CN109495700A - A kind of circuit and its system of the elimination dark current using novel inclined generator - Google Patents
A kind of circuit and its system of the elimination dark current using novel inclined generator Download PDFInfo
- Publication number
- CN109495700A CN109495700A CN201811273815.1A CN201811273815A CN109495700A CN 109495700 A CN109495700 A CN 109495700A CN 201811273815 A CN201811273815 A CN 201811273815A CN 109495700 A CN109495700 A CN 109495700A
- Authority
- CN
- China
- Prior art keywords
- signal
- switch
- dark current
- output
- voltage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000008030 elimination Effects 0.000 title claims abstract description 17
- 238000003379 elimination reaction Methods 0.000 title claims abstract description 17
- 238000012937 correction Methods 0.000 claims abstract description 62
- 238000003384 imaging method Methods 0.000 claims abstract description 15
- 238000005070 sampling Methods 0.000 claims description 33
- 230000008859 change Effects 0.000 claims description 10
- 108091008695 photoreceptors Proteins 0.000 claims description 9
- 238000012935 Averaging Methods 0.000 claims description 6
- 230000000295 complement effect Effects 0.000 claims description 3
- 230000009467 reduction Effects 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 6
- 230000005611 electricity Effects 0.000 description 4
- 230000008901 benefit Effects 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
- H04N25/60—Noise processing, e.g. detecting, correcting, reducing or removing noise
- H04N25/63—Noise processing, e.g. detecting, correcting, reducing or removing noise applied to dark current
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
- H04N25/60—Noise processing, e.g. detecting, correcting, reducing or removing noise
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Transforming Light Signals Into Electric Signals (AREA)
Abstract
The circuit and its system of a kind of elimination dark current using novel inclined generator disclosed by the invention, the second input terminal of comparator in parallel correction module and corrective capacity in traditional ramp generator, the dark current noise average number value of dark pixel is first read out in the circuit course of work, and this digital value is fed back into correction module, when reading valid pixel, since correction module has recorded the noise level of dark current and is superimposed upon in ramp signal, so in the reading data of valid pixel and not including dark current noise, this framework has effectively eliminated dark current noise, reduce the reduction of the image sensor dynamic range as caused by dark current, effectively raise the picture quality of imaging sensor.
Description
Technical field
The present invention relates to technical field of integrated circuits, and in particular to a kind of elimination dark current using novel inclined generator
Circuit and its system.
Background technique
In cmos image sensor (CIS), the serious picture quality for affecting imaging sensor of dark current, dark current
Influence to imaging sensor image quality is mainly reflected in two aspects, first is that, the heterogeneity of dark current is fixed in CIS
One important sources of modal noise, so that the permeability of imaging sensor is deteriorated；Second is that dark current can raise entire image
Average value, especially at high temperature, dark current value significantly increase, so that the dynamic range of image reduces, although in manufacturing process
On can reduce the intrinsic dark current of photodiode, and improve uniformity, but still need to eliminate or inhibit in later image processing
Dark current noise is to improve picture quality.
Ramp generator is widely used in the fields such as analog-to-digital conversion, has become indispensable one in imaging sensor
Part, many characteristics such as noise, fixed pattern noise and linearity of sensor largely all rely on slope
The design of device.Existing ramp generator circuit resets reset capacitance Cf as shown in Figure 1, reset switch S7 conducting, the
When five switch conductions, the voltage signal of the first input end of operational amplifier, the second input terminal and output end is equal, i.e.,
Vramp=Vinp3=Vinm3=Vref, when reset switch S7 is disconnected, Vramp exports ramp signal.
