Automatic activated getter structure of infrared detector

Abstract

The invention relates to the technical field of infrared detectors, in particular to an automatically-activated getter structure of an infrared detector, which comprises at least one group of adsorption units, the first end of a conduction unit penetrates through a Dewar main cylinder to be connected with an external power supply circuit, the second end of the conduction unit is connected with the electric input end of a getter, and the control end of the conduction unit is connected with a pressure sensor; the pressure sensor continuously detects the real-time pressure in the Dewar main cylinder and outputs a conduction signal to the conduction unit for conduction when the real-time pressure exceeds a pressure limit value, so that the getter is activated by the power supply circuit. In order to solve the problem that in the prior art, a getter is relatively difficult to activate again after being activated for the first time and loaded into a product, in the scheme, a pressure sensor and a conduction unit are integrated in a Dewar main cylinder, the vacuum degree in the Dewar main cylinder is detected through the pressure sensor, and when the vacuum degree does not meet the requirement, the conduction unit is switched on to activate the getter again; therefore, the purpose of ensuring the internal vacuum degree of the detector is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of infrared detector, and particularly relates to an automatically activated getter structure of an infrared detector. BACKGROUND

[0002] An infrared detector is a sensor for detecting infrared radiation, and is widely used in night vision, thermal imaging, industrial detection and other fields. Its structure includes a detector chip, a Dewar, a cold head, a circuit and a package, etc. Generally, in order to achieve a good signal-to-noise ratio, the detector chip needs to be cooled to reduce the temperature, thereby reducing the thermal noise of the device itself, and then facilitating the separation of the tiny thermal radiation signal from the background signal. To achieve this cooling process, the detector chip and related peripheral circuits are usually arranged in a Dewar bottle, which can better isolate heat transfer, and then the cold head contacts the substrate of the detector chip to continuously cool it. At the same time, in order to avoid the problem that the internal gas of the Dewar bottle causes heat convection and changes the temperature of the detector chip, the internal Dewar bottle usually needs to be evacuated.

[0003] In the prior art, there is a technical solution for evacuating the Dewar based on a getter.

[0004] For example, the patent document with the application number CN200910226511.4 discloses an installation structure and implementation method of an infrared detector Dewar getter, which is suitable for the component technology of an engineering Dewar for infrared detector packaging. The installation structure of the infrared detector Dewar getter includes a hollow cylindrical shell of the Dewar, a Kovar cylindrical pin, a hollow cylindrical ceramic column, a getter, a mechanical support omega ring, a circular arc cross pin, a series cross pin and a loop L-shaped pin. Specific structures and implementation methods are introduced in terms of mechanical support, electrical connection and air-tight vacuum extraction of the getter, to realize high-reliability air-tight installation of the getter in the infrared detector Dewar, thereby facilitating the improvement of the vacuum life and miniaturization of the infrared detector Dewar assembly. It is also suitable for the installation of the getter in the infrared detector Dewar, which is discharged from one side of the hollow cylindrical electrode pin. The present application is also suitable for the installation structure of the getter in the infrared detector Dewar, which has a flat installation surface.

[0005] For example, patent application CN202410988308.5 discloses an infrared detector structure with an electrically activated getter and its manufacturing method. The infrared detector structure includes a detector chip wafer and a cap. The detector chip wafer includes electrical connection pads, and the cap is bonded to the detector chip wafer. The cap includes a deep cavity, a protrusion at the bottom of the deep cavity, a metal layer covering the surface of the protrusion, and a getter layer covering part of the surface of the metal layer. The getter layer is disposed on the surface of the protrusion at the bottom of the deep cavity of the cap, which greatly increases the surface area of ​​the getter layer, providing sufficient getter area without affecting the size of the infrared window, thereby improving the getter's gas-taking capacity. Furthermore, by using the electrical connection pads to energize the metal layer, the getter layer covering the surface of the metal layer can be heated, thereby achieving high-temperature activation of the getter layer without affecting the microbridge array area on the detector chip, greatly improving the performance of the detector's thermal pixel material. Moreover, the getter layer can be reactivated, improving the detector's vacuum level.

