CN117348323A - Projection lens and projection display device - Google Patents

Projection lens and projection display device Download PDF

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Publication number
CN117348323A
CN117348323A CN202311643378.9A CN202311643378A CN117348323A CN 117348323 A CN117348323 A CN 117348323A CN 202311643378 A CN202311643378 A CN 202311643378A CN 117348323 A CN117348323 A CN 117348323A
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CN
China
Prior art keywords
lens
projection
group
image light
cemented
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Legal status (The legal status 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 status listed.)
Withdrawn
Application number
CN202311643378.9A
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Chinese (zh)
Inventor
王志煌
李文宗
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Shenzhen Shengyang Optical Technology Co ltd
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Shenzhen Shengyang Optical Technology Co ltd
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Priority to CN202311643378.9A priority Critical patent/CN117348323A/en
Publication of CN117348323A publication Critical patent/CN117348323A/en
Withdrawn legal-status Critical Current

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Classifications

    • 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
    • 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
    • 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
    • G02B13/0055—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras employing a special optical element
    • G02B13/006—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras employing a special optical element at least one element being a compound optical element, e.g. cemented elements

Abstract

The invention discloses a projection lens and projection display equipment, which can solve the distortion problem and the chromatic aberration problem at the front end of the projection lens and effectively reduce the number of lenses in the projection lens. A projection lens comprising: the first lens group, the second lens group and the front group reflection module are sequentially arranged along the image light propagation direction; the front group reflection module comprises: the lens assembly comprises a bonding lens and a penetrating lens, wherein the bonding lens is arranged on one side of the penetrating lens, which faces to the second lens group, and the bonding lens and the penetrating lens have positive focal power; the image light is incident to the bonding lens through the first lens group and the second lens group, the bonding lens is used for transmitting the image light to a reflecting area penetrating through the reflecting lens, and the reflecting area is used for reflecting the image light to the bonding lens, so that the image light forms a projection picture through the bonding lens; wherein, the cemented lens and the lens of wearing to turn over satisfy: t is t 1 ＞t 2 The method comprises the steps of carrying out a first treatment on the surface of the Wherein t is 1 To pass through the center thickness of the lens, t 2 Is the center thickness of the cemented lens.

Description

Projection lens and projection display device
Technical Field
The present invention relates to the field of projection display technologies, and in particular, to a projection lens and a projection display device.
Background
In recent years, ultra-short focal projection technology is becoming a hotspot of the domestic projection display market. The ultra-short focal projection display device has small requirements on distance, and often only needs a projection distance of tens of centimeters to project a large picture. In the related art, since the field angle FOV of the ultra-short focal projection display device is very large, aberration problems with different degrees are usually formed at the front end of the lens, and the design requirement on the lens is very high.
Disclosure of Invention
The present invention aims to solve at least one of the technical problems in the related art to some extent. Therefore, the invention provides the projection lens and the projection display device, which can solve the distortion problem and the chromatic aberration problem at the front end of the projection lens, simplify the imaging system composition formed by the first lens group and the second lens group, effectively reduce the number of lenses in the projection lens and improve the optical performance of the projection lens.
In a first aspect, an embodiment of the present invention provides a projection lens, including: the first lens group, the second lens group and the front group reflection module are sequentially arranged along the image light propagation direction; the front group reflection module comprises: the lens comprises a cemented lens and a trans-lens, wherein the cemented lens is arranged on one side of the trans-lens facing the second lens group, and the cemented lens and the trans-lens have positive focal power; the image light is incident to the cemented lens through the first lens group and the second lens group, the cemented lens is used for transmitting the image light to a reflection area of the through-reflection lens, and the reflection area is used for reflecting the image light to the cemented lens so that the image light can form a projection picture from the cemented lens; wherein, the cemented lens and the transflector lens satisfy: t1 > t2; wherein t1 is the center thickness of the through lens, and t2 is the center thickness of the cemented lens.
According to the projection lens and the projection display device provided by the embodiment, the central thickness of the through-reflecting lens is larger than that of the cemented lens by reasonably configuring the central thicknesses of the cemented lens and the through-reflecting lens, and the front group distortion is easier to correct by combining the reflection characteristics of the reflection area of the through-reflecting lens on image light; the structure of the double-cemented lens formed by the penetrating reverse lens and the cemented lens is combined, so that chromatic aberration in the projection lens can be corrected, chromatic aberration correction effect of a front group in the projection lens is improved, and chromatic aberration is corrected together with a second lens group of a middle group and a first lens group of a rear group; therefore, the distortion problem and the chromatic aberration problem are solved by the front group of the projection lens, the structures of the first lens group and the second lens group can be simplified, the number of lenses in the projection lens can be effectively reduced, and the optical performance of the projection lens can be improved.
