(19)
(11)EP 3 426 003 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
29.07.2020 Bulletin 2020/31

(21)Application number: 16892148.4

(22)Date of filing:  29.03.2016
(51)International Patent Classification (IPC): 
H05B 33/08(2020.01)
G02B 13/22(2006.01)
H04N 5/225(2006.01)
(86)International application number:
PCT/CN2016/077702
(87)International publication number:
WO 2017/147957 (08.09.2017 Gazette  2017/36)

(54)

TELECENTRIC ILLUMINATION AND IMAGE CAPTURING SYSTEM FOR TESTING MARINE MICROORGANISM

TELEZENTRISCHES BELEUCHTUNGS- UND BILDERFASSUNGSSYSTEM ZUR TESTUNG VON MEERESMIKROORGANISMEN

SYSTÈME D'ÉCLAIRAGE ET DE CAPTURE D'IMAGE TÉLÉCENTRIQUE POUR TEST DE MICROORGANISME MARIN


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 29.02.2016 CN 201610109858

(43)Date of publication of application:
09.01.2019 Bulletin 2019/02

(73)Proprietor: Graduate School at Shenzhen, Tsinghua University
Shenzhen, Guangdong 518055 (CN)

(72)Inventors:
  • CHENG, Xuemin
    Shenzhen, Guangdong 518055 (CN)
  • BI, Hongsheng
    Shenzhen, Guangdong 518055 (CN)
  • HE, Yonghong
    Shenzhen, Guangdong 518055 (CN)
  • CAI, Zhonghua
    Shenzhen, Guangdong 518055 (CN)
  • LIN, Jiayong
    Shenzhen, Guangdong 518055 (CN)

(74)Representative: Mewburn Ellis LLP 
Aurora Building Counterslip
Bristol BS1 6BX
Bristol BS1 6BX (GB)


(56)References cited: : 
CN-A- 1 121 998
CN-A- 101 174 093
CN-A- 103 412 543
JP-A- 2016 008 816
US-A1- 2011 058 388
CN-A- 101 051 179
CN-A- 102 147 233
CN-U- 204 831 214
US-A1- 2007 195 025
  
  • KENICHIRO TANAKA ET AL: "Descattering of transmissive observation using Parallel High-Frequency Illumination", COMPUTATIONAL PHOTOGRAPHY (ICCP), 2013 IEEE INTERNATIONAL CONFERENCE ON, IEEE, 19 April 2013 (2013-04-19), pages 1-8, XP032424248, DOI: 10.1109/ICCPHOT.2013.6528300 ISBN: 978-1-4673-6463-8
  • LIU JUNYING ET AL: "The stability analysis and improvement of SPIDNN control system", AUTOMATION AND LOGISTICS, 2009. ICAL '09. IEEE INTERNATIONAL CONFERENCE ON, 1 August 2009 (2009-08-01), pages 992-996, XP055542361, Piscataway, NJ, USA DOI: 10.1109/ICAL.2009.5262564 ISBN: 978-1-4244-4794-7
  
Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


Description

BACKGROUND OF THE INVENTION


Field of the Invention



[0001] The present invention relates to an illumination and imaging technology, and in particular, to a telecentric illumination and photographing system for detection of marine microscopic organisms, providing illumination to detection of marine microscopic organisms.

Related Arts



[0002] With the development of scientific researches, it is found that data such as existence and growth of microscopic organisms in water system environments such as oceans, lakes, and rivers, ingredients of metabolins, and water-soluble gas ingredients all closely and accurately reflects a condition of a local environment and is closely linked with a living environment of people. However, there are quite a lot of technical problems for technical means of researching microscopic organisms because sizes and dimensions of microscopic organisms are mostly at the micrometer scale, especially in a relatively turbid water body and in a water body of a sludge mixture. When imaging microscopic organisms, a general illumination light source and a photographing camera have problems such as scattering, light interference, and non-uniform imaging illuminance, causing many adverse effects on observation of the microscopic organisms. For example, scattering results in vague imaging and low contrast, coherent stripes are formed and an alternation of bright and dark areas of a part of an image surface is caused due to light interference, and non-uniform imaging illuminance affects overall observation of imaging.

[0003] In addition, a high-power LED system for illumination also needs a better drive, and available drives mainly include three types, that is, a current-limiting resistor, a linear voltage regulator, and a switching converter. A current-limiting resistor solution is applicable to an application scenario with low efficiency and has an extremely high requirement for efficiency. Therefore, the method is not used for an illumination drive requiring high image acquisition accuracy. The linear regulator is only applicable to a scenario of a low current or a scenario in which a forward voltage drop of an LED is slightly lower than a power supply voltage, but also has problems of low efficiency and a small input voltage range. A switching-type synchronous-buck drive has characteristics of flexible circuit topology, high efficiency, and a broad input voltage range, and has high current sampling accuracy. After factors such as working efficiency, an installation size, a static current, a working voltage, noise, and output regulation are comprehensively considered, currently, most of drive circuits of image illumination detection devices use switching converters. A topology structure of a switching converter includes a buck manner, a boost manner, a buck-boost manner, and the like. However, such a switching converter cannot well resolve the following five problems and a problem that lighting effects of an LED attenuate due to long-time working:
  1. (1) A buck-boost function. When an input voltage or a voltage drop of an LED fluctuates, an output voltage is regulated, to satisfy a requirement that an output current is constant and ensure that the LED stably and reliably emits light.
  2. (2) High power conversion efficiency. A circuit drive loss is lowered, energy consumption is reduced, a quantity of times of charging a storage battery is reduced, and a service life of a battery is prolonged.
  3. (3) A brightness regulation function. When an exposure time of an imaging system needs to be regulated, a current may be regulated by using a PWM signal.
  4. (4) There is a complete protection circuit. Various protection measures need to be taken to ensure reliable working of the protection circuit and the LED. The protection measures are, for example, low-voltage latching, over-voltage protection, overheat protection, and output open-circuit or short-circuit protection.
  5. (5) A good heat dissipation function. Because of thermal properties of the LED, a temperature is one of important factors that affect stable working of the LED. When working at night, the LED is in a state of being lit up for a long time. Therefore, a good heat dissipation function is necessary, to ensure a service life and reliable working of the LED.


