Projection optical system, projection component and projector

Abstract

The present invention discloses a projection optical system, a projection assembly and a projector. The projection optical system comprises a projection device and a projection screen. The projection screen and the projection device are arranged in sequence from front to back. The projection device comprises a first lens with negative optical power, a second lens with positive optical power, a third lens with negative optical power, a fourth lens with negative optical power, a fifth lens with positive optical power and a sixth lens with positive optical power arranged in sequence from front to back; wherein the first lens and the third lens are plastic aspherical lenses, the second lens, the fourth lens and the fifth lens are glass spherical lenses, and the sixth lens is a plastic spherical lens. The present invention provides a projection optical system with simple structure, low cost, large aperture and no focus deviation at high temperature.

Description

Technical Field

[0001] The present invention relates to the field of projection technology, and in particular to a projection optical system, a projection component and a projector. Background Art

[0002] As the core component of a projector, the lens determines the brightness, resolution and cost of the projector. High-brightness projectors often require large-aperture lenses. In order to achieve a large aperture, a large number of glass lenses are used in the design of the lens, which leads to a rapid increase in costs. In order to reduce costs, some lenses on the market use plastic lenses, but the focus shift is often more obvious at high temperatures. Currently, there is no projection lens on the market that overcomes all of the above shortcomings. Summary of the invention

[0003] The main purpose of the present invention is to provide a projection optical system, a projection assembly and a projector.

[0004] To achieve the above object, the present invention provides a projection optical system, comprising a projection device and a projection screen, wherein the projection screen and the projection device are arranged sequentially from front to back, and the projection device comprises a first lens with negative optical power, a second lens with positive optical power, a third lens with negative optical power, a fourth lens with negative optical power, a fifth lens with positive optical power, and a sixth lens with positive optical power, which are arranged sequentially from front to back;

[0005] Wherein, the first lens and the third lens are plastic aspherical lenses, the second lens, the fourth lens and the fifth lens are glass spherical lenses, and the sixth lens is a plastic spherical lens.

[0006] Optionally, the optical focal power of the first lens is a1, the optical focal power of the second lens is a2, the optical focal power of the third lens is a3, the optical focal power of the fourth lens is a4, the optical focal power of the fifth lens is a5, and the optical focal power of the sixth lens is a6, 0.02<|a1|<06, and 0.02<|a2|<06, and 0.005<|a3|<0.015, and 0.001<|a4|<0.015, and 0.001<|a5|<0.015, and 0.015<|a6|<0.03.

[0007] Optionally, -0.05<a1+a2<-0.035, and

[0008] Optionally, the fourth lens and the fifth lens are cemented lenses.

[0009] Optionally, two opposite ends of the third lens are bent forward.

[0010] Optionally, the projection device further includes a prism, and the prism is arranged at the rear side of the sixth lens.

[0011] Optionally, the projection device further comprises a light source assembly, wherein the light source assembly comprises a light emitting chip, and the light emitting chip is arranged at the rear side of the prism.

[0012] Optionally, the projection device further includes a light beam, wherein the light beam is disposed between the first lens and the second lens and is close to the second lens.

[0013] In addition, to achieve the above-mentioned purpose, the present invention further provides a projection assembly, comprising a projection device and a projection screen, wherein the projection screen and the projection device are arranged sequentially from front to back, and the projection device comprises a first lens with negative optical power, a second lens with positive optical power, a third lens with negative optical power, a fourth lens with negative optical power, a fifth lens with positive optical power, and a sixth lens with positive optical power, which are arranged sequentially from front to back;

[0014] Wherein, the first lens and the third lens are plastic aspherical lenses, the second lens, the fourth lens and the fifth lens are glass spherical lenses, and the sixth lens is a plastic spherical lens.

[0015] In addition, to achieve the above object, the present invention also provides a projector, which includes the projection component as described above.

