An infrared optical system capable of non-uniformity correction

Abstract

The utility model discloses an infrared optical system that can realize non-uniform correction. The system comprises a front fixed group, a zoom group, a compensation group, a rear fixed group, a mechanical assembly and a control module; the front fixed group is used for receiving external light and performing preliminary focusing; the zoom group is used for changing the overall focal length of the infrared optical system by moving along the optical axis; the compensation group is used for moving along the optical axis in cooperation with the zoom group to offset the image plane shift caused by the movement of the zoom group; the rear fixed group is used for performing final focusing on the light passing through the front fixed group, the zoom group and the compensation group and fixing the image plane position; the control module is used for controlling the mechanical assembly, driving the zoom group and the compensation group to move along the optical axis through the mechanical assembly and realizing non-uniform correction. The utility model can cover the image elements on the entire detector focal plane after defocusing the high-energy target, form uniform light intensity distribution and finally enable the infrared imaging system to complete the purpose of non-uniform correction without baffles.

Description

Technical Field

[0001] This utility model relates to the field of infrared optical equipment technology, and more specifically, to an infrared optical system capable of achieving non-uniform correction. Background Technology

[0002] Due to limitations in component materials and manufacturing processes, infrared thermal imagers produce infrared images with significant non-uniformity, severely impacting image quality. Furthermore, this non-uniformity is greatly affected by changes in the image scene; in uncooled infrared imaging systems, it is also influenced by ambient temperature, further degrading the imaging quality of the infrared system.

[0003] Currently, the non-uniformity problem of infrared thermal imagers cannot be completely eliminated. The common method is to add a baffle correction mechanism to the design of the infrared imaging system. The image is corrected after the baffle cuts off the light path transmission. However, the application of shutter not only increases cost and power consumption, but also, when the infrared system is working under harsh temperature conditions, the temperature difference between the baffle and the outside temperature is large, which will also lead to a large temperature difference between the corrected image and the actual environment. Utility Model Content

[0004] In view of the above-mentioned defects or improvement needs of the existing technology, this utility model provides an infrared optical system that can achieve non-uniform correction, so that even after a high-energy target is defocused, it can still cover the pixels on the entire focal plane of the detector to form a uniform light intensity distribution. At the same time, it does not introduce stray light and cold reflection into the system during the defocusing process, and finally enables the infrared imaging system to achieve the purpose of non-uniform correction without the addition of a baffle.

[0005] To achieve the above objectives, according to one aspect of this utility model, an infrared optical system is provided, comprising a front fixed group, a zoom group, a compensation group, a rear fixed group, mechanical components, and a control module. The front fixed group, zoom group, compensation group, and rear fixed group are sequentially arranged on the optical axis of the infrared optical system along the incident direction of light. The front fixed group is used to receive external light and perform preliminary focusing. The zoom group is used to change the overall focal length of the infrared optical system by moving along the optical axis. The compensation group is used to cooperate with the zoom group to move along the optical axis and counteract the image plane shift caused by the movement of the zoom group. The rear fixed group is used to finally focus the light passing through the front fixed group, zoom group, and compensation group to fix the image plane position. The control module is used to control the mechanical components, which drive the zoom group and compensation group to move along the optical axis to achieve non-uniform correction.

[0006] In some embodiments, the infrared optical system further includes a detector for acquiring an imaging image; and a control module for controlling mechanical components to drive the zoom group and compensation group to move along the optical axis based on the image of the detector's focal plane, so as to maximize the image of the detector's focal plane and achieve non-uniform correction.

[0007] In some implementations, the control module is used to first control the mechanical components to drive the zoom group to move along the optical axis based on the image of the detector focal plane, and then control the mechanical components to drive the compensation group to move along the optical axis, so as to maximize the image of the detector focal plane and achieve non-uniform correction.

[0008] In some implementations, the front fixing group consists of one or more lenses; the front fixing group is a positive lens or a combination of positive and negative lenses.

[0009] In some implementations, the zoom group consists of one or more lenses; the zoom group is a negative lens or a combination of positive and negative lenses.

[0010] In some implementations, the compensation group consists of one or more lenses; the compensation group is a positive lens, a negative lens, or a combination of positive and negative lenses.

[0011] In some embodiments, the rear fixing group consists of one or more lenses; the rear fixing group is a positive lens or a combination of positive and negative lenses.

