Vehicle-mounted DVR optical lens and imaging method

Abstract

The application relates to a vehicle-mounted DVR optical lens and an imaging method. The vehicle-mounted DVR optical lens comprises a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens, a sixth lens and a filter in sequence from an object side to an imaging surface along an optical axis. The first lens, the second lens, the third lens and the sixth lens are all glass spherical lenses, the fourth lens is a plastic aspherical lens, the first lens and the second lens both have negative focal lengths, the third lens has a positive focal length, and the fourth lens and the fifth lens form a cemented lens group. The scheme provided by the application can reduce the volume of the lens of the vehicle-mounted DVR and improve the imaging quality.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical lens, in particular to a vehicle-mounted DVR optical lens and imaging method. BACKGROUND

[0002] The vehicle-mounted DVR refers to a vehicle-mounted DVR in a vehicle, which is usually installed on the front windshield of the vehicle. The vehicle-mounted DVR can record and save the road conditions and information at the moment of an accident when the vehicle is driving.

[0003] In the related art, the lens of the vehicle-mounted DVR is usually large in size and low in pixel, resulting in poor imaging quality. SUMMARY

[0004] The present application aims to overcome the shortcomings of the prior art, and provides a vehicle-mounted DVR optical lens and imaging method, which can reduce the size of the lens of the vehicle-mounted DVR while improving the imaging quality.

[0005] The present application is achieved by the following technical solutions:

[0006] The first aspect of the present application provides a vehicle-mounted DVR optical lens, comprising: a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens, a sixth lens and a filter arranged in sequence along an optical axis from an object side to an imaging surface; the first lens, the second lens, the third lens and the sixth lens are all glass spherical lenses, the fourth lens and the fifth lens are plastic aspherical lenses, the first lens and the second lens both have negative focal power, the third lens has positive focal power, and the fourth lens and the fifth lens form a cemented lens group.

[0007] The object side of the first lens is a convex surface, the image side of the first lens is a concave surface, the object side of the second lens is a concave surface, the image side of the second lens is a convex surface, the object side of the third lens is a convex surface, and the image side of the third lens is a convex surface.

[0008] The object side of the fourth lens is a convex surface, the image side of the fourth lens is a convex surface, the object side of the fifth lens is a concave surface, the image side of the fifth lens is a concave surface, the object side of the sixth lens is a convex surface, and the image side of the sixth lens is a convex surface.

[0009] The vehicle-mounted DVR optical lens satisfies -1.6≤f1 / f≤-1.2, -5.6≤f2 / f≤-5.4, 1.5≤f3 / f≤1.8, 1.0≤f4 / f≤1.2, -1.0≤f5 / f≤-0.7, and 2.6≤f6 / f≤2.9, wherein f is an effective focal length of the vehicle-mounted DVR optical lens, f1 is an effective focal length of the first lens, f2 is an effective focal length of the second lens, f3 is an effective focal length of the third lens, f4 is an effective focal length of the fourth lens, f5 is an effective focal length of the fifth lens, and f6 is an effective focal length of the sixth lens.

[0010] The vehicle-mounted DVR optical lens also satisfies 60≤(FOVxf) / h≤63, wherein FOV is a field of view angle of the vehicle-mounted DVR optical lens, and h is a height of a corresponding image of the field of view angle.

[0011] The vehicle-mounted DVR optical lens also satisfies 1.72≤Nd1≤1.76, 1.80≤Nd2≤1.85, 1.86≤Nd3≤1.90, 1.51≤Nd4≤1.54, 1.61≤Nd5≤1.66, and 1.86≤Nd6≤1.90, wherein Nd1 is a refractive index of the first lens, Nd2 is a refractive index of the second lens, Nd3 is a refractive index of the third lens, Nd4 is a refractive index of the fourth lens, Nd5 is a refractive index of the fifth lens, and Nd6 is a refractive index of the sixth lens.

