KR-20260064350-A - Method and System for Aligning Focal Plane of Electro-Optical Camera

KR20260064350AKR 20260064350 AKR20260064350 AKR 20260064350AKR-20260064350-A

Abstract

The present invention relates to a method and system for aligning the focal plane of an electro-optical camera. The method according to the present invention comprises the steps of: receiving reflected light reflected from the focal plane array of the electro-optical camera by irradiating parallel light into the aperture of the electro-optical camera while the reflective surface analysis unit is aligned in front of the aperture of the electro-optical camera; measuring wavefront information of the reflected light in the reflective surface analysis unit—wavefront information includes a tilt value corresponding to the inclination of the wavefront and a Power value corresponding to the curvature of the wavefront—and verifying whether the optical part of the electro-optical camera is aligned with the focal plane array based on the tilt value and the Power value. According to the present invention, the alignment state of the focal plane of the light detection unit and the optical part can be precisely evaluated, and the tilt and position can be automatically adjusted, thereby significantly improving the accuracy and efficiency of focal plane alignment of the electro-optical camera. Furthermore, by utilizing equipment such as an interferometer, which is generally used in the development of optical components, the alignment work can be performed without separate additional equipment, thereby eliminating the inconvenience of the preparation process.

Inventors

육영춘

Assignees

한국항공우주연구원

Dates

Publication Date: 20260507
Application Date: 20241031

Claims (8)

A step of receiving reflected light reflected from the focal plane array of the electro-optical camera by irradiating parallel light into the aperture of the electro-optical camera while the reflective surface analysis unit is aligned in front of the aperture of the electro-optical camera, A step of measuring wavefront information of the reflected light in the reflection surface analysis unit above - the wavefront information includes a tilt value corresponding to the slope of the wavefront and a Power value corresponding to the curvature of the wavefront -, A step of checking whether there is alignment between the optical part of the electro-optical camera and the focal plane array based on the tilt value and the Power value. A method for aligning the focal plane of an electro-optical camera, including
In Article 1, A method for aligning the focal plane of an electro-optical camera, wherein if the above tilt value and Power value are '0', it is determined that alignment has been achieved between the optical part of the electro-optical camera and the focal plane array.
In Article 1, A method for aligning the focal plane of an electro-optical camera, further comprising the step of adjusting the attitude and position of the focal plane array in a direction where the tilt value and Power value become '0' if the tilt value and Power value are not '0'.
In Article 1, The above-mentioned reflection surface analysis unit is, A method for aligning the focal plane of an electro-optical camera that is an interferometer device or a Wavefront Sensor (WFS).
A reflection surface analysis unit that, while aligned in front of the aperture of an electro-optical camera, receives reflected light reflected from the focal plane array of the electro-optical camera by irradiating parallel light through the aperture of the electro-optical camera, and measures wavefront information of the reflected light—the wavefront information includes a tilt value corresponding to the slope of the wavefront and a Power value corresponding to the curvature of the wavefront—, and A control unit that checks whether there is alignment between the optical part of the electro-optical camera and the focal plane array based on the above tilt value and the above Power value. A focal plane alignment system for an electro-optical camera including
In Paragraph 5, The above control unit is, A focal plane alignment system for an electro-optical camera that determines that alignment has been achieved between the optical part of the electro-optical camera and the focal plane array when the above tilt value and Power value are '0'.
In Paragraph 5, It further includes a focal plane adjustment unit for adjusting the attitude and position of the focal plane array, and The above control unit controls the focal plane adjustment unit, and if the tilt value and Power value are not '0', the attitude and position of the focal plane array are adjusted in a direction in which the tilt value and Power value become '0', thereby forming a focal plane alignment system for an electro-optical camera.
In Paragraph 5, The above-mentioned reflection surface analysis unit is, A focal plane alignment system for an electro-optical camera that is an interferometer device or a Wavefront Sensor (WFS).

Description

Method and System for Aligning Focal Plane of Electro-Optical Camera The present invention relates to a method and system for aligning the focal plane of an electro-optical camera. An electro-optical camera consists of an optical section and an electronic section; the image formed through the optical section is converted into a signal by the electronic section and output. The optical section is composed of optical elements such as lenses or mirrors and performs the function of collecting light incident on the electro-optical camera, changing its path, and focusing it onto the photodetector (focal plane array) of the electronic section. In electro-optical cameras, the assembly and alignment processes of the optical and photodetector units are critical; in particular, aligning the focal plane of the photodetector with the focal position of the optical unit is a vital step that determines the camera's performance. Accurate alignment of the focal plane significantly impacts image resolution, focus accuracy, and overall performance. Therefore, it is essential to evaluate the alignment status by verifying alignment indicators and assessing the performance of the electro-optical camera. To assemble and align the photodetector of an electro-optical camera, the work must be carried out while verifying the camera's field-specific performance or alignment indicators. This requires additional optical equipment, targets, and auxiliary devices. FIG. 1 is a conceptual diagram provided to explain a conventional electro-optical camera alignment method, and FIG. 2 is a diagram showing the collimator and optical part of FIG. 1 in more schematic terms. Referring to FIGS. 1 and 2, a light source (10) is set to irradiate light toward a target (20) so that parallel light is detected by a light detector (42) through an optical part (41) of an electro-optical camera (40) via a collimator (30). Then, by repeatedly moving the target (20) in the transverse/axial direction and processing the signal detected by the light detector (42) to measure the Modulation Transfer Function (MTF), the position of the light detector (42) that produces optimal performance can be found and aligned. Alternatively, the light detector (42) can be aligned and fixed at a position where the target image projected onto the light detector (42) becomes clear while the target (20) is fixed. However, with these conventional methods, as the aperture of the electro-optical camera increases, the size and performance of the required equipment also increase. This leads to higher equipment costs for alignment and increased manufacturing complexity. These factors can act as risk factors in camera development. Furthermore, while alignment using existing methods has the advantage of verifying focal plane balance by checking performance or alignment indicators for each camera field, it has the disadvantage of being time-consuming. Figure 1 is a conceptual diagram provided to explain a conventional electro-optical camera alignment method. Figure 2 is a diagram showing the collimator and optical part of Figure 1 in a more schematic manner. FIG. 3 is a configuration diagram of an electro-optical camera alignment system according to one embodiment of the present invention. Figure 4 is a diagram illustrating an exemplary state in which the focal plane array is not aligned perpendicularly to the optical axis of the optical section. FIG. 5 is a diagram exemplarily showing a state in which the focal plane array is out of focus from the focal position of the optical part. FIG. 6 is a flowchart provided to explain an electro-optical camera alignment method according to one embodiment of the present invention. Then, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. The terms used in this specification are for describing embodiments and are not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. The terms "comprises" and/or "comprising" used in this specification do not exclude the presence or addition of one or more other components in addition to the components mentioned. Throughout the specification, the same reference numerals refer to the same components, and "and/or" includes each of the mentioned components and all combinations of one or more. Although terms such as "first," "second," etc., are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another. Therefore, the first component mentioned below may be the second component within the technical scope of the invention. FIG. 3 is a configuration diagram of an electro-optical camera alignment system according to one embodiment of the present invention. Referring to FIG. 3, the electro-optical camera alignme