The principle of dark current correction is carried out in imaging sensor are as follows: count DARK PIXELARRAY (dark pixel battle array first
Column) output average value, each Active Pixel (valid pixel) digital signal subtract DarkPixel (dark pixel) number letter
Number average value, as shown in Fig. 2.When above-mentioned ramp generator is used in imaging sensor, row reading circuit is for example attached
Shown in Fig. 3, timing diagram is as shown in phantom in Figure 5, working principle: when row selects signal SEL is high, selection exports the picture of certain row
Plain (pixel) signal value, signal RX are height, and the signal of Vfd node is reset to PVDD electricity by the metal-oxide-semiconductor conducting of signal RX control
Signal is pressed, signal RX is disconnected, and due to channel charge injection effect and clock feedthrough, and node Vfd arrives ground access, node without any
Vfd will keep being less than about PVDD voltage signal, and the reset signal Vrst of output pixel (Pixel), signal RST_COUNT are height,
By counter resets, when first switch S1 is high, comparator resets, and (Vcm is comparator to Vinp1=Vinm1=Vcm voltage
Common mode voltage signal), PIXEL output reset signal Vrst is sampled on sampling capacitance Cs1, and signal TX is opened, and exports Pixel
Photoreceptor signal Vsig, Vinp1 voltage signal jump be Vcm- (Vrst-Vsig), when signal EN_COUNT be it is high when, count
Device starts counting, and ramp signal Vramp signal starts to change, and Vinp1 signal follows ramp signal to change, when comparator is sent out
When raw overturning, counter stops counting, and output digit signals D, and the digital signal D of output is the photoreceptor signal value of PIXEL.
Since in the signal averaging of image sensor system statistics dark pixel array, numeral output is not 0, and with
The variation of temperature and change, using above-mentioned ramp generator carry out dark current correction will lead to image dynamic range reduce, especially
It is that under the high temperature conditions, dark current value increases.
Summary of the invention
The object of the present invention is to provide it is a kind of using novel inclined generator elimination dark current circuit and its system, into
Row dark current correction, to improve the dynamic range of image.
To achieve the goals above, the present invention adopts the following technical scheme: a kind of novel inclined generator, including reset are electric
Hold, corrective capacity, reset switch, correction switch, the 5th switch, the 6th switch, correction module and operational amplifier, wherein institute
The one end for stating the first input end of operational amplifier and one end of the reset capacitance, reset switch is commonly connected to simulation electricity
Source；Second input terminal of the operational amplifier is connect simultaneously with one end of one end of the 5th switch, corrective capacity；It is described
The other end connection signal end (Vref) of 5th switch；The other end of the corrective capacity corrects the one of switch with described simultaneously
End, the 6th switch one end connect simultaneously, it is described correction switch the other end connect correction module, it is described 6th switch it is another
It holds connection signal end (Vref)；The output end of the operational amplifier connects the other end of the reset capacitance simultaneously and reset is opened
The other end of pass, and export ramp signal.
Further, the correction switch is controlled by Vdark_ctrl signal, and the 6th switch is believed by Vdark_ctrlb
Number control, and Vdark_ctrl signal be the Vdark_ctrlb signal complementary signal.
Further, the voltage range of the correction module output is the maximum amplitude value of dark current noise.
A kind of circuit of elimination dark current using novel inclined generator provided by the invention, is sent out using above-mentioned slope
Raw device, comprising:
Dot structure, output end connect one end of the first sampling capacitance；
One end of first sampling capacitance, the other end and first switch is commonly connected to the first input end of amplifier, the
The other end connection signal end (Vcm) of one switch；
Second sampling capacitance, one end are connect with ramp generator, and one end of the other end and second switch is commonly connected to
Second input terminal of amplifier, the other end connection signal end (Vcm) of second switch；
One end of the first output end connection third sampling capacitance of amplifier, second output terminal connect the 4th sampling capacitance
One end；
One end that the other end and the first input end of comparator, third of third sampling capacitance switch connects jointly；
The other end of 4th sampling capacitance is connect jointly with one end of the second input terminal of the comparator, the 4th switch；
First output end of the comparator is connect with the other end that third switchs；The second output terminal of the comparator with
The other end of 4th switch is commonly connected to the input terminal of backward dioded；The output end linkage counter of backward dioded it is defeated
Enter end；Counter is connected with EN_COUNT signal end and RST_COUNT signal end, and has output signal end；
Further, the dot structure includes:
The first transistor, grid end connection signal (TX), source are grounded by diode；
The grid of the drain terminal of second transistor, grid end connection signal (RX), source and the first transistor, third transistor
End, which is connected, is connected to node (Vfd)；Its drain terminal is connected with the drain terminal of third transistor；
Third transistor, source are connect with the drain terminal of the 4th transistor；
4th transistor, grid end connection signal (SEL), source connect and connect jointly with one end of the first sampling capacitance
Ground；
Further, the voltage range of the correction module output is the maximum amplitude value of dark current noise.
