CN112543271A

CN112543271A - Bimodal ultraviolet bionic vision sensor

Info

Publication number: CN112543271A
Application number: CN202011409267.8A
Authority: CN
Inventors: 施路平; 杨哲宇; 赵蓉; 王韬毅; 裴京
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2020-12-03
Filing date: 2020-12-03
Publication date: 2021-03-23
Anticipated expiration: 2040-12-03
Also published as: CN112543271B

Abstract

The embodiment of the invention discloses a bimodal ultraviolet bionic vision sensor. The bimodal ultraviolet bionic vision sensor comprises: the first sensing circuit is used for extracting an optical signal of a first set waveband in a target optical signal and outputting a current signal representing the light intensity variation of the optical signal of the first set waveband; the second sensing circuit is used for extracting an optical signal of a second set waveband in the target optical signal and outputting a voltage signal representing the light intensity of the optical signal of the second set waveband; wherein at least one of the first set wavelength band and the second set wavelength band includes an ultraviolet wavelength band. The bimodal ultraviolet bionic vision sensor provided by the embodiment of the invention not only can simultaneously acquire a high-quality color light intensity signal and a high-speed gray scale variation signal, but also can sense the color light intensity information and/or the light intensity variation information of ultraviolet rays in a target light signal, thereby further widening the application scene of the bimodal ultraviolet bionic vision sensor.

Description

Bimodal ultraviolet bionic vision sensor

Technical Field

The embodiment of the invention relates to the technical field of image sensing, in particular to a bimodal ultraviolet bionic vision sensor.

Background

The vision sensor refers to an apparatus for acquiring image information of an external environment by using an optical element and an imaging device, and the vision sensor in the prior art generally includes: active Pixel Sensors (APS) and Dynamic Vision Sensors (DVS). Among them, the active pixel sensor is usually an image sensor based on a voltage signal or a current signal, and is widely applied to an image pickup unit of a mobile phone or a camera, and such an image sensor has the advantages of high color reproduction and high image quality, but the dynamic range of the acquired image signal is small, and the shooting speed is slow. The dynamic vision sensor is commonly used in the field of industrial control, and is characterized by being capable of sensing a dynamic scene, and because the shooting speed is high and the dynamic range of the obtained image signal is large, the quality of the image acquired by the sensor is poor.

At present, the existing vision sensor has the following defects: (1) the application scenarios are limited: the active pixel sensor has a slow shooting speed and a small dynamic range, is difficult to be widely applied, and is not suitable for a static scene because the quality of an image shot by the dynamic visual sensor is poor. (2) The stability is poor: both the active pixel sensor and the dynamic vision sensor only comprise a single sensing mode, so when the sensing mode fails, the sensor also fails, for example, when the ambient light intensity is dark, the active pixel sensor is difficult to capture images due to limited dynamic range, and when the scene has no target motion, the dynamic vision sensor is difficult to capture images due to sensitivity to only moving targets. (3) The performance is limited: the image quality, the dynamic range and the shooting speed are three indexes for evaluating the performance of the vision sensor, and the three indexes of the traditional vision sensor are often mutually exclusive, for example, when the shooting speed of the sensor is increased, the dynamic range is reduced, and when the image quality is increased, the shooting speed is reduced. The active pixel sensor and the dynamic vision sensor have advantages and disadvantages, and cannot simultaneously meet the three performance indexes.

Thus, the prior art lacks a vision sensor that combines the advantages of both a source pixel sensor and a dynamic vision sensor, and has no solution for a voltage-current type vision sensor.

Disclosure of Invention

The embodiment of the invention provides a bimodal ultraviolet bionic vision sensor, which is used for simultaneously acquiring a high-quality color light intensity signal and a high-speed gray scale variation signal.

The embodiment of the invention provides a bimodal ultraviolet bionic vision sensor, which comprises:

the first sensing circuit is used for extracting an optical signal of a first set waveband in a target optical signal and outputting a current signal representing the light intensity variation of the optical signal of the first set waveband;

the second sensing circuit is used for extracting an optical signal of a second set waveband in the target optical signal and outputting a voltage signal representing the light intensity of the optical signal of the second set waveband;

wherein at least one of the first set wavelength band and the second set wavelength band includes an ultraviolet wavelength band.

Optionally, the first sensing circuit includes a first excitation type photosensitive unit and a first inhibition type photosensitive unit, and the first excitation type photosensitive unit and the first inhibition type photosensitive unit are both configured to extract an optical signal in a first set wavelength band from a target optical signal and convert the optical signal in the first set wavelength band into a current signal;

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

Optionally, the first set wavelength band includes an ultraviolet wavelength band, and the first excitation type photosensitive unit and the first inhibition type photosensitive unit each include a first photosensitive device, and the first photosensitive device is an ultraviolet photosensitive device.

Optionally, the first set wavelength band includes an ultraviolet wavelength band, and the first excitation type photosensitive unit and the first inhibition type photosensitive unit each include a first photosensitive device and a first filter device disposed on the first photosensitive device;

the first photosensitive device is an ultraviolet photosensitive device and/or the first light filtering device is an ultraviolet light filtering device.

the first light sensing device in the first excitation type light sensing unit is an ultraviolet light sensing device, and the first light filtering device in the first inhibition type light sensing unit is an ultraviolet light filtering device; or, the first light filter device in the first excitation type photosensitive unit is an ultraviolet filter device, and the first photosensitive device in the first inhibition type photosensitive unit is an ultraviolet photosensitive device;

the first sensing circuit is further configured to correct the consistency of the spectral response characteristics of the first excitation type photosensitive unit and the first inhibition type photosensitive unit.

Optionally, the second sensing circuit includes at least one second photosensitive unit, and the second photosensitive unit is configured to extract an optical signal in a second set wavelength band from the target optical signal and convert the optical signal in the second set wavelength band into a current signal;

the second sensing circuit is further used for outputting a voltage signal representing the light intensity of the optical signal of the second set waveband according to the current signal converted by the second photosensitive unit.

Optionally, the second photosensitive unit includes a second photosensitive device and a second filter device disposed on the second photosensitive device, and the filter colors of the second filter device corresponding to the plurality of second photosensitive units are at least three.

Optionally, the second set wavelength band comprises an ultraviolet wavelength band and the second filter device comprises an ultraviolet filter device.

Optionally, the first sensing circuit includes a first excitation type photosensitive unit and a first inhibition type photosensitive unit, and the second sensing circuit includes a second photosensitive unit;

the first excitation type photosensitive unit, the first inhibition type photosensitive unit and the second photosensitive unit are arranged in an array mode to form a pixel unit.

Optionally, the pixel unit comprises one first excitation type photosensitive unit, four first inhibition type photosensitive units and four second photosensitive units;

the four second photosensitive units in the pixel units surround the first excitation type photosensitive unit and are respectively arranged adjacent to the first excitation type photosensitive unit; four of the pixel units are arranged around the first excitation type photosensitive unit, and the first inhibition type photosensitive units and the second photosensitive units are alternately arranged in a row direction and a column direction with the first inhibition type photosensitive units.

Optionally, a plurality of the pixel units are arranged in an array to form a pixel array, and two adjacent pixel units share the second photosensitive unit between the two first excitation type photosensitive units and two first inhibition type photosensitive units adjacent to the second photosensitive unit.

Optionally, four of the second light sensing units in the pixel unit include a red light sensing unit, a green light sensing unit and a blue light sensing unit.

Optionally, the ratio of the number of the green photosensitive units to the sum of the numbers of the red photosensitive units and the blue photosensitive units is 1: 1.

Optionally, the second set wavelength band includes an ultraviolet wavelength band, and four of the second photosensitive units in the pixel units include a red photosensitive unit, a green photosensitive unit, a blue photosensitive unit, and an ultraviolet photosensitive unit.

