A large-field-of-view, high-pixel optical system and a mobile phone camera module using the optical system

Abstract

The invention discloses a large-field-of-view, high-pixel optical system and a mobile phone camera module using the optical system. The optical system is a five-piece aspherical structure, comprising a first lens, a second lens, a third lens, a fourth lens and a fifth lens arranged in sequence from the object side to the image side, the first lens is a convex lens, the second lens is a concave lens, and the third lens, the fourth lens and the fifth lens are anti-curved curved lenses. Due to the special design of the aspherical profile shape of the optical system and the reasonable setting of the refractive index of each piece material, the large image field and high-pixel design requirements of the optical system with an image plane diagonal length H between 7.80mm-10.50mm are achieved, thereby increasing the overall brightness of the optical system and reducing the production cost. The mobile phone camera module using the optical system adopts a deformed elastic body embedded positioning structure to ensure the stability of shooting resolution and improve the assembly yield of the camera module.

Description

Technical Field

[0001] The present invention relates to the technical field of mobile phone camera modules, and in particular to a large-field-of-view, high-pixel optical system and a mobile phone camera module using the optical system. Background Art

[0002] The existing mobile phone camera modules with more than 40 million pixels are all large-field-of-view camera modules with relatively large sensor areas, generally larger than 1 / 2.5” color CMOS sensors. In order to improve the image quality, most camera module manufacturers generally design the camera lens into a six-piece structure with six aspherical surfaces or a structure with seven or more aspherical surfaces. In this way, various aberrations can be corrected better, and the modulation transfer function (MTF) that determines the clarity of the camera module can meet the design requirements.

[0003] The common problem of existing mobile phone camera modules with a large field of view of more than 40 million pixels is that due to the large number of plastic lenses, the transmittance of the overall camera module is relatively poor. Since the transmittance of each plastic lens is below 95%, when six or seven plastic lenses are combined, the transmittance of the entire camera module is less than 75%, and the light passing through the entire camera module is relatively dark. In addition, since each surface of the lens is aspherical, it is particularly sensitive to assembly tolerances. Any tilt, eccentricity, air spacing and thickness errors caused during lens assembly, as well as shrinkage errors, surface errors or Yass caused by injection molding of the lens itself, will directly cause ghosting or blurring of the camera module, resulting in a low yield rate of finished optical lenses.

[0004] There are currently more than 40 million pixels of large field of view mobile phone camera modules, Figure 1The structure of a traditional six-piece mobile phone camera module is shown. The structure of a traditional six-piece mobile phone camera module is generally as follows: the first four lenses generally use high and low refractive index material components alternately, while the last two lenses use low refractive index, high dispersion coefficient material components, that is, its first lens 100, third lens 300, fifth lens 500 and sixth lens 600 generally use low refractive index, high dispersion coefficient optical plastic material components, generally their refractive index nd is less than 1.59, and their dispersion coefficient vd is greater than 55, while the second lens 200 and the fourth lens 400 are usually high refractive index, low dispersion coefficient optical plastic material components, generally their refractive index nd is greater than 1.60, and their dispersion coefficient vd is less than 30. For the assembly of lenses, black light-absorbing Mylar sheets are generally used for spacing at locations with relatively thin gaps, such as a first Mylar sheet 700 is installed between the flanges of the first lens 100 and the second lens 200, a second Mylar sheet 800 is installed between the flanges of the second lens 200 and the third lens 300, and a third Mylar sheet 900 is installed between the flanges of the third lens 300 and the fourth lens 400. For locations with relatively thick gaps, black light-absorbing spacers are used for spacing, such as a first spacer ring 1000 is installed between the flanges of the fourth lens 400 and the fifth lens 500, and a second spacer ring 1100 is installed between the flanges of the fifth lens 500 and the sixth lens 600, so as to eliminate stray light generated at the flange edges of the lenses.

