WO2005122555A1

WO2005122555A1 - Operation of imaging-sensing unit and imaging-sensing device with the same

Info

Publication number: WO2005122555A1
Application number: PCT/CN2004/001410
Authority: WO
Inventors: Cheng-Hsiao Lai; Ya-Chin King; Yueh-Ping Yu
Original assignee: Via Technologies, Inc.
Priority date: 2004-06-09
Filing date: 2004-12-03
Publication date: 2005-12-22
Also published as: BRPI0418823B1; RU2006141414A; BRPI0418823A; RU2352080C2

Abstract

An operation of an imaging-sensing unit and the imaging-sensing device with the same are disclosed.The imaging-sensing unit comprises a photogate, a photodiode with the photogate, and a first switch.The operation comprises the following steps.(a) Exerting a first voltage on the photogate.(b) Turning on a first switch.(c) Turning off the first switch in a first time.(d) Stopping exerting a first voltage on the photogate in a second time.(e) The photodiode being lighting by à light.(f) Exerting a second voltage on the photogate in a third time.(g) Maintaining the turn-off-state of the first switch until a fourth time.The operation of an imaging-sensing unit can make the imaging-sensing device with the same extend its dynamic range.

Description

Method for operating image sensing unit and image sensing device using the same

The invention relates to an operation method of an image sensing unit and an image sensing device using the same, and particularly to an operation method of an image sensing unit capable of increasing the dynamic range of the image sensing unit and an image sensing using the same.测装置。 Testing device. Background technique

More and more electronic products have built-in photography functions, such as mobile phones, personal digital assistants (PDAs), and toys. Coupled with the rapid advancement of electronic technology, image sensors have gradually replaced traditional negatives and become the main image sensor. The function of the image sensor is to convert the optical signal into an electronic signal. At present, many image sensors on the market are built-in photodiodes for capturing light signals.

FIG. 1 is a circuit diagram of a conventional image sensor. Please refer to FIG. 1. The image sensor 100 includes a reference voltage V, a photodiode 120, a first switch 130, a source follower 140, a second switch 180, and a memory circuit 160. The first switch 130, the source follower 140, and the second switch 180 may be transistors (transistors are transistors, and are hereinafter referred to as transistors). The photodiode 120 and the source follower 140 are both electrically coupled to the first switch 130. Both the diode 120 and the source follower 140 are electrically coupled to the reference voltage V _cc . A first switch 1 30 disposed between the diode 120 and the reference voltage V _M. In addition, the gate of the source follower 140 is electrically coupled between the first switch 130 and the photodiode 120. The memory circuit 160 of the image sensor 100 is used to record the output voltage V of the second switch 180. _ut changes this output voltage V. _{ut is} proportional to the voltage of the gate of the source follower 140. The operation flow of the image sensor 100 will be described in detail as follows.

FIG. 2 is a schematic diagram showing a change in the output voltage of FIG. 1 during an operation period of the image sensor. Please refer to FIG. 1 and FIG. 2 at the same time. At the beginning of the operation cycle, the switch 130 is first turned on. The voltage V on the photodiode 120 and the voltage on the gate of the source follower 140 will be equal to the reference voltage V. Then the switch 1 30 is cut off at the first time T _{1 5} , and the external light 150 passes through the lens ( (Not shown) is irradiated on the photodiode 120. The photodiode 120 generates a pho to current due to the irradiation of the light 150, causing the voltage V of the photodiode 120 to decrease. The voltage of the gate of the source follower 140 The following also follows. Among them, the output voltage V. _ut also changes as the gate voltage of the source follower 140 changes. Then, at the second time T ₂ , the first switch 1 30 is turned on again to start Another new cycle. The output voltage V. _ut at the first time T, and the output voltage V. _{u at the} second time T ₂ will be recorded in the memory circuit 160, and the difference between the two will be used for image sensing. The device 100 can determine the intensity of the external light 150.

Please continue to refer to FIG. 1 and FIG. 2, we can find that when the intensity of the external light 150 increases, Strong, output voltage v. _The faster the value of _ut decreases. When the output voltage v. _{ut drops to} before the second time t ₂

At 0, the image sensor 100 can no longer determine the intensity of the external light 150. Therefore, the dynamic range of the image sensor 100 has an upper limit (dynamic range = maximum light intensity that can be sensed by the image sensor / minimum light intensity that can be sensed by the image sensor).

