CN203608418U - Brightness adjusting circuit - Google Patents
Brightness adjusting circuit Download PDFInfo
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- CN203608418U CN203608418U CN201320692877.2U CN201320692877U CN203608418U CN 203608418 U CN203608418 U CN 203608418U CN 201320692877 U CN201320692877 U CN 201320692877U CN 203608418 U CN203608418 U CN 203608418U
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- 230000001105 regulatory effect Effects 0.000 claims description 25
- 238000010586 diagram Methods 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 230000001276 controlling effect Effects 0.000 description 4
- 238000009434 installation Methods 0.000 description 3
- 230000000712 assembly Effects 0.000 description 2
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- 230000001186 cumulative effect Effects 0.000 description 1
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Abstract
A brightness adjusting circuit is used for driving a light emitting element. The brightness adjusting circuit includes: a pulse width modulation controller and a duty cycle controller. The PWM controller is used for generating an output signal to drive the light emitting device according to a control signal, wherein the control signal indicates a duty cycle. The duty cycle controller is coupled to the PWM controller for generating the control signal and adjusting the control signal according to an adjustment period to change the duty cycle, wherein a length of the adjustment period is changed according to a current value of the duty cycle.
Description
Technical field
The utility model relates to brightness regulating circuit, particularly relates to a kind of brightness regulating circuit that possesses variable adjustment cycle.
Background technology
Light-emitting diode (light emitting diode, LED) is used in all types of electronic installations conventionally, the specific motion state of display electronics assemblies, for example: start, shutdown, standby or fault etc.In the time that LED element is used as the power supply indicator of electronic installation or status indicator lamp, often control the brightness of LED element by brightness regulating circuit, make the color of power supply indicator or status indicator lamp change or glimmer, the operating state of display electronics assemblies.A common utilization is: make indicator light gradually by bright extremely dark, then by dark extremely bright, represent that electronic installation is in holding state.In prior art, conventionally by continue to increase or reduce to drive the intensity of signal to reach this effect in Fixed Time Interval.But this method, in the time that each brightness changes, can allow user experience lofty brightness and change, but not the brightness of remarkable fluency changes.
Utility model content
In order to address the above problem, the utility model provides a kind of brightness regulating circuit, and it in the time that adjustment cycle arrives, adjusts the brightness of light-emitting component repeatedly.In the utility model, the length of adjustment cycle is the brightness current along with light-emitting component and changing, therefore, can present smoothness and naturally brightness change.
Embodiment of the present utility model provides a kind of brightness regulating circuit, and it is in order to drive a light-emitting component.This brightness regulating circuit comprises a Pwm controller and a kind of work period controller.This Pwm controller drives this light-emitting component in order to produce an output signal according to a control signal, and wherein this control signal is pointed out a work period.This kind of work period controller is coupled to this Pwm controller, in order to produce this control signal, and adjust this control signal to change this work period according to an adjustment cycle, wherein this adjustment cycle changes according to one of this work period current value.
Can be further understood by the detailed description below in conjunction with accompanying drawing about advantage of the present utility model and spirit.
Accompanying drawing explanation
Fig. 1 is the function block schematic diagram of an embodiment of brightness regulating circuit of the present utility model.
Fig. 2 is the function block schematic diagram of an embodiment of the work period controller in brightness regulating circuit of the present utility model.
Fig. 3 is the function block schematic diagram of an embodiment of the Pwm controller in brightness regulating circuit of the present utility model.
Reference numeral explanation
100 brightness regulating circuits
110 clock generators
120 Pwm controllers
130 work period controllers
200 light-emitting components
121,132 adders
122,133 counters
123,124,134,135,136 comparators
125,138 control units
131 processors
137 decision circuitry
Embodiment
Please refer to Fig. 1, it is the function block schematic diagram of an embodiment of the utility model brightness regulating circuit.Brightness regulating circuit 100 includes a clock generator 110, a Pwm controller 120 and a work period controller 130.In the present embodiment, clock generator 110 is used for producing a clock signal led_clk, and then the running of trigger pulse width modulation controller 120 and work period controller 130.But in other embodiment of the utility model, brightness regulating circuit 100 may not comprise clock generator, and provide clock signal led_clk to Pwm controller 120 and work period controller 130 by external circuit.Pwm controller 120, in order to according to a control signal led_duty, produces an output signal led_ouput and drives light-emitting component 200.Wherein control signal led_duty and point out a work period (duty cycle).Along with controlling the signal led_duty change of pointed work period, will make output signal led_ouput drive light-emitting component 200 with the different work periods.In the time that the work period of output signal led_ouput increases, light-emitting component 200 blasts, and in the time that the work period of output signal led_ouput reduces, light-emitting component 200 is dimmed.Moreover work period controller 130 is controlled signal led_duty in order to produce, in the time that an adjustment cycle arrives, just change and control the work period that signal led_duty points out, can make light-emitting component 200 dimmed or brighten gradually with it.
