CN102215345A - Device for removing flicker through automatic detection and related method - Google Patents
Device for removing flicker through automatic detection and related method Download PDFInfo
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- CN102215345A CN102215345A CN2010101642981A CN201010164298A CN102215345A CN 102215345 A CN102215345 A CN 102215345A CN 2010101642981 A CN2010101642981 A CN 2010101642981A CN 201010164298 A CN201010164298 A CN 201010164298A CN 102215345 A CN102215345 A CN 102215345A
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Abstract
The invention provides a device for removing flickers through automatic detection and a related method. The device comprises a light detecting circuit, a signal processing circuit and an automatic gain control circuit, wherein the light detecting circuit detects environment light and generates a detection signal; the signal processing circuit is coupled with the light detecting circuit and generates a signal related to the frequency of the environment light and a feedback signal according to the detection signal; the automatic gain control circuit is coupled with the signal processing circuit, and generates a control signal according to the feedback signal for controlling the light detecting circuit in a feedback way to regulate the detection signal or controlling the signal processing circuit in the feedback way to regulate the signal related to the frequency of the environment light.
Description
Technical field
The present invention relates to a kind of Auto-Sensing and remove the device and the correlation technique of flicker, particularly a kind of Auto-Sensing with automatic gain control is removed the device and the correlation technique of flicker.
Background technology
When surround lighting is non-when being indoor light source for natural daylight, the flicker (flicker) that can produce 50Hz or 60Hz because of the frequency of power supply supply.Therefore in image capture unit (for example image sensor), the processing that generally need remove flicker (de-flicker) is to avoid the bright degree varies of each picture.The general practice of removing flicker is to adjust the time for exposure, is 1/100 second integral multiple during for 50Hz in the power supply supplied frequency, is 1/120 second integral multiple during for 60Hz in the power supply supplied frequency.But the problem applied environment that is image capture unit, it is which kind of frequency actually? to this, prior art has several practices: the first decides at 50Hz or 60Hz removal flicker according to the area that sells of the machine (for example digital camera, digital camera, monitor etc.) of installing image capture unit.The problem of this practice is, the machine of some type such as digital video camera, and the user is possibly because of the transregional use of travelling.The another kind of practice is detected in surveillance at present, be outside monitor, to establish supply frequency circuit for detecting and switch in addition, supply frequency circuit for detecting detecting power supply supplied frequency is 50Hz or 60Hz, and switches monitor at 50Hz or 60Hz removal flicker according to this result.The feasible condition of this practice be because of the surveillance position in the fixed location and use local power supply.Problem is, as uses portable machine such as digital video camera, is with the power supply of machine itself but not from local power supply power taking when then using the machine shooting, removes accordingly just can't obtain the frequency information of local power supply and glimmers.
In view of this, the present invention promptly proposes device and the correlation technique that a kind of Auto-Sensing is removed flicker, and this device has automatic gain control function, so that integrated circuit can be done more accurate processing.
Summary of the invention
One of the object of the invention is to overcome the deficiencies in the prior art and defective, proposes the device that a kind of Auto-Sensing is removed flicker, and it is such as but not limited to being applied in the system relevant with image capture.
Another purpose of the present invention is, proposes the method that a kind of Auto-Sensing is removed flicker.
For reaching above-mentioned purpose, with regard to one of them viewpoint speech, the invention provides the device that a kind of Auto-Sensing is removed flicker, comprise: the light circuit for detecting, the detecting surround lighting also produces a detection signal; Signal processing circuit couples with this light circuit for detecting, according to this detection signal, and generation one and a surround lighting frequency signal related and a back coupling signal; And automatic gain control circuit, couple with this signal processing circuit, produce controlling signal according to this back coupling signal, feedback control this light circuit for detecting, adjusting this detection signal, or feedback control this signal processing circuit, with adjust should and surround lighting frequency signal related.
In a kind of therein preferable form of implementation, this automatic gain control circuit is adjusted the intensity of light detection signal that circuit for detecting produces according to the back coupling signal.
In a kind of therein preferable form of implementation, described signal processing circuit comprises amplifying circuit, the detection signal that the light circuit for detecting is produced is amplified to be produced one and amplifies signal, and wherein this automatic gain control circuit according to feedbacking the enlargement ratio that signal adjusts this amplifying circuit.