It can be seen that there are obviously inconveniences and defects in the operation method and use of the existing image sensing unit and the image sensing device using the same, and further improvement is urgently needed. In order to solve the problems of the operation method of the image sensing unit and the image sensing device using the same, the relevant manufacturers have made every effort to find a solution, but for a long time no applicable design has been developed and the general operation method And the image sensing device using it does not have a proper operation method and structure that can solve the above problems, which is obviously a problem that related industry is anxious to solve.

In view of the defects existing in the above-mentioned operation method of the existing image sensing unit and the image sensing device using the same, the inventor is based on many years of rich practical experience and professional knowledge in the design and manufacture of such products, and cooperates with the application of science, Actively carry out research and innovation, with a view to creating a new method for operating the image sensing unit and an image sensing device using the same, which can improve the existing method of operating the image sensing unit and the image sensing device using the same, so that It is more practical. After continuous research, design, and repeated trials and improvements, the invention has finally been created with practical value. Summary of the invention

The purpose of the present invention is to overcome the defects in the existing method of operating an image sensing unit and provide a new method of operating an image sensing unit. The technical problem to be solved is to make it possible to add an image sensing unit The dynamic range and the sensitivity of the image sensing unit are taken into consideration, so that it is more suitable for practical use.

Another object of the present invention is to overcome the shortcomings of the existing image sensing device and provide a new structured image sensing device. The technical problem to be solved is to increase the dynamic range of the image sensing unit and Considering the sensitivity of the image sensing unit, it is more suitable for practical use.

The object of the present invention and the solution of its technical problems are achieved by using the following technical solutions. According to the present invention, an operation method of an image sensing unit is provided. The image sensing unit includes: a photogate, a photodiode combined with the photogate, and a first switch. The other end is connected to the photodiode, and the operation method includes the following steps: applying a first voltage value to the photogate; turning on the first switch; cutting off the first switch at a first time; Time, reducing the voltage value applied to the photocell; increasing the voltage value applied to the photogate at a third time; and maintaining the first switch off for a fourth time.

The objective of the present invention and its technical problems can be further achieved by using the following technical measures. The foregoing method of operating the image sensing unit further includes the following possible changes: at the second time, stopping applying the first voltage value to the photogate; and at the third time, applying a second The voltage is at the photogate.

The operation method of the image sensing unit is to adjust the second voltage value to be equal to the first voltage value.

The foregoing method of operating the image sensing unit is to adjust the voltage applied to the photogate from the first voltage value to a third voltage value at the second time, where the third voltage value is less than the first voltage value.

The foregoing method of operating the image sensing unit is to adjust the voltage applied to the photoelectric cell from the third voltage value to a second voltage value at the third time, where the second voltage value is greater than the third voltage value. Voltage value.

The foregoing operation method of the image sensing unit further includes the following possible changes: adjusting the fourth time to change the dynamic sensing range of the image sensing unit; and increasing the interval between the fourth time and the third time To reduce the range of dynamic 'j.

The aforementioned method of operating the image sensing unit further includes the following possible changes: adjusting the first voltage value to change the maximum light sensing measurement of the image sensing unit; and increasing the maximum light by increasing the first voltage value Sense measurement.

The object of the present invention and its technical problems are also achieved by the following technical solutions. An image sensing device according to the present invention includes: an image sensing unit including: a photogate; a photodiode combined with the photogate; a first switch, a first of the first switch Terminal is connected to a reference voltage, the second terminal of the first switch is connected to one end of the photodiode; a source follower, the first terminal of the source follower is connected to the reference voltage, and the source follower The control terminal is connected to the other end of the photodiode; and a second switch, the first end of the second switch is connected to the second end of the source follower, and the second end of the second switch outputs an output voltage; And a control circuit is coupled to the image sensing unit, and the control circuit can apply different voltage values to the first switch, the photodiode and the second switch, respectively.

The objective of the present invention and its technical problems can be further achieved by using the following technical measures. In the foregoing image sensing device, the control circuit may apply different voltage values to the first switch, the photodiode, and the second switch at different times.