A kind of image sensor system of elimination dark current using novel inclined generator provided by the invention, comprising:
The circuit of dark pixel array, valid pixel array and above-mentioned elimination dark current；The circuit and dark picture for eliminating dark current
Pixel array, valid pixel array are connected；
Image sensor system counts the signal averaging of dark pixel array, and output digit signals；
When signal end (SEL) is high, certain row pixel letter of the circuit output valid pixel array for eliminating dark current
Number value；
When signal end (RX) is high, node (Vfd) is reset to voltage by the first transistor conducting of signal end (RX) control
Signal (PVDD), then signal end (RX) disconnects, at this point, node (Vfd), without any access to ground, node (Vfd) will be kept
Lower than voltage signal (PVDD), if the output reset signal of pixel is Vrst, RST_COUNT signal end is height, and counter is answered
Position；
When the voltage of first switch (S1) is high, amplifier resets, the voltage signal of the first input end of amplifier
(Vinm1)=second voltage signal (Vinp1)=voltage signal Vcm of input terminal, wherein Vcm is the common-mode voltage of comparator
Signal；
The circuit output reset signal (Vrst) for eliminating dark current is sampled the first sampling capacitance (Cs1)；
Signal end (TX) is opened, and the photoreceptor signal (Vsig) of valid pixel array is exported, meanwhile, the first signal of amplifier
Voltage signal (Vinm1) jump of input terminal is Vcm- (Vrst-Vsig)；
When correction switch disconnects, the ramp generator output voltage is Vref, when correcting switch conduction, correction electricity
Hold access correction module, the correction voltage signal Vdac of correction module output, at this point, the second input terminal of the operational amplifier
Voltage signal (Vinp3) jump is Vref-Vdac；
When EN_COUNT signal end is high, counter is started counting, and the ramp signal that ramp generator issues
(Vramp) start to change, the second input end signal (Vinp1) of amplifier follows ramp signal to change, when comparator turns over
When turning, counter stops counting, and output digit signals (D), and the digital signal (D) of output is the photosensitive of valid pixel array
Signal value.
Further, the correction voltage signal Vdac=D of the correction module outputb*DRAD/2NAD, wherein DRADFor figure
As the amplitude of sensor, NADFor the precision of imaging sensor, DbFor the dark current noise digital signal of dark pixel output.
Further, in the signal averaging of image sensor system statistics dark pixel array, numeral output is not 0,
And change with the variation of temperature.
Further, the voltage range of the correction module output is the maximum amplitude value of dark current noise.
The invention has the benefit that the circuit of the elimination dark current in the present invention, compares in traditional ramp generator
In parallel compared with the second input terminal of device correction module and corrective capacity, first read out the dark of dark pixel in the circuit course of work
Current noise average number value, and this digital value is fed back into correction module, when reading valid pixel, since correction module is remembered
It has recorded the noise level of dark current and has been superimposed upon in ramp signal, so in the reading data of valid pixel and not including dark current
Noise, this framework have effectively eliminated dark current noise, reduce the image sensor dynamic range as caused by dark current
Reduce, effectively raises the picture quality of imaging sensor.
Detailed description of the invention
Attached drawing 1 is ramp generator schematic diagram in the prior art.
Attached drawing 2 is the frame diagram of cmos image sensor.
Attached drawing 3 is the row reading circuit figure for eliminating dark current.
Attached drawing 4 is ramp generator schematic diagram in the present invention.
Attached drawing 5 is the timing diagram of the reading circuit where the ramp generator of Fig. 1 and Fig. 4.
Specific embodiment
To make the object, technical solutions and advantages of the present invention clearer, with reference to the accompanying drawing to specific reality of the invention
The mode of applying is described in further detail；It should be noted that attached drawing is all made of very simplified form, using non-accurate ratio
Example, and only conveniently, clearly to achieve the purpose that aid illustration the present embodiment.
