WO2014199766A1 - Converter lens, image capture optical assembly, and portable terminal - Google Patents

Converter lens, image capture optical assembly, and portable terminal Download PDF

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Publication number
WO2014199766A1
WO2014199766A1 PCT/JP2014/062792 JP2014062792W WO2014199766A1 WO 2014199766 A1 WO2014199766 A1 WO 2014199766A1 JP 2014062792 W JP2014062792 W JP 2014062792W WO 2014199766 A1 WO2014199766 A1 WO 2014199766A1
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WO
WIPO (PCT)
Prior art keywords
lens
converter
object side
main
image
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Application number
PCT/JP2014/062792
Other languages
French (fr)
Japanese (ja)
Inventor
敦司 山下
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コニカミノルタ株式会社
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Publication date
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Publication of WO2014199766A1 publication Critical patent/WO2014199766A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G02B13/001—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras
    • G02B13/0015—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design
    • G02B13/002—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design having at least one aspherical surface
    • G02B13/0045—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design having at least one aspherical surface having five or more lenses
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G02B13/18—Optical objectives specially designed for the purposes specified below with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B17/00—Details of cameras or camera bodies; Accessories therefor
    • G03B17/56—Accessories
    • G03B17/565—Optical accessories, e.g. converters for close-up photography, tele-convertors, wide-angle convertors

Definitions

  • the present invention relates to a converter lens, an imaging optical system, and a mobile terminal that are mounted on the object side of the main lens and convert the photographing field angle of the main lens to the wide angle side.
  • a portable terminal is generally mounted with an imaging device, and is used in various ways such as transferring an image captured by the imaging device or performing image processing on the portable terminal.
  • an imaging device incorporated therein is strictly required to be compact. Accordingly, a single-focus optical system is usually mounted on an imaging device mounted on a conventional portable terminal.
  • some users have a desire to image a wider range of subjects.
  • a converter lens that can change the focal length of the photographic lens to the wide-angle side by positioning it in front of the photographic lens (main lens) provided in the photographing apparatus is disclosed in Patent Documents 1 and 2. Is disclosed.
  • the converter lenses disclosed in Patent Documents 1 and 2 have a large overall optical system length and diameter, and it is difficult to say that they are sufficiently compact to be mounted on a portable terminal and used. In order to satisfy the compactness, it is necessary to suppress the overall length and diameter as much as possible.
  • the present invention provides a converter lens having a conversion ratio of 0.7 times or less and sufficiently thin in the thickness direction of the imaging device and having a small diameter, and an imaging optical system and an imaging device used therefor.
  • the purpose is to provide.
  • a converter lens reflecting one aspect of the present invention is mounted on the object side of the main lens, and converts the shooting field angle of the main lens to the wide angle side.
  • the converter lens includes, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, and a third lens having positive refractive power, The following conditional expression is satisfied.
  • this converter lens Since this converter lens is mounted on the object side of the main lens to shorten the focal length of the combined optical system of the converter lens and the main lens, the refractive power arrangement of the negative lens group and the positive lens group in order from the object side.
  • the so-called reverse Galileo type is adopted, and the angular magnification of the converter lens is 1 or less.
  • the entrance pupil position is moved closer to the object side by increasing the refractive power of the negative lens group.
  • this negative lens group is composed of a single negative lens, various aberrations occurring here and aberration fluctuations due to manufacturing errors also increase. Therefore, by constructing the negative lens group from two negative lenses and dividing the refractive power, aberration and error sensitivity of each lens can be suppressed while suppressing the outer diameter of the converter lens.
  • the value of the expression (1) exceeds the lower limit, the second lens and the third lens are not too close to each other, so that the refractive power of each lens does not become too strong, and astigmatism and coma generated here. Can be suppressed. In addition, aberration variations due to manufacturing errors can be suppressed.
  • the value of the formula (1) is below the upper limit, the second lens and the third lens are not separated from each other. Therefore, it is possible to suppress an increase in the converter lens by suppressing the total length.
  • the following (1) 'formula, 0.04 ⁇ d4 / d5 ⁇ 0.26 (1) ′ It is more preferable to satisfy
  • the curvature radius of the image side surface of the third lens does not become too small, and various aberrations occurring on this surface can be suppressed.
  • the front principal point position of the third lens is less likely to move toward the image side, the distance between the principal points of the second lens is not excessively widened, and as a result, miniaturization of the converter lens can be maintained by suppressing the overall length. It becomes possible.
  • the value of the expression (2) is below the upper limit, the radius of curvature of the object side surface of the third lens does not become too small, and various aberrations occurring on this surface can be suppressed.
  • the imaging optical system includes the converter lens and the main lens, and the main lens is provided with an aperture stop closer to the object side than the second lens from the object side of the main lens. .
  • the aperture stop of the main lens is disposed in the vicinity of the lens closest to the object side of the main lens, that is, the object side or the image side of the lens closest to the object side of the main lens. More preferably, by placing the front aperture on the object side of the lens closest to the object side, it is possible to keep the light beam passing through the converter lens of off-axis light low, so that the optical dimensions such as the front lens diameter Can be kept small.
  • the main lens may be disposed closer to the image side than the position on the optical axis of the object side surface of the lens closest to the object side and closer to the object side than the most peripheral portion of the object side surface.
  • This mobile terminal is characterized in that the main lens and the image sensor are built in the main body, and the converter lens can be mounted.
  • a converter lens that has a conversion ratio of 0.7 times or less and is sufficiently thin in the thickness direction of the imaging device and has a small diameter, and an imaging optical system and an imaging device used therefor. it can.
  • FIG. 1 is a cross-sectional view of an imaging optical system according to Example 1.
  • FIG. FIG. 4 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) of the imaging optical system of Example 1.
  • FIG. 6 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion aberration (c)) of the main lens. 6 is a cross-sectional view of an imaging optical system according to Example 2.
  • FIG. FIG. 6 is an aberration diagram of Example 2 (spherical aberration (a), astigmatism (b), distortion (c)). 6 is a cross-sectional view of an imaging optical system according to Example 3.
  • FIG. 6 is an aberration diagram of Example 3 (spherical aberration (a), astigmatism (b), distortion (c)). 6 is a cross-sectional view of an imaging optical system according to Example 4.
  • FIG. FIG. 6 is an aberration diagram of Example 4 (spherical aberration (a), astigmatism (b), distortion (c)).
  • 10 is a cross-sectional view of an imaging optical system according to Example 5.
  • FIG. FIG. 6 is an aberration diagram of Example 5 (spherical aberration (a), astigmatism (b), distortion (c)).
  • 10 is a cross-sectional view of an imaging optical system according to Example 6.
  • FIG. FIG. 10 is an aberration diagram of Example 6 (spherical aberration (a), astigmatism (b), distortion (c)).
  • FIG. 10 is a cross-sectional view of an image pickup optical system according to a seventh embodiment.
  • FIG. 10 is an aberration diagram of Example 7 (spherical aberration (a), astigmatism (b), distortion (c)).
  • 10 is a cross-sectional view of an image pickup optical system according to Example 8.
  • FIG. 10 is an aberration diagram of Example 9 (spherical aberration (a), astigmatism (b), distortion (c)).
  • 10 is a cross-sectional view of an image pickup optical system according to Example 9.
  • FIG. 10 is an aberration diagram of Example 9 (spherical aberration (a), astigmatism (b), distortion (c)).
  • FIG. 12 is a cross-sectional view of the imaging optical system according to Example 10.
  • FIG. 10 is an aberration diagram of Example 10 (spherical aberration (a), astigmatism (b), distortion (c)).
  • FIG. 1 is a perspective view showing a state in which the imaging optical system according to the present embodiment is attached to a portable terminal.
  • the mobile terminal SF which is a thin smartphone, has a built-in image pickup apparatus including a main lens ML and an image pickup device (not shown).
  • the main lens ML has its subject side facing the front side (front side in FIG. 1) of the mobile terminal SF.
  • the converter lens CL is arranged in a cylindrical lens barrel HLD attached to a rectangular plate body (main body) BD of the mobile terminal SF.
  • the lens barrel HLD is formed as a separate unit from the body BD and may be attached to the body BD or may be a part of the body BD.
  • the optical axis of the converter lens CL is coincident with the optical axis of the main lens ML.
  • the converter lens CL and the main lens ML constitute an imaging optical system.
  • the converter lens CL has negative refractive power in order from the object side, as shown in FIGS. 2, 5, 7, 9, 11, 13, 15, 15, 17, and 21, which will be described later.
  • a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power and satisfy the following conditional expressions (1) and (2).
  • the parallel light beam incident on the converter lens CL is emitted as a parallel light beam and is incident on the main lens ML.
  • the subject light that has passed through the converter lens CL and the main lens ML is received by the image sensor and converted into an electrical signal. Note that while the converter lens CL is removed, the subject can be imaged only with the main lens ML, but by attaching the converter lens CL, an imaging optical system capable of converting the photographic field angle to the wide angle side is obtained.