In some embodiments, the projection lens satisfies: t is less than or equal to 0.1mm 1 －t 2 Less than or equal to 0.3mm. In this embodiment, by reasonably configuring the difference between the center thickness of the cemented lens 32 and the center thickness of the through lens 31, the front group distortion is more easily corrected.
In some embodiments, the projection lens satisfies: t is t 2 And is more than or equal to 1mm. The present embodiment makes it easier to correct the front group distortion by reasonably setting the center thickness of the cemented lens 32.
In some embodiments, the cemented lens and the transflector lens satisfy: r is R 1 ＜R 2 The method comprises the steps of carrying out a first treatment on the surface of the Wherein R is 1 A radius of curvature R for a first surface of the transflector lens facing away from the cemented lens 2 A radius of curvature for a second surface of the cemented lens facing away from the transflector. According to the embodiment, the size relation between the curvature radius of the cemented lens and the curvature radius of the through lens is reasonably set, so that smaller volume, smaller projection ratio and better optical performance can be realized, namely, the miniaturization requirement and the good optical performance requirement of the projection lens are considered.
In some embodiments, the projection lens satisfies: r is R 1 Not less than 10mm; and/or R 2 And the diameter is more than or equal to 20mm. The curvature radius of the cemented lens and the curvature radius of the through-reflecting lens are reasonably set, so that smaller volume, smaller projection ratio and better optical performance can be realized, namely, the miniaturization requirement and the good optical performance requirement of the projection lens are considered.
In some embodiments, the first lens group includes: the first positive optical focus lens, the second positive optical focus lens, the third positive optical focus lens, the fourth negative optical focus lens, the fifth negative optical focus lens and the sixth positive optical focus lens are sequentially arranged along the image light propagation direction. In the embodiment, the optical powers of the first positive optical focus lens, the second positive optical focus lens, the third positive optical focus lens, the fourth negative optical focus lens, the fifth negative optical focus lens and the sixth positive optical focus lens are reasonably configured, so that the system phase difference of the projection lens is balanced, and the distortion image quality of the projection lens is improved.
In some embodiments, the second lens group includes: and a seventh positive focusing lens, an eighth positive focusing lens and a ninth negative focusing lens which are sequentially arranged along the image light propagation direction. In the embodiment, the focal power of the seventh positive focal lens, the eighth positive focal lens and the ninth negative focal lens is reasonably configured, so that the spherical aberration, the distortion and the curvature of field of the system can be corrected, and the imaging quality of the lens can be improved.
In some embodiments, the effective focal lengths of the first lens group, the second lens group and the front group reflection module are negative, and the effective focal lengths of the first lens group, the second lens group and the front group reflection module satisfy: f (f) 2 ＜f 1 ＜f 3 The method comprises the steps of carrying out a first treatment on the surface of the Wherein f 2 F is the effective focal length of the second lens group 3 F is the effective focal length of the front group reflection module 1 Is the effective focal length of the first lens group. Through the arrangement, the embodiment is beneficial to reducing the lens number of the first lens group and the second lens group and reducing the lens cost, so that the focal length range can effectively obtain high-efficiency imaging quality.
In some embodiments, the projection lens further satisfies: l (L) 1 ＜L 2 ＜L 3 The method comprises the steps of carrying out a first treatment on the surface of the Wherein L is 1 L is the length of the first lens group along the propagation direction of the image light 2 L is the length of the second lens group along the propagation direction of the image light 3 The length of the front group reflection module along the propagation direction of the image light. Through the arrangement, the embodiment is beneficial to shortening the length of the lens and reducing the volume size of the lens under the condition of high imaging quality.
In some embodiments, the projection lens further satisfies: f (f) 3 /f 2 ＜f 3 /f 1 。
In some embodiments, the projection lens further satisfies: l (L) 3 /L 2 ＞L 3 /L 1 。
In a second aspect, an embodiment of the present invention provides a shadow display device including: a projection lens as claimed in any preceding claim, and a spatial light modulator, projection light source; the projection light source is used for generating illumination light, the illumination light is modulated Cheng Yingxiang by the spatial light modulator, the image light is projected to the projection lens, and a projection picture is formed by the projection lens.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
FIG. 1 is a schematic view of an application scenario of a projection lens according to an exemplary embodiment;
FIG. 2 is a schematic view of a projection lens according to an exemplary embodiment;
FIG. 3 is a schematic diagram of a front group reflector module in a projection lens according to an exemplary embodiment;
FIG. 4 is a graph of MTF for a projection lens provided by an exemplary embodiment;
FIG. 5 is a longitudinal spherical aberration plot of a projection lens provided by an exemplary embodiment;
fig. 6 is an astigmatic aberration diagram of a projection lens according to an exemplary embodiment.
