CN107728295B - Projection lens - Google Patents
Projection lens Download PDFInfo
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- CN107728295B CN107728295B CN201711166983.6A CN201711166983A CN107728295B CN 107728295 B CN107728295 B CN 107728295B CN 201711166983 A CN201711166983 A CN 201711166983A CN 107728295 B CN107728295 B CN 107728295B
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- 238000003384 imaging method Methods 0.000 claims abstract description 61
- 230000003287 optical effect Effects 0.000 claims abstract description 49
- 238000002834 transmittance Methods 0.000 claims description 11
- 230000004075 alteration Effects 0.000 description 15
- 230000014509 gene expression Effects 0.000 description 8
- 230000009286 beneficial effect Effects 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 3
- 230000035945 sensitivity Effects 0.000 description 3
- 238000011161 development Methods 0.000 description 2
- 230000018109 developmental process Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- MKYBYDHXWVHEJW-UHFFFAOYSA-N N-[1-oxo-1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propan-2-yl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(C(C)NC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 MKYBYDHXWVHEJW-UHFFFAOYSA-N 0.000 description 1
- 201000009310 astigmatism Diseases 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
Classifications
-
- 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
-
- 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
- G02B13/003—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 two lenses
-
- 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
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- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Lenses (AREA)
Abstract
The application discloses a projection lens, which sequentially comprises from an image source side to an imaging side along an optical axis: a first lens and a second lens. The first lens has negative focal power, the image source side surface of the first lens is concave, and the image forming side surface of the first lens is convex; the second lens has positive optical power, and its imaging side surface is convex.
Description
Technical Field
The present application relates to a projection lens, and more particularly, to a projection lens including two lenses.
Background
With the rapid development of technology, interactive devices are gradually rising, and the application range of projection lenses is also wider and wider. Today, chip technology and intelligent algorithms are rapidly developed, and three-dimensional images with position depth information can be calculated by projecting images to space objects by using an optical projection lens and receiving the image signals. The three-dimensional image with depth information can be further used in various depth application developments such as biological recognition.
Conventional projection lenses for imaging generally eliminate various aberrations and improve resolution by increasing the number of lenses. However, increasing the number of lenses causes an increase in the total optical length of the projection lens, thereby being disadvantageous in achieving miniaturization of the lens. In addition, the general projection lens has a plurality of problems such as large distortion and poor imaging quality.
Disclosure of Invention
The present application provides a projection lens applicable to a portable electronic product, which at least solves or partially solves at least one of the above-mentioned drawbacks of the prior art.
In one aspect, the present application provides a projection lens comprising, in order from an image source side to an image forming side along an optical axis: a first lens and a second lens. The first lens may have negative optical power, the image source side surface thereof may be concave, and the image forming side surface thereof may be convex; the second lens may have positive optical power, and an imaging side surface thereof may be convex.
In one embodiment, the object numerical aperture NA of the projection lens may satisfy NA.gtoreq.0.18.
In one embodiment, the maximum half field angle HFOV of the projection lens may satisfy HFOV < 15.
In one embodiment, the total optical length TTL of the projection lens may satisfy 3mm < TTL < 3.7mm.
In one embodiment, the light transmittance of the projection lens may be greater than 85% in the light wave band of 800nm to 1000 nm.
In one embodiment, the effective focal length f2 of the second lens and the total effective focal length f of the projection lens may satisfy 0.7 < f2/f < 1.2.
In one embodiment, the radius of curvature R4 of the imaging side surface of the second lens and the total effective focal length f of the projection lens may satisfy-0.6 < R4/f < -0.2.
In one embodiment, the radius of curvature R2 of the imaging side surface of the first lens and the radius of curvature R1 of the image source side surface of the first lens may satisfy (R2-R1)/(R2+R1) < 0.5.
In one embodiment, the effective half-caliber DT22 of the imaging side surface of the second lens and the effective half-caliber DT21 of the image source side surface of the second lens may satisfy 1.0 < DT22/DT21 < 1.3.
In another aspect, the present application further provides a projection lens, including, in order from an image source side to an imaging side along an optical axis: a first lens and a second lens. The first lens may have negative optical power, the image source side surface thereof may be concave, and the image forming side surface thereof may be convex; the second lens may have positive optical power, and an imaging side surface thereof may be convex; and wherein the total optical length TTL of the projection lens can satisfy 3mm < TTL < 3.7mm.
