CN221149024U - Camera ranging lens group - Google Patents

Abstract

The utility model relates to a camera ranging lens group, and belongs to the technical field of optical imaging. The camera ranging lens group comprises a first lens, a diaphragm, a second lens, a third lens, a fourth lens, a fifth lens and an optical filter. The first lens, the diaphragm, the second lens, the third lens, the fourth lens, the fifth lens and the optical filter are sequentially arranged from the object side to the image side. The first lens is a convex-concave type positive focal power lens. The second lens is a convex-concave type negative focal power lens. The third lens is a convex positive focal power lens. The fourth lens is a concave-convex type negative focal power lens. The fifth lens is a convex-concave positive focal power lens. Therefore, the camera ranging lens group provided by the utility model can improve the transmittance of the lens, has the characteristics of high resolution, high relative illuminance and good imaging quality, and simultaneously meets the working environments of white light and infrared.

Description

Camera ranging lens group

Technical Field

The utility model belongs to the technical field of optical imaging, and particularly relates to a camera ranging lens group.

Background

The existing camera ranging technology mainly scans a target object point by a 3D laser sensor principle, and an image obtained by the point by point scanning mode has the problems of low resolution and low imaging quality. The principle of TOF ranging is to obtain the distance of an object by continuously sending light pulses to the object, then receiving the light returned from the object with a sensor, and detecting the flight (round trip) time of the light pulses. The principle of TOF technology ranging is basically similar to that of a 3D laser sensor, but TOF technology ranging is used for simultaneously obtaining depth (distance) information of the whole image, so that the TOF technology ranging has the characteristics of high transmittance, high resolution, high relative illuminance, good imaging quality and the like, and simultaneously meets the working environments of white light and infrared. The TOF ranging technology can be applied to the fields of intelligent cabins, industrial identification and detection and the like.

Disclosure of utility model

The utility model provides a camera ranging lens group which is used for solving the technical problems of low transmission, low resolution and small shooting angle of the existing camera ranging lens.

In order to achieve the above purpose, the present utility model is realized by the following technical scheme: the camera ranging lens group comprises a first lens, a diaphragm, a second lens, a third lens, a fourth lens, a fifth lens and an optical filter. The first lens, the diaphragm, the second lens, the third lens, the fourth lens, the fifth lens and the optical filter are sequentially arranged from the object side to the image side. The focal length of the first lens is f1, and the first lens is a convex-concave positive focal power lens. The focal length of the second lens is f2, and the second lens is a convex-concave type negative focal power lens. The focal length of the third lens is f3, and the third lens is a convex positive focal power lens. The focal length of the fourth lens is f4, and the fourth lens is a concave-convex negative focal power lens. The focal length of the fifth lens is f5, and the fifth lens is a convex-concave positive focal power lens.

Optionally, f1 and f2 satisfy-2.ltoreq.f1/f2.ltoreq.0.5. The f2 and the f3 satisfy that the f2/f3 is less than or equal to-3 and less than or equal to-1.5. The f3 and the f4 satisfy that the f3/f4 is less than or equal to-1 and less than or equal to-0.5. The f4 and the f5 satisfy that the f4/f5 is less than or equal to-2 and less than or equal to-1. And f5 and f1 are 0-0.ltoreq.f5/f1-0.5.

Alternatively, in the case where the wavelength of the light wave is 589.3nm, the refractive index of the first lens is Nd1, and Nd1 satisfies 1.5.ltoreq.Nd1.ltoreq.1.7. In the case of a wavelength of 589.3nm, the refractive index of the second lens is Nd2, and Nd2 satisfies 1.5.ltoreq.Nd2.ltoreq.1.7. In the case of a wavelength of 589.3nm, the refractive index of the third lens is Nd3, and Nd3 satisfies 1.5.ltoreq.Nd3.ltoreq.1.7. In the case of a wavelength of 589.3nm, the refractive index of the fourth lens is Nd4, and Nd4 satisfies 1.5.ltoreq.Nd4.ltoreq.1.7. In the case of a wavelength of 589.3nm, the refractive index of the fifth lens is Nd5, and Nd5 satisfies 1.5.ltoreq.Nd5.ltoreq.1.7.

Alternatively, in the case where the wavelength of the light wave is 589.3nm, the Abbe number of the first lens is Vd1, and Vd1 satisfies 40.ltoreq.Vd1.ltoreq.60. And under the condition that the wavelength of the light wave is 589.3nm, the Abbe number of the second lens is Vd2, and Vd2 satisfies that Vd2 is more than or equal to 15 and less than or equal to 35. In the case that the wavelength of the light wave is 589.3nm, the Abbe number of the third lens is Vd3, and Vd3 satisfies that Vd3 is more than or equal to 40 and less than or equal to 60. And under the condition that the wavelength of the light wave is 589.3nm, the Abbe number of the fourth lens is Vd4, and the Vd4 satisfies 15-35 Vd 4. In the case of the wavelength of the light wave being 589.3nm, the Abbe number of the fifth lens is Vd5, and Vd5 satisfies 40.ltoreq.Vd3.ltoreq.60.

Optionally, the first lens is a spherical glass lens, and the second lens, the third lens, the fourth lens and the fifth lens are all aspheric resin lenses.

Optionally, the outer surfaces of the first lens, the second lens, the third lens, the fourth lens and the fifth lens are all provided with a coating film.

Optionally, the aperture value of the camera ranging lens group is F/NO, and the F/NO is more than or equal to 2.3 and less than or equal to 4.7.

Optionally, the total optical length TTL of the camera ranging lens group is less than or equal to 11mm.

Optionally, the image height of the camera ranging lens group is more than or equal to 6mm.

Optionally, the focal length of the camera ranging lens group is EFL, and the EFL satisfies 1 < TTL/EFL < 2.

According to the technical scheme, the camera ranging lens group provided by the utility model has the beneficial effects that:

The utility model provides a camera ranging lens group which comprises a first lens, a diaphragm, a second lens, a third lens, a fourth lens, a fifth lens and an optical filter. The first lens, the diaphragm, the second lens, the third lens, the fourth lens, the fifth lens and the optical filter are sequentially arranged from the object side to the image side. The focal length of the first lens is f1, and the first lens is a convex-concave type positive focal power lens. The focal length of the second lens is f2, and the second lens is a convex-concave type negative focal power lens. The focal length of the third lens is f3, and the third lens is a convex positive focal power lens. The focal length of the fourth lens is f4, and the fourth lens is a concave-convex negative focal power lens. The focal length of the fifth lens is f5, and the fifth lens is a convex-concave positive focal power lens.

Through the structure, the camera ranging lens group provided by the utility model overcomes the defects of the prior art, and has the characteristics of high transmittance, high resolution, high relative illuminance and good imaging quality, and simultaneously meets the working environments of white light and infrared.

Drawings

In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a camera ranging lens set according to an embodiment of the present utility model;

fig. 2 to fig. 4 are optical transfer function resolution graphs of a camera ranging lens set according to an embodiment of the present utility model;

fig. 5 to 14 are field diagrams and distortion diagrams of a camera ranging lens set according to an embodiment of the present utility model;

fig. 15 is a diagram illustrating relative illumination of a ranging lens set of a camera according to an embodiment of the present utility model.

In the figure: 1-a first lens; 2-a second lens; 3-a third lens; 4-a fourth lens; 5-a fifth lens; 6-diaphragm; 7-an optical filter.

Detailed Description

Embodiments of the present application will be described in detail below with reference to the accompanying drawings.

In the description of the present application, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application.

The terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

Examples

The existing camera ranging technology mainly scans a target object point by a 3D laser sensor principle, and an image obtained by the point by point scanning mode has the problems of low resolution and low imaging quality.

In order to solve the above technical problem, the present embodiment provides a camera ranging lens group including a first lens 1, a stop 6, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, and an optical filter 7. The first lens 1, the stop 6, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, and the filter 7 are sequentially arranged along the object side to the image side. The focal length of the first lens 1 is f1, and the first lens 1 is a convex-concave positive power lens. The focal length of the second lens 2 is f2, and the second lens 2 is a convex-concave type negative power lens. The focal length of the third lens 3 is f3, and the third lens 3 is a convex positive power lens. The focal length of the fourth lens 4 is f4, and the fourth lens 4 is a concave-convex negative power lens. The focal length of the fifth lens 5 is f5, and the fifth lens 5 is a convex-concave positive power lens.

Through the structure, the camera ranging lens group provided by the embodiment overcomes the defects of the prior art and provides the characteristics of high transmittance, high resolution, high relative illuminance and good imaging quality, and simultaneously meets the working environments of white light and infrared.

On the basis, f1 and f2 satisfy-2 is less than or equal to f1/f2 is less than or equal to-0.5. f2 and f3 satisfy-3 is less than or equal to-1.5 and f2/f3 is less than or equal to-3. f3 and f4 satisfy-1.ltoreq.f3/f4.ltoreq.0.5. f4 and f5 satisfy-2 is less than or equal to f4/f5 is less than or equal to-1. f5 and f1 satisfy 0.ltoreq.f5/f1.ltoreq.0.5. The focal length of a lens refers to the degree to which light rays converge or diverge after passing through the lens, and the size of the focal length is related to the shape and refractive index of the lens. For thin lenses, the focal length may be calculated from the radius of curvature and refractive index of the lens.

On the basis of the above, in the case where the wavelength of the light wave is 589.3nm, the refractive index of the first lens 1 is Nd1, nd1 satisfies 1.5.ltoreq.nd1.ltoreq.1.7. In the case where the wavelength of the light wave is 589.3nm, the refractive index of the second lens 2 is Nd2, and Nd2 satisfies 1.5.ltoreq.Nd2.ltoreq.1.7. When the wavelength of the light wave is 589.3nm, the refractive index of the third lens 3 is Nd3, and Nd3 satisfies 1.5.ltoreq.Nd3.ltoreq.1.7. When the wavelength of the light wave is 589.3nm, the refractive index of the fourth lens 4 is Nd4, and Nd4 satisfies 1.5.ltoreq.Nd4.ltoreq.1.7. When the wavelength of the light wave is 589.3nm, the refractive index of the fifth lens 5 is Nd5, and Nd5 satisfies 1.5.ltoreq.Nd5.ltoreq.1.7.

The light wave having a wavelength of 589.3nm is generally referred to as D light or ordinary light. The refractive index of an optical wave refers to the ratio of the speeds of light propagating in different media. The refractive index is generally denoted by the symbol n. When light propagates from one medium to another medium having a different refractive index, the direction of propagation of the light is deflected. This is caused by the different propagation speeds of light in different media.

The refractive index is calculated as

n＝c/v

Where n is the refractive index, c is the speed of light in vacuum (about 3.00 x 10-8 m/s), and v is the speed of light propagation in the medium. The magnitude of the refractive index determines the propagation speed and the degree of change in propagation direction of light in the medium. When light propagates from a medium with a higher refractive index to a medium with a lower refractive index, the light rays are deflected towards the normal direction; conversely, when light propagates from a medium with a lower refractive index into a medium with a higher refractive index, the light rays are deflected away from normal.

On the basis of the above, in the case where the wavelength of the light wave is 589.3nm, the Abbe number of the first lens 1 is Vd1, vd1 satisfies 40.ltoreq.Vd1.ltoreq.60. In the case where the wavelength of the light wave is 589.3nm, the Abbe number of the second lens 2 is Vd2, and Vd2 satisfies 15.ltoreq.Vd2.ltoreq.35. When the wavelength of the light wave is 589.3nm, the Abbe number of the third lens 3 is Vd3, and Vd3 satisfies 40.ltoreq.Vd3.ltoreq.60. In the case where the wavelength of the light wave is 589.3nm, the Abbe number of the fourth lens 4 is Vd4, and Vd4 satisfies 15.ltoreq.Vd4.ltoreq.35. When the wavelength of the light wave is 589.3nm, the Abbe number of the fifth lens 5 is Vd5, and Vd5 satisfies 40.ltoreq.Vd3.ltoreq.60.

The abbe number of the light wave is a physical quantity used to describe the dispersion property of the material. The larger the abbe number, the smaller the dispersion of the material, i.e., the smaller the refractive index difference in the material for light of different wavelengths. Conversely, a smaller abbe number indicates a greater material dispersion and a greater difference in refractive index between different wavelengths of light.

In addition to the above, the first lens 1 is a spherical glass lens, and the second lens 2, the third lens 3, the fourth lens 4, and the fifth lens 5 are aspherical resin lenses.