[0005] This structure is a common structure for mobile phone camera modules with a large field of view of more than 40 million pixels on the market. It can obtain a clearer image, but because all lenses are plastic or glass aspherical surfaces, they are more sensitive. When assembling, the eccentricity and tilt, as well as other assembly tolerances are particularly strict. The positioning and mutual nesting between lenses are generally controlled by a step with an inclination of 20°-30° set on the flange edge of the lens, such as the first step 110, the second step 210 and the third step 310 set on the flange edge of adjacent lenses. The accuracy of the step has a crucial influence on the assembly accuracy of the lens. Since the lens is a hard plastic component, there will be shrinkage, burrs and draft angle errors during the injection molding of the lens, which will directly affect the accuracy of the step on the flange edge. When the mating contact surfaces of the two lenses are in an interference fit state, because it is a hard contact state, it is easy to fail to install to the set position, which will cause one of the lenses to tilt or the air gap between the two to become larger, reducing the imaging resolution, low production yield, increased production costs and reduced quality. Summary of the invention

[0006] The purpose of the present invention is to overcome the above-mentioned defects in the prior art and to provide a large field of view, high pixel optical system which uses only five lenses to achieve the design requirements of large image field and high pixel with an image plane diagonal length H between 7.80mm and 10.50mm, reduce the production cost, and a deformable elastomer interlocking positioning structure and a mobile phone camera module using the optical system.

[0007] To achieve the above object, the present invention provides a large field of view, high pixel optical system, the optical system is a five-piece aspherical structure, including a first lens, a second lens, a third lens, a fourth lens and a fifth lens arranged in sequence from the object side to the image side, the first lens is a convex lens, the second lens is a concave lens, the third lens, the fourth lens and the fifth lens are anti-curved curved lenses, the second lens and the third lens are optical material components with a refractive index nd between 1.62-1.80 and a dispersion coefficient vd less than 35, the first lens is a refractive index nd less than 1.60, the dispersion coefficient vd is less than 35, The optical material component has a number vd greater than 20, the fourth lens and the fifth lens are optical material components with a refractive index nd between 1.50-1.80 and a dispersion coefficient vd between 20-70, the third lens has a second curved surface of the third lens, the curvature direction of the middle concave part of the surface profile of the second curved surface of the third lens is opposite to the curvature direction of the edge of the outer field of view, the edge chief ray angle θ between the third lens and the fourth lens is between 59° and 75°, and the image plane diagonal length H of the optical system is between 7.80mm-10.50mm.

[0008] Preferably, the first lens has a first surface of the first lens, and the radius of curvature of the first surface of the first lens is between 1.2 mm and 1.85 mm.

[0009] Preferably, the half field angle α of the optical system is between 20° and 85°.

[0010] Preferably, the total optical length L of the optical system is between 4.2 mm and 7.5 mm.

[0011] Preferably, the total number of image plane pixels of the optical system is greater than 40 million pixels.

[0012] Preferably, the first lens, the second lens, the third lens, the fourth lens and the fifth lens of the optical system are optical resin material components, liquid silicone material components, glass material components, quartz components, sapphire material components or transparent optical ceramic material components.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] The present invention provides an optical system, which is a five-piece aspherical structure, including a first lens, a second lens, a third lens, a fourth lens and a fifth lens arranged in sequence from the object side to the image side, the first lens is a convex lens, the second lens is a concave lens, the third lens, the fourth lens and the fifth lens are anti-curved curved lenses, the second lens and the third lens are optical material components with a refractive index nd between 1.62-1.80 and a dispersion coefficient vd less than 35, the first lens is an optical material component with a refractive index nd less than 1.60 and a dispersion coefficient vd greater than 20, the fourth lens and the fifth lens are optical material components with a refractive index nd between 1.50-1.80 and a dispersion coefficient vd between 20-70, the edge chief ray angle θ between the third lens and the fourth lens is between 59° and 75°, and the image plane diagonal length H of the optical system is between 7.80 mm and 8.5 mm. 10.50mm, since the second lens and the third lens are optical material components with a refractive index nd between 1.62-1.80 and a dispersion coefficient vd less than 35, and since the edge principal ray angle θ between the second lens and the fourth lens is between 59° and 75° through the special design of the aspheric profile shape of the optical system and the reasonable setting of the refractive index of each lens material, a large-angle extension of the principal ray and the edge principal ray to each field of view outside the axis is provided, and the large image field and high pixel design requirements of the image plane diagonal length H of the optical system between 7.80mm-10.50mm are achieved, so that the total optical length L of the optical system is further shortened, and the number of lenses is reduced by at least one lens compared with the prior art, and only five lenses are needed. Due to the reduction in the number of lenses, the light transmittance of the optical system is improved, the overall brightness of the optical system is improved, and the production cost of the optical system is reduced.