  • a monitor (not shown) on the back of the mobile terminal SF displays an image based on an electrical signal output from the image sensor, functions as an electronic viewfinder, and displays a captured image in almost real time. Furthermore, when a user performs a release operation at a timing at which still image shooting is desired, a still image is shot. As a result, the image data is recorded in the memory.
  • the chromatic dispersion of the first lens does not become too large when the value of the expression (4) exceeds the lower limit, axial chromatic aberration that causes the short wavelength to be over or magnification that reduces the image height of the short wavelength. Chromatic aberration can be suppressed small.
  • the chromatic dispersion of the first lens does not become too small when the value of the expression (4) is below the upper limit, the axial chromatic aberration that causes the short wavelength to be under or the image height of the short wavelength is increased. The lateral chromatic aberration can be reduced.
  • the following formula (4) ′, 35 ⁇ 1 ⁇ 45 (4) ′ More preferably, the following (4) ′′ formula: 37 ⁇ 1 ⁇ 43 (4) ′′ If it satisfies, it is more preferable.
  • the chromatic dispersion of the third lens does not become too large because the value of the expression (5) exceeds the lower limit, axial chromatic aberration that causes the short wavelength to be under, and magnification that increases the image height of the short wavelength. Chromatic aberration can be suppressed small.
  • the chromatic dispersion of the third lens does not become too small when the value of the expression (5) is below the upper limit, the axial chromatic aberration that causes the short wavelength to be over or the image height of the short wavelength is reduced. Chromatic aberration of magnification can be kept small.
  • the following (5) 'formula, 30 ⁇ 3 ⁇ 45 (5) ′ It is more preferable to satisfy
  • d2 axial air space between the first lens and the second lens
  • d35 axial distance from the object side surface of the second lens to the image side surface of the third lens
  • the value of the expression (6) exceeds the lower limit, the first lens and the second lens are not too close to each other, so that the refractive power of each lens does not become too strong, and various aberrations occurring here can be suppressed. In addition, it is possible to suppress aberration fluctuations caused by manufacturing errors.
  • the value of the expression (6) is below the upper limit, the first lens and the second lens are not separated from each other, so the diameter of the first lens (front lens diameter) is increased, and the enlargement of the converter lens is prevented. be able to.
  • f1 Focal length of the first lens
  • f2 Focal length of the second lens
  • the refractive power of the second lens does not become too strong, so that various aberrations occurring here can be suppressed.
  • aberration fluctuations caused by manufacturing errors can be reduced, and the front lens diameter can be reduced.
  • the refractive power of the first lens does not become too strong because the value of the expression (7) is below the upper limit, various aberrations occurring here can be suppressed.
  • the first lens has at least an aspheric surface on the object side surface and satisfies the following conditional expression. -25 ⁇ APE1 / ASP1 ⁇ -5 (8)
  • APE1 Effective radius of the object side surface of the first lens
  • ASP1 Aspheric amount at an effective radius of the object side surface of the first lens
  • the “aspheric amount” means an amount expressed by (sag amount of actual shape of lens surface) ⁇ (sag amount by lens surface spherical component).
  • the value of the radius of curvature of the lens surface for obtaining the sag amount by the spherical component of the lens surface is the vicinity of the center of the lens (specifically, the center within 10% of the lens outer diameter) in the actual lens measurement scene.
  • the shape measurement value in (region) can be regarded as the approximate radius of curvature when fitting by the method of least squares.
  • the radius of curvature takes into account the secondary aspherical coefficient in the reference curvature radius of the aspherical definition formula (for example, Matsui as a reference).
  • Matsui as a reference
  • the value of the equation (8) exceeds the lower limit, the aspherical amount of the object side surface of the first lens can be secured, so that distortion, astigmatism, etc. generated on this surface can be corrected well.
  • the first lens preferably has at least an aspheric surface on the image side surface and satisfies the following conditional expression. -90 ⁇ APE2 / ASP2 ⁇ -5 (9) However, APE1: Effective radius of the image side surface of the first lens ASP1: Aspheric amount at an effective radius of the image surface of the first lens
  • the first lens has an aspheric surface on both the object side surface and the image side surface and satisfies the following conditional expression. 1 ⁇ ASP1 / ASP2 ⁇ 8 (10) However, ASP1: Aspheric amount at effective radius of object side surface of first lens ASP2: Aspheric amount at effective radius of image side surface of first lens
  • the imaging optical system can also be mounted on a digital still camera or a video camera.
  • the surface provided with * next to the surface number is a surface having an aspheric shape, and the shape of the aspheric surface has the vertex of the surface as the origin and the X-axis in the optical axis direction.
  • the height in the direction perpendicular to the axis is represented by h as follows.
  • the radius of curvature of the lens surface in this specification is the vicinity of the center of the lens (specifically, The approximate radius of curvature when the shape measurement value in the central region within 10% of the lens outer diameter) is fitted by the method of least squares.
  • the reference radius of curvature of the aspheric definition formula also includes a curvature radius that takes into account the secondary aspheric coefficient.
  • FIG. 2 is a sectional view of the image pickup optical system according to the first embodiment.
  • CL is a converter lens, and in order from the object side, a first lens L1 having a negative refractive power, a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power. Composed.
  • S denotes an aperture stop provided on the object side from the position on the optical axis of the object side surface of the fourth lens L4 on the object side from the most peripheral part of the object side surface
  • IM denotes an image pickup surface of the image pickup apparatus.
  • CG is a cover glass of the main lens ML
  • F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, and the like.
  • the converter lens CL (surface numbers 1 to 6) and the main lens ML (surface numbers 7 to 22) constitute an imaging optical system.
  • the converter lens CL includes only a spherical lens
  • the main lens ML includes an aspheric lens.
  • Example 1 Surface number (aspherical surface) R (mm) d (mm) nd ⁇ d Effective diameter (mm) 1 15.068 0.80 1.83481 42.7 10.90 2 4.905 3.25 8.14 3 42.025 0.70 1.83400 37.3 7.46 4 11.930 0.20 7.05 5 5.804 2.64 1.67270 32.2 6.91 6 -59.293 1.24 5.95 7 ⁇ 0.79 1.51633 64.1 4.15 8 ⁇ 1.24 3.51 9 ⁇ 0.05 1.80 10 (Aperture) ⁇ -0.24 1.80 11 * 1.676 0.63 1.54470 56.2 1.87 12 * -13.857 0.05 1.90 13 * 4.012 0.28 1.63469 23.9 1.92 14 * 1.559 0.57 1.90 15 * -36.876 0.31 1.63469 23.9 2.15 16 * -35.075 0.42 2.46 17 * -6.434 0.86 1.54470 56.2 3.72 18 * -0.965 0.23 4.08 19 * -2.637 0.45 1.53048 55.7
  • FIG. 3 is an aberration diagram of Example 1 (spherical aberration (a), astigmatism (b), distortion aberration (c)), and the aberration diagram is a combination of the converter lens and the main lens.
  • FIG. 4 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) of only the main lens.
  • the dotted line represents the amount of spherical aberration with respect to the g line
  • the solid line represents the amount of spherical aberration with respect to the d line.
  • the solid line S represents the sagittal plane
  • the dotted line M represents the meridional plane (the same applies hereinafter).
  • Example 1 the ratio of the effective diameter of the object side surface of the first lens L1 to the aperture stop diameter of the main lens ML is about 0.17, thereby realizing a compact imaging optical system.
  • FIG. 5 is a sectional view of the image pickup optical system according to the second embodiment.
  • CL is a converter lens, and in order from the object side, a first lens L1 having a negative refractive power, a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power.
  • ML is a main lens, and is composed of a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8 in this order from the object side.
  • S denotes an aperture stop provided on the object side from the position on the optical axis of the object side surface of the fourth lens L4 on the object side from the most peripheral part of the object side surface
  • IM denotes an image pickup surface of the image pickup apparatus.
  • CG is a cover glass of the main lens ML
  • F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, and the like.
  • the converter lens CL surface numbers 1 to 6
  • the main lens ML surface numbers 7 to 22
  • the converter lens CL includes only a spherical lens
  • the main lens ML includes an aspheric lens. Since the main lens ML used in the second embodiment is the same as that used in the first embodiment, the aspheric coefficient is omitted.
  • FIG. 6 is an aberration diagram of Example 2 (spherical aberration (a), astigmatism (b), distortion aberration (c)), and the aberration diagram is a combination of the converter lens and the main lens. .
  • Example 2 the ratio of the effective diameter of the object side surface of the first lens L1 to the aperture stop diameter of the main lens ML is about 0.17, thereby realizing a compact imaging optical system.
  • FIG. 7 is a cross-sectional view of the image pickup optical system according to the third embodiment.
  • CL is a converter lens, and in order from the object side, a first lens L1 having a negative refractive power, a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power.
  • ML is a main lens, and is composed of a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8 in this order from the object side.
