WO2022267383A1 - 投影镜头 - Google Patents

投影镜头 Download PDF

Info

Publication number
WO2022267383A1
WO2022267383A1 PCT/CN2021/137668 CN2021137668W WO2022267383A1 WO 2022267383 A1 WO2022267383 A1 WO 2022267383A1 CN 2021137668 W CN2021137668 W CN 2021137668W WO 2022267383 A1 WO2022267383 A1 WO 2022267383A1
Authority
WO
WIPO (PCT)
Prior art keywords
lens
projection
cemented
facing
convex
Prior art date
Application number
PCT/CN2021/137668
Other languages
English (en)
French (fr)
Inventor
陈朋波
丁卫涛
王亿新
Original Assignee
歌尔光学科技有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 歌尔光学科技有限公司 filed Critical 歌尔光学科技有限公司
Publication of WO2022267383A1 publication Critical patent/WO2022267383A1/zh

Links

Images

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G02B13/18—Optical objectives specially designed for the purposes specified below with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration
    • 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

Definitions

  • the present application relates to the technical field of projection imaging, in particular to a projection lens and projection equipment.
  • Micro-projection is a projection technology that miniaturizes and makes portable traditional projection display devices.
  • micro-projection equipment is gradually developing in the direction of miniaturization, high brightness, and portability.
  • digital light processing projection equipment Digital Light Processing, DLP
  • DLP Digital Light Processing
  • the optical structure of the current micro-projection lens is too complex and the volume is large, which is difficult to meet the miniaturization requirements of the micro-projection lens, and its processing and assembly are relatively difficult, and the production cost is relatively high.
  • the main purpose of this application is to propose a projection lens, which aims to meet the requirements of small-sized modularization of the projection lens, which can eliminate the aberration of optical imaging, reduce the difficulty of processing and assembly, and reduce the production cost.
  • the present application proposes a projection lens, the projection lens is along the same optical axis from the object side to the image side, including: a first lens, a first cemented lens, a second cemented lens and a sixth lens, the The first lens has negative refractive power; the first cemented lens includes a second lens and a third lens, the second lens is located between the first lens and the third lens, and the second lens The surfaces opposite to the third lens are cemented together, the first cemented lens has positive power; the second cemented lens includes a fourth lens and a fifth lens, and the fourth lens is located between the third lens and the fifth lens. Between the fifth lens and the opposite surfaces of the fourth lens and the fifth lens are cemented together, the second cemented lens has a negative refractive power; the sixth lens has a positive refractive power.
  • the surface of the first lens facing the object side is convex, and the surface facing the image side is concave; the surface of the second lens facing the object side is concave, and the surface facing the image side is concave.
  • the surface is concave; the surface of the third lens facing the object side is convex, and the surface facing the image side is convex; the surface of the fourth lens facing the object side is concave, and the surface facing the image side is concave.
  • the surface is convex.
  • the focal length of the first lens is f1
  • the focal length of the first cemented lens is f2/3
  • the focal length of the second cemented lens is f4/5
  • the focal length of the sixth lens is f6, Among them, -15.5 ⁇ f1 ⁇ -9.5, 15.5 ⁇ f2/3 ⁇ 22.5, -80.5 ⁇ f4/5 ⁇ -52.5, 9.2 ⁇ f6 ⁇ 16.5.
  • the focal length of the projection lens is f, where 5.2 ⁇ f ⁇ 8.5.
  • the first lens is an aspheric lens
  • the sixth lens is an aspheric lens
  • the first lens is made of optical plastic material; and/or, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are all optical Glass material.
  • the projection lens further includes: an aperture disposed between the first cemented lens and the second cemented lens.
  • the present application also provides a projection device, which includes the above-mentioned projection lens and a display unit, and the display unit is arranged on the side of the sixth lens away from the second cemented lens .
  • the projection device further includes: a right-angle prism, and the right-angle prism is arranged between the sixth lens and the display unit.
  • the projection device further includes: a transparent protective layer, the transparent protective layer is disposed on a side of the display unit away from the sixth lens.
  • the projection lens includes a first lens distributed along the same optical axis from the object side to the image side, a first cemented lens, a second cemented lens and a sixth lens, the first lens has a negative refractive power, and the first The cemented lens includes a second lens and a third lens, the first cemented lens has a positive refractive power, the second cemented lens includes a fourth lens and a fifth lens, the second cemented lens has a negative refractive power, and the sixth lens has a positive refractive power , the present application only forms the projection lens through the combination of six lenses, the number of lenses is small, and the structure is compact, which can meet the requirements of small-sized modularization of the projection lens, and, through the cooperative use of lenses of different structures, the optical imaging can be effectively eliminated.
  • the aberrations generated in the projection lens can ensure the imaging quality, so that the projection lens has small distortion, small chromatic aberration, and excellent optical performance, and realizes the effect of small size and high image quality.
  • the use of two cemented lenses enables the projection lens to have a low sensitivity tolerance, thereby reducing the difficulty of lens processing and lens assembly, and reducing production costs.
  • FIG. 1 is a schematic structural view of an embodiment of the projection lens of the present application
  • FIG. 2 is a schematic diagram of the optical path of an embodiment of the projection lens of the present application.
  • Fig. 3 is a modulation transfer function diagram of an embodiment of the projection lens of the present application.
  • Fig. 4 is a ray spot diagram of an embodiment of the projection lens of the present application.
  • FIG. 5 is a field curvature and distortion diagram of an embodiment of the projection lens of the present application.
  • FIG. 6 is a vertical axis chromatic aberration diagram of an embodiment of the projection lens of the present application.
  • label name label name 10 first lens 60 sixth lens 20 second lens 70 aperture 30 third lens 81
  • Display unit 40 fourth lens 82 prism 50
  • fifth lens 83 transparent protective layer
  • This application proposes a projection lens.
  • the projection lens is along the same optical axis from the object side to the image side, including: a first lens 10, a first cemented lens, a second cemented lens and a sixth lens 60 , the first lens 10 has a negative power; the first cemented lens includes a second lens 20 and a third lens 30, the second lens 20 is located between the first lens 10 and the third lens 30, and the second lens 20 and the third lens 30 The opposite surfaces of the three lenses 30 are cemented together, the first cemented lens has positive refractive power; the second cemented lens includes a fourth lens 40 and a fifth lens 50, and the fourth lens 40 is located between the third lens 30 and the fifth lens 50, And the opposite surfaces of the fourth lens 40 and the fifth lens 50 are cemented together, the second cemented lens has a negative power; the sixth lens 60 has a positive power.
