A large wide-angle optical lens module and an in-vehicle personnel monitoring optical lens

Abstract

The application relates to the technical field of lenses, in particular to a large-aperture optical lens module, which comprises a front-end lens module, a rear-end lens module and a diaphragm between the front-end lens module and the rear-end lens module, the front-end lens module comprises a first lens, a second lens and a third lens, the rear-end lens module comprises a fourth lens, a fifth lens, a sixth lens and a plane mirror, the first lens is a convex-concave lens with a negative focal length, the second lens is a convex-concave lens with a negative focal length, the third lens is a double-convex lens with a positive focal length, the fourth lens is a double-concave lens with a negative focal length, the fifth lens is a double-convex lens with a positive focal length, and the sixth lens is a double-convex lens with a positive focal length.The large-aperture optical lens module has a larger wide angle and a wide field of view, has good imaging resolution in any environment, such as day or low-illumination environment, without needing to make any switching, can reduce the difficulty of algorithm software, and improves the accuracy.

Description

Technical Field

[0001] This invention relates to the field of lens technology, and in particular to a wide-angle optical lens module and an in-vehicle personnel monitoring optical lens. Background Technology

[0002] From the Driver Monitoring System (DMS) to the Occupancy Monitoring System (OMS), and then to the monitoring of the overall in-vehicle environment, safety is paramount. Every year, hundreds of children worldwide suffer personal safety issues due to their parents leaving them in cars, which can easily lead to irreparable tragedies.

[0003] More and more new cars launched in China are now equipped with OMS (On-Board Management) systems featuring in-cabin cameras for facial recognition, fatigue and distraction warnings. The functions of OMS include the following:

[0004] 1. Occupancy Detection: Detects the occupancy status of the seats in the first and second rows and checks the correct seat positions;

[0005] 2. Passenger facial recognition: Detecting changes in the driver's appearance;

[0006] 3. Occupant Classification: Children and adults can be classified.

[0007] 4. Body posture: Passenger posture detection;

[0008] The main technical challenge of the above functions lies in the low accuracy of various algorithms. Visual algorithms are greatly affected by ambient light and facial decorations, which can lead to inaccurate recognition results. Furthermore, the high development cost of the algorithms hinders the process of improving the accuracy of the above functions. Summary of the Invention

[0009] This invention addresses the problems of existing technologies by providing a wide-angle optical lens module. It achieves a wider angle and field of view through a front lens module and a rear lens module. Regardless of whether it is daytime or low-light environment, it has good imaging resolution without any switching. It can reduce the difficulty of algorithm software and improve its accuracy.

[0010] To address the aforementioned technical problems, the first aspect of this invention discloses a wide-angle optical lens module, comprising a front lens module, a rear lens module, and an aperture stop located between the front lens module and the rear lens module. The front lens module includes a first lens, a second lens, and a third lens arranged sequentially from the object side to the image side. The rear lens module includes a fourth lens, a fifth lens, a sixth lens, and a plane mirror arranged sequentially from the object side to the image side. The first lens is a negative focal length convex-concave lens, the second lens is a negative focal length convex-concave lens, the third lens is a positive focal length biconvex lens, the fourth lens is a negative focal length biconcave lens, the fifth lens is a positive focal length biconvex lens, and the sixth lens is a positive focal length biconvex lens.

[0011] Preferably, the first lens, the third lens, the fourth lens, and the fifth lens are all glass lenses, and the second lens and the sixth lens are both plastic aspherical lenses.

[0012] Preferably, the focal length f formed between the front lens module, the aperture, and the rear lens module satisfies: 2.05mm≤f≤2.43mm.

[0013] Preferably, the aperture (F / NO) formed between the front lens module, the aperture stop and the rear lens module satisfies: 2.00≤aperture(F / NO)≤2.35.

