Centering instrument system for measuring objective lens based on liquid crystal polarizing lens

Abstract

The invention relates to a centrescope system for measuring an objective lens based on a liquid crystal polarizing lens. The system is characterized by comprising a CCD (Charge Coupled Device) camera, an autocollimator and a reticle, the device is characterized by also comprising at least two groups of components consisting of liquid crystal electric control wave plates and electric control liquid crystal polarizing lenses, and a plurality of components are cascaded for use; and a plurality of components used in cascade connection are arranged at the front end of the collimator and are aligned with the to-be-measured surface of the lens. Through proper combination of the liquid crystal electric control wave plate and the electric control liquid crystal polarizing lens, electric control switching of a plurality of focal lengths is realized, center deviation measurement and adjustment detection of a plurality of lenses in an optical lens group can be realized in cooperation with a centering instrument, and the measurement and state efficiency is improved.

Description

Technical Field

[0001] This invention relates to a centering device based on a liquid crystal polarizing lens as the measuring objective, belonging to the field of centering measurement technology. Background Technology

[0002] In the field of optical manufacturing and system assembly, precise alignment (centering) of the optical axis (or mechanical axis) of optical components (such as lenses and mirrors) with the system reference axis (such as the rotation axis of a turntable) is a crucial step in ensuring image quality, reducing wavefront aberration, and improving system performance. Centering instruments are primarily used to measure the deviation between the optical axis of an optical lens and the mechanical axis of the lens barrel in an optical assembly. During the measurement process, measuring objectives with different focal lengths are used to image the center of curvature of each spherical surface being measured onto a detector, thereby measuring the center deviation of each surface. Therefore, during the measurement of the entire assembly, it is necessary to frequently change measuring objectives with different focal lengths to match the spherical surfaces with different radii of curvature. This makes the operation very cumbersome throughout the measurement process, affecting the assembly efficiency of the lens assembly. Current solutions involve using manual or electric objective turrets to replace the replacement of measuring objectives, enabling rapid switching between several objectives. However, since the number of objectives that can be placed on the turret is still less than the total number of measuring objectives, the measuring objectives on the objective turret still need to be replaced, and the cumbersome operation is not fundamentally resolved. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a centering system based on a liquid crystal polarizing lens measuring objective lens. This system can realize the electronically controlled switching of multiple focal lengths, thereby improving the measurement and adjustment efficiency of the center deviation of optical lenses in the optical lens group.

[0004] To solve the above-mentioned technical problems, the present invention provides a centering system based on a liquid crystal polarizing lens measuring objective lens, characterized in that it includes a CCD camera, an autocollimator, and a reticle; and further characterized in that it includes at least two sets of components composed of liquid crystal electrically controlled waveplates and electrically controlled liquid crystal polarizing lenses, with multiple components used in cascade; the multiple cascaded components are arranged at the front end of the collimator and aligned with the surface to be measured of the lens.

[0005] Furthermore, the two components are cascaded and used together, and the electric field can be controlled to achieve nine combined focal length states.

[0006] Furthermore, the three components are cascaded together, and the electric field control enables 27 combined focal length states.

[0007] Beneficial effects: This invention achieves electronic switching of multiple focal lengths by combining an appropriate liquid crystal electronically controlled waveplate and an electronically controlled liquid crystal polarizing lens. When used with a centering instrument, it can realize the measurement and adjustment detection of the center deviation of multiple lenses in an optical lens group, thereby improving measurement and status efficiency. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the testing principle of an existing reflective autocollimator.

[0009] Figure 2 is a schematic diagram of the beam exit state of circularly polarized parallel light with different polarization directions after passing through the liquid crystal polarizing lens used in this invention.

[0010] Figure 3 This is a schematic diagram of the beam emission state of the liquid crystal polarizing lens used in this invention after being modulated by an electric field.

[0011] Figure 4 This is a schematic diagram illustrating the principle of using an electronically controlled liquid crystal waveplate and an electronically controlled liquid crystal polarizing lens in combination in this invention. Detailed Implementation

[0012] The present invention 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 invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present invention are shown in the drawings, not the entire structure.

[0013] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0014] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0015] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0016] like Figure 1 As shown, existing reflective autocollimating centering instruments require multiple measuring objectives with different focal lengths (the focusing lenses in the figure). The center deviation between lenses with different radii of curvature and the rotation axis is measured by switching between these objectives. When multiple lenses are present in a set of lenses, frequent switching of the measuring objectives is necessary, reducing measurement efficiency and increasing operational complexity.

[0017] The centering system based on a liquid crystal polarizing lens measuring objective of the present invention, on the basis of the existing reflective autocollimating centering system, integrates a liquid crystal electrically controlled waveplate and an electrically controlled liquid crystal polarizing lens as a single component, and multiple components are cascaded to replace the focusing lens in the figure.