[0006] However, in practice, the inventors discovered that this type of technical solution typically involves encapsulating a getter inside a Dewar flask and configuring external leads. After the infrared detector is assembled, the getter is energized to activate it and control the vacuum level. The external drive device is then removed to complete the fabrication of the finished detector. However, due to the limited surface area of ​​the getter, after a period of use, it reaches its maximum adsorption capacity and can no longer absorb residual gas, necessitating reactivation. Summary of the Invention

[0007] In view of the above-mentioned problems in the prior art, an automatically activated getter structure for an infrared detector is provided.

[0008] The specific technical solution is as follows: An automatically activated getter structure for an infrared detector includes at least one set of adsorption units disposed inside the Dewar main tube of the infrared detector. The adsorption unit includes: a getter, a pressure sensor, a conductive unit, and a conductive column; The first end of the conducting unit passes through the Dewar main cylinder and connects to the external power supply circuit; The second end of the conducting unit is connected to the electrical input terminal of the getter; The control terminal of the conduction unit is connected to a pressure sensor located inside the Dewar main cylinder. The electrical output terminal of the getter is connected to the Dewar main cylinder via a conductive post as the ground terminal; The pressure sensor continuously detects the real-time pressure inside the Dewar main cylinder, and outputs a conduction signal to the conduction unit when the real-time pressure exceeds the pressure limit, so that the getter is activated by the power supply circuit.

[0009] On the other hand, the getter is a columnar getter; The getter is arranged vertically inside the Dewar main cylinder; The electrical input terminal of the getter is located at the bottom of the getter, and the electrical output terminal of the getter is located at the top of the getter; The conductive unit and the conductive post are fixed at different heights along the horizontal direction.

[0010] On the other hand, the getter is covered by an adsorption unit shell; The outer shell of the adsorption unit is cylindrical, and multiple vent holes are provided on the outer shell of the adsorption unit to connect to the interior of the Dewar main cylinder; The conductive unit and the conductive post pass through the outer shell of the adsorption unit and are connected and fixed to the getter.

[0011] On the other hand, a first cooling device is fitted onto the outer side of the Dewar main cylinder; The main body of the first cooling device is cylindrical; The first cooling device has a plurality of first thermoelectric semiconductor cooling chips distributed on its inner side, and the conductive ends of the first thermoelectric semiconductor cooling chips are respectively connected to the power supply circuit. The cold end of the first thermoelectric semiconductor cooling chip contacts the Dewar main cylinder, and the hot end of the first thermoelectric semiconductor cooling chip contacts the inner side of the main body of the first cooling device. The outer side of the main body of the first cooling device has first heat dissipation fins.

[0012] On the other hand, a second cooling device is fitted onto the outer side of the Dewar main cylinder; The main body of the second cooling device is cylindrical; The outer side of the main body of the second cooling device is provided with second heat dissipation fins; The inner side of the second cooling device has a plurality of second thermoelectric semiconductor cooling chips, and the conductive ends of the second thermoelectric semiconductor cooling chips are respectively connected to the power supply circuit; A heat-conducting base is provided at the bottom of the adsorption unit shell, and the heat-conducting base is fixed to the bottom of the Dewar main cylinder; The side of the heat-conducting base is provided with an extension structure, which passes through the Dewar main cylinder and connects to the cold end of the second thermoelectric semiconductor cooling chip. The hot end of the second thermoelectric semiconductor cooling chip contacts the inner side of the main body of the second cooling device.

[0013] On the other hand, the first cooling device and the second cooling device are arranged at a certain interval in the height direction outside the Dewar main cylinder.

[0014] On the other hand, the conducting unit includes: a fixed conductive rod, a conductive slider, and a hydraulic conductive rod; The fixed conductive rod is fixed to the housing of the adsorption unit and passes through the housing of the adsorption unit to connect to the getter; The fixed part of the hydraulic conductive rod is fixed to the main cylinder of the Dewar, and the fixed part of the hydraulic conductive rod passes through the main cylinder of the Dewar to reach the outside. The movable part of the hydraulic conductive rod is provided with a conductive slider at its end. When the hydraulic conductive rod is extended, the conductive slider abuts against the fixed conductive rod and forms an electrical connection. The pressure sensor is mounted on the fixed part of the hydraulic conductive rod.

