Vehicle-mounted DVR optical lens and imaging method

Abstract

The invention relates to a vehicle-mounted DVR optical lens and an imaging method. The vehicle-mounted DVR optical lens sequentially comprises a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens, a sixth lens and an optical filter 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 aspheric lens, the first lens and the second lens have negative focal power, the third lens has positive focal power, and the fourth lens and the fifth lens form a balsaming lens group. According to the scheme provided by the invention, the size of the lens of the vehicle-mounted DVR can be reduced, and meanwhile, the imaging quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical lenses, and in particular to an optical lens and an imaging method for a vehicle-mounted DVR. Background Art

[0002] Car DVR refers to the driving recorder in the car, which is usually installed on the front windshield of the car. The driving recorder can record and save information such as the road conditions when the vehicle is driving and the moment of the accident.

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

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a vehicle-mounted DVR optical lens and imaging method, which can reduce the size of the lens of the vehicle-mounted DVR and improve the quality of imaging.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] In a first aspect, the present application provides an optical lens for a vehicle-mounted DVR, comprising: a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens, a sixth lens and a filter in sequence from the object side to the imaging surface along the optical axis; 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 optical power, the third lens has positive optical power, and the fourth lens and the fifth lens form a cemented lens group.

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

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

[0009] The vehicle-mounted DVR optical lens satisfies the following requirements: -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 the effective focal length of the vehicle-mounted DVR optical lens, 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.

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

[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, 1.86≤Nd6≤1.90, wherein 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.

[0012] The vehicle-mounted DVR optical lens also satisfies: 48≤Vd1≤51, 43≤Vd2≤46, 38≤Vd3≤43, 52≤Vd4≤57, 21≤Vd5≤25, 40≤Vd6≤43, wherein 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.

[0013] The interval range between the first lens and the second lens is: 2.4mm~2.6mm, the interval range between the second lens and the third lens is: 0.05mm~0.1mm; the interval range between the third lens and the aperture is: -0.1mm~0mm; the interval range between the aperture and the fourth lens is: 0.8mm~1.1mm; the interval range between the fifth lens and the sixth lens is: 0.9mm~1.1mm.

[0014] The aspheric curve equations of the fourth lens and the fifth lens satisfy the following equations:

[0015]

[0016] A vehicle-mounted DVR optical lens imaging method includes imaging after light passes through a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens, a sixth lens, and a filter in sequence from an object side to an imaging surface.

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

[0018] The first and second lenses have negative focal lengths, which can collect light at large angles and reduce the size of the lens head, thus miniaturizing the optical lens as a whole. Secondly, the third lens has positive focal length, which can focus light onto the lens behind it. Together with the fourth and fifth lenses, the combined lens group can improve the quality of the optical lens, optimize chromatic aberration, and achieve low-temperature drift. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below.

[0020] Figure 1 It is a structural schematic diagram of the vehicle-mounted DVR optical lens in one embodiment of the present invention;

[0021] Figure 2 The field curvature and distortion diagram of the vehicle-mounted DVR optical lens in the full working band in one embodiment of the present invention;

[0022] Figure 3 A vertical axis aberration diagram of the vehicle-mounted DVR optical lens in the full working band in one embodiment of the present invention;

[0023] Figure 4 The MTF curve diagram of the vehicle-mounted DVR optical lens in the full working band in one embodiment of the present invention;

[0024] Figure 5 This is a defocus MTF curve diagram of the vehicle-mounted DVR optical lens in the full working band at -40°C in one embodiment of the present invention;

[0025] Figure 6 This is a defocus MTF curve diagram of the vehicle-mounted DVR optical lens in the full working band at +95°C in one embodiment of the present invention. DETAILED DESCRIPTION

[0026] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to 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. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0028] Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, or a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0029] Car DVR refers to the driving recorder in the car, which is usually installed on the front windshield of the car. The driving recorder can record and save information such as the road conditions when the vehicle is driving and the moment of the accident. At present, the lens of the car DVR is usually large in size and has low pixels, resulting in poor image quality.

