Imaging lens and signal projection lamp using the same

Abstract

The present invention discloses an imaging lens and a signal projection lamp using the same, comprising: an aperture stop, a first lens, a second lens, a third lens, a fourth lens and a fifth lens arranged in sequence along an optical axis from an image side to an object side; wherein the first lens, the fourth lens and the fifth lens all have positive focal lengths; and the second lens and the third lens all have negative focal lengths. The present invention can reduce production costs and reduce chromatic aberration during use and improve light source utilization.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile accessories, and in particular to an imaging lens and a signal projection lamp using the same. Background Art

[0002] Projection lamps used on vehicles are generally used for vehicle warnings and personalized customization. At present, signal projection lamps are mainly used in the field of small lights, such as welcome lights, carpet lights, turn projection lamps, reversing projection lamps and reversing warning lights. Specifically, the main projection methods used in small lights are microlens arrays (MLA) and film lenses. Due to technical limitations, MLA projection is prone to stray light and dispersion, while conventional film lens designs require the use of collimated light paths to improve light efficiency. Since the collimated light path and projection light path in the film lens need to be designed separately, there is a lack of correction for chromatic aberration, and the light spot passing through the collimated light path is limited by the aperture diaphragm. When used for oblique projection patterns, the light spot size is much larger than the film plate opening pattern size, which will lead to a reduction in the light source utilization rate of the entire module.

[0003] From the perspective of production cost, the use of film lenses is low-cost and cost-effective compared to MLA projection technology. However, on the basis of reducing production costs, when using film lenses, it is also necessary to consider overcoming the chromatic aberration problem caused by the use of film lenses and improving the utilization rate of the light source for the entire module. Summary of the invention

[0004] The first object of the present invention is to provide an imaging lens to solve the technical problems of reducing production costs and reducing chromatic aberration during use and improving light source utilization.

[0005] The second object of the present invention is to provide a signal projection lamp to solve the technical problems of reducing production costs and reducing color difference during use and improving light source utilization.

[0006] The imaging lens of the present invention is implemented as follows:

[0007] An imaging lens comprises: an aperture stop, a first lens, a second lens, a third lens, a fourth lens and a fifth lens arranged in sequence along an optical axis from an image side to an object side; wherein

[0008] The first lens, the fourth lens and the fifth lens all have positive refractive power; the second lens and the third lens all have negative refractive power.

[0009] In an optional embodiment of the present invention, the numerical aperture NA of the imaging lens is ≥ 0.5.

[0010] In an optional embodiment of the present invention, the chief ray angle MaxCRA of the maximum field of view of the imaging lens is <10°; wherein

[0011] The principal ray angle is the angle formed by the ray passing through the center of the aperture stop and the optical axis.

[0012] In an optional embodiment of the present invention, the diameter D1 of the first lens and the diameter D2 of the second lens satisfy the condition: 0.9<D1 / D2<1.1.

[0013] In an optional embodiment of the present invention, the focal length f2 of the second lens and the focal length f3 of the third lens satisfy the condition: |f2|<|f3|.

[0014] In an optional embodiment of the present invention, both the image-side surface and the object-side surface of the first lens are convex surfaces;

[0015] The image side surface of the second lens is concave and the object side surface is convex;

[0016] The image side surface of the third lens is convex and the object side surface is concave;

[0017] The image-side surface and the object-side surface of the fourth lens are both convex surfaces; and

[0018] The image-side surface of the fifth lens is convex and the object-side surface thereof is concave.

[0019] The signal projection lamp of the present invention is realized as follows:

[0020] A signal projection lamp comprises an imaging lens, a film and a light source which are arranged in sequence along an optical axis from an image side to an object side.

[0021] In an optional embodiment of the present invention, the light emitting surface of the light source is perpendicular to the optical axis direction.

[0022] In an optional embodiment of the present invention, the minimum distance D between the fifth lens of the imaging lens and the light source is greater than 1 mm.

[0023] In an optional embodiment of the present invention, the light emitting surface SL of the light source and the size SF of the opening pattern on the film satisfy the condition: SL>SF.