In still another aspect, the present application further provides a projection lens, including, in order from an image source side to an imaging side along an optical axis: a first lens and a second lens. The first lens may have negative optical power, the image source side surface thereof may be concave, and the image forming side surface thereof may be convex; the second lens may have positive optical power, and an imaging side surface thereof may be convex; and wherein the maximum half field angle HFOV of the projection lens may satisfy HFOV < 15 °.
In still another aspect, the present application further provides a projection lens, including, in order from an image source side to an imaging side along an optical axis: a first lens and a second lens. The first lens may have negative optical power, the image source side surface thereof may be concave, and the image forming side surface thereof may be convex; the second lens may have positive optical power, and an imaging side surface thereof may be convex; and wherein the light transmittance of the projection lens may be greater than 85% in the light wave band of 800nm to 1000 nm.
In still another aspect, the present application further provides a projection lens, including, in order from an image source side to an imaging side along an optical axis: a first lens and a second lens. The first lens may have negative optical power, the image source side surface thereof may be concave, and the image forming side surface thereof may be convex; the second lens may have positive optical power, and an imaging side surface thereof may be convex; and wherein the radius of curvature R4 of the imaging side surface of the second lens and the total effective focal length f of the projection lens may satisfy-0.6 < R4/f < -0.2.
In still another aspect, the present application further provides a projection lens, including, in order from an image source side to an imaging side along an optical axis: a first lens and a second lens. The first lens may have negative optical power, the image source side surface thereof may be concave, and the image forming side surface thereof may be convex; the second lens may have positive optical power, and an imaging side surface thereof may be convex; and wherein the effective half-caliber DT22 of the imaging side surface of the second lens and the effective half-caliber DT21 of the image source side surface of the second lens may satisfy 1.0 < DT22/DT21 < 1.3.
The application adopts a plurality of (for example, two) lenses, and the projection lens has at least one beneficial effects of miniaturization, large numerical aperture, high imaging quality and the like by reasonably distributing the focal power, the surface type, the center thickness of each lens, the axial spacing between each lens and the like.
Drawings
Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments, taken in conjunction with the accompanying drawings. In the drawings:
fig. 1 shows a schematic configuration of a projection lens according to embodiment 1 of the present application;
fig. 2A to 2B show a distortion curve and a magnification chromatic aberration curve of the projection lens of embodiment 1, respectively;
fig. 3 is a schematic view showing the structure of a projection lens according to embodiment 2 of the present application;
fig. 4A to 4B show a distortion curve and a magnification chromatic aberration curve of the projection lens of embodiment 2, respectively;
fig. 5 shows a schematic structural view of a projection lens according to embodiment 3 of the present application;
fig. 6A to 6B show a distortion curve and a magnification chromatic aberration curve of the projection lens of embodiment 3, respectively;
fig. 7 is a schematic view showing the structure of a projection lens according to embodiment 4 of the present application;
fig. 8A to 8B show a distortion curve and a magnification chromatic aberration curve of the projection lens of embodiment 4, respectively;
fig. 9 is a schematic view showing the structure of a projection lens according to embodiment 5 of the present application;
fig. 10A to 10B show distortion curves and magnification chromatic aberration curves of the projection lens of embodiment 5.
Detailed Description
For a better understanding of the application, various aspects of the application will be described in more detail with reference to the accompanying drawings. It should be understood that the detailed description is merely illustrative of exemplary embodiments of the application and is not intended to limit the scope of the application in any way. Like reference numerals refer to like elements throughout the specification. The expression "and/or" includes any and all combinations of one or more of the associated listed items.
It should be noted that in this specification, the expressions first, second, etc. are only used to distinguish one feature from another feature, and do not represent any limitation of the feature. Accordingly, a first lens discussed below may also be referred to as a second lens, and a second lens may also be referred to as a first lens, without departing from the teachings of the present application.
In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for convenience of explanation. In particular, the spherical or aspherical shape shown in the drawings is shown by way of example. That is, the shape of the spherical or aspherical surface is not limited to the shape of the spherical or aspherical surface shown in the drawings. The figures are merely examples and are not drawn to scale.
Herein, the paraxial region refers to a region near the optical axis. If the lens surface is convex and the convex position is not defined, then the lens surface is convex at least in the paraxial region; if the lens surface is concave and the concave position is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the image source side is referred to as an image source side surface, and the surface of each lens closest to the image side is referred to as an image side surface.