[0015] On the other hand, the fixed part of the hydraulic conductive rod is fitted with an insulator at the part that passes through the Dewar main cylinder and is located on the outside of the Dewar main cylinder.

[0016] On the other hand, the pressure sensor also includes a delay module. When the real-time pressure exceeds the pressure limit, the pressure sensor outputs a conduction signal to the conduction unit to conduct, and the delay module controls the output duration of the conduction signal to be greater than a preset duration.

[0017] On the other hand, the first cooling device covers the area where the adsorption unit housing is located in the height direction; The detection window and substrate of the infrared detector are positioned higher than the first cooling device.

[0018] The above technical solution has the following advantages or beneficial effects: To address the issue that existing technologies present difficulties in reactivating getters after initial activation and product loading, this solution integrates a pressure sensor and a conduction unit inside the Dewar main cylinder. The pressure sensor detects the vacuum level inside the Dewar main cylinder, and when the vacuum level does not meet the requirements, the conduction unit is activated to reactivate the getter, thereby ensuring the vacuum level inside the detector. Attached Figure Description

[0019] Embodiments of the invention will be described more fully with reference to the accompanying drawings. However, the drawings are for illustration and explanation only and do not constitute a limitation on the scope of the invention.

[0020] Figure 1 This is an overall schematic diagram of an embodiment of the present invention; Figure 2 This is a schematic diagram of the adsorption unit assembly in an embodiment of the present invention; Figure 3 This is a schematic diagram of the adsorption unit shell in an embodiment of the present invention; Figure 4 This is a schematic diagram of the hydraulic rod in an embodiment of the present invention; Figure 5 This is a schematic diagram of the pressure sensor circuit in an embodiment of the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0024] This invention includes: An automatically activated getter structure for an infrared detector, such as Figure 1 As shown, it includes at least one set of adsorption units, which are disposed inside the Dewar main tube A1 of the infrared detector. The adsorption unit includes: getter 1, pressure sensor 2, conduction unit 3, and conductive column 4; The first end of the conducting unit 3 passes through the Dewar main cylinder A1 and connects to the external power supply circuit; The second end of the conducting unit 3 is connected to the electrical input terminal of the getter; The control end of the conduction unit 3 is connected to the pressure sensor 2 located inside the Dewar main cylinder A1; The electrical output terminal of getter 1 is connected to the Dewar main cylinder A1 via conductive post 4 as the ground terminal; Pressure sensor 2 continuously monitors the real-time pressure inside the Dewar main cylinder A1, and outputs a conduction signal to the conduction unit when the real-time pressure exceeds the pressure limit, so that the getter is activated by the power supply circuit.

[0025] Specifically, addressing the problem that it is relatively difficult to reactivate the getter after initial activation and product loading in existing technologies, this solution integrates a pressure sensor and a conduction unit inside the Dewar main cylinder. The pressure sensor detects the vacuum level inside the Dewar main cylinder, and when the vacuum level does not meet the requirements, the conduction unit is activated to reactivate the getter, thereby ensuring the vacuum level inside the detector.

[0026] Specifically, the aforementioned automatically activated getter structure is mainly used in infrared detectors and can be either cooled or uncooled. Its main feature is a sealed Dewar main cylinder A1, inside which an infrared detector substrate A2 is installed, and a vacuum process is performed after sealing. The getter 1 is used to absorb gases that have seeped in due to seal failure, residual gases from vacuuming, volatile gases from the adhesive, etc., during long-term use, in order to maintain the vacuum level inside the Dewar main cylinder A1.

[0027] The figure shows an embodiment in which two sets of adsorption units are arranged opposite each other on both sides of the cold stage, but one set can also be arranged as needed, or multiple sets can be arranged around the cold stage.

