Glass-plastic hybrid scanning lens with low distortion and high image quality

Abstract

The invention relates to a low-distortion high-image-quality glass-plastic hybrid scanning lens, which sequentially comprises a first lens with negative focal power along an optical axis from an object side to an image side, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power and a fifth lens with negative focal power from the object side to the image side, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a convex surface; the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface; the first lens and the third lens are made of plastic materials, and the second lens is a glass lens. By adopting the structural design of the first lens, the second lens and the third lens, the full visual angle of the glass-plastic hybrid scanning lens can be increased, and the TV distortion of the system is lower than 2%, so that the image deformation is small, and the imaging picture is more real; according to the glass-plastic mixed scanning lens optical system, the scheme of mixed design of the glass material and the plastic material is adopted, so that the problem of temperature drift is favorably corrected, the glass-plastic mixed scanning lens optical system is not defocused in a temperature range of-30 DEG C to 70 DEG C, the risk of defocusing during shooting in a severe environment is avoided, and higher imaging quality is met.

Description

Technical Field

[0001] The present invention relates to the field of optical imaging, and particularly to a hybrid plastic and glass scanning lens with low distortion and high image quality. Background Art

[0002] With the development of technology and modern information technology, scanning lenses are very common and widespread in life, and are a very valuable type of optical lens. First, with the popularization and rapid development of electronic payment in recent years, scanning lenses are widely used in electronic payment systems. It can quickly read barcodes or two-dimensional codes on objects, accurately capture the actual situation, with very little optical distortion, effectively improving payment security and reducing the risk of theft, etc. Secondly, by using scanning lenses, express parcels can be scanned, and with the supporting software, sorting and logistics tracking can be accelerated, improving efficiency. In addition, scanning lenses are also widely used in the industrial field, such as secondary packaging inspection, packaging tracking, quality assembly, and traceability of medical devices. However, these scanning lenses need to be able to resolve extremely tiny content and have very strict requirements for distortion.

[0003] Therefore, scanning lenses with low distortion and high image quality have received increasing attention. Thus, it is particularly important to design a scanning lens that can meet relatively low distortion and achieve high image quality. Summary of the Invention

[0004] The purpose of the present invention is to provide a hybrid plastic and glass scanning lens with low distortion and high image quality, which has small image distortion, a more realistic imaging picture, and can avoid the risk of out-of-focus shooting in harsh environments.

[0005] A hybrid plastic and glass scanning lens with low distortion and high image quality, which sequentially includes from the object side to the image side along the optical axis: a first lens with a negative focal power, its object side is convex, and its image side is concave; a second lens with a positive focal power, its object side is convex, and its image side is convex; a third lens with a negative focal power, its object side is concave, and its image side is convex; both the first lens and the third lens are made of plastic material, and the second lens is a glass lens.

[0006] In the above solution, by adopting the structural design of the above first lens, second lens, and third lens, the full viewing angle of the hybrid plastic and glass scanning lens can be increased, and the TV distortion of the system is lower than 2%, so that the image distortion is small and the imaging picture is more realistic; due to the adoption of the hybrid design of glass material and plastic material, it is beneficial to correct the temperature drift problem, so that the optical system of the hybrid plastic and glass scanning lens does not go out of focus within the temperature range of -30°C to 70°C, avoiding the risk of out-of-focus shooting in harsh environments, thereby meeting higher imaging quality.

[0007] Preferably, the glass-plastic hybrid scanning lens satisfies the conditional formula: -7 < f1 / f < -5, 1 < f2 / f < 3, -20 < f3 / f < -15, where f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, and f is the focal length of the glass-plastic hybrid scanning lens.

[0008] In the above solution, the optical powers of the first lens, the second lens, and the third lens have a reasonable distribution ratio. The first lens is beneficial to reducing the angle between the light beam and the optical axis after passing through the system, quickly reducing the light brightness, and incident on the second lens at a reasonable height. In this way, the first lens prepares for further correcting aberration and improving the lens resolution by the second lens and the third lens in the rear group.