Optionally, the first sensing circuit further comprises a first excitatory control circuit and at least one first inhibitory control circuit connected to the first excitatory control circuit;

the first excitation type control circuit is connected with the first excitation type photosensitive unit, the first inhibition type control circuit is connected with the first inhibition type photosensitive unit and is arranged in one-to-one correspondence with the first inhibition type photosensitive unit, and the first inhibition type control circuit is used for transmitting a current signal converted by the first inhibition type photosensitive unit to the first excitation type control circuit connected with the first inhibition type control circuit;

the first excitation control circuit is used for controlling the self and the first inhibition control circuit to be switched on or switched off according to the received control signal, and outputting a current signal representing the light intensity variation of the optical signal of the first set waveband according to the difference between the current signals converted by the first excitation photosensitive unit and the first inhibition photosensitive unit.

Optionally, the first excitation control circuit comprises: the device comprises a signal amplifying 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 amplification unit is connected with the first excitation type photosensitive unit, and the output end of the signal amplification unit is connected with the first input end of the comparator;

the first inhibition type control circuit is connected with the input end of the adder through the first switch, and the output end of the adder is connected with the second input end of the comparator;

the input end of the digital-to-analog converter is connected with the output end of the comparator, the analog signal output end of the digital-to-analog converter is respectively connected with the input end of the signal amplification unit and the input end of the adder, and the digital-to-analog converter is used for inputting an analog signal to the input end of the signal amplification unit or the input end of the adder according to a comparison result signal output by the comparator so that the comparator outputs a comparison result signal containing the light intensity variation of the optical signal of the first set waveband;

the control end of the tri-state gate is connected with the output end of the comparator, the input end of the tri-state gate is connected with the input end of the digital-to-analog converter, and the tri-state gate is used for outputting a current signal representing the light intensity variation of the optical signal of the first set waveband according to the signal output by the comparator.

Optionally, the first excitation control circuit further comprises a storage unit connected to the output terminal of the tri-state gate, for storing and outputting the signal output by the tri-state gate.

Optionally, the first suppression control circuit comprises: the first excitation type control circuit comprises a first switch connected with the first inhibition type photosensitive unit and at least one mirror image switch connected with the first inhibition type photosensitive unit and the second switch, and the first inhibition type control circuit is connected with the first excitation type control circuit through the mirror image switch.

Optionally, the second sensing circuit further comprises a third switch, a shutter circuit, a current integration circuit, and an analog-to-digital converter;

the second photosensitive unit is connected with the input end of the current integrating circuit through the third switch, the third switch is used for switching on or switching off the second photosensitive unit and the current integrating circuit according to a received control signal, and the third switch connected with different second photosensitive units is switched on in a time-sharing manner;

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

the current integration circuit is used for integrating the current signal output by the second photosensitive unit so as to convert the current signal into an analog voltage signal;

the input end of the analog-to-digital converter is connected with the output end of the current integrating circuit and used for converting the analog voltage signal into a digital voltage signal.

The technical scheme of the embodiment of the invention provides a bimodal ultraviolet bionic vision sensor, which is used for simulating different vision perception cells in retina of human eyes, perceiving an optical signal of a first set waveband in an optical signal of a target through a first sensing circuit, and outputting a current signal representing the light intensity variation of the optical signal of the first set waveband so as to simulate a rod cell to acquire light intensity gradient information, thereby improving the perception capability of the sensor on a dynamic target, enlarging the dynamic range of an image acquired by the sensor and improving the shooting speed of the sensor; the second sensing circuit senses the optical signal of the second set waveband in the target optical signal and outputs a voltage signal representing the light intensity of the optical signal of the second set waveband to simulate the cone cells to acquire color light intensity information, thereby being beneficial to improving the color reduction degree and the image quality of the image shot by the sensor. The technical scheme of the embodiment of the invention overcomes the defects of limited application scene, poor stability, limited performance and the like of the existing visual sensor, realizes the simultaneous acquisition of high-quality color light intensity signals and high-speed gray scale variable quantity signals, enriches the visual information of images through the complementation of image signals of two modes, and has the advantages of high speed, high fidelity, high dynamic range and high time resolution shooting. In addition, the bimodal ultraviolet bionic vision sensor can also sense the color light intensity information and/or the light intensity change information of ultraviolet rays in the target light signal, and the application scenes of the sensor are further widened.

Drawings

FIG. 1 is a schematic block diagram of a bimodal ultraviolet bionic vision sensor according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a pixel unit in a bimodal ultraviolet bionic vision sensor according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of pixel arrangement of a bimodal ultraviolet bionic vision sensor provided in an embodiment of the present invention;

FIG. 4 is a schematic diagram of pixel arrangement of another bimodal ultraviolet bionic vision sensor provided in the embodiments of the present invention;

FIG. 5 is a schematic diagram of pixel arrangement of another bimodal ultraviolet bionic vision sensor provided in the embodiments of the present invention;

FIG. 6 is a schematic diagram of pixel arrangement of another bimodal ultraviolet bionic vision sensor provided in the embodiments of the present invention;

fig. 7 is a schematic block diagram of a first sensing circuit according to an embodiment of the present invention;

fig. 8 is a block diagram of a first excitation control circuit according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of a signal waveform provided by an embodiment of the present invention;

fig. 10 is a schematic circuit diagram of a first excitation control circuit according to an embodiment of the present invention;

fig. 11 is a schematic structural diagram of a first suppression control circuit according to an embodiment of the present invention;

fig. 12 is a schematic block diagram of a second sensing circuit according to an embodiment of the present invention;

fig. 13 is a schematic circuit diagram of a second sensing circuit according to an embodiment of the present invention;

FIG. 14 is a schematic diagram of an image output by a bimodal ultraviolet bionic vision sensor according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

As described in the background art, the existing vision sensor has the defects of limited application scene, poor stability, limited performance and the like, and the existing technology lacks a vision sensor having the advantages of both the source pixel sensor and the dynamic vision sensor and has no solution of the voltage current type vision sensor.

In order to solve the above problems, an embodiment of the present invention provides a bimodal ultraviolet bionic vision sensor. Fig. 1 is a schematic block structure diagram of a dual-mode ultraviolet bionic vision sensor provided in an embodiment of the present invention, as shown in fig. 1, the dual-mode ultraviolet bionic vision sensor includes a first sensing circuit 10 and a second sensing circuit 20; the first sensing circuit 10 is configured to extract an optical signal in a first set wavelength band from the target optical signal, and output a current signal representing a light intensity variation of the optical signal in the first set wavelength band; the second sensing circuit 20 is configured to extract an optical signal in a second set wavelength band from the target optical signal, and output a voltage signal representing the light intensity of the optical signal in the second set wavelength band; wherein at least one of the first set wavelength band and the second set wavelength band includes an ultraviolet wavelength band.

The bimodal ultraviolet bionic vision sensor provided by the embodiment of the invention can be used for shooting a target object to acquire an image signal or a video signal, wherein the target object can be a static person, a dynamic person, a static scene, a dynamic scene or the like, and can also be an object in other forms, and the embodiment of the invention is not limited to this.

Specifically, referring to fig. 1, the first sensing circuit 10 and the second sensing circuit 20 may each be an active pixel sensing circuit including an image sensor, the dual-mode ultraviolet bionic vision sensor may include a plurality of the first sensing circuits 10 and the second sensing circuits 20, and the image sensors in the plurality of the first sensing circuits 10 and the second sensing circuits 20 may be capable of forming a pixel sensing structure to achieve acquisition of an image signal or a video signal of a target object. The target optical signal is an optical signal reflected by the surface of a target object, and when the target object is photographed by using the dual-mode ultraviolet bionic vision sensor, the optical signal reflected by the surface of the target object can directly or indirectly irradiate the surfaces of the image sensors in the first sensing circuit 10 and the second sensing circuit 20, so that the image sensors convert the target optical signal into an electrical signal reflecting the characteristics of the target object.

The optical signal of the first set wavelength band may be, for example, an optical signal of at least a partial wavelength band of the visible light and ultraviolet light wavelength bands. The first sensing circuit 10 may directly collect the optical signal of the first set wavelength band through an image sensor therein, or may extract the optical signal of the first set wavelength band in the target optical signal through an optical lens or a filter device, sense the light intensity change in the optical signal of the first set wavelength band, and output a current signal representing the light intensity change amount of the optical signal of the first set wavelength band. Wherein, the light intensity variation is gray scale variation or light intensity gradient information.

