CN113075842A

CN113075842A - Projection optical machine

Info

Publication number: CN113075842A
Application number: CN202011540911.5A
Authority: CN
Inventors: 朱青; 孙峰; 杨浩; 王源
Original assignee: Shenzhen Anhua Optoelectronics Technology Co Ltd
Current assignee: Shenzhen Anhua Photoelectric Technology Co ltd
Priority date: 2020-12-23
Filing date: 2020-12-23
Publication date: 2021-07-06
Anticipated expiration: 2040-12-23
Also published as: CN113075842B

Abstract

The invention discloses a projection optical machine, which comprises a shell, a gland component, a beam splitter prism, a DMD optical modulator and a projection lens, wherein the shell is provided with an upper mounting port communicated with an inner cavity of the shell; the beam splitting prism comprises a near side prism and a far side prism, wherein the near side prism comprises a near side critical surface, an emergent incident surface and a downward initial incident surface; the top of the far-side prism is provided with an emergent connecting surface; the near-side critical surface is glued with the far-side prism, and the emergent incident surface faces the DMD optical modulator; the near-side critical surface and the emergent connecting surface enclose to form a concave part with an upward opening; the gland component comprises a gland, an elastic pressing block and elastic glue, the gland is fixed to cover the upper mounting opening, the inner surface of the gland comprises a front inclined plane and a rear inclined plane, the front inclined plane extends into the concave portion, the front inclined plane is adjacent to the emergent connecting surface and is fixed with the emergent connecting surface through the elastic glue, and the elastic pressing block is pressed between the rear inclined plane and the near side critical surface. The beam splitter prism of the projection optical machine is easy to assemble and high in stability.

Description

Projection optical machine

Technical Field

The invention relates to the technical field of optical projection equipment, in particular to a projection optical machine.

Background

The core component of the micro projector is a projector, and the beam splitter prism and the DMD optical modulator are two major core components of the projector. The accuracy of the relative position between the beam splitting prism and the DMD light modulator has a considerable impact on the projection quality. In the production process, in order to modulate the projector, the common practice includes: firstly, taking a DMD optical modulator as a fixed reference to adjust the position of a beam splitting prism; in contrast to the first method, the position of the DMD light modulator is adjusted with the beam splitter prism as a fixed reference. In the latter approach, the splitting prism itself is required to be assembled highly stably.

A TIR (Total Internal Reflection) prism is a commonly used light splitting prism in a projection light machine, and comprises a near side prism and a far side prism which are formed by gluing, wherein the near side prism comprises a first end surface and a second end surface which are oppositely arranged, and an initial incident surface, a near side critical surface and an emergent incident surface which are positioned between the first end surface and the second end surface; the far-side prism comprises a third end surface and a fourth end surface which are oppositely arranged, and a far-side critical surface, an imaging emergent surface and an emergent connecting surface which are positioned between the third end surface and the fourth end surface; the emergent incident surface is arranged towards the DMD light modulator, and the imaging emergent surface is arranged towards the projection lens; the distal critical surface is glued to the proximal critical surface with an air gap formed between them.

In the related art, a housing of the optical projection machine is provided with a cavity with an upward opening, a beam splitter prism is arranged in the cavity of the housing along a direction perpendicular to an end face of a near side prism or a far side prism, the end face of the beam splitter prism faces upward or downward, and the orientation of other optical processing interfaces is parallel to the assembling direction of the beam splitter prism. In the structure, the limiting and fixing of the beam splitter prism are realized by adopting the extrusion assembly of a plurality of elastic pieces. However, if the prior art is still directly applied after the spatial position of the splitting prism is changed to make the end face of the near-side prism or the far-side prism face in the horizontal direction, on one hand, the splitting prism needs to be laterally installed, and on the other hand, the original extrusion assembly may be unbalanced under the action of extra inertia to cause the splitting prism to swing and further cause assembly errors with the DMD optical modulator.

Disclosure of Invention

In view of the above situation, a primary object of the present invention is to provide a projection optical system that can facilitate the installation of a beam splitter prism and ensure the stable assembly position of the beam splitter prism.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a projection optical machine comprises a shell, a gland component, a beam splitter prism, a DMD optical modulator and a projection lens,

the shell is provided with an inner cavity, an upper mounting port, a front mounting port and a rear mounting port, wherein the upper mounting port, the front mounting port and the rear mounting port are communicated with the inner cavity; the bottom wall surface of the inner cavity is provided with lower limiting surfaces at the positions adjacent to the left wall surface and the right wall surface, and the rear wall surface of the inner cavity comprises a rear limiting surface positioned at the periphery of the rear mounting opening;