[0012] According to another aspect of this utility model, an infrared optical system is provided, including a front fixed group, a zoom group, a compensation group, a focusing group, a mechanical component, and a control module. The front fixed group, zoom group, compensation group, and focusing group are sequentially arranged on the optical axis of the infrared optical system along the incident direction of light. The front fixed group is used to receive external light and perform preliminary focusing. The zoom group is used to change the overall focal length of the infrared optical system by moving along the optical axis. The compensation group is used to cooperate with the zoom group to move along the optical axis and counteract the image plane shift caused by the movement of the zoom group. The focusing group is used to cooperate with the compensation group to move along the optical axis and further compensate for the image plane shift during the zoom process, ensuring clear imaging. The control module is used to control the mechanical component, which drives the zoom group, compensation group, and focusing group to move along the optical axis to achieve non-uniform correction.

[0013] In some embodiments, the infrared optical system further includes a detector for acquiring an imaging image; the control module is used to control the mechanical components to drive the zoom group, compensation group and focusing group to move along the optical axis according to the image of the detector focal plane, so as to maximize the image of the detector focal plane and achieve non-uniform correction.

[0014] In some implementations, the control module is used to first control the mechanical components to drive the zoom group to move along the optical axis based on the image of the detector focal plane, then control the mechanical components to drive the compensation group to move along the optical axis, and then control the mechanical components to drive the focusing group to move along the optical axis, so as to maximize the image of the detector focal plane and achieve non-uniform correction.

[0015] Overall, compared with the prior art, the above-described technical solution conceived by this utility model has the following beneficial effects: By utilizing the overtravel movement of the motion group to induce defocus, a uniform background is achieved through non-uniform correction of the defocused value of the optical lens without the need for a baffle or external lens, resulting in good correction effect; by increasing the travel of the motion group at the telephoto position, the motion group element is placed in a non-conjugate position to change the optical path of the infrared imaging system, providing sufficient optical power variation, so that even after high-energy targets are defocused, they can still cover the pixels on the entire detector focal plane (or several small uniform areas cover the entire image plane), forming a uniform light intensity distribution and improving the image quality; in addition to increasing the travel of the motion group, non-uniform correction of scene-based defocus can also be achieved by combining the increased travel of the motion group with the moving focusing group. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of an infrared optical system according to an embodiment of the present invention;

[0017] Figure 2 This is a schematic diagram of the structure of an infrared optical system according to another embodiment of the present invention;

[0018] Figure 3 This is a schematic diagram illustrating the principle of non-uniform correction in the infrared optical system of this utility model embodiment;

[0019] Figure 4 These are images of the imaging state and non-uniform correction state of the infrared optical system according to an embodiment of the present invention: (a) imaging state, (b) non-uniform correction state.

[0020] Figure 5 These are comparison images of real-world effects of non-uniform correction using the infrared optical system of this utility model embodiment versus non-uniform correction using the traditional method of moving the focusing group to defocus: (a) original scene, (b) non-uniform correction using the infrared optical system of this utility model embodiment, and (c) traditional non-uniform correction using the moving focusing group to defocus. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this application. Therefore, the drawings and description are considered exemplary in nature and not restrictive.

[0022] like Figure 1As shown, the infrared optical system of this utility model embodiment includes a front fixed group, a zoom group, a compensation group, a rear fixed group, a detector, mechanical components, and a control module. The front fixed group, zoom group, compensation group, rear fixed group, and detector are arranged sequentially on the optical axis of the infrared optical system along the incident direction of light.

[0023] The front fixed group, serving as the front window of the infrared optical system, receives external light and performs initial focusing. It fixes the position of the incident pupil, limits the maximum field of view, and provides a stable optical path reference for subsequent components, ensuring the stability of the initial segment of the overall optical path during zooming. The zoom group is the core component for zooming. By moving the zoom group along the optical axis, its distance from other components changes, thereby altering the overall focal length of the infrared optical system. The compensation group, moving along the optical axis with the zoom group, compensates for image plane shift caused by the zoom group's movement, ensuring that the image remains clearly focused on the detector's focal plane throughout the zoom process. The rear fixed group, located at the rear of the infrared optical system and close to the detector, performs final focusing of the light passing through the front fixed group, zoom group, and compensation group, fixing the image plane position and correcting residual phase aberrations, ensuring a clear output image with minimal distortion.

[0024] In some implementations, the front fixation group consists of one or more lenses, which can be positive lenses or a combination of positive and negative lenses. The lens material of the front fixation group is selected according to the system wavelength, for example, it can be optical glass, germanium, or silicon. The zoom group consists of one or more lenses, which can be negative lenses or a combination of positive and negative lenses. The compensation group consists of one or more lenses, which can be positive lenses, negative lenses, or a combination of positive and negative lenses. The rear fixation group consists of one or more lenses, which can be positive lenses or a combination of positive and negative lenses. The material of the rear fixation group matches that of the front fixation group.

