CN220232106U - High-precision three-degree-of-freedom adjusting device for digital micromirror device DMD - Google Patents

Abstract

The utility model relates to a high-precision three-degree-of-freedom adjusting device for a Digital Micromirror Device (DMD), belonging to the technical field of optical equipment. The device comprises a rotating part, a positioning part, a reference part and a supporting part, wherein the rotating part is connected with the positioning part through an inner sleeve, an outer sleeve, a first fine grain screw, a first tension spring and the like, the positioning part is connected with the reference part through a second fine grain screw, a second tension spring, a headless fastening bolt and the like, and the reference part is fixedly connected with the supporting part. The device realizes pitching and swaying adjustment by adjusting the second fine grain screw rod to be matched with the second tension spring, and realizes rolling adjustment by adjusting the first fine grain screw rod to be matched with the first tension spring; the device design science, structure ingenious, easy operation, convenient to use have realized pitching, beat, the high accuracy adjustment of three angle degrees of freedom of rolling to the DMD, have simplified the optics of based on the DMD and have built, have played the effect of protecting the DMD chip simultaneously, have greatly promoted the performance of whole optical system.

Description

High-precision three-degree-of-freedom adjusting device for digital micromirror device DMD

Technical Field

The utility model relates to the technical field of optical equipment, in particular to a high-precision three-degree-of-freedom adjusting device for a Digital Micromirror Device (DMD).

Background

DLP projection technology plays an important role in the fields of super-resolution microscopes, 3D laser printing, holographic 3D display, maskless lithography and the like. The digital micromirror device (Digital Micromirror Devices, DMD) is used as a core optical control device for DLP projection, has millions of micro-mirror units which independently work at high speed, and ensures the advantages of unique high resolution, high contrast, quick response, high flexibility and the like of projection equipment. Each micro-mirror unit of the DMD is capable of independently turning over by a different angle (+ -12 °) around the diagonal of each small positive-direction mirror, when a micro-mirror signal "1" is given, which is deflected by +12°, the micro-mirror is in an on state, and when the incident light source and the micro-mirror exhibit 24 ° incidence, the reflected light is imaged on the screen through the projection objective exactly along the optical axis direction, forming a bright pixel. When the micromirror is given a signal "0" which is deflected by-12 degrees, the micromirror is in the off state, and the reflected beam after 24 ° incidence will not pass through the projection lens in the direction of the optical axis, presenting a dark pixel. Therefore, the incident light is modulated through the DMD, namely, the reflection angle of the light is determined by controlling the deflection of the DMD micro-reflector, so that the light path control is realized, the gray scale modulation is realized by controlling the accumulation time of the light irradiating the micro-reflector, and finally, the display of different patterns is realized.

In the construction process of an actual DMD optical system, the DMD usually has three placement angles of 0 °, 45 °, and 90 ° along the surface direction thereof. In order to strictly ensure the direction of the DMD illumination light path and the direction of the modulated emergent light path, the freedom degrees of the DMD in three angles of pitching, swaying and rolling are required to be adjusted with high precision, so that the performance of an optical system is ensured. Considering that the dimension of the DMD projection module is large, the DMD chip is made of ceramic and other materials, and the DMD chip is fragile, so that the DMD can be adjusted in three degrees of freedom of pitching, swinging and rolling in a high-precision manner, the integrated three-degree-of-freedom adjusting frame which can clamp the DMD at three angles of 0 degree, 45 degrees and 90 degrees and has good protection on the DMD can be met, the construction process of a high-precision DMD system is complicated, the precision cannot be effectively ensured, and the damage of the DMD chip and the like are easy to cause.

Disclosure of Invention

The utility model aims to solve the problems that the existing device for realizing high-precision adjustment of three degrees of freedom of pitching, swaying and rolling of a Digital Micromirror Device (DMD) is not available, the construction of an optical system is complex, the precision cannot be effectively ensured, and a DMD chip is damaged, and provides the high-precision three-degree-of-freedom adjustment device for the DMD of the digital micromirror device. The device utilizes ingenious supporting structural design, can realize the high accuracy adjustment to three degrees of freedom of pitch, beat, roll of DMD, ensures the performance of whole optical system.