  • S denotes an aperture stop provided on the object side from the position on the optical axis of the object side surface of the fourth lens L4 on the object side from the most peripheral part of the object side surface
  • IM denotes an image pickup surface of the image pickup apparatus.
  • CG is a cover glass of the main lens ML
  • F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, and the like.
  • the converter lens CL surface numbers 1 to 6
  • the main lens ML surface numbers 7 to 22
  • the converter lens CL includes only a spherical lens
  • the main lens ML includes an aspheric lens. Since the main lens ML used in the third embodiment is the same as that used in the first embodiment, the aspheric coefficient is omitted.
  • FIG. 8 is an aberration diagram of Example 3 (spherical aberration (a), astigmatism (b), distortion aberration (c)), and the aberration diagram is a state where the converter lens and the main lens are combined. .
  • Example 3 a compact imaging optical system is realized in which the ratio of the effective diameter of the object side surface of the first lens L1 to the aperture stop diameter of the main lens ML is about 0.14.
  • Example 4 Table 4 shows lens data of Example 4.
  • FIG. 9 is a sectional view of the image pickup optical system according to the fourth embodiment.
  • CL is a converter lens, and in order from the object side, a first lens L1 having a negative refractive power, a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power.
  • ML is a main lens, and is composed of a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8 in this order from the object side.
  • S denotes an aperture stop provided on the object side from the position on the optical axis of the object side surface of the fourth lens L4 on the object side from the most peripheral part of the object side surface
  • IM denotes an image pickup surface of the image pickup apparatus.
  • CG is a cover glass of the main lens ML
  • F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, and the like.
  • the converter lens CL surface numbers 1 to 6
  • the main lens ML surface numbers 7 to 22
  • the converter lens CL includes only a spherical lens
  • the main lens ML includes an aspheric lens. Since the main lens ML used in the second embodiment is the same as that used in the first embodiment, the aspheric coefficient is omitted.
  • FIG. 10 is an aberration diagram of Example 4 (spherical aberration (a), astigmatism (b), distortion aberration (c)).
  • the aberration diagram shows a state in which the converter lens and the main lens are combined. .
  • Example 4 the ratio of the effective diameter of the object side surface of the first lens L1 to the aperture stop diameter of the main lens ML is about 0.17, thereby realizing a compact imaging optical system.
  • FIG. 11 is a sectional view of the image pickup optical system according to the fifth embodiment.
  • CL is a converter lens, and in order from the object side, a first lens L1 having a negative refractive power, a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power.
  • ML is a main lens, and is composed of a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8 in this order from the object side.
  • S denotes an aperture stop provided on the object side from the position on the optical axis of the object side surface of the fourth lens L4 on the object side from the most peripheral part of the object side surface
  • IM denotes an image pickup surface of the image pickup apparatus.
  • CG is a cover glass of the main lens ML
  • F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, and the like.
  • the converter lens CL surface numbers 1 to 6
  • the main lens ML surface numbers 7 to 22
  • the converter lens CL includes only a spherical lens
  • the main lens ML includes an aspheric lens. Since the main lens ML used in the fifth embodiment is the same as that used in the first embodiment, the aspheric coefficient is omitted.
  • FIG. 12 is an aberration diagram of Example 5 (spherical aberration (a), astigmatism (b), distortion aberration (c)), and the aberration diagram is a state where the converter lens and the main lens are combined. .
  • Example 5 realizes a compact imaging optical system in which the ratio of the effective diameter of the object side surface of the first lens L1 to the aperture stop diameter of the main lens ML is about 0.17.
  • FIG. 13 is a sectional view of the image pickup optical system according to the sixth embodiment.
  • CL is a converter lens, and in order from the object side, a first lens L1 having a negative refractive power, a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power.
  • ML is a main lens, and is composed of a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8 in this order from the object side.
  • S denotes an aperture stop provided on the object side from the position on the optical axis of the object side surface of the fourth lens L4 on the object side from the most peripheral part of the object side surface
  • IM denotes an image pickup surface of the image pickup apparatus.
  • CG is a cover glass of the main lens ML
  • F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, and the like.
  • the converter lens CL surface numbers 1 to 6
  • the main lens ML surface numbers 7 to 22
  • the converter lens CL includes only a spherical lens
  • the main lens ML includes an aspheric lens. Since the main lens ML used in the sixth embodiment is the same as that used in the first embodiment, the aspheric coefficient is omitted.
  • FIG. 14 is an aberration diagram of Example 6 (spherical aberration (a), astigmatism (b), distortion aberration (c)), and the aberration diagram is a state where the converter lens and the main lens are combined. .
  • Example 6 the ratio of the effective diameter of the object side surface of the first lens L1 to the aperture stop diameter of the main lens ML is about 0.17, thereby realizing a compact imaging optical system.
  • FIG. 15 is a sectional view of the image pickup optical system according to the seventh embodiment.
  • CL is a converter lens, and in order from the object side, a first lens L1 having a negative refractive power, a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power.
  • ML is a main lens, and is composed of a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8 in this order from the object side.
  • S denotes an aperture stop provided on the object side from the position on the optical axis of the object side surface of the fourth lens L4 on the object side from the most peripheral part of the object side surface
  • IM denotes an image pickup surface of the image pickup apparatus.
  • CG is a cover glass of the main lens ML
  • F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, and the like.
  • the converter lens CL surface numbers 1 to 6
  • the main lens ML surface numbers 7 to 22
  • the first lens L1 is an aspheric lens
  • the other lenses are spherical lenses
  • the main lens ML has an aspheric lens. Since the main lens ML used in the seventh embodiment is the same as that used in the first embodiment, the aspheric coefficient is omitted.
  • FIG. 16 is an aberration diagram of Example 7 (spherical aberration (a), astigmatism (b), distortion aberration (c)), and the aberration diagram shows a state in which the converter lens and the main lens are combined. .
  • Example 7 realizes a compact imaging optical system in which the ratio of the effective diameter of the object side surface of the first lens L1 to the aperture stop diameter of the main lens ML is about 0.16.
  • FIG. 17 is a cross-sectional view of the image pickup optical system according to the eighth embodiment.
  • CL is a converter lens, and in order from the object side, a first lens L1 having a negative refractive power, a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power.
  • ML is a main lens, and is composed of a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8 in this order from the object side.
  • S denotes an aperture stop provided on the object side from the position on the optical axis of the object side surface of the fourth lens L4 on the object side from the most peripheral part of the object side surface
  • IM denotes an image pickup surface of the image pickup apparatus.
  • CG is a cover glass of the main lens ML
  • F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, and the like.
  • the converter lens CL surface numbers 1 to 6
  • the main lens ML surface numbers 7 to 22
  • the first lens L1 is an aspheric lens
  • the other lenses are spherical lenses
  • the main lens ML has an aspheric lens. Since the main lens ML used in the eighth embodiment is the same as that used in the first embodiment, the aspheric coefficient is omitted.
  • Example 8 Surface number (aspherical surface) R (mm) d (mm) nd ⁇ d Effective diameter (mm) 1 * 30.226 0.75 1.88202 37.2 10.96 2 * 6.282 2.58 8.48 3 -117.270 0.70 1.78590 43.9 7.98 4 11.258 0.20 7.60 5 7.256 4.34 1.64769 33.8 7.65 6 -11.702 1.24 6.46 7 ⁇ 0.79 1.51633 64.1 4.13 8 ⁇ 1.24 3.50 9 ⁇ 0.05 1.80 10 (Aperture) ⁇ -0.24 1.80 11 * 1.676 0.63 1.54470 56.2 1.87 12 * -13.857 0.05 1.90 13 * 4.012 0.28 1.63469 23.9 1.92 14 * 1.559 0.57 1.90 15 * -36.876 0.31 1.63469 23.9 2.15 16 * -35.075 0.42 2.46 17 * -6.434 0.86 1.54470 56.2 3.74 18 * -0.965 0.23 4.09 19 * -2.637 0.45 1.53048
  • FIG. 18 is an aberration diagram of Example 8 (spherical aberration (a), astigmatism (b), distortion aberration (c)), and the aberration diagram shows a state in which the converter lens and the main lens are combined. .
  • Example 8 the ratio of the effective diameter of the object side surface of the first lens L1 to the aperture stop diameter of the main lens ML is about 0.16, thereby realizing a compact imaging optical system.
  • Example 9 shows lens data of Example 9.
  • FIG. 19 is a cross-sectional view of the image pickup optical system according to the ninth embodiment.
  • CL is a converter lens, and in order from the object side, a first lens L1 having a negative refractive power, a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power.
  • ML is a main lens, and is composed of a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8 in this order from the object side.
  • S denotes an aperture stop provided on the object side from the position on the optical axis of the object side surface of the fourth lens L4 on the object side from the most peripheral part of the object side surface
  • IM denotes an image pickup surface of the image pickup apparatus.
  • CG is a cover glass of the main lens ML
  • F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, and the like.
