CN108169918A - Underwater imaging laser illumination light spot homogenization adjusting device - Google Patents

Abstract

The invention belongs to the technical field of optical illumination and imaging, and in particular relates to an underwater imaging laser illumination spot homogenization adjustment device. It includes a lens barrel, a first fixed block arranged in the lens barrel and coaxial with the lens barrel, a second fixed block, a first ring and a second ring; the first fixed block and the second fixed block are respectively used to fix the second One ring and the second ring, the first ring and the second ring are respectively used to fix two micro-lenses; through the design of the mechanical structure, four degrees of freedom are used to adjust the way to effectively realize the gap between the two sets of micro-lenses. The micro-adjustment of the relative wheelbase error, relative rotation error and relative translation error (plane movement in X and Y directions) ensures the strict alignment of the optical axes of the two sets of microlens arrays, high adjustment accuracy, simple adjustment method, and Good quality.

Description

A uniform adjustment device for underwater imaging laser illumination spot

technical field

The invention belongs to the technical field of optical illumination and imaging, and in particular relates to a device for homogenizing the output beam of an illumination laser in underwater imaging by using a double-column microlens array adjustment mechanism.

Background technique

In underwater imaging, the water body has strong absorption and scattering of natural light, and the energy attenuation of light is large when natural light is used as the lighting source, and the transmission distance is short. Therefore, in underwater imaging camera systems, laser light sources are often used for illumination. The light spot emitted directly by the laser obeys the Gaussian distribution, the energy distribution is uneven, and it presents the characteristics of high center energy and low edge energy. Using this light source for illumination will affect the imaging effect of the underwater camera, so it cannot be used directly, and the laser needs to be emitted directly The spot is shaped into a top-hat beam, so that the energy of the entire spot is evenly distributed.

Currently, there are three widely used solutions: binary diffraction elements, hollow conduits, and microlens arrays. Because the microlens array method has the advantages of small beam homogenization system, high energy transmission efficiency, insensitivity to input light intensity distribution, etc., and can also achieve a certain depth of focus, so this method is more and more applied to laser Homogenization is in use.

The commonly used microlens array method is composed of two series of microlenses. There must be a strict relative positional relationship between the two microlenses, that is, under the premise of ensuring the focal length between the two lenses, each microlens unit must be strictly align. This requires that the two microlenses have a certain adjustment mechanism to eliminate errors caused by the processing and assembly of the mounting body.

Contents of the invention

The purpose of the present invention is to provide an underwater imaging laser illumination spot homogenization adjustment device, through the design of the mechanical structure, the relative axis distance error and the relative rotation between the two sets of micro-lenses can be effectively realized by adopting four degrees of freedom for independent adjustment. The micro-adjustment of error and relative translation error (plane movement in X and Y directions) ensures the strict alignment of the optical axes of the two sets of microlens arrays, high adjustment accuracy, simple adjustment method, and good spot quality.

The technical solution of the present invention is to provide an underwater imaging laser illumination spot uniform adjustment device, which is special in that it includes a lens barrel, a first fixed block arranged in the lens barrel and coaxial with the lens barrel, a second The fixed block, the first ring and the second ring; microlens;

It also includes a fixed adjustment device, the above-mentioned fixed adjustment device includes a first set screw, a second set screw, an adjustment screw and a shaft shift screw;

The center of the first fixed block has an elliptical through hole, the short axis direction of the elliptical through hole is defined as the up and down direction, and the long axis direction of the elliptical through hole is defined as the left and right direction;

The inner wall of the lens barrel is provided with holes, the outer wall on the left side of the first fixed block and the outer wall on the right are both planes, and fits flatly with the holes in the lens barrel, the distance between the upper and lower arcs of the hole is greater than the upper and lower arcs of the first fixed block face spacing;

The above-mentioned first ring is located inside the elliptical through hole, and the upper and lower parts of the elliptical through hole closely fit with the outer circle of the first ring;

