Unilateral positioning cam driving mechanism for continuous zoom lens

Abstract

The invention discloses a unilateral positioning cam driving mechanism for a continuous zoom lens. The unilateral positioning cam driving mechanism comprises a main support, a sliding rod, an optical sliding assembly, a unilateral positioning curve sleeve, a semi-flexible pin assembly and a locking pressing ring; the optical sliding assembly is connected with the main support through the sliding rod; the sliding rod is fixed to the main support; the optical sliding assembly performs rotation-free linear movement relative to the main support along the sliding rod; the unilateral positioning curve sleeve is coaxially connected with the main support through the locking pressing ring; the unilateral positioning curve sleeve can rotate along a central axis relative to the main support; and the semi-flexible pin assembly penetrates through the curve groove of the unilateral positioning curve sleeve along a radial direction and is fixed to the optical sliding assembly. According to the unilateral positioning cam driving mechanism for the continuous zoom lens of the invention, the unilateral positioning curve sleeve rotates around the central axis, so as to drive the optical sliding assembly to perform linear movement along the sliding rod, and therefore, the axial movement of an optical element in the continuous zoom lens is realized; the semi-flexible pin assembly and the unilateral positioning curve sleeve are adopted, and therefore, the machining and assembling difficulty of a system are reduced, and the precision of the system and the temperature applicability of the system in use are improved.

Description

technical field [0001] The invention relates to a continuous zoom driving mechanism, in particular to a single-side positioning cam driving mechanism for a continuous zoom lens, which belongs to the category of precision optical-mechanical design. Background technique [0002] The continuous zoom optomechanical system has been widely used due to its characteristics such as continuous change of focal length, large zoom ratio, coaxial multi-field of view, and compact structure. The continuous zoom system changes the focal length of the entire system by moving multiple lens groups in the system. On the premise of keeping the position of the image plane unchanged, it can achieve continuous and clear images during the entire zooming process. [0003] At present, there are mainly two driving modes of continuous zooming: motor direct drive and motor driven cam mechanism drive. [0004] For the motor direct drive mode, the optical sliding assembly can achieve precise positioning un...

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Problems solved by technology

[0004] For the motor direct drive mode, the optical sliding assembly can achieve precise positioning under the drive of the motor, and then realize the precise continuous zoom function; this mechanism is widely used in continuous zoom lenses with fewer optical sliding components. The continuous zoom lens with an optical slide assembly is limited in application due to the need for more motors and position sensors, and the complexity of the mechanism and control circuit

[0005] For the cam drive method, the curve sleeve in a cam mechanism can process multiple sets of drive curves, so it can simultaneously drive multiple sets of optical sliding components to achieve continuous zooming, and has been widely used; however, due to the difficulty of processing the cam curve and the Due to the limitation of processing accuracy, especially for the processing stress of the curved groove, the consistency of the drive positioning groove walls on both sides of the curved groove is reduced, resulting in the system's continuous zooming process. The consistency of the image plane is not high, and the movement of the driving optical slider is not stable. At the same time, due to the high and low temperature load (temperature range from -45°C to 60°C), the curved groove and positioning pin in the driving mechanism are often stuck.

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