It will be further understood that the terms "comprises," "comprising," "includes," "including," "having," "containing," and/or "including," when used in this specification, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof. Furthermore, when a statement such as "at least one of the following" appears after a list of features that are listed, the entire listed feature is modified instead of modifying a separate element in the list. Furthermore, when describing embodiments of the application, use of "may" means "one or more embodiments of the application. Also, the term "exemplary" is intended to refer to an example or illustration.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The application will be described in detail below with reference to the drawings in connection with embodiments.
The features, principles, and other aspects of the present application are described in detail below.
The projection lens according to an exemplary embodiment of the present application may include, for example, two lenses having optical power, i.e., a first lens and a second lens. The two lenses are sequentially arranged from the image source side to the image side along the optical axis.
In an exemplary embodiment, the first lens may have negative optical power, an image source side surface of which is concave, and an image forming side surface of which is convex; the second lens has positive optical power, and its imaging side surface is convex.
In an exemplary embodiment, the projection lens of the present application may satisfy the condition HFOV < 15, where HFOV is the maximum half field angle of the projection lens. More specifically, HFOV's may further satisfy 8 < HFOV < 12, e.g., 8.5 < HFOV < 11.3. Satisfying the conditional HFOV < 15 facilitates control of reducing aberrations in the off-axis field of view region and improving projection quality; and meanwhile, the uniformity of imaging quality and projection focal depth of an on-axis view field area and an off-axis view field area are improved.
In an exemplary embodiment, the projection lens of the present application may satisfy the conditional expression 3mm < TTL < 3.7mm, where TTL is the optical total length of the projection lens. The total optical length of the projection lens refers to the distance on the optical axis from the center of the imaging side surface of the second lens to the image source (e.g., the surface of a spatial light modulator for modulating the projection signal). More specifically, TTL can further satisfy TTL of 3.25 mm.ltoreq.TTL.ltoreq.3.51 mm. The method satisfies the condition that TTL is smaller than 3.7mm and is beneficial to realizing miniaturization of the projection lens, thereby being beneficial to the projection lens to be widely carried on various portable electronic products.
In an exemplary embodiment, the projection lens of the present application may satisfy the conditional expression 0.7 < f2/f < 1.2, where f2 is an effective focal length of the second lens and f is a total effective focal length of the projection lens. More specifically, f2 and f may further satisfy 0.80.ltoreq.f2/f.ltoreq.1.16. The focal power of the second lens is reasonably controlled, so that the miniaturization and projection imaging quality of the lens are balanced.
In an exemplary embodiment, the projection lens of the present application may satisfy a conditional expression NA being equal to or greater than 0.18, where NA is an object-side numerical aperture of the projection lens. More specifically, NA may further satisfy na=0.20. The projection lens has a larger numerical aperture, and can improve the projection energy efficiency, thereby obtaining a projection image with higher brightness.
In an exemplary embodiment, the projection lens of the present application has a light transmittance of greater than 85% in the light wavelength band of about 800nm to about 1000 nm. Such an arrangement is advantageous in improving the transmittance of near infrared light through the projection lens, thereby obtaining a near infrared projection image of higher brightness.
In an exemplary embodiment, the projection lens of the present application may satisfy the condition-0.6 < R4/f < -0.2, where R4 is a radius of curvature of an imaging side surface of the second lens and f is a total effective focal length of the projection lens. More specifically, R4 and f may further satisfy-0.54.ltoreq.R4/f.ltoreq.0.40. The ratio of R4 to f is reasonably controlled, so that astigmatism of a projection lens is reduced, and projection imaging quality is improved.
In an exemplary embodiment, the projection lens of the present application may satisfy the conditional expression (R2-R1)/(r2+r1) < 0.5, where R2 is a radius of curvature of an imaging side surface of the first lens and R1 is a radius of curvature of an image source side surface of the first lens. More specifically, R2 and R1 may further satisfy 0 < (R2-R1)/(R2+R1) < 0.5, for example, 0.13.ltoreq.R 2-R1)/(R2+R1).ltoreq.0.47. Satisfies the conditional expression (R2-R1)/(R2+R1) < 0.5, and is beneficial to the processing and manufacturing of the first lens; at the same time, an increase in tolerance sensitivity due to too small a radius of curvature can also be avoided.
In an exemplary embodiment, the projection lens of the present application may satisfy the conditional expression 1.0 < DT22/DT21 < 1.3, wherein DT22 is an effective half-caliber of an image side surface of the second lens and DT21 is an effective half-caliber of an image source side surface of the second lens. More specifically, DT22 and DT21 may further satisfy 1.05.ltoreq.DT 22/DT 21.ltoreq.1.19. Satisfies the condition that DT22/DT21 is smaller than 1.3 and is beneficial to avoiding the degradation of imaging quality caused by excessive bending of light; meanwhile, the method is also beneficial to avoiding the problems of difficult processing and manufacturing and the like caused by higher tolerance sensitivity.
