CN108319002A - A kind of camera lens - Google Patents
A kind of camera lens Download PDFInfo
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- CN108319002A CN108319002A CN201810327263.1A CN201810327263A CN108319002A CN 108319002 A CN108319002 A CN 108319002A CN 201810327263 A CN201810327263 A CN 201810327263A CN 108319002 A CN108319002 A CN 108319002A
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- 230000003287 optical effect Effects 0.000 claims description 52
- 239000000463 material Substances 0.000 claims description 19
- 230000005499 meniscus Effects 0.000 claims description 19
- 102220616555 S-phase kinase-associated protein 2_E48R_mutation Human genes 0.000 claims description 14
- 229920003023 plastic Polymers 0.000 claims description 9
- 239000004033 plastic Substances 0.000 claims description 8
- 238000009434 installation Methods 0.000 abstract description 8
- 238000007323 disproportionation reaction Methods 0.000 abstract 1
- 230000004075 alteration Effects 0.000 description 25
- 238000000034 method Methods 0.000 description 16
- 238000005516 engineering process Methods 0.000 description 9
- 230000008569 process Effects 0.000 description 9
- 201000009310 astigmatism Diseases 0.000 description 6
- 206010010071 Coma Diseases 0.000 description 4
- 230000008901 benefit Effects 0.000 description 4
- 238000005286 illumination Methods 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000003384 imaging method Methods 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 238000013461 design Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000001746 injection moulding Methods 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 238000002834 transmittance Methods 0.000 description 2
- 230000008859 change Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
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- 238000007781 pre-processing Methods 0.000 description 1
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Classifications
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B13/00—Optical objectives specially designed for the purposes specified below
- G02B13/001—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras
- G02B13/0015—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design
- G02B13/002—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design having at least one aspherical surface
- G02B13/0045—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design having at least one aspherical surface having five or more lenses
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B13/00—Optical objectives specially designed for the purposes specified below
- G02B13/24—Optical objectives specially designed for the purposes specified below for reproducing or copying at short object distances
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B21/00—Projectors or projection-type viewers; Accessories therefor
- G03B21/14—Details
- G03B21/142—Adjusting of projection optics
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B21/00—Projectors or projection-type viewers; Accessories therefor
- G03B21/14—Details
- G03B21/20—Lamp housings
- G03B21/2066—Reflectors in illumination beam
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Lenses (AREA)
Abstract
An embodiment of the present invention provides a kind of camera lens, which includes：Including the first lens set, the second lens set and free-form surface mirror；First lens set includes the first preset quantity piece non-spherical lens, key light axial alignment of the first preset quantity piece non-spherical lens along a non-spherical lens；Second lens set includes the second preset quantity piece free-form surface lens, key light axial alignment of the second quantity piece free-form surface lens along a free-form surface lens；The incidence surface of first lens set is the face for receiving camera lens incident light, and above-mentioned second lens set is located at the light emission side of above-mentioned first lens set, and positioned at the incident side of above-mentioned free-form surface mirror.Camera lens provided in an embodiment of the present invention reduces the complexity of camera lens assembly, phenomena such as avoiding since the number of lenses for constituting camera lens is more, cause anamorphose caused by the error assembled as eyeglass or brightness disproportionation, improves the installation accuracy of camera lens.
Description
Technical Field
The invention relates to the technical field of projection optical systems, in particular to a lens.
Background
Projection display technology has been developed in recent years due to the increasing maturity of technologies such as high brightness light sources, optical processing, and ultra-high resolution image sources. Especially, the short-focus projection technology in the projection display technology has the advantage of projecting a large picture in a short distance, so the short-focus projection technology is always a research hotspot in the market of projectors, and is favored by wide users in the development process.