[0024] By adopting the above technical solution, the present invention has the following beneficial effects: the imaging lens of the present invention and the signal projection lamp using the same can eliminate aberrations through the positive and negative lens combination formed by the first lens, the second lens, the third lens, the fourth lens and the fifth lens, and have good image resolution and chromatic aberration correction capabilities under large aperture conditions. Furthermore, the overall signal projection lamp only has the cooperation of the light source, the film plate and the imaging lens, and there is no other redundant structure, so that the overall structure of the signal projection lamp is simple, the mass production is high, and the production cost is controlled at a low level. When applied to oblique projection, the light source utilization rate of the imaging lens can be further improved through the effective cooperation of the light-emitting surface of the light source and the smaller main light angle, and the pattern illumination of the oblique projection can be improved simultaneously, making the effect of the projection signal more obvious. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic structural diagram of an imaging lens of the present invention in an optional implementation case;

[0026] Figure 2 is a schematic structural diagram of an imaging lens of the present invention in another optional implementation;

[0027] Figure 3 is a schematic structural diagram of an imaging lens of the present invention in yet another optional implementation;

[0028] Figure 4 It is a schematic structural diagram of the signal projection lamp of the present invention in an optional implementation.

[0029] In the figure: aperture stop b, first lens 1, second lens 2, third lens 3, fourth lens 4 and fifth lens 5. DETAILED DESCRIPTION

[0030] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments in conjunction with the accompanying drawings.

[0031] Embodiment 1:

[0032] See also Figures 1 to 3 As shown, this embodiment provides an imaging lens, comprising: an aperture stop b, a first lens 1, a second lens 2, a third lens 3, a fourth lens 4 and a fifth lens 5 arranged in sequence along an optical axis a from the image side to the object side; wherein the first lens 1, the fourth lens 4 and the fifth lens 5 all have positive focal power; the second lens 2 and the third lens 3 all have negative focal power. wherein the diameter D1 of the first lens 1 and the diameter D2 of the second lens 2 satisfy the condition: 0.9<D1 / D2<1.1.

[0033] More specifically, the image side surface and the object side surface of the first lens 1 are both convex; the image side surface of the second lens 2 is concave and the object side surface thereof is convex; the image side surface of the third lens 3 is convex and the object side surface thereof is concave; the image side surface and the object side surface thereof of the fourth lens 4 are both convex; and the image side surface of the fifth lens 5 is convex and the object side surface thereof is concave. Under such a structure, a five-piece lens structure with alternating positive and negative focal powers and matching concave and convex surfaces can be used to reasonably control the direction of light and correct the aberration of the system, so that the imaging lens of this embodiment has good resolution.

[0034] Based on the above structure, it should be noted that the first lens 1, the second lens 2, the third lens 3, the fourth lens 4 and the fifth lens 5 in this embodiment can be either spherical or aspherical. As for the lens material of each of the above lenses, plastic or glass can be used, or one or more lenses can be made of plastic, while the other lenses can be made of glass.

[0035] Furthermore, it is necessary to explain that the focal length f2 of the second lens 2 and the focal length f3 of the third lens 3 satisfy the condition: |f2|<|f3|. The significance of this design is that the second lens 2 has a greater light divergence ability than the third lens 3, while the first lens 1 has a stronger light convergence ability. The positive and negative combination of the focal power of the first lens 1 and the second lens 2 can effectively eliminate aberrations such as spherical aberration.

[0036] In addition, the present embodiment also has the following design: the numerical aperture NA of the imaging lens is ≥ 0.5. The design of the numerical aperture of the imaging lens increases the light collection angle, which can effectively improve the light source utilization rate of the imaging lens, increase the illumination of the projection pattern, and make the projection signal effect more obvious.

[0037] Finally, regarding the imaging lens of this embodiment, it is also necessary to explain that the chief ray angle MaxCRA of the maximum field of view of the imaging lens is less than 10°; the chief ray angle is the angle formed by the light passing through the center of the aperture stop b and the optical axis. Here, a smaller chief ray angle can improve the light source utilization rate of the imaging lens.

[0038] Embodiment 2:

[0039] See also Figures 1 to 4 As shown, based on the imaging lens of Example 1, this embodiment provides a signal projection lamp, including an imaging lens, a film 7 and a light source 8 arranged in sequence along the optical axis from the image side to the object side. Based on this structure, when the signal projection lamp performs signal projection, the light emitted by the light source 8 passes through the opening pattern on the film 7 and finally enters the imaging lens for projection. The projected pattern depends on the opening pattern on the film 7, and the illumination of the projected pattern depends on the light density of the light source 8 and the numerical aperture NA of the imaging lens.

[0040] It should be noted that the light source 8 and the imaging lens in this embodiment are arranged along the optical axis, and the light emitting surface of the light source 8 is perpendicular to the optical axis. In this structure, the light source utilization rate of the imaging lens can be further improved with a smaller chief light angle.

[0041] In an optional implementation, the minimum distance D between the fifth lens 5 of the imaging lens and the light source 8 is greater than 1 mm. With such a structure, the convenience of assembling the signal projection lamp can be improved, and interference between the imaging lens and the light source 8 during the assembly process can be avoided.

[0042] Finally, it is necessary to explain the signal projection lamp of this embodiment that the light-emitting surface SL of the light source 8 and the size SF of the hole pattern on the film sheet 7 satisfy the condition: SL>SF. In such a structure, the size of the light-emitting surface of the light source 8 can completely cover the size of the hole pattern on the film sheet 7, so that the hole pattern on the film sheet 7 can be fully projected.

[0043] In combination with the specific structure of the projection signal lamp, in the first specific optional implementation, the relevant parameters of each lens of the projection signal lamp are as follows:

[0044]

[0045]

[0046] Based on the above structure, the numerical aperture NA of the imaging lens is 0.68, the half field angle is 10°, the focal length f2 of the second lens 2 is -28.4 mm, the focal length f3 of the third lens 3 is -131.4 mm, and the chief ray angle MaxCRA of the maximum field of view is 0.89°. When the signal projection lamp under this structure is used for signal projection, not only the light source utilization rate is high, but also the projection quality is clear.

[0047] In the second specific optional implementation, the relevant parameters of each lens of the projection signal lamp are as follows:

[0048]

[0049]

[0050] Based on the above structure, the numerical aperture NA of the imaging lens is 0.68, the half field angle is 12.9°, the focal length f2 of the second lens 2 is -69.1 mm, the focal length f3 of the third lens 3 is 736 mm, and the chief ray angle MaxCRA of the maximum field of view is 5.4°. When used for signal light projection, not only is the light source utilization rate high, but the projection quality is also clear.

[0051] In a third specific optional implementation, the relevant parameters of each lens of the projection signal lamp are as follows:

[0052]

[0053] The aspheric equation can be expressed as follows:

[0054]

[0055] Among them, z: the distance from the vertex of the lens to the optical axis a, c: the basic curvature of the lens, r: the distance in the direction perpendicular to the optical axis a, k: the quadratic cone constant, a i : Aspheric coefficient, p i : radial coordinate, N sets the number of items, i: subscript coefficient.

[0056] The aspheric coefficients corresponding to the aspheric lenses in the above table are shown in the following table:

[0057] Aspheric coefficient S1 S2 S3 S4 S5 K -0.7998 3.5720 -0.0715 -86.0909 -0.0037 a4 -7.5668e-005 -4.4597e-005 2.3173e-005 3.7708e-005 6.3341e-005 a6 8.74308e-007 -1.9464e-006 5.7939e-007 4.1966e-006 -2.5378e-006 a8 9.4837e-009 -2.3120e-008 1.3967e-008 2.9413e-007 -2.5993e-007 a10 5.4582e-010 -9.6402e-010 6.0430e-009 1.3595e-008 -1.2065e-008 a12 6.3651e-011 -1.5636e-010 9.4880e-010 4.3539e-010 -5.1078e-010 a14 -2.4122e-012 -1.1941e-011 1.0363e-010 5.0805e-012 -2.2696e-011 a16 -1.7591e-012 2.2028e-013 9.2669e-012 -4.1993e-013 -1.3677e-012 a18 -3.4872e-013 2.2848e-013 7.0305e-013 -6.4967e-015 -1.0671e-013 a20 -5.1480e-014 4.6871e-014 4.3407e-014 7.2941e-015 -9.0137e-015 Aspheric coefficient S6 S7 S8 S9 S10 K -0.1715 0.1317 -0.7930 -0.1142 2.8904 a4 -0.0003 2.8166e-005 4.0384e-005 -0.0005 0.0050 a6 -7.0745e-007 -1.5696e-007 2.7257e-006 -6.3380e-005 -0.0010 a8 2.4111e-007 -3.2771e-008 9.2509e-008 -1.9572e-005 -0.0001 a10 -4.3864e-010 -2.1456e-010 1.4535e-009 -2.0263e-006 -0.0002 a12 -9.8184e-010 1.0057e-011 4.3558e-012 -1.2264e-007 -3.1274e-006 a14 -1.8647e-010 1.0200e-012 1.0340e-012 -3.7942e-010 -3.1541e-007 a16 -2.0620e-011 5.8305e-014 -7.9672e-015 7.0725e-010 -8.6461e-009 a18 -2.1987e-012 -1.0376e-015 1.9493e-014 -6.7111e-011 3.4148e-009 a20 -2.5246e-013 -5.1474e-016 1.0764e-015 -1.0998e-011 9.2969e-010

[0058] Based on the above structure, the numerical aperture NA of the imaging lens is 0.5, the half field angle is 10°, the focal length f2 of the second lens 2 is -10.4 mm, the focal length f3 of the third lens 3 is 42.5 mm, and the chief ray angle MaxCRA of the maximum field of view is 8°. When used for signal light projection, not only is the light source utilization rate high, but the projection quality is also clear.

[0059] In summary, for the signal projection lamp of this embodiment, the overall structure only includes the cooperation of the light source, the film board and the imaging lens, and there is no other redundant structure, so that the overall structure of the signal projection lamp is simple, the mass production is high, and the production cost is controlled at a low level. When applied to oblique projection, the light source utilization rate of the imaging lens can be further improved through the effective cooperation of the light emitting surface of the light source and the smaller main light angle.

[0060] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0061] In the description of the present invention, it is necessary to understand that the terms indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0062] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0063] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0064] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0065] In the present invention, unless otherwise clearly specified and limited, a first feature being above or below a second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. Moreover, a first feature being above, above, and above a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being below, below, and below a second feature includes the first feature being directly below and obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

Claims

1. An imaging lens, It is characterized in that include: An aperture stop, a first lens, a second lens, a third lens, a fourth lens and a fifth lens are sequentially arranged along the optical axis from the image side to the object side; in The first lens, the fourth lens and the fifth lens all have positive optical power; the second lens and the third lens all have negative optical power; The numerical aperture NA of the imaging lens is ≥ 0.5; the chief ray angle MaxCRA of the maximum field of view of the imaging lens is < 10°; the chief ray angle is the angle formed by the light passing through the center of the aperture stop and the optical axis; The diameter D1 of the first lens and the diameter D2 of the second lens satisfy the condition: 0.9<D1 / D2<1.1; The focal length f2 of the second lens and the focal length f3 of the third lens satisfy the condition: |f2|<|f3|; The image side surface and the object side surface of the first lens are both convex; the image side surface of the second lens is concave and the object side surface is convex; the image side surface of the third lens is convex and the object side surface is concave; The image side surface and the object side surface of the fourth lens are both convex; and the image side surface of the fifth lens is convex and the object side surface is concave; The number of lenses of the imaging lens is five.

2. A signal projection lamp, It is characterized in that The imaging lens, film and light source as claimed in claim 1 are arranged in sequence along the optical axis from the image side to the object side.

3. The signal projection lamp according to claim 2, It is characterized in that The light emitting surface of the light source is perpendicular to the optical axis direction.

4. The signal projection lamp according to claim 2 or 3, It is characterized in that The minimum distance D between the fifth lens of the imaging lens and the light source is greater than 1 mm.

5. The signal projection lamp according to claim 2 or 3, It is characterized in that The light emitting surface SL of the light source and the size SF of the opening pattern on the film satisfy the condition: SL>SF.

Images