CN102883115B - Image sensor and black level correction method thereof - Google Patents
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- CN102883115B CN102883115B CN201110198654.6A CN201110198654A CN102883115B CN 102883115 B CN102883115 B CN 102883115B CN 201110198654 A CN201110198654 A CN 201110198654A CN 102883115 B CN102883115 B CN 102883115B
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Abstract
The invention discloses an image sensor and a black level correction method thereof. The image sensor comprises a pixel array, a sampling circuit and a black level correction circuit, wherein the pixel array comprises a first non-photosensitive region, a second non-photosensitive region and a photosensitive pixel region; the sampling circuit reads first non-photosensitive analog data from the first non-photosensitive region, reads second non-photosensitive analog data from the second non-photosensitive region and reads photosensitive analog data from the photosensitive pixel region; and the black level correction circuit determines a black level deviation value according to the first non-photosensitive analog data and determines a black level correction value for performing black level correction on the photosensitive analog data according to the black level deviation value and the second non-photosensitive analog data.
Description
Technical field
The present invention relates to a kind of image sensor, particularly relate to a kind of image sensor and the bearing calibration of black rank thereof.
Background technology
Image sensor is kind of the digital photo-sensitive cell replacing traditional egative film, and image sensor is such as charge coupled device (CCD) image sensor or complementary metal-Oxidc-Semiconductor (CMOS) image sensor.The photosensitive pixel of image sensor can detect different lightnesses and the wavelength of light that radiated by different objects read analogue data from detected numerical value, and analogue data is pixel voltage such as.Analogue data can be converted to the numerical data of acceptable signal process by image sensor.
The equipment of an image sensor inherently consumed energy (electric power).Have the consumption of the energy, nature will produce heat, and " heat " causes the electronic behavior of chip material to aggravate, and the electronics be heated constantly moves and creates electric current, forms so-called " dark current " (Black Level) phenomenon.
Its dark current of desirable image sensor should be zero, but the many factors of the real world person of existence can cause the generation of dark current.Wherein " heat " is the most significant influencing factor.But when the voltage of dark current voltage and low intensity light is suitable, the pixel of image sensor Buddhist of just walking back and forth " sees " scenery, thus causes exposure, and result is presented on picture.
Summary of the invention
The invention relates to a kind of image sensor and the bearing calibration of black rank thereof, it carries out the correction of black rank to the photosensitive analogue data in photosensitive pixel district in time, to improve black rank (Black Level) phenomenon because dark current causes according to the first non-photo-sensing data in the first non-photo-sensing district and the second non-photo-sensing district and the second non-photo-sensing data.
According to the present invention, a kind of black rank bearing calibration of image sensor is proposed.Image sensor at least comprises a pel array, and pel array comprises the first non-photo-sensing district, the second non-photo-sensing district and photosensitive pixel district.The bearing calibration of black rank comprises: read the first non-photo-sensing analogue data from the first non-photo-sensing district; Black rank deviant is determined according to the first non-photo-sensing analogue data; The second non-photo-sensing analogue data is read from the second non-photo-sensing district; Black rank corrected value is determined according to black rank deviant and the second non-photo-sensing analogue data; A photosensitive analogue data is read from photosensitive pixel district; And according to black rank corrected value, the correction of black rank is carried out to photosensitive analogue data.
According to the present invention, a kind of image sensor is proposed.Image sensor comprises pel array, sample circuit and black rank correcting circuit.Pel array comprises the first non-photo-sensing district, the second non-photo-sensing district and photosensitive pixel district.Sample circuit reads the first non-photo-sensing analogue data from the first non-photo-sensing district, reads the second non-photo-sensing analogue data, read photosensitive analogue data from photosensitive pixel district from the second non-photo-sensing district.Black rank correcting circuit determines black rank deviant according to the first non-photo-sensing analogue data and determines that one in order to carry out the black rank corrected value of black rank correction to photosensitive analogue data according to black rank deviant and the second non-photo-sensing analogue data.
In order to have better understanding to above-mentioned and other aspect of the present invention, preferred embodiment cited below particularly, and be described with reference to the accompanying drawings as follows.
