CN220401828U - Polarization conversion assembly and projection optical machine - Google Patents

Abstract

The application discloses a polarization conversion assembly and a projection optical machine, wherein the polarization conversion assembly comprises a first light homogenizing lens, a polarization converter and a second light homogenizing lens; the first light homogenizing lens comprises a first sub-lens array positioned at the light emitting side of the first light homogenizing lens, and the first sub-lens array is used for homogenizing the light received by the first light homogenizing lens and emitting a first light beam; the polarization converter is positioned at the light emitting side of the first light homogenizing lens and is used for converting the first light beam into a first polarized light beam and a second polarized light beam with a first polarization direction; the second light homogenizing lens is positioned on the light emitting side of the polarization converter, and comprises a second sub-lens array positioned on the light emitting side of the second light homogenizing lens, and the second sub-lens array is used for homogenizing the first polarized light beam and the second polarized light beam. The light energy of the light generated by the light source can be fully utilized, the light efficiency can be effectively improved, and the brightness of the picture projected by the projection optical machine can be further improved.

Description

Polarization conversion assembly and projection optical machine

Technical Field

The present disclosure relates to the field of optical technologies, and particularly to a polarization conversion assembly and a projection optical engine.

Background

In a liquid crystal projector adopting an LED as a light source, since light emitted by the LED is natural light (i.e., unpolarized light), a reflective polarizer is generally used in the projector to polarize the natural light emitted by the LED, so that a first polarized light beam in a first polarization direction required by a liquid crystal light valve of the projector can pass through the reflective polarizer, and a second polarized light beam in a second polarization direction not required by the liquid crystal light valve can be reflected by the reflective polarizer, thereby reducing heat generated by the liquid crystal light valve absorbing the second polarized light beam.

However, since the reflective polarizer reflects the second polarized light beam, the light energy of the second polarized light beam is wasted, which results in lower brightness of the image projected by the projection light machine.

Disclosure of Invention

The application provides a polarization conversion assembly and projection ray apparatus for the light energy of the light that the light source produced can obtain make full use of, can effectively promote the light efficiency, thereby can project the luminance of the picture that the ray apparatus projected.

In a first aspect, the present application provides a polarization conversion assembly comprising: the first light homogenizing lens comprises a first sub-lens array positioned at the light emergent side of the first light homogenizing lens, and the first sub-lens array is used for homogenizing the light received by the first light homogenizing lens and emergent a first light beam; the polarization converter is positioned at the light emitting side of the first light homogenizing lens and is used for converting the first light beam into a first polarized light beam and a second polarized light beam with a first polarization direction; the second light homogenizing lens is positioned on the light emitting side of the polarization converter and comprises a second sub-lens array positioned on the light emitting side of the second light homogenizing lens, and the second sub-lens array is used for homogenizing the first polarized light beam and the second polarized light beam.

In some embodiments of the present application, the polarization converter includes: the prism group comprises a plurality of first rhombic prisms and a plurality of second rhombic prisms, the first rhombic prisms and the second rhombic prisms are alternately arranged, the first rhombic prisms are provided with inclined first splicing surfaces, the second rhombic prisms are provided with inclined second splicing surfaces, and the second splicing surfaces are spliced with the first splicing surfaces; the polarization beam splitting film is arranged between the first splicing surface and the second splicing surface, the polarization converter is used for converting the first light beam into the first polarized light beam and a third polarized light beam with a second polarization direction, the first polarized light beam is emitted from the light emitting surface of the first rhombic prism, the third polarized light beam is emitted from the light emitting surface of the second rhombic prism, and the second polarization direction is orthogonal to the first polarization direction; the half wave plate is positioned on the light emitting surface of the second rhombic prism, is arranged in one-to-one correspondence with the second rhombic prism and is used for converting the third polarized light beam into the second polarized light beam; or the half wave plate is positioned on the light-emitting surface of the first rhombic prism and is arranged in one-to-one correspondence with the first rhombic prism, the half wave plate is used for converting the first polarized light beam into a fourth polarized light beam with the second polarized direction, and the third polarized light beam is emitted from the light-emitting surface of the second rhombic prism to form the second polarized light beam. So that an incident light beam of the incident polarization converter can be converted into two linearly polarized light beams having the same polarization direction.

