CN2371569Y - Focusing mechanism - Google Patents

Abstract

The utility model discloses a focusing mechanism with large stroke, high guiding precision and nanometer micro-motion resolution. The focusing mechanism uses a high-speed constant-speed motor to drive a planetary gear reducer with a large transmission ratio, which is transmitted to the lead screw through a coupling, and then uses a small-angle inclined flexible hinge parallelogram mechanism to convert horizontal displacement into vertical displacement. Focusing is complete. The focusing mechanism can be widely used in high-power microscopes, projection photolithography machines, laser direct writing machines and other precision instruments and equipment.

Description

Focus mechanism

The utility model relates to a focus adjustment mechanism, which belongs to the transformation of the guide and transmission structure of the focus adjustment part in precision instruments and equipment.

The focusing of precision instruments and equipment usually requires high micro-motion resolution and a large motion stroke, and strict guidance. Some of the existing focusing mechanisms use a motor plus a screw nut (or a rack and pinion mechanism) for transmission, guided by a mechanical guide rail. gap", so the micro-motion resolution is not high, and the guiding accuracy is also limited by the machining accuracy; there is another focusing mechanism that is driven by piezoelectric ceramics and guided by a double-leaf spring mechanism. The micro-motion resolution of this mechanism and The guiding precision is high, but due to the small amount of expansion and contraction of the piezoelectric ceramics, and the double-leaf spring mechanism can only strictly move in translation within a small stroke range, the movement stroke is small, and because the double-leaf spring mechanism has "internal friction" and " Empty return”, the micro-motion resolution cannot reach very high.

The purpose of the utility model is to avoid the disadvantages of the above-mentioned prior art and provide a focusing mechanism with a large working stroke, high guiding precision and nanometer micro-motion resolution.

The purpose of this utility model can be achieved through the following technical measures: a high-speed constant-speed motor is coaxially connected with a planetary gear reducer with a large transmission ratio, and then connected to the lead screw through a coupling, and the lead screw nut structure passes through the crank slider structure Connected with the flexible hinge lever, the top block fixed on the flexible hinge lever mechanism is connected to the flexible hinge parallelogram guide mechanism with a small angle inclination, so as to realize the focus displacement. The flexible hinge lever mechanism is also connected with anti-backlash spring and unloading load spring.

The purpose of this utility model can also be achieved by the following measures: the flexible hinge parallelogram guide structure has an inclination angle of 60°-75°, and when the horizontally moving top block pushes the parallel quadrilateral mechanism, the movement bar of the mechanism promptly produces horizontal displacement and Produces a focus shift perpendicular to its direction.

The purpose of this utility model can also be achieved through the following technical measures: the flexible hinge lever is made up of a moving rod, a hinge neck and a fixed body, the walls in the two holes constitute the hinge neck, and the fixed body is connected with the base by screws, and moves horizontally The slider crank mechanism is connected to the movement rod, on which the top block is fixed.

Compared with the prior art, the utility model has the following advantages: the parallelogram guiding mechanism of the flexible hinge with a small angle inclination is used to reduce the horizontal displacement generated by the motor plus the screw nut transmission structure and convert it into a vertical focus displacement, so it can Obtain a large (up to 2mm) focusing stroke; the parallelogram guide structure of the flexible hinge is made of a piece of spring steel through boring and wire cutting. Ordinary machining accuracy can ensure high guide accuracy, and the workbench The control system compensates the additional horizontal displacement of the flexible hinge parallelogram guide structure in the completion of the focus displacement, so that the precisely guided focus displacement can be obtained; the utility model adopts a flexible hinge lever without gaps and a flexible hinge parallelogram guide mechanism inclined at a small angle As well as the anti-backlash spring, etc., the anti-backlash treatment can be obtained, so the micro-motion resolution of nanometer level can be obtained. This focusing mechanism with large stroke, high guiding precision, and high micro-motion resolution can be widely used in precision instruments such as high-power microscopes, projection lithography machines, and laser direct writers.

Below in conjunction with accompanying drawing and embodiment the utility model is described in further detail.