Accompanying drawing explanation
Fig. 1 shows the schematic diagram of a kind of image sensor according to the embodiment of the present invention.
Fig. 2 shows the flow chart of the black rank bearing calibration of a kind of image sensor according to the embodiment of the present invention.
The image sensor that Fig. 3 shows Fig. 1 exports the schematic diagram of the first non-photo-sensing numerical data.
Fig. 4 shows the thin portion flow chart of the step 22 according to an embodiment.
Fig. 5 illustrates the schematic diagram of numerical data into exporting according to the analog-digital converter of an embodiment and analog gain.
Fig. 6 shows the schematic diagram of allowing deviant according to an embodiment.
Fig. 7 shows the thin portion flow chart of step 24.
Fig. 8 shows the schematic diagram that image sensor exports the second non-photo-sensing numerical data.
Fig. 9 shows the thin portion flow chart of step 241 in Fig. 7 of an embodiment.
Figure 10 shows the first the thin portion flow chart of the step 26 implementing profit according to.
The image sensor 1 that Figure 11 shows Fig. 1 exports the schematic diagram of photosensitive numerical data in time implementing this embodiment.
Figure 12 shows the thin portion flow chart of step 261.
Figure 13 shows the second thin portion flow chart of the step 26 of the Fig. 2 according to another embodiment.
Reference numeral explanation
1: image sensor
11: pel array
12: sample circuit
13: analogue amplifier
14: analog-digital converter
15: black rank correcting circuit
21 ~ 26,221 ~ 225,241 ~ 244,261 ~ 264,2411 ~ 2412,2611 ~ 2612: step
111: the first non-photo-sensing districts
112: the second non-photo-sensing districts
113: photosensitive pixel district
151: digital analog converter
152: arithmetic element
AL: analog level
AG: analog gain
AD: analogue data
DD: numerical data
OB1: the first non-photo-sensing analogue data
OB2: the second non-photo-sensing analogue data
OBD1: the first non-photo-sensing numerical data
OBD2: the second non-photo-sensing numerical data
BC0: start offset value
BC1: correcting offset value
BCA0: initial analog level
BCA1: correct analog level
TL: allow deviant
AP: photosensitive analogue data
APD: photosensitive numerical data
Embodiment
In order to improve black rank (Black Level) phenomenon because dark current causes, following embodiment discloses a kind of image sensor and the bearing calibration of black rank thereof.Image sensor comprises pel array, sample circuit and black rank correcting circuit.Pel array comprises the first non-photo-sensing district, the second non-photo-sensing district and photosensitive pixel district.Sample circuit reads the first non-photo-sensing analogue data from the first non-photo-sensing district, reads the second non-photo-sensing analogue data, read photosensitive analogue data from photosensitive pixel district from the second non-photo-sensing district.Black rank correcting circuit determines black rank deviant according to the first non-photo-sensing analogue data and determines that one in order to carry out the black rank corrected value of black rank correction to photosensitive analogue data according to black rank deviant and the second non-photo-sensing analogue data.
The bearing calibration of black rank comprises: read the first non-photo-sensing analogue data from the first non-photo-sensing district; Black rank deviant is determined according to the first non-photo-sensing analogue data; The second non-photo-sensing analogue data is read from the second non-photo-sensing district; Black rank corrected value is determined according to black rank deviant and the second non-photo-sensing analogue data; A photosensitive analogue data is read from photosensitive pixel district; And according to black rank corrected value, the correction of black rank is carried out to photosensitive analogue data.
Please refer to Fig. 1, Fig. 1 shows the schematic diagram of a kind of image sensor according to the embodiment of the present invention.Image sensor 1 comprises pel array 11, sample circuit 12, analogue amplifier 13, analog-digital converter 14 and black rank correcting circuit 15.Pel array 11 comprises the first non-photo-sensing district 112 of non-photo-sensing district 111, second and photosensitive pixel district 113.First non-photo-sensing district 111 and the second non-photo-sensing district 112 comprise several non-photo-sensing pixel respectively, and photosensitive pixel district 113 comprises several photosensitive pixel.Sample circuit 12 is in order to sequentially to read the first non-photo-sensing analogue data OB1, the second non-photo-sensing analogue data OB2 and photosensitive analogue data AP from the first non-photo-sensing district 112 of non-photo-sensing district 111, second and photosensitive pixel district 113.