[0016] In the technical solution provided by the present invention, the projection optical system includes a projection device and a projection screen, the projection screen and the projection device are arranged from front to back in sequence, and the projection device includes a first lens with negative optical power, a second lens with positive optical power, a third lens with negative optical power, a fourth lens with negative optical power, a fifth lens with positive optical power, and a sixth lens with positive optical power arranged from front to back in sequence; wherein, the first lens and the third lens are plastic aspheric lenses, the second lens, the fourth lens, and the fifth lens are glass spherical lenses, and the sixth lens is a plastic spherical lens. The present invention provides a projection optical system with a simple structure, low cost, large aperture, and high temperature without defocusing. The aperture is large and can support apertures below F1.4; a mixed use of glass lenses and plastic lenses is adopted, and the projector outputs no defocusing when the brightness is ≤4000lm; the structure is simple, and 3 plastic aspheric lenses are used, which greatly reduces the cost of the lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0018] Figure 1 A schematic structural diagram of an embodiment of a projection optical system provided by the present invention.

[0019] Description of Figure Numbers:

[0020] Label name Label name 100 Projection optical system 6 The sixth lens 1 First lens 7 Prism 2 Second lens 8 Guanglan 3 The third lens 9 Light source components 4 The fourth lens 10 Projection screen 5 Fifth lens

[0021] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0024] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0025] Taking projector lenses as an example, projector camera lenses, as standard equipment for smart projectors, have shown a rapid growth trend in recent years. With the growing development of projector camera lenses, people have also put forward higher requirements on the performance and quality of projector lenses, especially in terms of zoom projector lenses. Traditional digital zoom can no longer meet the growing consumer demand.

[0026] As the core component of a projector, the lens determines the brightness, resolution and cost of the projector. High-brightness projectors often require large-aperture lenses. In order to achieve a large aperture, a large number of glass lenses are used in the design of the lens, which leads to a rapid increase in costs. In order to reduce costs, some lenses on the market use plastic lenses, but the focus shift is often more obvious at high temperatures. Currently, there is no projection lens on the market that overcomes all of the above shortcomings.

[0027] In view of the above, the present invention provides a projection optical system, which can be applied to any projection component, and the projection component can be applied to electronic devices with projection functions, especially electronic devices with small thickness, such as projectors, etc. However, for ease of understanding, in the following embodiments, the projection optical system is applied to a projector as an example for description.

[0028] See also Figure 1 The projection optical system 100 provided by the present invention includes a projection device and a projection screen 10, wherein the projection screen 10 and the projection device are arranged sequentially from front to back, and the projection device includes a first lens 1 with negative optical power, a second lens 2 with positive optical power, a third lens 3 with negative optical power, a fourth lens 4 with negative optical power, a fifth lens 5 with positive optical power, and a sixth lens 6 with positive optical power, which are arranged sequentially from front to back.

[0029] The first lens 1 and the third lens 3 are plastic aspherical lenses, the second lens 2, the fourth lens 4 and the fifth lens 5 are glass spherical lenses, and the sixth lens 6 is a plastic spherical lens.

[0030] In the technical solution provided by the present invention, the use of three plastic lenses at the same time greatly reduces the cost of the system. This embodiment adopts the mixed use of glass lenses and plastic lenses, and achieves that the projector does not defocus when the output brightness is ≤4000lm.

[0031] Furthermore, in this embodiment, the focal power of the first lens 1 is a1, the focal power of the second lens 2 is a2, the focal power of the third lens 3 is a3, the focal power of the fourth lens 4 is a4, the focal power of the fifth lens 5 is a5, and the focal power of the sixth lens 6 is a6. 0.02<|a1|<06, 0.02<|a2|<06, 0.005<|a3|<0.015, 0.001<|a4|<0.015, 0.001<|a5|<0.015, 0.015<|a6|<0.03. The focal power of the first lens 1 is negative and is a plastic aspheric surface, which can correct the astigmatism and field curvature of large-angle light, so that the light entering the rear group has a smaller angle and residual aberration. The second lens 2 is a double convex lens, which can increase the height of the light entering the rear group and correct the aperture spherical aberration; the third lens 3 is an aspherical lens, which further corrects the aperture spherical aberration. The sixth lens 6 is an aspherical lens, which can correct the distortion aberration of the system. The lenses are arranged from front to back in the order of negative, positive, negative, negative, positive and positive focal length, which can correct aberrations such as spherical aberration and coma of higher light, achieve a large aperture and improve the system resolution.

[0032] Furthermore, in this embodiment, -0.05<a1+a2<-0.035, and The projector can output 4000lm brightness without shifting focus. The use of three plastic lenses greatly reduces the cost of the system.

