WO2022116991A1

WO2022116991A1 - Bionic vision sensor

Info

Publication number: WO2022116991A1
Application number: PCT/CN2021/134726
Authority: WO
Inventors: 施路平; 杨哲宇; 赵蓉; 王韬毅; 何伟; 裴京; 祝夭龙
Original assignee: 北京灵汐科技有限公司
Priority date: 2020-12-03
Filing date: 2021-12-01
Publication date: 2022-06-09

Abstract

Disclosed is a bionic vision sensor. The bionic vision sensor comprises: a first sensing circuit, which comprises an excitatory photosensitive unit, an inhibitory photosensitive unit, and a sensing control unit, where the excitatory photosensitive unit and the inhibitory photosensitive unit are used for extracting from a target optical signal an optical signal of a first set band and converting the optical signal of the first set band into corresponding current signals; the sensing control unit is used for outputting, on the basis of the difference between the current signals converted by the excitatory photosensitive unit and the inhibitory photosensitive unit, a current signal expressing the variation in the light intensity of the optical signal of the first set band. The bionic vision sensor provided in the embodiments of the disclosure increases the capability for perceiving a dynamic target, thus increasing the photographing speed of the bionic vision sensor.

Description

Bionic Vision Sensor

technical field

The embodiments of the present disclosure relate to the technical field of image sensing, and in particular, to a bionic vision sensor.

Background technique

Vision sensor refers to an instrument that uses optical elements and imaging devices to obtain image information of the external environment. Active Pixel Sensor (APS) is a commonly used visual sensor. Its principle is to convert optical signals into electrical signals, and then obtain images based on electrical signals. It has the advantages of high color reproduction and high image quality, and is widely used. on your phone or camera. However, the dynamic range of the image signal obtained by the active pixel sensor is small, the shooting speed is slow, and the ability to perceive dynamic targets is poor, resulting in poor shooting stability, especially when the ambient light is dark, it is difficult to shoot clear images. images, making it difficult for vision sensors to be widely used.

SUMMARY OF THE INVENTION

The embodiments of the present disclosure provide a bionic vision sensor, which is used to improve the dynamic range and improve the shooting speed, so as to facilitate the application of the vision sensor.

An embodiment of the present disclosure provides a bionic visual sensor, including: a first sensing circuit, the first sensing circuit includes an excitatory photosensitive unit, an inhibitory photosensitive unit, and a sensing control unit, wherein,

The excitation type photosensitive unit and the inhibitory photosensitive unit are both used for extracting the light signal of the first set wavelength band in the target light signal, and converting the light signal of the first set wavelength band into a current signal;

The sensing control unit is configured to output a current representing the light intensity variation of the light signal of the first set wavelength band according to the difference between the current signals converted by the excitation type photosensitive unit and the inhibition type photosensitive unit Signal.

The technical solution of the embodiment of the present disclosure provides a bionic visual sensor, which senses the light signal of the first set wavelength band in the target light signal through the excitation type photosensitive unit and the inhibitory type photosensitive unit, and converts the light signal of the first set wavelength band. Converted into a current signal, and then according to the difference between the current signals converted by the excitatory photoreceptor unit and the inhibitory photoreceptor unit, output the current signal representing the light intensity change of the light signal in the first set band, to simulate the rod photoreceptor cell acquisition. The light intensity gradient information can achieve high-speed acquisition of grayscale change signals, thereby improving the perception ability of the bionic vision sensor for dynamic targets, increasing the dynamic range of the images collected by the bionic vision sensor, and increasing the shooting speed of the sensor.

Description of drawings

1 is a schematic diagram of a module structure of a bionic vision sensor provided by an embodiment of the present disclosure;

2 is a schematic structural diagram of a first pixel unit in a bionic vision sensor provided by an embodiment of the present disclosure;

3 is a schematic diagram of the arrangement of a first pixel unit of a bionic vision sensor provided by an embodiment of the present disclosure;

4 is a schematic diagram of the arrangement of a second pixel unit of another bionic vision sensor provided by an embodiment of the present disclosure;

5 is a schematic structural diagram of a module of a first sensing circuit provided by an embodiment of the present disclosure;

6 is a schematic structural diagram of a module of an excitation control circuit provided by an embodiment of the present disclosure;

7 is a schematic diagram of a signal waveform provided by an embodiment of the present disclosure;

8 is a schematic diagram of a circuit structure of an excitation control circuit provided by an embodiment of the present disclosure;

FIG. 9 is a schematic structural diagram of a suppression type control circuit provided by an embodiment of the present disclosure;

10 is a schematic diagram of a module structure of a bionic vision sensor provided by an embodiment of the present disclosure;

11 is a schematic structural diagram of a second pixel unit in a bionic vision sensor provided by an embodiment of the present disclosure;

12 is a schematic diagram of the arrangement of second pixel units of a bionic vision sensor provided by an embodiment of the present disclosure;

13 is a schematic diagram of the arrangement of second pixel units of another bionic vision sensor provided by an embodiment of the present disclosure;

14 is a schematic diagram of the arrangement of second pixel units of another bionic vision sensor provided by an embodiment of the present disclosure;

15 is a schematic diagram of the arrangement of a second pixel unit of another bionic vision sensor provided by an embodiment of the present disclosure;

16 is a schematic diagram of a module structure of a second sensing circuit provided by an embodiment of the present disclosure;

17 is a schematic diagram of a circuit structure of a second sensing circuit provided by an embodiment of the present disclosure;

FIG. 18 is a schematic diagram of an image output by a bionic vision sensor provided by an embodiment of the present disclosure.

Detailed ways

The present disclosure will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present disclosure, but not to limit the present disclosure. In addition, it should be noted that, for the convenience of description, the drawings only show some but not all structures related to the present disclosure.

As described in the background art, the existing active pixel sensor is difficult to be widely used due to its slow shooting speed and small dynamic range, resulting in limited application scenarios. However, other existing visual sensors all have the problem of mutually exclusive visual performance such as dynamic range, shooting speed and stability.

In view of the above problems, embodiments of the present disclosure provide a bionic vision sensor. FIG. 1 is a schematic diagram of a module structure of a bionic visual sensor provided by an embodiment of the present disclosure. As shown in FIG. 1 , the bionic visual sensor includes: a first sensing circuit 10 , and the first sensing circuit 10 includes an excitation type photosensitive unit 110. The inhibition type photosensitive unit 120 and the sensing control unit 100, the excitation type photosensitive unit 110 and the inhibition type photosensitive unit 120 can both be used to extract the light signal of the first set wavelength band in the target light signal, and convert the light signal of the first set wavelength band to the target light signal. The optical signal is converted into a current signal. The sensing control unit 100 is configured to output a current signal representing the light intensity variation of the light signal of the first set wavelength band according to the difference between the current signals converted by the excitation type photosensitive unit 110 and the inhibition type photosensitive unit 120 .

The target light signal is the light signal reflected by the surface of the photographed target object. The target object may be a static character, a dynamic character, a static scene or a dynamic scene, etc., or may be other forms of objects, which are not limited in this embodiment of the present disclosure.

Referring to FIG. 1 , the first sensing circuit 10 includes an excitatory photosensitive unit 110 and an inhibitory photosensitive unit 120 , but in practical applications, the bionic visual sensor may include multiple excitatory photosensitive units 110 and multiple inhibitory photosensitive units 120 . For the photosensitive units 120, the present embodiment does not limit the number of the excitation-type photosensitive units 110 and the inhibition-type photosensitive units 120. The excitatory photoreceptor unit 110 and the inhibitory photoreceptor unit 120 are distributed in different regions in the infrared bionic vision sensor, so that the excitatory photoreceptor unit 110 and the inhibitory photoreceptor unit 120 can form a pixel sensing structure, so as to realize the image signal or image signal of the target object. Acquisition of video signals.

When the bionic vision sensor shoots the target object, the light signal reflected from the surface of the target object can be directly or indirectly irradiated on the photosensitive surfaces of the excitation type photosensitive unit 110 and the inhibition type photosensitive unit 120, and the excitation type photosensitive unit 110 and the inhibition type photosensitive unit 120 will The target light signal is converted into an electrical signal reflecting the characteristics of the target object.