In an exemplary embodiment, the projection lens may further include at least one diaphragm to improve the imaging quality of the lens. The diaphragm may be disposed at an arbitrary position as needed, for example, the diaphragm may be disposed between the second lens and the imaging side.
Alternatively, the projection lens may further include other well-known optical projection elements, such as a prism, a field lens, and the like.
The projection lens according to the above embodiment of the present application may employ, for example, two lenses, and may have at least one advantageous effect of miniaturization, large numerical aperture, low sensitivity, high imaging quality, etc. by reasonably distributing the optical power of each lens, the surface, the center thickness of each lens, the on-axis spacing between each lens, etc.
In an embodiment of the present application, at least one of the mirrors of each lens is an aspherical mirror. The aspherical lens is characterized in that: the curvature varies continuously from the center of the lens to the periphery of the lens. Unlike a spherical lens having a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has a better radius of curvature characteristic, and has advantages of improving distortion aberration and improving astigmatic aberration. By adopting the aspherical lens, aberration occurring at the time of imaging can be eliminated as much as possible, thereby improving imaging quality.
However, those skilled in the art will appreciate that the various results and advantages described in this specification can be obtained by varying the number of lenses making up a projection lens without departing from the technical solution claimed in the present application. For example, although the description has been made by taking two lenses as an example in the embodiment, the projection lens is not limited to include two lenses. The projection lens may also include other numbers of lenses, if desired.
Specific examples of projection lenses applicable to the above embodiments are further described below with reference to the accompanying drawings.
Example 1
A projection lens according to embodiment 1 of the present application is described below with reference to fig. 1 to 2B. Fig. 1 shows a schematic configuration of a projection lens according to embodiment 1 of the present application.
As shown in fig. 1, a projection lens according to an exemplary embodiment of the present application sequentially includes, along an optical axis from an image source side to an image forming side: a first lens E1, a second lens E2 and a stop STO.
The first lens E1 has negative power, the image source side surface S1 thereof is concave, and the image forming side surface S2 is convex. The second lens E2 has positive power, the image source side surface S3 thereof is concave, and the image forming side surface S4 thereof is convex. The projection lens has a light transmittance of greater than 85% in the light wave band of about 800nm to about 1000 nm. Light from the image source passes sequentially through the respective surfaces S1 to S4 and is finally imaged on an imaging surface (not shown) such as a projection screen.
Table 1 shows the surface types, radii of curvature, thicknesses, materials, and cone coefficients of the respective lenses of the projection lens of example 1, wherein the radii of curvature and thicknesses are each in millimeters (mm).
TABLE 1
As can be seen from table 1, the image source side surface S1 and the image side surface S2 of the first lens E1 and the image source side surface S3 and the image side surface S4 of the second lens E2 are aspherical surfaces. In the present embodiment, the surface shape x of each aspherical lens can be defined by, but not limited to, the following aspherical formula:
wherein x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at the position with the height h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c=1/R (i.e., paraxial curvature c is the inverse of radius of curvature R in table 1 above); k is the conic coefficient (given in table 1); ai is the correction coefficient of the aspherical i-th order. Table 2 below shows the higher order coefficients A that can be used for each of the aspherical mirror surfaces S1-S4 in example 1 4 、A 6 、A 8 、A 10 And A 12 。
| Face number | A4 | A6 | A8 | A10 | A12 |
| S1 | -3.1511E-01 | -4.7845E-01 | 1.1704E+00 | -3.5529E+00 | 3.1022E+00 |
| S2 | -1.9839E-01 | 2.7878E-02 | -1.0343E-01 | 7.7254E-02 | -7.2984E-03 |
| S3 | -4.5669E-03 | 8.2476E-02 | -8.0116E-02 | 5.1704E-02 | -1.8540E-02 |
| S4 | 1.6442E-02 | 1.4075E-02 | 2.1974E-02 | -1.2275E-02 | -7.8684E-04 |
TABLE 2
Table 3 shows the total effective focal length f of the projection lens, the effective focal lengths f1 and f2 of the respective lenses, the total optical length TTL of the projection lens, the maximum half field angle HFOV of the projection lens, and the object numerical aperture NA of the projection lens in example 1.
