CN101309535A - Brightness control apparatus and method for light source and display apparatus - Google Patents
Brightness control apparatus and method for light source and display apparatus Download PDFInfo
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- CN101309535A CN101309535A CNA2007101025580A CN200710102558A CN101309535A CN 101309535 A CN101309535 A CN 101309535A CN A2007101025580 A CNA2007101025580 A CN A2007101025580A CN 200710102558 A CN200710102558 A CN 200710102558A CN 101309535 A CN101309535 A CN 101309535A
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
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Abstract
The invention provides a luminous source brightness controlling method and a luminous source system adopting a controlling device, a displaying device and a controlling method thereof. The luminous source controlling device of the invention comprises an optical sensor used for detecting the change of a luminous source and a luminous source managing and controlling circuit used for proving a controlling and adjusting signal according to the feedback signal of the optical sensor for the luminous source. The luminous source managing and controlling circuit obtains the output signal of the optical sensor when the luminous source is closed, the luminous source is controlled and adjusted according to a detecting signal, thereby, the brightness for the luminous source is compensated, and a stable luminous source is provided. The luminous source controlling method of the invention can control the brightness of the luminous source effectively; and provides the stable luminous source for the luminous source and the displaying device.
Description
Technical field
The present invention relates to a kind of control device and control method thereof of light source, particularly a kind of light-emitting diode (Light Emitting Diode; LED) brightness controlling device of light source and use light-source system, display unit and the control method thereof of this control device.
Background technology
Light-emitting diode operating voltage low (only 1.5-3V), can active illuminating and certain brightness is arranged, brightness voltage available or Current Regulation, possess shock-resistant, anti-vibration, the characteristics in life-span long (100,000 hours) simultaneously, be with, light-emitting diode is widely used in various terminal equipments, from car headlamp, traffic lights, literal display, billboard and large-screen video display, to fields such as common and architectural lighting and LCD are backlight.
Along with the increase of light-emitting diodes tube efficiency and brightness and the minimizing of cost, the light-emitting diode market development is increasingly mature.Especially in high-end demonstration field, display platform requires very high to the light-source brightness coupling, need to obtain even, consistent display color and brightness, guarantees that display effect all the time as new.
Yet, owing to the luminous intensity of light source can be because the aging or temperature factor of light source itself changes (increasing or the minimizing luminous intensity), so if will keep the stable of light source, just must know variation and the feedback compensation and the control light source of light source, reach the purpose of keeping light stability at last.
Existing two kinds of dimming modes are simulation or pulse-width modulation (Pulse Width Modulation, PWM) mode.Wherein, the simulation light modulation is to adjust brightness by changing stream by the size of current of light-emitting diode.Simulation light-dimming method shortcoming is the led color skew to occur, and needs to adopt analog control signal.Another kind of light-dimming method is the PWM light modulation, and it adopts fixed current driven for emitting lights diode, utilizes the time ratio (Duty Ratio) that opens and closes light-emitting diode to adjust effect to reach brightness.For example: use 20mA to decide electric current and come the driven for emitting lights diode, and duty ratio be 50% brightness that is produced will be that dutyratio is half of 100%.Decide the current drives light-emitting diode owing to adopt, the PWM light modulation the color shift problem can not occur.Simultaneously, can't see the scintillation that opens and closes light-emitting diode for the eyes of guaranteeing the user, the switching frequency that light source opens and closes should be enough fast, and maximum PWM frequency depends on power initiation and response time, in theory as long as human eye just can't be discovered when switching frequency surpasses about 200Hz.
Relevant prior art also can be consulted the United States Patent (USP) announced US6127783 number, and US6894442 number, US6495964 number.
The common feature of above-mentioned various existing control methods is to use optical sensor to come detection light source, obtain the output information of optical sensor in (between high period) during the light source igniting, and then the feedback adjusting light source, to reach the function of compensate for brightness, its control timing figure is as shown in Figure 1.
Yet, the influence of the system noise that its driver was caused when existing control method was subjected to light source igniting.Please consult shown in Figure 2 that the present invention approaches a subject earlier, LED driving circuit is having in the drive current output, and promptly LED source is lighted time zone 24 (high level period), has big noise in the Circuits System simultaneously; And the output signal of light sensors has control method now and exists the LED source than big noise to carry out data sampling the period of lighting originally as a weak electric signal, and this will reduce the detection signal signal to noise ratio, influence the precision of testing result in the reality.Especially extensive dot matrix LEDs light source, required drive current is very big, and the noise that produces in the Circuits System is bigger, might flood detecting output signal, and What is more will detect required feedback signal.