In some embodiments of the present application, the first sub-lens array includes a plurality of first sub-lenses distributed in an array, and a center of one of the first sub-lenses is opposite to a center position of the light incident surface of one of the second rhombic prisms. Most of light rays in the first light beam can enter the second rhombic prism from the light incident surface of the second rhombic prism, so that the first light beam is prevented from being directly emitted from the light emergent surface of the first rhombic prism after entering the first rhombic prism from the light incident surface of the first rhombic prism.

In some embodiments of the present application, the second sub-lens array includes a plurality of second sub-lenses distributed in an array, one of the first rhombic prisms being opposite to one of the second sub-lenses, one of the second rhombic prisms being opposite to one of the second sub-lenses. The first polarized light beam and the second polarized light beam may be both homogenized.

In some embodiments of the present application, the first sub-lens array includes a plurality of first sub-lenses distributed in an array, and the second sub-lens array includes a plurality of second sub-lenses distributed in an array, and the number of the second sub-lenses is twice the number of the first sub-lenses. On the basis of ensuring that a sufficient number of second sub-lenses process each beam of the first polarized light beam and each beam of the second polarized light beam, the number of the second sub-lenses is reduced, and the production cost of the second dodging lens is reduced.

In some embodiments of the present application, a plurality of the first sub-lenses are connected in sequence, and a plurality of the second sub-lenses are connected in sequence. Light beams which are not subjected to uniform light are prevented from being emitted from gaps between two adjacent first sub-lenses and gaps between two adjacent second sub-lenses.

In some embodiments of the present application, a projection of the half-wave plate on the prism set coincides with the light-emitting surface of the second rhombic prism. So that the third polarized light beams emitted from the light emitting surface of the second rhombic prism can be converted into the second polarized light beams through the half-wave plate.

In a second aspect, the application further provides a projection light machine, including a light source, an imaging module and a projection lens, the imaging module is located on the light emitting side of the light source, the projection lens is located on the light emitting side of the imaging module, and the imaging module includes the polarization conversion assembly according to any one of the above embodiments.

In some embodiments of the present application, the imaging module further comprises: the curved surface condensing lens is positioned on the light emitting side of the light source and is used for collimating the light emitted by the light source; the first reflector is positioned on the light emitting side of the curved condensing lens and on the light entering side of the first light homogenizing lens, and is used for reflecting the light collimated by the curved condensing lens to the first light homogenizing lens; the liquid crystal light valve is positioned at the light emitting side of the second light homogenizing lens and is used for transmitting a first polarized light beam and a second polarized light beam with a first polarization direction; the second reflector is positioned on the light emitting side of the liquid crystal light valve and is used for reflecting the light emitted by the liquid crystal light valve to the projection lens.

In some embodiments of the present application, the imaging module further comprises: the first Fresnel lens is positioned between the first reflector and the first dodging lens and is used for collimating the light reflected by the first reflector; the second Fresnel lens is positioned between the second dodging lens and the second reflecting mirror and is used for collimating the light emitted by the second dodging lens.

The beneficial effects of this application are: when the polarization conversion assembly is applied to the projection light machine, light generated by a light source in the projection light machine is emitted into the first light homogenizing lens from the light incident side of the first light homogenizing lens and is emitted out from the light emergent side of the second light homogenizing lens, and the light incident into the polarization conversion assembly can be completely converted into linearly polarized light in a single polarization direction required by the liquid crystal light valve through the polarization converter, so that the light energy of the light generated by the light source can be fully utilized, the light efficiency can be effectively improved, and the brightness of a picture projected by the projection light machine can be further improved; in addition, through all setting up the dodging lens at the income light side and the light-emitting side of polarization converter, utilize first dodging lens can carry out dodging processing before light incident to polarization converter, utilize the second dodging lens can carry out the dodging processing to the first polarized light beam and the second polarized light beam that go out the polarization converter, can promote the illuminance homogeneity of the light that goes out from polarization conversion component to make the luminance of the picture that projection ray apparatus projected more even.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the related art, the drawings that are required to be used in the embodiments or the related technical descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to the drawings without inventive effort for those skilled in the art.

