Optical lens group

Abstract

This invention provides an optical lens assembly, comprising, from a first side to a second side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens sequentially along the optical axis. The first side is the light-emitting side, and the second side is the light-receiving side. The optical lens assembly is used for projection, and multiple imaging rays pass sequentially through the sixth, fifth, fourth, third, second, and first lenses from the second side, generating multiple imaging rays that exit from the first side. The first lens has a negative refractive index, and the optical axis region of the first side of the first lens is concave. The second, third, and fourth lenses all have positive refractive indices. The optical lens assembly contains only the aforementioned first to sixth lenses. This optical lens assembly has the advantages of small size, large field of view, good thermal stability, and the ability to maintain good optical quality even when allowing light of different wavelengths to pass through.

Description

[0001] This invention patent application is a divisional application. The original application number is 202011017585.X, the application date is September 24, 2020, and the invention title is: Optical Lens Assembly. Technical Field

[0002] This invention relates to the field of optics, and more particularly to an optical lens assembly. Background Technology

[0003] In recent years, the applications of portable electronic products have become increasingly diversified. Besides photography and video recording, the development of head-mounted devices has led to a gradual increase in the use of miniaturized projection lenses. A projection lens projects an image from a light source through an optical lens assembly; however, the focal plane of light varies depending on the wavelength. Furthermore, different ambient temperatures can also affect optical quality. These issues have become challenges in the development of optical lens assemblies. Summary of the Invention

[0004] This invention provides an optical lens assembly that is small in size, has a large field of view, excellent thermal stability, and can maintain good optical quality while allowing light of different wavelengths to pass through.

[0005] An embodiment of the present invention provides an optical lens assembly, which includes, from a first side to a second side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens sequentially along the optical axis. The first side is the light-emitting side, and the second side is the light-receiving side. The optical lens assembly is used for projection, and multiple imaging rays pass sequentially through the sixth lens, the fifth lens, the fourth lens, the third lens, the second lens, and the first lens via the second side, generating multiple imaging rays that exit from the first side. Each of the first to sixth lenses includes a first side facing the first side and allowing the imaging rays to pass through, and a second side facing the second side and allowing the imaging rays to pass through. The first lens has a negative refractive index, and the optical axis region of the first side of the first lens is concave. The second lens has a positive refractive index; the third lens has a positive refractive index; the fourth lens has a positive refractive index; and the optical lens assembly consists only of the aforementioned first to sixth lenses.

[0006] An embodiment of the present invention provides an optical lens assembly, comprising, from a first side to a second side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens sequentially along the optical axis. The first side is the light-emitting side, and the second side is the light-receiving side. The optical lens assembly is used for projection, and multiple imaging rays pass sequentially through the sixth lens, the fifth lens, the fourth lens, the third lens, the second lens, and the first lens via the second side, generating multiple imaging rays that exit from the first side. Each of the first to sixth lenses includes a first side facing the first side and allowing the imaging rays to pass through, and a second side facing the second side and allowing the imaging rays to pass through. The first lens has a negative refractive index; the second lens has a positive refractive index; the third lens has a positive refractive index, and the optical axis region of the first side of the third lens is concave; the fourth lens has a positive refractive index; the optical lens assembly consists only of the aforementioned first to sixth lenses.

[0007] An embodiment of the present invention provides an optical lens assembly, which includes, from a first side to a second side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens sequentially along the optical axis. The first side is the light-emitting side, and the second side is the light-receiving side. The optical lens assembly is used for projection, and multiple imaging rays pass sequentially through the sixth lens, the fifth lens, the fourth lens, the third lens, the second lens, and the first lens via the second side, generating multiple imaging rays that exit from the first side. Each of the first to sixth lenses includes a first side facing the first side and allowing the imaging rays to pass through, and a second side facing the second side and allowing the imaging rays to pass through. The first lens has a negative refractive index; the second lens has a positive refractive index; the third lens has a positive refractive index; the fourth lens has a positive refractive index, and the circumferential region of the first side of the fourth lens is concave. The optical lens assembly consists only of the aforementioned first to sixth lenses.

[0008] An embodiment of the present invention provides an optical lens assembly, comprising, from a first side to a second side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens sequentially along the optical axis. The first side is the light-emitting side, and the second side is the light-receiving side. The optical lens assembly is used for projection, and multiple imaging rays pass sequentially through the sixth lens, the fifth lens, the fourth lens, the third lens, the second lens, and the first lens via the second side, generating multiple imaging rays that exit from the first side. Each of the first to sixth lenses includes a first side facing the first side and allowing the imaging rays to pass through, and a second side facing the second side and allowing the imaging rays to pass through. The first lens has a negative refractive index; the second lens has a positive refractive index; the third lens has a positive refractive index; the fourth lens has a positive refractive index; the optical axis region of the second side of the fifth lens is convex; the optical lens assembly consists only of the aforementioned first to sixth lenses.

[0009] An embodiment of the present invention provides an optical lens assembly, which includes, from a first side to a second side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens sequentially along the optical axis. The first side is the light-emitting side, and the second side is the light-receiving side. The optical lens assembly is used for projection, and multiple imaging rays pass sequentially through the sixth lens, the fifth lens, the fourth lens, the third lens, the second lens, and the first lens via the second side, generating multiple imaging rays that exit from the first side. Each of the first to sixth lenses includes a first side facing the first side and allowing the imaging rays to pass through, and a second side facing the second side and allowing the imaging rays to pass through. The first lens has a negative refractive index; the second lens has a positive refractive index; the third lens has a positive refractive index; the fourth lens has a positive refractive index; the optical lens assembly consists only of the aforementioned first to sixth lenses, and satisfies the following condition: EFL / BFL ≥ 3.800.

[0010] An embodiment of the present invention provides an optical lens assembly, comprising, from a first side to a second side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens sequentially along the optical axis. The first side is the light-emitting side, and the second side is the light-receiving side. The optical lens assembly is used for projection, and multiple imaging rays pass sequentially through the sixth lens, the fifth lens, the fourth lens, the third lens, the second lens, and the first lens via the second side, generating multiple imaging rays that exit from the first side. Each of the first to sixth lenses includes a first side facing the first side and allowing the imaging rays to pass through, and a second side facing the second side and allowing the imaging rays to pass through. The first lens has a negative refractive index; the second lens has a positive refractive index; the third lens has a positive refractive index; the fourth lens has a positive refractive index; the optical lens assembly consists only of the aforementioned first to sixth lenses, and satisfies the following condition: TL / BFL ≥ 8.500.

[0011] The aforementioned optical lens group may also optionally satisfy any of the following conditions:

[0012] ALT / AAG ≥ 3.300

[0013] EFL / (T2+T4)≦2.800,

[0014] TTL / (G12+G23+G34)≧13.500,

[0015] (T2+T3+T4) / T1≧6.400,

[0016] V1+V2+V3≦110.000,

[0017] ALT / (AAG+BFL)≧2.000

[0018] TL / (T2+G23)≧8.200,

[0019] (EFL+AAG) / (T3+T5)≦3.500

[0020] TTL / (T5+G56+T6)≦3.000

[0021] (T5+T6) / T1≧4.700,

[0022] V3+V4+V5≧130.000

[0023] ALT / (T3+T6)≦3.600,

[0024] (TL+EFL) / (T3+G34)≦8.900

[0025] AAG / (G45+G56)≦1.700

[0026] TTL / AAG ≥ 4.800

[0027] (T4+G45+T5) / (T1+G12)≧2.800.

[0028] Where EFL is the effective focal length of the optical lens group, BFL is the distance on the optical axis from the second side surface of the sixth lens to the reference surface, the reference surface is the emitting surface or imaging surface, ALT is the sum of the thicknesses of the six lenses from the first lens to the sixth lens on the optical axis, AAG is the sum of the five air gaps from the first lens to the sixth lens on the optical axis, TL is the distance on the optical axis from the first side surface of the first lens to the second side surface of the sixth lens, and TTL is the distance on the optical axis from the first side surface of the first lens to the reference surface.

[0029] G12 is the air gap between the first lens and the second lens on the optical axis; G23 is the air gap between the second lens and the third lens on the optical axis; G34 is the air gap between the third lens and the fourth lens on the optical axis; G45 is the air gap between the fourth lens and the fifth lens on the optical axis; and G56 is the air gap between the fifth lens and the sixth lens on the optical axis.

[0030] T1 is the thickness of the first lens on the optical axis. T2 is the thickness of the second lens on the optical axis, T3 is the thickness of the third lens on the optical axis, T4 is the thickness of the fourth lens on the optical axis, T5 is the thickness of the fifth lens on the optical axis, and T6 is the thickness of the sixth lens on the optical axis.

[0031] V1 is the Abbe coefficient of the first lens, V2 is the Abbe coefficient of the second lens, V3 is the Abbe coefficient of the third lens, V4 is the Abbe coefficient of the fourth lens, and V5 is the Abbe coefficient of the fifth lens.

