Optical imaging device

Abstract

The present invention provides an optical imaging device, comprising: a lens group, wherein the lens group is sequentially arranged at intervals from the object side to the image side of the optical imaging device with: a first lens having a negative optical power, a second lens having a positive optical power, a third lens, a fourth lens having a positive optical power, a fifth lens having a negative optical power, and a sixth lens having a negative optical power; a spacer element group, the spacer element group at least comprising: a first spacer element, a second spacer element, a third spacer element, a fourth spacer element, a fifth spacer element; a lens barrel, the inner ring surface of the lens barrel being stepped, and the lens group and the spacer element group being accommodated in the lens barrel; wherein, the curvature radius R1 of the object side surface of the first lens and the curvature radius R12 of the image side surface of the sixth lens satisfy: -3.6 < R1 / R12 < -1.5; the total length L of the lens barrel, the effective focal length f1 of the first lens, and the effective focal length f6 of the sixth lens satisfy: 0.42 < L / (f1 - f6) < 0.83. The present invention solves the problem that the MTF performance of the six-piece wide-angle optical imaging device in the prior art is relatively poor.

Description

Technical Field

[0001] The present invention relates to the technical field of optical imaging equipment, and in particular to an optical imaging device. Background Art

[0002] With the advancement of science and technology, obtaining three-dimensional spatial position through optical imaging devices has become an indispensable part of VR, AR and other products. Due to the differences in the application environment of the products, the optical performance quality of the products is particularly important, especially the resolution quality of the optical imaging devices. However, in existing six-element wide-angle optical imaging devices, when the surface shapes of the first lens and the sixth lens differ significantly, the deflection angle of the light inside the optical imaging device is too large. Under the influence of factors such as the lens processing accuracy, slight fluctuations in the surface shape will cause significant changes in the deflection direction of the light, resulting in greater sensitivity of the optical imaging device, which in turn leads to serious MTF offset in the outer field of view and blurred imaging. Therefore, how to control the focal length and structural parameters of the lenses of the six-element optical imaging device to ensure the MTF effect in each field of view is a very important issue. Summary of the Invention

[0003] The main purpose of the present invention is to provide an optical imaging device to solve the problem of poor MTF performance of six-element wide-angle optical imaging devices in the prior art.

[0004] In order to achieve the above object, according to one aspect of the present invention, there is provided an optical imaging device, comprising: a lens group, the number of lenses with optical power in the lens group is six, and the lens group is sequentially arranged at intervals from the object side to the image side of the optical imaging device: a first lens with negative optical power, a second lens with positive optical power, a third lens, a fourth lens with positive optical power, a fifth lens with negative optical power, and a sixth lens with negative optical power. The object side surface of the first lens is concave, the object side surface of the second lens is convex, the object side surface of the third lens is convex, the image side surface of the third lens is concave, the image side surface of the fourth lens is convex, the object side surface of the fifth lens is convex, and the image side surface of the fifth lens is concave; a spacer element group, the spacer element group at least includes: a first spacer element placed between the image side surface of the first lens and the second lens and at least partially contacting the image side surface of the first lens, a second spacer element placed between the image side surface of the second lens and the third lens and at least partially contacting the image side surface of the second lens, a third spacer element placed between the image side surface of the third lens and the fourth lens and at least partially contacting the image side surface of the third lens, a fourth spacer element placed between the image side surface of the fourth lens and the fifth lens and at least partially contacting the image side surface of the fifth lens, a fifth spacer element placed between the image side surface of the fifth lens and the sixth lens and at least partially contacting the image side surface of the fifth lens; a lens barrel, the inner ring surface of the lens barrel is stepped, and the lens group and the spacer element group are accommodated in the lens barrel; wherein, the curvature radius R1 of the object side surface of the first lens and the curvature radius R12 of the image side surface of the sixth lens satisfy: -3.6 < R1 / R12 < -1.5; the total length L of the lens barrel, the effective focal length f1 of the first lens, and the effective focal length f6 of the sixth lens satisfy: 0.42 < L / (f1 - f6) < 0.83.

[0005] According to another aspect of the present invention, an optical imaging device is provided, including: a lens group, the number of lenses with optical power in the lens group is six, and the lens group is sequentially arranged at intervals from the object side to the image side of the optical imaging device as follows: a first lens with negative optical power, a second lens with positive optical power, a third lens, a fourth lens with positive optical power, a fifth lens with negative optical power, and a sixth lens with negative optical power. The object side surface of the first lens is concave, the object side surface of the second lens is convex, the object side surface of the third lens is convex, the image side surface of the third lens is concave, the image side surface of the fourth lens is convex, the object side surface of the fifth lens is convex, and the image side surface of the fifth lens is concave; a spacer element group, the spacer element group at least includes: a first spacer element placed between the image side surface of the first lens and the second lens and at least partially contacting the image side surface of the first lens, a second spacer element placed between the image side surface of the second lens and the third lens and at least partially contacting the image side surface of the second lens, a third spacer element placed between the image side surface of the third lens and the fourth lens and at least partially contacting the image side surface of the third lens, a fourth spacer element placed between the image side surface of the fourth lens and the fifth lens and at least partially contacting the image side surface of the fifth lens, a fifth spacer element placed between the image side surface of the fifth lens and the sixth lens and at least partially contacting the image side surface of the fifth lens; a lens barrel, the inner ring surface of the lens barrel is stepped, and the lens group and the spacer element group are accommodated in the lens barrel; wherein, the curvature radius R1 of the object side surface of the first lens and the curvature radius R12 of the image side surface of the sixth lens satisfy: -3.6 < R1 / R12 < -1.5; the inner diameter d1s of the object side surface of the first spacer element, the curvature radius R2 of the image side surface of the first lens, and the curvature radius R3 of the object side surface of the second lens satisfy: -0.1 ≤ d1s / (R2 + R3) < 0.65.

[0006] Further, the inner diameter d1s of the object side surface of the first spacer element, the curvature radius R2 of the image side surface of the first lens, and the curvature radius R3 of the object side surface of the second lens satisfy: -0.1 ≤ d1s / (R2 + R3) < 0.65.

[0007] Further, the outer diameter D0s of the object side end surface of the lens barrel, the inner diameter d0s of the object side end surface of the lens barrel, and the curvature radius R1 of the object side surface of the first lens satisfy -0.75 < (D0s - d0s) / R1 < -0.05.

[0008] Further, the outer diameter D0s of the object side end surface of the lens barrel and the outer diameter D1s of the object side surface of the first spacer element satisfy: 1.2 < D0s / D1s < 2.2.

