CN107396007B

CN107396007B - TDI CCD time sequence driving method and system under continuous transfer mode

Info

Publication number: CN107396007B
Application number: CN201710779958.9A
Authority: CN
Inventors: 李云辉; 王晓东; 王稚
Original assignee: Changchun Institute of Optics Fine Mechanics and Physics of CAS
Current assignee: Changchun Institute of Optics Fine Mechanics and Physics of CAS
Priority date: 2017-09-01
Filing date: 2017-09-01
Publication date: 2020-02-14
Anticipated expiration: 2037-09-01
Also published as: CN107396007A

Abstract

The application discloses a TDI CCD time sequence driving method and a TDI CCD time sequence driving system under a continuous transfer mode, wherein the method comprises the following steps: acquiring a line transfer signal; the line transfer signals comprise N trapezoidal wave periodic signals with the same waveform and the phases lagging by 360 DEG/N in sequence; in the 1 st trapezoidal wave periodic signal of the line transfer signal, the levels in the 1 st 1/2N period and the 2N 1/2N period are both high, the level in the 2 nd 1/2N period transitions from high to low, the level in the (2N-1) th 1/2N period transitions from low to high, and the levels in the remaining periods are all low; wherein N is an integer greater than 2; the TDI CCD is driven with the line transfer signal to transfer charge vertically to the horizontal shift register. Compared with the situation that the existing continuous transfer mode adopts the rectangular wave as the line transfer signal, the charge displacement curve can be more approximate to the displacement curve of the target scene image point on the focal plane, and the charge transfer image shift is reduced.

Description

TDI CCD time sequence driving method and system under continuous transfer mode

Technical Field

The invention relates to the technical field of optical imaging, in particular to a TDI CCD time sequence driving method and a TDI CCD time sequence driving system in a continuous transfer mode.

Background

For imaging some objects moving at high speed, a TDI (Time Delay Integration) CCD (Charge Coupled Device), i.e. a Time Delay Integration Charge Coupled Device, is usually used. A CCD, which may be referred to as a CCD image sensor, also called an image controller, a semiconductor device, is capable of converting an optical image into an electrical signal. The tiny photosensitive substances implanted on the CCDs are called pixels (pixels), and the larger the number of pixels contained in a CCD, the higher the resolution of the picture provided by the CCD. The CCD acts like a film, but it converts light signals into charge signals. The CCD has many photodiodes arranged in order to sense light and convert the light signal into an electrical signal, which is converted into a digital image signal by an external sampling amplifier and an analog-to-digital conversion circuit.

The TDI CCD carries out multiple integration accumulation on the same scene in a time delay integration mode, so that the exposure time is prolonged, and more photons are allowed to be collected. Compared with the common linear array CCD, the CCD linear array has the advantages of high responsivity, large dynamic range, high signal-to-noise ratio and the like. The high responsivity can reduce the relative aperture of an optical system, so that the weight and the volume of the space remote sensor are reduced, and the space remote sensor is very suitable for being applied to the technical field of space optical remote sensing.

The TDI CCD detector can be divided into two-phase, three-phase and four-phase transfer according to a charge transfer mode, and the basic principles are consistent. Taking three-phase TDI CCD as an example for analysis, the photo-generated charge packet is vertically transferred under the drive of a line transfer signal, and when a line of charges is transferred into a horizontal shift register, the quantization and reading operation of the line of charges is completed under the drive of a horizontal reading signal. In practical systems, the image of the object scene passing through the optical system on the focal plane of the TDI CCD detector is continuously moving, while the vertical transfer of charge driven by the pulse signal is stepwise, and image shift between the two is necessarily generated, and this image shift due to charge transfer is called charge transfer image shift. The problem of image motion inherent in the conventional TDI CCD detector and the driving mode cannot be solved by a compensation mode. In recent years, a continuous transfer mode has been proposed as a drive method of the TDI CCD, and the charge transfer image shift is reduced compared to the conventional burst transfer mode.