The optical signal in the first set wavelength band may be an optical signal in at least part of the visible light and infrared wavelength bands. The excitation type photosensitive unit 110 and the inhibition type photosensitive unit 120 in the first sensing circuit 10 can directly collect the optical signal of the first set wavelength band, or can extract the first set wavelength band in the target optical signal through an optical lens or an optical filter device. The optical signal of the first set wavelength band is sensed, and the light intensity change in the optical signal of the first set wavelength band is sensed, and a current signal representing the change amount of the light intensity of the optical signal of the first set wavelength band is output. Among them, the light intensity change amount is the gray level change amount or light intensity gradient information. The light signals extracted from the target light signal by the excitation type photosensitive unit 110 and the inhibition type photosensitive unit 120 include infrared light signals (ie, infrared rays), that is, the light intensity change information of infrared rays in the target light signal is sensed, so that the bionic vision sensor can be widely used in Infrared cameras in various fields.

In some embodiments, the first sensing circuit 10 may use an active pixel sensing circuit whose working mode is a current mode. Here, the current mode refers to a mode capable of converting an optical signal into a current signal. The first sensing circuit 10 includes at least two image sensors, and the current signal output by the first sensing circuit 10 representing the light intensity variation of the light signal in the first set wavelength band may be the first sensing circuit 10 according to the The current signal converted by one image sensor is compared with the current signal converted by at least one image sensor around the image sensor, so as to obtain a current signal representing the variation of light intensity. The first sensing circuit 10 using the current mode can quickly convert the optical signal and output a current signal, and the current signal has the function of facilitating mathematical operation to obtain a high-speed differential signal.

In some embodiments, the first set wavelength band includes an infrared wavelength band, and both the excitation-type photosensitive unit 110 and the inhibition-type photosensitive unit 120 include a first photosensitive device, and the first photosensitive device is an infrared photosensitive device.

Specifically, each of the first photosensitive devices may be a photodiode (Photo-Diode, PD), and the photodiode can convert an optical signal into a corresponding electrical signal. When the first photosensitive device is an infrared photosensitive device, the first photosensitive device may be an infrared photodiode. In this way, the bionic vision sensor can perceive the light intensity change information of infrared light in the target light signal.

In some embodiments, the first set wavelength band includes an infrared wavelength band, and the excitation-type photosensitive unit 110 and the suppression-type photosensitive unit 120 both include a first photosensitive device and a first filter device disposed on the first photosensitive device; the first photosensitive device The device is an infrared photosensitive device and/or the first filter device is an infrared filter device.

Specifically, the first filter device in the excitation-type photosensitive unit 110 is used to select the wavelength band of the light passing through itself, and the first filter device may be a color filter, or a set component can be extracted. Optical lenses for optical signals, such as Byron lenses. The first filter device can be arranged on the photosensitive surface of the first photosensitive device, so that the target light signal is first irradiated to the surface of the first filter device, and the first filter device includes the first setting of the infrared band in the target light signal. The optical signal of the wavelength band is extracted, so that the optical signal of the first set wavelength band is irradiated to the photosensitive surface of the first photosensitive device, and the optical signal of the first set wavelength band is converted into a corresponding current signal by the first photosensitive device. Similarly, in the suppression-type photosensitive unit 120, the first filter device may be disposed on the photosensitive surface of the first photosensitive device, and the target light signal including the first set wavelength band of the infrared wavelength band is detected by the first filter device. Extraction is performed, and the optical signal of the first set wavelength band is converted into a corresponding current signal by the first photosensitive device. The first filter device in the excitation type photosensitive unit 110 and the inhibition type photosensitive unit 120 are both infrared filter devices, which can improve the ability of the bionic vision sensor to perceive the light intensity change information of infrared light in the target light signal.

In some embodiments, the first set wavelength band includes an infrared wavelength band, and the excitation-type photosensitive unit 110 and the inhibition-type photosensitive unit 120 both include a first photosensitive device and a first filter device disposed on the first photosensitive device; The first photosensitive device in the unit is an infrared photosensitive device, and the first filter device in the suppression type photosensitive unit is an infrared filter device; The first photosensitive device in the photosensitive unit is an infrared photosensitive device; the first sensing circuit is also used for correcting the consistency of the spectral response characteristics of the excited photosensitive unit and the inhibitory photosensitive unit.

Specifically, the first photosensitive device in the exciting photosensitive unit 110 is an infrared photosensitive device, and the first filter device in the inhibited photosensitive unit 120 is an infrared filter device; or, the first filter device in the exciting photosensitive unit 110 The device is an infrared filter device, and the first photosensitive device in the suppression photosensitive unit 120 is an infrared photosensitive device, which can also improve the ability of the bionic vision sensor to perceive the light intensity change information of infrared light in the target light signal. When one of the excitation type photosensitive unit 110 and the inhibition type photosensitive unit 120 uses the infrared photosensitive device and the common filter device to extract the light signal of the first set wavelength band including the infrared wavelength band in the target light signal, the other one passes the infrared filter. When the optical device cooperates with the ordinary photosensitive device to extract the optical signal of the first set wavelength band including the infrared wavelength band in the target optical signal, in order to avoid the difference between the optical signals extracted by the two being too large, the excitation type photosensitive unit 110 and the inhibition type photosensitive unit can be used. The consistency of the spectral response characteristics of 120 is corrected to improve the ability of the bionic vision sensor to perceive the light intensity change information of infrared light in the target light signal. In some embodiments, the consistency of the spectral response characteristics of the excitation-type photoreceptor unit 110 and the inhibitory-type photoreceptor unit 120 is corrected by the sensor control unit.

In some embodiments, the excitatory photoreceptor units 110 and the inhibitory photoreceptor units 120 are distributed in different regions of the bionic vision sensor, so as to acquire target light signals illuminated on the respective photosensitive surfaces respectively. For example, the excitation-type photosensitive cells 110 and the inhibition-type photosensitive cells 120 are arranged in an array.

FIG. 2 is a schematic structural diagram of a first pixel unit in a bionic vision sensor provided by an embodiment of the present disclosure. The first pixel unit P1 may be a pixel unit in the bionic vision sensor. 1 and 2 , the excitation-type photosensitive units 110 and the inhibition-type photosensitive units 120 are arranged in an array to form a first pixel unit P1.

In some embodiments, as shown in FIG. 1 and FIG. 2 , the first pixel unit P1 may include an excitatory photoreceptor unit 110 and at least one inhibitory photoreceptor unit 120 located around the excitatory photoreceptor unit 110 . The excitatory photoreceptor unit 110 can be used to simulate the excitatory rod cells of the human eye, and the inhibitory photoreceptor unit 120 can be used to simulate the inhibitory rod cells of the human eye. The grayscale information of the signal, the sensing control unit 100 outputs the current difference representing the light intensity variation of the light signal of the first set wavelength band according to the difference between the current signals converted by the excitation type photosensitive unit 110 and the inhibition type photosensitive unit 120 Signal to simulate the rod photoreceptor cells to obtain light intensity gradient information.

As shown in FIG. 1 and FIG. 2 , the first pixel unit P1 includes an excitatory photoreceptor unit 110 and four inhibitory photoreceptor units 120; The photosensitive units 110 are connected.

When the target light signal is irradiated to the photosensitive surface of the first pixel unit P1, the excitation type photosensitive unit 110 and the four suppression type photosensitive units 120 respectively sense the grayscale information of the light signal of the first set wavelength band in the target light signal, and convert the A light signal of a set wavelength band is converted into a corresponding current signal. The sensing control unit 100 can make a difference between the current signal converted by the exciting photosensitive unit 110 and the average value of the current signals converted by the four inhibitory photosensitive units 120 to obtain a differential current signal, that is, the light intensity reflecting the change of light intensity. gradient signal. The first pixel unit P1 can simulate the rod cells of the human eye through an excitatory photoreceptor unit 110 and four inhibitory photoreceptor units 120 surrounding the excitatory photoreceptor unit 110, and obtain a light intensity gradient signal reflecting the change of light intensity.

In some embodiments, the excitatory photoreceptor units 110 and the inhibitory photoreceptor units 120 are both rectangular in shape, and the top corners of the four inhibitory photoreceptor units 120 are respectively connected to the four top corners of the excitatory photoreceptor units 110 .