In view of this, providing a kind of light-source brightness control technology that can effectively reduce noise jamming, improve the detection precision, also is that the dealer needs the actively direction of research and development.
Summary of the invention
The invention provides a kind of light-source brightness control device that can effectively reduce interference noise, improve the detection precision.
The invention provides a kind of light source brightness control method that can effectively reduce interference noise, improve the detection precision.
The invention provides a kind of light-source system that possesses the steady display effect.
The invention provides a kind of display unit that possesses the steady display effect.
The invention provides a kind of light-source brightness control device, be used to obtain stable light source, it comprises: an optical sensor is used for the variation of detection light source; And a light source management control circuit, be used for providing the regulating and controlling signal to light source according to the feedback signal of optical sensor; Wherein, described light source management control circuit is the output signal that obtains optical sensor when light source is closed, and calculates and adjust light source according to the signal that detects, and the brightness of compensatory light changes by this.
The invention provides a kind of light source brightness control method, this control method comprises the following steps: the variation by the light sensors light source; And when light source is closed, obtain the output signal of optical sensor, and come the variation of compensatory light brightness according to the feedback of optical sensor, obtain stable light source by this.
Light-source system of the present invention, it comprises: light source; One is used for the optical sensor that detection light source changes; An and light source management control circuit that is used for providing to light source the regulating and controlling signal according to the feedback signal of optical sensor; Wherein, described light source management control circuit is the output signal that obtains optical sensor when light source is closed, and calculates and adjust light source according to the signal that detects, and the brightness of compensatory light changes to obtain stable display effect by this.
Display unit of the present invention comprises a light-source system, and described light-source system comprises: light source; One is used for the optical sensor that detection light source changes; An and light source management control circuit that is used for providing to light source the regulating and controlling signal according to the feedback signal of optical sensor; Wherein, described light source management control circuit is the output signal that obtains optical sensor when light source is closed, and calculates and adjust light source according to the signal that detects, and the brightness of compensatory light changes to obtain stable display effect by this.
Compared to prior art, advantage of the present invention comprises and being: light source brightness control method of the present invention is to carry out data sampling in the light source down periods, because light source drive was closed simultaneously in the light source down periods, be that the system noise that its driver is caused when can avoid being subjected to light source igniting influences, improve the signal to noise ratio of signal, improvement can more effectively be controlled light-source brightness the detection precision that light source changes, for light-source system and display unit provide stable light source.
For above and other objects of the present invention, feature and advantage can be become apparent, preferred embodiment cited below particularly, and conjunction with figs. are described in detail below.
Description of drawings
Fig. 1 is the control timing figure of existing light-source brightness and color balance.
Fig. 2 is the noise relationship schematic diagram of light source state and light source measurement signal.
Fig. 3 shows the light-source brightness controlling mechanism schematic diagram according to an embodiment of the present invention.
Fig. 4 shows the control timing schematic diagram according to an embodiment of the present invention.
Fig. 5,6 shows the light-source brightness controlling mechanism schematic diagram according to another execution mode of the present invention.
Fig. 7 shows the control timing schematic diagram of another embodiment of the present invention.
The potential diagram schematic diagram of mechanism that the voltage charging that Fig. 8 shows sampling point rises, keeps, decays.
The reference numeral explanation
100: light-source system
102: light-emitting diode driver circuit 308: analog to digital converter
104: light-emitting diode 310: the light source management engine
106,220: optical sensor 312:PWM Control Engine
110,232: the light source Management Controller
108,302,304,306: filter circuit
230,300: light source management control circuit
Embodiment
The present invention carries out probing into of its problem in order to solve the problem that light source changes.Fig. 2 shows the noise relationship schematic diagram of light source state and light source measurement signal.Consulting Fig. 2, is example with the luminous disome of two different colours, controlled by voltage modulation signal PWM1 and PWM2.When time zone 20, the two all is in closed condition, that is to say that light source is a buttoned-up status.In addition, all being in high level at PWM1 and PWM2 is complete bright state at time zone.After the variation of light source converts electronic signal to by optical sensor, through resulting light intensity signal behind the filter, it generally is input signal as the light source Management Controller, the signal in its zone 22 is states 20 of corresponding luminescence component contract fully, and the signal in zone 24 is states that corresponding luminescence component is opened.From the noise level of signal, the signal of the signal opposed area 24 regional 22 has obviously comparatively stable value.