FIG. 1 is a schematic diagram of a polarization conversion assembly according to an embodiment of the present disclosure;

FIG. 2 is a schematic diagram illustrating an arrangement of a first rhombic prism and a second rhombic prism according to an embodiment of the present disclosure;

FIG. 3 is a schematic view of a polarization conversion assembly according to another embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of a projection light machine according to an embodiment of the present application.

Reference numerals:

10. a polarization conversion assembly; 20. a first dodging lens; 21. a first sub-lens array; 211. a first sub-lens; 30. a polarization converter; 31. a prism group; 311. a first rhombic prism; 311a, a first splicing surface; 312. a second rhombic prism; 312a, a second splicing surface; 32. a half wave plate; 40. a second dodging lens; 41. a second sub-lens array; 411. a second sub-lens; 50. an imaging module; 51. a curved condensing lens; 52. a first mirror; 53. a liquid crystal light valve; 54. a second mirror; 55. a first fresnel lens; 56. a second fresnel lens; 60. a light source, 70, a projection lens; 71. a spherical lens.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.

The application provides a polarization conversion component and projection ray apparatus to in solving the correlation technique, can adopt reflective polarizer to carry out the polarization with the natural light that LED sent in the projection ray apparatus generally, make the first polarized light beam of the first polarization direction that the liquid crystal light valve of projection ray apparatus needs can see through reflective polarizer, and the second polarized light beam of the second polarization direction that liquid crystal light valve does not need can be reflected by reflective polarizer, because reflective polarizer will second polarized light beam reflection back, the light energy of second polarized light beam is extravagant, can lead to the lower problem of the luminance of the picture of projection ray apparatus projection.

In a first aspect, the present application provides a polarization conversion assembly 10, as shown in fig. 1, the polarization conversion assembly 10 includes a first dodging lens 20, a polarization converter 30, and a second dodging lens 40. Taking the viewing angle shown in fig. 1 as an example, the light incident side of the first light homogenizing lens 20 is the lower side of the first light homogenizing lens 20, and the light emergent side of the first light homogenizing lens 20 is the upper side of the first light homogenizing lens 20; the light incident side of the polarization converter 30 is the lower side of the polarization converter 30, and the light emergent side of the polarization converter 30 is the upper side of the polarization converter 30; the light incident side of the second light homogenizing lens 40 is the lower side of the second light homogenizing lens 40, and the light emergent side of the second light homogenizing lens 40 is the upper side of the second light homogenizing lens 40.

The first dodging lens 20 includes a first sub-lens array 21 located at the light emitting side, and the first sub-lens array 21 is configured to dodging the light received by the first dodging lens 20 and emit a first light beam K1; it can be understood that the first dodging lens 20 may be made of an optical transparent material such as glass or resin, the first sub-lens array 21 is formed by a plurality of sub-lenses distributed in an array, after light enters the first dodging lens 20 from the light incident side of the first dodging lens 20, the incident light is split and converged by the first sub-lens array 21 to form a plurality of light beams (i.e. the first light beam K1), and each light beam is emitted from a corresponding sub-lens in the first sub-lens array 21, so as to achieve the purpose of dodging.

The polarization converter 30 is located on the light emitting side of the first dodging lens 20, and the polarization converter 30 is configured to convert the first light beam K1 into a first polarized light beam O1 and a second polarized light beam O2 having a first polarization direction; it will be appreciated that the polarization direction of the first polarized light beam O1 is the same as that of the second polarized light beam O2, and the first polarization direction may be S-direction or P-direction, that is, the first polarized light beam O1 and the second polarized light beam O2 are both S-polarized light or P-polarized light, and the specific direction of the first polarization direction may be determined according to the direction of the linearly polarized light required by the liquid crystal light valve 53 of the projection light machine, and the polarization converter 30 may divide and convert the incident first light beam K1 (the first light beam K1 is natural light) into two sub-light beams (that is, the first polarized light beam O1 and the second polarized light beam O2), and convert all the two sub-light beams into S-polarized light or P-polarized light.