The mode that automatic gain control circuit produces controlling signal for example is: back coupling signal and reference signal that signal processing circuit produced are compared, and according to comparative result, produce controlling signal.Or, back coupling signal and reference signal that signal processing circuit produced are subtracted each other, and, produce controlling signal according to difference.
Can comprise a plurality of measure-alike or different light detecing elements in the light circuit for detecting, the light detecing element that connects different numbers or different size by selectivity is adjusted the intensity of detection signal.
Can comprise current mirroring circuit, switching circuit, variable resistor in the amplifying circuit, by the different current replications path in the selectivity connection current mirroring circuit, or adjust variable-resistance resistance, to adjust the enlargement ratio of amplifying circuit.
With regard to another viewpoint speech, the invention provides the method that a kind of Auto-Sensing is removed flicker, comprise: the detecting surround lighting also produces detection signal; Amplify this detection signal; According to the detection signal of this amplification, generation one and a surround lighting frequency signal related and a back coupling signal; And according to this back coupling signal generation controlling signal, to feedback the intensity of adjusting this detection signal or the enlargement ratio of adjusting this detection signal.
Just another viewpoint is sayed again, the invention provides the method that a kind of Auto-Sensing is removed flicker, comprises: receive a unsettled signal of frequency; With high frequency this signal is taken a sample; When the high low level number of sampling gained signal is all non-0 stationary value, according to the output signal of generation with a stabilized frequency; When the accurate number in the high or low position of sampling gained signal is in variation, keep the present frequency of output signal; When the high low level number one of sampling gained signal is 0, keep the present frequency of output signal; And when the high low level number of sampling gained signal is all another stationary value of non-0, according to the output signal of generation with another stabilized frequency.
Illustrate in detail below by specific embodiment, when the effect that is easier to understand purpose of the present invention, technology contents, characteristics and is reached.
Description of drawings
Figure 1A, 1B, 2 illustrate three embodiment of the present invention respectively;
Fig. 3 shows that the device of Auto-Sensing removal flicker of the present invention can combine the construction system single-chip with transmission interface circuit;
Fig. 4 A-4I illustrates several embodiment of signal processing circuit 20 for example;
Fig. 5 A-5B, 6A-6B, Fig. 7 A-7C illustrate several embodiment of the present invention respectively;
Fig. 8 to Figure 10 illustrates three embodiment of automatic gain control circuit 30 for example;
Figure 11 illustrates amplifying circuit 22 (or 22a, embodiment 22b) for example;
Figure 12 illustrates the embodiment of clock pulse generator 40 for example;
The operation of the delay-locked loop 42 in Figure 13-14 explanation clock pulse generator 40.
Symbol description among the figure
10 smooth circuit for detecting
11 switching circuits
20 signal processing circuits
22,22a, 22b amplifying circuit
221 switching circuits
222 current mirroring circuits
223 variable resistors
24 analog-to-digital conversion circuits
The 24a comparator
26 filter circuits
28 digital signal treatment circuits
30 automatic gain control circuits
31 first comparison circuits
32 second comparison circuits
33 operational amplification circuits
34 analog-to-digital conversion circuits
35 digital subtraction circuit
36 feedback control circuits
38 decoding circuits
40 clock pulse generators
42 delay-locked loops
100 Auto-Sensings are removed flashing device
120 transmission interface circuit
Embodiment
Please refer to Figure 1A, wherein show first embodiment of the present invention.As shown in the figure, the device 100 of the Auto-Sensing of present embodiment removal flicker comprises light circuit for detecting 10, signal processing circuit 20 and automatic gain control circuit 30.Light circuit for detecting 10 detecting surround lightings also produce corresponding detection signal DS.Signal processing circuit 20 draws the flicker frequency in the surround lighting according to the detection signal DS of light circuit for detecting 10 outputs.After learning flicker frequency, can produce and surround lighting frequency signal related, for example be one one digital signal, the expression frequency is 50Hz or 60Hz, then a level circuit can switch signal according to this and adjusts the time for exposure, removes flicker.Perhaps, should can be a numeral or an analog signal with surround lighting frequency signal related with flicker frequency, for example be square wave or string ripple signal, then the level circuit can be adjusted the time for exposure according to the frequency of this signal, removes flicker.Again for example, should and surround lighting frequency signal related can be the frequency values that detected or the error amount between periodic quantity or the variable quantity in frequency or cycle or frequency or cycle and a certain set point.