[0025] The control module is used to control the mechanical components, which drive the zoom group and compensation group to move along the optical axis to achieve zoom; further, the control module is also used to drive the zoom group and compensation group to move along the optical axis through the mechanical components to achieve non-uniform correction.

[0026] In some embodiments, the control module is used to control the mechanical components to drive the zoom group and compensation group to move along the optical axis based on the image of the detector focal plane, so as to maximize the image of the detector focal plane and achieve non-uniform correction. In some embodiments, the control module is used to first control the mechanical components to drive the zoom group to move along the optical axis, and then control the mechanical components to drive the compensation group to move along the optical axis based on the image of the detector focal plane, so as to maximize the image of the detector focal plane and achieve non-uniform correction.

[0027] like Figure 2As shown, the infrared optical system of this utility model embodiment includes a front fixed group, a zoom group, a compensation group, a focusing group, a detector, mechanical components, and a control module. The front fixed group, zoom group, compensation group, focusing group, and detector are arranged sequentially on the optical axis of the infrared optical system along the incident direction of light. Figure 2 The infrared optical system shown will Figure 1 The rear fixed group is replaced with a focusing group. The focusing group, in conjunction with the compensation group, moves along the optical axis to further compensate for image plane shift during zooming, ensuring clear imaging.

[0028] In some implementations, the focusing group consists of one or more lenses, which can be positive lenses or a combination of positive and negative lenses.

[0029] The control module is used to control the mechanical components, which drive the zoom group and compensation group to move along the optical axis to achieve zooming; furthermore, the control module is also used to drive the zoom group, compensation group and focus group to move along the optical axis through the mechanical components to achieve non-uniform correction.

[0030] In some embodiments, the control module is used to control the mechanical components to drive the zoom group, compensation group, and focusing group to move along the optical axis based on the image of the detector focal plane, thereby maximizing the image of the detector focal plane and achieving non-uniform correction. In some embodiments, the control module is used to first control the mechanical components to drive the zoom group to move along the optical axis, then control the mechanical components to drive the compensation group to move along the optical axis, and then control the mechanical components to drive the focusing group to move along the optical axis, thereby maximizing the image of the detector focal plane and achieving non-uniform correction.

[0031] Continuous zoom infrared optical systems achieve object-image conjugate zooming by moving several components according to different motion laws, while simultaneously changing the focal length. A typical example is the two-motion-component positive-group compensation zoom model. For example... Figure 3 As shown, f1 is the front fixed group, f2 is the zoom group, f3 is the compensation group, and f4 is the rear fixed group. In the short focal length state, the zoom group f2 and the compensation group f3 are located at the conjugate positions of a0 and b0, respectively. In the long focal length state, the zoom group f2 and the compensation group f3 are located at the conjugate positions of a1 and b1, respectively. To achieve non-uniform correction, the control module, based on the image at the detector's focal plane, controls the mechanical components to drive the zoom group f2 from position a1 to position a2, and controls the mechanical components to drive the compensation group f3 from position b1 to position b2. Since a2 and b2 are non-conjugate positions, this defocuses the original imaging optical path onto the detector's focal plane FPA, forming a uniform light intensity distribution.

[0032] Furthermore, f4 can also be the focusing group. In order to achieve non-uniform correction, the control module controls the mechanical components to drive the zoom group f2 to move along the optical axis, the compensation group f3 to move along the optical axis, and the focusing group f4 to move along the optical axis, based on the image of the detector focal plane. This causes the original imaging optical path to defocus on the detector focal plane FPA, forming a uniform light intensity distribution.

[0033] Figure 4 These are images of the imaging state and non-uniform correction state of the infrared optical system according to an embodiment of this utility model. In the conventional imaging state, the light intensity is approximately focused within the pixel, resulting in a clear image, such as... Figure 4 (a); Non-uniform correction state is when the light intensity is defocused and uniformly covered on the image plane, such as Figure 4 (b) Traditional infrared optical systems use a focusing group to move and defocus, but due to their limited optical power and focusing range, some high-energy targets still cannot be defocused to an ideal, uniform distribution. This invention increases the travel of the moving group at the telephoto position, providing greater optical power to blur the focus of the optical system, thus achieving a relatively uniform defocus for high-energy targets as well.

[0034] Figure 5 This image shows a comparison of real-world effects between non-uniform correction using the infrared optical system of this invention and traditional non-uniform correction using a moving focus group. It can be seen that the moving focus group's long-distance defocusing method proposed in this invention achieves a better uniform distribution of light intensity compared to existing technologies.