  • the converter lens CL surface numbers 1 to 6
  • the main lens ML surface numbers 7 to 22
  • the first lens L1 is an aspheric lens
  • the other lenses are spherical lenses
  • the main lens ML has an aspheric lens. Since the main lens ML used in the ninth embodiment is the same as that used in the first embodiment, the aspheric coefficient is omitted.
  • FIG. 20 is an aberration diagram of Example 9 (spherical aberration (a), astigmatism (b), distortion aberration (c)), and the aberration diagram is a state where the converter lens and the main lens are combined. .
  • the ratio of the effective diameter of the object side surface of the first lens L1 to the aperture stop diameter of the main lens ML is about 0.16, thereby realizing a compact imaging optical system.
  • FIG. 21 is a sectional view of the image pickup optical system according to the tenth embodiment.
  • CL is a converter lens, and in order from the object side, a first lens L1 having a negative refractive power, a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power.
  • ML is a main lens, and is composed of a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8 in this order from the object side.
  • S denotes an aperture stop provided on the object side from the position on the optical axis of the object side surface of the fourth lens L4 on the object side from the most peripheral part of the object side surface
  • IM denotes an image pickup surface of the image pickup apparatus.
  • CG is a cover glass of the main lens ML
  • F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, and the like.
  • the converter lens CL surface numbers 1 to 6
  • the main lens ML surface numbers 7 to 22
  • the converter lens CL has an aspheric object side surface of the first lens L1 and a spherical surface other than that, and the main lens ML has an aspheric lens. Since the main lens ML used in the tenth embodiment is the same as that used in the first embodiment, the aspheric coefficient is omitted.
  • FIG. 22 is an aberration diagram of Example 10 (spherical aberration (a), astigmatism (b), distortion aberration (c)), and the aberration diagram shows a state in which the converter lens and the main lens are combined. .
  • Example 10 realizes a compact imaging optical system in which the ratio of the effective diameter of the object side surface of the first lens L1 to the aperture stop diameter of the main lens ML is about 0.16.
  • Table 11 shows values of each example corresponding to each conditional expression.
  • the present invention is not limited to the embodiments and examples described in the specification, and includes other embodiments, examples, and modified examples. It will be apparent to those skilled in the art from the technical idea. For example, even when a dummy lens having substantially no power is further provided, it is within the scope of the present invention.

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Abstract

Provided are a converter lens which, while having a conversion ratio of 0.7x or less, is sufficiently thin with respect to the thickness direction of an image capture device and has a small diameter as well, and an image capture optical assembly and an image capture device wherein said converter lens is employed. A converter lens (CL) is configured, in order from the object side, from a first lens (L1) having a negative refractive power, a second lens (L2) having a negative refractive power, and a third lens (L3) having a positive refractive power, and satisfies the following conditional formulae: 0.4<d4/d5<0.3 (1), 0.1<(R6+R5)/(R6-R5)<2.0 (2), where d4 is an axial air gap between the second lens and the third lens, d5 is an axial thickness of the third lens, R5 is a radius of curvature of the object-side face of the third lens, and R6 is a radius of curvature of the image-side face of the third lens.

Description

コンバータレンズ、撮像光学系及び携帯端末Converter lens, imaging optical system, and portable terminal
　本発明は、主レンズより物体側に装着され、主レンズの撮影画角を広角側に変換するコンバータレンズ、撮像光学系及び携帯端末に関する。 The present invention relates to a converter lens, an imaging optical system, and a mobile terminal that are mounted on the object side of the main lens and convert the photographing field angle of the main lens to the wide angle side.
　近年、スマートフォンをはじめとする携帯端末が発売され、急速に市場が拡大している。かかる携帯端末は、一般的に撮像装置を搭載し、これにより撮像した画像を転送したり、携帯端末上で画像処理を行うなど種々の用い方がなされている。しかるに、一般的な携帯端末は薄形であることから、それに内蔵される撮像装置はコンパクト化が厳しく要求される。従って、従来の携帯端末に搭載されている撮像装置には、通常は単焦点の光学系が搭載されている。しかしながら、ユーザーによっては、より広範囲な被写体を撮像したい等の要望がある。 In recent years, mobile terminals such as smartphones have been released, and the market is rapidly expanding. Such a portable terminal is generally mounted with an imaging device, and is used in various ways such as transferring an image captured by the imaging device or performing image processing on the portable terminal. However, since a general portable terminal is thin, an imaging device incorporated therein is strictly required to be compact. Accordingly, a single-focus optical system is usually mounted on an imaging device mounted on a conventional portable terminal. However, some users have a desire to image a wider range of subjects.
　このような要望に対し、撮影装置に設けられた撮影レンズ（主レンズ）の前方に位置させることで、撮影レンズの焦点距離を広角側に変化させることのできるコンバータレンズが、特許文献１、２に開示されている。 In response to such a demand, a converter lens that can change the focal length of the photographic lens to the wide-angle side by positioning it in front of the photographic lens (main lens) provided in the photographing apparatus is disclosed in Patent Documents 1 and 2. Is disclosed.
特許第４５５７３５５号明細書Japanese Patent No. 4557355 特許第２９９７０２６号明細書Japanese Patent No. 2997026
　しかしながら、上記特許文献１、２のコンバータレンズは光学系の全長や径寸法が大きく、携帯端末に装着して使用できる程度に十分なコンパクト性を満たしているとは言い難い。コンパクト性を満たすには、全長及び径寸法を極力抑えることが必要とされる。 However, the converter lenses disclosed in Patent Documents 1 and 2 have a large overall optical system length and diameter, and it is difficult to say that they are sufficiently compact to be mounted on a portable terminal and used. In order to satisfy the compactness, it is necessary to suppress the overall length and diameter as much as possible.
　本発明は、かかる問題点に鑑み、０．７倍以下の変換比を持ちながらも撮像装置の厚み方向に対し十分に薄く、径寸法も小さいコンバータレンズ、及びそれに用いる撮像光学系並びに撮像装置を提供することを目的とする。 In view of such a problem, the present invention provides a converter lens having a conversion ratio of 0.7 times or less and sufficiently thin in the thickness direction of the imaging device and having a small diameter, and an imaging optical system and an imaging device used therefor. The purpose is to provide.
　上述した目的のうち少なくとも一つを実現するために、本発明の一側面を反映したコンバータレンズは、主レンズより物体側に装着され、前記主レンズの撮影画角を広角側に変換するコンバータレンズにおいて、
　前記コンバータレンズは物体側から順に、負の屈折力を有する第１レンズと、負の屈折力を有する第２レンズと、正の屈折力を有する第３レンズから構成され、
　以下の条件式を満たすことを特徴とする。
　０．０４＜ｄ４／ｄ５＜０．３　　　　　　　　　　　　（１）
　０．１＜（Ｒ６＋Ｒ５）／（Ｒ６－Ｒ５）＜２．０　　　（２）
ただし、
ｄ４：前記第２レンズと前記第３レンズの軸上空気間隔
ｄ５：前記第３レンズの軸上厚
Ｒ５：前記第３レンズの物体側面の曲率半径
Ｒ６：前記第３レンズの像側面の曲率半径 In order to achieve at least one of the objects described above, a converter lens reflecting one aspect of the present invention is mounted on the object side of the main lens, and converts the shooting field angle of the main lens to the wide angle side. In
The converter lens includes, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, and a third lens having positive refractive power,
The following conditional expression is satisfied.
0.04 <d4 / d5 <0.3 (1)
0.1 <(R6 + R5) / (R6-R5) <2.0 (2)
However,
d4: On-axis air space between the second lens and the third lens d5: On-axis thickness of the third lens R5: Curvature radius of the object side surface of the third lens R6: Radius of curvature of the image side surface of the third lens
　本コンバータレンズは、主レンズの物体側に装着することでコンバータレンズと主レンズの合成光学系の焦点距離を短くするため、物体側から順に、負レンズ群、正レンズ群の屈折力配置とする、いわゆる逆ガリレオ型を採用し、コンバータレンズの角倍率を１以下としている。このとき、コンバータレンズの中で最も外径が大きくなりがちな前玉径等の光学寸法を小さくするには、前記負レンズ群の屈折力を強くすることで入射瞳位置を物体側に寄せることが考えられる。しかし、この負レンズ群を１枚の負レンズで構成してしまうと、ここで発生する諸収差や製造誤差による収差変動も増大してしまう。そこで負レンズ群を２枚の負レンズから構成し、屈折力を分割させることで、コンバータレンズの外径を抑えつつ、各レンズにおける収差や誤差感度を抑制することができるのである。 Since this converter lens is mounted on the object side of the main lens to shorten the focal length of the combined optical system of the converter lens and the main lens, the refractive power arrangement of the negative lens group and the positive lens group in order from the object side. The so-called reverse Galileo type is adopted, and the angular magnification of the converter lens is 1 or less. At this time, in order to reduce the optical dimension such as the front lens diameter that tends to be the largest in the converter lens, the entrance pupil position is moved closer to the object side by increasing the refractive power of the negative lens group. Can be considered. However, if this negative lens group is composed of a single negative lens, various aberrations occurring here and aberration fluctuations due to manufacturing errors also increase. Therefore, by constructing the negative lens group from two negative lenses and dividing the refractive power, aberration and error sensitivity of each lens can be suppressed while suppressing the outer diameter of the converter lens.