The first sensing circuit 10 is an active pixel sensing circuit whose operation mode is a current mode, where the current mode is that an image sensor in the first sensing circuit 10 can convert an optical signal into a current signal, the first sensing circuit 10 may include at least two image sensors, the current signal output by the first sensing circuit 10 and representing the amount of change in optical intensity of the optical signal in a first set wavelength band may be a current signal obtained by comparing the current signal converted by the first sensing circuit 10 according to one of the image sensors with a difference between current signals converted by at least one image sensor around the image sensor, and the current signal representing the amount of change in optical intensity is obtained. The first sensing circuit 10 in the current mode can rapidly convert an optical signal and output a current signal having a function of facilitating a mathematical operation to obtain a high-speed differential signal.

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

The second sensing circuit 20 is an active pixel sensing circuit whose operating mode is a voltage mode, where the voltage mode is that an image sensor in the second sensing circuit 20 can convert an optical signal in a second set wavelength band into a current signal, the second sensing circuit 20 can integrate the current signal to obtain a voltage signal representing the light intensity of the optical signal in the second set wavelength band, and the second sensing circuit 20 in the voltage mode is more suitable for obtaining a high-precision color vision signal.

The first set wavelength band and the second set wavelength band may be the same wavelength band or different wavelength bands. The ultraviolet band is lower than the visible band, for example, 760nm to 1 mm. At least one of the first set waveband and the second set waveband includes an ultraviolet waveband, that is, the optical signal extracted from the target optical signal by at least one of the first sensing circuit 10 and the second sensing circuit 20 includes an ultraviolet signal (i.e., ultraviolet), so that the dual-mode ultraviolet bionic vision sensor can also sense color light intensity information and/or light intensity change information of the ultraviolet in the target optical signal, so that the dual-mode ultraviolet bionic vision sensor can be widely applied to ultraviolet cameras in various fields.

The technical scheme of the embodiment of the invention provides a voltage-current dual-mode ultraviolet bionic vision sensor, which is used for simulating different vision perception cells in the retina of a human eye, perceiving an optical signal of a first set waveband in a target optical signal through a first sensing circuit, outputting a current signal representing the light intensity variation of the optical signal of the first set waveband, and simulating a rod eye cell to acquire light intensity gradient information, so that the perception capability of the sensor on a dynamic target is improved, the dynamic range of an image acquired by the sensor is enlarged, and the shooting speed of the sensor is improved; the second sensing circuit senses the optical signal of the second set waveband in the target optical signal and outputs a voltage signal representing the light intensity of the optical signal of the second set waveband to simulate the cone cells to acquire color light intensity information, thereby being beneficial to improving the color reduction degree and the image quality of the image shot by the sensor. The technical scheme of the embodiment of the invention overcomes the defects of limited application scene, poor stability, limited performance and the like of the existing visual sensor, realizes the simultaneous acquisition of high-quality color light intensity signals and high-speed gray scale variable quantity signals, enriches the visual information of images through the complementation of image signals of two modes, and has the advantages of high speed, high fidelity, high dynamic range and high time resolution shooting. In addition, the bimodal ultraviolet bionic vision sensor can also sense the color light intensity information and/or the light intensity change information of ultraviolet rays in the target light signal, and the application scenes of the sensor are further widened.

Fig. 2 is a schematic structural diagram of a Pixel unit in a dual-mode ultraviolet bionic vision sensor provided by an embodiment of the present invention, where the Pixel unit Pixel 1 may be a Pixel unit in a Pixel sensing structure of the dual-mode ultraviolet bionic vision sensor. With reference to fig. 1 and 2, for example, on the basis of the above-described embodiment, the first sensing circuit 10 is provided to include the first excitation type photosensitive unit 110 and the first inhibition type photosensitive unit 120, and each of the first excitation type photosensitive unit 110 and the first inhibition type photosensitive unit 120 is configured to extract an optical signal of a first set wavelength band from the target optical signal and convert the optical signal of the first set wavelength band into a current signal; the first sensing circuit 10 is further configured to output a current signal representing a light intensity variation of the optical signal of the first set wavelength band according to a difference between the current signals converted by the first excitation type photosensitive unit 110 and the first inhibition type photosensitive unit 120.

Specifically, referring to fig. 1 and 2, the first sensing circuit 10 may include a first excitation type photosensitive unit 110 and at least one first inhibition type photosensitive unit 120 located around the first excitation type photosensitive unit 110, the first excitation type photosensitive unit 110 may simulate an excitation type rod cell of a human eye, the first inhibition type photosensitive unit 120 may simulate an inhibition type rod cell of the human eye, the first excitation type photosensitive unit 110 and the first inhibition type photosensitive unit 120 may respectively sense gray scale information of an optical signal of a first set wavelength band, and the first sensing circuit 10 may output a current differential signal representing a light intensity variation amount of the optical signal of the first set wavelength band according to a difference between current signals converted by the first excitation type photosensitive unit 110 and the first inhibition type photosensitive unit 120 to simulate the rod cell to obtain light intensity gradient information.

With reference to fig. 1 and fig. 2, the operation principle of the first sensing circuit 10 will be described by taking an example in which the first sensing circuit 10 includes one first excitation type photosensitive unit 110 and four first inhibition type photosensitive units 120 surrounding the first excitation type photosensitive unit 110. When the target light signal is irradiated to the surface of the Pixel unit Pixel 1, the first excitation type photosensitive unit 110 and the four first inhibition type photosensitive units 120 respectively sense the gray scale information of the light signal of the first set waveband in the target light signal, and convert the light signal of the first set waveband into a corresponding current signal. The first sensing circuit 10 may subtract the current signal converted by the first excitation type photosensitive unit 110 from the average value of the current signals converted by the four first inhibition type photosensitive units 120 to obtain a differential current signal, i.e., a light intensity gradient signal reflecting the light intensity variation.

Referring to fig. 1 and 2, for example, in one embodiment of the present invention, the first set wavelength band is set to include an ultraviolet wavelength band, and the first excitation type photosensitive unit 110 and the first inhibition type photosensitive unit 120 each include a first photosensitive device, which is an ultraviolet photosensitive device.

In particular, the first Photo sensing device may be a Photo-Diode (PD) capable of converting an optical signal into a corresponding electrical signal. When the first set wavelength band includes an ultraviolet wavelength band, the first photosensitive device may be an ultraviolet-sensitive photosensitive device, such as an ultraviolet photodiode. Therefore, the bimodal ultraviolet bionic vision sensor can sense the light intensity change information of the ultraviolet rays in the target light signal.

Referring to fig. 1 and 2, for example, in some embodiments of the present invention, the first set wavelength band is set to include an ultraviolet wavelength band, and each of the first excitation type photosensitive unit 110 and the first inhibition type photosensitive unit 120 includes a first photosensitive device and a first filter device disposed on the first photosensitive device; the first photosensitive device is an ultraviolet photosensitive device and/or the first light filtering device is an ultraviolet light filtering device.

Specifically, the first filter device is used to select a wavelength band of light passing through the device, and the first filter device may be a Color filter (Color filter) or an optical lens capable of extracting a light signal of a set component, such as a bayer lens. The first optical filter device may be disposed on a photosensitive surface of the first optical sensor device, such that the target optical signal is first irradiated to the surface of the first optical filter device, and the first optical filter device extracts an optical signal in a set wavelength band in the target optical signal, for example, an optical signal in a first set wavelength band including an ultraviolet wavelength band in the target optical signal, so that the optical signal in the first set wavelength band is irradiated to the photosensitive surface of the first optical sensor device, and the optical signal in the first set wavelength band is converted into a corresponding current signal by the first optical sensor device. When the first set waveband comprises an ultraviolet waveband, the first photosensitive device is set to be an ultraviolet photosensitive device and/or the first filtering device is set to be an ultraviolet filtering device, and the sensing capability of the bimodal ultraviolet bionic vision sensor on the light intensity change information of ultraviolet rays in the target light signal is improved.