  • the image side is the side where the image source (display unit 81) of the projected image is located during the projection process (as shown at B in the figure), and the object side is the projected image imaged on the projection surface (such as a wall) The side where it is located (as shown at A in the figure).
  • a display unit 81 is also provided on the side of the sixth lens 60 away from the second cemented lens, and the projection light signal is sent out by the display unit 81, from the image side to the object side.
  • the fifth lens 50 and the fourth lens 40 the two are cemented to form the second cemented lens
  • the third lens 30 and the second lens 20 the two are cemented to form the first cemented lens
  • the sixth lens A lens 10 finally outputs to the projection surface on the side of the first lens 10 away from the first cemented lens, so as to display the projected image.
  • the result obtained by non-paraxial ray tracing is inconsistent with the result obtained by paraxial ray tracing, and the deviation from the ideal state of Gaussian optics (the first approximation theory or paraxial ray) is called aberration.
  • Aberrations are mainly divided into distortion, field curvature, chromatic aberration, spherical aberration, coma, astigmatism, etc. Aberration will affect the imaging quality of the projection lens. Therefore, when designing the projection lens, it is necessary to eliminate the aberration generated by the imaging of the optical system as much as possible.
  • the focal power is the difference between the convergence degree of the image beam and the object beam convergence, which represents the ability of the optical system to deflect light.
  • a negative power lens is a kind of lens with a thin center and a thick periphery, also known as a concave lens, which has the function of diverging light;
  • a positive power lens is a kind of lens with a thick center and a thin periphery, also known as a convex lens, which has the function of converging light .
  • the optical Field curvature and distortion generated during imaging through the combination of the first lens 10 with negative optical angle, the first cemented lens with positive refractive power, the second cemented lens with negative refractive power, and the sixth lens 60 with positive refractive power, the optical Field curvature and distortion generated during imaging.
  • the first cemented lens composed of the second lens 20 and the third lens 30 and the second cemented lens composed of the fourth lens 40 and the fifth lens 50 can effectively eliminate the chromatic aberration generated in the optical imaging process.
  • the second lens 20 may specifically be a high refractive index flint glass negative lens
  • the third lens 30 may specifically be a low refractive index crown glass positive lens.
  • the projection lens has a low sensitivity tolerance (referring to the eccentricity tolerance of the lens away from the optical axis, that is, the distance between the lens and the lens barrel) gap tolerance), thereby reducing the difficulty of lens processing and lens assembly, and can reduce production costs.
  • the technical solution of the present application only six lenses are combined to form a projection lens, the number of lenses is small, and the structure is compact, which can meet the requirements of small-sized modularization of the projection lens, and through the cooperative use of lenses of different structures , can effectively eliminate the aberration generated in optical imaging, thereby ensuring the imaging quality, making the projection lens have small distortion, small chromatic aberration, excellent optical performance, and achieving the effect of small size and high image quality.
  • the optical focus of the entire optical path of the projection lens Reasonable allocation of degrees, and the use of two cemented lenses makes the projection lens have a low sensitivity tolerance, thereby reducing the difficulty of lens processing and lens assembly, and can reduce production costs.
  • the surface of the first lens 10 facing the object side is convex, and the surface facing the image side is concave;
  • the second lens 20 is facing the object side.
  • the surface is concave, and the surface facing the image side is concave;
  • the surface of the third lens 30 facing the object side is convex, and the surface facing the image side is convex;
  • the surface of the fourth lens 40 facing the object side is The surface of the fifth lens 50 facing the side of the object side is a convex surface, and the surface of the fifth lens 50 facing the side of the image side is a convex surface;
  • the surface of the sixth lens 60 facing the side of the object side is a convex surface.
  • the surface facing the image side is convex.
  • the first lens 10 is a concave-convex lens, which is a meniscus lens, and the first lens 10 is curved toward the object side
  • the second lens 20 is a biconcave lens
  • the third lens 30 is a plano-convex lens
  • the fourth lens 40 is Biconcave lens
  • the fifth lens 50 is a biconvex lens
  • the sixth lens 60 is a biconvex lens.
  • the above-mentioned lens structure is conducive to expanding the viewing angle of the projection lens and realizing the effect of a large viewing angle
  • the first lens 10, the first cemented lens , the second cemented lens and the sixth lens 60 are compact in structure, which is beneficial to the small-sized modularization of the projection lens.
  • the first lens 10 is an aspherical lens.
  • the surfaces on both sides of the first lens 10 are set as aspherical surfaces, and the curvature of the center position and the curvature of the edge position are different, so that the imaging results of the position close to the optical axis and the imaging result of the position far away from the optical axis can be adjusted, reducing
  • the difference between the imaging near the optical axis and the imaging far away from the optical axis reduces the aberration, makes the imaging clearer, realizes the effect of correcting the aberration, and is beneficial to the miniaturization of the projection lens.
  • the entire projection lens only uses two aspheric lenses.
  • the projection lens in this embodiment reduces the number of aspheric lenses to achieve The purpose of reducing production costs while ensuring high-definition, low-distortion image quality.
  • the first lens 10 is made of optical plastic material.
  • the display unit 81 generates heat during operation, so that the plastic lens in the projection lens is susceptible to deformation due to high temperature, which easily shortens its service life and affects the imaging quality of the projection lens. Since the first lens 10 is the farthest from the display unit 81 in the projection lens, it is least affected by high temperature, therefore, the first lens 10 can be set to be made of optical plastic material. Compared with optical glass, optical plastic has strong plasticity, light weight, and easy processing. The advantage of low cost.
  • the second lens 20 , the third lens 30 , the fourth lens 40 , the fifth lens 50 and the sixth lens 60 are made of optical glass.