　さらに（１）式の値が下限を上回ることで、第２レンズと第３レンズが接近し過ぎないので、互いのレンズの屈折力が強くなり過ぎず、ここで発生する非点収差やコマ収差を抑制することが可能となる。また、製造誤差による収差変動を抑えることができる。一方、（１）式の値が上限を下回ることで、第２レンズと第３レンズが離れ過ぎないため、全長を抑えることでコンバータレンズが大きくなることを抑制できる。以下の（１）′式、
　０．０４＜ｄ４／ｄ５＜０．２６　　　　　（１）′
を満たすと、より好ましい。 Further, since the value of the expression (1) exceeds the lower limit, the second lens and the third lens are not too close to each other, so that the refractive power of each lens does not become too strong, and astigmatism and coma generated here. Can be suppressed. In addition, aberration variations due to manufacturing errors can be suppressed. On the other hand, since the value of the formula (1) is below the upper limit, the second lens and the third lens are not separated from each other. Therefore, it is possible to suppress an increase in the converter lens by suppressing the total length. The following (1) 'formula,
0.04 <d4 / d5 <0.26 (1) ′
It is more preferable to satisfy
　更に、（２）式の値が下限を上回ることで、第３レンズの像側面の曲率半径が小さくなり過ぎず、この面で発生する諸収差を抑制できる。加えて、第３レンズの前側主点位置が像側に寄りにくくなり、第２レンズとの主点間隔が広がり過ぎず、その結果、全長を抑えることでコンバータレンズの小型化を維持することが可能となる。一方、（２）式の値が上限を下回ることで、第３レンズの物体側面の曲率半径が小さくなり過ぎず、この面で発生する諸収差を抑制することができる。以下の（２）′式、
　０．１５＜（Ｒ６＋Ｒ５）／（Ｒ６－Ｒ５）＜１．５　　　（２）′
を満たすと、より好ましく、以下の（２）″式、
　０．２＜（Ｒ６＋Ｒ５）／（Ｒ６－Ｒ５）＜０．８５　　　（２）″
を満たすと、更に好ましい。 Furthermore, when the value of the expression (2) exceeds the lower limit, the curvature radius of the image side surface of the third lens does not become too small, and various aberrations occurring on this surface can be suppressed. In addition, the front principal point position of the third lens is less likely to move toward the image side, the distance between the principal points of the second lens is not excessively widened, and as a result, miniaturization of the converter lens can be maintained by suppressing the overall length. It becomes possible. On the other hand, when the value of the expression (2) is below the upper limit, the radius of curvature of the object side surface of the third lens does not become too small, and various aberrations occurring on this surface can be suppressed. The following (2) 'formula,
0.15 <(R6 + R5) / (R6-R5) <1.5 (2) ′
More preferably, the following (2) ″ formula:
0.2 <(R6 + R5) / (R6-R5) <0.85 (2) ″
If it satisfies, it is more preferable.
　本撮像光学系は、上記コンバータレンズと、前記主レンズとからなり、前記主レンズは、前記主レンズの物体側から２番目のレンズより物体側に開口絞りが設けられていることを特徴とする。 The imaging optical system includes the converter lens and the main lens, and the main lens is provided with an aperture stop closer to the object side than the second lens from the object side of the main lens. .
　主レンズの開口絞りは、主レンズの最も物体側のレンズ近傍、すなわち主レンズの最も物体側のレンズの物体側又は像側に配置されていると好ましい。より好ましくは最も物体側のレンズの物体側に配置して前置絞りとすることにより、軸外光のコンバータレンズでの光線通過高さを低く抑えることができるため、前玉径等の光学寸法を小さく抑えることが可能となる。尚、主レンズの最も物体側のレンズの物体側面の光軸上の位置より像側であって、物体側面の最周辺部より物体側に配置されていても良い。 It is preferable that the aperture stop of the main lens is disposed in the vicinity of the lens closest to the object side of the main lens, that is, the object side or the image side of the lens closest to the object side of the main lens. More preferably, by placing the front aperture on the object side of the lens closest to the object side, it is possible to keep the light beam passing through the converter lens of off-axis light low, so that the optical dimensions such as the front lens diameter Can be kept small. The main lens may be disposed closer to the image side than the position on the optical axis of the object side surface of the lens closest to the object side and closer to the object side than the most peripheral portion of the object side surface.
　本携帯端末は、前記主レンズと撮像素子を本体内に内蔵し、上記コンバータレンズが装着可能となされたことを特徴とする。 This mobile terminal is characterized in that the main lens and the image sensor are built in the main body, and the converter lens can be mounted.
　コンパクトな外観形状で、主レンズよりも広角の撮影が可能な携帯端末を提供することが可能となる。 It is possible to provide a portable terminal that can take a wider angle than the main lens with a compact appearance.
　本発明によれば、０．７倍以下の変換比を持ちながらも撮像装置の厚み方向に対し十分に薄く、径寸法も小さいコンバータレンズ、及びそれに用いる撮像光学系並びに撮像装置を提供することができる。 According to the present invention, it is possible to provide a converter lens that has a conversion ratio of 0.7 times or less and is sufficiently thin in the thickness direction of the imaging device and has a small diameter, and an imaging optical system and an imaging device used therefor. it can.
本実施形態にかかる撮像光学系を携帯端末に取り付けた状態を示す斜視図である。It is a perspective view which shows the state which attached the imaging optical system concerning this embodiment to the portable terminal. 実施例１の撮像光学系の断面図である。1 is a cross-sectional view of an imaging optical system according to Example 1. FIG. 実施例１の撮像光学系の収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））である。FIG. 4 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) of the imaging optical system of Example 1. 主レンズの収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））である。FIG. 6 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion aberration (c)) of the main lens. 実施例２の撮像光学系の断面図である。6 is a cross-sectional view of an imaging optical system according to Example 2. FIG. 実施例２の収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））である。FIG. 6 is an aberration diagram of Example 2 (spherical aberration (a), astigmatism (b), distortion (c)). 実施例３の撮像光学系の断面図である。6 is a cross-sectional view of an imaging optical system according to Example 3. FIG. 実施例３の収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））である。FIG. 6 is an aberration diagram of Example 3 (spherical aberration (a), astigmatism (b), distortion (c)). 実施例４の撮像光学系の断面図である。6 is a cross-sectional view of an imaging optical system according to Example 4. FIG. 実施例４の収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））である。FIG. 6 is an aberration diagram of Example 4 (spherical aberration (a), astigmatism (b), distortion (c)). 実施例５の撮像光学系の断面図である。10 is a cross-sectional view of an imaging optical system according to Example 5. FIG. 実施例５の収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））である。FIG. 6 is an aberration diagram of Example 5 (spherical aberration (a), astigmatism (b), distortion (c)). 実施例６の撮像光学系の断面図である。10 is a cross-sectional view of an imaging optical system according to Example 6. FIG. 実施例６の収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））である。FIG. 10 is an aberration diagram of Example 6 (spherical aberration (a), astigmatism (b), distortion (c)). 実施例７の撮像光学系の断面図である。FIG. 10 is a cross-sectional view of an image pickup optical system according to a seventh embodiment. 実施例７の収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））である。FIG. 10 is an aberration diagram of Example 7 (spherical aberration (a), astigmatism (b), distortion (c)). 実施例８の撮像光学系の断面図である。10 is a cross-sectional view of an image pickup optical system according to Example 8. FIG. 実施例９の収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））である。FIG. 10 is an aberration diagram of Example 9 (spherical aberration (a), astigmatism (b), distortion (c)). 実施例９の撮像光学系の断面図である。10 is a cross-sectional view of an image pickup optical system according to Example 9. FIG. 実施例９の収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））である。FIG. 10 is an aberration diagram of Example 9 (spherical aberration (a), astigmatism (b), distortion (c)). 実施例１０の撮像光学系の断面図である。FIG. 12 is a cross-sectional view of the imaging optical system according to Example 10. 実施例１０の収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））である。FIG. 10 is an aberration diagram of Example 10 (spherical aberration (a), astigmatism (b), distortion (c)).
　以下、本発明の実施形態を図面に基づいて説明する。図１は、本実施形態にかかる撮像光学系を携帯端末に取り付けた状態を示す斜視図である。例えば薄形のスマートフォンである携帯端末ＳＦは、主レンズＭＬと不図示の撮像素子とを備えた撮像装置を内蔵している。主レンズＭＬは、その被写体側面を携帯端末ＳＦの前方側（図１で手前側）に向けている。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a state in which the imaging optical system according to the present embodiment is attached to a portable terminal. For example, the mobile terminal SF, which is a thin smartphone, has a built-in image pickup apparatus including a main lens ML and an image pickup device (not shown). The main lens ML has its subject side facing the front side (front side in FIG. 1) of the mobile terminal SF.