[0004] JP 2016/008816 A describes a shape measurement device, control method of shape measurement device, and shape measurement program. US 2011/058388 A1 describes rippled mixers for uniformity and color mixing. Kenichiro Tanaka et al. XP032424248 describes descattering of transmissive observation using parallel high-frequency illumination. US 2007/195025 A1 describes a voltage controlled backlight driver. CN 103,412,543 A describes a layered cage environment lighting control system for a laying hen house. Liu Junying et al. XP055542361 describes stability analysis and improvement of a SPIDNN control system.

SUMMARY OF THE INVENTION



[0005] The invention is defined in the appended set of claims. A main objective of the present invention is to provide a telecentric illumination and photographing system for detection of marine microscopic organisms, to make imaging illuminance be highly uniform and improve imaging quality, thereby overcoming disadvantages in the prior art.

[0006] A further objective of the present invention is to provide illumination drive with a large current and high reliability for detection of marine planktons.

[0007] To achieve the foregoing objectives, the following technical solutions are used in the present invention:
A telecentric illumination and photographing system for detection of marine microscopic organisms includes an optical path module and an illumination drive module, where the optical path module includes:

an LED light source, configured to provide an illumination light source;

a light homogenizing rod, configured to mix light beams emitted from the LED light source to obtain uniform light intensity distribution;

a decoherence light homogenizing sheet, configured to perform secondary light homogenization on the light beams emitted from an end surface of the light homogenizing rod and perform decoherence processing on the light beams, to obtain an incoherent and uniform light source surface;

a diaphragm, configured to determine a corresponding diaphragm aperture according to a requirement for a collimation degree of an illumination beam;

a telecentric collimation camera, where a light beam emitted from the diaphragm is incident into a microscopic organism area with uniform illuminance after passing through the telecentric collimation camera; and

a telecentric imaging camera, matching the telecentric collimation camera and configured to cooperate with the telecentric collimation camera to receive an illumination beam passing through the microscopic organism area and output the illumination beam to an imaging unit, to obtain an imaging result of uniform illuminance.



[0008] Further, a light spectrum range of the LED light source includes from near-ultraviolet 365 nm to an infrared band and may be a light spectrum area of a band of therein, for example, 420 nm to 680 nm, or a light spectrum of a single narrowband, for example, red light 635±50 nm.

[0009] Further, the light homogenizing rod may be a square or conical internal reflection cavity or may be a transparent optical material entity.

[0010] Further, a light emitting diameter D of the LED light source and a length L of the light homogenizing rod satisfy the following relationship: L ≧ D3.

[0011] Preferably, a light emitting surface of the LED light source is a rectangle, and the corresponding light emitting diameter D is a diagonal length of the rectangle.

[0012] Further, a scattering mode of the decoherence light homogenizing sheet is lambertian, and a scattering rate ≧ 0.5.

[0013] Further, a numerical aperture NA of the telecentric collimation camera ≧ 0.5.

[0014] Further, the telecentric collimation camera has a telecentric degree less than or equal to 2 degrees and is set to satisfy illumination and observation for microscopic organisms of a size of as small as 50 micrometers.

[0015] Further, the optical path module further includes:

a polarizer, disposed between the telecentric collimation camera and the microscopic organism area and configured to polarize a light beam emitted from the telecentric collimation camera to eliminate a scattering phenomenon of the light beam; and

an analyzer, disposed between the microscopic organism area and the telecentric imaging camera, where the analyzer is disposed by cooperating with the polarizer and is configured to eliminate stray light generated when microscopic organisms are illuminated.



[0016] Preferably, a transmission-extinction ratio Ts/Tp of the polarizer > 50:1, where Ts is a transmission rate of S-polarized light, and Tp is a transmission rate of P-polarized light; and a transmission-extinction ratio Ts/Tp of the analyzer > 50:1, where Ts is a transmission rate of S-polarized light, and Tp is a transmission rate of P-polarized light.

[0017] Further, the illumination drive module includes:

a PWM synchronization signal unit, configured to provide a PWM synchronization signal of an imaging system;

a processing unit, configured to receive the PWM synchronization signal and generate a digital signal after performing quantization processing on the PWM synchronization signal;

a digital-to-analog conversion unit, configured to receive the digital signal and output an analog voltage signal after performing digital-to-analog conversion on the digital signal;

an analog signal amplification unit, configured to receive the analog voltage signal and output an analog quantization voltage after performing synchronous following and amplification on the analog voltage signal, where the LED light source is driven by the analog quantization voltage; and

a synchronous current detection unit, configured to perform real-time sampling on a working current of the LED light source and transmit sampled current information to the processing unit, where the processing unit performs feedback control according to the sampled current information, so that the LED light source works in a stable state in which light emitting intensity is constant.



[0018] Further, the processing unit performs light intensity or light brightness attenuation compensation by using a single-output proportional-integral-derivative neural network (SPIDNN) and according to the sampled current information, the SPIDNN includes an input layer, a hidden layer, and an output layer, the input layer has two proportional neurons, the hidden layer has one proportional neuron, one integral neuron, and one derivative neuron, the output layer has one proportional neuron, one proportional neuron of the input layer inputs a preset ideal working current Ref_I, and the other proportional neuron of the input layer inputs a sampled actual working current Real_I, the SPIDNN outputs a control signal Out_pwm with a pulse width after processing, and a drive signal of the LED light source is based on the control signal Out_pwm.

[0019] Further, a network weight of the SPIDNN is automatically adjusted by making a formula (3.1) reach the minimum:

where E is an error evaluation function, Ref_I(k) is a value of an ideal working current at a moment k, and Real_I(k) is a value of an actual working current at the moment k.

[0020] Beneficial effects of the present invention are:
In the present invention, a highly uniform decoherence illumination light source is obtained in a manner of combining a light homogenizing rod and a decoherence homogenizing sheet and by combining a telecentric collimation camera and a telecentric imaging camera, so that illuminance of an imaging surface is extremely uniform.