In order to regulate more glibly the brightness of light-emitting component 200, the utility model brightness by dark to bright process, in the time that light-emitting component 200 has lower brightness, increase the work period of output signal led_ouput with lower frequency, and in the time that light-emitting component 200 has higher brightness, increase the work period of output signal led_ouput with higher frequency.Similarly, in by bright extremely dark process, in the time that light-emitting component 200 has higher brightness, reduce the work period of output signal led_ouput with higher frequency, and in the time that light-emitting component 200 has lower brightness, add the work period of reducing output signal led_ouput with slower frequency.This is because the mankind's vision, for the reaction of highlights, is not so good as the reaction of dark portion to come responsively.Therefore, if when light-emitting component 200 is darker, presents brightness with slower speed and change, and when light-emitting component 200 is brighter, presents brightness with higher speed and change.Can allow user think that the brightness of light-emitting component 200 changes comparatively remarkable fluency.So concept of the present utility model is: under the different operating cycle, adjust the work period with different frequencies.In order to reach above effect, work period controller 130 carries out brightness adjustment according to variable adjustment cycle.In by dark extremely bright process, along with the work period (work period has determined the brightness that light-emitting component 200 presents) increases gradually, the length of adjustment cycle just shortens, and accelerates to adjust the frequency of work period.On the contrary, in by bright extremely dark process, the length of adjustment cycle can extend gradually, reduces the frequency of adjusting the work period.
The detailed circuit framework of Pwm controller 120 and work period controller 130 will be further illustrated below.But, this is not to restriction of the present utility model, under the situation of the operating principle without prejudice to Pwm controller 120 and work period controller 130, Pwm controller 120 and work period controller 130 may be realized by the circuit framework that is different from following explanation.
Fig. 2 has illustrated the functional block diagram of an embodiment of the utility model work period controller.Work period controller 130 has utilized comparator 135 and 136 to judge and has controlled the signal led_duty pointed work period at present.Wherein, comparator 135 will be controlled dividing value upper_bound comparison in signal led_duty and a brightness, produce comparative result Inc; Comparator 136 will be controlled signal led_duty and a brightness floor value lower_bound comparison, produce comparative result Dec.Light-emitting component by dark to bright brightness change procedure, comparative result Inc can continue to point out to control work period that signal led_duty points out lower than dividing value upper_bound in brightness.Now, decision circuitry 137 continues to produce instruction to control unit 138, control unit 138 is continued to increase and control the work period that signal led_duty points out.Until control the work period that signal led_duty points out and equal dividing value upper_bound in brightness, represent that light-emitting component 200 arrives default brightness.Comparative result Inc will point out this phenomenon, cause work period controller 130 to start to reduce the work period that led_duty points out.Wherein, comparative result Inc can set the indicated value of decision circuitry 137 inside, makes decision circuitry 137 start to produce the instruction that reduces the work period to control unit 138, controls to reduce the work period that signal led_duty points out.In this stage, the comparative result Dec that comparator 136 produces can continue to point out to control work period that signal led_duty points out higher than brightness floor value lower_bound, and then makes judging unit 137 continue to make control unit 138 to reduce to control the work period that signal led_duty point out.Until the work period that control signal led_duty points out equals brightness floor value lower_bound, represent the default darkness that light-emitting component 200 arrives.Now, comparative result Dec points out this phenomenon, and then changes the indicated value of decision circuitry 137 inside, make decision circuitry 137 again command control unit 138 start to increase and control the work period that signal led_duty points out.Thus one, just can make light-emitting component 200 repeatedly produce by bright to dark, then by dark to bright variation.