[0015] The present invention also provides a mobile phone camera module, including a shell, and also including an optical system installed in the shell, the rear of the optical system is equipped with an infrared cutoff filter, the rear of the infrared cutoff filter is equipped with an image sensor, and the optical system is equipped with at least one deformable elastic body interlocking positioning structure.

[0016] Preferably, the deformable elastomer interlocking positioning structure includes a deformable first elastomer installed on the flange edge of the first lens, and a deformable second elastomer installed on the flange edge of the second lens. The flange edge of the second lens is provided with a first interlocking positioning groove that matches the deformed first elastomer, and the first elastomer is tightly fitted with the first interlocking positioning groove. The flange edge of the third lens is provided with a second interlocking positioning groove that matches the deformed second elastomer, and the second elastomer is tightly fitted with the second interlocking positioning groove.

[0017] Preferably, the first elastomer and the second elastomer are hump-shaped structures with protrusions on both sides and a concave middle. The number of protrusions of the hump-shaped structure is two or more, which are arranged in a point-like, ring-like or polygonal shape. The cross-sectional profile of the protrusions of the hump-shaped structure is that the two outer sides are inclined straight lines or circular arc curves, and the middle is connected by a transitional circular arc. The first interlocking positioning groove and the second interlocking positioning groove are concave positioning groove structures. The cross-sectional profile of the concave positioning groove structure is an inverted trapezoid, a V-shape or a U-shape. The hump-shaped structure and the concave positioning groove structure are arranged in correspondence with each other. The order in which the hump-shaped structure and the concave positioning groove structure are arranged is a hump-shaped structure on one side and a concave positioning groove structure on the other side, or a concave positioning groove structure on one side and a hump-shaped structure on the other side.

[0018] Preferably, the first elastomer and the first lens are a single-piece plastic component made of the same material or a double-piece plastic component made of different materials, and the second elastomer and the second lens are a single-piece plastic component made of the same material or a double-piece plastic component made of different materials.

[0019] Preferably, the first elastomer and the first lens are made of the same material and are molded at one time, and the second elastomer and the second lens are made of the same material and are molded at one time.

[0020] Preferably, the first elastomer and the first lens are made of different materials, the first elastomer is a flexible liquid silicone component or a silicone rubber component, the second elastomer and the second lens are made of different materials, the second elastomer is a flexible liquid silicone component or a silicone rubber component, and the first elastomer and the second elastomer are formed by double-material molding, in-mold molding, or injection molding followed by 3D printing silicone molding.

[0021] Preferably, a first Mylar sheet is installed between the flanges of the first lens and the second lens, a second Mylar sheet is installed between the flanges of the second lens and the third lens, a third Mylar sheet is installed between the flanges of the third lens and the fourth lens, and a spacer ring is installed between the flanges of the fourth lens and the fifth lens.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention is provided with at least one deformable elastic body interlocking positioning structure. During the assembly process, the elastic body is appropriately deformed along the radial and axial directions because the concave positioning groove structure has an avoidance space or the elastic body has a hump-shaped structure with convex sides and concave in the middle, so as to automatically optimize the stability of the interlocking between the front and rear lenses. When the two lenses are in an interference fit state when interlocking, the interlocking positioning structure with the deformable elastic body has the function of automatically balancing the assembly fit between the lenses, so that the front and rear lenses have a certain avoidance space and elasticity when they cooperate with each other, and under the action of the assembly force, the most precise and stable fit is automatically achieved, so as to avoid abnormal problems such as lens tilt or excessive air gap during the assembly process, and the eccentricity error, inclination error and thickness error introduced during the lens assembly are controlled to a minimum through the coordination and adjustment of the elastic body and the avoidance space, so that the concentricity of the assembly between the lenses reaches a precise positioning of less than the tolerance of ±0.0015mm, thereby improving the assembly quality of the camera module, ensuring the stability of the shooting resolution, and greatly improving the yield rate of the camera module assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 This is a cross-sectional view of a traditional large-field-of-view, high-pixel six-element mobile phone camera module;