Currently, short-focus projection lenses applying short-focus projection technology mainly include a reflective short-focus projection lens and a refractive short-focus projection lens. Wherein,
the refraction type short-focus projection lens consists of lenses, namely, the refraction type short-focus lens only comprises the lenses, and due to the structural characteristics of the refraction type short-focus projection lens, when the refraction type short-focus projection lens is used for projection, the phenomena of chromatic aberration, off-axis aberration, field curvature, distortion and the like of a projected image can be caused along with the increase of a field angle and an F number (F number), so that when the refraction type short-focus projection lens is used for projection, a larger field angle and a shorter projection distance are difficult to obtain;
the reflective short-focus projection lens consists of a refraction lens group and a reflector, and the reflector is positioned on the light-emitting side of the refraction lens group. In the prior art, a refractive lens group of a reflective short-focus projection lens includes 15 aspheric lenses, and a reflector includes 1 concave aspheric reflector. Due to the structural characteristics of the reflective short-focus projection lens, a larger field angle and a shorter projection distance can be obtained when the refractive short-focus projection lens is used for projection. However, since the refractive lens group is composed of 15 lenses and the number of lenses is large, the assembly process of the reflective short-focus projection lens is complicated, and the mounting accuracy of the reflective short-focus projection lens is difficult to ensure.
Disclosure of Invention
The embodiment of the invention aims to provide a lens, so that the assembly complexity is reduced, the installation precision of the lens is improved, and a large image with high quality is projected under the condition of short distance.
The specific technical scheme is as follows:
a lens comprises a first lens group, a second lens group and a free-form surface reflector;
the first lens group comprises a first preset number of aspheric lenses, and the first preset number of aspheric lenses are arranged along the main optical axis of one aspheric lens;
the second lens group comprises a second preset number of free-form surface lenses, and the second number of free-form surface lenses are arranged along the main optical axis of one free-form surface lens;
the light incident surface of the first lens group is a surface for receiving incident light of the lens, and the second lens group is located on the light emergent side of the first lens group and on the light incident side of the free-form surface reflector.
Further, the first preset number is 5, and the second preset number is 2.
Further, the first lens group satisfies the following relationship:
F1/F≤2；
wherein, F1 is the focal length of the first lens group, and F is the focal length of the lens.
Further, the first lens group, the second lens group and the free-form surface reflecting mirror satisfy the following relationship:
H1/H2>0.8；
h1 is the shortest distance from the edge of the area to be projected to the optical axis of the first lens group; h2 is the maximum distance from the point of the free-form surface mirror to the projection surface.
Further, a main optical axis of the first lens group and a main optical axis of the second lens group are coaxial, or the main optical axis of the first lens group, the main optical axis of the second lens group and a main optical axis of the free-form surface reflector are coaxial.
Further, the main optical axes of the 5 aspheric lenses are coaxial and are sequentially arranged along the main optical axis direction as follows: a first lens, a second lens, a third lens, a fourth lens, and a fifth lens; wherein,
the first lens is a biconvex lens with positive focal power, and a surface corresponding to the small curvature radius of the biconvex lens is a light incident surface of the first lens (301);
the second lens is a meniscus lens with negative focal power, and the convex surface of the meniscus lens is the light-emitting surface of the second lens;
the third lens is a plano-convex lens with positive focal power, and the convex surface of the plano-convex lens is the light incident surface of the third lens;
the fourth lens is a meniscus lens with negative focal power, and the convex surface of the meniscus lens is the light-emitting surface of the fourth lens;
the fifth lens is a meniscus lens with negative focal power, and the convex surface of the meniscus lens is the light-emitting surface of the fifth lens;
the light incident surface of the first lens is the light incident surface of the first lens group, and the light emergent surface of the fifth lens is the light emergent surface of the first lens group.
Further, the first lens, the second lens, the third lens, the fourth lens and the fifth lens are all axisymmetric aspheric lenses.
Further, the first lens group further includes: an aperture stop disposed between the second lens and the third lens.
Furthermore, the aspheric lens and the free-form surface lens are both made of optical plastic materials.
Furthermore, the material of the first lens is E48R; the material of the second lens is OKP 4; the third lens is made of E48R; the fourth lens is made of OKP 4; the material of the fifth lens is E48R; the free-form surface lens is made of E48R.
Further, the coefficient of the aspherical lens is less than or equal to tenth order.
Further, the coefficient of the free-form surface lens is less than or equal to 65 terms.
Further, the maximum distance between the free-form surface reflector and the first lens light incident surface is smaller than or equal to 75 mm.