Analogue amplifier 13 exports analog-digital converter 14 to after amplifying an analogue data AD according to analog gain AG, and analogue data AD is such as aforesaid first non-photo-sensing analogue data OB1, the second non-photo-sensing analogue data OB2 and photosensitive analogue data AP.
Analogue data AD conversion after amplification is numerical data DD, numerical data DD according to an analog level AL by analog-digital converter 14 is such as the first non-photo-sensing numerical data OBD1, the second non-photo-sensing numerical data OBD2 and photosensitive numerical data APD corresponding with the first non-photo-sensing analogue data OB1, the second non-photo-sensing analogue data OB2 and photosensitive analogue data AP respectively.Analog-digital converter 14 can in time carrying out above-mentioned conversion, along with the change of analog level AL, and upwards translation or downwards translation first non-photo-sensing analogue data OB1, the second non-photo-sensing analogue data OB2 or photosensitive analogue data AP.
Black rank correcting circuit 15 determines black rank deviant BC1 according to the first non-photo-sensing analogue data OB1, and exports analog level AL to analog-digital converter 14, to carry out the correction of black rank to the second non-photo-sensing analogue data OB2 according to black rank deviant BC1 again.Next, black rank correcting circuit 15 also determines a black rank corrected value BC2 according to black rank deviant BC1 and the second non-photo-sensing analogue data OB2, and export analog level AL to analog-digital converter 14, to carry out the correction of black rank to photosensitive analogue data AP according to black rank corrected value BC2 again.
Preferably, in the process determining black rank deviant BC1 and black rank corrected value BC2, black rank correcting circuit 15 does not directly process first and second non-photo-sensing analogue data OB1 and OB2, but receives the first non-photo-sensing numerical data OBD1 of feedbacking of analog-digital converter 14 and the second non-photo-sensing numerical data OBD2 to carry out Digital data processing.In other words, black rank correcting circuit 15 be use first non-photo-sensing numerical data OBD1 to calculate black rank deviant BC1, and re-use black rank deviant BC1 and the second non-photo-sensing numerical data OBD2 to calculate black rank corrected value BC2.
One specific characteristic of image sensor 1 is that black rank correcting circuit produces black rank corrected value BC2 according to both the first non-photo-sensing analogue data OB1 of same picture and the second non-photo-sensing analogue data OB2, in order to immediately and carry out the correction of black rank to the photosensitive analogue data AP of same picture exactly.
The flow chart of the black rank bearing calibration of a kind of image sensor according to the embodiment of the present invention is shown referring to Fig. 1 and Fig. 2, Fig. 2.The bearing calibration of black rank can be applied to the image sensor shown in Fig. 1 and comprise the steps 21 to 26.First, as shown in step 21, sample circuit 12 reads the first non-photo-sensing analogue data OB1 from the first non-photo-sensing district 111.Then as indicated at step 22, black rank correcting circuit 15 determines black rank deviant BC1 according to the first non-photo-sensing analogue data OB1.And then, as shown in step 23, sample circuit 12 reads the second non-photo-sensing analogue data OB2 from the second non-photo-sensing district 112.Then as shown in step 24, black rank correcting circuit 15 determines black rank corrected value BC2 according to black rank deviant BC1 and the second non-photo-sensing analogue data OB2.As previously mentioned, in step 22 and 24, first and second non-photo-sensing numerical data OBD1 and OBD2 that black rank correcting circuit 15 can adopt digital quantizer 14 to provide respectively calculates.Then, as shown in step 25, sample circuit 12 reads photosensitive analogue data AP from photosensitive pixel district 113.And then as shown in step 26, black rank correcting circuit 15 carries out the correction of black rank according to black rank corrected value BC2 to photosensitive analogue data AP.
It should be noted that can design abovementioned steps 21 to 26 just performs, to reduce unnecessary computing after analog gain AG changes.For example, black rank correcting circuit 15 first can judge whether analog gain AG changes, if analog gain AG does not change, can not recalculate black rank deviant BC1 and black rank corrected value BC2 to carry out the correction of black rank.Or can design abovementioned steps 21 to 26 and just perform after opening picture every n, n is positive integer.