| Parameters (parameters) | f(mm) | f1(mm) | f2(mm) | TTL(mm) | HFOV(°) | NA |
| Numerical value | 3.19 | -16.01 | 2.93 | 3.50 | 8.9 | 0.20 |
TABLE 3 Table 3
The projection lens in embodiment 1 satisfies:
f2/f=0.92, where f2 is the effective focal length of the second lens E2, and f is the total effective focal length of the projection lens;
r4/f= -0.44, where R4 is the radius of curvature of the imaging side surface S4 of the second lens E2, and f is the total effective focal length of the projection lens;
(r2—r1)/(r2+r1) =0.28, wherein R2 is the radius of curvature of the imaging side surface S2 of the first lens E1, and R1 is the radius of curvature of the image source side surface S1 of the first lens E1;
DT22/DT 21=1.08, where DT22 is the effective half-caliber of the image side surface S4 of the second lens E2 and DT21 is the effective half-caliber of the image source side surface S3 of the second lens E2.
Fig. 2A shows a distortion curve of the projection lens of embodiment 1, which represents distortion magnitude values at different angles of view. Fig. 2B shows a magnification chromatic aberration curve of the projection lens of embodiment 1, which represents the deviation of different image heights on the imaging plane after light passes through the lens. As can be seen from fig. 2A to 2B, the projection lens according to embodiment 1 can achieve good imaging quality.
Example 2
A projection lens according to embodiment 2 of the present application is described below with reference to fig. 3 to 4B. In this embodiment and the following embodiments, descriptions of portions similar to embodiment 1 will be omitted for brevity. Fig. 3 shows a schematic structure of a projection lens according to embodiment 2 of the present application.
As shown in fig. 3, the projection lens according to the exemplary embodiment of the present application sequentially includes, along an optical axis from an image source side to an image forming side: a first lens E1, a second lens E2 and a stop STO.
The first lens E1 has negative power, the image source side surface S1 thereof is concave, and the image forming side surface S2 is convex. The second lens E2 has positive power, and its image source side surface S3 is convex and its image forming side surface S4 is convex. The projection lens has a light transmittance of greater than 85% in the light wave band of about 800nm to about 1000 nm. Light from the image source passes sequentially through the respective surfaces S1 to S4 and is finally imaged on an imaging surface (not shown) such as a projection screen.
Table 4 shows the surface types, radii of curvature, thicknesses, materials, and cone coefficients of the respective lenses of the projection lens of example 2, wherein the radii of curvature and thicknesses are each in millimeters (mm).
TABLE 4 Table 4
As can be seen from table 4, in embodiment 2, the image source side surface S1 and the image side surface S2 of the first lens E1 and the image source side surface S3 and the image side surface S4 of the second lens E2 are both aspherical surfaces. Table 5 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example 2, wherein each of the aspherical surface types can be defined by the formula (1) given in example 1 above.
| Face number | A4 |
| S1 | 0.0000E+00 |
| S2 | -2.6235E-03 |
| S3 | 0.0000E+00 |
| S4 | 0.0000E+00 |
TABLE 5
Table 6 shows the effective focal lengths f1 and f2 of the lenses, the total effective focal length f of the projection lens, the total optical length TTL of the projection lens, the maximum half field angle HFOV of the projection lens, and the object numerical aperture NA of the projection lens in example 2.
| Parameters (parameters) | f(mm) | f1(mm) | f2(mm) | TTL(mm) | HFOV(°) | NA |
| Numerical value | 2.99 | -4.23 | 2.40 | 3.50 | 11.3 | 0.20 |
TABLE 6
Fig. 4A shows a distortion curve of the projection lens of embodiment 2, which represents distortion magnitude values at different angles of view. Fig. 4B shows a magnification chromatic aberration curve of the projection lens of embodiment 2, which represents the deviation of different image heights on the imaging plane after light passes through the lens. As can be seen from fig. 4A to 4B, the projection lens according to embodiment 2 can achieve good imaging quality.
Example 3
A projection lens according to embodiment 3 of the present application is described below with reference to fig. 5 to 6B. Fig. 5 shows a schematic structural view of a projection lens according to embodiment 3 of the present application.
As shown in fig. 5, the projection lens according to the exemplary embodiment of the present application sequentially includes, along an optical axis from an image source side to an image forming side: a first lens E1, a second lens E2 and a stop STO.