Counter 133 is mainly used to count adjustment cycle, and its count value limit_cnt will, by comparator 134 and a time critical values Time_TH comparison, in the time that count value limit_cnt is more than or equal to time critical values Time_TH, represent that adjustment cycle arrives.Now, the comparative result do of comparator 134 can trigger decision circuitry 137.Wherein, decision circuitry 137, just can be according to carrying out aforesaid control flow only in the time being triggered, and with reference to comparative result Inc, Dec and inner indicated value, determines how to adjust control signal led_duty.In addition, count value limit_cnt also will be reset.
The input value of counter 133 is decided by an adder 132.The count value limit_cnt that adder 132 produces counter 133 at present and the output valve of a work period device processor 131 are added, and produce the input value of counter 133.The count value limit_cnt of counter 133 is continued to increase according to the output valve of work period device processor 131.Work period device processor 131 produces output valve according to the work period of controlling signal led_duty representative, in the time that the work period is higher, the output valve that work period device processor 131 produces is higher, on the contrary, in the time that duty cycle is lower, the output that work period device processor 131 produces is low higher.Thus, when controlling work period of signal led_duty representative when more and more higher, the count value of counter 133 can reach time critical values Time_TH sooner, control unit 138 is adjusted quickly and controlled signal led_duty.On the contrary, when controlling work period of signal led_duty when more and more lower, the count value of counter 133 can be slower the time of advent critical value Time_TH, slow down and control adjusting frequency of signal led_duty.By above circuit, the utility model changes the length of adjustment cycle effectively along with the work period.
Fig. 3 illustrates the functional block diagram of an embodiment of Pwm controller of the present utility model.The work period that Pwm controller 120 is pointed out according to control signal led_duty, produce output signal led_ouput.Output signal led_ouput is the period signal with particular duty cycle, and its work period having is to decide the work period of pointing out according to control signal led_duty.The work period that control unit 125 can be pointed out according to control signal led_duty, when decision switches the level of output signal led_ouput.Wherein, by adder 121, the count value of counter 122 and a fixed value In are added, the count value of counter 122 can represent the length of an operating time.The operating time length that comparator 123 and 124 is counted counter 122 respectively with control that signal led_duty points out work period and a fixed value T_period comparison.When the operating time length of the count value representative of counter 122 be less than control that signal led_duty points out work period time, the comparative result of comparator 123 can allow control unit 125 that output signal led_ouput is maintained to high level.And in the time that the operating time length of the count value representative of counter 122 equals to control the work period that signal led_duty points out, the comparative result of comparator 123 can allow control unit 125 that output signal led_ouput is switched to low level.Equal fixed value T_period once operating time length, comparator 124 these results of reflection, cause control unit 125 that output signal led_ouput is switched to high level.For instance, be 40% when the work period that led_duty points out, and cycle of output signal led_ouput while being 10ms represent that output signal led_ouput has the time of 4ms need be in high level, and the time of 6ms need be in low level, and every 10ms gets back to high level.Therefore, the operating time that comparator 123 counts out according to counter 122, confirm that output signal led_ouput is maintained high level 4ms by control unit 125, and after time span meets, make control unit 125 that output signal led_ouput is switched to low level.Afterwards, comparator 124 judges that according to fixed value T_period the cycle 10ms of output signal led_ouput arrives, switches back high level by output signal led_ouput.Because light-emitting component 200 is subject to the driving of output signal led_ouput, therefore can be along with the difference of the work period of output signal led_ouput, produce specific brightness, and along with increase gradually or the reduction of work period, and then reaching gradually dimmed after certain brightness, and reaching after certain darkness, gradually brighten.
The brightness regulating circuit providing due to the utility model constantly changes along with the current brightness of light-emitting component the time interval of adjusting its brightness, therefore can allow light-emitting component present nature and bright smooth brightness is cumulative decrescence changes with brightness.
Claims (10)
1. a brightness regulating circuit, in order to drive a light-emitting component, is characterized in that comprising:
One Pwm controller, drives this light-emitting component in order to produce an output signal according to a control signal, and wherein this control signal is pointed out a work period; And
One work period controller, be coupled to this Pwm controller, in order to produce this control signal, and adjust this control signal according to an adjustment cycle, change its this pointed work period, wherein a length of this adjustment cycle changed according to this work period.