[0028] Getter 1 is typically a non-evaporable getter fixed in a specific frame structure. These materials can chemically react or adsorb with active gases after being heated and activated. For example, they are metals or alloys containing titanium, zirconium, vanadium, etc. For ease of installation and structural stability, they are usually fixed with a frame. In addition, for ease of activation, they usually need to be wound or have resistance wires embedded in the core. By heating the resistance wires, getter 1 is heated to the activation temperature and then continuously adsorbs the gas until adsorption saturation.

[0029] In existing technologies, the Dewar is typically activated during product assembly by evacuating the device, connecting leads to an activation device, and then removing the activation device before continuing assembly. The purpose of removing the activation device is to prevent the resistance wire from continuously heating and affecting the operating temperature of the detector chip. This results in the detector needing to be disassembled and the leads reconnected after the getter 1 becomes saturated before it can be reactivated.

[0030] To address this issue, in this embodiment, the conductive path of the getter 1 inside the Dewar main cylinder A1 was adjusted. A pressure sensor 2 and a normally closed conduction unit 3 were installed. The pressure sensor 2 continuously detects the real-time pressure inside the Dewar main cylinder A1 and compares it using a comparison circuit. When the real-time pressure exceeds the pressure limit, a conduction signal is output to the conduction unit to activate the getter 1, thereby activating the power supply circuit.

[0031] This configuration allows the assembled detector to activate the getter 1 multiple times during use, maintaining a vacuum for the longest possible time. Simultaneously, the normally closed conduction unit 3 ensures that the getter 1 remains de-energized after the initial vacuuming, preventing additional heat generation and eliminating the need to remove the external power supply circuit.

[0032] In one embodiment, such as Figure 2 , 3 As shown, getter 1 is a columnar getter; Getter 1 is arranged vertically inside the Dewar main cylinder A1; The electrical input terminal of getter 1 is located at the bottom of getter 1, and the electrical output terminal of getter 1 is located at the top of getter 1; The conductive unit 3 and the conductive post 4 are fixed at different heights along the horizontal direction.

[0033] Specifically, to achieve a more compact structural layout, in this embodiment, the frame structure of the getter 1 is adjusted so that the getter 1 is roughly columnar, and the resistance wire in the getter 1 is set to lead out at both ends. Subsequently, the getter 1 is arranged vertically inside the Dewar main cylinder A1, with the electrical input terminal of the getter 1 located at the bottom of the getter 1 and the electrical output terminal of the getter 1 located at the top of the getter 1.

[0034] Then, the conductive unit 3 and the conductive post 4 are fixed at different heights along the horizontal direction, extending from the Dewar main cylinder A1 toward the getter 1, and are fixedly connected to the electrical input terminal and electrical output terminal of the getter 1, respectively. This fixed connection includes a rigid connection in structure and a conductive connection in circuit.

[0035] It is important to note that when designing the frame of getter 1, certain mechanical structural designs are required for the lead frames of the electrical input and output terminals, so that the lead frame of the bottom electrical input terminal can stably support the getter 1 above, and the lead frame of the top electrical output terminal can provide a limit.

[0036] In one embodiment, the getter 1 is fitted with an adsorption unit housing 5. The outer shell 5 of the adsorption unit is cylindrical, and multiple vent holes are provided on the outer shell 5 of the adsorption unit to connect to the interior of the Dewar main cylinder A1. The conductive unit 3 and the conductive post 4 pass through the adsorption unit housing 5 and are connected and fixed to the getter 1.

[0037] Specifically, considering that some infrared detectors are easily affected by strong vibrations during application, such as in the aerospace field, which can lead to friction between the getter 1 and the inner wall coating, resulting in excess material, in this embodiment, an adsorption unit shell 5 is fitted over the getter 1. The adsorption unit shell 5 is a closed cylindrical structure, with the bottom connected to and fixed to the detector base, and the top sealed to completely enclose the getter 1. Ventilation holes are provided around the shell to connect the interior of the adsorption unit shell 5 with the interior of the Dewar main cylinder A1, thereby allowing gas to pass through.