Reference numerals illustrate:
10-a first lens group; 11-a first positive focal lens; 12-a second positive focal lens; 13-a third positive focal lens; 14-a fourth negative focal lens; 15-a fifth negative focal lens; 16-a sixth positive focal lens; 20-a second lens group; 21-seventh positive focal lens; 22-eighth positive focal lens; 23-a ninth negative focal lens; 30-front group reflection module; 31-a lens; 31 a-a reflective region; 31 b-transmissive region; 32-a cemented lens; 41-a first sheet glass; 42-second plate glass.
Detailed Description
Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.
The structure, function and implementation of the projection lens according to the embodiment of the present invention are described below with reference to the accompanying drawings.
In addition, other structures and functions of the projection lens according to the embodiments of the present invention are known to those skilled in the art, and are not described herein for redundancy reduction.
In the projection lens provided in this embodiment, the image light propagates from the image side to the object side of the projection lens. For convenience of description in this embodiment, the surface of each lens facing the image side is referred to as an image side surface, and the surface facing the object side is referred to as an object side surface.
Referring to fig. 1 to 2, a projection lens provided in the present embodiment includes: the first lens assembly 10, the second lens assembly 20 and the front group reflection module 30 are sequentially arranged along the image light propagation direction. The dashed line in fig. 1 is only used to illustrate the propagation direction of the image light.
Wherein the first lens group 10 has negative optical power; the second lens group 20 has negative optical power; the front group reflection module 30 has positive optical power. The spherical aberration and chromatic aberration generated in the projection lens can be effectively balanced by reasonably configuring the positive and negative focal powers of each module of the projection lens, so that the imaging quality can be effectively improved, clear projection images can be displayed on a projection surface, the length of the projection lens can be reduced, and the cost is reduced.
For example, the first lens group 10 and the second lens group 20 may each include at least one lens. An air space can be arranged between any two adjacent lenses in the projection lens, or the two adjacent lenses can be glued. By reasonably configuring the shape, focal power, surface shape, etc. of each lens in the first lens group 10, it is beneficial to balance the system aberration of the projection lens and improve the imaging quality of the projection lens. By reasonably configuring the shape, focal power, surface shape, etc. of each lens in the second lens group 20, the optical distortion can be ensured to a certain extent, and the bending degree of the lens can be effectively reduced, which is more beneficial to optical lens processing and mass production.
The front group reflection module 30 includes: the cemented lens 32 and the through-reflecting lens 31, the cemented lens 32 is disposed on a side of the through-reflecting lens 31 facing the second lens group 20, and both the cemented lens 32 and the through-reflecting lens 31 have positive optical power. The object side surfaces of the cemented lens 32 and the through lens 31 are convex, and the image side surfaces are concave. By reasonably configuring the focal power and the surface shape of the cemented lens 32 and the through-reflecting lens 31, the optical distortion can be ensured to a certain extent, the bending degree of the lens can be effectively reduced, and the processing and mass production of the optical lens are facilitated.
In the imaging process, the image light is incident to the cemented lens 32 through the first lens group 10 and the second lens group 20, the cemented lens 32 is configured to transmit the image light to the reflective area 31a penetrating the reflective lens 31, and the reflective area 31a is configured to reflect the image light to the cemented lens 32, so that the image light can form a projection screen from the cemented lens 32.
The cemented lens 32 and the through lens 31 satisfy: t is t 1 ＞t 2。 Wherein t is 1 To pass through the center thickness of the counter lens 31, t 2 Is the center thickness of the cemented lens 32. The center thickness refers to the distance between the point on the optical axis of the lens where the entrance surface of the lens is located and the point on the optical axis of the lens where the exit surface of the lens is located.
In this embodiment, by reasonably configuring the central thicknesses of the cemented lens 32 and the through-reflecting lens 31, the central thickness of the through-reflecting lens 31 is larger than the central thickness of the cemented lens 32, and by combining the reflection characteristics of the reflection area 31a of the through-reflecting lens 31 on the image light, the front group distortion is more easily corrected; the structure of the double cemented lens 32 formed by the through-reflecting lens 31 and the cemented lens 32 can correct the chromatic aberration in the projection lens, thereby improving the chromatic aberration correction function of the front group in the projection lens, and correcting chromatic aberration together with the second lens group 20 of the middle group and the first lens group 10 of the rear group. Thus, the present embodiment can simplify the structures of the first lens group 10 and the second lens group 20 by solving the distortion problem and the chromatic aberration problem at the front end of the projection lens, and effectively reduce the number of lenses in the projection lens, for example, the second lens group 20 adopts 3 lenses, the first lens group 10 adopts 6 lenses, the projection ratio can be less than 0.25, and the optical performance of the projection lens can be improved.