Even be noted that here in luminescence component closing state 20, because the RC circuit of filter has still retained current potential, the decay of its current potential and luminescence component luminous efficacy have corresponding relation.Therefore, even measure signal 20 times in the illuminating part closing state, if the time point of fixing sampling, whether the luminous efficiency that then still can judge illuminating part changes.So after the behavioural analysis of Fig. 2, the present invention proposes the light-source brightness controlling mechanism, can reach light source is compensated control more accurately, to reach stable light source.Below for some embodiment, as the description of feature of the present invention, but the present invention not only be subject to for embodiment.
Fig. 3 shows the light-source brightness controlling mechanism schematic diagram according to an embodiment of the present invention.Fig. 4 shows the control timing figure according to an embodiment of the present invention.See also Fig. 3 and Fig. 4, it is to the present invention is directed to the embodiment that light-source system 100 is controlled and compensated.Light-source system 100 can for example be the light source module of light-emitting diode, and it for example comprises light emitting source 104 and light-emitting diode driver circuit 102.Light emitting source 104, for example be that the light that light-emitting diode sent is not subject to white light, it also more can form the light source of white light for example by the luminescence component of red, green, blue, and luminescence component also needs not to be light-emitting diode, but the present invention gets the example of light-emitting diode as explanation.
Light-source control system of the present invention comprises optical sensor 106 and light source Management Controller 110.The output of optical sensor 106 is connected to light source Management Controller 110 by an appropriate filter circuit 108.Control method of the present invention is to detect the brightness variation of LED source 102 by optical sensor 106, light source Management Controller 110 receives the detection signal of optical sensor 106 and in view of the above to light-emitting diode driver circuit 102 output regulating and controlling signals, realizes control and adjusting to LED source 104 brightness or color.
The control timing figure of control method of the present invention as shown in Figure 4, control method of the present invention is in 104 down periods of LED source (between low period shown in Figure 4) LED source 104 to be measured, or data sampling.The output voltage of optical sensor 106 (" A " point voltage) meeting changes along with the change of the luminous intensity of LED source 104, through after the suitable filter circuit 108, " B " point voltage (input voltage of light source Management Controller 110) is along with the reaction speed of LED source 104 Strength Changes will significantly reduce.When the switch speed of LED source 104 open and close is enough fast, when light source is closed, " B " point voltage can be kept stable.According to the phenomenon of Fig. 2, control method of the present invention is promptly closed the closed interval in LED source 104, promptly carries out data sampling between the low period among Fig. 4, obtains " B " point voltage, with this reference as correction LED source 104.
Fig. 5 shows the complete structure schematic diagram according to embodiment of the invention light source management system.Fig. 6 shows according to the embodiment of the invention, the light source management control circuit schematic diagram in the light source management system (Fig. 5).See also Fig. 5, it is the execution mode of control method of the present invention and control device thereof, it for example is application at ruddiness, green glow, blue light colorful light-emitting diode matrix light source, itself and first kind of execution mode difference are that its light source is ruddiness, green glow, blue light-emitting diode matrix light source, its optical sensor 220 detects ruddiness, green glow, blue light-emitting diode light-source brightness situation of change respectively, to provide optical feedback signal to light source management control circuit 230.Its light source management control circuit 230 comprises a light source Management Controller 232, and described light source Management Controller 232 is to use ruddiness, green glow, the blue light-emitting diode detection signal control light-source brightness of optical sensor 220 outputs to change.
Fig. 6 then provides a kind of execution mode of light source management control circuit 300.See also shown in Figure 6, described light source management control circuit 300 comprises: the filter circuit 302,304306 that is connected with ruddiness, green glow, blue light-emitting diode, analog to digital converter (adc circuit) 308, light source management engine (Engine) 310 and PWM Control Engine (PWM Dimming Control Engine) 312 respectively.This light source management control circuit 300 is intended to convert the aanalogvoltage of optical sensor 220 outputs to digital value, is convenient to utilize the digital processing mode to obtain to divide other monochrome information from these digital values, and concrete operation principle is as follows:
(1), ruddiness, green glow, blue light-emitting diode intensity are changed into change in voltage by light sensors light-emitting diode luminance situation of change;
(2) output voltage of optical sensor carries out analog-digital conversion through behind the suitable filter circuit 302,304,306 by analog to digital converter 308, transfers analog voltage signal to digital numerical value, offers light source supervisor engine 3 10;
(3) light source supervisor engine 3 10 transmits a control signal to PWM Control Engine 312 at last with the digital numerical value of (2) gained and desired value compares and computing;
(4) PWM Control Engine 312 changes the work ratio of PWM according to the control signal of (3), it promptly is width ratio, and to light-emitting diode driver circuit 102 output pwm control signals adjusting ruddiness, green glow, blue light-emitting diode brightness, guarantee the stable of brightness that light source shows, also therefore stablely obtain desired color.