Attached drawing 4 is please referred to, in a kind of circuit using the elimination dark current of novel inclined generator provided in the present invention
Ramp generator circuit increase correction module in traditional ramp generator circuit framework, specifically, slope occur
The circuit of device includes: reset capacitance Cf again, and corrective capacity Cs, reset switch S7, correction switch S8, the 5th switch S5, the 6th open
Close S6, correction module and operational amplifier.Wherein, reset switch S7 is by signal
Correction switch is controlled by Vdark_ctrl signal, and the 6th switch is controlled by Vdark_ctrlb signal, and Vdark_
Ctrl signal is the complementary signal of Vdark_ctrlb signal.The first input end inm3's and reset capacitance Cf of operational amplifier
One end, reset switch S7 one end be commonly connected to analog power AVDD；Second input terminal inp3 of operational amplifier and the 5th
One end of switch S5, one end of corrective capacity Cs connect simultaneously；The other end connection signal end Vref of 5th switch S5；Correction electricity
The other end of appearance is connect with one end of one end of correction switch S8, the 6th switch S6 simultaneously simultaneously, corrects the other end of switch S8
Connect correction module, the other end connection signal end Vref of the 6th switch S6；The output end of operational amplifier connects reset simultaneously
The other end of capacitor Cf and the other end of reset switch S7, and export ramp signal Vramp.When correcting switch S8 disconnection, tiltedly
Slope generator exports Vref signal, and when correcting switch S8 conducting, corrective capacity Cs accesses correction module, correction module output
Correction voltage signal Vdac, at this point, the second input terminal voltage signal Vinp3 jump of operational amplifier is Vref-Vdac.Correction
The correction voltage signal Vdac=D of module outputb*DRAD/2NAD, wherein DRADFor the amplitude of imaging sensor, NADFor image biography
The precision of sensor, DbFor the dark current noise digital signal of dark pixel output.
When the ramping amplifier in the present invention is used in dark current correction, column select circuit is still as shown in Fig. 3,
It uses 4T dot structure, specifically, a kind of circuit of elimination dark current using novel inclined generator of the present embodiment, packet
It includes: the first transistor, second transistor, third transistor, the 4th transistor, the first sampling capacitance Cs1, the second sampling capacitance
Cs2, third sampling capacitance Cs3, the 4th sampling capacitance Cs4, comparator, amplifier, diode, backward dioded, counter,
One switch S1, second switch S2, third switch S3, the 4th switch S4.The first transistor of the present embodiment is equal to the 4th transistor
For same type of metal-oxide-semiconductor, such as NMOS tube.
Specifically, the grid end connection signal end TX of the first transistor, the source of the first transistor is grounded by diode；The
The grid of the drain terminal of the grid end connection signal end RX of two-transistor, the source of second transistor and the first transistor, third transistor
End, which is connected, is connected to node Vfd；The drain terminal of second transistor is connected with the drain terminal of third transistor；The source of third transistor with
The drain terminal of 4th transistor connects；The grid end connection signal end SEL of 4th transistor, the source of the 4th transistor and the first sampling
The common connect and ground in one end of capacitor Cs1；The other end of first sampling capacitance Cs1 is connect jointly with one end of first switch S1
To the input terminal inm1 of amplifier；The other end of first switch S1 connects Vcm signal end；One end of second sampling capacitance Cs2 with
Ramp generator connection, the other end of the second sampling capacitance Cs2 and one end of second switch S2 are commonly connected to the defeated of amplifier
Enter to hold inp1；The other end of second switch S2 connects Vcm signal end.
One end of the first output end outp connection third sampling capacitance connection third sampling capacitance Cs3 of amplifier, amplification
One end of the 4th sampling capacitance Cs4 of second output terminal outm connection of device；The other end and a comparator of third sampling capacitance Cs3
First input end inm2, third switch S3 one end connect jointly；The other end of 4th sampling capacitance Cs4 and the comparator
Second input terminal inp2, the 4th switch S4 one end connect jointly；First output end of comparator is another with third switch S3's
End connection；The other end of the second output terminal of comparator and the 4th switch S4 are commonly connected to the input terminal of a backward dioded
Vcom out；The input terminal of the output end linkage counter of backward dioded；Counter is connected with EN_COUNT signal end, RST_
COUNT signal end, and there is output signal end Dout.
Next combine Fig. 5 that the image sensor system of the present embodiment is described in detail.Referring to Fig. 5, being this reality
Apply the circuit timing diagram of the above-mentioned elimination resistance in the dark of example.Wherein, D1 is indicated using the ramp generator in attached drawing 1 in Vcom_out
The photoreceptor signal value of circuit, D0 indicates the photoreceptor signal value using the ramp generator circuit in attached drawing 4 in Vcom_out.