In some embodiments, t 1 To pass through the center thickness of the counter lens 31, t 2 Is the center thickness of the cemented lens 32. The cemented lens 32 and the through lens 31 satisfy: t is less than or equal to 0.1mm 1 －t 2 Less than or equal to 0.3mm. Wherein t is 1 And t 2 The difference between them may be 0.1mm or 0.15mm or 0.2mm or 0.25mm or 0.3mm, or a difference between any of the above.
In some examples, the center thickness t of the cemented lens 32 2 And is more than or equal to 1mm. Illustratively, the center thickness t of the transflector 31 1 And is more than or equal to 1.1mm. For example, t 1 May be 1.1mm or 1.2mm or 1.3mm, or a thickness therebetween. Also for example, t 1 May be 2.1mm or 2.2mm or 2.3mm, or a thickness therebetween. For another example, t 1 Can be 1.981mm, t 2 May be 1.869mm. Of course, t 1 And t 2 Difference, t 1 T 2 The values of (2) are not limited thereto, and the present embodiment is merely exemplified herein.
In this embodiment, by reasonably configuring the difference between the center thickness of the cemented lens 32 and the center thickness of the through lens 31, and by reasonably configuring the center thickness of the cemented lens 32, the front group distortion is more easily corrected. Through the cemented lens 32 and the through lens 31, the imaging system assembly of the first lens assembly 10 and the second lens assembly 20 can be simplified, and the optical performance can be improved while using a smaller number of lenses.
In some embodiments, referring to fig. 3, the cemented lens 32 and the through-lens 31 satisfy: r is R 1 ＜R 2 The method comprises the steps of carrying out a first treatment on the surface of the Wherein R is 1 To penetrate the radius of curvature of the first surface of the counter lens 31 facing away from the cemented lens 32, R 2 The radius of curvature of the second surface facing away from the through lens 31 is the cemented lens 32.
In some examples, R 2 -R 1 And the diameter is more than or equal to 10mm. Exemplary, R 2 And R is R 1 The difference between them may be 10mm or 15mm or 20mm or 25mm or 30mm or 35mm or 40mm or 45mm or 50mm or more, or a difference between any two of the above.
For example, it may be provided that the radius of curvature R of the first surface of the through-reflecting lens 31 facing away from the cemented lens 32 1 And the diameter is more than or equal to 10mm. At R 1 At 10mm, R 2 May be 20mm or 21mm or 22mm or 23mm or 24mm or 25mm or 26mm or 27mm or 28mm or 29mm or 30mm or more, or a difference between any two of the above. At R 1 At 20mm, R 2 May be 30mm or 31mm or 32mm or 33mm or 34mm or 35mm or 36mm or 37mm or 38mm or 39mm or 40mm or more, or a difference between any two of the above.
As another example, it may be provided that the cemented lens 32 has a radius of curvature R facing away from the second surface of the transflector 31 2 And the diameter is more than or equal to 20mm. At R 2 At 20mm, R 1 May be 10mm. At R 2 At 25mm, R 1 May be 10mm or 11mm or 12mm or 13mm or 14mm or 15mm, or a difference between any two of the above.
It will be appreciated that R 1 And R is R 2 Difference between R 1 R is R 2 The values of (2) are not limited thereto, and the present embodiment is merely exemplified herein.
In the present embodiment, by reasonably setting the curvature radii of the cemented lens 32 and the through-reflection lens 31, a smaller volume, a smaller projection ratio, and a better optical performance can be achieved, that is, the miniaturization requirement and the good optical performance requirement of the projection lens are both satisfied. Under the condition that the cemented lens 32 and the through lens 31 correct larger aberration, the imaging system composed of the first lens group 10 and the second lens group 20 is simplified, the lens volume is effectively reduced, and better optical performance is obtained.
With continued reference to fig. 1 and 2, in some embodiments, a first surface of the through-reflecting lens 31 facing away from the cemented lens 32 has a reflective area 31a, and a third surface of the through-reflecting lens 31 facing toward the cemented lens 32 has a transmissive area 31b.
For example, a first surface of the through reflection lens 31 facing away from the cemented lens 32 may be provided with a reflective film layer, and a region of the first surface provided with the reflective film layer forms the reflective area 31a. Wherein the first surface may be entirely provided with the reflective film layer; or the reflection film layer is arranged in a preset area on the first surface for reflecting the image light, and whether the functional film layer is arranged in other areas of the first surface can be set according to actual needs.
For example, when the through lens 31 is an approximately semicircular lens, a reflective film layer may be provided on the first surface; when the through lens 31 is an approximately circular lens, a reflective film material may be provided on the first surface in the lower half region for reflecting the image light.
