Curved prism lens and electronic equipment

Abstract

The invention discloses a curved prism lens and electronic equipment. The curved prism lens comprises a curved prism and a plurality of lenses from an object side to an image side, the curved prism comprises an incident surface, a reflecting surface and an emergent surface, the curved prism is equivalently used as a first lens, the incident surface of the curved prism is an object side surface of the first lens, and the emergent surface of the curved prism is an image side surface of the first lens; the plurality of lenses are arranged in sequence and are arranged between the curved prism and the imaging surface; wherein the first lens has positive focal power, and the focal length f1 of the first lens and the focal length f'of the curved prism lens meet the condition that f1 / f 'is larger than or equal to 0.5 and smaller than or equal to 2.3. According to the curved prism lens and the electronic equipment, the local thickness of the lens is reduced, miniaturization of the lens is facilitated, and the light and thin requirements of a user on the electronic equipment are met.

Description

Technical Field

[0001] The present invention relates to the field of optical imaging technology, and in particular to a curved prism lens and electronic equipment. Background Art

[0002] With the development of multifunctionality of various electronic products, the camera function has become a necessary function of many electronic products, such as smart phones and tablet computers with camera functions. However, as users' demand for thinner and lighter electronic devices increases, it is necessary to provide a miniaturized lens. Summary of the invention

[0003] In view of the above problems, an object of the present invention is to provide a curved prism lens and an electronic device, which reduce the local thickness of the lens, facilitate miniaturization of the lens, and meet users' demands for thinner and lighter electronic devices. The present invention provides a curved prism lens, which comprises a curved prism and a plurality of lenses from the object side to the image side; the curved prism comprises an incident surface, a reflection surface and an exit surface, the curved prism is equivalent to a first lens, the incident surface of the curved prism is the object side surface of the first lens, and the exit surface of the curved prism is the image side surface of the first lens; the plurality of lenses are arranged in sequence and are disposed between the curved prism and the imaging surface; wherein the first lens has positive optical power, and the focal length f1 of the first lens and the focal length f′ of the curved prism lens satisfy: 0.5≤f1 / f′≤2.3.

[0004] Optionally, the reflective surface of the curved prism forms an angle of 45 degrees with both the incident light axis and the emergent light axis.

[0005] Optionally, the incident surface of the curved prism is a curved surface, and the exit surface of the curved prism is a flat surface.

[0006] Optionally, the multiple lenses include a second lens and other lenses in sequence, and a center thickness CT1, an object side sag SAG1 of the first lens and a diameter D5 of the second lens satisfy: 0mm≤CT1-SAG1-D5≤1mm.

[0007] Optionally, the aperture F#, field of view FOV and focal length f′ of the curved prism lens satisfy: 0.24≤F#*TAN(FOV / 2)*SQRT(f′ / 100).

[0008] Optionally, the plurality of lenses sequentially include a second lens, a third lens, a fourth lens and a fifth lens.

[0009] Optionally, the curved prism lens further includes a filter arranged between the fifth lens and the imaging surface.

[0010] Optionally, the object side sag SAG3 of the second lens, the image side sag SAG4 of the second lens, the object side sag SAG6 of the third lens, the image side sag SAG7 of the third lens…the image side sag SAG11 of the fifth lens satisfy: MAX(ABS(SAG3), ABS(SAG4),…ABS(SAG11))≤1.5mm.

[0011] Optionally, a sag height SAG1 of the object side surface of the first lens and a sag height SAG3 of the object side surface of the second lens satisfy: 0.8mm≤SAG1+SAG3≤3mm.

[0012] Optionally, the object-side sag height SAG1 of the first lens and the image-side sag height SAG11 of the fifth lens satisfy: 1mm≤SAG1-SAG11≤3.5mm.

[0013] Optionally, the Abbe number Ab1 of the first lens, the Abbe number Ab2 of the second lens, and the Abbe number Ab3 of the third lens satisfy: 1.5≤(Ab1+Ab2) / Ab3≤9.

[0014] Optionally, the curved prism lens further includes an aperture stop disposed between the second lens and the third lens.

[0015] The present invention also provides an electronic device, comprising the above-mentioned curved prism lens.

[0016] The curved prism lens and electronic device provided by the present invention, the curved prism is equivalent to the first lens, the first lens has positive focal power, and the focal length f1 of the first lens and the focal length f′ of the curved prism lens satisfy: 0.5≤f1 / f′≤2.3, which is conducive to the convergence of large-angle light by a lens group formed by a plurality of lenses after the first lens, so that the lens group has a smaller aperture, that is, the local thickness of the lens is correspondingly reduced, which is conducive to the miniaturization of the lens and meets the user's demand for thin and light electronic equipment, and specifically includes the following beneficial effects: 1) It can be used to achieve a 1 / 2″ large target surface, a focal length of 13.3mm, and a 2.2 large aperture telephoto lens; 2) The system has good aberration correction and good resolution, meeting the requirements of high-definition image quality; 3) The apertures of the second lens to the fifth lens can be set within 5 mm, which effectively reduces the thickness of the lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 The optical path diagram of the curved prism lens according to the embodiment of the present application is shown.

[0019] Figure 2 yes Figure 1 Equivalent replacement optical path diagram of the curved prism lens.

[0020] Figure 3 A schematic structural diagram of a curved prism of a curved prism lens according to an embodiment of the present application is shown.

[0021] Figure 4 A schematic diagram of an equivalent replacement structure of the curved prism lens according to Embodiment 1 of the present application is shown.

[0022] Figures 5 to 8 The distortion diagram, MTF curve diagram, relative illumination and Y field angle diagram and light fan diagram of the curved prism lens of Example 1 are respectively shown.

[0023] Fig. 9 A schematic diagram of an equivalent replacement structure of the curved prism lens according to Embodiment 2 of the present application is shown.

[0024] Figures 10 to 13 The distortion diagram, MTF curve diagram, relative illumination and Y field angle diagram and light fan diagram of the curved prism lens of Example 2 are respectively shown.

[0025] Fig.14 A schematic diagram of an equivalent replacement structure of the curved prism lens according to Example 3 of the present application is shown.

[0026] Figures 15 to 18 The distortion diagram, MTF curve diagram, relative illumination and Y field angle diagram and light fan diagram of the curved prism lens of Example 3 are respectively shown. DETAILED DESCRIPTION

[0027] The aforementioned and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of the preferred embodiments with reference to the drawings. Through the description of the specific implementation methods, the technical means and effects adopted by the present invention to achieve the intended purpose can be more deeply and specifically understood. However, the attached drawings are only for reference and illustration purposes, and are not used to limit the present invention. Some well-known parts may not be shown. In each of the drawings, the same elements are represented by similar reference numerals. For the sake of clarity, the various parts in the drawings are not necessarily drawn strictly in accordance with the actual proportions.

[0028] It should be understood that the terms "first", "second", "third", "fourth", etc. are only used to distinguish components or circuits with similar properties, rather than indicating or implying relative importance or a specific order. The terms "include", "comprises", or any other variation thereof, are intended to cover non-exclusive inclusion, and may include other elements not explicitly listed in addition to those listed elements.

[0029] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0030] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is called the object side of the lens, and the surface of each lens closest to the imaging plane is called the image side of the lens.

[0031] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0032] The features, principles and other aspects of the present application are described in detail below.

[0033] Figure 1 shows an optical path diagram of a curved prism lens according to an embodiment of the present application, Figure 2 yes Figure 1 Please also refer to the equivalent optical path diagram of the curved prism lens Figure 1 and Figure 2 According to the curved prism lens of the exemplary embodiment of the present application, Figure 1As shown, from the object side to the image side, it includes a curved prism P1 and a plurality of lenses; the curved prism P1 includes an incident surface, a reflection surface and an emission surface, as shown in FIG. Figure 2 As shown, the curved prism P1 is equivalent to the first lens L1, the incident surface of the curved prism P1 is the object side surface of the first lens L1, and the exit surface of the curved prism P1 is the image side surface of the first lens L1; a plurality of lenses are arranged in sequence and disposed between the curved prism P1 and the imaging surface IMG; wherein the first lens L1 has positive optical power, and the focal length f1 of the first lens L1 and the focal length f′ of the curved prism lens satisfy: 0.5≤f1 / f′≤2.3. Thus, Figure 1 The off-axis curved prism P1 can be Figure 2 The coaxial first lens L1 is equivalently replaced by Figure 1 The off-axis system can be equivalently replaced by Figure 2 coaxial system. Figure 2 In the embodiment, the first lens L1 has positive focal power and can focus light within a certain range; and satisfies 0.5≤f1 / f′≤2.3. By controlling the focal length of the first lens L1 and the focal length f′ of the curved prism lens within a suitable range, it is beneficial for the lens group formed by the multiple lenses after the first lens L1 to converge large-angle light, so that the lens group has a smaller aperture, that is, the apertures of multiple lenses such as the second lens to the fifth lens can be set within 5 mm, which effectively reduces the thickness of the lens and correspondingly reduces the local thickness of the lens, which is beneficial to the miniaturization of the lens and meets the user's demand for thin and light electronic devices.

[0034] In an exemplary embodiment, according to the curved prism lens of the present application, the reflection surface of the curved prism P1 forms an angle of 45 degrees with both the incident optical axis and the exit optical axis. Figure 3 FIG. 4 shows a schematic structural diagram of a curved prism P1 of a curved prism lens according to an embodiment of the present application. Figure 3 As shown, the upper surface of the curved prism P1 is the incident surface, the inclined surface at 45 degrees is the reflection surface, and the right surface is the emission surface. The reflection surface of the curved prism P1 can be set at an angle of 45 degrees to the incident optical axis and the emission optical axis, so that after the light enters from the upper side, it can be emitted from the right side, and multiple lenses can be placed on the right side, so that the light finally converges on the imaging surface IMG to form an image. It can be understood that the present invention is not limited to this, and the reflection surface of the curved prism P1 can also be at other angles to the incident optical axis and the emission optical axis, as long as the object light enters from the incident surface of the curved prism P1, then reflects on the reflection surface of the curved prism P1, and finally emits from the emission surface of the curved prism P1 to multiple lenses.

[0035] In an exemplary embodiment, according to the curved prism lens of the present application, the incident surface of the curved prism P1 is a curved surface, and the emitting surface of the curved prism P1 is a flat surface. Figure 3As shown, the upper surface of the curved prism P1 is the incident surface and is a curved surface, and the right surface is the exit surface and is a flat surface, which can facilitate compact arrangement of multiple lenses on the right side to achieve miniaturization of the lens. However, the present invention is not limited to this, and in other embodiments, both the incident surface and the exit surface can be set as curved surfaces.

[0036] In one exemplary embodiment, according to the curved prism lens of the present application, the plurality of lenses sequentially include the second lens L2 and other lenses, and can satisfy 0mm≤CT1-SAG1-D5≤1mm; wherein the center thickness of the first lens L1 is CT1, the object side sag is SAG1, and the diameter of the second lens L2 is D5, i.e., 2 times the half aperture. Satisfying 0mm≤CT1-SAG1-D5≤1mm, by controlling the center thickness CT1 of the first lens L1, the object side sag SAG1, and the diameter D5 of the second lens L2 within a suitable range, the curved prism P1 does not generate light leakage, avoids affecting the relative illumination, and can prevent stray light ghosting.

[0037] In one exemplary embodiment, the curved prism lens according to the present application may satisfy 0.24≤F#*TAN(FOV / 2)*SQRT(f′ / 100); wherein the aperture of the curved prism lens is F#, the field of view angle is FOV, and the focal length is f′. By satisfying 0.24≤F#*TAN(FOV / 2)*SQRT(f′ / 100), by controlling the aperture F#, the field of view angle FOV, and the focal length f′ of the curved prism lens within a suitable range, thereby avoiding a certain parameter from deviating from the normal range, it is possible to achieve excellent resolution under ultra-large aperture and ultra-wide-angle performance, meeting the needs of various usage scenarios.

[0038] In an exemplary embodiment, according to the curved prism lens of the present application, the plurality of lenses sequentially include a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5. By providing fewer lenses, the miniaturization of the lens can be achieved.

[0039] In an exemplary embodiment, according to the curved prism lens of the present application, the curved prism lens further includes a filter IR disposed between the fifth lens L5 and the imaging surface IMG. The filter IR can be used to correct color deviation. In another exemplary embodiment, according to the curved prism lens of the present application, the curved prism lens further includes a protective glass disposed between the fifth lens L5 and the imaging surface IMG for protecting the photosensitive element located on the imaging surface IMG.

[0040] In an exemplary embodiment, according to the curved prism lens of the present application, MAX(ABS(SAG3), ABS(SAG4), ...ABS(SAG11))≤1.5mm may be satisfied; wherein, MAX(ABS(SAG3), ABS(SAG4), ...ABS(SAG11)) represents the maximum value of the absolute values ​​of the object side sag and the image side sag of the second lens L2 to the fifth lens L5, wherein the object side sag of the second lens L2 is SAG3, the image side sag of the second lens L2 is SAG4, the object side sag of the third lens L3 is SAG6, the image side sag of the third lens L3 is SAG7 ..., the object side sag of the fifth lens L5 is SAG10, and the image side sag of the fifth lens L5 is SAG11. By satisfying MAX(ABS(SAG3), ABS(SAG4), ...ABS(SAG11))≤1.5mm, the manufacturability of the lens may be enhanced by controlling the sags of the second lens L2 to the fifth lens L5 to be less than a certain value.

[0041] In an exemplary embodiment, according to the curved prism lens of the present application, 0.8mm≤SAG1+SAG3≤3mm may be satisfied, wherein the object side sag of the first lens L1 is SAG1, and the object side sag of the second lens L2 is SAG3. Satisfying 0.8mm≤SAG1+SAG3≤3mm, by controlling the sum of the object side sag SAG1 of the first lens L1 and the object side sag SAG3 of the second lens L2, it is beneficial for the system to converge light and meet the field of view angle requirement.

[0042] In an exemplary embodiment, according to the curved prism lens of the present application, 1mm≤SAG1-SAG11≤3.5mm may be satisfied, wherein the object side sag of the first lens L1 is SAG1, and the image side sag of the fifth lens L5 is SAG11. Satisfying 1mm≤SAG1-SAG11≤3.5mm, by controlling the difference between the object side sag SAG1 of the first lens L1 and the image side sag SAG11 of the fifth lens L5, it is beneficial to control the incident angle of the main light, and avoid poor illumination and color in the imaging.

[0043] In an exemplary embodiment, according to the curved prism lens of the present application, 1.5≤(Ab1+Ab2) / Ab3≤9 may be satisfied, wherein the Abbe number of the first lens L1 is Ab1, the Abbe number of the second lens L2 is Ab2, and the Abbe number of the third lens L3 is Ab3. Satisfying 1.5≤(Ab1+Ab2) / Ab3≤9, by controlling the Abbe number Ab1 of the first lens L1, the Abbe number Ab2 of the second lens L2, and the Abbe number Ab3 of the third lens L3, is conducive to reducing the chromatic aberration of the system and improving the imaging quality.

[0044] In an exemplary embodiment, according to the curved prism lens of the present application, the curved prism lens further includes a stop STO, and the stop STO is disposed between the second lens L2 and the third lens L3. By controlling the stop STO to be disposed between the second lens L2 and the third lens L3, the difference between the number of lenses on the left side of the stop STO and the number of lenses on the right side of the stop STO is less than or equal to 1, which is beneficial to distortion correction.

[0045] Based on the same inventive concept, according to an exemplary embodiment of the present application, the electronic device includes the above-mentioned curved prism lens. The electronic device includes but is not limited to a smartphone, a tablet computer, a laptop computer, a PTZ shooting device, a surveillance camera, and other imaging devices. The implementation of the electronic device can refer to the embodiment of the curved prism lens, and the repeated parts will not be repeated.

[0046] However, those skilled in the art should understand that, without departing from the technical solution claimed in the present application, the number of lenses constituting the optical imaging lens can be changed to obtain the various results and advantages described in this specification. For example, although five lenses are described as an example in the embodiments, the optical imaging lens is not limited to including five lenses. If necessary, the optical imaging lens may also include other numbers of lenses.

[0047] Specific embodiments of the curved prism lens applicable to the above-mentioned embodiments are further described below with reference to the accompanying drawings.

[0048] Example 1 The following reference Figure 4 The curved prism lens according to Embodiment 1 of the present application is described. Figure 4 A schematic diagram of an equivalent replacement optical structure of the curved prism lens according to Example 1 of the present application is shown.

[0049] The curved prism lens of Example 1 includes an object surface, a curved prism and a plurality of lenses in order from the object side to the image side. Figure 4 As shown, the curved prism is equivalent to the first lens L1, and the plurality of lenses may include the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5 in sequence. The aperture STO is arranged between the second lens L2 and the third lens L3. The filter IR is arranged between the fifth lens L5 and the imaging surface IMG.

[0050] The first lens L1 has positive focal power, its object side surface is convex, and its image side surface is flat. The second lens L2 has negative focal power, its object side surface is convex, and its image side surface is concave. The third lens L3 has negative focal power, its object side surface is concave, and its image side surface is convex. The fourth lens L4 has positive focal power, its object side surface is convex, and its image side surface is concave. The fifth lens L5 has negative focal power, its object side surface is concave, and its image side surface is convex. The filter IR has an object side surface and an image side surface. The light from the object passes through the first lens L1 to the object side surface and the image side surface of the filter IR in sequence, and is finally imaged on the imaging surface IMG.

[0051] Table 1 shows the basic parameters of the curved prism lens of Example 1, wherein the units of the radius of curvature, thickness, focal length, half aperture and sagittal height are all in millimeters (mm).

[0052] Table 1:

[0053] Among them, L1 R1 represents the object-side surface of the first lens L1, L1 R2 represents the image-side surface of the first lens L1, L2 R1 represents the object-side surface of the second lens L2, L2 R2 represents the image-side surface of the second lens L2, L3 R1 represents the object-side surface of the third lens L3, L3 R2 represents the image-side surface of the third lens L3, L4 R1 represents the object-side surface of the fourth lens L4, L4 R2 represents the image-side surface of the fourth lens L4, L5 R1 represents the object-side surface of the fifth lens L5, L5 R2 represents the image-side surface of the fifth lens L5, IR R1 represents the object-side surface of the filter IR, and IR R2 represents the image-side surface of the filter IR.

[0054] In Embodiment 1, the object side surface and the image side surface of any lens among the first lens L1 to the fifth lens L5 are both even-order aspherical surfaces, and the surface shape x of each aspherical lens can be defined by but not limited to the following aspherical surface formula: (1) Wherein, Z represents the height in the optical axis direction, c is the inverse of the surface radius, k is the cone coefficient, r is the diameter in the radial direction; α represents the aspheric coefficient, α1 represents the aspheric coefficient A2, α2 represents the aspheric coefficient A4... Table 2 shows the high-order coefficients A2, A4, A6, A8, A10, A12, A14 and A16 that can be used for each aspheric mirror surface in Example 1.

[0056] Table 2:

[0057] In Example 1, the focal length f' of the curved prism lens is 13.3 mm, the working band of the curved prism lens is the visible light band, the aperture of the curved prism lens is 2.21, the imaging circle diameter of the curved prism lens is 8.2 mm, the field of view angle of the curved prism lens is 34°, and the total optical length is 20.1 mm; the relationship between the focal length f1 of the first lens L1 and the focal length f' of the curved prism lens is: f1 / f'=1.953; the relationship between the center thickness CT1 of the first lens L1, the object side sag SAG1 and the diameter D5' of the second lens L2 is: There is: CT1-SAG1-D5=0.489mm; the relationship between the aperture F#, field of view FOV and focal length f' of the curved prism lens is: F#*TAN(FOV / 2)*SQRT(f' / 100)=0.246; the relationship between the object side sag height SAG3 of the second lens L2, the image side sag height SAG4 of the second lens L2, ... the image side sag height SAG11 of the fifth lens L5 is: MAX(ABS(SAG3), ABS(SAG4), ...ABS(SAG11))=0.890mm. The relationship between the object side sag height SAG1 of the first lens L1 and the object side sag height SAG3 of the second lens L2 is SAG1+SAG3=1.117mm. The relationship between the object side sag height SAG1 of the first lens L1 and the image side sag height SAG11 of the fifth lens L5 is SAG1-SAG11=1.684mm. The relationship among the Abbe number Ab1 of the first lens L1, the Abbe number Ab2 of the second lens L2 and the Abbe number Ab3 of the third lens L3 is (Ab1+Ab2) / Ab3=6.604.

[0058] Figure 5 The distortion diagram of the curved prism lens of Example 1 is shown, and the distortion is less than 2%, which is very small. Figure 6 The MTF curve of the curved prism lens of Example 1 is shown, and the MTF (Modulation Transfer Function) curve shows the transmission of image details (i.e., image contrast) of different spatial frequencies by the imaging system. The OTF modulus is greater than 0.37 at a spatial frequency of 125lp / mm, and has good resolution. Figure 7 The relative illumination and Y field angle diagram of the curved prism lens of Example 1 is shown. The relative illumination is greater than 0.6, and the brightness of the picture is uniform. Figure 8 The ray fan diagram of the curved prism lens of Example 1 is shown. The ray fan diagram generally shows the cross-section of the light beam at different positions, as well as the path and changes of the light beam propagation in the optical system. It is a comprehensive evaluation diagram of various aberrations. Its scale is ±20um, that is, the scale range in the horizontal and vertical directions is ±20um, and various aberrations are well corrected. Figures 5 to 8 It can be seen that the curved prism lens provided in Example 1 can achieve good imaging quality.

[0059] Example 2 The following reference Fig. 9 The curved prism lens according to Embodiment 2 of the present application is described. In this embodiment, for the sake of brevity, some descriptions similar to Embodiment 1 will be omitted. Fig. 9 A schematic diagram of an equivalent replacement structure of the curved prism lens according to Embodiment 2 of the present application is shown.

[0060] The curved prism lens of Example 2 includes an object surface, a curved prism, and a plurality of lenses in order from the object side to the image side. Fig. 9 As shown, the curved prism is equivalent to the first lens L1, and the plurality of lenses may include the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5 in sequence. The aperture STO is arranged between the second lens L2 and the third lens L3. The filter IR is arranged between the fifth lens L5 and the imaging surface IMG.

[0061] The first lens L1 has positive focal power, its object side surface is convex, and its image side surface is flat. The second lens L2 has negative focal power, its object side surface is convex, and its image side surface is concave. The third lens L3 has positive focal power, its object side surface is concave, and its image side surface is convex. The fourth lens L4 has positive focal power, its object side surface is convex, and its image side surface is concave. The fifth lens L5 has negative focal power, its object side surface is concave, and its image side surface is convex. The filter IR has an object side surface and an image side surface. The light from the object passes through the first lens L1 to the object side surface and the image side surface of the filter IR in sequence, and is finally imaged on the imaging surface IMG.

[0062] Table 3 shows the basic parameters of the curved prism lens of Example 2, wherein the units of the radius of curvature, thickness, focal length, half aperture and sagittal height are all in millimeters (mm).

[0063] Table 3:

[0064] Table 4 shows the high-order coefficients of each aspherical mirror surface that can be used in Example 2, wherein each aspherical surface shape can be defined by the formula (1) given in the above-mentioned Example 1.

[0065] Table 4:

[0066] In Example 2, the focal length f' of the curved prism lens is 13.3 mm, the working band of the curved prism lens is the visible light band, the aperture of the curved prism lens is 2.2, the imaging circle diameter of the curved prism lens is 8.2 mm, the field of view angle of the curved prism lens is 34°, and the total optical length is 19.6 mm; the relationship between the focal length f1 of the first lens L1 and the focal length f' of the curved prism lens is: f1 / f'=1.092; the relationship between the center thickness CT1 of the first lens L1, the object side sag SAG1 and the diameter D5' of the second lens L2 is : CT1-SAG1-D5=0.000mm; the relationship between the aperture F#, the field of view FOV and the focal length f′ of the curved prism lens is: F#*TAN(FOV / 2)*SQRT(f′ / 100)=0.245; the relationship between the object side sag height SAG3 of the second lens L2, the image side sag height SAG4 of the second lens L2, ... the image side sag height SAG11 of the fifth lens L5 is: MAX(ABS(SAG3), ABS(SAG4), ...ABS(SAG11))=0.800mm. The relationship between the object side sag height SAG1 of the first lens L1 and the object side sag height SAG3 of the second lens L2 is SAG1+SAG3=1.351mm. The relationship between the object side sag height SAG1 of the first lens L1 and the image side sag height SAG11 of the fifth lens L5 is SAG1-SAG11=1.329mm. The relationship among the Abbe number Ab1 of the first lens L1, the Abbe number Ab2 of the second lens L2 and the Abbe number Ab3 of the third lens L3 is (Ab1+Ab2) / Ab3=3.571.

[0067] Fig.10 The distortion diagram of the curved prism lens of Example 2 is shown, and the distortion is less than 2%, which is very small. Fig.11 The MTF curve of the curved prism lens of Example 2 is shown, and the MTF (Modulation Transfer Function) curve shows the transmission of image details (i.e., image contrast) of different spatial frequencies by the imaging system. The OTF modulus is greater than 0.4 at a spatial frequency of 125lp / mm, and has good resolution. Fig.12 The relative illumination and Y field angle diagram of the curved prism lens of Example 2 is shown. The relative illumination is greater than 0.55, and the brightness of the picture is uniform. Fig.13 The light fan diagram of the curved prism lens of Example 2 is shown. The light fan diagram generally shows the cross-section of the light beam at different positions, as well as the path and changes of the light beam propagation in the optical system. It is a comprehensive evaluation diagram of various aberrations. Its scale is ±10um, that is, the scale range in the horizontal and vertical directions is ±10um, and various aberrations are well corrected. Figures 10 to 13 It can be seen that the curved prism lens provided in Example 2 can achieve good imaging quality.

[0068] Example 3 The following reference Fig.14 The curved prism lens according to Embodiment 3 of the present application is described. In this embodiment, for the sake of brevity, some descriptions similar to Embodiment 1 will be omitted. Fig.14 A schematic diagram of an equivalent replacement structure of the curved prism lens according to Example 3 of the present application is shown.

[0069] The curved prism lens of Example 3 includes an object surface, a curved prism and a plurality of lenses in order from the object side to the image side. Fig.14 As shown, the curved prism is equivalent to the first lens L1, and the plurality of lenses may include a second lens L2, a third lens L3, a fourth lens L4 and a fifth lens L5 in sequence.

[0070] The first lens L1 has positive focal power, its object side surface is convex, and its image side surface is flat. The second lens L2 has negative focal power, its object side surface is convex, and its image side surface is concave. The third lens L3 has positive focal power, its object side surface is convex, and its image side surface is convex. The fourth lens L4 has positive focal power, its object side surface is concave, and its image side surface is convex. The fifth lens L5 has negative focal power, its object side surface is concave, and its image side surface is convex. The filter IR has an object side surface and an image side surface. The light from the object passes through the first lens L1 to the object side surface and the image side surface of the filter IR in sequence, and is finally imaged on the imaging surface IMG.

[0071] Table 5 shows the basic parameters of the curved prism lens of Example 3, wherein the units of the radius of curvature, thickness, focal length, half aperture and sagittal height are all in millimeters (mm).

[0072] Table 5:

[0073] Table 6 shows the high-order coefficients of each aspherical mirror surface that can be used in Example 3, wherein each aspherical surface shape can be defined by the formula (1) given in the above Example 1.

[0074] Table 6:

[0075] In this embodiment, the focal length f' of the curved prism lens is 13.299 mm, the working band of the curved prism lens is the visible light band, the aperture of the curved prism lens is 2.22, the imaging circle diameter of the curved prism lens is 8.2 mm, the field angle of the curved prism lens is 34°, and the total optical length is 18.13 mm; the relationship between the focal length f1 of the first lens L1 and the focal length f' of the curved prism lens is: f1 / f'=1.163; the relationship between the center thickness CT1 of the first lens L1, the object side sag SAG1 and the diameter D5' of the second lens L2 is: The relationship is: CT1-SAG1-D5=0.000mm; the relationship between the aperture F#, the field of view FOV and the focal length f′ of the curved prism lens is: F#*TAN(FOV / 2)*SQRT(f′ / 100)=0.247; the relationship between the object side sag SAG3 of the second lens L2, the image side sag SAG4 of the second lens L2, ... the image side sag SAG11 of the fifth lens L5 is: MAX(ABS(SAG3), ABS(SAG4), ...ABS(SAG11))=1.080mm. The relationship between the object side sag SAG1 of the first lens L1 and the object side sag SAG3 of the second lens L2 is SAG1+SAG3=2.374mm. The relationship between the object side sag SAG1 of the first lens L1 and the image side sag SAG11 of the fifth lens L5 is SAG1-SAG11=2.641mm. The relationship among the Abbe number Ab1 of the first lens L1, the Abbe number Ab2 of the second lens L2 and the Abbe number Ab3 of the third lens L3 is (Ab1+Ab2) / Ab3=2.007.

[0076] Fig.15 The distortion diagram of the curved prism lens of Example 3 is shown, and the distortion is less than 2%, which is very small. Fig.16 The MTF curve of the curved prism lens of Example 3 is shown, and the MTF (Modulation Transfer Function) curve shows the transmission of image details (i.e., image contrast) of different spatial frequencies by the imaging system. The OTF modulus is greater than 0.35 at a spatial frequency of 125lp / mm, and has good resolution. Fig.17 The relative illumination and Y field angle diagram of the curved prism lens of Example 3 is shown. The relative illumination is greater than 0.53, and the brightness of the picture is uniform. Fig.18 The ray fan diagram of the curved prism lens of Example 3 is shown. The ray fan diagram generally shows the cross-section of the light beam at different positions, as well as the path and changes of the light beam propagation in the optical system. It is a comprehensive evaluation diagram of various aberrations. Its scale is ±10um, that is, the scale range in the horizontal and vertical directions is ±10um, and various aberrations are well corrected. Figures 15 to 18It can be seen that the curved prism lens provided in Example 3 can achieve good imaging quality.

[0077] In summary, Example 1, Example 2 and Example 3 respectively satisfy the relationship shown in Table 7.

[0078] Table 7:

[0079] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

Claims

1. A curved prism lens, characterized in that: From the object side to the image side includes: A curved prism, the curved prism comprising an incident surface, a reflecting surface and an exiting surface, the curved prism being equivalent to a first lens, the incident surface of the curved prism being the object side surface of the first lens, and the exiting surface of the curved prism being the image side surface of the first lens; A plurality of lenses, the plurality of lenses are arranged in sequence and disposed between the curved prism and the imaging surface; The first lens has positive optical power, and the focal length f1 of the first lens and the focal length f′ of the curved prism lens satisfy: 0.5≤f1 / f′≤2.

3.

2. The curved prism lens according to claim 1, characterized in that: The reflection surface of the curved prism forms an angle of 45 degrees with both the incident light axis and the outgoing light axis.

3. The curved prism lens according to claim 1, characterized in that: The plurality of lenses include a second lens and other lenses in sequence, and a center thickness CT1, an object side sag SAG1 of the first lens and a diameter D5 of the second lens satisfy: 0mm≤CT1-SAG1-D5≤1mm.

4. The curved prism lens according to claim 1, characterized in that: The aperture F#, field of view FOV and focal length f′ of the curved prism lens satisfy: 0.24≤F#*TAN(FOV / 2)*SQRT(f′ / 100).

5. The curved prism lens according to claim 1, characterized in that: The plurality of lenses sequentially include a second lens, a third lens, a fourth lens, and a fifth lens.

6. The curved prism lens according to claim 5, characterized in that: The object side sag SAG3 of the second lens, the image side sag SAG4 of the second lens, the object side sag SAG6 of the third lens, the image side sag SAG7 of the third lens…the image side sag SAG11 of the fifth lens satisfies: MAX(ABS(SAG3), ABS(SAG4),…ABS(SAG11))≤1.5mm.

7. The curved prism lens according to claim 5, characterized in that: The object side sag height SAG1 of the first lens and the object side sag height SAG3 of the second lens satisfy: 0.8mm≤SAG1+SAG3≤3mm.

8. The curved prism lens according to claim 5, characterized in that: The object-side sag height SAG1 of the first lens and the image-side sag height SAG11 of the fifth lens satisfy: 1 ​​mm ≤ SAG1 - SAG11 ≤ 3.5 mm.

9. The curved prism lens according to claim 5, characterized in that: The Abbe number Ab1 of the first lens, the Abbe number Ab2 of the second lens, and the Abbe number Ab3 of the third lens satisfy: 1.5≤(Ab1+Ab2) / Ab3≤9.

10. An electronic device, characterized in that: It comprises the curved prism lens as claimed in any one of claims 1 to 9.

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