[0032] Based on the above, the beneficial effects of the optical lens group in the embodiments of the present invention are as follows: by satisfying the above-mentioned concave and convex surface arrangement design of the lens, the refractive index condition, and the design that satisfies the above-mentioned conditional formula, the optical lens group has small size, large field of view, good thermal stability, and can maintain good optical quality even when light of different wavelengths passes through. Attached Figure Description

[0033] Figure 1 A is a schematic diagram illustrating the application of the optical lens group of the present invention to a projection lens.

[0034] Figure 1 B is Figure 1 A front view of an embodiment of the multi-light source generating unit in A.

[0035] Figure 2 This is a schematic diagram illustrating the surface structure of a lens.

[0036] Figure 3 It is a schematic diagram illustrating the concave and convex structure of a lens and the focal point of light rays.

[0037] Figure 4 This is a schematic diagram illustrating the surface structure of a lens in Example 1.

[0038] Figure 5 This is a schematic diagram illustrating the surface structure of a lens in Example 2.

[0039] Figure 6 This is a schematic diagram illustrating the surface structure of a lens in Example 3.

[0040] Figure 7 This is a schematic diagram of the optical lens group according to the first embodiment of the present invention.

[0041] Figure 8 This is a diagram showing the longitudinal spherical aberration and various aberrations of the optical lens group in the first embodiment.

[0042] Figure 9 This is a detailed optical data table diagram of the optical lens group according to the first embodiment of the present invention.

[0043] Figure 10 This is a table of aspherical parameters of the optical lens group according to the first embodiment of the present invention.

[0044] Figure 11 This is a schematic diagram of the optical lens group according to the second embodiment of the present invention.

[0045] Figure 12 This is a diagram showing the longitudinal spherical aberration and various aberrations of the optical lens group in the second embodiment.

[0046] Figure 13This is a detailed optical data table diagram of the optical lens group according to the second embodiment of the present invention.

[0047] Figure 14 This is a table of aspherical parameters of the optical lens group according to the second embodiment of the present invention.

[0048] Figure 15 This is a schematic diagram of the optical lens group according to the third embodiment of the present invention.

[0049] Figure 16 This is a diagram showing the longitudinal spherical aberration and various aberrations of the optical lens group in the third embodiment.

[0050] Figure 17 This is a detailed optical data table diagram of the optical lens group according to the third embodiment of the present invention.

[0051] Figure 18 This is a table of aspherical parameters of the optical lens group according to the third embodiment of the present invention.

[0052] Figure 19 This is a schematic diagram of the optical lens group according to the fourth embodiment of the present invention.

[0053] Figure 20 This is a diagram showing the longitudinal spherical aberration and various aberrations of the optical lens group in the fourth embodiment.

[0054] Figure 21 This is a detailed optical data table diagram of the optical lens group according to the fourth embodiment of the present invention.

[0055] Figure 22 This is a table of aspherical parameters of the optical lens group according to the fourth embodiment of the present invention.

[0056] Figure 23 This is a schematic diagram of the optical lens group according to the fifth embodiment of the present invention.

[0057] Figure 24 This is a diagram showing the longitudinal spherical aberration and various aberrations of the optical lens group in the fifth embodiment.

[0058] Figure 25 This is a detailed optical data table diagram of the optical lens group according to the fifth embodiment of the present invention.

[0059] Figure 26 This is a table of aspherical parameters of the optical lens group according to the fifth embodiment of the present invention.

[0060] Figure 27 and Figure 28 This is a numerical table diagram showing the important parameters and their relationships of the optical lens group in the first to fifth embodiments of the present invention. Detailed Implementation

[0061] Before describing the invention in detail, the symbols in the accompanying drawings are clearly explained: 0: aperture; 1: first lens; 2: second lens; 3: third lens; 4: fourth lens; 5: fifth lens; 6: sixth lens; 10: optical lens group; 20: projection lens; 11, 21, 31, 41, 51, 61, 110, 410, 510: first side surface; 12, 22, 32, 42, 52, 62, 120, 320: second side surface; 100a: reference plane; 100, 200, 300, 400, 50 0: Lens; 130: Assembly section; 115, 125, 127, 215, 217, 225, 227, 315, 325, 415, 417, 425, 427, 515, 517, 525, 615, 617, 625, 627, Z1: Optical axis region; 116, 126, 216, 218, 226, 228, 316, 326, 416, 426, 428, 516, 526, 528, 616, 626, Z2: Circumferential region; 211, 212: Parallel rays;

[0062] A1: First side; A2: Second side; a, b, c: Imaging rays; CP: Center point; CP1: First center point; CP2: Second center point; EL: Extension line; I: Optical axis; Lm: Edge ray; Lc: Principal ray; LCR: Radius of emission circle; M, R: Intersection point; OB: Optical boundary; P, Pa, Pb, Pc: Light source; PM: Multi-source generation unit; TP1: First conversion point; TP2: Second conversion point; Z3: Relay region; ω: Maximum half-emission angle.

[0063] Please refer to Figure 1 In one embodiment, the optical lens group 10 of this invention is suitable for projection. The projection lens 20 emits multiple imaging rays from a multi-source generating unit PM, which, through the optical lens group 10 of this invention, generate multiple imaging rays a, b, and c with different exit angles for projection onto the environment in front. The range of exit angles is, for example, between -ω degrees and ω degrees, where ω is the maximum half-exit angle of the optical lens group 10. The imaging rays a, b, and c are not limited to any particular form; their directions are described here as dashed lines. The number of imaging rays a, b, and c is not limited to three; it can be any number other than three or one. Figure 1In diagram A, imaging rays a, b, and c are used as representatives. These rays each have a chief ray and a marginal ray (not shown in the diagram). The chief and marginal rays of imaging ray a are approximately parallel to each other; similarly, the chief and marginal rays of imaging ray b and imaging ray c are also approximately parallel to each other. In detail... Figure 1 The imaging rays a, b, and c of A are respectively... Figure 1 The light emitted by the light sources Pa, Pb, and Pc at different positions in B, from Figure 1 As can be seen from A, the imaging rays emitted by the light source P at different positions will all exit the optical lens group 10 in a parallel manner after passing through the optical lens group 10, but the direction of exit will vary depending on the position. Figure 1 For example, light source Pa passes through optical lens group 10 and exits optical lens group 10 obliquely to the lower left and parallel (as shown by imaging ray a). Light source Pb at another position passes through optical lens group 10 and exits optical lens group 10 directly to the left and parallel (as shown by imaging ray b). Light source Pc at yet another position passes through optical lens group 10 and exits optical lens group 10 obliquely to the upper left and parallel (as shown by imaging ray c).

[0064] Please refer to Figure 1 In one embodiment, the multi-source light generation unit PM includes a plurality of light sources P arranged in an array. The light sources P are, for example, near-infrared light sources or green light sources, but this invention is not limited thereto. Furthermore, in other embodiments, these light sources P may be arranged in a ring or other arrangements, and this invention is not limited thereto. The types of light sources P include, for example, laser diodes, light-emitting diodes (LEDs), mini LEDs, or micro LEDs, wherein the size range of mini LEDs is, for example, between 75 μm and 300 μm, and the size range of micro LEDs is, for example, less than 75 μm. The emitting surfaces of these light sources P form a reference surface 100a. In one embodiment, the reference surface 100a is the emitting surface of the multi-source light generation unit PM.

[0065] It should be noted that if the optical lens group 10 of the embodiments of the present invention is used for projection, for example, if the optical lens group 10 is the projection lens of a projector, then the following description of the optical specifications of the embodiments of the present invention is based on the assumption that reversely tracking of the light direction means that a parallel imaging ray passes through the optical lens group 10 from the first side to the reference surface 100a located on the second side for focusing and imaging. The reference surface 100a is the light-emitting surface of the multi-source generating unit PM, the second side is the side facing the multi-source generating unit PM (i.e., the incident light side), and the first side is the opposite side (i.e., the emitting light side). Furthermore, if the optical lens group 10 of the embodiments of the present invention is used for projection, then the second side surface of each lens of the optical lens group 10 referred to below refers to the surface facing the multi-source generating unit PM (i.e., the incident light surface), and the first side surface of each lens of the optical lens group 10 referred to below is the opposite surface (i.e., the emitting light surface).

[0066] If the optical lens group 10 of the embodiments of the present invention is used for imaging, for example, if the optical lens group 10 is the imaging lens of a camera, then the following description of the criteria for determining the optical specifications of the embodiments of the present invention assumes that the ray tracing is a parallel imaging ray that passes through the optical lens group 10 from the first side to the reference surface 100a located on the second side for focusing and imaging, wherein the reference surface 100a is the imaging surface, the second side is the side facing the imaging surface (i.e., the image side), and the first side is the side facing the object to be photographed (i.e., the object side). Furthermore, if the optical lens group 10 of the embodiments of the present invention is used for imaging, then the second side surface of each lens of the optical lens group 10 referred to below refers to the surface facing the imaging surface (i.e., the image side surface), and the first side surface of each lens of the optical lens group 10 referred to below refers to the surface facing the object to be photographed (i.e., the object side surface).