[0009] Further, the interval distance EP12 from the image side surface of the first spacer element to the object side surface of the second spacer element along the optical axis direction of the optical imaging device and the effective focal length f2 of the second lens satisfy: 0.1 < EP12 / f2 < 0.45.

[0010] Furthermore, the inner diameter d2m of the image-side surface of the second spacer element, the inner diameter d3m of the image-side surface of the third spacer element, and the center thickness CT2 of the second lens satisfy the following relationship: 0.02<(d3m-d2m) / CT2<0.55.

[0011] Furthermore, an inner diameter d4s of the object-side surface of the fourth spacer, an outer diameter D4s of the object-side surface of the fourth spacer, and an effective diameter DT42 of the image-side surface of the fourth lens satisfy the following relationship: 0.4≤(D4s-d4s) / DT42<2.45.

[0012] Furthermore, the on-axis distance T56 from the image side surface of the fifth lens to the object side surface of the sixth lens, the center thickness CT5 of the fifth lens, and the center thickness CT6 of the sixth lens satisfy the following conditions: 1.3 <T56 / (CT5+CT6)<1.85。

[0013] Furthermore, the object-side surface of the sixth lens and the image-side surface of the sixth lens each include at least one inflection point, and the curvature radius R11 of the object-side surface of the sixth lens and the curvature radius R12 of the image-side surface of the sixth lens satisfy the following relationship: 1.2 <R11 / R12<1.55。

[0014] Furthermore, the center thickness CP5 of the fifth spacer element, the center thickness CT5 of the fifth lens, and the center thickness CT6 of the sixth lens satisfy the following relationship: 0.55 <CP5 / (CT5+CT6)<1.05。

[0015] Furthermore, the spacer element group further includes at least two auxiliary spacer elements.

[0016] Furthermore, the i-th auxiliary spacer element is placed between the image side surface of the i-th spacer element and the object side surface of the j-th lens, and the center thickness Cpi of the i-th spacer element, the center thickness Cpib of the i-th auxiliary spacer element, and the on-axis distance Tij from the image side surface of the i-th lens to the object side surface of the j-th lens satisfy the following conditions: 0.35<(Cpi+Cpib) / Tij<2, where j=i+1, and i can be 1, 2, 3, 4, or 5.

[0017] Further, the spacer element group includes a fifth auxiliary spacer element, and the fifth auxiliary spacer element is placed between the image-side surface of the fifth spacer element and the sixth lens.

[0018] Applying the technical solution of the present invention, the optical imaging device includes a lens group, a spacer element group, and a lens barrel. The number of lenses with optical power in the lens group is six. The lens group is sequentially arranged at intervals from the object side to the image side of the optical imaging device as follows: a first lens with negative optical power, a second lens with positive optical power, a third lens, a fourth lens with positive optical power, a fifth lens with negative optical power, and a sixth lens with negative optical power. The object side surface of the first lens is concave, the object side surface of the second lens is convex, the object side surface of the third lens is convex, the image side surface of the third lens is concave, the image side surface of the fourth lens is convex, the object side surface of the fifth lens is convex, and the image side surface of the fifth lens is concave; the spacer element group at least includes: a first spacer element placed between the image side surface of the first lens and the second lens and at least partially contacting the image side surface of the first lens, a second spacer element placed between the image side surface of the second lens and the third lens and at least partially contacting the image side surface of the second lens, a third spacer element placed between the image side surface of the third lens and the fourth lens and at least partially contacting the image side surface of the third lens, a fourth spacer element placed between the image side surface of the fourth lens and the fifth lens and at least partially contacting the image side surface of the fifth lens, a fifth spacer element placed between the image side surface of the fifth lens and the sixth lens and at least partially contacting the image side surface of the fifth lens; the inner ring surface of the lens barrel is stepped, and the lens group and the spacer element group are accommodated in the lens barrel; wherein, the curvature radius R1 of the object side surface of the first lens and the curvature radius R12 of the image side surface of the sixth lens satisfy: -3.6 < R1 / R12 < -1.5; the total length L of the lens barrel, the effective focal length f1 of the first lens, and the effective focal length f6 of the sixth lens satisfy: 0.42 < L / (f1 - f6) < 0.83.

[0019] Based on the imaging requirements of wide-angle, the above six-lens architecture with the combination of optical power and surface type is proposed for the optical imaging device of the present application. Under this architecture, the image side surface of the sixth lens is more curved than the object side surface of the first lens, satisfying -3.6 < R1 / R12 < -1.5, which will cause the deflection angle of the light received by the object side surface of the first lens in the optical imaging device to be too large. Considering the influence of factors such as the processing accuracy of the lens, the sensitivity of the optical imaging device is relatively large, resulting in the problem that the optical imaging device is prone to field curvature shift. By restricting the total length L of the lens barrel, the effective focal length f1 of the first lens, and the effective focal length f6 of the sixth lens, the present application ensures the total length of the optical imaging device, while restricting the effective focal lengths of the first lens and the sixth lens, which can effectively limit the deflection angle of the light, prevent the surface types of the first lens and the sixth lens from having a greater impact on the sensitivity of the optical imaging device, and ensure that even if there are slight deviations during the lens processing, the optical imaging device can still maintain good optical performance, especially preventing the field curvature shift caused by the change of the lens surface type, thereby maintaining the stability and peak performance of the modulation transfer function (MTF) and ensuring the imaging quality of the optical imaging device. Brief Description of the Drawings

[0020] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 A schematic diagram showing some parameters of an optical imaging device according to any optional embodiment of the present invention;

[0022] Figure 2 Another partial parameter diagram of the optical imaging device according to any optional embodiment of the present invention is shown;

[0023] Figure 3 FIG2 shows a schematic structural diagram of an optical imaging device according to a first embodiment of the present invention;

[0024] Figure 4 shows an on-axis chromatic aberration curve of the optical imaging device according to the first embodiment of the present invention;

[0025] Figure 5 shows an astigmatism curve of the optical imaging device according to the first embodiment of the present invention;

[0026] Figure 6 shows a distortion curve of the optical imaging device according to the first embodiment of the present invention;

[0027] Figure 7 A schematic structural diagram of an optical imaging device according to a second embodiment of the present invention is shown;

[0028] Figure 8 A schematic structural diagram of an optical imaging device according to a third embodiment of the present invention is shown;

[0029] Figure 9 A schematic structural diagram of an optical imaging device according to a fourth embodiment of the present invention is shown;