[0014] Preferably, the focal length f1 of the first lens is -4.25mm≤f1≤-3.66mm; the focal length f2 of the second lens is -5.15mm≤f2≤-4.70mm; the focal length f3 of the third lens is 2.85mm≤f3≤3.28mm; the focal length f4 of the fourth lens is -2.61mm≤f4≤-2.15mm; the focal length f5 of the fifth lens is 2.74mm≤f5≤3.25mm; and the focal length f6 of the sixth lens is 6.05mm≤f6≤6.44mm.

[0015] Preferably, the refractive index Nd1 of the first lens is 1.70≤Nd1≤1.86; the refractive index Nd2 of the second lens is 1.48≤Nd2≤1.57; the refractive index Nd3 of the third lens is 1.68≤Nd3≤1.88; the refractive index Nd4 of the fourth lens is 1.80≤Nd4≤1.95; the refractive index Nd5 of the fifth lens is 1.71≤Nd5≤1.86; and the refractive index Nd6 of the sixth lens is 1.48≤Nd6≤1.58.

[0016] Preferably, the distance CV1 between the first lens and the second lens is: 1.35mm ≤ CV1 ≤ 1.71mm; the distance CV2 between the second lens and the third lens is: 0.37mm ≤ CV3 ≤ 0.76mm; the distance CV3 between the third lens and the fourth lens is: 0.46mm ≤ CV3 ≤ 0.77mm; the fourth lens and the fifth lens are cemented together; and the distance CV4 between the fifth lens and the sixth lens is: 0.01mm ≤ CV4 ≤ 0.28mm.

[0017] Preferably, the interval CV1 and the interval CV2 satisfy the following condition: 2.4 ≤ CV1 / CV2 ≤ 3.55.

[0018] Preferably, the ratio of the concave sagitta h of the second lens to the aperture d satisfies: 0.29 ≤ h / d ≤ 0.42.

[0019] Another aspect of the present invention provides an in-vehicle occupant monitoring optical lens, including a lens barrel and the aforementioned wide-angle optical lens module, wherein the wide-angle optical lens module is assembled in the lens barrel.

[0020] The beneficial effects of this invention are:

[0021] This invention provides a wide-angle optical lens module, comprising a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, and a sixth lens along the optical axis. The first lens is a negative focal length convex-concave lens, the second lens is a negative focal length concave-convex lens, the third lens is a positive focal length biconvex lens, the fourth lens is a negative focal length biconcave lens, the fifth lens is a positive focal length biconvex lens, and the sixth lens is a positive focal length biconvex lens. Therefore, this invention provides a wider angle of view and a broader field of view, maintaining good imaging resolution regardless of whether it is in daylight or low-light conditions, without requiring any switching. This also reduces the complexity of the algorithm software and improves its accuracy. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the wide-angle optical lens module of the present invention;

[0023] Figure 2 This is a schematic diagram of the lens barrel structure of the present invention.

[0024] exist Figures 1 to 2 The reference numerals in the figures include:

[0025] 1-First lens, 2-Second lens, 3-Third lens, 4-Aperture, 5-Fourth lens, 6-Fifth lens, 7-Sixth lens, 8-Plane mirror, 9-Mirror tube. Detailed Implementation

[0026] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention. The present invention will be described in detail below with reference to the accompanying drawings.

[0027] Example 1:

[0028] This embodiment provides a wide-angle optical lens module, such as... Figure 1 The system includes a front lens module, a rear lens module, and an aperture 4 located between the front lens module and the rear lens module. The front lens module includes a first lens 1, a second lens 2, and a third lens 3 arranged sequentially from the object side to the image side. The rear lens module includes a fourth lens 5, a fifth lens 6, a sixth lens 7, and a plane mirror 8 arranged sequentially from the object side to the image side. The first lens 1 is a negative focal length convex-concave lens, the second lens 2 is a negative focal length concave-convex lens, the third lens 3 is a positive focal length biconvex lens, the fourth lens 5 is a negative focal length biconcave lens, the fifth lens 6 is a positive focal length biconvex lens, and the sixth lens 7 is a positive focal length biconvex lens.