[0038] The adsorption unit housing 5 has high rigidity and does not come into contact with the Dewar main cylinder A1 or the getter 1, thereby reducing the probability of friction with them under severe vibration. At the same time, when the getter 1 rubs against the adsorption unit housing 5, the excess material that falls off will be collected inside the adsorption unit housing 5 and will not escape.

[0039] Furthermore, the conductive unit 3 and the conductive post 4 pass through the through holes opened on the outer shell 5 of the adsorption unit and are connected and fixed to the getter 1. The through holes also serve to further fix and limit the conductive unit 3 and the conductive post 4, preventing the ends of the excessively long conductive unit 3 and the conductive post 4, i.e., the parts connected to the getter 1, from undergoing large displacement during vibration. An insulating gasket is fitted inside the through hole to prevent short circuits.

[0040] In one embodiment, a first cooling device 6 is fitted onto the outer side of the Dewar main cylinder A1; The main body of the first cooling device 6 is cylindrical; Multiple first thermoelectric semiconductor cooling chips 61 are distributed inside the first cooling device 6, and the conductive ends of the first thermoelectric semiconductor cooling chips 61 are respectively connected to the power supply circuit. The cold end of the first thermoelectric semiconductor cooling chip 61 contacts the Dewar main cylinder A1, and the hot end of the first thermoelectric semiconductor cooling chip 61 contacts the inner side of the main body of the first cooling device 6. The outer side of the main body of the first cooling device 6 is provided with first heat dissipation fins 62.

[0041] Specifically, in cooled infrared detectors, cooling of the Dewar and its internal components is necessary to achieve good detection accuracy. To address this, in this design, a first cooling device 6 is fitted onto the outside of the main Dewar cylinder A1. The main body of the first cooling device 6 is a hollow cylindrical structure, open at both ends with its inner diameter matching the outer diameter of the main Dewar cylinder A1. Multiple first thermoelectric semiconductor cooling elements 61 are embedded on its inner surface, with the cold ends of the first thermoelectric semiconductor cooling elements 61 facing inwards and abutting against the main Dewar cylinder A1, and the hot ends facing outwards and abutting against the main body of the first cooling device 6.

[0042] The first thermoelectric semiconductor cooling chip 61 is made based on the Peltier effect and mainly includes a PN junction structure. When a certain voltage is applied through the conductive end, it cools the cold end and releases heat at the hot end. Cooling is achieved by the first thermoelectric semiconductor cooling chip 61, and heat dissipation is achieved by the first heat dissipation fins 62 on the outside of the first cooling device 6.

[0043] In one embodiment, a second cooling device 7 is fitted onto the outer side of the Dewar main cylinder A1; The main body of the second cooling device 7 is cylindrical; The outer side of the main body of the second cooling device 7 is provided with second heat dissipation fins 72. The inner side of the second cooling device 7 is provided with a plurality of second thermoelectric semiconductor cooling chips 71, and the conductive ends of the second thermoelectric semiconductor cooling chips 71 are respectively connected to the power supply circuit. A heat-conducting base 51 is provided at the bottom of the adsorption unit housing 5, and the heat-conducting base 51 is fixed to the bottom of the Dewar main cylinder A1; The side of the heat-conducting base 51 is provided with an extension structure, which passes through the Dewar main cylinder A1 and connects to the cold end of the second thermoelectric semiconductor cooling chip 71. The hot end of the second thermoelectric semiconductor cooling chip 71 contacts the inner side of the main body of the second cooling device 7.

[0044] Specifically, considering that the infrared detector may need to reactivate the getter 1 during operation, and that the resistance wire of the getter 1 will generate additional heat during activation, which may affect the operation of the detector, in this embodiment, a heat-conducting base 51 is provided at the bottom of the adsorption unit housing 5. The heat-conducting base 51 is fixed to the bottom of the Dewar main cylinder A1. An extension structure is provided on the side of the heat-conducting base 51. The extension structure passes through the Dewar main cylinder A1 and connects to the cold end of the second thermoelectric semiconductor cooling chip 71.