The image sensor system of a kind of elimination dark current using novel inclined generator of the present embodiment, comprising: dark
The circuit of the above-mentioned elimination dark current of pixel array, valid pixel array and the present embodiment；Eliminate the circuit of dark current and dark
Pixel array, valid pixel array are respectively connected with.
In the present embodiment, image sensor system obtains the signal averaging Db of dark pixel array by statistics, and defeated
Digital signal out；It should be noted that ideally this digital signal should be 0, but in practice, due to dark current noise
It influences, the output of this digital signal is not 0, and is changed with the variation of temperature.
Here, when signal end SEL is high, certain row picture element signal of the circuit output valid pixel array of dark current is eliminated
Value；When signal end RX is high, node Vfd is reset to voltage signal PVDD, so by the first transistor conducting of signal end RX control
Afterwards, signal end RX is disconnected, due to channel charge injection effect and clock feedthrough, at this point, node Vfd is without any access to ground,
Holding is less than about PVDD voltage signal by node Vfd, if the output reset signal of pixel is Vrst, RST_COUNT signal end is
Height, by counter resets.
When the voltage of first switch S1 is high, comparator resets, and the voltage signal Vinm1=second of first input end is defeated
Voltage signal Vinp1=the voltage Vcm, Vcm for entering end are the common mode voltage signal of comparator.The circuit output for eliminating dark current is multiple
Position signal Vrst is sampled the first sampling capacitance Cs1；Then, signal TX is opened, and exports the photoreceptor signal of valid pixel array
Vsig；Meanwhile the voltage signal Vinp1 jump of the first signal input part of comparator is Vcm- (Vrst-Vsig).When correction is opened
When closing S8 disconnection, ramp generator exports Vref signal, and when correcting switch S8 conducting, corrective capacity Cs accesses correction module,
The correction voltage signal Vdac of correction module output, at this point, the second input terminal voltage signal Vinm3 jump of operational amplifier is
Vref-Vdac.Wherein, the voltage range of correction module output is the maximum amplitude value of dark current noise, and correction module exports
Correction voltage signal Vdac=Db*DRAD/2NAD, wherein DRADFor the amplitude of imaging sensor, NADFor the essence of imaging sensor
Degree, DbFor the dark current noise digital signal of dark pixel output.
When signal EN_COUNT signal end is high, counter is started counting, and the slope letter that ramp generator issues
Number Vramp starts to change, and the second input end signal Vinp1 of amplifier follows ramp signal to change, when comparator is flipped
When, counter stops counting, and output digit signals D0, the digital signal D0 of output are the photoreceptor signal of valid pixel array
Value.
In conclusion the circuit of the elimination dark current in the present invention, the second of comparator in traditional ramp generator
Input terminal in parallel correction module and corrective capacity, the dark current noise that dark pixel is first read out in the circuit course of work is flat
Equal digital value, and this digital value is fed back into correction module, when reading valid pixel, since correction module has recorded dark current
Noise level and be superimposed upon in ramp signal, so in the reading data of valid pixel and do not include dark current noise, this
Structure has effectively eliminated dark current noise, reduces the reduction of the image sensor dynamic range as caused by dark current, effectively
The picture quality for improving imaging sensor.
The above description is only a preferred embodiment of the present invention, and the embodiment is not intended to limit patent protection of the invention
Range, thus it is all with the variation of equivalent structure made by specification and accompanying drawing content of the invention, it similarly should be included in this
In the protection scope of invention appended claims.
Claims (10)
1. a kind of novel inclined generator, which is characterized in that including reset capacitance, corrective capacity, reset switch, correction switch,
5th switch, the 6th switch, correction module and operational amplifier, wherein the first input end of the operational amplifier with it is described
One end of reset capacitance, one end of reset switch are commonly connected to analog power；Second input terminal of the operational amplifier with
One end of 5th switch, one end of corrective capacity connect simultaneously；The other end connection signal end of 5th switch
(Vref)；The other end of the corrective capacity is connect with one end of one end of the correction switch, the 6th switch simultaneously simultaneously, institute
State the other end connection correction module of correction switch, the other end connection signal end (Vref) of the 6th switch；The operation
The output end of amplifier connects the other end of the reset capacitance and the other end of reset switch simultaneously, and exports ramp signal.