[0009] Preferably, the glass-plastic hybrid scanning lens satisfies the following conditional formula: 1.5 ≤ Nd1 ≤ 1.6, 50 ≤ Vd1 ≤ 60; 1.5 ≤ Nd2 ≤ 1.6, 50 ≤ Vd2 ≤ 60; 1.6 ≤ Nd3 ≤ 1.7, 20 ≤ Vd3 ≤ 30;

[0010] Wherein, Nd1 is the refractive index of the first lens, Vd1 is the dispersion coefficient of the first lens, Nd2 is the refractive index of the second lens, Vd2 is the dispersion coefficient of the second lens, Nd3 is the refractive index of the third lens, and Vd3 is the dispersion coefficient of the third lens.

[0011] In the above solution, the combined structure of the first lens, the second lens, and the third lens that satisfies the above refractive index relationship is beneficial to achieving a reasonable distribution of optical power, better correcting aberrations such as spherical aberration and field curvature, thereby improving the lens resolution; and, through the combination of materials with different dispersion coefficients, the chromatic aberration of the optical system can be effectively reduced, so that the optical system has a better imaging effect.

[0012] Preferably, both the first lens and the third lens are aspherical lenses.

[0013] In the above solution, due to the large degree of freedom of the aspherical lens, the ability to deflect light and correct aberration is significantly stronger than that of the spherical surface, which is beneficial to improving the lens resolution and correcting the lens distortion. At the same time, it is also beneficial to correcting the angle of the outgoing light of the lens and can better match the photosensitive element.

[0014] Preferably, the glass-plastic hybrid scanning lens satisfies the conditional formula: 0.4 < f / TTL < 0.5, where f is the focal length of the glass-plastic hybrid scanning lens, and TTL is the axial distance from the object side surface of the first lens to the imaging surface.

[0015] In the above solution, a suitable ratio of f / TTL can control the volume and weight of the lens while maintaining good imaging performance, enabling the lens to provide a large field of view without affecting the image quality, and helping to reduce lens aberrations, especially distortion and spherical aberration, thus helping to maintain image sharpness and accuracy under different imaging conditions and improving the resolving power of the lens.

[0016] Preferably, the hybrid glass-plastic scanning lens satisfies the conditional formula: TTL < 7.45 mm, where TTL is the on-axis distance from the object side surface of the first lens to the imaging surface.

[0017] In the above solution, a smaller TTL can make the aperture position in the design closer to the imaging surface, thereby optimizing the aperture design, such as being able to increase the actual aperture value of the aperture, thus reducing optical distortion, and shortening TTL helps to reduce the path length of light propagation in the optical system, helps to reduce aberrations, and improves imaging quality.

[0018] Preferably, the hybrid glass-plastic scanning lens satisfies the conditional formula: DFOV > 54°, where DFOV is the full field of view angle of the hybrid glass-plastic scanning lens.

[0019] In the above solution, through the optimized design of the first lens, the second lens, and the third lens, the full field angle can reach more than 54°, so that the lens can capture a wider perspective and thus cover a larger imaging area.

[0020] Preferably, a diaphragm is provided between the first lens and the second lens.

[0021] In the above solution, by setting the diaphragm between the first lens and the second lens, it is beneficial to meet the requirement of smaller distortion, thus being able to better balance the exit angle of the optical system, being beneficial to matching the corresponding image sensor, and thus improving imaging quality.

[0022] Preferably, the hybrid glass-plastic scanning lens satisfies the conditional formula: -8.1×10 -6 ≤dn / dt(L2)≤ -7×10 -6 , where dn / dt(L2) is the relative refractive index temperature coefficient of the second lens.

[0023] In the above solution, the change in refractive index will cause an increase in aberrations, affecting the sharpness and accuracy of imaging. Keeping the relative refractive index stability coefficient within this range can effectively reduce the optical errors caused by temperature changes and improve imaging performance.

[0024] Preferably, the hybrid glass-plastic scanning lens satisfies the conditional formula: FNO ≤ 5.1, where FNO is the aperture of the hybrid glass-plastic scanning lens.

[0025] In the above solution, a smaller FNO value, that is, a larger aperture allows more light to enter the lens, thereby improving the imaging ability in low-light environments. This is very useful for shooting or scanning in low-light conditions and can enhance the brightness and clarity of the image.