[0021] Further, in the present invention, the illumination drive module performs real-time sampling on a working current of the LED light source and transmits sampled current information to the processing unit, and the processing unit performs feedback control according to the sampled current information, so that the LED light source works in a stable state in which light emitting intensity is constant. Therefore, current output accuracy is improved, a current can be controlled to reach output accuracy of 0.1 mA, and reliability is high. The present invention can achieve a gain function of automatically regulating a current along with a lighting effect attenuation curve of the LED light source, greatly prolonging a service life of an LED array module.

[0022] In conclusion, the present invention can provide an illumination drive system with a large current and high reliability for detection of marine planktons.

BRIEF DESCRIPTION OF THE DRAWINGS



[0023] 

FIG. 1 is a schematic structural diagram of an optical path module according to an embodiment of the present invention;

FIG. 2a and FIG. 2b are schematic structural diagrams of a light homogenizing rod according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a light emitting surface of an LED light source according to an embodiment of the present invention;

FIG. 4 is a circuit block diagram of an illumination drive module according to an embodiment of the present invention;

FIG. 5 is a control flowchart according to an embodiment of the present invention;

FIG. 6 is a structural diagram of a current automatic control system according to an embodiment of the present invention; and

FIG. 7 is a structural diagram of an SPIDNN according to an embodiment of the present invention.


DETAILED DESCRIPTION OF THE INVENTION



[0024] Embodiments of the present invention are described in detail below. It should be emphasized that the following descriptions are merely exemplary and are not intended to limit the scope and application of the present invention.

[0025] Referring to FIG. 1, in an embodiment, a telecentric illumination and photographing system for detection of marine microscopic organisms includes an optical path module and an illumination drive module. The optical path module includes an LED light source 1, a light homogenizing rod 2, a decoherence light homogenizing sheet 3, a diaphragm 4, a telecentric collimation camera 5, and a telecentric imaging camera 9. The LED light source 1 provides an illumination light source. The light homogenizing rod 2 mixes light beams emitted from the LED light source 1 to obtain uniform light intensity distribution. The decoherence light homogenizing sheet 3 performs secondary light homogenization on a light beam emitted from an end surface of the light homogenizing rod 2 and performs decoherence processing on the light beam, to obtain an incoherent and uniform light source surface. The diaphragm 4 determines a corresponding aperture of the diaphragm 4 according to a requirement for a collimation degree of an illumination beam. A light beam emitted by the telecentric collimation camera 5 from the diaphragm 4 is incident into a microscopic organism area 7 with uniform illuminance after passing through the telecentric collimation camera 5. The illumination beam passes through a water body of the microscopic organism area 7, illuminates a microscopic organism environment, and provides an optimal imaging light source to the telecentric imaging camera 9. The telecentric imaging camera 9 matches the telecentric collimation camera 5, and the telecentric imaging camera 9 cooperates with the telecentric collimation camera 5 to receive the illumination beam passing through the microscopic organism area and outputs the illumination beam to an imaging unit 10, to obtain an imaging result of uniform illuminance.

[0026] In some embodiments, a light spectrum range of the LED light source 1 may be from near-ultraviolet 365 nm to an infrared band, and specifically, may be a light spectrum area of a band of therein, for example, 420 nm to 680 nm, or a light spectrum of a single narrowband, for example, red light 635±50 nm. The light spectrum range of the LED light source 1 adapts to observation of different types of microscopic organisms or other related objects.

[0027] As shown in FIG. 2a and FIG. 2b, in some embodiments, the light homogenizing rod 2 may be a square or conical internal reflection cavity or may be a transparent optical material entity.

[0028] In a preferred embodiment, a light emitting diameter D of the LED light source 1 and a length L of the light homogenizing rod 2 satisfy the following relationship: L ≧ D3. As shown in FIG. 3, in a specific embodiment, a light emitting surface of the LED light source 1 is a rectangle, and the corresponding light emitting diameter D is a diagonal length of the rectangle.

[0029] In a preferred embodiment, a scattering mode of the decoherence light homogenizing sheet 3 is lambertian, and a scattering rate ≧ 0.5.

[0030] In a preferred embodiment, an NA of the telecentric collimation camera 5 ≧ 0.5. The telecentric collimation camera 5 uses an optical telecentric structure to ensure uniform illuminance of a light beam emitted from the telecentric collimation camera 5 being incident into all imaging point areas of the microscopic organism area.

[0031] In a preferred embodiment, the telecentric collimation camera 5 has a telecentric degree less than or equal to 2 degrees and is set to satisfy illumination and observation for microscopic organisms of a size of as small as 50 micrometers.

[0032] As shown in FIG. 1, in a further embodiment, the optical path module of the telecentric illumination and photographing system further includes a polarizer 6 and an analyzer 8. The polarizer 6 is disposed between the telecentric collimation camera 5 and the microscopic organism area and is configured to polarize a light beam emitted from the telecentric collimation camera 5 to eliminate a scattering phenomenon of the light beam, to obtain an imaging effect with higher contrast. The analyzer 8 is disposed between the microscopic organism area and the telecentric imaging camera 9, and the analyzer 8 is disposed by cooperating with the polarizer 6 and is configured to eliminate stray light generated when microscopic organisms are illuminated, so that the telecentric imaging camera 9 can obtain clearer imaging effects.

[0033] In a more preferred embodiment, a transmission-extinction ratio Ts/Tp of the polarizer 6 > 50:1, where Ts is a transmission rate of S-polarized light, and Tp is a transmission rate of P-polarized light; and a transmission-extinction ratio Ts/Tp of the analyzer 8 > 50:1, where Ts is a transmission rate of S-polarized light, and Tp is a transmission rate of P-polarized light.