The first lens E1 has negative power, the image source side surface S1 thereof is concave, and the image forming side surface S2 is convex. The second lens E2 has positive power, the image source side surface S3 thereof is concave, and the image forming side surface S4 thereof is convex. The projection lens has a light transmittance of greater than 85% in the light wave band of about 800nm to about 1000 nm. Light from the image source passes sequentially through the respective surfaces S1 to S4 and is finally imaged on an imaging surface (not shown) such as a projection screen.
Table 7 shows the surface types, radii of curvature, thicknesses, materials, and cone coefficients of the respective lenses of the projection lens of example 3, wherein the radii of curvature and thicknesses are each in millimeters (mm).
TABLE 7
As can be seen from table 7, in embodiment 3, the image source side surface S1 and the image side surface S2 of the first lens E1 and the image source side surface S3 and the image side surface S4 of the second lens E2 are both aspherical surfaces. Table 8 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example 3, wherein each of the aspherical surface types can be defined by the formula (1) given in example 1 above.
TABLE 8
Table 9 shows the effective focal lengths f1 and f2 of the lenses, the total effective focal length f of the projection lens, the total optical length TTL of the projection lens, the maximum half field angle HFOV of the projection lens, and the object numerical aperture NA of the projection lens in example 3.
| Parameters (parameters) | f(mm) | f1(mm) | f2(mm) | TTL(mm) | HFOV(°) | NA |
| Numerical value | 3.35 | -13.03 | 3.15 | 3.51 | 8.5 | 0.20 |
TABLE 9
Fig. 6A shows a distortion curve of the projection lens of embodiment 3, which represents distortion magnitude values at different angles of view. Fig. 6B shows a magnification chromatic aberration curve of the projection lens of embodiment 3, which represents the deviation of different image heights on the imaging plane after light passes through the lens. As can be seen from fig. 6A to 6B, the projection lens according to embodiment 3 can achieve good imaging quality.
Example 4
A projection lens according to embodiment 4 of the present application is described below with reference to fig. 7 to 8B. Fig. 7 shows a schematic configuration of a projection lens according to embodiment 4 of the present application.
As shown in fig. 7, the projection lens according to the exemplary embodiment of the present application sequentially includes, along an optical axis from an image source side to an image forming side: a first lens E1, a second lens E2 and a stop STO.
The first lens E1 has negative power, the image source side surface S1 thereof is concave, and the image forming side surface S2 is convex. The second lens E2 has positive power, the image source side surface S3 thereof is concave, and the image forming side surface S4 thereof is convex. The projection lens has a light transmittance of greater than 85% in the light wave band of about 800nm to about 1000 nm. Light from the image source passes sequentially through the respective surfaces S1 to S4 and is finally imaged on an imaging surface (not shown) such as a projection screen.
Table 10 shows the surface types, radii of curvature, thicknesses, materials, and cone coefficients of the respective lenses of the projection lens of example 4, in which the units of the radii of curvature and thicknesses are millimeters (mm).
Table 10
As can be seen from table 10, in embodiment 4, the image source side surface S1 and the image side surface S2 of the first lens E1 and the image source side surface S3 and the image side surface S4 of the second lens E2 are both aspherical surfaces. Table 11 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example 4, wherein each of the aspherical surface types can be defined by the formula (1) given in example 1 above.
| Face number | A4 | A6 | A8 | A10 |
| S1 | 7.4576E-01 | 8.2269E-01 | -5.6806E-01 | -1.4221E-01 |
| S2 | 3.4599E-01 | 8.2827E-01 | -3.3316E-01 | 1.1853E+00 |
| S3 | 9.0238E-02 | -1.1208E-01 | 8.6073E-02 | -2.3359E-02 |
| S4 | 1.0819E-02 | -5.1419E-03 | 3.8858E-04 | 9.7104E-04 |
TABLE 11
Table 12 shows the effective focal lengths f1 and f2 of the respective lenses, the total effective focal length f of the projection lens, the total optical length TTL of the projection lens, the maximum half field angle HFOV of the projection lens, and the object numerical aperture NA of the projection lens in example 4.
| Parameters (parameters) | f(mm) | f1(mm) | f2(mm) | TTL(mm) | HFOV(°) | NA |
| Numerical value | 2.65 | -22.18 | 3.08 | 3.25 | 10.8 | 0.20 |
Table 12
Fig. 8A shows a distortion curve of the projection lens of embodiment 4, which represents distortion magnitude values at different angles of view. Fig. 8B shows a magnification chromatic aberration curve of the projection lens of embodiment 4, which represents the deviation of different image heights on the imaging plane after light passes through the lens. As can be seen from fig. 8A to 8B, the projection lens according to embodiment 4 can achieve good imaging quality.