The second light homogenizing lens 40 is located at the light emitting side of the polarization converter 30, and the second light homogenizing lens 40 includes a second sub-lens array 41 located at the light emitting side thereof, and the second sub-lens array 41 is used for performing light homogenizing treatment on the first polarized light beam O1 and the second polarized light beam O2. It can be understood that the second light homogenizing lens 40 may be made of an optical transparent material such as glass or resin, and the second sub-lens array 41 is also formed by a plurality of sub-lenses distributed in an array, and after the first polarized light beam O1 and the second polarized light beam O2 enter the second light homogenizing lens 40 from the light entrance side of the second light homogenizing lens 40, the first polarized light beam O1 and the second polarized light beam O2 are subjected to light homogenizing treatment respectively by the second sub-lens array 41, so that the brightness of the first polarized light beam O1 and the second polarized light beam O2 exiting the second sub-lens array 41 is more uniform.

It should be noted that, in the present application, when the polarization conversion assembly 10 is applied to a projection light machine, when light generated by a light source 60 (as shown in fig. 4) in the projection light machine is directed to the polarization conversion assembly 10, light enters the first light homogenizing lens 20 from the light entrance side of the first light homogenizing lens 20 and exits from the light exit side of the second light homogenizing lens 40, the light entering the polarization conversion assembly 10 can be completely converted into linear polarized light with a single polarization direction required by the liquid crystal light valve 53 through the polarization converter 30, so that light energy of the light generated by the light source 60 can be fully utilized, and light efficiency can be effectively improved, so that brightness of a picture projected by the projection light machine can be projected; in addition, by providing the light homogenizing lenses on both the light incident side and the light emitting side of the polarization converter 30, the first light homogenizing lens 20 can perform light homogenizing treatment before the light is incident on the polarization converter 30, and the second light homogenizing lens 40 can perform light homogenizing treatment on the first polarized light beam O1 and the second polarized light beam O2 emitted from the polarization converter 30, so that illuminance uniformity of the light emitted from the polarization conversion assembly 10 can be improved, and brightness of a picture projected by the projection optical machine can be more uniform.

With continued reference to fig. 1 and 2, in some embodiments of the present application, polarization converter 30 includes a prism assembly 31, a polarizing beam splitting film, and a half wave plate 32.

The prism group 31 includes a plurality of first rhombic prisms 311 and a plurality of second rhombic prisms 312, the first rhombic prisms 311 and the second rhombic prisms 312 are alternately arranged, the first rhombic prisms 311 have inclined first splicing surfaces 311a, the second rhombic prisms 312 have inclined second splicing surfaces 312a, and the second splicing surfaces 312a are spliced with the first splicing surfaces 311 a; it should be noted that, taking the view angle shown in fig. 1 as an example, the first rhombic prisms 311 and the second rhombic prisms 312 are alternately arranged along the transverse direction, the lateral sides of the first rhombic prisms 311 along the transverse direction are the first splicing surfaces 311a, the lateral sides of the second rhombic prisms 312 along the transverse direction are the second splicing surfaces 312a, the first splicing surfaces 311a and the second splicing surfaces 312a may be spliced in a gluing manner, the angles formed by the first splicing surfaces 311a and the light incident surfaces and the light emergent surfaces of the first rhombic prisms 311 may be 45 degrees, the angles formed by the second splicing surfaces 312a and the light incident surfaces and the light emergent surfaces of the second rhombic prisms 312 may be 45 degrees, and the angles formed by the first splicing surfaces 311a and the light incident surfaces and the light emergent surfaces of the first rhombic prisms 311 may be 30 degrees, 60 degrees, 75 degrees or other angles, and the angles formed by the second splicing surfaces 312a and the light incident surfaces and the light emergent surfaces of the second rhombic prisms 312 may be 30 degrees, 60 degrees, 75 degrees or other angles according to practical needs.