Because the brightness of surround lighting may change (for example closed portion light source, unlatching new light sources, light are covered by object etc.) because of various reasons and to some extent, therefore in the present invention, more set up automatic gain control circuit 30, change with the brightness of the light that conforms and to feedback adjustment, make integrated circuit can operate and produce more accurate output signal more accurately.In detail, in the present embodiment, signal processing circuit 20 produces back coupling signal FB in addition except that generation and surround lighting frequency signal related, and FB is relevant with the brightness of surround lighting for this back coupling signal.Automatic gain control circuit 30 produces the first controlling signal CS1 according to back coupling signal FB, feedback to control and adjust light circuit for detecting 10, with compensation detection signal DS, spend the intensity that increases detection signal DS when hanging down in environment bright, and when environmental light brightness is too high, reduce the intensity of detection signal DS, make the signal processing circuit 20 can proper operations and the unlikely negative effect that is subjected to environmental light brightness also makes integrated circuit can accurately export and surround lighting frequency signal related.
Figure 1B shows an alternative embodiment of the invention.As shown in the figure, the device that the Auto-Sensing of present embodiment is removed flicker comprises light circuit for detecting 10, signal processing circuit 20, automatic gain control circuit 30, and clock pulse generator 40.The difference of present embodiment and last embodiment is: in the present embodiment, after learning flicker frequency, further make clock pulse generator 40 produce the clock pulse CLK relevant with this flicker frequency, for example when flicker frequency is 60Hz, this clock pulse CLK can be 60Hz, 30Hz, 20Hz or the like.This clock pulse CLK solves the stationary problem that the multi-section video camera is made a video recording simultaneously except that can more can be used as sync signal in order to adjust the time for exposure, or as locking (Line lock) frequency.
Please refer to Fig. 2, wherein show an embodiment more of the present invention.As shown in the figure, the device of the Auto-Sensing of present embodiment removal flicker comprises light circuit for detecting 10, signal processing circuit 20 and automatic gain control circuit 30.Similar to first embodiment, light circuit for detecting 10 detecting surround lightings also produce corresponding detection signal DS.Signal processing circuit 20 draws the flicker frequency in the surround lighting according to the detection signal DS of light circuit for detecting 10 outputs.After learning flicker frequency, can produce and surround lighting frequency signal related.In the present embodiment, automatic gain control circuit 30 produces the second controlling signal CS2 according to back coupling signal FB, feedback to control and adjust signal processing circuit 20, make the signal processing circuit 20 can proper operations and the unlikely negative effect that is subjected to environmental light brightness also makes integrated circuit can accurately export and surround lighting frequency signal related.
Certainly, more than each embodiment can do various combinations, for example automatic gain control circuit 30 is not limited to only produce one of controlling signal CS1 and CS2, but and both all produce, to return controlled smooth circuit for detecting 10 and signal processing circuit 20 simultaneously.
Fig. 3 shows that Auto-Sensing of the present invention removes the device 100 of flicker and can integrate the construction system single-chip with transmission interface circuit 120.Transmission interface circuit 120 for example can be I2C, SPI, or usb circuit etc.
Fig. 4 B illustrates another embodiment for example, also filter circuit 26 can be set at the back of amplifying circuit 22, this filter circuit for example is low pass or band pass filter, with the higher noise of rejection frequency, or keeps and to comprise signal in (but only be not limited to for) 50Hz to 60Hz scope.
Fig. 4 C illustrates another embodiment for example.Handle for convenient signal, analog-to-digital conversion circuit (ADC) 24 can be set in the signal processing circuit 20, transfer digital signal AD to will amplify signal AS.It is the change-over circuit of (but also can be certainly) complexity that this analog-to-digital conversion circuit 24 does not need, and its simplest form can only be a comparator, and the comparator 24a as among Fig. 4 D so can transfer analog signal to digital signal.