The utility model is realized by the following technical scheme:

a high-precision three-degree-of-freedom adjusting device for a Digital Micromirror Device (DMD) comprises a rotating piece, a positioning piece, a reference piece and a supporting piece.

The rotating piece comprises a circular ring fixing plate, an inner sleeve which is extended backwards is fixed at the annular position of the rear end of the circular ring fixing plate, a first upper boss which is extended backwards is fixed at the top of the rear end of the circular ring fixing plate, a first lower boss which is extended backwards is fixed at the bottom of the rear end of the circular ring fixing plate, and a mounting gap is reserved between the bottom end of the first upper boss and the bottom end of the first lower boss and the outer surface of the inner sleeve; eight bottom plate mounting threaded holes are formed in the circular ring fixing plate and uniformly distributed around the circular ring fixing plate; four circular arc strip-shaped holes are formed in the circular ring fixing plate, the four circular arc strip-shaped holes are symmetrically distributed at the left side and the right side of the circular ring fixing plate, and the two circular arc strip-shaped holes on each side are vertically symmetrically arranged.

The positioning piece comprises a positioning plate with a circular through hole at the center, an outer sleeve extending forwards is fixed at the orifice of the front end of the positioning plate, a second upper boss extending forwards is fixed at the top of the front end of the positioning plate, a second lower boss extending forwards is fixed at the bottom of the front end of the positioning plate, and the bottom end of the second upper boss and the top end of the second lower boss are connected with the outer surface of the outer sleeve; four angle locking threaded holes are formed in the positioning plate, the four angle locking threaded holes are symmetrically distributed at the left side and the right side of the positioning plate, and the two threaded holes on each side are vertically symmetrically arranged.

The reference piece comprises a reference plate with a circular through hole at the center.

The support piece comprises a bottom plate, and counter sunk holes are formed in four corners of the bottom plate.

The rotating piece is connected with the positioning piece: the inner sleeve is inserted into the outer sleeve, the first upper boss is arranged opposite to the second upper boss, the first upper boss is positioned on the left side, the second upper boss is positioned on the right side, the second upper boss is connected with a first fine-grain screw rod in a threaded manner, and the end part of the first fine-grain screw rod passes through the second upper boss and then is propped against the first upper boss; the first lower boss is arranged opposite to the second lower boss, the first lower boss is positioned on the right side, the first lower boss is positioned on the left side, and a first tension spring is fixedly connected between the first lower boss and the second lower boss.

The locating piece is connected with the reference piece: a second tension spring is respectively connected and fixed between the left lower part, the right lower part and the right upper part of the positioning plate and the reference plate; the left lower part and the right upper part of the reference plate are respectively in threaded connection with a second fine grain screw rod, and the end part of the second fine grain screw rod penetrates through the reference plate and then is propped against the positioning plate; the right lower side of the reference plate is in threaded connection with a headless fastening bolt, and the end part of the headless fastening bolt passes through the reference plate and then is arranged on the positioning plate in a jacking mode.

The reference piece is connected with the support piece: the reference plate is fixedly connected with the bottom plate vertically, and an operation gap is reserved between the bottom end of the positioning plate and the bottom plate.

Further, the rear end hole of the positioning plate is provided with a circular ring retainer ring, and the rear end part of the inner sleeve penetrates through the outer sleeve and then is detachably connected with the circular ring retainer ring through a bolt at the rear end hole of the positioning plate.

Further, a hole is punched in the center of the first upper boss, and a steel pad is fixed in the hole in an interference manner; punching a hole in the center of the second upper boss, fixing a copper pad in the hole in an interference manner, arranging a screw threaded hole in the center of the copper pad, connecting a first fine thread screw thread in the screw threaded hole, and jacking the end part of the first fine thread screw on the steel pad; punching a hole in the center of the first lower boss, and forming a pin hole extending forwards from the rear end face of the first lower boss, wherein a pin penetrating through the center hole of the first lower boss is inserted into the pin hole; punching a hole in the center of the second lower boss, and arranging a pin hole extending backwards from the front end face of the second lower boss, wherein a pin penetrating through the center hole of the second lower boss is inserted into the pin hole; the two ends of the first tension spring are respectively connected and fixed on the pins in the first lower boss and the second lower boss.

