CN219799964U - Symmetrical projection light path structure - Google Patents
Symmetrical projection light path structure Download PDFInfo
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- CN219799964U CN219799964U CN202320550056.9U CN202320550056U CN219799964U CN 219799964 U CN219799964 U CN 219799964U CN 202320550056 U CN202320550056 U CN 202320550056U CN 219799964 U CN219799964 U CN 219799964U
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- 238000005286 illumination Methods 0.000 claims abstract description 56
- 239000004973 liquid crystal related substance Substances 0.000 claims abstract description 22
- 230000003287 optical effect Effects 0.000 claims abstract description 19
- 241000276498 Pollachius virens Species 0.000 claims abstract description 7
- 230000005499 meniscus Effects 0.000 claims description 7
- 230000015572 biosynthetic process Effects 0.000 claims description 5
- 238000003384 imaging method Methods 0.000 abstract description 15
- 239000000463 material Substances 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000012938 design process Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 229920003229 poly(methyl methacrylate) Polymers 0.000 description 1
- 239000004926 polymethyl methacrylate Substances 0.000 description 1
- 210000001747 pupil Anatomy 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
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Abstract
The utility model discloses a symmetrical projection light path structure, which comprises a light source, an illumination lens, a first Fresnel lens, a liquid crystal screen, a second Fresnel lens and a projection lens which are sequentially and coaxially arranged, wherein the projection lens comprises a first lens, a second lens, a third lens and a diaphragm. The optical path structure adopts a coaxial system, a light source, an illumination lens, a first Fresnel lens, a liquid crystal screen, a second Fresnel lens and a first lens form an illumination optical path, the liquid crystal screen, the second Fresnel lens and a projection lens form an imaging optical path, the illumination optical path adopts a Kohler illumination mode, and the second Fresnel lens and the first lens participate in the illumination optical path, so that an image formed by the light source after passing through the illumination lens, the first Fresnel lens and part of the imaging optical path coincides with a diaphragm of the projection lens. The utility model adopts symmetrical structure design to make the structures of the first Fresnel lens and the second Fresnel lens identical, thereby effectively reducing cost.
Description
Technical Field
The utility model relates to the field of projection display, in particular to a symmetrical projection light path structure.
Background
The existing monolithic LCD projector uses a full-color, transmissive liquid crystal screen as a light valve, and projects an image of the light valve on the screen through a projection lens based on kohler or critical illumination mode. The aim of converging light is achieved by arranging two Fresnel lenses in front and behind the LCD. In general, since the focal lengths of two fresnel lenses used are not uniform, double mold cost is required to be paid at the time of manufacturing, and the cost is high.
In view of the above, it is an urgent problem for those skilled in the art to provide a monolithic LCD projector that can use two identical fresnel lenses to achieve the cost saving purpose.
Disclosure of Invention
The utility model aims to overcome the defects in the prior art and provide a symmetrical projection light path structure.
In order to achieve the above object, the technical scheme of the present utility model is as follows:
the utility model provides a symmetrical projection light path structure, includes coaxial arrangement's in order light source, illumination lens, first fresnel lens, LCD screen, second fresnel lens and projection lens, projection lens includes first lens, second lens, third lens and diaphragm, light source, illumination lens, first fresnel lens, LCD screen, second fresnel lens and first lens constitute the illumination light path, LCD screen, second fresnel lens, first lens, second lens and third lens constitute the formation of image light path, the illumination light path adopts the kohler illumination mode, the light source passes through behind illumination lens, first fresnel lens and the partial formation of image light path the diaphragm coincidence of projection lens.
Preferably, the first fresnel lens and the second fresnel lens have identical structures.
Preferably, the focal length of the first Fresnel lens and the second Fresnel lens is 90-110mm, and the aperture spacing on the plane is 0.4+/-0.1 mm.
Preferably, the projection lens has a three-plate type kuke structure, and the focal length ratio of the optical system composed of the first lens, the second lens and the third lens to the optical system composed of the illumination lens, the first fresnel lens and the second fresnel lens is 1.2±0.1.
Preferably, the liquid crystal screen is an LCD liquid crystal screen and is located at a diaphragm position between the first fresnel lens and the second fresnel lens, and a distance between the liquid crystal screen and the second fresnel lens is 4-6mm.
Preferably, the illumination lens includes a spherical lens, an aspherical lens, or a free-form surface lens.