It should be noted that spherical glass lenses may be used to focus light or change the direction of propagation of light. Due to the limitation of the spherical shape, spherical glass lenses may introduce some aberrations, such as spherical aberration, astigmatism, etc., during imaging. The aspherical resin lens is a relatively new type of optical lens, and the surface curvature of the aspherical resin lens can be freely designed according to specific requirements to minimize aberrations and improve imaging quality. The design of the aspherical resin lenses can be optimized according to optical requirements to achieve better optical performance and imaging quality. Because the aspherical resin lens has a higher degree of freedom in design, aberrations such as spherical aberration, astigmatism, etc. can be corrected better, and thus in some applications, the aspherical resin lens can provide a better imaging effect.

On the basis of the above, the outer surfaces of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4 and the fifth lens 5 are all provided with plating films.

It should be noted that, the plating films in the camera ranging lens group generally include an anti-reflection plating film and an anti-reflection plating film. The anti-reflection coating is used for reducing the reflection of the surface of the lens group and improving the transmittance. This helps to reduce scattering and loss of light inside the lens group, improving the definition and brightness of imaging. The anti-reflection coating film generally adopts a multi-layer film structure, and the thickness and the refractive index of each layer of film are precisely controlled, so that light rays interfere between different layers, and reflection is reduced. The anti-reflection coating is used for reducing reflection on the surface of the lens group and improving the anti-reflection capability. The lens group can reduce light reflection on the surface of the lens group, avoid interference and loss of light inside the lens group, and improve imaging contrast and detail definition. The anti-reflection coating film generally adopts a multi-layer film structure similar to the anti-reflection coating film, but more emphasis is placed on reducing the reflection on the surface of the lens group.

On the basis, the aperture value of the camera ranging lens group is F/NO, and F/NO is more than or equal to 2.3 and less than or equal to 4.7. The aperture value is a relative value (reciprocal of relative aperture) obtained by the focal length of the lens and the lens light-passing diameter.

On the basis of the above, the total optical length TTL of the camera ranging lens group is less than or equal to 11mm.

On the basis of the above, the image height of the camera ranging lens group is more than or equal to 6mm.

On the basis of the above, the focal length of the camera ranging lens group is EFL, and the EFL satisfies 1 < TTL/EFL < 2.

In summary, fig. 2 to 4 are graphs of optical transfer function solutions according to the present utility model, wherein the abscissa is the line logarithm and the ordinate is the modulation value. The line pair number is 84lp/mm, and the modulation value is more than 60%. The line pair number is a method of measuring the resolution of a lens and describes the number of lines that can be resolved per unit length of millimeter. The modulation value is an index for measuring the resolution of the lens. It represents the ability of the optical system to pass details of the input signal into the output image.

Fig. 6, 8, 10, 12 and 14 are diagrams of lens distortion performance, where the abscissa is distortion value and the ordinate is image height value; distortion value of 0% < 0.5% under full field.

Fig. 5, 7, 9, 11 and 13 are schematic views of lens field curves, wherein the abscissa is field values and the ordinate is image height values; the curvature of field is within 0.04mm over the full field of view. The optical structure is simple, the resolution is high, the distortion is small, and the relative illumination is high.

Fig. 15 is a graph of relative illuminance, which is the ratio of the central illuminance to the peripheral illuminance, of an object or an illuminated surface illuminated by a light source according to the present utility model. Too low a contrast level is manifested by a brighter center of the image and darker surroundings.

In summary, as shown in the optical analysis chart, the optical system has high imaging resolution, small distortion, high transmittance and wide shooting angle.

As can be seen from the above, in the camera ranging lens set provided by the present utility model, the first lens 1 is a spherical glass lens, and the second lens 2, the third lens 3, the fourth lens 4 and the fifth lens 5 are all aspheric resin lenses. The requirements of imaging definition and color good performance of the lens are met, and meanwhile, the lens is simpler and more convenient and has good light transmittance; the lens adopts professional optical resin and glass materials, so that the temperature drift change is minimized by reasonably setting the curvature radius and the center thickness of the lens in the working environment of-40-80 ℃ and the temperature change has no influence on imaging pixels of an imaging system basically. Therefore, the problems of low transmittance, low resolution, low relative illuminance and poor imaging quality in the prior art are solved.