[0026] Figure 2 This is a schematic diagram of the decomposed structure of a large field of view and high pixel optical system according to Embodiment 1 of the present invention;

[0027] Figure 3 is a cross-sectional view of a large field of view and high pixel optical system according to a first embodiment of the present invention;

[0028] Figure 4 is a cross-sectional view of a first lens of a large-field-of-view, high-pixel optical system according to a first embodiment of the present invention;

[0029] Figure 5 is a cross-sectional view of a second lens of a large-field-of-view, high-pixel optical system according to a first embodiment of the present invention;

[0030] Figure 6 is a cross-sectional view of a third lens of a large-field-of-view, high-pixel optical system according to Embodiment 1 of the present invention;

[0031] Figure 7is a cross-sectional view of a fourth lens of a large-field-of-view, high-pixel optical system according to a first embodiment of the present invention;

[0032] Figure 8 is a cross-sectional view of a fifth lens of a large-field-of-view, high-pixel optical system according to a first embodiment of the present invention;

[0033] Fig. 9 This is a light path diagram of a large field of view, high pixel optical system according to embodiment 1 of the present invention;

[0034] Fig.10 is a modulation transfer function of a large field of view and high pixel optical system according to embodiment 1 of the present invention;

[0035] Fig.11 This is a dot matrix diagram of a large field of view, high pixel optical system according to embodiment 1 of the present invention;

[0036] Fig.12 This is an image plane grid diagram of a large field of view, high pixel optical system according to Embodiment 1 of the present invention;

[0037] Fig.13 is the relative illumination of a large field of view and high pixel optical system according to embodiment 1 of the present invention;

[0038] Fig.14 This is a stereoscopic diagram of a mobile phone camera module using a large field of view and high pixel optical system according to a second embodiment of the present invention;

[0039] Fig.15 This is an exploded view of a mobile phone camera module using a large field of view and high pixel optical system according to a second embodiment of the present invention;

[0040] Fig.16 It is a cross-sectional view of a mobile phone camera module using a large field of view and high pixel optical system according to a second embodiment of the present invention.

[0041] Included in the figure are:

[0042] 1-housing, 2-optical system, 3-infrared cut-off filter, 21-first lens, 22-first Mylar sheet, 23-second lens, 24-second Mylar sheet, 25-third lens, 26-third Mylar sheet, 27-fourth lens, 28-spacer, 29-fifth lens, 212-first elastomer, 213-first surface of the first lens, 214-second surface of the first lens, 231-first fitting positioning groove, 232-second elastomer, 233-first surface of the second lens, 234-second surface of the second lens, 251-second fitting positioning groove, 253-first surface of the third lens, 254-second surface of the third lens, 273-first surface of the fourth lens, 274-second surface of the fourth lens, 293-first surface of the fifth lens, 294-second surface of the fifth lens, 33-first surface of the infrared cut-off filter, 34-second surface of the infrared cut-off filter, 4-image sensor, 5-deformed elastic fitting positioning structure. DETAILED DESCRIPTION

[0043] The technical scheme in this embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in this embodiment of the present invention. Obviously, the described embodiment is one embodiment of the present invention, not all embodiments of the present invention. Based on this embodiment of the present invention, all other embodiments of the present invention obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] Embodiment 1

[0045] Please refer to Figures 2 to 8The present invention provides a large field of view, high pixel optical system, the optical system 2 is a five-piece aspherical structure, including a first lens 21, a second lens 23, a third lens 25, a fourth lens 27 and a fifth lens 29 arranged in sequence from the object side to the image side, the first lens 21 is a convex lens, the second lens 23 is a concave lens, the third lens 25, the fourth lens 27 and the fifth lens 28 are anti-curved curved surface lenses, the anti-curved curved surface lens refers to a lens in which the direction of curvature in the middle of the curved surface is opposite to the direction of curvature at the edge, the second lens 23 and the third lens 25 are optical material components with a refractive index nd between 1.62-1.80 and a dispersion coefficient vd less than 35, and the second lens 23 and the third lens 25 can be two optical material components with different refractive indices The components may also be two optical material components with the same refractive index, the first lens 21 is an optical material component with a refractive index nd less than 1.60 and a dispersion coefficient vd greater than 20, the fourth lens 27 and the fifth lens 29 are optical material components with a refractive index nd between 1.50-1.80 and a dispersion coefficient vd between 20-70, the third lens 25 has a second curved surface 254 of the third lens, the curvature direction of the middle concave part of the surface contour of the second curved surface 254 of the third lens is opposite to the curvature direction of the edge of the outer field of view, the edge principal ray angle θ between the third lens 25 and the fourth lens 27 is between 59° and 75°, and the image plane diagonal length H of the optical system 2 is between 7.80mm-10.50mm.