Referring to Fig. 1, Fig. 3, Fig. 4, Fig. 5 and Fig. 6, with the operation correlative detail of step 22 in Fig. 2 more than you know.The image sensor that Fig. 3 shows Fig. 1 exports the schematic diagram of the first non-photo-sensing numerical data; Fig. 4 shows the thin portion flow chart of the step 22 according to an embodiment; Fig. 5 shows the schematic diagram of numerical data that the analog-digital converter according to an embodiment exports and analog gain; And Fig. 6 shows the schematic diagram of allowing deviant according to an embodiment.
In this embodiment, abovementioned steps 22 comprises step 221 further to 225.And in order to put into practice this embodiment, black rank correcting circuit 15 can comprise digital analog converter 151 and arithmetic element 152.First, as depicted at step 221, the analog level AL that digital analog converter 151 sets analog-digital converter 14 according to an initial deviant BC0 equals initial analog level BCA0.Then as seen in step 222, the first non-photo-sensing analogue data OB1 is converted to the first non-photo-sensing numerical data OBD1 according to initial analog level BCA0 by analog-digital converter 14, and feedbacks to arithmetic element 152.And then, as shown in step 223, arithmetic element 152 calculates the mean value of the first non-photo-sensing numerical data OBD1.Preferably, after arithmetic element 152 first gets rid of the bad point (Dead Pixel) in pel array 11, then the mean value of the first non-photo-sensing numerical data OBD1 is calculated.
Then as shown at step 224, according to start offset value BC0 and, arithmetic element 152 allows that deviant TL calculates a control level.Control level such as equals start offset value BC0 and the difference of allowing deviant TL.The corresponding relation of the numerical data DD that analog-digital converter 14 exports and analog gain AG is as shown in Fig. 5 dotted line.Intactly export the second non-photo-sensing numerical data OBD2 in order to ensure analog-digital converter 14 afterwards, start offset value BC0 can deduct by arithmetic element 152 allows that deviant is to obtain control level.Then as illustrated by step 225, arithmetic element 152 determines black rank deviant according to the mean value of the first non-photo-sensing numerical data OBD1 and control level.Black rank deviant such as equals the mean value of this first non-photo-sensing numerical data and the summation of this control level.For example, start offset value BC0, allow that the mean value of deviant TL and the first non-photo-sensing numerical data OBD1 is respectively 100,10 and 50.Start offset value BC0 first deducts by arithmetic element 152 allows that deviant TL equals 90 to obtain control level.The mean value of the first non-photo-sensing numerical data OBD1 is added that control level equals 140 to obtain black rank deviant by arithmetic element 152 again.
Referring to Fig. 7 and Fig. 8, with the operation correlative detail of step 24 in Fig. 2 more than you know.Fig. 7 shows the thin portion flow chart of the step 24 of an embodiment, and the image sensor 1 that Fig. 8 shows Fig. 1 exports the schematic diagram of the second non-photo-sensing numerical data in time implementing this embodiment.In this embodiment, step 24 comprises step 241 further to 244.First, as shown in step 241, the analog level AL that digital analog converter 151 sets analog-digital converter 14 according to the black rank deviant BC1 that step 22 obtains equals skew analog level BCA1.Then as indicated at step 242, the second non-photo-sensing analogue data OB2 is converted to the second non-photo-sensing numerical data OBD2 according to skew analog level BCA1 by analog-digital converter 14.Because the analog level of analog-digital converter 14 changes into skew analog level BCA1 by initial analog level BCA0, therefore analog-digital converter 14 can by the second non-photo-sensing analogue data OB2 upwards translation or translation downwards to improve black rank (Black Level) phenomenon because dark current causes.And then, as shown in step 243, arithmetic element 152 calculates the mean value of the second non-photo-sensing numerical data.Preferably, after arithmetic element 152 gets rid of the bad point (Dead Pixel) in pel array 11, then the mean value of the second non-photo-sensing numerical data OBD2 is calculated.Then as indicated at step 244, arithmetic element 152 determines black rank corrected value according to the mean value of the second non-photo-sensing numerical data.