Further, spring fixing holes are formed in the left lower part, the right lower part and the right upper part of the positioning plate and the reference plate, spring locking screws are installed in the spring fixing holes, and two ends of each second tension spring are respectively connected and fixed on the corresponding two spring locking screws.

Further, holes are drilled at the left lower part and the right upper part of the reference plate, copper pads are fixed in the holes in an interference manner, screw threaded holes are formed in the centers of the copper pads, and second fine thread screws are connected in the screw threaded holes in a threaded mode; the steel pad is arranged at the position of the locating plate corresponding to the end part of the second fine grain screw rod, and the end part of the second fine grain screw rod is arranged on the steel pad in a top mode.

Further, a threaded hole is formed in the right lower position of the reference plate, and the headless fastening bolt is in threaded connection with the threaded hole; the steel pad is arranged at the position of the locating plate corresponding to the end part of the headless fastening bolt, and the end part of the headless fastening bolt is propped against the steel pad.

Further, three positioning and fixing threaded holes are respectively formed in the bottom end of the reference plate and the bottom plate at corresponding positions, and the reference plate is detachably connected with the bottom plate through screws in the positioning and fixing threaded holes in a threaded mode.

Further, an optical support rod threaded hole is formed in the center of the bottom plate.

Further, the first fine grain screw and the second fine grain screw adopt electric screws.

Compared with the prior art, the utility model has the following beneficial effects:

1) According to the adjusting device, pitch and yaw adjustment is achieved through adjustment of two second fine-grain screws arranged between the positioning piece and the reference piece and matching with three second tension springs, and rolling adjustment is achieved through adjustment of the first fine-grain screws arranged between the rotating piece and the positioning piece and matching with the first tension springs; according to the utility model, fine adjustment of three degrees of freedom of the DMD is realized for the first time, the complexity of constructing and adjusting the optical system is reduced, and the performance of the whole system is ensured.

2) By adopting the adjusting device, the DMD does not need to be directly operated and adjusted, and the DMD chip is protected.

3) Eight screw holes with equal angles (45 degrees) are arranged on the rotating part in the adjusting device, so that the practical requirement of the DMD on multiple angles in an actual optical system is met.

4) The adjusting device adopts a highly integrated design structure, the bottom plate of the supporting piece is provided with the countersunk holes matched with the optical platform, so that the adjusting device is convenient to fix on the optical platform, and meanwhile, the center of the bottom plate of the supporting piece is provided with the threaded holes of the optical support rod, so that the adjusting device can be matched with the optical support rod to adjust the height.

In a word, the adjusting device provided by the utility model has the advantages of scientific design, ingenious structure, simplicity in operation and convenience in use, realizes high-precision adjustment of three degrees of freedom of pitching, swaying and rolling of the DMD, simplifies optical construction based on the DMD, plays a role in protecting the DMD chip, and greatly improves the performance of the whole optical system.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the utility model and together with the description serve to explain the utility model.

Fig. 1 is a front view of the present utility model.

Fig. 2 is a rear view of fig. 1.

Fig. 3 is a top view of fig. 1.

Fig. 4 is a right side view of fig. 1.

Fig. 5 is a schematic perspective view of the present utility model.

Fig. 6 is a schematic diagram of the explosive structure of fig. 5.

Fig. 7 is a schematic perspective view of the device of the present utility model after mounting a backsheet for fixing the DMD.

In the figure: the device comprises a 1-circular ring fixing plate, a 2-inner sleeve, a 3-first upper boss, a 4-first lower boss, a 5-negative mounting threaded hole, a 6-circular arc strip-shaped hole, a 7-locating plate, an 8-outer sleeve, a 9-second upper boss, a 10-second lower boss, an 11-angle locking threaded hole, a 12-reference plate, a 13-locating fixing threaded hole, a 14-bottom plate, a 15-countersunk hole, a 16-optical strut threaded hole, a 17-first fine thread screw, a 18-steel pad, a 19-copper pad, a 20-first tension spring, a 21-pin, a 22-circular ring retainer ring, a 23-second tension spring, a 24-spring fixing screw, a 25-spring locking screw, a 26-second fine thread screw, a 27-endless fastening screw, a 28-negative, a 29-upper connecting piece, a 30-lower connecting piece and a 31-right connecting piece.