The third surface of the through lens 31 facing the cemented lens 32 has a transmissive region 31b. The transmission region 31b allows the image light emitted from the cemented lens 32 to enter the reflective lens 31 and to enter the reflective region 31a passing through the first surface of the reflective lens 31, and the image light reflected by the reflective region 31a can pass through the transmission region 31b and the cemented lens 32 to form a projection image. The transmissive region 31b on the third surface of the reflective lens 31 for receiving or emitting the image light may be provided with an anti-reflection film layer.
The front projection of the transmissive region 31b on the projection plane can completely cover the front projection of the reflective region 31a on the projection plane with the plane perpendicular to the propagation direction of the image light as the projection plane. Alternatively, the front projection of the transmissive region 31b on the projection plane may be slightly larger than the front projection of the reflective region 31a on the projection plane, so that the image light can be incident on the reflective region 31a through the transmissive region 31b, and the image light reflected by the reflective region 31a can be incident on the cemented lens 32 through the transmissive region 31b.
Illustratively, the third surface may be entirely provided as the transmissive region 31b; or the preset area on the third surface for the image light to be incident or emitted is set as the transmission area 31b, and whether the other areas of the third surface are provided with the functional film layer or not may be set according to actual needs.
For example, when the through lens 31 employs an approximately semicircular lens, the third surfaces may all be provided as the transmissive area 31b; when the through lens 31 employs an approximately circular lens, a lower half area for the image light to be incident or emitted on the third surface may be set as the transmission area 31b.
Similarly, the cemented lens 32 may be an approximately semicircular lens, or an approximately circular lens. The specific shape and size of the cemented lens 32, if not illustrated, may be set as desired.
With continued reference to fig. 1 and 2, in some embodiments, the first lens assembly 10 includes: a first positive focal lens 11, a second positive focal lens 12, a third positive focal lens 13, a fourth negative focal lens 14, a fifth negative focal lens 15, and a sixth positive focal lens 16, which are disposed in this order along the image light propagation direction.
The object side surface of the first positive focal lens 11 is convex, and the image side surface is convex. The second positive focal lens 12 has a convex object-side surface and a convex image-side surface. The third positive focal lens 13 has a convex object-side surface and a convex image-side surface. The fourth negative focal lens 14 has a convex object-side surface and a concave image-side surface. The fifth negative focal lens 15 has a concave object-side surface and a convex image-side surface. The sixth positive focal lens 16 has a concave object-side surface and a convex image-side surface. The sixth positive focal lens 16 and the fifth negative focal lens 15 form a double cemented lens 32 to correct chromatic aberration in the projection lens. The third positive focal lens 13 and the fourth negative focal lens 14 constitute a double cemented lens 32 to correct chromatic aberration in the projection lens.
In addition, a first plate glass 41 and a second plate glass 42 may be further provided on a side of the first positive focal lens 11 facing away from the second positive focal lens 12. The second plate glass 42 is located between the first plate glass 41 and the first lens with a distance between the second plate glass 42 and the first lens.
In this embodiment, the optical powers and the surfaces of the first positive focal lens 11, the second positive focal lens 12, the third positive focal lens 13, the fourth negative focal lens 14, the fifth negative focal lens 15 and the sixth positive focal lens 16 are reasonably configured, so as to be beneficial to balancing the system phase difference of the projection lens and improving the distortion image quality of the projection lens.
In some embodiments, the second lens group 20 includes: a seventh positive focal lens 21, an eighth positive focal lens 22, and a ninth negative focal lens 23, which are disposed in this order along the image light propagation direction. The object-side surface of the seventh positive focal lens 21 may be convex, and the image-side surface may be concave. The object-side surface of the eighth positive focal lens 22 can be concave and the image-side surface can be convex. The object-side surface of the ninth negative focal lens 23 can be concave and the image-side surface can be concave.
In this embodiment, by reasonably configuring the focal powers and the surface shapes of the seventh positive focal lens 21, the eighth positive focal lens 22 and the ninth negative focal lens 23, the spherical aberration, the distortion and the curvature of field of the system can be corrected, and the imaging quality of the lens can be improved.
In the above embodiment, the object-side surface S1 of the through-lens 31 is convex, and the image-side surfaces S2 and S3 are concave. The object-side surface S4 of the cemented lens 32 is concave, and the image-side surfaces S5 and S6 are concave. The object side surface S7 of the ninth negative optical focus lens 23 is a concave surface, and the image side surface S8 is a concave surface. The object-side surface S9 of the eighth positive focal lens 22 is concave, and the image-side surface S10 is convex. The object side surface S11 of the seventh positive focal lens 21 is convex, and the image side surface S12 is concave. The object-side surface S13 of the sixth positive focal lens 16 is concave, and the image-side surface S14 is convex. The object-side surface S15 of the fifth negative focal lens 15 is concave, and the image-side surface S16 is convex. The fourth negative focal lens 14 has a convex object-side surface S17 and a convex image-side surface S18. The object-side surface S19 of the third positive focal lens 13 is convex, and the image-side surface S20 is convex. The object-side surface S21 of the second positive focal lens 12 is convex, and the image-side surface S22 is convex. The object side surface S23 of the first positive focal lens 11 is convex, and the image side surface S24 is convex. The second plate glass 42 has an object side surface S25 and an image side surface S26, and the first plate glass 41 has an object side surface S27 and an image side surface S28. The projection lens has an imaging surface Image, and Image light on the imaging surface Image sequentially passes through each surface S25 to the object side OBJ and finally forms a projection picture.