2 schematically shows that the shapes of the excitatory photoreceptor unit 110 and the inhibitory photoreceptor unit 120 are square, and the four inhibitory photoreceptor units 120 are respectively located on the diagonal of the excitatory photoreceptor unit 110, and the four The top corners of the inhibitory photosensitive unit 120 are respectively connected to the four top corners of the exciting photosensitive unit 110 . This setting is beneficial to improve the pixel fill factor of the bionic vision sensor.

FIG. 3 is a schematic diagram of the arrangement of a first pixel unit of an infrared bionic vision sensor provided by an embodiment of the present disclosure. 1 to 3 , a plurality of first pixel units P1 form a first pixel array in an array manner, and two adjacent first pixel units P1 share a row or a column of suppression type photosensitive units 120 .

In the first pixel array formed by the excitatory photoreceptor units 110 and the inhibitory photoreceptor units 120 , one row of the array includes two types of arrangements, that is, a row of the excited photoreceptor units 110 arranged at intervals, or a row of all rows of the photoreceptors arranged at intervals Inhibition-type photosensitive cells 120, and pixel rows with excitation-type photosensitive cells 110 and pixel rows with inhibition-type photosensitive cells 120 are alternately arranged in the first pixel array. One column of the array includes two types of arrangements, that is, a column of excitatory photoreceptor units 110 arranged at intervals, or a column of inhibitory photoreceptor units 120 arranged at intervals, and a pixel row with excitation type photoreceptor units 110, and a row of pixels with inhibitory photoreceptor units 110. The pixel columns of the photosensitive units 120 are alternately arranged in the first pixel array. The excitation type photosensitive unit 110 and the inhibition type photosensitive unit 120 are located in different rows and columns of the first pixel array, which can improve the ability of the infrared bionic vision sensor to perceive the grayscale variation of the light signal.

This embodiment also implements multiplexing of the suppression-type photosensitive units 120 . As shown in FIG. 3 , the current signal converted by each exciting photosensitive unit 110 can be calculated with the current signals converted by the surrounding four inhibitory photosensitive units 120 , so the current signal converted by each inhibitory photosensitive unit 120 can be At the same time, the operation is performed with the current signals converted by the surrounding four exciting photosensitive units 110, which not only realizes the multiplexing of the inhibited photosensitive units 120, but also helps to improve the pixel fill factor.

FIG. 4 is a schematic diagram of the arrangement of a first pixel unit of another infrared bionic vision sensor provided by an embodiment of the present disclosure. The pixel arrangement structure includes a pixel array of M rows and N columns, and the pixel structure of each coordinate point is a first pixel unit, and the first pixel unit may be the first pixel unit P1 shown in FIG. 2 and FIG. 3 . . Each first pixel unit P1 includes one excitatory photosensitive unit 110 and four inhibitory photosensitive units 120, and the first pixel unit at each coordinate point can sense the grayscale change signal, thereby enriching the images captured by the bionic vision sensor visual information.

FIG. 5 is a schematic structural diagram of a first sensing circuit according to an embodiment of the present disclosure. As shown in FIG. 1 and FIG. 5 , the first sensing circuit 10 includes an excitatory photosensitive unit 110 , an inhibitory photosensitive unit 120 and a sensing control unit 100 , an excitatory photosensitive unit 110 and an inhibitory photosensitive unit 120 and a sensing control unit 100 signal connection, the sensing control unit 100 outputs a current signal representing the light intensity variation of the light signal of the first set wavelength band according to the difference between the current signals converted by the excitation type photosensitive unit 110 and the inhibition type photosensitive unit 120 .

The sensing control unit 100 includes an excitatory control circuit 130 and at least one inhibitory control circuit 140 connected to the excitatory control circuit 130; the excitatory control circuit 130 is connected to the excitatory photosensitive unit 110, and the inhibitory control circuit 140 is connected to the inhibitory photosensitive unit Moreover, each suppression type photosensitive unit 120 is correspondingly provided with a suppression type control circuit 140 . The inhibition type control circuit 140 is used to transmit the current signal converted by the inhibition type photosensitive unit 120 to the excitation type control circuit 130 connected to the inhibition type control circuit 140; the excitation type control circuit 130 is used to control itself and the inhibition type according to the received control signal The control circuit 140 is turned on or off, and according to the difference between the current signals converted by the excitation-type photosensitive unit 110 and the inhibition-type photosensitive unit 120, a current signal representing the light intensity variation of the light signal in the first set wavelength band is output .

As shown in FIG. 5 , the sensor control unit 100 includes one excitation type control circuit 130 and four inhibitory type control circuits 140 . The excitatory photoreceptor unit 110 and the inhibitory photoreceptor unit 120 may correspond to one excitatory photoreceptor unit 110 in the first pixel unit P1 shown in FIGS. 2 and 3 and four inhibitory photoreceptor units surrounding the excitatory photoreceptor unit 110 120. The four inhibitory control circuits 140 simultaneously transmit the current signals converted by the corresponding inhibitory photoreceptor units 120 to the excitatory control circuit 130, so that the excitatory control circuit 130 can combine the current signals converted by the excitatory photoreceptor units 110 with the four inhibitory photoreceptors. The average value of the current signals converted by the photosensitive unit 120 is subtracted to obtain a differential current signal, that is, a light intensity gradient signal reflecting the amount of light intensity change.

In the sensing control unit 100, a corresponding switch (not shown in the figure) is set between the excitatory control circuit 130 and the inhibitory control circuit 140, and each inhibitory control circuit 140 is connected to the excitatory control circuit 130 through the switch, The excitatory control circuit 130 can control the switch to be turned on or off according to the received control signal, so as to control itself and the inhibitory control circuit 140 to be turned on or off.

In this embodiment, the control signal for turning on or off the excitatory control circuit 130 and the inhibitory control circuit 140 is related to the lighting condition. For example, in the case where the light intensity of the target light signal is greater than the first preset value, that is, in the case of strong light, in order to improve the accuracy of the current signal representing the light intensity change output by the sensing control unit 100, the excitatory control can be controlled. All switches between the circuit 130 and the inhibitory control circuit 140 are turned on. At this time, each inhibitory control circuit 140 is valid, and the current signal output by the sensing control unit 100 is a differential mode signal, that is, the excitation photosensitive unit 110 and the four inhibitory The differential signal of the current signal converted by the type photosensitive unit 120 . For the case where the light intensity of the target light signal is less than the second preset value, that is, in the case of weak light, the current signal converted by the excitation type photosensitive unit 110 is relatively small, and the current signal converted by the excitation type photosensitive unit 110 is controlled by the control signal between the excitation type control circuit 130 and the inhibition type control circuit 140. All switches of 1 are turned off, at this time each inhibitory control circuit 140 fails, and the current signal output by the sensing control unit 100 is a common mode signal, that is, the current signal converted by the exciting photosensitive unit 110 . The specific values of the first preset value and the second preset value may be specifically set in combination with the type of the photosensitive unit and the ambient light intensity. The sensing control unit 100 provided by the embodiment of the present disclosure can simulate the Gap Junction connection of the human eye, thereby improving the dynamic range of the image captured by the infrared bionic vision sensor.

FIG. 6 is a schematic diagram of a module structure of an excitation type control circuit provided by an embodiment of the present disclosure, which may be a specific module structure of the excitation type control circuit in FIG. 5 . As shown in FIG. 5 and FIG. 6 , on the basis of the above embodiments, the excitatory control circuit 130 includes: a signal amplifying unit 131 , an adder 132 , a digital-to-analog converter 133 , a comparator 134 , a tri-state gate 135 and at least one The first switch 136 ; the input end of the signal amplifying unit 131 is connected to the exciting photosensitive unit 110 , the output end of the signal amplifying unit 131 is connected to the first input end of the comparator 134 ; the suppressing control circuit 140 is connected to the adder 132 through the first switch 136 The output end of the adder 132 is connected to the second input end of the comparator 134; the input end of the digital-to-analog converter 133 is connected to the output end C1 of the comparator 134, and the analog signal output end of the digital-to-analog converter 133 is connected to the signal The input end of the amplifying unit 131 and the input end of the adder 132, the digital-to-analog converter 133 is used to input an analog signal to the input end of the signal amplifying unit 131 or the input end of the adder 132 according to the comparison result signal output by the comparator 134, In order to make the comparator 134 output the comparison result signal including the light intensity variation of the optical signal of the first set band; The input end of the analog converter 133, the tri-state gate 135 is used for outputting a current signal representing the light intensity variation of the light signal of the first set wavelength band according to the signal output by the comparator 134.