[0046] Due to the special design of the aspheric profile shape of the optical system and the reasonable setting of the refractive index of each lens material, the edge principal ray angle θ between the third lens and the fourth lens is between 59° and 75°, providing an angle of the principal ray and the edge principal ray of each field of view extended to the outside axis at a large angle, achieving the large image field and high pixel design requirements of the image plane diagonal length H of the optical system between 7.80mm-10.50mm, so that the total optical length L of the optical system is further shortened, and the number of lenses is reduced by at least one lens compared with the prior art, and only five lenses are needed. Due to the reduction in the number of lenses, the light transmittance of the optical system is improved, the overall brightness of the optical system is improved, and the production cost of the optical system is reduced.

[0047] The first lens 21 has a first surface 213 of the first lens, and the curvature radius of the first surface 213 of the first lens is between 1.2 mm and 1.85 mm.

[0048] The half-viewing angle α of the optical system 2 is between 20° and 85°, and in the first embodiment, the preferred half-viewing angle is 39.3°.

[0049] The total optical length L of the optical system 2 is between 4.2 mm and 7.5 mm.

[0050] The total number of image plane pixels of the optical system 2 is more than 40 million pixels.

[0051] The first lens 21, the second lens 23, the third lens 25, the fourth lens 27 and the fifth lens 29 of the optical system 2 are optical resin material components, liquid silicone material components, glass material components, quartz components, sapphire material components or transparent optical ceramic material components.

[0052] The optical path parameters of the lens of the optical system 2 in the first embodiment, including the radius of curvature, thickness, refractive index nd, Abbe coefficient Vd, clear aperture, cone coefficient and aspheric coefficient of each surface are shown in Table 1, Table 2 and Table 3 respectively.

[0053] The first lens 21 and the fourth lens 27 are optical material components with low refractive index and high dispersion coefficient. The refractive index nd=1.544502, the dispersion coefficient Vd=55.986991, the first lens 21 is a convex lens, the curvature radius R of the first surface 213 of the first lens is 1.687764mm, and the fifth lens 29 is a reverse curved lens, that is, the curvature direction in the middle of the curved surface is opposite to the curvature direction at the edge.

[0054] The second lens 23 and the third lens 25 are made of the same high refractive index material component and low dispersion coefficient optical material component, the refractive index nd=1.661319, and the Abbe coefficient Vd=20.374576. The fifth lens 29 is made of a high refractive index and low dispersion coefficient optical material component, the refractive index nd=1.650971, and the Abbe coefficient Vd=21.516276.

[0055] The infrared cutoff filter 3 has a thickness of d=0.21 mm and is a bandpass filter that transmits visible light and blocks infrared light. The first surface 33 and the second surface 34 of the infrared cutoff filter are both coated with a dielectric film that transmits visible light and blocks infrared light. The transmittance of the infrared cutoff filter 3 in the 720nm-1100nm band is less than 3%.

[0056] Table 1 is the optical path parameters of the lens of the optical system in the first embodiment.

[0057]

[0058] Table 2 Aspheric coefficients of the first to third lenses of the optical system in the first embodiment:

[0059]

[0060]

[0061] Table 3 Aspheric coefficients of the fourth lens and the fifth lens of the optical system in the first embodiment:

[0062]

[0063] Fig. 9 : shows the optical path diagram of the optical system in the first embodiment, Fig.10 The modulation transfer function (resolution) of the optical system in the first embodiment is shown. When the spatial frequency is 110, except for the outermost field of view, the MTF of all other fields of view almost reaches between 0.6 and 0.8, and the clarity is very good. The MTF of the outermost field of view also reaches nearly 0.5, and the clarity reaches the goal of very good.

[0064] Fig.11 The spot diagram of the optical system in the first embodiment is shown, and the root mean square of the spot diagram of the paraxial field of view at the center position is 4.8 μm.