The polarization splitting film is disposed between the first splicing surface 311a and the second splicing surface 312a, the polarization converter 30 is configured to convert the first light beam K1 into a first polarized light beam O1 and a third polarized light beam O3 having a second polarization direction, the first polarized light beam O1 is emitted from the light emitting surface of the first rhombic prism 311, the second polarized light beam O2 is emitted from the light emitting surface of the second rhombic prism 312, and the second polarization direction is orthogonal to the first polarization direction; it can be understood that a polarizing beam splitting film is disposed between any first splicing surface 311a and the adjacent second splicing surface 312a, the shape of the polarizing beam splitting film is adapted to the shape of the first splicing surface 311a and the shape of the second splicing surface 312a, the polarizing beam splitting film is an optical film for generating polarized light, the polarizing beam splitting film can perform polarization treatment on the first light beam K1 to split the first light beam K1 into a first polarized light beam O1 with a first polarization direction and a third polarized light beam O3 with a second polarization direction, and the polarizing beam splitting film can transmit the first polarized light beam O1 with the first polarization direction and can reflect the third polarized light beam O3 with the second polarization direction, and the specific working principle of the polarizing beam splitting film is disclosed in the related art earlier, which is not described in detail in the present application; when the first polarization direction is the S direction, the second polarization direction is the P direction; when the first polarization direction is the P-direction, the second polarization direction is the S-direction.

As shown in fig. 1, in an embodiment of the present application, the half-wave plate 32 is located on the light exit surface of the second rhombic prism 312 and is disposed in one-to-one correspondence with the second rhombic prism 312, and the half-wave plate 32 is used for converting the third polarized light beam O3 into the second polarized light beam O2. It should be noted that, the side surface of the first rhombic prism 311 on the light incident side is the light incident surface of the first rhombic prism 311, the side surface of the first rhombic prism 311 on the light emergent side is the light emergent surface of the first rhombic prism 311, the side surface of the second rhombic prism 312 on the light incident side is the light incident surface of the second rhombic prism 312, and the side surface of the second rhombic prism 312 on the light emergent side is the light emergent surface of the second rhombic prism 312; the polarization direction of the light can be rotated by 90 degrees by the half-wave plate 32, and the specific working principle of the half-wave plate 32 is already disclosed in the related art, which is not described in detail in this application.

It can be understood that, taking the example shown in fig. 1 as an example, after the first light beam K1 enters the second rhombic prism 312, the first polarized light beam O1 and the third polarized light beam O3 are formed under the action of the right polarized light splitting film, the first polarized light beam O1 is directly emitted from the light emitting surface of the first rhombic prism 311, the third polarized light beam O3 is reflected by the polarized light splitting film onto the left polarized light splitting film, and is reflected again by the left polarized light splitting film onto the light emitting surface of the second rhombic prism 312, and the polarized direction of the third polarized light beam O3 emitted from the light emitting surface of the second rhombic prism 312 is rotated by 90 degrees through the half wave plate 32, so as to form the second polarized light beam O2 with the first polarized direction.

In another embodiment of the present application, as shown in fig. 3, the half-wave plate 32 is located on the light emitting surface of the first rhombic prism 311 and is disposed in one-to-one correspondence with the first rhombic prism 311, the half-wave plate 32 is used for converting the first polarized light beam O1 into a fourth polarized light beam O4 having the second polarization direction, and the third polarized light beam O3 is emitted from the light emitting surface of the second rhombic prism 312 to form the second polarized light beam O2. It can be understood that, taking the example shown in fig. 3, after the first light beam K1 enters the second rhombic prism 312, the first polarized light beam O1 and the third polarized light beam O3 are formed under the action of the right polarized light splitting film, after the first polarized light beam O1 is directly emitted from the light emitting surface of the first rhombic prism 311, the polarized direction of the first polarized light beam O1 is rotated by 90 degrees through the half wave plate 32 to form the fourth polarized light beam O4 with the second polarized direction, and the third polarized light beam O3 is directly emitted from the light emitting surface of the second rhombic prism 312 to form the second polarized light beam O2.

It should be noted that, the polarizing beam splitter film is generally used to reflect S-polarized light and transmit P-polarized light, and when the linearly polarized light required by the liquid crystal light valve 53 in the projector is P-polarized light, the half wave plate 32 may be disposed corresponding to the second rhombic prism 312 (as shown in fig. 1), and when the linearly polarized light required by the liquid crystal light valve 53 in the projector is S-polarized light, the half wave plate 32 may be disposed corresponding to the first rhombic prism 311 (as shown in fig. 3).

