Refraction-reflection type thermal imaging optical system
By combining a folding-reflective optical system with a window and a reflector, the high cost problem of existing thermal imaging optical systems is solved, achieving cost reduction and improved imaging quality.
Patent Information
- Application Number
- CN202423127103.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-17
- Publication Date
- 2025-10-14
- Estimated Expiration
- 2034-12-17
AI Technical Summary
The existing thermal imaging optical system uses a refractive optical system, which results in high costs. The material and processing costs remain high and cannot meet customer needs.
It adopts a catadioptric optical system, using a combination of windows, reflectors and small lenses. The windows and reflectors are made of chalcogenide glass or germanium. The reflectors are aspherical. Light passes through the range of 8μm-14μm, combining reflection and refraction to form an image. The window is flat with a hole in the middle, and the small lens is also made of chalcogenide glass or germanium.
It reduces material and processing costs, improves imaging quality, ensures thermal imaging effects, and uses less material, significantly reducing costs.
Smart Images
Figure CN223436151U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to a catadioptric thermal imaging optical system. BACKGROUND
[0002] Infrared thermal imaging, all objects, whether it is the polar ice, or flame, human body, or even the extremely cold deep space, as long as its temperature is higher than absolute zero (-273 DEG C) can radiate electromagnetic waves. Thermal imaging mainly through the collection of thermal infrared band (8um-14um) light, to detect the thermal radiation of the object. Thermal imaging converts thermal radiation into gray value, and then uses the gray value difference of each object to image, and converts into the thermal image of the target object through system processing, and displays in gray level or pseudo color, so as to find and identify the target. The thermal imager is a kind of detection equipment which converts the infrared energy (heat) into electrical signal through non-contact detection, and then generates thermal image and temperature value on the display, and can calculate the temperature value.
[0003] At present, the thermal imaging optical system adopts the refractive optical system, the structure is shown in Figure 1 The first lens and the second lens are made of chalcogenide glass or germanium material, the cost of these materials is very high, and the processing cost is also very high, according to the estimation, the material cost of the first lens and the second lens is several hundred yuan, and the processing cost also needs several hundred yuan (because the shape is complex), so the cost is high. SUMMARY
[0004] The utility model discloses a kind of catadioptric thermal imaging optical systems, solve the technical problem that the thermal imaging optical system of prior art refractive optical system leads to high cost, cannot meet customer requirements.
[0005] The technical scheme of the utility model is realized as follows:
[0006] A kind of catadioptric thermal imaging optical system, it is characterized by: including window piece, second reflector, small lens and first reflector from object side to imaging surface sequentially along optical axis S interval distribution, wherein: the outer diameter of window piece and first reflector is greater than the outer diameter of second reflector;Hole is excavated in the middle of first reflector, small lens is arranged in the left side of hole, window piece is made of chalcogenide glass or germanium material to prevent visible light and pass the light of wavelength in the range of 8um-14um, first reflector is made of aspheric reflector containing concave surface, second reflector is made of aspheric reflector containing convex surface, concave surface and convex surface are all reflecting surface, concave surface faces window piece and is opposite to convex surface, the light of wavelength in the range of 8um-14um emitted from object side passes the periphery of window piece to reach first reflector, reaches second reflector after first reflection of concave surface, after second reflection of convex surface, then, small lens is refracted on imaging surface and forms image.
[0007] The aforementioned small lenses are also made of chalcogenide glass or germanium.
[0008] The above-mentioned window piece is in the shape of a flat plate with a hole dug out in the middle.
[0009] A thermal imaging image sensor is placed at the imaging surface position.
[0010] Compared with the prior art, the utility model has the following advantages:
[0011] Effect 1: The utility model utilizes a combination of reflection and refraction to improve imaging quality, and the window piece is made of chalcogenide glass or germanium material so that it can block visible light and pass light with a wavelength in the range of 8μm-14μm. The window piece has a simple shape, is easy to process, and uses less material, so the cost can be greatly reduced.
[0012] Effect 2: The window is flat with a hole in the middle, which can further reduce material usage and lower costs;
[0013] Effect 3: The small lens is also made of chalcogenide glass or germanium. Although the material cost increases, the cost will not increase too much due to the small size of the small lens and the small amount of material used. It can also perform secondary blocking of visible light and pass light with a wavelength in the range of 8μm-14μm, effectively ensuring the effect of thermal imaging. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 The optical path diagram of the thermal imaging optical system in the prior art;
[0015] Figure 2 This is a schematic diagram of the thermal imaging optical system of the present invention;
[0016] Figure 3 This is a light path diagram of the thermal imaging optical system of the present utility model. DETAILED DESCRIPTION
[0017] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are 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 making creative efforts are within the scope of protection of the present invention.
[0018] Example 1:
[0019] like Figures 2 to 3As shown, this embodiment provides a catadioptric thermal imaging optical system, comprising a window 1, a second reflector 3, a small lens 4, and a first reflector 2, which are spaced apart along the optical axis S from the object side to the imaging surface. The outer diameters of the window 1 and the first reflector 2 are larger than the outer diameter of the second reflector 3. A through hole 22 is bored in the middle of the first reflector 2, and a small lens 4 is arranged on the left side of the through hole 22. The window 1 is made of chalcogenide glass or germanium material to block visible light and pass light with a wavelength in the range of 8 μm to 14 μm. Light, the first reflector 2 adopts an aspheric reflector with a concave surface 21, and the second reflector 3 adopts an aspheric reflector with a convex surface 31. The concave surface 21 and the convex surface 31 are both reflective surfaces. The concave surface 21 faces the window 1 and is opposite to the convex surface 31. The light with a wavelength in the range of 8μm-14μm emitted from the object side passes through the periphery of the window 1 to reach the first reflector 2, and after the first reflection by the concave surface 21, it reaches the second reflector 3, and after the second reflection by the convex surface 31, it is refracted by the small lens 4 to form an image on the imaging surface.
[0020] The present invention utilizes a combination of reflection and refraction to improve imaging quality, and the window 1 is made of chalcogenide glass or germanium material so as to block visible light and pass light with a wavelength of 8-14 μm. The window has a simple shape, is easy to process, and uses less material, so the cost can be greatly reduced.
[0021] The aforementioned small lens 4 is also made of chalcogenide glass or germanium. Although the material cost increases, the cost does not increase too much due to the small size of the small lens and the small amount of material used. In addition, the lens can perform secondary blocking of visible light and pass light with a wavelength in the range of 8μm-14μm, effectively ensuring the thermal imaging effect.
[0022] The window piece 1 is in the shape of a flat plate with a hole 11 dug out in the middle, which can further reduce the amount of material used and lower the cost.
[0023] A thermal imaging image sensor 5 is placed at the imaging surface.
[0024] The above embodiments are preferred implementation methods of the present invention, but the implementation methods of the present invention are not limited thereto. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention are equivalent replacement methods and are included in the scope of protection of the present invention.
Claims
1. A catadioptric thermal imaging optical system, characterized in that: The invention comprises a window (1), a second reflector (3), a small lens (4) and a first reflector (2) which are sequentially spaced along an optical axis S from the object side to the imaging surface, wherein: the outer diameters of the window (1) and the first reflector (2) are larger than the outer diameter of the second reflector (3); a through hole (22) is dug out in the middle of the first reflector (2), and the small lens (4) is arranged on the left side of the through hole (22); the window (1) is made of chalcogenide glass or germanium material so as to block visible light and pass light with a wavelength in the range of 8μm-14μm; the first reflector (2) is made of a material containing The concave surface (21) is an aspheric reflector, and the second reflector (3) is an aspheric reflector including a convex surface (31). The concave surface (21) and the convex surface (31) are both reflective surfaces. The concave surface (21) faces the window (1) and is opposite to the convex surface (31). Light with a wavelength in the range of 8μm-14μm emitted from the object side passes through the periphery of the window (1) and reaches the first reflector (2). After the first reflection by the concave surface (21), it reaches the second reflector (3). After the second reflection by the convex surface (31), it is refracted by the small lens (4) to form an image on the imaging surface.
2. The catadioptric thermal imaging optical system according to claim 1, wherein: The small lens (4) is also made of chalcogenide glass or germanium material.
3. The catadioptric thermal imaging optical system according to claim 1 or 2, characterized in that: The window piece (1) is in the shape of a flat plate, with a hole (11) dug out in the middle.
4. The catadioptric thermal imaging optical system according to claim 3, wherein: A thermal imaging image sensor (5) is placed at the imaging surface.