the DMD optical modulator is arranged at the rear mounting port, and the projection lens is arranged at the front mounting port; the upper mounting opening is used for the beam splitter prism to pass through, and the beam splitter prism passes through the upper mounting opening and is mounted in the inner cavity of the shell;

the beam splitting prism comprises a near side prism and a far side prism which are mutually glued, and the near side prism comprises an initial incidence plane, a near side critical plane and an emergent incidence plane; the top of the far-side prism is provided with an emergent connecting surface inclined backwards from top to bottom;

the initial incident surface faces downwards and is attached to the lower limiting surface, the near side critical surface faces away from the DMD optical modulator and is glued with the far side prism, and the emergent incident surface faces towards the DMD optical modulator and is attached to the rear limiting surface;

the far-side prism and the near-side critical surface are glued and are arranged far away from the DMD optical modulator, the emergent connecting surface is adjacent to the near-side critical surface, the upper part of the near-side critical surface protrudes out of the emergent connecting surface, and the near-side critical surface and the emergent connecting surface enclose a concave part with an upward opening;

the gland component comprises a gland, an elastic pressing block and elastic glue, the gland is fixedly covered on the upper mounting opening, the inner surface of the gland comprises a front inclined plane and a rear inclined plane which extend into the concave part, and the front inclined plane is adjacent to the emergent connecting surface and is fixed with the emergent connecting surface through the elastic glue; the back inclined plane is opposite to the near side critical surface, and the elastic pressing block is pressed between the back inclined plane and the near side critical surface.

Preferably, the gland includes base plate and backplate, the base plate lid closes go up the installing port, the backplate is followed the inboard face downwardly extending of base plate forms and is stretched into the concave part, the back inclined plane is formed on the backplate.

Preferably, one side of the rear baffle plate facing the near side critical surface is provided with an installation groove, the rear inclined surface forms a bottom wall surface of the installation groove, and the elastic pressing block is embedded in the installation groove.

Preferably, the mounting groove is arranged downwards in an open manner.

Preferably, the mounting groove comprises side wall surfaces which are oppositely arranged in the left-right direction and a downward top wall surface, the joint of the top wall surface and the two side wall surfaces is provided with a position avoiding groove, and the elastic pressing block is attached to the top wall surface and the side wall surfaces.

Preferably, the elastic pressing block is fixed on the rear inclined plane in an adhering mode.

Preferably, the rear baffle is provided with two mounting grooves which are arranged at intervals in the left and right directions; the elastic pressing blocks are arranged in the mounting grooves in a one-to-one correspondence mode.

Preferably, the base plate is recessed downward from the top surface to form an outer groove, and the rear baffle plate forms a rear side portion of the outer groove.

Preferably, the inner wall surface of the outer groove is provided with a partition plate extending in the front-rear direction, and the position of the partition plate is between the corresponding positions of the two mounting grooves.

Preferably, the back slope is parallel to the proximal critical surface, and the cross-sectional size of the elastic pressing block in the normal direction of the proximal critical surface is constant.

Preferably, the gland includes base plate and preceding baffle, the base plate lid closes go up the installing port, preceding baffle is certainly the inboard face downwardly extending of base plate forms and stretches into the concave part, preceding baffle is from top to bottom to incline the setting backward, preceding inclined plane forms on the preceding baffle.

Preferably, the gland further comprises a rear baffle plate, the rear baffle plate extends downwards from the inner side surface of the base plate and extends into the concave part, and the rear inclined surface is formed on the rear baffle plate; the lower edge of the rear baffle is connected with the lower edge of the front baffle.

Preferably, the base plate is recessed downwards from the top surface to form the outer groove, the front baffle plate forms the front side part of the outer groove, and the rear baffle plate forms the rear side part of the outer groove.

Preferably, the front baffle is provided with a glue dispensing hole penetrating through the front inclined plane.

Preferably, the front baffle is provided with two dispensing holes, and the two dispensing holes are arranged at intervals along the left-right direction; one side of the rear baffle facing the near side critical surface is provided with two mounting grooves, the rear inclined surface forms a bottom wall surface of the mounting grooves, and the mounting grooves are arranged at intervals in the left-right direction; the elastic pressing blocks are provided with two elastic pressing blocks which are correspondingly embedded in the mounting grooves one by one.