In an alternative embodiment, the projection of the half wave plate 32 on the prism set 31 coincides with the light exit surface of the second rhombic prism 312, so that the third polarized light beam O3 emitted from the light exit surface of the second rhombic prism 312 can be converted into the second polarized light beam O2 through the half wave plate 32, and the half wave plate 32 can be prevented from covering the light exit surface of the first rhombic prism 311, so that the first polarized light beam O1 emitted from the first rhombic prism 311 can be prevented from being converted into the polarized light beam of the second polarization direction by the half wave plate 32.

Specifically, with continued reference to fig. 1, the first sub-lens array 21 includes a plurality of first sub-lenses 211 distributed in an array, where the first sub-lenses 211 may collect light to form a first light beam K1, and one first light beam K1 is emitted from one first sub-lens 211, and the first sub-lens 211 may be a spherical lens, a rectangular lens, or a lens with another shape.

Since most of the light in the first light beam K1 is mainly concentrated at the center of the first sub-lens 211 and near the center of the first sub-lens 211, the center of one first sub-lens 211 may be opposite to the center of the light entrance surface of one second rhombic prism 312, so that most of the light in the first light beam K1 may enter the second rhombic prism 312 from the light entrance surface of the second rhombic prism 312, and the first light beam K1 is prevented from directly exiting from the light exit surface of the first rhombic prism 311 after entering the first rhombic prism 311 from the light entrance surface of the first rhombic prism 311.

Specifically, with continued reference to fig. 1, the second sub-lens array 41 includes a plurality of second sub-lenses 411 distributed in an array, where the second sub-lenses 411 may also collect the first polarized light beam O1 and the second polarized light beam O2 to form a light beam with more uniform brightness, and the second sub-lenses 411 may be spherical lenses, rectangular lenses, or lenses with other shapes.

One of the first rhombic prisms 311 is opposite to one of the second sub-lenses 411, and one of the second rhombic prisms 312 is opposite to one of the second sub-lenses 411, so that one of the first polarized light beams O1 is incident from one of the second sub-lenses 411, is homogenized and then exits from the second sub-lens 411, and one of the second polarized light beams O2 is incident from the other of the second sub-lenses 411, is homogenized and then exits from the second sub-lens 411, thereby performing the light homogenizing treatment on both the first polarized light beam O1 and the second polarized light beam O2.

With continued reference to fig. 1, in one embodiment of the present application, the number of second sub-lenses 411 is twice the number of first sub-lenses 211. It can be understood that, after the first light beam K1 emitted from one first sub-lens 211 passes through the prism group 31 and is split into one first polarized light beam O1 and one second polarized light beam O2, by setting the number of the second sub-lenses 411 to be twice the number of the first sub-lenses 211, the number of the second sub-lenses 411 can be reduced and the production cost of the second dodging lens 40 can be reduced on the basis of ensuring that a sufficient number of the second sub-lenses 411 process each of the first polarized light beams O1 and the second polarized light beams O2.

In an alternative embodiment, the plurality of first sub-lenses 211 are sequentially connected, and the plurality of second sub-lenses 411 are sequentially connected, so as to prevent the light beams that are not uniformly emitted from the gaps between the adjacent two first sub-lenses 211 and the gaps between the adjacent two second sub-lenses 411.

In a second aspect, based on the above-mentioned polarization conversion assembly 10, the present application further provides a projection light machine, as shown in fig. 4, the projection light machine includes a light source 60, an imaging module 50 and a projection lens 70, the imaging module 50 is located on the light emitting side of the light source 60, the projection lens 70 is located on the light emitting side of the imaging module 50, and the imaging module 50 includes the polarization conversion assembly 10 according to any one of the above-mentioned embodiments.

It is understood that the light source 60 is a device for generating light in the projection light machine, the light source 60 may be an LED, and the light generated by the LED is natural light (natural light is unpolarized light); the imaging module 50 is used for processing the light generated by the light source 60 to generate an image meeting the projection requirement of the projection optical machine; the projection lens 70 is used for magnifying the image output by the imaging module 50 and projecting the magnified image onto the receiving screen for imaging.