In other embodiments of the present invention, as shown in fig. 1 and 2, the first set wavelength band is set to include an ultraviolet wavelength band, and each of the first excitation type photosensitive unit 110 and the first inhibition type photosensitive unit 120 includes a first photosensitive device and a first filter device disposed on the first photosensitive device. The first photosensitive device in the first excitation type photosensitive unit 110 is an ultraviolet photosensitive device, and the first filter device in the first inhibition type photosensitive unit 120 is an ultraviolet filter device; alternatively, the first filter device in the first excitation type photosensitive unit 110 is an ultraviolet filter device, and the first filter device in the first inhibition type photosensitive unit 120 is an ultraviolet filter device. The first sensor circuit 10 is also used to correct the uniformity of the spectral response characteristics of the first excitation type photosensitive unit 110 and the first inhibition type photosensitive unit 120.

Specifically, the first photosensitive device in the first excitation type photosensitive unit 110 is set to be an ultraviolet photosensitive device, the first optical filter in the first inhibition type photosensitive unit 120 is set to be an ultraviolet optical filter, or the first optical filter in the first excitation type photosensitive unit 110 is set to be an ultraviolet optical filter, and the first optical filter in the first inhibition type photosensitive unit 120 is set to be an ultraviolet optical filter, so that the sensing capability of the bimodal ultraviolet bionic vision sensor on the light intensity change information of ultraviolet rays in the target optical signal is improved. When one of the first excitation type photosensitive unit 110 and the first inhibition type photosensitive unit 120 extracts the optical signal of the first set wavelength band including the ultraviolet wavelength band in the target optical signal through the ultraviolet photosensitive device in cooperation with the common optical filter device, and the other extracts the optical signal of the first set wavelength band including the ultraviolet wavelength band in the target optical signal through the ultraviolet optical filter in cooperation with the common photosensitive device, in order to avoid too large difference between the optical signals extracted by the two, the consistency of the spectral response characteristics of the first excitation type photosensitive unit 110 and the first inhibition type photosensitive unit 120 can be corrected, so that the capability of the bimodal ultraviolet bionic visual sensor for sensing the light intensity change information of the ultraviolet in the target optical signal is improved.

Referring to fig. 1 and fig. 2, in the present embodiment, it may be further provided that the second sensing circuit 20 includes at least one second photosensitive unit 210, and the second photosensitive unit 210 is configured to extract an optical signal in a second set wavelength band from the target optical signal and convert the optical signal in the second set wavelength band into a current signal; the second sensing circuit 20 is further configured to output a voltage signal representing the light intensity of the optical signal of the second set wavelength band according to the current signal converted by the second light sensing unit 210.

Specifically, the second sensing circuit 20 may include a plurality of second light sensing units 210, the second light sensing units 210 may simulate the cones of human eyes, sense the light intensity information of the light signals in the second set wavelength band in the target light signal, and different second light sensing units 210 may sense the light intensity information of the light signals in different color components, so that the light intensity information sensed by the second sensing circuit 20 includes the absolute light intensity information and the chromaticity information of the light signals, thereby simulating the cones to obtain the color light intensity information. The second sensing circuit 20 can also integrate the current signal converted by the second light sensing unit 210 to obtain a voltage signal representing the light intensity of the optical signal in the second set wavelength band.

Still referring to fig. 1 and 2, on the basis of the above embodiment, the second photosensitive units 210 may be arranged to include second photosensitive devices and second filter devices arranged on the second photosensitive devices, and the filter colors of the second filter devices corresponding to the plurality of second photosensitive units 210 are at least three.

In particular, the second Photo sensing device may be a Photo-Diode (PD) capable of converting an optical signal into a corresponding electrical signal. The second filter device is used to select the wavelength band of light passing through the device, and the first filter device may be a Color filter (Color filter) or an optical lens capable of extracting a light signal of a set component, such as a bayer lens. The second optical filter device may be disposed on a photosensitive surface of the second optical filter device, and after the second optical filter device extracts an optical signal in a second set wavelength band from the target optical signal, the second optical filter device may convert the optical signal in the second set wavelength band into a corresponding current signal.

Illustratively, the filter colors of the second filter devices corresponding to the plurality of second photosensitive units 210 include at least red, green, and blue. With reference to fig. 1 and fig. 2, the second sensing circuit 20 includes four second light sensing units 210, and the second filter devices corresponding to the four second light sensing units 210 include a red second filter device, a green second filter device, and a blue second filter device, and the red, green, and blue second filter devices are used, so that the second light sensing units form a red light sensing unit 210(R), a green light sensing unit 210(G), and a blue light sensing unit 210(B), respectively. When the target light signal is firstly irradiated to the surface of the Pixel unit Pixel 1, the second optical filter devices in the four second photosensitive units respectively extract the light signal of the red waveband, the light signal of the green waveband and the light signal of the blue waveband in the target light signal, so that the second photosensitive devices in the second photosensitive units can convert the light signal of the corresponding waveband into corresponding current signals. The second sensing circuit 20 realizes high-precision acquisition of absolute light intensity information and chromaticity information of the optical signals of different components by sensing the optical signals of different components in the target optical signal.

Illustratively, on the basis of the above embodiment, when the second set wavelength band includes an ultraviolet wavelength band, the second filter device corresponding to the second photosensitive unit 210 may further include an ultraviolet filter device. Therefore, the second sensing circuit 20 can sense not only 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 ultraviolet component, and the sensing capability of the dual-mode ultraviolet bionic vision sensor on the color light intensity information of the ultraviolet in the target light signal is improved.

With reference to fig. 1 and 2, the first sensing circuit 10 is exemplarily provided to include a first excitation type photosensitive unit 110 and a first inhibition type photosensitive unit 120, and the second sensing circuit 20 includes a second photosensitive unit 210; the first excitation type photosensitive unit 110, the first inhibition type photosensitive unit 120, and the second photosensitive unit 210 are arranged in an array to form a pixel unit. This is advantageous in that the Pixel unit Pixel 1 can simulate the rod cells of the human eye through the first excitation type photosensitive unit 110 and the first inhibition type photosensitive unit 120 to obtain the gray scale variation of the target light signal, and simulate the cone cells of the human eye through the second photosensitive unit 210 to obtain the color light intensity information of the target light signal.

With reference to fig. 1 and 2, the pixel units are exemplarily provided to include one first excitation type photosensitive unit 110, four first inhibition type photosensitive units 120, and four second photosensitive units 210; four second photosensitive units 210 in the pixel unit surround the first excitation type photosensitive unit 110, and are respectively arranged adjacent to the first excitation type photosensitive unit 110; four first inhibition type photosensitive cells 120 among the pixel cells are disposed around the first excitation type photosensitive cell 110, and the first inhibition type photosensitive cells 120 are alternately disposed with the second photosensitive cells 210 in the row direction and the column direction having the first inhibition type photosensitive cells 120.

Specifically, the Pixel unit Pixel 1 can simulate the rod cells of human eyes through one first excitation type photosensitive unit 110 and four first inhibition type photosensitive units 120 surrounding the first excitation type photosensitive unit 110, and the current signal converted by the first excitation type photosensitive unit 110 can be differentiated from the average value of the current signals converted by the four first inhibition type photosensitive units 120 to obtain a differential current signal, i.e., a light intensity gradient signal reflecting the light intensity variation. The Pixel unit Pixel 1 can simulate the cone cells of human eyes and sense the color light intensity information of different positions through the four second photosensitive units 210.

Fig. 3 is a schematic diagram of pixel arrangement of a bimodal ultraviolet bionic vision sensor according to an embodiment of the present invention, and with reference to fig. 1 to 3, in this embodiment, a plurality of pixel unit arrays are arranged to form a pixel array, and two adjacent pixel units share a second photosensitive unit 210 between two first excitation photosensitive units 110, and two first inhibition photosensitive units 120 adjacent to the second photosensitive unit 210.