[0018] A liquid crystal polarizing lens is a geometric phase optical element that controls the focusing of polarized light by modulating the geometric phase difference of the optical wavefront. Liquid crystal polarizing lenses exhibit selectivity in the polarization state of the light beam; that is, when different circularly polarized light is incident on the lens, the outgoing beam diverges or focuses. In other words, a liquid crystal lens has +f and -f focal lengths. To achieve +f and -f focal length switching, the polarization state of the light beam needs to be switched. Therefore, liquid crystal polarizing lenses are usually used in combination with waveplates. Utilizing the electrical tuning characteristics of liquid crystal materials, liquid crystal polarizing lenses can also align liquid crystal molecules perpendicular to the glass substrate by applying an electric current. At this point, the liquid crystal loses its anisotropic spatial distribution, meaning the liquid crystal polarizing lens structure disappears, exhibiting a flat plate device with a focal length f = ∞. Therefore, a single liquid crystal polarizing lens has three operating states: +f, -f, and f = ∞. By cascading multiple liquid crystal polarizing gratings, multiple combined focal length switching can be achieved, and different focal length operating states can be controlled by switching the electric field.

[0019] like Figure 2a As shown, right-hand circularly polarized light is incident on a liquid crystal polarizing lens, and the outgoing beam is a focused beam, which is focused at the focal point F; as Figure 2b As shown, when left-handed circularly polarized light is incident on a liquid crystal polarizing lens, the outgoing beam is a diverging beam, and the beam is focused in the opposite direction at the focal point -F.

[0020] like Figure 3As shown, the output state of the liquid crystal polarizing lens under electric field control is such that after applying an electric field to the liquid crystal polarizing lens, the element loses its modulation effect on the beam, and the element no longer has the function of focusing or converging the beam. The effect is only equivalent to a parallel plate.

[0021] The centering system based on a liquid crystal polarizing lens measuring objective of the present invention, on the basis of the existing reflective autocollimating centering system, integrates a liquid crystal electrically controlled waveplate and an electrically controlled liquid crystal polarizing lens as a single component, and multiple components are cascaded to replace the focusing lens in the figure.

[0022] This invention utilizes a liquid crystal electrically controlled waveplate and an electrically controlled liquid crystal polarizing lens as a single component, with multiple components cascaded together. The cascaded module replaces... Figure 1 The medium-focusing lens can achieve different focal lengths for measuring the lens group under test by adjusting the electric field.

[0023] For a single component, three operating states—+f, -f, and f=∞—are achieved through electric field control.

[0024] Nine focal length states can be achieved by using electric field control in the cascade of two components. The combination principle is shown in Table 1 below.

[0025] Table 1

[0026]

[0027] For cascading N components, electric field control is used to achieve individual Focal length status. With the three components cascaded in use, there are a total of 27 combined focal lengths, as detailed in Table 2.

[0028] Figure 4 Multiple liquid crystal electrically controlled waveplates and electrically controlled liquid crystal polarizing lenses are cascaded together. By adjusting the liquid crystal electrically controlled waveplates and liquid crystal polarizing lenses with an electric field, multiple working focal lengths of the optical lens group can be achieved. The figure only illustrates two sets of liquid crystal electrically controlled waveplates and electrically controlled liquid crystal polarizing lenses linked together. In actual use, multiple sets can be stacked; the two sets of lenses can achieve a total of nine working focal lengths for adjustment and switching.

[0029] When the three components are cascaded, the focal lengths of the three liquid crystal polarizing lenses are f1=200mm, f2=180mm, and f3=160mm, respectively.

[0030] The distance between lenses f1 and f2 is 40 mm; the distance between lenses f2 and f3 is 40 mm; d1=d2=40 mm.

[0031] Table 2

[0032] .

Claims

1. A centering system based on a liquid crystal polarizing lens measuring objective, characterized in that: The system includes a CCD camera, an autocollimator, and a reticle; its characteristic is that it also includes at least two sets of components consisting of liquid crystal electronically controlled waveplates and electronically controlled liquid crystal polarizing lenses, with multiple components used in cascade; the multiple cascaded components are set at the front end of the collimator and aligned with the surface to be measured of the lens.

2. The centering system based on a liquid crystal polarizing lens measuring objective lens according to claim 1, characterized in that: Two components are cascaded together, and electric field control enables nine combined focal length states.

3. The centering system based on a liquid crystal polarizing lens measuring objective lens according to claim 1, characterized in that: The three components are cascaded together, and the electric field can be controlled to achieve 27 combined focal length states.

Images