CN101738841B - CMOS image sensor - Google Patents
CMOS image sensor Download PDFInfo
- Publication number
- CN101738841B CN101738841B CN 200910242353 CN200910242353A CN101738841B CN 101738841 B CN101738841 B CN 101738841B CN 200910242353 CN200910242353 CN 200910242353 CN 200910242353 A CN200910242353 A CN 200910242353A CN 101738841 B CN101738841 B CN 101738841B
- Authority
- CN
- China
- Prior art keywords
- pixel
- signal
- sub
- exposure
- output
- 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.)
- Expired - Fee Related
Links
Images
Landscapes
- Transforming Light Signals Into Electric Signals (AREA)
- Solid State Image Pick-Up Elements (AREA)
Abstract
The invention discloses a CMOS image sensor comprising a pixel array, an exposure control circuit, a line gating circuit and a signal output circuit, wherein the pixel array comprises a plurality of pixel dots. Each pixel dot comprises a plurality of sub pixels; reset control and signal keeping control lines of the sub pixels the relative positions of which are the same in each pixel dot are connected together; the signal lines share or independently possess a signal output line in manner of line; the exposure control circuit is used for controlling the exposure of each sub pixel to be started and ended in sequence according to the preset time difference; the line gating circuit is used for gating each sub pixel in sequence so as to output signals to the signal lines; and the signal output circuit is used for buffering or amplifying the output signals of the sub pixel and driving an analog to digital converter connected with the output of the CMOS image sensor. The invention can break through the physical lower limit existing in the exposure time of the CMOS image sensor and can solve the problem that the signal quality is lowered because of excessivel short time of integration.
Description
Technical field
The present invention relates to the image sensor technologies field, particularly a kind of cmos image sensor that is used for high-speed photography.
Background technology
At present, practical cmos image sensor mostly relies on diffusion process and collects photo-generated carrier, and this is a kind of slow process, makes that the time shutter of imageing sensor generally need be greater than 1 μ s.Even by changing technology, improve the movement velocity of photo-generated carrier in semiconductor material, the time shutter still must could guarantee higher collection efficiency much larger than the photo-generated carrier transit time.In case the time shutter is approaching or less than the transit time, imageing sensor will sharply descend to the collection efficiency of photo-generated carrier.
On the other hand, though mean more data in the unit interval littler integral time, owing to have various noises in the whole sensor circuit, the noise contribution in these data is also big more, from the angle of quantity of information, can not obtain more information promptly littler integral time.In fact, have the integral time of an optimum, make that the signal quality of imageing sensor is better, integral time is also less, thereby obtains maximum quantity of information.
Therefore, realizing high-speed photography, can not only rely on to reduce time shutter and signal amplification with cmos image sensor---its cost is a sacrifice picture quality.Simultaneously, there is this physics limit of photo-generated carrier transit time in cmos image sensor, makes the time shutter further to reduce.
Summary of the invention
(1) technical matters that will solve
The technical matters that the present invention solves is under the condition that ensures signal quality, and perhaps when the time shutter reaches the physics limit of device, how further to improve the temporal resolution of cmos image sensor in the high-speed photography.In order to solve this technical matters, the present invention proposes a kind of cmos image sensor that is used for high-speed photography.
(2) technical scheme
For achieving the above object, the invention provides a kind of cmos image sensor, this cmos image sensor comprises pel array, exposure control circuit, ranks gating circuit and signal output apparatus, wherein:
Pel array comprises a plurality of pixels, and each pixel is made up of a plurality of sub-pixels, and reset control and the signal retentive control line of the sub-pixel that relative position is identical in each pixel link together, and signal wire is shared or independently have an output line by linescan method;
The exposure that exposure control circuit is used to control each sub-pixel began successively and finishes according to the default mistiming;
The ranks gating circuit is used for each sub-pixel of gating successively, and signal is outputed on the signal wire;
Signal output apparatus is used to cushion or amplify the output signal of sub-pixel, drives the analog to digital converter that is connected with the output of this cmos image sensor.
In the such scheme, described each sub-pixel comprises photosensitive unit, the control module that resets, signal holding unit, signal output unit and gating control module, the beginning of each sub-pixel time shutter and finish all can independently control, wherein:
Photosensitive unit is used for exposure is converted to voltage signal;
The control module that resets is used for the electric signal of photosensitive unit output is reset to initial value, resets and finishes to be the moment of exposure beginning;
The signal holding unit is used to sample and keeps the voltage signal of photosensitive unit, and sampling instant is the moment of end exposure;
Signal output unit is used to reduce the output impedance of signal holding unit, drive signal line;
The gating control module is used for control signal output or keeps high-impedance state.
In the such scheme, reset control and the signal retentive control line of described each sub-pixel are independently drawn, and be shared or independently have an output line.