Illustratively, referring to fig. 3, in a pixel array formed by the first excitation type photosensitive unit 110, the first inhibition type photosensitive unit 120, and the second photosensitive unit 210, one row of the array includes two arrangements, i.e., the first excitation type photosensitive unit 110 and the second photosensitive unit 210 are alternately arranged, or the first inhibition type photosensitive unit 120 and the second photosensitive unit 210 are alternately arranged. One column of the array includes two arrangements, that is, the first excitation type photosensitive unit 110 and the second photosensitive unit 210 are alternately disposed, or the first inhibition type photosensitive unit 120 and the second photosensitive unit 210 are alternately disposed. In this way, the first excitation type photosensitive unit 110 and the first inhibition type photosensitive unit 120 are located in different rows and different columns of the pixel array, so as to improve the perception capability of the first sensing circuit 10 for the gray scale variation of the optical signal. Each row and each column of the pixel array includes the second light sensing unit 210 to enhance the perception capability of the second sensing circuit 20 for color intensity information of the light signal.

With continued reference to fig. 3, the present embodiment implements multiplexing of the first suppression-type photosensitive units 120. Specifically, the current signal converted by each first excitation type photosensitive unit 110 can be operated with the current signals converted by the four surrounding first inhibition type photosensitive units 120, so that the current signal converted by each first inhibition type photosensitive unit 120 can be operated with the current signals converted by the four surrounding first excitation type photosensitive units 110 at the same time, thereby not only realizing multiplexing of the first inhibition type photosensitive units 120, but also being beneficial to improving the pixel fill factor. In addition, the embodiment also realizes multiplexing of the second photosensitive cell 210, for example, the second green photosensitive cell 210(G) in the second row in the Pixel unit Pixel 1 can be used as a green photosensitive cell in the present Pixel unit, and can be used as a green photosensitive cell in another Pixel unit.

In conjunction with fig. 1 to 3, it may also be exemplarily provided that the four second photosensitive cells 210 among the pixel cells include a red photosensitive cell 210(R), a green photosensitive cell 210(G), and a blue photosensitive cell 210 (B). Alternatively, the ratio of the number of green photosensitive cells 210(G) to the sum of the numbers of red photosensitive cells 210(R) and blue photosensitive cells 210(B) is 1: 1.

Fig. 3 schematically shows an arrangement manner that the second photosensitive units 210 in the pixel array form R (red) -G (green) -B (blue) -G which are sequentially staggered from top to bottom and are periodically arranged, and in this arrangement manner, the ratio of the pixel color light intensities sensed by the bimodal ultraviolet bionic vision sensor is: 50% green, 25% red, and 25% blue, the percentage of green is the highest, and the number of green photosensitive units 210(G) is equal to the sum of the numbers of red photosensitive units 210(R) and blue photosensitive units 210 (B). The bimodal ultraviolet bionic vision sensor can reconstruct a full-color image from incomplete color samples output by the photosensitive units covered with the color filter arrays by adopting a demosaicing digital image processing algorithm, and because human eyes are most sensitive to green, the green sampling ratio can be improved by adopting the arrangement mode, so that a required target image can be obtained.

Fig. 4 is a schematic diagram of a Pixel arrangement of another bimodal ultraviolet bionic vision sensor according to an embodiment of the present invention, where the Pixel arrangement includes a Pixel array of M rows and N columns, and a Pixel structure of each coordinate location point is a Pixel unit, which may be a Pixel unit Pixel 1 shown in fig. 2 and 3. One Pixel unit Pixel 1 comprises one first excitation type photosensitive unit 110, four first inhibition type photosensitive units 120 and four second photosensitive units 210, so that in the dual-mode ultraviolet bionic vision sensor, the Pixel unit at each coordinate position point can sense a color light intensity signal and a gray scale variation signal, and visual information of an image shot by the dual-mode ultraviolet bionic vision sensor is enriched.

Fig. 5 is a schematic pixel arrangement diagram of another bimodal ultraviolet bionic vision sensor provided in an embodiment of the present invention, where fig. 5 schematically illustrates an arrangement manner in which the second photosensitive units 210 in the pixel array form G-R-B-R that are sequentially staggered and periodically arranged from top to bottom, and in this arrangement manner, a ratio of pixel color light intensities sensed by the bimodal ultraviolet bionic vision sensor is as follows: 50% red, 25% green and 25% blue, the percentage of red being the highest. The pixel arrangement shown in fig. 5 can be selected according to the requirement of the target image to improve the red sampling ratio.

Fig. 6 is a schematic diagram of pixel arrangement of another bimodal ultraviolet bionic vision sensor according to an embodiment of the present invention, referring to fig. 6, optionally, a second set wavelength band is set to include an ultraviolet wavelength band, and four second photosensitive units 210 in the pixel units include a red photosensitive unit 210(R), a green photosensitive unit 210(G), a blue photosensitive unit 210(B), and an ultraviolet photosensitive unit (U). At the moment, ultraviolet light can be directly collected through the ultraviolet light sensing unit (U), and changes of light at home and abroad can be sensed through the first light sensing unit.

Fig. 6 schematically shows that the second photosensitive units 210 in the pixel array are alternately arranged from top to bottom, R and B, and from left to right, G and U (ultraviolet), in this arrangement, the ratio of pixel color light intensity sensed by the bimodal ultraviolet bionic vision sensor is: 25% red, 25% green, 25% blue and 25% uv. Compared with the pixel arrangement structure in the embodiment, the pixel arrangement structure in the embodiment improves the sampling ratio of ultraviolet light so as to improve the perception capability of the bimodal ultraviolet bionic vision sensor on the color light intensity information of the ultraviolet light in the target light signal.

Ultraviolet is understood that when the sampling ratio of blue or other colors of the bimodal ultraviolet bionic vision sensor needs to be increased, the arrangement mode of the pixels may be other forms similar to those of fig. 3, fig. 5 or fig. 6, which is not limited in this embodiment of the present invention.

Fig. 7 is a schematic block diagram of a first sensing circuit according to an embodiment of the present invention, and as shown in fig. 7, the first sensing circuit further includes a first excitation control circuit 130 and at least one first inhibition control circuit 140 connected to the first excitation control circuit 130; the first excitation control circuit 130 is connected to the first excitation photosensitive unit 110, the first inhibition control circuit 140 is connected to the first inhibition photosensitive unit 120 and is disposed in one-to-one correspondence with the first inhibition photosensitive unit 120, and the first inhibition control circuit 140 is configured to transmit a current signal converted by the first inhibition photosensitive unit 120 to the first excitation control circuit 130 connected to the first inhibition control circuit 140; the first excitation control circuit 130 is configured to control itself and the first inhibition control circuit 140 to be turned on or off according to the received control signal, and output a current signal representing a light intensity variation of the optical signal in the first set wavelength band according to a difference between current signals converted by the first excitation photosensitive unit 110 and the first inhibition photosensitive unit 120.

Fig. 7 schematically shows a case where the first sensor circuit includes one first excitation type photosensitive unit 110 and a first excitation type control circuit 130 connected thereto, and four first inhibition type photosensitive units 120 and a first inhibition type control circuit 140 connected thereto. Here, the first excitation type photosensitive unit 110 and the first inhibition type photosensitive unit 120 may correspond to one first excitation type photosensitive unit 110 and four first inhibition type photosensitive units 120 surrounding the first excitation type photosensitive unit 110 in the Pixel unit Pixel 1 shown in fig. 3. During the operation of the first sensing circuit, the four first inhibitory type control circuits 140 simultaneously transmit the current signals converted by the corresponding first inhibitory type photosensitive units 120 to the first excitatory type control circuit 130, so that the first excitatory type control circuit 130 makes a difference between the current signals converted by the first excitatory type photosensitive units 110 and an average value of the current signals converted by the four first inhibitory type photosensitive units 120 to obtain a differential current signal, i.e., a light intensity gradient signal reflecting the variation of light intensity.

Referring to fig. 7, for example, the first excitation control circuit 130 may further include switches (not shown) corresponding to the first inhibition control circuits 140, each of the first inhibition control circuits 140 is connected to the first excitation control circuit 130 through a switch, and the first excitation control circuit 130 may control the switches to be turned on or off according to a received control signal to control itself to be turned on or off with the first inhibition control circuit 140.