Specifically, with continued reference to fig. 4, the imaging module 50 further includes a curved condensing lens 51, a first mirror 52, a liquid crystal light valve 53, and a second mirror 54;

the curved surface condensing lens 51 is located on the light emitting side of the light source 60, and is used for collimating the light emitted by the light source 60; the curved surface condensing lens 51 may be made of an optically transparent material such as glass or resin, and the curved surface condensing lens 51 has one or more curved surfaces, and may change the propagation direction of light and control the distribution of light, so that the light emitted from the light source 60 may be collimated, where the specific principle of the collimation is that the divergent light is changed into collimated light, and is not described in detail in the related art.

The first reflector 52 is located at the light emitting side of the curved condensing lens 51 and at the light entering side of the first dodging lens 20, and the first reflector 52 is used for reflecting the light collimated by the curved condensing lens 51 to the first dodging lens 20.

The liquid crystal light valve 53 is located at the light emitting side of the second dodging lens 40, and the liquid crystal light valve 53 is used for transmitting the first polarized light beam O1 and the second polarized light beam O2 with the first polarization direction; the liquid crystal light valve 53 is a device for realizing phase retardation of light by controlling refractive index of liquid crystal molecules through voltage, the liquid crystal light valve 53 can modulate linearly polarized light incident from an incident side of the liquid crystal light valve 53 to generate an image source so as to generate an image meeting projection requirements of a projection light machine, and specific structures and working principles of the liquid crystal light valve 53 are disclosed in related technologies, and are not repeated in the application.

The second reflector 54 is located at the light emitting side of the liquid crystal light valve 53, and the second reflector 54 is used for reflecting the light emitted from the liquid crystal light valve 53 to the projection lens 70.

It can be understood that after the light generated by the light source 60 is collimated and shaped by the curved condensing lens 51, the light is reflected to the first light homogenizing lens 20 by the first reflecting mirror 52, the light incident into the first light homogenizing lens 20 is processed by the polarization conversion assembly 10 to form a first polarized light beam O1 and a second polarized light beam O2 with a first polarization direction, then the first polarized light beam O1 and the second polarized light beam O2 penetrate the liquid crystal light valve 53 and provide illumination for the liquid crystal light valve 53, so that the liquid crystal light valve 53 generates an image meeting the projection requirement of the projector, then the light beam emitted by the liquid crystal light valve 53 is reflected to the projection lens 70 by the second reflecting mirror 54, and the projection lens 70 amplifies the image and projects the image onto the receiving screen for imaging.

With continued reference to FIG. 4, in one embodiment of the present application, the imaging module 50 further includes a first Fresnel lens 55 and a second Fresnel lens 56; the first fresnel lens 55 is located between the first reflecting mirror 52 and the first dodging lens 20, and the first fresnel lens 55 is used for collimating the light reflected by the first reflecting mirror 52; the second fresnel lens 56 is located between the second dodging lens 40 and the second reflecting mirror 54, and the second fresnel lens 56 is used for collimating the light emitted from the second dodging lens 40.

It can be understood that after the light generated by the light source 60 is collimated by the curved condensing lens 51 for the first time, the light needs to be collimated by the first fresnel lens 55 for the second time and collimated by the second fresnel lens 56 for the third time, so that the collimation degree of the light beam output by the projection optical machine can be improved; in an alternative embodiment, the first fresnel lens 55 may also collimate and shape the light generated by the light source 60 into a rectangular spot (the spot being the collection of all the light beams emitted by the first fresnel lens 55) such that the shape of the spot matches the shape of the liquid crystal stop.

Specifically, with continued reference to fig. 4, the projection lens 70 may include a plurality of spherical lenses 71, and the plurality of spherical lenses 71 may be arranged along the optical axis direction of the projection lens 70, wherein the number of spherical lenses 71 may be preferably 4, and of course, the number of spherical lenses 71 may be 1, 2, 3 or more according to actual requirements; the spherical lens 71 may be a convex lens or a concave lens.

The foregoing description of the preferred embodiment of the present utility model is not intended to limit the utility model to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the utility model.