[0065] Fig.12 The image plane grid diagram of the optical system in the first embodiment is shown, and it can be seen that there is almost no distortion on the image plane.

[0066] Fig.13 The relative illumination of the optical system in the first embodiment is shown. It can be seen that the relative illumination of the maximum field of view at the edge reaches about 37%.

[0067] Embodiment 2

[0068] like Figures 14 to 16 As shown, the present invention also provides a mobile phone camera module adopting a large field of view and high pixel optical system, including a shell 1, and also including an optical system 2 installed in the shell 1, an infrared cutoff filter 3 is installed at the rear of the optical system 2, an image sensor 4 is installed at the rear of the infrared cutoff filter 3, and the optical system 2 is equipped with at least one deformable elastomer interlocking positioning structure 5. The number of deformable elastomer interlocking positioning structures 5 in the optical system 2 can be single, two or more, and preferably two in this embodiment two.

[0069] The deformed elastomer interlocking positioning structure 5 includes a deformed first elastomer 212 installed on the flange edge of the first lens 21, and a deformed second elastomer 232 installed on the flange edge of the second lens 23. The flange edge of the second lens 23 is provided with a first interlocking positioning groove 231 that matches the deformed first elastomer 212, and the first elastomer 212 is tightly matched with the first interlocking positioning groove 231. The flange edge of the third lens 25 is provided with a second interlocking positioning groove 251 that matches the deformed second elastomer 232, and the second elastomer 232 is tightly matched with the second interlocking positioning groove 251.

[0070] The first elastomer 212 and the second elastomer 232 are hump-shaped structures with protrusions on both sides and a concave middle. The number of protrusions of the hump-shaped structure is two or more, which are arranged in a point-shaped, ring-shaped or polygonal shape. The cross-sectional profile of the protrusions of the hump-shaped structure is that the two outer sides are inclined straight lines or circular arc curves, and the middle is connected by a transitional arc. The first interlocking positioning groove 231 and the second interlocking positioning groove 251 are concave positioning groove structures. The cross-sectional profile of the concave positioning groove structure is an inverted trapezoid, a V-shape or a U-shape. The hump-shaped structure and the concave positioning groove structure are arranged in correspondence with each other. The order in which the hump-shaped structure and the concave positioning groove structure are arranged is that one side is a hump-shaped structure and the other side is a concave positioning groove structure, or one side is a concave positioning groove structure and the other side is a hump-shaped structure.

[0071] The first elastomer 212 and the first lens 21 are a single-piece plastic component made of the same material, or the first elastomer 212 and the first lens 21 are a double-piece plastic component made of different materials. The second elastomer 232 and the second lens 23 are a single-piece plastic component made of the same material, or the second elastomer 232 and the second lens 23 are a double-piece plastic component made of different materials.

[0072] The first elastomer 212 and the first lens 21 are made of the same material, and the first elastomer 212 and the first lens 21 are molded at one time. The second elastomer 232 and the second lens 23 are made of the same material, and the second elastomer 232 and the second lens 23 are molded at one time. The one-time molding manufacturing method can save production costs.

[0073] The first elastomer 212 and the first lens 21 are made of different materials. The first elastomer 212 is a flexible liquid silicone component or a silicone rubber component. The second elastomer 232 and the second lens 23 are made of different materials. The second elastomer 232 is a flexible liquid silicone component or a silicone rubber component. The first elastomer 212 and the second elastomer 232 are formed by double-material molding, in-mold molding, or injection molding followed by 3D printing silicone molding.

[0074] In the second embodiment of the present invention, two deformed elastic body fitting positioning structures 5 are installed. During the assembly process, the elastic body is appropriately deformed along the radial and axial directions because the concave positioning groove structure has an avoidance space or the elastic body with a hump-shaped structure with convex sides and concave in the middle automatically optimizes the fitting stability between the front and rear lenses. When the two lenses are in an interference fit state when fitting, the fitting positioning structure with the deformed elastic body has the function of automatically balancing the assembly fit between the lenses, so that the front and rear lenses have a certain avoidance space and elasticity when fitting each other. Under the action of the assembly force, the most precise and stable fit is automatically achieved, so as to avoid abnormal problems such as lens tilt or excessive air gap during the assembly process. The eccentricity error, inclination error and thickness error introduced during the lens assembly are controlled to a minimum through the coordination and adjustment of the elastic body and the avoidance space, so that the concentricity of the assembly between the lenses reaches a precision positioning of less than a tolerance of ±0.0015mm, thereby improving the assembly quality of the camera module, ensuring the stability of the shooting resolution, and greatly improving the assembly yield of the camera module.

