CN112887571B

CN112887571B - Image sensor, camera module and electronic equipment

Info

Publication number: CN112887571B
Application number: CN202110115174.2A
Authority: CN
Inventors: 李沛德; 刘庚龙
Original assignee: Vivo Mobile Communication Co Ltd
Current assignee: Vivo Mobile Communication Co Ltd
Priority date: 2021-01-27
Filing date: 2021-01-27
Publication date: 2022-06-10
Anticipated expiration: 2041-01-27
Also published as: CN112887571A

Abstract

The application discloses image sensor, module and electronic equipment make a video recording, including a plurality of pixel, the pixel includes: the light sensing component comprises a light sensing element, a first switch and a light filter corresponding to the sensed color, the light sensing element and the first switch are connected between a signal end and a grounding end in series, and a light emitting surface of the light filter faces the light sensing element; the reset circuit is connected between a power supply end and the grounding end, the reset circuit comprises a control module and a reset switch, and the output end of the control module is connected with the reset switch; an electrical energy storage circuit connected between the signal terminal and the ground terminal; the processing module is connected with the input end of the control module, and the structure of the image sensor can control the exposure capability of the pixel unit in one exposure process.

Description

Image sensor, camera module and electronic equipment

Technical Field

The application belongs to the technical field of photoelectricity, concretely relates to image sensor, camera module and electronic equipment.

Background

High-Dynamic Range (HDR) is a High Dynamic illumination rendering, which can provide more Dynamic Range and image details than a normal image, and is closer to the image seen by human eyes.

In the related art, the final HDR image is synthesized by combining an exposure fusion (exposure fusion) algorithm according to low dynamic range images with different exposure times, so that the finally synthesized HDR image better reflects the visual effect in the real environment.

In the process of implementing the application, the inventor finds that the following problems exist in the prior art, and in the process of taking a picture by a mobile terminal user, the HDR mode has large exposure difference of captured frames, so that the difficulty of an exposure fusion algorithm is high, and the alignment of multiple frames is not easy to make, thereby causing the problem of image distortion.

Disclosure of Invention

The present application is directed to an image sensor, a camera module and an electronic device, which solve at least one of the problems mentioned in the background.

In order to solve the technical problem, the present application is implemented as follows:

in a first aspect, an embodiment of the present application provides an image sensor, which includes a plurality of pixel units, where each pixel unit includes:

the light sensing component comprises a light sensing element, a first switch and a light filter corresponding to the sensed color, the light sensing element and the first switch are connected between a signal end and a grounding end in series, and a light emitting surface of the light filter faces the light sensing element;

the reset circuit is connected between a power supply end and the grounding end, the reset circuit comprises a control module and a reset switch, and the output end of the control module is connected with the reset switch;

an electrical energy storage circuit connected between the signal terminal and the ground terminal;

the processing module is connected with the input end of the control module;

the processing module sends a forced emptying signal to the control module at a set time within a first exposure time length;

and the control module controls the reset switch to be conducted to enable the photosensitive element to be in an emptying state under the condition of receiving the forced emptying signal.

In a second aspect, an embodiment of the present application provides a camera module, which includes:

a circuit board;

an image sensor electrically connected to the circuit board, the image sensor being the image sensor according to the second aspect; and the number of the first and second groups,

the lens is arranged on one side, far away from the circuit board, of the image sensor.

In a third aspect, an embodiment of the present application provides an electronic device, which includes a camera module, where the camera module is the camera module according to the third aspect.

In this embodiment, the pixel unit of the image sensor includes a reset circuit and a processing module, the reset circuit includes a control module and a reset switch, the processing module sends a forced clearing signal to the control module at a set time within the first exposure duration, and the control module controls the reset switch to be turned on to enable the photosensitive element to be in a clearing state and restart exposure when receiving the forced clearing signal. That is, in the present embodiment, the exposure capability of the pixel unit can be controlled during one exposure.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic structural diagram of a pixel unit according to an embodiment of the present invention;

FIG. 2 is a schematic top view of a pixel unit shown in FIG. 1;

fig. 3 is a schematic diagram illustrating an arrangement structure of pixel units of an image sensor according to an embodiment of the present invention;

FIG. 4 is a schematic circuit diagram of the pixel unit shown in FIG. 1;

fig. 5 is a schematic diagram of an arrangement structure of the camera module according to the embodiment of the present invention;

fig. 6 is a schematic structural diagram of another camera module according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of an electronic device according to an embodiment of the present invention.