Detailed Description

For a better understanding of the present utility model, reference will be made to the following description of the utility model taken in conjunction with the accompanying drawings and examples. In addition, features in the embodiments and examples of the present application may be combined with each other without conflict.

In the description of the present utility model, it should be understood that the terms "front", "rear", "upper", "lower", "left", "right", "top", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in fig. 1, are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the devices or elements being referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted", "connected" and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected or integrally connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art in a specific case.

As shown in fig. 1 to 6, a high-precision three-degree-of-freedom adjustment device for a DMD of a digital micromirror device includes a rotating member, a positioning member, a reference member, and a supporting member.

The rotating piece comprises a circular ring fixing plate 1, an inner sleeve 2 which is arranged in a backward extending way is fixed at the annular position of the rear end of the circular ring fixing plate 1, a first upper boss 3 which is arranged in a backward extending way is fixed at the top of the rear end of the circular ring fixing plate 1, a first lower boss 4 which is arranged in a backward extending way is fixed at the bottom of the rear end of the circular ring fixing plate 1, and installation gaps are reserved between the bottom ends of the first upper boss 3 and the first lower boss 4 and the outer surface of the inner sleeve 2; eight film installation threaded holes 5 are formed in the circular ring fixing plate 1, the eight film installation threaded holes 5 are uniformly distributed around the circular ring fixing plate 1, and the eight film installation threaded holes 5 can meet the fixed installation of all angles of the DMD; four circular arc strip-shaped holes 6 are formed in the circular ring fixing plate 1, the four circular arc strip-shaped holes 6 are symmetrically arranged at the left side and the right side of the circular ring fixing plate 1 in pairs, the two circular arc strip-shaped holes 6 at each side are arranged symmetrically up and down, and the four circular arc strip-shaped holes 6 can be fixed with a positioning piece after the rotating piece is adjusted, so that the angle is locked.

The positioning piece comprises a positioning plate 7 with a circular through hole at the center, an outer sleeve 8 extending forwards is fixed at the orifice of the front end of the positioning plate 7, a second upper boss 9 extending forwards is fixed at the top of the front end of the positioning plate 7, a second lower boss 10 extending forwards is fixed at the bottom of the front end of the positioning plate 7, and the bottom end of the second upper boss 9 and the top end of the second lower boss 10 are connected with the outer surface of the outer sleeve 8; four angle locking threaded holes 11 are formed in the positioning plate 7, the four angle locking threaded holes 11 are symmetrically distributed at the left side and the right side of the positioning plate 7, and the two angle locking threaded holes 11 at each side are symmetrically arranged up and down.

The reference piece comprises a reference plate 12 with a circular through hole in the center, and three positioning and fixing threaded holes 13 are formed in the bottom end of the reference plate 12.

The supporting piece comprises a bottom plate 14, counter sunk holes 15 are formed in four corners of the bottom plate 14, the hole spacing is integral multiple of the optical platform, and the supporting piece can be conveniently installed on the optical platform; an optical strut threaded hole 16 is formed in the center of the bottom plate 14 and can be matched with an optical strut to adjust the height so as to meet the requirements of different heights of the DMD under different conditions; three positioning and fixing threaded holes 13 are further formed in the bottom plate 14, and the three positioning and fixing threaded holes 13 in the bottom plate 14 correspond to the three positioning and fixing threaded holes 13 in the bottom end of the reference plate 12 one by one.