The first set screw and the second set screw are located on the short axis and the long axis extension line of the oval through hole respectively, the first set screw and the second set screw pass through the lens barrel, the first set screw and the second set screw The heads of the two setscrews press against the first ring and the first fixing block respectively;

An annular protrusion is also provided along the circumference of the inner wall of the lens barrel, and the second fixed block is in contact with an end surface of the annular protrusion; one end of the above-mentioned shaft-moving screw passes through the front end cover of the lens barrel, the second fixed block and the annular protrusion in turn through the shaft for use. The elastic circlip is limited on the other end surface of the annular protrusion; the other end of the pivot screw contacts the front end cover of the lens barrel; the pivot screw is threadedly connected with the second fixed block;

The center of the second fixed block is provided with a circular through hole, the second ring is fixed in the circular through hole and can rotate along the inner wall of the circular through hole, and the second ring has a threaded hole in the radial direction , the second fixed block and the lens barrel are provided with a waist hole, and the adjusting screw passes through the waist hole of the lens barrel and the second fixed block and is fixed to the threaded hole on the second ring.

Preferably, in order to achieve the second fast fixation and the stable axial movement of the second ring, the underwater imaging laser illumination spot homogenization adjustment device of the present invention further includes a guide rod, one end of which passes through the front end cover of the lens barrel, the second The two fixing blocks and the annular protrusion are limited on the other end surface of the annular protrusion; the other end of the light guide rod is pressed against the end surface of the front end cover of the lens barrel.

Preferably, there are two threaded holes on the top and bottom of the lens barrel, and two through holes on the left and right. The two threaded holes are located on the extension line of the short axis of the oval through hole, and the through hole is located on the extension line of the long axis of the oval through hole. on-line;

There are two threaded holes on the first fixed block, and the two threaded holes are located on the extension line of the major axis of the oval hole, and the first set screw passes through the through hole of the lens barrel and the threaded rear top on the first fixed block Tighten the first ring.

Preferably, two blind holes are provided on the first fixing block, and the second set screw passes through the thread of the lens barrel to fasten the blind holes.

Preferably, the thickness of the first fixing block is greater than that of the first ring, and the inner wall of the first fixing block has a groove in the circumferential direction, and the first ring is partially snapped into the groove.

Preferably, the present invention also includes a small end cap, the above-mentioned small end cap is located on the end face of the second fixed block, the second fixed block is provided with an annular groove along the circumference of the circular through hole, and the second ring is located in the annular groove Inside, and fixed by the small end cap.

Preferably, the present invention further includes a locking mechanism, through which the adjusting screw is locked at a fixed position.

Preferably, the above-mentioned locking mechanism includes a lock nut and a washer.

Preferably, the microlens is fixed in the first ring and the second ring by injecting glue.

Preferably, the other end of the light guide rod is pressed against the end surface of the front end cover of the lens barrel through a nut.

The beneficial effects of the present invention are:

1), the adjustment device of the present invention can be simplified to the adjustment of four degrees of freedom, which can completely align the optical axes of the two groups of microlens arrays, and the adjustment of each degree of freedom does not interfere with each other, and the adjustment accuracy is high;

2), the present invention realizes left and right translation and up and down translation through two independent adjustment modules, without the incidental rotation effect caused by joint adjustment;

3) Using threads to adjust translation and axis movement has high adjustment accuracy. For relatively large adjustments of rotation adjustment and axial adjustment, a locking mechanism is added, which has good adjustment stability and convenient operation.

4) After the adjustment, the interference fringe of the laser exit spot is effectively reduced, the speckle phenomenon is reduced, and the illumination of the spot is more uniform;

5) The device of the present invention has small volume, uniform distribution of output light intensity, and high energy efficiency.