In the such scheme, the exposure of described a plurality of sub-pixels begins successively and finishes, and former and later two mistiming is T, and the time shutter of each sub-pixel is (N-1) T, and N is the number of sub-pixel in each pixel, gets the natural number greater than 2.
In the such scheme, behind the end exposure of certain sub-pixel,, and output signal carried out analog to digital conversion at T identical sub-pixel of relative position in the gating output entire image sensor array successively in the time.
In the such scheme, the output of each sub-pixel in each pixel is considered as a sequence, each of this sequence is a N-1 T time exposure signal sum, if preceding N-2 T time exposure signal is known, then can does subtraction and obtain last T time exposure signal; Like this recursion can be the information of acquisition temporal resolution T the signal of (N-1) T from the time shutter then.
(3) beneficial effect
The invention discloses a kind of cmos image sensor, a pixel is divided into N the sub-pixel that can independently control the exposure beginning and finish, the exposure beginning and the end of control adjacent subpixels differ T, each sub-pixel time shutter (N-1) T, and finish analog to digital conversion in the time at T subsequently, then can recover the signal that temporal resolution is T for the signal of (N-1) T by calculating from the time shutter.There is the physics lower limit in the time shutter that the present invention can break through cmos image sensor, also can solve the signal quality decline problem that causes too short integral time.
Description of drawings
Fig. 1 is a dot structure that is divided into 4 sub-pixels (N=4), its reset, sample, select and export control separate.
Fig. 2 is the mode of operation of 4 sub-pixels.
Fig. 3 is the relation between y among Fig. 2 (n) and the x (n), if x (1), x (0) are known, then can calculate x (2), x (3), x (4), x (5) successively.
Embodiment
For making the purpose, technical solutions and advantages of the present invention clearer, below in conjunction with specific embodiment, and with reference to accompanying drawing, the present invention is described in more detail.
The present invention will have only the image sensor pixel of one group of sensitization and control module originally, be divided into a plurality of sub-pixels, and each sub-pixel has and independently resets and the retentive control unit of sampling, and the exposure of each sub-pixel begins and finishes and can independently control like this.
For the above-mentioned novel pixel that comprises N sub-pixel, its mode of operation is that the exposure of each sub-pixel begins successively and finishes, and front and back differ T, the classification duration of each sub-pixel (N-1) T, and will the T time subsequently leave analog to digital conversion for.Concerning each sub-pixel, its work period is NT like this, and former and later two sub-pixels differ T.
Suppose that y (n) is the burst of time shutter (N-1) T, x (n) is to be the burst of T the time shutter, then
y(n)＝x(n-1)+x(n-2)+...+x(n-N-1)
If x (n-2) is known to x (n-N-1), then can from y (n), calculate x (n-1).Like this recursion can be the information of acquisition temporal resolution T the signal of (N-1) T from the time shutter then.
The invention provides a kind of cmos image sensor, this cmos image sensor comprises pel array, exposure control circuit, ranks gating circuit and signal output apparatus.Wherein: pel array comprises a plurality of pixels, each pixel is made up of a plurality of sub-pixels, reset control and the signal retentive control line of the sub-pixel that relative position is identical in each pixel link together, and signal wire is shared or independently have an output line by linescan method; The exposure that exposure control circuit is used to control each sub-pixel began successively and finishes according to the default mistiming; The ranks gating circuit is used for each sub-pixel of gating successively, and signal is outputed on the signal wire; Signal output apparatus is used to cushion or amplify the output signal of sub-pixel, drives the analog to digital converter that is connected with the output of this cmos image sensor.
Described each sub-pixel comprises photosensitive unit, the control module that resets, signal holding unit, signal output unit and gating control module, the beginning of each sub-pixel time shutter and finish all can independently control.Wherein: photosensitive unit is used for exposure is converted to voltage signal; The control module that resets is used for the electric signal of photosensitive unit output is reset to initial value, resets and finishes to be the moment of exposure beginning; The signal holding unit is used to sample and keeps the voltage signal of photosensitive unit, and sampling instant is the moment of end exposure; Signal output unit is used to reduce the output impedance of signal holding unit, drive signal line; The gating control module is used for control signal output or keeps high-impedance state.
Reset control and the signal retentive control line of described each sub-pixel are independently drawn, and be shared or independently have an output line.The exposure of described a plurality of sub-pixels begins successively and finishes, and former and later two mistiming is T, and the time shutter of each sub-pixel is (N-1) T, and N is a natural number.Behind the end exposure of certain sub-pixel,, and output signal carried out analog to digital conversion at T identical sub-pixel of relative position in the gating output entire image sensor array successively in the time.The output of each sub-pixel in each pixel is considered as a sequence, and each of this sequence is a N-1 T time exposure signal sum, if preceding N-2 T time exposure signal is known, then can does subtraction and obtain last T time exposure signal; Like this recursion can be the information of acquisition temporal resolution T the signal of (N-1) T from the time shutter then.