In the foregoing image sensing device, the control circuit may sequentially adjust respective voltage values of the first switch, the photodiode, and the second switch in the following steps: applying a first voltage value to the photoelectric alarm, and Turn on the first switch; cut off the first switch at a first time and start to let the photodiode be illuminated by light; stop applying the first voltage value to the photogate at a second time; at a third time A second voltage value is applied to the photogate at a time, and the first switch is kept off until a fourth time, and the second switch is turned on at the same time to output the output voltage.

In the aforementioned image sensing device, the control circuit generally makes the first voltage equal to the second voltage, but does not limit the relationship between the first voltage and the second voltage and the reference voltage. In the aforementioned image sensing device, the control circuit can adjust at least one of the following: the fourth time, the interval between the fourth time and the third time, the first voltage value, and the second voltage value.

In the aforementioned image sensing device, the first switch is a transistor, the source follower is a transistor, and the second switch is a transistor.

Compared with the prior art, the present invention has obvious advantages and beneficial effects. It can be known from the foregoing technical solutions that, in order to achieve the foregoing object of the present invention, the main technical contents of the invention are as follows:

The invention provides a method for operating an image sensing unit. The image sensing unit includes a photogate, a photodiode combined with a photogate, and a first switch. One end of the first switch is connected to a reference voltage and the other end is connected to the light. diode. The operation method of the image sensing unit includes the following steps: (a) applying a first voltage value to the photogate. (B) Turn on the first switch. (C) Turn off the first switch at the first time. (D) Begin to expose the photodiode to light. (E) At the second time, decrease the voltage value applied to the photo-gate. (F) At the third time, increase the voltage value applied to the photogate. (G) Keep the first switch off until the fourth time.

The present invention further provides an image sensing device, which includes an image sensing unit and a control circuit. The image sensing unit includes a photogate, a photodiode, a first switch, a source follower, and a second switch. The photodiode and the photogate are combined with each other. The first terminal of the first switch is connected to the reference voltage, and the second terminal of the first switch is connected to one end of the photodiode. The first terminal of the second switch is connected to the reference voltage, and the control terminal of the source follower is connected to the other end of the photodiode. The first terminal of the second switch is connected to the second terminal of the source follower, and the second terminal of the second switch outputs an output voltage.

The control circuit of the image sensing device is coupled to the image sensing unit. The control circuit applies a first voltage value to the photogate and turns on the first switch. Then, the first switch is turned off at the first time. The photodiode can then be exposed to light. Then, the application of the first voltage value to the photogate is stopped at the second time. After that, a second voltage value is applied to the photogate at a third time. And, the interruption of the first switch is maintained to the fourth time. At the same time, the second switch is turned on to output the output voltage.

It can be known from the foregoing that the present invention relates to an operation method of an image sensing unit and an image sensing device using the same. The image sensing unit includes a photogate, a photodiode of a combined photogate, and a first switch. One end of the first switch is connected to the reference voltage, and the other end is connected to the photodiode. The operation method includes the following steps: (a) Applying a first voltage value to the photogate. (B) Turn on the first switch. (C) At the first time, cut off the first switch. (D) Expose the photodiode to light. (E) At the second time, stop applying the first voltage value to the photogate. (F) At the third time, a second voltage value is applied to the photogate. (G) Keep the first switch off until the fourth time. Such an operation method of the image sensing unit allows the image sensing device using the same to have a larger dynamic sensing range.

In summary, the special operation method of the image sensing unit of the present invention can increase the dynamic range of the image sensing unit and take into account the sensitivity of the image sensing unit. Special structure image of the present invention The sensing device can increase the dynamic range of the image sensing unit and take into account the sensitivity of the image sensing unit. It has many of the above advantages and practical values. It is indeed an innovation without similar publication or use of similar designs in similar methods. It has been greatly improved in terms of operation methods and functions. Great progress, and has produced useful and practical effects, and has more improved functions than the existing method of operating the image sensing unit and the image sensing device using it, so it is more suitable for practical use, and has The extensive use value of the industry is a new, progressive and practical new design.

The above description is only an overview of the technical solution of the present invention. In order to understand the technical means of the present invention more clearly, it can be implemented in accordance with the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more comprehensible. The following is a detailed description of a preferred embodiment in conjunction with the accompanying drawings: ¾ 口口。 Brief description of the drawings

FIG. 1 is a circuit diagram of a conventional image sensor.

FIG. 2 is a schematic diagram of changes in the output voltage of FIG. 1 during the operation period of the image sensor.

