JP3458692B2 - Zoom lens device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention includes a zoom lens .
And a small zoom lens with a high zoom ratio, which is particularly suitable for digital still cameras.
It relates to the device .

[0002]

2. Description of the Related Art In recent years, along with the widespread use of personal computers, digital still cameras that can easily capture images have become widespread. With the spread thereof, there is a demand for a digital still camera that is compact, low-cost, and has a high zoom ratio, and the photographing optical system is also required to have a small size, a low cost, and a high zoom ratio. Higher image quality is also required for digital still cameras. The image quality of a digital still camera is generally determined by the number of pixels of a solid-state image sensor, but the mainstream at present is the so-called VGA class of about 330,000 pixels.

[0003]

As a VGA-class photographing optical system, a high-magnification, low-cost consumer movie camera optical system can be substituted. However, the image quality of VGA class is far lower than that of silver halide cameras, so that it cannot meet the demand for high image quality. In order to obtain a high-quality image, the number of pixels of 1 million or more is required, but as the number of pixels increases, the photographic optical system also needs to have high optical performance. However, most of the photographing optical systems that satisfy the image quality of 1 million pixels or more are single focus lenses. When it comes to zoom lenses (especially high-magnification zoom lenses), there is no choice but to use interchangeable lenses for single-lens reflex cameras or zoom lenses for commercial video cameras. However, these zoom lenses are very large and expensive.

[0004] The present invention was made in view of such circumstances, it is possible to obtain a high-quality image, a compact, low cost,'s having a high zoom ratio zoom lens
A lens lens device is provided.

[0005]

In order to achieve the above object, a zoom lens device of the present invention comprises, in order from the object side, a zoom lens and a solid-state image pickup element for receiving an optical image formed by the zoom lens. This zoom lens has the following features. The zoom lens of the first invention is
A first lens group having positive power in order from the object side;
It is composed of a second lens group having negative power, a third lens group having positive power, and a fourth lens group having positive power, and the third lens group is fixed during zooming. A zoom lens in which the first lens group, the second lens group, and the fourth lens group move in a closed state, the conditional expressions (1) and (2) below are satisfied , and the second lens group is Article
Characterized by have a non-spherical surface which satisfies the matter (4). -5.0 <M1 / Ymax <-1.0 (1) -1.0 <M4 / M2 <-0.1 (2) 0 <(x-x0) / (N'-N) <0.9 (4) However, M1: Amount of change in the position of the first lens group at the telephoto end relative to the wide-angle end (object side direction is negative), M2: Amount of change in the position of the second lens group at the telephoto end relative to the wide-angle end (object side direction M4: The amount of change in the position of the fourth lens group at the telephoto end with respect to the wide-angle end (the direction toward the object side is negative), Ymax: maximum image height, x: relative to the optical axis of the aspherical surface. Optical axis at vertical height
Displacement (mm; negative in the object side), x0: optical axis at the height in the direction perpendicular to the optical axis of the reference spherical surface
Direction (mm; object side direction is negative), N: Refractive index of the medium on the object side of the aspherical surface to the d-line, N ': Refractive index of the medium on the image side of the aspherical surface to the d-line, Is.

The zoom lens of the second invention comprises, in order from the object side, a first lens group having a positive power, a second lens group having a negative power, and a third lens group having a positive power. A fourth lens group having a positive power, and the first lens group, the second lens group, and the fourth lens group move with the third lens group fixed during zooming. A zoom lens, which has the following conditional expression (1) and
(3) is satisfied , and the second lens group satisfies the following conditional expression (4).
Characterized by have a non-spherical surface foot. -5.0 <M1 / Ymax <-1.0 (1) 0.2 <log (β2T / β2W) / log (Z) <0.9 (3) 0 <(x-x0) / (N'-N) <0.9 (( 4) However, M1: the amount of change in the position of the first lens group at the telephoto end with respect to the wide-angle end (the object side direction is negative), Ymax: maximum image height, β2W: the second lens group at the wide-angle end. Lateral magnification, β2T: Lateral magnification of the second lens group at the telephoto end, Z: Zoom ratio (= fT / fW; fT: Focal length of the entire system at the telephoto end, fW: Focal length of the entire system at the wide-angle end ), X: Optical axis direction at a height perpendicular to the optical axis of the aspherical surface
Displacement (mm; negative in the object side), x0: optical axis at the height in the direction perpendicular to the optical axis of the reference spherical surface
Direction (mm; object side direction is negative), N: Refractive index of the medium on the object side of the aspherical surface to the d-line, N ': Refractive index of the medium on the image side of the aspherical surface to the d-line, Is.

[0007]

A zoom lens according to a third aspect of the invention is characterized in that, in the constitution of the first or second aspect of the invention, the third lens group has an aspherical surface that satisfies the following conditional expression (5) . -0.35 <(x-x0) / (N'-N) <0 (5) where x is the amount of displacement in the optical axis direction at the height perpendicular to the optical axis of the aspherical surface (mm; object Lateral direction is negative.), X0: Amount of displacement in the optical axis direction at a height perpendicular to the optical axis of the reference spherical surface (mm; object side direction is negative), N: From an aspherical surface Refractive index of the medium on the object side to the d-line, N ′: Refractive index of the medium on the image side of the aspherical surface to the d-line.