The thin portion flow chart of step 241 in Fig. 7 of an embodiment is shown referring to Fig. 8 and Fig. 9, Fig. 9.In this embodiment, abovementioned steps 241 comprises step 2411 further to 2412.First, as shown in step 2411, digital analog converter 151 changes black rank deviant BC1 for skew analog level BCA1.Then, as shown in step 2412, the analog level AL of setting analog-digital converter 151 equals skew analog level BCA1.It should be noted that digital analog converter 151 can add clamp design further in the process performing step 2411.For example, if when black rank deviant BC1 is less than or equal to a lower limit, the skew analog level BCA1 that digital analog converter 151 exports equals this lower limit.If when black rank deviant BC1 is more than or equal to a higher limit, the skew analog level that digital analog converter 151 exports equals this higher limit.If black rank deviant BC1 is greater than lower limit and is less than higher limit, then digital analog converter 151 directly changes black rank deviant BC1 for skew analog level BCA1.
Referring to Figure 10 and Figure 11, with the operation correlative detail of step 26 in Fig. 2 more than you know.Figure 10 shows the first the thin portion flow chart of step 26 implementing profit according to, and the image sensor 1 that Figure 11 shows Fig. 1 exports the schematic diagram of photosensitive numerical data in time implementing this embodiment.In this embodiment, step 26 comprises step 261 further to 262.First, as shown in step 261, the analog level that digital analog converter 151 sets analog-digital converter 14 according to black rank corrected value BC2 equals a correction analog level BCA2.Then, as shown in step 262, photosensitive analogue data AP is converted to photosensitive numerical data APD according to correction analog level BCA2 by analog-digital converter 14.
Correct analog level BCA2 because the analog level of analog-digital converter 14 is changed into by initial analog level BCA1, therefore analog-digital converter 14 can by photosensitive analogue data AP upwards translation or translation downwards to improve black rank (Black Level) phenomenon because dark current causes.
The thin portion flow chart of step 261 is shown referring to Figure 11 and Figure 12, Figure 12.Abovementioned steps 261 comprises step 2611 further to 2612.First, as shown in step 2611, digital analog converter 151 changes black rank corrected value BC2 into a correction analog level BCA2.Then, as shown in step 2612, the analog level AL that digital analog converter 151 sets analog-digital converter 14 equals to correct analog level BCA2.It should be noted that aforementioned digital analog converter 151 can add clamp design further in the process performing step 2611.For example, if when black rank corrected value BC2 is less than or equal to a lower limit, the correction analog level BCA2 that digital analog converter 151 exports equals lower limit.If when black rank corrected value BC2 is more than or equal to a higher limit, the correction analog level BCA2 that digital analog converter 151 exports equals higher limit.If black rank corrected value BC2 is greater than lower limit and is less than higher limit, then digital analog converter 151 directly changes black rank corrected value BC2 for correcting analog level BCA2.
The thin portion flow chart of the step 26 of the Fig. 2 according to another embodiment is shown referring to Figure 11 and Figure 13, Figure 13.Abovementioned steps 26 comprises step 263 further to 264.As shown in step 263, photosensitive analogue data is converted to photosensitive numerical data APD by the black rank deviant that analog-digital converter 14 obtains according to step 22, and feedbacks to arithmetic element 152.Then, as shown in step 264, the black rank corrected value that arithmetic element 152 obtains according to step 24 adjusts photosensitive numerical data APD.The Main Differences of the embodiment shown in this embodiment and Figure 10 is: the embodiment that Figure 10 illustrates adjusts the photosensitive numerical data APD of rear output by analog-digital converter 14, and the embodiment that Figure 13 illustrates adjusts the photosensitive numerical data APD of rear output by arithmetic element 152.
In above-described embodiment, black rank correcting circuit 15 performs two stage trimming process.In the first stage, black rank correcting circuit 15 first obtains black rank deviant BC1 according to the first non-photo-sensing analogue data OB1 associated with the first non-photo-sensing district 111, and the level of digital analog converter 14 can be adjusted according to black rank deviant BC1, to carry out the correction of black rank to the second non-photo-sensing analogue data OB2.Therefore, the second non-photo-sensing numerical data OBD2 that analog-digital converter 14 exports is the non-photo-sensing numerical data obtained after living through the correction of first stage.