The projection optical machine of the invention is characterized in that the upper mounting port is arranged on the shell, the beam splitter prism can be arranged in the cavity of the shell from top to bottom, and the concave part formed by enclosing the near-side critical surface of the beam splitter prism and the emergent connecting surface faces upwards. The back inclined plane is arranged to extend into the concave part, and the elastic pressing block is arranged between the back inclined plane and the near side critical plane, so that the upper end of the near side prism can abut against the back limiting plane, and the lower end of the near side prism can abut against the lower limiting plane, and the stability of the near side prism in the front-back direction is guaranteed. In combination with the above, a concave part is further arranged, wherein the front inclined plane extends into the upper end of the beam splitter prism, and elastic glue is arranged to bond and fix the front inclined plane and the outgoing connecting surface, so that when the upper end of the beam splitter prism tilts backwards and the lower end of the beam splitter prism dislocates backwards under the inertia effect of the beam splitter prism or the elastic force of the elastic pressing block is unbalanced, the pressure stress generated by the elastic glue can block or buffer the trend; and when the upper end of the beam splitter prism swings backwards and the lower end of the beam splitter prism turns forwards, the tensile stress generated by the elastic glue can reinforce the elastic pressing block, so that the trend can be hindered or buffered. And because the elastic glue and the elastic pressing block are arranged adjacently and are both positioned in the concave part at the upper end of the beam splitter prism, the force arms of the elastic glue and the elastic pressing block relative to the gravity center of the beam splitter prism are also close to each other, so that the elastic glue and the elastic pressing block can resist larger inertia force which possibly causes the dislocation of the beam splitter prism by mutual matching. Therefore, the projection optical machine of the invention has the advantages that on one hand, the beam splitter prism can keep the original assembly mode from top to bottom, so that the assembly is convenient, the space of the side surface of the shell is not occupied, and if the shell is integrally formed by injection molding or metal die-casting, the lateral die-drawing direction for manufacturing the shell can be reduced, thereby reducing the manufacturing cost; on the other hand, the assembly stability of the beam splitter prism is improved by matching the elastic pressing block with the elastic glue to fix the beam splitter prism, and the working reliability of the projection light machine is further ensured.

Other advantages of the present invention will be described in the detailed description, and those skilled in the art will understand the technical features and technical solutions presented in the description.

Drawings

A preferred embodiment of a projection light engine according to the present invention will be described below with reference to the accompanying drawings. In the figure:

FIG. 1 is a schematic perspective view of a preferred embodiment of a projection light machine according to the present invention, wherein the front side of the lens is a projection beam simulation;

FIG. 2 is a schematic top view of the projector of FIG. 1;

FIG. 3 is a schematic cross-sectional view taken along line III-III of FIG. 2;

FIG. 4 is a schematic view of a portion of the enlarged structure at A in FIG. 3;

FIG. 5 is a schematic side view of the projector of FIG. 1;

FIG. 6 is a schematic cross-sectional view taken along line VI-VI in FIG. 5;

FIG. 7 is a schematic view of a portion of the upper housing of FIG. 1;

FIG. 8 is an exploded view of the structure of FIG. 7;

FIG. 9 is a schematic structural view of the inside of the gland of FIG. 8;

FIG. 10 is a schematic view of a matching structure of the beam splitter prism and the elastic pressing block in FIG. 8;

fig. 11 is a schematic view of the structure of fig. 10 from another angle.

The reference numbers illustrate:

Detailed Description

Referring to fig. 1 to 6, in an embodiment, the optical projection engine provided by the present invention includes a housing 10, a cover assembly 20, a beam splitter prism 30, a DMD optical modulator 40 and a projection lens 50, wherein,

the housing 10 has an inner cavity 111, and an upper mounting port 112, a front mounting port 113, and a rear mounting port 114 communicating with the inner cavity 111; the bottom wall surface of the inner cavity 111 is provided with lower limiting surfaces 115 at the positions adjacent to the left wall surface and the right wall surface, and the rear wall surface of the inner cavity 111 comprises a rear limiting surface 116 positioned at the periphery of the rear mounting opening 114;

the DMD light modulator 40 is mounted at the rear mounting port 114, and the projection lens 50 is mounted at the front mounting port 113; the upper mounting port 112 is used for the beam splitter prism 30 to pass through, and the beam splitter prism 30 passes through the upper mounting port 112 and is mounted in the inner cavity 111 of the shell 10;

the beam splitter prism 30 includes a near side prism 31 and a far side prism 32 glued to each other, and the near side prism 31 includes an initial incident surface 311, a near side critical surface 312, and an exit incident surface 313; the top of the distal prism 32 has an exit connection surface 321 inclined backward from top to bottom;

the initial incident surface 311 faces downwards and is attached to the lower limiting surface 115, the near side critical surface 312 deviates from the DMD optical modulator 40 and is glued with the far side prism 32, and the emergent incident surface 313 faces towards the DMD optical modulator 40 and is attached to the rear limiting surface 116;