A zoom lens according to a fourth invention is characterized in that, in the constitution of the first or second invention, the fourth lens group has an aspherical surface which satisfies the following conditional expression (6) . -0.85 <(x-x0) / (N'-N) <0 (6) where x is the amount of displacement in the optical axis direction at the height in the direction perpendicular to the optical axis of the aspherical surface (mm; object Lateral direction is negative.), X0: Amount of displacement in the optical axis direction at a height perpendicular to the optical axis of the reference spherical surface (mm; object side direction is negative), N: From an aspherical surface Refractive index of the medium on the object side to the d-line, N ′: Refractive index of the medium on the image side of the aspherical surface to the d-line.

[0010]

[0011] In addition,5The zoom lens of the invention of
Note 1Or secondIn the structure of the invention of claim 1,
It has a filter.

[0012]

DETAILED DESCRIPTION OF THE INVENTION A zoom lens embodying the present invention will be described below with reference to the drawings. 1 to 3 are lens configuration diagrams corresponding to the zoom lenses of the first to third embodiments, respectively, and show the lens arrangement at the wide-angle end [W]. The arrow mj (j = 1,2,3,4) in each lens configuration diagram is
J-th zooming from wide-angle end [W] to telephoto end [T]
The movement of the lens group (Gri) (however, the broken line arrow mj indicates fixing during zooming) is schematically shown. Also,
In each lens configuration diagram, the surface marked ri (i = 1,2,3, ...) is the i-th surface counted from the object (subject) side, and the surface marked * for ri. Is an aspherical surface. The axial upper surface spacing marked with di (i = 1,2,3, ...) is a variable spacing that changes during zooming among the i-th axial upper surface spacing counted from the object side.

In each of the first to third embodiments, the first lens group (Gr1) having positive power is arranged in order from the object side.
And a second lens group (Gr2) having negative power, a third lens group (Gr3) having positive power, and a fourth lens group (Gr4) having positive power, the wide-angle end During zooming from [W] to the telephoto end [T], the first and fourth lens groups (Gr1, Gr4) move monotonically toward the object side while the third lens group (Gr3) is fixed. The second lens group (Gr2) is a zoom lens that moves monotonically toward the image side. The parallel plate arranged on the image side of the fourth lens group (Gr4) is a low-pass filter (L
PF).

In the first embodiment, each lens group is constructed in the following order from the object side. First
The lens group (Gr1) is composed of a cemented lens including a negative meniscus lens having a convex surface on the object side and a biconvex lens, and a positive meniscus lens having a convex surface on the object side. Second lens group (G
r2) is composed of a negative meniscus lens element convex to the object side and a cemented lens element including a biconcave lens element and a biconvex lens element. The third lens group (Gr3) includes a diaphragm (S), a biconvex lens, and a negative meniscus lens having a convex surface on the object side. The fourth lens group (Gr4) is composed of a biconvex lens, a negative meniscus lens having a convex surface on the object side, and a positive meniscus lens having a convex surface on the object side.

In the second embodiment, each lens group is constructed in the following order from the object side. First
The lens group (Gr1) is composed of a cemented lens including a negative meniscus lens having a convex surface on the object side and a biconvex lens, and a positive meniscus lens having a convex surface on the object side. Second lens group (G
r2) is composed of a negative meniscus lens having a convex surface on the object side, a biconcave lens, and a biconvex lens. Third lens group
(Gr3) is composed of a diaphragm (S), a biconvex lens, and a negative meniscus lens convex on the object side. 4th lens group (G
r4) is composed of a biconvex lens, a negative meniscus lens convex on the object side, and a positive meniscus lens convex on the object side.

In the third embodiment, each lens group is constructed in the following order from the object side. First
The lens group (Gr1) is composed of a cemented lens including a negative meniscus lens having a convex surface on the object side and a biconvex lens, and a positive meniscus lens having a convex surface on the object side. Second lens group (G
r2) is composed of a negative meniscus lens element convex to the object side and a cemented lens element including a biconcave lens element and a biconvex lens element. The third lens group (Gr3) includes a diaphragm (S) and a cemented lens including a biconvex lens and a biconcave lens. The fourth lens group (Gr4) is composed of a positive meniscus lens having a convex surface on the object side, a biconvex lens, and a biconcave lens.

As in each of the above embodiments, positive / negative / positive /
It is composed of a positive lens group, and the third lens group (Gr
3) is fixed, the first, second and fourth lens groups (Gr1, G
In a zoom lens of the type in which (r2, Gr4) moves,
It is desirable to satisfy the following conditional expression (1). -5.0 <M1 / Ymax <-1.0 (1) However, M1: The first lens group at the telephoto end [T] with respect to the wide-angle end [W].
The amount of change in the position of (Gr1) (the object side direction is negative), Ymax: maximum image height.