  • the second lens 20, the third lens 30, and the fourth lens 40 close to the display unit 81 can be placed.
  • the fifth lens 50 and the sixth lens 60 are made of glass, so as to avoid the impact of high temperature on the projection lens to the greatest extent. Further, in order to reduce the production cost, the sixth lens 60 can choose common molded glass with lower price.
  • the projection lens further includes: an aperture 70 disposed between the first cemented lens and the second cemented lens.
  • the diaphragm 70 is specifically an aperture diaphragm 70, and the diaphragm 70 is used to limit the diameter of the projection light passing through, adjust the luminous flux exiting the optical system, and reduce the stray light interference generated by other lenses through reflection, thereby Make the imaging of projected light clearer.
  • the aperture of the aperture 70 is a fixed value.
  • the aperture 70 can also be set in a manner that can adjust the aperture size.
  • the focal length of the first lens 10 is f1
  • the focal length of the first cemented lens is f2/3
  • the focal length of the second cemented lens is f4/5
  • the focal length of the sixth lens 60 is f6, wherein- 15.5 ⁇ f1 ⁇ -9.5, 15.5 ⁇ f2/3 ⁇ 22.5, -80.5 ⁇ f4/5 ⁇ -52.5, 9.2 ⁇ f6 ⁇ 16.5
  • the focal length of the projection lens is f, among which, 5.2 ⁇ f ⁇ 8.5.
  • FIG. 3 illustrates the surface curvature radius and thickness of each lens, as well as the refractive index and Abbe number of each lens in this application.
  • the thickness at the space between serial numbers is expressed as the distance between two adjacent lenses.
  • the throw ratio of the projection lens is 1.2. Specifically, the throw ratio refers to the ratio of the projection distance to the width of the projection screen.
  • the aperture ratio of the projection lens is a large aperture F no1.7, which largely meets the brightness requirements of the projection lens. Specifically, the aperture ratio refers to the ratio of the focal length to the diameter of the aperture. When the aperture ratio is smaller, the relative aperture of the projection lens is larger and the amount of light is greater; when the aperture ratio is larger, the relative aperture of the projection lens is smaller and the amount of light is larger. smaller.
  • the image telecentric optical path of the projection lens is within 1°, and it has a large field of view (the field of view is also called the field of view in optical engineering. The size of the field of view determines the field of view of the optical instrument. The field of view can be FOV Indicated), the field of view meets: 50° ⁇ FOV ⁇ 70°.
  • the projection lens works at 960 ⁇ 540 resolution.
  • Figure 3 is the modulation transfer function diagram of each field of view chip surface of the projection lens, that is, the MTF (ModulationTransferFunction) diagram.
  • the MTF diagram is used to refer to the modulation degree and the number of lines per millimeter in the image. The relationship between them is used to evaluate the ability to restore the details of the scene.
  • the projection distance of the projection equipment is 1329mm, and the projection screen is 50 inches as the judgment.
  • the projection angle is the frequency coordinate between sampling of the field of view, and the ordinate is the MTF value of the transfer function. It can be seen from Figure 3 that MTF>0.51@all field.
  • Figure 4 is the spot diagram of the projection lens; the spot diagram means that after many rays of light emitted from one point pass through the optical component, the intersection point with the image plane is no longer due to aberration Concentrate on the same point to form a diffuse pattern scattered in a certain range, which is used to evaluate the imaging quality of the projection optical system.
  • Figure 5 is the field curvature and distortion diagram of the projection lens, where the field curvature refers to the curvature of the image field, and is mainly used to indicate the intersection point of the entire beam and the ideal image point in the optical component degree of misalignment.
  • Distortion refers to the aberration of different parts of the object with different magnifications when the object is imaged by the optical component. The distortion will cause the similarity of the object image to deteriorate, but it will not affect the clarity of the image. It can be seen from Fig. 5 that the distortion is less than 0.8%, and the target is less than 1%.
  • Figure 6 is the vertical axis chromatic aberration diagram of the projection lens.
  • the vertical axis chromatic aberration refers to the chromatic aberration of magnification, and mainly refers to a complex-color chief ray on the image side.
  • There is dispersion in the refraction system which turns into multiple rays when the object space exits, and the difference between the focus positions of hydrogen blue light and hydrogen red light on the image plane.
  • the present application also proposes a projection device, please refer to Figures 1 to 2, the projection device includes a projection lens and a display unit 81, the specific structure of the projection lens refers to the above-mentioned embodiments, since this projection device adopts all of the above-mentioned embodiments
  • the technical solution therefore, at least has all the beneficial effects brought by the technical solutions of the above embodiments, and will not be described here one by one.
  • the display unit 81 is disposed on a side of the sixth lens 60 away from the second cemented lens.
  • the display unit 81 may be a digital micromirror device (Digital Micromirror Device, DMD) chip, with a specific size of 0.23 inches.
  • DMD Digital Micromirror Device
  • DMD is composed of many digital micro-mirrors arranged in a matrix. When working, each micro-mirror can be deflected and locked in two directions, so that the light is projected in a predetermined direction, and at a frequency of tens of thousands of hertz Swing, the light beam from the illumination source is reflected by the flip of the micro-mirror into the projection lens and imaged on the screen.
  • DMD has the advantages of high resolution and no need for digital-to-analog conversion of signals.
  • the display unit 81 can also use a liquid crystal on silicon (Liquid Crystal On Silicon, LCOS) chip or other display elements that can be used to emit light.
  • LCOS liquid crystal on Silicon
  • the projection device further includes: a rectangular prism 82 disposed between the sixth lens 60 and the display unit 81 .
  • the prism 82 is specifically a rectangular prism 82, and the length of the rectangular side is 10.5 mm.
  • the prism 82 can combine the three-color images of the light pulse signal sent by the display unit 81 into one image, and transmit the corresponding projected light signal to the projection lens for subsequent image display.
  • the projection device further includes: a transparent protective layer 83 , and the transparent protective layer 83 is disposed on a side of the display unit 81 away from the sixth lens 60 .
  • the transparent protective layer 83 is specifically a cover glass, the thickness of the cover glass is 1.1mm, and the cover glass is set on the light-emitting surface of the display unit 81, which can ensure a good light transmittance. , to effectively protect the display unit 81 and prevent external dust from entering the display unit 81 .