Reference numerals:

10. 610-an image sensor; 11. 11a, 11b, 11 c-pixel cells; 111-a photosensitive component; 1111-a photosensitive element; 1112-an optical filter; 1113-spectroscope; 1114 — a first switch; 1115-a voltage judgment module; 1116-a reset switch; 1117-counting module; 1118-a control module; 1119-processing module; 112-electrical energy storage circuitry; vs-signal terminal; VDD-power supply terminal; GND-ground; RST-reset switch; SF-source follower; SET-select switch; vout-signal output; 600-a camera module; 620-lens; 630-a circuit board; 640-an optical filter; 650-a motor; 660-a base; 670-a protective film; 700-electronic device.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention. 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 application.

The features of the terms first and second in the description and in the claims of the present application may explicitly or implicitly include one or more of such features. Further, "and/or" in the specification and claims means at least one of the connected objects.

In the description of the present invention, it is to be understood that the terms "center", "row direction", "column direction", "upper", "lower", "outer periphery", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the term "connected" is to be interpreted broadly, e.g. as a fixed connection, a detachable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The embodiment of the invention relates to an image sensor which is used as a component of a camera module and used for sensing optical signals and converting the optical signals into electric signals to be output so as to form image data.

The structure of an image sensor according to an embodiment of the present invention is described below with reference to fig. 1 to 5.

As shown in fig. 1, an image sensor 10 according to some embodiments of the present invention includes a plurality of pixel units 11. These pixel units 11 are arranged according to a set rule to form a pixel array, for example, a pixel unit 11a, a pixel unit 11b, a pixel unit 11c, and the like are included in the pixel array in this order. In this embodiment, one pixel unit 11 of the image sensor 10 corresponds to one pixel point of the acquired image, for example, the pixel unit 11a corresponds to one pixel point of the acquired image, the pixel unit 11b corresponds to one pixel point of the acquired image, and the pixel unit 11c corresponds to one pixel point of the acquired image.

The basic structure of a pixel unit 11 of the image sensor 10 will be described with reference to fig. 2 by taking the pixel unit 11 as an example.

As shown in fig. 2, the pixel unit 11 includes a photosensitive element 111, and the photosensitive element 11 may be any one of a red photosensitive element, a green photosensitive element and a blue photosensitive element. The Red light sensing component is used for sensing Red (Red, R) light signals, the Green light sensing component is used for sensing Green (Green, G) light signals, and the Blue light sensing component is used for sensing Blue (Blue, B) light signals. The red photosensitive assembly R includes a photosensitive diode and a red light filter covering the photosensitive diode, the green photosensitive assembly Gb includes a photosensitive diode and a green light filter covering the photosensitive diode, and the blue photosensitive assembly B includes a photosensitive diode and a blue light filter covering the photosensitive diode.

For example, as shown in fig. 3 and 5, the pixel units 11 are arranged according to a set rule to form a conventional RGB pixel array, wherein one pixel unit 11 includes one photosensitive element 111, that is, the photosensitive element 111 in the RGB pixel array may include a red photosensitive element R, a green photosensitive element Gb and a blue photosensitive element B, and the RGB pixel array may be a bayer pixel array shown in fig. 3 and 5.

The camera module shown in fig. 5 is a CMOS camera module. The CMOS camera module roughly comprises the following working procedures: the light signals are sensed by a large number of photosensitive diodes and converted into electric signals, the electric signals are amplified by an amplifying circuit, and the electric signals are subjected to analog-to-digital conversion by an analog-to-digital conversion circuit to form a digital signal matrix (namely an image). In this application embodiment, this module of making a video recording adopts roll up curtain formula exposure, adopts the line-by-line scanning mode to expose pixel array promptly, until all pixel points all are exposed.

The basic structure of the photosensitive element 111 of the pixel unit 11 is described below with reference to fig. 2 and 4.