[0030] Figure 10 shows an on-axis chromatic aberration curve of the optical imaging device of the fourth embodiment of the present invention;

[0031] Figure 11 shows an astigmatism curve of the optical imaging device according to the fourth embodiment of the present invention;

[0032] Figure 12 shows a distortion curve of the optical imaging device according to the fourth embodiment of the present invention;

[0033] Figure 13 A schematic structural diagram of an optical imaging device according to a fifth embodiment of the present invention is shown;

[0034] Figure 14 FIG2 shows a schematic structural diagram of an optical imaging device according to a sixth embodiment of the present invention;

[0035] Figure 15 FIG2 shows a schematic structural diagram of an optical imaging device according to a seventh embodiment of the present invention;

[0036] Figure 16 shows an on-axis chromatic aberration curve of the optical imaging device according to the seventh embodiment of the present invention;

[0037] Figure 17 shows an astigmatism curve of the optical imaging device according to the seventh embodiment of the present invention;

[0038] Figure 18 shows a distortion curve of the optical imaging device according to the seventh embodiment of the present invention;

[0039] Figure 19 FIG2 shows a schematic structural diagram of an optical imaging device according to an eighth embodiment of the present invention;

[0040] Figure 20 FIG2 shows a schematic structural diagram of an optical imaging device according to a ninth embodiment of the present invention;

[0041] Figure 21 The figure shows the defocus MTF curve of the optical imaging device of an optional solution 1 of the present invention under the condition of L / (f1-f6)=0.6;

[0042] Figure 22 The defocus MTF curve of the optical imaging device of Comparative Example 1 under the condition of L / (f1-f6)=0.4 is shown;

[0043] Figure 23 The defocus MTF curve of the optical imaging device of Comparative Example 2 under the condition of L / (f1-f6)=1 is shown.

[0044] The above drawings include the following reference numerals:

[0045] P0, lens barrel; E1, first lens; S1, object-side surface of the first lens; S2, image-side surface of the first lens; P1, first spacer; P1b, first auxiliary spacer; E2, second lens; S3, object-side surface of the second lens; S4, image-side surface of the second lens; P2, second spacer; P2b, second auxiliary spacer; E3, third lens; S5, object-side surface of the third lens; S6, image-side surface of the third lens; P3, third spacer; P3b, third auxiliary spacer; E4, fourth lens; S7, object-side surface of the fourth lens; S8, image-side surface of the fourth lens; P4, fourth spacer; E5, fifth lens; S9, object-side surface of the fifth lens; S10, image-side surface of the fifth lens; P5, fifth spacer; P5b, fifth auxiliary spacer; E6, sixth lens; S11, object-side surface of the sixth lens; S12, image-side surface of the sixth lens. DETAILED DESCRIPTION

[0046] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0047] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0048] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity direction; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above directional words are not used to limit the present invention.

[0049] It should be noted that in this specification, the terms "first," "second," "third," etc., are used solely to distinguish one feature from another and do not limit the features. Thus, the first lens discussed below could also be referred to as the second lens or the third lens without departing from the teachings of this application.

[0050] In the drawings, the thickness, size, and shape of the lenses are slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical and aspherical surfaces shown in the drawings are provided by way of example. That is, the shapes of the spherical and aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0051] In this article, the paraxial region refers to the area near the optical axis. If a lens surface is convex and the location of the convex surface is undefined, it indicates that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the location of the concave surface is undefined, it indicates that the lens surface is concave at least in the paraxial region. The surface shape in the paraxial region can be determined according to the judgment method commonly used by those skilled in the art, using the positive or negative R value (R refers to the radius of curvature of the paraxial region, typically the R value in the lens database in optical software) to determine whether it is convex or concave. For the object-side surface, a positive R value indicates a convex surface, and a negative R value indicates a concave surface. For the image-side surface, a positive R value indicates a concave surface, and a negative R value indicates a convex surface.

[0052] In order to solve the problem of poor MTF performance of the six-element wide-angle optical imaging device in the prior art, the present invention provides an optical imaging device.

[0053] First embodiment

[0054] As shown Figures 1 to 21 in FIG. 1, the optical imaging device includes a lens group, a spacer element group, and a lens barrel. The number of lenses with optical power in the lens group is six. The lens group is sequentially arranged at intervals from the object side to the image side of the optical imaging device as follows: a first lens with negative optical power, a second lens with positive optical power, a third lens, a fourth lens with positive optical power, a fifth lens with negative optical power, and a sixth lens with negative optical power. The object side surface of the first lens is concave, the object side surface of the second lens is convex, the object side surface of the third lens is convex, the image side surface of the third lens is concave, the image side surface of the fourth lens is convex, the object side surface of the fifth lens is convex, and the image side surface of the fifth lens is concave. The spacer element group at least includes: a first spacer element placed between the image side surface of the first lens and the second lens and at least partially contacting the image side surface of the first lens, a second spacer element placed between the image side surface of the second lens and the third lens and at least partially contacting the image side surface of the second lens, a third spacer element placed between the image side surface of the third lens and the fourth lens and at least partially contacting the image side surface of the third lens, a fourth spacer element placed between the image side surface of the fourth lens and the fifth lens and at least partially contacting the image side surface of the fifth lens, and a fifth spacer element placed between the image side surface of the fifth lens and the sixth lens and at least partially contacting the image side surface of the fifth lens. The inner ring surface of the lens barrel is stepped, and the lens group and the spacer element group are accommodated in the lens barrel. Among them, the curvature radius R1 of the object side surface of the first lens and the curvature radius R12 of the image side surface of the sixth lens satisfy: -3.6 < R1 / R12 < -1.5. The total length L of the lens barrel, the effective focal length f1 of the first lens, and the effective focal length f6 of the sixth lens satisfy: 0.42 < L / (f1 - f6) < 0.83.

[0055] Based on the imaging requirements of a wide angle, the optical imaging device of the present application proposes the above six-lens architecture with the combination of optical power and surface type. Under this architecture, the image side surface of the sixth lens is more curved than the object side surface of the first lens, satisfying -3.6 < R1 / R12 < -1.5, which will cause the deflection angle of the light received by the object side surface of the first lens in the optical imaging device to be too large. Considering the influence of factors such as the processing accuracy of the lens, the sensitivity of the optical imaging device is relatively large, resulting in the problem that the optical imaging device is prone to field curvature shift. By restricting the total length L of the lens barrel, the effective focal length f1 of the first lens, and the effective focal length f6 of the sixth lens, the present application ensures the total length of the optical imaging device, while restricting the effective focal lengths of the first lens and the sixth lens, which can effectively limit the deflection angle of the light, prevent the surface types of the first lens and the sixth lens from having a greater impact on the sensitivity of the optical imaging device, and ensure that even if there are slight deviations during the lens processing, the optical imaging device can still maintain good optical performance, especially preventing the field curvature shift caused by the change of the lens surface type, thereby maintaining the stability and peak performance of the modulation transfer function (MTF) and ensuring the imaging quality of the optical imaging device.