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Lenses (AREA)

Abstract

一种投影镜头，投影镜头由物方至像方沿同一光轴，包括：第一透镜（10）、第一胶合透镜、第二胶合透镜以及第六透镜（60），第一透镜（10）具有负光焦度；第一胶合透镜包括第二透镜（20）和第三透镜（30），第二透镜（20）位于第一透镜（10）和第三透镜（30）之间，且第二透镜（20）和第三透镜（30）相对的表面相互胶合，第一胶合透镜具有正光焦度；第二胶合透镜包括第四透镜（40）和第五透镜（50），第四透镜（40）位于第三透镜（30）和第五透镜（50）之间，且第四透镜（40）和第五透镜（50）相对的表面相互胶合，第二胶合透镜具有负光焦度；第六透镜（60）具有正光焦度。能够满足投影镜头的小尺寸模块化的要求，消除光学成像的像差，降低加工及装配难度，减少生产成本。

Description

投影镜头
本申请要求于2021年6月22日提交中国专利局、申请号为202121395120.8、发明名称为“投影镜头”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及投影成像技术领域，特别涉及一种投影镜头及投影设备。
背景技术
微型投影是将传统投影显示装置进行小型化，便携化的一种投影技术。在微型投影技术领域中，微投设备正逐步向着微型化，高亮度，便携式的方向发展。其中，数字化光处理投影设备(Digital Light Procession，DLP)凭借其高清晰的画面、高亮度的图像、丰富的色彩及高对比度的显示已逐渐成为主流投影设备之一。
但目前的微型投影镜头的光学结构过于复杂，体积较大，难以满足微型投影镜头对小型化的要求，且其加工和装配难度较大，生产成本较高。
发明内容
本申请的主要目的是提出一种投影镜头，旨在满足投影镜头的小尺寸模块化的要求，能够消除光学成像的像差，降低加工及装配难度，减少生产成本。
为实现上述目的，本申请提出一种投影镜头，所述投影镜头由物方至像方沿同一光轴，包括：第一透镜、第一胶合透镜、第二胶合透镜以及第六透镜，所述第一透镜具有负光焦度；所述第一胶合透镜包括第二透镜和第三透镜，所述第二透镜位于所述第一透镜和所述第三透镜之间，且所述第二透镜和所述第三透镜相对的表面相互胶合，所述第一胶合透镜具有正光焦度；所述第二胶合透镜包括第四透镜和第五透镜，所述第四透镜位于所述第三透镜 和所述第五透镜之间，且所述第四透镜和所述第五透镜相对的表面相互胶合，所述第二胶合透镜具有负光焦度；所述第六透镜具有正光焦度。
可选地，所述第一透镜朝向物方一侧的表面为凸面、朝向像方一侧的表面为凹面；所述第二透镜朝向物方一侧的表面为凹面、朝向像方一侧的表面为凹面；所述第三透镜朝向物方一侧的表面为凸面、朝向像方一侧的表面为凸面；所述第四透镜朝向物方一侧的表面为凹面、朝向像方一侧的表面为凹面；所述第五透镜朝向物方一侧的表面为凸面、朝向像方一侧的表面为凸面；所述第六透镜朝向物方一侧的表面为凸面、朝向像方一侧的表面为凸面。
可选地，所述第一透镜的焦距为f1，所述第一胶合透镜的焦距为f2/3，所述第二胶合透镜的焦距为f4/5，所述第六透镜的焦距为f6，其中，-15.5<f1<-9.5，15.5<f2/3<22.5，-80.5<f4/5<-52.5，9.2<f6<16.5。
可选地，所述投影镜头的焦距为f，其中，5.2<f<8.5。
可选地，所述第一透镜为非球面透镜；和/或，所述第六透镜为非球面透镜。
可选地，所述第一透镜为光学塑料材质；和/或，所述第二透镜、所述第三透镜、所述第四透镜、所述第五透镜以及所述第六透镜均为光学玻璃材质。
可选地，所述投影镜头还包括：光阑，所述光阑设于所述第一胶合透镜和所述第二胶合透镜之间。
为实现上述目的，本申请还提供一种投影设备，所述投影设备包括如上所述的投影镜头以及显示单元，所述显示单元设于所述第六透镜背离所述第二胶合透镜的一侧。
可选地，所述投影设备还包括：直角棱镜，所述直角棱镜设于所述第六透镜和所述显示单元之间。
可选地，所述投影设备还包括：透明保护层，所述透明保护层设于所述显示单元背离所述第六透镜的一侧。
本申请技术方案中，投影镜头包括由物方至像方沿同一光轴分布的第一透镜、第一胶合透镜、第二胶合透镜以及第六透镜，第一透镜具有负光焦度，第一胶合透镜包括第二透镜和第三透镜，第一胶合透镜具有正光焦度，第二胶合透镜包括第四透镜和第五透镜，第二胶合透镜具有负光焦度，第六透镜 具有正光焦度，本申请仅通过六个透镜组合形成投影镜头，镜片数量少，结构紧凑，能够满足投影镜头的小尺寸模块化的要求，并且，通过不同结构的透镜之间的配合使用，能够有效消除光学成像中产生的像差，从而保证成像质量，使得投影镜头的畸变小、色差小、光学性能优良，实现小尺寸高像质的效果，另外，通过投影镜头整个光路的光焦度的合理分配，并采用两个胶合透镜，使得投影镜头具有低灵敏性的公差，从而降低了镜片加工的难度以及镜片装配的难度，能够减少生产成本。
附图说明
为了更清楚地说明本申请实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本申请的一部分附图，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据提供的附图获得其他的附图。
图1为本申请投影镜头一实施例的结构示意图；
图2为本申请投影镜头一实施例的光路示意图；
图3为本申请投影镜头一实施例的调制传递函数图；
图4为本申请投影镜头一实施例的光线点列图；
图5为本申请投影镜头一实施例的场曲与畸变图；
图6为本申请投影镜头一实施例的垂轴色差图。
附图标号说明：
标号 名称 标号 名称
10 第一透镜 60 第六透镜
20 第二透镜 70 光阑
30 第三透镜 81 显示单元
40 第四透镜 82 棱镜
50 第五透镜 83 透明保护层
本申请目的的实现、功能特点及优点将结合实施例，参照附图做进一步说明。
具体实施方式