[0034] Referring to FIG. 4, the illumination drive module of the telecentric illumination and photographing system includes a PWM synchronization signal unit, a processing unit, a digital-to-analog conversion unit, an analog signal amplification
unit, and a synchronous current detection unit. The PWM synchronization signal unit provides a PWM synchronization signal of an imaging system. The processing unit receives the PWM synchronization signal and generates a digital signal after performing quantization processing on the PWM synchronization signal. The digital-to-analog conversion unit receives the digital signal and outputs an analog voltage signal after performing digital-to-analog conversion on the digital signal. The analog signal amplification unit receives the analog voltage signal and outputs an analog quantization voltage after performing synchronous following and amplification on the analog voltage signal. The LED light source 1 is driven by the analog quantization voltage. The synchronous current detection unit performs real-time sampling on a working current of the LED light source 1 and transmits sampled current information to the processing unit. The processing unit performs feedback control according to the sampled current information, so that the LED light source 1 works in a stable state in which light emitting intensity is constant.

[0035] Further, the PWM synchronization signal unit may provide a PWM signal of a synchronous imaging system, and a PWM pulse width ratio thereof is adjustable, effectively prolonging electric endurance of a microscopic organism detection system. The processing unit may perform control processing by using a CPU. The digital-to-analog conversion unit may implement accurate control over currents by using a digital-to-analog conversion chip with 14-bit accuracy.

[0036] As shown in FIG. 4, when the system runs, the CPU (STM32F103) receives, by using a level shift chip (ADM3202), a PWM synchronization signal provided by the PWM synchronization signal unit (PWM). The CPU performs quantization processing on the input PWM signal and transmits a calculation result to the digital-to-analog conversion chip (AD5732) with as high as 14-bit accuracy by using an SPI digital interface for analog voltage output. A rear-end high-voltage large-current operational amplifier (OPA548) performs synchronization circuit following output on an input voltage analog quantity, and an analog quantization voltage drives the LED. In addition, the synchronous current detection unit performs real-time sampling on the working current of the LED. The sampled current information is transmitted to the CPU, and the CPU performs output according to the sampled information, thereby implementing current control of high accuracy.

[0037] To accurately perform light intensity or light brightness attenuation compensation, a photodetector may be added to detect a magnitude of light brightness and perform current compensation according to the light brightness.

[0038] According to the system, stable working of the LED and constant lighting effects can be ensured, so that LED light emitting brightness does not have a light intensity or light brightness attenuation phenomenon after long-time working, and a gain function of automatically regulating a current along with an LED lighting effect attenuation curve can be achieved, thereby greatly prolonging a service life of an LED array module.

[0039] A control procedure of running of the system is shown in FIG. 5. When the system works, the synchronous current detection unit performs real-time sampling on the working current of the LED. The CPU reads an actual current value of a currently driven LED, determines whether the current value is higher than a specified value, and performs current control if the current value is higher than the specified value, to ensure stable working of the LED. After performing current control, the CPU further determines whether the actual current value is higher than a predetermined alarm value, and gives an alarm and takes protection measures if the actual current value is higher than the predetermined alarm value.

[0040] As shown in FIG. 6 and FIG. 7, in a preferred embodiment, the system establishes an SPIDNN to perform current control. The processing unit performs light intensity or light brightness attenuation compensation by using the SPIDNN and according to the sampled current information. The SPIDNN includes an input layer, a hidden layer, and an output layer. The input layer has two proportional neurons. The hidden layer has one proportional neuron, one integral neuron, and one derivative neuron. The output layer has one proportional neuron. One proportional neuron of the input layer inputs a preset ideal working current Ref_I, and the other proportional neuron of the input layer inputs a sampled actual working current Real_I. The SPIDNN outputs a control signal Out_pwm with a pulse width after processing. A drive signal of the LED light source is based on the control signal Out_pwm.

[0041] Information sampled by the synchronous current detection unit is transmitted to the CPU to perform SPIDNN algorithm control, and the CPU performs attenuation compensation by using a current control PID algorithm, to ensure consistency of light emitting intensity of the LED. The system may control current accuracy to be within a range of 0.1 mA.

[0042] The structure of a current automatic control system using the SPIDNN is shown in FIG. 6. Ref_I represents the most appropriate working current of a device, Real_I represents an actual working current of the device, and Out_pwm represents an output pulse width (that is, a duty cycle of a pulse) of a single chip microcomputer obtained by processing by the SPIDNN.

[0043] The structure of the SPIDNN is shown in FIG. 7. The SPIDNN has five neurons. The input layer includes two proportional neurons. The hidden layer includes one proportional neuron, one integral neuron, and one derivative neuron. The output layer includes one proportional neuron. Connections between the neurons and corresponding connection weights are shown in FIG. 7. A forward algorithm of the SPIDNN is used. Initial values of the connection weights in the SPIDNN are as follows:

where kP is a proportional connection weight, kI is an integral connection weight, kD is a derivative connection weight, and values thereof should ensure that the system is initially stable.

[0044] In FIG. 7, symbols from left to right in each circle sequentially represent an input value, a calculation value, and an output value.

[0045] It is first specified as follows: r(k) = Ref_I(k), y(k) = Real_I(k), v(k) = Out_pwm(k).
netl and net2 are respectively an input value and a feedback value of an neuron on the input layer. u1 and u2 are respectively calculation values, x1 and x2 are output values of the neuron on the input layer. At a moment k, relationships between them are as follows:

and



[0046] Correspondingly, calculation manners of symbols of the three neurons on the hidden layer are as follows:



and

where U1', U2', and U3' respectively represent calculation values of the proportional neuron, the integral neuron, and the derivative neuron.

[0047] A method for calculating symbols on the output layer is as follows:

and



[0048] Finally, total output of the network is as follows:



[0049] To achieve learning and memory functions of the SPIDNN and enable an actual current of the device to more rapidly and more stably approach an optimal working current thereof, the system completes automatic regulation of a network weight of the SPIDNN by using an error back propagation learning algorithm. Making a formula (3.1) be the minimum is a criterion and a goal for training and learning, thereby implementing automatic regulation of the network weight:

where E is an error evaluation function, Ref_I(k) is a value of an ideal working current at a moment k, and Real_I(k) is a value of an actual working current at the moment k.

[0050] An iterative formula of weights from the hidden layer to the output layer is as follows:

where Wj(n) is a weight from the hidden layer to the output layer after learning for n steps, and ηj is a weight between learning steps.