At least one of the object side surface and the image side surface of each lens may be aspherical. In some examples, the object side and image side of each lens may be both aspheric. In other examples, surfaces S3-S9 may be aspheric, and the remaining surfaces may be spherical.
In the present embodiment, the aspherical lens has a planar shapeThe following aspherical formula (1) may be used but is not limited thereto:
；（1）
wherein,when the height of the aspherical surface is h along the optical axis direction, the distance from the vertex of the aspherical surface is sagittal; 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); k is a conic coefficient; />Is the correction coefficient of the i-th order of the aspheric surface.
Table 1 below shows K values and higher order coefficients A4, A6, A8, a10, a12, a14, and a16 of respective aspherical mirror faces S3 (i.e., surface 4 in table 1) to S9 (i.e., surface 10 in table 1) that can be used in the projection lens of the present embodiment.
TABLE 1
In some embodiments, the effective focal lengths of the first lens group 10, the second lens group 20 and the front group reflection module 30 are negative, and the effective focal lengths of the first lens group 10, the second lens group 20 and the front group reflection module 30 satisfy: f (f) 2 ＜f 1 ＜f 3 The method comprises the steps of carrying out a first treatment on the surface of the Wherein f 2 Is the effective focal length, f, of the second lens group 20 3 Is the effective focal length f of the front group reflection module 30 1 Is the effective focal length of the first lens group 10.
The projection lens can also satisfy: f is more than or equal to 0.55 2 /f 1 Less than or equal to 2.68; wherein f 2 Is the focal length, f, of the second lens group 20 1 Is a first lens group 1Focal length of 0. Illustratively f 2 /f 1 May be 2.68 or 2.15 or 1.78 or 1.11 or 0.88 or 0.55, or a ratio between any two of the above. Through the arrangement, the higher-order aberration generated by the first lens group 10 and the second lens group 20 can be corrected, and the imaging performance and the distortion effect can be effectively improved.
The projection lens can also satisfy: -17.90mm < f 2 ＜-6.18mm，-10.01mm＜f 1 -5.58mm; wherein f 2 Is the focal length, f, of the second lens group 20 1 Is the focal length of the first lens group 10. Illustratively f 2 Can be-14.92 mm or-12.81 mm or-7.73 mm, or a focal length between any two of the above. f (f) 1 Can be-8.33 mm or-7.19 mm or-6.98 mm, or a focal length between any two of the above.
In some examples, the projection lens may also satisfy: f (f) 3 /f 2 ＜f 3 /f 1 . Wherein f 3 /f 2 And f 3 /f 1 The difference between them can be set according to the actual needs. Exemplary, 0.19 < f 3 /f 2 ＜1.03，f 3 /f 3 May be 0.20 or 0.40 or 0.60 or 0.80 or 1.0 or 1.03, or a ratio between any two of the above. For example, f 3 /f 2 0.33. F is 0.03 < f 3 /f 1 ＜1.14，f 3 /f 1 May be 0.04 or 0.20 or 0.40 or 0.60 or 0.80 or 1.0 or 1.14, or a ratio between any two of the above. For example, f 3 /f 1 May be 0.59.
In some examples, the projection lens may also satisfy: -6.38mm < f 3 And < -3.43mm. Illustratively f 3 Can be-6.37 mm or-4.91 mm or-3.42 mm, or a focal length between any two of the above.
In the present embodiment, the above arrangement is beneficial to reduce the number of lenses of the first lens group 10 and the second lens group 20 and reduce the lens cost, so that the focal length range can effectively obtain high-performance imaging quality.
In some embodiments, the projection lens further satisfies: l (L) 1 ＜L 2 ＜L 3 The method comprises the steps of carrying out a first treatment on the surface of the Wherein L is 1 L is the length of the first lens group 10 along the propagation direction of the image light 2 L is the length of the second lens group 20 along the propagation direction of the image light 3 The length of the front group reflection module 30 along the propagation direction of the image light. Exemplary, L 1 Can be 11.70mm, L 2 Can be 17.23mm, L 3 May be 27.35mm. L (L) 1 And L is equal to 2 And L is equal to 3 The specific difference between the two may be set according to actual needs, and the embodiment is not specifically limited herein. Through the arrangement, the embodiment is beneficial to shortening the length of the lens and reducing the volume size of the lens under the condition of high imaging quality.