Example 5
A projection lens according to embodiment 5 of the present application is described below with reference to fig. 9 to 10B. Fig. 9 shows a schematic configuration of a projection lens according to embodiment 5 of the present application.
As shown in fig. 9, the projection lens according to the exemplary embodiment of the present application sequentially includes, along an optical axis from an image source side to an image forming side: a first lens E1, a second lens E2 and a stop STO.
The first lens E1 has negative power, the image source side surface S1 thereof is concave, and the image forming side surface S2 is convex. The second lens E2 has positive power, the image source side surface S3 thereof is concave, and the image forming side surface S4 thereof is convex. The projection lens has a light transmittance of greater than 85% in the light wave band of about 800nm to about 1000 nm. Light from the image source passes sequentially through the respective surfaces S1 to S4 and is finally imaged on an imaging surface (not shown) such as a projection screen.
Table 13 shows the surface types, radii of curvature, thicknesses, materials, and cone coefficients of the respective lenses of the projection lens of example 5, in which the units of the radii of curvature and thicknesses are millimeters (mm).
TABLE 13
As can be seen from table 13, in embodiment 5, the image source side surface S1 and the image side surface S2 of the first lens E1 and the image source side surface S3 and the image side surface S4 of the second lens E2 are both aspherical surfaces. Table 14 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example 5, wherein each of the aspherical surface types can be defined by the formula (1) given in example 1 above.
| Face number | A4 | A6 | A8 | A10 | A12 | A14 | A16 |
| S1 | 1.0312E+00 | -1.4399E+00 | 9.9617E+00 | -5.1343E+01 | 1.5539E+02 | -2.5274E+02 | 1.5977E+02 |
| S2 | 8.2510E-01 | -4.9940E-01 | 9.6016E+00 | -5.6121E+01 | 1.8908E+02 | -3.1914E+02 | 2.0013E+02 |
| S3 | 4.3806E-02 | -5.7311E-02 | 9.6542E-02 | -7.9879E-02 | 4.1774E-02 | -1.2636E-02 | 1.6612E-03 |
| S4 | -1.6735E-02 | -1.5435E-02 | 1.6578E-02 | -2.5667E-02 | 2.2051E-02 | -1.0380E-02 | 2.0921E-03 |
TABLE 14
Table 15 shows the effective focal lengths f1 and f2 of the respective lenses, the total effective focal length f of the projection lens, the total optical length TTL of the projection lens, the maximum half field angle HFOV of the projection lens, and the object numerical aperture NA of the projection lens in example 5.
| Parameters (parameters) | f(mm) | f1(mm) | f2(mm) | TTL(mm) | HFOV(°) | NA |
| Numerical value | 3.17 | -5.79 | 3.03 | 3.45 | 9.1 | 0.20 |
TABLE 15
Fig. 10A shows a distortion curve of the projection lens of embodiment 5, which represents distortion magnitude values at different angles of view. Fig. 10B shows a magnification chromatic aberration curve of the projection lens of embodiment 5, which represents the deviation of different image heights on the imaging plane after light passes through the lens. As can be seen from fig. 10A to 10B, the projection lens according to embodiment 5 can achieve good imaging quality.
In summary, examples 1 to 5 satisfy the relationships shown in table 16, respectively.
Table 16
The above description is only illustrative of the preferred embodiments of the present application and of the principles of the technology employed. It will be appreciated by persons skilled in the art that the scope of the application referred to in the present application is not limited to the specific combinations of the technical features described above, but also covers other technical features formed by any combination of the technical features described above or their equivalents without departing from the inventive concept. Such as the above-mentioned features and the technical features disclosed in the present application (but not limited to) having similar functions are replaced with each other.
Claims (11)
1. The projection lens sequentially comprises from an image source side to an imaging side along an optical axis: a first lens and a second lens, characterized in that,
the first lens has negative focal power, the image source side surface of the first lens is concave, and the image forming side surface of the first lens is convex;
the second lens has positive focal power, and the imaging side surface of the second lens is a convex surface;
the number of the lenses with the focal power of the projection lens is two;
the maximum half field angle HFOV of the projection lens satisfies 8 DEG & lt HFOV & lt 15 DEG;
the radius of curvature R2 of the imaging side surface of the first lens and the radius of curvature R1 of the image source side surface of the first lens satisfy 0 < (R2-R1)/(R2+R1) < 0.5;
in the light wave band of 800nm to 1000nm, the light transmittance of the projection lens is more than 85%.
