Large-view fixed-focus projection lens

Abstract

The utility model relates to the field of projection lenses, in particular to a large-view fixed-focus projection lens, which comprises a lens barrel, a cavity arranged in the middle inside the lens barrel, a channel arranged at the top of the lens barrel, a first step and a second step sequentially arranged inside the lens barrel from the middle to the two ends, a first lens and a second lens are fixed in the first step, a third lens and fourth lenses are fixed in the second step, a space ring is further fixed in the second step and abuts against the position between the second lens and the third lens, the two ends of the lens barrel are in threaded connection with pressing rings, and the two pressing rings abut against the two fourth lenses respectively. The beneficial effects of the utility model are that only eight lenses are used for completing the operation, the processing is convenient, the cost is low, the distortion rate is low, it is ensured that the image is not distorted, and the lens is compact in structure, small in size and convenient to operate.

Description

Technical Field

[0001] The utility model relates to the field of projection lenses, and particularly to a large-field fixed-focus projection lens. Background Technique

[0002] The DMD chip (Digital Micromirror Device) is a micro-optical device commonly used in digital projection systems, especially in DLP (Digital Light Processing) projection technology. There are millions of tiny mirrors on the DMD chip, and each mirror can be tilted independently to control the reflection direction of light, thereby generating an image. This technology has been widely used in projectors, 3D printing, and other optical applications. 3D printers based on the DMD chip optical engine have gradually become popular in the industrial and consumer industries in recent years. Among them, the DMD chip is the core component of the digital light processor and is commonly used in DLP projection technology.

[0003] Although the projection objective lens in the DLP optical engine is designed to reduce distortion, there may still be a certain degree of distortion in the case of a large field of view. This distortion may cause deformation or distortion at the image edge, affecting the overall visual effect, and the large number of lenses leads to high production costs.

[0004] Therefore, it is necessary to invent a large-field fixed-focus projection lens. Content of the Utility Model

[0005] For this reason, the utility model provides a large-field fixed-focus projection lens to solve the problems raised in the above background technique.

[0006] To achieve the above object, the utility model provides the following technical solution: A large-field fixed-focus projection lens includes a lens barrel. A cavity is provided in the middle of the lens barrel. A channel is opened at the top of the lens barrel, and the bottom end of the channel is communicated with the top of the cavity. A first step and a second step are sequentially arranged in the lens barrel from the middle to both ends. A first lens and a second lens are fixed inside the first step, and a third lens and a fourth lens are fixed inside the second step. A spacer is also fixed inside the second step, and the spacer abuts between the second lens and the third lens. Pressing rings are threadedly connected to both ends of the lens barrel, and the two pressing rings respectively abut against the two fourth lenses. A diaphragm adjustment assembly is rotatably connected in the cavity and the channel, and a projection optical machine connection assembly is provided at the end of the lens barrel.

[0007] Preferably, the diaphragm adjustment assembly includes an adjustable diaphragm. The adjustable diaphragm rotates inside the cavity. A diaphragm adjustment rod is fixed to the top end of the adjustable diaphragm. The top end of the diaphragm adjustment rod vertically passes through the channel, and a diaphragm adjustment ring is fixed to the top end of the diaphragm adjustment rod. The diaphragm adjustment ring is rotatably connected to the outer surface of the lens barrel.

[0008] Preferably, a first locking ring is also threadedly connected to the outer surface of the lens barrel. A gasket is fixed to one end of the first locking ring close to the diaphragm adjusting ring, and the gasket abuts against one end of the diaphragm adjusting ring close to the first locking ring.

[0009] Preferably, the projection optical machine connection assembly includes a connection flange plate for fixedly connecting the lens barrel and the projection optical machine, and the connection flange plate is threadedly connected to one end of the lens barrel.

[0010] Preferably, a second locking ring is also threadedly connected to the outer surface of the lens barrel, and one end of the second locking ring close to the connection flange plate abuts against the connection flange plate.

[0011] The beneficial effects of the present utility model are as follows: Through the combined use of the lens barrel, cavity, channel, first step, second step, first lens, second lens, third lens, fourth lens, spacer, retaining ring, diaphragm adjusting assembly and projection optical machine connection assembly, it is only completed with 8 lenses, which is convenient for processing, has low cost, low distortion rate, ensures that the image is not distorted, and the lens structure is compact, small in volume and convenient to operate. Description of the Drawings

[0012] Figure 1 is a structural sectional view provided by the present utility model;

[0013] Figure 2 is a three-dimensional structural view provided by the present utility model.

[0014] In the figure: 1, lens barrel; 2, cavity; 3, channel; 4, first step; 5, second step; 6, first lens; 7, second lens; 8, third lens; 9, fourth lens; 10, spacer; 11, retaining ring; 12, adjustable diaphragm; 13, diaphragm adjusting rod; 14, diaphragm adjusting ring; 15, first locking ring; 16, gasket; 17, connection flange plate; 18, second locking ring. Detailed Embodiments

[0015] The following describes the preferred embodiments of the present utility model with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present utility model, and are not used to limit the present utility model.

[0016] Please refer to the attached Figure 1 - Figure 2, a large-field-of-view fixed-focus projection lens provided by the present utility model includes a lens barrel 1. A cavity 2 is arranged in the middle inside the lens barrel 1. A channel 3 is opened at the top of the lens barrel 1, and the bottom end of the channel 3 is communicated with the top of the cavity 2. A first step 4 and a second step 5 are sequentially arranged inside the lens barrel 1 from the middle to both ends. A first lens 6 and a second lens 7 are fixed inside the first step 4 respectively. A third lens 8 and a fourth lens 9 are fixed inside the second step 5 respectively. A spacer 10 is also fixed inside the second step 5. The spacer 10 abuts between the second lens 7 and the third lens 8. Pressing rings 11 are threadedly connected to both ends of the lens barrel 1, and the two pressing rings 11 abut against the two fourth lenses 9 respectively, realizing the function of installing eight lenses inside the lens barrel 1. A diaphragm adjustment assembly is rotatably connected inside the cavity 2 and the channel 3, and a projection optical machine connection assembly is arranged at the end of the lens barrel 1;

[0017] The diaphragm adjustment assembly includes an adjustable diaphragm 12 which rotates inside the cavity 2. A diaphragm adjustment rod 13 is fixed at the top end of the adjustable diaphragm 12. The top end of the diaphragm adjustment rod 13 vertically passes through the channel 3, and a diaphragm adjustment ring 14 is fixed at the top end of the diaphragm adjustment rod 13. The diaphragm adjustment ring 14 is rotatably connected to the outer surface of the lens barrel 1. That is, when an operator rotates the diaphragm adjustment ring 14, the adjustable diaphragm 12 can be driven to rotate synchronously through the diaphragm adjustment rod 13, thereby realizing the function of adjusting the aperture. A first locking ring 15 is also threadedly connected to the outer surface of the lens barrel 1. A gasket 16 is fixed at one end of the first locking ring 15 close to the diaphragm adjustment ring 14. The gasket 16 abuts against one end of the diaphragm adjustment ring 14 close to the first locking ring 15. Specifically, under the locking action of the first locking ring 15, the diaphragm adjustment ring 14 can be fixed by squeezing through the gasket 16, realizing the fixing operation of the diaphragm adjustment ring 14 with the adjusted position;

[0018] The projection optical machine connection assembly includes a connection flange plate 17 for fixedly connecting the lens barrel 1 and the projection optical machine. The connection flange plate 17 is threadedly connected to one end of the lens barrel 1. That is, under the action of the connection flange plate 17, the lens barrel 1 can be fixed on the projection optical machine through fixing screws, etc. A second locking ring 18 is also threadedly connected to the outer surface of the lens barrel 1. One end of the second locking ring 18 close to the connection flange plate 17 abuts against the connection flange plate 17. Specifically, under the locking action of the second locking ring 18, the connection flange plate 17 can be squeezed and fixed to prevent the connection flange plate 17 from reversing and falling off;

[0019] In summary, this projection lens is completed only by using 8 lenses, which is convenient for processing, has a low cost, a low distortion rate, ensures that the image is not distorted, and has a compact lens structure, a small volume and convenient operation.

[0020] The above are only the preferred embodiments of the present utility model. Any person skilled in the art can modify the present utility model by using the technical solutions described above or modify it into an equivalent technical solution. Therefore, any simple modification or equivalent replacement made according to the technical solutions of the present utility model falls within the scope of protection required by the present utility model.

Claims

1. A fixed-focus projection lens with a large field of view, comprising a lens barrel (1), characterized in that: A cavity (2) is arranged in the middle of the lens barrel (1), a channel (3) is provided at the top of the lens barrel (1), the bottom end of the channel (3) is connected to the top of the cavity (2), a first step (4) and a second step (5) are arranged in sequence from the middle to the two ends of the lens barrel (1), a first lens (6) and a second lens (7) are fixed inside the first step (4), a third lens (8) and a fourth lens (9) are fixed inside the second step (5), a spacer (10) is also fixed inside the second step (5), the spacer (10) is abutted between the second lens (7) and the third lens (8), both ends of the lens barrel (1) are threadedly connected with a pressing ring (11), the two pressing rings (11) are respectively abutted with two fourth lenses (9), an aperture adjustment component is rotatably connected in the cavity (2) and the channel (3), and a projection optical machine connection component is arranged at the end of the lens barrel (1).

2. The large-viewing-field fixed-focus projection lens according to claim 1, characterized in that: The iris adjustment assembly comprises an adjustable iris (12), the adjustable iris (12) is rotatable inside the cavity (2), an iris adjustment rod (13) is fixed at the top end of the adjustable iris (12), the top end of the iris adjustment rod (13) vertically passes through the channel (3), and an iris adjustment ring (14) is fixed at the top end of the iris adjustment rod (13), and the iris adjustment ring (14) is rotatably connected to the outer surface of the lens barrel (1).

3. The large-viewing-field fixed-focus projection lens according to claim 2, characterized in that: The outer surface of the lens barrel (1) is also threadedly connected with a first locking ring (15); a gasket (16) is fixed to one end of the first locking ring (15) close to the aperture adjustment ring (14); the gasket (16) abuts against one end of the aperture adjustment ring (14) close to the first locking ring (15).

4. The large-viewing-field fixed-focus projection lens according to claim 1, characterized in that: The projection optical machine connection assembly comprises a connection flange plate (17) for fixedly connecting the lens barrel (1) and the projection optical machine, wherein the connection flange plate (17) is threadedly connected to one end of the lens barrel (1).

5. The large-viewing-field fixed-focus projection lens according to claim 4, characterized in that: The outer surface of the lens barrel (1) is also threadedly connected with a second locking ring (18), and one end of the second locking ring (18) close to the connecting flange plate (17) is in contact with the connecting flange plate (17).

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