CN117930481A - Zoom lens and imaging device - Google Patents
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- CN117930481A CN117930481A CN202311340087.2A CN202311340087A CN117930481A CN 117930481 A CN117930481 A CN 117930481A CN 202311340087 A CN202311340087 A CN 202311340087A CN 117930481 A CN117930481 A CN 117930481A
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Abstract
The object is to provide a zoom lens and an imaging device which are bright in a wide angle of view, small in size, and high in imaging performance. The solution is that the zoom lens is composed of a1 st lens group with negative refractive power, a middle group with more than 1 lens groups and with synthesized refractive power being positive refractive power, a L-1 st lens group with negative refractive power and a L-th lens group with positive refractive power in sequence from the object side to the image side, and the magnification is changed by changing the interval between adjacent lens groups along the optical axis, so as to meet the preset formula.
Description
Technical Field
Cross-reference to related applications
The present application claims priority from japanese patent application No. 2022-170087, filed to the japanese patent office on the basis of 24 th 10 th 2022, the entire contents of which are incorporated herein by reference.
The present invention relates to an optical system, an optical apparatus, and an imaging device, and more particularly to a zoom lens and an imaging device suitable for an imaging device using a solid-state imaging element (CCD, CMOS, or the like) such as a digital still camera or a digital video camera.
Background
In recent years, imaging devices using a solid-state imaging element such as a digital still camera have been widely used. At the same time, with the development of high performance and miniaturization of optical systems, miniaturized imaging device systems are rapidly spreading. Among conventional lenses, particularly, it is desired to miniaturize an optical system while maintaining high optical performance, such as a monitoring lens for an optical system, a video camera lens, a digital still camera lens, a single lens reflex, and a mirror-less single lens reflex, which are short and compact. The present invention has been made in view of the above-described problems, and provides a compact zoom lens and an image pickup apparatus including the same.
Under such circumstances, for example, patent documents 1 and 2 disclose optical systems.
Prior art literature
Patent literature
[ Patent document 1] Japanese patent application laid-open 2020-140142
[ Patent document 2] Japanese patent application laid-open No. 2021-067805
Disclosure of Invention
Problems to be solved by the invention
Patent document 1 is an invention regarding a zoom lens composed of, in order from the object side, a 1 st lens group having negative refractive power, a2 nd lens group having positive refractive power, a 3 rd lens group having negative refractive power, and a 4 th lens group having positive refractive power. Although this zoom lens has a wide angle of view, fno is 4 dark, and the amount of movement of the 4 th lens group is large, so that miniaturization of the lens barrel is hindered if Fno is to be lightened.
Patent document 2 is an invention regarding a zoom lens composed of, in order from the object side, a1 st lens group having negative refractive power, a2 nd lens group having positive refractive power, a 3 rd lens group having negative refractive power, and a4 th lens group having positive refractive power. Although this zoom lens has a wide angle of view, since the lateral magnification at the telephoto end of the 4 th lens group is small, magnification correction needs to be performed by other groups, and the amount of movement of the object group becomes large or the optical power becomes strong, making it difficult to correct spherical aberration or coma between the magnifications.
The present invention has been made in view of the above-described problems, and an object thereof is to provide a zoom lens having a wide angle of view, which is bright and small, and which has high imaging performance, and an image pickup apparatus having the zoom lens.
Means for solving the problems
A zoom lens is characterized by comprising, in order from an object side to an image side, a 1 st lens group having a negative refractive power, an intermediate group having 1 or more lens groups and having a combined refractive power of positive refractive power, an L-1 st lens group having a negative refractive power, and an L-th lens group having a positive refractive power,
The magnification change is performed by changing the interval of adjacent lens groups along the optical axis,
The zoom lens satisfies the following formula:
-100.00＜M1/ML＜-2.85……(1)
0.18＜|βLt|……(2)
wherein,
M 1: the amount of movement of the 1 st lens group (positive to the image side) when changing magnification from the wide-angle end to the telephoto end
M L: the amount of movement of the L-th lens group (positive to the image side) when changing magnification from the wide-angle end to the telephoto end
Beta Lt: and the lateral magnification of the L-th lens group at the telescopic end of the L-th lens group during infinite focusing.
A zoom lens is characterized in that,
Comprising, in order from the object side to the image side, a1 st lens group having a negative refractive power, an intermediate group having 1 or more lens groups and having a combined refractive power of positive refractive power, an L-1 st lens group having a negative refractive power, an L-th lens group having a positive refractive power,
The magnification change is performed by changing the interval of adjacent lens groups along the optical axis,
The zoom lens satisfies the following formula:
1.00＜fL/|f1|＜2.10……(7)
1.90＜fL/|fL-1|＜10.00……(8)
0.50＜|βLt/βLw|＜5.50……(9)
wherein,
F 1: focal length of the 1 st lens group
F L-1: focal length of the L-1 th lens group
F L: focal length of the L-th lens group
Beta Lw: lateral magnification at the time of infinity focusing at the wide-angle end of the L-th lens group
Beta Lt: and the lateral magnification of the L-th lens group at the telescopic end of the L-th lens group during infinite focusing.
In order to solve the above-described problems, an image pickup apparatus according to the present invention includes the zoom lens and an image pickup device that converts an optical image formed by the zoom lens into an electrical signal.
Effects of the invention
According to the present invention, a zoom lens having a wide angle of view, which is bright and small and has high imaging performance, and an image pickup apparatus having the zoom lens can be provided.
Drawings
Fig. 1 is a cross-sectional view showing an example of a lens structure of a zoom lens according to embodiment 1.
Fig. 2 is a longitudinal aberration diagram in the wide-angle end state at the time of infinity focusing of the zoom lens of embodiment 1.
Fig. 3 is a longitudinal aberration diagram in the intermediate region state at the time of infinity focusing in the zoom lens of embodiment 1.
Fig. 4 is a longitudinal aberration diagram in a telephoto end state at the time of infinity focusing of the zoom lens of embodiment 1.
Fig. 5 is a cross-sectional view showing an example of a lens structure of the zoom lens according to embodiment 2.
Fig. 6 is a longitudinal aberration diagram in the wide-angle end state at the time of infinity focusing of the zoom lens of embodiment 2.
Fig. 7 is a longitudinal aberration diagram in a middle area state at the time of infinity focusing of the zoom lens of embodiment 2.
Fig. 8 is a longitudinal aberration diagram in a telephoto end state at the time of infinity focusing of the zoom lens of embodiment 2.
Fig. 9 is a cross-sectional view showing an example of a lens structure of the zoom lens according to embodiment 3.
Fig. 10 is a longitudinal aberration diagram in the wide-angle end state at the time of infinity focusing of the zoom lens of embodiment 3.
Fig. 11 is a longitudinal aberration diagram in a middle area state at the time of infinity focusing of the zoom lens of embodiment 3.
Fig. 12 is a longitudinal aberration diagram in a telephoto end state at the time of infinity focusing of the zoom lens of embodiment 3.
Fig. 13 is a cross-sectional view showing an example of a lens structure of the zoom lens according to embodiment 4.
Fig. 14 is a longitudinal aberration diagram in the wide-angle end state at the time of infinity focusing of the zoom lens of embodiment 4.
Fig. 15 is a longitudinal aberration diagram in a middle area state at the time of infinity focusing of the zoom lens of embodiment 4.
Fig. 16 is a longitudinal aberration diagram in a telephoto end state at the time of infinity focusing of the zoom lens of embodiment 4.
Fig. 17 is a cross-sectional view showing an example of a lens structure of the zoom lens according to embodiment 5.
Fig. 18 is a longitudinal aberration diagram in the wide-angle end state at the time of infinity focusing of the zoom lens of embodiment 5.
Fig. 19 is a longitudinal aberration diagram in a middle area state at the time of infinity focusing of the zoom lens of embodiment 5.
Fig. 20 is a longitudinal aberration diagram in a telephoto end state at the time of infinity focusing of the zoom lens of embodiment 5.
Fig. 21 is a cross-sectional view showing an example of a lens structure of the zoom lens according to embodiment 6.
Fig. 22 is a longitudinal aberration diagram in the wide-angle end state at the time of infinity focusing of the zoom lens of embodiment 6.
Fig. 23 is a longitudinal aberration diagram in an intermediate region state at the time of infinity focusing of the zoom lens of embodiment 6.
Fig. 24 is a longitudinal aberration diagram in a telephoto end state at the time of infinity focusing of the zoom lens of embodiment 6.
Fig. 25 is a cross-sectional view showing an example of a lens structure of the zoom lens according to embodiment 7.
Fig. 26 is a longitudinal aberration diagram in the wide-angle end state at the time of infinity focusing of the zoom lens of embodiment 7.
Fig. 27 is a longitudinal aberration diagram in a middle area state at the time of infinity focusing of the zoom lens of embodiment 7.
Fig. 28 is a longitudinal aberration diagram in a telephoto end state in the infinity focusing of the zoom lens of embodiment 7.
Fig. 29 is a cross-sectional view showing an example of the lens structure of the zoom lens according to embodiment 8.
Fig. 30 is a longitudinal aberration diagram in the wide-angle end state at the time of infinity focusing of the zoom lens of embodiment 8.
Fig. 31 is a longitudinal aberration diagram in a middle area state at the time of infinity focusing of the zoom lens of embodiment 8.
Fig. 32 is a longitudinal aberration diagram in a telephoto end state at the time of infinity focusing of the zoom lens of embodiment 8.
Fig. 33 is a cross-sectional view showing an example of a lens structure of the zoom lens according to embodiment 9.
Fig. 34 is a longitudinal aberration diagram in the wide-angle end state at the time of infinity focusing of the zoom lens of embodiment 9.
Fig. 35 is a longitudinal aberration diagram in a middle area state at the time of infinity focusing of the zoom lens of embodiment 9.
Fig. 36 is a longitudinal aberration diagram in a telephoto end state in the infinity focusing of the zoom lens of embodiment 9.
Fig. 37 is a diagram schematically showing an example of the configuration of an imaging device according to an embodiment of the present invention.
Detailed Description
Embodiments of a zoom lens and an imaging apparatus according to the present invention are described below. However, the zoom lens and the image pickup apparatus described below are one aspect of the zoom lens and the image pickup apparatus according to the present invention, and the zoom lens and the image pickup apparatus according to the present invention are not limited to the following aspects.
