CN116228883A - IsCMOS camera dynamic range calibration system - Google Patents

Abstract

The invention provides an IsCMOS camera dynamic range calibration system, which comprises an LED calibration light source system, a driving circuit, a grooving structure, an enhanced mirror reflection film and an optical fiber; the LED calibration light source system is arranged at an outlet position below the HERD calorimeter system; the LED calibration light source system comprises a plurality of groups of LED calibration light sources, the LED calibration light source system comprises a structural panel, a notch structure is arranged on the structural panel, an enhanced mirror reflection film is laid in the notch structure, an optical fiber passes through the notch structure from the enhanced mirror reflection film, a PCB board provided with the plurality of groups of LED calibration light sources is covered on the notch structure, each notch structure is provided with an independent group of LED calibration light sources, and a driving circuit matched with the plurality of groups of LED calibration light sources is arranged on the PCB board. The invention solves the problem of large dynamic range calibration of the HERD calorimeter IsCMOS camera.

Description

IsCMOS camera dynamic range calibration system

Technical Field

The invention belongs to the field of space science, and particularly relates to an IsCMOS camera dynamic range calibration system.

Background

The camera dynamic range calibration system in the prior art comprises an optical fiber, an optoelectronic device, a HERD detection facility and an IsCMOS camera.

The optical fiber is a glass fiber capable of transmitting optical signals, has a very large variety, and is characterized by good flexibility and flexible arrangement. In physical experiments, optical fibers are often used as photoconductive media to guide out fluorescent signals generated in crystals to the photoelectric device at the rear end, wherein the wavelength of the fluorescent signals ranges from 400nm to 760nm.

The photoelectric device is a device for converting a scintillation fluorescent signal into an electric signal based on a photoelectric effect, and common photoelectric conversion devices include a photomultiplier tube, a photodiode, an ICCD camera and the like. Different photoelectric devices have different working wavelengths, and photons with different energies can be converted into electric signals. When charged particles or gamma rays enter the scintillation crystal, various ionizing radiation effects can occur according to the energy magnitude, and fluorescent signals can be generated. These fluorescence can reach the rear end of the optoelectronic device either directly (crystal directly coupled to the optoelectronic device) or indirectly (fluorescence propagates through the fiber) and is converted into an electrical signal by photoelectric conversion.

The space high-energy radiation detection facility (HERD) is a detection facility which is installed on a Chinese space station and used for measuring high-energy cosmic rays, and consists of a plurality of detector subsystems such as a calorimeter (calorimeter, CALO), a track instrument (FIberTracker, FIT), a plastic flash detector (PlasticScintillation Detector, PSD), a silicon detector (SiliconChargeDetector, SCD), a traversing radiation detector (TransitionRadiation Detector, TRD) and the like.

Foremost in the HERD detection facility is the intermediate located calorimeter CALO. The calorimeter CALO detector subsystem consists of three parts: 7500 LYSO crystals with square 3cm form crystal array, which is responsible for converting high energy cosmic ray signals into fluorescent signals; an IsCMOS camera responsible for reading the fluorescent signal; PD system, responsible for reading fluorescent signals. The fluorescent signal generated by cosmic rays in each LYSO crystal is extracted by a fiber optic light guide plate coupled to the upper surface of the crystal. The optical fiber light guide sheet has four leading-out ports, wherein one optical fiber port sends signals to the low-range IsCMOS camera, and one optical fiber port sends signals to the high-range IsCMOS camera. The other two paths of optical fiber ports are connected with the triggering system. The low-range IsCMOS camera is identical to the high-range IsCMOS camera, and only the set working parameters are different. The high range IsCMOS camera has a lower gain factor to facilitate measurement of higher energy range signals.

The total number of optical fibers coupled by each camera is 7500. Particle shower signals occurring in the calorimeter reach the camera via 7500 fibers, which can convert these signals into a two-dimensional digitized gray map. After the equipment is developed, calibration is needed to accurately understand the detected signals. Furthermore, the entire HERD facility needs to be run on-track for years, and the performance of each sub-detector and IsCMOS camera may change, which also requires calibration and calibration to be performed periodically. The calibration is mainly to determine the dynamic range of the detector and the two IsCMOS cameras.