The above description is merely an embodiment of the present utility model, but the scope of the present utility model is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present utility model, and it is intended to cover the scope of the present utility model. Therefore, the protection scope of the present utility model shall be subject to the protection scope of the claims.

Claims (10)

1. Camera ranging lens group, its characterized in that includes:

A first lens (1), a diaphragm (6), a second lens (2), a third lens (3), a fourth lens (4), a fifth lens (5) and an optical filter (7) which are sequentially arranged from an object side to an image side;

The focal length of the first lens (1) is f1, and the first lens (1) is a convex-concave positive focal power lens;

The focal length of the second lens (2) is f2, and the second lens (2) is a convex-concave negative focal power lens;

The focal length of the third lens (3) is f3, and the third lens (3) is a convex positive focal power lens;

The focal length of the fourth lens (4) is f4, and the fourth lens (4) is a concave-convex negative focal power lens;

the focal length of the fifth lens (5) is f5, and the fifth lens (5) is a convex-concave positive focal power lens.

2. The camera rangefinder lens package of claim 1 wherein the f1 and the f2 satisfy-2 +.f1/f2 +.0.5;

The f2 and the f3 satisfy that the f2/f3 is less than or equal to-3 and less than or equal to-1.5;

The f3 and the f4 satisfy that the f3/f4 is less than or equal to-1 and less than or equal to-0.5;

The f4 and the f5 satisfy that the f4/f5 is less than or equal to-2 and less than or equal to-1;

and f5 and f1 are 0-0.ltoreq.f5/f1-0.5.

3. The camera ranging lens group according to claim 1, wherein the refractive index of the first lens (1) is Nd1 at a wavelength of 589.3nm of the light wave, the Nd1 satisfying 1.5.ltoreq.nd1.ltoreq.1.7;

In the case of a wavelength of 589.3nm of the light wave, the refractive index of the second lens (2) is Nd2, and Nd2 satisfies 1.5-Nd 2-1.7;

In the case of a wavelength of 589.3nm of the light wave, the refractive index of the third lens (3) is Nd3, and Nd3 satisfies 1.5-1.7;

In the case of a wavelength of 589.3nm of the light wave, the refractive index of the fourth lens (4) is Nd4, and Nd4 satisfies 1.5-Nd 4-1.7;

At a wavelength of 589.3nm, the refractive index of the fifth lens (5) is Nd5, and Nd5 satisfies 1.5.ltoreq.Nd5.ltoreq.1.7.

4. The camera ranging lens group according to claim 1, wherein the abbe number of the first lens (1) is Vd1 in the case where the wavelength of the light wave is 589.3nm, the Vd1 satisfying 40.ltoreq.vd1.ltoreq.60;

In the case that the wavelength of the light wave is 589.3nm, the Abbe number of the second lens (2) is Vd2, and the Vd2 satisfies 15-35 Vd 2;

In the case that the wavelength of the light wave is 589.3nm, the Abbe number of the third lens (3) is Vd3, and Vd3 satisfies 40-Vd 3-60;

In the case that the wavelength of the light wave is 589.3nm, the Abbe number of the fourth lens (4) is Vd4, and the Vd4 satisfies 15-35 Vd 4;

In the case of a wavelength of 589.3nm of the light wave, the Abbe number of the fifth lens (5) is Vd5, and Vd5 satisfies 40.ltoreq.Vd3.ltoreq.60.

5. The camera ranging lens set according to claim 1, wherein the first lens (1) is a spherical glass lens, and the second lens (2), the third lens (3), the fourth lens (4) and the fifth lens (5) are all aspherical resin lenses.

6. The camera ranging lens group according to claim 1, wherein outer surfaces of the first lens (1), the second lens (2), the third lens (3), the fourth lens (4) and the fifth lens (5) are each provided with a plating film.

7. The camera rangefinder lens group of claim 1 having an aperture value of F/NO that satisfies 2.3 ∈f/NO ∈4.7.

8. The camera rangefinder lens package of claim 1 wherein the overall optical length TTL of the camera rangefinder lens package is less than or equal to 11mm.

9. The camera rangefinder lens package of claim 1 wherein the camera rangefinder lens package has an image height of ≡6mm.

10. The camera rangefinder lens assembly of claim 8 wherein the focal length of the camera rangefinder lens assembly is EFL, the EFL satisfying 1 < TTL/EFL < 2.