to-analog converter 254. Comparing the first electrical parameter (eg: reference current value) with the second electrical parameter (eg, feedback current value), and generating a drive signal DRV corresponding to the difference between the two input currents (eg, driving bias current), and a current regulator 212 is connected to the comparator 235 and adjusts the working driving current of the at least one illuminating light source 214 according to the driving bias current.
  • the current regulator 212 includes a metal oxide semiconductor (MOS) transistor 240, and the MOS transistor 240 is used to adjust the illuminating.
  • MOS metal oxide semiconductor
  • the working drive current of the light source 214, the gate terminal of the MOS transistor 240 is connected to the current comparator 237, and receives the driving signal DR V , and the source terminal of the MOS transistor 240 is grounded, and the drain terminal of the MOS transistor 240 is further connected to the light source 214 via the diode D.
  • the diode D is also grounded via a bypass capacitor C. The diode D is used to protect the illumination source 214 from malfunction of the controller 260 and to use unwanted high frequencies. Drainage flow through the bypass capacitor C is grounded.
  • the current comparator 237 when the current comparator 237 detects that the second electrical parameter is different from the first electrical parameter, the current comparator 237 generates a driving signal DRV corresponding to the difference, and the driving signal DRV adjusts the current adjustment.
  • the driving current of the device 212 for example, the use condition 225 is the ambient brightness in front of the display device.
  • the predetermined drive current is 5 A
  • the first electrical parameter (reference current value) is 5 A
  • the first electrical parameter is 5 A
  • the second electrical parameter (feedback current value) is 3 A
  • the first electrical parameter and the second electrical parameter The difference between the two produces a relatively strong drive signal DRV, causing the operating drive current of the illuminating source 214 to increase to produce a higher backlight.
  • the current comparator 237 generates a relatively weak drive signal DRV, which reduces the operating drive current of the illuminating light source 214.
  • the use condition 225 can be set in the current controller 260, and the current controller 260 is based on the use condition 2 25 automatically selects the corresponding digital reference value 226, and does not measure the working drive current of the illuminating light source 214, but sets the photo sensor 251 to directly sense the brightness to avoid the total illuminating time or different at the same current.
  • the difference in brightness caused by the operating temperature, the corresponding working drive current is obtained by sensing the brightness, so that the adjustment of the working drive current is more accurate.
  • the steps are performed in a specific order. However, if executed in an appropriate circuit, the above steps may be performed in any specific order, and may be performed in any order or sequentially.
  • the conversion use condition is a first digital reference value, wherein the first digital reference value corresponds to a predetermined driving current of the illuminating light source.
  • Step 423 then converting the digital reference value to a first electrical parameter (voltage or current).
  • Step 433 sensing brightness of the corresponding illuminating light source, and converting the brightness of the illuminating light source to a second digital reference value, and then converting the second digital reference value to a second electrical parameter (voltage or current), wherein the second digital reference value corresponds to illuminating The working drive current of the light source.
  • Step 443 Compare the first electrical parameter with the second electrical parameter.
  • step 453 it is determined whether there is a difference between the measured first electrical parameter and the second electrical parameter. If there is a difference, step 463 is performed, and a driving bias current is generated according to the comparison result to adjust the working driving current of the illuminating light source, and steps 433 to 463 are repeatedly performed until there is no difference between the first electrical parameter and the second electrical parameter. , then it ends.
  • the present application provides a method and apparatus for controlling the operating drive current of a light source in a liquid crystal display system according to different usage conditions.
  • the present application may not measure the working driving current of the illuminating light source 214, but set the photo sensor 251 to directly sense the brightness to obtain the corresponding working driving current.
  • the corresponding working driving current is obtained by sensing the brightness, so that the adjustment working driving current is more accurate.

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  • Circuit Arrangement For Electric Light Sources In General (AREA)

Abstract

La présente invention concerne un système d'affichage ajustable et un procédé de commande de courant associé. Le procédé consiste à : convertir une première valeur numérique de référence en un premier paramètre électrique (423), la première valeur numérique de référence correspondant à un courant d'attaque prédéfini d'au moins une source électroluminescente ; détecter la luminosité de la source électroluminescente correspondante, convertir la luminosité de la source électroluminescente en une seconde valeur numérique de référence, puis convertir la seconde valeur numérique de référence en un second paramètre électrique (433), la seconde valeur numérique de référence correspondant à un courant d'attaque de fonctionnement de ladite source électroluminescente ; comparer le premier paramètre électrique au second paramètre électrique (443), et générer un courant de polarisation d'attaque en fonction du résultat de la comparaison ; et ajuster le courant d'attaque de fonctionnement de ladite source électroluminescente en fonction du courant de polarisation d'attaque.
PCT/CN2017/116294 2017-10-26 2017-12-14 Système d'affichage et procédé de commande de courant associé WO2019080306A1 (fr)

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CN201711016415.8A CN107808640A (zh) 2017-10-26 2017-10-26 显示系统及其电流驱动方法
CN201711016415.8 2017-10-26

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WO2019080306A1 true WO2019080306A1 (fr) 2019-05-02

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1591109A (zh) * 2003-10-28 2005-03-09 友达光电股份有限公司 显示系统中控制发光光源的驱动电流的方法及装置
CN101210846A (zh) * 2006-12-27 2008-07-02 汉阳大学校产学协力团 环境光传感器电路和具有该电路的平板显示设备
US20090091560A1 (en) * 2004-02-09 2009-04-09 Microsemi Corporation Method and apparatus to control display brightness with ambient light correction
CN102242888A (zh) * 2010-05-12 2011-11-16 鸿富锦精密工业（深圳）有限公司 发光装置及其发光强度调节方法
CN202189539U (zh) * 2011-08-24 2012-04-11 周继军 自适应调整的led背光电路

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1591109A (zh) * 2003-10-28 2005-03-09 友达光电股份有限公司 显示系统中控制发光光源的驱动电流的方法及装置
US20090091560A1 (en) * 2004-02-09 2009-04-09 Microsemi Corporation Method and apparatus to control display brightness with ambient light correction
CN101210846A (zh) * 2006-12-27 2008-07-02 汉阳大学校产学协力团 环境光传感器电路和具有该电路的平板显示设备
CN102242888A (zh) * 2010-05-12 2011-11-16 鸿富锦精密工业（深圳）有限公司 发光装置及其发光强度调节方法
CN202189539U (zh) * 2011-08-24 2012-04-11 周继军 自适应调整的led背光电路

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