Through the digital signal AD after the analog digital conversion for example can be again through the processing of digital signal treatment circuit (DSP) 28, to produce more accurate signal DP, as the usefulness of complicated control, shown in Fig. 4 E.Wherein, the digital signal treatment circuit only is that the circuit that it can replace and can handle digital signal for any is as microcontroller (MCU) or specific function integrated circuit (ASIC) etc. for example.
In addition, through the digital signal AD after the analog digital conversion can be again the Filtering Processing of wave circuit 26 after filtration, producing a filtering signal FS, or analog signal is converted to digital signal AD again through Filtering Processing earlier, shown in Fig. 4 F, 4G.
Fig. 4 H shows, also can use two stage amplification mode, amplifies detection signal DS with the first amplifying circuit 22a earlier, produces and amplifies signal AS1, comprises direct current and Alternating Component among this signal AS1; Filter direct current composition among the signal AS1 with filter circuit 26 again, stay Alternating Component (filtering signal FS); Afterwards,, produce and amplify signal AS2, only comprise Alternating Component among this signal AS2 again with the second amplifying circuit 22b amplification filtering signal FS.
Certainly, the circuit of Fig. 4 H also can remake variation, analog-to-digital conversion circuit and/or digital signal treatment circuit or the like is set, Fig. 4 I after the second amplifying circuit 22b; Also have various variation patterns in addition, for example can be after light circuit for detecting 10 be obtained signal first filtering remove flip-flop, amplified or the like again, those skilled in the art ought be able to analogize according to above circuit, another one does not illustrate.
Fig. 5 A illustrates an embodiment more specifically for example, and in the present embodiment, light circuit for detecting 10 comprises that a plurality of smooth detecing elements and have the switching circuit 11 of a plurality of switches, and one or more light detecing element with correspondence is connected in signal processing circuit 20 for you to choose.Each light detecing element can be identical or different size, and for example dimension scale is 1: 1: 1: 1 or 1: 2: 4: 8 or other ratio etc.Automatic gain control circuit (AGC) 30 can be obtained from the output of amplifying circuit 22 and feedback signal (path FB1), obtains also or by the output of filter circuit 26 and feedbacks signal (path FB2), can the alternatively (so be represented by dotted lines, down with).In the present embodiment, this feedbacks signal through automatic gain control circuit 30 processing, export the first controlling signal CS1, as shown in the figure, this first controlling signal CS1 can be a switch controlling signal, in order to a plurality of switches in the control switch circuit 11, selected light detecing element is connected in signal processing circuit 20.For example, when environmental light brightness was low, the first controlling signal CS1 can select the light detecing element of more or large-size is connected in signal processing circuit 20, to strengthen the intensity of amplifying circuit 22 input signals; Otherwise, when environmental light brightness is higher, the first controlling signal CS1 can select the light detecing element of less or reduced size is connected in signal processing circuit 20, to weaken input signal, make the signal processing circuit 20 can proper operations and the unlikely negative effect that is subjected to environmental light brightness also makes integrated circuit can accurately export and surround lighting frequency signal related thus.
Fig. 5 B illustrates another embodiment more specifically for example, in the present embodiment, feedbacks signal and can take from the output (path FB1) of amplifying circuit 22 or the output (path FB2) of filter circuit 26 equally, can the alternatively; This feedbacks signal through automatic gain control circuit 30 processing, exports the second controlling signal CS2, and as shown in the figure, this second controlling signal CS2 feedbacks and controls amplifying circuit 22, amplifies signal AS in order to adjust.For example, when environmental light brightness was low, the second controlling signal CS2 can make amplifying circuit 22 increase enlargement ratio, amplified signal AS to strengthen; Otherwise, when environmental light brightness is higher, the second controlling signal CS2 can make amplifying circuit 22 reduce enlargement ratio, amplify signal AS to weaken, make the signal processing circuit 20 can proper operations and the unlikely negative effect that is subjected to environmental light brightness also makes integrated circuit can accurately export and surround lighting frequency signal related thus.