Description of drawings

Fig. 1 is the rear end view of the uniform light lens comprising the adjusting device of the present invention;

Fig. 2 is A-A sectional view among Fig. 1;

Fig. 3 is B-B sectional view among Fig. 1;

Fig. 4 is C-C sectional view among Fig. 1;

Fig. 5 is the D direction view among Fig. 1;

The reference signs in the figure are: 1-lens barrel, 2-front end cover, 3-first fixing block, 4-first ring, 5-second set screw, 6-second fixing block, 7-small end Cover, 8-second ring, 9-axis shifting screw, 10-guide light rod, 11-spring washer, 12-nut, 13-circlip for shaft, 14-first set screw, 15-adjusting screw, 16-lock nut, 17-washer, 18-first hexagon socket bolt, 19-second hexagon socket bolt, 20-micro lens, 21-annular protrusion.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

1 and 2, it can be seen that the adjustment device of the present invention mainly includes a lens barrel 1, a first fixed block 3 arranged in the lens barrel 1 and coaxial with the lens barrel 1, a second fixed block 6, a first round ring 4 and second ring 8;

It can be seen from Figure 1 that the inner wall of the lens barrel 1 is provided with a hole, the outer wall on the left side of the first fixing block 3 is flat with the outer wall on the right side, and fits the plane of the hole in the lens barrel 1, and the upper and lower arc surfaces of the hole The spacing is greater than the spacing between the upper and lower arc surfaces of the first fixed block 3;

The center of the first fixed block 3 has an elliptical through hole, and the elliptical through hole is an opening in the left and right directions. The outer circle closely fits;

There are two threaded holes on the top and bottom of the lens barrel 1, and two through holes on the left and right. The two threaded holes are located on the short axis extension of the oval through hole, and the through hole is located on the long axis extension of the oval through hole;

There are two threaded holes (see Fig. 3) on the first fixed block 3, and two threaded holes are positioned at the extension line of the long axis of oval hole, and the first set screw 14 passes through the through hole of lens barrel 1 and the second threaded hole successively. A threaded hole on the fixing block 3 backs up against the first ring 4, where the first ring 4 can be provided with a blind hole, and the head of the first set screw 14 pushes against the blind hole.

The second set screw 5 passes through the threaded hole of the lens barrel 1 located in the direction of the minor axis of the elliptical through hole to tighten the first fixing block 3 .

As can be seen from Fig. 2, the center of the second fixed block 6 is provided with a circular through hole, the second fixed block 6 is provided with an annular groove along the circumference of the circular through hole, and the second ring 8 is located in the annular groove, And fixed by the small end cap 7, the second ring 8 is fixed in the circular through hole and can rotate circumferentially along the inner wall of the circular through hole;

An annular protrusion 21 is also provided along the circumference of the inner wall of the lens barrel 1, and the second fixed block 6 is in contact with an end surface of the annular protrusion 21; The annular protrusion 21 is limited on the other end surface of the annular protrusion 21 by the circlip 13 for the shaft; the other end of the pivot screw 9 loosens the front end cover 2 of the contact lens barrel 1; the pivot screw 9 is threadedly connected with the second fixed block 6 One end of the light guide rod 10 passes through the front end cover 2 of the lens barrel, the second fixed block 6 and the annular protrusion 21 to be limited on the other end surface of the annular protrusion 21; the other end of the light guide rod 10 is pressed on the front end of the lens barrel by a nut 12 Cover 2.

As can be seen from Figure 4, the second circular ring 8 has threaded holes in the radial direction, the second fixed block 6 and the lens barrel 1 are provided with waist holes, and the adjusting screw 15 passes through the lens barrel 1 and the second fixed block 6 The threaded hole on the waist hole of the second ring 8 is fixed, and the adjusting screw rod 15 is also provided with a locking nut 16 and a washer 17.

The two microlenses 20 are divided into two different rings by injecting glue, wherein the first ring 4 can drive the microlens 20 to move up and down, left and right, and the second ring 8 can drive the microlens 20 to move relative to the first circle. The microlenses 20 in the ring 4 undergo axial movement and rotation.