Illustratively, the control signals differ for different lighting conditions, and the switching conditions of the switches differ. For example, in order to improve the accuracy of the current signal representing the light intensity variation output by the first sensing circuit when the illumination intensity of the target light signal is greater than the first preset value, that is, when the target light signal is strongly illuminated, all the switches in the first excitation control circuit 130 may be controlled to be turned on by the control signal, at this time, each first inhibition control circuit 140 is enabled, and the current signal output by the first sensing circuit is a differential mode signal, that is, a differential signal of the current signals converted by the first excitation photosensitive unit 110 and the four first inhibition photosensitive units 120. For the case that the illumination intensity of the target light signal is smaller than the second preset value, i.e. the case of weak illumination, the current signal converted by the first excitation type light sensing unit 110 is smaller, so that all the switches in the first excitation type control circuit 130 can be controlled to be turned off by the control signal, at this time, each first inhibition type control circuit 140 fails, and the current signal output by the first sensing circuit is a common-mode signal, i.e. the current signal converted by the first excitation type light sensing unit 110. Specific values of the first preset value and the second preset value can be specifically set by combining the type of the photosensitive unit, the ambient light intensity and the like. The first sensing circuit provided by the embodiment of the invention can simulate Gap Junction connection of human eyes, so that the dynamic range of an image shot by the dual-mode ultraviolet bionic vision sensor is improved.

Fig. 8 is a schematic block diagram of a first excitation control circuit according to an embodiment of the present invention, which may be a specific block structure of the first excitation control circuit in the first sensing circuit shown in fig. 7. As shown in fig. 8, in addition to the above-described embodiment, the first excitation type control circuit 130 includes: a signal amplifying unit 131, an adder 132, a digital-to-analog converter 133, a comparator 134, a tristate gate 135, and at least one first switch 136; the input end of the signal amplification unit 131 is connected to the first excitation type photosensitive unit 110, and the output end of the signal amplification unit 131 is connected to the first input end of the comparator 134; the first suppressing control circuit 140 is connected to the input terminal of the adder 132 through the first switch 136, and the output terminal of the adder 132 is connected to the second input terminal of the comparator 134; a digital signal input end of the digital-to-analog converter 133 is connected to the output end C1 of the comparator 134, an analog signal output end of the digital-to-analog converter 133 is respectively connected to the input end of the signal amplifying unit 131 and the input end of the adder 132, and the digital-to-analog converter 133 is configured 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, so that the comparator 134 outputs a comparison result signal including the light intensity variation of the optical signal in the first set waveband; the control terminal of the tri-state gate 135 is connected to the output terminal C1 of the comparator 134, the input terminal of the tri-state gate 135 is connected to the input terminal of the digital-to-analog converter 133, and the tri-state gate 135 is configured to output a current signal representing the light intensity variation of the optical signal in the first set band according to the signal output by the comparator 134.

Specifically, see FIG. 8, in the first sensing circuitThe first excitation type photosensitive unit 110 converts the optical signal of the first set waveband into a current signal I₀And outputs a current signal I₀To the signal amplification unit 131. The four first suppressed type light sensing units 120 in the first sensing circuit respectively convert the optical signals of the first set waveband into current signals I₁To I₄And the current I is controlled by the corresponding first suppression-type control circuit 140₁To I₄To the first excitation control circuit 130. The signal amplifying unit 131 may include a first amplifier 131a, and the first amplifier 131a may amplify the current signal I₀Amplifying to make current signal I₀And a current signal I₁To I₄In the same order of magnitude, it is convenient for the first sensing circuit to calculate the differential current.

The signal amplifying unit 131 amplifies the amplified current signal I₀The four first suppressing control circuits 140 respectively output the current signals I to the first input terminal of the comparator 134₁To I₄The current signal I is inputted to the input terminal of the adder 132 through the conductive first switch 136, so that the adder 132 adds the current signal I₁To I₄Sums up and outputs the result of the summation to a second input terminal of the comparator 134. The comparator 134 compares the signals inputted from the first input terminal and the second input terminal, and if the comparison result at the previous time and the comparison result at the next time are the same, the comparator 134 does not output the comparison result signal, and if the comparison result at the previous time and the comparison result at the next time are opposite, the comparator 134 outputs the comparison result signal containing the variation of the light intensity of the optical signal in the first setting wavelength band through the output terminal C1, and the comparison result signal may be a digital signal of, for example, 0 or 1.

The dac 133 may convert the digital signal into an analog signal, and input the analog signal I to the input terminal of the adder 132 according to a comparison result signal output by the comparator_DA1Or an analog signal I is inputted to an input terminal of the signal amplifying unit 131_DA2. The signal amplifying unit 131 may further include a second amplifier 131b, and the second amplifier 131b may be based on the analog signal I_DA2For current signal I₀Continues to amplify and inputs the amplified signal to the first input of the comparator 134And (4) an end. The adder 132 can also add the current signal I₁To I₄And an analog signal I_DA1Sums up and outputs the result of the summation to a second input terminal of the comparator 134. The comparator 134 continues to compare the signals inputted from the first input terminal and the second input terminal, and outputs a comparison result signal containing the variation of the light intensity of the optical signal in the first predetermined wavelength band when the comparison result at the previous time and the comparison result at the next time are opposite.

Fig. 9 is a waveform diagram of a signal according to an embodiment of the present invention, and specifically, may be a waveform diagram of a digital signal input by the digital-to-analog converter 133 in fig. 8. Illustratively, referring to fig. 9, the digital-to-analog converter 133 may convert the digital signal to an analog signal I_DA1Or an analog signal I_DA2The output is performed, and the digital signal can be a specified digital signal which is periodically changed and input by human beings, such as a step digital signal with the numerical value increasing along with time shown in fig. 9. When a certain time N _ step occurs, the comparator 134 outputs a comparison result signal that changes, and the value of the digital signal is Δ I, so that Δ I can be used as a current signal representing the light intensity variation of the optical signal in the first set band. The control end of the tri-state gate 135 inputs the comparison result signal of the comparator 134 at this time, the digital signal input end of the digital-to-analog converter 133 is communicated with the input end of the tri-state gate 135, and the current signal with the value Δ I output by the digital-to-analog converter 133 is output through the output end of the tri-state gate 135.

With continued reference to fig. 8, based on the above embodiment, the first excitation control circuit 130 further includes a storage unit 137 connected to the output terminal 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 specifically a register, a latch, a memristor, or the like. Taking the memory 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.

Fig. 10 is a schematic circuit configuration diagram of a first excitation control circuit according to an embodiment of the present invention, which may be a specific circuit configuration of the first excitation control circuit shown in fig. 8. Illustratively, as shown in fig. 10, the first excitation type control circuit is connected to a first excitation type light sensing unit, which includes a first light sensing device, which may be a photodiode PD 11. The first excitatory control circuit includes a first circuit structure 130a and a second circuit structure 130b, the first circuit structure 130a simulating human eye rod cells, and the second circuit structure 130b simulating human eye horizontal cells, bipolar cells, and amacrine cells.

With reference to fig. 8 and 10, specifically, the photodiode PD11 is connected to the current mirror 131c, and the photodiode PD11 generates the current signal I under the irradiation of the optical signal of the first set wavelength band₀And outputs a current signal I₀To the current mirror 131c, the current mirror 131c can realize the function of the signal amplifying unit 131 in fig. 8, and the current signal I is amplified₀Amplifying by a factor of N (e.g., N ═ 4). Fig. 10 only schematically shows the current signal I output by the first suppression control circuit 140₁To I₄And the amplified current signal I output by the current mirror 131c₀In the case where the current signal is inputted to the comparator 134 through a connection line, the comparator 134 outputs the amplified current signal I to the current mirror 131c₀And a current signal I₁To I₄And comparing the sums. If the comparison results at the previous time and the next time are the same, the comparator 134 does not output the comparison result signal, and if the comparison results at the previous time and the next time are opposite, the comparator 134 outputs the comparison result signal including the light intensity variation of the optical signal of the first set wavelength band. The digital-to-analog converter 133 converts the digital signal into an analog signal, outputs the analog signal according to the comparison result signal of the comparator 134, and converts the current signal I into the analog signal₀Continuing amplification, or by comparing the current signal I with an analog signal₁To I₄The sum continues to accumulate so that the comparator 134 continues to perform the comparison function. When the comparison results at the previous time and the next time are opposite, the comparator outputs a comparison result signal. When the comparison result signal output by the comparator 134 changes, the tri-state gate 135 outputs the digital signal of the dac 133 at this time as a current signal representing the light intensity change amount of the optical signal in the first set band. The memory unit 137 is a register, and is coupled to the tri-state gate 135And storing and outputting the output signal.