[0056] Table 1 below shows the defocus MTF curves of the optical imaging devices of Comparative Example 1, Comparative Example 2, and Option 1 of the present application under different conditions of L / (f1-f6). The defocus MTF curves are used to demonstrate changes in the imaging quality of the optical imaging device and describe the image transmission capability of the optical imaging device at different spatial frequencies. The abscissa represents the defocus position (unit: mm), indicating the position where the image deviates from the optimal focus (the abscissa is 0 mm), and the ordinate represents the MTF value.

[0057] Table 1

[0058]

[0059] like Figure 22 As shown, the optical imaging device of Comparative Example 1 satisfies L / (f1-f6)=0.4, that is, L / (f1-f6) is less than 0.42. The total length of the optical imaging device is short, the light deflection angle is large, and the peak value of the defocus curve of each field of view of the optical imaging device is reduced, which may cause blurred image and unqualified performance. Figure 23 As shown, the optical imaging device of Comparative Example 2 satisfies L / (f1-f6)=1, that is, L / (f1-f6) is greater than 0.83, and the transmission distance of light in the optical imaging device is too long. At this time, the defocus curves of each field of view of the optical imaging device diverge, which may cause the MTF effect of the external field of view to deteriorate, and the performance judgment is also unqualified.

[0060] like Figure 21 As shown, the optical imaging device of an optional solution 1 of the present application satisfies L / (f1-f6)=0.6, that is, L / (f1-f6) is in the range of 0.42 to 0.83, the defocus curves of each field of view of the optical imaging device are concentrated, the degree of discreteness is small, the optical performance is stable, and it meets the requirements.

[0061] In this embodiment, the inner diameter d1s of the object side surface of the first spacer element, the curvature radius R2 of the image side surface of the first lens, and the curvature radius R3 of the object side surface of the second lens satisfy the following relationship: -0.1≤d1s / (R2+R3)<0.65. By controlling d1s / (R2+R3) within a reasonable range, it is possible to ensure that light effectively converges when passing through the image side surface of the first lens and the object side surface of the second lens inside the optical imaging device, while limiting the deflection angle of light inside the optical imaging device, thereby greatly reducing the sensitivity of the optical performance to surface shape changes. It is also possible to improve the stray light generated by the structural part of the first lens, ensure the improvement effect of the stray light, and thus enhance the purity of the imaging.

[0062] In this embodiment, the outer diameter D0s of the object-side end face of the lens barrel, the inner diameter d0s of the object-side end face of the lens barrel, and the radius of curvature R1 of the object-side surface of the first lens satisfy: -0.75 < (D0s - d0s) / R1 < -0.05. By controlling (D0s - d0s) / R1 within a reasonable range, it is possible to ensure that the bearing width and adsorption width provided by the lens barrel in the optical imaging device reach an optimal balance, thereby enhancing the structural stability during the lens assembly process. It can also limit the object-side surface of the first lens to have an appropriate concave shape, effectively avoiding the appearance defect of the optical imaging device caused by the convexity of the first lens, protecting the overall aesthetics of the optical imaging device, and at the same time improving the yield rate during the production process.

[0063] In this embodiment, the outer diameter D0s of the object-side end face of the lens barrel and the outer diameter D1s of the object-side surface of the first spacer element satisfy: 1.2 < D0s / D1s < 2.2. By controlling D0s / D1s within a reasonable range, it is possible to effectively limit the maximum outer dimension of the object-side end face of the lens barrel, ensure the structural compactness of the head of the optical imaging device, improve the assembly compatibility with the whole machine, and at the same time ensure that the stray light of the structural part of the image-side surface of the first lens is intercepted, optimize the transmission path of the principal ray, and ensure the imaging range and imaging cleanliness of the optical imaging device.

[0064] In this embodiment, the spacing distance EP12 from the image-side surface of the first spacer element to the object-side surface of the second spacer element along the optical axis direction of the optical imaging device and the effective focal length f2 of the second lens satisfy: 0.1 < EP12 / f2 < 0.45. By controlling EP12 / f2 within a reasonable range, it is possible to finely control the edge thickness and effective focal length of the second lens, optimize the structure of the central and edge parts of the second lens, facilitate the processing and forming of the second lens, ensure the surface quality and processing yield rate of the second lens, and stabilize the optical performance of the optical imaging device.

[0065] In this embodiment, the inner diameter d2m of the image-side surface of the second spacer element, the inner diameter d3m of the image-side surface of the third spacer element, and the central thickness CT2 of the second lens satisfy: 0.02 < (d3m - d2m) / CT2 < 0.55. By controlling (d3m - d2m) / CT2 within a reasonable range, it is possible to limit the deflection angle of the light ray at the second lens and the third lens. At the same time, by controlling the central thickness of the second lens, it helps to compress the overall axial dimension of the second lens and the third lens, optimize the internal structure layout of the optical imaging device, and improve the compactness and optical performance of the optical imaging device.

[0066] In this embodiment, the inner diameter d4s of the object side surface of the fourth spacer element, the outer diameter D4s of the object side surface of the fourth spacer element, and the effective diameter DT42 of the image side surface of the fourth lens satisfy: 0.4 ≤ (D4s - d4s) / DT42 < 2.45. By controlling (D4s - d4s) / DT42 within a reasonable range, it can be ensured that the internal stray light and transmitted stray light generated by the structural part of the fourth lens are effectively intercepted by the fourth spacer element, while ensuring the normal transmission path of the chief ray, maintaining the optical imaging range of the optical imaging device, reducing the stray light interference, and improving the imaging quality.

[0067] In this embodiment, the on-axis distance T56 from the image side surface of the fifth lens to the object side surface of the sixth lens, the central thickness CT5 of the fifth lens, and the central thickness CT6 of the sixth lens satisfy: 1.3 < T56 / (CT5 + CT6) < 1.85. By controlling T56 / (CT5 + CT6) within a reasonable range, through reasonable allocation of the central thicknesses of the fifth lens and the sixth lens and the air gap therebetween, it is ensured that after the optical imaging device is assembled, the influence of the change in the air gap on the resolution performance is minimized, thereby ensuring that the optical imaging device can maintain high resolution even in a compact space and improving the user's visual experience.