Referring to FIG. 6 , the excitation-type photosensitive unit 110 converts the light signal of the first set wavelength band into a current signal I0 , and outputs the current signal I0 to the signal amplifying unit 131 . The four suppression photosensitive units 120 respectively convert the light signals of the first set wavelength band into current signals I1 to I4 , and transmit the current signals I1 to I4 to the excitation control circuit 130 through the corresponding suppression control circuit 140 . The signal amplifying unit 131 may include a first amplifier 131a, and the first amplifier 131a can amplify the current signal I0, so that the current signal I0 and the current signals I1 to I4 are in the same order of magnitude, which is convenient for the sensing control unit 100 to calculate the differential current.

The signal amplifying unit 131 inputs the amplified current signal I0 to the first input terminal of the comparator 134 , and the four suppression control circuits 140 respectively input the current signals I1 to I4 to the input of the adder 132 through the first switch 136 that is turned on terminal, so that the adder 132 sums the current signals I1 to I4 and outputs the summed result to the second input terminal of the comparator 134 . The comparator 134 compares the signals input from the first input terminal and the second input terminal. If the comparison results of the previous moment and the next moment are consistent, the comparator 134 does not output the comparison result signal. When the comparison result at time is opposite, the comparator 134 outputs a comparison result signal including the light intensity variation of the optical signal of the first set wavelength band through the output terminal C1 , and the comparison result signal may be a digital signal such as 0 or 1.

The digital-to-analog converter 133 can convert the digital signal into an analog signal, and according to the comparison result signal output by the comparator 134, input the analog signal IDA1 to the input end of the adder 132, or input the analog signal IDA2 to the input end of the signal amplifying unit 131 . The signal amplifying unit 131 may further include a second amplifier 131b. The second amplifier 131b may continue to amplify the current signal I0 according to the analog signal IDA2, and input the amplified signal to the first input terminal of the comparator 134. The adder 132 may also sum the current signals I1 to I4 and the analog signal IDA1 and output the summation result to the second input of the comparator 134 . The comparator 134 continues to compare the signals input from the first input terminal and the second input terminal, and when the comparison result between the previous moment and the next moment is opposite, it outputs a signal including the light intensity variation of the optical signal of the first set wavelength band. Compare the resulting signals.

FIG. 7 is a schematic diagram of a signal waveform provided by an embodiment of the present disclosure, which may specifically be a schematic diagram of a waveform of a digital signal input by the digital-to-analog converter 133 in FIG. 6 . In FIG. 7 , the abscissa is time, and the ordinate is the value of the digital signal. As shown in FIG. 7 , the digital-to-analog converter 133 can convert the digital signal into an analog signal IDA1 or an analog signal IDA2 for output, and the digital signal can be a designated digital signal that is input by humans and changes periodically. For example, Figure 7 shows a step digital signal with increasing magnitude over time. At the time of N_step, the comparison result signal output by the comparator 134 changes. At this time, the value of the digital signal is ΔI, and then ΔI can be used as a current signal representing the light intensity variation of the optical signal in the first set wavelength band. The control terminal of the tri-state gate 135 inputs the comparison result signal of the comparator 134 at this time, the digital signal input terminal of the digital-to-analog converter 133 is connected to the input terminal of the tri-state gate 135, and the value output by the digital-to-analog converter 133 is ΔI The current signal is output through the output terminal of the tri-state gate 135 .

Referring to FIG. 6 , on the basis of the above embodiment, the excitation control circuit 130 further includes a storage unit 137 connected to the output end of the tri-state gate 135 for storing and outputting the signal output by the tri-state gate 135 . The storage unit 137 may be a register, a latch, a memristor, or the like. Taking the storage unit 137 as a register as an example, the number of bits of the register can be selected according to the precision of the digital-to-analog converter 133, for example, a 4-bit register is selected.

Referring to FIG. 8 , it is a schematic diagram of a circuit structure of an excitation type control circuit provided by an embodiment of the present disclosure, which may be a specific circuit structure of the excitation type control circuit shown in FIG. 6 . As shown in FIG. 6 and FIG. 8 , the exciting control circuit 130 is connected to the exciting photosensitive unit 110 , and the exciting photosensitive unit 110 includes a first photosensitive device, and the first photosensitive device may be a photodiode PD11 . The excitatory control circuit 130 includes a first circuit structure 130a and a second circuit structure 130b, the first circuit structure 130a can simulate human eye rod cells, and the second circuit structure 130b can simulate human eye horizontal cells, bipolar cells and amacrine cells cell.

Specifically, the photodiode PD11 is connected to the current mirror 131c. The photodiode PD11 generates a current signal I0 under the irradiation of the optical signal of the first set wavelength band, and outputs the current signal I0 to the current mirror 131c. The current mirror 131c can realize the The function of the signal amplifying unit 131 is to amplify the current signal I0 by N (for example, N=4) times. FIG. 8 only schematically shows a case where the current signals I1 to I4 output by the suppression control circuit 140 and the amplified current signal I0 output by the current mirror 131c are input to the comparator 134 through a connection line. In fact, the comparator 134 compares the amplified current signal I0 output by the current mirror 131c and the sum of the current signals I1 to I4. If the comparison results of the previous time and the next time are consistent, the comparator 134 does not output the comparison result signal, and if the comparison results of the previous time and the next time are opposite, the comparator 134 outputs the optical signal including the first set wavelength band The comparison result signal of the amount of light intensity change. The digital-to-analog converter 133 converts the digital signal into an analog signal, and outputs an analog signal according to the comparison result signal of the comparator 134, and continues to amplify the current signal I0 through the analog signal, or continues to amplify the current signal I1 to I4 through the analog signal. The accumulation is performed so that the comparator 134 continues to perform the comparison function. The comparator 134 outputs a comparison result signal when the comparison result between the previous time and the next time is opposite. When the comparison result signal output by the comparator 134 changes, the tri-state gate 135 outputs the digital signal of the digital-to-analog converter 133 as a current signal representing the variation of the light intensity of the light signal in the first set wavelength band. The storage unit 137 is a register, and stores and outputs the signal output by the tri-state gate 135 .

As shown in FIGS. 6 and 8 , the four first switches 136 include switches M1 to M4 , which may be transistors and can be turned on or off according to control signals received by their control terminals (eg, gates) . Corresponding to different lighting conditions, the control signals received by the switches M1 to M4 are different, and the switching conditions of the switches are different. In the case of strong light, if the light intensity of the target light signal is greater than 50 lux, the control signal can control the switches M1 to M4 to be turned on. At this time, the photodiodes in the suppression type photosensitive unit 120 are all valid, and the excitation type control circuit 130 outputs the output A differential signal between the current signal I0 and the current signals I1 to I4, that is, a differential mode signal. In the case of weak light, for example, when the light intensity of the target light signal is lower than 20 lux, the switches M1 to M4 can be controlled to be turned off by the control signal. At this time, the photodiodes in the suppression type photosensitive unit 120 are all invalid, and the excitation type control circuit 130 The output current signal I0 is the common mode signal.

The setting of the conduction state of the switches M1 to M4 can be used to configure the convolution differential current calculation of the excitation control circuit 130. When the lighting conditions allow, the image acquisition speed of the bionic vision sensor is high, and the gap between the two frames of images is very small. . Since the calculation speed of the differential current is high, the calculation of the 1-bit convolution differential current in the first pixel unit (in pixel) can be realized, thereby realizing high-speed image feature extraction.

As shown in FIG. 8 , on the basis of the above-mentioned embodiment, a capacitor Cpar may be further included between the input terminal of the comparator 134 and the ground terminal. The parasitic capacitance, the capacitance Cpar, can be used to store the signal at the input end of the comparator 134, so as to ensure the calculation accuracy when the excitation control circuit performs high-speed differential current operation.

FIG. 9 is a schematic structural diagram of a suppression type control circuit provided by an embodiment of the present disclosure. As shown in FIG. 9 , the suppression type control circuit 140 includes: a second switch 141 connected to the suppression type photosensitive unit 120 and at least one mirror switch 142 connected to the suppression type photosensitive unit 120 and the second switch 141 , the suppression type control circuit 140 The excitation type control circuit 130 is connected through the mirror switch 142 .