[0026] A hybrid glass-plastic scanning lens with low distortion and high image quality of the present invention has the beneficial effects of small image distortion, more realistic imaging pictures, and the ability to avoid the risk of out-of-focus shooting in harsh environments. By adopting the above structural design of the first lens, the second lens, and the third lens, the full viewing angle of the hybrid glass-plastic scanning lens can be increased to more than 54°, and the TV distortion of the system is lower than 2%. In this way, the image distortion is small and the imaging picture is more realistic; due to the adoption of the hybrid design of glass materials and plastic materials, it is beneficial to correct the temperature drift problem, so that the optical system of the hybrid glass-plastic scanning lens is in focus within the temperature range of -30°C to 70°C, avoiding the risk of out-of-focus shooting in harsh environments, thus meeting higher imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is the lens cross-section and optical path diagram of the hybrid glass-plastic scanning lens with low distortion and high image quality in Embodiment 1.

[0028] Figure 2 It is the field curvature distortion diagram of the hybrid glass-plastic scanning lens with low distortion and high image quality in Embodiment 1.

[0029] Figure 3 It is the axial aberration diagram of the hybrid glass-plastic scanning lens with low distortion and high image quality in Embodiment 1.

[0030] Figure 4 It is the defocus MTF curve diagram of the hybrid glass-plastic scanning lens with low distortion and high image quality in Embodiment 1 at room temperature of 20°C.

[0031] Figure 5 It is the defocus MTF curve diagram of the hybrid glass-plastic scanning lens with low distortion and high image quality in Embodiment 1 at low temperature of -30°C.

[0032] Figure 6 It is the defocus MTF curve diagram of the hybrid glass-plastic scanning lens with low distortion and high image quality in Embodiment 1 at high temperature of 70°C.

[0033] Figure 7 It is the lens cross-section and optical path diagram of the hybrid glass-plastic scanning lens with low distortion and high image quality in Embodiment 2.

[0034] Figure 8 It is the field curvature distortion diagram of the hybrid glass-plastic scanning lens with low distortion and high image quality in Embodiment 2.

[0035] Figure 9Axial aberration diagram of the hybrid glass-plastic scanning lens with low distortion and high image quality in Example 2.

[0036] Figure 10 Defocus MTF curve diagram of the hybrid glass-plastic scanning lens with low distortion and high image quality in Example 2 at room temperature of 20°C.

[0037] Figure 11 Defocus MTF curve diagram of the hybrid glass-plastic scanning lens with low distortion and high image quality in Example 2 at low temperature of -30°C.

[0038] Figure 12 Defocus MTF curve diagram of the hybrid glass-plastic scanning lens with low distortion and high image quality in Example 2 at high temperature of 70°C.

[0039] Figure 13 Lens cross-section and optical path diagram of the hybrid glass-plastic scanning lens with low distortion and high image quality in Example 3.

[0040] Figure 14 Field curvature and distortion diagram of the hybrid glass-plastic scanning lens with low distortion and high image quality in Example 3.

[0041] Figure 15 Axial aberration diagram of the hybrid glass-plastic scanning lens with low distortion and high image quality in Example 3.

[0042] Figure 16 Defocus MTF curve diagram of the hybrid glass-plastic scanning lens with low distortion and high image quality in Example 3 at room temperature of 20°C.

[0043] Figure 17 Defocus MTF curve diagram of the hybrid glass-plastic scanning lens with low distortion and high image quality in Example 3 at low temperature of -30°C.

[0044] Figure 18 Defocus MTF curve diagram of the hybrid glass-plastic scanning lens with low distortion and high image quality in Example 3 at high temperature of 70°C.

[0045] Explanation of reference numerals: L1, the first lens; L2, the second lens; L3, the third lens; STO, the aperture; IR&CG, IR and CG films; IMA, the imaging surface. Detailed implementation manners

[0046] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

[0047] The low-distortion and high-image-quality plastic-glass hybrid scanning lens of the present invention is composed of three lenses, with a simple structure and a small volume. By combining different-structured lenses and reasonably distributing the optical powers of each lens, it can ensure a small distortion while having a high imaging quality.