Figure 1 is a structural diagram of the focusing mechanism.

Fig. 2 is a structural diagram of a parallelogram guiding mechanism of a flexible hinge inclined at a small angle.

Figure 3 is a structural diagram of the flexible hinge lever mechanism.

As shown in Figure 1, the high-speed constant-speed motor 7 is coaxially connected with the planetary gear reducer 6 with a large transmission ratio, and then connected to the lead screw 4 through a coupling, and its angular displacement is converted into a horizontal position by the lead screw nut structure 3 Then the crank slider structure 8 drives the flexible hinge lever 9 to reduce its displacement, and finally the top block 11 fixed on the flexible hinge lever mechanism 9 pushes the parallelogram guide structure of the flexible hinge inclined at a small angle to further reduce the horizontal displacement And converted into focus displacement perpendicular to the horizontal direction.

The utility model adopts the following clearance elimination structure in order to achieve higher micro-motion resolution: the planetary gear reducer 6 with a large clearance is placed at the front stage, and its output is connected to the lead screw 4 through a shaft coupling 5 without clearance , the anti-backlash spring 10 and the unloading spring 12 connected on the flexible hinge lever 9 provide a larger spring force to eliminate the clearance of the lead screw nut mechanism 3 and the slider crank mechanism 8, and the flexible hinge lever 9 without gap And the flexible hinge of small angle inclination is placed on the rear stage in row quadrilateral guide mechanism 1.

The flexible hinge eliminates the additional level 14 compensation generated when the quadrilateral guide mechanism 1 obtains the required focusing displacement.

Figure 2 shows the structural diagram of the flexible hinge on the small-angle inclined surface and the quadrilateral guide mechanism 1: 23 is the fixed rod, 24 and 26 are the guide rods on the inclined surface, and the wall between the holes 15 and 16 constitutes the first hinge. The wall between holes 17 and 18 forms the second hinge neck, the wall between holes 19 and 20 forms the third hinge neck, and the wall between holes 21 and 22 forms the fourth hinge neck. The flexible hinge parallelogram guide mechanism 1 has an inclination angle of 60°-75°. When the top block 11 fixed on the flexible hinge lever mechanism 9 pushes the inclined parallelogram guide mechanism, the moving rod 25 produces both horizontal displacement and focus adjustment displacement. The thickness of fixed rod 23, guide rods 24 and 26, and motion rod 25 is all much greater than the thickness of hinge neck, and when the flexible hinge parallelogram guide mechanism 1 of small-angle inclination is working, only hinge deformation, and bar is not deformed.

Fig. 3 is the structural diagram of flexible hinge lever mechanism 9: flexible hinge lever mechanism 9 is made up of motion bar 31, hinge neck and fixed body 29, and the wall between hole 27 and 28 forms hinge neck, and fixed body 29 is made of screw 30 Connected with the base, the crank slider structure 8 moving horizontally is driven and connected with the moving rod 31, and the top block 11 is fixed on the moving rod 31, and moves horizontally with it; when the flexible hinge lever mechanism 9 works, only the hinge neck is deformed, And the fixed body 29 and the motion bar 31 are not deformed.

Claims (3)

1. focus adjusting mechanism, by planetary reducer (6) coaxial connect of high-revolving constant speed motor (7) with big speed ratio, link to each other with leading screw (4) through shaft coupling (5) again, screw-nut structure (3) is connected to crank block structure (8), it is characterized in that: flexible hinge leverage (9) is connected to slider-crank mechanism (8), be fixed on the flexible hinge parallelogram guide frame (1) of the small angle inclination of jacking block (11) the connection realization focusing displacement on the hinge leverage (9), also connect backlash spring (10) on the flexible hinge leverage (9).

2. focus adjusting mechanism according to claim 1 is characterized in that: the pitch angle of flexible hinge parallelogram guiding mechanism (1) is 60 °-75 °.

3. according to claim 1 and 2 described focus adjusting mechanisms, it is characterized in that: flexible hinge leverage (9) by moving lever (31), hinge neck and not kinetoplast (29) form, the wall between hole (27) and hole (28) constitutes the hinge neck.

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