Similarly, Fig. 6 A and Fig. 6 B demonstration back coupling signal can be taken from the output (path FB1) of amplifying circuit 22, the output (path FB2) of filter circuit 26, the output (path FB3) of analog-to-digital conversion circuit 24 or the output (path FB4) of digital signal treatment circuit 28, can appoint and select one; And automatic gain control circuit 30 can be controlled light circuit for detecting 10 (Fig. 6 A) or control amplifying circuit 22 (Fig. 6 B).
When adopting two stage amplification mode in the signal processing circuit 20, shown in Fig. 7 A-7C, automatic gain control circuit 30 can be controlled light circuit for detecting 10 (Fig. 7 A) or control the first amplifying circuit 22a (Fig. 7 B) or control the second amplifying circuit 22b (Fig. 7 C).Under the situation of Fig. 7 A, 7B, the back coupling signal can be taken from the output (path FB1) of the first amplifying circuit 22a, the output (path FB2) of filter circuit 26, the output (path FB3) of the second amplifying circuit 22b, the output (path FB4) of analog-to-digital conversion circuit 24 or the output (path FB5) of digital signal treatment circuit 28, can appoint and select one; And under the situation of Fig. 7 C, the back coupling signal can be taken from the output (path FB3) of the second amplifying circuit 22b, the output (path FB4) of analog-to-digital conversion circuit 24 or the output (path FB5) of digital signal treatment circuit 28, can appoint and select one.
At above Fig. 5 A, 5B, 6A, 6B, 7A, 7B is among the embodiment of 7C, certainly, automatic gain control circuit 30 also can be exported controlling signal CS1 and CS2 simultaneously, to control light circuit for detecting 10 and amplifying circuit 22 simultaneously or to control light circuit for detecting 10 and amplifying circuit 22a and/or 22b simultaneously.
Automatic gain control circuit 30 has numerous embodiments, and Fig. 8 illustrates one of them embodiment for example.Back coupling signal FB in the present embodiment for example can be from aforementioned arbitrary path FB1～FB5, first comparison circuit 31 compares this back coupling signal FB and the first reference signal Ref1, to judge whether environmental light brightness is too high, whether second comparison circuit 32 compares this back coupling signal FB and the second reference signal Ref2, low excessively to judge environmental light brightness.Feedback control circuit 36 is according to comparative result, produce controlling signal CS1 and/or CS2, in order to feedback control adjustment light circuit for detecting 10 or signal processing circuit 20, when environmental light brightness is too high, reduce the intensity of light circuit for detecting 10 output signals or reduce the enlargement ratio of amplifying circuit 22, otherwise spend when low then in environment bright.Described comparison circuit 31,32 can be the analog or digital comparison circuit, and FB is that the analog or digital signal is decided on the back coupling signal.Certainly, be not limited in the automatic gain control circuit 30 two comparison circuits 31,32 only are set, also more comparison circuits can be set, to carry out more accurate adjustment.
Fig. 9 illustrates the embodiment of another automatic gain control circuit 30 for example.Back coupling signal FB in the present embodiment for example is an analog signal.Operational amplification circuit 33 compares the luminance state of its difference display environment light with this back coupling signal FB and the 3rd reference signal Ref3.Analog-to-digital conversion circuit 34 is converted to digital signal with the output of operational amplification circuit 33, and decoding circuit 38 produces corresponding controlling signal CS1 or CS2 according to this digital signal, for example the difference of exporting when operational amplification circuit 33 is extremely being hanged down scope, during expression environmental light brightness wretched insufficiency, significantly strengthen the intensity of light circuit for detecting 10 output signals or the enlargement ratio of increase amplifying circuit 22, when the difference of operational amplification circuit 33 outputs is being hanged down scope, when the expression environmental light brightness is not enough a little, strengthen the intensity of light circuit for detecting 10 output signals or the enlargement ratio of increase amplifying circuit 22 a little, when the difference of operational amplification circuit 33 output in higher range, when the expression environmental light brightness is bright a little excessively, do not adjust, and when the difference of operational amplification circuit 33 output in high scope, the expression environmental light brightness is crossed when strong, significantly reduce the intensity of light circuit for detecting 10 output signals or the enlargement ratio of reduction amplifying circuit 22, or the like.Certainly, the adjustment mode of the above quadravalence section can be changed into less or more multistage adjustment mode.