The present invention is a kind of cmos image sensor that is used for high-speed photography.By each pixel in the imageing sensor is divided into N sub-pixel, and allow the exposure of the sub-pixel T that staggers mutually, can allow the time shutter of single sub-pixel be (N-1) T, and treated image sequence is T.
With N=4 is example, and as shown in Figure 1, a cmos image sensor pixel is divided into 4 sub-pixels, have 4 and reset and 4 controlling of sampling, and, 4 output ports and 4 selection controls.
When reset terminal was effective, sub-pixel was ready to receive incident light; When reset terminal is invalid from effectively becoming, the exposure beginning, at this moment controlling of sampling is in disarmed state, and the level of sampling is followed the level of optical sensor.When controlling of sampling becomes effectively, then sampled level remains unchanged, at this moment end exposure.Because each sub-pixel all has a reseting controling end and a controlling of sampling end, the exposure of each sub-pixel begins and finishes and can independently control.When forming array, reset control and the controlling of sampling of the sub-pixel of same position links together in the different pixels, so just can realize the exposure of entire pixel array is controlled.
When the selection control end of a sub-pixel was in effective status, this sub-pixel can output to the signal of sampling thief on the output bus; Otherwise if select control end to be in disarmed state, then the output port of this sub-pixel is in high-impedance state.When a plurality of sub-pixels (in the same pixel or different pixels) are shared same output bus, by the control selecting side, allow and have only a sub-pixel output signal, all the other all are in high-impedance state.Can allow a plurality of pixel forming arrays like this, thereby finish the task of imaging.
The mode of operation of this image sensor pixel as shown in Figure 2, wherein to represent length be the time of T to each lattice.Comprise the exposure of 3T and the analog to digital conversion of T in the work period of each pixel.
When t=0, the control that resets of sub-pixel 0 is invalid from effectively becoming, i.e. the exposure of sub-pixel 0 begins.When t=T, the exposure of sub-pixel 1 begins, and at this moment sub-pixel 0 has exposed the T time, and the level on the optical sensor is x (0).When t=2T, the exposure of sub-pixel 2 begins, and at this moment sub-pixel 0 has exposed the 2T time, and the level on the optical sensor is x (0)+x (1), and the 1 exposure T time of sub-pixel, level is x (1).When t=3T, the exposure of sub-pixel 3 begins, and the controlling of sampling of sub-pixel 0 becomes effectively, and the level that obtains on the sampling thief is x (0)+x (1)+x (2).In time, sub-pixel 0 is carried out analog to digital conversion at subsequently T, can obtain y (3)=x (0)+x (1)+x (2).Similarly, allow work period of sub-pixel 1,2,3 T that staggers, can obtain sequences y (n), the relation of sequences y (n) and x (n) as shown in Figure 3.
As shown in Figure 3, from the sequences y that certain pixel obtains, its each is continuous 3 sums among the sequence x.As can be seen from Figure 3, if x (1) and x (0) are known, then can from y (n), recursion go out each x (n) afterwards.Like this, though the real exposure time of each sub-pixel is 3T, can obtain the image sequence that temporal resolution is T.
Above-described specific embodiment; purpose of the present invention, technical scheme and beneficial effect are further described; institute is understood that; the above only is specific embodiments of the invention; be not limited to the present invention; within the spirit and principles in the present invention all, any modification of being made, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (6)
1. a cmos image sensor is characterized in that, this cmos image sensor comprises pel array, exposure control circuit, ranks gating circuit and signal output apparatus, wherein:
Pel array comprises a plurality of pixels, and each pixel is made up of a plurality of sub-pixels, and reset control and the signal retentive control line of the sub-pixel that relative position is identical in each pixel link together, and signal wire is shared or independently have an output line by linescan method;
The exposure that exposure control circuit is used to control each sub-pixel began successively and finishes according to the default mistiming;
The ranks gating circuit is used for each sub-pixel of gating successively, and signal is outputed on the signal wire;
Signal output apparatus is used to cushion or amplify the output signal of sub-pixel, drives the analog to digital converter that is connected with the output of this cmos image sensor.
2. cmos image sensor according to claim 1, it is characterized in that, described each sub-pixel comprises photosensitive unit, the control module that resets, signal holding unit, signal output unit and gating control module, the beginning of each sub-pixel time shutter and finish all can independently control, wherein:
Photosensitive unit is used for exposure is converted to voltage signal;
The control module that resets is used for the electric signal of photosensitive unit output is reset to initial value, resets and finishes to be the moment of exposure beginning;
The signal holding unit is used to sample and keeps the voltage signal of photosensitive unit, and sampling instant is the moment of end exposure;
Signal output unit is used to reduce the output impedance of signal holding unit, drive signal line;
The gating control module is used for control signal output or keeps high-impedance state.