[0051] Upon calculation,

where r(k) = Ref_I(k), y(k) = Real_I(k), v(k) = Out_pwm(k), v(k) is Out_pwm(k) and is a linear superposition value of a proportion, an integer, and a derivative for an offset, and



[0052] An iterative formula of weights from the input layer to the hidden layer is as follows:

where Wij(n) is a weight from the input layer to the hidden layer after learning for n steps, and ηi is a weight between learning steps.

[0053] Upon calculation,

where

η in the formula (3.2) and the formula (3.3) is a learning step length. To ensure an SPIDNN control system to converge in a learning process, a value of η should satisfy:

and

(3.4) where



and



[0054] In a specific embodiment, an internal structure of an LED light source matrix uses a parallel physical package form. A working voltage of an LED light source module is approximately 2.6 V. A light source drive system performs synchronous buck large-current control by using a working voltage adapting to the LED light source module. The light source drive system preferably introduces low-voltage latching, over-voltage protection, overheat protection, and output open-circuit or short-circuit protection. Even if the drive system abnormally works, other system modules are not invalid or damaged.

[0055] Although the present invention is described above in further detail through specific/preferred embodiments, the present invention is not limited to the specific embodiments. A person of ordinary skill in the art may make several replacements or modifications to these described embodiments without departing from the idea of the present invention, and these replacements or modifications all should be considered as falling within the protection scope of the present invention.


Claims

1. A telecentric illumination and photographing system for detection of marine microscopic organisms, comprising an optical path module and an illumination drive module, wherein the optical path module comprises:

an LED light source (1), configured to provide an illumination light source;

a light homogenizing rod (2), configured to mix light beams emitted from the LED light source (1) to obtain uniform light intensity distribution;

a decoherence light homogenizing sheet (3), configured to perform secondary light homogenization on the light beams emitted from an end surface of the light homogenizing rod (2) and perform decoherence processing on the light beams, to obtain an incoherent and uniform light source surface;

a diaphragm (4), configured to determine a corresponding diaphragm aperture according to a requirement for a collimation degree of an illumination beam;

a telecentric collimation camera (5), wherein a light beam emitted from the diaphragm (4) is incident into a microscopic organism area (7) with uniform illuminance after passing through the telecentric collimation camera (5); and

a telecentric imaging camera (9), matching the telecentric collimation camera (5) and configured to cooperate with the telecentric collimation camera (5) to receive an illumination beam passing through the microscopic organism area (7) and output the illumination beam to an imaging unit (10), to obtain an imaging result of uniform illuminance;

wherein the illumination drive module comprises:

a PWM synchronization signal unit, configured to provide a PWM synchronization signal of an imaging system;

a processing unit, configured to receive the PWM synchronization signal and generate a digital signal after performing quantization processing on the PWM synchronization signal;

a digital-to-analog conversion unit, configured to receive the digital signal and output an analog voltage signal after performing digital-to-analog conversion on the digital signal;

an analog signal amplification unit, configured to receive the analog voltage signal and output an analog quantization voltage after performing synchronous following and amplification on the analog voltage signal, wherein the LED light source (1) is driven by the analog quantization voltage; and

a synchronous current detection unit, configured to perform real-time sampling on a working current of the LED light source (1) and transmit sampled current information to the processing unit, wherein the processing unit performs feedback control according to the sampled current information, so that the LED light source (1) works in a stable state in which light emitting intensity is constant; and

wherein the processing unit performs light intensity or light brightness attenuation compensation by using a single-output proportional-integral-derivative neural network (SPIDNN) and according to the sampled current information, the SPIDNN comprises an input layer, a hidden layer, and an output layer, the input layer has two proportional neurons, the hidden layer has one proportional neuron, one integral neuron, and one derivative neuron, the output layer has one proportional neuron, one proportional neuron of the input layer inputs a preset ideal working current Ref_I, and the other proportional neuron of the input layer inputs a sampled actual working current Real_I, the SPIDNN outputs a control signal Out_pwm with a pulse width after processing, and a drive signal of the LED light source (1) is based on the control signal Out_pwm.


 
2. The telecentric illumination and photographing system for detection of marine microscopic organisms according to claim 1, characterized in that the spectrum range of the LED light source (1) includes from near-ultraviolet 365 nm to infrared band, and may be a light spectrum area of a band of therein, such as 420 nm to 680 nm, or a light spectrum of a single narrowband, such as red light 635±50 nm.
 
3. The telecentric illumination and photographing system for detection of marine microscopic organisms according to claim 1, characterized in that the light homogenizing rod (2) is a square or conical internal reflection cavity, or a transparent optical material entity; preferably, a light emitting diameter D of the LED light source (1) and a length L of the light homogenizing rod (2) satisfy the following relationship: L ≧ D3; more preferably, a light emitting surface of the LED light source (1) is a rectangle, and the corresponding light emitting diameter D is a diagonal length of the rectangle.
 
4. The telecentric illumination and photographing system for detection of marine microscopic organisms according to claim 1, characterized in that a scattering mode of the decoherence light homogenizing sheet (3) is lambertian, and a scattering rate ≧ 0.5.
 
5. The telecentric illumination and photographing system for detection of marine microscopic organisms according to claim 1, characterized in that a numerical aperture (NA) of the telecentric collimation camera ≧ 0.5.
 
6. The telecentric illumination and photographing system for detection of marine microscopic organisms according to claim 1, characterized in that the telecentric collimation camera (5) has a telecentric degree less than or equal to 2 degrees and is set to satisfy illumination and observation for microscopic organisms of a size of as small as 50 micrometers.
 