Illustratively, in conjunction with fig. 8 and 10, the four first switches 136 include switches M1 to M4, and the switches M1 to M4 may be transistors capable of being turned on or off according to a control signal received by a control terminal (e.g., a gate) thereof. The control signals received by the switches M1-M4 are different for different lighting conditions, and the switching conditions of the switches are different. For strong illumination, for example, when the illumination intensity of the target light signal is greater than 50lux, the switches M1 to M4 can be controlled to be all turned on by the control signal, at this time, the photodiode in the first inhibition type light sensing unit is active, and the first excitation type control circuit outputs the current signal I₀And a current signal I₁To I₄I.e., differential mode signals. For weak illumination, for example, when the illumination intensity of the target light signal is lower than 20lux, the switches M1 to M4 can be controlled to be all turned off by the control signal, at this time, the photodiode in the first inhibition type photosensitive unit fails, and the first excitation type control circuit outputs the current signal I₀I.e. common mode signals.

The conduction conditions of the switches M1 to M4 can be set for calculating the convolution differential current of the first excitation control circuit, when the illumination condition allows, the image acquisition speed of the dual-mode ultraviolet bionic vision sensor is high, and the difference between two frames of images is small. Due to the fact that the calculation speed of the differential current is high, 1bit convolution differential current calculation of in pixel can be achieved, and therefore high-speed image feature extraction is achieved.

On the basis of the above embodiment, a capacitor Cpar may be further included between the input terminal of the comparator 134 and the ground terminal, where the capacitor Cpar may be an actual capacitor structure or a parasitic capacitor in the first excitation control circuit, and the capacitor Cpar has a function of storing a signal at the input terminal of the comparator 134, so as to ensure the calculation accuracy when the first excitation control circuit performs the high-speed differential current operation.

Fig. 11 is a schematic structural diagram of a first suppression control circuit according to an embodiment of the present invention, and as shown in fig. 11, the first suppression control circuit 140 includes: a second switch 141 connected to the first inhibiting type photosensitive unit 120, and at least one mirror switch 142 connected to the first inhibiting type photosensitive unit 120 and the second switch 141, and the first inhibiting type control circuit 140 is connected to the first excitation type control circuit 130 through the mirror switch 142.

Specifically, referring to fig. 11, the first inhibition type control circuit 140 is connected to a first inhibition type photosensitive unit including a first photosensitive device, which may be a photodiode PD 12. The second switch 141 and the mirror switch 142 may be transistors capable of being turned on or off according to a control signal received by a control terminal (e.g., a gate) thereof. The second switch 141 and each mirror switch 142 form a mirror unit to mirror the current signal I generated by the photodiode PD12 according to the optical signal of the first set wavelength band₁Duplicated into four, the first suppression-type control circuit 140 can divide the current signal I into four₁The signals are respectively transmitted to four first excitation control circuits around, so that multiplexing of the first inhibition type photosensitive units is realized, and pixel filling factors of the bimodal ultraviolet bionic vision sensor are improved.

Fig. 12 is a schematic block diagram of a second sensing circuit according to an embodiment of the present invention, and as shown in fig. 12, in this embodiment, the second sensing circuit 20 further includes a third switch 220, a shutter circuit 230, a current integrating circuit 240, and an analog-to-digital converter 250; the second light sensing unit 210 is connected to the input terminal of the current integration circuit 240 through a third switch 220, the third switch 220 is used for turning on or off the second light sensing unit 210 and the current integration circuit 240 according to a received control signal, and the third switch 220 connected to different second light sensing units 210 is turned on in a time-sharing manner; the shutter circuit 230 is connected in parallel with the current integration circuit 240 and used for controlling the integration time of the current integration circuit 240; the current integration circuit 240 is configured to integrate the current signal output by the second photosensitive unit 210 to convert the current signal into an analog voltage signal; the input terminal of the analog-to-digital converter 250 is connected to the output terminal of the current integrating circuit 240 for converting the analog voltage signal into a digital voltage signal.

Fig. 12 schematically shows a case where the second sensing circuit includes four second light sensing units 210, each of the second light sensing units 210 being connected to the current integration circuit 240 through the third switch 220. Here, the four second photosensitive cells 210 may correspond to the four second photosensitive cells 210 surrounding one first excitation type photosensitive cell 110 in the Pixel unit Pixel 1 shown in fig. 3. In the operation process of the second sensing circuit, the second sensing circuit outputs the electrical signal corresponding to each second light sensing unit 210 in a time-sharing manner, for example, outputs the electrical signal corresponding to the second light sensing unit 210 in a time-sharing manner in a line scanning manner.

Referring to fig. 12, the shutter circuit 230 may be a switch, the Current Integrator circuit 240 may be a Current Integrator (IC), and the Analog-to-Digital Converter 250 may be an Analog-to-Digital Converter (ADC), for example. Each of the second photo sensing units 210 is connected in series with one of the third switches 220, and only one of the third switches 220 is turned on at the same time, so that the second photo sensing unit 210 transmits the current signal converted according to the optical signal of the second set wavelength band to the current integrating circuit 240 through the third switch 220. The current integration circuit 240 may obtain a voltage analog signal of the target capacitor in the second sensing circuit, where the voltage analog signal corresponds to the current signal converted by the second light sensing unit 210, that is, the current integration circuit 240 integrates the current signal to obtain a corresponding voltage signal. The switching time of the shutter circuit 230 may control the integration time of the current integration circuit 240, for example, after the shutter circuit 230 controls the integration time of the current integration circuit 240 to 33ms, and 33ms later, the switch in the shutter circuit 230 is closed, the current integration circuit 240 obtains a voltage signal representing the light intensity of the optical signal in the second set wavelength band according to the current signal converted by the second light sensing unit 210, and converts the voltage signal into a digital signal through 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 be turned off, so that the current integration circuit 240 continues to integrate the current signal converted by the second light sensing unit 210.

Fig. 13 is a schematic circuit structure diagram of a second sensing circuit according to an embodiment of the present invention, which may be an embodied circuit structure of the second sensing circuit shown in fig. 12. As shown in fig. 12, the second sensing circuit includes four second light sensing units, each of which includes a second light sensing device and a second filter device disposed on the second light sensing device. Illustratively, the second photosensitive device is a photodiode, and the second filter device is a bayer lens or a color filter. The four photodiodes are photodiodes PD21 to PD24, a red second filter device 211(R) is disposed on the photodiode PD21, a green second filter device 211(G) is disposed on the photodiode PD22, a green second filter device 211(G) is disposed on the photodiode PD23, and a blue second filter device 211(B) is disposed on the photodiode PD 24. After the target light signal is irradiated to the second optical filter 211, the second optical filter 211 with different filter colors respectively extracts the light signals in the corresponding color bands from the target light signal, so that the photodiodes PD21 to PD24 convert the light signals in each color band into current signals representing the light intensity of the corresponding color.

Referring to fig. 13, the second sensing circuit further includes a switch M_TG1To M_TG4Switch M_RSSwitch M_SFAnd switch M_SELEach of the switches may be a transistor. The first electrodes (e.g., anodes) of the photodiodes PD21 to PD24 are grounded, and the second electrode of the photodiode PD21 is connected to the switch M_TG1The second pole of the photodiode PD22 is connected to the switch M_TG2The second pole of the photodiode PD23 is connected to the switch M_TG3The second pole of the photodiode PD24 is connected to the switch M_TG4Wherein the second electrode of each photodiode may be a cathode. Switch M_TG1To M_TG4Respectively connected with the switches M_RSSecond pole and switch M_SFControl terminal of, switch M_RSFirst pole of (1) and switch M_SFA first pole of the switch M is connected to a power supply signal VCC_SFSecond pole of the connecting switch M_SELFirst pole of (1), switch M_SELAs a signal output terminal of the second sensing circuit. Switch M_TG1To M_TG4Switch M_RSSwitch M_SFAnd switch M_SELMay be turned on or off in response to a control signal received at a respective control terminal (e.g., gate). Optionally, a second sensorThe circuit further comprises a capacitor FD which can be an actual capacitor structure or a parasitic capacitor in the second sensing circuit, and the capacitor FD can be opposite to the switch M_SFThe control terminal of (a) stores the received current signal.

