Infrared lens and imaging device

Abstract

The application discloses an infrared lens, which comprises a lens barrel, a first lens, a second lens, a cam and a pin. The first lens and the second lens are arranged in the lens barrel along the axial direction of the lens barrel, and the second lens can move reciprocatingly along the axial direction of the lens barrel; the cam is connected to the outer side of the lens barrel and can rotate around the radial central axis of the lens barrel, and a cam groove is formed on one side of the cam; the pin is connected to the second lens and protrudes from the lens barrel and extends into the cam groove, so that the cam drives the second lens to move reciprocatingly during rotation; when the second lens is subjected to an external force along the axial direction of the lens barrel, the frictional force of the inner wall of the cam groove on the pin is greater than the driving force of the pin. By using the above infrared lens, when the lens is impacted, the frictional force of the cam on the pin is greater than the driving force of the pin, so that the displacement of the second lens under the action of the inertial force can be avoided, the focal length of the lens can be prevented from changing, and the imaging effect can be ensured to be stable. The application further discloses an imaging device.

Description

Technical Field

[0001] This application belongs to the field of infrared optical equipment technology, specifically relating to an infrared lens and imaging device. Background Technology

[0002] Infrared lenses are used to focus infrared light, accurately illuminating the focal plane of an infrared detector to obtain a clear image. With the development of thermal infrared technology, the application of infrared lenses is becoming increasingly widespread. In the application of infrared lenses, except for lenses with large depth of field, focusing is generally required to achieve clear imaging of objects at different distances.

[0003] Existing focusing lenses typically consist of multiple lenses, with focusing achieved by moving one of these lenses. However, current focusing mechanisms usually employ a focusing wheel coaxial with the lens, meaning that rotating the focusing wheel drives the lens to move. When the lens is subjected to an impact, the movable lens may shift, affecting image quality. Utility Model Content

[0004] The technical problem to be solved by this application is that the position of the lens of an existing focusing lens will shift when it is impacted, which will affect the imaging effect. In order to solve this technical problem, an infrared lens and imaging device are provided that can prevent the lens from shifting when the lens is impacted.

[0005] The technical solution proposed in this application is as follows:

[0006] An infrared lens, comprising:

[0007] Lens tube;

[0008] The first lens and the second lens are arranged at intervals along the axial direction of the lens barrel inside the lens barrel, and the second lens is capable of reciprocating along the axial direction of the lens barrel.

[0009] A cam and a pin are provided. The cam is connected to the outside of the lens barrel and can rotate about the radial central axis of the lens barrel. A cam groove is provided on one side of the cam. The pin is connected to the second lens and one end extends out of the lens barrel and into the cam groove, so that the second lens is driven to reciprocate during the rotation of the cam.

[0010] When the second lens is subjected to an external force along the axial direction of the lens barrel, the frictional force between the inner wall of the cam groove and the pin is greater than the driving force of the pin.

[0011] Using the aforementioned infrared lens, focusing can be achieved by rotating a cam to drive the second lens. When the lens is impacted, the second lens experiences an inertial force along the lens barrel axis. Because the frictional force between the cam and the pin is greater than the driving force of the pin, displacement of the second lens under the action of inertial force can be prevented, thus avoiding changes in the lens's focal length and ensuring stable imaging. Furthermore, there is no need to readjust the position of the second lens after an impact, simplifying operation and enhancing the lens's usability.

[0012] Furthermore, the shape of the cam groove satisfies tanα=μ, where μ is the coefficient of friction between the pin and the inner wall of the cam groove, and α is the angle of friction between the pin and the inner wall of the cam groove.

[0013] Furthermore, the air gap between the first lens and the second lens is 43.1782~47.1782mm.

[0014] Furthermore, the first lens is a positive meniscus lens with its convex surface facing the object side, and the second lens is a negative meniscus lens with its convex surface facing the object side.

[0015] Furthermore, a guide hole is provided on the side wall of the lens barrel, the guide hole extends along the axial direction of the lens barrel, and the pin passes through the guide hole.

[0016] Furthermore, it also includes a moving coil, which is reciprocally disposed within the lens barrel along the axial direction of the lens barrel, the second lens is mounted on the moving coil, and the pin is connected to the moving coil.

[0017] Furthermore, it also includes a knob, which is fixedly connected to the cam.

[0018] An imaging device includes the infrared lens and a detector that receives the image from the infrared lens.

[0019] Furthermore, the detector includes a protective window and an image plane arranged sequentially.

[0020] Furthermore, the total optical length of the imaging device is 86.496 mm.

[0021] In summary, the infrared lens and imaging device provided in this application have at least the following advantages:

[0022] 1. The frictional force between the inner wall of the cam groove and the pin is greater than the driving force of the pin, which prevents the second lens from shifting when the lens is impacted, thus not affecting the imaging effect; at the same time, there is no need to readjust the second lens again, making it more convenient to use.

[0023] 2. It achieves clear imaging at distances of 5 meters and above by using two lenses. The structure is simple and the cost is low. Attached Figure Description

[0024] The accompanying drawings are provided to further understand this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof.

[0025] Figure 1 This is a schematic diagram of the structure of an imaging device provided in an embodiment of this application;

[0026] Figure 2 for Figure 1 An exploded schematic diagram of a portion of the imaging device shown;

[0027] Figure 3 for Figure 1 A schematic diagram of the shape of the cam groove in the imaging device shown;

[0028] Figure 4 This is a schematic diagram of the optical path structure of an imaging device provided in an embodiment of this application.

[0029] Label Explanation:

[0030] 110. Lens barrel; 111. Mounting protrusion; 121. First lens; 122. Second lens; 130. Cam; 131. Cam groove; 141. Pin; 142. Moving coil; 151. Knob; 152. Sealing ring; 210. Protective window; 220. Image plane. Detailed Implementation

[0031] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0032] In the description of this application, 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., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, 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 orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0034] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0035] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0036] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0037] To facilitate understanding of the technical solution of this application, the shortcomings of existing focusing lenses are explained below: When a lens is impacted, the movable lens inside the lens shifts relative to the lens due to inertia; that is, the lens shifts under the action of inertial force, and the direction of the inertial force is the direction of the lens's movement. This lens displacement causes a change in the lens's focal length, thus affecting the imaging effect. Furthermore, if it is necessary to restore the focal length to its pre-impact state, the lens position needs to be readjusted, which is a cumbersome operation.

[0038] On the one hand, such as Figure 1 and Figure 2 As shown, this application provides an infrared lens, including a lens barrel 110, a first lens 121, a second lens 122, a cam 130, and a pin 141.

[0039] The first lens 121 and the second lens 122 are along the axial direction of the lens barrel 110 (i.e. Figure 1 The second lens 122 is arranged at intervals (left and right) inside the lens barrel 110, and can reciprocate along the axial direction of the lens barrel 110. A cam 130 is connected to the outside of the lens barrel 110 and can rotate about the radial central axis of the lens barrel 110. One side of the cam 130 (i.e.,...) Figure 1 The bottom surface of the cam 130 has a cam groove 131 (see [reference]). Figure 3 The pin 141 is connected to the second lens 122, and one end extends out of the lens barrel 110 and into the cam groove 131, so that the second lens 122 is driven to reciprocate during the rotation of the cam 130.

[0040] When the second lens 122 is subjected to an external force along the axial direction of the lens barrel 110, the frictional force between the inner wall of the cam groove 131 and the pin 141 is greater than the driving force of the pin 141, thereby locking the second lens 122 relative to the lens barrel 110 and preventing the second lens 122 from being displaced under the action of the external force.

[0041] Using the aforementioned infrared lens, focusing can be achieved by rotating the cam 130 to drive the second lens 122 to move. When the lens is impacted, the second lens 122 experiences an inertial force along the axis of the lens barrel 110. Since the frictional force of the cam 130 on the pin 141 is greater than the driving force of the pin 141, the second lens 122 is prevented from shifting under the action of the inertial force, thus preventing changes in the lens's focal length and ensuring stable imaging. Furthermore, there is no need to readjust the position of the second lens 122 after the lens is impacted, simplifying operation and enhancing the lens's usability.

[0042] Please see Figure 3 It should be explained that, assuming the lens is impacted, the inertial force experienced by the second lens 122 and the pin 141 is F. 合 F 合 This can be divided into F1 and F2. F1 is the pressure exerted by the pin 141 on the cam groove 131, and the direction of the pressure is perpendicular to the contact surface (the contact surface between the pin 141 and the inner wall of the cam groove 131). F2 is the driving force of the pin 141, and the driving force is in the tangential direction of the contact surface. F1 and F2 are... 合 The included angle between them is the friction angle α.

[0043] The inner wall of the cam groove 131 provides a frictional force f to the pin 141, f = F1 * μ = F 合*cosα*μ, where μ is the coefficient of friction between the pin 141 and the inner wall of the cam groove 131. To limit the displacement of the pin 141 and the second lens 122, f ≥ F2 should be satisfied, combined with F2 = F 合 *sinα can be derived to mean tanα ≤ μ. In other words, the shape of the cam groove 131 must satisfy this formula. In a preferred embodiment, tanα = μ

[0044] It needs further explanation that the coefficient of friction between the inner wall of the cam groove 131 and the pin 141 is affected by the material and lubrication factors. For example, if one of the cam 130 and the pin 141 is made of steel and the other is made of aluminum alloy, and grease is applied between them, the coefficient of friction μ = 0.09. Combined with the shape of the cam groove 131, this coefficient of friction can limit the movement of the second lens 122 due to impact while facilitating the movement of the second lens 122 driven by the cam 130.

[0045] In one embodiment, the air gap between the first lens 121 and the second lens 122 is 43.1782~47.1782mm, meaning the movement distance of the second lens 122 is 4mm. Figure 2 In this case, l1-l2=4mm, thus enabling the second lens 122 to move 4mm by rotating the cam 130. Specifically, the rotation angle of the cam 130 is 1.8π.

[0046] In one embodiment, the infrared lens further includes a moving coil 142, which is reciprocally disposed within the lens barrel 110 along the axial direction of the lens barrel 110. A second lens 122 is mounted on the moving coil 142 to move with the moving coil 142. A pin 141 is connected to the moving coil 142. Further, a guide hole is provided on the side wall of the lens barrel 110, extending along the axial direction of the lens barrel 110. The pin 141 passes through the guide hole and extends into the cam groove 131, thereby limiting and guiding the movement of the pin 141 through the guide hole.

[0047] In one embodiment, the infrared lens further includes a knob 151, which is fixedly connected to the cam 130 for operation. The knob 151 may have anti-slip grooves and decorative elements.

[0048] In one embodiment, a mounting protrusion 111 is formed on the side wall of the lens barrel 110. The mounting protrusion 111 is hollow and communicates with a guide hole. A cam 130 is rotatably disposed inside the mounting protrusion 111, and a knob 151 is rotatably sleeved on the outside of the mounting protrusion 111. Specifically, a sealing ring 152 is provided between the cam 130 and the inner wall of the mounting protrusion 111, and between the knob 151 and the outer wall of the mounting protrusion 111.

[0049] It should be explained that when the lens is impacted, the rotating cam 130 will not usually rotate due to the impact; at the same time, a sealing ring 152 is provided between the cam 130 and the mounting protrusion 111, as well as between the knob 151 and the mounting protrusion 111, which can further increase the damping of the rotation of the cam 130, further prevent the cam 130 from rotating when the lens is impacted, and thus limit the rotation of the cam 130.

[0050] On the other hand, such as Figure 1 and Figure 4 As shown, this application also provides an imaging device, including the above-mentioned infrared lens and a detector capable of receiving the image from the infrared lens.

[0051] Furthermore, the detector includes a protective window 210 and an image plane 220 arranged sequentially, that is, the protective window 210 and the image plane 220 are arranged sequentially along the optical axis transmission direction, and the light beam passes through the first lens 121, the second lens 122 and the protective window 210 in sequence, and then forms an image on the image plane 220.

[0052] In one embodiment, the first lens 121 is a positive meniscus lens with its convex surface facing the object side, and the second lens 122 is a negative meniscus lens with its convex surface facing the object side. Further, the image-side surface of the first lens 121 and the surface of the second lens 122 are both aspherical. It should be noted, in conjunction with the aforementioned movement of the second lens 122, that the imaging distance of this imaging device is ≥5m.

[0053] In one embodiment, the total optical length of the imaging device is 86.496 mm.

[0054] In summary, the infrared lens and imaging device provided in this application have at least the following advantages:

[0055] 1. The frictional force between the inner wall of the cam groove 131 and the pin 141 is greater than the driving force of the pin 141, which prevents the second lens 122 from shifting when the lens is impacted, thus not affecting the imaging effect; at the same time, there is no need to adjust the second lens 122 again, making it more convenient to use.

[0056] 2. It achieves clear imaging at distances of 5 meters and above by using two lenses. The structure is simple and the cost is low.

[0057] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An infrared lens characterized by, include: Lens tube; The first lens and the second lens are arranged at intervals along the axial direction of the lens barrel inside the lens barrel, and the second lens is capable of reciprocating along the axial direction of the lens barrel. A cam and a pin are provided. The cam is connected to the outside of the lens barrel and can rotate about the radial central axis of the lens barrel. A cam groove is provided on one side of the cam. The pin is connected to the second lens and one end extends out of the lens barrel and into the cam groove, so that the second lens is driven to reciprocate during the rotation of the cam. When the second lens is subjected to an external force along the axial direction of the lens barrel, the frictional force between the inner wall of the cam groove and the pin is greater than the driving force of the pin.

2. The infrared lens of claim 1, wherein, The shape of the cam groove satisfies tanα=μ, where μ is the coefficient of friction between the pin and the inner wall of the cam groove, and α is the angle of friction between the pin and the inner wall of the cam groove.

3. The infrared lens of claim 1, wherein, The air gap between the first lens and the second lens is 43.1782~47.1782mm.

4. The infrared lens of claim 1, wherein, The first lens is a positive meniscus lens with its convex surface facing the object side, and the second lens is a negative meniscus lens with its convex surface facing the object side.

5. The infrared lens of claim 1, wherein, The side wall of the lens barrel is provided with a guide hole, which extends along the axial direction of the lens barrel, and the pin passes through the guide hole.

6. The infrared lens of claim 1, wherein, It also includes a moving coil, which is reciprocally disposed within the lens barrel along the axial direction of the lens barrel, the second lens is mounted on the moving coil, and the pin is connected to the moving coil.

7. The infrared lens of claim 1, wherein, It also includes a knob, which is fixedly connected to the cam.

8. An image forming apparatus characterized by comprising: It includes the infrared lens as described in any one of claims 1-7 and the detector that receives the image from the infrared lens.

9. The imaging apparatus according to claim 8, wherein The detector includes a protective window and an image plane arranged sequentially.

10. The imaging apparatus according to claim 9, wherein The total optical length of the imaging device is 86.496 mm.

Images