下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行描述，显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
需要说明，若本申请实施例中有涉及方向性指示(诸如上、下、左、右、前、后……)，则该方向性指示仅用于解释在某一特定姿态(如附图所示)下各部件之间的相对位置关系、运动情况等，如果该特定姿态发生改变时，则该方向性指示也相应地随之改变。
另外，若本申请实施例中有涉及“第一”、“第二”等的描述，则该“第一”、“第二”等的描述仅用于描述目的，而不能理解为指示或暗示其相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”、“第二”的特征可以明示或者隐含地包括至少一个该特征。另外，各个实施例之间的技术方案可以相互结合，但是必须是以本领域普通技术人员能够实现为基础，当技术方案的结合出现相互矛盾或无法实现时应当认为这种技术方案的结合不存在，也不在本申请要求的保护范围之内。
本申请提出一种投影镜头。
在本申请实施例中，如图1至2所示，该投影镜头由物方至像方沿同一光轴，包括：第一透镜10、第一胶合透镜、第二胶合透镜以及第六透镜60，第一透镜10具有负光焦度；第一胶合透镜包括第二透镜20和第三透镜30，第二透镜20位于第一透镜10和第三透镜30之间，且第二透镜20和第三透镜30相对的表面相互胶合，第一胶合透镜具有正光焦度；第二胶合透镜包括第四透镜40和第五透镜50，第四透镜40位于第三透镜30和第五透镜50之间，且第四透镜40和第五透镜50相对的表面相互胶合，第二胶合透镜具有负光焦度；第六透镜60具有正光焦度。
需要说明的是，像方为投影过程中，投影图像的图像源(显示单元81) 所在的一侧(如图中B处所示)，物方为投影图像成像于投影面(比如墙面)所在的一侧(如图中A处所示)。
具体地，本申请的投影镜头应用于投影设备中时，在第六透镜60背离第二胶合透镜的一侧还设有显示单元81，投影光信号由显示单元81发出，自像方朝物方发射，依次经过第六透镜60、第五透镜50和第四透镜40(二者胶合形成第二胶合透镜)、第三透镜30和第二透镜20(二者胶合形成第一胶合透镜)、第一透镜10，最终输出至位于第一透镜10背离第一胶合透镜一侧的投影面上，从而显示出投影图像。
在光学系统中，由非近轴光线追迹所得的结果和近轴光线追迹所得的结果不一致，与高斯光学(一级近似理论或近轴光线)的理想状况的偏差，称为像差。像差主要分为畸变、场曲、色差、球差、彗差、像散等。像差会影响投影镜头的成像质量，因此，在设计投影镜头时，需要尽可能地消除光学系统成像时产生的像差。
其中，光焦度为像方光束会聚度与物方光束会聚度之差，表征光学系统偏折光线的能力。负光焦度透镜是中间薄、周边厚的一种透镜，又称凹透镜，具有发散光线的作用；正光焦度透镜是中间厚、周边薄的一种透镜，又称凸透镜，具有汇聚光线的作用。本实施例中，通过负光角度的第一透镜10、正光焦度的第一胶合透镜、负光焦度的第二胶合透镜以及正光焦度的第六透镜60的组合，能够有效减小光学成像过程中产生的场曲和畸变。而第二透镜20和第三透镜30组成的第一胶合透镜、由第四透镜40和第五透镜50组成的第二胶合透镜，能够有效消除光学成像过程中产生的色差。以第一胶合透镜为例，第二透镜20具体可以为高折射率的火石玻璃负透镜，第三透镜30具体可以为低折射率的冕牌玻璃正透镜。同时，通过投影镜头整个光路的光焦度的合理分配，并采用两个胶合透镜，使得投影镜头具有低灵敏性的公差(指镜片偏离光轴的偏心距公差，也即镜片与镜筒之间的间隙公差)，从而降低了镜片加工的难度以及镜片装配的难度，能够减少生产成本。
因此，本申请的技术方案中，仅通过六个透镜组合形成投影镜头，镜片数量少，结构紧凑，能够满足投影镜头的小尺寸模块化的要求，并且，通过不同结构的透镜之间的配合使用，能够有效消除光学成像中产生的像差，从而保证成像质量，使得投影镜头的畸变小、色差小、光学性能优良，实现小 尺寸高像质的效果，另外，通过投影镜头整个光路的光焦度的合理分配，并采用两个胶合透镜，使得投影镜头具有低灵敏性的公差，从而降低了镜片加工的难度以及镜片装配的难度，能够减少生产成本。
在本申请的一实施例中，请参阅图1至2，第一透镜10朝向物方一侧的表面为凸面、朝向像方一侧的表面为凹面；第二透镜20朝向物方一侧的表面为凹面、朝向像方一侧的表面为凹面；第三透镜30朝向物方一侧的表面为凸面、朝向像方一侧的表面为凸面；第四透镜40朝向物方一侧的表面为凹面、朝向像方一侧的表面为凹面；第五透镜50朝向物方一侧的表面为凸面、朝向像方一侧的表面为凸面；第六透镜60朝向物方一侧的表面为凸面、朝向像方一侧的表面为凸面。
本实施例中，第一透镜10为凹凸透镜，为弯月形透镜，且第一透镜10朝向物方弯曲，第二透镜20为双凹透镜，第三透镜30为平凸透镜，第四透镜40为双凹透镜，第五透镜50为双凸透镜，第六透镜60为双凸透镜，上述镜片结构，有利于扩大投影镜头的视场角，实现大视场角效果，且第一透镜10、第一胶合透镜、第二胶合透镜以及第六透镜60结构紧凑，有利于投影镜头的小尺寸模块化。
在本申请的一实施例中，第一透镜10为非球面透镜。
本实施例中，将第一透镜10的两侧表面均设置为非球面，通过中心位置的曲率和边缘位置的曲率不同，可以调整靠近光轴位置的成像和远离光轴位置的成像结果，减少靠近光轴位置的成像和远离光轴位置的成像差异，进而减少像差，使成像更清晰，实现校正像差的效果，有利于投影镜头的小型化。同样地，通过设置第六透镜60的两侧表面均为非球面，可以有效消除光学成像过程中产生的球差、彗差和像散，实现校正像差的效果。本申请技术方案中，整个投影镜头仅采用两片非球面镜片，相比其他采用三片甚至更多非球面镜片的投影镜头来说，本实施例的投影镜头通过减少非球面镜片的数量，达到降低生产成本的目的，同时能够保证高清晰度、低畸变的像质。
在本申请的一实施例中，第一透镜10为光学塑料材质。