In some examples, the projection lens may also satisfy: 0.33 < (L) 1 +L 2 +L 3 ) TTL < 0.79; wherein L is 1 Is the total length L of the front group reflection module 30 2 Is the total length of the second lens group 20, L 3 Is the total length of the first lens group 10 and TTL is the total length of the projection lens. Illustratively, (L) 1 +L 2 +L 3 ) the/TTL can be 0.48 or 0.56 or 0.61, or a ratio between any two of the above.
In some examples, the projection lens may also satisfy: l (L) 3 /L 2 ＞L 3 /L 1 . Exemplary, 1.06 < L 3 /L 2 ＜2.38。L 3 /L 2 May be 1.07 or 1.20 or 1.40 or 1.60 or 1.80 or 2.0 or 2.2 or 2.37, or a ratio between any two of the above. For example, L 3 /L 2 May be 1.59.
1.56＜L 3 /L 1 ＜3.51。L 3 /L 1 May be 1.55 or 1.80 or 2.10 or 2.40 or 2.70 or 3.00 or 3.30 or 3.50, or a ratio between any two of the above. For example, L 3 /L 1 May be 2.34.
Exemplary, 21.88mm < L 3 ＜32.82mm。L 3 May be 21.89mm or 22mm or 24mm or 26mm or 28mm or 30mm or 32mm or 32.81mm, or a length between any two of the above. For example, L 3 May be 27.35mm.
Exemplary, 13.784mm ＜L 2 ＜20.676mm。L 2 May be 13.783mm or 14mm or 15mm or 16mm or 17mm or 18mm or 19mm or 20mm or 20.675mm, or a length between any two of the above. For example, L 2 May be 17.23mm.
Exemplary, 9.36mm < L 1 ＜14.04mm。L 1 May be 9.37mm or 10mm or 11mm or 12mm or 13mm or 14mm or 14.03mm or a length between any two of the above. For example, L 1 May be 11.70mm.
In this embodiment, through the above arrangement, the lens length can be effectively shortened and the size of the lens can be reduced under the condition of being favorable to high imaging quality.
As shown in fig. 4, the projection lens of the present embodiment is used for projection display, the spatial frequency (spatial frequency) is 93.Lp/mm, and the Modulation Transfer Function (MTF) is greater than 0.6, so as to achieve a better resolution effect. As can be seen from fig. 4 to fig. 6, the projection lens of the present embodiment has good imaging quality.
Specifically, fig. 5 shows a longitudinal spherical aberration curve of the projection lens of the present embodiment using light rays with wavelengths of 455mm, 550mm, and 630mm, which represents spherical aberration corresponding to different focal lengths. Fig. 6 shows astigmatism curves of the projection lens of this embodiment using light rays of wavelengths 455mm, 550mm, and 630mm, which represent meridional image surface curvature (curved surface without hollow sphere) and sagittal image surface curvature (curved surface with hollow sphere), and fig. 5 and 6 reflect that the projection lens has a lower optical distortion level to some extent. Fig. 4 shows an MTF curve of the imaging quality of the projection lens of this embodiment, and as can be seen from fig. 4, the ordinate values corresponding to the abscissa of the MTF curve of 0.80lp/mm (line pair/millimeter) are all greater than 60%, which represents that each pixel can be clearly resolved, and good image quality is obtained.
The present embodiment also provides a projection display apparatus including: the projection lens as in any preceding embodiment, as well as a spatial light modulator, a projection light source; the projection light source is used for generating illumination light, the illumination light is modulated Cheng Yingxiang by the spatial light modulator, the image light is projected to the projection lens, and a projection picture is formed by the projection lens. The structure, function and implementation process of the projection lens are the same as or similar to those of any of the above embodiments.
In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.
Furthermore, the terms "first," "second," and the like, as used in embodiments of the present invention, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or as implying any particular number of features in the present embodiment. Thus, a feature of an embodiment of the invention that is defined by terms such as "first," "second," etc., may explicitly or implicitly indicate that at least one such feature is included in the embodiment. In the description of the present invention, the word "plurality" means at least two or more, for example, two, three, four, etc., unless explicitly defined otherwise in the embodiments.
In the present invention, unless explicitly stated or limited otherwise in the examples, the terms "mounted," "connected," and "fixed" as used in the examples should be interpreted broadly, e.g., the connection may be a fixed connection, may be a removable connection, or may be integral, and it may be understood that the connection may also be a mechanical connection, an electrical connection, etc.; of course, it may be directly connected, or indirectly connected through an intermediate medium, or may be in communication with each other, or in interaction with each other. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to specific embodiments.
In the present invention, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.
While embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the invention.