When back coupling signal FB is digital signal, can change operational amplification circuit 33 into digital subtraction circuit 35, and can not need analog-to-digital conversion circuit 34, can reach same function, as shown in figure 10.
Amplifying circuit 22 (or 22a, 22b is also together) numerous embodiments is arranged, Figure 11 illustrates one of them embodiment for example.Amplifying circuit 22 in the present embodiment comprises switching circuit 221, current mirroring circuit 222 and variable resistor 223.Current mirroring circuit 222 has a plurality of current replications path, and the current ratio in each path can be 1: 1: 1: 1 or 1: 2: 4: 8 or other ratio etc., and to duplicate and to amplify detection signal DS.Switching circuit 221 has a plurality of switches, is controlled by controlling signal CS21, to select that one or many current replication paths of correspondence are electrically connected at variable resistor 223, so, amplifies the electric current that signal AS promptly equals to flow through variable resistor 223 and multiply by its resistance value.The resistance of variable resistor 223 is controlled by controlling signal CS23, adjusted by it.So, amplify the multiplying power size of signal AS, can adjust by controlling signal CS21 and/or controlling signal CS23 with respect to detection signal DS, that is aforementioned controlling signal CS2 in order to control amplifying circuit 22 can be CS21 or CS23 one of them, also can be both.When environmental light brightness is low, but more switch and/or change the resistance of variable resistor 23 in the actuating switch circuit 221 amplifies signal AS to strengthen; Otherwise when environmental light brightness is higher then.Certainly, if only when using controlling signal CS21, variable resistor 223 can only needn't be variable resistor for simple resistance; When only using controlling signal CS23, current mirroring circuit 222 can only have single current replication path and needn't have a plurality of current replications path.
See also Figure 13, may not stablize, use for late-class circuit but the clock pulse generator 40 that the present invention utilizes delay-locked loop 42 to be constituted still can produce stable output signal from the flicker frequency that surround lighting is obtained.As shown in figure 13, in period T1, the output signal of signal processing circuit 20 is at first kind of stable state (for example 50Hz), and delay-locked loop 42 also produces the signal f2 of respective frequencies according to signal f1, its producing method is to calculate high levle clock pulse number and the low level clock pulse number of signal f1 with the sample signal of a high frequency, and duplicates generation signal f2 according to this.In period T2, the output signal of signal processing circuit 20 disappears or presents labile state (for example because of surround lighting too weak or shift one's position because of the user), and this moment, the output signal of delay-locked loop 42 was still kept previous frequency.In period T3, the output signal of signal processing circuit 20 is changed into second kind of stable state (for example 60Hz), and delay-locked loop 42 just also produces the signal f2 of respective frequencies after several cycles are determined new state at this moment.
The state machine of delay-locked loop 42 (state machine) as shown in figure 14, in state S0, delay-locked loop 42 is in lazy attitude (idle), when high levle clock pulse number (Cnt_high) and low level clock pulse number (Cnt_low) is neither when being 0, expression receives signal f1, this moment, the S1 that gets the hang of produced output signal f2.When as (Cnt_high) or (Cnt_low) changing, the S2 that gets the hang of, be labile state this moment, comes output signal f2 but still keep with previous frequency.In state S2, if (Cnt_high) and (Cnt_low) recover value originally, then delay-locked loop 42 is got back to state S1; If be 0 (Cnt_high) or (Cnt_low), expression signal f1 has disappeared, the S3 that then gets the hang of, but still keep with previous frequency output signal f2.In state S3, if (Cnt_high) and (Cnt_low) neither be 0, expression signal f1 has occurred again, this moment, delay-locked loop 42 was got back to state S2.In state S2, if (Cnt_high) and (Cnt_low) stably continuous several times keep new value, then delay-locked loop 42 S4 that gets the hang of changes into new frequency with signal f2, and returns state S1, operates under new frequency.
It should be noted that, among Figure 1B and 12 clock pulse generator 40 separated illustrating with signal processing circuit 20, is for the ease of understanding; In fact, produce the function of clock pulse, be not limited to and must be reached separately by the circuit beyond the signal processing circuit 20, above-mentioned delay-locked loop 42 can be arranged within the signal processing circuit 20 with the function of its state machine, is for example carried out by signal processing circuit (or microcontroller etc.).