2. the ramp generator according to claim 1 for eliminating dark current, which is characterized in that the correction switch by
The control of Vdark_ctrl signal, the 6th switch is controlled by Vdark_ctrlb signal, and Vdark_ctrl signal is described
The complementary signal of Vdark_ctrlb signal.
3. the circuit according to claim 1 for eliminating dark current, which is characterized in that the voltage model of the correction module output
Enclose the maximum amplitude value for dark current noise.
4. a kind of circuit of the elimination dark current using novel inclined generator, which is characterized in that using described in claim 1
Ramp generator, comprising:
Dot structure, output end connect one end of the first sampling capacitance；
One end of first sampling capacitance, the other end and first switch is commonly connected to the first input end of amplifier, and first opens
The other end connection signal end (Vcm) of pass；
Second sampling capacitance, one end are connect with ramp generator, and one end of the other end and second switch is commonly connected to amplify
Second input terminal of device, the other end connection signal end (Vcm) of second switch；
One end of the first output end connection third sampling capacitance of amplifier, second output terminal connect the one of the 4th sampling capacitance
End；
One end that the other end and the first input end of comparator, third of third sampling capacitance switch connects jointly；
The other end of 4th sampling capacitance is connect jointly with one end of the second input terminal of the comparator, the 4th switch；
First output end of the comparator is connect with the other end that third switchs；The second output terminal of the comparator and the 4th
The other end of switch is commonly connected to the input terminal of backward dioded；The input of the output end linkage counter of backward dioded
End；Counter is connected with EN_COUNT signal end and RST_COUNT signal end, and has output signal end.
5. the circuit according to claim 4 for eliminating dark current, which is characterized in that the dot structure includes:
The first transistor, grid end connection signal (TX), source are grounded by diode；
Second transistor, grid end connection signal (RX), source and the drain terminal of the first transistor, the grid end phase of third transistor
It is connected to node (Vfd)；Its drain terminal is connected with the drain terminal of third transistor；
Third transistor, source are connect with the drain terminal of the 4th transistor；
4th transistor, grid end connection signal (SEL), the common connect and ground in one end of source and the first sampling capacitance.
6. the circuit according to claim 4 for eliminating dark current, which is characterized in that the voltage model of the correction module output
Enclose the maximum amplitude value for dark current noise.
7. a kind of image sensor system of the elimination dark current using novel inclined generator characterized by comprising dark picture
The circuit of dark current is eliminated described in pixel array, valid pixel array and claim 5；The circuit for eliminating dark current
It is connected with dark pixel array, valid pixel array；
Image sensor system counts the signal averaging of dark pixel array, and output digit signals；
When signal end (SEL) is high, certain row pixel signal values of the circuit output valid pixel array for eliminating dark current；
When signal end (RX) is high, node (Vfd) is reset to voltage signal by the first transistor conducting of signal end (RX) control
(PVDD), then signal end (RX) disconnects, at this point, node (Vfd), without any access to ground, node (Vfd) will be kept below
Voltage signal (PVDD), if the output reset signal of pixel is Vrst, RST_COUNT signal end is height, by counter resets；
When the voltage of first switch is high, amplifier resets, voltage signal (Vinm1)=the of the first input end of amplifier
Voltage signal (Vinp1)=voltage signal Vcm of two input terminals, wherein Vcm is the common-mode voltage of comparator；
The circuit output reset signal (Vrst) for eliminating dark current is sampled the first sampling capacitance (Cs1)；
Signal end (TX) is opened, and the photoreceptor signal (Vsig) of valid pixel array is exported, meanwhile, the first signal input of amplifier
Voltage signal (Vinm1) jump at end is Vcm- (Vrst-Vsig)；
When correction switch disconnects, the ramp generator output voltage is Vref, and when correcting switch conduction, corrective capacity is connect
Enter correction module, the correction voltage signal Vdac of correction module output, at this point, the second input terminal voltage of the operational amplifier
Signal (Vinp 3) jump is Vref-Vdac；
When EN_COUNT signal end is high, counter is started counting, and the ramp signal (Vramp) that ramp generator issues
Starting to change, the second input end signal (Vinp1) of amplifier follows ramp signal to change, when comparator is flipped, meter
Number device stops counting, and output digit signals (D), the digital signal (D) of output are the photoreceptor signal value of valid pixel array.