Next, black rank correcting circuit 15 carries out the correction of second stage again.The second non-photo-sensing analogue data OB2 that black rank correcting circuit 15 is associated according to the second non-photo-sensing district 112 obtains black rank corrected value.The the second non-photo-sensing numerical data OBD2 living through first stage correction process can be used for calculating black rank corrected value BC2.Black rank correcting circuit 15 can adjust the level of digital analog converter 14 then according to black rank corrected value BC2, to carry out the correction of black rank to photosensitive analogue data AP.Therefore, the photosensitive numerical data obtained after the photosensitive numerical data APD that analog-digital converter 14 exports is through the correction of second stage.
Because black rank correcting circuit produces black rank corrected value BC2 according to both the first non-photo-sensing analogue data OB1 of same picture and the second non-photo-sensing analogue data OB2, therefore, it is possible to instant and carry out the correction of black rank to the photosensitive analogue data AP of same picture exactly.
In sum, although the present invention with preferred embodiment disclose as above, so itself and be not used to limit the present invention.Those skilled in the art, under the premise without departing from the spirit and scope of the present invention, can be used for a variety of modifications and variations.Therefore, protection scope of the present invention is as the criterion with claim of the present invention.
Claims (22)
1. the black rank bearing calibration of an image sensor, this image sensor at least comprises a pel array and an analog-digital converter, this pel array comprises one first non-photo-sensing district, one second non-photo-sensing district and a photosensitive pixel district, and this black rank bearing calibration comprises:
A () reads one first non-photo-sensing analogue data from this first non-photo-sensing district;
B () determines a black rank deviant according to this first non-photo-sensing analogue data;
C () reads one second non-photo-sensing analogue data from this second non-photo-sensing district;
D () sets an analog level of this analog-digital converter according to this black rank deviant, to determine a black rank corrected value according to this black rank deviant and this second non-photo-sensing analogue data;
E () reads a photosensitive analogue data from this photosensitive pixel district; And
F () carries out the correction of black rank according to this black rank corrected value to this photosensitive analogue data.
2. black rank bearing calibration as claimed in claim 1, wherein this step (b) comprising:
(b1) this analog level of this analog-digital converter is set according to an initial deviant;
(b2) according to this start offset value, this first non-photo-sensing analogue data is converted to one first non-photo-sensing numerical data;
(b3) mean value of this first non-photo-sensing numerical data is calculated;
(b4) allow that deviant calculates a control level according to this start offset value and one; And
(b5) this black rank deviant is determined according to the mean value of this first non-photo-sensing numerical data and this control level.
3. black rank bearing calibration as claimed in claim 2, wherein this black rank deviant equals the mean value of this first non-photo-sensing numerical data and the summation of this control level.
4. black rank bearing calibration as claimed in claim 2, wherein this control level equals this start offset value and this allows the difference of deviant.
5. black rank bearing calibration as claimed in claim 1, wherein this step (d) comprising:
(d1) according to this black rank deviant, this second non-photo-sensing analogue data is converted to one second non-photo-sensing numerical data;
(d2) mean value of this second non-photo-sensing numerical data is calculated; And
(d3) this black rank corrected value is determined according to the mean value of this second non-photo-sensing numerical data.
6. black rank bearing calibration as claimed in claim 1, wherein this step (d) comprising:
(d1-1) this black rank deviant is changed into a skew analog level; And
(d1-2) this analog level setting this analog-digital converter equals this skew analog level.
7. black rank bearing calibration as claimed in claim 6, if wherein this black rank deviant is less than or equal to a lower limit, this skew analog level equals this lower limit, if this black rank deviant is more than or equal to a higher limit, this skew analog level equals this higher limit.
8. black rank bearing calibration as claimed in claim 1, wherein this step (f) comprising:
(f1) according to this black rank corrected value, this photosensitive analogue data is converted to a photosensitive numerical data.
9. black rank bearing calibration as claimed in claim 8, wherein also comprises before this step (f1):
(f1-1) this black rank corrected value is changed into a correction analog level; And
(f1-2) this analog level setting this analog-digital converter equals this correction analog level.