Claims (11)

1. A projection lens, comprising:
the first lens group, the second lens group and the front group reflection module are sequentially arranged along the image light propagation direction;
the front group reflection module comprises: the lens comprises a cemented lens and a trans-lens, wherein the cemented lens is arranged on one side of the trans-lens facing the second lens group, and the cemented lens and the trans-lens have positive focal power;
the image light is incident to the cemented lens through the first lens group and the second lens group, the cemented lens is used for transmitting the image light to a reflection area of the through reflection lens, and the reflection area is used for reflecting the image light to the cemented lens so that the image light forms a projection picture through the cemented lens;
wherein, the cemented lens and the transflector lens satisfy:
t 1 ＞t 2 the method comprises the steps of carrying out a first treatment on the surface of the Wherein t is 1 T is the center thickness of the lens 2 Is the center thickness of the cemented lens.
2. The projection lens of claim 1, wherein the projection lens satisfies: t is less than or equal to 0.1mm 1 －t 2 ≤0.3mm。
3. The projection lens of claim 1, wherein the projection lens satisfies: t is t 2 ≥1mm。
4. The projection lens of claim 1, wherein the cemented lens and the transflector lens satisfy:
R 1 ＜R 2 the method comprises the steps of carrying out a first treatment on the surface of the Wherein R is 1 A radius of curvature R for a first surface of the transflector lens facing away from the cemented lens 2 A radius of curvature for a second surface of the cemented lens facing away from the transflector.
5. The projection lens of claim 4, wherein the projection lens satisfies: r is R 1 Not less than 10mm; and/or R 2 ≥20mm。
6. The projection lens of claim 4, wherein the projection lens satisfies: r is R 2 -R 1 ≥10mm。
7. The projection lens of claim 1 wherein the first lens group comprises: the first positive optical focus lens, the second positive optical focus lens, the third positive optical focus lens, the fourth negative optical focus lens, the fifth negative optical focus lens and the sixth positive optical focus lens are sequentially arranged along the image light propagation direction;
the second lens group includes: and a seventh positive focusing lens, an eighth positive focusing lens and a ninth negative focusing lens which are sequentially arranged along the image light propagation direction.
8. The projection lens of claim 1, wherein the effective focal lengths of the first lens group, the second lens group and the front group reflection module are negative, and the effective focal lengths of the first lens group, the second lens group and the front group reflection module satisfy:
f 2 ＜f 1 ＜f 3 ；
wherein f 2 F is the effective focal length of the second lens group 3 F is the effective focal length of the front group reflection module 1 Is the effective focal length of the first lens group.
9. The projection lens of claim 8, wherein the projection lens further satisfies:
L 1 ＜L 2 ＜L 3 ；
wherein L is 1 L is the length of the first lens group along the propagation direction of the image light 2 L is the length of the second lens group along the propagation direction of the image light 3 The length of the front group reflection module along the propagation direction of the image light.
10. The projection lens of claim 9, wherein the projection lens further satisfies:
f 3 /f 2 ＜f 3 /f 1 ；
L 3 /L 2 ＞L 3 /L 1 。
11. a projection display device, comprising: the projection lens of any one of claims 1 to 10, and a spatial light modulator, projection light source;
the projection light source is used for generating illumination light, the illumination light is modulated Cheng Yingxiang by the spatial light modulator, the image light is projected to the projection lens, and a projection picture is formed by the projection lens.
CN202311643378.9A 2023-12-04 2023-12-04 Projection lens and projection display device Withdrawn CN117348323A (en)

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Publication number Priority date Publication date Assignee Title
JP2006349747A (en) * 2005-06-13 2006-12-28 Canon Inc Adapter lens
JP2018180031A (en) * 2017-04-04 2018-11-15 株式会社東京スコープ Dot sight
CN108957704A (en) * 2018-08-30 2018-12-07 安徽仁和光电科技有限公司 High definition short focus projection lens
CN109001895A (en) * 2018-09-21 2018-12-14 杭州有人光电技术有限公司 A kind of small-sized high definition ultra-short focus projection lens
CN114296218A (en) * 2021-12-29 2022-04-08 青岛海信激光显示股份有限公司 Projection lens and projection system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006349747A (en) * 2005-06-13 2006-12-28 Canon Inc Adapter lens
JP2018180031A (en) * 2017-04-04 2018-11-15 株式会社東京スコープ Dot sight
CN108957704A (en) * 2018-08-30 2018-12-07 安徽仁和光电科技有限公司 High definition short focus projection lens
CN109001895A (en) * 2018-09-21 2018-12-14 杭州有人光电技术有限公司 A kind of small-sized high definition ultra-short focus projection lens
CN114296218A (en) * 2021-12-29 2022-04-08 青岛海信激光显示股份有限公司 Projection lens and projection system

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