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CN-121995598-A - System, imaging device including the system, and lens device including the system

CN121995598ACN 121995598 ACN121995598 ACN 121995598ACN-121995598-A

Abstract

The present disclosure relates to a system, an imaging apparatus including the system, and a lens apparatus including the system. A system includes, in order from an object side to an image side, a front unit having a negative refractive power, an aperture stop, a rear unit having a positive refractive power, and at least ten lenses. The rear cell includes an aspherical lens having an inflection point, and the system satisfies a predetermined inequality when a focal length of the system as a whole is represented by f, a focal length of the front cell is represented by f1, a maximum image height of the system is represented by ImgH, and a total length of the system is represented by L.

Inventors

  • Da Ku Zhen You

Assignees

  • 佳能株式会社

Dates

Publication Date
20260508
Application Date
20251104
Priority Date
20241107

Claims (20)

  1. 1. A system comprising, in order from an object side to an image side: A front unit having a negative refractive power; An aperture stop; A rear unit having a positive refractive power, and At least ten of the lenses are arranged in the lens housing, Wherein the rear cell includes an aspherical lens A having an inflection point, and Wherein the following inequality is satisfied: -2.98 < f1/f < 0.00 0.40 < ImgH/L where f denotes a focal length of the system as a whole, f1 denotes a focal length of the front unit, imgH denotes a maximum image height of the system, and L denotes a total length of the system.
  2. 2. The system according to claim 1, Wherein the following inequality is satisfied: 0.52 < fG1/f1 where fG1 denotes a focal length of a lens G1 disposed closest to the object among lenses included in the front unit.
  3. 3. The system according to claim 1 or 2, Wherein the front unit includes a positive lens.
  4. 4. The system according to claim 1 or 2, Wherein in the rear unit, a positive lens, another positive lens, and a negative lens are disposed in this order from a position closest to the object toward the image.
  5. 5. The system according to claim 1 or 2, Wherein the following inequality is satisfied: -3.00 < fω1/|f1| < 0.00 where fω1 represents the off-axis focal length of the front unit in the meridian direction.
  6. 6. The system according to claim 1 or 2, Wherein the following inequality is satisfied: -6.00 < fGR/f2 < -2.00 Wherein fGR denotes a focal length of the lens GR included in the rear unit and disposed closest to the image, and f2 denotes a focal length of the rear unit.
  7. 7. The system according to claim 1 or 2, Wherein the following inequality is satisfied: 48.0 < ω < 70.0 wherein omega [ And represents the half viewing angle corresponding to the maximum image height of the system.
  8. 8. The system according to claim 1 or 2, Wherein the following inequality is satisfied: 14.0 < νd < 40.0 Where vd denotes an abbe number of a material of the negative lens GN1 disposed closest to the object among the negative lenses included in the rear unit.
  9. 9. The system according to claim 8, Wherein the following inequality is satisfied: 1.50 < nd < 1.70 Where nd denotes a refractive index of a material of the negative lens GN1 with respect to d-line.
  10. 10. The system according to claim 1, Wherein the following inequality is satisfied: 0.40 < ImgH/L < 3.00。
  11. 11. the system according to claim 1, Wherein the following inequality is satisfied: 0.52 < fG1/f1 < 2.00 where fG1 denotes a focal length of a lens G1 disposed closest to the object among lenses included in the front unit.
  12. 12. The system according to claim 1 or 2, Wherein the system includes a lens B made of a resin material, and Wherein at least one of an object side lens surface and an image side lens surface of the lens B is an aspherical surface.
  13. 13. The system according to claim 1 or 2, Wherein the object side lens surface of the lens GR included in the rear unit and disposed closest to the image includes a portion in the vicinity of the axis and convex on the object side and a peripheral portion concave on the object side, and Wherein the image side lens surface of the lens GR includes a portion that is concave on the image side in the vicinity of the axis and a peripheral portion that is convex on the image side.
  14. 14. The system according to claim 1 or 2, Wherein an object side lens surface of the lens GR1 includes a portion in the vicinity of an axis and convex on the object side and a peripheral portion concave on the object side, the lens GR1 being disposed on the object side of a lens included in the rear unit and disposed closest to the image and adjacent to the lens included in the rear unit and disposed closest to the image, and Wherein the image side lens surface of the lens GR1 includes a portion which is concave on the image side in the vicinity of the axis and a peripheral portion which is convex on the image side.
  15. 15. The system according to claim 1 or 2, Wherein an object side lens surface of a negative lens GN1 disposed closest to the object among the negative lenses included in the rear unit includes a portion in the vicinity of the axis and convex on the object side and a peripheral portion concave on the object side, and Wherein the image side lens surface of the negative lens GN1 includes a portion that is concave on the image side in the vicinity of the axis and a peripheral portion that is convex on the image side.
  16. 16. The system according to claim 1 or 2, Wherein the front unit is composed of three lenses and the rear unit is composed of seven lenses.
  17. 17. The system according to claim 1 or 2, Wherein the front unit consists of four lenses and the rear unit consists of seven lenses.
  18. 18. A system comprising, in order from an object side to an image side: A front unit having a negative refractive power; An aperture stop; A rear unit having a positive refractive power, and An aspherical lens having an inflection point, Wherein the front unit comprises at least three lenses, and Wherein the following inequality is satisfied: -2.98 < f1/f < 0.00 Where f represents the focal length of the system as a whole, and f1 represents the focal length of the front unit.
  19. 19. An image forming apparatus comprising: The system according to claim 1 or 2, and An imaging element that receives an image formed by the system.
  20. 20. A lens apparatus comprising: The system according to claim 1 or 2, and An operation unit configured to be operated by a user.