An embodiment of the present invention provides a lens, including: the free-form surface mirror comprises a first lens group, a second lens group and a free-form surface reflector; the first lens group comprises a first preset number of aspheric lenses, and the first preset number of aspheric lenses are arranged along the main optical axis of one aspheric lens; the second lens group comprises a second preset number of free-form surface lenses, and the second number of free-form surface lenses are arranged along the axial direction of a main optical axis of one free-form surface lens; the light incident surface of the first lens group is a surface for receiving incident light of the lens, and the second lens group is positioned on the light emergent side of the first lens group and on the light incident side of the free-form surface reflector. Compared with the prior art, the lens provided by the embodiment of the invention adopts the free-form surface lens and the free-form surface reflector, so that the lens provided by the embodiment of the invention and applying the reflective short-focus projection technology does not need to comprise a large number of refraction lenses, and further the number of the lenses forming the lens is reduced, therefore, the complexity of lens assembly can be reduced, the phenomena of image deformation or uneven brightness and the like caused by errors of lens assembly due to the large number of the lenses forming the lens are avoided, the mounting precision of the lens is improved, and when the lens is used for projection, a large image with high quality can be projected under the condition of short distance. Of course, it is not necessary for any product or method of practicing the invention to achieve all of the above-described advantages at the same time.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below.
FIG. 1 is a schematic diagram of a projection lens system constructed using lenses provided in the practice of the present invention;
fig. 2 is a schematic diagram of a lens projection provided by the implementation of the present invention.
The lens comprises a display chip 1, a prism 2, a lens 3, a first lens group 30, a second lens group 40, a free-form surface reflector 50, a first lens 301, a second lens 302, a third lens 303, a fourth lens 304, a fifth lens 305, an aperture diaphragm 306, a sixth lens 401 and a seventh lens 402.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In order to solve the problem that the assembly process of the reflective short-focus projection lens is complex due to the fact that the number of the refraction lenses is large in the prior art, and the installation precision of the reflective short-focus projection lens is difficult to guarantee, the embodiment of the invention provides a lens.
FIG. 1 is a schematic diagram of a projection lens system constructed using lenses provided in the practice of the present invention; the projection lens system comprises a display chip 1, a prism 2 and a lens 3; the prism 2 is arranged on the light emergent side of the display chip and on the light incident side of the lens.
The illumination light beam emitted by the illumination light source is incident into the prism 2 from the first light incident surface of the prism 2, the light is emitted to the display chip 1 from the second light incident surface of the prism 2 through the refraction effect inside the prism 2, the display chip 1 forms the signal light ray of the image to be projected to be emitted through modulating the incident light ray, the signal light ray in the image to be projected is incident into the prism 2 through the second light incident surface and is emitted into the light incident surface of the lens 3 through the light emergent surface of the prism 2, and finally the signal light ray of the image to be projected is emitted into the projection surface after being processed through the lens 3. In this embodiment, the display chip 1 may be an LCOS chip, a DLP chip, or an LCD chip. The lens processes the signal light, including reflection and refraction of the light, so that the signal light is projected to the projection surface to form a standard picture. The projection surface is understood to be the surface on which the image is projected.
The first light incident surface may be one surface of the prism 2 close to the illumination light source, and there may be a plurality of surfaces close to the light source for different prisms.
The second light incident surface is a surface of the prism 2 close to the display chip, and there may be a plurality of surfaces of different prisms close to the display chip.
In an implementation manner of the present invention, when the projection lens system is a lens system in a projection apparatus, the illumination light source may be a laser light source in the projection apparatus.
It should be noted that the display chip 1 can adopt an LCOS display chip with a specification of 0.37 in; the 0.37in display chip can support various resolutions including WXGA (Wide Extended Graphics Array), 720P, 1080P, etc., and the main optical axis of the first lens group 30 of the lens can be offset by about 2.3mm with respect to the main optical axis of the 0.37in display chip. It can be seen that the projection lens system composed of the 0.37in display chip, the prism 2 and the lens 3 can provide high quality imaging with a projection ratio of 0.3 to 0.35, an F number of 3.5 to 4.5, and various resolutions such as 1080P, WXGA, XGA (Extended Graphics Array, computer display mode).