Preferably, the illumination lens is a positive meniscus lens, the concave surface radius is 74+ -2 mm, the convex surface radius is 27+ -2 mm, and the center thickness is 22+ -1 mm.
Preferably, the first lens is of a biconvex structure, the spherical radius of two convex surfaces of the first lens is 72+/-2 mm and 167+/-2 mm respectively, and the center thickness is 10+/-1 mm.
Preferably, the second lens is of a biconcave structure, the spherical radius of two concave surfaces of the second lens is 45+/-2 mm and 178+/-2 mm respectively, and the center thickness is 5+/-1 mm.
Preferably, the third lens has a positive meniscus structure, the spherical radius of the concave surface is 140+ -2 mm, the spherical radius of the convex surface is 43+ -2 mm, and the center thickness is 10+ -1 mm.
Compared with the prior art, the utility model has the following beneficial effects:
(1) According to the utility model, the design thought of Kohler illumination is adopted, and when the illumination light path design is carried out, the second Fresnel lens and the first lens in the projection lens participate in the illumination light path design, so that the image formed by the light source passing through the system coincides with the diaphragm position of the projection lens, and the symmetrical structure design method is adopted, so that the structures of the first Fresnel lens and the second Fresnel lens are completely the same, and the cost can be effectively reduced.
(2) The symmetrical projection light path structure provided by the utility model enables the second Fresnel lens and the first lens to participate in an illumination light path, designs a light path structure with two Fresnel lenses completely consistent by adjusting the structures, materials and intervals of the lenses, and also enables the second Fresnel lens and the first lens to participate in an imaging light path to determine the surface structures of the second lens and the third lens, thereby ensuring that an illumination system and an imaging system are overlapped but are not mutually influenced.
(3) The symmetrical projection light path structure provided by the utility model adopts an imaging light path formed by the second Fresnel lens and the projection lens, and optimizes the combination of illumination and imaging, so that the manufacturing cost can be saved while the illumination and imaging requirements are met, and the symmetrical projection light path structure has higher cost performance and practicability.
Drawings
The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and together with the description serve to explain the principles of the utility model. Many of the intended advantages of other embodiments and embodiments will be readily appreciated as they become better understood by reference to the following detailed description.
FIG. 1 is a schematic view of an illumination light path of a symmetrical projection light path structure according to an embodiment of the present utility model;
FIG. 2 is a schematic diagram of an imaging optical path of a symmetrical projection optical path structure according to an embodiment of the present utility model;
FIG. 3 is a schematic diagram of a symmetrical projection light path structure according to an embodiment of the present utility model;
reference numerals: 1. a light source; 2. an illumination lens; 3. a first fresnel lens; 4. a liquid crystal panel; 5. a second fresnel lens; 6. a first lens; 7. a diaphragm; 8. a second lens; 9. and a third lens.
Detailed Description
The utility model is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the utility model and are not limiting of the utility model. It should be noted that, for convenience of description, only the portions related to the present utility model are shown in the drawings.
It should be noted that, without conflict, the embodiments of the present utility model and features of the embodiments may be combined with each other. The utility model will be described in detail below with reference to the drawings in connection with embodiments.
Referring to fig. 1-3, in an embodiment of the present utility model, a symmetrical projection light path structure is provided, which includes a light source 1, an illumination lens 2, a first fresnel lens 3, a liquid crystal screen 4, a second fresnel lens 5, and a projection lens sequentially coaxially arranged, the projection lens includes a first lens 6, a second lens 8, a third lens 9, and a diaphragm 7, the diaphragm 7 is disposed between the first lens 6 and the second lens 8, the light path structure is a coaxial system, the light source 1 includes an LED light source for emitting LED outgoing light, and the liquid crystal screen 4 is an LCD liquid crystal screen. The illumination lens 2 and the first fresnel lens 3 and the second fresnel lens 5 and the projection lens are arranged approximately symmetrically on both sides of the liquid crystal panel 4, respectively. Referring to fig. 1, a light source 1, an illumination lens 2, a first fresnel lens 3, a liquid crystal panel 4, a second fresnel lens 5, and a first mirror 6 constitute an illumination light path. Referring to fig. 2, the liquid crystal panel 4, the second fresnel lens 5, the first lens 6, the second lens 8, and the third lens 9 constitute an imaging optical path. The illumination light path adopts a Kohler illumination mode, and an image formed by the light source 1 after passing through the illumination lens 2, the first Fresnel lens 3 and part of the imaging light path is overlapped with the diaphragm 7 of the projection lens. In the design process, 1 Fresnel lens and optical lenses are distributed on the left side and the right side respectively by taking an LCD (liquid crystal display) as the center, the two Fresnel lenses and the optical lenses are symmetrically distributed, the LED light source 1 and the illumination light outlet are also symmetrical, the purpose that the structures of the first Fresnel lens 3 and the second Fresnel lens 5 are completely the same is achieved by using the similar symmetrical design thought, and the LED light source has lower cost and higher cost performance and practicability. By letting the second fresnel lens 5 and the first lens 6 participate in both the illumination light path design and the imaging light path design, it is ensured that the illumination system and the imaging system overlap but do not interact with each other.
