TWI476440B - Telephoto zoom lens - Google Patents

Description

Telephoto zoom lens

The invention relates to a telephoto zoom lens, in particular to a handheld electronic product such as a digital camera (DV), a digital camera (DSC), a tablet computer, or a CCTV CCTV camera, a security monitoring system, etc. Take the high magnification telephoto zoom lens inside the device.

Cameras used for filming often need to zoom in on tiny objects in the foreground to the close-up of the person through the zoom lens. This action has become an important photography technique. In the CCTV system for security monitoring, it is also necessary to enlarge the distant scene to a clear image that can recognize the appearance, so in the CCTV CCTV camera and the security camera system, it is necessary to use the telephoto zoom with high magnification. Lens.

In the telescope head, a large magnification image is possible due to the long focal length, and because the long focal length is required, the total length of the lens system is also long. Because of the wide-angle end image, the aperture of the first group of mirrors is generally larger, that is, the volume of the entire high-powered telescope head is larger.

First, U.S. Patent No. 7,532,411 discloses a four-group zoom system with PNPP (positive and negative positive), which has a function of high zoom (10X), but the front mirror group is in the process of zooming. 4 The mirror group has all displacements, so the architecture can obtain good imaging quality. However, the effective diameter of the first group of mirrors is the largest in the lens system. This large and heavy mirror is driven. Energy-consuming work.

Further, Japanese Laid-Open Patent Publication No. Sho 50-26931 discloses a zoom system of five groups of PNPNPs, in which the second and fourth group of mirrors maintain the images on the same focal plane in a coordinated optical compensation manner. In addition, a mechanically compensated zoom structure in which four groups of refractive powers are PNPP has been disclosed in Japanese Patent Publication No. 45-08840, but the first, second, third, and fourth group mirror groups are all motion groups, and the manufacturing cost is It is unfavorable.

In addition, Japanese Patent Publication No. Sho 46-32989 also discloses a zoom design that achieves a high zoom (15X), which is a structure in which four groups of refractive powers are PNNPs, in which the second and third groups of mirrors move to achieve mechanical Compensated zoom structure. Furthermore, U.S. Patent No. 5,815,322 adopts an internal focusing design, and can also achieve a high zoom (20X) zoom design, but the previous case is a PNNP architecture. In addition, U.S. Patent No. 7,672,061 adopts an internal focusing design, and can also achieve a high zoom (22X) zoom design, but the previous case is a PNNP architecture.

The embodiment of the invention provides a telephoto zoom lens, which adopts a group of 4 groups of refractive powers in the order of PNPP, and belongs to an inner focus type mechanical compensation zoom lens structure.

A telephoto zoom lens according to an embodiment of the present invention includes: a first lens group having positive refractive power, a second lens group having negative refractive power, and a positive refractive power a third lens group, and a fourth lens group having positive refractive power. The first group of lenses having positive refractive power is fixed at a first predetermined position. The second lens group having the negative refractive power described above moves along the optical axis of the telephoto zoom lens as the magnification of the telephoto zoom lens changes. The third lens group having positive refractive power is fixed to a second predetermined position. The fourth lens group having positive refractive power is moved along the optical axis of the telephoto zoom lens to keep the imaging surface generated by the telephoto zoom lens accurately projected on an image recorder. The first lens group, the second lens group, the third lens group, and the fourth lens group are sequentially arranged along the optical axis and from the object side of the telephoto zoom lens toward the imaging side, and the first lens group The focal lengths of the group, the second lens group, the third lens group, and the fourth lens group must meet the following two sets of conditions: Condition (1): ; and condition (2): Wherein F1 is the focal length of the first lens group, F2 is the focal length of the second lens group, and F3 is the focal length of the third lens group.

A telephoto zoom lens according to another embodiment of the present invention includes: a first lens group having positive refractive power, a second lens group having negative refractive power, and a positive refractive power a third lens group, and a fourth lens group having positive refractive power. The first group of lenses having positive refractive power is fixed at a first predetermined position. The second lens group having the negative refractive power described above moves along the optical axis of the telephoto zoom lens as the magnification of the telephoto zoom lens changes. The third lens group having positive refractive power is fixed to a second predetermined position. The fourth lens group having positive refractive power is moved along the optical axis of the telephoto zoom lens to keep the imaging surface generated by the telephoto zoom lens accurately projected on an image recorder. The first lens group, the second lens group, the third lens group, and the fourth lens group are sequentially arranged along the optical axis and from the object side of the telephoto zoom lens toward the imaging side. The first lens group includes a first lens, a second lens, a third lens and a fourth lens. The first lens and the second lens are glued together to form a double cemented lens, the first lens and the second lens. The third lens and the fourth lens are sequentially arranged along the optical axis and from the object side toward the imaging side, and the focal lengths of the double cemented lens and the third lens are subject to the following conditions: Wherein F _{1_12} is the focal length of the double lens of the first lens group, F ₁₃ is the focal length of the third lens of the first lens group, and F ₁₄ is the focal length of the fourth lens of the first lens group.

According to still another embodiment of the present invention, a telephoto zoom lens includes: a first lens group having positive refractive power, a second lens group having negative refractive power, and a positive refractive power. a third lens group and a fourth lens group having positive refractive power. The first group of lenses having positive refractive power is fixed at a first predetermined position. The second lens group having the negative refractive power described above moves along the optical axis of the telephoto zoom lens as the magnification of the telephoto zoom lens changes. The third lens group having positive refractive power is fixed to a second predetermined position. The fourth lens group having positive refractive power is moved along the optical axis of the telephoto zoom lens to keep the imaging surface generated by the telephoto zoom lens accurately projected on an image recorder. The first lens group, the second lens group, the third lens group, and the fourth lens group are sequentially arranged along the optical axis and from the object side of the telephoto zoom lens toward the imaging side. The second lens group includes a first lens, a second lens, and a third lens, and the second lens and the third lens are glued together to form a double cemented lens, the first lens, the second lens, and the third lens Arranged along the optical axis and from the object side toward the imaging side, and the focal length of the first lens and the double cemented lens must meet the following conditions: Wherein F ₂₁ is the focal length of the first lens of the second lens group, and F _{2_23} is the focal length of the double lens of the second lens group.

Therefore, the beneficial effects of the present invention include at least:

1. The present invention can provide a zoom lens for image capturing with high zoom ratio, long focal length, and high image quality.

2. The present invention is capable of designing and manufacturing a high-quality, first lens group having an appropriate radial diameter and an imaging zoom lens having a magnification of up to 20X.

For a better understanding of the features and technical aspects of the present invention, reference should be made to the accompanying drawings.

[First Embodiment]

Please refer to FIG. 1A to FIG. 1C , which respectively show the lens groups of the telephoto zoom lens according to the first embodiment of the present invention at the wide angle end (Wide), the standard position (Normal) and the telephoto end (Tele). A schematic diagram of a lens configuration in which D1 to D24 in Fig. 1A indicate axial distances between optical surfaces, and S1 to S24 in Fig. 1B are optical surface numbers of the respective lenses.

The telephoto zoom lens of the first embodiment of the present invention can be composed of 12 lenses. As shown in FIG. 1A to FIG. 1C, the telephoto zoom lens of the first embodiment of the present invention includes: a first lens group G1, a second lens group G2, and a third lens. Group G3, and a fourth lens group G4, wherein the first lens group G1 and the third lens group Both the group G3 and the fourth lens group G4 have a positive refractive power, and the second lens group G2 has a negative refractive power. Using the first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4 to change from each other (that is, by changing the lens group along the optical axis The distance in the Z direction can be changed to change the focal length of this telephoto zoom lens.

In the first embodiment of the present invention, the first lens group G1 includes a first lens L ₁₁ , a second lens L ₁₂ , a third lens L ₁₃ , and a fourth lens L ₁₄ , wherein the first lens L ₁₁ , the second lens L ₁₂ , the third lens L ₁₃ , and the fourth lens L ₁₄ may be sequentially arranged along the optical axis Z and from the object side toward the imaging side, and the first lens L ₁₁ and the second lens L ₁₂ can be glued to each other to form a double cemented lens L _{1_12} . Furthermore, the second lens group G2 includes a first lens L ₂₁ , a second lens L ₂₂ , and a third lens L ₂₃ , wherein the first lens L ₂₁ , the second lens L ₂₂ , and the third lens L ₂₃ may be sequentially arranged along the optical axis Z and from the object side toward the imaging side, and the second lens L ₂₂ and the third lens L ₂₃ may be cemented to each other to form a double cemented lens L _{2_23} . In addition, the third lens group G3 includes a first lens L ₃₁ , a second lens L ₃₂ , and a third lens L ₃₃ , and the first lens L ₃₁ , the second lens L ₃₂ , and the third lens L ₃₃ may be sequentially arranged along the optical axis Z and from the object side toward the imaging side. In addition, the fourth lens group G4 includes a first lens L ₄₁ and a second lens L ₄₂ , wherein the first lens L ₄₁ and the second lens L ₄₂ are glued to each other to form a double cemented lens L _{4_12} , and the first The lens L ₄₁ and the second lens L ₄₂ may be sequentially arranged along the optical axis Z and from the object side toward the imaging side. Furthermore, the telephoto zoom lens may further include: a pupil A disposed along the optical axis Z and disposed between the second lens group G2 and the third lens group G3, and the size of the aperture A may be used Adjust as needed.

In other words, the first lens group G1 having positive refractive power can be fixed at a first predetermined position. The second lens group G2 having the negative refractive power described above can be moved along the optical axis Z of the telephoto zoom lens as the magnification of the telephoto zoom lens changes. The third lens group G3 having positive refractive power can be fixed to a second predetermined position. The fourth lens group G4 having the positive refractive power can be moved along the optical axis Z of the telephoto zoom lens to keep the imaging surface generated by the telephoto zoom lens accurately projected on the image recorder 1. In addition, the first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4 may be along the optical axis Z and from the object side of the telephoto zoom lens toward the imaging side. Ordering. For example, as follows:

(1) The focal lengths of the first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4 are subject to the following two sets of conditions: Condition (1): ; and condition (2): Wherein F1 is the focal length of the first lens group, F2 is the focal length of the second lens group, and F3 is the focal length of the third lens group.

(2) The distance between the focal length of the first lens group G1 and the first lens group G1 to the third lens group G3 is subject to the following conditions: Wherein d _1-3 are distances of the first lens group G1 to the third lens group G3.

(3) The third lens L ₁₃ and the fourth lens L _{14 of the} first lens group G1 may each be a single-piece meniscus lens, and the double lens L _{1_12} and the third lens of the first lens group G1 The focal length of lens L ₁₃ must meet the following conditions: Wherein F _{1_12} is the focal length of the double cemented lens L _{1_12} of the first lens group G1, F ₁₃ is the focal length of the third lens L ₁₃ of the first lens group G1, and F ₁₄ is the fourth lens group G1. The focal length of the lens L ₁₄ .

(4) The first lens L _{21 of the} second lens group G2 may be a monolithic lens, and the focal length of the first lens L _{21 of the} second lens group G2 and the double cemented lens L _{2_23} shall meet the following conditions: Wherein F ₂₁ is the focal length of the first lens L ₂₁ of the second lens group G2, and F _{2_23} is the focal length of the double cemented lens L _{2_23} of the second lens group G2.

(5) The focal length of the third lens group G3 and the focal length of the fourth lens group G4 are subject to the following conditions: Wherein F3 is the focal length of the third lens group G3, and F4 is the focal length of the fourth lens group G4.

Please refer to FIG. 1D to FIG. 1F, FIG. 1D shows the first embodiment. FIG. 1E is a graph showing longitudinal spherical aberration, astigmatism, and distortion in a wide-angle mode; FIG. 1E is a graph showing longitudinal spherical aberration, astigmatism, and distortion in the standard position type of the first embodiment; FIG. A graph of longitudinal spherical aberration, astigmatism, and distortion in a telephoto mode.

The data of the first embodiment of the present invention is shown in the following table, where R represents the radius of curvature of each lens surface (numbered from S1 to S24), and D represents the axial distance between the optical surfaces (numbered from D1 to D24). n _d represents the refractive index of each optical surface, and V _d represents the Abbe number of each optical surface, which represents the value of the chromatic dispersion characteristic of the material.

The relationship between focal length, aperture value, field of view and position D7, D12, D19 and D22 with respect to different zoom positions are as follows:

Where f denotes the focal length of the system corresponding to the wide-angle end, the standard end and the telephoto end, F _NO denotes the aperture value corresponding to the wide-angle end, the standard end and the telephoto end, and FOV(ω) denotes the angle of view corresponding to the wide-angle end, the standard end and the telephoto end .

Further, among the plurality of lenses, the optical surface numbers S18 and S19 are aspherical, and the aspherical coefficient data are as follows:

The above aspheric equation can be expressed as: Wherein, Z is a sag, C (=1/R) is a spherical curvature, K is a conic constant, Y is a height perpendicular to the optical axis Z of the lens, A ₄ is a fourth-order aspheric coefficient, and A ₆ is The 6th-order aspheric coefficient, the representative of A ₈ to A ₁₆ and so on.

[Second embodiment]

Please refer to FIG. 2A to FIG. 2C , which respectively show three lens groups of the telephoto zoom lens according to the second embodiment of the present invention at the wide angle end ( FIG. 2A ), the standard position ( FIG. 2B ) and the telephoto end ( FIG. 2C ). Schematic diagram of lens configuration . Referring to FIG. 2D to FIG. 2F, FIG. 2D is a graph showing longitudinal spherical aberration, astigmatism and distortion in the wide-angle mode of the second embodiment, and FIG. 2E is a vertical view showing the second embodiment in the standard positional state. A graph of spherical aberration, astigmatism, and distortion, and FIG. 2F is a graph showing longitudinal spherical aberration, astigmatism, and distortion in the telescopic mode of the second embodiment.

Please refer to the following table for the data of the second embodiment of the present invention:

The relationship between focal length, aperture value, field of view and position D7, D12, D19 and D22 with respect to different zoom positions are as follows:

Further, among the plurality of lenses, the optical surface numbers S18 and S19 are aspherical, and the aspherical equation is the same as that of the first embodiment of the present invention. The aspheric coefficient data of the second embodiment are as follows:

[Possible effects of the examples]

In summary, the beneficial effects of the present invention include at least:

1. The present invention can provide a zoom lens for image capturing with high zoom ratio, long focal length, and high image quality.

2. The present invention is capable of designing and manufacturing a high-quality, first lens group having an appropriate radial diameter and an imaging zoom lens having a magnification of up to 20X.

The above are only the preferred embodiments of the present invention, and are not intended to limit the scope of the invention, and the equivalents of the invention are included in the scope of the invention.

G1‧‧‧First lens group

G2‧‧‧Second lens group

G3‧‧‧ third lens group

L ₁₁ ‧‧‧first lens

L ₁₂ ‧‧‧second lens

L _{1_12 ‧‧‧Double} cemented lens

L ₁₃ ‧‧‧ third lens

L ₁₄ ‧‧‧Fourth lens

L ₂₁ ‧‧‧first lens

L ₂₂ ‧‧‧second lens

L ₂₃ ‧‧‧ third lens

L _{2_23 ‧‧‧Double} cemented lens

L ₃₁ ‧‧‧first lens

L ₃₂ ‧‧‧second lens

G4‧‧‧Fourth lens group

L ₃₃ ‧‧‧ third lens

L ₄₁ ‧‧‧first lens

L ₄₂ ‧‧‧second lens

L _{4_12 ‧‧‧Double} cemented lens

S1 to S24‧‧‧ optical surface

D1 to D24‧‧‧ axial distance

A‧‧‧Light

I‧‧‧Image Recorder

Z‧‧‧ optical axis

1A is a view showing a lens configuration of each lens group of a telephoto zoom lens according to a first embodiment of the present invention in a wide-angle end state.

FIG. 1B is a view showing a lens configuration of each lens group of the telephoto zoom lens according to the first embodiment of the present invention in a standard positional state.

FIG. 1C is a view showing a lens configuration of each lens group of the telephoto zoom lens according to the first embodiment of the present invention in a telephoto end mode.

1D to 1F are graphs showing longitudinal spherical aberration, astigmatism, and distortion in the wide-angle mode, the standard position type, and the telephoto mode, respectively, of the first embodiment.

2A is a view showing a lens configuration of each lens group of the telephoto zoom lens according to the second embodiment of the present invention in a wide-angle end state.

2B is a view showing a lens configuration of each lens group of the telephoto zoom lens according to the second embodiment of the present invention in a standard position mode.

2C is a schematic view showing the lens configuration of each lens group of the telephoto zoom lens according to the second embodiment of the present invention in a telephoto end mode.

2D to 2F are graphs showing longitudinal spherical aberration, astigmatism, and distortion in the wide-angle mode, the standard position type, and the telephoto mode, respectively, of the second embodiment.

G1. . . First lens group

L ₁₁ . . . First lens

L ₁₂ . . . Second lens

L _{1_12} . . . Double cemented lens

L ₁₃ . . . Third lens

L ₁₄ . . . Fourth lens

G2. . . Second lens group

L ₂₁ . . . First lens

L ₂₂ . . . Second lens

L ₂₃ . . . Third lens

L _{2_23} . . . Double cemented lens

G3. . . Third lens group

L ₃₁ . . . First lens

L ₃₂ . . . Second lens

L ₃₃ . . . Third lens

G4. . . Fourth lens group

L ₄₁ . . . First lens

L ₄₂ . . . Second lens

L _{4_12} . . . Double cemented lens

D1 to D24. . . Axial distance

A. . . Light

I. . . Image recorder

Z. . . Optical axis

Claims (15)

A telephoto zoom lens comprising: a first lens group having positive refractive power fixed to a first predetermined position; and a second lens group having negative refractive power, zooming with the telephoto a change in magnification of the lens to move along an optical axis of the telephoto zoom lens; a third lens group having positive refractive power fixed to a second predetermined position; and a positive refractive power a fourth lens group that moves along an optical axis of the telephoto zoom lens to keep an imaging surface generated by the telephoto zoom lens accurately projected on an image recorder; wherein the first lens group, the first lens group The two lens groups, the third lens group, and the fourth lens group are sequentially arranged along the optical axis and from the object side of the telephoto zoom lens toward the imaging side, and the first lens group, The focal lengths of the second lens group, the third lens group, and the fourth lens group are subject to the following two conditions: Wherein F1 is the focal length of the first lens group, F2 is the focal length of the second lens group, and F3 is the focal length of the third lens group. The telephoto zoom lens of claim 1, wherein a focal length of the first lens group and a distance from the first lens group to the third lens group are subject to the following conditions: Wherein d _{1-3 is} the distance from the first lens group to the third lens group. The telephoto zoom lens of claim 1, wherein the first lens group comprises a first lens, a second lens, a third lens, and a fourth lens, the first lens and the first lens The two lenses are glued together to form a double cemented lens, and the third lens and the fourth lens are both a single-piece meniscus lens, the first lens, the second lens, the third lens, and the fourth The lenses are sequentially arranged along the optical axis and from the object side toward the imaging side, and the focal lengths of the double cemented lens and the third lens are subject to the following conditions: Wherein F _{1_12 is} the focal length of the double lens of the first lens group, F _{13 is} the focal length of the third lens of the first lens group, and F ₁₄ is the fourth lens of the first lens group. The focal length. The telephoto zoom lens of claim 1, wherein the second lens group comprises a first lens, a second lens, and a third lens, the first lens being a monolithic lens, The second lens and the third lens are glued together to form a double cemented lens, and the first lens, the second lens, and the third lens are sequentially along the optical axis and from the object side toward the imaging side. Arranged, and the focal length of the first lens and the double cemented lens must meet the following conditions: Wherein F _{21 is} the focal length of the first lens of the second lens group, and F _{2_23 is} the focal length of the double cemented lens of the second lens group. The telephoto zoom lens of claim 1, wherein the third lens group comprises a first lens, a second lens, and a third lens, and the first lens, the second lens, and The third lens is sequentially arranged along the optical axis and from the object side toward the imaging side, wherein the fourth lens group includes a first lens and a second lens, the first lens and the second lens The lenses are glued to each other to form a double cemented lens, the first lens and the second lens are sequentially arranged along the optical axis and from the object side toward the imaging side, and the focal length of the third lens group is The focal length of the fourth lens group must meet the following conditions: Wherein F4 is the focal length of the fourth lens group. A telephoto zoom lens comprising: a first lens group having positive refractive power fixed to a first predetermined position; and a second lens group having negative refractive power, zooming with the telephoto a change in magnification of the lens to move along an optical axis of the telephoto zoom lens; a third lens group having positive refractive power fixed to a second predetermined position; and a positive refractive power a fourth lens group that moves along an optical axis of the telephoto zoom lens to keep an imaging surface generated by the telephoto zoom lens accurately projected on an image recorder; wherein the first lens group and the first lens group The second lens group, the third lens group, and the fourth lens group are sequentially arranged along the optical axis and from the object side of the telephoto zoom lens toward the imaging side; wherein the first lens group a first lens, a second lens, a third lens and a fourth lens, the first lens and the second lens are glued together to form a double cemented lens, the first lens, the second lens, the Third lens and the The fourth lens is sequentially arranged along the optical axis and from the object side toward the imaging side, and the focal length of the double cemented lens and the third lens are subject to the following conditions: Wherein F _{1_12 is} the focal length of the double lens of the first lens group, F _{13 is} the focal length of the third lens of the first lens group, and F ₁₄ is the fourth lens of the first lens group. The focal length. The telephoto zoom lens of claim 6, wherein the first lens group, the second lens group, the third lens group, and the fourth lens group have a focal length that meets the following two groups; Condition: Condition (1): ; and condition (2): Wherein F1 is the focal length of the first lens group, F2 is the focal length of the second lens group, and F3 is the focal length of the third lens group. The telephoto zoom lens of claim 6, wherein a focal length of the first lens group and a distance from the first lens group to the third lens group are subject to the following conditions: Wherein, F1 for the focal length of the first lens group, d _1-3 of the first lens group to the distance of the third lens group for. The telephoto zoom lens of claim 6, wherein the second lens group comprises a first lens, a second lens, and a third lens, and the first lens of the second lens group is a single lens, the second lens of the second lens group and the third lens are glued together to form a double cemented lens, the first lens, the second lens, and the second lens group The third lens is sequentially arranged along the optical axis and from the object side toward the imaging side, and the focal length of the first lens of the second lens group and the double cemented lens is subject to the following conditions: Wherein F _{21 is} the focal length of the first lens of the second lens group, and F _{2_23 is} the focal length of the double cemented lens of the second lens group. The telephoto zoom lens of claim 6, wherein the third lens group comprises a first lens, a second lens, and a third lens, and the first lens of the third lens group The second lens and the third lens are sequentially arranged along the optical axis and from the object side toward the imaging side, wherein the fourth lens group includes a first lens and a second lens. The first lens and the second lens of the fourth lens group are glued together to form a double cemented lens, the first lens and the second lens of the fourth lens group are along the optical axis and from the object side The direction toward the imaging side is sequentially arranged, and the focal length of the third lens group and the focal length of the fourth lens group are subject to the following conditions: And wherein F3 is the focal length of the third lens group and F4 is the focal length of the fourth lens group. A telephoto zoom lens comprising: a first lens group having positive refractive power fixed to a first predetermined position; and a second lens group having negative refractive power, zooming with the telephoto a change in magnification of the lens to move along an optical axis of the telephoto zoom lens; a third lens group having positive refractive power fixed to a second predetermined position; and a positive refractive power a fourth lens group that moves along an optical axis of the telephoto zoom lens to keep an imaging surface generated by the telephoto zoom lens accurately projected on an image recorder; wherein the first lens group, the first lens group The second lens group, the third lens group, and the fourth lens group are sequentially arranged along the optical axis and from the object side of the telephoto zoom lens toward the imaging side; wherein the second lens group a first lens, a second lens, and a third lens, the second lens and the third lens are glued together to form a double cemented lens, the first lens, the second lens, and the third lens Along the optical axis Direction of the object side towards the image side are arranged sequentially, and the first lens and the focal length of the doublet lens must meet the following conditions: Wherein F _{21 is} the focal length of the first lens of the second lens group, and F _{2_23 is} the focal length of the double cemented lens of the second lens group. The telephoto zoom lens of claim 11, wherein the focal length of the first lens group, the second lens group, the third lens group, and the fourth lens group are in accordance with the following two groups; condition: Wherein F1 is the focal length of the first lens group, F2 is the focal length of the second lens group, and F3 is the focal length of the third lens group. The telephoto zoom lens of claim 11, wherein a focal length of the first lens group and a distance from the first lens group to the third lens group are subject to the following conditions: Wherein, F1 for the focal length of the first lens group, d _1-3 of the first lens group to the distance of the third lens group for. The telephoto zoom lens of claim 11, wherein the first lens group comprises a first lens, a second lens, a third lens, and a fourth lens, the first lens group The first lens and the second lens are glued together to form a double cemented lens, and the third lens and the fourth lens of the first lens group are each a single-piece meniscus lens, and the first lens group The first lens, the second lens, the third lens, and the fourth lens of the group are sequentially arranged along the optical axis and from the object side toward the imaging side, and the first lens group The focal length of the double cemented lens and the third lens must meet the following conditions: Wherein F _{1_12 is} the focal length of the double lens of the first lens group, F _{13 is} the focal length of the third lens of the first lens group, and F ₁₄ is the fourth lens of the first lens group. The focal length. The telephoto zoom lens of claim 11, wherein the third lens group comprises a first lens, a second lens, and a third lens, and the first lens of the third lens group The second lens and the third lens are sequentially arranged along the optical axis and from the object side toward the imaging side, wherein the fourth lens group includes a first lens and a second lens. The first lens and the second lens of the fourth lens group are glued together to form a double cemented lens, the first lens and the second lens of the fourth lens group are along the optical axis and from the object side The direction toward the imaging side is sequentially arranged, and the focal length of the third lens group and the focal length of the fourth lens group are subject to the following conditions: And wherein F3 is the focal length of the third lens group and F4 is the focal length of the fourth lens group.