[0012] The vehicle-mounted DVR optical lens also satisfies 48≤Vd1≤51, 43≤Vd2≤46, 38≤Vd3≤43, 52≤Vd4≤57, 21≤Vd5≤25, and 40≤Vd6≤43, wherein Vd1 is a dispersion coefficient of the first lens, Vd2 is a dispersion coefficient of the second lens, Vd3 is a dispersion coefficient of the third lens, Vd4 is a dispersion coefficient of the fourth lens, Vd5 is a dispersion coefficient of the fifth lens, and Vd6 is a dispersion coefficient of the sixth lens.

[0013] The interval between the first lens and the second lens is in a range of 2.4mm-2.6mm, the interval between the second lens and the third lens is in a range of 0.05mm-0.1mm, the interval between the third lens and the diaphragm is in a range of -0.1mm-0mm, the interval between the diaphragm and the fourth lens is in a range of 0.8mm-1.1mm, and the interval between the fifth lens and the sixth lens is in a range of 0.9mm-1.1mm.

[0014] The aspheric curve equation of the fourth lens and the fifth lens satisfies the following equation:

[0015]

[0016] The vehicle-mounted DVR optical lens imaging method comprises the following steps: light rays sequentially pass through a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens, a sixth lens and a filter from an object side to an imaging surface for imaging.

[0017] Compared with the prior art, the present application has at least the following advantages:

[0018] The first lens and the second lens are negative lenses, which can collect large-angle light rays and reduce the size of the lens head, thereby realizing the miniaturization of the optical lens. In addition, the third lens has positive focal power, which can converge light rays into the rear lens, and the fourth lens and the fifth lens form a cemented lens group, which can improve the imaging quality of the optical lens, optimize the chromatic aberration, and realize the characteristics of low temperature drift. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows.

[0020] Figure 1 Fig. 1 is a structural schematic diagram of the vehicle-mounted DVR optical lens in an embodiment of the present application;

[0021] Figure 2 Fig. 2 is a field curvature and distortion diagram of the vehicle-mounted DVR optical lens in an embodiment of the present application in the full working waveband;

[0022] Figure 3 Fig. 3 is an axial aberration diagram of the vehicle-mounted DVR optical lens in an embodiment of the present application in the full working waveband;

[0023] Figure 4 Fig. 4 is an MTF curve diagram of the vehicle-mounted DVR optical lens in an embodiment of the present application in the full working waveband;

[0024] Figure 5 Fig. 5 is an out-of-focus MTF curve diagram of the vehicle-mounted DVR optical lens in an embodiment of the present application in the full working waveband at -40℃;

[0025] Figure 6 Fig. 6 is an out-of-focus MTF curve diagram of the vehicle-mounted DVR optical lens in an embodiment of the present application in the full working waveband at +95℃. DETAILED DESCRIPTION

[0026] Embodiments of the present application will be described in more detail with reference to the drawings. Although the embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present application will be thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0027] It should be understood that, although the terms "first", "second", "third", etc. can be used in this application to describe various information, these information should not be limited by these terms. These terms are only used to distinguish the same type of information from each other. For example, the first information can also be referred to as the second information, and similarly, the second information can also be referred to as the first information without departing from the scope of the present application. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0028] Unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixed connection, or detachable connection or integral; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0029] The vehicle-mounted DVR refers to the vehicle-mounted DVR in the vehicle, which is usually installed on the front windshield of the vehicle. The vehicle-mounted DVR can record and save the road conditions when the vehicle is running, the moment when the accident occurs and other information. At present, the lens of the vehicle-mounted DVR is usually large in size and low in pixel, resulting in poor imaging quality.

[0030] In view of the above problems, the present application provides a vehicle-mounted DVR optical lens and an imaging method, which can reduce the size of the lens of the vehicle-mounted DVR and improve the imaging quality.

[0031] The technical solutions of the embodiments of the present application will be described in detail below with reference to the drawings.