8. image sensor system according to claim 7, which is characterized in that the correction voltage of the correction module output
Signal Vdac=Db*DRAD/2NAD, wherein DRADFor the amplitude of imaging sensor, NADFor the precision of imaging sensor, DbFor dark picture
The dark current noise digital signal of element output.
9. image sensor system according to claim 7, which is characterized in that count dark pixel in image sensor system
When the signal averaging of array, numeral output is not 0, and is changed with the variation of temperature.
10. image sensor system according to claim 7, which is characterized in that the voltage model of the correction module output
Enclose the maximum amplitude value for dark current noise.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811273815.1A CN109495700B (en) | 2018-10-30 | 2018-10-30 | Circuit and system for eliminating dark current by using slope generator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811273815.1A CN109495700B (en) | 2018-10-30 | 2018-10-30 | Circuit and system for eliminating dark current by using slope generator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109495700A true CN109495700A (en) | 2019-03-19 |
| CN109495700B CN109495700B (en) | 2021-04-16 |
Family
ID=65691754
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811273815.1A Active CN109495700B (en) | 2018-10-30 | 2018-10-30 | Circuit and system for eliminating dark current by using slope generator |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109495700B (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110720212A (en) * | 2019-09-02 | 2020-01-21 | 深圳市汇顶科技股份有限公司 | Signal processing circuit and method for pixel array and image sensor |
| CN110784668A (en) * | 2019-10-28 | 2020-02-11 | 成都微光集电科技有限公司 | Image sensor reading circuit and method for correcting dark current |
| CN111399585A (en) * | 2020-03-12 | 2020-07-10 | 成都微光集电科技有限公司 | Dark current eliminating circuit using novel slope generator and system thereof |
| CN112261327A (en) * | 2020-11-13 | 2021-01-22 | 中国科学院高能物理研究所 | Pixel detector and distributed front-end analog-digital conversion and reading circuit and method thereof |
| CN114071039A (en) * | 2021-11-18 | 2022-02-18 | 成都微光集电科技有限公司 | Correction circuit, readout circuit of pixel unit and CMOS image sensor |
| CN115022565A (en) * | 2022-06-21 | 2022-09-06 | 西安理工大学 | Slope consistency correction circuit applied to CMOS image sensor |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114979513A (en) | 2022-05-19 | 2022-08-30 | 成都微光集电科技有限公司 | Method and system for reducing column noise of image sensor |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102647566A (en) * | 2011-02-17 | 2012-08-22 | 全视科技有限公司 | Analog row black level calibration for cmos image sensor |
| US20140146210A1 (en) * | 2012-11-26 | 2014-05-29 | Samsung Electronics Co., Ltd. | Solid state imaging devices and methods using single slope adc with adjustable slope ramp signal |
| CN106060434A (en) * | 2015-04-13 | 2016-10-26 | 全视科技有限公司 | Image sensor power supply rejection ratio noise reduction through ramp generator |
| CN106791496A (en) * | 2015-11-16 | 2017-05-31 | 豪威科技股份有限公司 | Imageing sensor PSRR is improved by the Ramp generator in continuous time reading circuit |
| CN106937063A (en) * | 2015-12-30 | 2017-07-07 | 豪威科技股份有限公司 | Method and system for reducing the analog/digital conversion time of dark signal |
| CN108322679A (en) * | 2017-12-29 | 2018-07-24 | 成都微光集电科技有限公司 | A kind of circuit and system for eliminating dark current |
-
2018
- 2018-10-30 CN CN201811273815.1A patent/CN109495700B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102647566A (en) * | 2011-02-17 | 2012-08-22 | 全视科技有限公司 | Analog row black level calibration for cmos image sensor |
| US20140146210A1 (en) * | 2012-11-26 | 2014-05-29 | Samsung Electronics Co., Ltd. | Solid state imaging devices and methods using single slope adc with adjustable slope ramp signal |
| CN106060434A (en) * | 2015-04-13 | 2016-10-26 | 全视科技有限公司 | Image sensor power supply rejection ratio noise reduction through ramp generator |