The control timing figure of present embodiment as shown in Figure 7, its control method is identical with first kind of execution mode, that is: between the low period that light source is closed, carry out data sampling, obtain the output information of optical sensor 220, adjust light source according to this feedback information again, to reach the function of compensating color and brightness.
In sum, light-source brightness of the present invention and color balance control method are to carry out data sampling in the light source down periods, because light source drive was closed simultaneously in the light source down periods, so the system noise that its driver is caused in the time of can avoiding being subjected to light source igniting influences, improve Signal-to-Noise, be the detection precision that light source is changed to improve, more effective light-source brightness controlled.
Light-source brightness control device of the present invention and control method thereof can be applicable to any system that needs stabilized light source, as: be applied in led lighting, back light source system or the various display unit, as: be applied in the liquid crystal indicator, provide stable back light for liquid crystal indicator.
Thus, the optical sensor 106,220 that the present invention adopts can be color light transducer (Color Sensor) or optical diode (Photo diode) or visible light sensor (Ambient light sensor), and optical sensor 106,220 quantity does not have particular restriction, can set according to actual demand.
Thus, also to be equally applicable to the driving force of frequency very slow (being lower than 200Hz) that light source opens and closes or optical sensor strong or can not find the situation of suitable filter circuit for light source brightness control method of the present invention.Under above-mentioned situation, B point voltage as shown in Figure 3 will be not can similar direct voltage (DCvoltage), also can come as the foundation of judging the intensity of light source by the change in voltage in the set time of closing behind the light source this moment.The potential diagram mechanism that charging is risen, kept, decays about the B point voltage can be with reference to figure 8.In Fig. 8, interval in unlatching as PWM, the B point can begin charging according to the characteristic of RC circuit and rise, and when PWM closed, the B point can begin discharge.But because the RC constant of circuit has fixing in fact attenuation curve.Therefore close the sampling time point of back t1 at PWM, under normal condition, still can keep certain certain current potential at the current potential that B is ordered.If condition changing, then the current potential of this sampling point still can reflect abnormal situation.
Though the present invention discloses as above with preferred embodiment; right its is not in order to limit the present invention; anyly have the knack of this skill person; without departing from the spirit and scope of the present invention; when can doing a little change and retouching, so protection scope of the present invention is as the criterion when looking the claim person of defining of the present invention.
Claims (27)
1. a light-source brightness control device is used to control a light source cell to obtain a target light source brightness, comprising:
One optical sensor is used for the variation of detection light source; And
One light source management control circuit is used for providing a regulating and controlling signal according to a feedback signal of this optical sensor to this light source cell;
Wherein, described light source management control circuit is an output signal that obtains this optical sensor when this light source is closed, and calculates and adjust this light source according to this output signal that detects, and the brightness that compensates this light source by this changes.
2. light-source brightness control device as claimed in claim 1, wherein, this light source comprises light-emitting diode.
3. light-source brightness control device as claimed in claim 1, wherein, this optical sensor comprises color light transducer, optical diode or visible light sensor.
4. light-source brightness control device as claimed in claim 1, wherein, this light source management control circuit comprises a light source Management Controller and a filter circuit, this filter circuit is connected to the output of this optical sensor and the input of this light source management control circuit.
5. light-source brightness control device as claimed in claim 1, wherein, this light source management control circuit comprises filter circuit, analog to digital converter, light source management engine and pulse width modulation controlled engine.
6. light-source system comprises:
One light source;
One optical sensor is used to detect the variation of this light source; And
One light source management control circuit is used for providing a regulating and controlling signal according to a feedback signal of this optical sensor to this light source;
Wherein, described light source management control circuit is an output signal that obtains this optical sensor when this light source is closed, and calculates and adjust this light source according to this signal that detects, and compensates the brightness of this light source by this.
7. light-source system as claimed in claim 6, wherein, this light source comprises LED source or diode displaying matrix.
8. light-source system as claimed in claim 6, wherein, this light source comprises the LED lamp source of red, green, blue.
9. light-source system as claimed in claim 8 wherein, is obtained this output signal of this optical sensor when this light source management control circuit is closed the LED lamp source of this red, green, blue at the same time.
10. light-source system as claimed in claim 8, wherein, this light source management control circuit is to obtain this optical sensor to correspond to this red output signal when closing this red LED lamp source.
11. light-source system as claimed in claim 8, wherein, this light source management control circuit is to obtain this optical sensor to correspond to this green output signal when closing this green LED lamp source.
12. light-source system as claimed in claim 8, wherein, this light source management control circuit is to obtain this optical sensor to correspond to this blue output signal when closing this blue LED lamp source.