Conditional expression (1) defines the amount of movement of the first lens group (Gr1) during zooming, which is desirable mainly for maintaining a good balance between the overall length and the front lens diameter. If the lower limit of conditional expression (1) is exceeded, the amount of movement of the first lens group (Gr1) during zooming becomes too large, so the total length at the telephoto end [T] increases and at the telephoto end [T]. Therefore, the diameter of the front lens is increased in order to secure the surrounding illuminance. On the other hand, if the upper limit of conditional expression (1) is exceeded, the amount of movement of the first lens unit (Gr1) during zooming will be too small, and the overall length at the wide-angle end [W] will increase and at the wide-angle end. In order to secure the peripheral illuminance at [W], the front lens diameter is increased.

As in each of the above embodiments, positive / negative / positive /
It is composed of a positive lens group, and the third lens group (Gr
3) is fixed, the first, second and fourth lens groups (Gr1, G
In a zoom lens of the type in which (r2, Gr4) moves,
It is desirable to satisfy the following conditional expression (2), and it is more desirable to satisfy the conditional expression (1) at the same time. -1.0 <M4 / M2 <-0.1 (2) However, M2: The second lens group (G) at the telephoto end [T] with respect to the wide-angle end [W].
r2) position change amount (the object side direction is negative), M4: the fourth lens group (G) at the telephoto end [W] with respect to the wide-angle end [W].
The amount of change in the position of r4) (the object side direction is negative).

Conditional expression (2) defines a desirable moving amount ratio of the second and fourth lens groups (Gr2, Gr4) at the time of zooming. When the lower limit of conditional expression (2) is exceeded, the movement amount of the fourth lens group (Gr4) becomes relatively large, and accordingly, the fourth lens group (Gr4)
Since the burden of zooming becomes large, it becomes difficult to correct spherical aberration. On the contrary, when the upper limit of conditional expression (2) is exceeded, the moving amount of the second lens group (Gr2) becomes relatively large, and the second lens group (Gr2) and the aperture stop (S) at the wide-angle end [W]. The distance between and increases, and as a result, the position of the entrance pupil becomes far, and the diameter of the front lens increases. Further, since the variable magnification load of the second lens group (Gr2) becomes large, it becomes difficult to correct distortion and field curvature.

As in each of the above embodiments, positive / negative / positive /
It is composed of a positive lens group, and the third lens group (Gr
3) is fixed, the first, second and fourth lens groups (Gr1, G
In a zoom lens of the type in which (r2, Gr4) moves,
It is desirable to satisfy the following conditional expression (3), and it is more desirable to satisfy the conditional expression (1) at the same time. 0.2 <log (β2T / β2W) / log (Z) <0.9 (3) However, β2W: lateral magnification of the second lens group (Gr2) at the wide-angle end [W], β2T: at the telephoto end [T] Lateral magnification of the second lens group (Gr2), Z: Zoom ratio (= fT / fW; fT: Focal length of entire system at telephoto end [T], fW: Focal length of entire system at wide angle end [W] ),

Log (β2T / β2W) / log in conditional expression (3)
(Z) is the second lens group (Gr
2) indicates whether or not it is paid. When the value goes below the lower limit of the conditional expression (3), the zooming load after the second lens group (Gr2) becomes too large, which makes it difficult to correct spherical aberration. vice versa,
If the upper limit of conditional expression (3) is exceeded, the variable magnification load of the second lens group (Gr2) will become too large, making it difficult to correct distortion and image plane distortion.

As in each of the above embodiments, positive / negative / positive /
It is composed of a positive lens group, and the third lens group (Gr
3) is fixed, the first, second and fourth lens groups (Gr1, G
r2, Gr4) are movable types, among them, when changing the magnification from the wide-angle end [W] to the telephoto end [T], the first and fourth lens groups (Gr1, Gr
In the zoom lens of the type in which 4) monotonously moves to the object side and the second lens group (Gr2) monotonically moves to the image side,
An aspherical surface is effective in obtaining better optical performance. For example, it is desirable that the second lens group (Gr2) be provided with an aspherical surface that satisfies the following conditional expression (4).
It is more desirable to satisfy (1) and (2), or (1) and (3) at the same time. 0 <(x-x0) / (N'-N) <0.9 (4) However, x: Displacement in the optical axis (AX) direction at a height perpendicular to the optical axis (AX) of the aspherical surface. Amount (mm; object side direction is negative), x0: Amount of displacement in the optical axis (AX) direction at a height perpendicular to the optical axis (AX) of the reference spherical surface (mm; object side direction) N): Refractive index of the medium on the object side of the aspherical surface with respect to d-line, N ': Refractive index of the medium on the image side of the aspherical surface with respect to d-line.