The lens 3 provided by the embodiment of the present invention will be described in detail, specifically, the lens 3 includes: comprises a first lens group 30, a second lens group 40 and a free-form surface reflector 50;
the first lens group 30 includes a first predetermined number of aspheric lenses, and the first predetermined number of aspheric lenses are arranged along a main optical axis of one aspheric lens;
the second lens group 40 includes a second predetermined number of free-form surface lenses, and the second number of free-form surface lenses are arranged along a main optical axis of a free-form surface lens;
the light incident surface of the first lens group 30 is a surface for receiving incident light from the lens, and the second lens group 40 is located on the light emitting side of the first lens group 30 and on the light incident side of the free-form surface reflector 50.
The first lens group 30 is composed of a plurality of aspheric lenses, and the aspheric lenses can correct more high-level aberrations relative to the spherical lenses, so that system aberrations can be balanced, the number of lenses can be reduced, and the size of the lens can be reduced; therefore, each aspheric lens adopted by the first lens group 30 is used for providing the main focal power of the lens, and can effectively balance the overall aberration of the projection lens system, which mainly includes spherical aberration, coma aberration and chromatic aberration; the above aberration can be understood as a phenomenon that an actual ray deviates from an ideal image of a paraxial ray in an actual optical system. The aberration is mainly classified into spherical aberration, coma aberration, curvature of field, astigmatism, distortion, chromatic aberration, and the like.
The second lens group 40 employs a free-form surface lens, which has a larger surface type degree of freedom than a spherical lens and an aspheric lens, and can better correct various aberrations, that is, one free-form surface lens can replace a plurality of common spherical lenses, so that the complexity of the projection lens system is greatly reduced, and the projection imaging quality of the projection lens system is not reduced, and the second lens group 40 can balance the aberrations which may be unbalanced due to the first lens group 30, and can further balance astigmatism and curvature of field formed after the signal light of the image to be projected passes through the free-form surface reflector 50.
The free-form surface reflector 50 is designed by performing pre-calculation fitting on the free-form surface of the free-form surface reflector 50, so that a large amount of distortion caused by the fact that the optical axis of the projection lens is not perpendicular to a preset projection picture can be corrected.
It should be noted that, while the free-form surface mirror 50 corrects a large amount of distortion caused by non-perpendicularity of the predetermined projection image, astigmatism and curvature of field are additionally generated. The second lens group 40 may be specifically designed so that the second lens group 40 can balance astigmatism and curvature of field formed by the signal light to be projected after passing through the free-form surface mirror 50 through a pre-processing. To further improve the display effect.
Based on the description of the first lens group 30, the second lens group 40, and the free-form surface reflector 50, it can be known that, by performing the combination optimization design on the various lenses of the lens, the lens provided in the embodiment of the present invention can correct not only the large distortion caused by the non-perpendicularity of the optical axis of the projection lens and the preset projection image, but also the remaining aberrations can be corrected well, so as to implement the high-quality ultra-short-focus projection imaging.
It should be noted that, according to the application scenario of the projection lens system, the free-form surface shape of the free-form surface reflector 50 can be obtained by calculation and fitting design.
Therefore, compared with the prior art, the lens 3 provided by the embodiment of the invention adopts the free-form surface lens and the free-form surface reflector, so that the lens provided by the embodiment of the invention and applying the reflective short-focus projection technology does not need to comprise a large number of refraction lenses, and further the number of lenses forming the lens is reduced, therefore, the complexity of lens assembly can be reduced, the phenomena of image deformation or uneven brightness and the like caused by errors of lens assembly due to the large number of lenses forming the lens are avoided, the mounting precision of the lens is improved, and a large image with high quality is projected under the condition of short distance.
In one implementation, the first predetermined number may be 5, and the second predetermined number may be 2, and thus, the total number of the lenses used in the lens 3 provided in the embodiment of the present invention is 8, while the reflective short-focus projection lens in the prior art uses 15 aspheric lenses and 1 concave aspheric mirror, and the number of the lenses is 16 in total, compared with the prior art, the lens 3 provided in the embodiment of the present invention has the advantages of low cost and light weight, and the lens assembly process is relatively simple and the installation accuracy is relatively high.
In one implementation, the first lens group 3 satisfies the following relationship:
F1/F≤2；
wherein F1 is the focal length of the first lens group 3, and F is the focal length of the lens.
It should be noted that the focal length of the lens can be understood as the focal length of the whole lens, and when F1/F is less than or equal to 2, the projection lens system using the lens provided by the embodiment of the present invention can not only project a large image with high quality in a short distance, but also enable the transmittance of the lens to be high.
In one implementation, the first lens group 3, the second lens group 4 and the free-form surface reflector 5 satisfy the following relationship:
H1/H2>0.8；
wherein, H1 is the shortest distance from the edge of the area to be projected to the optical axis of the first lens group 3; h2 is the maximum distance from the point of the free-form surface mirror 5 to the projection plane.
In one implementation, the main optical axis of the first lens group 3 and the main optical axis of the second lens group 4 are coaxial, which not only facilitates the installation of the first lens group 3 and the second lens group 4, but also improves the installation accuracy of the first lens group 3 and the second lens group 4, and saves the installation time;
in another implementation, the main optical axis of the first lens group 3, the main optical axis of the second lens group 4, and the main optical axis of the free-form surface reflector 5 are coaxial, so that the first lens group 3, the second lens group 4, or the free-form surface reflector 5 can be conveniently mounted, the mounting accuracy of the first lens group 3, the second lens group 4, and the free-form surface reflector 5 can be improved, and the mounting time can be saved.
In one implementation, the principal optical axes of the 5-chip aspheric lenses are coaxial and arranged in the following order along the principal optical axis: a first lens 301, a second lens 302, a third lens 303, a fourth lens 304, and a fifth lens 305; wherein,
the first lens 301 is a biconvex lens having positive refractive power, and a surface corresponding to a small curvature radius of the biconvex lens is a light incident surface of the first lens 301;
the second lens 302 is a meniscus lens with negative focal power, and the convex surface of the meniscus lens is the light-emitting surface of the second lens 302;
the third lens 303 is a plano-convex lens with positive focal power, and the convex surface of the plano-convex lens is the light incident surface of the third lens 303;
the fourth lens element 304 is a meniscus lens element with negative refractive power, and the convex surface of the meniscus lens element is the light-emitting surface of the fourth lens element 304;
the fifth lens element 305 is a meniscus lens element with negative refractive power, and the convex surface of the meniscus lens element is the light-emitting surface of the fifth lens element 305;
the light incident surface of the first lens element 301 is the light incident surface of the first lens group 3, and the light emitting surface of the fifth lens element 305 is the light emitting surface of the first lens group 3.
The lenticular lens is mainly used for condensing light from a point light source or signal light for transmitting an image to other optical systems.
The plano-convex lens can converge the collimated light beam on a back focus and also can change a point light source into the collimated light beam, and the focal length of the plane of the plano-convex lens is smaller than that of the convex surface of the plano-convex lens.
The meniscus lens is a crescent lens formed by two spherical surfaces with smaller curvature radius and little difference of the curvature radius values, and if a proper thickness is selected, the self-eliminating chromatic aberration can be realized.
It should be noted that, as can be seen from the above description of the aberration, the aberration mainly includes spherical aberration, coma, curvature of field, astigmatism, distortion, chromatic aberration, etc., the lens with positive focal power converges the light beam and generates negative spherical aberration, and the lens with negative focal power diverges the light beam and generates positive spherical aberration, and the above 5 aspheric lenses are used in cooperation with each other to effectively balance spherical aberration, chromatic aberration, coma, etc.
In one implementation, the first lens element 301, the second lens element 302, the third lens element 303, the fourth lens element 304 and the fifth lens element 305 are all axisymmetric aspheric lenses, which facilitates assembly and processing of the first lens group 3.
In one implementation, the first lens group 3 further includes: an aperture stop 306, wherein the aperture stop 306 is disposed between the second lens 302 and the third lens 303, and the aperture stop 306 is disposed to limit the range of the signal light emitted from the predetermined display chip to be projected onto the projection surface, and to eliminate the stray light generated by the optical engine.
In an implementation manner, the two free-form surface lenses of the second lens group 4 have coaxial principal optical axes, such as the sixth lens 401 and the seventh lens 402 shown in fig. 1, and the coaxial principal optical axes of the two free-form surface lenses can improve the installation progress and can effectively balance astigmatism.
In one implementation, the aspheric lens and the free-form surface lens are both made of optical plastic.
Optical plastic is understood to mean, among others, plastic used as optical medium material. The method is mainly used in optical instruments needing to generate a large number of lenses in batches, and is used for manufacturing optical substrates, lenses, contact lenses, organic optical fibers and the like; the optical plastics which are used at present mainly comprise transparent plastics. Therefore, the aspheric lens and the free-form surface lens provided by the embodiment of the invention can be processed by an injection molding process, so that the first lens group and the second lens group can be produced and processed in batch, and further the cost can be saved and the weight of the lens can be reduced.
In one implementation, the material of the first lens element 301 is E48R; the material of the second lens element 302 is OKP 4; the material of the third lens element 303 is E48R; the fourth lens element 304 is made of OKP 4; the material of the fifth lens element 305 is E48R; the material of the free-form surface lens is E48R. OKP4 and E48R are numbers of optical plastic materials, which are conventional materials known in the art. OKP4 and E48R are advantageous in that they are low in cost and light in weight because they can be injection molded.
In one implementation, the coefficient of the aspheric lens is less than or equal to ten orders, so that the aspheric lens with the structure is more convenient to process.
In one implementation, the coefficient of the free-form surface lens is less than or equal to 65 items, and the surface shape of the free-form surface in the free-form surface reflector 5 is a surface shape which can be fitted by calculation to achieve a coefficient of less than or equal to 65 items, and the surface shape facilitates processing.
In one implementation, the maximum distance between the free-form surface reflector 5 and the light incident surface of the first lens 301 is less than or equal to 75mm, and the lens is formed by more than fifteen lenses in the prior art, and the overall length of the lens is about more than 100 mm.
Therefore, the lens provided by the embodiment of the invention adopts the free-form surface lens and the free-form surface reflector, so that the lens provided by the embodiment of the invention and applying the reflective short-focus projection technology does not need to comprise a large number of refraction lenses, and further the number of the lenses forming the lens is reduced, therefore, the complexity of lens assembly can be reduced, the phenomena of image deformation or uneven brightness and the like caused by errors of lens assembly due to the large number of the lenses forming the lens are avoided, the mounting precision of the lens is improved, and a large image with high quality is projected under the condition of short distance. And because the lens materials for constructing the lens are all plastics and can be processed by an injection molding process, the lens has the advantages of low cost, small volume, light weight, high transmittance and the like.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the same element.
All the embodiments in the present specification are described in a related manner, and the same and similar parts among the embodiments may be referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the system embodiment, since it is substantially similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment.
The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.
Claims (13)
1. A lens barrel comprising a first lens group (30), a second lens group (40), and a free-form mirror (50);
the first lens group (30) comprises a first preset number of aspheric lenses, and the first preset number of aspheric lenses are arranged along the main optical axis of one aspheric lens;
the second lens group (40) comprises a second preset number of free-form surface lenses, and the second number of free-form surface lenses are arranged along the main optical axis of one free-form surface lens;
the light incident surface of the first lens group (30) is a surface for receiving incident light of the lens, and the second lens group (40) is located on the light emergent side of the first lens group (30) and on the light incident side of the free-form surface reflector (50).
2. The lens barrel as claimed in claim 1, wherein the first predetermined number is 5 and the second predetermined number is 2.
3. The lens barrel as claimed in claim 2, wherein the first lens group (30) satisfies the following relationship:
F1/F≤2；
f1 is the focal length of the first lens group (30), and F is the focal length of the lens.
4. The lens barrel as set forth in claim 3, wherein the first lens group (30), the second lens group (40), and the free-form surface mirror (50) satisfy the following relationship:
H1/H2>0.8；
h1 is the shortest distance from the edge of the area to be projected to the optical axis of the first lens group (30); h2 is the maximum distance between the point of the free-form surface reflector (50) and the projection surface.