The rotating piece is connected with the positioning piece: the inner sleeve 2 is inserted into the outer sleeve 8, and the mounting gaps among the first upper boss 3, the first lower boss 4 and the inner sleeve 2 ensure that the outer sleeve 8 can be smoothly and completely sleeved on the inner sleeve 2, and the inner sleeve 2 and the outer sleeve 8 can flexibly rotate; the first boss 3 and the second boss 9 of going up set up relatively, and the first boss 3 of going up is located the left side, the second is gone up boss 9 and is located the right side, and threaded connection has first fine line screw 17 on the second boss 9, and the tip of first fine line screw 17 passes the second and goes up boss 9 back overhead on first boss 3, and is specific: punching a hole in the center of the first upper boss 3, and fixing a steel pad 18 in the hole in an interference manner; the center department of boss 9 punches on the second, and downthehole interference is fixed with copper pad 19, and copper pad 19 center is equipped with screw threaded hole, and first fine grain screw 17 threaded connection is on screw threaded hole, and the tip overhead of first fine grain screw 17 is on steel pad 18, and copper pad 19 and steel pad 18's setting can improve the stability of adjustment, increases the life of device. The first boss 4 of falling sets up with the boss 10 relatively under the second, and boss 4 is located the right side under the first boss 4 is located the left side under, and boss 4 is connected and is fixed with first extension spring 20 under the first between boss 4 and the boss 10 under the second, and is specific: the center of the first lower boss 4 is perforated, a pin hole extending forwards is formed in the rear end face of the first lower boss, and a pin 21 penetrating through the center hole of the first lower boss is inserted into the pin hole; the center of the second lower boss 10 is perforated, a pin hole which is extended backwards is formed from the front end surface of the second lower boss, and a pin 21 penetrating through the center hole of the second lower boss is inserted into the pin hole; the two ends of the first tension spring 20 are respectively connected and fixed on the pins 21 in the first lower boss 4 and the second lower boss 10. In order to prevent the rotary member from being separated from the outer sleeve 8 of the positioning member during the rotation of the inner sleeve 2 of the rotary member relative to the outer sleeve 8 of the positioning member, a circular ring retainer 22 is further disposed at the rear end hole of the positioning plate 7, and the rear end portion of the inner sleeve 2 is detachably connected with the circular ring retainer 22 through bolts at the rear end hole of the positioning plate 7 after passing through the outer sleeve 8.

The locating piece is connected with the reference piece: second tension springs 23 are respectively connected and fixed between the lower left part, the lower right part and the upper right part of the positioning plate 7 and the reference plate 12, and specifically: spring fixing holes 24 are formed in the lower left, lower right and upper right positions of the positioning plate 7 and the reference plate 12, spring locking screws 25 are installed in the spring fixing holes 24, and two ends of each second tension spring 23 are respectively connected and fixed on the corresponding two spring locking screws 25. The lower left and upper right of the reference plate 12 are respectively connected with a second fine thread screw 26 in a threaded manner, and the end part of the second fine thread screw 26 passes through the reference plate 12 and then is arranged on the positioning plate 7 in a jacking manner, specifically: punching holes at the left lower part and the right upper part of the reference plate 12, fixing a copper pad 19 in the holes in an interference manner, arranging a screw threaded hole in the center of the copper pad 19, and connecting a second fine thread screw 26 in the screw threaded hole in a threaded manner; a steel pad 18 is arranged on the positioning plate 7 at a position corresponding to the end part of the second fine grain screw 26, and the end part of the second fine grain screw 26 is propped against the steel pad 18; the arrangement of the copper pad 19 and the steel pad 18 can improve the stability of adjustment and increase the service life of the device. The lower right side of the reference plate 12 is connected with a headless fastening bolt 27 in a threaded manner, and the end part of the headless fastening bolt 27 passes through the reference plate 12 and then is overhead on the positioning plate 7, specifically: a threaded hole is formed in the right lower position of the reference plate 12, and a headless fastening bolt 27 is in threaded connection with the threaded hole; the positioning plate 7 is provided with a steel pad 18 at a position corresponding to the end part of the headless fastening bolt 27, and the end part of the headless fastening bolt 27 is propped against the steel pad 18.