Specifically, referring to fig. 13, switch M_RSFor resetting, switch M_TG1To M_TG4Time-sharing conduction is carried out to transmit current signals which are converted by the photodiodes PD 21-PD 24 and represent the light intensity of corresponding colors to the switch M in time-sharing mode_SFControl terminal of, switch M_SFThe control terminal of the switch M can receive a current signal as a bias signal to control the switch M_SFThe switch M corresponding to different current signals_SFAre different in conduction degree, so that the switch M_SFAnd switch M_SELThe output voltage signals are different, and the switch M_SFAnd switch M_SELThe combination of (a) and (b) has an integrating effect on the current signal, so that the second sensing circuit can output a voltage signal representing the light intensity of the optical signal in the second set wavelength band.

On the basis of the above embodiment, the bimodal ultraviolet bionic vision sensor provided by the embodiment of the present invention can fuse a current signal representing the light intensity variation of the optical signal of the first set wavelength band and a bimodal signal representing the voltage signal of the light intensity of the optical signal of the second set wavelength band, so as to form an image signal including bimodal signals.

Specifically, the bimodal ultraviolet bionic vision sensor may fuse a current signal representing a light intensity variation of an optical signal of a first set waveband output by the first sensing circuit and a voltage signal representing a light intensity of an optical signal of a second set waveband output by the second sensing circuit, and obtain a final image output signal by combining spatial position arrangement of a pixel array formed by the first excitation type photosensitive unit, the first inhibition type photosensitive unit, and the second photosensitive unit. It should be noted that the output form and speed of the current signal representing the variation of the light intensity of the optical signal in the first set wavelength band and the voltage signal representing the light intensity of the optical signal in the second set wavelength band are not the same. The output speed of the voltage signal of the second sensing circuit is about 30ms, and the scanning speed of the digital-to-analog converter in the first sensing circuit is about 1 ms. The first sensing circuit outputs a current signal representing the light intensity variation of the optical signal of the first set waveband in an asynchronous event address representation mode, and the output signal is specifically in the form of (X, Y, P, T). Where "X, Y" is the event address, such as the coordinates of the pixel cell shown in fig. 4, "P" is the 4-value event output (including the first sign bit), such as the P value representing the amount of light intensity change, and "T" is the time when the event occurred, such as the capture time.

Fig. 14 is a schematic diagram of an image output by a dual-mode ultraviolet bionic vision sensor according to an embodiment of the present invention, and fig. 14 schematically shows two frames of color images before and after the output by the dual-mode ultraviolet bionic vision sensor, where the two frames of color images are formed by a voltage signal output by a second sensing circuit and representing the light intensity of an optical signal in a second set wavelength band, and an edge point between the two frames of color images is formed by a current signal output by a first sensing circuit and representing the light intensity variation of an optical signal in a first set wavelength band.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A bimodal ultraviolet biomimetic vision sensor, comprising:

2. The bimodal ultraviolet bionic vision sensor as claimed in claim 1, wherein the first sensing circuit comprises a first excitation type photosensitive unit and a first inhibition type photosensitive unit, and the first excitation type photosensitive unit and the first inhibition type photosensitive unit are both used for extracting an optical signal of a first set waveband in a target optical signal and converting the optical signal of the first set waveband into a current signal;

3. The bimodal ultraviolet biomimetic vision sensor as claimed in claim 2, wherein the first set wavelength band includes an ultraviolet wavelength band, and the first excitation type photosensitive unit and the first inhibition type photosensitive unit each include a first photosensitive device, the first photosensitive device being an ultraviolet photosensitive device.

4. The bimodal ultraviolet biomimetic vision sensor as claimed in claim 2, wherein the first set wavelength band includes an ultraviolet wavelength band, and the first excitation type photosensitive unit and the first inhibition type photosensitive unit each include a first photosensitive device and a first filter device disposed on the first photosensitive device;

5. The bimodal ultraviolet biomimetic vision sensor as claimed in claim 2, wherein the first set wavelength band includes an ultraviolet wavelength band, and the first excitation type photosensitive unit and the first inhibition type photosensitive unit each include a first photosensitive device and a first filter device disposed on the first photosensitive device;

6. The bimodal ultraviolet bionic vision sensor as claimed in claim 1, wherein the second sensing circuit comprises at least one second photosensitive unit, and the second photosensitive unit is configured to extract an optical signal of a second set wavelength band from the target optical signal and convert the optical signal of the second set wavelength band into a current signal;

7. The bimodal ultraviolet bionic vision sensor as claimed in claim 6, wherein the second photosensitive unit comprises a second photosensitive device and a second filter device disposed on the second photosensitive device, and the filter colors of the second filter devices corresponding to the plurality of second photosensitive units are at least three.

8. The bimodal ultraviolet biomimetic vision sensor as recited in claim 7, wherein the second set wavelength band comprises an ultraviolet band and the second filter comprises an ultraviolet filter.

9. The bimodal ultraviolet biomimetic vision sensor as claimed in any one of claims 1-8, wherein the first sensing circuit includes a first excitation type photosensing unit and a first inhibition type photosensing unit, and the second sensing circuit includes a second photosensing unit;

10. The bimodal ultraviolet biomimetic vision sensor as recited in claim 9, wherein the pixel units include one of the first excitation type photosensing unit, four of the first inhibition type photosensing units, and four of the second photosensing units;

11. The bimodal ultraviolet biomimetic vision sensor as recited in claim 10, wherein a plurality of the pixel units are arranged in an array to form a pixel array, and two adjacent pixel units share the second photosensitive unit between two of the first excitation type photosensitive units and two of the first inhibition type photosensitive units adjacent to the second photosensitive unit.

12. The bimodal ultraviolet biomimetic vision sensor as recited in claim 11, wherein four of the second photo-sensing units in the pixel unit comprise a red photo-sensing unit, a green photo-sensing unit, and a blue photo-sensing unit.

13. The bimodal ultraviolet biomimetic vision sensor as claimed in claim 12, wherein a ratio of the number of green photosensitive elements to a sum of the number of red photosensitive elements and the number of blue photosensitive elements is 1: 1.

14. The bimodal ultraviolet biomimetic vision sensor as claimed in claim 11, wherein the second set waveband includes an ultraviolet waveband, and four of the second photo-sensing units in the pixel unit include a red photo-sensing unit, a green photo-sensing unit, a blue photo-sensing unit, and an ultraviolet photo-sensing unit.

15. The bimodal ultraviolet biomimetic vision sensor as recited in claim 2, wherein the first sensing circuit further comprises a first excitatory control circuit and at least one first inhibitory control circuit coupled to the first excitatory control circuit;

16. The bimodal ultraviolet biomimetic vision sensor as recited in claim 15, wherein the first excitation control circuit comprises: the device comprises a signal amplifying unit, an adder, a digital-to-analog converter, a comparator, a three-state gate and at least one first switch;

17. The bimodal ultraviolet biomimetic vision sensor as recited in claim 16, wherein the first excitation control circuit further comprises a storage unit coupled to the output of the tri-state gate for storing and outputting the signal output by the tri-state gate.

18. The bimodal ultraviolet biomimetic vision sensor as recited in claim 15, wherein the first inhibition type control circuit comprises: the first excitation type control circuit comprises a first switch connected with the first inhibition type photosensitive unit and at least one mirror image switch connected with the first inhibition type photosensitive unit and the second switch, and the first inhibition type control circuit is connected with the first excitation type control circuit through the mirror image switch.

19. The bimodal ultraviolet biomimetic vision sensor as claimed in claim 6, wherein the second sensing circuit further comprises a third switch, a shutter circuit, a current integration circuit, and an analog-to-digital converter;