distal prism 32 is glued to proximal critical surface 312 and is disposed away from DMD light modulator 40, exit connection surface 321 is adjacent to proximal critical surface 312, the upper portion of proximal critical surface 312 protrudes from exit connection surface 321, and proximal critical surface 312 and exit connection surface 321 enclose to form upward-opening recess 33;

the gland assembly 20 comprises a gland 21, an elastic pressing block 22 and elastic glue (not shown), the gland 21 is fixedly covered on the upper mounting opening 112, the inner surface of the gland 21 comprises a front inclined surface 211 and a rear inclined surface 212 which extend into the concave part 33, and the front inclined surface 211 is adjacent to the emergent connection surface 321 and is fixed with the emergent connection surface 321 through the elastic glue; back slope 212 is disposed opposite to proximal critical surface 312, and spring pressing piece 22 is pressed between back slope 212 and proximal critical surface 312.

In this embodiment, the housing 10 is used to provide support for various components inside or outside the housing, and is a relatively complex component of the projection optical system. Specifically, the optical projection engine further includes an optical illumination system and a reflector 70, the optical illumination system includes a light source (61a, 61b, 61c, 61d) and a three-color modulation assembly, the housing 10 may be an integrated structure or a split structure, and the optical illumination system, the reflector 70 and the light splitting prism 30 may be laid along the same plane and installed on the housing 10, or may be installed on the housing 10 along more than one plane.

The DMD optical modulator 40 includes a DMD optical modulator 40 receiving light incident from a long side and a DMD optical modulator 40 receiving light incident from a short side, when the DMD optical modulator 40 receiving light incident from a long side is applied, that is, when a rectangular modulation area of the DMD optical modulator 40 uses the long side as an incident side of an illumination light beam, in order to reduce the height of the projection light machine, the housing 10 includes a first housing 11 and a second housing 12, the first housing 11 and the second housing 12 are spliced up and down, and the spliced portions communicate with respective internal cavities, so that the above-mentioned inner cavity 111, the upper mounting port 112, the front mounting port 113, the rear mounting port 114, the lower limiting surface 115, and the rear limiting surface 116 are formed in the first housing 11. The light source (61a, 61b, 61c, 61d) is arranged in the second shell 12, and the three-color modulation component is arranged in the inner cavity of the second shell 12 along the horizontal plane; the reflector 70 is installed in the inner cavity of the second housing 12 through the splicing opening of the second housing 12; the reflector 70 is used for reflecting the three-color light modulated by the three-color modulation assembly toward the inner cavity 111 of the first housing 11; the projection lens 50 is connected with the first shell 11, and the beam splitter prism 30 is installed in the internal cavity of the first shell 11; the initial incident surface 311 of the splitting prism 30 faces the second housing 12 to receive the light reflected by the reflecting mirror 70. In this way, the mirror 70 provided in the lower case 10 can reflect the illumination light beams of the three substantially horizontal colors upward, so that the illumination light beams processed by the dichroic prism 30 can directly enter through the long side of the modulation area of the DMD optical modulator 40, thereby ensuring that the DMD optical modulator 40 modulates a rectangular picture. Since the light beam received by the reflector 70 is substantially horizontal, the light sources (61a, 61b, 61c, 61d) and the three-color modulation assembly can still be arranged and mounted on the lower housing 10 along the horizontal plane, thereby reducing the height of the whole projector engine. In addition, because the lower splicing interface is utilized for installing the reflector 70, installation openings do not need to be arranged at other positions of the lower shell 10 for installing the reflector 70, and the shell 10 of the projector is more compact in structure.

Referring to fig. 3 and 6 again, the optical illumination system is used to generate parallel three-color light beams, which are not strictly parallel light beams, but are substantially parallel light beams allowing a certain angle error. The light sources of the optical illumination system are in particular LED light sources (61a, 61b, 61c, 61 d). In a variant embodiment of the optical illumination system, the light source may be an RGB laser, a mixed light laser, and a bulb type light source. The constitution of trichromatic modulation subassembly has multiple deformation according to prior art, if trichromatic modulation subassembly for example can arrange again and select for use dichroic mirror, colour wheel, fluorescence wheel and X prism etc. according to the difference of light source. Specifically, the trichromatic modulation assembly includes a trichromatic modulation assembly including a collimating lens group (621a, 621b, 621c), a dichroic mirror (622a, 622b), a relay lens 623, and a fly eye lens group 624.