[0033] Furthermore, in this embodiment, the fourth lens 4 and the fifth lens 5 are cemented lenses to correct the chromatic aberration of the system.

[0034] Furthermore, in this embodiment, two opposite ends of the third lens 3 are bent forward.

[0035] Furthermore, in this embodiment, the projection device further includes a prism 7 , and the prism is arranged at the rear side of the sixth lens 6 .

[0036] Furthermore, in this embodiment, the projection device further comprises a light source assembly 9, wherein the light source assembly 9 comprises a light emitting chip, and the light emitting chip is arranged at the rear side of the prism 7 to provide a light source.

[0037] Furthermore, in this embodiment, the projection device also includes a light beam 8 , and the light beam 8 is arranged between the first lens 1 and the second lens 2 , and is close to the second lens 2 .

[0038] In addition, in this embodiment, the surface shapes of the aspherical surfaces of the first lens 1, the third lens 3 and the sixth lens 6 satisfy the following equation:

[0039]

[0040] In the formula, parameter c is the curvature corresponding to the radius, y is the radial coordinate whose unit is the same as the lens length unit, and k is the coefficient of the conic quadratic curve; when the k coefficient is less than -1, the surface curve of the lens is a hyperbola, and when the k coefficient is equal to -1, the surface curve of the lens is a parabola; when the k coefficient is between -1 and 0, the surface curve of the lens is an ellipse, when the k coefficient is equal to 0, the surface curve of the lens is a circle, and when the k coefficient is greater than 0, the surface curve of the lens is an oblate circle; a1 to a8 respectively represent the coefficients corresponding to each radial coordinate.

[0041] The following example shows the actual design parameters of a projection lens with an F1.4 lens output brightness of 4000lm:

[0042] Face number type Radius R thickness Optical Materials OBJ Physical surface Infinity 1700 S1 Aspheric 392.6774 2.5 E48R S2 Aspheric 13.29371 32.17 STO standard Infinity 0.027 S4 standard 40.96475 5.81 H-LAF50B S5 standard -53.2023 6.18 S6 Aspheric -10.5372 2.2 E48R S7 Aspheric -13.2243 18.66 S8 standard -378.069 1.2 H-ZF52A S9 standard 27.46325 6.29 H-QK3L S9 standard -30.2841 0.09 S10 Aspheric 47.69166 5.12 E48R S11 Aspheric -43.0567 5.00 S12 standard Infinity 24.72 H-K9L S13 Aspheric Infinity 5.47 IMA Image plane Infinity 0

[0043] Among them, the coefficients of the first surface (front surface) S1 of the first lens 1 are: k: 242.2274; a1: 0; a2: 2.253011e-005; a3: -2.4772503e-007; a4: 1.2123465e-009; a5: 4.9812139e-013; a6: -3.1646308e-014; a7: 1.2507921e-016; a8: -1.5150952e-019.

[0044] The coefficients of the second surface (the rear surface) S2 of the first lens 1 are: k: -3.214459; a1: 0; a2: 0.00016277035; a3: -9.5808111e-007; a4: 4.3818958e-009; a5: 3.3296685e-013;

[0045] a6: -6.8294818e-014; a7: 4.2242395e-017; a8: 4.9865941e-019.

[0046] The coefficients of the first surface (front surface) S6 of the third lens 3 are: k: -0.8754676; a1: 0; a2: 0.00021390646; a3: -2.8111872e-007; a4: -2.9501779e-009; a5: 1.8417366e-011;

[0047] a6: -5.930315e-015; a7: -2.6778756e-016; a8: 6.7713675e-019.

[0048] The coefficients of the second surface (the rear surface) S7 of the third lens 3 are: k: -1.494332; a1: 0; a2: 0.00015146284; a3: -6.0888052e-008; a4: -2.3747859e-009; a5: 4.7828386e-012;

[0049] a6: 7.6128755e-014; a7: -5.040236e-016; a8: 9.4580096e-019.

[0050] The coefficients of the first surface (front surface) S10 of the sixth lens 6 are: k: 4.146394; a1: 0; a2: -5.5192332e-006; a3: -1.8574166e-007; a4: 2.2442854e-009; a5: -1.6600066e-011;

[0051] a6: -9.0406174e-014; a7: 1.5345096e-015; a8: -5.5397503e-018.

[0052] The coefficients of the second surface (rear surface) S11 of the sixth lens 6 are: k: -32.58995; a1: 0; a2: -4.8838987e-005; a3: 2.4758444e-007; a4: -1.2999814e-009; a5: -3.0089076e-012; a6: 1.9916348e-018; a7: 3.7221193e-016; a8: -1.9646656e-018.

[0053] In addition, the present invention also provides a projection assembly, which includes the above-mentioned projection optical system 100.

[0054] It should be noted that the detailed structure of the projection optical system in the projection assembly can refer to the embodiment of the projection optical system 100 mentioned above, which will not be described in detail here; since the projection optical system 100 mentioned above is used in the projection assembly of the present invention, the embodiment of the projection assembly of the present invention includes all technical solutions of all embodiments of the projection optical system 100 mentioned above, and the technical effects achieved are also exactly the same, which will not be described in detail here.

[0055] In addition, the present invention also provides a projector, wherein the projection component includes the above-mentioned projection component.

[0056] It should be noted that the detailed structure of the projection assembly in the projector can refer to the embodiment of the above-mentioned projection assembly, which will not be repeated here; since the above-mentioned projection assembly is used in the projector of the present invention, the embodiment of the projector of the present invention includes all technical solutions of all embodiments of the above-mentioned projection assembly, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0057] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A projection optical system, characterized in that: The projection device comprises a projection screen, wherein the projection screen and the projection device are arranged in sequence from front to back, and the projection device comprises a first lens with negative optical power, a second lens with positive optical power, a third lens with negative optical power, a fourth lens with negative optical power, a fifth lens with positive optical power, and a sixth lens with positive optical power, which are arranged in sequence from front to back; Wherein, the first lens and the third lens are plastic aspherical lenses, the second lens, the fourth lens and the fifth lens are glass spherical lenses, and the sixth lens is a plastic spherical lens; The optical power of the first lens is , the focal power of the second lens is , the focal power of the third lens is , the optical power of the fourth lens is , the optical power of the fifth lens is , the focal power of the sixth lens is , ,and ,and ,and ; The radius of curvature of the object side of the first lens is 392.6774, the thickness of the first lens is 2.5, the radius of curvature of the image side of the first lens is 13.29371, the distance from the image side of the first lens to the object side of the second lens is 32.197, the radius of curvature of the object side of the second lens is 40.96475, the thickness of the second lens is 5.81, the radius of curvature of the image side of the second lens is -53.2023, the distance from the image side of the second lens to the object side of the third lens is 6.18, the radius of curvature of the object side of the third lens is -10.5372, the thickness of the third lens is 2.2, the radius of curvature of the image side of the third lens is -13.2243, the distance from the image side of the third lens to the The distance from the object side of the fourth lens is 18.66, the radius of curvature of the object side of the fourth lens is -378.069, the thickness of the fourth lens is 1.2, the radius of curvature of the image side of the fourth lens is 27.46325, the distance from the image side of the fourth lens to the object side of the fifth lens is 0, the radius of curvature of the object side of the fifth lens is 27.46325, the thickness of the fifth lens is 6.29, the radius of curvature of the image side of the fifth lens is -30.2841, the distance from the image side of the fifth lens to the object side of the sixth lens is 0.09, the radius of curvature of the object side of the sixth lens is 47.69166, the thickness of the sixth lens is 5.12, and the radius of curvature of the image side of the sixth lens is -43.0567; The fourth lens and the fifth lens are cemented lenses.

2. The projection optical system according to claim 1, characterized in that: Two opposite ends of the third lens are bent forward.

3. The projection optical system according to claim 1, wherein: The projection device further comprises a prism, and the prism is arranged at the rear side of the sixth lens.

4. The projection optical system according to claim 3, characterized in that: The projection device further comprises a light source assembly, wherein the light source assembly comprises a light emitting chip, and the light emitting chip is arranged at the rear side of the prism.

5. The projection optical system according to claim 1, wherein: The projection device further includes a light beam, which is disposed between the first lens and the second lens and is close to the second lens.

6. A projection assembly, characterized in that: The invention comprises a projection optical system as claimed in any one of claims 1 to 5.

7. A projector, characterized in that: Comprising the projection assembly as claimed in claim 6.

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