　コンバータレンズＣＬは、携帯端末ＳＦの矩形板状のボディ（本体）ＢＤに取り付けた筒状の鏡筒ＨＬＤ内に配置されている。尚、鏡筒ＨＬＤは、ボディＢＤと別ユニットとして形成され、ボディＢＤに装着されていても良いし、ボディＢＤの一部であっても良い。コンバータレンズＣＬの光軸と、主レンズＭＬの光軸は一致している。コンバータレンズＣＬと主レンズＭＬとで撮像光学系を構成する。 The converter lens CL is arranged in a cylindrical lens barrel HLD attached to a rectangular plate body (main body) BD of the mobile terminal SF. The lens barrel HLD is formed as a separate unit from the body BD and may be attached to the body BD or may be a part of the body BD. The optical axis of the converter lens CL is coincident with the optical axis of the main lens ML. The converter lens CL and the main lens ML constitute an imaging optical system.
　コンバータレンズＣＬは、後述の図２，図５，図７，図９，図１１，図１３，図１５，図１７，図１９，図２１に示すように、物体側から順に、負の屈折力を有する第１レンズＬ１と、負の屈折力を有する第２レンズＬ２と、正の屈折力を有する第３レンズＬ３から構成され、次の条件式（１）（２）を満たす。
　０．０４＜ｄ４／ｄ５＜０．３　　　　　　　　　　　　（１）
　０．１＜（Ｒ６＋Ｒ５）／（Ｒ６－Ｒ５）＜２．０　　　（２）
ただし、
ｄ４：第２レンズＬ２と第３レンズＬ３の軸上空気間隔
ｄ５：第３レンズＬ３の軸上厚
Ｒ５：第３レンズＬ３の物体側面の曲率半径
Ｒ６：第３レンズＬ３の像側面の曲率半径 The converter lens CL has negative refractive power in order from the object side, as shown in FIGS. 2, 5, 7, 9, 11, 13, 15, 15, 17, and 21, which will be described later. , A second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power, and satisfy the following conditional expressions (1) and (2).
0.04 <d4 / d5 <0.3 (1)
0.1 <(R6 + R5) / (R6-R5) <2.0 (2)
However,
d4: axial air space between the second lens L2 and the third lens L3 d5: axial thickness of the third lens L3 R5: radius of curvature of the object side surface of the third lens L3 R6: radius of curvature of the image side surface of the third lens L3
　コンバータレンズＣＬに入射した平行光束は、平行光束で出射され、主レンズＭＬに入射するようになっている。コンバータレンズＣＬ及び主レンズＭＬを通過した被写体光は、撮像素子に受光されて電気信号に変換される。尚、コンバータレンズＣＬを取り外した状態で、主レンズＭＬのみでも被写体を撮像することができるが、コンバータレンズＣＬを取り付けることで、撮影画角を広角側に変換できる撮像光学系となる。 The parallel light beam incident on the converter lens CL is emitted as a parallel light beam and is incident on the main lens ML. The subject light that has passed through the converter lens CL and the main lens ML is received by the image sensor and converted into an electrical signal. Note that while the converter lens CL is removed, the subject can be imaged only with the main lens ML, but by attaching the converter lens CL, an imaging optical system capable of converting the photographic field angle to the wide angle side is obtained.
　携帯端末ＳＦ背面のモニタ（不図示）は、撮像素子から出力された電気信号に基づいて画像表示を行い、電子ファインダとして機能し、撮像画像を、ほぼリアルタイムに表示する。更に、静止画撮影を行ないたいタイミングで、ユーザーがレリーズ操作を行うことにより、静止画像が撮影される。これにより画像データがメモリに記録される。 A monitor (not shown) on the back of the mobile terminal SF displays an image based on an electrical signal output from the image sensor, functions as an electronic viewfinder, and displays a captured image in almost real time. Furthermore, when a user performs a release operation at a timing at which still image shooting is desired, a still image is shot. As a result, the image data is recorded in the memory.
　以下、好ましい実施態様についてさらに説明する。 Hereinafter, preferred embodiments will be further described.
　上記コンバータレンズにおいて、以下の条件式を満たすことが好ましい。
　ｎ１＞１．７　　　　　　　　　　　　　　　　　　　（３）
ただし、
ｎ１：前記第１レンズの屈折率 In the converter lens, it is preferable that the following conditional expression is satisfied.
n1> 1.7 (3)
However,
n1: Refractive index of the first lens
　（３）式を満たすことにより、第１レンズにおいて十分な高屈折率が得られるため、同じ屈折力のレンズであっても曲率半径を大きくすることができ、その結果、外径を抑えながらも第１レンズで発生する歪曲収差や非点収差等を抑制することが可能となる。以下の（３）′式、
　ｎ１＞１．８　　　　　　　　　　　　（３）′
を満たすと、より好ましい。 By satisfying the expression (3), a sufficiently high refractive index can be obtained in the first lens. Therefore, even with a lens having the same refractive power, the radius of curvature can be increased, and as a result, the outer diameter is suppressed. It becomes possible to suppress distortion, astigmatism, and the like that occur in the first lens. The following (3) 'formula,
n1> 1.8 (3) ′
It is more preferable to satisfy
　また、以下の条件式を満たすことが好ましい。
　３０＜ν１＜５０　　　　　　　　　　　　　　　　　（４）
ただし
ν１：前記第１レンズのアッベ数 Moreover, it is preferable to satisfy the following conditional expressions.
30 <ν1 <50 (4)
Where ν1: Abbe number of the first lens
　（４）式の値が下限を上回ることで、第１レンズの色分散が大きくなり過ぎないので、短波長がオーバーとなるような軸上色収差や、短波長の像高が低くなるような倍率色収差を小さく抑えることが可能となる。一方、（４）式の値が上限を下回ることで第１レンズの色分散が小さくなり過ぎないので、短波長がアンダーとなるような軸上色収差や、短波長の像高が高くなるような倍率色収差を小さく抑えることができる。以下の（４）′式、　３５＜ν１＜４５　　　　　　（４）′
を満たすと、より好ましく、以下の（４）″式、
　３７＜ν１＜４３　　　　　　（４）″
を満たすと、更に好ましい。 Since the chromatic dispersion of the first lens does not become too large when the value of the expression (4) exceeds the lower limit, axial chromatic aberration that causes the short wavelength to be over or magnification that reduces the image height of the short wavelength. Chromatic aberration can be suppressed small. On the other hand, since the chromatic dispersion of the first lens does not become too small when the value of the expression (4) is below the upper limit, the axial chromatic aberration that causes the short wavelength to be under or the image height of the short wavelength is increased. The lateral chromatic aberration can be reduced. The following formula (4) ′, 35 <ν1 <45 (4) ′
More preferably, the following (4) ″ formula:
37 <ν1 <43 (4) ″
If it satisfies, it is more preferable.
　また、以下の条件式を満たすことが好ましい。
　２５＜ν３＜５０　　　　　　　　　　　　　　　　　（５）
ただし、
ν３：前記第３レンズのアッベ数 Moreover, it is preferable to satisfy the following conditional expressions.
25 <ν3 <50 (5)
However,
ν3: Abbe number of the third lens
　（５）式の値が下限を上回ることで、第３レンズの色分散が大きくなり過ぎないので、短波長がアンダーとなるような軸上色収差や、短波長の像高が高くなるような倍率色収差を小さく抑えることが可能となる。一方、（５）式の値が上限を下回ることで、第３レンズの色分散が小さくなり過ぎないので、短波長がオーバーとなるような軸上色収差や、短波長の像高が低くなるような倍率色収差を小さく抑えることができる。以下の（５）′式、
　３０＜ν３＜４５　　　　　　　（５）′
を満たすと、より好ましい。 Since the chromatic dispersion of the third lens does not become too large because the value of the expression (5) exceeds the lower limit, axial chromatic aberration that causes the short wavelength to be under, and magnification that increases the image height of the short wavelength. Chromatic aberration can be suppressed small. On the other hand, since the chromatic dispersion of the third lens does not become too small when the value of the expression (5) is below the upper limit, the axial chromatic aberration that causes the short wavelength to be over or the image height of the short wavelength is reduced. Chromatic aberration of magnification can be kept small. The following (5) 'formula,
30 <ν3 <45 (5) ′
It is more preferable to satisfy
　また、以下の条件式を満たすことが好ましい。
　０．０５＜ｄ２／ｄ３５＜２．０　　　　　　　　　　（６）
ただし、
ｄ２：前記第１レンズと前記第２レンズの軸上空気間隔
ｄ３５：前記第２レンズの物体側面から前記第３レンズの像側面までの軸上距離 Moreover, it is preferable to satisfy the following conditional expressions.
0.05 <d2 / d35 <2.0 (6)
However,
d2: axial air space between the first lens and the second lens d35: axial distance from the object side surface of the second lens to the image side surface of the third lens
　（６）式の値が下限を上回ることで、第１レンズと第２レンズが接近し過ぎないので、互いのレンズの屈折力が強くなり過ぎず、ここで発生する諸収差を抑えられる。また、製造誤差に起因する収差変動を小さく抑えることが可能になる。一方、（６）式の値が上限を下回ることで、第１レンズと第２レンズが離れ過ぎないので、第１レンズの径（前玉径）が大きくなる等、コンバータレンズの大型化を防ぐことができる。以下の（６）′式、　０．０５＜ｄ２／ｄ３５＜１．５　　　　（６）′
を満たすと、より好ましく、以下の（６）″式、
　０．１　＜ｄ２／ｄ３５＜０．９５　　　（６）″
を満たすと、更に好ましい。 When the value of the expression (6) exceeds the lower limit, the first lens and the second lens are not too close to each other, so that the refractive power of each lens does not become too strong, and various aberrations occurring here can be suppressed. In addition, it is possible to suppress aberration fluctuations caused by manufacturing errors. On the other hand, since the value of the expression (6) is below the upper limit, the first lens and the second lens are not separated from each other, so the diameter of the first lens (front lens diameter) is increased, and the enlargement of the converter lens is prevented. be able to. The following formula (6) ′, 0.05 <d2 / d35 <1.5 (6) ′
More preferably, the following (6) ″ formula:
0.1 <d2 / d35 <0.95 (6) ″
If it satisfies, it is more preferable.
　また、以下の条件式を満たすことが好ましい。
　０．５＜ｆ２／ｆ１＜１０　　　　　　　　　　　　（７）
ただし、
ｆ１：前記第１レンズの焦点距離
ｆ２：前記第２レンズの焦点距離 Moreover, it is preferable to satisfy the following conditional expressions.
0.5 <f2 / f1 <10 (7)
However,
f1: Focal length of the first lens f2: Focal length of the second lens
　（７）式の値が下限を上回ることで、第２レンズの屈折力が強くなり過ぎないので、ここで発生する諸収差を抑制できる。また、製造誤差に起因する収差変動を小さくすることができ、さらに、前玉径を小さくすることも可能である。一方、（７）式の値が上限を下回ることで、第１レンズの屈折力が強くなり過ぎないので、ここで発生する諸収差を抑制できる。また、製造誤差に起因する収差変動を小さくすることができる。以下の（７）′式、
　０．７＜ｆ２／ｆ１＜８．５　　　　　　　（７）′
を満たすと、より好ましく、以下の（７）″式、
　０．９＜ｆ２／ｆ１＜７．７　　　　　　　（７）″
を満たすと、更に好ましい。 When the value of the expression (7) exceeds the lower limit, the refractive power of the second lens does not become too strong, so that various aberrations occurring here can be suppressed. In addition, aberration fluctuations caused by manufacturing errors can be reduced, and the front lens diameter can be reduced. On the other hand, since the refractive power of the first lens does not become too strong because the value of the expression (7) is below the upper limit, various aberrations occurring here can be suppressed. In addition, it is possible to reduce aberration fluctuations caused by manufacturing errors. The following (7) 'formula,
0.7 <f2 / f1 <8.5 (7) ′
More preferably, the following (7) ″ formula:
0.9 <f2 / f1 <7.7 (7) ″
If it satisfies, it is more preferable.
　また、前記第１レンズは少なくとも物体側面に非球面を有し、以下の条件式を満たすことが好ましい。
　－２５＜ＡＰＥ１／ＡＳＰ１＜－５　　　　　　　（８）
ただし、
ＡＰＥ１：前記第１レンズの物体側面の有効半径
ＡＳＰ１：前記第１レンズの物体側面の有効半径における非球面量 Moreover, it is preferable that the first lens has at least an aspheric surface on the object side surface and satisfies the following conditional expression.
-25 <APE1 / ASP1 <-5 (8)
However,
APE1: Effective radius of the object side surface of the first lens ASP1: Aspheric amount at an effective radius of the object side surface of the first lens
　ここで、「非球面量」とは、（レンズ面実形状のサグ量）－（レンズ面球面成分によるサグ量）で表される量をいう。なお、レンズ面球面成分によるサグ量を求めるためのレンズ面曲率半径の値は、実際のレンズ測定の場面においては、レンズ中央近傍（具体的には、レンズ外径に対して１０％以内の中央領域）での形状測定値を、最小自乗法でフィッティングした際の近似曲率半径であるとみなすことができる。また、例えば２次の非球面係数を使用した場合には、非球面定義式の基準曲率半径に２次の非球面係数も勘案した曲率半径であるとみなすことができる（例えば参考文献として、松居吉哉著「レンズ設計法」（共立出版株式会社）のＰ４１～４２を参照のこと）。（８）式の値が下限を上回ることで、第１レンズの物体側面の非球面量を確保できるので、この面で発生する歪曲収差や非点収差等を良好に補正することができる。一方、（８）式の値が上限を下回ることで非球面量が多くなり過ぎないので、この面が偏芯した際の収差変動を抑制することができる。以下の（８）′式、
　－２１＜ＡＰＥ１／ＡＳＰ１＜－７　　　　　　　（８）′
を満たすと、より好ましい。 Here, the “aspheric amount” means an amount expressed by (sag amount of actual shape of lens surface) − (sag amount by lens surface spherical component). The value of the radius of curvature of the lens surface for obtaining the sag amount by the spherical component of the lens surface is the vicinity of the center of the lens (specifically, the center within 10% of the lens outer diameter) in the actual lens measurement scene. The shape measurement value in (region) can be regarded as the approximate radius of curvature when fitting by the method of least squares. For example, when a secondary aspherical coefficient is used, it can be considered that the radius of curvature takes into account the secondary aspherical coefficient in the reference curvature radius of the aspherical definition formula (for example, Matsui as a reference). (See pages 41-42 of Yoshiya's "Lens Design Method" (Kyoritsu Publishing Co., Ltd.)). Since the value of the equation (8) exceeds the lower limit, the aspherical amount of the object side surface of the first lens can be secured, so that distortion, astigmatism, etc. generated on this surface can be corrected well. On the other hand, since the amount of the aspherical surface does not increase excessively when the value of the expression (8) is less than the upper limit, fluctuations in aberrations when this surface is decentered can be suppressed. The following (8) 'formula,
−21 <APE1 / ASP1 <−7 (8) ′
It is more preferable to satisfy
　また、前記第１レンズは少なくとも像側面に非球面を有し、以下の条件式を満たすことが好ましい。
　－９０＜ＡＰＥ２／ＡＳＰ２＜－５　　　　　　　　　（９）
ただし、
ＡＰＥ１：前記第１レンズの像側面の有効半径
ＡＳＰ１：前記第１レンズの像面の有効半径における非球面量 The first lens preferably has at least an aspheric surface on the image side surface and satisfies the following conditional expression.
-90 <APE2 / ASP2 <-5 (9)
However,
APE1: Effective radius of the image side surface of the first lens ASP1: Aspheric amount at an effective radius of the image surface of the first lens
　（９）式の値が下限を上回ることで、第１レンズの像側面の非球面量を確保できるので、この面で発生する歪曲収差や非点収差等を良好に補正することができる。一方、（９）式の値が上限を下回ることで第１レンズの非球面量が多くなり過ぎないので、この面が偏芯した際の収差変動を抑制することができる。以下の（９）′式、
　－８５＜ＡＰＥ２／ＡＳＰ２＜－８　　　　　　　（９）′
を満たすと、より好ましい。 When the value of the expression (9) exceeds the lower limit, the aspheric amount on the image side surface of the first lens can be secured, and therefore, distortion aberration, astigmatism, etc. occurring on this surface can be corrected well. On the other hand, since the amount of the aspherical surface of the first lens does not increase too much because the value of the expression (9) is below the upper limit, it is possible to suppress aberration fluctuations when this surface is decentered. The following (9) 'formula,
-85 <APE2 / ASP2 <-8 (9) '
It is more preferable to satisfy
　また、前記第１レンズは物体側面と像側面何れにも非球面を有し、以下の条件式を満たすことが好ましい。
　１＜ＡＳＰ１／ＡＳＰ２＜８　　　　　　　（１０）
ただし、
ＡＳＰ１：前記第１レンズの物体側面の有効半径における非球面量
ＡＳＰ２：前記第１レンズの像側面の有効半径における非球面量 Further, it is preferable that the first lens has an aspheric surface on both the object side surface and the image side surface and satisfies the following conditional expression.