The light emitted from the light sources (61a, 61b, 61c, 61d) of the optical illumination system is internally adjusted to output parallel light, and the reflecting mirror 70 changes the propagation direction of the parallel light. The optical illumination system further comprises a converging lens group (63a, 63b), the converging lens group (63a, 63b) for converting the light beam having a substantially circular cross section into a light beam having a substantially rectangular cross section. In this embodiment, the parallel light transmitted through the fly eye lens is processed by a lens on the lower side of the converging lens group (63a, 63b) and then irradiated onto the reflecting mirror 70, and is further transmitted to the free-form surface lens on the upper side of the converging lens group (63a, 63b) in a changed direction. The light converted by the condensing lens groups (63a, 63b) is transmitted to the initial incident surface 311 of the beam splitting prism 30. The cross section of the prism 30 is perpendicular to the initial incident surface 311, and when the prism 30 is TIR (Total Internal Reflection) and is formed by gluing two prisms, the cross section of the prism 30 is also perpendicular to the gluing surfaces of the two prisms.

The DMD light modulator 40 is configured to control the on/off of the light beam according to the received image signal, thereby implementing image display. The projection lens 50 is used to enlarge and transmit the image modulated by the DMD light modulator 40 onto the screen.

Referring to fig. 3, 4, 8, 10 and 11, the beam splitter prism 30 is used with a DMD digital micromirror to convert the illumination light path into a projection light path under the action of the DMD light modulator 40. Proximal prism 31 further includes first end surface 314 and second end surface 315 disposed oppositely, and initial incident surface 311, proximal critical surface 312, and exit incident surface 313 are located between first end surface 314 and second end surface 315. Distal prism 32 further includes a third end surface 322, a fourth end surface 323, and a distal critical surface 324 and an imaging exit surface 325, which are disposed oppositely, wherein distal critical surface 324, imaging exit surface 325, and exit connection surface 321 are located between third end surface 322 and fourth end surface 323, imaging exit surface 325 is disposed toward projection lens 50, distal critical surface 324 is glued to proximal critical surface 312, and an air gap is formed therebetween. In order to reduce the cost, the proximal prism 31 and the distal prism 32 are made of materials with the same refractive index, and the two prisms have the same shape, so that the molding dies can be shared.

Referring to fig. 7 and 8, the cover of the pressing cover 21 and the upper mounting opening 112 is preferably detachable, for example, a plurality of fixing holes are disposed around the upper mounting opening 112 at the edge of the upper mounting opening 112, and a through hole is correspondingly disposed at the edge of the pressing cover 21, and then the detachable cover of the pressing cover 21 can be realized by passing a bolt through the through hole and screwing the bolt into the fixing hole. In order to prevent moisture or dust from entering the inner cavity 111 of the housing 10, an annular seal may be further provided between the gland 21 and the edge portion of the upper mounting port 112.

In the projection optical machine of the present invention, the upper mounting opening 112 is opened on the housing 10, the beam splitter prism 30 can be similarly loaded into the cavity of the housing 10 from top to bottom, and the concave portion 33 enclosed by the near-side critical surface 312 and the exit connection surface 321 of the beam splitter prism 30 faces upward. By providing rear inclined surface 212 extending into recess 33 and providing resilient pressing piece 22 between rear inclined surface 212 and proximal critical surface 312, the upper end of proximal prism 31 can abut against rear limiting surface 116, and the lower end can abut against lower limiting surface 115, thereby ensuring the stability of proximal prism 31 in the front-rear direction. In combination with this, the front inclined plane 211 is further provided to extend into the concave part 33 at the upper end of the beam splitter prism 30, and the elastic glue is provided to bond and fix the front inclined plane 211 and the outgoing connecting surface 321, so that when the upper end of the beam splitter prism 30 tilts backwards and the lower end of the beam splitter prism 30 dislocates backwards under the inertia effect of the beam splitter prism 30 or the elastic force of the elastic pressing block 22 is unbalanced, the pressure stress generated by the elastic glue will block or buffer the trend; and when the upper end of the beam splitter prism 30 swings backwards and the lower end of the beam splitter prism 30 turns forwards, the tensile stress generated by the elastic glue can reinforce the elastic pressing block 22 so as to also hinder or buffer the tendency. And because the elastic glue and the elastic pressing block 22 are arranged adjacently and are both positioned in the concave part 33 at the upper end of the beam splitter prism 30, the force arms of the elastic glue relative to the gravity center of the beam splitter prism 30 are also close in size, so that the elastic glue and the elastic pressing block can resist larger inertial force which possibly causes the dislocation of the beam splitter prism 30 by matching. Therefore, according to the projection optical machine of the present invention, on one hand, the original assembly mode of the beam splitter prism 30 from top to bottom can be maintained, so that the assembly is convenient and the space of the side surface of the housing 10 is not occupied, and if the housing 10 is integrally injection molded or metal die-cast molded, the lateral die-drawing direction for manufacturing the housing 10 can be reduced, thereby reducing the manufacturing cost; on the other hand, the elastic pressing block 22 and the elastic glue are matched to fix the beam splitter prism 30, so that the assembling stability of the beam splitter prism 30 is improved, and the working reliability of the projection light machine is further ensured.