[0030] In view of the above problems, the embodiments of the present application provide 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 solution of the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0032] See also Figures 1 to 6, an optical lens for a vehicle-mounted DVR, comprising: a first lens 100, a second lens 200, a third lens 300, an aperture 400, a fourth lens 500, a fifth lens 600, a sixth lens 700 and a filter 800 in sequence from the object side to the imaging surface along the optical axis; the first lens 100, the second lens 200, the third lens 300 and the sixth lens 700 are all glass spherical lenses, the fourth lens 500 is a glass spherical lens, and the fifth lens 600 is a plastic aspherical lens. The first lens 100 and the second lens 200 both have negative optical power, the third lens 300 has positive optical power, and the fourth lens 500 and the fifth lens 600 form a cemented lens group.

[0033] It should be noted that the first lens 100 and the second lens 200 have negative focal lengths, which can collect light at large angles and reduce the size of the lens head, thereby miniaturizing the optical lens as a whole. Secondly, the third lens 300 has positive focal lengths, which can converge light to the lens behind it. Together with the cemented lens group composed of the fourth lens 500 and the fifth lens 600, the optical lens can improve the quality of imaging, optimize chromatic aberration, and achieve the characteristics of low temperature drift.

[0034] It should also be noted that the plastic aspheric lens can better correct the distortion in vision and provide a higher quality imaging effect. At the same time, the plastic aspheric lens can reduce the range of edge distortion, making the imaging restoration higher. Therefore, the cemented lens group composed of the fourth lens 500 and the fifth lens 600 set in the present application not only makes the structure of the optical lens more compact, but also improves the display quality of the image.

[0035] See also Figure 1 In one embodiment, the object-side surface S1 of the first lens 100 is a convex surface, the image-side surface S2 of the first lens 100 is a concave surface, the object-side surface S3 of the second lens 200 is a concave surface, the image-side surface S4 of the second lens 200 is a convex surface, the object-side surface S5 of the third lens 300 is a convex surface, and the image-side surface S6 of the third lens 300 is a convex surface. Specifically, the object-side surface S7 of the fourth lens 500 is a convex surface, the image-side surface S8 of the fourth lens 500 is a convex surface, the object-side surface S9 of the fifth lens 600 is a concave surface, the image-side surface S10 of the fifth lens 600 is a concave surface, the object-side surface S11 of the sixth lens 700 is a convex surface, and the image-side surface 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 biconvex positive lens, the fourth lens 500 is a biconvex positive lens, the fifth lens 600 is a biconcave negative lens, and the sixth lens 700 is a biconvex positive lens.

[0037] In one embodiment, 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 the effective focal length of the vehicle-mounted DVR optical lens, f1 is the effective focal length of the first lens 100, f2 is the effective focal length of the second lens 200, f3 is the effective focal length of the third lens 300, f4 is the effective focal length of the fourth lens 500, f5 is the effective focal length of the fifth lens 600, and f6 is the effective focal length of the sixth lens 700.

[0038] See also Figure 1 In one embodiment, the vehicle-mounted DVR optical lens also satisfies: 60≤(FOV×f) / h≤63, where FOV is the field of view of the vehicle-mounted DVR optical lens, and h is the height of the image corresponding to the field of view.

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

[0040] In one embodiment, 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, 1.86≤Nd6≤1.90, wherein Nd1 is the refractive index of the first lens 100, Nd2 is the refractive index of the second lens 200, Nd3 is the refractive index of the third lens 300, Nd4 is the refractive index of the fourth lens 500, Nd5 is the refractive index of the fifth lens 600, and Nd6 is the refractive index of the sixth lens 700.

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

[0042] In one embodiment, the interval range between the first lens 100 and the second lens 200 is: 2.4mm~2.6mm, the interval range between the second lens 200 and the third lens 300 is: 0.05mm~0.1mm; the interval range between the third lens 300 and the aperture 400 is: -0.1mm~0mm; the interval range between the aperture 400 and the fourth lens 500 is: 0.8mm~1.1mm; the interval range between the fifth lens 600 and the sixth lens 700 is: 0.9mm~1.1mm.

[0043] In one embodiment, the vehicle-mounted DVR optical lens 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 center of the image side surface of the sixth lens 700 to the imaging surface of the vehicle-mounted DVR optical lens on the optical axis, and TTL is the distance from the center of the object side surface of the first lens 100 to the imaging surface of the vehicle-mounted DVR optical lens on the optical axis.