As shown in fig. 2 and 4, the photosensitive assembly 111 includes a photosensitive element 1111, a first switch 1114 and a filter 1112 corresponding to the sensed color. The light sensing element 1111 and the first switch 1114 are connected in series between the signal terminal Vs and the ground terminal GND. The light-emitting surface of the optical filter 1112 faces the photosensitive element 1111, so that light transmitted through the optical filter 1112 can be incident on the photosensitive element 1111, and conversion from an optical signal to an electrical signal is realized.

The photosensitive element 1111 may be, for example, the above-described photodiode.

As shown in fig. 4, the image sensor 10 further includes a reset circuit, the reset circuit is connected between a power supply terminal VDD2 and a ground terminal GND, the reset circuit includes a control module 1118 and a reset switch 1116, and an output terminal of the control module 1118 is connected to the reset switch 1116.

The reset switch 1116 may be a CMOS switch.

As shown in fig. 4, the image sensor 10 further includes a processing module 1119, and the processing module 1119 is connected to an input of the control module 1118.

In this embodiment, the processing module 1119 sends a forced clear signal to the control module 1118 at a setting time within the first exposure duration, and the control module 1118 controls the reset switch 1116 to be turned on to enable the photosensitive element 1111 to be in a clear state when receiving the forced clear signal.

In this embodiment, the photosensitive component 111 in each pixel unit 11 in the pixel array may be provided with a reset circuit and a processing module, or the photosensitive component in any one or more pixel units 11 in the pixel array may be provided with a reset circuit and a processing module. For example, the photosensitive element 111 in the pixel unit 11 indicated by a gray frame in fig. 5 is provided with a reset circuit and a processing block, and the photosensitive elements 111 in the other pixel units 11 than the pixel unit 11 indicated by a gray frame are not provided with a reset circuit and a processing block. Of course, it is also possible that the photosensitive elements 111 in all the pixel units 11 in fig. 5 are provided with a reset circuit and a processing block.

In the prior art, due to the lens vignetting effect, when an object point far away from an optical axis is imaged, due to the existence of a diaphragm, a light beam capable of reaching an image plane is gradually narrowed, and as a result, an off-axis image point is gradually darkened, namely, the distribution of an image from the center to the edge is uneven and is not suitable for an actual shooting scene.

Illustratively, the plurality of pixel units 11 may form a 10 × 10 pixel array, that is, each row in the pixel array includes 10 pixel units, the 10 pixel units correspond to 10 pixel points of the captured image, each column also includes 10 pixel units, the 10 pixel units also correspond to 10 pixel points of the captured image, taking an exposure parameter of 1000 lux for light exposure of 1ms as an example, for a central pixel unit (5, 5), the light signal received by the lens is transmitted to the pixel unit by a percentage of one hundred, that is, the pixel value of the image captured by the central pixel unit (5, 5) is usually 1000, since the energy of the light signal transmitted by the lens to the edge pixel units is usually only 20% of the energy of the central pixel unit, resulting in the edge pixel units such as pixel unit (1, 1), pixel unit (1, 10), pixel unit (10, 1) and the pixel unit (10, 10) usually has a pixel value of only 200 for a pixel point of the acquired image. In this embodiment, the processing module 1119 of the central pixel unit (5, 5) calculates the time t for triggering the forced clearing signal to be 1 ms-20% +1 ms-0.8 ms according to the first exposure time duration 1ms and the transmission ratio 20%, that is, the processing module 1119 sends the forced clearing signal to the control module 1118 of the central pixel unit (5, 5) at 0.8ms after the first exposure time duration 1ms starts, and the control module 1118 controls the reset switch 1116 to be turned on when receiving the forced clearing signal, so that the photosensitive element 111 of the central pixel unit (5, 5) is in a clearing state, that is, the photosensitive element 111 of the central pixel unit (5, 5) is exposed for only 0.2ms, and finally, the pixel value of the pixel point of the image acquired by the central pixel unit (5, 5) is 200, that is, by controlling the exposure capability of the central pixel unit (5, 5), the pixel values of the pixel points of the image collected by the central pixel units (5, 5) can be the same as the pixel values of the pixel points of the image collected by the edge pixel units. Of course, the exposure capability of other pixel units in the pixel array can be controlled, so that the pixel values of the pixel points of the whole image are the same, the whole image is uniformly distributed, and the whole image is the same as the actual shooting scene.