Further, referring to fig. 1 to 4 and fig. 7 to 9, in an embodiment, the pressing cover 21 includes a base plate 213 and a rear baffle 214, the base plate 213 covers the upper mounting opening 112, the rear baffle 214 extends downward from an inner side surface of the base plate 213 and extends into the concave portion 33, and the rear inclined surface 212 is formed on the rear baffle 214.

In this embodiment, the rear inclined surface 212 is formed on the rear baffle 214, which is advantageous to realize a light weight design of the gland 21 itself on the premise of ensuring the supporting strength of the rear inclined surface 212, compared with the case where it is formed on a solid block-shaped structure.

Further, the side of the back plate 214 facing the near-side critical surface 312 is opened with a mounting groove 215, the back inclined surface 212 forms a bottom wall surface of the mounting groove 215, and the elastic pressing piece 22 is fitted in the mounting groove 215.

In this embodiment, the reference direction of the bottom wall surface of the mounting groove 215 is the opening direction of the mounting groove 215, and the mounting groove 215 can help to position the elastic pressing piece 22, so that the elastic pressing piece 22 can be quickly mounted to a correct position. In addition, the deformation of the elastic pressing piece 22 is restricted within the designed range by the supporting action of the inner wall surface of the mounting groove 215, thereby ensuring the accuracy of the elastic force. Preferably, the mounting groove 215 is open downward for facilitating the drawing and increasing the mounting direction of the elastic pressing piece 22.

Further, the mounting groove 215 includes side wall surfaces 215a disposed opposite to each other in the left-right direction, and a top wall surface 215b facing downward, a clearance groove 215c is disposed at a connection portion between the top wall surface 215b and the side wall surfaces 215a, and the elastic pressing block 22 is attached to the top wall surface 215b and the side wall surfaces 215 a.

In this embodiment, when the elastic pressing block 22 is attached to the top wall surface 215b and the side wall surface 215a, both the avoiding groove 215c and the downward opening of the mounting groove 215 can provide a avoiding space for the lateral deformation of the elastic pressing block 22. Preferably, in order to facilitate assembly and prevent displacement of the spring pressing piece 22, the spring pressing piece 22 is fixed on the rear inclined surface 212 in an adhering manner, so that the spring pressing piece 22 can be installed together with the pressing cover 21 and the connection position of the spring pressing piece 22 is ensured to be unchanged.

Further, two mounting grooves 215 are formed in the rear baffle plate 214, and the two mounting grooves 215 are arranged at intervals in the left-right direction; two elastic pressing blocks 22 are arranged in the mounting groove 215 in a one-to-one correspondence manner.

In this embodiment, the two elastic pressing blocks 22 are separately installed on the back plate 214, so that the distribution of the elastic force is more balanced on the premise of ensuring that the elastic force is sufficiently large, and the stability of the beam splitter prism 30 along the vertical plane perpendicular to the front-back direction is also increased, that is, the possibility that the beam splitter prism 30 rotates around the axis parallel to the front-back direction is reduced.

Further, the base plate 213 is recessed downward from the top surface to form an outer groove 216, and the back plate 214 constitutes a rear side portion of the outer groove 216.

In this embodiment, the substrate 213 is recessed downward from the top surface to form the back plate 214, so that the back plate 214 has sufficient supporting structure, that is, the supporting strength of the back plate 214 is enhanced, thereby ensuring that the back plate 214 can reliably press the elastic pressing block 22.

Further, the inner wall surface of the outer groove 216 is provided with a partition 217 extending in the front-rear direction, and the position of the partition 217 is between the positions corresponding to the two mounting grooves 215.

In this embodiment, the partition 217 may further enhance the deformation resistance of the wall body of the outer groove 216, so as to ensure the accuracy of the elastic force of the elastic pressing block 22.

Further, trailing ramp surface 212 is parallel to proximal critical surface 312, and the cross-sectional size of spring compact 22 normal to proximal critical surface 312 is constant.

In this embodiment, rear slope 212 for transmitting the initial pressure to elastic pressing block 22 is disposed parallel to the target elastic force acting surface of elastic pressing block 22, so that when the distance between rear slope 212 and near-side critical surface 312 is gradually reduced, the size of the cross section of elastic pressing block 22 in the normal direction of near-side critical surface 312 is constant, and thus the change of the generated elastic force is close to linear change, thereby facilitating the design of an elastic force with a proper size for elastic pressing block 22.