Specifically, referring to FIG. 5 and FIG. 9 , the suppression type control circuit 140 is connected to the suppression type photosensitive unit 120 , and the suppression type photosensitive unit includes a second photosensitive device, and the second photosensitive device may be a photodiode PD12 . Both the second switch 141 and the mirror switch 142 may be transistors, which can be turned on or off according to a control signal received by their control terminals (eg, gates). The second switch 141 and each mirror switch 142 respectively form a mirror unit, so as to copy the current signal I1 generated by the photodiode PD12 according to the optical signal of the first set band into four parts, and the suppression control circuit 140 can copy the four parts of the current signal I1 is respectively transmitted to the surrounding four excitatory control circuits 130 to realize the multiplexing of the inhibitory photosensitive units 120 and improve the pixel fill factor of the infrared bionic vision sensor.

A bionic vision sensor provided by an embodiment of the present disclosure senses an optical signal of a first set wavelength band in a target optical signal through an excitatory photosensitive unit and an inhibitory photosensitive unit, and converts the optical signal of the first set wavelength band into a current signal , and then according to the difference between the current signals converted by the excitatory photoreceptor unit and the inhibitory photoreceptor unit, output a current signal representing the light intensity change of the light signal in the first set band, to simulate the rod cells to obtain light intensity gradient information , to achieve high-speed acquisition of grayscale change signals, thereby improving the perception ability of the bionic vision sensor for dynamic targets, increasing the dynamic range of the image collected by the bionic vision sensor, and improving the shooting speed of the sensor.

10 is a schematic diagram of a module structure of a bionic vision sensor provided by an embodiment of the present disclosure. The bionic vision sensor is a dual-modal bionic vision sensor, which can simulate rod cells to obtain light intensity gradient information, and can simulate cones Cells acquire color light intensity information.

As shown in FIG. 10 , the bionic vision sensor includes a first sensing circuit 10 and a second sensing circuit 20; the first sensing circuit 10 is used to extract the light signal of the first set wavelength band in the target light signal, and output the characteristic The current signal of the light intensity variation of the optical signal of the first set wavelength band; the second sensing circuit 20 is used to extract the optical signal of the second set wavelength band in the target optical signal, and output the optical signal representing the second set wavelength band The voltage signal of the light intensity; wherein, at least one of the first set wavelength band and the second set wavelength band includes an infrared wavelength band.

In some embodiments, the bionic vision sensor may include a plurality of first sensing circuits 10 and second sensing circuits 20, and the image sensors in the plurality of first sensing circuits 10 and second sensing circuits 20 can form a pixel sensor. The sensor structure is used to realize the acquisition of the image signal or video signal of the target object.

Wherein, the structure, arrangement and working principle of the first sensing circuit 10 can be referred to the above-mentioned embodiments, which will not be repeated here.

The optical signal of the second set wavelength band may be an optical signal of at least a part of wavelength bands of visible light and infrared wavelengths. The second sensing circuit 20 can directly collect the optical signal of the second set wavelength band through the image sensor therein, or can extract the optical signal of the second set wavelength band in the target optical signal through an optical lens or an optical filter device, and sense the second set wavelength band of the optical signal. the absolute light intensity information and color information of the optical signal of the fixed wavelength band, and output a voltage signal representing the light intensity of the optical signal of the second set wavelength band, the voltage signal can reflect the light intensity information of the optical signal of the second set wavelength band, This light intensity information includes not only absolute light intensity information, but also light chromaticity information.

Wherein, the second sensing circuit 20 may adopt an active pixel sensing circuit whose working mode is a voltage mode. The voltage mode refers to that the image sensor in the second sensing circuit 20 can convert the optical signal of the second set wavelength band into a current signal, and the second sensing circuit 20 can integrate the current signal to obtain the second Set the voltage signal of the light intensity of the light signal in the wavelength band, and the second sensing circuit 20 in the voltage mode is more suitable for the acquisition of high-precision color visual signals.

The first set band and the second set band may be the same band or different bands. At least one of the first set wavelength band and the second set wavelength band includes an infrared wavelength band, that is, an optical signal extracted from the target optical signal by at least one sensing circuit of the first sensing circuit 10 and the second sensing circuit 20 Including infrared light signals (ie, infrared rays) to sense the color light intensity information and/or light intensity change information of infrared light in the target light signal, so that the bionic vision sensor can be widely used in infrared cameras in various fields.

FIG. 11 is a schematic structural diagram of a second pixel unit in a bionic vision sensor provided by an embodiment of the present disclosure. The second pixel unit P2 may be a pixel unit in a pixel sensing structure of the bionic vision sensor. The difference between the second pixel unit P2 and the first pixel unit P1 is that the first pixel unit P1 includes an excitation type photosensitive unit 110 and an inhibitory type photosensitive unit 120, while the second pixel unit P2 not only includes an excitation type photosensitive unit 110 and an inhibitory type photosensitive unit 120 The type photosensitive unit 120 further includes a second photosensitive unit, and the excitation type photosensitive unit 110 , the inhibition type photosensitive unit 120 and the second photosensitive unit are distributed in different regions to obtain target light signals irradiated on the respective photosensitive surfaces. Only the parts of the second pixel unit P2 that are different from the first pixel unit P1 will be described below, and refer to the above embodiments for the same parts.

Referring to FIG. 10 and FIG. 11 , the second sensing circuit 20 includes at least one second photosensitive unit 210, and the second photosensitive unit 210 is used to extract the light signal of the second set wavelength band in the target light signal, and convert the second set wavelength band The second sensing circuit 20 is further configured to output a voltage signal representing the light intensity of the light signal of the second set wavelength band according to the current signal converted by the second photosensitive unit 210 .

Specifically, the second sensing circuit 20 may include a plurality of second photosensitive units 210, and the second photosensitive units 210 may simulate the cone cells of the human eye to sense the light intensity information of the light signal of the second set wavelength band in the target light signal , different second photosensitive units 210 can perceive the light intensity information of light signals of different color components, so that the light intensity information sensed by the second sensing circuit 20 includes the absolute light intensity information and chromaticity information of the light signal, so as to simulate the viewing cone Cells acquire color light intensity information. The second sensing circuit 20 may also integrate the current signal converted by the second photosensitive unit 210 to obtain a voltage signal representing the light intensity of the light signal in the second set wavelength band.

On the basis of the above embodiment, the second photosensitive unit 210 includes a second photosensitive device and a second filter device disposed on the second photosensitive device. At least three colors.

Specifically, the second photosensitive device may be a photodiode (Photo-Diode, PD), capable of converting optical signals into corresponding electrical signals. The second filter device is used to select the wavelength band of the light passing through the device, and the first filter device may be a color filter or an optical lens capable of extracting a set component of the optical signal, such as Byron lens. The second optical filter device can be arranged on the photosensitive surface of the second photosensitive device. After the second optical filter device extracts the optical signal of the second set wavelength band in the target optical signal, the second photosensitive device can extract the optical signal of the second set wavelength band. The optical signal is converted into a corresponding current signal.

Exemplarily, the filter colors of the second filter devices corresponding to the plurality of second photosensitive units 210 include at least red, green and blue. 10 and 11, the second sensing circuit 20 includes four second photosensitive units 210, and the second filter devices corresponding to the four second photosensitive units 210 include a red second filter device, a green second filter device The optical device and the blue second filter device are used as examples to illustrate. The red, green and blue second filter devices make the second photosensitive units respectively form the red photosensitive unit 210 (R) and the green photosensitive unit 210 (G ) and blue photosensitive unit 210(B). When the target light signal is first irradiated to the surface of the second pixel unit P2, the second filter devices in the four second photosensitive units respectively affect the light signal in the red band, the light signal in the green band and the blue band in the target light signal. The optical signal of the second photosensitive unit is extracted, so that the second photosensitive device in the second photosensitive unit can convert the optical signal of the corresponding wavelength band into a corresponding current signal. The second sensing circuit 20 realizes high-precision acquisition of the absolute light intensity information and chromaticity information of the light signals of different components by sensing the light signals of different components in the target light signal.