7. The telecentric illumination and photographing system for detection of marine microscopic organisms according to any one of claims 1-6, characterized in that the optical path module further comprises:

a polarizer (6), disposed between the telecentric collimation camera (5) and the microscopic organism area (7) and configured to polarize a light beam emitted from the telecentric collimation camera (5) to eliminate a scattering phenomenon of the light beam; and

an analyzer (8), disposed between the microscopic organism area (7) and the telecentric imaging camera (9), wherein the analyzer (8) is disposed by cooperating with the polarizer (6) and is configured to eliminate stray light generated when microscopic organisms are illuminated;

preferably, a transmission-extinction ratio Ts/Tp of the polarizer > 50:1, wherein Ts is a transmission rate of S-polarized light, and Tp is a transmission rate of P-polarized light; and a transmission-extinction ratio Ts/Tp of the analyzer > 50:1, wherein Ts is a transmission rate of S-polarized light, and Tp is a transmission rate of P-polarized light.


 
8. The telecentric illumination and photographing system for detection of marine microscopic organisms according to claim 1, characterized in that a network weight of the SPIDNN is automatically adjusted by making a formula (3.1) reach the minimum:

wherein E is an error evaluation function, Ref_I(k) is a value of an ideal working current at a moment k, and Real_I(k) is a value of an actual working current at the moment k.
 


Ansprüche

1. Telezentrisches Beleuchtungs- und Fotografiersystem zur Erkennung mikroskopischer Meeresorganismen, umfassend ein Lichtwegmodul und ein Beleuchtungsantriebsmodul, wobei das Lichtwegmodul Folgendes umfasst:

- eine LED-Lichtquelle (1), die zum Bereitstellen einer Beleuchtungslichtquelle eingerichtet ist,

- einen Lichthomogenisierungsstab (2), der zur Mischung von Lichtstrahlen, die aus der LED-Lichtquelle (1) emittiert werden, eingerichtet ist, um eine gleichmäßige Lichtintensitätsverteilung zu erreichen,

- ein Dekohärenz-Lichthomogenisierungsplättchen (3), das dazu eingerichtet ist, eine sekundäre Lichthomogenisierung der aus einer Stirnseite des Lichthomogenisierungsstabs (2) austretenden Lichtstrahlen und eine Dekohärenzbehandlung der Lichtstrahlen durchzuführen, um eine inkohärente und gleichmäßige Lichtquellenfläche zu erhalten,

- eine Blende (4), die zum Bestimmen einer entsprechenden Blendenöffnung in Abhängigkeit von der Anforderung des Kollimationsgrades der Beleuchtungs-Lichtstrahlen eingerichtet ist,

- eine telezentrische Kollimationskamera (5), wobei die aus der Blende (4) austretenden Lichtstrahlen nach Passieren der telezentrischen Kollimationskamera (5) mit einer gleichmäßigen Beleuchtungsstärke in einen mikroskopischen Organismenbereich (7) eintreten,

- eine telezentrische Bildkamera (9), die auf die telezentrische Kollimationskamera (5) abgestimmt und dazu eingerichtet ist, in Zusammenwirkung mit der telezentrischen Kollimationskamera (5) Beleuchtungs-Lichtstrahlen, die den mikroskopischen Organismenbereich (7) passieren, zu empfangen und diese an eine Bildgebungseinheit (10) auszugeben, um ein Bildgebungsergebnis mit gleichmäßiger Beleuchtungsstärke zu erhalten,

wobei das Beleuchtungsantriebsmodul Folgendes umfasst:

- eine PWM-Synchronisationssignaleinheit, die zum Bereitstellen eines PWM-Synchronisationssignals eines Bildgebungssystems eingerichtet ist,

- eine Verarbeitungseinheit, die zum Empfangen des PWM-Synchronisationssignals und zum Erzeugen eines digitalen Signals nach einer Quantisierungsverarbeitung des PWM-Synchronisationssignals eingerichtet ist,

- eine Digital-Analog-Wandlungseinheit, die zum Empfangen des digitalen Signals und zum Ausgeben eines analogen Spannungssignals nach einer Digital-Analog-Wandlung des digitalen Signals eingerichtet ist,

- eine Analogsignal-Verstärkungseinheit, die zum Empfangen des analogen Spannungssignals und zum Ausgeben einer analogen quantisierten Spannung nach synchronem Folgen und Verstärken des analogen Spannungssignals eingerichtet ist, wobei die LED-Lichtquelle (1) durch die analoge quantisierte Spannung angetrieben wird,

- eine Synchronstromerfassungseinheit, die zur echtzeitigen Abtastung des Betriebsstroms der LED-Lichtquelle (1) und zum Übertragen der Information abgetasteten Stroms an die Verarbeitungseinheit eingerichtet ist, wobei die Verarbeitungseinheit anhand der Information abgetasteten Stroms eine Rückkopplungssteuerung durchführt, sodass die LED-Lichtquelle (1) in einem stabilem Zustand mit konstanter Lichtintensität arbeitet, und

wobei die Verarbeitungseinheit anhand der Information abgetasteten Stroms eine Lichtintensitäts- oder Lichthelligkeits-Dämpfungskompensation über ein Proportional-Integral-Differential-Neuronnetz mit Einfachausgang, welches Proportional-Integral-Differential-Neuronnetz mit Einfachausgang eine Eingangsschicht, eine verborgene Schicht und eine Ausgangsschicht umfasst, wobei die Eingangsschicht zwei Proportional-Neuronen, die verborgene Schicht ein Proportional-Neuron, ein Integral-Neuron und ein Differential-Neuron und die Ausgangsschicht ein Proportional-Neuron aufweist, wobei ein Proportional-Neuron der Eingangsschicht einen voreingestellten Soll-Betriebsstrom Ref_I und das andere Proportional-Neuron der Eingangsschicht einen abgetasteten Ist-Betriebsstrom Real_I eingibt, wobei das Proportional-Integral-Differential-Neuronnetz mit Einfachausgang nach der Verarbeitung ein Steuersignal Out_pwm mit einer Pulsbreite ausgibt, und wobei ein Antriebssignal der LED-Lichtquelle (1) auf dem Steuersignal Out_pwm basiert ist.
 
2. Telezentrisches Beleuchtungs- und Fotografiersystem zur Erkennung mikroskopischer Meeresorganismen nach Anspruch 1, dadurch gekennzeichnet, dass der Spektrum-Bereich der LED-Lichtquelle (1) 365 nm im Nah-Ultraviolettband bis zu Infrarot-Band umfasst und ein Spektrum-Bereich eines der Bänder dazwischen, wie z.B. 420 nm bis 680 nm, oder ein Lichtspektrum eines einzelnen Schmalbands, wie z. B. rotes Licht 635±50 nm, sein kann.
 