5. The lens barrel according to any one of claims 2 to 4, wherein a main optical axis of the first lens group (30) and a main optical axis of the second lens group (40) are coaxial, or a main optical axis of the first lens group (30), a main optical axis of the second lens group (40), and a main optical axis of the free-form surface mirror (50) are coaxial.
6. The lens barrel as claimed in claim 5, wherein the 5 aspheric lenses have their principal optical axes coaxial and arranged in the order of the principal optical axis: a first lens (301), a second lens (302), a third lens (303), a fourth lens (304), and a fifth lens (305); wherein,
the first lens (301) is a biconvex lens with positive focal power, and a surface corresponding to a small curvature radius of the biconvex lens is a light incident surface of the first lens (301);
the second lens (302) is a meniscus lens with negative focal power, and the convex surface of the meniscus lens is the light-emitting surface of the second lens (302);
the third lens (303) is a plano-convex lens with positive focal power, and the convex surface of the plano-convex lens is the light incident surface of the third lens (303);
the fourth lens (304) is a meniscus lens with negative focal power, and the convex surface of the meniscus lens is the light-emitting surface of the fourth lens (304);
the fifth lens (305) is a meniscus lens with negative focal power, and the convex surface of the meniscus lens is the light-emitting surface of the fifth lens (305);
the light incident surface of the first lens element (301) is the light incident surface of the first lens group (30), and the light emergent surface of the fifth lens element (305) is the light emergent surface of the first lens group (30).
7. The lens barrel as claimed in claim 6, wherein the first lens (301), the second lens (302), the third lens (303), the fourth lens (304) and the fifth lens (305) are all axisymmetric aspherical lenses.
8. The lens barrel according to any one of claims 6 to 7, wherein the first lens group (30) further comprises: an aperture stop (306), the aperture stop (306) disposed between the second lens (302) and the third lens (303).
9. The lens barrel as claimed in claim 8, wherein the aspheric lens and the free-form surface lens are made of optical plastic material.
10. The lens barrel as recited in claim 9,
the material of the first lens (301) is E48R;
the material of the second lens (302) is OKP 4;
the material of the third lens (303) is E48R;
the material of the fourth lens (304) is OKP 4;
the material of the fifth lens (305) is E48R;
the free-form surface lens is made of E48R.
11. The lens barrel as claimed in claim 10, wherein the aspherical lens has a coefficient less than or equal to a tenth order.
12. The lens barrel as claimed in claim 11, wherein the coefficient of the free-form surface lens is less than or equal to 65 terms.
13. A lens barrel according to any one of claims 9 to 12, wherein the maximum distance of the free-form surface reflector (50) from the light incident surface of the first lens (301) is less than or equal to 75 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810327263.1A CN108319002A (en) | 2018-04-12 | 2018-04-12 | A kind of camera lens |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810327263.1A CN108319002A (en) | 2018-04-12 | 2018-04-12 | A kind of camera lens |
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| CN108319002A true CN108319002A (en) | 2018-07-24 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201810327263.1A Pending CN108319002A (en) | 2018-04-12 | 2018-04-12 | A kind of camera lens |
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| CN109445237A (en) * | 2019-01-10 | 2019-03-08 | 上海白泽网络科技有限公司 | Ultrashort coke optical projection system and electronic equipment |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109283774A (en) * | 2018-11-09 | 2019-01-29 | 广景视睿科技（深圳）有限公司 | A kind of projection lens and optical projection system |
| WO2020119421A1 (en) * | 2018-12-10 | 2020-06-18 | 青岛海信激光显示股份有限公司 | Projection imaging system and laser projection device |
| CN109445237A (en) * | 2019-01-10 | 2019-03-08 | 上海白泽网络科技有限公司 | Ultrashort coke optical projection system and electronic equipment |
| CN110286468A (en) * | 2019-06-28 | 2019-09-27 | 沂普光电(天津)有限公司 | A kind of ultrashort out-of-focus projection's system of small size |
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