Exemplarily, on the basis of the foregoing embodiment, when the second set wavelength band includes an infrared wavelength band, the second filter device corresponding to the second photosensitive unit 210 may further include an infrared filter device. In this way, the second sensing circuit 20 can not only sense the light signal of the red light component, the light signal of the green light component and the light signal of the blue light component in the target light signal, but also the light signal of the infrared component, which improves the accuracy of the bionic vision sensor. The perception ability of infrared color light intensity information in the target light signal.

10 and FIG. 11 , the excitatory photosensitive unit 110 , the inhibitory photosensitive unit 120 and the second photosensitive unit 210 are arranged in an array to form a second pixel unit P2 , and the excitatory photosensitive unit 110 and the inhibitory photosensitive unit 120 are used to simulate a human being The rod cells of the eye obtain the grayscale variation of the target light signal, and the second photosensitive unit 210 simulates the cone cells of the human eye to obtain the color intensity information of the target light signal.

10 and 11 , the second pixel unit P2 exemplarily includes one excitation type photosensitive unit 110 , four inhibitory type photosensitive units 120 and four second photosensitive units 210 ; Two photoreceptor units 210 surround the excitatory photoreceptor unit 110 and are respectively disposed adjacent to the excitatory photoreceptor unit 110; In the column direction, the suppression type photosensitive units 120 and the second photosensitive units 210 are alternately arranged.

12 is a schematic diagram of pixel arrangement of a bionic vision sensor provided by an embodiment of the present disclosure. With reference to FIGS. 10 to 12 , a plurality of second pixel units P2 are arranged in an array to form a pixel array, and two adjacent second pixel units are arranged in an array. P2 shares the second photosensitive unit 210 between the two excited photosensitive units 110 and the two inhibited photosensitive units 120 adjacent to the second photosensitive unit 210 .

In the pixel array formed by the excitation type photosensitive unit 110, the inhibition type photosensitive unit 120 and the second photosensitive unit 210, a row of the pixel array includes two types of arrangements, that is, the excitation type photosensitive unit 110 and the second photosensitive unit 210 are alternately arranged, Alternatively, the suppression-type photosensitive units 120 and the second photosensitive units 210 are alternately arranged. One column of the array includes two types of arrangement, that is, the excitation type photosensitive units 110 and the second photosensitive units 210 are alternately arranged, or the inhibition type photosensitive units 120 and the second photosensitive units 210 are alternately arranged. The excitation type photosensitive unit 110 and the inhibition type photosensitive unit 120 are located in different rows and columns of the pixel array, which can improve the ability of the first sensing circuit 10 to perceive the grayscale variation of the light signal. Each row and each column of the pixel array includes a second photosensitive unit 210 to improve the ability of the second sensing circuit 20 to perceive color and light intensity information of the light signal.

In this embodiment, the current signal converted by each exciting photosensitive unit 110 can be calculated with the current signals converted by the surrounding four inhibitory photosensitive units 120, so the current signal converted by each inhibitory photosensitive unit 120 can be At the same time, the operation is performed with the current signals converted by the surrounding four exciting photoreceptor units 110, so as to realize the multiplexing of the inhibitory photoreceptor units 120, which is beneficial to improve the pixel fill factor. In addition, this embodiment also implements multiplexing of the second photosensitive unit 210. For example, the second green photosensitive unit 210 (G) in the second row in the second pixel unit P2 can be used as the green photosensitive unit 210 (G) in the second pixel unit. The photosensitive unit can also be used as a green photosensitive unit in another second pixel unit.

In some embodiments, the second pixel unit P2 includes four second photosensitive units 210 including a red photosensitive unit 210(R), a green photosensitive unit 210(G), and a blue photosensitive unit 210(B). Optionally, the ratio of the number of green photosensitive units 210(G) to the sum of the numbers of red photosensitive units 210(R) and blue photosensitive units 210(B) is 1:1. As shown in FIG. 12 , the second photosensitive unit 210 in the pixel array forms an arrangement of R (red)-G (green)-B (blue)-G, which are sequentially dislocated and periodically arranged from top to bottom. The proportion of pixel color light intensity is: 50% green, 25% red and 25% blue, green has the highest proportion, and the number of green photosensitive units 210 (G) is equal to the number of red photosensitive units 210 (R) and blue photosensitive units 210 ( B) the sum of the quantities. The bionic vision sensor can use the demosaicing digital image processing algorithm to reconstruct the full-color image from the incomplete color samples output by the photosensitive units of the multiplexed green array. Since the human eye is most sensitive to green, this arrangement can be used. Increase the green sampling ratio to obtain the desired target image.

FIG. 13 is a schematic diagram of the second pixel unit arrangement of another bionic vision sensor provided by an embodiment of the present disclosure. Exemplarily, the pixel arrangement structure includes a pixel array of M rows and N columns, and a pixel structure of each coordinate position point. Both are a second pixel unit. In this way, the second pixel unit at each coordinate point can perceive the color light intensity signal and the grayscale change signal, thereby enriching the visual information of the image captured by the bionic vision sensor. Among them, M and N are positive integers.

FIG. 14 is a schematic diagram of the arrangement of a second pixel unit of another bionic vision sensor provided by an embodiment of the present disclosure. As shown in FIG. 14 , the second photosensitive unit 210 in the pixel array forms a G-R-B-R arrangement that is staggered and periodically arranged from top to bottom, and the perceived pixel color light intensity ratio is: 50% red, 25% green and 25% blue, with the highest proportion of red, which can increase the proportion of red sampling.

FIG. 15 is a schematic diagram of the arrangement of a second pixel unit of another bionic vision sensor provided by an embodiment of the present disclosure. Referring to FIG. 15 , the second pixel unit includes four second photosensitive units 210 including a red photosensitive unit 210 (R), a green photosensitive unit 210 (G), a blue photosensitive unit 210 (B) and an infrared photosensitive unit (U), both The infrared light can be directly collected by the infrared photosensitive unit (U), and the change of the infrared light can be sensed by the first photosensitive unit. In some embodiments, the second photosensitive units 210 are alternately arranged R and B from top to bottom, and G and U (infrared) are alternately arranged from left to right, so that the perceived pixel color light intensity ratio is: 25% Red, 25% Green, 25% Blue, and 25% Infrared. The pixel arrangement structure in this embodiment increases the sampling ratio of infrared light, so as to improve the ability of the bionic vision sensor to perceive the color light intensity information of infrared light in the target light signal.

It can be understood that when the sampling ratio of blue or other colors of the bionic vision sensor needs to be increased, the arrangement of pixels can also be in other forms similar to those shown in FIG. 12 , FIG. 14 or FIG. 15 . This is not restricted.

FIG. 16 is a schematic block diagram of a second sensing circuit provided by an embodiment of the present disclosure. As shown in FIG. 16 , the second sensing circuit 20 further includes a third switch 220 , a shutter circuit 230 , a current integration circuit 240 and a module The digital converter 250; the second photosensitive unit 210 is connected to the input end of the current integration circuit 240 through the third switch 220, and the third switch 220 is used to turn on or off the second photosensitive unit 210 and the current integration circuit according to the received control signal 240, the third switch 220 connected to the different second photosensitive unit 210 is turned on in a time-sharing manner; the shutter circuit 230 is connected in parallel with the current integrating circuit 240 for controlling the integration time of the current integrating circuit 240; the current integrating circuit 240 is used for integrating the second The current signal output by the photosensitive unit 210 is integrated to convert the current signal into an analog voltage signal; the input end of the analog-to-digital converter 250 is connected to the output end of the current integration circuit 240 for converting the analog voltage signal into a digital voltage signal.

FIG. 16 schematically shows that the second sensing circuit includes four second photosensitive units 210 , and each of the second photosensitive units 210 is connected to the current integration circuit 240 through the third switch 220 . The four second photosensitive units 210 may correspond to the four second photosensitive units 210 surrounding one excited photosensitive unit 110 in the second pixel unit shown in FIG. 11 . During the operation of the second sensing circuit, the second sensing circuit outputs the electrical signal corresponding to each second photosensitive unit 210 time-divisionally, for example, in the form of line scanning.