[0068] In this embodiment, both the object side surface and the image side surface of the sixth lens include at least one inflection point, and the radius of curvature R11 of the object side surface of the sixth lens and the radius of curvature R12 of the image side surface of the sixth lens satisfy: 1.2 < R11 / R12 < 1.55. By controlling R11 / R12 within a reasonable range, it is possible to limit the surface shape and radius of curvature of the last lens, i.e., the sixth lens, ensure that the surface bending degree of the sixth lens is appropriate, provide support for the focusing of light rays in each field of view on the image plane, and also avoid the generation of high-intensity reflected light inside the sixth lens, prevent ghost images from occurring, optimize the imaging effect, and ensure the user's visual experience.

[0069] In this embodiment, the central thickness CP5 of the fifth spacer element, the central thickness CT5 of the fifth lens, and the central thickness CT6 of the sixth lens satisfy: 0.55 < CP5 / (CT5 + CT6) < 1.05. By controlling CP5 / (CT5 + CT6) within a reasonable range, it is possible to precisely adjust the relationship between the central thickness of the fifth spacer element and the central thicknesses of the adjacent fifth lens and sixth lens, limit the influence of the processing error of the central thickness of the lens on the optical quality of the optical imaging device, and ensure that even when limited by the lens processing accuracy, the optical imaging device can still maintain good optical performance, improving the production yield and imaging consistency.

[0070] In this embodiment, the spacer element assembly also includes at least two auxiliary spacer elements. The introduction of these auxiliary spacer elements provides additional structural support for the optical imaging device. Especially when dealing with large gaps between lens structures, their use in conjunction with the spacer elements significantly enhances assembly stability and precision, optimizes inter-lens reflected stray light, and improves the quality and production efficiency of the optical imaging device.

[0071] In this embodiment, the i-th auxiliary spacer is positioned between the image-side surface of the i-th spacer and the object-side surface of the j-th lens, where j = i + 1, and i can be 1, 2, 3, 4, or 5. The center thickness Cpi of the i-th spacer, the center thickness Cpib of the i-th auxiliary spacer, and the on-axis distance Tij from the image-side surface of the i-th lens to the object-side surface of the j-th lens satisfy the following conditions: 0.35 < (Cpi + Cpib) / Tij < 2. By controlling (Cpi + Cpib) / Tij within a reasonable range, stray light reflected from the inner diameter surface of the thicker spacer is effectively suppressed. This optimizes the assembly process of the optical imaging device, improves automated assembly efficiency, and minimizes the negative impact of air gap changes on the resolution of the optical imaging device after assembly, thereby facilitating improved optical resolution yield of the optical imaging device.

[0072] In this embodiment, the spacer assembly includes a fifth auxiliary spacer element positioned between the image-side surface of the fifth spacer element and the sixth lens. The provision of the fifth auxiliary spacer element further enhances the stray light management capabilities of the optical imaging device, effectively preventing stray light generated by reflections from the inner diameter surface of the fifth spacer element from reaching the image plane. This ensures the purity and quality of the image and enhances the visual experience, particularly in high-contrast scenes, by significantly reducing ghosting and glare, and enhancing image contrast and detail.

[0073] Second embodiment

[0074] like Figures 1 to 21As shown, the optical imaging device includes a lens group, a spacer element group, and a barrel. The number of lenses with optical power in the lens group is six. The lens group is arranged at intervals in sequence from the object side to the image side of the optical imaging device as follows: a first lens with negative optical power, a second lens with positive optical power, a third lens, a fourth lens with positive optical power, a fifth lens with negative optical power, and a sixth lens with negative optical power. The object side surface of the first lens is concave, the object side surface of the second lens is convex, the object side surface of the third lens is convex, the image side surface of the third lens is concave, the image side surface of the fourth lens is convex, the object side surface of the fifth lens is convex, and the image side surface of the fifth lens is concave. The spacer element group at least includes: a first spacer element placed between the image side surface of the first lens and the second lens and at least partially contacting the image side surface of the first lens, a second spacer element placed between the image side surface of the second lens and the third lens and at least partially contacting the image side surface of the second lens, a third spacer element placed between the image side surface of the third lens and the fourth lens and at least partially contacting the image side surface of the third lens, a fourth spacer element placed between the image side surface of the fourth lens and the fifth lens and at least partially contacting the image side surface of the fifth lens, and a fifth spacer element placed between the image side surface of the fifth lens and the sixth lens and at least partially contacting the image side surface of the fifth lens. The inner ring surface of the barrel is stepped, and the lens group and the spacer element group are accommodated in the barrel. Among them, the following relationships are satisfied between the curvature radius R1 of the object side surface of the first lens and the curvature radius R12 of the image side surface of the sixth lens: -3.6 < R1 / R12 < -1.5; the following relationships are satisfied among the inner diameter d1s of the object side surface of the first spacer element, the curvature radius R2 of the image side surface of the first lens, and the curvature radius R3 of the object side surface of the second lens: -0.1 ≤ d1s / (R2 + R3) < 0.65.

[0075] Based on the imaging requirements of a wide angle, the optical imaging device of the present application proposes the six-lens architecture with the above-mentioned combination of optical power and surface shape. Under this architecture, the image side of the sixth lens is more curved than the object side of the first lens, satisfying -3.6 < R1 / R12 < -1.5, which will cause the deflection angle of the light received by the object side of the first lens in the optical imaging device to be too large. Considering the influence of factors such as the processing accuracy of the lens, the sensitivity of the optical imaging device is relatively large, resulting in the problem that the optical imaging device is prone to field curvature deviation. The present application ensures the effective convergence of light when passing through the image side of the first lens and the object side of the second lens inside the optical imaging device by restricting the inner diameter d1s of the object side of the first spacer element, the curvature radius R2 of the image side of the first lens, and the curvature radius R3 of the object side of the second lens. At the same time, it indirectly controls the deflection angle of the first lens for light, greatly reducing the sensitivity of the optical performance to surface shape changes, ensuring that even if there are slight deviations during the lens processing, the optical imaging device can still maintain good optical performance, especially preventing field curvature deviation caused by lens surface shape changes, thus maintaining the stability and peak performance of the modulation transfer function (MTF). In addition, it can also improve the stray light generated by the structural part of the first lens, ensuring the improvement effect of stray light, thereby improving the imaging purity and ensuring the imaging quality of the optical imaging device.

