Thermal imaging lens

Abstract

The thermal imaging lens comprises a lens barrel and a plurality of lenses, the plurality of lenses comprise a diaphragm, a second reflector, a small lens and a first reflector, a through hole is dug in the middle of the first reflector, the small lens is arranged on the left side of the through hole, the diaphragm is made of chalcogenide glass or germanium materials, and the second reflector is made of silicon carbide. The first reflector is an aspheric reflector with a concave surface, the second reflector is an aspheric reflector with a convex surface, the concave surface faces the diaphragm and is opposite to the convex surface, and light emitted from the object side and having the wavelength ranging from 8 micrometers to 14 micrometers penetrates through the periphery of the diaphragm to reach the first reflector and then reaches the second reflector through first reflection of the concave surface. And after being reflected for the second time by the convex surface, the light is refracted by the small lens to form an image on the imaging surface, so that the manufacturing cost is low, the imaging quality is good, the function is complete and the cost performance is high.

Description

TECHNICAL FIELD

[0001] The utility model belongs to a kind of thermal imaging lens. BACKGROUND

[0002] Infrared thermal imaging, everything, whether it is the polar ice, or flame, human body, 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 light of the collection thermal infrared band (8 μm-14 μm), to detect the thermal radiation of object. Thermal imaging converts thermal radiation into gray value, then utilize the gray value difference of each object to image, after system processing change into the thermal image of target object, with gray level or pseudo-color display, to find and identify target. Thermal imager is through non-contact detection infrared energy (heat), and it is converted into electrical signal, and then generate thermal image and temperature value on display, and can calculate temperature value a kind of detection equipment.

[0003] At present, thermal imaging lens generally adopts refractive optical system, its structure sees Figure 1 As shown, the combination mode of first lens and second lens is adopted, and the first lens and the second lens adopt chalcogenide glass or germanium material. The cost of these materials is very high, and the processing cost is also very high. According to 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 that the cost is high.

[0004] In addition, the general thermal imaging lens has single function and low cost performance. SUMMARY

[0005] The utility model aims at providing a kind of thermal imaging lens, solve the technical problem that the cost of the refractive optical system of prior art thermal imaging lens is high, cannot meet customer requirements.

[0006] The technical scheme of the utility model is realized as follows:

[0007] A thermal imaging lens comprises a lens barrel and a plurality of lenses mounted in the lens barrel, characterized in that the plurality of lenses comprise, from left to right, a window sheet, a second mirror, a small lens and a first mirror, the outer diameter of the window sheet and the first mirror is larger than that of the second mirror; a through hole is formed in the middle of the first mirror, the small lens is arranged on the left side of the through hole, the window sheet is made of chalcogenide glass or germanium material so as to block visible light and allow light with a wavelength in the range of 8-14 microns to pass through, the first mirror is a aspherical mirror comprising a concave surface, the second mirror is a aspherical mirror comprising a convex surface, the concave surface and the convex surface are reflective surfaces, the concave surface faces the window sheet and is opposite to the convex surface, light with a wavelength in the range of 8-14 microns emitted from the object side passes through the periphery of the window sheet to reach the first mirror, is reflected by the concave surface for the first time to reach the second mirror, is reflected by the convex surface for the second time, and is refracted by the small lens on the imaging plane to form an image.

[0008] The small lens is also made of chalcogenide glass or germanium material.

[0009] The window sheet is flat and has a hole formed in the middle, and a laser ranging module is mounted in the space between the hole and the second mirror.

[0010] The laser ranging module comprises a transmitting part and a receiving part, the transmitting part comprises a first transmitting mirror, a second transmitting mirror and a laser light source, and the receiving part comprises a first receiving mirror, a second receiving mirror and a sensor.

[0011] A second window sheet is mounted on the left side of the laser ranging module and the end of the lens barrel, and the hole is located between the laser ranging module and the second window sheet.

[0012] The lens barrel comprises a left barrel and a right barrel, the laser ranging module and the second mirror are mounted in an inner barrel assembly, the inner barrel assembly is sleeved in the left barrel, the window sheet is mounted on the left end of the left barrel, and the small lens and the first mirror are mounted in the right barrel.

[0013] The right end of the left barrel is sleeved in the right barrel, and the left barrel and the right barrel are locked together by an external locking sleeve.

[0014] The right end surface of the right barrel protrudes a circular boss in the middle, and the circular boss is provided with external threads.

[0015] Compared with the prior art, the utility model has the following advantages:

[0016] Effect 1: the combination of reflection and refraction can improve imaging quality, the window piece is made of chalcogenide glass or germanium material to block visible light and pass light with wavelength in the range of 8-14 μm, the window piece is simple in shape, easy to process, and the material is less, so the cost can be greatly reduced.

[0017] Effect 2: the window piece is flat, and a hole is dug in the middle, which can further reduce the material usage and reduce the cost;

[0018] Effect 3: the small lens is also made of chalcogenide glass or germanium material, although the material cost increases, but due to the small size of the small lens, the material usage is small, the cost will not increase too much, and the visible light can be blocked twice and the light with wavelength in the range of 8-14 μm can be passed, effectively ensuring the effect of thermal imaging;

[0019] Effect 4: the laser ranging module is installed in the space between the hole and the second reflecting mirror, so that the lens has the function of distance measurement, the product has high performance price ratio, perfect function and compact structure. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is the optical path diagram of the prior art thermal imaging optical system;

[0021] Figure 2 is the structure sectional view of the thermal imaging lens of the utility model;

[0022] Figure 3 is the optical principle diagram of the thermal imaging lens of the utility model;

[0023] Figure 4 is the optical path diagram of the thermal imaging lens of the utility model. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model, obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the utility model.

[0025] Embodiment one:

[0026] As Figures 2 to 4As shown, the embodiment provides a thermal imaging lens, which comprises a lens barrel 10 and a plurality of lenses mounted in the lens barrel 10, characterized in that the plurality of lenses comprise a window sheet 1, a second mirror 3, a small lens 4 and a first mirror 2 arranged in sequence from left to right with a spacing, the outer diameter of the window sheet 1 and the first mirror 2 is larger than that of the second mirror 3, a through hole 22 is excavated in the middle of the first mirror 2, the small lens 4 (i.e. an imaging lens) is arranged on the left side of the through hole 22, the window sheet 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 8-14 μm, the first mirror 2 is a aspherical mirror comprising a concave surface 21, the second mirror 3 is a aspherical mirror comprising a convex surface 31, the concave surface 21 and the convex surface 31 are reflective surfaces, the concave surface 21 faces the window sheet 1 and is opposite to the convex surface 31, light with a wavelength in the range of 8-14 μm emitted from the object side passes the periphery of the window sheet 1 to reach the first mirror 2, reaches the second mirror 3 after the first reflection of the concave surface 21, and is refracted on the imaging surface by the small lens 4 after the second reflection of the convex surface 31. Figure 3 The window sheet 1, the second mirror 3, the small lens 4 and the first mirror 2 are arranged in sequence along the optical axis S with a spacing.

[0027] The embodiment utilizes the combination of reflection and refraction to improve the imaging quality, the window sheet 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 8-14 μm, the window sheet has a simple shape and is easy to process, and the material usage is small, so the cost can be greatly reduced.

[0028] The small lens 4 is also made of chalcogenide glass or germanium material, although the material cost increases, but the small lens has a small size and the material usage is small, so the cost does not increase too much, and the small lens can block visible light and pass light with a wavelength in the range of 8-14 μm twice, effectively ensuring the thermal imaging effect.

[0029] The window sheet 1 is a flat plate with a hole 11 excavated in the middle, and a laser ranging module 5 is mounted in the space between the hole 11 and the second mirror 3, which can further reduce the material usage of the window sheet 1 and reduce the cost, and has the function of laser ranging, so the product has high performance price ratio, perfect function and compact structure.

[0030] The laser ranging module 5 comprises a transmitting part and a receiving part, the transmitting part comprises a first transmitting mirror 51, a second transmitting mirror 52 and a laser light source 53, and the receiving part comprises a first receiving mirror 54, a second receiving mirror 55 and a sensor 56.

[0031] The second window sheet 6 is installed at the left side of the laser ranging module 5 and the end of the lens barrel 10, and the hole 11 is located between the laser ranging module 5 and the second window sheet 6, and the second window sheet 6 is made of plastic material and has the functions of light transmission and sealing.

[0032] The lens barrel 10 is assembled by the left lens barrel 10a and the right lens barrel 10b, the laser ranging module 5 and the second mirror 3 are installed in an inner barrel assembly 15, the inner barrel assembly 15 is sleeved in the left lens barrel 10a, the window sheet 1 is installed at the left end of the left lens barrel 10a, and the lenslet 4 and the first mirror 2 are installed in the right lens barrel, so that the structure is reasonable and the assembly is convenient.

[0033] The right end of the left lens barrel 10a is sleeved in the right lens barrel 10b, and the left lens barrel 10a and the right lens barrel 10b are locked together by the external locking sleeve 12, so that the structure is simple and the installation is convenient.

[0034] The right end surface of the right lens barrel 10b is provided with a circular boss 13 in the middle, and the circular boss 13 is provided with external threads.

[0035] The imaging surface is provided with the image sensor 14.

[0036] The above embodiment is a preferred embodiment of the present application, but the embodiment of the present application is not limited to this, and any change, modification, replacement, combination and simplification without departing from the spirit and principle of the present application are equivalent replacement methods, and are all included in the protection scope of the present application.

Claims

1. A thermal imaging lens comprising a lens barrel (10) and a plurality of lenses mounted in the lens barrel (10), characterized in that: The several lenses include window piece (1), second mirror (3), small lens (4) and first mirror (2) which are arranged in sequence from left to right, the outer diameter of window piece (1) and first mirror (2) is larger than that of second mirror (3); a through hole (22) is dug in the middle of first mirror (2), small lens (4) is arranged at the left side of through hole (22), window piece (1) is made of chalcogenide glass or germanium material so as to block visible light and pass light with wavelength in the range of 8-14 μm, first mirror (2) is made of aspheric mirror containing concave surface (21), second mirror (3) is made of aspheric mirror containing convex surface (31), concave surface (21) and convex surface (31) are both reflecting surfaces, concave surface (21) faces window piece (1) and is opposite to convex surface (31), light with wavelength in the range of 8-14 μm emitted from the object side passes the periphery of window piece (1) to reach first mirror (2), reaches second mirror (3) after first reflection by concave surface (21), and is refracted on the imaging plane after second reflection by convex surface (31) and then small lens (4).

2. A thermal imaging lens according to claim 1, characterized in that: Small lens (4) is also made of chalcogenide glass or germanium material.

3. A thermal imaging lens according to claim 1 or 2, characterized in that: Window piece (1) is flat and has a hole (11) dug in the middle, laser ranging module (5) is installed in the space between hole (11) and second mirror (3).

4. A thermal imaging lens according to claim 3, characterized in that: Laser ranging module (5) includes emitting part and receiving part, the emitting part includes first emitting mirror (51), second emitting mirror (52) and laser light source (53), the receiving part includes first receiving mirror (54), second receiving mirror (55) and sensor (56).

5. A thermal imaging lens according to claim 4, characterized in that: Second window piece (6) is installed at the left side of laser ranging module (5) and the end of lens barrel (10), hole (11) is located between laser ranging module (5) and second window piece (6).

6. A thermal imaging lens according to claim 5, characterized in that: Lens barrel (10) is assembled by left lens barrel (10a) and right lens barrel (10b), laser ranging module (5) and second mirror (3) are installed in an inner barrel assembly (15), the inner barrel assembly (15) is sleeved in left lens barrel (10a), window piece (1) is installed at the left end of left lens barrel (10a), small lens (4) and first mirror (2) are installed in right lens barrel.

7. A thermal imaging lens according to claim 6, characterized in that: The right end of left lens barrel (10a) is sleeved in right lens barrel (10b), and left lens barrel (10a) and right lens barrel (10b) are locked together by external locking sleeve (12).

8. A thermal imaging lens according to claim 7, characterized in that: A circular boss (13) is protruded in the middle of the right end surface of right lens barrel (10b), and external threads are arranged on the periphery of circular boss (13).

Images