[0045] The heat-conducting base 51 and the adsorption unit housing 5 are made of high thermal conductivity materials, such as copper and nickel, and insulation can be achieved through surface coating, anodizing and other processes as needed.

[0046] Subsequently, a second cooling device 7 was fitted onto the outside of the Dewar main cylinder A1. The main body of the second cooling device 7 is a hollow cylindrical structure with openings at both ends and an inner diameter matching the outer diameter of the Dewar main cylinder A1. Multiple second thermoelectric semiconductor cooling chips 71 are embedded on the inner surface, with the cold end of the second thermoelectric semiconductor cooling chip 71 facing inward against the Dewar main cylinder A1 and the hot end facing outward against the main body of the second cooling device 7.

[0047] The second thermoelectric semiconductor cooler 71 is made based on the Peltier effect and mainly includes a PN junction structure. When a certain voltage is applied through the conductive end, it cools the cold end and releases heat at the hot end. Cooling is achieved by the second thermoelectric semiconductor cooler 71, and heat dissipation is achieved by the second heat dissipation fins 72 on the outside of the second cooling device 7.

[0048] Based on the above settings, the adsorption unit housing 5 itself establishes a heat conduction path from the self-heating base to the second cooling device 7, thereby continuously cooling the adsorption unit housing 5 to maintain it at a low temperature.

[0049] When the getter 1 is activated, since the adsorption unit housing 5 itself does not come into contact with the getter 1, no heat conduction will occur, and the getter 1 will not fall below the activation temperature.

[0050] As the getter 1 is gradually activated, it adsorbs the surrounding environment. Therefore, the air pressure in the adsorption unit housing 5 is slightly lower than the external air pressure. At the same time, the adsorption unit housing 5 itself has a top cover, which blocks and absorbs heat to prevent the generation of heat convection.

[0051] Furthermore, since the adsorption unit shell 5 completely encloses the getter 1, it can absorb the heat output of the getter 1 through a lower surface temperature, thus avoiding affecting the operation of the detector chip.

[0052] In one embodiment, the first cooling device 6 and the second cooling device 7 are arranged at a certain interval in the height direction outside the Dewar main cylinder A1.

[0053] Specifically, in order to avoid the heat generated by the first cooling device 6 and the second cooling device 7 forming a hot zone and thus affecting the cooling efficiency, in this embodiment, the first cooling device 6 and the second cooling device 7 are arranged at a certain interval in the height direction on the outside of the Dewar main cylinder A1 to provide heat dissipation space.

[0054] In addition, the first cooling device 6 covers the area where the adsorption unit shell 5 is located in the height direction. This area serves as the cold zone inside the Dewar main cylinder A1, used to cool the inside of the Dewar and to cool the infrared detector substrate A2 above it through the cold stage.

[0055] The detection window and the infrared detector substrate A2 are positioned above the first cooling device 6.

[0056] In one embodiment, such as Figure 4 As shown, the conducting unit 3 includes: a fixed conductive rod 31, a conductive slider 32, and a hydraulic conductive rod 33; The fixed conductive rod 31 is fixed on the adsorption unit housing 5 and passes through the adsorption unit housing 5 to connect to the getter 1; The fixed part of the hydraulic conductive rod 33 is fixed on the Dewar main cylinder A1, and the fixed part of the hydraulic conductive rod 33 passes through the Dewar main cylinder A1 to reach the outside. The end of the movable part of the hydraulic conductive rod 33 is provided with a conductive slider 32. When the hydraulic conductive rod extends, the conductive slider 32 abuts against the fixed conductive rod 31 and forms an electrical connection. A pressure sensor 2 is installed on the fixed part of the hydraulic conductive rod 33.

[0057] Specifically, in order to achieve conduction control of getter 1, this embodiment uses a detachable conductive rod to achieve this process.