3. Telezentrisches Beleuchtungs- und Fotografiersystem zur Erkennung mikroskopischer Meeresorganismen nach Anspruch 1, dadurch gekennzeichnet, dass der Lichthomogenisierungsstab (2) ein quadratischer oder konischer interner Reflexionshohlraum oder ein massives Element aus einem transparenten optischen Material ist, wobei vorzugsweise der Lichtemissionsdurchmesser D der LED-Lichtquelle (1) und die Länge L des Lichthomogenisierstabs (2) die folgende Beziehung erfüllen: L ≧ D×3, wobei bevorzugterweise die Lichtemissionsfläche der LED-Lichtquelle (1) ein Rechteck und der entsprechende Lichtemissionsdurchmesser D die diagonale Länge des Rechtecks ist.
 
4. Telezentrisches Beleuchtungs- und Fotografiersystem zur Erkennung mikroskopischer Meeresorganismen nach Anspruch 1, dadurch gekennzeichnet, dass das Dekohärenz-Lichthomogenisierungsplättchen (3) ein Lambertian-Diffusionsmodell und eine Diffusionsrate von ≧ 0,5 aufweist.
 
5. Telezentrisches Beleuchtungs- und Fotografiersystem zur Erkennung mikroskopischer Meeresorganismen nach Anspruch 1, dadurch gekennzeichnet, dass die numerische Apertur (NA) der telezentrischen Kollimationskamera ≧ 0,5 ist.
 
6. Telezentrisches Beleuchtungs- und Fotografiersystem zur Erkennung mikroskopischer Meeresorganismen nach Anspruch 1, dadurch gekennzeichnet, dass die telezentrische Kollimationskamera (5) eine Telezentrie von kleiner oder gleich 2 Grad aufweist und so eingestellt ist, dass sie die Anforderung der Beleuchtung und Beobachtung für mikroskopische Organismen mit einer Größe von kleiner als 50 Mikrometer erfüllt.
 
7. Telezentrisches Beleuchtungs- und Fotografiersystem zur Erkennung mikroskopischer Meeresorganismen nach einem der Ansprüche 1 bis 6, dadurch gekennzeichnet, dass das Lichtwegmodul ferner Folgendes umfasst:

- einen Polarisator (6), der zwischen der telezentrischen Kollimationskamera (5) und dem mikroskopischen Organismenbereich (7) angeordnet und dazu eingerichtet ist, die aus der telezentrischen Kollimationskamera (5) austretenden Lichtstrahlen zu polarisieren, um die Diffusion der Lichtstrahlen aufzuheben,

- einen Analysator (8), der zwischen dem mikroskopischen Organismus-Bereich (7) und der telezentrischen Bildkamera (9) angeordnet ist, wobei der Analysator (8) in Abstimmung auf den Polarisator (6) angeordnet und dazu eingerichtet ist, Streulicht zu entfernen, das beim Beleuchten mikroskopischer Organismen erzeugt wird,

wobei vorzugsweise das Transmissions-Extinktionsverhältnis Ts/Tp des Polarisators > 50:1 ist, wobei Ts für die Transmissionsrate für S-polarisiertes Licht und Tp für die Transmisionsrate für P-polarisiertes Licht steht, wobei das Transmissions-Extinktionsverhältnis Ts/Tp des Analysators > 50:1 ist, wobei Ts für die Transmissionsrate für S-polarisiertes Licht und Tp für die Transmisionsrate für P-polarisiertes Licht steht.
 
8. Telezentrisches Beleuchtungs- und Fotografiersystem zur Erkennung mikroskopischer Meeresorganismen nach Anspruch 1, dadurch gekennzeichnet, dass ein Netzgewicht des Proportional-Integral-Differential-Neuronnetzes mit Einfachausgang automatisch eingestellt wird, indem die Formel (3.1) das Minimum erreicht:

wobei E für eine Fehlerbewertungsfunktion, Ref_I(k) für den Wert des Soll-Betriebsstroms zu einem Zeitpunkt k und Real_I(k) für den Wert des Ist-Betriebsstroms zu dem Zeitpunkt k steht.
 


Revendications

1. Un système d'éclairage télécentrique et de photographie pour détection de micro-organismes marins, comprenant un module à trajet optique et un module de déclenchement d'éclairage, dans lequel le module à trajet optique comprend :

une source lumineuse DEL (1), configurée de façon à fournir une source lumineuse d'éclairage ;

une tige d'homogénéisation de lumière (2), configurée de façon à mélanger les faisceaux lumineux émis par la source lumineuse DEL (1) afin d'obtenir une distribution d'intensité lumineuse uniforme ;

une plaque d'homogénéisation de lumière de décohérence (3), configurée de façon à effectuer une deuxième homogénéisation de lumière sur les faisceaux lumineux émis depuis une surface d'extrémité de la tige d'homogénéisation de lumière (2) et à effectuer un processus de décohérence sur les faisceaux lumineux, afin d'obtenir une surface de source lumineuse uniforme et décohérente ;

un diaphragme (4), configuré de façon à déterminer une ouverture correspondante de diaphragme selon une exigence pour un degré de collimation d'un faisceau d'éclairage ;

une caméra télécentrique (5), dans lequel le faisceau lumineux émis depuis un diaphragme (4) est incident dans une zone d'organismes microscopiques (7) avec un éclairage uniforme après passage à travers la caméra télécentrique (5) ; et

une caméra d'imagerie télécentrique (9), correspondant à la caméra télécentrique (5) et configurée de façon à coopérer avec la caméra télécentrique (5) afin de recevoir un faisceau d'éclairage passant à travers une zone d'organismes microscopiques (7) et de produire le faisceau d'éclairage vers une unité d'imagerie (10) afin d'obtenir un résultat d'imagerie de l'éclairage uniforme ;

dans lequel le module de déclenchement d'éclairage comprend :

