[0033] Example one
[0034] Such as figure 1 As shown, a swing polarizer-type polarization imaging measurement device provided by an embodiment of the present invention includes a lens module 1, a polarization module 2, a detection module 3, and a control module ( figure 1 Not shown in). The lens module 1 includes an optical lens for imaging a target scene, and the detection module 3 includes a detector for receiving light emitted by the optical lens, and the central axis of the detector coincides with the central axis of the optical lens to receive light. Preferably, the lens module 1 further includes a lens fixing seat for setting an optical lens, and the detection module 3 further includes a detector fixing seat for setting a detector. An adjustable lens is preferably provided between the lens fixing seat and the detector fixing seat. Slide rail, used to locate the relative position of the detector and the optical lens.
[0035] Such as figure 1 with figure 2 As shown, the polarization module 2 includes a rotation axis and a balance wheel 22 arranged on the rotation axis. The balance wheel 22 is relatively fixed to the rotation axis and can rotate with the rotation axis. The rotating shaft is located on one side of the optical lens, and its central axis is parallel and spaced apart from the central axis of the optical lens. The balance wheel 22 is provided with at least three polarizers 23 with different polarization directions. The function of the balance wheel 22 is to install the polarizers 23 with different polarization directions. Wherein, the polarization direction here refers to the relative angle direction between the transmission axis of the polarizer 23 itself and the perpendicular from the center of the polarizer 23 to the central axis of the rotation axis.
[0036] Each polarizer 23 is arranged adjacently along the circumferential direction of the rotation axis, that is, each polarizer 23 is located at an equal distance from the central axis of the rotation axis, and is arranged around the central axis. The distance between any two adjacent polarizers 23 ( On the premise of not interfering with each other and being fixed and stable) as small as possible. The balance wheel 22 is located between the detector and the optical lens. Each polarizer 23 can follow the axis of rotation to the measurement position. The central axis of the polarizer 23 at the measurement position coincides with the central axis of the detector and the optical lens, and at this moment the polarizer 23 is at the entrance pupil of the detector. , The optical lens is at the entrance pupil of the clear aperture of the polarizer 23.
[0037] Preferably, the effective clear aperture of each polarizer 23 is larger than the size of the total image unit of the detector. Further, the geometric dimensions of the polarizing plates 23 are the same. The balance wheel 22 can adopt a polarizer frame structure (such as image 3 As shown), the polarizer 23 is clamped and fixed by a pressing ring to prevent it from slipping off. After the fixed installation is completed, the effective clear aperture of the polarizer 23 has a small difference from its effective diameter. The balance wheel 22 can also adopt a plate-shaped, fan-shaped or wheel-shaped structure, and can carry each polarizer 23, which is not further limited here, but the polarizer 23 should be concentrated on one side of the axis of rotation (that is, each polarizer 23 should be located as much as possible Compact layout), so that the balance wheel 22 shortens the reciprocating swing path, realizes the rapid switching of different polarization directions, and improves the imaging measurement efficiency.
[0038] Preferably, the rotation axis is set horizontally, the vertical line from the center of the polarizer 23 at the measurement position to the center axis of the rotation axis is horizontal, and the polarization direction can be considered as the angle between the light transmission axis of the polarizer 23 and the horizontal direction.
[0039] The control module is electrically connected to the polarization module 2 and the detection module 3, and is used to generate a swing control command and send it to the polarization module 2 to control the rotation of the rotation axis to realize the periodic reciprocating swing of the balance wheel 22, which means that each polarizer 23 is The optical lens and the detector move back and forth to switch different polarization directions, and the way of reciprocating swing is preferably uniform swing. The control module is also used to generate acquisition control instructions and send them to the detection module 3 to control the exposure of the detectors, so as to measure the radiation intensity images of the target scene under different polarization directions.
[0040] Further, the detection module 3 also includes an image processor, which is used to resolve each group of radiation intensity images corresponding to different polarization directions swinging from one side of the balance wheel 22 to the other side to obtain a polarization image. The polarization image includes a polarization degree image and a polarization angle image.
[0041] When the swing polarizer type polarization imaging measurement device provided by the present invention is used, the image information of the target scene is transmitted to the polarization module 2 through the optical lens. The image of the lens passes through the polarizer 23 and then enters the detector, and the detector obtains the radiation intensity image in the polarization direction of the polarizer 23. With the balance wheel 22 periodically swinging back and forth, the radiation intensity images of the target scene under different polarization angles can be measured, and then the Stokes vector characterizing the target polarization state can be obtained by calculation, and then the polarization degree image and polarization angle of the target scene can be obtained Image, realizing time-sharing polarization imaging measurement. The device provided by the present invention realizes switching of different polarization directions by only swinging, and can traverse the polarizer 23 of different polarization directions from one side of the balance wheel 22 to the other side, and has a high frame rate polarization image output, which improves the time sharing The sampling speed of the polarization imaging system solves the problem of rapid measurement of polarization imaging of moving target scenes.
[0042] Preferably, the polarization module 2 further includes a servo motor 21 and an encoder 24. Such as figure 2 As shown, the output shaft of the servo motor 21 is connected to the rotating shaft, and is used to drive the rotating shaft to rotate according to the swing control command of the control module, so as to realize the periodic reciprocating swing of the balance wheel 22. The encoder 24 is connected with the rotating shaft, and is used to measure the swing angle information of the balance wheel 22, that is, obtain the current posture information of the balance wheel 22, and feed back the measured angle information to the control module.
[0043] Further, the control module is used for generating swing control instructions and collecting control instructions according to the received angle information. The control module determines the current posture of the balance wheel 22 according to the angle information fed back by the encoder 24, and determines whether to generate and send corresponding swing control instructions and acquisition control instructions according to the current posture of the balance wheel 22.
[0044] Specifically, the detector can be a CCD detector, and the encoder 24 can be an absolute photoelectric encoder, preferably connected to the rotating shaft through a flexible coupling, such as figure 2 As shown, the absolute photoelectric encoder is preferably arranged on the side of the rotating shaft away from the servo motor 21, so as to accurately measure the rotation angle information actually generated by the balance wheel 22 when driven.
[0045] In some preferred embodiments, the balance wheel 22 is provided with three or four polarizers 23. When the device uses three or four polarizers 23, the balance wheel 22 has a small volume and a short swing path, making it easier to achieve rapid swing, so as to increase the output polarization frame rate.
[0046] Further, when the balance wheel 22 is provided with three polarizers 23, the polarization directions of the three polarizers 23 preferably correspond to 0°, 60°, and 120° respectively, such as image 3 As shown, in order to facilitate the distinction, the three polarizers are labeled A, B, and C respectively. The reference coordinate axis 222 of each polarizer is located at the vertical line from the center of the polarizer to the rotation axis, and the polarization direction of the polarizer labeled A is 60°, the angle between its own transmission axis 221 and the reference coordinate axis 222 is 60°, the polarization direction of the polarizer labeled C is 120°, and the angle between its own transmission axis 221 and the reference coordinate axis 222 is 120°, In the same way, the polarization direction of the polarizer labeled B is 0°, and its own light transmission axis 221 is arranged along the vertical line from the center to the rotation axis, and coincides with its own reference coordinate axis 222. It should be noted that the specific polarization directions of the three polarizers 23 can be exchanged as required, and there is no need to completely follow image 3 Shown.
[0047] Preferably, when the balance wheel 22 is provided with four polarizers 23, the polarization directions of the four polarizers 23 correspond to 0°, 45°, 90°, and 135°, respectively, which is beneficial to resolve the polarization image.