An IsCMOS camera is a photodetection device comprising a front and a back light cone, an image intensifier and an sCMOS chip. 7500 fibers are coupled to the camera through a front end microplate (Fiberplate). Each optical fiber is coupled to a different region of the camera, and the amplified signals can be collected independently from each other in the different regions of the camera. In the HERD calorimeter, the fluorescent signal generated by the single particle incident instance is transmitted to the IsCMOS camera through the optical fiber to form two-dimensional image data. And storing and downloading, and then analyzing. IsCMOS has a microchannel plate (MCP), where each microchannel on the plate is functionally equivalent to a photomultiplier tube, and can perform photoelectric conversion and signal amplification. In general, an IsCMOS camera corresponds to an aggregate of a plurality of micro photomultiplier tubes. Multiple signals can be acquired simultaneously.

The dynamic range calibration in the prior art is based on determining the input-output relationship.

After the detector is developed, the detector is mainly used for testing unknown signals. For example, two-dimensional image data is obtained on the camera, and the determination of the energy and flux represented by the two-dimensional image data requires a pre-calibration process. I.e. the output response of the test camera, using as input some signal source of known energy, flux (or intensity). From the low energy end to the high energy end, a plurality of energy points can be measured continuously. And establishing an input-output relation curve according to the response result. The curve is a calibration curve, and the range from the low energy end to the high energy end corresponding to the curve is the dynamic range of the detector. When the detector is used for testing the unknown signal, the test results are within the dynamic range, namely the range covered by the calibration curve. The calibration curve can be used to obtain the information of the energy, flux, etc. of the unknown signal.

There are two commonly used energy calibration methods, one is to irradiate LYSO crystals with rays of different energies (with known energies) to generate fluorescent signals, the response of the system to the known energies can be known according to the test results, and the relationship between the input energy and the output signal can be established by combining the simulation method. Resulting in a dynamic range of the camera or CALO subsystem response to the input signal. The details are as follows:

the energy of the radiation source is known and different radiation sources may provide radiation of different energies. The beam energy extracted by the accelerator is also known and the accelerator can provide radiation with continuously adjustable energy. These rays of known energy are denoted E1, E2. Firstly, irradiating the crystal with radiation with energy E1, and marking the response of a camera as C1; irradiating the crystal with radiation with energy E2, and marking the response of the camera as C2; ... Finally, the crystal is irradiated with radiation of energy En, the response of the camera being noted Cn. By this method, a response relationship between the incident energy E and the camera can be established. With this response, the data from the on-track operation of the calorimeter can be interpreted.

In addition to this method of calibrating using known energy rays, the device can also be calibrated using an LED calibration light source. The LED calibration light source has adjustable wavelength and power and small volume, and can generate a fluorescence signal very similar to a real particle signal by matching with a proper control circuit. The LED brightness can be continuously adjusted, and the upper limit of the light intensity is higher, so that a wide dynamic range can be calibrated. This approach may be employed when conventional energy methods cannot be used or require separate dynamic range calibration of optoelectronic devices such as cameras. The invention discloses an energy meter calibration method based on LED calibration light source.

In the long-time use process of the LED calibration light source, the light output amplitude can be changed due to aging, service life and the like. Therefore, in the high-precision test, it is not possible to use the light source as a standard light source. The dynamic range of the system is generally calibrated by a double-light-source calibration method. The basic idea of the dual-light-source calibration method is to calibrate the system by adopting two light sources (respectively named as a light source and a light source B). The A, B light source is respectively turned on and the response result of the system is recorded as A _i 、B _i Then the A, B light source is turned on simultaneously, and the response result of the system is recorded as AB _i . Multiple measurements to obtain multiple sets of data A ₁ ...A _N ，B ₁ ...B _N ，AB ₁ ...AB _N . If the system is linear in response, there must be A _i +B _i ＝AB _i . Otherwise, define (A _i +B _i -AB _i )/AB _i Is a linear deviation and represents the degree of deviation of the system from the linear response. With multiple sets of data points, a linear deviation and an input signal AB can be established _i Relationship between them. The degree of deviation of the input signals with different magnitudes from linearity is obtained. This is the result that dynamic range calibration is to be achieved. By utilizing the relation between the input signal and the linear deviation, the output result can be linearly corrected, and a linear output result is obtained. The linear relationship is given by the low energy section energy calibration. By combining the two relations, the situation of how much energy corresponds to the result obtained by the measurement of the camera can be understood. For example, the camera measures a 50-ten-thousand gray-scale value, and judges whether the gray-scale value is in a linear region or not according to the calibration relation of the dynamic range of the LED, if not, the gray-scale value deviates from the linear region. And multiplying the data by a correction factor by using the dynamic range calibration relation, and correcting the data to a linear region. And then the energy value of the case can be deduced by using the energy linear calibration result.