[0076] It should be noted that in this embodiment, other conditional formulas in the above embodiment may also be included, which will not be elaborated here one by one.

[0077] Optionally, the above optical imaging device may further include a protective glass for protecting the photosensitive element located on the imaging surface.

[0078] The optical imaging device in the present application may employ multiple lenses, such as the six lenses mentioned above. In the present application, at least one of the lens surfaces of each lens is an aspherical surface. The characteristics of an aspherical lens are that the curvature changes continuously from the center of the lens to the periphery of the lens. Different from a spherical lens with a constant curvature from the center of the lens to the periphery, an aspherical lens has better curvature radius characteristics and has the advantages of improving distortion aberration and astigmatism aberration. After using an aspherical lens, it is possible to eliminate the aberration that appears during imaging as much as possible, thereby improving the imaging quality.

[0079] However, those skilled in the art should understand that without departing from the technical solutions claimed in the present application, the number of lenses constituting the optical imaging device can be changed to obtain the various results and advantages described in this specification. For example, although the six-lens case is described as an example in the embodiment, the optical imaging device is not limited to including six lenses. If necessary, the optical imaging device may also include other numbers of lenses.

[0080] Figure 1 and Figure 2 A schematic diagram of the dimensions of an optical imaging device of the present application is shown. Figure 1 and Figure 2 Parameters such as d1s, d3m, L, and EP12 are marked in the figure to clearly and intuitively understand their meaning. In order to facilitate the description of the optical imaging device and the surface shape of the specific lens, these parameters will no longer be reflected in the drawings when describing the specific embodiments later.

[0081] It should be noted that in an optical imaging device, the surface of the lens barrel's object-side end closest to the object side is the object-side end face of the lens barrel, and the surface of the lens barrel's image-side end closest to the image side is the image-side end face of the lens barrel. The lens barrel's height, L, represents the distance from the object-side end face to the image-side end face of the lens barrel along the optical axis.

[0082] In this embodiment, each lens is composed of an integrally formed effective diameter portion and a structural portion. The structural portion is annular and connected to the outer peripheral side of the effective diameter portion. The effective diameter portion is used for light to pass through and participate in imaging; while the structural portion is not used for light to pass through and does not participate in imaging, but is used to contact adjacent spacer elements, adjacent lenses or the lens barrel.

[0083] The following further describes examples of specific surface shapes and parameters of the optical imaging device applicable to the above-mentioned embodiments with reference to the accompanying drawings.

[0084] It should be noted that any one of the following examples 1 to 9 is applicable to all implementation methods of the present application.

[0085] Example 1

[0086] like Figure 3 As shown, the optical imaging device of embodiment 1 of the present application is described. Figure 3 A schematic structural diagram of the optical imaging device of embodiment 1 is shown.

[0087] like Figure 3 As shown, the optical imaging device includes, from the object side to the image side, the following housed in the lens barrel P0: a first lens E1, a first spacer P1, a first auxiliary spacer P1b, a second lens E2, a second spacer P2, a second auxiliary spacer P2b, a third lens E3, a third spacer P3, a fourth lens E4, a fourth spacer P4, a fifth lens E5, a fifth spacer P5, a fifth auxiliary spacer P5b, and a sixth lens E6.

[0088] In this embodiment, the first lens E1 has negative optical power, the object-side surface S1 of the first lens is concave, and the image-side surface S2 of the first lens is concave. The second lens E2 has positive optical power, the object-side surface S3 of the second lens is convex, and the image-side surface S4 of the second lens is concave. The third lens E3 has positive optical power, the object-side surface S5 of the third lens is convex, and the image-side surface S6 of the third lens is concave. The fourth lens E4 has positive optical power, the object-side surface S7 of the fourth lens is convex, and the image-side surface S8 of the fourth lens is convex. The fifth lens E5 has negative optical power, the object-side surface S9 of the fifth lens is convex, and the image-side surface S10 of the fifth lens is concave. The sixth lens E6 has negative optical power, the object-side surface S11 of the sixth lens is convex, and the image-side surface S12 of the sixth lens is concave. The optical imaging device also includes a filter or protective glass (not shown in the figure), which has an object-side surface S13 (not shown in the figure) and an image-side surface S14 (not shown in the figure). The light from the object plane passes through S1 to S14 and reaches the imaging plane S15 (not shown in the figure).

[0089] Table 2 shows the basic structural parameters of the optical imaging device of Example 1. The units for the radius of curvature, thickness / distance, effective radius, and focal length are all in millimeters (mm). OBJ (not shown) represents the object plane, and STO (not shown) represents the aperture, which is located between the second and third lenses.

[0090] Table 2

[0091]

[0092] In the first embodiment, each lens is an aspheric lens, and the aspheric surface shape can be defined by, but not limited to, the following aspheric surface formula:

[0093] Formula (1);

[0094] Where x is the distance vector from the vertex of the aspheric surface at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface, c = 1 / R, i.e., the paraxial curvature c is the reciprocal of the radius of curvature R in Table 2 above; k is the conic coefficient; Ai is the correction coefficient for the i-th order of the aspheric surface. Table 3 below lists the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for each aspheric mirror surface S1-S12 in Example 1.

[0095] Table 3

[0096]

[0097] Figure 4 The axial chromatic aberration curve of the optical imaging device of the first embodiment is shown, which indicates the deviation of the focal point of light of different wavelengths after passing through the optical imaging device. Figure 5 The astigmatism curve of the optical imaging device of Example 1 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 6 The distortion curve of the optical imaging device of Example 1 is shown, which represents the distortion magnitude values ​​corresponding to different field angles.

[0098] according to Figures 4 to 6 It can be seen that the optical imaging device provided in the first embodiment can achieve good imaging quality.

[0099] Example 2

[0100] like Figure 7 The optical imaging device of the second embodiment of the present application is described as shown in FIG. The optical parameters of the optical imaging device of this embodiment are the same as those of the first embodiment, but the structural parameters are different. Please refer to the relevant description of the first embodiment and will not be repeated here.

[0101] Example 3

[0102] like Figure 8 , which describes the optical imaging device of Example 3 of the present application. The optical parameters of the optical imaging device of this embodiment are the same as those of Example 1, but the structural parameters are different, and only a first spacer element is provided between the first lens and the second lens. Please refer to the relevant description of Example 1 and will not be repeated here.

[0103] Example 4

[0104] like Figure 9 As shown, the optical imaging device of embodiment 4 of the present application is described. Figure 9 A schematic structural diagram of an optical imaging device according to a fourth embodiment is shown.

[0105] like Figure 9 As shown, the optical imaging device includes, from the object side to the image side, the following housed in the lens barrel P0: a first lens E1, a first spacer P1, a second lens E2, a second spacer P2, a second auxiliary spacer P2b, a third lens E3, a third spacer P3, a third auxiliary spacer P3b, a fourth lens E4, a fourth spacer P4, a fifth lens E5, a fifth spacer P5, a fifth auxiliary spacer P5b, and a sixth lens E6.

[0106] In this embodiment, the first lens E1 has negative optical power, the object-side surface S1 of the first lens is concave, and the image-side surface S2 of the first lens is concave. The second lens E2 has positive optical power, the object-side surface S3 of the second lens is convex, and the image-side surface S4 of the second lens is convex. The third lens E3 has positive optical power, the object-side surface S5 of the third lens is convex, and the image-side surface S6 of the third lens is concave. The fourth lens E4 has positive optical power, the object-side surface S7 of the fourth lens is convex, and the image-side surface S8 of the fourth lens is convex. The fifth lens E5 has negative optical power, the object-side surface S9 of the fifth lens is convex, and the image-side surface S10 of the fifth lens is concave. The sixth lens E6 has negative optical power, the object-side surface S11 of the sixth lens is convex, and the image-side surface S12 of the sixth lens is concave. The optical imaging device also includes a filter or protective glass (not shown in the figure), which has an object-side surface S13 (not shown in the figure) and an image-side surface S14 (not shown in the figure). The light from the object plane passes through S1 to S14 and reaches the imaging plane S15 (not shown in the figure).

[0107] Table 4 shows the basic structural parameters of the optical imaging device of Example 4. The units for the radius of curvature, thickness / distance, effective radius, and focal length are all in millimeters (mm). OBJ (not shown) represents the object plane, and STO (not shown) represents the aperture stop, which is located between the second and third lenses.

[0108] Table 4

[0109]

[0110] In the fourth embodiment, each lens is an aspheric lens, and the shape of the aspheric surface can be defined by, but not limited to, the formula (1) in the first embodiment.

[0111] Table 5 below lists the higher-order coefficients of the aspheric mirror surfaces S1-S12 that can be used in Example 4.

[0112] Table 5

[0113]

[0114] Figure 10 An on-axis chromatic aberration curve of the optical imaging device of Example 4 is shown, which indicates the deviation of the focal point of light of different wavelengths after passing through the optical imaging device. Figure 11 The astigmatism curve of the optical imaging device of Example 4 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 12 The distortion curve of the optical imaging device of Example 4 is shown, which represents the distortion magnitude values ​​corresponding to different field angles.

[0115] according to Figures 10 to 12 It can be seen that the optical imaging device provided in the fourth embodiment can achieve good imaging quality.

[0116] Example 5

[0117] like Figure 13 , which describes the optical imaging device of the fifth embodiment of the present application. The optical parameters of the optical imaging device of this embodiment are the same as those of the fourth embodiment, but the structural parameters are different. Please refer to the relevant description of the fourth embodiment and will not be repeated here.

[0118] Example 6

[0119] like Figure 14 , which describes the optical imaging device of Example 6 of the present application. The optical parameters of the optical imaging device of this embodiment are the same as those of Example 4, but the structural parameters are different. Please refer to the relevant description of Example 4 and will not repeat them here.

[0120] Example 7

[0121] like Figure 15 As shown, the optical imaging device of embodiment seven of the present application is described. Figure 15 A schematic structural diagram of the optical imaging device of Example 7 is shown.

[0122] like Figure 15 As shown, the optical imaging device includes, from the object side to the image side, the following housed in the lens barrel P0: a first lens E1, a first spacer P1, a first auxiliary spacer P1b, a second lens E2, a second spacer P2, a third lens E3, a third spacer P3, a fourth lens E4, a fourth spacer P4, a fifth lens E5, a fifth spacer P5, a fifth auxiliary spacer P5b, and a sixth lens E6.

[0123] In this embodiment, the first lens E1 has negative optical power, the object-side surface S1 of the first lens is concave, and the image-side surface S2 of the first lens is convex. The second lens E2 has positive optical power, the object-side surface S3 of the second lens is convex, and the image-side surface S4 of the second lens is convex. The third lens E3 has negative optical power, the object-side surface S5 of the third lens is convex, and the image-side surface S6 of the third lens is concave. The fourth lens E4 has positive optical power, the object-side surface S7 of the fourth lens is concave, and the image-side surface S8 of the fourth lens is convex. The fifth lens E5 has negative optical power, the object-side surface S9 of the fifth lens is convex, and the image-side surface S10 of the fifth lens is concave. The sixth lens E6 has negative optical power, the object-side surface S11 of the sixth lens is convex, and the image-side surface S12 of the sixth lens is concave. The optical imaging device also includes a filter or protective glass (not shown in the figure), which has an object-side surface S13 (not shown in the figure) and an image-side surface S14 (not shown in the figure). The light from the object plane passes through S1 to S14 and reaches the imaging plane S15 (not shown in the figure).

[0124] Table 6 shows the basic structural parameters of the optical imaging device of Example 7. The units for the radius of curvature, thickness / distance, effective radius, and focal length are all in millimeters (mm). OBJ (not shown) represents the object plane, and STO (not shown) represents the aperture stop, which is located between the second and third lenses.

[0125] Table 6

[0126]

[0127] In the seventh embodiment, each lens is an aspheric lens, and the shape of the aspheric surface can be defined by, but not limited to, the formula (1) in the first embodiment.

[0128] Table 7 below lists the higher-order coefficients of the aspheric mirror surfaces S1-S12 that can be used in Example 7.

[0129] Table 7

[0130]

[0131] Figure 16 An on-axis chromatic aberration curve of the optical imaging device of Example 7 is shown, which indicates the deviation of the focal point of light of different wavelengths after passing through the optical imaging device. Figure 17 The astigmatism curve of the optical imaging device of Example 7 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 18 The distortion curve of the optical imaging device of Example 7 is shown, which represents the distortion magnitude values ​​corresponding to different field angles.

[0132] according to Figures 16 to 18 It can be seen that the optical imaging device provided in the seventh embodiment can achieve good imaging quality.

[0133] Example 8

[0134] like Figure 19 , which describes the optical imaging device of Example 8 of the present application. The optical parameters of the optical imaging device of this embodiment are the same as those of Example 7, but the structural parameters are different. Please refer to the relevant description of Example 7 and will not be repeated here.

[0135] Embodiment 9

[0136] like Figure 20 , which describes the optical imaging device of Example 9 of the present application. The optical parameters of the optical imaging device of this embodiment are the same as those of Example 7, but the structural parameters are different. Please refer to the relevant description of Example 7 and will not be repeated here.

[0137] In summary, embodiments 1 to 9 of the optical imaging device respectively satisfy the relationships shown in Table 8.

[0138] Table 8

[0139]

[0140] Table 9 gives the parameters of each lens, spacer element and lens barrel of the optical imaging device of Examples 1 to 9, in mm, where Fno is the F number of the optical imaging device, and Semi-FOV is half of the maximum field of view of the optical imaging device, in degrees.

[0141] Table 9

[0142]

[0143] This application also provides an imaging device, whose electronic photosensitive element can be a charge-coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). The imaging device can be a standalone imaging device such as a digital camera, or an imaging module integrated into a mobile electronic device such as a mobile phone. The imaging device is equipped with the optical imaging device described above.

[0144] Obviously, the embodiments described above are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0145] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, tasks, devices, components and / or combinations thereof.

[0146] It should be noted that the terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0147] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. An optical imaging device, characterized in that: The optical imaging device comprises: A lens group, wherein the number of lenses having optical power in the lens group is six, and the lens group is arranged in order from the object side to the image side of the optical imaging device: a first lens with negative optical power, a second lens with positive optical power, a third lens, a fourth lens with positive optical power, a fifth lens with negative optical power, and a sixth lens with negative optical power, wherein the object-side surface of the first lens is concave, the object-side surface of the second lens is convex, the object-side surface of the third lens is convex, the image-side surface of the third lens is concave, the image-side surface of the fourth lens is convex, the object-side surface of the fifth lens is convex, and the image-side surface of the fifth lens is concave. a spacer element group, the spacer element group comprising at least: a first spacer element disposed between the image-side surface of the first lens and the second lens and in at least partial contact with the image-side surface of the first lens, a second spacer element disposed between the image-side surface of the second lens and the third lens and in at least partial contact with the image-side surface of the second lens, a third spacer element disposed between the image-side surface of the third lens and the fourth lens and in at least partial contact with the image-side surface of the third lens, a fourth spacer element disposed between the image-side surface of the fourth lens and the fifth lens and in at least partial contact with the image-side surface of the fourth lens, and a fifth spacer element disposed between the image-side surface of the fifth lens and the sixth lens and in at least partial contact with the image-side surface of the fifth lens; a lens barrel, wherein the inner annular surface of the lens barrel is stepped, and the lens group and the spacer element group are accommodated in the lens barrel; The curvature radius R1 of the object side surface of the first lens and the curvature radius R12 of the image side surface of the sixth lens satisfy the following relationship: -3.6 <R1 / R12<-1.5; The total length L of the lens barrel, the effective focal length f1 of the first lens, and the effective focal length f6 of the sixth lens satisfy the following conditions: 0.42 <L / (f1-f6)<0.83。 2. The optical imaging device according to claim 1, wherein: The inner diameter d1s of the object-side surface of the first spacer element, the curvature radius R2 of the image-side surface of the first lens, and the curvature radius R3 of the object-side surface of the second lens satisfy the following relationship: -0.1≤d1s / (R2+R3)<0.

65.

3. The optical imaging device according to claim 1, wherein: An outer diameter D0s of the object-side end surface of the lens barrel, an inner diameter d0s of the object-side end surface of the lens barrel, and a curvature radius R1 of the object-side surface of the first lens satisfy -0.75<(D0s-d0s) / R1<-0.

05.

4. The optical imaging device according to claim 1, wherein: The outer diameter D0s of the object side end surface of the lens barrel and the outer diameter D1s of the object side surface of the first spacer element satisfy the following relationship: 1.2 <D0s / D1s<2.2。 5. The optical imaging device according to claim 1, wherein: The spacing distance EP12 from the image side surface of the first spacing element to the object side surface of the second spacing element along the optical axis direction of the optical imaging device and the effective focal length f2 of the second lens satisfy: 0.1 <EP12 / f2<0.45。 6. The optical imaging device according to claim 1, wherein: The inner diameter d2m of the image-side surface of the second spacer element, the inner diameter d3m of the image-side surface of the third spacer element, and the center thickness CT2 of the second lens satisfy the following relationship: 0.02<(d3m-d2m) / CT2<0.

55.

7. The optical imaging device according to claim 1, wherein: An inner diameter d4s of the object-side surface of the fourth spacer, an outer diameter D4s of the object-side surface of the fourth spacer, and an effective diameter DT42 of the image-side surface of the fourth lens satisfy the following: 0.4≤(D4s-d4s) / DT42<2.

45.

8. The optical imaging device according to claim 1, wherein: The on-axis distance T56 from the image side surface of the fifth lens to the object side surface of the sixth lens, the center thickness CT5 of the fifth lens, and the center thickness CT6 of the sixth lens satisfy the following conditions: 1.3 <T56 / (CT5+CT6)<1.85。 9. The optical imaging device according to claim 1, wherein: The object-side surface of the sixth lens and the image-side surface of the sixth lens each include at least one inflection point, and the curvature radius R11 of the object-side surface of the sixth lens and the curvature radius R12 of the image-side surface of the sixth lens satisfy the following relationship: 1.2 <R11 / R12<1.55。 10. The optical imaging device according to claim 1, wherein: The center thickness CP5 of the fifth spacer element, the center thickness CT5 of the fifth lens, and the center thickness CT6 of the sixth lens satisfy the following conditions: 0.55 <CP5 / (CT5+CT6)<1.05。 11. The optical imaging device according to claim 1, wherein: The set of spacer elements further comprises at least two auxiliary spacer elements.

12. The optical imaging device according to claim 11, wherein: The i-th auxiliary spacer element is placed between the image side surface of the i-th spacer element and the object side surface of the j-th lens, and the center thickness Cpi of the i-th spacer element, the center thickness Cpib of the i-th auxiliary spacer element, and the on-axis distance Tij from the image side surface of the i-th lens to the object side surface of the j-th lens satisfy the following: 0.35<(Cpi+Cpib) / Tij<2, where j=i+1, and i can be 1, 2, 3, 4, or 5.

13. The optical imaging device according to claim 11, wherein: The spacer element group includes a fifth auxiliary spacer element disposed between the image-side surface of the fifth spacer element and the sixth lens.

Images