In a specific embodiment, the first fresnel lens 3 and the second fresnel lens 5 are identical in structure. Specifically, the focal length of the first Fresnel lens 3 and the second Fresnel lens 5 is 90-110mm, and the aperture spacing on the plane is 0.4+/-0.1 mm. The first Fresnel lens 3 is used for focusing light rays in parallel on an LCD liquid crystal screen to realize uniform vertical incidence. The second fresnel lens 5 is used for converging the light transmitted through the LCD panel and participating in the imaging light path.
Specifically, the projection lens has a three-lens type kuke structure, and the focal length ratio of the optical system formed by the first lens 6, the second lens 8 and the third lens 9 to the optical system formed by the illumination lens 2, the first fresnel lens 3 and the second fresnel lens 5 is 1.2+/-0.1.
Specifically, the liquid crystal screen 4 is located at a diaphragm position between the first Fresnel lens 3 and the second Fresnel lens 5, and the distance between the liquid crystal screen 4 and the second Fresnel lens 5 is 4-6mm.
In a specific embodiment, the illumination lens 2 may be a spherical lens, or may be an aspherical lens or a free-form surface lens. In one preferred embodiment, the illumination lens 2 is a positive meniscus lens with a concave radius of 74±2mm, a convex radius of 27±2mm, and a center thickness of 22±1mm, for collecting the emergent light of the large-angle LED, and improving the light utilization rate.
Specifically, the first lens 6 has a biconvex structure, the spherical radii of the two convex surfaces of the first lens 6 are 72±2mm and 167±2mm respectively, and the center thickness is 10±1mm, so that emergent light rays of the LCD liquid crystal screen can be focused and imaged at the position of the diaphragm 7 of the projection lens.
Specifically, the second lens 8 has a biconcave structure, the spherical radii of the two concave surfaces of the second lens 8 are 45+ -2 mm and 178+ -2 mm respectively, and the center thickness is 5+ -1 mm.
Specifically, the third lens 9 has a positive meniscus structure, the spherical radius of the concave surface is 140±2mm, the spherical radius of the convex surface is 43±2mm, and the center thickness is 10±1mm.
The convex surface on the side of the first lens 6 with the larger spherical radius is adjacent to the concave surface on the side of the second lens 8 with the smaller spherical radius. The concave side surface of the second lens 8 having a larger spherical radius is adjacent to the concave side surface of the third lens 9 having a larger spherical radius.
Specific examples are described below.
In this embodiment, the illumination lens 2 has a positive meniscus structure, and both surfaces of the illumination lens are standard spherical surfaces, the radius of the concave surface is 74.6mm, the radius of the convex surface is 27.2mm, the thickness of the center is 22.3mm, and the material is H-ZLAF55D or its international trade mark. The focal length of the first Fresnel lens 3 and the second Fresnel lens 5 is 93.6mm, the aperture spacing on the plane is 0.4mm, the spacing between the first Fresnel lens 3 and the second Fresnel lens 5 is 20mm, the thickness is 2mm, and the material is COC or PMMA.
In this embodiment, the LCD panel is located at a stop position between the first fresnel lens 3 and the second fresnel lens 5, and has a distance of 5mm from the second fresnel lens 5. The spherical radius of the two surfaces of the first lens 6 is 71.4mm and 167.0mm respectively, the center thickness is 10mm, and the material is H-LAF50B or international trade mark thereof. The spherical radius of the two surfaces of the second lens 8 is 45.1mm and 178.7mm respectively, the center thickness is 5mm, and the material is H-ZF52 or the international trade mark thereof. The third lens 9 has a concave spherical radius of 140.7mm, a convex spherical radius of 43.3mm, a center thickness of 10.677mm, and is made of H-ZLAF75A or its international trade mark.