[0035] This invention utilizes the overtravel movement of the motion group to induce defocusing, achieving a uniform background through non-uniform correction of the defocused value of the optical lens without the need for baffles or external lenses, resulting in good correction effect. By increasing the travel of the motion group at the telephoto position, the motion group elements are placed in a non-conjugate position, altering the optical path of the infrared imaging system and providing sufficient optical power variation. This allows even defocused high-energy targets to cover the entire pixel on the detector's focal plane (or several small uniform areas to cover the entire image plane), forming a uniform light intensity distribution and improving the image quality. In addition to increasing the travel of the motion group, combining the increased travel of the motion group with the moving focus group can achieve non-uniform correction of scene-based defocusing.

[0036] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0037] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0038] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more (two or more) executable instructions for implementing a particular logical function or process. Furthermore, the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functionality involved.

[0039] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this application, and these should all be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An infrared optical system, characterized in that, It includes a front fixing group, a zoom group, a compensation group, a rear fixing group, mechanical components, and a control module. The front fixing group, the zoom group, the compensation group, and the rear fixing group are arranged sequentially on the optical axis of the infrared optical system along the incident direction of light. The front fixed group is used to receive external light and perform initial focusing; the zoom group is used to change the overall focal length of the infrared optical system by moving along the optical axis; the compensation group is used to cooperate with the zoom group to move along the optical axis and counteract the image plane shift caused by the movement of the zoom group; the rear fixed group is used to finally focus the light that has passed through the front fixed group, the zoom group and the compensation group, and fix the image plane position. The control module is used to control the mechanical components, which drive the zoom group and the compensation group to move along the optical axis to achieve non-uniform correction.

2. The infrared optical system as described in claim 1, characterized in that, It also includes a detector for acquiring imaging images; the control module is used to control the mechanical components to drive the zoom group and the compensation group to move along the optical axis according to the image of the detector's focal plane, so as to maximize the image of the detector's focal plane and achieve non-uniform correction.

3. The infrared optical system as described in claim 2, characterized in that, The control module is used to first control the mechanical component to drive the zoom group to move along the optical axis based on the image of the detector focal plane, and then control the mechanical component to drive the compensation group to move along the optical axis, so as to maximize the image of the detector focal plane and achieve non-uniform correction.

4. The infrared optical system as described in any one of claims 1 to 3, characterized in that, The front fixing group consists of one or more lenses; the front fixing group is a positive lens or a combination of positive and negative lenses.

5. The infrared optical system as described in any one of claims 1 to 3, characterized in that, The zoom group consists of one or more lenses; the zoom group is a negative lens or a combination of positive and negative lenses.

6. The infrared optical system as described in any one of claims 1 to 3, characterized in that, The compensation group consists of one or more lenses; the compensation group is a positive lens, a negative lens, or a combination of positive and negative lenses.

7. The infrared optical system as described in any one of claims 1 to 3, characterized in that, The rear fixation group consists of one or more lenses; the rear fixation group is a positive lens or a combination of positive and negative lenses.

8. An infrared optical system, characterized in that, It includes a front fixed group, a zoom group, a compensation group, a focusing group, mechanical components, and a control module. The front fixed group, the zoom group, the compensation group, and the focusing group are arranged sequentially on the optical axis of the infrared optical system along the incident direction of light. The front fixed group is used to receive external light and perform initial focusing; the zoom group is used to change the overall focal length of the infrared optical system by moving along the optical axis; the compensation group is used to cooperate with the zoom group to move along the optical axis and counteract the image plane shift caused by the zoom group's movement; the focusing group is used to cooperate with the compensation group to move along the optical axis and further compensate for the image plane shift during the zoom process, ensuring clear imaging. The control module is used to control the mechanical components, which drive the zoom group, the compensation group, and the focusing group to move along the optical axis to achieve non-uniform correction.

9. The infrared optical system as described in claim 8, characterized in that, It also includes a detector for acquiring imaging images; the control module is used to control the mechanical components to drive the zoom group, the compensation group and the focusing group to move along the optical axis according to the image of the detector focal plane, so as to maximize the image of the detector focal plane and realize non-uniform correction.

10. The infrared optical system as described in claim 9, characterized in that, The control module is used to, based on the image of the detector focal plane, first control the mechanical component to drive the zoom group to move along the optical axis, then control the mechanical component to drive the compensation group to move along the optical axis, and then control the mechanical component to drive the focusing group to move along the optical axis, so as to maximize the image of the detector focal plane and achieve non-uniform correction.

Images