In circuit design, there is a delay circuit that functions to push or delay the signal arrival time. Such a delay circuit may be incorporated in the driving circuit when calibrating the camera using the dual light source method.

The dynamic range calibration method has some disadvantages as follows:

a. the choice of energy points is not free enough. The radiation source has few alternative energy ranges and particle types, and generally can only perform calibration work below the MeV level. And the energy selection in this interval is limited, and only the existing energy of the radioactive source can be selected. The beam line driven by the accelerator is better, the upper energy limit can be provided is higher, and the energy value can be continuously adjusted. Currently up to several hundred gevs. However, the calibration requirement for higher energy is not sufficient.

b. The use is not convenient enough, the activity of the radioactive source can not be adjusted, and the beam line needs to be adjusted to proper energy and flux, so that great workload is also required. Therefore, the total time required for completing the whole calibration work is very long, the operation flow is complex, and a plurality of people are required to cooperate in a specific environment to complete the calibration work.

c. On-track use is difficult. This approach is also of little relevance for detectors carried on space stations or satellites. It is difficult to carry multiple sources up to the sky or to carry the beam up to the sky for calibration. Although during in-orbit flight calibration can be performed using some known source such as Crab. However, the choice of suitable choice is after all limited. Therefore, a convenient and quick calibration mode needs to be found. An alternative option is to use the LED light to simulate the fluorescent signal generated by the real particle for calibration. The LED light size and wavelength can be adjusted. By selecting an LED of the appropriate wavelength, and setting an appropriate pulsed drive current, pulsed light of equivalent real particle energy can be "produced". The camera or the photo detection device performs calibration by detecting this equivalent pulse signal. For HERD calorimeter, the dynamic range to be calibrated is relatively large, about 1-6000 MIP (1 MIP equivalent of 200 photoelectrons). The on-orbit dynamic range calibration cannot be achieved by adopting the traditional radioactive source/ray/cosmic ray mode.

d. The camera cannot be calibrated alone. When using a beam or radiation source for calibration, a system such as a "crystal-light guide-camera" must be built to obtain the signal. The system can only be calibrated on the whole energy meter system, and the camera performance in the system cannot be calibrated independently.

Disclosure of Invention

In order to solve the technical problems, the invention provides an IsCMOS camera dynamic range calibration system which solves the problem of large dynamic range calibration of an HERD calorimeter IsCMOS camera and solves the problem of camera dynamic range calibration by adopting an optical fiber-camera as an calorimeter of a reading system.

In order to achieve the above purpose, the invention adopts the following technical scheme:

an IsCMOS camera dynamic range calibration system comprises an LED calibration light source system, a driving circuit, a grooving structure, an enhanced specular reflection film and an optical fiber; the LED calibration light source system is arranged at an outlet position right below a near-cube structure formed by 7500 LYSO crystals of the HERD calorimeter system; the optical fiber is led out from the right lower part of the near-cube structure to reach an IsCMOS camera; the LED calibration light source system comprises a plurality of groups of LED calibration light sources, wherein each LED calibration light source comprises a structural panel, a notch structure is arranged on the structural panel, an enhanced mirror reflection film is laid in the notch structure, an optical fiber passes through the notch structure from the enhanced mirror reflection film, a PCB (printed Circuit Board) provided with the plurality of groups of LED calibration light sources is covered on the notch structure, each notch structure is provided with an independent group of LED light sources, and a driving circuit matched with the plurality of groups of LED light sources is arranged on the PCB; and the optical fiber passes through the notch structure and is LED out, so that the LED calibration light source system is integrated on the HERD calorimeter system.