Description

System, imaging device including the system, and lens device including the system Technical Field Aspects of the embodiments relate to a system suitable for a digital still camera, a digital video camera, a monitoring camera, an in-vehicle camera, a smart phone camera, and the like, an imaging apparatus including the system, and a lens apparatus including the system. Background In the wide-angle optical system, distortion aberration generated in the optical system can be corrected by disposing the lens unit on the object side with respect to the aperture. Japanese patent laid-open No. 2023-184065 discloses a wide-angle optical system in which a front lens unit having a negative refractive power, an aperture stop, and a rear lens unit having a positive refractive power are disposed in order from the object side. Disclosure of Invention A system comprising, in order from an object side to an image side, a front unit having a negative refractive power, an aperture stop, a rear unit having a positive refractive power, and at least ten lenses, wherein the rear unit includes an aspherical lens having an inflection point, and the following inequality is satisfied: -2.98 < f1/f < 0.00 0.40 < ImgH/L Where f denotes a focal length of the entire system, f1 denotes a focal length of the front unit, imgH denotes a maximum image height of the system, and L denotes a total length of the system. Features of the present disclosure will become apparent from the following description of embodiments with reference to the accompanying drawings. The following description of the embodiments is described by way of example. Drawings Fig. 1 is a cross-sectional view of the optical system of example 1 during infinity focusing. Fig. 2 is a longitudinal aberration diagram corresponding to example 1. Fig. 3 is a cross-sectional view of the optical system of example 2 during infinity focusing. Fig. 4 is a longitudinal aberration diagram corresponding to example 2. Fig. 5 is a cross-sectional view of the optical system of example 3 during infinity focusing. Fig. 6 is a longitudinal aberration diagram corresponding to example 3. Fig. 7 is a cross-sectional view of the optical system of example 4 during infinity focusing. Fig. 8 is a longitudinal aberration diagram corresponding to example 4. Fig. 9 is a schematic diagram relating to the hit point (hit point) of off-axis rays on an optical surface. Fig. 10 is a schematic diagram of an image forming apparatus using the optical system of one of examples 1 to 4. Fig. 11 is a schematic diagram of a lens apparatus using the optical system of one of examples 1 to 4. Detailed Description Hereinafter, embodiments disclosed in the specification will be described in detail with reference to the accompanying drawings. In the drawings, the same members are given the same reference numerals, and repetitive description thereof will be omitted. Fig. 1, 3, 5, and 7 are sectional views of the optical system L0 of examples 1 to 4, respectively, during infinity focusing. The optical system L0 of each example will be used in an imaging apparatus such as a digital still camera, a digital video camera, a monitoring camera, or an in-vehicle camera. In each sectional view, the left side is the object side, and the right side is the image side. The optical system L0 of each example includes a plurality of lens units. Note that the lens unit in the specification refers to a group of lenses isolated from each other by the aperture stop SP. Further, each lens unit may be composed of one lens or may be composed of a plurality of lenses. Further, each lens unit may include an aspherical lens, a fresnel lens, a superlens, a diffractive optical element, and the like. In the optical system L0 of each example, li represents an i-th (i is a natural number) lens unit counted from the object side among the lens units included in the optical system L0. Further, gk represents a kth (k is a natural number) lens counted from the object side among lenses included in the optical system. In the optical system L0 of each example, L1 (LF) denotes a front unit as a lens unit disposed on the object side with respect to the aperture stop. Further, L2 (LR) denotes a rear unit which is a lens unit disposed on the image side with respect to the aperture stop. In each sectional view, SP is an aperture stop. The FL is an optical element corresponding to an optical filter, a low-pass filter, an infrared cut filter, or the like. IP is an image plane, and when the optical system L0 of each example is used as an imaging optical system of a digital still camera or a digital video camera, an imaging surface of a solid-state image sensing device (such as a CCD sensor or a CMOS sensor) is arranged on the image plane IP. When the optical system L0 of each example is used as an imaging optical system of a silver halide film camera, the image plane IP serves as a photosensitive surface corresponding to the film surface. Note that the optical system in ea