Of course, it is also possible to control the color of the light signal sensed by the pixel unit by controlling the exposure capability of the pixel unit. For example, the sensing component 1111 of the pixel unit 11 is a red sensing component, that is, the sensing color corresponding to the sensing component 1111 is red, and usually, the color ratio of the captured image is different from the color ratio of the image perceived by human eyes, for example, the digital signal value of red in the color ratio of the captured image is different from the digital signal value of red in the color ratio of the image perceived by human eyes, for example, the digital signal value of red perceived by human eyes is 800, and the digital signal value of red captured is 1000, since the corresponding exposure parameter is 1ms of light exposure of 1000 lux, in order to make the digital signal value of red in the color ratio of the captured image and the digital signal value of red perceived by human eyes be the same, that is, the processing module 1119 of all red pixel units is 0.2ms after the first exposure time length is 1ms, a forced emptying signal is sent to the corresponding control module 1118, and when the control module 1118 receives the forced emptying signal, the corresponding reset switch 1116 is controlled to be turned on so that the corresponding photosensitive element 111 is in an emptying state, that is, the photosensitive elements 111 of all the red pixel units are exposed for only 0.8ms, and finally, the pixel value of the red pixel point of the image acquired by all the red pixel units is 900, that is, the color ratio of the photographed image is the same as the color ratio of the image sensed by human eyes by controlling the exposure capability of all the red pixel units.

In this embodiment, the pixel unit of the image sensor includes a reset circuit and a processing module, where the reset circuit includes a control module and a reset switch, the processing module sends a forced clearing signal to the control module at a set time within the first exposure duration, and the control module controls the reset switch to be turned on to enable the photosensitive element to be in a clearing state and restart exposure when receiving the forced clearing signal. That is, in the present embodiment, during one exposure, the exposure capability of the pixel unit may be controlled, so as to make the pixel values of the respective pixel points in the finally presented image the same, or make the color ratio of the captured image the same as the color ratio of the image perceived by the human eyes, thereby improving the image quality.

In some embodiments, as shown in fig. 4, the pixel unit 11 further includes a voltage determining module 1115 and a counting module 1117.

In this embodiment, a first input terminal of the voltage determining module 1115 is connected to a first terminal of the photosensitive element 111, a second input terminal of the voltage determining module 1115 is connected to a second terminal of the photosensitive element 111, an input terminal of the counting module 1117 is connected to a first output terminal of the voltage determining module 1115, and a second output terminal of the voltage determining module 1115 is connected to the reset switch 1116.

In this embodiment, the photosensitive component 111 in each pixel unit 11 in the pixel array may be provided with a reset circuit and a counting module, or the photosensitive component in any one or more pixel units 11 in the pixel array may be provided with a reset circuit and a counting module. For example, the photosensitive element 111 in the pixel unit 11 indicated by a gray frame in fig. 5 is provided with the reset circuit and the counting block, and the photosensitive elements 111 in the other pixel units 11 except for the pixel unit 11 indicated by a gray frame are not provided with the reset circuit and the counting block. Of course, it is also possible that the photosensitive elements 111 in all the pixel units 11 in fig. 5 are provided with a reset circuit and a counting module.

In the related art, the final HDR image is synthesized by combining an exposure fusion algorithm according to low dynamic range images with different exposure times, so that the finally synthesized HDR image better reflects the visual effect in the real environment. However, in the process of taking a picture by a mobile terminal user in a scene with a large light ratio, the HDR mode has a large difficulty in exposure algorithm due to too large difference of captured frames, and multi-frame alignment is not easy to make, which causes the problem of image distortion.

In this embodiment, taking any of the light sensing units 11 as an example, for each sampling time within the first exposure time period, when the voltage across the light sensing element 111 reaches the set voltage threshold, the voltage comparison module 1115 controls the reset switch 11116 to be turned on so as to enable the light sensing element 1111 to be in the clear state, and the voltage comparison module 1115 controls the counting module to count once, so that the signal processing unit of the camera module obtains the light sensing digital value of the light sensing element 1111 within the first exposure time period according to the light sensing digital value of the light sensing element at the end of the first exposure time period and the counting result of the counting module at the end of the first exposure time period.