The reference piece is connected with the support piece: the reference plate 12 is fixedly connected with the bottom plate 14 vertically, specifically: after the three positioning and fixing threaded holes 13 at the bottom end of the reference plate 12 are aligned with the three positioning and fixing threaded holes 13 on the bottom plate 14, the reference plate 12 and the bottom plate 14 are connected and fixed by screwing in screws. An operation gap is reserved between the bottom end of the positioning plate 7 and the bottom plate 14, and the operation gap ensures the free movement of the positioning plate 7.

The use principle of the adjusting device of the utility model is as follows:

1) The DMD is installed and fixed on a special bottom plate 28, an upper connecting sheet 29 is arranged on the top of the bottom plate 28 in an upward extending mode, a lower connecting sheet 30 is arranged on the bottom of the bottom plate in a downward extending mode, a right connecting sheet 31 is arranged on the right end portion in a rightward extending mode, counter sunk holes are formed in the three connecting sheets, the bottom plate 28 can be connected and fixed with a rotating piece through the three connecting sheets with counter sunk holes and eight equidistant bottom plate installation threaded holes 5 in the rotating piece, and as shown in fig. 7, the eight equidistant bottom plate installation threaded holes 5 in the rotating piece can meet the requirement of the fixed installation of the DMD at three angles of 0 degree, 45 degree and 90 degree.

2) By rotating the first fine-grain screw 17 at the top and matching with the first tension spring 20 at the bottom, the rolling adjustment can be realized.

3) The distance between the positioning element and the reference element can be adjusted by means of the headless fastening bolt 27 as a reference point for the entire adjustment.

4) By adjusting the two second fine-grain screws 26 and matching with the three second tension springs 23, the pitching and the swaying can be adjusted.

In addition, the first fine thread screw 17 and the second fine thread screw 26 in the adjusting device of the present utility model may employ electric screws in addition to manual screws, thereby realizing three degrees of freedom electric adjustment.

The above examples illustrate only one embodiment of the utility model, which is described in more detail and is not to be construed as limiting the scope of the utility model. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the utility model, which are all within the scope of the utility model.

Claims (9)

1. A high accuracy three degree of freedom adjusting device for digital micromirror device DMD, its characterized in that: comprises a rotating piece, a positioning piece, a reference piece and a supporting piece;

the rotating piece comprises a circular ring fixing plate, an inner sleeve which is extended backwards is fixed at the annular position of the rear end of the circular ring fixing plate, a first upper boss which is extended backwards is fixed at the top of the rear end of the circular ring fixing plate, a first lower boss which is extended backwards is fixed at the bottom of the rear end of the circular ring fixing plate, and a mounting gap is reserved between the bottom end of the first upper boss and the bottom end of the first lower boss and the outer surface of the inner sleeve; eight bottom plate mounting threaded holes are formed in the circular ring fixing plate and uniformly distributed around the circular ring fixing plate; four circular arc strip-shaped holes are formed in the circular ring fixing plate, the four circular arc strip-shaped holes are symmetrically distributed at the left side and the right side of the circular ring fixing plate, and the two circular arc strip-shaped holes at each side are symmetrically arranged up and down;

the positioning piece comprises a positioning plate with a circular through hole at the center, an outer sleeve extending forwards is fixed at the orifice of the front end of the positioning plate, a second upper boss extending forwards is fixed at the top of the front end of the positioning plate, a second lower boss extending forwards is fixed at the bottom of the front end of the positioning plate, and the bottom end of the second upper boss and the top end of the second lower boss are connected with the outer surface of the outer sleeve; four angle locking threaded holes are formed in the positioning plate, the four angle locking threaded holes are symmetrically arranged at the left side and the right side of the positioning plate in pairs, and the two angle locking threaded holes at each side are symmetrically arranged up and down;

the reference piece comprises a reference plate with a circular through hole at the center;

the support piece comprises a bottom plate, and counter sunk holes are formed in four corners of the bottom plate;

the rotating piece is connected with the positioning piece: the inner sleeve is inserted into the outer sleeve, the first upper boss is arranged opposite to the second upper boss, the first upper boss is positioned on the left side, the second upper boss is positioned on the right side, the second upper boss is connected with a first fine-grain screw rod in a threaded manner, and the end part of the first fine-grain screw rod passes through the second upper boss and then is propped against the first upper boss; the first lower boss is arranged opposite to the second lower boss, the first lower boss is positioned on the right side, the first lower boss is positioned on the left side, and a first tension spring is fixedly connected between the first lower boss and the second lower boss;