2. brightness regulating circuit as claimed in claim 1, is characterized in that wherein this work period controller comprises:
One counter, in order to count to produce a count value to an input value;
One first comparator, is coupled to this counter, in order to this count value and a time critical values are relatively produced to one first comparative result, and in the time that this first comparative result points out that this count value is more than or equal to this time critical values, this count value of resetting; And
One adder, is coupled to this counter, in order to the counting reference value corresponding to this work period is produced to this input value with this count value phase Calais.
3. brightness regulating circuit as claimed in claim 2, is characterized in that wherein this work period controller comprises:
One second comparator, in order to relatively to produce one second comparative result by critical value in this control signal and a brightness; And
One the 3rd comparator, in order to relatively to produce one the 3rd comparative result by this control signal and a brightness lower critical value.
4. brightness regulating circuit as claimed in claim 3, is characterized in that wherein this work period controller comprises:
One decision circuitry, be coupled to this first comparator, this second comparator and the 3rd comparator, when being used to this first comparative result and pointing out that this count value is more than or equal to this time critical values, produce an adjusted value according to this second comparative result, the 3rd comparative result and an indicated value; And
One control unit, is coupled to this decision circuitry, in order to adjust this control signal according to this adjusted value.
5. brightness regulating circuit as claimed in claim 4, is characterized in that wherein this decision circuitry:
Point out that in this second comparative result this control signal is less than critical value in this brightness, and this indicated value is while being the first value, produces this adjusted value and makes this control unit increase this pointed work period of this control signal; And
Point out that in the 3rd comparative result this control signal is greater than this brightness lower critical value, and this indicated value is while being the second value, produces this adjusted value and makes this control unit reduce this pointed work period of this control signal.
6. brightness regulating circuit as claimed in claim 5, is characterized in that wherein this decision circuitry:
Point out that in this second comparative result this control signal equals critical value in this brightness, setting this indicated value is the second value; And
Point out that in the 3rd comparative result this control signal equals this brightness lower critical value, setting this indicated value is the first value.
7. brightness regulating circuit as claimed in claim 2, is characterized in that wherein this work period controller comprises:
One processor, in order to produce this counting reference value according to this control signal and a ratio value, wherein, in the time that this work period that this control signal is pointed out is larger, this counting reference value is larger, and this work period of pointing out when this control signal more hour, this counting reference value is less.
8. brightness regulating circuit as claimed in claim 1, is characterized in that wherein this pulse bandwidth modulation controller comprises:
One counter, in order to count to produce a count value to an input value; And
One adder, is coupled to this counter, in order to a fixed value is produced to this input value with this count value phase Calais.
9. brightness regulating circuit as claimed in claim 8, is characterized in that wherein this pulse bandwidth modulation controller comprises:
One first comparator, is coupled to this counter, in order to this count value and this control signal are relatively produced to one first comparative result; And
One second comparator, in order to by this count value of this work period with relatively produce one second comparative result with a counting critical value.
10. brightness regulating circuit as claimed in claim 9, is characterized in that wherein this pulse bandwidth modulation controller comprises:
One control unit, is coupled to this first comparator and this second comparator, in order to switch a voltage level of this output signal according to this first comparative result and this second comparative result.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW102217641U TWM475121U (en) | 2013-09-18 | 2013-09-18 | Dimmer circuit |
| TW102217641 | 2013-09-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203608418U true CN203608418U (en) | 2014-05-21 |
Family
ID=50721072
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201320692877.2U Expired - Lifetime CN203608418U (en) | 2013-09-18 | 2013-11-05 | Brightness adjusting circuit |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN203608418U (en) |
| TW (1) | TWM475121U (en) |
-
2013
- 2013-09-18 TW TW102217641U patent/TWM475121U/en not_active IP Right Cessation
- 2013-11-05 CN CN201320692877.2U patent/CN203608418U/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| TWM475121U (en) | 2014-03-21 |
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| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term |
Granted publication date: 20140521 |
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| CX01 | Expiry of patent term |