13. light-source system as claimed in claim 6, wherein, this optical sensor comprises color light transducer, optical diode or visible light sensor.
14. light-source system as claimed in claim 6, wherein, this light source management control circuit comprises a light source Management Controller and a filter circuit, and this filter circuit is connected to the output of this optical sensor and the input of this light source Management Controller.
15. light-source system as claimed in claim 6, wherein, this light source management control circuit comprises filter circuit, analog to digital converter, light source management engine and pulse width modulation controlled engine.
16. a display unit, this display unit comprises a light-source system, and described light-source system comprises:
One light source;
One optical sensor is used to detect the variation of this light source; And
One light source management control circuit is used for providing a regulating and controlling signal according to a feedback signal of this optical sensor to this light source;
Wherein, described light source management control circuit is an output signal that obtains this optical sensor when this light source is closed, and calculates and adjust this light source according to this signal that detects, and compensates the brightness of this light source by this.
17. display unit as claimed in claim 16, wherein, this light source comprises LED source or diode displaying matrix.
18. display unit as claimed in claim 16, wherein, this light source comprises the LED lamp source of red, green, blue.
19. display unit as claimed in claim 18, wherein, this light source management control circuit is this output signal that obtains this optical sensor when closing the LED lamp source of this red, green, blue at the same time.
20. display unit as claimed in claim 18, wherein, this light source management control circuit is to obtain this optical sensor to correspond to this red output signal when closing this red LED lamp source.
21. display unit as claimed in claim 18, wherein, this light source management control circuit is to obtain this optical sensor to correspond to this green output signal when closing this green LED lamp source.
22. display unit as claimed in claim 18, wherein, this light source management control circuit is to obtain this optical sensor to correspond to this blue output signal when closing this blue LED lamp source.
23. display unit as claimed in claim 16, wherein, this light-source system is a light source module or backlight module.
24. display unit as claimed in claim 16, wherein, this display unit comprises a liquid crystal indicator.
25. a light source brightness control method comprises:
Variation by a light sensors one light source; And
When closing, this light source obtains an output signal of this optical sensor; And;
According to this output signal, compensate the brightness of this light source to produce a control signal.
26. light source brightness control method as claimed in claim 25, wherein, this control signal comprises analog voltage signal or digital numerical value signal.
27. light source brightness control method as claimed in claim 25, wherein, it is strong or when not having suitable filter circuit that the frequency that opens and closes when this light source is lower than a frequency values or this optical sensor driving force, comes as the foundation of judging this intensity of light source by the change in voltage in the set time of closing behind this light source.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2007101025580A CN101309535A (en) | 2007-05-14 | 2007-05-14 | Brightness control apparatus and method for light source and display apparatus |
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| Application Number | Priority Date | Filing Date | Title |
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| CNA2007101025580A CN101309535A (en) | 2007-05-14 | 2007-05-14 | Brightness control apparatus and method for light source and display apparatus |
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| CNA2007101025580A Pending CN101309535A (en) | 2007-05-14 | 2007-05-14 | Brightness control apparatus and method for light source and display apparatus |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101959346A (en) * | 2009-07-14 | 2011-01-26 | 艾沃特有限公司 | The self adaptation dimmer that is used for the LED lamp detects and control |
| WO2011124083A1 (en) * | 2010-04-08 | 2011-10-13 | 英飞特光电（杭州）有限公司 | Illuminating device with centrally driven led colored lights |
| CN102404901A (en) * | 2010-09-14 | 2012-04-04 | 扬光绿能股份有限公司 | Lighting device and control method thereof |
| CN110573909A (en) * | 2017-04-25 | 2019-12-13 | 罗伯特·博世有限公司 | Control of directional light sources |
-
2007
- 2007-05-14 CN CNA2007101025580A patent/CN101309535A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101959346A (en) * | 2009-07-14 | 2011-01-26 | 艾沃特有限公司 | The self adaptation dimmer that is used for the LED lamp detects and control |
| CN101959346B (en) * | 2009-07-14 | 2014-06-04 | 戴乐格半导体公司 | Adaptive dimmer detection and control for LED lamp |
| WO2011124083A1 (en) * | 2010-04-08 | 2011-10-13 | 英飞特光电（杭州）有限公司 | Illuminating device with centrally driven led colored lights |
| CN102404901A (en) * | 2010-09-14 | 2012-04-04 | 扬光绿能股份有限公司 | Lighting device and control method thereof |
| CN110573909A (en) * | 2017-04-25 | 2019-12-13 | 罗伯特·博世有限公司 | Control of directional light sources |
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Open date: 20081119 |