2. The projection lens of claim 1, wherein the object numerical aperture NA of the projection lens satisfies NA ≡0.18.
3. The projection lens according to claim 2, characterized in that the total optical length TTL of the projection lens satisfies 3mm < TTL < 3.7mm.
4. Projection lens according to claim 1 or 2, characterized in that the effective focal length f2 of the second lens and the total effective focal length f of the projection lens satisfy 0.7 < f2/f < 1.2.
5. The projection lens according to claim 1 or 2, characterized in that the radius of curvature R4 of the imaging side surface of the second lens and the total effective focal length f of the projection lens satisfy-0.6 < R4/f < -0.2.
6. The projection lens according to claim 1 or 2, wherein an effective half-caliber DT22 of the imaging side surface of the second lens and an effective half-caliber DT21 of the image source side surface of the second lens satisfy 1.0 < DT22/DT21 < 1.3.
7. The projection lens sequentially comprises from an image source side to an imaging side along an optical axis: a first lens and a second lens, characterized in that,
the first lens has negative focal power, the image source side surface of the first lens is concave, and the image forming side surface of the first lens is convex;
the second lens has positive focal power, and the imaging side surface of the second lens is a convex surface;
wherein, the number of the lenses with focal power of the projection lens is two;
the total optical length TTL of the projection lens is more than 3mm and less than 3.7mm;
the maximum half field angle HFOV of the projection lens satisfies 8 DEG & lt HFOV & lt 15 DEG;
the radius of curvature R2 of the imaging side surface of the first lens and the radius of curvature R1 of the image source side surface of the first lens satisfy 0 < (R2-R1)/(R2+R1) < 0.5;
in the light wave band of 800nm to 1000nm, the light transmittance of the projection lens is more than 85%.
8. The projection lens of claim 7, wherein the effective half-caliber DT22 of the imaging side surface of the second lens and the effective half-caliber DT21 of the image source side surface of the second lens satisfy 1.0 < DT22/DT21 < 1.3.
9. The projection lens of claim 7 wherein the radius of curvature R4 of the imaging side surface of the second lens and the total effective focal length f of the projection lens satisfy-0.6 < R4/f < -0.2.
10. The projection lens of claim 7, wherein the effective focal length f2 of the second lens and the total effective focal length f of the projection lens satisfy 0.7 < f2/f < 1.2.
11. Projection lens according to any of claims 8 to 10, characterized in that the object numerical aperture NA of the projection lens satisfies NA > 0.18.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
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| CN201711166983.6A CN107728295B (en) | 2017-11-21 | 2017-11-21 | Projection lens |
| PCT/CN2018/087037 WO2019100671A1 (en) | 2017-11-21 | 2018-05-16 | Projection lens |
| US16/231,147 US10996433B2 (en) | 2017-11-21 | 2018-12-21 | Projection lens assembly |
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| CN201711166983.6A CN107728295B (en) | 2017-11-21 | 2017-11-21 | Projection lens |
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| CN107728295B true CN107728295B (en) | 2023-12-08 |
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| US10996433B2 (en) | 2017-11-21 | 2021-05-04 | Zhejiang Sunny Optical Co., Ltd. | Projection lens assembly |
| WO2019100671A1 (en) * | 2017-11-21 | 2019-05-31 | 浙江舜宇光学有限公司 | Projection lens |
| CN112230403B (en) * | 2018-11-08 | 2022-09-30 | 深圳市汇顶科技股份有限公司 | Lens group, fingerprint identification device and electronic equipment |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106461914A (en) * | 2014-04-22 | 2017-02-22 | 达美生物识别科技有限公司 | Lens assembly for optical imaging |
| CN106932886A (en) * | 2017-05-17 | 2017-07-07 | 浙江舜宇光学有限公司 | Iris lens |
| CN207780339U (en) * | 2017-11-21 | 2018-08-28 | 浙江舜宇光学有限公司 | Projection lens |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106461914A (en) * | 2014-04-22 | 2017-02-22 | 达美生物识别科技有限公司 | Lens assembly for optical imaging |
| CN106932886A (en) * | 2017-05-17 | 2017-07-07 | 浙江舜宇光学有限公司 | Iris lens |
| CN207780339U (en) * | 2017-11-21 | 2018-08-28 | 浙江舜宇光学有限公司 | Projection lens |
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