[0044] Further, in one embodiment, the aspheric curve equations of the fourth lens 500 and the fifth lens 600 satisfy the following equations:

[0045]

[0046] It should be noted that z is the axial vector height of the aspheric surface in the Z direction; r is the height of the aspheric surface; c is the curvature of the fitted spherical surface, which is the inverse of the radius of curvature; k is the fitting cone coefficient; AG is the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order coefficients of the aspheric polynomial.

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

[0048]

[0049] Table 1

[0050] The parameters of each lens in one embodiment are shown in Table 2:

[0051]

[0052] Table 2

[0053] Among them, PL refers to plane and Infinity refers to infinity.

[0054] Other optical information of the vehicle-mounted DVR optical lens of this application is shown in Table 3:

[0055] TTL 15.4 FOV / 2 75 D 8 f 2.668 BFL 2.56 h 3.305 (FOV×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 optically effective full aperture of the first lens.

[0058] In summary, the present application sets the first lens 100 and the second lens 200 to have negative focal length, thereby being able to collect light at a large angle and reduce the size of the lens head, thereby miniaturizing the overall volume of the optical lens. Furthermore, the third lens 300 is set to have positive focal length, which can converge the light to the rear lens, and at the same time, the fourth lens 500 and the fifth lens 600 are used to form a cemented lens group, which can improve the quality of the optical lens, optimize chromatic aberration, and achieve the characteristics of low temperature drift.

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

[0060] The scheme of the present application has been described in detail above with reference to the accompanying drawings. In the above embodiments, the descriptions of the various embodiments have their own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments. Those skilled in the art should also be aware that the actions and modules involved in the specification are not necessarily required for the present application. In addition, it can be understood that the steps in the method of the embodiment of the present application can be adjusted in order, merged and deleted according to actual needs, and the modules in the device of the embodiment of the present application can be merged, divided and deleted according to actual needs.

[0061] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A vehicle-mounted DVR optical lens, characterized in that: The optical axis includes, from the object side to the imaging surface, a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens, a sixth lens and a filter; 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 optical power, the third lens has positive optical power, and the fourth lens and the fifth lens form a cemented lens group.

2. The vehicle-mounted DVR optical lens according to claim 1, characterized in that: The object side surface of the first lens is convex, the image side surface of the first lens is concave, the object side surface of the second lens is concave, the image side surface of the second lens is convex, the object side surface of the third lens is convex, and the image side surface of the third lens is convex.

3. The vehicle-mounted DVR optical lens according to claim 1, characterized in that: The object side surface of the fourth lens is convex, the image side surface of the fourth lens is convex, the object side surface of the fifth lens is concave, the image side surface of the fifth lens is concave, the object side surface of the sixth lens is convex, and the image side surface of the sixth lens is convex.

4. The vehicle-mounted DVR optical lens according to claim 1, characterized in that: The vehicle-mounted DVR optical lens satisfies the following requirements: -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 the effective focal length of the vehicle-mounted DVR optical lens and the 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.

5. The vehicle-mounted DVR optical lens according to claim 3, characterized in that: The vehicle-mounted DVR optical lens also satisfies: 60≤(FOV×f) / h≤63, wherein FOV is the field of view of the vehicle-mounted DVR optical lens and the imaging method, and h is the height of the image corresponding to the field of view.

6. The vehicle-mounted DVR optical lens and imaging method according to claim 1, characterized in that: 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, 1.86≤Nd6≤1.90, wherein 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.

7. The vehicle-mounted DVR optical lens according to claim 1, characterized in that: The vehicle-mounted DVR optical lens also satisfies: 48≤Vd1≤51, 43≤Vd2≤46, 38≤Vd3≤43, 52≤Vd4≤57, 21≤Vd5≤25, 40≤Vd6≤43, wherein 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.

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

9. The vehicle-mounted DVR optical lens according to claim 1, characterized in that: The aspheric curve equations of the fourth lens and the fifth lens satisfy the following equations:

10. A vehicle-mounted DVR optical lens imaging method, characterized in that: The method includes imaging after light passes through a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens, a sixth lens, and a filter from the object side to the imaging surface.

Images