Referring to fig. 1 and fig. 2, fig. 1 is a schematic diagram illustrating a vertical charge transfer process driven by three phase row transfer signals in a continuous transfer mode in the prior art, which is a timing diagram of three phase row transfer signals CI1, CI2, and CI3 in the continuous transfer mode in the prior art. The charges in the pixels are transferred stage by stage under the pulse time sequence driving of row transfer signals CI1, CI2 and CI3, and after the charges in a row are transferred into the horizontal shift register, the horizontal shift register reads out signals CR1, CR2 and CR3 to drive and finish the quantization and reading out operation of the charges one by one. In the time period from T1 to T2, CI1 and CI2 are at high level to generate potential wells to collect charges, CI3 is at low level to form a potential barrier, and the charges are accumulated under CI1 and CI2 electrodes; in a period from T2 to T3, a potential well is generated at a high level of CI2 to collect charges, potential barriers are formed at low levels of CI1 and CI3, and the charges are accumulated under a CI2 electrode; in the time period from T3 to T4, the high level of CI2 and CI3 generates potential wells to collect charges, the low level of CI1 forms a potential barrier, and the charges are accumulated under CI2 and CI3 electrodes. By analogy, in the period from T6 to T1 of the next period, the CI1 high level generates a potential well to collect charges, and the CI2 and the CI3 low levels form a potential barrier, so that the charges are transferred to the CI1 electrode of the next pixel, and therefore, the transfer of one row of charges is completed. At time T1 of the next cycle, a row transfer cycle is completed, the transmission gate driving signal TCK pulls low to form a potential barrier, and the charge transferred to the horizontal register starts a read operation.

Referring to fig. 3, fig. 3 is a graph comparing the charge displacement curves with time in the three-phase TDI CCD burst transfer mode and the continuous transfer mode in the prior art. In fig. 3, a charge displacement curve 303 of the three-phase TDI CCD operating in the continuous transfer mode is closer to a displacement curve 301 of an image point of an object scene on a focal plane than a charge displacement curve 302 of the three-phase TDI CCD operating in the burst transfer mode, so that the charge transfer image shift can be reduced to some extent in the continuous transfer mode. And the lower the charge transfer image shift, the better the imaging effect of the TDI CCD.

Therefore, a problem to be solved by those skilled in the art is how to provide a TDI CCD timing driving method and system under a continuous transfer mode, which further reduces the charge transfer image shift compared to the TDI CCD continuous transfer mode in the prior art.

Disclosure of Invention

In view of the above, the present invention provides a TDI CCD timing driving method and system under a continuous transfer mode, which further reduces the charge transfer image shift compared to the TDI CCD continuous transfer mode in the prior art. The specific scheme is as follows:

in one aspect, the present invention provides a TDI CCD timing driving method in a continuous transfer mode, comprising:

acquiring a line transfer signal; the line transfer signals comprise N trapezoidal wave periodic signals with the same waveform and the phases lagging by 360 DEG/N in sequence; in the 1 st trapezoidal wave periodic signal of the line transfer signal, the levels in the 1 st 1/2N period and the 2N 1/2N period are both high, the level in the 2 nd 1/2N period transitions from high to low, the level in the (2N-1) th 1/2N period transitions from low to high, and the levels in the remaining periods are all low; wherein N is an integer greater than 2;

the TDI CCD is driven with the line transfer signal to transfer charge vertically to the horizontal shift register.

Preferably, N is 3.

Preferably, said N is 4.

Preferably, the period of each trapezoidal wave periodic signal is T ═ v · b;

wherein, T is the period of each trapezoidal wave periodic signal, v is the moving speed of the image point of the target scene on the focal plane, and b is the pixel size of the TDI CCD.

Preferably, the level transition in each trapezoidal wave periodic signal is a linear transition.

Preferably, the level transition in each trapezoidal wave periodic signal is an arc transition.

Preferably, after the process of driving the TDI CCD with the line transfer signal to vertically transfer charges to the horizontal shift register, the method further comprises:

converting a transmission gate driving signal TCK from a high level to a low level to isolate charges in the horizontal shift register;

a horizontal readout signal is activated to quantize the electric charges in the horizontal shift register and then the transfer gate drive signal TCK is changed from a low level to a high level.

Preferably, the process of changing the transmission gate driving signal TCK from a low level to a high level includes:

before the current 2 nth 1/2N period, the transmission gate driving signal TCK is transitioned from low to high.

In another aspect, the present invention further provides a TDI CCD timing driving system in a continuous transfer mode, comprising:

a signal acquisition unit for acquiring a line transfer signal; the line transfer signals comprise N trapezoidal wave periodic signals with the same waveform and the phases lagging by 360 DEG/N in sequence; in the 1 st trapezoidal wave periodic signal of the line transfer signal, the levels in the 1 st 1/2N period and the 2N 1/2N period are both high, the level in the 2 nd 1/2N period transitions from high to low, the level in the (2N-1) th 1/2N period transitions from low to high, and the levels in the remaining periods are all low; wherein N is an integer greater than 2;

and the time sequence driving unit is used for driving the TDI CCD by adopting the line transfer signal so as to vertically transfer the charges to the horizontal shift register.

Preferably, further comprising:

the charge isolation unit is used for converting a transmission gate driving signal TCK from a high level to a low level so as to isolate the charges in the horizontal shift register;

and a charge output unit for enabling a horizontal readout signal to quantize and output the charges in the horizontal shift register, and then converting the transfer gate driving signal TCK from a low level to a high level.

The invention provides a TDI CCD time sequence driving method in a continuous transfer mode, which comprises the following steps: acquiring a line transfer signal; the line transfer signals comprise N trapezoidal wave periodic signals with the same waveform and the phases lagging by 360 DEG/N in sequence; in the 1 st trapezoidal wave periodic signal of the line transfer signal, the levels in the 1 st 1/2N period and the 2N 1/2N period are both high, the level in the 2 nd 1/2N period transitions from high to low, the level in the (2N-1) th 1/2N period transitions from low to high, and the levels in the remaining periods are all low; wherein N is an integer greater than 2; the TDI CCD is driven with the line transfer signal to transfer charge vertically to the horizontal shift register.

The line transfer signals adopted in the invention are N trapezoidal wave periodic signals with the same waveform and the phase lags by 360 DEG/N in sequence, and compared with the situation that rectangular waves are adopted as the line transfer signals in the existing continuous transfer mode, the charge displacement curve can be closer to the displacement curve of the image point of the target scenery on the focal plane, thereby reducing the charge transfer image shift.

The TDI CCD time sequence driving system under the continuous transfer mode can operate the method and has the beneficial effects.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic diagram of a prior art vertical charge transfer process driven by three phase row transfer signals in a continuous transfer mode;

FIG. 2 is a timing diagram of three phase row transfer signals CI1, CI2, and CI3 in a continuous transfer mode in the prior art;

FIG. 3 is a graph comparing charge displacement versus time curves for a three-phase TDI CCD burst transfer mode and a continuous transfer mode of the prior art;

FIG. 4 is a flowchart illustrating a TDI CCD timing driving method under a continuous transfer mode according to a first embodiment of the present invention;

FIG. 5 is a timing diagram of three-phase TDI CCD driving signals according to a second embodiment of the present invention;

FIG. 6 is a graph comparing charge displacement curves of a three-phase TDI CCD respectively operating in a second embodiment of the present invention and in a prior art continuous transfer mode;

FIG. 7 is a timing diagram of the driving signals of a four-phase TDI CCD according to a third embodiment of the present invention;

FIG. 8 is a graph comparing charge displacement curves of a four-phase TDI CCD respectively operating in a third embodiment of the present invention and in a prior art continuous transfer mode;

FIG. 9 is a schematic diagram of a TDI CCD timing driving system under a continuous transfer mode according to an embodiment of the present invention;

fig. 10 is an expanded schematic view of a TDI CCD timing driving system in a continuous transfer mode according to an embodiment of the present invention.

Detailed Description

The core of the invention is to provide a TDI CCD time sequence driving method under a continuous transfer mode, which comprises the following steps: acquiring a line transfer signal; the line transfer signals comprise N trapezoidal wave periodic signals with the same waveform and the phases lagging by 360 DEG/N in sequence; in the 1 st trapezoidal wave periodic signal of the line transfer signal, the levels in the 1 st 1/2N period and the 2N 1/2N period are both high, the level in the 2 nd 1/2N period transitions from high to low, the level in the (2N-1) th 1/2N period transitions from low to high, and the levels in the remaining periods are all low; wherein N is an integer greater than 2; the TDI CCD is driven with the line transfer signal to transfer charge vertically to the horizontal shift register. The adopted line transfer signals are N trapezoidal wave periodic signals with the same waveform and the phases are sequentially lagged by 360 DEG/N to drive the TDI CCD, and compared with the situation that rectangular waves are adopted as the line transfer signals in the existing continuous transfer mode, the charge displacement curve can be closer to the displacement curve of the target scene image point on the focal plane, so that the charge transfer image shift is reduced.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 4, fig. 4 is a flowchart of a method for driving a TDICCD timing sequence in a continuous transfer mode according to a first embodiment of the present invention, where the method includes:

step S11: acquiring a line transfer signal; the line transfer signals comprise N trapezoidal wave periodic signals with the same waveform and the phases lagging by 360 DEG/N in sequence; in the 1 st trapezoidal wave periodic signal of the line transfer signal, the levels in the 1 st 1/2N period and the 2N 1/2N period are both high, the level in the 2 nd 1/2N period transitions from high to low, the level in the (2N-1) th 1/2N period transitions from low to high, and the levels in the remaining periods are all low; wherein N is an integer greater than 2.

In a first specific implementation manner of the present invention, in the TDI CCD timing driving method in the continuous transfer mode provided in the embodiments of the present invention, first, a line transfer signal needs to be acquired, as described in the background art, in the TDI CCD driving process in the existing continuous transfer mode, a line transfer signal needs to be used to implement vertical transfer of charges, and in the embodiments of the present invention, the TDI CCD driving process in the continuous transfer mode needs to be improved, except for differences between the line transfer signals.

In the first embodiment of the present invention, the basic principle is the same since the TDI CCD can have two, three, four or more phases. The number of phases of the TDI CCD can be represented by the parameter N. In the present invention, since the line transfer signal of the two-phase TDI CCD is modified differently in the trapezoidal wave, the number of phases N is defined as an integer greater than 2.

When the number of phases of the TDI CCD is limited to be N, the waveform of a line transfer signal of the N-phase TDI CCD can be described, wherein the line transfer signal sequentially comprises N sub-signals including CI1, CI2, … … and CIN, and the sub-signals CI1, CI2, … … and CIN are trapezoidal wave periodic signals which lag behind the phases of 360/N degrees in sequence and have the same waveform; in the division signal CI1, the first 1/2N period and the 2 nth 1/2N period thereof are at a high level; the level of the second 1/2N period is transited from high level to low level, and the level of the (2N-1) th 1/2N period is transited from low level to high level; the other times in the cycle are low.

It should be noted that the waveform during the transition from high level to low level or from low level to high level may be linear, or may be curved, or other waveforms that are favorable for generation may be possible. For example, the high level is +5V, the low level is-5V, and when a linear transition level is adopted, the level is increased from-5V to +5V or decreased from +5V to-5V in a linear form within a specified time, namely a certain period of 1/2N.

Furthermore, the period of the line transfer signal needs to be determined, which is generally determined by using a calculation formula T ═ v · b; wherein, T is the period of each trapezoidal wave periodic signal, v is the moving speed of the image point of the target scene on the focal plane, and b is the pixel size of the TDI CCD.

In the first embodiment of the present invention, the transition process between the high and ground levels is improved so that the transition between the high and low levels becomes gentle, and thus the original rectangular wave signal is improved to become a trapezoidal wave signal.

Step S12: the TDI CCD is driven with the line transfer signal to transfer charge vertically to the horizontal shift register.

After the above-mentioned line transfer signals are obtained, the charge transfer of the TDI CCD can be driven using the above-mentioned line transfer signals, so that the charges are transferred into the horizontal shift register.

TDI CCDs are well known for use in imaging objects moving at high speed. After the charge accumulation is transferred to the horizontal shift register by adopting the row transfer signal, further, a transmission gate driving signal TCK is converted from a high level to a low level so as to isolate the charge in the horizontal shift register; a horizontal readout signal is activated to quantize the electric charges in the horizontal shift register and then the transfer gate drive signal TCK is changed from a low level to a high level.

Further, in order to ensure smooth transfer of charges, the transmission gate driving signal TCK is changed from a low level to a high level before the current 2 nth 1/2N period; and the charges are read out between the transition of the transfer gate driving signal TCK from the low level to the high level.

Referring to fig. 5, fig. 5 is a timing diagram of three-phase TDI CCD driving signals according to a second embodiment of the present invention.

Under the existing conditions, the principle of three-phase TDI CCD, four-phase TDI CCD or more multi-phase TDI CCD is the same, but the three-phase TDI CCD is widely used. As shown in fig. 5, the row transfer signal has three sub-signals CI1, CI2, and CI3, which are delayed by 120 degrees in phase, and have the same waveform, and are all trapezoidal wave signals, and only one cycle of waveform is shown in the figure.

