Lens, projection light machine and projection equipment

Abstract

The utility model provides a lens, a projection light machine and projection equipment. The lens comprises a first lens, a second lens and a third lens which are coaxially arranged in sequence along the opposite direction of emergent light of the lens, and the MTF (Modulation Transfer Function) value of the lens is 0.45 to 0.85. According to the technical scheme, the first lens, the second lens and the third lens are sequentially and coaxially arranged in the opposite direction of the emergent light of the lens; the value range of the MTF (Modulation Transfer Function) of the lens is 0.45 to 0.85; the value range of the MTF value of the lens is 0.45-0.85, so that the lens performance of a single-chip LCD is optimized, and the lens with high resolution and high light flux is realized.

Description

Technical Field

[0001] The present application relates to the technical field of projectors, and in particular to a lens, a projection optical machine, and a projection device. Background Art

[0002] LCD (Liquid Crystal Display) projectors typically consist of an illumination system, an LCD display system, and an imaging system. Using Köhler illumination, they project the image displayed on the LCD onto a screen through a lens. Compared to projectors based on other principles, such as DLP (Digital Light Processing) and LCoS (Liquid Crystal on Silicon), single-chip LCD projectors are inexpensive and simple to manufacture, making them a popular choice in the projector market. However, single-chip LCDs still have some significant drawbacks, such as poor lens performance, resolution, and light throughput. Summary of the Invention

[0003] The present application provides a lens, a projection optical machine, and a projection device to improve the performance of the projection lens and ensure sufficient resolution and light throughput.

[0004] In a first aspect, a lens is provided, comprising:

[0005] A first lens, a second lens, and a third lens are coaxially arranged in sequence along the opposite direction of the output light of the lens;

[0006] The first lens has positive power, the second lens has negative power, and the third lens has positive power;

[0007] Along the reverse direction of the emitted light, the first lens has a first lens surface and a second lens surface, the second lens has a third lens surface and a fourth lens surface, and the third lens has a fifth lens surface and a sixth lens surface; the first lens surface, the third lens surface and the sixth lens surface are convex surfaces, and the second lens surface, the fourth lens surface and the fifth lens surface are concave surfaces;

[0008] The MTF value of the lens ranges from 0.45 to 0.85.

[0009] In the above technical solution, the first, second, and third lenses are coaxially arranged in the opposite direction of the lens's outgoing light. The lens's MTF value ranges from 0.45 to 0.85. The lens's MTF (Modulation Transfer Function) is a function used to quantitatively describe the clarity of a lens's image. The MTF value is a number between 0 and 1, with the larger the value (the closer it is to 1), the stronger the lens's ability to restore reality. Therefore, by achieving an MTF value range of 0.45 to 0.85, the lens performance of the single-chip LCD is optimized, achieving a high-resolution and high-light-throughput lens.

[0010] In a specific embodiment, the F number of the lens is 2.3 to 2.55.

[0011] In a specific embodiment, the throw ratio of the lens is 1.1 to 1.26.

[0012] In a specific implementation scheme, the total length of the lens is 46 mm to 56 mm.

[0013] In a specific embodiment, the first lens is a glass lens; and the second lens and the third lens are resin lenses.

[0014] In a specific embodiment, the first lens surface and the second lens surface are spherical surfaces; and the third lens surface, the fourth lens surface, the fifth lens surface and the sixth lens surface are aspherical surfaces.

[0015] In a specific embodiment,

[0016] The refractive index of the first lens is 1.71 to 1.76.

[0017] The refractive index of the second lens is 1.60 to 1.68.

[0018] The refractive index of the third lens is 1.50 to 1.58.

[0019] In a specific embodiment, the lens further includes an aperture stop located between the second lens and the third lens.

[0020] In a second aspect, a projection optical machine is provided, comprising any lens.

[0021] In the above technical solution, the first, second, and third lenses are coaxially arranged in the opposite direction of the lens's outgoing light. The lens's MTF value ranges from 0.45 to 0.85. The lens's MTF (Modulation Transfer Function) is a function used to quantitatively describe the clarity of a lens's image. The MTF value is a number between 0 and 1, with the larger the value (the closer it is to 1), the stronger the lens's ability to restore reality. Therefore, by achieving an MTF value range of 0.45 to 0.85, the lens performance of the single-chip LCD is optimized, achieving a high-resolution and high-light-throughput lens.

[0022] In a third aspect, a projection device is provided, including a projection optical engine.

[0023] In the above technical solution, the first, second, and third lenses are coaxially arranged in the opposite direction of the lens's outgoing light. The lens's MTF value ranges from 0.45 to 0.85. The lens's MTF (Modulation Transfer Function) is a function used to quantitatively describe the clarity of a lens's image. The MTF value is a number between 0 and 1, with the larger the value (the closer it is to 1), the stronger the lens's ability to restore reality. Therefore, by achieving an MTF value range of 0.45 to 0.85, the lens performance of the single-chip LCD is optimized, achieving a high-resolution and high-light-throughput lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the structure of the lens provided in an embodiment of the present application;

[0025] Figure 2 A schematic diagram of the parameters and dimensions of the lens provided in an embodiment of the present application.

[0026] In the picture:

[0027] 1-first lens, 2-second lens, 3-third lens, 4-aperture, 101-first lens surface, 102-second lens surface, 201-third lens surface, 202-fourth lens surface, 301-fifth lens surface, 302-sixth lens surface. DETAILED DESCRIPTION

[0028] The present application will be further described in detail below through the accompanying drawings and examples, through which the features and advantages of the present application will become more clear and distinct.

[0029] The word "exemplary" is used exclusively herein to mean "serving as an example, example, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

[0030] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0031] To facilitate understanding of the lens, projection engine, and projection device provided in the embodiments of the present application, let's first explain their application scenarios. LCD (Liquid Crystal Display) projection equipment typically consists of an illumination system, an LCD display system, and an imaging system. Using Köhler illumination, the image displayed on the LCD is imaged onto a screen through a lens. Compared to projectors based on other principles, such as DLP (Digital Light Processing) and LCoS (Liquid Crystal on Silicon), single-chip LCD projectors are inexpensive and simple to manufacture, thus securing a niche in the projector market. However, single-chip LCDs still have some significant drawbacks, such as poor lens performance, resolution, and light throughput. To address this, the embodiments of the present application provide a lens, projection engine, and projection device to improve lens performance and ensure sufficient resolution and light throughput. While the lens of the present application is primarily intended for use in projection engines or projection devices, it can also be used in any other suitable device. The following describes these details using specific embodiments with reference to the accompanying drawings.

[0032] refer to Figure 1 and Figure 2 , Figure 1 A schematic diagram of the structure of the lens provided in an embodiment of the present application. Figure 2 This is a schematic diagram of the parameters and dimensions of the lens provided in the embodiment of the present application. Figure 1 In the embodiment of the present application, a lens is provided, which includes: a first lens 1, a second lens 2, and a third lens 3 coaxially arranged in sequence along the opposite direction of the output light of the lens; the first lens has positive focal power, the second lens has negative focal power, and the third lens has positive focal power; the MTF value of the lens ranges from 0.45 to 0.85.

[0033] In the above technical solution, the first lens 1, the second lens 2, and the third lens 3 are coaxially arranged in sequence along the opposite direction of the output light of the lens; the second lens surface 102 of the first lens 1 is arranged opposite to the third lens surface 201 of the second lens 2, and the fourth lens surface 202 of the second lens 2 is arranged opposite to the fifth lens surface 301 of the third lens 3.

[0034] Specifically, the first lens 1 includes a first lens surface 101 and a second lens surface 102, the second lens 2 includes a third lens surface 201 and a fourth lens surface 202, and the third lens 3 includes a fifth lens surface 301 and a sixth lens surface 302. Incident light passes through the sixth lens surface 302, the fifth lens surface 301, the fourth lens surface 202, the third lens surface 201, the second lens surface 102, and the first lens surface 101 in sequence. The first, third, and sixth lens surfaces are convex, while the second, fourth, and fifth lens surfaces are concave. The MTF value of the lens ranges from 0.45 to 0.85. The MTF (Modulation Transfer Function) of a lens is a function used to quantitatively describe the clarity of the lens's imaging. The MTF value is a value between 0 and 1. The larger the value (the closer to 1), the stronger the lens's ability to restore reality. Therefore, by achieving an MTF range of 0.45 to 0.85, the lens performance for single-chip LCDs is optimized, achieving both high resolution and high light throughput. High resolution refers to a lens's ability to capture and reproduce detail. A high-resolution lens captures more detail and texture, making images appear clearer and more realistic; thus, achieving optimized lens performance.

[0035] In a specific embodiment, preferably, the MTF value of the lens is 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.7, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.8, 0.81, 0.82, 0.83, 0.84, or 0.85. This optimizes the lens performance of a single-chip LCD and achieves a lens with high resolution and high light throughput.

[0036] In a specific embodiment, the F number of the lens is 2.3 to 2.55. Preferably, the F number of the lens is 2.3, 2.31, 2.32, 2.33, 2.34, 2.35, 2.36, 2.37, 2.38, 2.39, 2.4, 2.41, 2.42, 2.43, 2.44, 2.45, 2.46, 2.47, 2.48, 2.49, 2.5, 2.51, 2.52, 2.53, 2.54, 2.55. The F number (also known as the F value or aperture number) is an important parameter of the lens, which represents the ratio of the focal length to the effective aperture of the lens. A smaller F number means that the lens has a larger effective aperture and a relatively smaller focal length, which can bring greater light transmission and a shallower depth of field effect. This allows a small F number lens to still capture bright and clear images in a dark environment. By achieving an F number of 2.3 to 2.55, a high-light-throughput lens is achieved, further optimizing the lens performance for single-chip LCDs.

[0037] In one specific embodiment, the lens has a throw ratio of 1.1 to 1.26. Preferably, the lens has a throw ratio of 1.1, 1.11, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.19, 1.2, 1.21, 1.22, 1.23, 1.24, 1.25, or 1.26. A lens's throw ratio refers to the ratio of projection distance to image width. This ratio reflects the lens's ability to project images at different distances. A smaller throw ratio indicates that the lens can achieve a larger image width at a shorter projection distance, which is very useful for applications requiring large-screen projection within a limited space.

[0038] It’s important to note that different lenses may have different throw ratios, so when choosing a lens, you need to select the appropriate throw ratio based on your actual needs. The throw ratio is also affected by the optical performance of the lens itself, the performance of the projector, and the projection environment.

[0039] In a specific embodiment, the total length of the lens is 46mm to 56mm. Preferably, the total length of the lens is 46mm, 46.5mm, 47mm, 47.5mm, 48mm, 48.5mm, 49mm, 49.5mm, 50mm, 50.5mm, 51mm, 51.5mm, 52mm, 52.5mm, 53mm, 53.5mm, 54mm, 54.5mm, 55mm, 55.5mm, 56mm. Since the lens of the present application has a higher MTF value and a smaller F number, the lens has optimized lens performance. For an optical machine with fixed brightness, the length of the lens can be made smaller, the volume of the optical machine can be significantly reduced, the volume of the final product can be made smaller, and there is more space to place other components such as a radiator, etc., so that a higher brightness of the optical machine can be obtained.

[0040] In one specific embodiment, the first lens is a glass lens; the second and third lenses are resin lenses. Compared to existing three-piece glass lenses, the lens of the present application uses a combination of one glass lens and two resin lenses. Resin lenses are less expensive than glass lenses, effectively reducing the cost of the lens.

[0041] In one specific embodiment, the first and second lens surfaces are spherical; the third, fourth, fifth, and sixth lens surfaces are aspherical. Compared to existing three-element lenses in which each lens element is spherical, the lens of this application utilizes a combination of spherical and aspherical lenses, achieving optimized lens performance with a higher MTF value and a smaller F-number.

[0042] In a specific embodiment, the refractive index of the first lens 1 is 1.71-1.76, the refractive index of the second lens 2 is 1.60-1.68, and the refractive index of the third lens 3 is 1.50-1.58.

[0043] Preferably, the refractive index of the first lens element 1 is 1.71, 1.72, 1.73, 1.74, 1.75, or 1.76; the refractive index of the second lens element 2 is 1.60, 1.61, 1.62, 1.63, 1.64, 1.65, 1.66, 1.67, or 1.68; and the refractive index of the third lens element 3 is 1.50, 1.51, 1.52, 1.53, 1.54, 1.55, 1.56, 1.57, or 1.58. Selecting appropriate refractive indices for the first, second, and third lenses helps achieve optimized lens performance, with a higher MTF value and a smaller F-number.

[0044] In a specific embodiment, the lens further includes a stop 4 located between the second lens and the third lens.

[0045] In one specific embodiment, the designed lens is suitable for 4-inch 1080p LCD chips. It has a total length of 52.65mm, an F-number of 2.5, a throw ratio of 1.17, a focal length of 120mm, and an MTF value of 0.5. It offers excellent resolution and light throughput, achieving high-precision lens performance. The lens surface data is shown in Table 1; an n-order even-order aspheric equation is used, where n is 4, 6, 8, 10, or 12; s1 and s2 are the two surfaces of the first lens, s3 and s4 are the two surfaces of the second lens, s5 is the aperture, and s6 and s7 are the two surfaces of the third lens.

[0046] Radius of curvature thickness Refractive index Conic parameters Tier 4 Tier 6 Tier 8 Level 10 Level 12 S1 36.05816 12.20 1.73 S2 238.2765 1.18 S2 129.9399 8.27 1.64 -17.2204 -3.555E-07 2.318E-10 -2.184E-13 7.773E-20 3.918E-22 S4 25.57883 14.20 0.422937 -1.566E-06 2.970E-09 -9.345E-12 -7.230E-19 -3.174E-21 S5 unlimited 6.37 S6 -94.6121 10.43 1.54 -1.56839 -4.316E-06 -3.628E-09 -1.091E-11 -8.925E-20 1.740E-21 S7 -42.0255 1.845544 -9.339E-07 3.843E-10 -5.107E-12 -5.575E-19 6.771E-22

[0047] Table 1 Lens surface data

[0048] An embodiment of the present application further provides a projection optical engine, comprising the above-mentioned lens.

[0049] In the above technical solution, a first lens element 1, a second lens element 2, and a third lens element 3 are coaxially arranged in the direction opposite to the outgoing light from the lens. The lens's MTF value ranges from 0.45 to 0.85. The MTF (Modulation Transfer Function) of a lens is a function that quantitatively describes the clarity of the image produced by the lens. The MTF value is a number between 0 and 1, with a larger value (the closer to 1) indicating a greater ability of the lens to reproduce reality. Therefore, by achieving an MTF value range of 0.45 to 0.85, the lens performance of a single-chip LCD is optimized, achieving a high-resolution and high-light-throughput lens. High resolution refers to the ability of a lens to capture and reproduce detail. A high-resolution lens can capture more details and textures, making images appear clearer and more realistic, thereby achieving optimized lens performance.

[0050] An embodiment of the present application further provides a projection device, comprising the above-mentioned projection optical engine.

[0051] In the above technical solution, a first lens element 1, a second lens element 2, and a third lens element 3 are coaxially arranged in the direction opposite to the outgoing light from the lens. The lens's MTF value ranges from 0.45 to 0.85. The MTF (Modulation Transfer Function) of a lens is a function that quantitatively describes the clarity of the image produced by the lens. The MTF value is a number between 0 and 1, with a larger value (the closer to 1) indicating a greater ability of the lens to reproduce reality. Therefore, by achieving an MTF value range of 0.45 to 0.85, the lens performance of a single-chip LCD is optimized, achieving a high-resolution and high-light-throughput lens. High resolution refers to the ability of a lens to capture and reproduce detail. A high-resolution lens can capture more details and textures, making images appear clearer and more realistic, thereby achieving optimized lens performance.

[0052] In the description of this application, it should be noted that the terms "upper", "lower", "inside", "outside", "front", "back", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships in the working state of this application. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on this application.

[0053] In the description of this application, it should be noted that, unless otherwise specified or limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0054] The present application has been described above in conjunction with preferred embodiments, but these embodiments are merely exemplary and serve only as an illustrative example. On this basis, various replacements and improvements can be made to the present application, all of which fall within the scope of protection of the present application.

Claims

1. A lens, characterized in that: The lens includes: A first lens, a second lens, and a third lens coaxially arranged in sequence along a direction opposite to the direction of the light emitted from the lens; The first lens has positive optical power, the second lens has negative optical power, and the third lens has positive optical power; Along the reverse direction of the emitted light, the first lens has a first lens surface and a second lens surface, the second lens has a third lens surface and a fourth lens surface, and the third lens has a fifth lens surface and a sixth lens surface; the first lens surface, the third lens surface, and the sixth lens surface are convex surfaces, and the second lens surface, the fourth lens surface, and the fifth lens surface are concave surfaces; The MTF value of the lens is 0.5; The total length of the lens is 46 mm to 56 mm.

2. The lens according to claim 1, wherein: The F number of the lens is 2.3 to 2.

55.

3. The lens according to claim 1 or 2, characterized in that: The throw ratio of the lens is 1.1 to 1.

26.

4. The lens according to claim 1, wherein: The first lens is a glass lens; the second lens and the third lens are resin lenses.

5. The lens according to claim 1, wherein: The first lens surface and the second lens surface are spherical surfaces; the third lens surface, the fourth lens surface, the fifth lens surface and the sixth lens surface are aspherical surfaces.

6. The lens according to claim 4 or 5, characterized in that: The refractive index of the first lens is 1.71 to 1.76, The refractive index of the second lens is 1.60 to 1.68, The refractive index of the third lens is 1.50-1.

58.

7. The lens according to claim 1, wherein: The lens further includes an aperture stop located between the second lens and the third lens.

8. A projection light machine, characterized in that: The lens comprises the lens according to any one of claims 1 to 7.

9. A projection device, characterized in that: Comprising the projection light engine as described in claim 8.

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