The second sensing circuit further includes a shutter circuit 230 which may be a switch, a current integrating circuit 240 which may be a current integrator (IC), and an analog-to-digital converter 250 which may be an analog-to-digital converter (Analog-to-Digital Converter). , ADC). Each second photosensitive unit 210 is connected in series with a third switch 220, and only one third switch 220 is turned on at the same time, so that the second photosensitive unit 210 converts its current signal according to the optical signal of the second set wavelength band It is transmitted to the current integration circuit 240 through the third switch 220 . The current integration circuit 240 can obtain the voltage analog signal of the target capacitor in the second sensing circuit, and the voltage analog signal corresponds to the current signal converted by the second photosensitive unit 210, that is, the current integration circuit 240 realizes the integration of the current signal to obtain the corresponding current signal. voltage signal. The switching time of the shutter circuit 230 can control the integration time of the current integration circuit 240 . For example, the shutter circuit 230 controls the integration time of the current integration circuit 240 to be 33ms. After 33ms, the switch in the shutter circuit 230 is closed. The voltage signal of the light intensity of the optical signal is converted into a digital signal by the analog-to-digital converter 250 for output. After the readout operation of the analog-to-digital converter 250 is completed, the switch in the shutter circuit 230 may also be turned off, so that the current integration circuit 240 continues to integrate the current signal converted by the second photosensitive unit 210 .

FIG. 17 is a schematic diagram of a circuit structure of a second sensing circuit provided by an embodiment of the present disclosure, which may be a specific circuit structure of the second sensing circuit shown in FIG. 16 . Each of the second photosensitive units 210 includes a second photosensitive device and a second filter device disposed on the second photosensitive device. Exemplarily, the second photosensitive device is a photodiode, and the second filter device is a Byron lens or a color filter. The four photodiodes are respectively photodiodes PD21 to PD24. The photodiode PD21 is provided with a red second filter device 211 (R), the photodiode PD22 is provided with a green second filter device 211 (G), and the photodiode PD23 is provided with a second filter device 211 (G). A green second filter device 211 (G) is provided, and a blue second filter device 211 (B) is provided on the photodiode PD24. After the target light signal is irradiated to the second filter device, the second filter devices of different filter colors extract the light signal of the corresponding color band in the target light signal respectively, so that the photodiodes PD21 to PD24 convert the light signal of each color band To characterize the current signal of the corresponding color light intensity.

Referring to FIG. 17 , the second sensing circuit further includes switches MTG1 to MTG4 , switches MRS, switches MSF, and switches MSEL, and each of the switches may be transistors. The first electrodes (eg anodes) of the photodiodes PD21 to PD24 are grounded, the second electrode of the photodiode PD21 is connected to the first electrode of the switch MTG1, the second electrode of the photodiode PD22 is connected to the first electrode of the switch MTG2, and the second electrode of the photodiode PD23 is connected to the first electrode of the switch MTG2. The second electrode of the photodiode PD24 is connected to the first electrode of the switch MTG3, and the second electrode of the photodiode PD24 is connected to the first electrode of the switch MTG4, wherein the second electrode of each photodiode may be a cathode. The second poles of the switches MTG1 to MTG4 are respectively connected to the second pole of the switch MRS and the control terminal of the switch MSF, the first pole of the switch MRS and the first pole of the switch MSF are connected to the power supply signal VCC, and the second pole of the switch MSF is connected to the switch The first pole of the MSEL and the second pole of the switch MSEL serve as the signal output terminal of the second sensing circuit. The switches MTG1 to MTG4, the switch MRS, the switch MSF, and the switch MSEL may be turned on or off according to control signals received by respective control terminals (eg, gates). Optionally, the second sensing circuit further includes a capacitor FD, which can be an actual capacitor structure or a parasitic capacitor in the second sensing circuit, and the capacitor FD can affect the current received by the control terminal of the switch MSF. signal is stored.

Specifically, referring to FIG. 17 , the switch MRS is used for resetting, and the switches MTG1 to MTG4 are turned on in time division, so as to transmit the current signal representing the corresponding color light intensity converted by the photodiodes PD21 to PD24 to the control terminal of the switch MSF in time division. The current signal received by the control terminal of the MSF can be used as a bias signal to control the conduction degree of the switch MSF. The conduction degree of the switch MSF corresponding to different current signals is different, so that the voltage signals output by the switch MSF and the switch MSEL are also different. The combination of the switch MSF and the switch MSEL plays an integral role in the current signal, so that the second sensing circuit can output a voltage signal representing the light intensity of the light signal in the second set wavelength band.

On the basis of the above embodiments, the bionic vision sensor provided by the embodiments of the present disclosure can detect the current signal representing the light intensity variation of the optical signal of the first set wavelength band, and the light representing the optical signal of the second set wavelength band. The bimodal signals of the strong voltage signals are fused to form an image signal including the bimodal signals.

Specifically, the bionic vision sensor can combine the current signal output by the first sensing circuit representing the light intensity variation of the optical signal in the first set wavelength band, and the light signal output by the second sensing circuit representing the second set wavelength band The voltage signal of the light intensity is fused, and combined with the spatial arrangement of the pixel array formed by the excitatory photosensitive unit, the inhibitory photosensitive unit and the second photosensitive unit, the final image output signal is obtained. It should be noted that the output form and speed of the current signal representing the light intensity variation of the optical signal in the first set wavelength band and the output form and speed of the voltage signal representing the light intensity of the optical signal in the second set wavelength band are different. The output speed of the voltage signal of the second sensing circuit is about 30ms, while the scanning speed of the digital-to-analog converter in the first sensing circuit is about 1ms. The first sensing circuit uses an asynchronous event address representation method to output a current signal representing the light intensity variation of the optical signal in the first set band, and the output signal is in the form of (X, Y, P, T). Where "X, Y" is the event address, such as the coordinates of the pixel unit shown in Figure 4, "P" is the 4-value event output (including the first sign bit), for example, the P value can represent the amount of light intensity change, "T" The time at which the event occurred, such as the time of the shot.

FIG. 18 is a schematic diagram of an image output by a bionic vision sensor provided by an embodiment of the present disclosure. FIG. 18 schematically shows two frames of color images before and after the output of the bionic vision sensor, wherein the two frames of color images are generated by the second sensing circuit. The output voltage signal representing the light intensity of the optical signal in the second set band is formed, and the edge point between the two frames of color images is output by the first sensing circuit. The amount of change in the light intensity of the optical signal representing the first set band The current signal is formed.

A voltage-current type bionic vision sensor provided by an embodiment of the present disclosure senses an optical signal of a first set wavelength band in a target optical signal through a first sensing circuit, and outputs a light intensity representing the optical signal of the first set wavelength band The current signal of the changing amount is used to simulate the rod cells to obtain the light intensity gradient information, so as to improve the sensor's ability to perceive dynamic targets, increase the dynamic range of the image collected by the sensor, and improve the shooting speed of the sensor; sensed by the second sensing circuit In the target light signal, the light signal of the second set wavelength band is output, and a voltage signal representing the light intensity of the light signal of the second set wavelength band is output to simulate the cone cells to obtain color light intensity information, which is beneficial to improve the quality of the image captured by the sensor. Color reproduction and image quality. It solves the defects of limited application scenarios, poor stability and limited performance of existing vision sensors, and realizes the simultaneous acquisition of high-quality color light intensity signals and high-speed grayscale change signals, through the complementation of image signals of the two modalities. , enriches the visual information of the image, and combines the advantages of high-speed, high-fidelity, high dynamic range and high temporal resolution shooting. In addition, the bionic vision sensor can also sense the color light intensity information and/or light intensity change information of infrared light in the target light signal, which can broaden the application scenarios of the sensor.

Note that the above are only preferred embodiments of the present disclosure and applied technical principles. Those skilled in the art will understand that the present disclosure is not limited to the specific embodiments described herein, and various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present disclosure. Therefore, although the present disclosure has been described in detail through the above embodiments, the present disclosure is not limited to the above embodiments, and can also include more other equivalent embodiments without departing from the concept of the present disclosure. The scope is determined by the scope of the appended claims.