Claims (10)

1. A polarization conversion assembly, comprising:

the first light homogenizing lens comprises a first sub-lens array positioned at the light emergent side of the first light homogenizing lens, and the first sub-lens array is used for homogenizing the light received by the first light homogenizing lens and emergent a first light beam;

the polarization converter is positioned at the light emitting side of the first light homogenizing lens and is used for converting the first light beam into a first polarized light beam and a second polarized light beam with a first polarization direction;

the second light homogenizing lens is positioned on the light emitting side of the polarization converter and comprises a second sub-lens array positioned on the light emitting side of the second light homogenizing lens, and the second sub-lens array is used for homogenizing the first polarized light beam and the second polarized light beam.

2. The polarization conversion assembly of claim 1, wherein the polarization converter comprises:

the prism group comprises a plurality of first rhombic prisms and a plurality of second rhombic prisms, the first rhombic prisms and the second rhombic prisms are alternately arranged, the first rhombic prisms are provided with inclined first splicing surfaces, the second rhombic prisms are provided with inclined second splicing surfaces, and the second splicing surfaces are spliced with the first splicing surfaces;

the polarization beam splitting film is arranged between the first splicing surface and the second splicing surface, the polarization converter is used for converting the first light beam into the first polarized light beam and a third polarized light beam with a second polarization direction, the first polarized light beam is emitted from the light emitting surface of the first rhombic prism, the third polarized light beam is emitted from the light emitting surface of the second rhombic prism, and the second polarization direction is orthogonal to the first polarization direction;

the half wave plate is positioned on the light emitting surface of the second rhombic prism, is arranged in one-to-one correspondence with the second rhombic prism and is used for converting the third polarized light beam into the second polarized light beam; or the half wave plate is positioned on the light-emitting surface of the first rhombic prism and is arranged in one-to-one correspondence with the first rhombic prism, the half wave plate is used for converting the first polarized light beam into a fourth polarized light beam with the second polarized direction, and the third polarized light beam is emitted from the light-emitting surface of the second rhombic prism to form the second polarized light beam.

3. The polarization conversion assembly of claim 2, wherein the first sub-lens array comprises a plurality of first sub-lenses distributed in an array, and a center of one of the first sub-lenses is opposite to a center of the light incident surface of one of the second rhombic prisms.

4. The polarization conversion assembly of claim 2, wherein the second sub-lens array comprises a plurality of array-distributed second sub-lenses, one of the first rhombic prisms being opposite one of the second sub-lens positions, one of the second rhombic prisms being opposite one of the second sub-lens positions.

5. The polarization conversion assembly of claim 2, wherein the first sub-lens array comprises a plurality of array-distributed first sub-lenses and the second sub-lens array comprises a plurality of array-distributed second sub-lenses, the number of second sub-lenses being twice the number of first sub-lenses.

6. The polarization conversion assembly of claim 5, wherein a plurality of the first sub-lenses are connected in sequence and a plurality of the second sub-lenses are connected in sequence.

7. The polarization conversion assembly of claim 2, wherein the projection of the half wave plate on the prism set coincides with the light exit face of the second rhombic prism.

8. A projection light machine, comprising a light source, an imaging module and a projection lens, wherein the imaging module is positioned on the light emitting side of the light source, the projection lens is positioned on the light emitting side of the imaging module, and the imaging module comprises the polarization conversion assembly according to any one of claims 1 to 7.

9. The projection light engine of claim 8, wherein the imaging module further comprises:

the curved surface condensing lens is positioned on the light emitting side of the light source and is used for collimating the light emitted by the light source;

the first reflector is positioned on the light emitting side of the curved condensing lens and on the light entering side of the first light homogenizing lens, and is used for reflecting the light collimated by the curved condensing lens to the first light homogenizing lens;

the liquid crystal light valve is positioned at the light emitting side of the second light homogenizing lens and is used for transmitting a first polarized light beam and a second polarized light beam with a first polarization direction;

the second reflector is positioned on the light emitting side of the liquid crystal light valve and is used for reflecting the light emitted by the liquid crystal light valve to the projection lens.

10. The projection light engine of claim 9, wherein the imaging module further comprises:

the first Fresnel lens is positioned between the first reflector and the first dodging lens and is used for collimating the light reflected by the first reflector;

the second Fresnel lens is positioned between the second dodging lens and the second reflecting mirror and is used for collimating the light emitted by the second dodging lens.