[0058] Specifically, the structure consists of two parts. The fixed conductive rod 31 is fixed on the adsorption unit shell 5 and passes through the adsorption unit shell 5 to connect to the getter 1. One end of the rod is fixedly connected to the getter 1, while the other end protrudes from the adsorption unit shell 5 to provide a conductive contact. The rod itself is made of conductive material, and an insulating gasket is provided at the contact part with the adsorption unit shell 5.

[0059] The fixed part of the hydraulic conductive rod 33 is fixed to the Dewar main cylinder A1, while the movable part is located inside the Dewar main cylinder A1 and can extend and retract horizontally. The hydraulic conductive rod 33 consists of two parts: a fixed part and a movable part. The fixed part is an outer cylinder with a hydraulic structure, and the movable part is a push rod with a hydraulic structure. The cavity inside the fixed part is driven by a connected hydraulic cylinder to move the movable part. At the same time, the contact area between the fixed part and the movable part can form a conductive connection.

[0060] To achieve better control, a pressure sensor 2 is installed on the fixed part of the hydraulic conductive rod 33. The pressure sensor 2 is directly connected to the hydraulic cylinder and provides a control signal, thereby causing the movable part to extend or shorten.

[0061] When the movable part extends, the conductive slider 32 at the end of the movable part abuts against the fixed conductive rod 31 and forms an electrical connection. When it retracts, the electrical connection is broken.

[0062] In one embodiment, the fixed portion of the hydraulic conductive rod 33 is fitted with an insulator at the portion passing through the Dewar main cylinder A1 and located outside the Dewar main cylinder A1.

[0063] Specifically, in order to achieve better insulation, in this embodiment, an insulator is sleeved on the fixed part of the hydraulic conductive rod 33, which passes through the Dewar main cylinder A1 and is located on the outside of the Dewar main cylinder A1. The conductive inner core part is wrapped by the insulator to prevent the shell from short-circuiting.

[0064] In one embodiment, the pressure sensor 2 further includes a delay module. When the real-time pressure exceeds the pressure limit, the pressure sensor outputs a conduction signal to the conduction unit to conduct, and the delay module controls the output duration of the conduction signal to be longer than a preset duration.

[0065] Specifically, in order to achieve better control, such as Figure 5 As shown, the control circuit of pressure sensor 2 consists of the following parts: Sampling module 21 connects to the thin film portion of the thin film pressure sensor and converts the elongation of the thin film into an electrical signal, which is then amplified by an amplifier circuit. The comparison module 22 is mainly a comparator circuit. Its non-inverting input is connected to the amplified output of the sampling module 21, and its inverting input is connected to the reference voltage. The value of the reference voltage is obtained through pre-experimental calibration, that is, the voltage of the amplified electrical signal of the air pressure value measured by the thin-film pressure sensor under the target vacuum degree.

[0066] The delay module 23 is primarily an output stage circuit used to further amplify the enable signal output by the comparator module 22 to provide a certain output swing. A delay control circuit, based on an RC delay circuit, is also introduced here. When an enable signal is input, the output remains high; when the enable signal disappears, the output continues to maintain a high level until the capacitor discharges. The delay length is changed by adjusting the capacitance and resistance. This design aims to prevent the output of the comparator module 22 from oscillating with real-time gas pressure changes when the gas generation rate is low. Since the activation process of getter 1 requires energization to reach the activation temperature, oscillations caused by only activating a portion and absorbing a small amount of gas cannot ensure that getter 1 is fully activated. By extending the activation time, the getter 1 is fully activated, thereby significantly increasing the amount of gas adsorbed.

[0067] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should recognize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. An automatically activatable getter structure for an infrared detector, characterized in that, The adsorption unit comprises a getter, a pressure sensor, a conducting unit and a conductive column. The first end of the conducting unit penetrates the Dewar main cylinder to connect an external power supply circuit. The second end of the conducting unit is connected to the electrical input end of the getter. The control end of the conducting unit is connected to the pressure sensor arranged inside the Dewar main cylinder. The electrical output end of the getter is connected to the Dewar main cylinder as a ground end via the conductive column. The pressure sensor continuously detects the real-time pressure inside the Dewar main cylinder and outputs a conducting signal to the conducting unit to conduct when the real-time pressure exceeds a pressure limit, so that the getter is activated by the power supply circuit. The getter is a columnar getter.