FIG. 3 is a schematic diagram of an image sensing device according to a preferred embodiment of the present invention.

Figure 4 is a graph of the relationship between reset voltage and photogate voltage versus time.

FIG. 5 is a diagram illustrating the relationship between output voltage and time under different light intensities according to a preferred embodiment of the present invention, and FIG. 6 is a schematic diagram of a potential well of a photodiode.

Fig. 7 is to adjust the dynamic range of the image sensor by changing the difference between the fourth time and the third time. Fig. 8 is to adjust the dynamic range of the image sensor by changing the voltage of the photogate.

100 image sensor 120 photodiode

1 30 First switch 140 source follower

142 gate 150 light

160 memory circuit 180 second switch

Vout two output voltage V ^T cc · · Reference voltage

First time T ₂ : Second time

200: Image sensing device 210: Image sensing unit

212: Photodiode 212a: n-type doped region

212b: p-well 220: control circuit

230: Ji Yi circuit Ml: first switch

Μ2: Source follower M3: Second switch

Mia, M2a M3a: first end Mlb, M2b M3b: second end

PG: Photogate RST, Se l, M2c: Control terminal

V. _ut : output voltage V _cc : reference voltage

t,: first time: second time t ₃ : third time t ₄ : fourth time

CpD, CpG: the best way to achieve invention

In order to further explain the technical means and effects adopted by the present invention to achieve the intended purpose of the present invention, an operation method of an image sensing unit according to the present invention and image sensing using the same are described below with reference to the drawings and preferred embodiments The specific implementation manners, operation methods, steps, structures, features, and functions of the device are described in detail below.

FIG. 3 is a schematic diagram of an image sensing device according to a preferred embodiment of the present invention. Please refer to FIG. 3, an image sensing device 200 includes an image sensing unit 210, a control circuit 220 and a memory circuit 230. The image sensing unit 210 includes a photogate PG, a photodiode 212, a first switch M1, a source follower M2, and a second switch M3. The photodiode 212 may be, for example, a metal-oxide semiconductor, which is combined with the photogate PG, so that two ends of the photodiode 212 are located on two sides of the photogate PG, respectively. The first terminal Mia of the first switch M1 is connected to the reference voltage V. The second terminal Mlb of the first switch M1 is connected to one end of the photodiode 212. The first terminal M2a of the source follower M2 is connected to the reference voltage V, the source The control terminal M2c of the electrode follower M2 is connected to the other end of the photodiode 212. The first terminal M3a of the second switch M3 is connected to the second terminal M2b of the source follower M2, and the second terminal M3b of the second switch M3 outputs a output voltage V. _llt. it should be noted that the first switch Ml, M2 source tracking device and a second switch M3, for example, may be a transistor.

FIG. 4 is a relationship diagram of reset voltage and photogate voltage with time. Please also refer to FIG. 3 and FIG. 4, the control circuit 200 of the image sensing device 220 coupled to the image sensing unit ^210. The control circuit 220 applies a first voltage value VI to the photoelectric alarm PG. Next, the control circuit 220 applies a reset voltage V _RST to the control terminal RST of the first switch M1 to turn on the first switch M1. Then, the application of the reset voltage V _{RST is} stopped at the first time to turn off the first switch M1. At the same time, the memory circuit 230 records the output voltage V at the first time. The value of _ut . After that, the external light (not shown) starts to shine on the photodiode 212, and the voltage V is output. The value of _ut also started to decrease. Then, the control circuit 220 stops applying the first voltage value VI to the photo gate PG at the second time t ₂ . After that, at a third time t _{3, the} control circuit 220 applies a second voltage value V2 to the photogate PG. The second voltage value V2 is substantially equal to the first voltage value VI, but both the first voltage VI and the second voltage V2 may be equal to V ′ or not equal to V _cc . In addition, the control circuit 220 maintains the cutoff of the first switch M1 to At the same time at the fourth time, the control circuit 220 turns on the second switch M3 to output the output voltage V. _ut . At this time, the memory circuit 230 records the output voltage V. _{ut at the} fourth time t _4. By this, the memory circuit 230 records the first output voltage V. _ut fourth time t and the time difference between the output voltage V. _ut _4, the image sensing apparatus 200 may determine the intensity of ambient light.