1. Zoom lens
1-1 Optical Structure
The zoom lens according to the present invention is composed of, in order from an object side to an image side, a 1 st lens group having a negative refractive power, an intermediate group having 1 or more lens groups and having a combined refractive power of positive refractive power, an L-1 st lens group having a negative refractive power, and an L-th lens group having a positive refractive power. With this configuration, a zoom lens having a wide angle of view and a small size can be easily formed.
(1) 1 St lens group
The 1 st lens group is not particularly limited as long as it is a lens group having negative refractive power. Preferably, the 1 st lens group is constituted by 3 or less lenses on the basis of downsizing. In addition, it is preferable that the 1 st lens group is composed of 2 negative lenses and 1 positive lens in order from the object side to the image side, and particularly preferable is composed of a negative meniscus lens, a positive meniscus lens or a negative meniscus lens, a biconcave lens, and a positive meniscus lens.
The "lens group" has 1 or more lens. The "lens group" refers to a set of 1 lens or 2 or more lenses in which the interval between adjacent lens groups varies at the time of varying magnification between the wide-angle end and the telephoto end. In the case where the lens group has a plurality of lenses, the plurality of lenses maintain a relative positional relationship at the time of magnification change between the wide-angle end and the telephoto end. The lens group may be movable on the optical axis or may be fixed.
(2) Intermediate group
The specific structure is not particularly limited as long as the intermediate group has one or more lens groups and has a positive refractive power as a combined refractive power. May be composed of two lens groups, but is preferably composed of one lens group.
(3) L-1 th lens group
The specific configuration of the L-1 lens group is not particularly limited as long as the lens group is arranged on the image side of the intermediate group and has a negative refractive power. In order to correct chromatic aberration, it is preferable to have 1 or more positive lenses and 1 or more negative lenses. Preferably, it is composed of 2 negative lenses and 1 positive lens in order from the object side to the image side. Preferably, there is a cemented lens of a negative lens and a positive lens on the most image side.
(4) L-th lens group
The specific configuration of the L-th lens group is not particularly limited as long as the lens group is disposed on the most image side and has a negative refractive power. In order to correct the aberration, it is preferable to have a negative lens on the most image side. In addition, it is preferable to have a negative meniscus lens on the most image side. Preferably, the 2 nd has a negative lens from the image side. Preferably, the image side surface of the 2 nd lens component is concave toward the image side from the image side. In order to correct the aberration, it is preferable to have a lens having a convex shape toward the object side at the most object side. In addition, it is preferable to have a lenticular lens on the most object side.
In the present specification, the lens component includes a lens and a bonded lens in which a plurality of lenses are integrated without an air gap. The lens includes 1 single lens and a compound lens formed by integrating 1 single lens and resin without passing through an air gap. The single lens is composed of 1 material. Specifically, 1 lens segment formed by joining 2 single lenses is counted as 1 lens component and 2 lenses are counted as 2 lenses. The number of lenses (single lens and compound lens) is 1 as a lens component, and 1 sheet as a lens. Here, the single lens means a spherical lens and an aspherical lens (including a compound aspherical lens).
(5) Aperture diaphragm
Preferably, the aperture stops are arranged in the intermediate group. According to this structure, a bright and small zoom lens with high imaging performance can be easily formed.
1-2. Action
(1) Zoom ratio
The magnification change from the wide-angle end to the telephoto end is performed by changing the interval between adjacent lens groups. When changing magnification from the wide-angle end to the telephoto end, the 1 st lens group is monotonously moved to the image side, and the interval between the intermediate group and the L-1 st lens group is monotonously increased, so that the desired zoom magnification can be achieved, the diameters of the lens groups after the intermediate group can be reduced, and the lens barrel can be easily miniaturized. Further, more preferably, the interval between the L-1 th lens group and the L-th lens group monotonously increases when magnification is changed from the wide-angle end to the telephoto end.
(2) Focusing
The zoom lens is focused by the L-1 th lens group moving on the optical axis. According to this configuration, the beam diameter passing through the focusing group can be reduced by the focusing action of the intermediate group, which is effective for downsizing the product.
1-3A Chinese medicinal composition
Preferably, the zoom lens adopts the above-described structure, and satisfies at least one of the formulae described above and below.
1-3-1. Formula (1)
-100.00＜M1/ML＜-2.85……(1)
Wherein,
M 1: shift amount of 1 st lens group (positive to image side) when changing magnification from wide-angle end to telephoto end
M L: the amount of movement of the L-th lens group (positive to the image side) when changing magnification from the wide-angle end to the telephoto end
Equation (1) specifies the ratio of the amount of movement of the 1 st lens group to the amount of movement of the L-th lens group when varying magnification from the wide-angle end to the telephoto end. By satisfying the expression (1), miniaturization of the lens barrel, mainly miniaturization in the radial direction, can be achieved, and at the same time, a desired zoom magnification can be achieved.
If the amount of movement of the 1 st lens group becomes larger, it is difficult to construct the cam cylinder in 1 st order, which is not preferable because miniaturization of the lens barrel is hindered. If the upper limit value of the formula (1) is exceeded, the movement amount of the L-th lens group becomes large, and if Fno is kept bright, the reduction of the diameter of the L-th lens group becomes difficult, and the downsizing of the lens barrel is hindered, which is not preferable.
In order to obtain the above-mentioned effect, the lower limit value of the formula (1) is preferably-80.00, more preferably-60.00. The upper limit of the formula (1) is preferably-2.90, more preferably-3.00. In the case where these preferable lower limit or upper limit are used, the inequality sign (. Ltoreq.) with the equal sign may be replaced with the inequality sign (. <) in the formula (1). The same applies in principle to the other formulae.
1-3-2. Formula (2)
0.18＜|βLt|……(2)
Wherein,
Beta Lt: lateral magnification at infinity focusing at the telephoto end of the L-th lens group.
Equation (2) specifies the lateral magnification of the telephoto end of the L-th lens group. By satisfying the expression (2), the magnification of the other lens group can be optimized, and a zoom lens having high optical performance can be realized.
If the lateral magnification at the telephoto end of the L-th lens group is lower than the lower limit value of the formula (2), magnification correction by other lens groups is required, and thus it is necessary to increase the amount of movement or increase the optical power of the group, and thus deterioration of each aberration such as spherical aberration or coma aberration is caused, which is not preferable for realizing a lens with high optical performance.
In order to obtain the above effect, the lower limit value of the formula (2) is preferably 0.20, more preferably 0.22.
1-3-3. 1 (3)
-0.95＜fs-1/ft＜-0.25……(3)
Wherein,
F s-1: focal length of lens component adjacent to object side of aperture stop
F t: focal length at the telephoto end of the zoom lens.
Equation (3) specifies the ratio of the focal length of the lens component adjacent to the object side of the aperture stop to the focal length at the telephoto end of the zoom lens.
1-3-4. 1 (4)
-0.95＜fs+1/ft＜-0.25……(4)
Wherein,
F s+1: focal length of lens component adjacent to image side of aperture diaphragm
F t: focal length at the telephoto end of the zoom lens.
By satisfying at least one of the expression (3) and the expression (4), the aperture can be reduced, the aperture of the aperture unit can be reduced, and the lens barrel can be miniaturized.
If the refractive power is lower than the lower limit value of the formula (3) or (4), the refractive power of the lens component adjacent to the diaphragm becomes weak, and the reduction of the diaphragm diameter becomes insufficient, which is not preferable because the miniaturization of the lens barrel is hindered. If the upper limit value of the expression (3) or the expression (4) is exceeded, the optical power of the lens component adjacent to the aperture becomes strong, and correction of each aberration such as spherical aberration or coma becomes difficult, which is not preferable for realizing a lens having high optical performance.
The lower limit of the formula (3) is preferably-0.90, more preferably-0.85. The upper limit of the formula (3) is preferably-0.30, more preferably-0.35.
The lower limit of the formula (4) is preferably-0.90, more preferably-0.85. The upper limit of the formula (4) is preferably-0.30, more preferably-0.35.
1-3-5. 1. 5)
0.01＜|fL-1|/fw＜2.00……(5)
Wherein,
F L-1: focal length of L-1 th lens group
F w: a focal length at a wide angle end of the zoom lens.
Equation (5) specifies the ratio of the focal length of the L-1 th lens group to the focal length at the wide-angle end of the zoom lens. By satisfying the expression (5), both the downsizing and the high performance of the L-1 th lens group can be achieved.
If it is less than the lower limit value of the formula (5), since the optical power of the L-1 th lens group becomes strong, correction of spherical aberration becomes difficult, which is not preferable for realizing a lens with high optical performance. If the upper limit value of the formula (5) is exceeded, the optical power of the L-1 th lens group becomes weak, and the L-1 th lens group becomes insufficient in diameter reduction, which is not preferable because miniaturization of the lens barrel is hindered. In addition, the amount of movement of the L-1 th lens group during magnification change becomes large, which hinders miniaturization in the overall length direction, and is not preferable.
The lower limit of the formula (5) is preferably 0.10, more preferably 0.20. The upper limit of the formula (5) is preferably 1.90, more preferably 1.80.
1-3-6. 1 (6)
1.850＜Ndave……(6)
Wherein,
N dave: average refractive index of d-line (587.5 nm) of material constituting each lens of the L-1 th lens group.
Equation (6) specifies the average refractive index of d-rays of the materials constituting each lens of the L-1 th lens group. By satisfying the expression (6), both the reduction in diameter and the high performance of the L-1 th lens group can be achieved.
If the value is less than the lower limit value of the formula (6), it is difficult to correct each aberration while maintaining the reduction in diameter, which is not preferable from the viewpoints of downsizing and high performance of the lens barrel.
The lower limit of the formula (5) is preferably 1.860, more preferably 1.870.
1-3-7. Formula (7)
1.00＜fL/|f1|＜2.10……(7)
Wherein,
F 1: focal length of 1 st lens group
F L: focal length of the L-th lens group.
Equation (7) specifies the ratio of the absolute value of the focal length of the 1 st lens group to the focal length of the L-th lens group. By satisfying the expression (7), both the downsizing and the high performance of the L-th lens group can be achieved.
If it is less than the lower limit value of the formula (7), correction of the image surface curvature becomes difficult because the optical power of the L-th lens group becomes strong, which is not preferable for realizing a lens with high optical performance. If the upper limit value of the expression (7) is exceeded, the optical power of the L-th lens group becomes weak, and the bright Fno design becomes difficult.
The lower limit of the formula (7) is preferably 1.05, more preferably 1.10. The upper limit of the formula (7) is preferably 2.05, more preferably 2.00.
1-3-8. 1 (8)
1.90＜fL/|fL-1|＜10.00……(8)
Wherein,
F L-1: focal length of L-1 th lens group
F L: focal length of the L-th lens group.
Equation (8) specifies the ratio of the absolute value of the focal length of the L-1 th lens group to the focal length of the L-th lens group. By satisfying the expression (8), both the downsizing and the high performance of the L-th lens group can be achieved.
If it is less than the lower limit value of the formula (8), the power of the L-th lens group becomes strong, and correction of the image surface curvature becomes difficult, which is not preferable for realizing a lens with high optical performance. If the upper limit value of expression (8) is exceeded, the optical power of the L-th lens group becomes weak, and the bright Fno design becomes difficult.
The lower limit of the formula (8) is preferably 1.95, more preferably 2.00. The upper limit of the formula (8) is preferably 8.00, more preferably 6.00.
1-3-9. 1 (9)
0.50＜|βLt/βLw|＜5.50……(9)
Wherein,
Beta Lw: lateral magnification at infinity focusing at wide-angle end of the L-th lens group
Beta Lt: lateral magnification at infinity focusing at the telephoto end of the L-th lens group.
Equation (9) specifies an absolute value of a ratio of a lateral magnification at the wide-angle end of the L-th lens group at the time of infinity focusing to a lateral magnification at the telephoto end of the L-th lens group at the time of infinity focusing. By satisfying the expression (9), the magnification ratio of the L-th lens group can be made appropriate, and the lens barrel can be miniaturized and a desired zoom magnification can be achieved.
If the amount is less than the lower limit value of the formula (9), the amount of movement of the other lens group becomes large, and downsizing of the lens barrel becomes difficult, which is not preferable. If the upper limit value of the formula (9) is exceeded, the amount of movement of the L-th lens group becomes large, and downsizing of the lens barrel becomes difficult, which is not preferable.
The lower limit of the formula (9) is preferably 0.60, more preferably 0.70. The upper limit of the formula (9) is preferably 5.00, more preferably 4.50.
1-3-10. 1 (10)
2.00＜|βL-1t|＜10.00……(10)
Wherein,
Beta L-1t: lateral magnification at infinity focusing at the telephoto end of the L-1 th lens group.
Equation (10) specifies the absolute value of the lateral magnification at the telephoto end of the L-1 th lens group at the time of infinity focusing. By satisfying the expression (10), the magnification of the other lens group can be optimized, and a zoom lens having high optical performance can be realized.
If the lateral magnification at the telephoto end of the L-1 th lens group is lower than the lower limit value of the formula (10), magnification correction by other lens groups is required, and thus the amount of movement needs to be increased or the optical power of the group needs to be increased, so that deterioration of each aberration such as spherical aberration or coma aberration is caused, which is not preferable for realizing a lens with high optical performance. If the upper limit value of the formula (10) is exceeded, the lateral magnification at the telephoto end of the L-1 th lens group becomes large, resulting in deterioration of each aberration generated in the L-1 th lens group, which is not preferable for realizing a lens with high optical performance.
The lower limit of the formula (10) is preferably 2.50, more preferably 3.00. The upper limit of the formula (10) is preferably 9.00, more preferably 8.00.
1-3-11. Formula (11)
0.20＜fpt/ft＜1.50……(11)
Wherein,
F pt: composite focal length at infinity focusing at the telephoto end of the intermediate group
F t: focal length at the telephoto end of the zoom lens.
Equation (11) specifies the ratio of the combined focal length at the telephoto end of the intermediate group at the time of infinity focusing to the focal length at the telephoto end of the zoom lens. By satisfying the expression (11), the diameter of the lens group subsequent to the intermediate group can be reduced.
If it is less than the lower limit value of the formula (11), since the optical power of the intermediate group becomes strong, correction of spherical aberration becomes difficult, which is not preferable for realizing a lens with high optical performance. If the upper limit value of the expression (11) is exceeded, the optical power of the intermediate group becomes weak, and the reduction in diameter of the lens group after the intermediate group becomes insufficient, which is not preferable because miniaturization of the lens barrel is hindered.
The lower limit of the formula (11) is preferably 0.30, more preferably 0.40. The upper limit of the formula (11) is preferably 1.25, more preferably 1.00.
1-3-12. 1 (12)
1.00＜fL/fpt＜6.00……(12)
Wherein,
F pt: composite focal length at infinity focusing at the telephoto end of the intermediate group
F L: focal length of the L-th lens group.
Equation (12) specifies the ratio of the combined focal length at the telephoto end of the intermediate group at the time of infinity focusing to the focal length of the L-th lens group. By satisfying the expression (12), both the downsizing and the high performance of the L-th lens group can be achieved.
If the value is less than the lower limit value of the formula (12), correction of the image surface curvature becomes difficult because the optical power of the L-th lens group becomes strong, which is not preferable for realizing a lens with high optical performance. If the upper limit value of the expression (12) is exceeded, the optical power of the L-th lens group becomes weak, and the bright Fno design becomes difficult.
The lower limit of the formula (12) is preferably 1.25, more preferably 1.50. The upper limit of the formula (12) is preferably 5.50, more preferably 5.00.
1-3-13. Formula (13)
0.01＜fL-1/f1＜2.00……(13)
Wherein,
F 1: focal length of 1 st lens group
F L-1: focal length of the L-1 th lens group.
Equation (13) specifies the ratio of the focal length of the 1 st lens group to the focal length of the L-1 st lens group. By satisfying the expression (13), both the reduction in diameter and the high performance of the L-1 th lens group can be achieved.
If it is less than the lower limit value of the formula (13), since the optical power of the L-1 th lens group becomes strong, correction of spherical aberration becomes difficult, which is not preferable for realizing a lens with high optical performance. If the upper limit value of the formula (13) is exceeded, the optical power of the L-1 th lens group becomes weak, and the L-1 th lens group becomes insufficient in diameter reduction, which is not preferable because miniaturization of the lens barrel is hindered. In addition, the amount of movement of the L-1 th lens group during magnification change becomes large, which hinders miniaturization in the overall length direction, and is not preferable.
The lower limit of the formula (13) is preferably 0.15, more preferably 0.30. The upper limit of the formula (13) is preferably 1.75, more preferably 1.50.
1-3-14. Formula (14)
-2.00＜fL-1/fpt＜-0.50……(14)
Wherein,
F pt: composite focal length at infinity focusing at the telephoto end of the intermediate group
F L-1: focal length of the L-1 th lens group.
Equation (14) specifies the ratio of the combined focal length at the telephoto end of the intermediate group at the time of infinity focusing to the focal length of the L-1 th lens group. By satisfying the expression (14), both the downsizing and the high performance of the L-1 th lens group can be achieved.
If it is less than the lower limit value of the formula (14), since the optical power of the L-1 th lens group becomes strong, correction of spherical aberration becomes difficult, which is not preferable for realizing a lens with high optical performance. If the upper limit value of the formula (14) is exceeded, the optical power of the L-1 th lens group becomes weak, and the L-1 th lens group becomes insufficient in diameter reduction, which is not preferable because miniaturization of the lens barrel is hindered. In addition, the amount of movement of the L-1 th lens group during magnification change becomes large, which hinders miniaturization in the overall length direction, and is not preferable.
The lower limit of the formula (14) is preferably-1.90, more preferably-1.80. The upper limit of the formula (14) is preferably-0.60, more preferably-0.70.
1-3-15. Formula (15)
-2.00＜fpt/f1＜-0.01……(15)
Wherein,
F 1: focal length of 1 st lens group
F pt: a resultant focal length at infinity focusing at the telephoto end of the intermediate group.
Equation (15) specifies the ratio of the focal length of the 1 st lens group to the combined focal length at the telephoto end of the intermediate group at the time of infinity focusing. By satisfying the expression (15), the diameter of the lens group subsequent to the intermediate group can be reduced.
If it is less than the lower limit value of the formula (15), since the optical power of the intermediate group becomes strong, correction of spherical aberration becomes difficult, which is not preferable for realizing a lens with high optical performance. If the upper limit value of the expression (15) is exceeded, the optical power of the intermediate group becomes weak, and the reduction in diameter of the lens group after the intermediate group becomes insufficient, which is not preferable because miniaturization of the lens barrel is hindered.
The lower limit of the formula (15) is preferably-1.75, more preferably-1.50. The upper limit of the formula (15) is preferably-0.15, more preferably-0.30.
1-3-16. 1 (16)
-7.00＜(1-βL-1t2)×βLt2＜-1.00……(16)
Wherein,
Beta L-1t: lateral magnification at infinity focusing at the telephoto end of the L-1 th lens group
Beta Lt: lateral magnification at infinity focusing at the telephoto end of the L-th lens group.
Equation (16) specifies the ratio of the lateral magnification at the telephoto end of the L-1 th lens group at the time of infinity focusing to the lateral magnification at the telephoto end of the L-th lens group at the time of infinity focusing. By satisfying the expression (16), the amount of movement during focusing from an object at infinity to an object at a limited distance can be suppressed during focusing in the L-1 group, and miniaturization of the lens barrel can be achieved.
If the value is less than the lower limit value of the formula (16), the focusing sensitivity of the L-1 th lens group becomes small, and the amount of movement when focusing from an object at infinity to an object at a limited distance becomes large, which is not preferable because miniaturization of the lens barrel is hindered. If the upper limit value of the conditional expression (16) is exceeded, the focus sensitivity increases, and high-precision control is required, which is not preferable.
The lower limit of the formula (16) is preferably-6.50, more preferably-6.00. The upper limit of the formula (16) is preferably-1.50, more preferably-2.00.
2. Image pickup apparatus
Next, an image pickup apparatus according to the present invention will be described. An imaging device according to the present invention includes the zoom lens according to the present invention and an imaging element provided on an image side of the zoom lens to convert an optical image formed by the zoom lens into an electrical signal. The imaging device and the like are not particularly limited, and a solid-state imaging device such as a CCD sensor or a CMOS sensor may be used. The imaging device may be a lens-fixed type imaging device in which a lens is fixed to a housing, or may be a lens-replaced type imaging device such as a single-lens reflex camera or a mirror-less single-lens reflex camera.
Fig. 37 is a diagram schematically showing an example of the configuration of the imaging device according to the present embodiment. As shown in fig. 37, the imaging device 1 includes a camera 2 and a lens 3 that is detachable from the camera 2. The image pickup apparatus 1 is one aspect of an image pickup apparatus. The camera 2 has a CCD sensor 21 as an image pickup element and a cover glass 22. The CCD sensor 21 is disposed in the camera 2 at a position centered on the optical axis of the zoom lens in the lens 3 attached to the camera 2. The camera 2 may have an IR cut filter or the like instead of the cover glass 22.
Next, the present invention will be described in detail with reference to examples. Wherein the present invention is not limited to the following examples. The zoom lens of each of the embodiments described below is a photographing zoom lens used for an imaging device such as a digital camera, a video camera, and a silver-salt film digital camera. In the lens cross-sectional views (fig. 1, 5, 9, 13, 17, 21, 25, 29, and 33), the object side is the left side of the drawing, and the image side is the right side. The 1 st to 8 th examples correspond to the present embodiment, and the 9 th example is a reference example.
Example 1
(1) Structure of zoom lens
Fig. 1 is a lens cross-sectional view showing the configuration of a zoom lens according to embodiment 1 of the present invention. The zoom lens is composed of, in order from an object side to an image side, a1 st lens group G1 having a negative refractive power, a2 nd lens group G2 having a positive refractive power, a 3 rd lens group G3 having a negative refractive power, and a4 th lens group G4 having a positive refractive power. Here, the intermediate group is the 2 nd lens group G2, the L-1 st lens group is the 3 rd lens group G3, and the L-th lens group is the 4 th lens group G4.
In fig. 1, "S" shown in the zoom lens is an aperture stop, and "IP" shown on the image side of the zoom lens is an image plane, specifically, an image pickup plane of a solid-state image pickup device such as a CCD sensor or a CMOS sensor, a film plane of a silver salt film, or the like. The object side of the image plane IP is provided with a filter CG. The matters shown in these drawings are similar to those in other embodiments, and therefore, the description thereof will be omitted below.
When changing magnification from the wide-angle end to the telephoto end, the 1 st lens group G1 moves from the object side to the image side, the 2 nd lens group G2 moves from the image side to the object side, the 3 rd lens group G3 moves from the image side to the object side, and the 4 th lens group G4 moves from the image side to the object side along the optical axis.
Upon focusing from an infinitely distant object to a close object, the 3 rd lens group G3 moves from the object side to the image side along the optical axis.
The 1 st lens group G1 is constituted by a negative meniscus lens, and a positive meniscus lens in this order from the object side.
The 2 nd lens group G2 is composed of a cemented lens formed by a negative meniscus lens and a positive meniscus lens cemented together, a biconcave lens, a biconvex lens, and a biconvex lens in this order from the object side.
The 3 rd lens group G3 is composed of a biconcave lens and a cemented lens formed by a negative meniscus lens and a biconvex lens, in order from the object side.
The 4 th lens group G4 is composed of a biconvex lens, a negative meniscus lens, and a negative meniscus lens in this order from the object side.
(2) Numerical examples
Next, a numerical example 1 to which specific numerical values of the zoom lens are applied will be described.
[ Lens data ] lens data of the zoom lens are displayed. The plane numbers indicate the order of lens surfaces from the object side, r indicates the radius of curvature of the lens surfaces, d indicates the interval on the optical axis of the lens surfaces, nd indicates the refractive index at d-line (wavelength λ=587.6 nm), and vd indicates the abbe number at d-line (wavelength λ=587.6 nm). The aperture STOP S is denoted by STOP on the surface number. Further, in the case where the lens surface is an aspherical surface, the surface number indicates ASPH, and the column of the radius of curvature r indicates the paraxial radius of curvature. The specification table shows the F number (fno.) and the half angle (ω) of each focal length (F) of the zoom lens. The [ variable interval ] represents a variable interval of the zoom lens.
The aspherical coefficient indicates an aspherical coefficient and a conic constant when the aspherical shape is expressed by the following formula. The aspherical surface is defined by the following formula. Where z represents the displacement amount from the reference plane in the optical axis direction, c represents the curvature (1/r), h represents the height from the optical axis, k represents the conic coefficient, and A4, A6, A8, a10, a12 … represent the aspherical coefficients of each number of times.
z＝ch2/[1+{1-(1+k)c2h2}1/2]+A4h4+A6h6+A8h8+A10h10+A12h12……
In addition, since the matters in these numerical embodiments are similar to those in other embodiments, the description thereof will be omitted below.
Fig. 2,3, and 4 show longitudinal aberration diagrams of the zoom lens at the wide-angle end, the intermediate region, and the telephoto end when an object at infinity is in focus. The longitudinal aberration diagrams shown in the respective diagrams are spherical aberration (mm), astigmatism (mm), and distortion aberration (%) in order from the left side of the drawing. In the spherical aberration diagram, a solid line indicates spherical aberration at d-line (wavelength 587.56 nm), a long-dashed line indicates spherical aberration at F-line (wavelength 486.13 nm), and a short-dashed line indicates spherical aberration at C-line (wavelength 656.27 nm). In the astigmatic diagram, the vertical axis represents a half field angle (ω), the horizontal axis represents defocus, the solid line represents a sagittal image plane (S) corresponding to the d-line, and the broken line represents a meridional image plane (M) corresponding to the d-line. In the distortion aberration diagram, the vertical axis represents the half field angle (ω), and the horizontal axis represents distortion aberration. These matters are the same in the aberration diagrams shown in other embodiments, and therefore, the description thereof will be omitted below. The focal length of each lens group of each example, the numerical values of formulas (1) to (16), and the focal length of each lens group are shown in [ table 1 ].
[ Lens data ]
[ Specification Table ]
| Wide angle end | Intermediate part | Telescope end | |
| f | 20.5972 | 31.5154 | 48.5030 |
| Fno. | 2.8840 | 2.8840 | 2.8840 |
| ω | 47.9625 | 34.6745 | 22.7164 |
[ Variable spacing ]
| Wide angle end | Intermediate part | Telescope end | Wide angle end | Intermediate part | Telescope end | |
| d(0) | ∞ | ∞ | ∞ | 151.4994 | 269.0881 | 277.0999 |
| d(7) | 42.8854 | 18.524 | 1.4308 | 42.8854 | 18.524 | 1.4308 |
| d(17) | 2.4396 | 7.0203 | 15.4465 | 3.4735 | 8.422 | 18.8078 |
| d(22) | 4.9147 | 5.6069 | 6.1999 | 3.8806 | 4.2052 | 2.8386 |
| d(29) | 12.8748 | 14.3748 | 14.4369 | 12.8748 | 14.3748 | 14.4369 |
[ Aspherical coefficient ]
| Face numbering | k | A4 | A6 | A8 | A10 | A12 |
| 3 | 1.0000 | 3.59443E-06 | -2.29549E-10 | 2.40032E-12 | 2.00892E-15 | 0.00000E+00 |
| 14 | 0.0000 | -3.92939E-05 | 5.35795E-08 | -4.69585E-10 | 1.06911E-12 | 0.00000E+00 |
| 15 | 0.0000 | -2.08482E-06 | -5.04189E-10 | -2.24861E-10 | 0.00000E+00 | 0.00000E+00 |
| 27 | 1.0000 | -9.99870E-06 | 1.09391E-07 | -1.07303E-09 | 5.75479E-12 | -1.09696E-14 |
Example 2
(1) Structure of zoom lens
Fig. 4 is a lens cross-sectional view showing the configuration of a zoom lens according to embodiment 2 of the present invention. The zoom lens is composed of, in order from an object side to an image side, a1 st lens group G1 having a negative refractive power, a2 nd lens group G2 having a positive refractive power, a 3 rd lens group G3 having a negative refractive power, and a4 th lens group G4 having a positive refractive power. Here, the intermediate group is the 2 nd lens group G2, the L-1 st lens group is the 3 rd lens group G3, and the L-th lens group is the 4 th lens group G4.
When changing magnification from the wide-angle end to the telephoto end, the 1 st lens group G1 moves from the object side to the image side, the 2 nd lens group G2 moves from the image side to the object side, the 3 rd lens group G3 moves from the image side to the object side, and the 4 th lens group G4 moves from the image side to the object side along the optical axis.
Upon focusing from an infinitely distant object to a close object, the 3 rd lens group G3 moves from the object side to the image side along the optical axis.
The 1 st lens group G1 is constituted by a negative meniscus lens, and a positive meniscus lens in this order from the object side.
The 2 nd lens group G2 is composed of a cemented lens formed by a negative meniscus lens and a positive meniscus lens cemented together, a biconcave lens, a biconvex lens, and a biconvex lens in this order from the object side.
The 3 rd lens group G3 is composed of a biconcave lens and a cemented lens formed by a negative meniscus lens and a biconvex lens, in order from the object side.
The 4 th lens group G4 is composed of a biconvex lens, a negative meniscus lens, and a negative meniscus lens in this order from the object side.
(2) Numerical examples
Next, a numerical example to which specific numerical values of the zoom lens are applied is shown. Fig. 6,7, and 8 show longitudinal aberration diagrams of the zoom lens at the time of focusing at infinity in the wide-angle end, the intermediate region, and the telephoto end.
[ Lens data ]
[ Specification Table ]
| Wide angle end | Intermediate part | Telescope end | |
| f | 20.5957 | 31.5201 | 48.5062 |
| Fno. | 2.8840 | 2.8840 | 2.8840 |
| ω | 47.9019 | 34.6525 | 22.7313 |
[ Variable spacing ]
| Wide angle end | Intermediate part | Telescope end | Wide angle end | Intermediate part | Telescope end | |
| d(0) | ∞ | ∞ | ∞ | 152.1506 | 269.8715 | 277.7508 |
| d(7) | 42.5668 | 18.3612 | 1.445 | 42.5668 | 18.3612 | 1.445 |
| d(17) | 2.3166 | 7.1104 | 15.8971 | 3.3323 | 8.5057 | 19.3014 |
| d(22) | 4.7942 | 5.3935 | 6.2199 | 3.7783 | 3.9981 | 2.8157 |
| d(29) | 12.9817 | 14.0735 | 13.497 | 12.9817 | 14.0735 | 13.497 |
[ Aspherical coefficient ]
| Face numbering | k | A4 | A6 | A8 | A10 | A12 |
| 3 | 1.0000 | 3.84798E-06 | -5.28637E-10 | 2.27038E-12 | 2.69063E-15 | 0.00000E+00 |
| 14 | 0.0000 | -4.23492E-05 | 4.69520E-08 | -3.85566E-10 | 9.12372E-13 | 0.00000E+00 |
| 15 | 0.0000 | -2.02233E-06 | -1.04895E-08 | -1.78429E-10 | 0.00000E+00 | 0.00000E+00 |
| 27 | 1.0000 | -4.39704E-06 | 7.89047E-08 | -2.84121E-10 | 1.29772E-12 | 1.75538E-15 |
Example 3
(1) Structure of zoom lens
Fig. 9 is a lens cross-sectional view showing the configuration of a zoom lens according to embodiment 2 of the present invention. The zoom lens is composed of, in order from an object side to an image side, a1 st lens group G1 having a negative refractive power, a2 nd lens group G2 having a positive refractive power, a 3 rd lens group G3 having a positive refractive power, a 4 th lens group G4 having a negative refractive power, and a 5 th lens group G5 having a positive refractive power. Here, the intermediate group is a combination group of the 2 nd lens group G2 and the 3 rd lens group G3, the L-1 th lens group is the 4 th lens group G4, and the L-th lens group is the 5 th lens group G5.
When changing magnification from the wide-angle end to the telephoto end, along the optical axis, the 1 st lens group G1 moves from the object side to the image side, the 2 nd lens group G2 moves from the image side to the object side, the 3 rd lens group G3 moves from the image side to the object side, the 4 th lens group G4 moves from the image side to the object side, and the 5 th lens group G5 moves from the image side to the object side.
Upon focusing from an infinitely distant object to a close object, the 4 th lens group G4 moves from the object side to the image side along the optical axis.
The 1 st lens group G1 is constituted by a negative meniscus lens, and a positive meniscus lens in this order from the object side.
The 2 nd lens group G2 is composed of a cemented lens formed by a negative meniscus lens and a positive meniscus lens cemented in order from the object side.
The 3 rd lens group G3 is composed of a biconcave lens, a biconvex lens, and a biconvex lens in this order from the object side.
The 4 th lens group G4 is composed of a biconcave lens and a cemented lens formed by a negative meniscus lens and a biconvex lens, in order from the object side.
The 5 th lens group G5 is constituted by a biconvex lens, a negative meniscus lens, and a negative meniscus lens in this order from the object side.
(2) Numerical examples
Next, a numerical example to which specific numerical values of the zoom lens are applied is shown. Fig. 10, 11, and 12 show longitudinal aberration diagrams of the zoom lens at the time of focusing at infinity in the wide-angle end, the intermediate region, and the telephoto end.
[ Lens data ]
| Face numbering | r | d | nd | vd |
| Object surface | ∞ | d(0) | ||
| 1 | 196.0188 | 2.0000 | 1.72916 | 54.67 |
| 2 | 26.5655 | 8.3395 | ||
| 3ASPH | 450.0000 | 0.1500 | 1.53610 | 41.21 |
| 4 | 189.7567 | 1.5000 | 1.61800 | 63.39 |
| 5 | 34.3659 | 0.2000 | ||
| 6 | 30.7629 | 4.4623 | 1.92119 | 23.96 |
| 7 | 51.9847 | d(7) | ||
| 8 | 24.4785 | 2.3000 | 2.00100 | 29.13 |
| 9 | 14.8875 | 8.9125 | 1.80610 | 40.73 |
| 10 | 127.5789 | d(10) | ||
| 11Stop | ∞ | 3.3499 | ||
| 12 | -41.4259 | 1.0000 | 1.75520 | 27.53 |
| 13 | 38.6783 | 0.6538 | ||
| 14ASPH | 24.9171 | 6.3385 | 1.49710 | 81.56 |
| 15ASPH | -32.9164 | 0.1500 | ||
| 16 | 47.4069 | 3.8645 | 1.81600 | 46.62 |
| 17 | -98.2812 | d(17) | ||
| 18 | -132.7773 | 0.7500 | 1.91082 | 35.25 |
| 19 | 26.9107 | 1.4023 | ||
| 20 | 500.7998 | 0.7500 | 2.00100 | 29.13 |
| 21 | 26.4338 | 3.4000 | 1.86966 | 20.02 |
| 22 | -76.2816 | d(22) | ||
| 23 | 41.7619 | 8.3920 | 1.59282 | 68.62 |
| 24 | -29.2167 | 0.4499 | ||
| 25 | 58.1624 | 2.5000 | 1.64769 | 33.84 |
| 26 | 40.0000 | 7.4487 | ||
| 27ASPH | -24.8519 | 0.2000 | 1.53610 | 41.21 |
| 28 | -22.8164 | 1.5000 | 1.85451 | 25.15 |
| 29 | -66.5025 | d(29) | ||
| 30 | ∞ | 2.5000 | 1.51680 | 64.20 |
| 31 | ∞ | 1.0000 | ||
| Image plane | ∞ |
[ Specification Table ]
[ Variable spacing ]
| Wide angle end | Intermediate part | Telescope end | Wide angle end | Intermediate part | Telescope end | |
| d(0) | ∞ | ∞ | ∞ | 151.4994 | 268.7840 | 277.0999 |
| d(7) | 42.6246 | 18.5689 | 1.4672 | 42.6246 | 18.5689 | 1.4672 |
| d(10) | 2.5536 | 2.2481 | 2.1159 | 2.5536 | 2.2481 | 2.1159 |
| d(17) | 2.4157 | 6.8228 | 15.3822 | 3.4413 | 8.1954 | 18.6982 |
| d(22) | 4.7045 | 5.4435 | 6.0102 | 3.6788 | 4.0710 | 2.6943 |
| d(29) | 12.6880 | 14.6188 | 14.4106 | 12.6880 | 14.6188 | 14.4106 |
[ Aspherical coefficient ]
| Face numbering | k | A4 | A6 | A8 | A10 | A12 |
| 3 | -1.0000 | 3.69719E-06 | -8.10080E-10 | 3.98004E-12 | 1.11162E-16 | 0.00000E+00 |
| 14 | 0.0000 | -4.04202E-05 | 5.64227E-08 | -4.86052E-10 | 1.11699E-12 | 0.00000E+00 |
| 15 | 0.0000 | -1.93509E-06 | -2.08917E-09 | -2.25041E-10 | 0.00000E+00 | 0.00000E+00 |
| 27 | 1.0000 | -8.35998E-06 | 7.54260E-08 | -7.45593E-10 | 4.24879E-12 | -8.40884E-15 |
Example 4
(1) Structure of zoom lens
Fig. 13 is a lens cross-sectional view showing the configuration of a zoom lens according to embodiment 4 of the present invention. The zoom lens is composed of, in order from an object side to an image side, a1 st lens group G1 having a negative refractive power, a 2 nd lens group G2 having a positive refractive power, a 3 rd lens group G3 having a negative refractive power, and a4 th lens group G4 having a positive refractive power. Here, the intermediate group is the 2 nd lens group G2, the L-1 st lens group is the 3 rd lens group G3, and the L-th lens group is the 4 th lens group G4.
When changing magnification from the wide-angle end to the telephoto end, the 1 st lens group G1 moves from the object side to the image side, the 2 nd lens group G2 moves from the image side to the object side, the 3 rd lens group G3 moves from the image side to the object side, and the 4 th lens group G4 moves from the image side to the object side along the optical axis.
Upon focusing from an infinitely distant object to a close object, the 3 rd lens group G3 moves from the object side to the image side along the optical axis.
The 1 st lens group G1 is composed of a negative meniscus lens, a biconcave lens, and a positive meniscus lens in this order from the object side.
The 2 nd lens group G2 is composed of a cemented lens formed by joining a negative meniscus lens and a biconvex lens, a biconcave lens, a biconvex lens, and a biconvex lens in this order from the object side.
The 3 rd lens group G3 is composed of a biconcave lens and a cemented lens formed by a negative meniscus lens and a positive lens cemented together in this order from the object side.
The 4 th lens group G4 is composed of a biconvex lens and a biconcave lens in this order from the object side.
(2) Numerical examples
Next, a numerical example to which specific numerical values of the zoom lens are applied is shown. Fig. 14, 15, and 16 show longitudinal aberration diagrams of the zoom lens at the time of focusing at infinity in the wide-angle end, the intermediate region, and the telephoto end.
[ Lens data ]
[ Specification Table ]
| Wide angle end | Intermediate part | Telescope end | |
| f | 20.5984 | 28.2688 | 38.7967 |
| Fno. | 2.8840 | 2.8840 | 2.8840 |
| ω | 47.9553 | 37.6392 | 28.1785 |
[ Variable spacing ]
| Wide angle end | Intermediate part | Telescope end | Wide angle end | Intermediate part | Telescope end | |
| d(0) | ∞ | ∞ | ∞ | 166.2392 | 199.8734 | 246.0044 |
| d(6) | 33.1478 | 16.6131 | 3.6834 | 33.1478 | 16.6131 | 3.6834 |
| d(16) | 3.8314 | 6.2468 | 10.1311 | 4.7313 | 7.5596 | 12.0372 |
| d(21) | 3.0524 | 3.6783 | 3.9550 | 2.1524 | 2.3656 | 2.0489 |
| d(25) | 13.3290 | 16.1880 | 18.8257 | 13.3290 | 16.1880 | 18.8257 |
[ Aspherical coefficient ]
| Face numbering | k | A4 | A6 | A8 | A10 | A12 |
| 3 | 0.0000 | 1.30212E-06 | -8.77931E-10 | 7.42419E-12 | -6.22600E-15 | 3.64778E-18 |
| 13 | 0.0000 | -2.85709E-05 | 4.67333E-08 | -5.03353E-10 | 1.47935E-12 | 0.00000E+00 |
| 14 | 0.0000 | -3.50289E-06 | 4.04368E-09 | -2.81001E-10 | 0.00000E+00 | 0.00000E+00 |
| 24 | 0.0000 | -2.17570E-05 | 5.93674E-08 | -9.35228E-10 | 5.32498E-12 | -1.21704E-14 |
Example 5
(1) Structure of zoom lens
Fig. 17 is a lens cross-sectional view showing the configuration of a zoom lens according to embodiment 5 of the present invention. The zoom lens is composed of, in order from an object side to an image side, a1 st lens group G1 having a negative refractive power, a 2 nd lens group G2 having a positive refractive power, a 3 rd lens group G3 having a negative refractive power, and a4 th lens group G4 having a positive refractive power. Here, the intermediate group is the 2 nd lens group G2, the L-1 st lens group is the 3 rd lens group G3, and the L-th lens group is the 4 th lens group G4.
When changing magnification from the wide-angle end to the telephoto end, the 1 st lens group G1 moves from the object side to the image side, the 2 nd lens group G2 moves from the image side to the object side, the 3 rd lens group G3 moves from the image side to the object side, and the 4 th lens group G4 moves from the image side to the object side along the optical axis.
Upon focusing from an infinitely distant object to a close object, the 3 rd lens group G3 moves from the object side to the image side along the optical axis.
The 1 st lens group G1 is composed of a negative meniscus lens, a biconcave lens, and a positive meniscus lens in this order from the object side.
The 2 nd lens group G2 is composed of a cemented lens formed by joining a negative meniscus lens and a biconvex lens, a biconcave lens, a biconvex lens, and a biconvex lens in this order from the object side.
The 3 rd lens group G3 is composed of a biconcave lens and a cemented lens formed by a negative meniscus lens and a positive meniscus lens cemented together in this order from the object side.
The 4 th lens group G4 is composed of a biconvex lens and a biconcave lens in this order from the object side.
(2) Numerical examples
Next, a numerical example to which specific numerical values of the zoom lens are applied is shown. Fig. 18, 19, and 20 show longitudinal aberration diagrams of the zoom lens at the time of focusing at infinity in the wide-angle end, the intermediate region, and the telephoto end.
[ Lens data ]
[ Specification Table ]
| Wide angle end | Intermediate part | Telescope end | |
| f | 20.5976 | 28.2679 | 38.7960 |
| Fno. | 2.8840 | 2.8840 | 2.8840 |
| ω | 47.9746 | 37.6620 | 28.1848 |
[ Variable spacing ]
| Wide angle end | Intermediate part | Telescope end | Wide angle end | Intermediate part | Telescope end | |
| d(0) | ∞ | ∞ | ∞ | 165.9963 | 199.6520 | 246.0000 |
| d(6) | 32.9637 | 16.4892 | 3.5440 | 32.9637 | 16.4892 | 3.5440 |
| d(16) | 3.8647 | 6.2354 | 10.1131 | 4.7382 | 7.5116 | 11.9722 |
| d(21) | 3.1312 | 3.6736 | 3.8228 | 2.2576 | 2.3974 | 1.9637 |
| d(25) | 13.5803 | 16.4859 | 19.0562 | 13.5803 | 16.4859 | 19.0562 |
[ Aspherical coefficient ]
| Face numbering | k | A4 | A6 | A8 | A10 | A12 |
| 3 | 0.0000 | 1.31057E-06 | -9.23909E-10 | 7.74459E-12 | -5.95151E-15 | 2.76653E-18 |
| 13 | 0.0000 | -2.86716E-05 | 4.69847E-08 | -4.92228E-10 | 1.44954E-12 | 0.00000E+00 |
| 14 | 0.0000 | -3.56484E-06 | 3.82594E-09 | -2.65263E-10 | 0.00000E+00 | 0.00000E+00 |
| 24 | 0.0000 | -2.26912E-05 | 5.59506E-08 | -9.36964E-10 | 5.33124E-12 | -1.25164E-14 |
Example 6
(1) Structure of zoom lens
Fig. 21 is a lens cross-sectional view showing the configuration of a zoom lens according to embodiment 6 of the present invention. The zoom lens is composed of, in order from an object side to an image side, a1 st lens group G1 having a negative refractive power, a 2 nd lens group G2 having a positive refractive power, a 3 rd lens group G3 having a negative refractive power, and a4 th lens group G4 having a positive refractive power. Here, the intermediate group is the 2 nd lens group G2, the L-1 st lens group is the 3 rd lens group G3, and the L-th lens group is the 4 th lens group G4.
When changing magnification from the wide-angle end to the telephoto end, the 1 st lens group G1 moves from the object side to the image side, the 2 nd lens group G2 moves from the image side to the object side, the 3 rd lens group G3 moves from the image side to the object side, and the 4 th lens group G4 moves from the image side to the object side along the optical axis.
Upon focusing from an infinitely distant object to a close object, the 3 rd lens group G3 moves from the object side to the image side along the optical axis.
The 1 st lens group G1 is composed of a negative meniscus lens, a biconcave lens, and a positive meniscus lens in this order from the object side.
The 2 nd lens group G2 is composed of a cemented lens formed by joining a negative meniscus lens and a biconvex lens, a biconcave lens, a biconvex lens, and a biconvex lens in this order from the object side.
The 3 rd lens group G3 is composed of a biconcave lens and a cemented lens formed by a negative meniscus lens and a positive meniscus lens cemented together in this order from the object side.
The 4 th lens group G4 is composed of a biconvex lens and a biconcave lens in this order from the object side.
(2) Numerical examples
Next, a numerical example to which specific numerical values of the zoom lens are applied is shown. Fig. 22, 23, and 24 show longitudinal aberration diagrams of the zoom lens at the time of focusing at infinity in the wide-angle end, the intermediate region, and the telephoto end.
[ Lens data ]
[ Specification Table ]
| Wide angle end | Intermediate part | Telescope end | |
| f | 25.7547 | 35.3104 | 48.4964 |
| Fno. | 2.8840 | 2.8840 | 2.8840 |
| ω | 41.5116 | 32.1696 | 24.2739 |
[ Variable spacing ]
| Wide angle end | Intermediate part | Telescope end | Wide angle end | Intermediate part | Telescope end | |
| d(0) | ∞ | ∞ | ∞ | 202.9914 | 250.9440 | 314.9999 |
| d(6) | 44.3106 | 20.9995 | 4.0434 | 44.3106 | 20.9995 | 4.0434 |
| d(18) | 1.9968 | 4.2776 | 7.2721 | 2.7813 | 5.4929 | 9.0932 |
| d(23) | 4.6347 | 4.5959 | 4.9287 | 3.8501 | 3.3806 | 3.1075 |
| d(32) | 12.8644 | 13.9808 | 15.5536 | 12.8644 | 13.9808 | 15.5536 |
[ Aspherical coefficient ]
| Face numbering | k | A4 | A6 | A8 | A10 | A12 |
| 3 | 0.0000 | 7.66841E-07 | 1.07823E-09 | -1.60087E-12 | 1.09072E-15 | 0.00000E+00 |
| 15 | 0.0000 | -1.98365E-05 | -2.83753E-09 | -1.30804E-09 | 6.41585E-12 | 0.00000E+00 |
| 16 | 0.0000 | 8.78124E-06 | 2.12626E-08 | -1.37495E-09 | 6.93565E-12 | 0.00000E+00 |
| 30 | 0.1256 | 2.64615E-05 | 6.38335E-08 | -1.39001E-10 | 7.14896E-13 | 0.00000E+00 |
Example 7
(1) Structure of zoom lens
Fig. 25 is a lens cross-sectional view showing the configuration of a zoom lens according to embodiment 7 of the present invention. The zoom lens is composed of, in order from an object side to an image side, a1 st lens group G1 having a negative refractive power, a 2 nd lens group G2 having a positive refractive power, a 3 rd lens group G3 having a negative refractive power, and a4 th lens group G4 having a positive refractive power. Here, the intermediate group is the 2 nd lens group G2, the L-1 st lens group is the 3 rd lens group G3, and the L-th lens group is the 4 th lens group G4.
When changing magnification from the wide-angle end to the telephoto end, the 1 st lens group G1 moves from the object side to the image side, the 2 nd lens group G2 moves from the image side to the object side, the 3 rd lens group G3 moves from the image side to the object side, and the 4 th lens group G4 moves from the image side to the object side along the optical axis.
Upon focusing from an infinitely distant object to a close object, the 3 rd lens group G3 moves from the object side to the image side along the optical axis.
The 1 st lens group G1 is constituted by a negative meniscus lens, and a positive meniscus lens in this order from the object side.
The 2 nd lens group G2 is composed of a cemented lens formed by a negative meniscus lens and a positive meniscus lens cemented together, a biconcave lens, a biconvex lens, and a biconvex lens in this order from the object side.
The 3 rd lens group G3 is composed of a negative meniscus lens and a cemented lens formed by a biconcave lens and a biconvex lens cemented in this order from the object side.
The 4 th lens group G4 is composed of a biconvex lens, a positive meniscus lens, a negative meniscus lens, and a negative meniscus lens in this order from the object side.
(2) Numerical examples
Next, a numerical example to which specific numerical values of the zoom lens are applied is shown. Fig. 26, 27, and 28 show longitudinal aberration diagrams of the zoom lens at the time of focusing at infinity in the wide-angle end, the intermediate region, and the telephoto end.
[ Lens data ]
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[ Specification Table ]
| Wide angle end | Intermediate part | Telescope end | |
| f | 25.7545 | 35.3112 | 48.4971 |
| Fno. | 2.8840 | 2.8840 | 2.8840 |
| ω | 41.1458 | 32.0076 | 24.1524 |
[ Variable spacing ]
/>
[ Aspherical coefficient ]
| Face numbering | k | A4 | A6 | A8 | A10 | A12 |
| 3 | 0.0000 | 8.87533E-08 | 9.88321E-10 | -1.29946E-12 | 6.17501E-16 | 0.00000E+00 |
| 15 | 0.0000 | -2.86036E-05 | 1.65178E-08 | -1.38528E-09 | 6.21215E-12 | 0.00000E+00 |
| 16 | 0.0000 | 1.05243E-05 | 4.74826E-08 | -1.43932E-09 | 6.90455E-12 | 0.00000E+00 |
| 30 | 0.2847 | 3.52548E-05 | 8.80676E-08 | -1.53186E-10 | 1.34800E-12 | 0.00000E+0 |
Example 8
(1) Structure of zoom lens
Fig. 29 is a lens cross-sectional view showing the configuration of a zoom lens according to embodiment 8 of the present invention. The zoom lens is composed of, in order from an object side to an image side, a1 st lens group G1 having a negative refractive power, a 2 nd lens group G2 having a positive refractive power, a 3 rd lens group G3 having a negative refractive power, and a4 th lens group G4 having a positive refractive power. Here, the intermediate group is the 2 nd lens group G2, the L-1 st lens group is the 3 rd lens group G3, and the L-th lens group is the 4 th lens group G4.
When changing magnification from the wide-angle end to the telephoto end, the 1 st lens group G1 moves from the object side to the image side, the 2 nd lens group G2 moves from the image side to the object side, the 3 rd lens group G3 moves from the image side to the object side, and the 4 th lens group G4 moves from the image side to the object side along the optical axis.
Upon focusing from an infinitely distant object to a close object, the 3 rd lens group G3 moves from the object side to the image side along the optical axis.
The 1 st lens group G1 is constituted by a negative meniscus lens, and a positive meniscus lens in this order from the object side.
The 2 nd lens group G2 is composed of a cemented lens formed by a negative meniscus lens and a positive meniscus lens cemented together, a biconcave lens, a biconvex lens, and a biconvex lens in this order from the object side.
The 3 rd lens group G3 is composed of a biconcave lens and a cemented lens formed by joining the biconcave lens and a biconvex lens in this order from the object side.
The 4 th lens group G4 is composed of a biconvex lens, a positive meniscus lens, a negative meniscus lens, and a negative meniscus lens in this order from the object side.
(2) Numerical examples
Next, a numerical example to which specific numerical values of the zoom lens are applied is shown. Fig. 30, 31, and 32 show longitudinal aberration diagrams of the zoom lens at the time of focusing at infinity in the wide-angle end, the intermediate region, and the telephoto end.
[ Lens data ]
[ Specification Table ]
| Wide angle end | Intermediate part | Telescope end | |
| f | 25.7567 | 35.3092 | 48.4896 |
| Fno. | 2.8840 | 2.8840 | 2.8840 |
| ω | 41.4241 | 31.9237 | 23.9497 |
[ Variable spacing ]
| Wide angle end | Intermediate part | Telescope end | Wide angle end | Intermediate part | Telescope end | |
| d(0) | ∞ | ∞ | ∞ | 203.3034 | 250.8089 | 315.0000 |
| d(6) | 42.0723 | 18.9596 | 1.8835 | 42.0723 | 18.9596 | 1.8835 |
| d(18) | 1.9950 | 4.3467 | 7.5913 | 2.8183 | 5.6199 | 9.5114 |
| d(23) | 6.7549 | 6.8108 | 7.1154 | 5.9315 | 5.5376 | 5.1954 |
| d(32) | 12.9412 | 14.1408 | 15.4766 | 12.9412 | 14.1408 | 15.4766 |
[ Aspherical coefficient ]
| Face numbering | k | A4 | A6 | A8 | A10 | A12 |
| 3 | 0.0000 | 6.88011E-07 | 9.79734E-10 | -1.18012E-12 | 7.24893E-16 | 0.00000E+00 |
| 15 | 0.0000 | -1.40550E-05 | 1.87594E-08 | -1.43708E-09 | 6.14972E-12 | 0.00000E+00 |
| 16 | 0.0000 | 1.04210E-05 | 3.68277E-08 | -1.46209E-09 | 6.34065E-12 | 0.00000E+00 |
| 30 | 0.7870 | 1.86991E-05 | 5.63455E-08 | -1.37452E-10 | 6.52518E-13 | 0.00000E+00 |
Example 9
(1) Structure of zoom lens
Fig. 33 is a lens cross-sectional view showing the configuration of a zoom lens according to embodiment 8 of the present invention. The zoom lens is composed of, in order from an object side to an image side, a1 st lens group G1 having a negative refractive power, a 2 nd lens group G2 having a positive refractive power, a 3 rd lens group G3 having a negative refractive power, and a4 th lens group G4 having a positive refractive power. Here, the intermediate group is the 2 nd lens group G2, the L-1 st lens group is the 3 rd lens group G3, and the L-th lens group is the 4 th lens group G4.
When changing magnification from the wide-angle end to the telephoto end, the 1 st lens group G1 moves from the object side to the image side, the 2 nd lens group G2 moves from the image side to the object side, the 3 rd lens group G3 moves from the image side to the object side, and the 4 th lens group G4 moves from the image side to the object side along the optical axis.
Upon focusing from an infinitely distant object to a close object, the 3 rd lens group G3 moves from the object side to the image side along the optical axis.
The 1 st lens group G1 is constituted by a negative meniscus lens, and a positive meniscus lens in this order from the object side.
The 2 nd lens group G2 is composed of a cemented lens formed by a negative meniscus lens and a positive meniscus lens cemented together, a biconcave lens, a positive meniscus lens, and a biconvex lens in this order from the object side.
The 3 rd lens group G3 is composed of a biconcave lens and a cemented lens formed by joining the biconcave lens and a biconvex lens in this order from the object side.
The 4 th lens group G4 is composed of, in order from the object side, a biconvex lens, a junction lens formed by joining a positive meniscus lens and a negative meniscus lens, and a negative meniscus lens.
(2) Numerical examples
Next, a numerical example to which specific numerical values of the zoom lens are applied is shown. Fig. 34, 35, and 36 show longitudinal aberration diagrams of the zoom lens at the time of focusing at infinity in the wide-angle end, the intermediate region, and the telephoto end.
[ Lens data ]
[ Specification Table ]
| Wide angle end | Intermediate part | Telescope end | |
| f | 25.7464 | 35.3314 | 48.4968 |
| Fno. | 2.8840 | 2.8840 | 2.8840 |
| ω | 41.0023 | 31.6763 | 23.1815 |
[ Variable spacing ]
| Wide angle end | Intermediate part | Telescope end | Wide angle end | Intermediate part | Telescope end | |
| d(0) | ∞ | ∞ | ∞ | 196.7296 | 246.1056 | 314.9999 |
| d(6) | 47.6180 | 24.3496 | 5.9939 | 47.6180 | 24.3496 | 5.9939 |
| d(18) | 2.0037 | 5.6419 | 12.3177 | 2.7870 | 6.9256 | 14.5861 |
| d(23) | 4.6345 | 4.4066 | 4.2664 | 3.8512 | 3.1230 | 1.9980 |
| d(32) | 19.3922 | 17.8742 | 12.8000 | 19.3922 | 17.8742 | 12.8000 |
[ Aspherical coefficient ]
| Face numbering | k | A4 | A6 | A8 | A10 | A12 |
| 3 | 0.0000 | 1.46228E-06 | 2.99178E-09 | -6.93311E-12 | 7.66797E-15 | 0.00000E+00 |
| 15 | 0.0000 | -2.38634E-05 | -3.04517E-08 | -1.39034E-09 | 7.96535E-12 | 0.00000E+00 |
| 16 | 0.0000 | 1.03978E-05 | -7.95414E-09 | -1.20995E-09 | 7.53481E-12 | 0.00000E+00 |
| 30 | 1.0000 | 8.05910E-06 | 3.37884E-08 | -7.28504E-11 | 3.50252E-13 | 0.00000E+00 |
TABLE 1
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[ Summary ]
A zoom lens according to a first aspect of the present invention,
Comprising, in order from the object side to the image side, a1 st lens group having a negative refractive power, an intermediate group having 1 or more lens groups and having a combined refractive power of positive refractive power, an L-1 st lens group having a negative refractive power, an L-th lens group having a positive refractive power,
The magnification change is performed by changing the interval of adjacent lens groups along the optical axis,
The zoom lens can satisfy the following formula:
-100.00＜M1/ML＜-2.85……(1)
0.18＜|βLt|……(2)
wherein,
M 1: the amount of movement of the 1 st lens group (positive to the image side) when changing magnification from the wide-angle end to the telephoto end
M L: the amount of movement of the L-th lens group (positive to the image side) when changing magnification from the wide-angle end to the telephoto end
Beta Lt: and the lateral magnification of the L-th lens group at the telescopic end of the L-th lens group during infinite focusing.
A zoom lens according to a second aspect of the present invention may, in the first aspect,
The aperture stop is arranged in the intermediate group and satisfies at least one of the following formulas:
-0.95＜fs-1/ft＜-0.25……(3)
-0.95＜fs+1/ft＜-0.25……(4)
wherein,
F s-1: focal length of lens component adjacent to object side of the aperture stop
F s+1: focal length of lens component adjacent to image side of aperture diaphragm
F t: the focal length at the telephoto end of the zoom lens.
A zoom lens according to a third aspect of the present invention may satisfy the following expression in the first or second aspect:
0.01＜|fL-1|/fw＜2.00……(5)
wherein,
F L-1: focal length of the L-1 th lens group
F w: the zoom lens has a focal length at a wide-angle end.
A zoom lens according to a fourth aspect of the present invention may satisfy the following formulas in the first to third aspects:
1.850＜Ndave……(6)
wherein,
N dave: the average refractive index of d-line of the material constituting each lens of the L-1 th lens group.
A zoom lens according to a fifth aspect of the present invention may satisfy the following formulas in the first to fourth aspects:
1.00＜fL/|f1|＜2.10……(7)
wherein,
F 1: focal length of the 1 st lens group
F L: focal length of the L-th lens group.
A zoom lens according to a sixth aspect of the present invention may satisfy the following formulas in the first to fifth aspects:
1.90＜fL/|fL-1|＜10.00……(8)
wherein,
F L-1: focal length of the L-1 th lens group
F L: focal length of the L-th lens group.
A zoom lens according to a seventh aspect of the present invention may satisfy the following formulas in the first to sixth aspects:
0.50＜|βLt/βLw|＜5.50……(9)
wherein,
Beta Lw: lateral magnification at the time of infinity focusing at the wide-angle end of the L-th lens group
Beta Lt: and the lateral magnification of the L-th lens group at the telescopic end of the L-th lens group during infinite focusing.
A zoom lens according to an eighth aspect of the present invention may satisfy the following formulas in the first to seventh aspects:
2.00＜|βL-1t|＜10.00……(10)
wherein,
Beta L-1t: and the L-1 lens group is provided with a lateral magnification at the telescopic end of the L-1 lens group during infinite focusing.
A zoom lens according to a ninth aspect of the present invention may satisfy the following formulas in the first to eighth aspects:
0.20＜fpt/ft＜1.50……(11)
wherein,
F pt: synthetic focal length at infinity focusing at the telephoto end of the intermediate group
F t: the focal length at the telephoto end of the zoom lens.
A zoom lens according to a tenth aspect of the present invention may satisfy the following formulas in the first to ninth aspects:
1.00＜fL/fpt＜6.00……(12)
wherein,
F pt: synthetic focal length at infinity focusing at the telephoto end of the intermediate group
F L: focal length of the L-th lens group.
A zoom lens according to an eleventh aspect of the present invention may satisfy the following formulas in the first to tenth aspects:
0.01＜fL-1/f1＜2.00……(13)
wherein,
F 1: focal length of the 1 st lens group
F L-1: focal length of the L-1 th lens group.
A zoom lens according to a twelfth aspect of the present invention may satisfy the following formulas in the first to eleventh aspects:
-2.00＜fL-1/fpt＜-0.50……(14)
wherein,
F pt: synthetic focal length at infinity focusing at the telephoto end of the intermediate group
F L-1: focal length of the L-1 th lens group.
A zoom lens according to a thirteenth aspect of the present invention may satisfy the following formulas in the first to twelfth aspects:
-2.00＜fpt/f1＜-0.01……(15)
wherein,
F 1: focal length of the 1 st lens group
F pt: and the synthesized focal length of the intermediate group is at the infinite focusing at the telescopic end.
A zoom lens according to a fourteenth aspect of the present invention may be the first to thirteenth aspects, wherein the negative lens is disposed on the most image side.
A zoom lens according to a fifteenth aspect of the present invention may be configured such that, in the first to fourteenth aspects, a negative lens is disposed at a2 nd piece from an image side.
A zoom lens according to a sixteenth aspect of the present invention is the zoom lens according to the first to fifteenth aspects, wherein the image side surface of the 2 nd lens component is concave toward the image side.
A seventeenth aspect of the present invention is directed to the zoom lens according to the first to sixteenth aspects, wherein the L-1 th lens group is moved toward the image side when focusing on an object from infinity to a close distance.
A zoom lens according to an eighteenth aspect of the present invention is the zoom lens according to the first to seventeenth aspects, wherein the L-1 th lens group has 1 or more positive lenses and 1 or more negative lenses.
A zoom lens according to a nineteenth aspect of the present invention may satisfy the following formulas in the first to eighteenth aspects:
-7.00＜(1-(βL-1t)2)×βLt 2＜-1.00……(16)
wherein,
Beta L-1t: lateral magnification at the telephoto end of the L-1 th lens group at the time of infinity focusing
Beta Lt: and the lateral magnification of the L-th lens group at the telescopic end of the L-th lens group during infinite focusing.
A zoom lens according to a twentieth aspect of the present invention is the zoom lens according to any one of the first to nineteenth aspects, wherein the 1 st lens group moves monotonously to the image side when changing magnification from the wide-angle end to the telephoto end.
A twenty-first aspect of the present invention relates to the zoom lens according to the first to twentieth aspects, wherein the interval between the intermediate group and the L-1 th lens group increases monotonously when changing magnification from the wide-angle end to the telephoto end.
A twenty-second aspect of the present invention provides the zoom lens according to the first to twenty-first aspects, wherein the distance between the L-1 th lens group and the L-th lens group increases monotonously when changing magnification from the wide-angle end to the telephoto end.
A twenty-third aspect of the present invention relates to the zoom lens, and in the first to twenty-second aspects, the aperture stop may be disposed within the intermediate group.
An imaging apparatus according to a twenty-fourth aspect of the present invention may include: the zoom lens according to the first to twenty-third aspects; an image pickup element provided on an image side of the zoom lens and converting an optical image formed by the zoom lens into an electric signal.
The optical system and the image pickup apparatus described in the above embodiments and examples are one aspect of the zoom lens and the image pickup apparatus according to the present invention, and correspond to the optical system according to the first to twenty-third aspects and the image pickup apparatus according to the twenty-fourth aspect. The zoom lens and the image pickup apparatus according to the above aspects have the same operational effects as those described in the above embodiments and examples. The zoom lens and the image pickup apparatus according to the present invention are not limited to those described in the embodiments and examples, and may be appropriately modified within the scope of the zoom lens and the image pickup apparatus according to the above aspects.
Industrial applicability
The zoom lens according to the present invention is applicable to, for example, a zoom lens of an imaging device such as a monitoring camera, a film camera, a digital still camera, or a digital video camera.
Description of the reference numerals
S … aperture diaphragm
CG … filter
IP … image plane
G … 1 st lens group
G2 … nd lens group
G3 … rd lens group
G4 … th lens group
G5 … th lens group
1 … Camera
2 … Main body
3 … Lens barrel
21 … CCD sensor
22 … Filters.
Claims (21)
1. A zoom lens is characterized in that,
Comprising, in order from the object side to the image side, a1 st lens group having a negative refractive power, an intermediate group having 1 or more lens groups and having a combined refractive power of positive refractive power, an L-1 st lens group having a negative refractive power, an L-th lens group having a positive refractive power,
The magnification change is performed by changing the interval of adjacent lens groups along the optical axis,
The zoom lens satisfies the following formula:
-100.00＜M1/ML＜-2.85……(1)
0.18＜|βLt|……(2)
wherein,
M 1: the amount of movement of the 1 st lens group (positive to the image side) when changing magnification from the wide-angle end to the telephoto end
M L: the amount of movement of the L-th lens group (positive to the image side) when changing magnification from the wide-angle end to the telephoto end
Beta Lt: and the lateral magnification of the L-th lens group at the telescopic end of the L-th lens group during infinite focusing.
2. A zoom lens is characterized in that,
Comprising, in order from the object side to the image side, a1 st lens group having a negative refractive power, an intermediate group having 1 or more lens groups and having a combined refractive power of positive refractive power, an L-1 st lens group having a negative refractive power, an L-th lens group having a positive refractive power,
The magnification change is performed by changing the interval of adjacent lens groups along the optical axis,
The zoom lens satisfies the following formula:
1.00＜fL/|f1|＜2.10……(7)
1.90＜fL/|fL-1|＜10.00……(8)
0.50＜|βLt/βLw|＜5.50……(9)
wherein,
F 1: focal length of the 1 st lens group
F L-1: focal length of the L-1 th lens group
F L: focal length of the L-th lens group
Beta Lw: lateral magnification β Lt at infinity focusing at the wide-angle end of the L-th lens group: and the lateral magnification of the L-th lens group at the telescopic end of the L-th lens group during infinite focusing.
3. The zoom lens according to claim 1 or 2, wherein,
The aperture stop is arranged in the intermediate group and satisfies at least one of the following formulas:
-0.95＜fs-1/ft＜-0.25……(3)
-0.95＜fs+1/ft＜-0.25……(4)
wherein,
F s-1: focal length f s+1 of lens component adjacent to object side of the aperture stop: focal length f t of lens component adjacent to image side of the aperture stop: the focal length at the telephoto end of the zoom lens.
4. The zoom lens according to claim 1 or 2, wherein,
The following formula is satisfied:
0.01＜|fL-1|/fw＜2.00……(5)
wherein,
F L-1: focal length of the L-1 th lens group
F w: the zoom lens has a focal length at a wide-angle end.
5. The zoom lens according to claim 1 or 2, wherein,
The following formula is satisfied:
1.850＜Ndave……(6)
wherein,
N dave: the average refractive index of d-line of the material constituting each lens of the L-1 th lens group.
6. The zoom lens according to claim 1 or 2, wherein,
The following formula is satisfied:
2.00＜|βL-1t|＜10.00……(10)
wherein,
Beta L-1t: and the L-1 lens group is provided with a lateral magnification at the telescopic end of the L-1 lens group during infinite focusing.
7. The zoom lens according to claim 1 or 2, wherein,
The following formula is satisfied:
0.20＜fpt/ft＜1.50……(11)
wherein,
F pt: a composite focal length f t at infinity focusing at the telephoto end of the intermediate group: the focal length at the telephoto end of the zoom lens.
8. The zoom lens according to claim 1 or 2, wherein,
The following formula is satisfied:
1.00＜fL/fpt＜6.00……(12)
wherein,
F pt: a composite focal length f L at infinity focusing at the telephoto end of the intermediate group: focal length of the L-th lens group.
9. The zoom lens according to claim 1 or 2, wherein,
The following formula is satisfied:
0.01＜fL-1/f1＜2.00……(13)
wherein,
F 1: focal length of the 1 st lens group
F L-1: focal length of the L-1 th lens group.
10. The zoom lens according to claim 1 or 2, wherein,
The following formula is satisfied:
-2.00＜fL-1/fpt＜-0.50……(14)
wherein,
F pt: a composite focal length f L-1 at infinity focusing at the telephoto end of the intermediate group: focal length of the L-1 th lens group.
11. The zoom lens according to claim 1 or 2, wherein,
The following formula is satisfied:
-2.00＜fpt/f1＜-0.01……(15)
wherein,
F 1: focal length of the 1 st lens group
F pt: and the synthesized focal length of the intermediate group is at the infinite focusing at the telescopic end.
12. The zoom lens according to claim 1 or 2, wherein,
A negative lens is disposed on the most image side.
13. The zoom lens according to claim 1 or 2, wherein,
A negative lens is arranged at the 2 nd sheet from the image side.
14. The zoom lens according to claim 1 or 2, wherein,
The image side of the 2 nd lens component is concave toward the image side from the image side.
15. The zoom lens according to claim 1 or 2, wherein,
The L-1 th lens group moves toward the image side upon focusing from infinity to a close object.
16. The zoom lens according to claim 1 or 2, wherein,
The L-1 th lens group has more than 1 positive lens and more than 1 negative lens.
17. The zoom lens according to claim 1 or 2, wherein,
The following formula is satisfied:
-7.00＜(1-(βL-1t)2)×βLt 2＜-1.00··(16)
wherein,
Beta L-1t: lateral magnification at the telephoto end of the L-1 th lens group at the time of infinity focusing
Beta Lt: and the lateral magnification of the L-th lens group at the telescopic end of the L-th lens group during infinite focusing.
18. The zoom lens according to claim 1 or 2, wherein,
The 1 st lens group moves monotonously to the image side when changing magnification from the wide-angle end to the telephoto end.
19. The zoom lens according to claim 1 or 2, wherein,
The interval between the intermediate group and the L-1 th lens group increases monotonously when changing magnification from the wide-angle end to the telephoto end.
20. The zoom lens according to claim 1 or 2, wherein,
The interval between the L-1 th lens group and the L-th lens group increases monotonously when changing magnification from the wide-angle end to the telephoto end.
21. An imaging device is characterized by comprising:
the zoom lens according to any one of claims 1 to 20; and
An image pickup element provided on an image side of the zoom lens, and converting an optical image formed by the zoom lens into an electric signal.
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| JP2022-170087 | 2022-10-24 | ||
| JP2022170087A JP2024062224A (en) | 2022-10-24 | 2022-10-24 | Zoom lens and imaging device |
| JP2022-170085 | 2022-10-24 |
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| CN117930481A true CN117930481A (en) | 2024-04-26 |
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|---|---|---|---|
| CN202311340087.2A Pending CN117930481A (en) | 2022-10-24 | 2023-10-17 | Zoom lens and imaging device |
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| Country | Link |
|---|---|
| JP (1) | JP2024062224A (en) |
| CN (1) | CN117930481A (en) |
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2022
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| JP2024062224A (en) | 2024-05-09 |
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