[0032] Referring to Figures 1 to 6The application discloses a vehicle-mounted DVR optical lens, which comprises a first lens 100, a second lens 200, a third lens 300, a diaphragm 400, a fourth lens 500, a fifth lens 600, a sixth lens 700 and a filter 800 arranged in sequence from an object side to an imaging surface along an optical axis.

[0033] It should be noted that the first lens 100 and the second lens 200 are negative lenses, which can collect large-angle light and reduce the size of the head of the lens, so that the overall optical lens is miniaturized. In addition, the third lens 300 has positive focal power, which can converge light into the rear lens, and the fourth lens 500 and the fifth lens 600 form a cemented lens group, which can improve the imaging quality of the optical lens, optimize the chromatic aberration, and realize the characteristics of low temperature drift.

[0034] In addition, the plastic aspheric lens can better correct the distortion in vision and provide higher quality imaging effect. At the same time, the plastic aspheric lens can reduce the range of edge distortion, so that the imaging restoration is higher. Therefore, the cemented lens group composed of the fourth lens 500 and the fifth lens 600 not only makes the structure of the optical lens more compact, but also improves the display quality of the image.

[0035] Referring to Figure 1 In an embodiment, the object side S1 of the first lens 100 is a convex surface, the image side S2 of the first lens 100 is a concave surface, the object side S3 of the second lens 200 is a concave surface, the image side S4 of the second lens 200 is a convex surface, the object side S5 of the third lens 300 is a convex surface, and the image side S6 of the third lens 300 is a convex surface. Specifically, the object side S7 of the fourth lens 500 is a convex surface, the image side S8 of the fourth lens 500 is a convex surface, the object side S9 of the fifth lens 600 is a concave surface, the image side S10 of the fifth lens 600 is a concave surface, the object side S11 of the sixth lens 700 is a convex surface, and the image side S12 of the sixth lens 700 is a convex surface.

[0036] It should be noted that the first lens 100 is a meniscus concave negative lens, the second lens 200 is a meniscus convex negative lens, the third lens 300 is a double-convex positive lens, the fourth lens 500 is a double-convex positive lens, the fifth lens 600 is a double-concave negative lens, and the sixth lens 700 is a double-convex positive lens.

[0037] In an embodiment, the vehicle DVR optical lens satisfies -1.6≤f1 / f≤-1.2, -5.6≤f2 / f≤-5.4, 1.5≤f3 / f≤1.8, 1.0≤f4 / f≤1.2, -1.0≤f5 / f≤-0.7, and 2.6≤f6 / f≤2.9, where f is an effective focal length of the vehicle DVR optical lens, f1 is an effective focal length of the first lens 100, f2 is an effective focal length of the second lens 200, f3 is an effective focal length of the third lens 300, f4 is an effective focal length of the fourth lens 500, f5 is an effective focal length of the fifth lens 600, and f6 is an effective focal length of the sixth lens 700.

[0038] Referring to Figure 1 In an embodiment, the vehicle DVR optical lens further satisfies 60≤(FOVxf) / h≤63, where FOV is a field of view angle of the vehicle DVR optical lens, and h is a height of an image corresponding to the field of view angle.

[0039] It is to be noted that FOV is a maximum field of view angle, and h is a height of an image corresponding to the maximum field of view angle.

[0040] In an embodiment, the vehicle DVR optical lens further satisfies 1.72≤Nd1≤1.76, 1.80≤Nd2≤1.85, 1.86≤Nd3≤1.90, 1.51≤Nd4≤1.54, 1.61≤Nd5≤1.66, and 1.86≤Nd6≤1.90, where Nd1 is a refractive index of the first lens 100, Nd2 is a refractive index of the second lens 200, Nd3 is a refractive index of the third lens 300, Nd4 is a refractive index of the fourth lens 500, Nd5 is a refractive index of the fifth lens 600, and Nd6 is a refractive index of the sixth lens 700.

[0041] In an embodiment, the vehicle DVR optical lens further satisfies 48≤Vd1≤51, 43≤Vd2≤46, 38≤Vd3≤43, 52≤Vd4≤57, 21≤Vd5≤25, and 40≤Vd6≤43, where Vd1 is a dispersion coefficient of the first lens 100, Vd2 is a dispersion coefficient of the second lens 200, Vd3 is a dispersion coefficient of the third lens 300, Vd4 is a dispersion coefficient of the fourth lens 500, Vd5 is a dispersion coefficient of the fifth lens 600, and Vd6 is a dispersion coefficient of the sixth lens 700.

[0042] In an embodiment, the interval between the first lens 100 and the second lens 200 ranges from 2.4mm to 2.6mm, the interval between the second lens 200 and the third lens 300 ranges from 0.05mm to 0.1mm, the interval between the third lens 300 and the diaphragm 400 ranges from -0.1mm to 0mm, the interval between the diaphragm 400 and the fourth lens 500 ranges from 0.8mm to 1.1mm, and the interval between the fifth lens 600 and the sixth lens 700 ranges from 0.9mm to 1.1mm.

[0043] In an embodiment, the optical lens for vehicle DVR of the present application also satisfies 0.9≤BFL / f≤1.0, 0.15≤BFL / TTL≤0.17, wherein BFL is the distance from the image-side center of the sixth lens 700 to the imaging plane of the optical lens for vehicle DVR on the optical axis, and TTL is the distance from the object-side center of the first lens 100 to the imaging plane of the optical lens for vehicle DVR on the optical axis.

[0044] Further, in an embodiment, the aspherical surface curve equation of the fourth lens 500 and the fifth lens 600 satisfies the following equation:

[0045]

[0046] It should be noted that z is the axial height of the aspherical surface Z direction, r is the height of the aspherical surface, c is the curvature of the fitting sphere, which is the reciprocal of the radius of curvature in value, k is the fitting conic coefficient, and A-G are the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order term coefficients of the aspherical surface polynomial.

[0047] Specifically, the aspherical surface coefficients of each aspherical lens are as shown in Table 1 below:

[0048]

[0049] Table 1

[0050] In an embodiment, the parameters of each lens are as shown in Table 2:

[0051]

[0052] Table 2

[0053] Wherein, PL refers to a plane, and Infinity refers to infinity.

[0054] Other optical information of the optical lens for vehicle DVR of the present application is as shown in Table 3:

[0055] TTL 15.4 FOV / 2 75 D 8 f 2.668 BFL 2.56 h 3.305 (FOV x f) / h 60.54 BFL / f 0.952 BFL / TTL 0.166 FNO 2.0

[0056] Table 3

[0057] It should be noted that D in Table 3 is the optical effective full aperture of the first lens.

[0058] In summary, the first lens 100 and the second lens 200 are set to have negative focal lengths, so that the large-angle light can be collected and the size of the lens head can be reduced, and the overall size of the optical lens can be reduced. Further, the third lens 300 is set to have a positive focal length, so that the light can be converged into the rear lens, and the fourth lens 500 and the fifth lens 600 form a cemented lens group, so that the optical lens can improve the imaging quality, optimize the chromatic aberration, and realize the characteristics of low temperature drift.

[0059] In another embodiment, a vehicle-mounted DVR optical lens imaging method includes sequentially passing light from an object side to an imaging surface through the first lens 100, the second lens 200, the third lens 300, the diaphragm 400, the fourth lens 500, the fifth lens 600, the sixth lens 700, and the optical filter 800 for imaging.

[0060] The above has been described in detail with reference to the accompanying drawings. In the above-described embodiments, the description of each embodiment is focused on, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments. Those skilled in the art should also know that the actions and modules involved in the specification are not necessarily required by the present application. In addition, it can be understood that the steps in the embodiment method of the present application can be adjusted, combined and reduced in sequence according to actual needs, and the modules in the embodiment device of the present application can be combined, divided and reduced according to actual needs.

[0061] The above has described various embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles, practical applications, or improvements to the technology in the market of the embodiments, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. An optical lens for a vehicle-mounted DVR, characterized in that, Along the optical axis from the object side to the imaging plane, it includes, in sequence, a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, a sixth lens, and a filter; The first, second, third, and sixth lenses are all glass spherical lenses, while the fourth and fifth lenses are plastic aspherical lenses. The first and second lenses have negative optical power, and the third lens has positive optical power. The fourth and fifth lenses form a cemented lens group. The object-side surface of the first lens is convex, and its image-side surface is concave. The object-side surface of the second lens is concave, and its image-side surface is convex. The object-side surface of the third lens is convex, and its image-side surface is convex. The object-side surface of the fourth lens is convex, and its image-side surface is convex. The object-side surface of the fifth lens is concave, and its image-side surface is concave. The object-side surface of the sixth lens is concave, and the image-side surface of the sixth lens is convex. The optical lens of the vehicle-mounted DVR satisfies the following: -1.6≤f1 / f≤-1.2, -5.6≤f2 / f≤-5.4, 1.5≤f3 / f≤1.8, 1.0≤f4 / f≤1.2, -1.0≤f5 / f≤-0.7, and 2.6≤f6 / f≤2.9, where f is the effective focal length of the vehicle-mounted DVR optical lens and imaging method, f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, f4 is the effective focal length of the fourth lens, f5 is the effective focal length of the fifth lens, and f6 is the effective focal length of the sixth lens.

2. The vehicle-mounted DVR optical lens according to claim 1, characterized in that, The vehicle-mounted DVR optical lens also satisfies the following condition: 60≤(FOV×f) / h≤63, where FOV is the field of view of the vehicle-mounted DVR optical lens and imaging method, and h is the height of the image corresponding to the field of view.

3. The vehicle-mounted DVR optical lens and imaging method according to claim 1, characterized in that, The optical lens of this vehicle-mounted DVR also satisfies the following: 1.72≤Nd1≤1.76, 1.80≤Nd2≤1.85, 1.86≤Nd3≤1.90, 1.51≤Nd4≤1.54, 1.61≤Nd5≤1.66, and 1.86≤Nd6≤1.90, where Nd1 is the refractive index of the first lens, Nd2 is the refractive index of the second lens, Nd3 is the refractive index of the third lens, Nd4 is the refractive index of the fourth lens, Nd5 is the refractive index of the fifth lens, and Nd6 is the refractive index of the sixth lens.

4. The vehicle-mounted DVR optical lens according to claim 1, characterized in that, The optical lens of the vehicle-mounted DVR also satisfies the following conditions: 48≤Vd1≤51, 43≤Vd2≤46, 38≤Vd3≤43, 52≤Vd4≤57, 21≤Vd5≤25, and 40≤Vd6≤43, where Vd1 is the dispersion coefficient of the first lens, Vd2 is the dispersion coefficient of the second lens, Vd3 is the dispersion coefficient of the third lens, Vd4 is the dispersion coefficient of the fourth lens, Vd5 is the dispersion coefficient of the fifth lens, and Vd6 is the dispersion coefficient of the sixth lens.

5. The vehicle-mounted DVR optical lens according to claim 1, characterized in that, The interval between the first lens and the second lens is 2.4mm to 2.6mm; the interval between the second lens and the third lens is 0.05mm to 0.1mm; the interval between the third lens and the aperture is -0.1mm to 0mm; the interval between the aperture and the fourth lens is 0.8mm to 1.1mm; and the interval between the fifth lens and the sixth lens is 0.9mm to 1.1mm.

6. The vehicle-mounted DVR optical lens according to claim 1, characterized in that, The aspherical curve equations of the fourth lens and the fifth lens satisfy the following equations: 。 7. An imaging method based on the optical lens of a vehicle-mounted DVR as described in claim 1, characterized in that, The process involves light rays passing sequentially through a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, a sixth lens, and a filter from the object side to the imaging plane before forming an image.

Images