[0067] The terms "optical axis region," "circumferential region," "concave surface," and "convex surface" used in this specification and the claims should be interpreted based on the definitions listed in this specification.

[0068] The optical system described in this specification includes at least one lens that receives imaging rays incident on the optical system, ranging from parallel to the optical axis to within a half-angle of view (HFOV) relative to the optical axis. The imaging rays (when the optical lens group is the imaging lens of a camera) or the reverse tracing of the imaging rays (when the optical lens group is the projection lens of a projector) image onto a reference plane through the optical system. The statement "a lens has a positive refractive index (or negative refractive index)" means that the paraxial refractive index of the lens, calculated using Gaussian optics theory, is positive (or negative). The statement "the first side (or second side) of the lens" is defined as the specific range through which the imaging rays pass on the lens surface. The imaging rays include at least two types of rays: the chief ray (Lc) and the marginal ray (Lm) (e.g., ...). Figure 2(As shown). The first side (or second side) of the lens may be divided into different regions depending on the location, including an optical axis region, a circumferential region, or one or more relay regions in some embodiments, which will be described in detail below.

[0069] Figure 2 This is a radial sectional view of lens 100. Two reference points are defined on the surface of lens 100: a center point and a transition point. The center point of the lens surface is the intersection of this surface and the optical axis I. For example... Figure 2 As illustrated, the first center point CP1 is located on the first side surface 110 of lens 100, and the second center point CP2 is located on the second side surface 120 of lens 100. A transition point is a point on the lens surface whose tangent is perpendicular to the optical axis I. The optical boundary OB of the lens surface is defined as the point where the outermost radially outermost edge ray Lm passing through the lens surface intersects the lens surface. All transition points are located between the optical axis I and the optical boundary OB of the lens surface. Furthermore, if a single lens surface has multiple transition points, these transition points are named sequentially from the first transition point in a radially outward direction. For example, the first transition point TP1 (closest to the optical axis I), the second transition point TP2 (as shown in the example), and the third transition point TP2 (as shown in the example) are named sequentially from the first transition point in a radially outward direction. Figure 5 (as shown) and the Nth conversion point (farthest from optical axis I).

[0070] The region from the center point to the first conversion point TP1 is defined as the optical axis region, which includes the center point. The region radially outward from the Nth conversion point farthest from the optical axis I to the optical boundary OB is defined as the circumferential region. In some embodiments, a relay region may be additionally included between the optical axis region and the circumferential region; the number of relay regions depends on the number of conversion points.

[0071] When a ray parallel to optical axis I passes through a region, if the ray bends towards optical axis I and intersects with optical axis I at the second side A2 of the lens, then that region is a convex surface. When a ray parallel to optical axis I passes through a region, if the extension of the ray intersects with optical axis I at the first side A1 of the lens, then that region is a concave surface.

[0072] In addition, see Figure 2 The lens 100 may also include an assembly portion 130 extending radially outward from the optical boundary OB. The assembly portion 130 is generally used for assembling the lens 100 to a corresponding element (not shown) in an optical system. Imaging rays do not reach the assembly portion 130. The structure and shape of the assembly portion 130 are merely illustrative examples of the invention and are not intended to limit the scope of the invention. The assembly portion 130 of the lens discussed below may be partially or entirely omitted in the drawings.

[0073] See Figure 3Define the region between the center point CP and the first conversion point TP1 as the optical axis region Z1. Define the region between the first conversion point TP1 and the optical boundary OB of the lens surface as the circumferential region Z2. For example... Figure 3 As shown, parallel ray 211 intersects optical axis I at the second side A2 of lens 200 after passing through optical axis region Z1. That is, the focal point of parallel ray 211 passing through optical axis region Z1 is located at point R on the second side A2 of lens 200. Since the ray intersects optical axis I at the second side A2 of lens 200, optical axis region Z1 is convex. Conversely, parallel ray 212 diverges after passing through circular region Z2. Figure 3 As shown, the extension EL of parallel ray 212 after passing through the circular region Z2 intersects the optical axis I on the first side A1 of the lens 200. That is, the focal point of parallel ray 212 after passing through the circular region Z2 is located at point M on the first side A1 of the lens 200. Since the extension EL of the ray intersects the optical axis I at the first side A1 of the lens 200, the circular region Z2 is concave. Figure 3 In the lens 200 shown, the first conversion point TP1 is the boundary between the optical axis region and the circumferential region, that is, the first conversion point TP1 is the boundary point between the convex surface and the concave surface.

[0074] On the other hand, the convexity / concavity of the optical axis region can also be determined using the method commonly used by those knowledgeable in the field: judging the convexity / concavity of the lens's optical axis region by the sign of the paraxial radius of curvature (R-value). The R-value is commonly used in optical design software, such as Zemax or CodeV. It is also frequently found in lens data sheets within optical design software. For the first side, a positive R-value indicates a convex optical axis region; a negative R-value indicates a concave optical axis region. Conversely, for the second side, a positive R-value indicates a concave optical axis region; a negative R-value indicates a convex optical axis region. This method yields results consistent with the aforementioned method using the intersection of a ray / ray extension with the optical axis, where the focal point of a ray parallel to the optical axis is located on either the first or second side of the lens to determine the convexity / concavity. The terms "a region is convex (or concave)," "a region is convex (or concave)," or "a convex (or concave) region" used in this specification may be used interchangeably.

[0075] Figures 4 to 6 Examples of determining the surface shape and boundaries of the lens region in various situations are provided, including the aforementioned optical axis region, circumferential region, and relay region.

[0076] Figure 4 This is a radial sectional view of lens 300. See also... Figure 4The second side surface 320 of lens 300 has only one transition point TP1 within the optical boundary OB. The optical axis region Z1 and circumferential region Z2 of the second side surface 320 of lens 300 are as follows... Figure 4 As shown. The R value of this second side surface 320 is positive (i.e., R>0), therefore, the optical axis region Z1 is concave.

[0077] Generally, the surface shape of each region bounded by a transition point will be opposite to that of its adjacent regions. Therefore, the transition point can be used to define the change in surface shape, i.e., from the transition point, a surface changes from concave to convex or from convex to concave. Figure 4 In the middle, since the optical axis region Z1 is concave and its shape changes at the transition point TP1, the circumferential region Z2 is convex.

[0078] Figure 5 This is a radial sectional view of lens 400. See also... Figure 5 The first side surface 410 of lens 400 has a first conversion point TP1 and a second conversion point TP2. The area between the optical axis I and the first conversion point TP1 is defined as the optical axis region Z1 of the first side surface 410. The R value of this first side surface 410 is positive (i.e., R>0), therefore, the optical axis region Z1 is convex.

[0079] A circular region Z2 is defined between the second conversion point TP2 and the optical boundary OB of the first side surface 410 of the lens 400. This circular region Z2 of the first side surface 410 is also convex. Furthermore, a relay region Z3 is defined between the first conversion point TP1 and the second conversion point TP2. This relay region Z3 of the first side surface 410 is concave. See again. Figure 5 The first side surface 410, radially outward from the optical axis I, sequentially includes the optical axis region Z1 between the optical axis I and the first conversion point TP1, the relay region Z3 located between the first conversion point TP1 and the second conversion point TP2, and the circumferential region Z2 between the second conversion point TP2 and the optical boundary OB of the first side surface 410 of the lens 400. Since the optical axis region Z1 is convex, and its surface shape changes to concave from the first conversion point TP1, the relay region Z3 is concave. And since its surface shape changes to convex again from the second conversion point TP2, the circumferential region Z2 is convex.

[0080] Figure 6 This is a radial sectional view of lens 500. The first side surface 510 of lens 500 has no transition point. For a lens surface without a transition point, such as the first side surface 510 of lens 500, the region from 0% to 50% of the distance measured from the optical axis I to the optical boundary OB of the lens surface is defined as the optical axis region, and the region from 50% to 100% of the distance measured from the optical axis I to the optical boundary OB of the lens surface is defined as the circumferential region. See also... Figure 6The lens 500 shown defines the optical axis region Z1 of the first side surface 510 as 50% of the distance between the optical axis I and the optical boundary OB of the lens 500 surface measured from the optical axis I. The R value of this first side surface 510 is positive (i.e., R>0), therefore, the optical axis region Z1 is convex. Since the first side surface 510 of the lens 500 has no transition point, the circumferential region Z2 of the first side surface 510 is also convex. The lens 500 may further have an assembly portion (not shown) extending radially outward from the circumferential region Z2.