本实施例中，显示单元81在工作过程中会产生热量，使得投影镜头中的塑料透镜容易受到高温的影响而产生形变，容易缩短其使用寿命，还会影响投影镜头的成像质量。由于第一透镜10在投影镜头中距离显示单元81最远，受高温影响最小，因此，可以设置第一透镜10为光学塑料材质，相比于光学玻璃，光学塑料具有可塑性强，重量轻，加工成本低的优点。
在本申请的一实施例中，第二透镜20、第三透镜30、第四透镜40、第五透镜50以及第六透镜60均为光学玻璃材质。
由于在同等温度下，玻璃材质的受热畸变率远远低于塑料材质，具有较好的稳定性，因此，可以将靠近显示单元81的第二透镜20、第三透镜30、第四透镜40第五透镜50以及第六透镜60设置为玻璃材质，从而最大程度上避免高温对投影镜头的影响。进一步地，为了降低制作成本，第六透镜60可以选择价格较低的常用模压玻璃。
在本申请的一实施例中，请参阅图1至2，投影镜头还包括：光阑70，光阑70设于第一胶合透镜和第二胶合透镜之间。
本实施例中，光阑70具体为孔径光阑70，光阑70用于限制通过的投影光线的直径，调节射出所述光学系统的光通量，同时减少其他透镜经过反射产生的杂散光干扰，从而使投影光线的成像更加清晰。通常，光阑70的孔径为一个固定值，当然，为了灵活调整成像清晰度，使投影镜头能够更好的适应高低分辨率的切换，还可以将光阑70设置为可以调整孔径大小的方式。
作为可选的实施方式，第一透镜10的焦距为f1，第一胶合透镜的焦距为f2/3，第二胶合透镜的焦距为f4/5，第六透镜60的焦距为f6，其中，-15.5<f1<-9.5，15.5<f2/3<22.5，-80.5<f4/5<-52.5，9.2<f6<16.5；投影镜头的焦距为f，其中，5.2<f<8.5。通过上述结构设置，可进一步优化本申请的投影镜头。
为了进一步优化投影镜头的性能，请参阅图3，本申请中举例说明各个透镜的表面曲率半径和厚度，以及各个透镜的折射率和阿贝数。其中，序号间隔位置的厚度表示为相邻两个透镜之间的距离。
表1：
Figure PCTCN2021137668-appb-000001
本实施例中，投影镜头的投射比为1.2，具体地，投射比是指投影距离与投影画面宽度的比值。投影镜头的光圈比为大光圈F no1.7，极大程度上满足了投影镜头对亮度的要求。具体地，光圈比是指焦距与光圈直径的比值，当光圈比越小时，投影镜头的相对口径越大，通光量越大；当光圈比越大时，投影镜头的相对口径越小，通光量越小。投影镜头的像方远心光路在1°内，并且具备大视场角(视场角在光学工程中又称视场，视场角的大小决定了光学仪器的视野范围，视场角可用FOV表示)，视场角满足：50°<FOV<70°。投影镜头工作时是960×540分辨率。
基于表1的参数数据，请参阅图3，图3为投影镜头的各视场芯片面调制传递函数图，即MTF(ModulationTransferFunction)图，MTF图用于是指 调制度与图像内每毫米线对数之间的关系，用于评价对景物细部还原能力。投影设备的投影距离为1329mm，投影屏幕50寸为判断情况，以投影角度为视场取样间频率坐标，纵坐标为传递函数MTF值。可图3可知，MTF＞0.51@all field。
基于表1的参数数据，请参阅图4，图4为投影镜头的点列图；其中点列图是指由一点发出的许多光线经光学组件后，因像差使其与像面的交点不再集中于同一点，而形成了一个散布在一定范围的弥散图形，用于评价所述投影光学系统的成像质量。均方根半径值和几何半径值越小成像质量越好。由图4可知，所有视场点列图均方根半径最大为3.2um，小于像素5.4um。
基于表1的参数数据，请参阅图5，图5为投影镜头的场曲与畸变图，其中，场曲是指像场弯曲，主要用于表示光学组件中，整个光束的交点与理想像点的不重合程度。畸变是指物体通过光学组件成像时，物体不同部分有不同的放大率的像差，畸变会导致物像的相似性变坏，但不影响像的清晰度。由图5可知，畸变小于0.8％，满足目标即小于1％。
基于表1的参数数据，请参阅图6，图6为投影镜头的垂轴色差图，其中，垂轴色差是指又称为倍率色差，主要是指像方的一根复色主光线，因折射系统存在色散，在物方出射时变成多根光线，氢蓝光与氢红光在像面上的焦点位置的差值。
本申请还提出一种投影设备，请参阅图1至2，该投影设备包括投影镜头和显示单元81，该投影镜头的具体结构参照上述实施例，由于本投影设备采用了上述所有实施例的全部技术方案，因此至少具有上述实施例的技术方案所带来的所有有益效果，在此不再一一赘述。其中，显示单元81设于第六透镜60背离第二胶合透镜的一侧。
本实施例中，显示单元81可选数字微镜元件(Digital Micromirror Device，DMD)芯片，具体大小为0.23英寸。DMD是由很多矩阵排列的数字微反射镜组成，工作时每个微反射镜都能够朝正反两个方向进行偏转并锁定，从而使光线按既定的方向进行投射，并且以数万赫兹的频率进行摆动，将来自照明光源的光束通过微反射镜的翻转反射进入投影镜头成像在屏幕上。DMD具有分辨率高，信号无需数模转换等优点。当然，显示单元81也可以选用硅上 液晶(Liquid Crystal On Silicon，LCOS)芯片或其他可用于出射光线的显示元件。
在本申请的一实施例中，请参阅图1至2，投影设备还包括：直角棱镜82，直角棱镜82设于第六透镜60和显示单元81之间。
本实施例中，棱镜82具体为直角棱镜82，直角边长为10.5mm。棱镜82可以将显示单元81发出光脉冲信号三色图像组合成一个图像，并将相应的投影光信号传递至投影镜头，以便后续图像的显示。
在本申请的一实施例中，请参阅图1至2，投影设备还包括：透明保护层83，透明保护层83设于显示单元81背离第六透镜60的一侧。
本实施例中，透明保护层83具体为一盖玻片，盖玻片的厚度为1.1㎜，盖玻片盖设于显示单元81的出光面，能够在保证很好的透光率的前提下，有效保护显示单元81，防止外界的灰尘进入显示单元81。
以上所述仅为本申请的优选实施例，并非因此限制本申请的专利范围，凡是在本申请的发明构思下，利用本申请说明书及附图内容所作的等效结构变换，或直接/间接运用在其他相关的技术领域均包括在本申请的专利保护范围内。