Further, the LED calibration light sources are independently driven and do not interfere with each other.

Further, the light intensity of a group of LED calibration light sources configured by each notch structure is independently adjusted.

Further, the optical fiber is packaged by optical coupling glue after the notch structure is fixed.

Further, the enhanced specular reflective film is an ESR optical reflective film.

Further, the LED calibration light source is in the form of a double-LED calibration light source.

Further, a delay design is provided in the driving circuit.

The beneficial effects are that:

the invention can effectively solve the coupling problem between a plurality of optical fibers and a photoelectric conversion device, and has the following advantages:

a. the structure is simple. The invention occupies very small space, and the calibration light source and the primary circuit are integrated on a PCB board, so that the structure is compact. The HERD calorimeter has limited space, and great space resources can be saved by adopting the HERD calorimeter.

b. The reliability is high. The invention adopts a plurality of groups of discrete light sources, and the light sources and the driving circuits thereof are independent and can be mutually backed up. If some light sources fail, other light sources can still calibrate the camera. The risk of the calibration system not being able to work does not occur.

c. The operation is flexible. The invention adopts the design that a plurality of groups of driving circuits independently drive a plurality of groups of LED light sources. The design can flexibly configure the calibration scheme. For example, a progressive scanning type calibration camera can be adopted, a regional mode can also be adopted for calibrating the camera, and the camera is flexibly configured according to real-time power consumption.

Drawings

FIG. 1 shows the operation mode of the driving circuit when calibrating the camera by the dual light source method;

FIG. 2 is a diagram of HERD calorimeter composition;

FIG. 3a is a top view of an LED scaled light source;

fig. 3b is a side view of an LED scaled light source.

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention. In addition, the technical features of the embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.

The invention relates to an LED calibration light source system, a driving circuit, a grooving structure, an enhanced mirror reflection film, an optical fiber and an optical coupling adhesive, wherein the LED calibration light source system is composed of a plurality of groups of LED calibration light sources. The driving circuit is responsible for controlling the light emission of a plurality of groups of LED calibration light sources, and is preferably a PCB. The grooved structure is used for placing a plurality of groups of optical fibers.

The HERD calorimeter system consists essentially of two parts, one is a near-cube structure consisting of 7500 crystals of lutetium yttrium silicate, which is responsible for converting cosmic rays into optical signals. The other is an IsCMOS camera, which is responsible for converting an optical signal into an electrical signal. The two are connected together through a large number of optical fibers, and the optical signals of the near-cube structure are transmitted to the IsCMOS camera through the optical fibers.

Four optical fibers from LYSO (lutetium yttrium silicate) crystals were connected to two IsCMOS cameras and a trigger PMT (photomultiplier tube), respectively. When 7500 optical fibers are LED out from the array of LYSO crystals, an appropriate position is selected on the path of the optical fibers to arrange the LED calibration light source system. The one suitable location is the array exit location of the LYSO crystals, i.e., directly below the HERD calorimeter. The positional structural relationship between the LED calibration light source system and the optical fiber is referred to fig. 3.

Because of space limitations, the near-cube structure and the IsCMOS camera are not located immediately in a single place with a distance between them, and therefore it is necessary to connect the two by optical fibers. The optical fiber is led out to the IsCMOS camera through the right below the near-cube structure. The LED indexing light source system is also disposed directly below the near-cube structure. The optical fiber needs to be LED out through a notch structure in the LED calibration light source system, so that the LED calibration light source system is integrated on the HERD calorimeter system. The LED calibration light source system comprises a plurality of groups of LED calibration light sources. The microplate in fig. 2 is a structural component of the HERD calorimeter and serves to constrain the position of the optical fibers and to help secure the optical fibers and IsCMOS cameras together.

The LED calibration light source system comprises the following components: a plurality of 6cm 4mm 5mm (length. Times. Width. Times. Depth) groove structures are engraved on a structural panel, and an enhanced specular reflection film, preferably an ESR optical reflection film, is laid in the groove structures. The optical fiber passes through the grooved structure from the enhanced specular reflection film. The grooved structure is covered with a PCB board equipped with LED calibration light sources. When the LED calibration light source is lightened, the calibration signal is sent out to enter the optical fiber and then reaches the IsCMOS camera through the optical fiber.