3. cmos image sensor according to claim 1 is characterized in that, reset control and the signal retentive control line of described each sub-pixel are independently drawn, and is shared or independently have an output line.
4. cmos image sensor according to claim 1 is characterized in that the exposure of described a plurality of sub-pixels begins successively and finishes, former and later two mistiming is T, the time shutter of each sub-pixel is (N-1) T, and N is the number of sub-pixel in each pixel, gets the natural number greater than 2.
5. cmos image sensor according to claim 4, it is characterized in that, behind the end exposure of certain sub-pixel,, and output signal carried out analog to digital conversion at T identical sub-pixel of relative position in the gating output entire image sensor array successively in the time.
6. cmos image sensor according to claim 4, it is characterized in that, the output of each sub-pixel in each pixel is considered as a sequence, each of this sequence is a N-1 T time exposure signal sum, if preceding N-2 T time exposure signal is known, then can does subtraction and obtain last T time exposure signal; Like this recursion can be the information of acquisition temporal resolution T the signal of (N-1) T from the time shutter then.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200910242353 CN101738841B (en) | 2009-12-09 | 2009-12-09 | CMOS image sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200910242353 CN101738841B (en) | 2009-12-09 | 2009-12-09 | CMOS image sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101738841A CN101738841A (en) | 2010-06-16 |
| CN101738841B true CN101738841B (en) | 2011-07-20 |
Family
ID=42462484
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200910242353 Expired - Fee Related CN101738841B (en) | 2009-12-09 | 2009-12-09 | CMOS image sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101738841B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9304301B2 (en) * | 2012-12-26 | 2016-04-05 | GM Global Technology Operations LLC | Camera hardware design for dynamic rearview mirror |
| US20160381274A1 (en) * | 2015-06-25 | 2016-12-29 | Novatek Microelectronics Corp. | Image Sensing Module |
| DE102016212776A1 (en) * | 2016-07-13 | 2018-01-18 | Robert Bosch Gmbh | Subpixel unit for a light sensor, light sensor, method of sensing a light signal, and method of generating an image |
| CN106454148B (en) * | 2016-11-15 | 2019-07-12 | 天津大学 | Piecemeal separate exposures CMOS image sensor pixel structure and its control method |
| US11140350B2 (en) | 2019-08-23 | 2021-10-05 | Semiconductor Components Industries, Llc | Imaging system with shot-noise-matched and floating-point ramp analog-to-digital converters |
-
2009
- 2009-12-09 CN CN 200910242353 patent/CN101738841B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN101738841A (en) | 2010-06-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101738841B (en) | CMOS image sensor | |
| EP1965585B1 (en) | Imaging apparatus and imaging system | |
| CN101485194B (en) | Solid-state image pickup device, data transmitting method and image pickup device | |
| US11405565B2 (en) | Information processing device and information processing method | |
| JP4500862B2 (en) | Driving method of solid-state imaging device | |
| CN104782111B (en) | Motion detection solid camera head and movement detection systems | |
| CN102934364B (en) | A/D converter, A/D conversion method, solid-state imaging element and camera system | |
| EP4160680A1 (en) | Image sensor with wide dynamic range | |
| JP2008312170A (en) | Imaging system, imaging sensor, and control method of imaging system | |
| CN108184081A (en) | A kind of high-speed data reading circuit in cmos image sensor | |
| CN102984469B (en) | Solid-state image pickup apparatus | |
| CN104580926A (en) | Solid-state imaging element and camera system | |
| JP2016082453A (en) | Solid-state imaging device and driving method thereof, and imaging system | |
| CN100336382C (en) | Solid state imaging apparatus | |
| JP2012049912A (en) | Photoelectric conversion device and imaging system | |
| JP5264095B2 (en) | Solid-state imaging device | |
| US20090262210A1 (en) | Solid-state imaging apparatus, imaging system, and method of driving solid-state imaging apparatus | |
| US8139132B2 (en) | Solid-state imaging apparatus and driving method for solid-state imaging apparatus | |
| KR101512810B1 (en) | Image Sensor Driving Circuit and Method for Supporting Binning through Oversampling | |
| CN1489392A (en) | Image signal processing device | |
| US20120268633A1 (en) | Image capture apparatus | |
| JP7072404B2 (en) | Image processing device and its control method, program, storage medium | |
| JP2006094192A5 (en) | ||
| JP7492345B2 (en) | Image pickup device and control method thereof, and image pickup apparatus and control method thereof | |
| JP4110369B2 (en) | High-speed photography device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110720 Termination date: 20121209 |