[0029] Specifically, such as Figure 1 The diagram shows the structure of the optical lens module in this embodiment. A first lens 1, a second lens 2, a third lens 3, an aperture 4, a fourth lens 5, a fifth lens 6, and a sixth lens 7 are arranged sequentially along the optical axis. Through the cooperation of the front lens module and the rear lens module, this embodiment has a wider angle and a wider field of view. Regardless of whether it is daytime or a low-light environment, there is no need to make any switching, and the imaging resolution is good. This can reduce the difficulty of the algorithm software and improve its accuracy.

[0030] Optionally, in this embodiment, the first lens 1, the third lens 3, the fourth lens 5, and the fifth lens 6 are all glass lenses, and the second lens 2 and the sixth lens 7 are both plastic aspherical lenses. This ensures that the focal length of the optical lens module in this embodiment satisfies 2.05mm ≤ f ≤ 2.43mm, and the aperture (F / NO) satisfies 2.00 ≤ aperture (F / NO) ≤ 2.35. Therefore, this embodiment, while possessing a wide angle and a wide field of view, can also achieve day and night co-focusing. In daylight and low-light environments, this embodiment does not require any switching and can still achieve clear shooting. In this embodiment, the preferred focal length f (EFL) of the optical lens module is 2.20mm, the aperture (F / NO) is 2.20, the operating temperature is -40℃ to +85℃, and the image plane is 6.40mm.

[0031] Furthermore, the shapes of the lenses in this embodiment are as follows: Figure 1 As shown, the focal lengths of each lens satisfy the following conditions:

[0032] The focal length f1 of the first lens 1 is: -4.25mm≤f1≤-3.66mm;

[0033] The focal length f2 of the second lens 2 is: -5.15mm≤f2≤-4.70mm; and the ratio of the concave sagitta h of the second lens 2 to the aperture d satisfies: 0.29≤h / d≤0.42;

[0034] The focal length f3 of the third lens 3 is: 2.85mm≤f3≤3.28mm;

[0035] The focal length f4 of the fourth lens 5 is: -2.61mm≤f4≤-2.15mm;

[0036] The focal length f5 of the fifth lens 6 is: 2.74mm≤f5≤3.25mm;

[0037] The focal length f6 of the sixth lens 7 is: 6.05mm≤f6≤6.44mm;

[0038] And the spacing between each lens satisfies the following:

[0039] The distance CV1 between the first lens 1 and the second lens 2 is: 1.35mm≤CV1≤1.71mm;

[0040] The distance CV2 between the second lens 2 and the third lens 3 is: 0.37mm≤CV3≤0.76mm;

[0041] The distance CV3 between the third lens 3 and the fourth lens 5 is: 0.46mm≤CV3≤0.77mm;

[0042] The fourth lens 5 and the fifth lens 6 are cemented together;

[0043] The spacing CV4 between the fifth lens 6 and the sixth lens 7 is: 0.01mm≤CV4≤0.28mm.

[0044] Furthermore, the intervals CV1 and CV2 satisfy the following condition: 2.4 ≤ CV1 / CV2 ≤ 3.55.

[0045] The refractive indices of the lenses in this embodiment are as follows:

[0046] The refractive index Nd1 of the first lens 1 is: 1.70≤Nd1≤1.86;

[0047] The refractive index Nd2 of the second lens 2 is: 1.48≤Nd2≤1.57;

[0048] The refractive index Nd3 of the third lens 3 is: 1.68≤Nd3≤1.88;

[0049] The refractive index Nd4 of the fourth lens 5 is: 1.80≤Nd4≤1.95;

[0050] The refractive index Nd5 of the fifth lens 6 is: 1.71≤Nd5≤1.86;

[0051] The refractive index Nd6 of the sixth lens 7 is: 1.48≤Nd6≤1.58.

[0052] Each lens in this embodiment has a high refractive index and light transmittance, which can effectively improve the optical performance of the lens, thereby obtaining a wider angle and a wider field of view. Regardless of daytime or low-light conditions, it has good imaging resolution without any switching, which can reduce the difficulty of the algorithm software, improve its accuracy, and thus better detect the situation of people inside the vehicle, reducing the probability of safety accidents.

[0053] Example 2:

[0054] This embodiment provides an optical lens for monitoring occupants inside a vehicle, such as... Figure 1 and Figure 2 It includes a lens barrel 9 and a wide-angle optical lens module as described in Embodiment 1, so that the optical lens can be applied to the interior of a vehicle or even other indoor environments that require a wide angle and a wide field of view.

[0055] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the present invention without departing from the scope of the present invention are within the scope of the present invention.

Claims

1. A wide-angle optical lens module, characterized in that: It consists of a front lens module, a rear lens module, and an aperture between the front lens module and the rear lens module. The front lens module consists of a first lens, a second lens, and a third lens arranged sequentially from the object side to the image side. The rear lens module consists of a fourth lens, a fifth lens, a sixth lens, and a plane mirror arranged sequentially from the object side to the image side. The first lens is a negative focal length convex-concave lens, the second lens is a negative focal length convex-concave lens, the third lens is a positive focal length biconvex lens, the fourth lens is a negative focal length biconcave lens, the fifth lens is a positive focal length biconvex lens, and the sixth lens is a positive focal length biconvex lens. The first, third, fourth, and fifth lenses are all glass lenses, while the second and sixth lenses are both plastic aspherical lenses. The focal length f formed between the front lens module, the aperture, and the rear lens module satisfies: 2.05mm ≤ f ≤ 2.43mm; The aperture (F / NO) formed between the front lens module, the aperture stop, and the rear lens module satisfies: 2.00 ≤ aperture (F / NO) ≤ 2.35; The focal length f1 of the first lens is -4.25mm ≤ f1 ≤ -3.66mm; the focal length f2 of the second lens is -5.15mm ≤ f2 ≤ -4.70mm; the focal length f3 of the third lens is 2.85mm ≤ f3 ≤ 3.28mm; the focal length f4 of the fourth lens is -2.61mm ≤ f4 ≤ -2.15mm; the focal length f5 of the fifth lens is 2.74mm ≤ f5 ≤ 3.25mm; and the focal length f6 of the sixth lens is 6.05mm ≤ f6 ≤ 6.44mm. The refractive index Nd1 of the first lens is 1.70 ≤ Nd1 ≤ 1.86; the refractive index Nd2 of the second lens is 1.48 ≤ Nd2 ≤ 1.57; the refractive index Nd3 of the third lens is 1.68 ≤ Nd3 ≤ 1.88; the refractive index Nd4 of the fourth lens is 1.80 ≤ Nd4 ≤ 1.95; the refractive index Nd5 of the fifth lens is 1.71 ≤ Nd5 ≤ 1.86; and the refractive index Nd6 of the sixth lens is 1.48 ≤ Nd6 ≤ 1.

58. The distance CV1 between the first lens and the second lens is: 1.35mm ≤ CV1 ≤ 1.71mm; the distance CV2 between the second lens and the third lens is: 0.37mm ≤ CV3 ≤ 0.76mm; the distance CV3 between the third lens and the fourth lens is: 0.46mm ≤ CV3 ≤ 0.77mm; the fourth lens and the fifth lens are cemented together; the distance CV4 between the fifth lens and the sixth lens is: 0.01mm ≤ CV4 ≤ 0.28mm.

2. The wide-angle optical lens module according to claim 1, characterized in that: The intervals CV1 and CV2 satisfy the following condition: 2.4 ≤ CV1 / CV2 ≤ 3.

55.

3. The wide-angle optical lens module according to claim 1, characterized in that: The ratio of the concave sagitta h of the second lens to its aperture d satisfies: 0.29 ≤ h / d ≤ 0.

42.

4. An optical lens for monitoring occupants inside a vehicle, characterized in that: It comprises a lens barrel and a wide-angle optical lens module as described in any one of claims 1 to 3, wherein the wide-angle optical lens module is assembled in the lens barrel.

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