The enhanced specular reflection film has the function of improving the efficiency of collecting fluorescence by the optical fiber, so that the calibrated fluorescence signal emitted by the LED calibrated light source is collected by the optical fiber as much as possible. The light intensity is required to be as high as possible in the large dynamic range calibration, and the improvement of fluorescence collection efficiency is beneficial to the realization of the large dynamic range calibration target.

The density of the engraved structures arranged on the structural panel is 7 per 3cm width. Three optical fibers can be arranged in each notch structure, and an independent group of LED calibration light sources is configured. This design is advantageous for achieving uniformity of optical signals between different fibers. After a group of LED calibration light sources configured by each notch structure send out calibration signals, the calibration signals are collected by all optical fibers arranged in the notch structure. If there are too many optical fibers, such as ten optical fibers, arranged in the grooved structure, there is a possibility that some optical fibers collect more photons and some optical fibers collect fewer photons due to shielding among the optical fibers. I.e. a problem of non-uniformity of the fiber signal. The non-uniformity of the fiber optic signal, if excessive, can affect the width of the calibratable dynamic range. If the uniformity among the optical fibers is better, the dynamic range calibration width of the IsCMOS camera can be made larger; if the uniformity between the fibers is poor, the dynamic range calibration width of the IsCMOS camera cannot be made large, which is severely limited by the fiber with the worst light collection efficiency.

A plurality of groups of LED calibration light sources and a matched driving circuit are arranged on the PCB, the PCB is covered on the top end of the grooving structure (shown in fig. 3a and 3 b), and each group of LED calibration light sources corresponds to one grooving structure and three optical fibers in the grooving structure. The top surface of the notch structure covers the PCB board, so that the positioning of the LED calibration light source and the configuration of the driving circuit can be completed. After the optical fiber is arranged in the notch structure, the optical fiber is encapsulated by the optical adhesive, so that the optical fiber can be protected by encapsulating the optical fiber by the optical adhesive, and the stability of the interrelation among the optical fiber, the enhanced mirror reflection film and the LED calibration light source system can be ensured, thereby ensuring the stability of the calibration index.

The invention relates to an IsCMOS camera dynamic range calibration method, which comprises the following steps:

step (a), determining a camera area needing calibration (assuming that the area needing calibration is Z), and checking whether an LED calibration light source and a working circuit corresponding to the area are normal or not; because the number of the LED calibration light sources is relatively large, if all LEDs are powered at the same time, the power consumption burden is excessive. Generally, a zoned calibration mode is adopted.

And (b) starting the driving circuit corresponding to the zone Z to calibrate. Turning on the LED calibration light source of group A, and recording the response of the camera as group A ₁ ；

Step (c), turning off the LED calibration light source of the group A, turning on the LED calibration light source of the group B, and recording the response of the camera as B1;

step (d), simultaneously turning on LED calibration light sources of the group A and the group B, and recording the response of the camera as AB1;

step (e) restarting from step (b), changing the light intensity, obtaining a series of test results (Ai, bi, aiBi) in order from weak to strong; a relationship between ai+bi-AiBi and AiBi is established, where i represents the number of groups. The greater the number of sampling points, the higher the calibration curve accuracy.

The LED calibration light source system adopts a near-end positioning design. An LED calibration light source system is disposed at the array exit location of the LYSO crystals. The array exit location is relatively close to the IsCMOS camera (the length of the fiber between the LED calibration light source and the IsCMOS camera is about 2.2 meters). The LED calibration light source system can reduce the loss caused by the optical signal in the optical fiber transmission process at the position, and is beneficial to the calibration of a large dynamic range.

The LED calibration light source system adopts an independent driving design. The IsCMOS camera is calibrated by configuring a number of LED calibration light source systems at the array exit locations of the LYSO crystals. The LED calibration light sources of the LED calibration light source systems can work independently and do not interfere with each other, the driving circuit can independently drive each LED calibration light source (not each group), namely, the driving circuit can light any specified LED calibration light source at will. The design has the advantages that the camera calibration is flexible, and not only can the whole pixel calibration be carried out, but also only partial areas can be calibrated. If part of the LED calibration light sources are in fault, the whole LED calibration light source system still has certain working capacity, cannot be in integral failure, and improves the fault tolerance of the system.

