Patent ID: 12212860

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The following will be combined with the drawings in the embodiment of the present invention, the technical solution in the embodiment of the present invention is clearly and completely described, obviously, the described embodiment is a part of the embodiment of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary knowledge of the technical field without performing creative labor are within the scope of protection of the present invention.

FIG.1is a schematic diagram of the image sensor circuit architecture according to an embodiment of the present invention. The image sensor circuit100of the present invention comprises at least one pixel array120and a driver circuit110. The pixel array120is configured to sense light and generate image data, comprising multiple pixel circuit groups arranged in an array. Wherein, multiple distinct types of pixel circuit groups, such as the first pixel circuit group121, the second pixel circuit group122, the third pixel circuit group123, and the fourth pixel circuit group124, can be arranged in the form of a Bayer pixel array, each used to sense red, green, green, and blue. It should be understood that for the sake of illustration,FIG.1only shows one first pixel circuit group121, one second pixel circuit group122, one third pixel circuit group123, and one fourth pixel circuit group124. In practice, the pixel array120can comprise multiple first pixel circuit groups121, multiple second pixel circuit groups122, multiple third pixel circuit groups123, and multiple fourth pixel circuit groups124. On the other hand, the arrangement of each color pixel circuit group within a pixel circuit group is not limited to the order shown inFIG.1. In one embodiment, the output of distinct types of pixel circuit groups can be read out by a differential signal to increase the sensitivity and reduce noise of image sensing. For example, the first pixel circuit group121and the second pixel circuit group122can serve as one end of the differential readout circuit, such as the P-side, while the third pixel circuit group123and the fourth pixel circuit group124can serve as the other end of the differential readout circuit, such as the N-side. The output values of the pixel circuit groups can be processed through subsequent processing (not shown) to obtain the image data.

As shown inFIG.1, each of the pixel circuit groups contains a plurality of pixel circuits that are designed to generate corresponding light sensitivity values varied with exposure durations. For example, the first pixel circuit group121comprises a first quantity of first red pixel circuits Rs and a second quantity of second red pixel circuits Rd. Similarly, the second pixel circuit group122, the third pixel circuit group123, and the fourth pixel circuit group124also correspondingly comprise first green pixel circuits Gs, second green pixel circuits Gd, first blue pixel circuits Bs, and second blue pixel circuits Bd, operated analogously. Therefore, for the sake of clarity, the following embodiment only describes the first pixel circuit group121as an example.

The driver circuit110is coupled to the pixel array120for driving the pixel circuit group, and includes at least a first control circuit112and a second control circuit114. In the embodiment, the driver circuit110can be a chip for controlling the pixel array120, including but not limited to concepts such as timing control, row driver, and column driver. The followings describe the controlling of the exposure duration and the output frame rate.

To consider the sensitivity of motion detection and the image quality of static scenes, the present embodiment of the invention allows the pixel array120to simultaneously generate image data with multiple exposure values. For example, the first control circuit112in the driver circuit110is coupled to the first quantity of first red pixel circuits Rs, and sends a first transmission signal TX1to control a first exposure duration of each first red pixel circuit Rs. The second control circuit114is coupled to the second quantity of second red pixel circuits Rd and sends a second transmission signal TX2to control a second exposure duration of the second red pixel circuits Rd. Since different pixel circuits in the pixel array120have different exposure durations, the speed of outputting image data is also varied. Typically, detection of dynamic scenes requires a higher frame rate, while recording static scenes does not require high frame rates but a higher signal-to-noise ratio (SNR). Therefore, in the embodiment, the first control circuit112can control the first red pixel circuit Rs to output a first photo-sensed value at a first frame rate, while the second control circuit114can control the second red pixel circuits Rd to output a second photo-sensed value at a second frame rate. The second frame rate is higher than the first frame rate. It should be noted that the first control circuit112and the second control circuit114may each have a first address decoder and a second address decoder, respectively, to respectively generate asynchronous first frame rate and second frame rate. Also, it should be noted that since the first transmission signal TX1and the second transmission signal TX2are controlled by the first control circuit112and the second control circuit114, respectively, the first exposure duration can be longer than the period of a frame operated at the second frame rate. For example, the driver circuit110can control the pixel array120to detect dynamic image changes at a speed of 30 frames per second, but at the same time, it can record first digital data at a speed of 1 frame per second. After the first frame data and the second frame data are stored in a frame buffer, the appropriate algorithm can be used to fuse the first frame data and the second frame data to obtain a high SNR image at a speed of 30 frames per second.