[0048] As Figures 1 to 18 shown, in a preferred embodiment, a low-distortion and high-image-quality plastic-glass hybrid scanning lens of the present invention sequentially includes, along the optical axis from the object side to the image side, a first lens L1 with a negative optical power, whose object side is convex and image side is concave; a first lens L2 with a positive optical power, whose object side is convex and image side is convex; and a third lens L3 with a negative optical power, whose object side is concave and image side is convex. Both the first lens L1 and the third lens L3 are made of plastic material, and the first lens L2 is a glass lens. By adopting the above structural design of the first lens L1, the first lens L2, and the third lens L3, the full viewing angle of the plastic-glass hybrid scanning lens can be increased, and the TV distortion of the system can be lower than 2%. In this way, the image distortion is small and the imaging picture is more real. Since the scheme of mixing glass material and plastic material is adopted, it is beneficial to correct the temperature drift problem, so that the optical system of the plastic-glass hybrid scanning lens does not defocus within the temperature range of -30°C to 70°C, avoiding the risk of defocus during shooting in harsh environments, thus meeting the requirements of high imaging quality.

[0049] As Figures 1 to 18 shown, in some embodiments, the plastic-glass hybrid scanning lens satisfies the conditional formula: -7 < f1 / f < -1, 0 < f2 / f < 3, -10 < f3 / f < -4, where f1 is the focal length of the first lens L1, f2 is the focal length of the first lens L2, f3 is the focal length of the third lens L3, and f is the focal length of the plastic-glass hybrid scanning lens. In this way, the optical powers of the first lens L1, the first lens L2, and the third lens L3 have a reasonable distribution ratio. The first lens L1 is beneficial to reducing the angle between the light beam and the optical axis after passing through the system, quickly reducing the light brightness, and incidenting on the first lens L2 at a reasonable height, so that the first lens L1 prepares for further correcting the aberration and improving the lens resolution by the first lens L2 and the third lens L3 in the rear group.

[0050] As Figures 1 to 18As shown, in some embodiments, the hybrid glass-plastic scanning lens satisfies the following conditional expressions: 1.5 ≤ Nd1 ≤ 1.6, 50 ≤ Vd1 ≤ 60; 1.5 ≤ Nd2 ≤ 1.6, 50 ≤ Vd2 ≤ 60; 1.6 ≤ Nd3 ≤ 1.7, 20 ≤ Vd3 ≤ 30; where Nd1 is the refractive index of the first lens L1, Vd1 is the dispersion coefficient of the first lens L1, Nd2 is the refractive index of the second lens L2, Vd2 is the dispersion coefficient of the second lens L2, Nd3 is the refractive index of the third lens L3, and Vd3 is the dispersion coefficient of the third lens L3. The combined structure of the first lens L1, the second lens L2, and the third lens L3 that satisfies the above refractive index relationship is conducive to achieving a reasonable distribution of optical power, can better correct aberrations such as spherical aberration and field curvature, thereby improving the lens resolution; and, through the combination of materials with different dispersion coefficients, the chromatic aberration of the optical system can be effectively reduced, enabling the optical system to have a better imaging effect.

[0051] As Figures 1 to 18 shown, in some embodiments, both the first lens L1 and the third lens L3 are aspherical lenses. Since the aspherical lens has a large degree of freedom, its ability to deflect light and correct aberrations is significantly stronger than that of a spherical surface, which is conducive to improving the lens resolution and correcting lens distortion. At the same time, it is also beneficial to correct the exit light angle of the lens and can better match the photosensitive element.

[0052] As Figures 1 to 18 shown, in some embodiments, the hybrid glass-plastic scanning lens satisfies the conditional expression: 0.4 < f / TTL < 0.5, where f is the focal length of the hybrid glass-plastic scanning lens, and TTL is the axial distance from the object side surface of the first lens L1 to the imaging surface IMA. This appropriate ratio of f / TTL can control the volume and weight of the lens while maintaining good imaging performance, enabling the lens to provide a large field of view without affecting the image quality, and helping to reduce the aberrations of the lens, especially distortion and spherical aberration, helping to maintain the clarity and accuracy of the image under different imaging conditions and improving the resolution of the lens.