Claims (10)

  1. 一种投影镜头，其特征在于，由物方至像方沿同一光轴，包括：
    第一透镜，所述第一透镜具有负光焦度；
    第一胶合透镜，所述第一胶合透镜包括第二透镜和第三透镜，所述第二透镜位于所述第一透镜和所述第三透镜之间，且所述第二透镜和所述第三透镜相对的表面相互胶合，所述第一胶合透镜具有正光焦度；
    第二胶合透镜，所述第二胶合透镜包括第四透镜和第五透镜，所述第四透镜位于所述第三透镜和所述第五透镜之间，且所述第四透镜和所述第五透镜相对的表面相互胶合，所述第二胶合透镜具有负光焦度；以及
    第六透镜，所述第六透镜具有正光焦度。
  2. 如权利要求1所述的投影镜头，其特征在于，所述第一透镜朝向物方一侧的表面为凸面、朝向像方一侧的表面为凹面；
    所述第二透镜朝向物方一侧的表面为凹面、朝向像方一侧的表面为凹面；
    所述第三透镜朝向物方一侧的表面为凸面、朝向像方一侧的表面为凸面；
    所述第四透镜朝向物方一侧的表面为凹面、朝向像方一侧的表面为凹面；
    所述第五透镜朝向物方一侧的表面为凸面、朝向像方一侧的表面为凸面；
    所述第六透镜朝向物方一侧的表面为凸面、朝向像方一侧的表面为凸面。
  3. 如权利要求1所述的投影镜头，其特征在于，所述第一透镜的焦距为f1，所述第一胶合透镜的焦距为f2/3，所述第二胶合透镜的焦距为f4/5，所述第六透镜的焦距为f6，
    其中，-15.5<f1<-9.5，15.5<f2/3<22.5，-80.5<f4/5<-52.5，9.2<f6<16.5。
  4. 如权利要求1所述的投影镜头，其特征在于，所述投影镜头的焦距为f，其中，5.2<f<8.5。
  5. 如权利要求1所述的投影镜头，其特征在于，所述第一透镜为非球面透镜；
    和/或，所述第六透镜为非球面透镜。
  6. 如权利要求1所述的投影镜头，其特征在于，所述第一透镜为光学塑料材质；
    和/或，所述第二透镜、所述第三透镜、所述第四透镜、所述第五透镜以及所述第六透镜均为光学玻璃材质。
  7. 如权利要求1至6中任一项所述的投影镜头，其特征在于，所述投影镜头还包括：
    光阑，所述光阑设于所述第一胶合透镜和所述第二胶合透镜之间。
  8. 一种投影设备，其特征在于，所述投影设备包括如权利要求1至7中任一项所述的投影镜头以及显示单元，所述显示单元设于所述第六透镜背离所述第二胶合透镜的一侧。
  9. 如权利要求8所述的投影设备，其特征在于，所述投影设备还包括：
    直角棱镜，所述直角棱镜设于所述第六透镜和所述显示单元之间。
  10. 如权利要求8或9所述的投影设备，其特征在于，所述投影设备还包括：
    透明保护层，所述透明保护层设于所述显示单元背离所述第六透镜的一侧。
PCT/CN2021/137668 2021-06-22 2021-12-14 投影镜头 WO2022267383A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202121395120.8 2021-06-22
CN202121395120.8U CN214751068U (zh) 2021-06-22 2021-06-22 投影镜头及投影设备