The invention adopts the optical fiber grouping and grooving structure design. A large number of optical fibers can be grouped by utilizing the notch structures, and each etched notch structure is provided with a plurality of optical fibers serving as a group to configure a group of LED light sources. Several optical fibers in the same groove are irradiated by a group of LED calibration light sources (usually, the group of LED calibration light sources comprises a plurality of LED calibration light sources), and the photon numbers received by different optical fibers are not very different. The different grooving structures are provided with independent LED calibration light sources, and the light intensity can be independently adjusted. Overall, this design ensures that the dynamic range of the nominal optical signal output by each fiber (i.e., the minimum optical signal lower limit and the maximum optical signal upper limit output by each fiber) is nearly identical. The upper limit range and the lower limit range of the calibrating light signals received by different areas of the IsCMO camera are basically the same, and the dynamic range calibration of the same size can be carried out on the different areas of the IsCMOS camera. The IsCMOS camera includes an IsCMOS high range camera and an IsCMOS low range camera.

The invention adopts the optical cement potting design. After the optical fiber is placed and fixed in the notch structure, the optical coupling glue is used for packaging, and the advantage lies in: protection can be formed on the optical fiber; the relative structure between the light source, the reflecting layer and the optical fiber and the groove can be cured, and the curing measure can enhance the stability of the optical system and reduce the fluctuation; and the optical signal transmission path is improved, and the transmission efficiency and stability are improved.

The invention adopts the design of a V-shaped ESR optical reflection film. The ESR optical reflection film has two functions, namely, the collection efficiency of the calibrated optical signal is improved, and the calibratable upper limit of the dynamic range is improved; and the second is to separate the optical fibers. As previously described, three LYSO crystals of optical fibers are placed in each groove, for a total of 12 fibers. And 6 signals from the LED calibration light source are sent to the trigger end and 6 signals from the LED calibration light source are sent to the IsCMOS camera end. Therefore, 6 fibers to the trigger end need to be isolated from the LED calibration light source. This need can be accomplished with ESR optically reflective films. The ESR optical reflection film is an enhanced specular reflection film manufactured by 3M company.

The invention adopts a double LED calibration light source design. The output of a single LED calibration light source is not stable, and a double-light source method is needed for dynamic range calibration. The basic idea of the dual-light-source calibration method is to calibrate the system by adopting two light sources (respectively named as a light source and a light source B). The A, B light source is respectively turned on and the response result of the system is recorded as A _i 、B _i Then the A, B light source is turned on simultaneously, and the response result of the system is recorded as AB _i . Multiple measurements to obtain multiple sets of data A ₁ ...A _N ，B ₁ ...B _N ，AB ₁ ...AB _N . If the system is linear in response, there must be A _i +B _i ＝AB _i . Otherwise, define (A _i +B _i -AB _i )/AB _i Is a linear deviation and represents the degree of deviation of the system from the linear response. With multiple sets of data points, a linear deviation and an input signal AB can be established _i Relationship between them. The degree of deviation of the input signals with different magnitudes from linearity is obtained. This is the result that dynamic range calibration is to be achieved. By utilizing the relation between the input signal and the linear deviation, the output result can be linearly corrected, and a linear output result is obtained. The linear relationship is given by the low energy section energy calibration. By combining the two relations, the situation of how much energy corresponds to the result obtained by the measurement of the camera can be understood. For example, a result of 50 ten thousand gray values is obtained by the camera, and whether the gray value is in a linear region or not is judged according to the dynamic range calibration relation of the LED calibration light source, if the gray value is not in the linear region, the gray value deviates from the linear region. And multiplying the data by a correction factor by using the dynamic range calibration relation, and correcting the data to a linear region. The energy value of this example can be deduced by using the energy linear calibration result.