[0053] As Figures 1 to 18 shown, in some embodiments, the hybrid glass-plastic scanning lens satisfies the conditional expression: TTL < 7.45 mm, where TTL is the axial distance from the object side surface of the first lens L1 to the imaging surface IMA. A smaller TTL can make the aperture position in the design closer to the imaging surface IMA, thereby optimizing the aperture design, such as being able to increase the actual aperture value of the aperture, thereby reducing optical distortion, and shortening TTL helps to reduce the path length of light propagation in the optical system, helps to reduce aberrations, and improves the imaging quality.

[0054] As Figures 1 to 18As shown, in some embodiments, the hybrid glass-plastic scanning lens satisfies the conditional formula: DFOV > 54°, where DFOV is the full field of view angle of the hybrid glass-plastic scanning lens. Through the optimized design of the first lens L1, the first lens L2, and the third lens L3, the full field of view angle can reach more than 54°. In this way, the lens can capture a wider viewing angle, thereby covering a larger imaging area.

[0055] As Figures 1 to 18 shown, in some embodiments, a stop STO is disposed between the first lens L1 and the first lens L2. By disposing the stop STO between the first lens L1 and the first lens L2, it is beneficial to meet the requirement of smaller distortion, thereby being able to better balance the exit angle of the optical system, being beneficial to matching the corresponding image sensor, and thus improving the imaging quality.

[0056] As Figures 1 to 18 shown, in some embodiments, the hybrid glass-plastic scanning lens satisfies the conditional formula: -8.1×10 -6 ≤dn / dt(L2)≤-7×10 -6 , where dn / dt(L2) is the relative refractive index temperature coefficient of the first lens L2. The change in refractive index will cause an increase in aberration, affecting the clarity and accuracy of imaging. Keeping the relative refractive index stability coefficient within this range can effectively reduce the optical error caused by temperature changes and improve the imaging performance.

[0057] As Figures 1 to 18 shown, in some embodiments, the hybrid glass-plastic scanning lens satisfies the conditional formula: FNO ≤ 5.1, where FNO is the aperture of the hybrid glass-plastic scanning lens. A smaller FNO value, that is, a larger aperture allows more light to enter the lens, thereby improving the imaging ability in low-light environments. This is very useful for shooting or scanning in low-light conditions and can enhance the brightness and clarity of the image.

[0058] Embodiments of the low-distortion and high-image-quality hybrid glass-plastic scanning lens of the present invention will be listed below and described in detail with reference to the accompanying drawings.

[0059] Embodiment 1

[0060] The design parameters of the low-distortion and high-image-quality hybrid glass-plastic scanning lens of this embodiment can be shown in the following table:

[0061]

[0062] In the above table, the units of the surface radius and thickness are both millimeters; the surface marked with "*" represents an aspherical surface, and the surface shape of the aspherical lens satisfies the following relational formula:

[0063]

[0064] In the formula, the parameter c is the curvature corresponding to the lens radius, y is the radial coordinate, and the unit of the radial coordinate is the same as that of the lens length. k is the conic coefficient. When the k coefficient is less than -1, the surface curve of the lens is a hyperbola. When the k coefficient is equal to -1, the surface curve of the lens is a parabola. When the k coefficient is between -1 and 0, the surface curve of the lens is an ellipse. When the k coefficient is equal to 0, the surface curve of the lens is a circle. When the k coefficient is greater than 0, the surface curve of the lens is a flattened ellipse. a4, a6, a8, a10, a12, a14, and a16 are the surface coefficients corresponding to the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order radial coordinates respectively. The value of the conic coefficient k is shown in the above table, and the remaining detailed aspheric-related parameters are shown in the following table.

[0065]

[0066] Refer to Figure 2 is the field curvature and distortion diagram of the low-distortion and high-image-quality glass-plastic hybrid scanning lens 1 of this embodiment; Figure 3 is the axial aberration diagram of the low-distortion and high-image-quality glass-plastic hybrid scanning lens 1 of this embodiment; Figure 4 is the defocus MTF curve diagram of the low-distortion and high-image-quality glass-plastic hybrid scanning lens 1 of this embodiment at room temperature of 20°C; Figure 5 is the defocus MTF curve diagram of the low-distortion and high-image-quality glass-plastic hybrid scanning lens 1 of this embodiment at low temperature of -30°C; Figure 6 is the defocus MTF curve diagram of the low-distortion and high-image-quality glass-plastic hybrid scanning lens 1 of this embodiment at high temperature of 70°C.

[0067] Embodiment 2

[0068] The design parameters of the low-distortion and high-image-quality glass-plastic hybrid scanning lens of this embodiment can be shown in the following table:

[0069]

[0070]

[0071] In the above table, the units of the surface radius and thickness are both millimeters. The surface marked with "*" represents an aspheric surface, and the surface shape of the aspheric lens satisfies the following relationship:

[0072] In the formula, the parameter c is the curvature corresponding to the lens radius, y is the radial coordinate, and the unit of the radial coordinate is the same as that of the lens length unit. k is the conic coefficient. When the k coefficient is less than -1, the surface curve of the lens is a hyperbola. When the k coefficient is equal to -1, the surface curve of the lens is a parabola. When the k coefficient is between -1 and 0, the surface curve of the lens is an ellipse. When the k coefficient is equal to 0, the surface curve of the lens is a circle. When the k coefficient is greater than 0, the surface curve of the lens is a flattened ellipse. a4, a6, a8, a10, a12, a14, and a16 are the surface coefficients corresponding to the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order radial coordinates respectively. The value of the conic coefficient k is shown in the above table, and the remaining detailed aspheric-related parameters are shown in the following table.

[0073]

[0074] Refer to Figure 8 is the field curvature and distortion diagram of the low-distortion and high-image-quality glass-plastic hybrid scanning lens 1 of this embodiment; Figure 9 is the axial aberration diagram of the low-distortion and high-image-quality glass-plastic hybrid scanning lens 1 of this embodiment; Figure 10 is the defocus MTF curve diagram of the low-distortion and high-image-quality glass-plastic hybrid scanning lens 1 of this embodiment at room temperature of 20°C; Figure 11 is the defocus MTF curve diagram of the low-distortion and high-image-quality glass-plastic hybrid scanning lens 1 of this embodiment at low temperature of -30°C; Figure 12 is the defocus MTF curve diagram of the low-distortion and high-image-quality glass-plastic hybrid scanning lens 1 of this embodiment at high temperature of 70°C.

[0075] Embodiment 3

[0076] The design parameters of the low-distortion and high-image-quality glass-plastic hybrid scanning lens of this embodiment can be shown in the following table:

[0077]

[0078] The remaining detailed aspheric-related parameters are shown in the following table:

[0079]

[0080] Refer to Figure 14 is the field curvature and distortion diagram of the low-distortion and high-image-quality glass-plastic hybrid scanning lens 1 of this embodiment; Figure 15 is the axial aberration diagram of the low-distortion and high-image-quality glass-plastic hybrid scanning lens 1 of this embodiment; Figure 16 is the defocus MTF curve diagram of the low-distortion and high-image-quality glass-plastic hybrid scanning lens 1 of this embodiment at room temperature of 20°C; Figure 17 is the defocus MTF curve diagram of the low-distortion and high-image-quality glass-plastic hybrid scanning lens 1 of this embodiment at low temperature of -30°C;Figure 18 It is the defocus MTF curve graph of the hybrid glass-plastic scanning lens 1 with low distortion and high image quality in this embodiment at a high temperature of 70°C.

[0081] A hybrid glass-plastic scanning lens with low distortion and high image quality according to the present invention, through the optimized design of the above-mentioned first lens L1, first lens L2 and third lens L3, the full-field viewing angle of the optical system can reach more than 54°, the corresponding TV distortion is lower than 2%, the image distortion is small, and the imaging picture is more real. Since aspherical surfaces are used in the system, the system aberrations are well corrected and high-definition imaging can be achieved.

[0082] In addition, due to the adoption of the hybrid design scheme of glass and plastic, it is beneficial to correct the temperature drift problem, so that the optical system does not defocus in the temperature range of -30°C to 70°C, avoiding the risk of out-of-focus during shooting in harsh environments. According to Figure 5 and Figure 6 such as the defocus MTF curve graphs of the hybrid glass-plastic scanning lens with low distortion and high image quality at low temperatures of -30°C and 70°C, it can be seen that the hybrid glass-plastic scanning lens with low distortion and high image quality in the embodiment of the present invention has excellent performance in high and low temperature environments and can meet relatively high imaging quality.