Claims

A bionic visual sensor, characterized in that it includes: a first sensing circuit, the first sensing circuit includes an excitation type photosensitive unit, an inhibitory type photosensitive unit and a sensing control unit, wherein,

The excitation type photosensitive unit and the inhibitory photosensitive unit are both used for extracting the light signal of the first set wavelength band in the target light signal, and converting the light signal of the first set wavelength band into a current signal;

The sensing control unit is configured to output a current representing the light intensity variation of the light signal of the first set wavelength band according to the difference between the current signals converted by the excitation type photosensitive unit and the inhibition type photosensitive unit Signal.
The bionic visual sensor according to claim 1, wherein the first set wavelength band includes an infrared wavelength band, the excitation-type photosensitive unit and the inhibition-type photosensitive unit each include a first photosensitive device, and the first photosensitive unit includes a first photosensitive device. The device is an infrared photosensitive device.
The bionic vision sensor according to claim 1, wherein the first set wavelength band includes an infrared wavelength band, and both the excitation-type photosensitive unit and the inhibition-type photosensitive unit include a first photosensitive device and a a first filter device on the first photosensitive device;

The first photosensitive device is an infrared photosensitive device and/or the first filter device is an infrared filter device.
The bionic vision sensor according to claim 1, wherein the first set wavelength band includes an infrared wavelength band, and both the excitation-type photosensitive unit and the inhibition-type photosensitive unit include a first photosensitive device and a a first filter device on the first photosensitive device;

The first photosensitive device in the exciting photosensitive unit is an infrared photosensitive device, and the first filter device in the inhibited photosensitive unit is an infrared filter device; or, the exciting photosensitive unit The first filter device is an infrared filter device, and the first photosensitive device in the suppression-type photosensitive unit is an infrared photosensitive device;

The first sensing circuit is further configured to correct the consistency of the spectral response characteristics of the excitatory photoreceptor unit and the inhibitory photoreceptor unit.
The bionic visual sensor according to any one of claims 1-4, wherein the excitatory photoreceptor units and the inhibitory photoreceptor units are distributed in different regions of the bionic visual sensor.
The bionic visual sensor according to claim 5, wherein the excitatory photosensitive units and the inhibitory photosensitive units are arranged in an array to form a first pixel unit.
The bionic visual sensor according to claim 6, wherein the first pixel unit comprises one of the excitatory photoreceptor units and four of the inhibitory photoreceptor units; and the four inhibitory photoreceptor units surround the Excited photoreceptor units are arranged and connected to the excited photoreceptor units respectively.
The bionic visual sensor according to claim 7, wherein the projections of the excitation-type photosensitive unit and the inhibitory-type photosensitive unit on the same plane are all rectangles, and the tops of the four inhibitory-type photosensitive units are all rectangular. The corners are respectively connected with the four top corners of the excitatory photoreceptor unit.
The bionic vision sensor according to claim 6, wherein a plurality of the first pixel units are arranged in an array to form a pixel array, and two adjacent first pixel units share a row or a column of the suppressed photosensitive unit.
The bionic visual sensor according to claim 1, wherein the sensing control unit further comprises an excitatory control circuit and at least one inhibitory control circuit connected to the excitatory control circuit;

The excitation type control circuit is connected to the excitation type photosensitive unit, the inhibition type control circuit is connected to the inhibition type photosensitive unit, and is set in a one-to-one correspondence with the inhibition type photosensitive unit, and the inhibition type control circuit is used to The current signal converted by the inhibitory photosensitive unit is transmitted to the excitatory control circuit connected to the inhibitory control circuit;

The excitatory control circuit is used for controlling itself to be turned on or off with the inhibitory control circuit according to the received control signal, and according to the current signal converted between the excitatory photosensitive unit and the inhibitory photosensitive unit. difference, output a current signal representing the light intensity variation of the light signal in the first set wavelength band.
The bionic vision sensor according to claim 10, wherein the excitation control circuit comprises: a signal amplification unit, an adder, a digital-to-analog converter, a comparator, a three-state gate and at least one first switch;

The input end of the signal amplifying unit is connected to the excited photosensitive unit, and the output end of the signal amplifying unit is connected to the first input end of the comparator;

The suppression type control circuit is connected to the input end of the adder through the first switch, and the output end of the adder is connected to the second input end of the comparator;

The input end of the digital-to-analog converter is connected to the output end of the comparator, the analog signal output end of the digital-to-analog converter is respectively connected to the input end of the signal amplifying unit and the input end of the adder, the The digital-to-analog converter is used for inputting an analog signal to the input terminal of the signal amplifying unit or the input terminal of the adder according to the comparison result signal output by the comparator, so that the output of the comparator includes the first device. The comparison result signal of the light intensity variation of the optical signal of the fixed wavelength band;

The control terminal of the three-state gate is connected to the output terminal of the comparator, the input terminal of the three-state gate is connected to the input terminal of the digital-to-analog converter, and the three-state gate is used for according to the output of the comparator. signal, and output a current signal representing the light intensity variation of the light signal in the first set wavelength band.
The bionic vision sensor according to claim 11, wherein the excitation control circuit further comprises a storage unit connected to the output end of the tri-state gate, for storing and outputting the signal output by the tri-state gate .
The bionic visual sensor according to claim 10, wherein the suppression type control circuit comprises: a second switch connected to the suppression type photosensitive unit and a second switch connected to the suppression type photosensitive unit and the second switch at least one mirror switch, the inhibitory control circuit is connected to the excitatory control circuit through the mirror switch.
The bionic vision sensor according to claim 1, further comprising a second sensing circuit for extracting an optical signal of a second set wavelength band in the target optical signal, and outputting an optical signal representing the second set The voltage signal of the light intensity of the light signal in the wavelength band;

At least one of the first set wavelength band and the second set wavelength band includes an infrared wavelength band.
The bionic vision sensor according to claim 14, wherein the second sensing circuit comprises at least one second photosensitive unit, and the second photosensitive unit is used to extract the light of the second set wavelength band in the target light signal signal, and convert the optical signal of the second set wavelength band into a current signal;

The second sensing circuit is further configured to output a voltage signal representing the light intensity of the light signal of the second set wavelength band according to the current signal converted by the second photosensitive unit.
The bionic visual sensor according to claim 15, wherein the second photosensitive unit comprises a second photosensitive device and a second filter device disposed on the second photosensitive device, and a plurality of the second photosensitive devices The filter colors of the second filter device corresponding to the unit are at least three.
The bionic vision sensor according to claim 16, wherein the second set wavelength band includes an infrared wavelength band, and the second filter device includes an infrared filter device.
The bionic visual sensor according to claim 15, wherein the excitation type photosensitive unit, the inhibitory type photosensitive unit and the second photosensitive unit are arranged in an array to form a second pixel unit.
The bionic visual sensor according to claim 18, wherein the second pixel unit comprises one of the excitatory photosensitive units, four of the inhibitory photosensitive units and four of the second photosensitive units;

The four second photosensitive units in the second pixel unit surround the excitatory photosensitive unit, and are respectively arranged adjacent to the excitatory photosensitive unit; the four second photosensitive units in the second pixel unit are inhibited A type photosensitive unit is arranged around the excitation type photosensitive unit, and in a row direction and a column direction having the inhibition type photosensitive unit, the inhibition type photosensitive unit and the second photosensitive unit are alternately arranged.
The bionic vision sensor according to claim 19, wherein a plurality of the second pixel units are arranged in an array to form a pixel array, and two adjacent second pixel units share two of the excited photosensitive units The second photosensitive unit therebetween, and the two suppression-type photosensitive units adjacent to the second photosensitive unit.
The bionic visual sensor according to claim 20, wherein the four second photosensitive units in the second pixel unit comprise a red photosensitive unit, a green photosensitive unit and a blue photosensitive unit.
The bionic visual sensor according to claim 20, wherein the second set wavelength band includes an infrared wavelength band, and the four second photosensitive units in the second pixel unit include a red photosensitive unit and a green photosensitive unit. , blue photosensitive unit and infrared photosensitive unit.
The bionic visual sensor according to claim 15, wherein the second sensing circuit further comprises a third switch, a shutter circuit, a current integrating circuit and an analog-to-digital converter;

The second photosensitive unit is connected to the input end of the current integrating circuit through the third switch, and the third switch is used to turn on or off the second photosensitive unit and the current according to the received control signal an integrating circuit, the third switch connected to the second photosensitive unit is time-divisionally turned on;

The shutter circuit is connected in parallel with the current integration circuit, and is used for controlling the integration time of the current integration circuit;

The current integration circuit is configured to integrate the current signal output by the second photosensitive unit, so as to convert the current signal into an analog voltage signal;

The input terminal of the analog-to-digital converter is connected to the output terminal of the current integration circuit, and is used for converting the analog voltage signal into a digital voltage signal.