As shown in the figure, T1, T2, T3, T4, T5 and T6 are the time in one cycle, and the whole cycle is divided into six segments:

in a period from T1 to T2, the CI1 signal keeps high level, the CI3 signal keeps low level, and the CI2 signal is low level value at the time of T1 and linearly rises along with time, and the CI2 signal just reaches the high level value at the time of T2;

in a period from T2 to T3, the CI2 signal keeps high level, the CI3 signal keeps low level, and the CI1 signal is high level value at the time of T2 and linearly decreases along with time, and the CI1 signal just reaches the low level value at the time of T3;

in a period from T3 to T4, the CI1 signal keeps low level, the CI2 signal keeps high level, and the CI3 signal is low level value at the time of T3 and linearly rises along with time, and the CI3 signal just reaches high level value at the time of T4;

in a period from T4 to T5, the CI1 signal keeps low level, the CI3 signal keeps high level, and the CI2 signal is high level value at the time of T4 and linearly decreases along with time, and the CI2 signal just reaches the low level value at the time of T5;

in a period from T5 to T6, the CI2 signal keeps low level, the CI3 signal keeps high level, and the CI1 signal is low level value at the time of T5 and linearly rises along with time, and the CI1 signal just reaches the low level value at the time of T6;

during the period from T6 to the end of the current cycle, the CI1 signal remains high, the CI2 signal remains low, the CI3 signal is at a high value at time T6 and decreases linearly with time, and the CI3 signal just reaches the low value by the end of the cycle. After the end of this cycle, the time T1 of the next cycle starts.

It should be noted that the above-mentioned increase linearly or decrease linearly with time means that the value of the electrical signal has a linear relationship with time, which is represented by the waveform that the waveform is a line segment with a slant angle and is linear.

Referring to fig. 6, fig. 6 is a graph comparing charge displacement curves of a three-phase TDI CCD respectively operating in a second embodiment of the present invention and a continuous transfer mode of the prior art.

Compared with the charge displacement curve 303 of the three-phase TDI CCD working in the continuous transfer mode, the charge displacement curve 304 of the three-phase TDI CCD working in the second embodiment of the invention is closer to the displacement curve 301 of the image point of the target scene on the focal plane, so that the charge transfer image shift can be reduced to a certain extent in the continuous transfer mode, and the lower the charge transfer image shift is, the better the imaging effect of the TDI CCD is.

Referring to fig. 7, fig. 7 is a timing diagram of four-phase TDI CCD driving signals according to a third embodiment of the present invention.

As shown in fig. 7, the line transfer signal has four sub-signals CI1, CI2, CI3, and CI4, and the four sub-signals are delayed by 90 degrees in phase in sequence, have the same waveform, are all trapezoidal wave signals, and only the waveform of one cycle is shown in the figure.

As shown in the figure, T1, T2, T3, T4, T5, T6, T7 and T8 are the time points in one cycle, and the whole cycle is divided into eight segments:

in a period from T1 to T2, the CI1 signal keeps high level, the CI3 and CI4 signals keep low level, the CI2 signal is low level value at the time of T1 and linearly rises along with time, and the CI2 signal just reaches the high level value by the time of T2;

in a period from T2 to T3, the CI2 signal keeps high level, the CI3 and CI4 signals keep low level, the CI1 signal is high level value at the time of T2 and linearly decreases along with time, and the CI1 signal just reaches the low level value by the time of T3;

in a period from T3 to T4, the CI1 and CI4 signals are kept at a low level, the CI2 signal is kept at a high level, and the CI3 signal is at a low level value at the time of T3 and linearly rises along with time, and the CI3 signal just reaches the high level value at the time of T4;

in a period from T4 to T5, the CI1 and CI4 signals are kept at a low level, the CI3 signal is kept at a high level, the CI2 signal is at a high level value at the time of T4 and linearly decreases along with time, and the CI2 signal just reaches the low level value at the time of T5;

in a period from T5 to T6, the CI1 and CI2 signals are kept at a low level, the CI3 signal is kept at a high level, the CI4 signal is at a low level value at the time of T5 and linearly rises along with time, and the CI1 signal just reaches the low level value at the time of T6;

during the period from T6 to T7, the CI1 and CI2 signals remain low, the CI4 signal remains high, the CI3 signal is at a high value at time T6 and decreases linearly with time, and the CI3 signal just reaches the low value by time T7;

during the period from T7 to T8, the CI2 and CI3 signals remain low, the CI4 signal remains high, the CI1 signal is at a low value at time T7 and rises linearly with time, and the CI1 signal just reaches the low value by time T8;

in the period from T8 to the end of the current cycle, the CI1 signal is kept at a high level, the CI2 and the CI3 signal are kept at a low level, the CI4 signal is at a high level value at the time of T8 and linearly decreases along with time, the CI3 signal just reaches the low level value by the time of the end of the cycle, and after the end of the cycle, the start of the time of T1 of the next cycle is started.