FIG. 5 illustrates the relationship between output voltage and time under different light intensities according to a preferred embodiment of the present invention. Please refer to FIG. 3 and FIG. 5 at the same time, the control circuit 220 cuts off the light at the second time t ₂ The voltage of the gate PG is restored to the voltage at the third time t ₃ . We can find that the stronger the light intensity, the faster the output voltage decreases. Moreover, after the third time t ₃ , the output voltage is significantly increased, and the reason will be discussed in more detail below.

FIG. 6 is a schematic diagram of a potential well as a photodiode. Please refer to FIG. 6, when the photogate PG is not supplied with voltage, there is a capacitor C _PD between the n-type doped region 212 a and the p-type well 212 b. When voltage is applied to the photogate PG, an inversion layer is generated under the p-well 212b relative to the photogate. In this way, in addition to the capacitor C _PD , the photodiode 212 also has a capacitor C _Pe . Because these capacitors C _PD and C _P 々 exist, a potential well (potent ia l-energy wel 1) will be generated in the p-type well 212b, and some of the electrons generated when the external light is irradiated will be stored here.

Please refer to FIG. 5 and FIG. 6 at the same time. When the light intensity is stronger, the output voltage decreases faster. The reason for this phenomenon is that the stronger the light intensity is, the higher the generation rate of electrons is, and the voltage of the n-type doped region 212a is lowered, which causes the output voltage value to decrease. When the photogate voltage is cut off at the second time t ₂ , the capacitance decreases from C _PD + C _re to C _PD , and the electrons below the capacitance C _{P (;} will run below the capacitance C _PD . If the capacitance is C _PD + C _P † When the number of stored electrons is greater than the maximum number of electrons that can be stored when the capacitor is C _PD , the excess electrons are discharged through the ground terminal. When the photovoltaic cell is re-energized at the third time t ₃ , the output voltage increases . This is because the voltage applied to the gate of the photoelectric joint region of the n-type doped 212a voltage is increased, and the number of electrons in this case has a second time t ₂ is also less than the cut off before the photo gate voltage is caused.

FIG. 7 illustrates adjusting the dynamic range of the image sensor by changing the difference between the fourth time and the third time. Please also refer to FIG. 6 and FIG. 7, through experimental measurements, it can be found that when the difference between the fourth time t ₄ and the third time ₁₃ is increased, the dynamic range would be reduced. The main reason is that the larger the difference between the fourth time t ₄ and the third time t ₃ is, the longer the time of light irradiation causes the output voltage at the fourth time t ₄ to decrease.

Figure 8 adjusts the dynamic range of the image sensor by changing the voltage of the photogate. Please refer to FIG. 5 and FIG. 8 at the same time. According to the experimental measurement results, as the voltage value applied to the photogate increases, the dynamic range of the image sensor also increases. Because, the output voltage at the first time increases as the voltage value of the photogate increases. Moreover, the output voltage picks up at the third time.

It is worth noting that the photodiode of the image sensor of the present invention is not limited to a metal oxide semiconductor. Other diodes with photogates do not depart from the scope of the invention. In addition, in the above embodiments, the second voltage value is usually equal to the first voltage value, but both the first voltage value and the second voltage value may be equal to the reference voltage V or not equal to the reference voltage ^. In addition, The control circuit can also apply a third voltage value to the photogate at the second time, and it is not necessary to cut off the voltage. As long as the third voltage value is smaller than the first voltage value and the second voltage value, the image sensor can reach Type effect.

In summary, in the image sensing device of the present invention, the control circuit stops applying the first voltage value to the photogate or reduces the voltage of the photogate to a specific voltage lower than the first voltage value at a second time. . After that, the control circuit applies a second voltage value to the photogate or allows the This particular voltage of the voltage of the photogate rises to a second voltage value. These steps can increase the output voltage value, so the dynamic range of the image sensing unit can be increased. In addition, the dynamic range of the image sensor can be increased by changing the difference between the fourth time and the third time. Moreover, the same effect can be achieved by adjusting the voltage of the photogate.

The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Although the present invention has been disclosed as above with the preferred embodiments, they are not intended to limit the present invention. A technician, without departing from the scope of the technical solution of the present invention, can use the disclosed method and technical content to make a few changes or modifications to equivalent equivalent embodiments. However, without departing from the technical solution of the present invention, Any simple modifications, equivalent changes, and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention. Industrial applicability

With the above technical solution, the method for operating the image sensing unit of the present invention and the image sensing device using the same have at least the following advantages:

In the method of operating the image sensing unit of the present invention and the image sensing device using the same, the application of the first voltage value to the photogate is stopped at the second time. After that, a second voltage value is applied to the photogate at a third time. These steps can increase the charge capacity and further increase the output voltage value, so the dynamic range of the image sensing unit can be increased.