[0075] like Fig.15 and Fig.16 As shown, a housing 1 is installed on the outside of the optical system 2, and an infrared cutoff filter 3 is installed on the rear of the optical system 2. The infrared cutoff filter 3 is a bandpass filter that transmits visible light and blocks infrared light. The first surface 33 of the infrared cutoff filter and the second surface 34 of the infrared cutoff filter are both coated with a dielectric film that transmits visible light and blocks infrared light. The transmittance of the infrared cutoff filter 3 in the 720nm-1100nm band is less than 3%, and an image sensor 4 is installed behind the infrared cutoff filter 3.

[0076] A first Mylar sheet 22 is installed between the flanges of the first lens 21 and the second lens 23, a second Mylar sheet 24 is installed between the flanges of the second lens 23 and the third lens 25, a third Mylar sheet 26 is installed between the flanges of the third lens 25 and the fourth lens 27, and a spacer ring 28 is installed between the flanges of the fourth lens 27 and the fifth lens 29.

[0077] When assembling the lenses, black light-absorbing Mylar sheets are generally used for spacing at locations where the gap between the flanges at the edges of the lenses is relatively thin, and black light-absorbing spacers are used for spacing at locations where the gap is relatively thick, so as to eliminate stray light generated at the flange edges of the lenses.

[0078] The large-field-of-view, high-pixel optical system described in the present invention can be used in different fields such as vehicle-mounted camera modules, industrial camera modules, infrared camera modules, and medical camera modules in addition to being used in mobile phone camera modules.

Claims

1. A large field of view, high pixel optical system, characterized in that: The optical system (2) is a five-piece aspherical structure, comprising a first lens (21), a second lens (23), a third lens (25), a fourth lens (27) and a fifth lens (29) arranged in sequence from the object side to the image side, the first lens (21) is a convex lens, the second lens (23) is a concave lens, the third lens (25), the fourth lens (27) and the fifth lens (29) are reverse curved lenses, the second lens (23) and the third lens (25) are optical material components with a refractive index nd between 1.62 and 1.80 and a dispersion coefficient vd less than 35, the first lens (21) is an optical material component with a refractive index nd less than 1.60 and a dispersion coefficient vd less than 35. The optical material component has a refractive index nd between 1.50 and 1.80, and a dispersion coefficient vd between 20 and 70. The third lens (25) has a second curved surface (254) of the third lens. The curvature direction of the middle concave portion of the surface profile of the second curved surface (254) of the third lens is opposite to the curvature direction of the edge of the outer field of view. The edge principal ray angle θ between the third lens (25) and the fourth lens (27) is between 59° and 75°. The image plane diagonal length H of the optical system (2) is between 7.80 mm and 10.50 mm. The optical axis region of the first surface (213) of the first lens is convex, The optical axis region of the second surface (214) of the first lens is concave, The optical axis region of the first surface (233) of the second lens is concave, The optical axis region of the second surface (234) of the second lens is convex, The optical axis region of the first curved surface (253) of the third lens is convex, The optical axis region of the second curved surface (254) of the third lens is concave, The optical axis region of the first surface (273) of the fourth lens is convex, The optical axis region of the second surface (274) of the fourth lens is concave, The optical axis area of ​​the first surface (293) of the fifth lens is concave, The optical axis region of the second surface (294) of the fifth lens is concave, The optical powers of the first lens (21), the second lens (23), the third lens (25), the fourth lens (27) and the fifth lens (29) are positive, negative, negative, positive and negative, respectively.

2. The large field of view, high pixel optical system according to claim 1, characterized in that: The first lens (21) has a first surface (213) of the first lens, and the radius of curvature of the first surface (213) of the first lens is between 1.2 mm and 1.85 mm.

3. The large field of view, high pixel optical system according to claim 1, characterized in that: The half field angle α of the optical system (2) is between 20° and 85°.