Referring to fig. 8, fig. 8 is a graph comparing charge displacement curves of a four-phase TDI CCD respectively operating in a third embodiment of the present invention and a prior art continuous transfer mode.

The charge displacement curve 803 of the four-phase TDI CCD operating in the third embodiment of the present invention is closer to the displacement curve 801 of the image point of the target scene on the focal plane than the charge displacement curve 802 of the four-phase TDI CCD operating in the continuous transfer mode, so that the continuous transfer mode can reduce the charge transfer image shift to a certain extent, and the lower the charge transfer image shift, the better the imaging effect of the TDI CCD.

It should be noted that the charge displacement curve 304 of the second embodiment of the present invention fluctuates up and down around the displacement curve 301 of the target scene image point on the focal plane, and curves like a snake; the charge displacement curves 803 of the third embodiment of the present invention are all located above the displacement curve 801 of the target scene image point on the focal plane. This is due to the difference in the number of phases of the TDI CCD, however, the second and third embodiments of the present invention have lower charge transfer image shift and better imaging effect than the TDI CCD in the continuous transfer mode in the prior art.

Referring to fig. 9, fig. 9 is a schematic diagram illustrating a TDI CCD timing driving system in a continuous transfer mode according to an embodiment of the present invention.

The invention also provides a TDI CCD time sequence driving system under the continuous transfer mode, which comprises:

a signal acquisition unit 901 configured to acquire a line transfer signal; the line transfer signals comprise N trapezoidal wave periodic signals with the same waveform and the phases lagging by 360 DEG/N in sequence; in the 1 st trapezoidal wave periodic signal of the line transfer signal, the levels in the 1 st 1/2N period and the 2N 1/2N period are both high, the level in the 2 nd 1/2N period transitions from high to low, the level in the (2N-1) th 1/2N period transitions from low to high, and the levels in the remaining periods are all low; wherein N is an integer greater than 2;

and a timing driving unit 902 for driving the TDI CCD with the line transfer signal to vertically transfer charges to the horizontal shift register.

Referring to fig. 10, fig. 10 is an expanded view of a TDI CCD timing driving system in a continuous transfer mode according to an embodiment of the present invention.

Preferably, the system further comprises:

a charge isolating unit 1001 for converting a transmission gate driving signal TCK from a high level to a low level to isolate charges in the horizontal shift register;

a charge output unit 1002 for enabling a horizontal readout signal to quantize and output the charges in the horizontal shift register, and then converting the transfer gate driving signal TCK from a low level to a high level.

Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The TDI CCD timing driving method and system in the continuous transfer mode provided by the present invention are described in detail above, and the principle and the implementation of the present invention are explained in this document by applying specific examples, and the description of the above examples is only used to help understanding the method and the core idea of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.

Claims

1. A TDI CCD time sequence driving method in a continuous transfer mode is characterized by comprising the following steps:

driving the TDI CCD with the line transfer signal to vertically transfer charge to a horizontal shift register;

before the current 2 Nth 1/2N period, the transmission gate driving signal TCK is changed from low level to high level to isolate the charges in the horizontal shift register;

2. The method of claim 1, wherein N is 3.

3. The method of claim 1, wherein N is 4.

4. The method according to claim 1, wherein the period of each trapezoidal wave periodic signal is T ═ v · b;

5. The method of claim 1, wherein the level transitions in each trapezoidal wave periodic signal are linear transitions.

6. The method of claim 1, wherein the level transitions in each trapezoidal wave periodic signal are arc transitions.

7. A TDI CCD timing driving system in a continuous transfer mode is characterized by comprising:

the time sequence driving unit is used for driving the TDI CCD by adopting the line transfer signal so as to vertically transfer charges to the horizontal shift register;