the locating piece is connected with the reference piece: a second tension spring is respectively connected and fixed between the left lower part, the right lower part and the right upper part of the positioning plate and the reference plate; the left lower part and the right upper part of the reference plate are respectively in threaded connection with a second fine grain screw rod, and the end part of the second fine grain screw rod penetrates through the reference plate and then is propped against the positioning plate; the right lower part of the reference plate is in threaded connection with a headless fastening bolt, and the end part of the headless fastening bolt passes through the reference plate and then is propped up on the positioning plate;

the reference piece is connected with the support piece: the reference plate is fixedly connected with the bottom plate vertically, and an operation gap is reserved between the bottom end of the positioning plate and the bottom plate.

2. The high precision three degree of freedom adjustment device for a digital micromirror device DMD according to claim 1, wherein: the rear end hole of the positioning plate is provided with a circular ring retainer ring, and the rear end of the inner sleeve penetrates through the outer sleeve and is detachably connected with the circular ring retainer ring through a bolt.

3. The high precision three degree of freedom adjustment device for a digital micromirror device DMD according to claim 1, wherein: punching a hole in the center of the first upper boss, and fixing a steel pad in the hole in an interference manner; punching a hole in the center of the second upper boss, fixing a copper pad in the hole in an interference manner, arranging a screw threaded hole in the center of the copper pad, connecting a first fine thread screw thread in the screw threaded hole, and jacking the end part of the first fine thread screw on the steel pad;

punching a hole in the center of the first lower boss, and forming a pin hole extending forwards from the rear end face of the first lower boss, wherein a pin penetrating through the center hole of the first lower boss is inserted into the pin hole; punching a hole in the center of the second lower boss, and arranging a pin hole extending backwards from the front end face of the second lower boss, wherein a pin penetrating through the center hole of the second lower boss is inserted into the pin hole; the two ends of the first tension spring are respectively connected and fixed on the pins in the first lower boss and the second lower boss.

4. The high precision three degree of freedom adjustment device for a digital micromirror device DMD according to claim 1, wherein: spring fixing holes are formed in the left lower part, the right lower part and the right upper part of the positioning plate and the reference plate, spring locking screws are installed in the spring fixing holes, and two ends of each second tension spring are respectively connected and fixed on the corresponding two spring locking screws.

5. The high precision three degree of freedom adjustment device for a digital micromirror device DMD according to claim 1, wherein: punching holes at the left lower part and the right upper part of the reference plate, fixing copper pads in the holes in an interference manner, arranging screw threaded holes in the centers of the copper pads, and connecting second fine thread screw threads in the screw threaded holes; the steel pad is arranged at the position of the locating plate corresponding to the end part of the second fine grain screw rod, and the end part of the second fine grain screw rod is arranged on the steel pad in a top mode.

6. The high precision three degree of freedom adjustment device for a digital micromirror device DMD according to claim 1, wherein: a threaded hole is formed in the right lower position of the reference plate, and the headless fastening bolt is in threaded connection with the threaded hole; the steel pad is arranged at the position of the locating plate corresponding to the end part of the headless fastening bolt, and the end part of the headless fastening bolt is propped against the steel pad.

7. The high precision three degree of freedom adjustment device for a digital micromirror device DMD according to claim 1, wherein: three positioning and fixing threaded holes are respectively formed in the bottom end of the reference plate and the bottom plate at corresponding positions, and the reference plate is detachably connected with the bottom plate through screws in the positioning and fixing threaded holes in a threaded mode.

8. The high precision three degree of freedom adjustment device for a digital micromirror device DMD according to claim 1, wherein: an optical support rod threaded hole is formed in the center of the bottom plate.

9. The high precision three degree of freedom adjustment device for a digital micromirror device DMD according to claim 1, wherein: the first fine grain screw rod and the second fine grain screw rod adopt electric screw rods.