une unité de signaux de synchronisation PWM, configurée de façon à fournir des signaux de synchronisation PWM d'un système d'imagerie ;

une unité de traitement, configurée de façon à recevoir les signaux de synchronisation PWM et à générer des signaux numériques après avoir effectué un traitement de quantification des signaux de synchronisation PWM ;

une unité de conversion numérique à analogique, configurée de façon à recevoir les signaux numériques et à produire des signaux de tension analogiques après avoir effectuée une conversion numérique à analogique des signaux numériques ;

une unité d'amplification de signaux analogiques, configurée de façon à recevoir les signaux de tension analogique et à produire une tension de quantification analogique après avoir effectué un suivi synchrone et une amplification des signaux de tension analogiques, dans laquelle la source lumineuse DEL (1) est déclenchée par la tension de quantification analogique ; et

une unité de détection de courant synchrone, configurée de façon à effectuer l'échantillonnage en temps réel d'un courant de fonctionnement de la source lumineuse DEL (1) et à transmettre les informations de courant échantillonné à une unité de traitement, dans laquelle l'unité de traitement effectue une commande rétroactive en fonction des informations de courant échantillonné, de sorte que la source lumineuse DEL (1) fonctionne selon un état stable dans lequel l'intensité de la lumière émise est constante ; et

dans lequel l'unité de traitement effectue une compensation d'atténuation d'intensité ou de clareté lumineuse en utilisant un réseau neuronal proportionnel intégral dérivatif à sortie unique (SPIDNN) et en fonction des informations de courant échantillonné, le SPIDNN comprenant une couche d'entrée, une couche cachée et une couche de sortie, la couche d'entrée étant dotée de deux neurones proportionnels, la couche cachée étant dotée d'un neurone proportionnel, d'un neurone intégral et d'un neurone dérivatif, la couche de sortie étant dotée d'un neurone proportionnel, un neurone proportionnel de la couche d'entrée introduit un courant de régime idéal de préréglage Ref_I, et l'autre neurone proportionnel de la couche d'entrée introduit un courant de régime réel échantillonné Real_I, le SPIDNN produit des signaux de commande Out_pwm avec une largeur de pulsation après traitement, et les signaux de déclenchement de la source lumineuse DEL (1) sont basés sur les signaux de commande Out_pwm.


 
2. Un système d'éclairage télécentrique et de photographie pour détection de micro-organismes marins selon la revendication 1, caractérisé en ce que la gamme de spectre de la source lumineuse DEL (1) comprend une bande du proche-ultraviolet 365 nm à l'infrarouge, et peut constituer en une zone de spectre lumineux d'une bande qu'elle comprend, telle que de 420 nm à 680 nm, ou un spectre lumineux de bande étroite unique, telle la lumière rouge 635 ± 50 nm.
 
3. Un système d'éclairage télécentrique et de photographie pour détection de micro-organismes marins selon la revendication 1, caractérisé en ce que la tige d'homogénéisation de lumière (2) est une cavité réflective interne carrée ou conique, ou une entité matérielle optique transparente ; préférablement, le diamètre D d'émission de lumière de la source lumineuse DEL (1) et la longueur L de la tige d'homogénéisation de lumière (2) satisfont la relation suivante : L ≧ D3 ; plus préférablement, la surface émettrice de lumière de la source lumineuse DEL (1) est un rectangle, et le diamètre D émetteur de lumière correspondant est la longueur diagonale du rectangle.
 
4. Un système d'éclairage télécentrique et de photographie pour détection de micro-organismes marins selon la revendication 1, caractérisé en ce que le mode de dispersion de la plaque d'homogénéisation de lumière de décohérence (3) est Lambertien et le taux de dispersion est ≧ 0,5.
 
5. Un système d'éclairage télécentrique et de photographie pour détection de micro-organismes marins selon la revendication 1, caractérisé en ce que l'ouverture numérique (NA) de la caméra de collimation télécentrique est ≧ 0,5.
 
6. Un système d'éclairage télécentrique et de photographie pour détection de micro-organismes marins selon la revendication 1, caractérisé en ce que la caméra télécentrique (5) est dotée d'un degré télécentrique inférieur ou égal à 2 degrés et est paramétrée pour satisfaire l'éclairage et l'observation d'organismes microscopiques d'une taille aussi petite que 50 micromètres.
 
7. Un système d'éclairage télécentrique et de photographie pour détection de micro-organismes marins selon l'une quelconque des revendications 1 à 6, caractérisé en ce que le module de trajet optique comprend en outre :

un polariseur (6) agencé entre la caméra télécentrique (5) et la zone d'organismes microscopiques (7) et qui est configuré pour polariser un faisceau lumineux émis depuis la caméra télécentrique (5) afin d'éliminer le phénomène de dispersion du faisceau lumineux ; et

un analyseur (8) agencé entre la zone d'organismes microscopiques (7) et la caméra d'imagerie télécentrique (9), dans lequel l'analyseur (8) est agencé en coopération avec le polariseur (6) et est configuré pour éliminer la lumière parasite générée lorsque les organismes microscopiques sont éclairés ;

préférablement, le rapport transmission-extinction Ts/Tp du polariseur est > 50 : 1, dans lequel Ts est le taux de transmission de la lumière S-polarisée, et Tp est le taux de transmission de la lumière P-polarisée ; et le rapport transmission-extinction Ts/Tp de l'analyseur est > 50 : 1, dans lequel Ts est le taux de transmission de la lumière S-polarisée, et Tp est le taux de transmission de la lumière P-polarisée.


 
8. Un système d'éclairage télécentrique et de photographie pour détection de micro-organismes marins selon la revendication 1, caractérisé en ce que le poids de SPIDNN est automatiquement ajusté en faisant atteindre le minimum à la formule (3.1) :

dans laquelle E est une fonction d'évaluation d'erreur, Ref_I(k) est la valeur de courant de fonctionnement idéal à un moment k et Real_I(k) est la valeur du courant de fonctionnement réel au moment k.
 




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Cited references

REFERENCES CITED IN THE DESCRIPTION



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Patent documents cited in the description