In the present embodiment, the focal length ratio of the optical system composed of the first lens 6, the second lens 8, and the third lens 9 to the optical system composed of the illumination lens 2, the first fresnel lens 3, and the second fresnel lens 5 is 1.234.
In this embodiment, the on-axis spacing of the illumination lens 2 from the first fresnel lens 3 is 63.051mm, the on-axis spacing of the second fresnel lens 5 from the first lens 6 is 90mm, the on-axis spacing of the first lens 6 and the second lens 8 is 8mm, and the on-axis spacing of the second lens 8 and the third lens 9 is 3.681mm.
The symmetrical projection light path structure provided by the embodiment of the utility model adopts a Kohler illumination mode, so that the image of the light source 1 is overlapped with the diaphragm 7 of the projection lens, and the window pupil matching of illumination and imaging is realized. The light path structure adopts a symmetrical design thought, and the curvature and the thickness of the illumination lens 2 and the first lens 6 near the light source 1, the plane structure of the Fresnel lens and the distance between the lenses are adjusted, so that the two Fresnel lenses can be completely consistent, the illumination and imaging requirements are met, meanwhile, the manufacturing cost is saved, and the light path structure has higher cost performance and practicability.
While the utility model has been described with reference to specific embodiments, the scope of the utility model is not limited thereto, and any changes or substitutions can be easily made by those skilled in the art within the scope of the utility model disclosed herein, and are intended to be covered by the scope of the utility model. Therefore, the protection scope of the present utility model shall be subject to the protection scope of the claims.
Claims (10)
1. The utility model provides a symmetrical projection light path structure, its characterized in that includes coaxial arrangement's in order light source, illumination lens, first fresnel lens, LCD screen, second fresnel lens and projection lens, the projection lens includes first lens, second lens, third lens and diaphragm, light source, illumination lens, first fresnel lens, LCD screen, second fresnel lens and first lens constitute the illumination light path, LCD screen, second fresnel lens, first lens, second lens and third lens constitute the formation of image light path, the illumination light path adopts kohler's illumination mode, the light source is through behind illumination lens, first fresnel lens and the partial formation of image light path the formation of image with the diaphragm of projection lens coincides.
2. The symmetric projection light path structure of claim 1 wherein the first fresnel lens and the second fresnel lens are identical in structure.
3. The symmetrical projection light path structure of claim 2, wherein the first and second fresnel lenses have a focal length of 90-110mm and an on-plane aperture spacing of 0.4 ± 0.1mm.
4. The symmetrical projection light path structure according to claim 1, wherein the projection lens is a three-plate type kuke structure, and a focal length ratio of an optical system composed of the first lens, the second lens and the third lens to an optical system composed of the illumination lens, the first fresnel lens and the second fresnel lens is 1.2±0.1.
5. The symmetric projection light path structure according to claim 1, wherein the liquid crystal screen is an LCD liquid crystal screen and is located at a stop position between the first fresnel lens and the second fresnel lens, and a distance between the liquid crystal screen and the second fresnel lens is 4-6mm.
6. The symmetric projection light path structure of claim 1 wherein the illumination lens comprises a spherical lens, an aspherical lens, or a free-form surface lens.
7. The symmetrical projection light path structure of claim 6, wherein the illumination lens is a positive meniscus lens having a concave radius of 74+ -2 mm, a convex radius of 27+ -2 mm, and a center thickness of 22+ -1 mm.
8. The symmetrical projection light path structure according to claim 1, wherein the first lens has a biconvex structure, spherical radii of two convex surfaces of the first lens are 72±2mm and 167±2mm, respectively, and a center thickness is 10±1mm.
9. The symmetrical projection light path structure according to claim 1, wherein the second lens has a biconcave structure, spherical radii of two concave surfaces of the second lens are 45±2mm and 178±2mm, respectively, and a center thickness is 5±1mm.
10. The symmetrical projection light path structure according to claim 1, wherein the third lens is a positive meniscus structure, the spherical radius of the concave surface is 140±2mm, the spherical radius of the convex surface is 43±2mm, and the center thickness is 10±1mm.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320550056.9U CN219799964U (en) | 2023-03-21 | 2023-03-21 | Symmetrical projection light path structure |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320550056.9U CN219799964U (en) | 2023-03-21 | 2023-03-21 | Symmetrical projection light path structure |
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| CN219799964U true CN219799964U (en) | 2023-10-03 |
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| CN202320550056.9U Active CN219799964U (en) | 2023-03-21 | 2023-03-21 | Symmetrical projection light path structure |
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