Further, the pressing cover 21 includes a base plate 213 and a front baffle 218, the base plate 213 covers the upper mounting opening 112, the front baffle 218 extends downward from the inner side surface of the base plate 213 and extends into the concave portion 33, the front baffle 218 is disposed to be inclined backward from the top to the bottom, and the front inclined surface 211 is formed on the front baffle 218.

In the present embodiment, as well as the previous embodiment in which the rear baffle 214 is provided, by providing the thin-walled structure of the front baffle 218 to form the front slope 211, it is advantageous to realize a light-weight design of the gland 21 itself while ensuring the bending strength of the front slope 211, compared to forming the front slope 211 on a solid block-shaped structure.

Further, the gland 21 further includes a back plate 214, the back plate 214 is formed to extend downward from the inner side surface of the base plate 213 and to protrude into the concave portion 33, and a back slope 212 is formed on the back plate 214; the lower edge of the tailgate 214 is connected to the lower edge of the front tailgate 218.

In this embodiment, the front and

rear baffles

218 and 214 can be connected to each other to support each other and to make the gland 21 more compact in structure.

Further, the base plate 213 is recessed downward from the top surface to form an outer groove 216, the front bezel 218 forms a front side of the outer groove 216, and the rear bezel 214 forms a rear side of the outer groove 216.

In this embodiment, the substrate 213 is recessed inward from the top surface to form the front and

rear baffles

218 and 214, so as to increase the supporting strength of the front and

rear baffles

218 and 214,

further, the front baffle 218 is provided with a dispensing hole 218a penetrating the front inclined plane 211. In this embodiment, by providing the dispensing hole 218a, it is possible to apply the elastic glue from the outside of the gland 21 after the assembly of the gland 21 is completed. Since the elastic glue is generally formed by curing a liquid material, the manner of applying the elastic glue may be to drop the liquid glue into the glue dispensing hole 218a, and then the glue fills between the front inclined surface 211 and the exit connecting surface 321, and after the glue is cured, the elastic glue for adhering and fixing the front inclined surface 211 and the exit connecting surface 321 is formed.

Further, two dispensing holes 218a are provided in the front baffle 218, and the two dispensing holes 218a are arranged at intervals in the left-right direction; one side of the back baffle plate 214 facing the near side critical surface 312 is provided with two mounting grooves 215, the back inclined surface 212 forms a bottom wall surface of the mounting grooves 215, and the mounting grooves 215 are arranged at intervals in the left-right direction; two elastic pressing blocks 22 are correspondingly embedded in the mounting grooves 215 one by one.

In this embodiment, the two elastic pressing blocks 22 are provided, so that the elastic force distribution of the elastic pressing blocks 22 is more balanced and the fixing of the beam splitter prism 30 is more stable. Two glue dispensing holes 218a are also provided to facilitate the application of the elastic glue corresponding to the two elastic pressing blocks 22, so that the elastic glue can be better matched with the elastic pressing blocks 22.

It will be appreciated by those skilled in the art that the above-described preferred embodiments may be freely combined, superimposed, without conflict.

It will be understood that the embodiments described above are illustrative only and not restrictive, and that various obvious and equivalent modifications and substitutions for details described herein may be made by those skilled in the art without departing from the basic principles of the invention.

Claims

1. A projection optical machine comprises a shell (10), a gland component (20), a beam splitter prism (30), a DMD optical modulator (40) and a projection lens (50), and is characterized in that,

the shell (10) is provided with an inner cavity (111), and an upper mounting port (112), a front mounting port (113) and a rear mounting port (114) which are communicated with the inner cavity (111); the bottom wall surface of the inner cavity (111) is provided with lower limiting surfaces (115) at positions adjacent to the left wall surface and the right wall surface, and the rear wall surface of the inner cavity (111) comprises a rear limiting surface (116) positioned at the periphery of the rear mounting opening (114);

the DMD light modulator (40) is arranged at the rear mounting port (114), and the projection lens (50) is arranged at the front mounting port (113); the upper mounting opening (112) is used for the light splitting prism (30) to pass through, and the light splitting prism (30) is mounted in the inner cavity (111) of the shell (10) through the upper mounting opening (112);

the beam splitting prism (30) comprises a near side prism (31) and a far side prism (32) which are mutually glued, and the near side prism (31) comprises an initial incidence plane (311), a near side critical plane (312) and an emergent incidence plane (313); the top of the far-side prism (32) is provided with an emergent connecting surface (321) inclining backwards from top to bottom;

the initial incident surface (311) faces downwards and is attached to the lower limiting surface (115), the near-side critical surface (312) faces away from the DMD light modulator (40) and is glued with the far-side prism (32), and the emergent incident surface (313) faces towards the DMD light modulator (40) and is attached to the rear limiting surface (116);