[0081] Figure 7 This is a schematic diagram of the optical lens assembly according to the first embodiment of the present invention. Figure 8 A to Figure 8 D represents the longitudinal spherical aberration and various aberration diagrams of the optical lens group in the first embodiment. Please refer to [the diagram first]. Figure 7 The optical lens group 10 of the first embodiment of the present invention includes, in sequence along an optical axis I from a first side A1 to a second side A2, an aperture 0, a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, and a sixth lens 6. When multiple imaging rays are emitted from the reference surface 100a (i.e., the light-emitting surface of the multi-source generating unit PM) and enter the optical lens group 10, after passing through the sixth lens 6, the fifth lens 5, the fourth lens 4, the third lens 3, the second lens 2, the first lens 1, and the aperture 0, multiple imaging rays with different exit angles are generated at the first side A1 and exit the optical lens group 10. It should be noted that in this embodiment, the second side A2 is the side facing the multi-source generating unit PM, and the first side A1 is the opposite side; the second side A2 is the light-incident side, and the first side A1 is the light-exit side.

[0082] The first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, and the sixth lens 6 each have a first side surface 11, 21, 31, 41, 51, 61 facing the first side A1 and allowing imaging light to pass through, and a second side surface 12, 22, 32, 42, 52, 62 facing the second side A2 and allowing imaging light to pass through.

[0083] In this embodiment, the materials of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5 and the sixth lens 6 are plastic, plastic, glass, plastic, plastic and plastic, respectively, but the present invention is not limited thereto.

[0084] The first lens 1 has a negative refractive index. The optical axis region 115 of the first side surface 11 of the first lens 1 is concave, and its circumferential region 116 is also concave. The optical axis region 125 of the second side surface 12 of the first lens 1 is convex, and its circumferential region 126 is also convex. In this embodiment, both the first side surface 11 and the second side surface 12 of the first lens 1 are aspherical, but the present invention is not limited thereto.

[0085] The second lens 2 has a positive refractive index. The optical axis region 215 of the first side surface 21 of the second lens 2 is convex, and its circumferential region 216 is concave. The optical axis region 225 of the second side surface 22 of the second lens 2 is concave, and its circumferential region 226 is convex. In this embodiment, both the first side surface 21 and the second side surface 22 of the second lens 2 are aspherical, but the present invention is not limited thereto.

[0086] The third lens 3 has a positive refractive index. The optical axis region 315 of the first side surface 31 of the third lens 3 is concave, and its circumferential region 316 is also concave. The optical axis region 325 of the second side surface 32 of the third lens 3 is convex, and its circumferential region 326 is convex. In this embodiment, both the first side surface 31 and the second side surface 32 of the third lens 3 are spherical, but the present invention is not limited thereto.

[0087] The fourth lens 4 has a positive refractive index. The optical axis region 415 of the first side surface 41 of the fourth lens 4 is concave, and its circumferential region 416 is also concave. The optical axis region 425 of the second side surface 42 of the fourth lens 4 is convex, and its circumferential region 426 is convex. In this embodiment, both the first side surface 41 and the second side surface 42 of the fourth lens 4 are aspherical, but the invention is not limited thereto.

[0088] The fifth lens 5 has a positive refractive index. The optical axis region 515 of the first side surface 51 of the fifth lens 5 is convex, and its circumferential region 516 is concave. The optical axis region 525 of the second side surface 52 of the fifth lens 5 is convex, and its circumferential region 526 is concave. In this embodiment, both the first side surface 51 and the second side surface 52 of the fifth lens 5 are aspherical, but the present invention is not limited thereto.

[0089] The sixth lens 6 has a negative refractive index. The optical axis region 615 of the first side surface 61 of the sixth lens 6 is concave, and its circumferential region 616 is convex. The optical axis region 625 of the second side surface 62 of the sixth lens 6 is concave, and its circumferential region 626 is convex. In this embodiment, both the first side surface 61 and the second side surface 62 of the sixth lens 6 are aspherical, but the invention is not limited thereto.

[0090] The optical lens group 10 of the first embodiment exhibits good thermal stability. Furthermore, the optical lens group 10 exhibits extremely small focal shift under different ambient temperatures. For example, setting a base temperature of 20°C, the focal shift of the optical lens group 10 is 0.000 mm at 20°C; 0.019 mm at -25°C; 0.008 mm at 0°C; and -0.020 mm at 70°C.

[0091] Other detailed optical data for the first embodiment are as follows: Figure 9 As shown, the effective focal length (EFL) of the first embodiment is 5.026 mm, the half field of view (HFOV) is 60.000 degrees, the system length (TTL) is 8.444 mm, the f-number (Fno) is 2.513, and the light circle radius (LCR) is 4.114 mm. The system length (TTL) refers to the distance along the optical axis I from the first side surface 11 of the first lens 1 to the reference surface 100a. When the optical lens group 10 is the projection lens of a projector, the "aperture value" in this specification is calculated based on the principle of light reversibility, treating aperture 0 as the entrance pupil. When the optical lens group 10 is the imaging lens of a camera, the aperture value of aperture 0 is the generally defined aperture value; that is, aperture 0 is the entrance pupil, and the aperture value is calculated based on this entrance pupil.

[0092] Furthermore, in this embodiment, the ten surfaces of the first side surface 11, 21, 41, 51, 61 and the second side surface 12, 22, 42, 52, 62 of the first lens 1, the second lens 2, the fourth lens 4, the fifth lens 5 and the sixth lens 6 are all aspherical surfaces, and these aspherical surfaces are defined according to the following formula (2):

[0093]

[0094] in:

[0095] Y: The distance between a point on the aspherical curve and the optical axis I;

[0096] Z: Depth of the aspherical surface (the perpendicular distance between a point on the aspherical surface that is Y away from the optical axis I and the tangent plane that is tangent to the vertex on the optical axis I of the aspherical surface).

[0097] R: Radius of curvature of the lens surface near the optical axis I;

[0098] K: Conic constant;

[0099] a i : The i-th order aspherical coefficient.

[0100] The aspherical coefficients of the first side surface 11 and the second side surface 12 of the first lens 1, the first side surface 21 and the second side surface 22 of the second lens 2, the first side surface 41 and the second side surface 42 of the fourth lens 4, the first side surface 51 and the second side surface 52 of the fifth lens 5, and the first side surface 61 and the second side surface 62 of the sixth lens 6 in formula (2) are as follows: Figure 10 As shown. Among them, Figure 10 The number 11 in the middle column indicates that it is the aspherical coefficient of the first side surface 11 of the first lens 1, and so on for the other columns.

[0101] Furthermore, the important parameters of the optical lens group 10 in the first embodiment and their relationships are as follows: Figure 27 and Figure 28 As shown.

[0102] in,

[0103] f1 is the focal length of the first lens 1; f2 is the focal length of the second lens 2; f3 is the focal length of the third lens 3; f4 is the focal length of the fourth lens 4; f5 is the focal length of the fifth lens 5; f6 is the focal length of the sixth lens 6.

[0104] n1 is the refractive index of the first lens 1; n2 is the refractive index of the second lens 2; n3 is the refractive index of the third lens 3; n4 is the refractive index of the fourth lens 4; n5 is the refractive index of the fifth lens 5; n6 is the refractive index of the sixth lens 6.

[0105] V1 is the Abbe number of the first lens 1, which can also be called the dispersion coefficient; V2 is the Abbe number of the second lens 2; V3 is the Abbe number of the third lens 3; V4 is the Abbe number of the fourth lens 4; V5 is the Abbe number of the fifth lens 5; V6 is the Abbe number of the sixth lens 6.

[0106] T1 is the thickness of the first lens 1 on optical axis I; T2 is the thickness of the second lens 2 on optical axis I; T3 is the thickness of the third lens 3 on optical axis I; T4 is the thickness of the fourth lens 4 on optical axis I; T5 is the thickness of the fifth lens 5 on optical axis I; T6 is the thickness of the sixth lens 6 on optical axis I.

[0107] G12 is the air gap between the first lens 1 and the second lens 2 on the optical axis I; G23 is the air gap between the second lens 2 and the third lens 3 on the optical axis I; G34 is the air gap between the third lens 3 and the fourth lens 4 on the optical axis I; G45 is the air gap between the fourth lens 4 and the fifth lens 5 on the optical axis I; G56 is the air gap between the fifth lens 5 and the sixth lens 6 on the optical axis I.

[0108] AAG is the sum of the five air gaps on optical axis I for lenses 1 to 6, namely G12, G23, G34, G45, and G56; ALT is the sum of the six lens thicknesses on optical axis I for lenses 1 to 6, namely T1, T2, T3, T4, T5, and T6; EFL is the effective focal length of optical lens group 10; BFL is the distance on optical axis I from the second side surface 62 of lens 6 to the reference surface 100a, which is either the emitting surface or the imaging surface; TTL is the distance on optical axis I from the first side surface 11 of lens 1 to the reference surface 100a, which is either the emitting surface or the imaging surface; TL is the distance on optical axis I from the first side surface 11 of lens 1 to the second side surface 62 of lens 6; HFOV is the half-angle of optical lens group 10, which is the maximum half-angle of light emitted from optical lens group 10. Figure 1 As shown in A, ω; LCR (Light circle radius) is the radius of the emitting circle (denoted as LCR, such as...). Figure 1 (as shown in B), is the radius of the smallest circumcircle of the light-emitting surface of the multi-source generating unit PM, or when the optical lens group 10 is used for imaging, its value can also be the image height (ImgH) of the optical lens group 10; Fno is the aperture value, which is the effective aperture value calculated based on the principle of light reversibility for the imaging light emitted by the optical lens group 10. In the embodiments of the present invention, aperture 0 is the aperture value calculated as the entrance pupil.

[0109] Figure 27 In the table, the units for the values ​​from column T1 to column AAG are all millimeters (mm).

[0110] See also Figure 8 A to Figure 8 D, Figure 8 The diagram illustrating A shows the longitudinal spherical aberration on reference plane 100a in the first embodiment when the wavelengths are 520 nm, 530 nm, and 540 nm. Figure 8 B and Figure 8 The diagrams for C illustrate the field curvature aberration in the sagittal and tangential directions on the reference plane 100a for wavelengths of 520 nm, 530 nm, and 240 nm, respectively, in the first embodiment. Figure 8 The diagram for D illustrates the distortion aberration on reference plane 100a in the first embodiment when the wavelengths are 520 nm, 530 nm, and 540 nm. This first embodiment's longitudinal spherical aberration diagram... Figure 8 In A, the curves formed by each wavelength are very close and move towards the center, indicating that off-axis light rays at different heights of each wavelength are concentrated near the imaging point. The skewing of the curves for each wavelength shows that the imaging point deviation of off-axis light rays at different heights is controlled within the range of ±0.012mm. Therefore, this embodiment does significantly improve spherical aberration of the same wavelength. In addition, the distances between the three representative wavelengths are also quite close, indicating that the imaging positions of light rays of different wavelengths are quite concentrated, thus significantly improving chromatic aberration.

[0111] exist Figure 8 In the field curvature aberration diagram of B, the focal length variation for the three representative wavelengths falls within ±0.04 mm across the entire field of view; Figure 8 In the field curvature aberration diagram of C, the focal length variation for the three representative wavelengths falls within ±0.04 mm across the entire field of view; this demonstrates that the optical system of this first embodiment can effectively eliminate aberrations. Figure 8 The distortion aberration diagram of D shows that the distortion aberration of the first embodiment is maintained within the range of ±60%, indicating that the distortion aberration of the first embodiment meets the optical quality requirements of the optical system. Therefore, it can be said that the first embodiment can still provide better optical quality than existing optical lens groups, even with the system length shortened to about 8.444 mm.

[0112] Figure 11 This is a schematic diagram of the optical lens assembly according to the second embodiment of the present invention. Figure 12 A to Figure 12 D represents the longitudinal spherical aberration and various aberration diagrams of the optical lens group in the second embodiment. Please refer to [the diagram first]. Figure 11 This invention provides a second embodiment of the optical lens group 10, which is generally similar to the first embodiment, except that the optical data, aspherical coefficients, and parameters of lenses 1, 2, 3, 4, 5, and 6 are slightly different. Furthermore, in this embodiment, the optical axis region 127 of the second side surface 12 of the first lens 1 is concave, the optical axis region 217 of the first side surface 21 of the second lens 2 is concave, the optical axis region 227 of the second side surface 22 of the second lens 2 is convex, the optical axis region 417 of the first side surface 41 of the fourth lens 4 is convex, the optical axis region 517 of the first side surface 51 of the fifth lens 5 is concave, and the circumferential region 528 of the second side surface 52 of the fifth lens 5 is convex. Moreover, in this embodiment, the second lens 2 and the fourth lens 4 are made of glass. It should be noted that, for clearer illustration, [further details are needed]. Figure 11 The labels for the optical axis region and the circumferential region that are similar in shape to the first embodiment are omitted.

[0113] The optical lens group 10 of the second embodiment exhibits excellent thermal stability. Furthermore, the optical lens group 10 exhibits extremely small focal length shifts under different ambient temperatures. For example, setting a base temperature of 20°C, the focal length shift of the optical lens group 10 is 0.000 mm at 20°C; -0.011 mm at -25°C; -0.005 mm at 0°C; and 0.012 mm at 70°C.

[0114] Detailed optical data for optical lens group 10 are as follows: Figure 13 As shown, the second embodiment has an effective focal length (EFL) of 3.897 mm, a half field of view (HFOV) of 60.000 degrees, a system length (TTL) of 7.464 mm, an aperture value (f-number, Fno) of 1.949, and a light circle radius (LCR) of 3.111 mm.

[0115] like Figure 14 As shown, the aspherical coefficients of the first side surface 11 and the second side surface 12 of the first lens 1, the first side surface 21 and the second side surface 22 of the second lens 2, the first side surface 41 and the second side surface 42 of the fourth lens 4, the first side surface 51 and the second side surface 52 of the fifth lens 5 and the first side surface 61 and the second side surface 62 of the sixth lens 6 in the second embodiment are in formula (2).

[0116] Furthermore, the important parameters of the optical lens group 10 in the second embodiment and their relationships are as follows: Figure 27 and Figure 28 As shown.

[0117] See also Figure 12 A to Figure 12 D, Figure 12 The diagram illustrating the second embodiment shows the longitudinal spherical aberration on reference plane 100a when the wavelengths are 520 nm, 530 nm, and 540 nm. Figure 12 B and Figure 12 The diagrams for C illustrate the field curvature aberration in the sagittal and tangential directions on the reference plane 100a for wavelengths of 520 nm, 530 nm, and 540 nm, respectively, in the second embodiment. Figure 12The diagram for D illustrates the distortion aberration on reference plane 100a in the second embodiment when the wavelengths are 520 nm, 530 nm, and 540 nm. This second embodiment's longitudinal spherical aberration diagram... Figure 12 In A, the imaging point deviation of off-axis rays at different heights is controlled within ±0.025mm. Figure 12 In the field curvature aberration diagram of B, the focal length variation for the three representative wavelengths falls within ±0.04 mm across the entire field of view. Figure 12 In the field curvature aberration diagram of C, the focal length variation of the three representative wavelengths falls within ±0.04 mm across the entire field of view. Figure 12 The distortion aberration diagram of D shows that the distortion aberration of this second embodiment is maintained within the range of ±60%. This demonstrates that, compared to existing optical lens groups, this second embodiment still provides better optical quality even with a system length reduced to approximately 7.464 mm.

[0118] As can be seen from the above description, the advantage of the second embodiment compared to the first embodiment is that the system length (i.e., TTL) of the second embodiment is shorter than that of the first embodiment.

[0119] Figure 15 This is a schematic diagram of the optical lens assembly according to the third embodiment of the present invention. Figure 16 A to Figure 16 D represents the longitudinal spherical aberration and various aberration diagrams of the optical lens group in the third embodiment. Please refer to [the diagram first]. Figure 15 This invention provides a third embodiment of the optical lens group 10, which is generally similar to the first embodiment, except that the optical data, aspherical coefficients, and parameters between lenses 1, 2, 3, 4, 5, and 6 are slightly different. Furthermore, in this embodiment, the optical axis region 517 of the first side surface 51 of the fifth lens 5 is concave, and the circumferential region 528 of the second side surface 52 of the fifth lens 5 is convex. It should be noted that, for clearer illustration, Figure 15 The labels for the optical axis region and the circumferential region that are similar in shape to the first embodiment are omitted.

[0120] The optical lens group 10 of the third embodiment exhibits excellent thermal stability. Furthermore, the optical lens group 10 exhibits extremely small focal length shifts under different ambient temperatures. For example, setting a base temperature of 20°C, the focal length shift of the optical lens group 10 is 0.000 mm at 20°C; 0.003 mm at -25°C; 0.001 mm at 0°C; and -0.003 mm at 70°C.

[0121] Detailed optical data for optical lens group 10 are as follows: Figure 17 As shown, the effective focal length (EFL) of the third embodiment is 4.181 mm, the half field of view (HFOV) is 60.000 degrees, the system length (i.e., TTL) is 7.990 mm, the aperture number (f-number, Fno) is 2.090, and the light circle radius (LCR) is 3.380 mm.

[0122] like Figure 18 As shown, the aspherical coefficients of the first side surface 11 and the second side surface 12 of the first lens 1, the first side surface 21 and the second side surface 22 of the second lens 2, the first side surface 41 and the second side surface 42 of the fourth lens 4, the first side surface 51 and the second side surface 52 of the fifth lens 5, and the first side surface 61 and the second side surface 62 of the sixth lens 6 in the third embodiment are in formula (2).

[0123] Furthermore, the important parameters of the optical lens group 10 in the third embodiment and their relationships are as follows: Figure 27 and Figure 28 As shown.

[0124] See also Figure 16 A to Figure 16 D, Figure 16 The diagram illustrating the third embodiment of A shows the longitudinal spherical aberration on reference plane 100a when the wavelengths are 520 nm, 530 nm, and 540 nm. Figure 16 B and Figure 16 The diagrams for C illustrate the field curvature aberration in the sagittal and tangential directions on the reference plane 100a for wavelengths of 520 nm, 530 nm, and 540 nm, respectively, in the third embodiment. Figure 16 The diagram for D illustrates the distortion aberration on reference plane 100a in the third embodiment when the wavelengths are 520 nm, 530 nm, and 540 nm. This third embodiment's longitudinal spherical aberration diagram... Figure 16 In A, the imaging point deviation of off-axis rays at different heights is controlled within ±0.05mm. Figure 16 In the field curvature aberration diagram of B, the focal length variation for the three representative wavelengths falls within ±0.06 mm across the entire field of view. Figure 16In the field curvature aberration diagram of C, the focal length variation of the three representative wavelengths falls within ±0.06 mm across the entire field of view. Figure 16 The distortion aberration diagram of D shows that the distortion aberration of this third embodiment is maintained in the range of -60% to 0%. This indicates that, compared to existing optical lens groups, this third embodiment still provides better optical quality even with a system length reduced to approximately 7.990 mm.

[0125] As can be seen from the above description, the advantages of the third embodiment compared to the first embodiment are: the system length of the third embodiment is shorter than that of the first embodiment; the thickness difference between the lens optical axis and the circumferential region in the third embodiment is smaller than that in the first embodiment, making it easier to manufacture and thus resulting in a higher yield.

[0126] Figure 19 This is a schematic diagram of the optical lens assembly according to the fourth embodiment of the present invention. Figure 20 A to Figure 20 D represents the longitudinal spherical aberration and various aberration diagrams of the optical lens group in the fourth embodiment. Please refer to [the diagram first]. Figure 19 This invention provides a fourth embodiment of the optical lens group 10, which is generally similar to the first embodiment, except that the optical data, aspherical coefficients, and parameters between lenses 1, 2, 3, 4, 5, and 6 are slightly different. Furthermore, in this embodiment, the optical axis region 417 of the first side surface 41 of the fourth lens 4 is convex, the optical axis region 427 of the second side surface 42 of the fourth lens 4 is concave, the fifth lens 5 has a negative refractive index, the optical axis region 517 of the first side surface 51 of the fifth lens 5 is concave, the circumferential region 528 of the second side surface 52 of the fifth lens 5 is convex, and the sixth lens 6 has a positive refractive index, and the optical axis region 617 of the first side surface 61 of the sixth lens 6 is convex. It should be noted that, for clearer illustration, [further details are needed]. Figure 19 The labels for the optical axis region and the circumferential region that are similar in shape to the first embodiment are omitted.

[0127] The optical lens group 10 of the fourth embodiment exhibits excellent thermal stability. Furthermore, the optical lens group 10 exhibits extremely small focal length shifts under different ambient temperatures. For example, setting a base temperature of 20°C, the focal length shift of the optical lens group 10 is 0.000 mm at 20°C; 0.015 mm at -25°C; 0.007 mm at 0°C; and -0.017 mm at 70°C.

[0128] Detailed optical data for optical lens group 10 are as follows: Figure 21As shown, the fourth embodiment has an effective focal length (EFL) of 4.006 mm, a half field of view (HFOV) of 60.000 degrees, a system length (TTL) of 10.011 mm, an aperture value (f-number, Fno) of 2.003, and a light circle radius (LCR) of 3.576 mm.

[0129] like Figure 22 As shown, the aspherical coefficients of the first side 11 and second side 12 of the first lens 1, the first side 21 and second side 22 of the second lens 2, the first side 41 and second side 42 of the fourth lens 4, the first side 51 and second side 52 of the fifth lens 5 and the first side 61 and second side 62 of the sixth lens 6 in formula (2) are aspherical coefficients.

[0130] Furthermore, the important parameters of the optical lens group 10 in the fourth embodiment and their relationships are as follows: Figure 27 and Figure 28 As shown.

[0131] See also Figure 20 A to Figure 20 D, Figure 20 The diagram illustrating the fourth embodiment of A shows the longitudinal spherical aberration on reference plane 100a when the wavelengths are 520 nm, 530 nm, and 540 nm. Figure 20 B and Figure 20 The diagram of C illustrates the field curvature aberration in the sagittal and tangential directions on the reference plane 100a for wavelengths of 520 nm, 530 nm, and 540 nm, respectively, in the fourth embodiment. Figure 20 The diagram for D illustrates the distortion aberration on reference plane 100a in the fourth embodiment when the wavelengths are 520 nm, 530 nm, and 540 nm. This fourth embodiment's longitudinal spherical aberration diagram... Figure 20 In A, the imaging point deviation of off-axis rays at different heights is controlled within ±0.025mm. Figure 20 In the field curvature aberration diagram of B, the focal length variation for the three representative wavelengths falls within ±0.08 mm across the entire field of view. Figure 20 In the field curvature aberration diagram of C, the focal length variation of the three representative wavelengths falls within ±0.14 mm across the entire field of view. Figure 20The distortion aberration diagram of D shows that the distortion aberration of this fourth embodiment is maintained within the range of ±50%. This demonstrates that, compared to existing optical lens groups, this fourth embodiment still provides better optical quality even with a system length reduced to approximately 10.011 mm.

[0132] As can be seen from the above description, the advantage of the fourth embodiment compared to the first embodiment is that the distortion aberration of the fourth embodiment is smaller than that of the first embodiment.

[0133] Figure 23 This is a schematic diagram of the optical lens assembly according to the fifth embodiment of the present invention. Figure 24 A to Figure 24 D represents the longitudinal spherical aberration and various aberration diagrams of the optical lens group in the fifth embodiment. Please refer to [the diagram first]. Figure 23 This fifth embodiment of the optical lens group 10 of the present invention is generally similar to the first embodiment, except that the optical data, aspherical coefficients, and parameters between lenses 1, 2, 3, 4, 5, and 6 are slightly different. Furthermore, in this embodiment, the optical axis region 417 of the first side surface 41 of the fourth lens 4 is convex, the optical axis region 427 of the second side surface 42 of the fourth lens 4 is concave, the circumferential region 528 of the second side surface 52 of the fifth lens 5 is convex, and the sixth lens 6 has a positive refractive index, and the optical axis region 627 of the second side surface 62 of the sixth lens 6 is convex. It should be noted that, for clearer illustration, Figure 23 The labels for the optical axis region and the circumferential region that are similar in shape to the first embodiment are omitted.

[0134] The optical lens group 10 of the fifth embodiment exhibits excellent thermal stability. Furthermore, the optical lens group 10 exhibits extremely small focal length shifts under different ambient temperatures. For example, setting a base temperature of 20°C, the focal length shift of the optical lens group 10 is 0.000 mm at 20°C; 0.012 mm at -25°C; 0.005 mm at 0°C; and -0.013 mm at 70°C.

[0135] Detailed optical data for optical lens group 10 are as follows: Figure 25 As shown, the fifth embodiment has an effective focal length (EFL) of 3.696 mm, a half field of view (HFOV) of 60.000 degrees, a system length (TTL) of 7.875 mm, an aperture value (f-number, Fno) of 1.848, and a light circle radius (LCR) of 3.521 mm.

[0136] like Figure 26 As shown, the aspherical coefficients of the first side surface 11 and the second side surface 12 of the first lens 1, the first side surface 21 and the second side surface 22 of the second lens 2, the first side surface 41 and the second side surface 42 of the fourth lens 4, the first side surface 51 and the second side surface 52 of the fifth lens 5 and the first side surface 61 and the second side surface 62 of the sixth lens 6 in the fifth embodiment are in formula (2).

[0137] Furthermore, the important parameters of the optical lens group 10 in the fifth embodiment and their relationships are as follows: Figure 27 and Figure 28 As shown.

[0138] See also Figure 24 A to Figure 24 D, Figure 24 The diagram illustrating the fifth embodiment of A shows the longitudinal spherical aberration on reference plane 100a when the wavelengths are 520 nm, 530 nm, and 540 nm. Figure 24 B and Figure 24 The diagram for C illustrates the field curvature aberration in the sagittal and tangential directions on the reference plane 100a for wavelengths of 520 nm, 530 nm, and 540 nm, respectively. Figure 24 The diagram for D illustrates the distortion aberration on reference plane 100a in the fifth embodiment when the wavelengths are 520 nm, 530 nm, and 540 nm. This fifth embodiment's longitudinal spherical aberration diagram. Figure 24 In A, the imaging point deviation of off-axis rays at different heights is controlled within ±0.035mm. Figure 24 In the field curvature aberration diagram of B, the focal length variation for the three representative wavelengths falls within ±0.06 mm across the entire field of view. Figure 24 In the field curvature aberration diagram of C, the focal length variation of the three representative wavelengths falls within ±0.16 mm across the entire field of view. Figure 24 The distortion aberration diagram of D shows that the distortion aberration of this fifth embodiment is maintained in the range of -50% to 10%. This indicates that, compared to existing optical lens groups, this fifth embodiment still provides better optical quality even with a system length reduced to approximately 7.875 mm.

[0139] As can be seen from the above description, the advantages of the fifth embodiment compared with the first embodiment are: the system length of the fifth embodiment is shorter than that of the first embodiment; and the distortion aberration of the fifth embodiment is smaller than that of the first embodiment.

[0140] See also Figure 27 and Figure 28 The table below shows the optical parameters of the five embodiments described above. When the relationships between the optical parameters in the optical lens group 10 of the embodiments of the present invention meet at least one of the following conditions, it can assist designers in designing an optical lens group with good optical performance and technical feasibility:

[0141] I. To improve chromatic aberration and ensure good thermal stability of the optical lens group, a better configuration can be achieved if the following conditions are met:

[0142] V1+V2+V3≦110.000, with a preferred range of 72.000≦V1+V2+V3≦110.000;

[0143] V3+V4+V5≧130.000, with a preferred range of 130.000≦V3+V4+V5≦175.000.

[0144] 2. In order to shorten the system length of the optical lens group 10, while considering the ease of manufacturing, the air gap between the lenses or the lens thickness can be adjusted appropriately. If the following conditions are met, a better configuration can be achieved:

[0145] ALT / AAG ≥ 3.300, with a preferred range of 3.300 ≤ ALT / AAG ≤ 4.500;

[0146] TL / BFL ≥ 8.500, with a preferred range of 8.500 ≤ TL / BFL ≤ 23.000;

[0147] EFL / (T2+T4)≦2.800, with a preferred range of 1.300≦EFL / (T2+T4)≦2.800;

[0148] TTL / (G12+G23+G34)≧13.500, with a preferred range of 13.500≦TTL / (G12+G23+G34)≦25.000;

[0149] (T2+T3+T4) / T1≧6.400, the preferred range is 6.400≦(T2+T3+T4) / T1≦17.200;

[0150] ALT / (AAG+BFL) ≥ 2.000, with a preferred range of 2.000 ≤ ALT / (AAG+BFL) ≤ 3.300;

[0151] TL / (T2+G23)≧8.200, with a preferred range of 8.200≦TL / (T2+G23)≦15.300;

[0152] (EFL+AAG) / (T3+T5)≦3.500, with a preferred range of 1.500≦(EFL+AAG) / (T3+T5)≦3.500;

[0153] TTL / (T5+G56+T6)≦3.000, with a preferred range of 2.000≦TTL / (T5+G56+T6)≦3.000;

[0154] (T5+T6) / T1≧4.700, with a better range of 4.700≦(T5+T6) / T1≦7.900;

[0155] ALT / (T3+T6)≦3.600, with a preferred range of 1.500≦ALT / (T3+T6)≦3.600;

[0156] (TL+EFL) / (T3+G34)≦8.900, with a preferred range of 4.600≦(TL+EFL) / (T3+G34)≦8.900;

[0157] AAG / (G45+G56)≦1.700, with a preferred range of 1.100≦AAG / (G45+G56)≦1.700;

[0158] TTL / AAG ≥ 4.800, with a preferred range of 4.800 ≤ TTL / AAG ≤ 6.100;

[0159] (T4+G45+T5) / (T1+G12)≧2.800, and the preferred range is 2.800≦(T4+G45+T5) / (T1+G12)≦8.500.

[0160] Furthermore, any combination of parameters in the alternative embodiments can be selected to increase the constraints on the optical lens group, thereby facilitating the design of optical lens groups with the same architecture as the present invention. Given the unpredictability of optical system design, under the architecture of the present invention, satisfying the above-mentioned conditions can better shorten the length of the optical lens group system, expand the field of view, improve thermal stability, enhance optical quality, and / or increase assembly yield, thus overcoming the shortcomings of prior art.

[0161] The exemplary limiting relationships listed above can be selectively combined and applied in varying numbers to embodiments of the present invention, and are not limited thereto. In implementing the present invention, in addition to the aforementioned relationships, further detailed structures such as the arrangement of concave and convex surfaces of multiple lenses are designed for a single lens or, more broadly, for multiple lenses, to enhance control over system performance and / or resolution. It should be noted that these details can be selectively combined and applied to other embodiments of the present invention, provided there is no conflict.

[0162] In addition, any combination of parameters in the alternative embodiments can be selected to increase the limitation of the optical lens group, so as to facilitate the design of optical lens groups with the same architecture as the present invention.

[0163] In view of the unpredictability of optical system design, under the framework of the present invention, meeting the above conditions can better shorten the length of the optical lens group system of the present invention, expand the field of view, improve thermal stability, improve optical quality, or improve assembly yield.

[0164] The numerical ranges, including the maximum and minimum values, obtained from the combined proportional relationships of the optical parameters disclosed in the various embodiments of the present invention can all be implemented accordingly.

[0165] In summary, the optical lens assembly of the embodiments of the present invention can achieve the following effects and advantages:

[0166] I. In the optical lens group of this invention, by designing the refractive index of the first lens to be negative, the circumferential region of the second side of the second lens to be convex, the refractive index of the third lens to be positive, the circumferential region of the first side of the third lens to be concave, and the refractive index of the fourth lens to be positive, aberrations can be effectively improved and distortion reduced. Furthermore, it allows light of different wavelengths to pass through while maintaining good optical quality and expanding the field of view. Moreover, when EFL / BFL ≥ 3.800, the size of the optical system can be reduced. The preferred range for EFL / BFL is 3.800 ≤ EFL / BFL ≤ 14.300.

[0167] II. In the optical lens group of the present invention, by designing the refractive index of the second lens to be positive, the circumferential area of ​​the first side of the second lens to be concave, the circumferential area of ​​the first side of the sixth lens to be convex, and at least four of the lenses from the first to the sixth lens to be designed with positive refractive indices, and by combining one of '(a) the circumferential area of ​​the second side of the third lens to be convex or (b) the circumferential area of ​​the second side of the sixth lens to be convex', aberrations can be effectively improved and distortion reduced, so that light of different wavelengths can still maintain good optical quality and expand the field of view when passing through the optical lens group, and further reducing the size of the optical system when EFL / BFL≧3.800 is satisfied.

[0168] III. In the optical lens group of the present invention, by designing the refractive index of the second lens to be positive, the circumferential region of the first side surface of the second lens to be concave, the circumferential region of the second side surface of the second lens to be convex, the refractive index of the third lens to be positive, the refractive index of the fourth lens to be positive, the refractive index of the fifth lens to be positive, and in conjunction with one of the following: (a) the optical axis region of the second side surface of the first lens is designed to be concave, (b) the circumferential region of the second side surface of the third lens is designed to be convex; or (c) the circumferential region of the second side surface of the sixth lens is designed to be convex, in addition to improving aberrations and reducing distortion, giving the optical lens group good thermal stability, it also allows light of different wavelengths to maintain good optical quality when passing through the optical lens group.

[0169] Fourth, by using appropriate materials, at least one lens can be made of glass, which can effectively improve thermal stability and increase the yield of lens processing, manufacturing and assembly.

[0170] Although the present invention has been disclosed above by way of embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. An optical lens set comprising, in order along an optical axis from a first side to a second side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens, the first side being an exit side, the second side being an entrance side, the optical lens set being used for projection and a plurality of imaging rays passing through the sixth lens, the fifth lens, the fourth lens, the third lens, the second lens, the first lens in order via the second side to generate a plurality of the imaging rays to exit at the first side, and the first lens to the sixth lens each comprising a first side surface facing the first side and passing the imaging rays and a second side surface facing the second side and passing the imaging rays; characterized in that: the first lens has negative refractive power and an optical axis area of the first side surface of the first lens is concave; the second lens has positive refractive power and a circumferential area of the first side surface of the second lens is concave; the third lens has positive refractive power; the fourth lens has positive refractive power; lenses of the optical lens set are only the first lens to the sixth lens.

2. An optical lens set comprising, in order along an optical axis from a first side to a second side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens, the first side being an exit side, the second side being an entrance side, the optical lens set being used for projection and a plurality of imaging rays passing through the sixth lens, the fifth lens, the fourth lens, the third lens, the second lens, the first lens in order via the second side to generate a plurality of the imaging rays to exit at the first side, and the first lens to the sixth lens each comprising a first side surface facing the first side and passing the imaging rays and a second side surface facing the second side and passing the imaging rays; characterized in that: the first lens has negative refractive power; the second lens has positive refractive power and a circumferential area of the first side surface of the second lens is concave; the third lens has positive refractive power and an optical axis area of the first side surface of the third lens is concave; the fourth lens has positive refractive power; lenses of the optical lens set are only the first lens to the sixth lens.

3. An optical lens set comprising, in order along an optical axis from a first side to a second side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens, the first side being an exit side, the second side being an entrance side, the optical lens set being used for projection and a plurality of imaging rays passing through the sixth lens, the fifth lens, the fourth lens, the third lens, the second lens, the first lens in order via the second side to generate a plurality of the imaging rays to exit at the first side, and the first lens to the sixth lens each comprising a first side surface facing the first side and passing the imaging rays and a second side surface facing the second side and passing the imaging rays; characterized in that: the first lens has negative refractive power; the second lens has positive refractive power and a circumferential area of the first side surface of the second lens is concave; the third lens has positive refractive power; the fourth lens has positive refractive power; The fourth lens has positive refractive power and a circumferential region of the first side surface of the fourth lens is concave; The optical lens set only has the first lens to the sixth lens.

4. An optical lens set sequentially comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens along an optical axis from a first side to a second side, the first side being an out-light side, the second side being an in-light side, the optical lens set being used for projection and a plurality of imaging rays sequentially passing through the sixth lens, the fifth lens, the fourth lens, the third lens, the second lens, the first lens via the second side to generate a plurality of the imaging rays emitted at the first side, and the first lens to the sixth lens each comprising a first side surface facing the first side and passing the imaging rays and a second side surface facing the second side and passing the imaging rays; characterized in that: The first lens has negative refractive power; The second lens has positive refractive power and a circumferential region of the first side surface of the second lens is concave; The third lens has positive refractive power; The fourth lens has positive refractive power; An optical axis region of the second side surface of the fifth lens is convex; The optical lens set only has the first lens to the sixth lens.

5. An optical lens set sequentially comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens along an optical axis from a first side to a second side, the first side being an out-light side, the second side being an in-light side, the optical lens set being used for projection and a plurality of imaging rays sequentially passing through the sixth lens, the fifth lens, the fourth lens, the third lens, the second lens, the first lens via the second side to generate a plurality of the imaging rays emitted at the first side, and the first lens to the sixth lens each comprising a first side surface facing the first side and passing the imaging rays and a second side surface facing the second side and passing the imaging rays; characterized in that: The first lens has negative refractive power; The second lens has positive refractive power and a circumferential region of the first side surface of the second lens is concave; The third lens has positive refractive power; The fourth lens has positive refractive power; The optical lens set only has the first lens to the sixth lens, and satisfies the following conditional expression: EFL / BFL≧3.800, wherein EFL is an effective focal length of the optical lens set, and BFL is a distance from the second side surface of the sixth lens to a reference surface on the optical axis, the reference surface being a light emitting surface.

6. An optical lens set comprising, in order along an optical axis from a first side to a second side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens, the first side being an exit side, the second side being an entrance side, the optical lens set being for projection and a plurality of imaging rays passing in order through the sixth lens, the fifth lens, the fourth lens, the third lens, the second lens, the first lens via the second side, generating a plurality of the imaging rays exiting at the first side, and the first lens to the sixth lens each comprising a first side surface facing the first side and passing the imaging rays and a second side surface facing the second side and passing the imaging rays, characterized in that: the first lens has a negative refractive power; the second lens has a positive refractive power and a peripheral region of the first side surface of the second lens is concave; the third lens has a positive refractive power; the fourth lens has a positive refractive power; the lenses of the optical lens set are only the first lens to the sixth lens and satisfy the following condition: TL / BFL > 8.500, where TL is the distance on the optical axis from the first side surface of the first lens to the second side surface of the sixth lens and BFL is the distance on the optical axis from the second side surface of the sixth lens to a reference surface, the reference surface being an emitting surface.

7. The optical lens set according to claim 1, 2, 3, 4 or 6, characterized in that, the optical lens set further satisfies the following condition: EFL / (T2+T4) < 2.800, where EFL is the effective focal length of the optical lens set, T2 is the thickness on the optical axis of the second lens and T4 is the thickness on the optical axis of the fourth lens.

8. The optical lens set according to claim 1, 2, 3, 4 or 6, characterized in that, the optical lens set further satisfies the following condition: (EFL+AAG) / (T3+T5) < 3.500, where EFL is the effective focal length of the optical lens set, AAG is the sum of the five air gaps on the optical axis from the first lens to the sixth lens, T3 is the thickness on the optical axis of the third lens and T5 is the thickness on the optical axis of the fifth lens.

9. The optical lens set according to any one of claims 1 to 5, wherein, the optical lens set further satisfies the following condition: TL / (T2+G23) > 8.200, where TL is the distance on the optical axis from the first side surface of the first lens to the second side surface of the sixth lens, T2 is the thickness on the optical axis of the second lens and G23 is the air gap on the optical axis between the second lens and the third lens.

10. The optical lens set according to any one of claims 1 to 6, wherein, the optical lens set further satisfies the following condition: ALT / AAG > 3.300, where ALT is the sum of the six lens thicknesses on the optical axis from the first lens to the sixth lens and AAG is the sum of the five air gaps on the optical axis from the first lens to the sixth lens.

11. The optical lens set according to any one of claims 5-6, wherein, the optical lens set further satisfies the following condition: TTL / (G12+G23+G34) > 13.500, where TTL is the distance on the optical axis from the first side surface of the first lens to the reference surface, G12 is the air gap on the optical axis between the first lens and the second lens, G23 is the air gap on the optical axis between the second lens and the third lens and G34 is the air gap on the optical axis between the third lens and the fourth lens.

12. The optical lens set according to any one of claims 1 to 6, wherein, The optical lens assembly further satisfies the condition: (T2+T3+T4) / T1≧6.400, where T2 is the thickness of the second lens on the optical axis, T3 is the thickness of the third lens on the optical axis, T4 is the thickness of the fourth lens on the optical axis, and T1 is the thickness of the first lens on the optical axis.

13. The optical lens assembly according to any one of claims 1 to 6, wherein, The optical lens assembly further satisfies the condition: V1+V2+V3≦110.000, where V1 is the Abbe number of the first lens, V2 is the Abbe number of the second lens, and V3 is the Abbe number of the third lens.

14. The optical lens set according to any one of claims 5-6, wherein, The optical lens assembly further satisfies the condition: TTL / (T5+G56+T6)≦3.000, where TTL is the distance from the first side of the first lens to the reference surface on the optical axis, T5 is the thickness of the fifth lens on the optical axis, G56 is the air gap between the fifth lens and the sixth lens on the optical axis, and T6 is the thickness of the sixth lens on the optical axis.

15. The optical lens set according to any one of claims 1 to 6, wherein, The optical lens assembly further satisfies the condition: (T5+T6) / T1≧4.700, where T5 is the thickness of the fifth lens on the optical axis, T6 is the thickness of the sixth lens on the optical axis, and T1 is the thickness of the first lens on the optical axis.

16. The optical lens set according to any one of claims 1 to 6, wherein, The optical lens assembly further satisfies the condition: V3+V4+V5≧130.000, where V3 is the Abbe number of the third lens, V4 is the Abbe number of the fourth lens, and V5 is the Abbe number of the fifth lens.

17. The optical lens set according to any one of claims 1 to 6, wherein, The optical lens assembly further satisfies the condition: ALT / (T3+T6)≦3.600, where ALT is the sum of the six lens thicknesses from the first lens to the sixth lens on the optical axis, T3 is the thickness of the third lens on the optical axis, and T6 is the thickness of the sixth lens on the optical axis.

18. The optical lens assembly according to any one of claims 1 to 6, wherein, The optical lens assembly further satisfies the condition: AAG / (G45+G56)≦1.700, where AAG is the sum of the five air gaps from the first lens to the sixth lens on the optical axis, G45 is the air gap between the fourth lens and the fifth lens on the optical axis, and G56 is the air gap between the fifth lens and the sixth lens on the optical axis.

19. The optical lens assembly according to any one of claims 5-6, wherein, The optical lens assembly further satisfies the condition: TTL / AAG≧4.800, where TTL is the distance from the first side of the first lens to the reference surface on the optical axis, and AAG is the sum of the five air gaps from the first lens to the sixth lens on the optical axis.

20. The optical lens assembly according to any one of claims 1 to 6, wherein, The optical lens assembly further satisfies the condition: (T4+G45+T5) / (T1+G12)≧2.800, where T4 is the thickness of the fourth lens on the optical axis, G45 is the air gap between the fourth lens and the fifth lens on the optical axis, T5 is the thickness of the fifth lens on the optical axis, T1 is the thickness of the first lens on the optical axis, and G12 is the air gap between the first lens and the second lens on the optical axis.

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