All-glass projection lens

Abstract

The present application relates to a kind of all glass projection lens, the optical system of the lens is by first lens, second lens, third lens, fourth lens, diaphragm, fifth lens, sixth lens, seventh lens and eighth lens are sequentially arranged from left to right along the light path of light incidence, first lens is double-convex positive lens;Second lens is meniscus positive lens;Third lens is meniscus positive lens;Fourth lens is meniscus negative lens;Fifth lens is double-concave negative lens;Sixth lens is double-convex positive lens;Seventh lens is double-convex positive lens;Eighth lens is meniscus positive lens, object side is convex, image side is concave.Using eight pieces of spherical glass lens, improve the projection image quality of lens, can project high-pixel, high-quality pattern or text;With F0.65 below big aperture and higher relative illumination, ensure that projection picture brightness is high and uniform;Adopt all glass design, glass material relative thermal stability is high, ensure that lens can normally project imaging under high temperature environment.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of lenses, and particularly relates to a full-glass projection lens. BACKGROUND

[0002] The projection lamp can image a picture in the form of light on an opaque plane (such as an indoor ceiling, a floor or a nearby wall), and can project a high-pixel and high-quality pattern, text and the like. The projected picture can be a static image or a dynamic picture, and is widely applied to commercial scenes, such as an advertisement logo projection lamp, an indoor floor mark, a wall decoration and the like. Compared with a traditional billboard or mark, the projection lamp has the advantages of higher flexibility and lower cost due to the changeable display content. The projection lamp is composed of an illumination system, a film pattern and a projection lens. However, the projection lens used at present has the defects of uneven picture, unclear projected pattern and poor thermal stability. SUMMARY

[0003] The application improves the prior art, and the technical problem to be solved by the application is to provide a full-glass projection lens, which has the advantages of reasonable design, large aperture, high brightness, high projection image quality and good thermal stability.

[0004] In order to achieve the above object, the application adopts the technical scheme of a full-glass projection lens, wherein the optical system of the lens is composed of a first lens, a second lens, a third lens, a fourth lens, a diaphragm, a fifth lens, a sixth lens, a seventh lens and an eighth lens arranged in sequence from left to right along the light incident path, the first lens is a double-convex positive lens; the second lens is a meniscus positive lens, the object side is a convex surface, and the image side is a concave surface; the third lens is a meniscus positive lens, the object side is a convex surface, and the image side is a concave surface; the fourth lens is a meniscus negative lens, the object side is a convex surface, and the image side is a concave surface; the fifth lens is a double-concave negative lens; the sixth lens is a double-convex positive lens; the seventh lens is a double-convex positive lens; and the eighth lens is a meniscus positive lens, the object side is a convex surface, and the image side is a concave surface.

[0005] Further, the first lens, the second lens, the third lens, the fourth lens, the diaphragm, the fifth lens, the sixth lens, the seventh lens and the eighth lens are all glass spherical lenses.

[0006] Further, the focal length of the optical system is f, and the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are f1, f2, f3, f4, f5, f6, f7, f8 respectively, wherein f1, f2, f3, f4, f5, f6, f7, f8 and f satisfy the following ratios: 2.0 < f1 / f < 3.0, 5.5 < f2 / f < 6.5, 2.0 < f3 / f < 3.0, -2.0 < f4 / f < -1.0, -1.5 < f5 / f < -0.5, 1.0 < f6 / f < 2.0, 1.0 < f7 / f < 2.0, 1.5 < f8 / f < 2.5.

[0007] Further, the first lens satisfies the relationship: N d ≥ 1.8, V d ≤ 50.0; the second lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, V d ≤ 50.0; the third lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, V d ≤ 50.0; the fourth lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, V d ≤ 50.0; the fifth lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, V d ≤ 50.0; the sixth lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, V d ≥ 50.0; the seventh lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, V d ≥ 50.0; the eighth lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, V d ≤ 50.0; wherein N d is the refractive index, and V d is the Abbe number.

[0008] Further, the air gap between the first lens and the second lens is 0.05-0.15 mm; the air gap between the second lens and the third lens is 0.05-0.15 mm; the air gap between the third lens and the fourth lens is 1.2-1.5 mm; the air gap between the fourth lens and the fifth lens is 9.5-9.7 mm; the air gap between the fifth lens and the sixth lens is 0.8-1.0 mm; the air gap between the sixth lens and the seventh lens is 0.05-0.15 mm; and the air gap between the seventh lens and the eighth lens is 0.05-0.15 mm.

[0009] Further, the optical total track length (TTL) of the optical system satisfies: TTL / f≤2.5, where f is the focal length of the optical system.

[0010] Further, the F number of the optical system is ≤0.65.

[0011] Further, the image height (H) of the optical system satisfies: H / f≥0.4, where f is the focal length of the optical system.

[0012] Further, the stop of the optical system is located between the fourth lens and the fifth lens.

[0013] Compared with the prior art, the present application has the following effects: the present application adopts eight pieces of spherical glass lenses, improves the projection image quality of the lens, and can project high-pixel and high-quality patterns or characters; has a large aperture of F0.65 or below and a relatively high relative luminance, and ensures that the projection picture has high and uniform brightness; adopts a full glass design, and the glass material has high thermal stability, which ensures that the lens can normally project and image under high temperature environment. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is the optical structure schematic diagram of the embodiment of the present application;

[0015] Figure 2 is the geometric transfer function curve diagram of the embodiment of the present application at 5lp / mm;

[0016] Figure 3 is the point column diagram of the embodiment of the present application;

[0017] Figure 4 is the full working waveband field curvature distortion diagram of the embodiment of the present application;

[0018] Figure 5 is the relative luminance diagram of the embodiment of the present application.

[0019] In the drawings:

[0020] L1-first lens; L2-second lens; L3-third lens; L4-fourth lens; STO-stop; L5-fifth lens; L6-sixth lens; L7-seventh lens; L8-eighth lens; IMA-imaging surface. DETAILED DESCRIPTION

[0021] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0022] As shown in the drawings, Figure 1 A full glass projection lens according to the present application, the optical system of the lens is composed of a first lens, a second lens, a third lens, a fourth lens, a stop, a fifth lens, a sixth lens, a seventh lens and an eighth lens arranged in order from left to right along the light path of the incident light.

[0023] Specifically, the first lens is a biconvex positive lens; the second lens is a meniscus positive lens, the object side is a convex surface, and the image side is a concave surface; the third lens is a meniscus positive lens, the object side is a convex surface, and the image side is a concave surface; the fourth lens is a meniscus negative lens, the object side is a convex surface, and the image side is a concave surface; the fifth lens is a biconcave negative lens; the sixth lens is a biconvex positive lens; the seventh lens is a biconvex positive lens; and the eighth lens is a meniscus positive lens, the object side is a convex surface, and the image side is a concave surface.

[0024] In this embodiment, the first lens, the second lens, the third lens, the fourth lens, the diaphragm, the fifth lens, the sixth lens, the seventh lens, and the eighth lens are all glass spherical lenses. The all-glass design has high thermal stability, which ensures that the lens can normally project an image in a high-temperature environment.

[0025] In this embodiment, the focal length of the optical system is f, and the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens are f1, f2, f3, f4, f5, f6, f7, and f8 respectively, wherein f1, f2, f3, f4, f5, f6, f7, and f8 satisfy the following ratios: 2.0 < f1 / f < 3.0, 5.5 < f2 / f < 6.5, 2.0 < f3 / f < 3.0, -2.0 < f4 / f < -1.0, -1.5 < f5 / f < -0.5, 1.0 < f6 / f < 2.0, 1.0 < f7 / f < 2.0, and 1.5 < f8 / f < 2.5.

[0026] In this embodiment, the first lens satisfies the relationship: N d ≥ 1.8, and V d ≤ 50.0; the second lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, and V d ≤ 50.0; the third lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, and V d ≤ 50.0; the fourth lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, and V d ≤ 50.0; the fifth lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, and V d ≤ 50.0; the sixth lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, and V d ≥ 50.0; the seventh lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, and V d ≥ 50.0; and the eighth lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, and V d≤ 50.0; wherein N d is the refractive index, V d is the Abbe number.

[0027] In the embodiment, the air gap between the first lens and the second lens is 0.05-0.15mm; the air gap between the second lens and the third lens is 0.05-0.15mm; the air gap between the third lens and the fourth lens is 1.2-1.5mm; the air gap between the fourth lens and the fifth lens is 9.5-9.7mm; the air gap between the fifth lens and the sixth lens is 0.8-1.0mm; the air gap between the sixth lens and the seventh lens is 0.05-0.15mm; and the air gap between the seventh lens and the eighth lens is 0.05-0.15mm.

[0028] In the embodiment, the total optical length TTL of the optical system and the focal length f of the optical system satisfy TTL / f≤2.5.

[0029] In the embodiment, the F number of the optical system is ≤0.65.

[0030] In the embodiment, the image height H of the optical system and the focal length f of the optical system satisfy H / f≥0.4.

[0031] In the embodiment, the stop of the optical system is located between the fourth lens and the fifth lens.

[0032] The technical index realized by the optical system in the embodiment is as follows:

[0033] (1) focal length: 27≤EFFL≤28mm; (2) aperture F≤0.65; (3) field of view angle: 2w≥20°; (4) working waveband: visible light waveband.

[0034] To realize the design parameters described above, the lens parameters adopted by the optical system in the embodiment are shown in the following table:

[0035]

[0036] The advantages of the present application are as follows: eight spherical glass lenses are adopted, the R value, thickness and spacing of each lens are reasonably matched, the projection image quality of the lens is improved, a high-pixel and high-quality pattern or text can be projected; a large aperture of F0.65 or below and a relatively high relative luminance are adopted, the brightness of the projection picture is high and uniform; a full glass design is adopted, the glass material has high thermal stability, and the lens can normally project and image under high temperature environment.

[0037] If the present application discloses or relates to mutually fixedly connected parts or structural members, unless otherwise stated, the fixed connection can be understood as: detachably fixedly connected (for example, connected using bolts or screws), and can also be understood as: non-detachable fixed connection (for example, riveting, welding), of course, the mutually fixed connection can also be replaced by an integral structure (for example, manufactured by integral forming using a casting process) (obviously, integral forming process cannot be used).

[0038] In addition, the terms used to represent the positional relationship or shape in any of the technical solutions disclosed in the present application include states or shapes similar, similar or close to them, unless otherwise stated.

[0039] Any component provided by the present application can be assembled from multiple individual components, or can be a single component manufactured by integral forming process.

[0040] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application and not to limit them; although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the specific embodiments of the present application can be modified or some technical features can be replaced by equivalents; without departing from the spirit of the technical solutions of the present application, they should be included in the technical solution range of the present application claimed.

Claims

1. An all-glass projection lens characterized by: The optical system of the lens is composed of a first lens, a second lens, a third lens, a fourth lens, a diaphragm, a fifth lens, a sixth lens, a seventh lens and an eighth lens arranged in sequence from left to right along the light path of light incidence, the first lens is a biconvex positive lens; the second lens is a meniscus positive lens, the object side is a convex surface, and the image side is a concave surface; the third lens is a meniscus positive lens, the object side is a convex surface, and the image side is a concave surface; the fourth lens is a meniscus negative lens, the object side is a convex surface, and the image side is a concave surface; the fifth lens is a biconcave negative lens; the sixth lens is a biconvex positive lens; the seventh lens is a biconvex positive lens; and the eighth lens is a meniscus positive lens, the object side is a convex surface, and the image side is a concave surface; The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are all glass spherical lenses; The air gap between the first lens and the second lens is 0.099mm; the air gap between the second lens and the third lens is 0.099mm; the air gap between the third lens and the fourth lens is 1.370; the air gap between the fourth lens and the fifth lens is 9.685mm; the air gap between the fifth lens and the sixth lens is 0.908mm; the air gap between the sixth lens and the seventh lens is 0.100mm; and the air gap between the seventh lens and the eighth lens is 0.100mm.

2. The all-glass projection lens of claim 1, wherein: The focal length of the optical system is f, and the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are f1, f2, f3, f4, f5, f6, f7 and f8 respectively, wherein f1, f2, f3, f4, f5, f6, f7 and f8 and f satisfy the following ratios: 2.0<f1 / f<3.0, 5.5<f2 / f<6.5, 2.0<f3 / f<3.0, -2.0<f4 / f<-1.0, -1.5<f5 / f<-0.5, 1.0<f6 / f<2.0, 1.0<f7 / f<2.0, and 1.5<f8 / f<2.

5.

3. The all-glass projection lens of claim 1, wherein: The first lens satisfies the relationship: N d = 1.834, V d = 37.229; the second lens satisfies the relationship: N d = 1.788, V d = 47.517; the third lens satisfies the relationship: N d = 1.788, V d = 47.517; the fourth lens satisfies the relationship: N d = 1.728, V d = 28.311; the fifth lens satisfies the relationship: N d = 1.741, V d = 27.762; the sixth lens satisfies the relationship: N d = 1.593, V d = 68.346; the seventh lens satisfies the relationship: N d = 1.639, V d = 55.472; the eighth lens satisfies the relationship: N d = 1.744, V d 44.904; wherein N d is the refractive index, V d is the Abbe number.

4. The all-glass projection lens of claim 1, wherein: The total optical length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f≤2.

5.

5. The all-glass projection lens of claim 1, wherein: The F number of the optical system is ≤0.

65.

6. The all-glass projection lens of claim 1, wherein: The image height H of the optical system and the focal length f of the optical system satisfy: H / f≥0.

4.

7. The all-glass projection lens of claim 1, wherein: The diaphragm of the optical system is located between the fourth lens and the fifth lens.

Images