In the invention, two independent LED calibration light sources are needed for dual LED calibration, namely, the two independent LED calibration light sources form a group of LED calibration light sources, and the group of independent LED calibration light sources directly irradiates a plurality of (6 are currently, can be specifically adjusted according to different conditions and are not fixed parameters) optical fibers, because different optical fibers are coupled to different positions of an IsCMOS camera screen (the screen is large, the pixels are small, and one optical fiber corresponds to a plurality of pixel points). Therefore, a group of LED calibration light sources can be used for calibrating partial areas of the IsCMOS camera by adopting the principle of a double light source method. For the whole HERD energy meter array (with 2 ten thousand optical fibers), an LED calibration light source system consisting of a plurality of groups of LED calibration light sources is needed to realize the coverage of an IsCMOS camera screen with a large area. A plurality of groups of LED calibration light sources (the quantity is a variable parameter and can be flexibly adjusted according to the requirement) can be arranged on one structural panel. And a PCB circuit board is covered above each structural panel and used for supplying power to each LED calibration light source and providing a matched circuit.

The invention adopts a signal delay design. The LED calibration light source is unstable, and the change of the signal output amplitude can be found when the LED calibration light source is turned on after each turn off. While if the powered state is maintained at all times, the LED calibration light source is still very stable for a period of time (> 1 hour). Based on the characteristic of the LED calibration light source, delay design can be adopted to replace the power-off operation of the light source when the camera calibration is carried out by adopting a double-light-source method. The delay design is adopted in the driving circuit, so that the circuit stability can be improved, and the calibration efficiency can be improved. When the calibration is performed by adopting the dual light source method, the test of one energy point is generally required to be completed according to the working mode of 'A switch B-A switch', as shown in figure 1. The same test can also be done using a delay circuit approach. When a delay circuit is used, a specific operation mode is "a-on B-on (plus delay) - - > a-on B-on (no delay)", as shown in fig. 2. At "a on B on (plus delay)" because of the delay of the circuit, the signals received by the camera can be divided into two sequences, 1, 3, 5. The signal acquisition of the A, B lamp can be completed once. When two light sources are required to be turned on simultaneously, the delay of the driving circuit is adjusted to be zero.

It will be readily appreciated by those skilled in the art that the foregoing description is merely a preferred embodiment of the invention and is not intended to limit the invention, but any modifications, equivalents, improvements or alternatives falling within the spirit and principles of the invention are intended to be included within the scope of the invention.

Claims (7)

1. An IsCMOS camera dynamic range calibration system, which is characterized in that: the LED light source calibration device comprises an LED calibration light source system, a driving circuit, a grooving structure, an enhanced specular reflection film and an optical fiber; the LED calibration light source system is arranged at an outlet position right below a near-cube structure formed by 7500 LYSO crystals of the HERD calorimeter system; the optical fiber is led out from the right lower part of the near-cube structure to reach an IsCMOS camera; the LED calibration light source system comprises a plurality of groups of LED calibration light sources, the LED calibration light source system comprises a structural panel, a notch structure is arranged on the structural panel, an enhanced mirror reflection film is laid in the notch structure, an optical fiber passes through the notch structure from the enhanced mirror reflection film, a PCB board provided with the plurality of groups of LED calibration light sources is covered on the notch structure, each notch structure is provided with an independent group of LED calibration light sources, and a driving circuit matched with the plurality of groups of LED calibration light sources is arranged on the PCB board; and the optical fiber passes through the notch structure and is LED out, so that the LED calibration light source system is integrated on the HERD calorimeter system.

2. An IsCMOS camera dynamic range calibration system of claim 1, wherein: the LED calibration light sources are independently driven and are not mutually interfered.

3. An IsCMOS camera dynamic range calibration system of claim 1, wherein: the light intensity of each LED calibration light source of a group of LED calibration light sources configured by each notch structure is independently adjusted.

4. An IsCMOS camera dynamic range calibration system of claim 1, wherein: and the optical fiber is packaged by adopting optical coupling glue after the notch structure is fixed.

5. An IsCMOS camera dynamic range calibration system of claim 1, wherein: the enhanced specular reflective film is an ESR optical reflective film.

6. An IsCMOS camera dynamic range calibration system of claim 1, wherein: each group of LED calibration light sources of the plurality of groups of LED calibration light sources comprises two LED calibration light sources, and each LED calibration light source is independently driven by a driving circuit.

7. An IsCMOS camera dynamic range calibration system of claim 6, wherein: a delay design is arranged in the driving circuit.

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