[0083] Moreover, by using different dispersion materials in combination, chromatic aberration can be effectively reduced, enabling the system to meet relatively high imaging quality and expanding the usage range of the lens.

[0084] In the description of the present invention, it should be understood that terms such as "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present invention.

[0085] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0086] In the present invention, unless otherwise clearly defined and limited, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0087] Although the description of the present invention is made in conjunction with the above specific embodiments, it is obvious that those skilled in the art can make many substitutions, modifications, and variations based on the above content. Therefore, all such substitutions, improvements, and variations are included within the spirit and scope of the appended claims.

Claims

1. A hybrid glass-plastic scanning lens with low distortion and high image quality, characterized in that, From the object side to the image side along the optical axis, it sequentially includes a first lens with a negative optical power, whose object side is convex and image side is concave; A second lens with a positive optical power, whose object side is convex and image side is convex; A third lens with a negative optical power, whose object side is concave and image side is convex; Both the first lens and the third lens are made of plastic material, and the second lens is a glass lens.

2. The hybrid glass-plastic scanning lens with low distortion and high image quality according to claim 1, wherein The plastic-glass hybrid scanning lens satisfies the conditional expressions: -7 < f1 / f < -1, 0 < f2 / f < 3, -10 < f3 / f < -4, where f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, and f is the focal length of the plastic-glass hybrid scanning lens.

3. The hybrid glass-plastic scanning lens with low distortion and high image quality according to claim 1, characterized in that The plastic-glass hybrid scanning lens satisfies the following conditional expressions: 1.5 ≤ Nd1 ≤ 1.6, 50 ≤ Vd1 ≤ 60; 1.5 ≤ Nd2 ≤ 1.6, 50 ≤ Vd2 ≤ 60; 1.6 ≤ Nd3 ≤ 1.7, 20 ≤ Vd3 ≤ 30; Where, Nd1 is the refractive index of the first lens, Vd1 is the dispersion coefficient of the first lens, Nd2 is the refractive index of the second lens, Vd2 is the dispersion coefficient of the second lens, Nd3 is the refractive index of the third lens, and Vd3 is the dispersion coefficient of the third lens.

4. The hybrid glass-plastic scanning lens with low distortion and high image quality according to claim 1, characterized in that, Both the first lens and the third lens are aspherical lenses.

5. The hybrid plastic and glass scanning lens with low distortion and high image quality according to claim 1, characterized in that, The plastic-glass hybrid scanning lens satisfies the conditional expression: 0.4 < f / TTL < 0.5, where f is the focal length of the plastic-glass hybrid scanning lens and TTL is the axial distance from the object side of the first lens to the imaging surface.

6. The hybrid glass-plastic scanning lens with low distortion and high image quality according to claim 1, characterized in that, The plastic-glass hybrid scanning lens satisfies the conditional expression: TTL < 7.45 mm, where TTL is the axial distance from the object side of the first lens to the imaging surface.

7. The hybrid glass-plastic scanning lens with low distortion and high image quality according to claim 1, wherein The plastic-glass hybrid scanning lens satisfies the conditional expression: DFOV > 54°, where DFOV is the full field of view angle of the plastic-glass hybrid scanning lens.

8. The hybrid glass-plastic scanning lens with low distortion and high image quality according to claim 1, characterized in that, A diaphragm is provided between the first lens and the second lens.

9. The hybrid glass-plastic scanning lens with low distortion and high image quality according to claim 1, characterized in that, The glass-plastic hybrid scanner lens satisfies the condition: -8.1×10 -6 ≤dn / dt(L2)≤-7×10 -6 , where dn / dt (L2) is the relative refractive index temperature coefficient of the second lens.

10. The hybrid plastic and glass scanning lens with low distortion and high image quality according to claim 1, wherein The plastic-glass hybrid scanning lens satisfies the conditional expression: FNO ≤ 5.1, where FNO is the aperture of the plastic-glass hybrid scanning lens.

Images