| CN106791496A (en) * | 2015-11-16 | 2017-05-31 | 豪威科技股份有限公司 | Imageing sensor PSRR is improved by the Ramp generator in continuous time reading circuit |
| CN106937063A (en) * | 2015-12-30 | 2017-07-07 | 豪威科技股份有限公司 | Method and system for reducing the analog/digital conversion time of dark signal |
| CN108322679A (en) * | 2017-12-29 | 2018-07-24 | 成都微光集电科技有限公司 | A kind of circuit and system for eliminating dark current |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110720212A (en) * | 2019-09-02 | 2020-01-21 | 深圳市汇顶科技股份有限公司 | Signal processing circuit and method for pixel array and image sensor |
| CN110784668A (en) * | 2019-10-28 | 2020-02-11 | 成都微光集电科技有限公司 | Image sensor reading circuit and method for correcting dark current |
| CN110784668B (en) * | 2019-10-28 | 2021-06-15 | 成都微光集电科技有限公司 | Image sensor reading circuit and method for correcting dark current |
| CN111399585A (en) * | 2020-03-12 | 2020-07-10 | 成都微光集电科技有限公司 | Dark current eliminating circuit using novel slope generator and system thereof |
| CN112261327A (en) * | 2020-11-13 | 2021-01-22 | 中国科学院高能物理研究所 | Pixel detector and distributed front-end analog-digital conversion and reading circuit and method thereof |
| CN114071039A (en) * | 2021-11-18 | 2022-02-18 | 成都微光集电科技有限公司 | Correction circuit, readout circuit of pixel unit and CMOS image sensor |
| CN114071039B (en) * | 2021-11-18 | 2023-10-20 | 成都微光集电科技有限公司 | Correction circuit, pixel unit readout circuit and CMOS image sensor |
| CN115022565A (en) * | 2022-06-21 | 2022-09-06 | 西安理工大学 | Slope consistency correction circuit applied to CMOS image sensor |
| CN115022565B (en) * | 2022-06-21 | 2024-07-23 | 西安理工大学 | Ramp consistency correction circuit applied to CMOS image sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109495700B (en) | 2021-04-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109495700A (en) | A kind of circuit and its system of the elimination dark current using novel inclined generator | |
| CN108322679B (en) | Circuit and system for eliminating dark current | |
| KR102324713B1 (en) | Ramp signal generator and image sensor | |
| KR101965632B1 (en) | Correlated Double Sampling Circuit, Image Sensor including the Same, And Method there-of | |
| US9756271B2 (en) | CMOS image sensor, pixel unit and control method thereof | |
| US5877715A (en) | Correlated double sampling with up/down counter | |
| JP5806566B2 (en) | A / D converter and solid-state imaging device | |
| US10447956B2 (en) | Analog-to-digital converter circuitry with offset distribution capabilities | |
| CN109314755A (en) | Reduced positive return circuit is extended for resetting in single-slope ADC | |
| CN101304469B (en) | Solid imaging apparatus and imaging apparatus | |
| US20090091648A1 (en) | Multi-resolution Image Sensor Array with High Image Quality Pixel Readout Circuitry | |
| CN109587420A (en) | A kind of imaging sensor high-precision reading circuit structure and working sequence control method | |
| EP0986898A1 (en) | Cmos image sensor with improved fill factor | |
| EP0986900A1 (en) | Dc offset and gain correction for cmos image sensor | |
| KR20100018586A (en) | Current/voltage mode image sensor with switchless active pixels | |
| CN103297721A (en) | Cmos sensor array | |
| CN104967793B (en) | Power supply noise cancellation circuit suitable for CMOS image sensor | |
| US9204069B2 (en) | Method for driving imaging apparatus, method for driving imaging system, imaging apparatus, and imaging system | |
| Okada et al. | 7.6 A high-speed back-illuminated stacked CMOS image sensor with column-parallel kT/C-cancelling S&H and delta-sigma ADC | |
| CN111399585B (en) | Dark current eliminating circuit using novel slope generator and system thereof | |
| CN101557462A (en) | Efficient wide-range and high-resolution black level and offset calibration system | |
| Teymouri et al. | An ultra‐linear CMOS image sensor for a high‐accuracy imaging system | |
| CN111193881B (en) | Comparator with low stripe noise | |
| CN104967794B (en) | Power supply noise cancellation circuit suitable for CMOS image sensor | |
| US10757356B2 (en) | Comparison device and CMOS image sensor including the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |