Broadband high-resolution low-distortion athermalization industrial lens

Abstract

A broadband high-resolution low-distortion athermalization industrial lens is characterized in that a first lens, a second lens, a diaphragm, a third lens, a fourth lens and a detector photosensitive surface are sequentially arranged in the light propagation direction from outside to inside; the industrial lens comprises a first lens, a second lens, a diaphragm, a third lens and a fourth lens which are coaxially arranged with the photosensitive surface of the detector; the industrial lens is used for receiving visible light reflection information inherent to a target and a background and converging the visible light reflection information to a photosensitive surface of the detector to realize photoelectric conversion, the detector adopts a 6,000,000-pixel high-resolution small-pixel detector with the resolution of 2500 * 2500 and the pixel size of 2.75 mu m, and the industrial lens is used for clearly imaging at the environment temperature of-40 DEG C to + 60 DEG C and the working distance of 150 mm to infinity. The optical distortion is less than or equal to 0.6%, and the system has the technical characteristics of excellent imaging quality, high resolution, low distortion, quick interface replacement and the like, and has a wide application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical imaging, and more specifically, relates to an athermalized industrial lens with a wide wavelength band, high resolution, low distortion. Background Art

[0002] With the rapid development of industrial automation and detector chip technology, the requirements for the performance and environmental adaptability of industrial lenses have been greatly improved. The market urgently demands an athermalized industrial lens with a wide working wavelength band, high resolution, low distortion, and strong environmental adaptability. Based on the above requirements, the present invention designs an athermalized industrial lens with a wide wavelength band, high resolution, and low distortion. The lens can clearly image within the environmental temperature range of -40°C to +60°C and the working distance range of 150 mm to infinity. It has excellent imaging quality, a wide working wavelength band, strong light-gathering ability, and good environmental adaptability, and can be widely applied to fields such as optical imaging, machine vision, non-destructive testing, driverless, and civilian security monitoring. Summary of the Invention

[0003] The purpose of the present invention is to design an athermalized visible light industrial lens with high resolution, a wide working wavelength band, low distortion, a wide working distance range, and strong environmental adaptability. The present invention provides an athermalized industrial lens with a wide wavelength band, high resolution, and low distortion.

[0004] To achieve the above purpose, the technical solutions adopted by the present invention are as follows:

[0005] An athermalized industrial lens with a wide wavelength band, high resolution, and low distortion, characterized in that: a first lens, a second lens, a diaphragm, a third lens, a fourth lens, and a detector photosensitive surface are sequentially arranged from outside to inside in the light propagation direction. The first lens, second lens, diaphragm, third lens, and fourth lens of the industrial lens are coaxially arranged with the detector photosensitive surface. The industrial lens is used to receive the visible light reflection information inherent in the target and background, converge it to the detector photosensitive surface, and achieve photoelectric conversion. The detector uses a 6 million pixel high-resolution small pixel detector with a resolution of 2500×2500 and a pixel size of 2.75 μm. The industrial lens can clearly image within the environmental temperature range of -40°C to +60°C and the working distance range of 150 mm to infinity, with an optical distortion ≤ 0.6%. It has technical characteristics such as excellent imaging quality, high resolution, low distortion, and a replaceable interface quickly, and has broad application prospects.

[0006] Further, the first lens in the industrial lens is a negative lens, the second lens is a cemented positive lens, the third lens is a cemented negative lens, and the fourth lens is a positive lens. The above lenses are all spherical lenses.

[0007] Further, the specific lens parameters of the industrial lens are as shown in Table 1.

[0008] Table 1 Industrial Lens Parameter Table

[0009]

[0010] Furthermore, the industrial lens has an operating band of 0.43 μm to 0.78 μm, a focal length of 12 mm, an F number of 3.2, a field of view of 32°×32°, and a detector that uses a high-resolution visible light detector with a resolution of 2500×2500 and a pixel size of 2.75 μm. At 180 lp / mm, the modulation transfer function value of 0 field of view is ≥0.48, and the transfer function values of the remaining fields of view are ≥0.19, the single pixel angle is ≤0.23 mrad, the optical distortion is ≤0.6%, and the clear imaging distance is 150 mm to infinity.

[0011] Furthermore, the industrial lens is designed with a one-shot imaging structure, domestic Chengdu Guangming visible light glass is selected as the lens material, and aluminum alloy is selected as the mechanical parts. The material properties are fully considered, and the contradiction between optical aberration and thermal difference is effectively balanced by reasonably matching the lens focal length and using advanced aberration theory. A full-spherical lens is used to achieve a wide-temperature athermal design of the industrial lens, and clear imaging is achieved within the operating temperature range of -40°C to +60°C. At -40°C, at 180lp / mm, the transfer function value of the 0 field of view is ≥0.45, and the transfer function value of the remaining fields of view is ≥0.18; at 20°C, at 180lp / mm, the transfer function value of the 0 field of view is ≥0.48, and the transfer function value of the remaining fields of view is ≥0.19; at +60°C, at 180lp / mm, the transfer function value of the 0 field of view is ≥0.45, and the transfer function value of the remaining fields of view is ≥0.15. The overall dimensions of the industrial lens are < Total optical weight <3.5g.

[0012] The beneficial effects of the present invention relative to the prior art are:

[0013] 1. The industrial lens described in the present invention has an operating band of 0.43 μm to 0.78 μm, a focal length of 12 mm, an F number of 3.2, a field of view of 32°×32°, and a detector selected from a high-resolution visible light detector having a resolution of 2500×2500 and a pixel size of 2.75 μm. At room temperature, at 180 lp / mm, the modulation transfer function value of 0 field of view is ≥0.48, and the transfer function values of the remaining fields of view are ≥0.19, the single pixel opening angle is ≤0.23 mrad, the optical distortion is ≤0.6%, and the clear imaging distance is 150 mm to infinity. The lens is a small F number wide spectrum imaging system, and has the characteristics of excellent image quality, high resolution, wide operating band, wide clear imaging distance range, small distortion, and strong light collecting ability.

[0014] 2. The industrial lens described in the present invention adopts a one-shot imaging optical structure, and its dimensions are less than The total optical weight is < 3.5 g. The use of a global spherical lens realizes the athermal design of an industrial lens with a wide temperature range. It can achieve clear imaging within the working temperature range of -40°C to +60°C. At -40°C, at 180 lp / mm, the transfer function value of the 0 field of view is ≥ 0.45, and the transfer function values of the remaining fields of view are ≥ 0.18; at 20°C, at 180 lp / mm, the transfer function value of the 0 field of view is ≥ 0.48, and the transfer function values of the remaining fields of view are ≥ 0.19; at +60°C, at 180 lp / mm, the transfer function value of the 0 field of view is ≥ 0.45, and the transfer function values of the remaining fields of view are ≥ 0.15. It has the characteristics of a compact structure, small size, light weight, and strong environmental adaptability. Description of the Drawings

[0015] Figure 1 It is a structural diagram of an athermal industrial lens with a wide band, high resolution, and low distortion;

[0016] Figure 2 It is the modulation transfer function curve of the industrial lens at the working temperature of -40°C;

[0017] Figure 3 It is the modulation transfer function curve of the industrial lens at the working temperature of +20°C;

[0018] Figure 4 It is the modulation transfer function curve of the industrial lens at the working temperature of +60°C;

[0019] Figure 5 It is the distortion and field curvature curve of the industrial lens;

[0020] In the figure: 1. The first lens, 2. The second lens, 3. The aperture, 4. The third lens, 5. The fourth lens, 6. The photosensitive surface of the detector. Detailed Embodiments

[0021] The present invention will be described in detail below with reference to the accompanying drawings.

[0022] Embodiment 1

[0023] This embodiment describes a wide-band, high-resolution, low-distortion, athermalized industrial lens, characterized in that: a first lens, a second lens, a diaphragm, a third lens, a fourth lens and a detector photosensitive surface are sequentially arranged from outside to inside in the light propagation direction. The first lens, the second lens, the diaphragm, the third lens, the fourth lens of the industrial lens and the detector photosensitive surface are coaxially arranged. The industrial lens is used to receive the visible light reflection information inherent in the target and the background, and converge it onto the detector photosensitive surface to achieve photoelectric conversion. The detector uses a 6-million-pixel high-resolution small pixel detector with a resolution of 2500×2500 and a pixel size of 2.75μm. The industrial lens can clearly image within the environmental temperature range of -40°C to +60°C and the working distance range of 150mm to infinity, with an optical distortion ≤ 0.6%. It has technical characteristics such as excellent imaging quality, high resolution, low distortion, and a quickly replaceable interface, and has broad application prospects.

[0024] The specific purpose of this technical solution is to achieve the design of an athermalized visible light industrial lens with high resolution, wide working band, low distortion, wide working distance range, and strong environmental adaptability. This lens can be widely used in fields such as optical imaging, machine vision, non-destructive testing, driverless, and civilian security monitoring.

[0025] Example 2

[0026] This embodiment describes a wide-band, high-resolution, low-distortion, athermalized industrial lens, characterized in that: a first lens, a second lens, a diaphragm, a third lens, a fourth lens and a detector photosensitive surface are sequentially arranged from outside to inside in the light propagation direction. The first lens, the second lens, the diaphragm, the third lens, the fourth lens of the industrial lens and the detector photosensitive surface are coaxially arranged. The industrial lens is used to receive the visible light reflection information inherent in the target and the background, and converge it onto the detector photosensitive surface to achieve photoelectric conversion. The detector uses a 6-million-pixel high-resolution small pixel detector with a resolution of 2500×2500 and a pixel size of 2.75μm. The industrial lens can clearly image within the environmental temperature range of -40°C to +60°C and the working distance range of 150mm to infinity, with an optical distortion ≤ 0.6%. It has technical characteristics such as excellent imaging quality, high resolution, low distortion, and a quickly replaceable interface, and has broad application prospects.

[0027] In the industrial lens, the first lens is a negative lens, the second lens is a cemented positive lens, the third lens is a cemented negative lens, and the fourth lens is a positive lens. All the above lenses are spherical lenses. The specific lens parameters of the industrial lens are as described in the following table.

[0028] Table 1 Industrial lens parameter table

[0029]

[0030]

[0031] This technical solution defines the refractive index, Abbe number, quantity, and surface shape of each lens. In order to adapt to extremely harsh working conditions, a single imaging structure form is adopted in the design. The lens optical power is reasonably matched, the material characteristics are fully considered, and the advanced aberration theory is used to effectively balance the contradiction between optical aberration and thermal aberration. A wide-temperature athermalized design of an industrial lens is achieved using all-spherical lenses, with excellent imaging quality, strong environmental adaptability, good processing technology, easy assembly and adjustment, and high yield rate within the working temperature range of -40°C to +60°C.

[0032] Example 3

[0033] This embodiment describes a wide-band, high-resolution, low-distortion athermalized industrial lens, which is characterized in that: a first lens, a second lens, a diaphragm, a third lens, a fourth lens, and a detector photosensitive surface are sequentially arranged from outside to inside in the light propagation direction. The first lens, second lens, diaphragm, third lens, and fourth lens of the industrial lens are coaxially arranged with the detector photosensitive surface. The industrial lens is used to receive the visible light reflection information inherent in the target and background, and converge it onto the detector photosensitive surface to achieve photoelectric conversion. The detector uses a 6-million-pixel high-resolution small pixel detector with a resolution of 2500×2500 and a pixel size of 2.75μm. The industrial lens clearly images within the environmental temperature range of -40°C to +60°C and the working distance range of 150mm to infinity, with an optical distortion ≤ 0.6%. It has technical characteristics such as excellent imaging quality, high resolution, low distortion, and a quickly replaceable interface, and has broad application prospects.

[0034] The working band of the industrial lens is 0.43μm to 0.78μm, the focal length is 12mm, the F number is 3.2, the field of view size is 32°×32°, the detector is a high-resolution visible light detector with a resolution of 2500×2500 and a pixel size of 2.75μm. At room temperature, at 180lp / mm, the modulation transfer function value of the 0 field of view ≥ 0.48, and the transfer function values of the remaining fields of view ≥ 0.19. The single-pixel angular spread ≤ 0.23mrad, the optical distortion ≤ 0.6%, and the clear imaging distance is 150mm to infinity.

[0035] This technical solution defines technical parameters such as the working band, focal length, F number, field of view size, detector resolution and pixel size, transfer function, pixel angular spread, and system clear imaging distance of the industrial lens. The lens is a small F number wide-spectrum imaging system, with characteristics such as excellent image quality, high resolution, wide working band, wide clear imaging distance range, small distortion, and strong light-gathering ability.

[0036] Example 4

[0037] This embodiment describes a wide-band high-resolution low-distortion athermalized industrial lens, characterized in that: a first lens, a second lens, a diaphragm, a third lens, a fourth lens and a detector photosensitive surface are sequentially arranged from outside to inside in the light propagation direction. The first lens, the second lens, the diaphragm, the third lens, the fourth lens of the industrial lens and the detector photosensitive surface are coaxially arranged. The industrial lens is used to receive the visible light reflection information inherent in the target and the background, and converge it onto the detector photosensitive surface to achieve photoelectric conversion. The detector uses a 6-million-pixel high-resolution small pixel detector with a resolution of 2500×2500 and a pixel size of 2.75μm, and can clearly image within the environmental temperature range of -40°C to +60°C and the working distance range of 150mm to infinity. The optical distortion is ≤0.6%, and it has technical characteristics such as excellent imaging quality, high resolution, low distortion, and a quickly replaceable interface, and has broad application prospects.

[0038] The industrial lens adopts a single-pass imaging optical structure form, and the external dimensions are < The total optical weight is <3.5g. The use of all-spherical lenses realizes the wide-temperature athermalized design of the industrial lens, and it can clearly image within the working temperature range of -40°C to +60°C. At -40°C, at 180lp / mm, the transfer function value of the 0 field of view is ≥0.45, and the transfer function values of the remaining fields of view are ≥0.18; at 20°C, at 180lp / mm, the transfer function value of the 0 field of view is ≥0.48, and the transfer function values of the remaining fields of view are ≥0.19; at +60°C, at 180lp / mm, the transfer function value of the 0 field of view is ≥0.45, and the transfer function values of the remaining fields of view are ≥0.15. The transfer function curve of the industrial lens described in this technical solution does not show an obvious decline compared with the transfer function curve at room temperature within the wide-temperature working temperature range of -40°C to +60°C, and it has excellent imaging quality, a compact structure, small size, light weight, and strong environmental adaptability, with prominent performance characteristics.

[0039] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A wide-band high-resolution low-distortion athermalized industrial lens, characterized in that: A first lens (1), a second lens (2), a diaphragm (3), a third lens (4), a fourth lens (5) and a detector photosensitive surface (6) are sequentially arranged from outside to inside in the light propagation direction; the first lens (1), the second lens (2), the diaphragm (3), the third lens (4), the fourth lens (5) of the industrial lens are coaxially arranged with the detector photosensitive surface (6); the industrial lens is used to receive the visible light reflection information inherent in the target and the background and converge it onto the detector photosensitive surface to achieve photoelectric conversion. The detector is a 6-million-pixel high-resolution small pixel detector with a resolution of 2500×2500 and a pixel size of 2.75μm. In the industrial lens, the first lens (1) is a negative lens, the second lens (2) is a cemented positive lens, the third lens (4) is a cemented negative lens, and the fourth lens (5) is a positive lens. The above lenses are all spherical lenses, and the specific lens parameters are shown in Table 1. Table 1 Industrial lens parameter table

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