The voltage threshold set above may be the maximum voltage that can be borne by the photosensitive element 1111, may also be half of the maximum voltage that can be borne by the photosensitive element 1111, and may also be other values, which is not limited herein. For example, the exposure parameter is 1000 lux of light for 1ms, the maximum voltage that the photosensitive element 1111 can bear is 10V, in this case, the set voltage threshold may be 10V, or may be any value smaller than 10V, for example, the set voltage threshold may be 5V.

For example, for any pixel unit 11, taking exposure parameters as exposing 1000 lux of light for 1ms, the maximum voltage that the photosensitive element 1111 can carry is 10V, and the set voltage threshold is 5V, that is, the first exposure time period is 1ms, at this time, if the light intensity of the environment is 2000 lux, for example, at the 0.25ms in the first exposure time period, the voltage across the photosensitive element 1111 reaches the set voltage threshold, that is, the voltage across the photosensitive element 1111 is 5V, at this time, the voltage comparison module 1115 controls the reset switch 1116 to be turned on and to empty the photosensitive electrons in the photosensitive element 1111, and the exposure is restarted, and at the same time, the voltage comparison module 1115 controls the counting module 1117 to count for one time, at this time, i is 0+ 1.

At the 0.5ms in the first exposure period, the voltage across the photosensitive element 1111 reaches the set voltage threshold again, that is, the voltage across the photosensitive element 1111 is 5V, at this time, the voltage comparison module 1115 controls the reset switch 1116 to turn on and empty the photosensitive electrons in the photosensitive element 1111, and the exposure is restarted, and at the same time, the voltage comparison module 1115 controls the counting module 1117 to count once, where i is 0+1+1 — 2.

At the 0.75ms in the first exposure period, the voltage across the photosensitive element 1111 reaches the set voltage threshold again, that is, the voltage across the photosensitive element 1111 is 5V, at this time, the voltage comparison module 1115 controls the reset switch 1116 to turn on and empty the photosensitive electrons in the photosensitive element 1111, and the exposure is restarted, and at the same time, the voltage comparison module 1115 controls the counting module 1117 to count once, where i is 0+1+1+ 3.

At the end of the first exposure time duration 1ms, the signal processing unit of the camera module obtains a photoreception digital value of the photosensitive element within the first exposure time duration 1ms, namely 2000, according to the photoreception digital value 500 of the photosensitive element at the end of the first exposure time duration 1ms and a counting result 3 x 500 of the counting module 1117 at the end of the first exposure time duration 1 ms. That is, this time of exposure through first exposure duration, alright acquire all information of big optical ratio scene, need not multiframe synthesis, through later stage simple processing alright obtain high dynamic range image, compare in the mode of multiple exposure can effectually avoid the image dislocation, phenomenons such as moving object ghost promote final picture quality level and user experience of shooing.

In this embodiment, when the pixel unit 11 is provided with both the control module 1118 and the voltage determining module 1115, the priority of the control module 1118 may be higher than the priority of the voltage determining module 1115.

In some embodiments, as shown in fig. 2, the photosensitive component 111 may further include a beam splitter 1113, the beam splitter 1113 is disposed on the light incident surface of the corresponding optical filter 1112, and the beam splitter 1113 may converge the light, so that the light is projected onto the corresponding optical filter 1112, thereby increasing the light energy capable of being incident on the photosensitive component 111.

As shown in fig. 4, the pixel unit 11 may further include an electric energy storage circuit 112, and the electric energy storage circuit 112 is also connected between the signal terminal Vs and the ground terminal GND. The power storage circuit 112 includes a capacitor capable of storing power released by the photosensitive element 1111 for reading.

In this embodiment, taking a pixel unit 11 of the image sensor 10 as an example, the light sensing element 111 of the pixel unit 11 obtains light energy of a sensed color through one exposure, and converts the light energy into electric energy to be stored in the light sensing element 1111, when the pixel unit 11 is selected to read an electric signal of the pixel unit, the first switch 1114 of the light sensing element 111 may be controlled to be turned on, so that the corresponding light sensing element 111 releases the electric energy to the electric energy storage circuit 112 for storage, so as to be read.