Specifically, it is achieved through the following methods:

Left and right translation of the microlens 20 in the first ring 4: as shown in Figure 1 and Figure 3, the first ring 4 is installed in the elliptical through hole of the first fixed block 3, and the elliptical through hole is an opening in the left and right direction. hole, the top and bottom of which are in close contact with the outer circle of the first ring 4, the first set screw 14 passes through the through holes on the left and right sides of the lens barrel 1 and is installed in the threaded hole of the first fixing block 3, the first ring The ring 4 can translate left and right under the action of the first set screw 14 .

The up and down translation of the microlens 20 in the first ring 4: as shown in Figure 1 and Figure 2, the first fixed block 3 is a non-standard circle, and its two sides are flattened and matched with the hole slots in the lens barrel 1 The planes fit together, the distance between the upper and lower arc surfaces of the hole groove is greater than the distance between the upper and lower arc surfaces of the first fixed block 3, the second set screw 5 is installed in the threaded holes on the upper and lower sides of the lens barrel 1, and the first fixed block 3 together with The first circular ring 4 can translate up and down under the action of the second set screw 5 .

Rotation of the microlens 20 in the second ring 8: as shown in Figure 4 and Figure 5, the second ring 8 is installed in the groove of the second fixed block 6 by the small end cap 7, because its matching circumferential surface is a circle shape, so the second ring 8 can rotate around its axis relative to the second fixed block 6, the second ring 8 has threaded holes in the radial direction, and the second fixed block 6 has holes in the direction of the corresponding circumferential position. Waist hole, the lens barrel 1 also has a larger hole at the adjusted position, therefore, the adjustment screw 15 passes through the larger hole in the lens barrel 1 and the waist hole in the second fixed block 6 and the second ring 8 The threaded hole in the center is connected, and it can drive the second ring 8 to rotate relative to the second fixed block 6. After the rotation is adjusted, the outer arc surface of the second ring 8 can be connected with the second fixed block by tightening the adjusting screw 15. The inner arc surface of the block 6 is compressed and locked.

Axial movement of the microlens 20 in the second ring 8: as shown in Figure 2, the front end cover 2 is connected with the lens barrel 1 by bolts, and the axial movement screw rod 9 and the light guide rod 10 are installed in the hole of the front end cover 2 at one end. The other end is installed in the hole in the lens barrel 1, and the shaft-shifting screw 9 is loosely fixed in the axial direction with a circlip 13 for the shaft. The second fixing block 6 is provided with a threaded hole and a light hole, which are respectively connected with the axis shifting screw 9 and the light guiding rod 10 and installed in the lens barrel 1 . The second fixed block 6 can be driven to move axially along the light guide rod 10 by rotating the shaft shifting screw 9 . After the adjustment, the second fixed block 6 is locked at the adjusted axial position by tightening the lock nut 16 .

Claims (10)