2. The self-activatable getter structure according to claim 1, characterized in that, The getter is arranged in the Dewar main cylinder in a vertical direction. The electrical input end of the getter is located at the bottom of the getter, and the electrical output end of the getter is located at the top of the getter. The conducting unit and the conductive column are respectively fixed at different heights in a horizontal direction. The getter is sleeved with an adsorption unit shell.

3. The self-activatable getter structure according to claim 2, characterized in that, The adsorption unit shell is cylindrical, and a plurality of air holes are formed on the adsorption unit shell to communicate with the inside of the Dewar main cylinder. The conducting unit and the conductive column respectively penetrate the adsorption unit shell and are fixedly connected with the getter. The Dewar main cylinder is sleeved with a first cooling device.

4. The self-activatable getter structure according to claim 3, characterized in that, The main body of the first cooling device is cylindrical. A plurality of first thermoelectric semiconductor refrigerating pieces are distributed on the inner side of the first cooling device, and the conductive ends of the first thermoelectric semiconductor refrigerating pieces are respectively connected to the power supply circuit. The cold end of the first thermoelectric semiconductor refrigerating piece contacts the Dewar main cylinder, and the hot end of the first thermoelectric semiconductor refrigerating piece contacts the inner side of the main body of the first cooling device. The outer side of the main body of the first cooling device is distributed with first heat dissipation fins. The Dewar main cylinder is sleeved with a second cooling device.

5. The self-activatable getter structure according to claim 3, characterized in that, The main body of the second cooling device is cylindrical. The outer side of the main body of the second cooling device is distributed with second heat dissipation fins. A plurality of second thermoelectric semiconductor refrigerating pieces are distributed on the inner side of the second cooling device, and the conductive ends of the second thermoelectric semiconductor refrigerating pieces are respectively connected to the power supply circuit. The bottom of the adsorption unit shell is provided with a heat-conducting base fixed to the bottom of the Dewar main cylinder. The side of the heat-conducting base is provided with an extension structure penetrating the Dewar main cylinder to connect the cold end of the second thermoelectric semiconductor refrigerating piece. The hot end of the second thermoelectric semiconductor refrigerating piece contacts the inner side of the main body of the second cooling device. The first cooling device and the second cooling device are arranged at a certain interval in the height direction of the outer side of the Dewar main cylinder.

6. The self-activatable getter structure according to claim 5, characterized in that, The conducting unit comprises a fixed conductive rod, a conductive sliding block and a hydraulic conductive rod.

7. The self-activatable getter structure according to claim 3, characterized in that, The fixed conductive rod is fixed on the adsorption unit shell and penetrates the adsorption unit shell to connect the getter. ​ The fixed part of the hydraulic conductive rod is fixed on the main cylinder of the Dewar, and the fixed part of the hydraulic conductive rod penetrates through the main cylinder of the Dewar to the outside; The end of the movable part of the hydraulic conductive rod is provided with a conductive sliding block, which abuts against the fixed conductive rod and forms an electrical connection when the hydraulic conductive rod is elongated; The pressure sensor is installed on the fixed part of the hydraulic conductive rod.

8. The self-activatable getter structure according to claim 7, characterized in that, The fixed part of the hydraulic conductive rod is sleeved with an insulator on the part penetrating through the main cylinder of the Dewar and located outside the main cylinder of the Dewar.

9. The self-activatable getter structure according to claim 1, characterized in that, The pressure sensor further comprises a delay module, the pressure sensor outputs a conduction signal to the conduction unit for conduction when the real-time pressure exceeds a pressure limit value, and the output duration of the conduction signal is controlled by the delay module to be longer than a preset duration.

10. The self-activatable getter structure according to claim 4, characterized in that, The first cooling device covers the area where the adsorption unit shell is located in the height direction. The detection window and the substrate of the infrared detector are higher than the first cooling device.

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