For example, taking a pixel unit 11a of the image sensor 10 as an example, when the image sensor completes one exposure and selects to read the pixel unit, the first switch 1114 connected in series with the photosensitive element 111a may be controlled to be turned on, and at this time, the photosensitive element 111a converts red light energy to obtain electric energy, which may be transferred to the electric energy storage circuit 112 for reading.

In an embodiment of the application, the pixel unit of the image sensor includes a reset circuit, the reset circuit includes a voltage comparison module and a reset switch, for each sampling time within the first exposure duration, when the voltage across the photosensitive element reaches a set voltage threshold, the voltage comparison module controls the reset switch to be turned on so as to enable the photosensitive element to be in an empty state and restart exposure, and the voltage comparison module controls the counting module to count once, so that the signal processing unit of the camera module obtains the photosensitive digital value of the photosensitive element within the first exposure duration according to the photosensitive digital value of the photosensitive element at the end of the first exposure duration and a counting result of the counting module at the end of the first exposure duration. That is, in the present embodiment, only by one exposure, all information of a scene with a large optical ratio can be acquired, and multi-frame synthesis is not required, so that the photographing quality level can be effectively improved, and further, the image quality is improved.

In some embodiments, for the same pixel unit 11, in order to facilitate time-sharing reading of the electrical signals converted by the different photosensitive assemblies 111, as shown in fig. 4, the pixel unit 11 may further include a reset switch RST1, and the reset switch RST1 is connected between the power source terminal VDD1 and the signal terminal Vs. In this embodiment, the reset switch RST1 is turned off to read the photosensitive element 1111 of the pixel unit 11, and after the photosensitive element 1111 is read, the reset switch RST1 is turned on to reset the pixel unit 11.

In some embodiments, as shown in fig. 4, the pixel unit 11 may further include a source follower SF having a gate connected to the signal terminal Vs, a drain connected to the power supply terminal VDD3, and a selection switch SET connected between the source of the source follower SF and the output terminal Vout of the pixel unit 11. In this embodiment, the source follower SF may amplify the electrical signal of the signal end Vs, so as to improve the signal acquisition precision. In this embodiment, the selection switch SET may select the pixel unit 11 scanned each time when the image sensor 10 is scanned, and the selection switch SET may be a row selection switch or a column selection switch as needed, which is not limited herein.

For example, as shown in fig. 5, the selection switch SET is a row selection switch, and the row selection switch can select the pixel unit 11 of each scan.

The switches in the above embodiments, including the first switch 1114, the reset switch 1116, the selection switch SET, the source follower SF, etc., may be CMOS switches, or may be other types of switches, which is not limited herein.

Taking fig. 4 as an example, the exposure process provided according to the embodiment of the present application is as follows:

step S202, the switching tube RST1 and the switching tube TG are turned on, a voltage is applied to the negative electrode of the photodiode PD and the capacitor FD, the photodiode PD is reverse-biased, and the electron clearance in the photodiode PD and the capacitor FD returns to zero.

Step S204, the switching tube RST1 and the switching tube TG are turned off, the photodiode PD starts to sense and store energy (corresponding to the exposure start time), and a voltage difference starts to be generated between the two ends.

Step S205, the voltage judging module sends a reset signal to the control end of the switch tube RST2, the switch tube RST2 is conducted once, photoelectrons in the photodiode PD are reset, photosensitive energy storage (corresponding to reset time) is restarted from zero, and voltage difference begins to be generated at two ends; meanwhile, the voltage judging module sends a counting signal to the counting module, and the counting module counts for one time.

In step S206, the switching tube RST1 is turned on to empty the capacitor FD again, so as to avoid interference/coupling caused by current electrons generated in the electronic circuit.

In step S208, the switch RST1 is turned off, the switch TG is turned on, the switch SET is turned on (corresponding to the exposure end time), the energy of the photodiode PD is stored in the capacitor FD, and the terminal Vout outputs a voltage signal to the column amplifier corresponding to the pixel unit.

Finally, the voltage output from the terminal Vout is a voltage signal converted from the light signal sensed by the photodiode PD from the reset time to the exposure end time.