1. An underwater imaging laser lighting spot homogenization adjustment device, characterized in that: it comprises a lens barrel (1), a first fixed block (3) that is arranged in the lens barrel (1) and is coaxial with the lens barrel (1) ), the second fixed block (6), the first ring (4) and the second ring (8); the first fixed block (3), the second fixed block (6) are used to fix the first ring ( 4) and the second ring (8), the first ring (4) and the second ring (8) are respectively used to fix two microlenses (20); It also includes a fixed adjustment device, the fixed adjustment device includes a first set screw (14), a second set screw (5), an adjustment screw (15) and a shaft shift screw (9); The center of the first fixed block (3) has an oval through hole, the short axis direction of the oval through hole is defined as the up and down direction, and the long axis direction of the oval through hole is defined as the left and right direction; The inner wall of the lens barrel (1) is provided with holes, and the left and right outer walls of the first fixed block (3) are both flat, and fit in the plane of the holes in the lens barrel (1). The upper and lower arc surfaces of the holes are The spacing is greater than the spacing between the upper and lower arc surfaces in the first fixed block (3); The first ring (4) is located inside the elliptical through hole, and the upper and lower parts of the elliptical through hole are in close contact with the outer circle of the first ring (4); The first set screw (14) and the second set screw (5) are located on the short axis and the long axis extension line of the oval through hole respectively, the first set screw (14) and the second set screw (5) Through the lens barrel (1), the heads of the first set screw (14) and the second set screw (5) press against the first ring (4) and the first fixed block (3) respectively; An annular protrusion (21) is also provided along the inner wall of the lens barrel (1), and the second fixed block (6) is in contact with an end surface of the annular protrusion (21); one end of the shaft-moving screw (9) passes through the Pass through the lens barrel front end cover (2), the second fixed block (6) and the annular protrusion (21) to be limited on the other end surface of the annular protrusion (21) by the circlip (13) for the shaft; the axial movement screw (9) The other end of the lens barrel contacts the front end cover (2); the shaft shift screw (9) is threadedly connected with the second fixed block (6); The center of the second fixed block (6) is provided with a circular through hole, the second ring (8) is fixed in the circular through hole and can rotate along the inner wall of the circular through hole, the second ring (8) 8) There are threaded holes in the radial direction, waist holes are opened on the second fixed block (6) and the lens barrel (1), and the adjusting screw (15) passes through the lens barrel (1) and the second fixed block (6) The waist hole and the threaded hole on the second ring (8) are fixed. 2. The underwater imaging laser illumination spot homogenization adjustment device according to claim 1, characterized in that: it also includes a light guide rod (10), one end of the light guide rod (10) passes through the front end cover of the lens barrel (2 ), the second fixed block (6) and the annular protrusion (21) are limited on the other end surface of the annular protrusion (21); the other end of the light guide rod (10) is pressed against the lens barrel front end cover end surface (2). 3. The underwater imaging laser lighting spot homogenization adjustment device according to claim 2, characterized in that: the lens barrel (1) has 2 threaded holes up and down, 2 through holes on the left and right, and two through holes. The threaded hole is located on the extension line of the minor axis of the elliptical through hole, and the through hole is located on the extension line of the major axis of the elliptical through hole; Two threaded holes are arranged on the first fixed block (3), and the two threaded holes are located on the extension line of the major axis of the oval hole, and the first set screw (14) passes through the through hole of the lens barrel (1) and The screw thread on the first fixed block (3) pushes against the first circular ring (4). 4. The underwater imaging laser lighting spot homogenization adjustment device according to claim 3, characterized in that: two blind holes are also provided on the first fixed block (3), and the second set screw (5) passes through the mirror The thread of the barrel (1) is tight against the blind hole. 5. The underwater imaging laser illumination spot homogenization adjustment device according to claim 4, characterized in that: the thickness of the first fixed block (3) is greater than the thickness of the first ring (4), and the first fixed block (3) ) the inner wall has a groove in the circumferential direction, and the first ring (4) is partially snapped into the groove. 6. The underwater imaging laser illumination spot homogenization adjustment device according to claim 5, characterized in that: it also includes a small end cap (7), and the small end cap (7) is located at the bottom of the second fixed block (6). On the end face, the second fixing block (6) defines an annular groove along the circumference of the circular through hole, and the second ring (8) is located in the annular groove and is fixed by the small end cap (7). 7. The underwater imaging laser illumination spot homogenization adjusting device according to claim 6, characterized in that it further comprises a locking mechanism, through which the adjusting screw (15) is locked at a fixed position. 8 . The underwater imaging laser illumination spot homogenization adjustment device according to claim 7 , characterized in that: the locking mechanism includes a locking nut ( 16 ) and a washer ( 17 ). 9. The underwater imaging laser illumination spot homogenization adjustment device according to claim 8, characterized in that: the microlens (20) is fixed in the first ring (4) and the second ring (8) by injecting glue . 10. The underwater imaging laser illumination spot homogenization adjustment device according to claim 9, characterized in that: the other end of the light guiding rod (10) is pressed against the end surface (2) of the front end cover of the lens barrel by a nut (12) .