10. black rank bearing calibration as claimed in claim 8, if wherein this black rank corrected value is less than or equal to a lower limit, this correction analog level equals this lower limit, if this black rank corrected value is more than or equal to a higher limit, this correction analog level equals this higher limit.
11. black rank bearing calibrations as claimed in claim 1, wherein this step (f) comprising:
(f1) according to this black rank deviant, this photosensitive analogue data is converted to a photosensitive numerical data; And
(f2) this photosensitive numerical data is adjusted according to this black rank corrected value.
12. black rank bearing calibrations as claimed in claim 1, wherein this step (a) to (f) performs after an analog gain changes.
13. black rank bearing calibrations as claimed in claim 1, this step (a) to (f) performs after opening picture every n, and n is positive integer.
14. 1 kinds of image sensor, comprising:
One pel array, comprising:
One first non-photo-sensing district;
One second non-photo-sensing district;
One photosensitive pixel district;
One sample circuit, in order to read one first non-photo-sensing analogue data from this first non-photo-sensing district, reads one second non-photo-sensing analogue data from this second non-photo-sensing district, reads a photosensitive analogue data from this photosensitive pixel district;
One analog-digital converter; And
One black rank correcting circuit, in order to determine a black rank deviant according to this first non-photo-sensing analogue data, and set an analog level of this analog-digital converter according to this black rank corrected value, to determine that according to this black rank deviant and this second non-photo-sensing analogue data one in order to carry out the black rank corrected value of black rank correction to this photosensitive analogue data.
15. image sensor as claimed in claim 14, wherein this black rank correcting circuit comprises:
One digital analog converter, in order to set this analog level of this analog-digital converter according to an initial deviant, makes this analog-digital converter, according to this start offset value, this first non-photo-sensing analogue data is converted to one first non-photo-sensing numerical data; And
One arithmetic element, in order to calculate the mean value of this first non-photo-sensing numerical data, according to this start offset value and one, this arithmetic element allows that deviant calculates a control level, and determine this black rank deviant according to the mean value of this first non-photo-sensing numerical data and this control level.
16. image sensor as claimed in claim 15, wherein this black rank deviant equals the mean value of this first non-photo-sensing numerical data and the summation of this control level.
17. image sensor as claimed in claim 15, wherein this control level equals this start offset value and this allows the difference of deviant.
18. image sensor as claimed in claim 14, wherein this second non-photo-sensing analogue data is converted to one second non-photo-sensing numerical data according to this black rank deviant by this analog-digital converter, and this black rank correcting circuit calculates the mean value of this second non-photo-sensing numerical data and determines this black rank corrected value according to the mean value of this second non-photo-sensing numerical data.
19. image sensor as claimed in claim 18, wherein this black rank correcting circuit comprises:
One digital analog converter, in order to change this black rank deviant into a skew analog level, and this analog level setting this analog-digital converter equals this skew analog level.
20. image sensor as claimed in claim 14, this photosensitive analogue data is converted to a photosensitive numerical data according to this black rank corrected value by this black rank correcting circuit.
21. image sensor as claimed in claim 20, wherein this black rank correcting circuit comprises:
One digital analog converter, in order to change this black rank corrected value into a correction analog level and this analog level setting this analog-digital converter equals this correction analog level.
22. image sensor as claimed in claim 14, this photosensitive analogue data is converted to a photosensitive numerical data according to this black rank deviant and adjusts this photosensitive numerical data according to this black rank corrected value by this analog-digital converter.
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| CN104333717B (en) * | 2014-07-31 | 2017-07-07 | 吉林省福斯匹克科技有限责任公司 | The algorithm and its system of a kind of black level offset compensation for cmos image sensor |
| CN106161999B (en) * | 2015-03-31 | 2019-04-26 | 原相科技股份有限公司 | Increase the digital imaging device and its operating method of dynamic range |
| US9652692B1 (en) * | 2016-09-26 | 2017-05-16 | Cognex Corporation | Machine vision system for capturing a digital image of a sparsely illuminated scene |
| TWI751873B (en) * | 2020-12-31 | 2022-01-01 | 晶相光電股份有限公司 | Image sensor device and method of black level calibration thereof |
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