As shown in fig. 6, an embodiment of the present invention further provides a camera module 600, where the camera module 600 includes an image sensor 610, the image sensor 610 may be the image sensor 10 of any of the above embodiments, the camera module 600 further includes a lens 620 and a circuit board 630, the image sensor 610 is electrically connected to the circuit board 630, and a digital signal processor, an analog-to-digital converter and the like may be disposed on the circuit board 630, so as to convert an analog electrical signal output by the image sensor 610 into a digital signal through the analog-to-digital converter, and output the digital signal to the digital signal processor for signal processing, thereby obtaining image data. The lens 620 is disposed on a side of the image sensor 610 away from the circuit board 630, i.e., the light incident surface of the image sensor 610 faces the lens 620.

In order to improve the shooting performance of the camera module 600, the camera module 600 may further include an optical filter 640, where the optical filter 640 is disposed between the image sensor 610 and the lens 620, and is used for filtering out invisible infrared light and the like of human eyes when shooting in the daytime, so as to improve the effective resolution of the collected image and the reducibility of the collected image to colors, and further improve the quality of the collected image.

In some embodiments, the camera module 600 may further include a motor 650, and the motor 650 is connected to the lens 620 and is used for driving the lens 620 to move.

The camera module 600 can drive the lens 620 to move by controlling the motor 650, so as to realize automatic zooming.

In some embodiments, the camera module 600 may further include a base 660 for mounting the motor 650, so as to facilitate mounting of the motor 650.

In some embodiments, the camera module 600 may further include a protective film 670 disposed on the lens 620 to protect the lens 620 from damage.

For the image capturing module 600 of this embodiment, the pixel unit of the image sensor includes a reset circuit and a processing module, the reset circuit includes a control module and a reset switch, the processing module sends a forced clearing signal to the control module at a setting time within the first exposure duration, and the control module controls the reset switch to be turned on to enable the photosensitive element to be in a clearing state and restart exposure when receiving the forced clearing signal. That is, in the present embodiment, during one exposure, the exposure capability of the pixel unit may be controlled, so as to make the pixel values of the respective pixel points in the finally presented image the same, or make the color ratio of the captured image the same as the color ratio of the image perceived by the human eyes, thereby improving the image quality.

As shown in fig. 7, an embodiment of the present invention further provides an electronic device 700 including the camera module 600 according to any of the above embodiments.

For example, the electronic device 700 includes a housing having a light-transmissive portion. The camera module 600 may be disposed in the electronic device housing, and the lens 610 of the camera module 600 faces the light-transmitting portion, so that image capturing can be performed through the light-transmitting portion.

The electronic device may be any device having a camera function, for example, a mobile phone, a tablet computer, a notebook computer, a wearable device, and the like, which is not limited herein.

The foregoing embodiments have focused on the differences between corresponding and other embodiments, and reference may be made to the same or similar components in each embodiment.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An image sensor comprising a plurality of pixel cells, the pixel cells comprising:

the processing module is connected with the input end of the control module;

the processing module sends a forced emptying signal to the control module at a set moment in a first exposure duration;

2. The image sensor of claim 1, wherein the pixel cell further comprises a reset switch connected between the power terminal and the signal terminal.

3. The image sensor of claim 1, wherein the pixel cell further comprises a source follower having a gate connected to the signal terminal, a drain connected to the power terminal, and a selection switch connected between a source of the source follower and an output of the image sensor.

4. The image sensor of claim 1, wherein the pixel unit further includes a beam splitter disposed at the light incident surface of the corresponding filter.

5. The image sensor of claim 1, wherein the photosensitive element is any one of a red photosensitive element, a green photosensitive element, and a blue photosensitive element.

6. The image sensor of any of claims 1-5, wherein the photosensitive element is a photodiode.

7. The utility model provides a module of making a video recording which characterized in that includes:

a circuit board;

an image sensor electrically connected to the circuit board, the image sensor being according to any one of claims 1-6; and the number of the first and second groups,

8. The camera module of claim 7, wherein a digital signal processor and an analog-to-digital converter are disposed on a circuit board of the camera module.

9. An electronic device, comprising a camera module according to claim 7 or 8.