Compare with prior art, the present invention not only can Auto-Sensing removes the flicker in the surround lighting, the use of convenient portable machine, more can reach the multi-section video camera synchronously or locking (Linelock), therefore show than prior art for progressive; And change at surround lighting, the present invention can make integrated circuit operate in preferable states by the back coupling adjustment of automatic gain control circuit 30, can accurately export and surround lighting frequency signal related.
Below at preferred embodiment the present invention is described, just the above for making those skilled in the art be easy to understand content of the present invention, is not to be used for limiting interest field of the present invention only.Under same spirit of the present invention, those skilled in the art can think and various equivalence changes.For example, the function that icon is finished by single circuit can separately change by a plurality of hardware circuits or software and finish.And for example, among Fig. 2 embodiment, except that output clock pulse CLK, can be in addition also from signal processing circuit 20 outputs and surround lighting frequency signal related.Therefore, more than all, and other various equivalence changes, and all should be included within the scope of the present invention.
Claims (22)
1. an Auto-Sensing is removed the device of flicker, it is characterized in that, comprises:
The light circuit for detecting, the detecting surround lighting also produces a detection signal;
Signal processing circuit couples with this light circuit for detecting, according to this detection signal, and generation one and a surround lighting frequency signal related and a back coupling signal; And
Automatic gain control circuit couples with this signal processing circuit, produces controlling signal according to this back coupling signal, feedback control this light circuit for detecting, adjusting this detection signal, or feedback control this signal processing circuit, with adjust should and surround lighting frequency signal related.
2. Auto-Sensing as claimed in claim 1 is removed the device of flicker, and wherein, this automatic gain control circuit is adjusted the intensity of light detection signal that circuit for detecting produces according to this back coupling signal.
3. Auto-Sensing as claimed in claim 1 is removed the device of flicker, wherein, this signal processing circuit comprises an amplifying circuit, the detection signal that the light circuit for detecting is produced is amplified to be produced one and amplifies signal, and wherein this automatic gain control circuit according to feedbacking the enlargement ratio that signal adjusts this amplifying circuit.
4. Auto-Sensing as claimed in claim 1 is removed the device of flicker, and wherein, this automatic gain control circuit comprises:
Comparison circuit compares back coupling signal and the reference signal that signal processing circuit produced, to produce comparative result; And
Feedback control circuit, the comparative result according to comparison circuit produces produces aforementioned controlling signal.
5. Auto-Sensing as claimed in claim 1 is removed the device of flicker, and wherein, this automatic gain control circuit comprises:
Operational amplification circuit is compared the back coupling signal that signal processing circuit produced with reference signal;
Analog-to-digital conversion circuit according to the output signal of this operational amplification circuit, is carried out the analog digital conversion to produce a digital signal; And
Decoding circuit, the digital signal according to analog-to-digital conversion circuit output produces aforementioned controlling signal.
6. Auto-Sensing as claimed in claim 1 is removed the device of flicker, and wherein, this automatic gain control circuit comprises:
Digital subtraction circuit is subtracted each other back coupling signal and reference signal that signal processing circuit produced; And
Decoding circuit according to subtracting each other the result, produces aforementioned controlling signal.
7. Auto-Sensing as claimed in claim 1 is removed the device of flicker, and wherein, this light circuit for detecting comprises:
A plurality of smooth detecing elements; And
A plurality of switches are controlled by aforementioned controlling signal, and one or more light detecing element with correspondence is coupled to signal processing circuit for you to choose.
8. Auto-Sensing as claimed in claim 3 is removed the device of flicker, and wherein, this amplifying circuit comprises:
One current mirroring circuit comprises more than one current replication path, to amplify this detection signal; And
The switch corresponding with the current replication path is controlled by aforementioned controlling signal, the current replication path of conducting correspondence for you to choose.
9. Auto-Sensing as claimed in claim 3 is removed the device of flicker, and wherein, this amplifying circuit comprises:
One current mirroring circuit comprises more than one current replication path, to amplify this detection signal; And
With the variable resistor that the current replication path couples, its resistance is controlled by aforementioned controlling signal.