4. The large field of view, high pixel optical system according to claim 1, characterized in that: The total optical length L of the optical system (2) is between 4.2 mm and 7.5 mm.

5. The large field of view, high pixel optical system according to claim 1, characterized in that: The total number of image plane pixels of the optical system (2) is more than 40 million pixels.

6. The large field of view, high pixel optical system according to claim 1, characterized in that: The first lens (21), the second lens (23), the third lens (25), the fourth lens (27) and the fifth lens (29) of the optical system (2) are optical resin material components, liquid silicone material components, glass material components, quartz components, sapphire material components or transparent optical ceramic material components.

7. A mobile phone camera module, characterized in that: The invention comprises a housing (1), and also comprises an optical system (2) according to any one of claims 1 to 6 installed in the housing (1), an infrared cut-off filter (3) is installed at the rear of the optical system (2), an image sensor (4) is installed at the rear of the infrared cut-off filter (3), and the optical system (2) is equipped with at least one deformable elastic body interlocking positioning structure (5).

8. A mobile phone camera module according to claim 7, characterized in that: The deformable elastic body interlocking positioning structure (5) comprises a deformable first elastic body (212) installed on the flange edge of the first lens (21), and a deformable second elastic body (232) installed on the flange edge of the second lens (23); the flange edge of the second lens (23) is provided with a first interlocking positioning groove (231) matching the deformable first elastic body (212); the first elastic body (212) and the first interlocking positioning groove (231) are tightly matched; the flange edge of the third lens (25) is provided with a second interlocking positioning groove (251) matching the deformable second elastic body (232); the second elastic body (232) and the second interlocking positioning groove (251) are tightly matched.

9. A mobile phone camera module according to claim 8, characterized in that: The first elastomer (212) and the second elastomer (232) are hump-shaped structures with protrusions on both sides and a concave middle. The number of protrusions on the hump-shaped structure is two or more, and they are arranged in a dot-shaped, ring-shaped or polygonal shape. The cross-sectional profile of the protrusions of the hump-shaped structure is that the two outer sides are straight lines or arc curves with slopes, and the middle is connected by a transition arc. The first embedded positioning groove (231) and the second embedded positioning groove (251) are concave positioning groove structures. The cross-sectional profile of the concave positioning groove structure is an inverted trapezoid, a V shape or a U shape. The hump-shaped structure and the concave positioning groove structure are arranged in a corresponding manner. The arrangement order of the hump-shaped structure and the concave positioning groove structure is that one side is a hump-shaped structure and the other side is a concave positioning groove structure, or one side is a concave positioning groove structure and the other side is a hump-shaped structure.

10. The mobile phone camera module according to claim 8, characterized in that: The first elastomer (212) and the first lens (21) are a single-piece plastic component made of the same material, or the first elastomer (212) and the first lens (21) are double-piece plastic components made of different materials; the second elastomer (232) and the second lens (23) are a single-piece plastic component made of the same material, or the second elastomer (232) and the second lens (23) are double-piece plastic components made of different materials.

11. A mobile phone camera module according to claim 10, characterized in that: The first elastomer (212) and the first lens (21) are made of the same material, and the first elastomer (212) and the first lens (21) are molded at one time; the second elastomer (232) and the second lens (23) are made of the same material, and the second elastomer (232) and the second lens (23) are molded at one time.

12. The mobile phone camera module according to claim 10, characterized in that: The first elastomer (212) and the first lens (21) are made of different materials, the first elastomer (212) is a flexible liquid silicone component or a silicone rubber component, the second elastomer (232) and the second lens (23) are made of different materials, the second elastomer (232) is a flexible liquid silicone component or a silicone rubber component, and the first elastomer (212) and the second elastomer (232) are formed by double-material molding, in-mold molding, or injection molding followed by 3D printing silicone molding.

13. A mobile phone camera module according to claim 7, characterized in that: A first Mylar sheet (22) is installed between the flanges of the first lens (21) and the second lens (23), a second Mylar sheet (24) is installed between the flanges of the second lens (23) and the third lens (25), a third Mylar sheet (26) is installed between the flanges of the third lens (25) and the fourth lens (27), and a spacer ring (28) is installed between the flanges of the fourth lens (27) and the fifth lens (29).

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