Interchangeable lens and imaging device

Abstract

The invention relates to the field of optics, in particular to an interchangeable lens which is sequentially composed of a first lens group with positive focal power, an interchangeable lens group with negative focal power and a second lens group with positive focal power from the object plane side to the image plane side, and the interchangeable lens meets the following conditional expressions that fno is smaller than 1.1; tTL / ft is less than 5; wherein fno is the number of apertures of the interchangeable lens, TTL is the total optical length of the interchangeable lens, and ft is the focal length of the interchangeable lens. Through setting of the structure and parameters, the interchangeable lens group can realize focusing, and under the condition that the total optical length and the aperture of the interchangeable lens are not increased, a large aperture of the interchangeable lens is realized, the interchangeable lens can realize high brightness, and user experience is improved.

Description

Technical Field

[0001] The present invention relates to the field of optics, and in particular to an interchangeable lens and an imaging device. Background Art

[0002] Interchangeable lenses, commonly used with single-lens reflex cameras, are a general term for lenses designed for different purposes, in addition to standard lenses. Special-purpose spares include fisheye lenses, swing lenses, reflex lenses, and soft-focus lenses. For 35mm single-lens reflex cameras, various manufacturers produce approximately 30 to 60 different types, ranging in focal length from 6mm (fisheye) to 2000mm (reflex).

[0003] However, since interchangeable lenses require a stable focal length, a focusing module still needs to be provided inside the interchangeable lenses because the focusing is performed internally. Existing interchangeable lenses are usually of low brightness, or the aperture number of the lens is usually increased by continuously increasing the diameter or length of the lens. Therefore, how to achieve an interchangeable lens with a small size and a large aperture remains an urgent problem to be solved. Summary of the Invention

[0004] The present invention will solve the existing technical problems and provide an interchangeable lens and an imaging device. Through the setting of the above-mentioned structure and parameters, the interchangeable lens group can achieve focusing. Without increasing the total optical length and aperture of the interchangeable lens, a larger aperture of the interchangeable lens is achieved. The interchangeable lens can achieve greater brightness, thereby enhancing the user experience.

[0005] The technical solutions provided by the present invention are as follows:

[0006] An interchangeable lens, comprising, from the object side to the image side, a first lens group having positive focal power, an interchangeable lens group having negative focal power, and a second lens group having positive focal power; the first lens group comprising, from the object side to the image side, a first lens having positive focal power, a second lens having negative focal power, a third lens having negative focal power, a fourth lens having negative focal power, a fifth lens having positive focal power, a stop, a sixth lens having positive focal power, and an eighth lens having positive focal power; the fourth lens and the fifth lens being cemented together;

[0007] The interchangeable lens satisfies the following conditional formula:

[0008] fno<1.1;

[0009] TTL / ft>4;

[0010] Wherein, fno is the aperture number of the interchangeable lens, TTL is the total optical length of the interchangeable lens, and ft is the focal length of the interchangeable lens.

[0011] Through the setting of the above structure and parameters, the interchangeable lens group can achieve focusing, and a larger aperture of the interchangeable lens is achieved without increasing the total optical length and aperture of the interchangeable lens. The interchangeable lens can achieve greater brightness, thereby enhancing the user experience.

[0012] Preferably, the second lens group consists of an eleventh lens with positive focal power, a twelfth lens with positive focal power, a thirteenth lens with negative focal power and a fourteenth lens with positive focal power from the object side to the image side, and the twelfth lens and the thirteenth lens are cemented together.

[0013] Preferably, the interchangeable lens group consists of a ninth lens with positive focal power and a tenth lens with negative focal power in sequence from the object plane side to the image plane side.

[0014] Preferably, a seventh lens with negative optical power is further included between the sixth lens and the eighth lens, and the seventh lens and the eighth lens are cemented together.

[0015] Preferably, the interchangeable lens group consists of a tenth lens with negative optical power.

[0016] Preferably, the interchangeable lens satisfies the following conditional formula:

[0017] 0.6<fG1 / ft<1.5;

[0018] Wherein, fG1 is the focal length of the first lens group.

[0019] In this technical solution, by limiting the focal length of the first lens group, the basic optical path of the interchangeable lens is determined, the moving distance of the interchangeable lens group is reduced, and the miniaturization of the interchangeable lens is achieved.

[0020] Preferably, the interchangeable lens satisfies the following conditional formula:

[0021] -2<fG2 / f<-3;

[0022] Wherein, fG2 is the focal length of the interchangeable lens group.

[0023] In this technical solution, by limiting the focal length of the interchangeable lens group, the coma and phase difference of the interchangeable lens are reduced, and the resolution of the interchangeable lens is increased.

[0024] Preferably, the interchangeable lens satisfies the following conditional formula:

[0025] XG2 / f>0.1;

[0026] XG2 is the moving distance of the interchangeable lens group.

[0027] By moving the interchangeable lens group over a large distance, the interchangeable lens can achieve a larger aperture at a smaller moving distance, thereby increasing the reliability of the interchangeable lens.

[0028] Preferably, the interchangeable lens satisfies the following conditional formula:

[0029] -1.2<fG2 / ft<-1.1;

[0030] Wherein, fG2 is the focal length of the interchangeable lens group.

[0031] In this technical solution, by limiting the focal length of the interchangeable lens group, the coma and phase difference of the interchangeable lens are reduced, and the resolution of the interchangeable lens is increased.

[0032] Preferably, the interchangeable lens satisfies the following conditional formula:

[0033] XG2 / ft<0.1;

[0034] Wherein, XG2 is the moving distance of the interchangeable lens group.

[0035] In this technical solution, the coma and phase difference of the interchangeable lens are reduced by the shorter moving distance of the interchangeable lens group, thereby increasing the resolution of the interchangeable lens.

[0036] Another object of the present invention is to provide an imaging device comprising: an interchangeable lens;

[0037] and an imaging element configured to receive an image formed by the interchangeable lens.

[0038] Compared with the prior art, the interchangeable lens and imaging device provided by the present invention have the following beneficial effects:

[0039] 1. Through the setting of the above structure and parameters, the interchangeable lens group can achieve focusing. Without increasing the total optical length and aperture of the interchangeable lens, a larger aperture of the interchangeable lens is achieved. The interchangeable lens can achieve greater brightness, thereby enhancing the user experience.

[0040] 2. Through the large movement distance of the interchangeable lens group, the interchangeable lens can achieve a larger aperture at a smaller movement distance, which increases the reliability of the interchangeable lens.

[0041] 3. The smaller moving distance of the interchangeable lens group reduces the coma and phase difference of the interchangeable lens, and increases the resolution of the interchangeable lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The preferred embodiments will be described below in a clear and understandable manner with reference to the accompanying drawings to further illustrate the above-mentioned characteristics, technical features, advantages and implementation methods of an interchangeable lens and imaging device.

[0043] Figure 1 It is a structural schematic diagram of an interchangeable lens of the present invention;

[0044] Figure 2 is an aberration diagram of an interchangeable lens of the present invention;

[0045] Figure 3 is a coma diagram of an interchangeable lens of the present invention;

[0046] Figure 4 It is a structural schematic diagram of another interchangeable lens of the present invention;

[0047] Figure 5 is an aberration diagram of another interchangeable lens of the present invention;

[0048] Figure 6 This is a coma diagram of another interchangeable lens of the present invention.

[0049] Explanation of Reference Numerals: G1, first lens group; G2, interchangeable lens group; G3, second lens group; G4, auxiliary assembly; L1, first lens; L2, second lens; L3, third lens; L4, fourth lens; L5, fifth lens; L6, sixth lens; L7, seventh lens; L8, eighth lens; L9, ninth lens; L10, tenth lens; L11, eleventh lens; L12, twelfth lens; L13, thirteenth lens; L14, fourteenth lens; STO, aperture stop; CG, cover glass. DETAILED DESCRIPTION

[0050] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0051] To simplify the drawings, only portions relevant to the invention are schematically depicted in each figure; they do not represent the actual structure of the product. Furthermore, to simplify the drawings and facilitate understanding, in some figures, only one component with the same structure or function is schematically depicted or labeled. In this document, "one" not only means "only one" but also "more than one."

[0052] Example 1

[0053] like Figure 1 and Figure 4 As shown, an interchangeable lens, which is composed, from the object side to the image side, of a first lens group G1 with positive focal power, an interchangeable lens group G2 with negative focal power, and a second lens group G3 with positive focal power. The first lens group G1 is composed, from the object side to the image side, of a first lens L1 with positive focal power, a second lens L2 with negative focal power, a third lens L3 with negative focal power, a fourth lens L4 with negative focal power, a fifth lens L5 with positive focal power, an aperture STO, a sixth lens L6 with positive focal power, and an eighth lens L8 with positive focal power. The fourth lens L4 and the fifth lens L5 are cemented together.

[0054] The interchangeable lens satisfies the following conditional formula:

[0055] fno<1.1;

[0056] TTL / ft>4;

[0057] Wherein, fno is the aperture number of the interchangeable lens, TTL is the total optical length of the interchangeable lens, and ft is the focal length of the interchangeable lens.

[0058] In this embodiment, through the setting of the above-mentioned structure and parameters, the interchangeable lens group G2 can achieve focusing, and a larger aperture of the interchangeable lens is achieved without increasing the total optical length and aperture of the interchangeable lens. The interchangeable lens can achieve greater brightness, thereby enhancing the user experience.

[0059] The second lens group G3 consists of an eleventh lens L11 with positive refractive power, a twelfth lens L12 with positive refractive power, a thirteenth lens L13 with negative refractive power and a fourteenth lens L14 with positive refractive power from the object side to the image side, and the twelfth lens L12 and the thirteenth lens L13 are cemented together.

[0060] The interchangeable lens group G2 consists of a ninth lens L9 with positive refractive power and a tenth lens L10 with negative refractive power in order from the object side to the image side.

[0061] A seventh lens L7 with negative optical power is further included between the sixth lens L6 and the eighth lens L8, and the seventh lens L7 and the eighth lens L8 are cemented together.

[0062] The interchangeable lens group G2 is composed of a tenth lens L10 with negative optical power.

[0063] The interchangeable lens satisfies the following conditional formula:

[0064] 0.6<fG1 / ft<1.5;

[0065] Wherein, fG1 is the focal length of the first lens group G1.

[0066] In this embodiment, by limiting the focal length of the first lens group G1 , the basic optical path of the interchangeable lens is determined, the moving distance of the interchangeable lens group G2 is reduced, and the miniaturization of the interchangeable lens is achieved.

[0067] The interchangeable lens satisfies the following conditional formula:

[0068] -2<fG2 / f<-3;

[0069] Wherein, fG2 is the focal length of the interchangeable lens group G2.

[0070] By limiting the focal length of the interchangeable lens group G2, the coma and phase aberration of the interchangeable lens are reduced, and the resolution of the interchangeable lens is increased.

[0071] The interchangeable lens satisfies the following conditional formula:

[0072] XG2 / f>0.1;

[0073] XG2 is the moving distance of the interchangeable lens group G2.

[0074] By moving the interchangeable lens group over a large distance, the interchangeable lens can achieve a larger aperture at a smaller moving distance, thereby increasing the reliability of the interchangeable lens.

[0075] The interchangeable lens satisfies the following conditional formula:

[0076] -1.2<fG2 / ft<-1.1;

[0077] Wherein, fG2 is the focal length of the interchangeable lens group G2.

[0078] By limiting the focal length of the interchangeable lens group G2, the coma and phase aberration of the interchangeable lens are reduced, and the resolution of the interchangeable lens is increased.

[0079] The interchangeable lens satisfies the following conditional formula:

[0080] XG2 / ft<0.1;

[0081] Wherein, XG2 is the moving distance of the interchangeable lens group G2.

[0082] By reducing the moving distance of the interchangeable lens group, the coma and phase difference of the interchangeable lens are reduced, and the resolution of the interchangeable lens is increased.

[0083] Example 2

[0084] like Figures 1 to 3As shown, an interchangeable lens consists of a first lens group G1 with positive focal length, an interchangeable lens group G2 with negative focal length, a second lens group G3 with positive focal length, and an auxiliary component G4 from the object side to the image side.

[0085] The first lens group G1 is composed, from the object side to the image side, of a first lens L1 with positive focal power, a second lens L2 with negative focal power, a third lens L3 with negative focal power, a fourth lens L4 with negative focal power, a fifth lens L5 with positive focal power, an aperture STO, a sixth lens L6 with positive focal power, a seventh lens L7 with negative focal power, and an eighth lens L8 with positive focal power; the fourth lens L4 and the fifth lens L5 are cemented together, and the seventh lens L7 and the eighth lens L8 are cemented together.

[0086] The interchangeable lens group G2 is composed of a tenth lens L10 with negative optical power.

[0087] The second lens group G3 consists of an eleventh lens L11 with positive refractive power, a twelfth lens L12 with positive refractive power, a thirteenth lens L13 with negative refractive power and a fourteenth lens L14 with positive refractive power from the object side to the image side, and the twelfth lens L12 and the thirteenth lens L13 are cemented together.

[0088] The auxiliary component G4 is a protective glass CG.

[0089] Table 1 shows basic lens data of the interchangeable lens of this embodiment, Table 2 shows variable parameters in Table 1, and Table 3 shows aspherical coefficients.

[0090] The surface number column shows the surface number when the object side surface is set as the first surface and the numbers increase one by one toward the image side; the surface type column shows the surface type of a certain lens; the curvature radius column shows the curvature radius of a certain lens, when the curvature radius is positive, it indicates that the surface is curved toward the object side, and when the curvature radius is negative, it indicates that the surface is curved toward the image side; the center thickness column shows the surface spacing on the optical axis between each surface and the surface adjacent to its image side; the refractive index column shows the refractive index of a certain lens; and the Abbe number column shows the Abbe number of a certain lens.

[0091] In Table 2, the WIDE column indicates the specific values of the various variable parameters when the interchangeable lens is in the wide-angle end state, and the TELE column indicates the specific values of the various variable parameters when the interchangeable lens is in the telephoto end state.

[0092] In Table 3, K is the cone coefficient, and e is the scientific notation, for example, e-05 represents 10 -5 .

[0093]

Table 1

[0094] Face number Surface type Curvature radius / mm Center thickness / mm Refractive index Abbe number OBJ S1 spherical surface 35.62 6.02 2.00 23.28 S2 spherical surface 84.76 0.10 S3 spherical surface 34.75 2.69 1.50 81.61 S4 spherical surface 14.80 8.01 S5 spherical surface -270.23 1.00 1.50 81.61 S6 spherical surface 33.68 12.51 S7 spherical surface -18.43 1.00 1.73 26.81 S8 spherical surface 70.79 8.16 1.59 68.63 S9 spherical surface -23.07 0.50 STO spherical surface INF 0.50 S11 Aspheric 42.96 8.00 1.81 40.73 S12 Aspheric -53.15 2.90 S13 spherical surface 113.04 1.00 1.70 28.43 S14 spherical surface 25.93 8.59 1.71 53.61 S15 spherical surface -65.33 0.70 S16 spherical surface INF D1 S17 spherical surface -1124.67 1.00 1.79 24.30 S18 spherical surface 22.16 D2 S19 Aspheric 38.39 4.46 1.62 63.85 S20 Aspheric -660.20 0.10 S21 spherical surface 25.55 4.09 2.00 19.32 S22 spherical surface -775.03 0.90 1.73 26.90 S23 spherical surface 21.19 2.71 S24 Aspheric 76.44 2.01 1.85 40.10 S25 Aspheric -250.00 11.00 S26 spherical surface INF 4.20 1.52 64.20 S27 spherical surface INF 0.20 IMG

[0095]

Table 2

[0096] Object distance INF 350 D1 1.51 0.1 D2 6.14 7.55

[0097]

Table 3

[0098]

[0099] In this embodiment, fw=23.5mm, ft=23.7mm, TTL=100mm, fno=0.98-1.02; TTL / ft=4.22;

[0100] Wherein, fno is the aperture number of the interchangeable lens, TTL is the total optical length of the interchangeable lens, and f is the focal length of the interchangeable lens.

[0101] fG1=22.72mm, fG1 / ft=0.959;

[0102] Wherein, fG1 is the focal length of the first lens group G1.

[0103] fG2=-27.59mm, fG2 / ft=-1.16;

[0104] Wherein, fG2 is the focal length of the interchangeable lens group G2.

[0105] XG2=1.41mm, XG2 / ft=0.059;

[0106] Wherein, XG2 is the moving distance of the interchangeable lens group G2.

[0107] Example 3

[0108] like Figures 4 to 6 As shown, an interchangeable lens, which is composed of, from the object side to the image side, a first lens group G1 with positive focal power, an interchangeable lens group G2 with negative focal power, and a second lens group G3 with positive focal power. The first lens group G1 is composed of, from the object side to the image side, a first lens L1 with positive focal power, a second lens L2 with negative focal power, a third lens L3 with negative focal power, a fourth lens L4 with negative focal power, a fifth lens L5 with positive focal power, an aperture STO, a sixth lens L6 with positive focal power, and an eighth lens L8 with positive focal power; the fourth lens L4 and the fifth lens L5 are cemented together.

[0109] The interchangeable lens group G2 consists of a ninth lens L9 with positive refractive power and a tenth lens L10 with negative refractive power in order from the object side to the image side.

[0110] The second lens group G3 consists of an eleventh lens L11 with positive refractive power, a twelfth lens L12 with positive refractive power, a thirteenth lens L13 with negative refractive power and a fourteenth lens L14 with positive refractive power from the object side to the image side, and the twelfth lens L12 and the thirteenth lens L13 are cemented together.

[0111] Basic lens data of the interchangeable lens of this embodiment is shown in Table 4, variable parameters in Table 4 are shown in Table 5, and aspheric coefficients are shown in Table 6.

[0112] The surface number column shows the surface number when the object side surface is set as the first surface and the numbers increase one by one toward the image side; the surface type column shows the surface type of a certain lens; the curvature radius column shows the curvature radius of a certain lens, when the curvature radius is positive, it indicates that the surface is curved toward the object side, and when the curvature radius is negative, it indicates that the surface is curved toward the image side; the center thickness column shows the surface spacing on the optical axis between each surface and the surface adjacent to its image side; the refractive index column shows the refractive index of a certain lens; and the Abbe number column shows the Abbe number of a certain lens.

[0113] In Table 5, the WIDE column indicates the specific values of the various variable parameters when the interchangeable lens is in the wide-angle end state, and the TELE column indicates the specific values of the various variable parameters when the interchangeable lens is in the telephoto end state.

[0114] In Table 6, K is the cone coefficient, and e is the scientific notation, for example, e-05 represents 10 -5 .

[0115]

Table 4

[0116]

[0117]

[0118]

Table 5

[0119] Object distance INF 350 D1 4.08 0.87 D2 4.97 8.18

[0120]

Table 6

[0121]

[0122]

[0123] In this embodiment, fw=23.2mm, ft=23.5mm, TTL=100mm, fno=0.98-1.02; TTL / ft=4.25;

[0124] Wherein, fno is the aperture number of the interchangeable lens, TTL is the total optical length of the interchangeable lens, and f is the focal length of the interchangeable lens.

[0125] fG1=32.8mm, fG1 / ft=1.4;

[0126] Wherein, fG1 is the focal length of the first lens group G1.

[0127] fG2=-49.11mm, fG2 / ft=-2.09;

[0128] Wherein, fG2 is the focal length of the interchangeable lens group G2.

[0129] XG2=3.21mm, XG2 / ft=0.137;

[0130] Wherein, XG2 is the moving distance of the interchangeable lens group G2.

[0131] Example 4

[0132] An imaging device, such as Figures 1 to 6 As shown, it includes: an interchangeable lens as described in any of the above embodiments, and an imaging element configured to receive an image formed by the interchangeable lens.

[0133] It should be noted that the above embodiments can be freely combined as needed. The above description is only a preferred embodiment of the present invention. It should be pointed out that those skilled in the art can make several improvements and modifications without departing from the principles of the present invention, and such improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An interchangeable lens, characterized in that: The interchangeable lens is composed, from the object side to the image side, of a first lens group with positive focal power, an interchangeable lens group with negative focal power, and a second lens group with positive focal power; the first lens group is composed, from the object side to the image side, of a first lens with positive focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power, a fifth lens with positive focal power, a stop, a sixth lens with positive focal power, and an eighth lens with positive focal power; the fourth lens and the fifth lens are cemented together; The interchangeable lens satisfies the following conditional formula: fno<1.1; TTL / ft<5; Wherein, fno is the aperture number of the interchangeable lens, TTL is the total optical length of the interchangeable lens, and ft is the focal length of the interchangeable lens.

2. The interchangeable lens according to claim 1, wherein: The second lens group consists of an eleventh lens with positive focal power, a twelfth lens with positive focal power, a thirteenth lens with negative focal power and a fourteenth lens with positive focal power from the object side to the image side, and the twelfth lens and the thirteenth lens are cemented together.

3. The interchangeable lens according to claim 2, wherein: The interchangeable lens group consists of a ninth lens with positive focal power and a tenth lens with negative focal power in sequence from the object plane side to the image plane side.

4. The interchangeable lens according to claim 2, wherein: A seventh lens with negative optical power is further included between the sixth lens and the eighth lens, and the seventh lens and the eighth lens are cemented together.

5. The interchangeable lens according to claim 4, wherein: The interchangeable lens group consists of a tenth lens with negative optical power.

6. The interchangeable lens according to claim 1 or 4, wherein: The interchangeable lens satisfies the following conditional formula: 0.6<fG1 / ft<1.5; Wherein, fG1 is the focal length of the first lens group.

7. The interchangeable lens according to claim 3, wherein: The interchangeable lens satisfies the following conditional formula: -2<fG2 / f<-3; Wherein, fG2 is the focal length of the interchangeable lens group.

8. The interchangeable lens according to claim 7, wherein: The interchangeable lens satisfies the following conditional formula: XG2 / f>0.1; XG2 is the moving distance of the interchangeable lens group.

9. The interchangeable lens according to claim 5, wherein: The interchangeable lens satisfies the following conditional formula: -1.2<fG2 / ft<-1.1; Wherein, fG2 is the focal length of the interchangeable lens group.

10. The interchangeable lens according to claim 9, wherein: The interchangeable lens satisfies the following conditional formula: XG2 / ft<0.1; Wherein, XG2 is the moving distance of the interchangeable lens group.

11. An imaging device, characterized in that: include: The interchangeable lens according to any one of claims 1 to 10; and an imaging element configured to receive an image formed by the interchangeable lens.

Images