In one embodiment, the sum of the first quantity and the second quantity is 4. The first quantity can be 3, and the second quantity can be 1. In another embodiment, the first quantity can be 2, and the second quantity can also be 2. In further derivative embodiments, the sum of the first quantity and the second quantity is not limited to 4, and can be 9 or higher. Therefore, the ratio of the first quantity and the second quantity can be changed as needed in implementation. For example, the ratio of the first quantity and the second quantity can be M:N, where M and N are integers.

The final image data can be generated from the photo-sensed values output from the red first pixel circuit Rs and the red second pixel circuit Rd through appropriate algorithms. For example, the image sensor circuit100multiplies the photo-sensed values of the first red pixel circuit Rs and the second red pixel circuits Rd by different gain values, and then adds them up to generate corresponding pixel values. The pixel values of distinct colors can be properly blended to determine the final image data, such as adjusting the balance ratio of the three colors according to the white balance algorithm. In other words, each pixel circuit can correspond to different specific weighting coefficients. The photo-sensed values of multiple different pixel circuits are multiplied by the corresponding specific weighting coefficients and then added up to generate corresponding pixel values. However, the present invention is not limited to the.

In other words, the pixel array120in the embodiment is designed to include multiple distinct types of pixel circuit groups. Each pixel circuit in the pixel circuit group can be equipped with different types of filters (not shown) to sense corresponding types of light, thus producing the first pixel circuit group121, the second pixel circuit group122, the third pixel circuit group123, and the fourth pixel circuit group124. Generally, the image data can be processed to become a video file with a frame rate of 30 frames per second (FPS). The embodiment is adaptable for low-light motion monitoring. Toi improve the image quality of low-light motion detection, the second control circuit114can record dynamic images to avoid motion blur, and the first control circuit112can lengthen the exposure duration of some pixel circuits in the pixel array120, reduce the gain value, and lower the frame rate to significantly increase the signal-to-noise (SNR) ratio. By properly fusing the image data of the first and second frames using appropriate algorithms, an image with high SNR ratio and no motion blur can be obtained.

FIG.2shows an image sensor circuit according to an embodiment of the present invention. Four pixel circuits212are illustrated in the embodiment ofFIG.2, which are used to sense light and generate signals. The image sensor circuit100further includes a readout circuit250, which is coupled to the output ends of each pixel circuit212. The readout circuit250is controlled by a reset signal RST and operates according to a specific timing to read the values output from the corresponding pixel circuit. For example, in the embodiment, the pixel circuit group210can be configured to use three pixel circuits212to sense static images and one pixel circuit212to sense dynamic images. As shown inFIG.2, the first control circuit112sends a first transmission signal TX1to control the three pixel circuits212in the pixel circuit group210to output the first output data at the first frame rate, and the second control circuit114controls the fourth pixel circuit212to output the second output data at the second frame rate. The first transmission signal TX1sent by the first control circuit112and the second transmission signal TX2sent by the second control circuit114can control the exposure output timing and reset timing of the corresponding pixel circuit212. It should be noted thatFIG.2only illustrates one readout circuit250shared by multiple pixel circuits212, which is particularly adaptable for pixel binning mode operations and can obtain lower noise and higher SNR, making it adaptable for image sensing in low light conditions. Furthermore, althoughFIG.2only illustrates one readout circuit250shared by multiple pixel circuits212, it is not limited to the in practice. For example, the image sensor circuit200may also set up corresponding readout circuits250for distinct types of pixel circuits212to simplify the timing arrangement for reading output values.

The embodiment ofFIG.2is adaptable for operation with a rolling shutter. The scan signal #S scans each row of pixel array120in turn. Only the pixel circuit group in the row opened by the scan signal #S will perform the data readout operation at the same time. The structure of the rolling shutter belongs to the known art, and therefore the basic introduction is omitted.

In the embodiment ofFIG.2, the readout circuit250includes a ramp capacitor Cr. The first end of the ramp capacitor Cr is coupled to the output terminal of each pixel circuit212in the pixel circuit group210, where it can receive and store the output data of the pixel circuit212at the corresponding timing. The second end of the ramp capacitor Cr is connected to a ramp voltage Vr. When the readout circuit250is controlled by a scan signal #S, the ramp capacitor Cr can be coupled to the ramp voltage to convert the potential stored in the floating diffusion node FD into a readout signal OUT according to a specific timing. The readout circuit250may include an input switch Mi and an output switch Mo. When the input switch Mi is turned on and the scan signal #S opens the output switch Mo, the readout circuit250reads out the signal OUT from the drain of the output switch Mo. On the other hand, the floating diffusion node FD is also reset by a reset signal RST. For example, the readout circuit250is coupled to a reset voltage Vrst through a reset switch Mr. When the reset signal RST is connected to the switch, the potential value on the floating diffusion node FD is pulled to the reset voltage Vrst. Therefore, the reset signal RST, together with the first transmission signal TX1and the second transmission signal TX2output by the first control circuit112and the second control circuit114, respectively, allows the readout circuit250to sequentially read out the photo-sensed values output by each pixel circuit212in an orderly manner. The design of the readout circuit250can vary with actual product development. The reset voltage Vrst can be 0V or a voltage with diverse levels. The ramp voltage Vr can be an upward continuous changing voltage or a downward continuous changing voltage. The embodiment of the present invention is not limited to that shown inFIG.2.

InFIG.2, the first control circuit112and second control circuit114control the timing of the first transmission signal TX1, the second transmission signal TX2, and the reset signal RST to convert the photo-sensed values output by each pixel circuit212to a readout signal OUT in a specific timing sequence. In the implementation ofFIG.2, the pixel circuit group210can be used to represent any of the first pixel circuit group121, the second pixel circuit group122, the third pixel circuit group123, or the fourth pixel circuit group124inFIG.1. Each pixel circuit212includes at least one photodiode PD and a switch circuit M1. One end of the photodiode PD is coupled to the ground, and the other end is coupled to the switch circuit M1, which can accumulate charge by photo sensing. The switch circuit M1can be a common transistor or semiconductor, with a source and drain that are respectively coupled to the photodiode PD and floating diffusion node FD. The gate of the switch circuit M1is coupled to the first control circuit112or second control circuit114and is controlled to be conductive. When the switch circuit M1is conductive, it can function as a signal transmitter.

Taking the operation of the first control circuit112as an example, the following describes an implementation of the signal operation when the photodiode PD in the pixel circuit212is reset. When the first control circuit112sends the first transmission signal TX1to turn on the switch circuit M1and sends a reset signal RST to turn on the reset switch Mr, the switch circuit M1is turned on to a reset voltage Vrst, causing the accumulated charge in the photodiode PD to be reset to the reset voltage Vrst. It can be understood that the reset voltage Vrst can be a voltage level, which can be a zero or high voltage signal depending on the implementation. The second control circuit114also controls the pixel circuit212through the second transmission signal TX2in an analogous way and will not be repeated here.

The following is an example of the signal operation when the photodiode PD is read out, using the operation of the first control circuit112as an example. When the first control circuit112sends the first transmission signal TX1to turn on the switching circuit M1, but the reset switch Mr is not turned on by the reset signal RST, the accumulated charge in the photodiode PD generates a photo-sensed value, which is stored in the floating diffusion node FD. When the readout circuit250is triggered by the scan signal #S, the readout circuit250outputs the photo-sensed value stored in the floating diffusion node FD through the input switch Mi and the output switch Mo as the readout signal OUT. In one embodiment, the photo-sensed values sensed by multiple pixel circuits212can be read out by the readout circuit250simultaneously through the control of the first transmission signal TX1, for example in the pixel binning mode. The readout signal OUT will be used for subsequent image-related signal processing, the details of which are mainly based on conventional techniques and will not be described in detail in the embodiment. The operation of the second control circuit114to control the pixel circuit212through the second transmission signal TX2is also the same and will not be repeated here.

In summary, in the present embodiment, the first control circuit112and the second control circuit114can utilize the timing of manipulating the first transmission signal TX1and the second transmission signal TX2, as well as the timing of the reset signal RST, to output data at different frame rates without significantly increasing the hardware of the pixel array120, and to adapt to at least two different image uses. It can be understood that the aforementioned switch circuit M1, input switch Mi, output switch Mo, and reset switch Mr can be implemented by distinct types of transistors. The present embodiment does not limit specific implementation methods.

In the embodiment, the three pixel circuits212controlled by the first transmission signal TX1of the first control circuit112perform the same functions as the first red pixel circuit Rs, the first green pixel circuit Gs, or the first blue pixel circuit Bs shown inFIG.1, and are used to specifically sense static images. Conversely, the pixel circuit212controlled by the second transmission signal TX2of the second control circuit114performs the same functions as the second red pixel circuit Rd, the second green pixel circuit Gd, or the second blue pixel circuit Bd shown inFIG.1, and is used to specifically sense dynamic images. The first control circuit112and the second control circuit114alternatively employ the two transmission signals, the scanning signal #S, and reset signal RST described inFIG.2to control the data sensed by each pixel circuit to be output as a readout signal OUT to the subsequent processing unit through the conversion of the readout circuit250. That is, the first control circuit112and the second control circuit114can co-work in a time-divisional manner. The signal operation timing of the image sensor circuit200is illustrated inFIG.3below.

FIG.3is a timing diagram illustrating the operation of the sensor circuit according to an embodiment of the present invention. The horizontal axis represents time t. The four pixel circuits212in the pixel circuit group210ofFIG.2are defined as two types of functions based on the different transmission signals received, hereafter referred as a static pixel circuit and a dynamic pixel circuit. The time at which the static pixel circuit is reset is represented by SRST, and the time at which the dynamic pixel circuit is reset is represented by DRST. The time at which the static pixel circuit is read out is represented by SOUT, and the time at which the dynamic pixel circuit is read out is represented by DOUT. The exposure duration for each pixel circuit can be calculated from the end of the reset to the readout time. Therefore, the exposure durations for the static and dynamic pixel circuits are represented by Tes and Ted, respectively. FromFIG.3, it can be seen that the exposure duration for the dynamic pixel circuit Ted is set to be shorter, and the output frame rate is higher. Within one exposure duration Tes of the static pixel circuit, the dynamic pixel circuit can perform multiple short exposures and output the accumulated charge. The ratio of the frame rates of the two types of pixel circuits can be any ratio depending on the implementation requirements, such as M:N, where M and N are integers.

In another embodiment, the static pixel circuit and dynamic pixel circuit in the pixel circuit group210of the present invention may have different exposure durations, but the data therefrom can be read out simultaneously.

In another derivative embodiment, the exposure duration of the static pixel circuit in the pixel set may be longer than a frame length in the dynamic pixel circuit.

FIG.4shows a schematic diagram of the sensor circuit structure according to another embodiment in the present invention. The image sensor circuit400inFIG.4can be a derivative of the image sensor circuit100inFIG.1. The driver circuit110is replaced by a driver circuit410, which provides four independent control circuits, namely, the first control circuit411, the second control circuit412, the third control circuit413, and the fourth control circuit414. Each control circuit is used to control different pixel circuits in each pixel circuit group in the pixel array120, respectively, by using the first transmission signal TX1, the second transmission signal TX2, the third transmission signal TX3, and the fourth transmission signal TX4. Therefore, the pixel circuits in the pixel array120can be set for multiple exposure settings in different ranges, which is conducive to further achieving High Dynamic Range (HDR) image sensing technology.

InFIG.4, the image sensor circuit400is another embodiment derived from the image sensor circuit100inFIG.1. In the embodiment, the driver circuit110is replaced by the driver circuit410, which provides four independent control circuits: the first control circuit411, the second control circuit412, the third control circuit413, and the fourth control circuit414, each controlling different pixel circuits in each pixel circuit group in the pixel array120via the first transmission signal TX1, the second transmission signal TX2, the third transmission signal TX3, and the fourth transmission signal TX4, respectively. Therefore, the pixel circuits in the pixel array120can be set to be applicable to multiple exposure settings for achieving high dynamic range (HDR) image sensing technology. In particular, the pixel circuits coupled to the first control circuit411are represented by R1, G1, and B1, and the corresponding numbers of pixel circuits coupled to the second, third, and fourth control circuits, represented by R2, G2, B2, R3, G3, B3, R4, G4, and B4, respectively, in the first pixel circuit group421. The number of pixel circuits in the other pixel circuit groups, namely, the second pixel circuit group422, the third pixel circuit group423, and the fourth pixel circuit group424, is similar to that in the first pixel circuit group421, and is not described again here.

Taking the first pixel circuit group421as an example, the first control circuit411is coupled to the corresponding pixel circuit Rs, and a first transmission signal TX1is transmitted to control the first exposure duration of the pixel circuit Rs. The second control circuit412is coupled to the pixel circuit R2and a second transmission signal TX2is transmitted to control the second exposure duration of the pixel circuit R2. The third control circuit413is coupled to the pixel circuit R3, and a third transmission signal TX3is transmitted to control the third exposure duration of the pixel circuit R3. The fourth control circuit414is coupled to the pixel circuit R4and a fourth transmission signal TX4is transmitted to control the fourth exposure duration of the pixel circuit R4. The control methods for corresponding pixel circuits in the second pixel circuit group422, the third pixel circuit group423, and the fourth pixel circuit group424are generally the same as those in the first pixel circuit group421and will not be repeated herein.

In control of the output frame rate, the embodiment ofFIG.4can produce image signals with four different frame rates from a pixel array420. The first control circuit411can also control the pixel circuits R1, G1, B1to output a first photo-sensed value at a first frame rate; the second control circuit412can also control the pixel circuits R2, G2, B2to output a second photo-sensed value at a second frame rate; the third control circuit413can also control the pixel circuits R3, G3, B3to output a third photo-sensed value at a third frame rate; and the fourth control circuit414can also control the pixel circuits R4, G4, B4to output a fourth photo-sensed value at a fourth frame rate. The image sensor circuit400of the embodiment can periodically fuse the first photo-sensed value, the second photo-sensed value, the third photo-sensed value, and the fourth photo-sensed value output from each pixel circuit group using a specific algorithm to generate corresponding pixel values.

FIG.5shows an image sensor circuit500according to a specific implementation of the present invention, based on the implementation ofFIG.4. The circuit structure of the pixel circuit group210, the pixel circuit212, and the readout circuit250is similar to that of the implementation example inFIG.2. The pixel circuit group210is functionally equivalent to one of the first pixel circuit group421, the second pixel circuit group422, the third pixel circuit group423, or the fourth pixel circuit group424in the pixel array420ofFIG.4. For example, the first quantity, second quantity, third quantity, and fourth quantity in the pixel array420ofFIG.4can be set to a minimum of 1 to form the pixel circuit group210inFIG.5. The pixel circuit212coupled with the first control circuit411is equivalent to a red, green, or blue pixel circuit R1, G1, or B1. The pixel circuit212coupled with the second control circuit412is equivalent to a red, green, or blue pixel circuit R2, G2, or B2. The pixel circuit212coupled with the third control circuit413is equivalent to a red, green, or blue pixel circuit R3, G3, or B3. The pixel circuit212coupled with the fourth control circuit414is equivalent to a red pixel circuit R4, green pixel circuit G4, or blue pixel circuit B4.

From the design ofFIG.5, it can be seen that the pixel circuit in a pixel circuit group210is controlled by four independent signals, which distinguish the pixel circuits into four distinct functions. By appropriately designing the control circuit, the exposure duration and output frame rate of these pixel circuits can correspond to various levels, so that the image sensor circuit500can achieve a balance in aspects such as image quality improvement, motion detection sensitivity, and dynamic range. It should be understood that althoughFIG.5only shows one readout circuit250shared by multiple pixel circuits212, this is not limited in implementation. For example, the image sensor circuit500can also set corresponding readout circuits250for distinct types of pixel circuits212to simplify the timing arrangement for output value reading.

FIG.6is another embodiment of the image sensor circuit. The image sensor circuit600inFIG.6is similar to the embodiment inFIG.1, and includes at least one driver circuit610and one pixel array620. The pixel array620contains at least three distinct colors of pixel circuit groups. For the sake of illustration,FIG.6only shows the first pixel array621used for sensing red. For example, each first pixel array621in the pixel array620can include a first quantity of pixel circuits R1, a second quantity of pixel circuits R2, and a third quantity of pixel circuits R3. In the embodiment ofFIG.6, the first quantity is 1, the second quantity is 2, and the third quantity is 1. The pixel circuit R1is controlled by the first transmission signal TX1of the first control circuit611, the pixel circuit R2is controlled by the second transmission signal TX2of the second control circuit612, and the pixel circuit R3is controlled by the third transmission signal TX3of the first control circuit611.

From the design ofFIG.6, it can be seen that a pixel circuit in a pixel array620is controlled by three independent signals, which determine three different pixel circuit functions. The first transmission signal TX1and the third transmission signal TX3are provided by the first control circuit611, while the second transmission signal TX2is provided by the second control circuit612. It should be noted that the first and third transmission signals are provided by the same TX3first control circuit611, so they have the same frame rate. The second transmission signal TX2is provided by the second control circuit612, so it can have a different frame rate. The embodiment ofFIG.6is intended to illustrate that each control circuit can generate multiple switching control signals for different pixel circuits, achieving an operation mode of the same frame rate but readout in a time-division manner. It can also generate a control signal for multiple pixel circuits to achieve a pixel merging mode. In some contexts, the design is particularly suitable. For example, the first transmission signal TX1and the third transmission signal TX3can have the same frame rate but a specific shift relationship in time. In the way, when the pixel circuits R1and R3are respectively driven by the first transmission signal TX1and the third transmission signal TX3, readout timing conflicts can be avoided.

FIG.7shows another embodiment of the image sensor circuit. The image sensor circuit700inFIG.7is similar to the embodiment shown inFIG.6, and includes at least one driver circuit710and one pixel array720. For ease of explanation,FIG.7only shows the first pixel circuit group721used to sense the color red. For example, each first pixel circuit group721in the pixel array720may include a first quantity of pixel circuits R1, a second quantity of pixel circuits R2, a third quantity of pixel circuits R3, and a fourth quantity of pixel circuits R4. In the embodiment ofFIG.7, the first quantity is 1, the second quantity is 1, the third quantity is 1, and the fourth quantity is 1. The pixel circuit R1is controlled by the first transmission signal TX1of the first control circuit711, the pixel circuit R2is controlled by the second transmission signal TX2of the second control circuit712, the pixel circuit R3is controlled by the third transmission signal TX3of the first control circuit711, and the pixel circuit R4is controlled by the fourth transmission signal TX4of the first control circuit711.

From the design ofFIG.7, it can be seen that the pixel circuit in the pixel array720is controlled by two control circuits and can distinguish four different pixel circuit types. Wherein, the first transmission signal TX1, the third transmission signal TX3, and the fourth transmission signal TX4are provided by the first control circuit711, and the second transmission signal TX2is provided by the second control circuit712. What this embodiment intends to express is that the driver circuit710can be designed to include multiple levels of control circuits. For example, the first control circuit711is a high-level control circuit that can generate multiple different transmission signals, while the second control circuit712is a simple control circuit that can only generate a single fixed transmission signal. By doing so, when designing a product, it can be flexibly configured according to implementation requirements to improve functional flexibility and reduce costs.

FIG.8shows an image sensor circuit800according to another embodiment of the present invention. The image sensor circuit800ofFIG.8is a further derivation of the embodiment ofFIG.7, and includes at least one driver circuit810and a pixel array820. For ease of explanation,FIG.8only illustrates the first pixel circuit group821as an example. For example, each first pixel circuit group821in the pixel array820may include a first quantity of pixel circuits R1, a second quantity of pixel circuits R2, a third quantity of pixel circuits R3, and a fourth quantity of pixel circuits R4. In the embodiment ofFIG.8, the first quantity is 1, the second quantity is 1, the third quantity is 1, and the fourth quantity is 1. The pixel circuit R1is controlled by the first transmission signal TX1of the first control circuit811, the pixel circuit R2is controlled by the second transmission signal TX2of the second control circuit812, the pixel circuit R3is controlled by the third transmission signal TX3of the first control circuit811, and the pixel circuit R4is controlled by the fourth transmission signal TX4of the second control circuit812.

From the design ofFIG.8, it can be seen that a pixel circuit in the pixel array820is controlled by two control circuits and can be distinguished into four different functional pixel circuits. Specifically, the first transmission signal TX1and the third transmission signal TX3are provided by the first control circuit811, while the second transmission signal TX2and the fourth transmission signal TX4are provided by the second control circuit812. The embodiment aims to express that the driver circuit810can be designed as a collection of multiple multi-functional control circuits. Each control circuit can generate multiple different transmission signals, each controlling the corresponding number of pixel circuits. With such design, the product can be flexibly configured according to implementation needs to improve functionality and reduce costs.

FIG.9shows another embodiment of an image sensor circuit. The image sensor circuit900includes at least a driver circuit910and a pixel array920, which is a further derivation of the embodiment shown inFIG.7. For ease of explanation,FIG.9only shows the first pixel circuit group921. For example, each first pixel circuit group921in the pixel array920may include a first quantity of pixel circuits R1, a second quantity of pixel circuits R2, a third quantity of pixel circuits R3, and a fourth quantity of pixel circuits R4. In the embodiment ofFIG.9, the first quantity is 1, the second quantity is 1, the third quantity is 1, and the fourth quantity is 1. In addition to the first control circuit911and the second control circuit912, the driver circuit910also includes a third control circuit913. The pixel circuit R1is controlled by the first transmission signal TX1of the first control circuit911, the pixel circuit R2is controlled by the second transmission signal TX2of the second control circuit912, the pixel circuit R3is controlled by the third transmission signal TX3of the third control circuit913, and the pixel circuit R4is controlled by the fourth transmission signal TX4of the first control circuit911.

Based on the design ofFIG.9, it can be seen that a pixel circuit in a pixel array920is controlled by three control circuits, and four different types of pixel circuits can be determined. Specifically, the first transmission signal TX1and the fourth transmission signal TX4are provided by the first control circuit911, the second transmission signal TX2is provided by the second control circuit912, and the third transmission signal TX3is provided by the third control circuit913. It should be noted that this embodiment has three control circuits, and therefore can have three different frame rates. The embodiment is intended to express that the driver circuit910can be designed to include multiple levels of control circuits. For example, the first control circuit911is a high-level control circuit that can generate multiple different transmission signals, while the second control circuit912and the third control circuit913are simple control circuits that can only generate a single fixed transmission signal. By doing so, the product design can be flexibly configured according to implementation requirements to improve functionality and reduce costs.

FIG.10is a structural diagram of an image sensor device1000according to an embodiment of the present invention. The image sensor device1000inFIG.10is derived from the image sensor circuit100of the previous embodiment and is adaptable for various applications that require simultaneous detection of motion and image capture or high dynamic range HDR, such as security monitors, car recorders, or electric vehicle autonomous driving systems. The image sensor device1000may include an image sensor circuit1020, which may be designed based on the embodiments of the various image sensor circuits described earlier, and includes a plurality of pixel circuit groups. Each of the pixel circuit groups is covered with distinct types of filters, such as a red filter1022, a green filter1024, and a blue filter1026, for sensing the corresponding visible light range. It can be understood that the wavelength ranges covered by the three primary color filters are different from each other. The image sensor device1000may also include a plurality of address decoders, such as the first address decoder1002and the second address decoder1004, as the control circuit mentioned in the previous embodiment. The image sensor device1000also includes an ADC1030coupled to the image sensor circuit1020. The original voltage or current signal sensed by the image sensor circuit1020is first transmitted to the ADC1030. The ADC1030can convert the signal into digital format and then transmit it to the digital signal processor1040for processing. The digital signal processor1040can process static image recording and dynamic image sensing functions based on the first and second frame rates, respectively, in conjunction with the first address decoder1002and the second address decoder1004. It can be understood that the first address decoder1002and the second address decoder1004provide functions equivalent to the control circuit of the embodiments inFIGS.1to9. The digital signal processor1040may include a dynamic sensor module1042and an image processor module1044, respectively responsible for distinct types of sensing functions. The dynamic sensor module1042can quickly detect dynamic changes in the picture based on the digital data output from the ADC1030at the second frame rate. The image processor module1044can generate high-quality video images that restore the on-site image quality and color by fusing data of different frame rates based on the second frame rate output from the ADC1030.

In the embodiment ofFIG.10, the digital signal processor1040includes a frame buffer1046, which is used to temporarily store the digital data output from the ADC1030. For example, the frame buffer1046stores multiple sensed signals. When the dynamic sensor module1042performs motion detection, it reads the digital data of two or more consecutive frames from the context of the frame buffer1046to perform differential comparison and determine the motion.

In the embodiment ofFIG.10, the frame buffer1046in the digital signal processor1040can be used to store the previous image, which can be used as a basis for comparison when the signal of the second image comes in. In general, the method for detecting motion in DVS is to subtract the two consecutive frames, so the ADC1030can store the signals of the first and second frames in the frame buffer1046, and then the motion sensor module1042reads the signals of the first and second frames from the frame buffer1046and performs subtraction to detect the dynamic changes.

When generating a video image, the image processor module1044reads the digital data generated by the multiple pixel circuits corresponding to a pixel from the frame buffer1046, and performs a specific fusion algorithm based on the parameters of each pixel circuit, such as exposure duration, gain value, or weighting coefficient, to fuse the digital data into the image value of the pixel. Because the video image generated by the image processor module1044is obtained by fusing the information of all pixel circuits, the spatial resolution is lossless, that is, the fused image has completed spatial resolution, so there is no problem of reduced image quality. In the embodiment of the present invention, the video signal with RGB format and the infrared motion signal DVS(IR) are generated on the same chip, and the two signals can be fused in the same chip.

In further embodiments, to enhance acquisition of infrared images by the image sensor circuit1020, the image sensor device1000may further include an LED driver circuit1006, which is coupled to an infrared LED1008for illuminating the target space or object. The actual design of the image sensor device1000can be flexible and may vary depending on the application scenario. The description ofFIG.10is provided for illustration purposes only and is not intended to be limiting.

FIG.11shows an operational example of the image sensor circuit according to the present invention. The operation of the control circuit in the image sensor circuits ofFIGS.1-10can be summarized in the following steps. In step1102, the first control circuit controls the first pixel circuit to expose for the first exposure duration and generate the first sensed data. In step1104, the first control circuit controls the readout circuit to generate the first output signal at the first frame rate based on the first sensed data. In step1106, the second control circuit controls the second pixel circuit to expose for the second exposure duration and generate the second sensed data. In step1108, the second control circuit controls the readout circuit to generate the second output signal at the second frame rate based on the second sensed data. Finally, the image sensor circuit of the present invention can also fuse the signals into a final image using a specific algorithm in step1110. For example, the algorithm can multiply the first and second output signals by different gain values based on the first and second exposure durations and the first and second frame rates, and then add them together to generate a composite value. The operation of the composite value can be flexibly adjusted based on implementation requirements to optimize the output performance of each image pixel in various application scenarios.

In a further embodiment, the pixel circuit groups in the pixel array120ofFIG.1or the pixel array1020ofFIG.10can be arranged in a Group Bayer Pattern.

In a further embodiment, the pixel circuit groups in the pixel array120ofFIG.1or the pixel array1020ofFIG.10can be arranged using a 2×2 shared floating diffusion node (2×2 share FD) configuration.

In a further embodiment, the first control circuit inFIG.1may include a first address decoder for controlling the first frame rate. The second control circuit114inFIG.1may include a second address decoder for controlling the second frame rate. The first frame rate and the second frame rate may operate asynchronously. Other embodiments, such as the controllers inFIG.2andFIGS.4-9, may also be implemented analogously.

It should be noted that herein the terms “comprising” and “including” or any other variations thereof are intended to cover non-exclusive inclusions so that a process, method, article or device comprising a series of elements comprises not only those elements, but also other elements not expressly listed, or also comprises elements inherent in such process, method, article or device. In the absence of further restrictions, the statement “comprises a . . . ” does not exclude the existence of other identical elements in the process, method, article or device comprising the element.

The embodiments of the present invention are described above in combination with the drawings, but the present invention is not limited to the specific embodiments described above, the above specific embodiments are only illustrative, not restrictive, and the usual knowledge of the technical field is inspired by the present invention, and does not depart from the purpose of the present invention Under the scope of protection of the patent scope of the invention, many forms can be made, all of which are within the protection of the application.