In the image sensing device of the present invention, the control circuit stops applying the first voltage value to the photogate or reduces the voltage of the photogate to a specific voltage lower than the first voltage value at a second time. After that, the control circuit applies a second voltage value to the photogate at a third time or allows the specific voltage of the photogate voltage to rise to the second voltage value. These steps can increase the output voltage value, so the dynamic range of the image sensing unit can be increased. In addition, the dynamic range of the image sensor can be increased by changing the difference between the fourth time and the third time. Moreover, the same effect can be achieved by adjusting the voltage of the photogate.

Claims

Rights request

1. An operating method of an image sensing unit, the image sensing unit includes: a photogate, a photodiode combined with the photogate, and a first switch, one end of the first switch is connected to a reference voltage, and the other end is connected To the photodiode, the operation method is characterized in that it includes the following steps: applying a first voltage value to the photogate;

Turn on the first switch;

Cut off the first switch at a first time;

At a second time, reducing the voltage value applied to the photogate;

Increasing the voltage value applied to the photogate at a third time; and

The interruption of the first switch is maintained until a fourth time.

2. The method for operating an image sensing unit according to claim 1, further comprising the following possible changes:

At the second time, stopping applying the first voltage value to the photoelectric cell; and

At the third time, a second voltage value is applied to the photogate.

3. The method of operating an image sensing unit according to claim 2, wherein the second voltage value is adjusted to be equal to the first voltage value.

4. The method of operating an image sensing unit according to claim 1, wherein at the second time, the voltage applied to the photogate is adjusted from the first voltage value to a third voltage value, wherein The third voltage value is smaller than the first voltage value.

5. The method of operating an image sensing unit according to claim 1, wherein at the third time, the voltage applied to the photogate is adjusted from the third voltage value to a second voltage value, The second voltage value is greater than the third voltage value.

6. The method for operating an image sensing unit according to claim 1, further comprising the following possible changes:

Adjusting the fourth time to change the dynamic sensing range of the image sensing unit; and reducing the dynamic sensing range by increasing the interval between the fourth time and the third time.

7. The method for operating an image sensing unit according to claim 1, further comprising the following possible changes:

Adjusting the first voltage value to change the maximum light sensing measurement of the image sensing unit; and increasing the maximum light sensing measurement by increasing the first voltage value.

8. An image sensing device, comprising:

An image sensing unit includes:

A photogate

A photodiode combined with the photogate;

A first switch, the first end of the first switch is connected to a reference voltage, and the first switch The second end of the switch is connected to one end of the photodiode;

A source follower, a first end of the source follower is connected to the reference voltage, and a control end of the source follower is connected to the other end of the photodiode; and

A second switch, the first end of the second switch is connected to the second end of the source follower, and the second end of the second switch outputs an output voltage; and

A control circuit is coupled to the image sensing unit, and the control circuit can apply different voltage values to the first switch, the photodiode, and the second switch, respectively.

9. The image sensing device according to claim 8, wherein the control circuit can apply different voltage values to the first switch, the photodiode, and the second switch at different times.

10. The image sensing device according to claim 8, wherein the control circuit can sequentially adjust respective voltage values of the first switch, the photodiode, and the second switch in the following steps:

Applying a first voltage value to the photogate and turning on the first switch;

Interrupting the first switch at a first time and starting to expose the photodiode to light; stopping applying the first voltage value to the photogate at a second time;

Applying a second voltage value to the photogate at a third time, maintaining the first switch off for a fourth time, and turning on the second switch to output the output voltage.

11. The image sensing device according to claim 9, wherein the control circuit generally makes the first voltage equal to the second voltage, but does not limit both the first voltage and the second voltage And the reference voltage.

12. The image sensing device according to claim 9, wherein the control circuit can adjust at least one of the following: the fourth time, an interval between the fourth time and the third time, and a first voltage Value and the second voltage value.

13. The image sensing device according to claim 8, wherein the first switch is a transistor, the source follower is a transistor, and the second switch is a transistor.