CN-122029410-A - Rotary adjustment table for optical element devices

Abstract

A rotary adjustment stage for in particular an optical element, preferably a grating and/or a mirror, device, comprising at least one rotary stage with at least one turntable, a drive device connected to the rotary stage, the drive device preferably comprising at least one motor and a gear and/or motor-gear combination and a rotation mechanism, wherein the rotary stage comprises an angle measurement system, preferably mounted directly on the turntable to determine an angular position.

Inventors

• Peter Spiezger
• Wolfram Ibach
• MANUEL SCHNEIDER

Assignees

• 威泰克科学仪器技术股份有限公司

Dates

Publication Date

20260512

Application Date

20241126

Priority Date

20231127

Claims (20)

1. 1. A rotary adjustment table (1) for in particular an optical element (3) (preferably a grating and/or a mirror) device, comprising: At least one rotary table with at least one rotary table, A drive device connected to the rotary table, said drive device preferably comprising at least one motor and gear and/or motor-gear combination and a rotation mechanism, Wherein the method comprises the steps of -The rotary table comprises an angle measuring system, preferably mounted directly on the turntable (4), for determining the angular position.
2. 2. The rotary adjustment station of claim 1, Wherein the method comprises the steps of The angle measurement system is an absolute measurement system.
3. 3. A rotary adjustment table for an optical element device in particular, Wherein the method comprises the steps of The angle measurement system is an indirect measurement system in which the angular position is determined by measuring the length of the circumference of the rotary table.
4. 4. A rotary adjustment table (1) according to claim 1 or 3, Wherein the method comprises the steps of Control and/or regulation means are provided.
5. 5. The rotary adjustment table (1) according to claim 4, Wherein the method comprises the steps of By means of the control and/or regulating device (14), the rotation angle is readjusted as a function of the determined angular position, preferably in order to compensate for mechanical inaccuracies of the rotation mechanism, which are caused, for example, by drift movements, mechanical stress accumulation or relaxation processes.
6. 6. The rotary adjustment table (1) according to one of claims 1 to 5, Wherein the method comprises the steps of The rotation angle is adjusted by means of the control and/or regulating device, whereby an angular accuracy of better than 1, preferably better than 0.5, is achieved.
7. 7. The rotary adjustment table (1) according to one of claims 1 to 6, Wherein the method comprises the steps of The driving device comprises a stepping motor.
8. 8. The rotary adjustment table (1) according to one of claims 1 to 7, Wherein the method comprises the steps of The angle measurement system includes a pitch circle angle measurement system.
9. 9. The rotary adjustment table (1) according to claim 8, Wherein the method comprises the steps of The pitch angle measurement system preferably comprises periodic measurement marks having reflection properties different from the adjacent material surface and is preferably applied to the edge, in particular the edge of the turntable.
10. 10. The rotary adjustment table according to one of claims 1 to 8, Wherein the method comprises the steps of The material of the rotary table is preferably metal, in particular steel with preferably periodically applied measuring marks, which are preferably applied to the edges, in particular the edges of the rotary table, preferably glued and/or pressed on and/or deposited on and/or etched in.
11. 11. The rotary adjustment table according to one of claims 1 to 9, Wherein the method comprises the steps of The rotary adjustment table comprises a metal strip comprising the measuring marks preferably glued and/or pressed on the circumference of the rotary table.
12. 12. The rotary adjustment table (1) according to one of claims 1 to 11, Wherein the method comprises the steps of The angle measurement system comprises at least one sensor, preferably an absolute sensor, in particular an optical sensor, preferably a digital optical sensor or a digital line camera.
13. 13. The rotary adjustment table (1) according to one of claims 1 to 12, Wherein the method comprises the steps of The gear, in particular the motor-gear combination, has a reduction ratio of at least 50:1, in particular 80:1, preferably at least 100:1.
14. 14. The rotary adjustment table (1) according to one of claims 1 to 13, Wherein the method comprises the steps of The gear is directly arranged on the motor flange.
15. 15. The rotary adjustment table (1) according to one of claims 1 to 14, Wherein the method comprises the steps of The gear and motor shaft are mounted directly on the shaft and aligned parallel to the shaft.
16. 16. The rotary adjustment table according to one of claims 1 to 15, Wherein the method comprises the steps of The rotary table of the rotary adjustment table is mounted in direct contact with the gear.
17. 17. The rotary adjustment table (1) according to one of claims 1 to 16, Wherein the method comprises the steps of The motor-gear combination includes a harmonic gear.
18. 18. A device for Raman, in particular confocal Raman and/or fluorescence microscopy and/or spectroscopy, Having at least one optical element, in particular a grating and/or a mirror, and at least one rotary adjustment stage, Wherein the method comprises the steps of The optical element is arranged on the rotary adjustment table (1).
19. 19. The apparatus according to claim 18, Wherein the method comprises the steps of The rotation adjustment station (1) according to one of claims 1 to 17.
20. 20. The device according to claim 18 to 19, Wherein the method comprises the steps of The device includes a housing that houses the rotation adjustment stage and the optical element.

Description

Rotary adjustment table for optical element devices The invention relates to a rotary adjustment table for an optical element arrangement, in particular, comprising an optical element, preferably in the form of a grating and/or a mirror. The rotary adjustment stage according to the invention is particularly suitable for use in a spectrometer or a spectrograph, preferably a spectrometer having one or more grating and/or mirror elements. The invention can also be applied in a wider field of optical instruments, such as microscopes or devices for adjusting mirrors. When used in optical settings requiring high spectral resolution (e.g. microscopes or in particular spectrometers), precise positioning of the optical element (e.g. mirror or grating of the spectrometer) is necessary. For example, for the accuracy of the spectral calibration of a spectrometer, it is critical that the rotation angle of an optical component (e.g., a grating) with respect to the light incident on the component (preferably the grating) is accurately, reproducibly set and maintained. In the prior art, the rotary adjustment table itself is typically driven by a stepper motor via a screw and bellows. A rotating plate comprising a turntable and driven by a rotation adjustment table, the rotation angle of which is indirectly determined by moving a stepper motor a known number of micro steps, whereby the rotation of the rotating plate is indirectly controlled via a reduction mechanism of the rotation adjustment table. The micro-steps are counted relative to a reference position attached to the rotating adjustment table, for example by using a mechanical limit switch or light barrier. In general, such simple arrangements for detecting the reference position have the disadvantage of poor resolution, which is further exacerbated in compact rotary tables with turntable, wherein small angular variations can cause extremely small movements of the rotary table with turntable. For high resolutions in the angular second range, additional information must therefore be obtained directly from other sensors on the drive motor shaft and thus before the motion is mechanically decelerated, or from extremely high resolution and thus more complex reference sensors. In this case, directly means that the other sensor is directly fixed to the drive shaft of the motor and thus senses the non-decelerating movement of the motor. This further complicates the indirect precise control of the angular position of the turntable that can be achieved. Furthermore, after the system is put into operation, the reference position must first be approached and the system initialized. The initialization of the system must take place after the spectrometer has been turned on, since for counting of steps a reference point is needed from which to start counting. The reference point is the light barrier position. Therefore, after each system turn-on, the light barrier position must be found as a reference position. Although the reduction ratio is 100:1 to 500:1, especially 100:1 to 1000:1, and further the stepping motor micro-steps per rotation of the rotary table is 100 tens to 500 tens of thousands, the precision of such rotary tables is still significantly lower than 1 angular second according to the prior art (e.g., the DV65-D37 type rotary table of OWIS, the ADT-65 type rotary table of Micos, and the DT-80 type rotary table of Physik Instrumente). Although the accuracy can be improved by increasing the mechanical pretension of the components used in the reduction mechanism to minimize the mechanical play, it is also important to ensure that the components run smoothly enough to avoid possible lost steps of the motor during the movement of the rotary adjustment table. Excessively rigid gears require large motors of high power, which in turn introduce significant amounts of heat and mechanical stress to the system during movement, resulting in drift and relaxation processes, while also impeding a compact design. Thus, adjusting the pretension is difficult and time consuming. Typically, the residual angle error can be reduced to a sinusoidal error of about 20-30 angular seconds, which is related to motor rotation. This is mainly caused by the worm drive, which according to the prior art always approaches the target position from the same direction, in order to minimize the residual gear play in the rotary adjustment table. However, according to the prior art, in order to compensate for such residual mechanical errors, it is necessary to measure the residual errors during the calibration of the rotary adjustment table and to fit the measured data with a mathematical model of the rotary adjustment table. The model is then used to approach the desired target location with greater accuracy. For worm gears, periodic errors can occur per revolution of the motor. In the model, the error component may be assumed to be sinusoidal and the result of the calibration measurement may be fitted wi