Publications (1)

Publication Number Publication Date
WO2022267383A1 true WO2022267383A1 (zh) 2022-12-29

Family

ID=78630758

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/137668 WO2022267383A1 (zh) 2021-06-22 2021-12-14 投影镜头

Country Status (2)

Country Link
CN (1) CN214751068U (zh)
WO (1) WO2022267383A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117031690A (zh) * 2023-08-02 2023-11-10 江苏泽景汽车电子股份有限公司 投影镜头、投影系统及抬头显示设备

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN214751068U (zh) * 2021-06-22 2021-11-16 歌尔股份有限公司 投影镜头及投影设备
CN114740600A (zh) * 2022-03-31 2022-07-12 歌尔光学科技有限公司 一种光学投影系统以及电子设备

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013174794A (ja) * 2012-02-27 2013-09-05 Nikon Corp レンズ系、光学機器、およびレンズ系の製造方法
CN106918890A (zh) * 2015-12-24 2017-07-04 宁波舜宇车载光学技术有限公司 光学成像镜头及其透镜组
CN109001887A (zh) * 2017-06-07 2018-12-14 宁波舜宇车载光学技术有限公司 光学镜头
CN111090168A (zh) * 2018-10-24 2020-05-01 宁波舜宇车载光学技术有限公司 光学镜头
CN112255767A (zh) * 2020-11-06 2021-01-22 歌尔光学科技有限公司 投影镜头和投影设备
CN214751068U (zh) * 2021-06-22 2021-11-16 歌尔股份有限公司 投影镜头及投影设备

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013174794A (ja) * 2012-02-27 2013-09-05 Nikon Corp レンズ系、光学機器、およびレンズ系の製造方法
CN106918890A (zh) * 2015-12-24 2017-07-04 宁波舜宇车载光学技术有限公司 光学成像镜头及其透镜组
CN109001887A (zh) * 2017-06-07 2018-12-14 宁波舜宇车载光学技术有限公司 光学镜头
CN111090168A (zh) * 2018-10-24 2020-05-01 宁波舜宇车载光学技术有限公司 光学镜头
CN112255767A (zh) * 2020-11-06 2021-01-22 歌尔光学科技有限公司 投影镜头和投影设备
CN214751068U (zh) * 2021-06-22 2021-11-16 歌尔股份有限公司 投影镜头及投影设备

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117031690A (zh) * 2023-08-02 2023-11-10 江苏泽景汽车电子股份有限公司 投影镜头、投影系统及抬头显示设备
CN117031690B (zh) * 2023-08-02 2024-04-23 江苏泽景汽车电子股份有限公司 投影镜头、投影系统及抬头显示设备

Also Published As

Publication number Publication date
CN214751068U (zh) 2021-11-16

Similar Documents

Publication Publication Date Title
WO2022267383A1 (zh) 投影镜头
CN103777314B (zh) 广角投影镜头
WO2023070811A1 (zh) 光学系统及投影装置
CN107422458B (zh) 一种低f数的l型短焦全高清投影镜头
US20160077319A1 (en) Projection-type video display device
WO2021036134A1 (zh) 投影镜头及投影设备
WO2023070810A1 (zh) 投影镜头及投影装置
WO2023184752A1 (zh) 一种光学投影系统以及电子设备
WO2022267342A1 (zh) 投影镜组和投影装置
CN114594574B (zh) 一种光学投影系统以及电子设备
CN109407288B (zh) 一种折反式超短焦投影镜头系统
CN107490846A (zh) 一种投影镜头
JP2000275729A (ja) 投影レンズ
CN111580247B (zh) 一种整体调焦高清微投投射镜头
WO2023231111A1 (zh) 投影镜头以及投影装置
CN114690377B (zh) 一种光学投影系统以及电子设备
CN214751069U (zh) 投影镜头和投影设备
WO2023206784A1 (zh) 一种光学投影系统以及电子设备
CN214504006U (zh) 投影镜头、投影显示系统及投影显示装置
CN110187470A (zh) 投影镜头、投影光学系统及投影设备
CN116125637A (zh) 投影镜头以及投影装置
CN110873955A (zh) 一种投影机用超短焦镜头
CN114545611A (zh) 4k超短焦投影镜头
CN110764221B (zh) 投影镜头系统
CN107329352B (zh) 一种投影镜头和投影系统

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21946857

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE