CN105486246A - Spherical surface interference splicing measuring device and adjusting method thereof - Google Patents

Abstract

The invention relates to a spherical error interference splicing measurement device and an adjustment method thereof. The device includes an interferometer, a support, a six-dimensional adjustment frame, a CGH, a one-dimensional rail platform, a test piece, a one-dimensional adjustment mechanism, a two-dimensional adjustment mechanism, a four-dimensional adjustment mechanism, and an electric control lifting platform. The adjustment method is used to adjust the above-mentioned spherical interference stitching measurement device. The device can conveniently, quickly and accurately adjust the spherical measured part to meet the measurement requirements, effectively solves the problem of difficult installation and adjustment of the measured spherical part during measurement, and realizes its full-caliber detection.

Description

Spherical surface interference splicing measuring device and its adjustment method

technical field

The invention relates to a spherical surface error detection device and method, in particular to a spherical surface interference splicing measurement device and an adjustment method thereof.

Background technique

With the development of scientific and technological level and industrial level, the requirements for large-diameter optical parts are getting higher and higher in modern industrial production. Using the traditional method, using interferometers to measure large spherical optical parts requires large interferometers and reference mirrors, resulting in long processing cycles and high processing costs. The splicing interferometric method can solve this problem. For the splicing interferometry device and method of spherical error, although it can measure with high precision, it is difficult to install and adjust the tested part, and the adjustment accuracy of the tested part is very high, which hinders the development and promotion of this method.

Contents of the invention

The purpose of the present invention is to provide a spherical interference splicing measurement device and its adjustment method for the defects in the prior art, which can realize fast, effective and accurate adjustment of the measured piece.

In order to achieve the above object, design of the present invention is:

Using the splicing idea to measure spherical parts, because the measured sub-aperture is small, to perform splicing detection, the tested part must not only move up and down, but also adjust the spherical center of the tested part to the computer-generated hologram (Computer-GeneratedHologram, CGH) The focus of the generated spherical wave coincides, and the center of the sphere and the focus of the spherical wave are always coincident during the rotation of the tested object.

The adjustment mechanism is divided into two parts, one part makes the spherical center of the tested part coincide with the rotation center line of the adjustment table, keep this part unchanged, and adjust the other part so that the spherical center of the tested part coincides with the focus of the spherical wave generated by CGH, which can ensure During the rotation of the tested piece, the spherical center of the tested piece coincides with the focal point of the spherical wave generated by CGH, and the measurement is stable; the one-dimensional lifting platform realizes the up and down movement of the tested piece; during the measurement process, the reflected light point on the tested surface is controlled at Center the crosshairs to ensure that each subaperture has interference fringes. The adjustment mechanism and its adjustment method finally realize the full-diameter detection of spherical parts.

According to above-mentioned inventive design, the present invention adopts following technical scheme:

A spherical interference splicing measurement device, including an interferometer, a support, a six-dimensional adjustment frame, a CGH, a one-dimensional guide rail platform, a test piece, a one-dimensional adjustment mechanism, a two-dimensional adjustment mechanism, a four-dimensional adjustment mechanism, and an electric control lifting platform; An interferometer and a one-dimensional guide rail platform are installed on the support, a six-dimensional adjustment frame is installed on the one-dimensional guide rail platform, and the CGH is installed on the six-dimensional adjustment frame, so that the interferometer exit optical axis can pass through the center of the CGH, And it can adjust the distance between the CGH and the tested piece; the tested piece adjustment mechanism is composed of the one-dimensional adjustment mechanism, the two-dimensional adjustment mechanism, the four-dimensional adjustment mechanism and the electric control lifting platform. Lifting platform, a four-dimensional adjustment mechanism is fixed on the electric control lifting platform, which is used to adjust the spherical center of the measured piece to coincide with the focus of the spherical wave generated by CGH, and a two-dimensional adjustment mechanism is fixed on the four-dimensional adjustment mechanism, which is used to adjust the measured The sphere center of the piece coincides with the rotation center line of the adjustment mechanism of the tested piece, the one-dimensional adjustment mechanism is fixed on the two-dimensional adjustment mechanism, and the tested piece is fixed on the one-dimensional adjustment mechanism.

The one-dimensional guide rail platform is as follows: slide rails are fixed on both sides of the installation plate, two sliders move freely along the parallel direction of the slide rails, a connection plate is fixed on the two sliders, and a six-dimensional adjustment frame is fixed on the connection plate.

The one-dimensional adjustment mechanism is: the tested piece is fixed on the rotating shaft, the rotating shaft is fixed on the first precision rotating platform, and the first precision rotating platform is fixed on the connecting plate, so that the degree of freedom of the tested piece around the rotating shaft is satisfied. adjustment.

The two-dimensional adjustment mechanism is: the connecting plate is fixed on the upper two-dimensional direct motion platform, which satisfies the adjustment of the two degrees of freedom of the measured piece moving forward, backward, left, and right on the horizontal plane.

The four-dimensional adjustment mechanism is: a one-dimensional vertical linear motion platform is fixed on the lower two-dimensional linear motion platform, and the second precision rotating platform is fixed on the one-dimensional vertical linear motion platform, so as to meet the requirements of the horizontal direction, front, back, left, and right of the measured piece Four degrees of freedom adjustment for movement, horizontal rotation, and up and down movement.

A method for adjusting a spherical interference stitching measuring device, which is used to adjust the above-mentioned spherical interference stitching measuring device, the operation steps are as follows:

1) Install and adjust CGH: CGH is installed on the six-dimensional adjustment frame, and the six-dimensional adjustment frame is installed on the one-dimensional guide rail platform;

2) Adjust the two-dimensional adjustment mechanism: use a horizontal dial gauge to align the tested part: centering is to put the pointer of the dial indicator on the tested part, and adjust the tested part by adjusting the upper two-dimensional direct motion platform The position of the center of the sphere until the number expressed in thousand is almost unchanged during the rotation of the tested part;

3) Adjust the one-dimensional guide rail platform and the electric control lifting platform: move the position of the one-dimensional guide rail platform and the electric control lifting platform, so that the distance between the CGH and the center of the test piece is the back focus of the spherical wave generated by the CGH, and adjust the measured The components are at a suitable height; adjust the orientation of the CGH so that the optical axis of the interferometer passes through the center of the CGH vertically;

4) Adjust the four-dimensional adjustment mechanism: first find the reflected light spot in the light source mode, and gradually adjust the reflected light spot to the center of the cross line by adjusting the two-dimensional linear motion platform and the one-dimensional vertical motion platform; then switch to the stripe mode for further adjustment. Fine adjustment, adjust different degrees of freedom according to different interference fringes: facing the interferometer, vertical stripes can be adjusted to move left and right, horizontal stripes can be adjusted to move up and down, and dense stripes in the middle can be adjusted to defocus; the less interference fringes, the better The better the center of the sphere coincides with the focal point of the spherical wave;

5) Keep the state of step 3), perform another alignment on the tested part, and switch to the light source mode, adjust the first precision rotating platform to a certain angle according to the size of the tested part, and repeat step 4);

6) Constantly adjust the first precision rotating platform, and switch to the light source mode, so that the light spot does not deviate from the center of the cross, to ensure that the tested part rotates a circle in the stripe mode, and each position has an interference fringe pattern to realize the whole circle detection .

7) For a larger DUT, repeat steps 5) and 6) until all areas of the DUT are measured.

Compared with the prior art, the beneficial effects of the spherical interference splicing measurement device and its adjustment method of the present invention are:

The device can conveniently, quickly and accurately adjust the spherical measured part to meet the measurement requirements, effectively solve the problem of difficult installation and adjustment of the measured spherical part during measurement, and realize its full-caliber detection.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of a spherical interference stitching measurement device.

Fig. 2 is a structural schematic diagram of the adjustment mechanism of the measured piece in the spherical interference splicing measurement device.

Fig. 3 is a schematic structural diagram of the one-dimensional adjustment mechanism.

Fig. 4 is a structural schematic diagram of a two-dimensional adjustment mechanism.

Fig. 5 is a structural schematic diagram of a four-dimensional adjustment mechanism.

Figure 6 is a schematic diagram of the structure of the CGH six-dimensional adjustment frame.

Fig. 7 is a schematic structural diagram of a one-dimensional rail platform.

detailed description

Embodiments of the present invention are described as follows in conjunction with accompanying drawings:

Embodiment one:

As shown in Figure 1, a spherical interference splicing measurement device includes an interferometer 1, a support 2, a six-dimensional adjustment frame 3, a CGH4, a one-dimensional guide rail platform 5, a test piece 6, a one-dimensional adjustment mechanism 7, a two-dimensional Adjustment mechanism 8, four-dimensional adjustment mechanism 9, electric control lifting platform 10; interferometer 1 and one-dimensional guide rail platform 5 are installed on the support 2, six-dimensional adjustment frame 3 is installed on the one-dimensional guide rail platform 5, and the CGH4 Installed on the six-dimensional adjustment frame 3, so that the exit optical axis of the interferometer 1 can pass through the center of the CGH4, and the distance between the CGH4 and the measured object 6 can be adjusted; by the one-dimensional adjustment mechanism 7 and the two-dimensional adjustment mechanism 8 , the four-dimensional adjustment mechanism 9 and the electronically controlled lifting platform 10 form the measured piece adjusting mechanism, the lower end of the tested piece adjusting mechanism is the electronically controlled lifting platform 10, and the four-dimensional adjusting mechanism 9 is fixed on the above described electronically controlled lifting platform 10, which is used to adjust the measured The center of the sphere of the piece 6 coincides with the focal point of the spherical wave generated by the CGH4, and the two-dimensional adjustment mechanism 8 is fixed on the four-dimensional adjustment mechanism 9, which is used to adjust the center of the sphere of the tested piece 6 to coincide with the rotation centerline of the tested piece adjustment mechanism, The one-dimensional adjustment mechanism 7 is fixed on the two-dimensional adjustment mechanism 8 , and the test piece 6 is fixed on the one-dimensional adjustment mechanism 7 .

Interferometer 1 in the described device is: Zygo company model is the interferometer of GPIXP/D, 640X480CCD image acquisition, adopts laser three-dimensional phase-shift interferometry, laser generator is helium-neon laser wavelength 632.8nm, can produce a standard plane wave , the plane measurement accuracy reaches λ/20.

The CGH4 and its supporting six-dimensional adjustment frame 3 are products of Zygo Company. The plane wave generated by the interferometer 1 is converted into a spherical wave by CGH4 and incident on the surface of the measured object 6, and the reflected wave carrying the surface shape information of the measured spherical surface 6 passes through the CGH4 for the second time and enters the interferometer 1. The plane wave interferes, and the interference fringe pattern is displayed in the CCD; the five knobs 18, 19, 20, 21, and 22 of the six-dimensional adjustment frame 3 control the attitude of the six degrees of freedom of the CGH4 through different combinations.

The one-dimensional guide rail platform 5 is: fixed slide rails 24, 24' on both sides of the mounting plate 23, two slide blocks 25, 25' move freely along the parallel directions of the slide rails 24, 24' respectively, two slide blocks 25, The connecting plate 26 is fixed on the top of 25 ′; the six-dimensional adjustment frame 3 is fixed on the connecting plate 26 .

The one-dimensional adjustment mechanism 7 is: the tested object 6 is fixed on the rotating shaft 12, the rotating shaft 12 is fixed on the first precision rotating platform 11, and the first precision rotating platform 11 is fixed on the connecting plates 13, 13', satisfying The adjustment of the degree of freedom of the measured object 6 around the rotation axis 12 .

The two-dimensional adjustment mechanism 8 is: the upper two-dimensional direct motion platform 14, 14' fixes the connecting plates 13, 13', which satisfies the adjustment of the two degrees of freedom of the measured piece 6 moving forward, backward, left, and right on the horizontal plane.

The four-dimensional adjustment mechanism 9 is: the lower two-dimensional linear motion platform 17, 17' is fixed with a one-dimensional vertical motion platform 16, and the second precision rotating platform 15 is fixed on the one-dimensional vertical motion platform 16, It satisfies the adjustment of four degrees of freedom for the measured piece 6 to move forward, backward, left, and right in the horizontal direction, to rotate horizontally, and to move up and down.

The electronically controlled lifting platform 10 is: the purchased product model is PSAV100-ZF, equipped with a one-dimensional 42/57 stepper motor drive controller, and the product number is SC300-1B, which can realize the vertical movement and positioning of the tested part 6 .

Embodiment two:

A method for adjusting a spherical interference stitching measuring device, which is used to adjust the above-mentioned spherical interference stitching measuring device, the operation steps are as follows:

1) Install and adjust CGH4: CGH4 is installed on the six-dimensional adjustment frame 3, and the six-dimensional adjustment frame 3 is installed on the one-dimensional guide rail platform 5;

2) Adjust the two-dimensional adjustment mechanism 8: use a horizontal dial indicator to align the tested part 6: centering is to put the pointer of the dial gauge on the tested part 6, and adjust the upper two-dimensional direct motion platform 14, 14' to adjust the position of the center of the spherical surface of the tested piece 6 until the thousandth indicator is almost constant during the rotation of the tested piece 6;

3) Adjust the one-dimensional guide rail platform 5 and the electric control lifting platform 10: move the positions of the one-dimensional guide rail platform 5 and the electric control lifting platform 10, so that the distance between the center of the sphere between CGH4 and the DUT 6 is the back focus of the spherical wave generated by CGH4 , and adjust the DUT 6 at a suitable height; adjust the orientation of CGH4 so that the optical axis of interferometer 1 passes through the center of CGH4 vertically;

4) Adjust the four-dimensional adjustment mechanism 9: first find the reflected light spot in the light source mode, and gradually adjust the reflected light spot to the center of the cross line by adjusting the two-dimensional linear motion platform 17, 17' and the one-dimensional vertical linear motion platform 16; Then switch to the fringe mode for fine adjustment, and adjust different degrees of freedom according to different interference fringes: facing the interferometer 1, the vertical stripes are adjusted to move left and right, the horizontal stripes are adjusted to move up and down, and the dense stripes in the middle are adjusted to defocus; interference The fewer fringes, the better the coincidence between the center of the test piece 6 and the focus of the spherical wave;

5) Keep the state of step 3), perform another alignment on the DUT 6, and switch to the light source mode, adjust the first precision rotating platform 11 to a certain angle according to the size of the DUT 6, and repeat step 4);

6) Constantly adjust the first precision rotating platform 11, and switch to the light source mode, so that the light spot does not deviate from the center of the cross, and ensure that the tested part 6 rotates once in the fringe mode, and each position has an interference fringe pattern, realizing the whole Weekly testing.

7) For a larger DUT 6, repeat steps 5) and 6) until all areas of the DUT 6 are measured.

Claims (5)

1. A spherical interference splicing measurement device, characterized in that it includes an interferometer (1), a support (2), a six-dimensional adjustment frame (3), a CGH (4), a one-dimensional guide rail platform (5), and a measured (6), one-dimensional adjustment mechanism (7), two-dimensional adjustment mechanism (8), four-dimensional adjustment mechanism (9), electric control lifting platform (10); the interferometer (1) is installed on the support (2) and a one-dimensional guide rail platform (5), the six-dimensional adjustment frame (3) is installed on the one-dimensional guide rail platform (5), and the CGH (4) is installed on the six-dimensional adjustment frame (3), so that the interferometer (1 ) The outgoing optical axis can pass through the center of the CGH (4), and the distance between the CGH (4) and the measured object (6) can be adjusted; the one-dimensional adjustment mechanism (7), the two-dimensional adjustment mechanism (8) , the four-dimensional adjustment mechanism (9) and the electric control lifting platform (10) constitute the adjustment mechanism of the tested piece, the lower end of the testing piece adjustment mechanism is the electric control lifting platform (10), and the four-dimensional adjustment mechanism is fixed on the electric control lifting platform (10). The mechanism (9) is used to adjust the spherical center of the test piece (6) to coincide with the focal point of the spherical wave generated by the CGH (4), and the two-dimensional adjustment mechanism (8) is fixed on the four-dimensional adjustment mechanism (9) to adjust The sphere center of the tested piece (6) coincides with the rotation center line of the tested piece adjustment mechanism, the one-dimensional adjustment mechanism (7) is fixed on the two-dimensional adjustment mechanism (8), and the one-dimensional adjustment mechanism (7) is fixed on the DUT (6). 2. The spherical interference splicing measurement device according to claim 1, characterized in that: the one-dimensional adjustment mechanism (7) is: the measured piece (6) is fixed on the rotating shaft (12), and the rotating shaft (12) It is fixed on the first precision rotating platform (11), and the first precision rotating platform (11) is fixed on the connecting plate (13, 13'), satisfying the degree of freedom of the test piece (6) around the rotation axis (12) adjust. 3. The spherical surface interference splicing measurement device according to claim 1, characterized in that: the two-dimensional adjustment mechanism (8) is: the upper two-dimensional linear motion platform (14, 14') is fixed on the connecting plate (13, 13 ') to meet the adjustment of the two degrees of freedom of the measured piece (6) moving forward, backward, left, and right on the horizontal plane. 4. The spherical interference splicing measuring device according to claim 1, characterized in that: the four-dimensional adjustment mechanism (9) is: a one-dimensional vertical motion fixed on the lower two-dimensional linear motion platform (17, 17') platform (16), and the second precision rotating platform (15) is fixed on the one-dimensional vertical linear motion platform (16), satisfying the four freedoms of the tested piece (6) moving back and forth, horizontally, horizontally, and up and down. degree of adjustment. 5. A method for adjusting a spherical interference stitching measurement device, used to adjust the spherical interference stitching measurement device according to claim 1, characterized in that the operating steps are as follows: 1) Install and adjust CGH (4): CGH (4) is installed on the six-dimensional adjustment frame (3), and the six-dimensional adjustment frame (3) is installed on the one-dimensional guide rail platform (5); 2) Adjust the two-dimensional adjustment mechanism (8): Use a horizontal dial gauge to align the tested piece (6): centering is to put the pointer of the dial gauge on the tested piece (6), and adjust the upper two Adjust the position of the center of the spherical surface of the test piece (6) with a three-dimensional straight-moving platform (14, 14') until the thousandth indicator is almost unchanged during the rotation of the test piece (6); 3) Adjust the one-dimensional guide rail platform (5) and the electric control lifting platform (10): move the position of the one-dimensional guide rail platform (5) and the electric control lifting platform (10), so that the CGH (4) and the DUT (6) The distance from the center of the sphere is the back focus of the spherical wave generated by the CGH (4), and adjust the measured object (6) at a suitable height; adjust the orientation of the CGH (4) so that the optical axis of the interferometer (1) passes through the CGH ( 4) the center; 4) Adjust the four-dimensional adjustment mechanism (9): first find the reflected light spot in the light source mode, and gradually adjust the reflected light spot by adjusting the two-dimensional linear motion platform (17, 17') and the one-dimensional vertical linear motion platform (16). To the center of the cross line; then switch to the fringe mode for fine adjustment, and adjust different degrees of freedom according to different interference fringes: facing the interferometer (1), the vertical stripes are adjusted to move left and right, and the horizontal stripes are adjusted to move up and down, and the two sides are sparse in the middle The dense fringes adjust the defocus; the less the interference fringes, the better the center of the test piece (6) coincides with the focus of the spherical wave; 5) Keep the state of step 3), and then adjust the center of the test piece (6) again, and switch to the light source mode, and adjust the first precision rotating platform (11) to a certain angle according to the size of the test piece (6) , repeat step 4); 6) Constantly adjust the first precision rotating platform (11), and switch to the light source mode, so that the light spot does not deviate from the center of the cross, and ensure that the tested part (6) rotates once in the fringe mode, and there are interference fringes at each position Figure, to achieve the whole week detection; 7) For a larger DUT (6), repeat steps 5) and 6) until all areas of the DUT (6) are measured.