The x representing the surface shape of the aspherical surface and the x0 representing the surface shape of the reference spherical surface are specifically expressed by the following equations (AS) and (RE), respectively. x ＝ {C0 ・ y ² } / {1 + √ (1-ε ・ C0 ²・ y ² )} + Σ (Ai ・ y ⁱ )… (AS) x0 ＝ {C0 ・ y ² } / {1 + √ (1-C0 ²・ y ² )} (RE) However, in the formulas (AS) and (RE), y: the height in the direction perpendicular to the optical axis (AX), C0: the curvature of the reference spherical surface (that is, (Reference curvature of aspherical surface), ε: quadric surface parameter, Ai: i-th order aspherical coefficient,

In conditional expression (4), the aspherical surface is the second lens group (Gr2).
It means that it has a shape that weakens the negative power of. By satisfying the conditional expression (4), it is possible to appropriately correct distortion and field curvature mainly on the wide angle side. When the value goes below the lower limit of the conditional expression (4), the positive distortion aberration on the wide-angle side becomes large and the tilt of the image surface to the over side becomes large. On the other hand, if the upper limit of conditional expression (4) is exceeded, negative distortion on the wide-angle side will increase and tilt of the image plane toward the under side will increase. The second lens group (G
r2) has a plurality of aspherical surfaces, and if at least one surface satisfies the conditional expression (4), the other aspherical surfaces satisfy the conditional expression (4) in consideration of other aberrations. It doesn't matter.

For the third lens group (Gr3), the following conditional expression (5)
It is desirable to provide an aspherical surface that satisfies the above condition, and it is further desirable that the above conditional expressions (1) and (2) or (1) and (3) are also satisfied at the same time. -0.35 <(x-x0) / (N'-N) <0… (5)

In conditional expression (5), the aspherical surface is the third lens group (Gr3).
It means that it has a shape that weakens the positive power of. By satisfying this conditional expression (5), mainly spherical aberration can be appropriately corrected. If the lower limit of conditional expression (5) is exceeded, the tendency for spherical aberration to become excessive mainly on the telephoto side becomes noticeable. On the other hand, when the value exceeds the upper limit of the conditional expression (5), the spherical aberration tends to be under-corrected mainly on the telephoto side. In addition,
In the case where the third lens group (Gr3) has a plurality of aspherical surfaces, if at least one surface satisfies the conditional expression (5), the other aspherical surfaces satisfy the above conditional expression (5) in consideration of other aberrations. ) Does not need to be satisfied.

For the fourth lens group (Gr4), the following conditional expression (6)
It is desirable to provide an aspherical surface that satisfies the above condition, and it is further desirable that the above conditional expressions (1) and (2) or (1) and (3) are also satisfied at the same time. -0.85 <(x-x0) / (N'-N) <0… (6)

In conditional expression (6), the aspherical surface is the fourth lens group (Gr4).
It means that it has a shape that weakens the positive power of. By satisfying this conditional expression (6), it is possible to appropriately correct mainly the distortion aberration and the field curvature on the wide angle side and the spherical aberration on the telephoto side. When the value goes below the lower limit of the conditional expression (6), the positive distortion on the wide-angle side increases, and the tilt of the image surface to the over side increases. Further, the tendency of spherical aberration to be excessive on the telephoto side becomes remarkable. vice versa,
If the upper limit of conditional expression (6) is exceeded, negative distortion on the wide-angle side will increase, and tilt of the image plane to the over side will increase. In addition, the spherical aberration tends to be under-corrected on the telephoto side. When the fourth lens group (Gr4) has a plurality of aspherical surfaces, if at least one surface satisfies the above conditional expression (6), the other aspherical surfaces satisfy the above conditional expressions in consideration of other aberrations. It does not matter if you do not satisfy (6).

Each of the lens groups constituting the first to third embodiments is composed of only a refraction type lens that deflects an incident light beam by refraction, but the invention is not limited to this.
For example, each lens group may be configured by a diffractive lens that deflects an incident light beam by diffraction, a refraction / diffraction hybrid lens that deflects an incident light beam by a combination of diffractive action and refraction action, and the like. The zoom lens according to each embodiment is suitable for a digital still camera, but is not limited to an optical system for a camera. Its characteristic configuration is part of the zoom lens or zoom optical system used in optical devices other than the camera (for example, the objective part of the afocal system).
It is also applicable to etc.

[0031]

EXAMPLES The structure of the zoom lens embodying the present invention will be described more specifically below with reference to construction data, aberration diagrams, and the like. In addition, Examples 1 to 3 listed below
Are lens configuration diagrams showing the first to third embodiments respectively corresponding to the first to third embodiments described above.
(FIGS. 1 to 3) show lens configurations of corresponding Embodiments 1 to 3, respectively.

In the construction data of each embodiment, ri (i = 1,2,3, ...) is the radius of curvature of the i-th surface counted from the object side, di (i = 1,2,3 ,. ..) indicates the i-th axial upper surface distance counted from the object side, and Ni (i = 1,2,3, ...), νi (i = 1,2,
3, ...) indicates the refractive index (Nd) and Abbe number (νd) of the i-th optical element with respect to the d-line counting from the object side. In the construction data, the axial upper surface distance (variable distance) that changes during zooming is the wide-angle end (short focal length end) [W].
-Middle (intermediate focal length state) [M] -Axial air distance between lens groups at the telephoto end (long focal length end) [T]. The focal length f of the entire system corresponding to each focal length state [W], [M], [T]
And F number FNO are also shown.

The surface marked with * on the radius of curvature ri is
The surface is defined as an aspherical surface, and is defined by the above-mentioned formula (AS) that represents the surface shape of the aspherical surface. Corresponding values of the aspherical surface data and conditional expressions (4) to (6) regarding the aspherical surface (where ymax is the maximum height (maximum effective radius) in the direction perpendicular to the optical axis (AX) of the aspherical surface. } Is also shown together with other data, and the corresponding values of conditional expressions (1) to (3) are shown in Table 1.

[0034]

[Aspherical surface data of the sixth surface (r6)] ε = 1.0000 A4 = 0.24880 × 10 ^-3 A6 = 0.69912 × 10 ^-5 A8 = -0.12045 × 10 ^-6

[Aspherical surface data of the seventh surface (r7)] ε = 1.0000 A4 = 0.19486 × 10 ^-3 A6 = 0.16546 × 10 ^-4 A8 = 0.68213 × 10 ^-6

[Aspherical surface data of 12th surface (r12)] ε = 1.0000 A4 = -0.63905 × 10 ^-3 A6 = -0.20691 × 10 ^-4 A8 = 0.38158 × 10 ^-7 A10 = -0.16639 × 10 ^-6

[Aspherical surface data of the 13th surface (r13)] ε = 1.0000 A4 = -0.28812 × 10 ^-3 A6 = -0.69833 × 10 ^-5 A8 = -0.13085 × 10 ^-5 A10 = -0.95789 × 10 ^-7

[Aspherical surface data of the 18th surface (r18)] ε = 1.0000 A4 = -0.47322 × 10 ^-2 A6 = 0.17987 × 10 ^-3 A8 = -0.10821 × 10 ^-4 A10 = 0.28645 × 10 ^-6

[Aspherical surface data of the 19th surface (r19)] ε = 1.0000 A4 = -0.53795 × 10 ^-2 A6 = 0.20587 × 10 ^-3 A8 = -0.14591 × 10 ^-4

[Corresponding value of conditional expression (4) of the sixth surface (r6)] y = 0.00ymax… (x-x0) / (N'-N) = 0.00000 y = 0.25ymax… (x-x0) / (N'-N) = 0.00106 y = 0.50ymax… (x-x0) / (N'-N) = 0.01900 y = 0.75ymax… (x-x0) / (N'-N) = 0.10847 y = 1.00ymax… (x-x0) / (N'-N) = 0.36418

[Corresponding Value of Conditional Expression (4) of 7th Surface (r7)] y = 0.00ymax… (x-x0) / (N'-N) =-0.00000 y = 0.25ymax… (x-x0) / (N'-N) =-0.00032 y = 0.50ymax… (x-x0) / (N'-N) =-0.00661 y = 0.75ymax… (x-x0) / (N'-N) =-0.05024 y = 1.00ymax… (x-x0) / (N'-N) =-0.25799

[Corresponding Value of Conditional Expression (5) of 12th Surface (r12)] y = 0.00ymax… (x-x0) / (N'-N) = 0.00000 y = 0.25ymax… (x-x0) / (N'-N) =-0.00025 y = 0.50ymax… (x-x0) / (N'-N) =-0.00414 y = 0.75ymax… (x-x0) / (N'-N) =-0.02287 y = 1.00ymax… (x-x0) / (N'-N) =-0.08500

[Corresponding Value of Conditional Expression (5) of 13th Surface (r13)] y = 0.00ymax… (x-x0) / (N'-N) =-0.00000 y = 0.25ymax… (x-x0) / (N'-N) = 0.00011 y = 0.50ymax… (x-x0) / (N'-N) = 0.00179 y = 0.75ymax… (x-x0) / (N'-N) = 0.01032 y = 1.00ymax… (x-x0) / (N'-N) = 0.04267

[Corresponding value of conditional expression (6) of the 18th surface (r18)] y = 0.00ymax… (x-x0) / (N'-N) = 0.00000 y = 0.25ymax… (x-x0) / (N'-N) =-0.00222 y = 0.50ymax… (x-x0) / (N'-N) =-0.03335 y = 0.75ymax… (x-x0) / (N'-N) =-0.15571 y = 1.00ymax… (x-x0) / (N'-N) =-0.45732

[Corresponding value of conditional expression (6) on the 19th surface (r19)] y = 0.00ymax… (x-x0) / (N'-N) =-0.00000 y = 0.25ymax… (x-x0) / (N'-N) = 0.00157 y = 0.50ymax… (x-x0) / (N'-N) = 0.02395 y = 0.75ymax… (x-x0) / (N'-N) = 0.11457 y = 1.00ymax… (x-x0) / (N'-N) = 0.35603

[0047]

[Aspherical surface data of the sixth surface (r6)] ε = 1.0000 A4 = 0.34989 × 10 ^-3 A6 = 0.29550 × 10 ^-5 A8 = -0.39655 × 10 ^-7

[Aspherical surface data of the seventh surface (r7)] ε = 1.0000 A4 = 0.26226 × 10 ^-3 A6 = 0.12936 × 10 ^-4 A8 = 0.40863 × 10 ^-6

[Aspherical surface data of thirteenth surface (r13)] ε = 1.0000 A4 = -0.64004 × 10 ^-3 A6 = -0.20905 × 10 ^-4 A8 = 0.14240 × 10 ^-6 A10 = -0.17189 × 10 ^-6

[Aspherical surface data of the 14th surface (r14)] ε = 1.0000 A4 = -0.30103 × 10 ^-3 A6 = -0.74213 × 10 ^-5 A8 = -0.10894 × 10 ^-5 A10 = -0.10624 × 10 ^-6

[Aspherical surface data of the 19th surface (r19)] ε = 1.0000 A4 = -0.47646 × 10 ^-2 A6 = 0.18766 × 10 ^-3 A8 = -0.10271 × 10 ^-4 A10 = 0.22819 × 10 ^-6

[Aspherical surface data of 20th surface (r20)] ε = 1.0000 A4 = -0.53163 × 10 ^-2 A6 = 0.22027 × 10 ^-3 A8 = -0.13269 × 10 ^-4

[Corresponding value of conditional expression (4) of the sixth surface (r6)] y = 0.00ymax… (x-x0) / (N'-N) = 0.00000 y = 0.25ymax… (x-x0) / (N'-N) = 0.00153 y = 0.50ymax… (x-x0) / (N'-N) = 0.02548 y = 0.75ymax… (x-x0) / (N'-N) = 0.13541 y = 1.00ymax… (x-x0) / (N'-N) = 0.44412

[Corresponding Value of Conditional Expression (4) of 7th Surface (r7)] y = 0.00ymax… (x-x0) / (N'-N) =-0.00000 y = 0.25ymax… (x-x0) / (N'-N) =-0.00047 y = 0.50ymax… (x-x0) / (N'-N) =-0.00894 y = 0.75ymax… (x-x0) / (N'-N) =-0.06020 y = 1.00ymax… (x-x0) / (N'-N) =-0.27574

[Corresponding Value of Conditional Expression (5) of 13th Surface (r13)] y = 0.00ymax… (x-x0) / (N'-N) = 0.00000 y = 0.25ymax… (x-x0) / (N'-N) =-0.00026 y = 0.50ymax… (x-x0) / (N'-N) =-0.00432 y = 0.75ymax… (x-x0) / (N'-N) =-0.02382 y = 1.00ymax… (x-x0) / (N'-N) =-0.08851

[Corresponding value of conditional expression (5) of the 14th surface (r14)] y = 0.00ymax… (x-x0) / (N'-N) =-0.00000 y = 0.25ymax… (x-x0) / (N'-N) = 0.00011 y = 0.50ymax… (x-x0) / (N'-N) = 0.00192 y = 0.75ymax… (x-x0) / (N'-N) = 0.01094 y = 1.00ymax… (x-x0) / (N'-N) = 0.04456

[Corresponding Value of Conditional Expression (6) of 19th Surface (r19)] y = 0.00ymax ... (x-x0) / (N'-N) = 0.00000 y = 0.25ymax ... (x-x0) / (N'-N) =-0.00224 y = 0.50ymax… (x-x0) / (N'-N) =-0.03347 y = 0.75ymax… (x-x0) / (N'-N) =-0.15514 y = 1.00ymax (x-x0) / (N'-N) =-0.
45265

[Corresponding value of conditional expression (6) on the 20th surface (r20)] y = 0.00ymax… (x-x0) / (N'-N) =-0.00000 y = 0.25ymax… (x-x0) / (N'-N) = 0.00156 y = 0.50ymax… (x-x0) / (N'-N) = 0.02354 y = 0.75ymax… (x-x0) / (N'-N) = 0.11104 y = 1.00ymax… (x-x0) / (N'-N) = 0.33662

[0060]

[Aspherical surface data of the eighth surface (r8)] ε = 1.0000 A4 = 0.70923 × 10 ^-3 A6 = -0.16701 × 10 ^-4 A8 = 0.44246 × 10 ^-6

[Aspherical surface data of 10th surface (r10)] ε = 1.0000 A4 = 0.42937 × 10 ^-3 A6 = -0.62961 × 10 ^-5 A8 = -0.22968 × 10 ^-6 A10 = 0.19206 × 10 ^-7

[Aspherical surface data of the twelfth surface (r12)] ε = 1.0000 A4 = -0.22084 × 10 ^-3 A6 = 0.24082 × 10 ^-4 A8 = -0.30206 × 10 ^-5 A10 = 0.14784 × 10 ^-6

[Aspherical surface data of 14th surface (r14)] ε = 1.0000 A4 = -0.67988 × 10 ^-4 A6 = 0.23632 × 10 ^-4 A8 = -0.28969 × 10 ^-5 A10 = 0.14902 × 10 ^-6

[Aspherical surface data of the 19th surface (r19)] ε = 1.0000 A4 = -0.13544 × 10 ^-2 A6 = 0.13398 × 10 ^-4 A8 = -0.21612 × 10 ^-6

[Aspherical surface data of the 20th surface (r20)] ε = 1.0000 A4 = -0.58348 × 10 ^-4 A6 = 0.59161 × 10 ^-4 A8 = -0.48072 × 10 ^-6

[Corresponding Value of Conditional Expression (4) of Eighth Surface (r8)] y = 0.00ymax… (x-x0) / (N'-N) = 0.00000 y = 0.25ymax… (x-x0) / (N'-N) = 0.00077 y = 0.50ymax… (x-x0) / (N'-N) = 0.01161 y = 0.75ymax… (x-x0) / (N'-N) = 0.05406 y = 1.00ymax… (x-x0) / (N'-N) = 0.15895

[Corresponding Value of Conditional Expression (4) for Surface No. 10 (r10)] y = 0.00ymax… (x-x0) / (N'-N) =-0.00000 y = 0.25ymax… (x-x0) / (N'-N) =-0.00028 y = 0.50ymax… (x-x0) / (N'-N) =-0.00428 y = 0.75ymax… (x-x0) / (N'-N) =-0.02026 y = 1.00ymax… (x-x0) / (N'-N) =-0.05928

[Corresponding Value of Conditional Expression (5) of 12th Surface (r12)] y = 0.00ymax ... (x-x0) / (N'-N) = 0.00000 y = 0.25ymax ... (x-x0) / (N'-N) =-0.00009 y = 0.50ymax… (x-x0) / (N'-N) =-0.00120 y = 0.75ymax… (x-x0) / (N'-N) =-0.00531 y = 1.00ymax (x-x0) / (N'-N) =-0.
01508

[Corresponding value of conditional expression (5) of the 14th surface (r14)] y = 0.00ymax… (x-x0) / (N'-N) =-0.00000 y = 0.25ymax… (x-x0) / (N'-N) = 0.00002 y = 0.50ymax… (x-x0) / (N'-N) = 0.00017 y = 0.75ymax… (x-x0) / (N'-N) = 0.00010 y = 1.00ymax… (x-x0) / (N'-N) =-0.00179

[Corresponding value of conditional expression (6) on the 19th surface (r19)] y = 0.00ymax… (x-x0) / (N'-N) = 0.00000 y = 0.25ymax… (x-x0) / (N'-N) =-0.00101 y = 0.50ymax… (x-x0) / (N'-N) =-0.01579 y = 0.75ymax… (x-x0) / (N'-N) =-0.07723 y = 1.00ymax… (x-x0) / (N'-N) =-0.23431

[Corresponding Value of Conditional Expression (6) of 20th Surface (r20)] y = 0.00ymax ... (x-x0) / (N'-N) =-0.00000 y = 0.25ymax ... (x-x0) / (N'-N) = 0.00001 y = 0.50ymax… (x-x0) / (N'-N) =-0.00042 y = 0.75ymax… (x-x0) / (N'-N) =-0.00673 y = 1.00ymax (x-x0) / (N'-N) =-0.
04052

[0073]

[Table 1]

4 to 6 are aberration charts corresponding to Examples 1 to 3, respectively. [W] is a wide-angle end, [M] is a middle, and [T] is various aberrations at the telephoto end (from left to right). Spherical aberration, astigmatism, and distortion; Y ': image height) are shown in order. Also,
In each aberration diagram, the solid line (d) is the aberration for the d line, and the broken line (SC)
Represents the sine condition, and the broken line (DM) and solid line (DS) are
The astigmatisms for the d-line on the meridional surface and the sagittal surface are shown respectively.

[0075]

As described above, according to the present invention, it is possible to realize a zoom lens device equipped with a zoom lens which is compact, low in cost, has a high zoom ratio, and has high optical performance. Then, the zoom lens according to the present invention
If the device is used, a high quality image can be obtained.

[Brief description of drawings]

FIG. 1 is a lens configuration diagram of a first embodiment (Example 1).

FIG. 2 is a lens configuration diagram of a second embodiment (Example 2).

FIG. 3 is a lens configuration diagram of a third embodiment (Example 3).

FIG. 4 is an aberration diagram of Example 1.

FIG. 5 is an aberration diagram of Example 2.

FIG. 6 is an aberration diagram of Example 3.

[Explanation of symbols]

Gr1 ... 1st lens group Gr2 ... 2nd lens group S ... diaphragm Gr3 ... 3rd lens group Gr4 ... 4th lens group LPF ... Low-pass filter AX ... optical axis

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-7-199124 (JP, A) JP-A-3-12625 (JP, A) JP-A-4-358108 (JP, A) JP-A-4- 14007 (JP, A) JP-A-4-14006 (JP, A) JP-A-3-12619 (JP, A) JP-A-3-12624 (JP, A) JP-A-3-12622 (JP, A) JP-A-3-12621 (JP, A) JP-A-3-12620 (JP, A) JP-A 64-79719 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02B 15/20

Claims (5)

(57) [Claims] 1. A zoom lens device comprising, in order from the object side, a zoom lens and a solid-state image sensor for receiving an optical image formed by the zoom lens, wherein the zoom lens is arranged in order from the object side. The first lens group having positive power, the second lens group having negative power, the third lens group having positive power, and the fourth lens group having positive power, When the third lens group is fixed, the first lens group and the second lens group
A zoom lens lens group and the fourth lens group move, and satisfies the following conditional expression (1) and (2), the second
The zoom lens system, characterized in that have a non-spherical surface which satisfies the following conditional expression (4) to the lens unit; -5.0 <M1 / Ymax <-1.0 ... (1) -1.0 <M4 / M2 <-0.1 ... (2) 0 <(x-x0) / (N'-N) <0.9 (4) However, M1: the amount of change in the position of the first lens group at the telephoto end with respect to the wide-angle end (when the object side direction is negative) , M2: Change in position of the second lens group at the telephoto end with respect to the wide-angle end (the object side direction is negative), M4: Change in position of the fourth lens group at the telephoto end with respect to the wide-angle end. Amount (negative in the direction of the object side), Ymax: maximum image height, x: optical axis direction at a height perpendicular to the optical axis of the aspherical surface
Displacement (mm; negative in the object side), x0: optical axis at the height in the direction perpendicular to the optical axis of the reference spherical surface
Direction (mm; object side direction is negative), N: Refractive index of the medium on the object side of the aspherical surface to the d-line, N ': Refractive index of the medium on the image side of the aspherical surface to the d-line, Is. 2. A zoom lens device comprising, in order from the object side, a zoom lens and a solid-state image sensor for receiving an optical image formed by the zoom lens, wherein the zoom lens is arranged in order from the object side. The first lens group having positive power, the second lens group having negative power, the third lens group having positive power, and the fourth lens group having positive power, When the third lens group is fixed, the first lens group and the second lens group
A zoom lens lens group and the fourth lens group move, and satisfies the following conditional expression (1) and (3), the second
The zoom lens system, characterized in that have a non-spherical surface which satisfies the following conditional expression (4) to the lens unit; -5.0 <M1 / Ymax <-1.0 ... (1) 0.2 <log (β2T / β2W) / log (Z) <0.9 ... (3) 0 <(x-x0) / (N'-N) <0.9 ... (4) However, M1: the amount of change in the position of the first lens unit at the telephoto end relative to the wide-angle end ( Object side direction is negative.), Ymax: maximum image height, β2W: lateral magnification of second lens group at wide-angle end, β2T: lateral magnification of second lens group at telephoto end, Z: zoom ratio (= fT / fW ； fT: focal length of the entire system at the telephoto end, fW: focal length of the entire system at the wide-angle end), x: optical axis direction at a height perpendicular to the optical axis of the aspherical surface
Displacement (mm; negative in the object side), x0: optical axis at the height in the direction perpendicular to the optical axis of the reference spherical surface
Direction (mm; object side direction is negative), N: Refractive index of the medium on the object side of the aspherical surface to the d-line, N ': Refractive index of the medium on the image side of the aspherical surface to the d-line, Is . 3. The zoom lens device according to claim 1, wherein the third lens group has an aspherical surface that satisfies the following conditional expression (5) : -0.35 <(x-x0 ) / (N'-N) <0 (5) However, x: the amount of displacement in the optical axis direction at the height in the direction perpendicular to the optical axis of the aspherical surface (mm; the object side direction is negative). ), X0: Amount of displacement in the optical axis direction at a height perpendicular to the optical axis of the reference spherical surface (mm; object side direction is negative), N: d line of the medium on the object side of the aspherical surface , N ′: Refractive index of the medium on the image side of the aspherical surface with respect to d-line. 4. The zoom lens device according to claim 1, wherein the fourth lens group has an aspherical surface that satisfies the following conditional expression (6) : -0.85 <(x-x0 ) / (N'-N) <0 (6) However, x: The amount of displacement in the optical axis direction at the height in the direction perpendicular to the optical axis of the aspherical surface (mm; the object side direction is negative). ), X0: Amount of displacement in the optical axis direction at a height perpendicular to the optical axis of the reference spherical surface (mm; object side direction is negative), N: d line of the medium on the object side of the aspherical surface , N ′: Refractive index of the medium on the image side of the aspherical surface with respect to d-line . 5. Furthermore, the zoom lens system according to claim 1 or claim 2, wherein it has a low-pass filter in the optical path.