10. Auto-Sensing as claimed in claim 1 is removed the device of flicker, wherein, should comprise one of following with surround lighting frequency signal related: one digital signal, and the expression frequency is 50Hz or 60Hz; Numeral or analog signal with flicker frequency; The variable quantity in frequency values, periodic quantity, frequency or cycle that expression is detected or the signal of the error amount between frequency or cycle and a certain set point.
11. Auto-Sensing as claimed in claim 1 is removed the device of flicker, wherein, this Auto-Sensing is removed the device and a transmission interface circuit of flicker and is integrated the construction system single-chip.
12. Auto-Sensing as claimed in claim 1 is removed the device of flicker, wherein, this transmission interface circuit is 12C, SPI, or usb circuit.
13. Auto-Sensing as claimed in claim 1 is removed the device of flicker, wherein, also comprise clock pulse generator, couple with this signal processing circuit, according to the output signal of signal processing circuit, produce the clock pulse relevant with the surround lighting flicker frequency, wherein this clock pulse generator comprises: delay-locked loop, according to the frequency of signal processing circuit output signal, produce the signal of a stabilized frequency.
14. an Auto-Sensing is removed the method for flicker, it is characterized in that, comprises:
The detecting surround lighting also produces detection signal;
Amplify this detection signal;
According to the detection signal of this amplification, generation one and a surround lighting frequency signal related and a back coupling signal; And
Produce controlling signal according to this back coupling signal, to feedback the intensity of adjusting this detection signal or the enlargement ratio of adjusting this detection signal.
15. Auto-Sensing as claimed in claim 14 is removed the method for flicker, wherein, this comprises according to the step that the back coupling signal produces controlling signal: should feedback signal and reference signal relatively; And, produce this controlling signal according to comparative result.
16. Auto-Sensing as claimed in claim 14 is removed the method for flicker, wherein, this comprises according to feedbacking step that signal produces controlling signal: should feedback signal and reference signal and subtract each other; And, produce this controlling signal according to subtracting each other the result.
17. Auto-Sensing as claimed in claim 16 is removed the method for flicker, wherein, this also comprises according to the step that the back coupling signal produces controlling signal: carry out the analog digital conversion to subtracting each other the gained signal.
18. Auto-Sensing as claimed in claim 14 is removed the method for flicker, wherein, the step that detection signal intensity is adjusted in this back coupling comprises:
A plurality of smooth detecing elements are provided; And
A plurality of switches are provided, are controlled by aforementioned controlling signal, couple one or more corresponding light detecing element for you to choose, to adjust the intensity of detection signal.
19. Auto-Sensing as claimed in claim 14 is removed the method for flicker, wherein, the step that the detection signal enlargement ratio is adjusted in this back coupling comprises:
One current mirroring circuit is provided, comprises more than one current replication path, to amplify this detection signal; And
The switch corresponding with the current replication path is provided, is controlled by aforementioned controlling signal, the current replication path of conducting correspondence for you to choose is to adjust the enlargement ratio of detection signal.
20. Auto-Sensing as claimed in claim 14 is removed the method for flicker, wherein, the step that the detection signal enlargement ratio is adjusted in this back coupling comprises:
One current mirroring circuit is provided, comprises more than one current replication path, to amplify this detection signal; And
With the variable resistor that the current replication path couples, its resistance is controlled by aforementioned controlling signal, adjusts the enlargement ratio of detection signal to change resistance.
21. Auto-Sensing as claimed in claim 14 is removed the method for flicker, wherein, also comprises: with a sampling frequency this and surround lighting frequency signal related are taken a sample, and duplicate this surround lighting frequency and produce a signal with stabilized frequency.
22. an Auto-Sensing is removed the method for flicker, it is characterized in that, comprises:
Receive a unsettled signal of frequency;
With high frequency this signal is taken a sample;
When the high low level number of sampling gained signal is all non-0 stationary value, according to the output signal of generation with a stabilized frequency;
When the accurate number in the high or low position of sampling gained signal is in variation, keep the present frequency of output signal;
When the high low level number one of sampling gained signal is 0, keep the present frequency of output signal; And
When the high low level number of sampling gained signal is all another stationary value of non-0, according to the output signal of generation with another stabilized frequency.
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