the far-side prism (32) is glued with the near-side critical surface (312) and is arranged far away from the DMD optical modulator (40), the emergent connection surface (321) is adjacent to the near-side critical surface (312), the upper part of the near-side critical surface (312) protrudes out of the emergent connection surface (321), and the near-side critical surface (312) and the emergent connection surface (321) enclose to form a concave part (33) with an upward opening;

the gland assembly (20) comprises a gland (21), an elastic pressing block (22) and elastic glue, the gland (21) is fixedly covered on the upper mounting opening (112), the inner surface of the gland (21) comprises a front inclined surface (211) and a rear inclined surface (212) which extend into the concave part (33), and the front inclined surface (211) is adjacent to the emergent connecting surface (321) and is fixed with the emergent connecting surface (321) through the elastic glue; the rear inclined surface (212) is arranged opposite to the near side critical surface (312), and the elastic pressing block (22) is pressed between the rear inclined surface (212) and the near side critical surface (312).

2. The light engine of claim 1, wherein the cover (21) comprises a base plate (213) and a back plate (214), the base plate (213) covers the upper mounting opening (112), the back plate (214) extends downward from the inner side surface of the base plate (213) and extends into the recess (33), and the back slope (212) is formed on the back plate (214).

3. The optical projection engine according to claim 2, wherein a mounting groove (215) is formed in a side of the rear baffle (214) facing the near-side critical surface (312), the rear inclined surface (212) forms a bottom wall surface of the mounting groove (215), and the elastic pressing block (22) is embedded in the mounting groove (215).

4. The optical projection engine of claim 3, wherein the mounting slot (215) is open downward.

5. The projection light engine according to claim 4, wherein the mounting groove (215) includes side wall surfaces (215a) disposed opposite to each other in the left-right direction, and a top wall surface (215b) facing downward, a position avoiding groove (215c) is disposed at a connection between the top wall surface (215b) and the two side wall surfaces (215a), and the elastic pressing block (22) is attached to the top wall surface (215b) and the side wall surfaces (215 a).

6. The projection light engine of claim 5, characterized in that the spring pressure block (22) is fixed on the back slope (212) by bonding.

7. The light engine of any of the claims 3-6, characterized in that the back plate (214) is provided with two mounting slots (215), and the two mounting slots (215) are arranged at intervals in the left-right direction; the two elastic pressing blocks (22) are arranged in the mounting groove (215) in a one-to-one correspondence mode.

8. The light engine of claim 7, wherein the base plate (213) is recessed downward from the top surface to form an outer recess (216), and the back plate (214) forms a back side of the outer recess (216).

9. The optical projection engine according to claim 8, wherein the inner wall surface of the outer groove (216) is provided with a partition plate (217) extending in the front-back direction, and the position of the partition plate (217) is between the corresponding positions of the two mounting grooves (215).

10. The light engine according to any of the claims 1 to 6, characterized in that the back slope (212) is parallel to the near-side critical plane (312), and the cross-sectional size of the spring press block (22) in the direction normal to the near-side critical plane (312) is constant.

11. The projection light engine of claim 1, wherein the cover (21) comprises a base plate (213) and a front baffle (218), the base plate (213) covers the upper mounting opening (112), the front baffle (218) extends downward from the inner side surface of the base plate (213) and extends into the concave portion (33), the front baffle (218) is arranged to be inclined backward from top to bottom, and the front inclined surface (211) is formed on the front baffle (218).

12. The light engine of claim 11, wherein the cover (21) further comprises a back plate (214), the back plate (214) extends downward from the inner side of the base plate (213) and extends into the recess (33), the back slope (212) is formed on the back plate (214); the lower edge of the tailgate (214) is connected to the lower edge of the front tailgate (218).

13. The light engine of claim 12, wherein the substrate (213) is recessed downward from a top surface to form the outer groove (216), the front bezel (218) forms a front side of the outer groove (216), and the back bezel (214) forms a back side of the outer groove (216).

14. The optical engine of claim 13, wherein the front bezel (218) has dispensing holes (218a) formed therethrough the front bevel (211).

15. The light engine of claim 14,

two dispensing holes (218a) are formed in the front baffle (218), and the two dispensing holes (218a) are arranged at intervals in the left-right direction; one side of the rear baffle plate (214) facing the near side critical surface (312) is provided with a mounting groove (215), the rear inclined surface (212) forms the bottom wall surface of the mounting groove (215), and the two mounting grooves (215) are arranged at intervals in the left-right direction; the two elastic pressing blocks (22) are correspondingly embedded in the mounting grooves (215).