1 <ASP1 / ASP2 <8 (10)
However,
ASP1: Aspheric amount at effective radius of object side surface of first lens ASP2: Aspheric amount at effective radius of image side surface of first lens
　（１０）式の値が下限を上回ることで、第１レンズの像側面の非球面量が多くなり過ぎないので、この面が偏芯した際の収差変動を抑制できる。一方、（１０）式の値が上限を下回ることで、第１レンズの物体側面の非球面量が多くなり過ぎないので、この面が偏芯した際の収差変動を抑制できる。以下の（１０）′式、
　１．４＜ＡＳＰ１／ＡＳＰ２＜７．１　　　　　　　（１０）′
を満たすと、より好ましい。 Since the value of the expression (10) exceeds the lower limit, the amount of aspherical surface on the image side surface of the first lens does not increase excessively, so that aberration fluctuation when this surface is decentered can be suppressed. On the other hand, since the value of the expression (10) is less than the upper limit, the amount of aspherical surface on the object side surface of the first lens does not increase too much, so that aberration fluctuation when this surface is decentered can be suppressed. The following (10) 'formula,
1.4 <ASP1 / ASP2 <7.1 (10) ′
It is more preferable to satisfy
　なお、上記実施形態及び各実施例における記述は、本発明に係る好適な例であり、これに限定されるものではない。又、本撮像光学系はデジタルスチルカメラやビデオカメラにも搭載可能である。 In addition, the description in the said embodiment and each Example is a suitable example which concerns on this invention, and is not limited to this. The imaging optical system can also be mounted on a digital still camera or a video camera.
（実施例）
　次に、上述した実施形態に好適な実施例について説明する。但し、以下に示す実施例により本発明が限定されるものではない。
ｆ　：全系の焦点距離（ｍｍ）
Ｒ　：曲率半径（ｍｍ）
ｄ　：軸上面間隔（ｍｍ）
ｎｄ：レンズ材料のｄ線に対する屈折率
νｄ：レンズ材料のアッベ数 (Example)
Next, examples suitable for the above-described embodiment will be described. However, the present invention is not limited to the following examples.
f: Focal length of the entire system (mm)
R: radius of curvature (mm)
d: Distance between shaft upper surfaces (mm)
nd: refractive index of lens material with respect to d-line νd: Abbe number of lens material
　各実施例において、面番号の横に＊が付与されてなる面が非球面形状を有する面であり、非球面の形状は、面の頂点を原点とし、光軸方向にＸ軸をとり、光軸と垂直方向の高さをｈとして以下の「数１」で表す。 In each embodiment, the surface provided with * next to the surface number is a surface having an aspheric shape, and the shape of the aspheric surface has the vertex of the surface as the origin and the X-axis in the optical axis direction. The height in the direction perpendicular to the axis is represented by h as follows.
Figure JPOXMLDOC01-appb-M000001
 ただし、
Ａｉ：ｉ次の非球面係数
Ｒ　：基準曲率半径
Ｋ　：円錐定数
　繰り返すが、実際のレンズ測定の場面においては、本明細書でいうレンズ面の曲率半径とは、レンズ中央近傍（具体的には、レンズ外径に対して１０％以内の中央領域）での形状測定値を最小自乗法でフィッティングした際の近似曲率半径の事を指す。また、例えば２次の非球面係数を使用した場合には、非球面定義式の基準曲率半径に２次の非球面係数も勘案した曲率半径も含める。
Figure JPOXMLDOC01-appb-M000001
 However,
Ai: i-th order aspherical coefficient R: reference radius of curvature K: conic constant Repeatedly, in the actual lens measurement scene, the radius of curvature of the lens surface in this specification is the vicinity of the center of the lens (specifically, The approximate radius of curvature when the shape measurement value in the central region within 10% of the lens outer diameter) is fitted by the method of least squares. For example, when a secondary aspheric coefficient is used, the reference radius of curvature of the aspheric definition formula also includes a curvature radius that takes into account the secondary aspheric coefficient.
（実施例１）
　実施例１のレンズデータを表１に示す。なお、これ以降（表のレンズデータを含む）において、１０のべき乗数（たとえば２．５×１０-02）を、Ｅ（たとえば２．５Ｅ－０２）を用いて表すものとする。図２は、実施例１の撮像光学系の断面図である。図中、ＣＬはコンバータレンズであり、物体側から順に、負の屈折力を有する第１レンズＬ１と、負の屈折力を有する第２レンズＬ２と、正の屈折力を有する第３レンズＬ３から構成される。また、ＭＬは主レンズ（焦点距離ｆ＝4.33ｍｍ）であり、物体側から順に、第４レンズＬ４，第５レンズＬ５，第６レンズＬ６，第７レンズＬ７，第８レンズＬ８からなる。又、Ｓは、第４レンズＬ４の物体側面の光軸上の位置より像側であって、物体側面の最周辺部より物体側に設けられた開口絞り、ＩＭは撮像装置の撮像面を示す。また、ＣＧは主レンズＭＬのカバーガラスであり、Ｆは光学的ローパスフィルタやＩＲカットフィルタ、固体撮像素子のシールガラス等を想定した平行平板を示す。コンバータレンズＣＬ（面番号１～６）と主レンズＭＬ（面番号７～２２）とで、撮像光学系を構成する。本実施例では、コンバータレンズＣＬは球面レンズのみからなり、主レンズＭＬは非球面レンズを有する。 (Example 1)
Table 1 shows lens data of Example 1. In the following (including the lens data in the table), a power of 10 (for example, 2.5 × 10 −02 ) is expressed using E (for example, 2.5E-02). FIG. 2 is a sectional view of the image pickup optical system according to the first embodiment. In the figure, CL is a converter lens, and in order from the object side, a first lens L1 having a negative refractive power, a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power. Composed. ML is a main lens (focal length f = 4.33 mm), and is composed of a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8 in this order from the object side. S denotes an aperture stop provided on the object side from the position on the optical axis of the object side surface of the fourth lens L4 on the object side from the most peripheral part of the object side surface, and IM denotes an image pickup surface of the image pickup apparatus. . Further, CG is a cover glass of the main lens ML, and F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, and the like. The converter lens CL (surface numbers 1 to 6) and the main lens ML (surface numbers 7 to 22) constitute an imaging optical system. In the present embodiment, the converter lens CL includes only a spherical lens, and the main lens ML includes an aspheric lens.
［表１］
実施例１

面番号(非球面)    R(mm)   d(mm)   nd         νd     有効径(mm)
1                 15.068  0.80    1.83481     42.7    10.90 
2                 4.905   3.25                        8.14 
3                 42.025  0.70    1.83400     37.3    7.46 
4                 11.930  0.20                        7.05 
5                 5.804   2.64    1.67270     32.2    6.91 
6               -59.293   1.24                        5.95 
7                 ∞      0.79    1.51633     64.1    4.15 
8                 ∞      1.24                        3.51 
9                 ∞      0.05                        1.80 
10(絞り)           ∞     -0.24                        1.80 
11  *             1.676   0.63    1.54470     56.2    1.87 
12  *           -13.857   0.05                        1.90 
13  *             4.012   0.28    1.63469     23.9    1.92 
14  *             1.559   0.57                        1.90 
15  *           -36.876   0.31    1.63469     23.9    2.15 
16  *           -35.075   0.42                        2.46 
17  *            -6.434   0.86    1.54470     56.2    3.72 
18  *            -0.965   0.23                        4.08 
19  *            -2.637   0.45    1.53048     55.7    4.59 
20  *             1.582   0.64                        5.12 
21                ∞      0.30    1.51633     64.1    5.66 
22                ∞      0.40                       5.78 
像 

主レンズの非球面係数  
     第11面      第12面     第13面      第14面      第15面  
K   -0.025      -29.823     -30.000     -6.295       30.000  
A4   5.4737E-03  2.9864E-02 -4.4484E-02  4.7985E-02 -1.2218E-01 
A6   1.8802E-03  3.6878E-02  1.4564E-01  5.1872E-02 -2.6536E-02 
A8  -3.1928E-03 -4.3208E-02 -1.2728E-01 -1.8852E-02  6.2354E-02  
A10  1.7037E-02 -2.3999E-02 -3.2604E-02 -6.3501E-03  2.0372E-02  
A12 -2.1868E-02  2.7062E-02  7.7790E-02 -4.1075E-03 -1.8554E-02 
A14  8.4210E-03  0.0000E+00 -1.8876E-02  2.2070E-02 -6.3386E-04 
                        
     第16面      第17面     第18面      第19面      第20面  
K    30.000      7.826      -4.059      -30.000     -12.523     
A4  -1.0027E-01 -3.7724E-04 -4.3185E-02 -1.4223E-02 -3.6784E-02 
A6   3.0627E-03  2.0421E-02  5.1578E-02 -1.5539E-03  7.2592E-03  
A8   1.9106E-02 -1.1047E-03 -1.1842E-02  2.1085E-03 -1.4441E-03 
A10  1.6054E-02 -1.6207E-03  6.5318E-04 -1.9864E-04  1.4444E-04  
A12 -2.2771E-03  2.6445E-04  1.9046E-05 -2.5376E-05 -5.0337E-06 
A14 -2.7944E-03  0.0000E+00  0.0000E+00  2.8800E-06  3.2341E-08  
  
コンバータレンズと主レンズの合成光学系における値 
焦点距離            3.03mm 
Fナンバー           2.41 
半画角              47.7°  
像高                3.02mm  
レンズ全長          15.82mm  
バックフォーカス    1.24mm 
ただし、レンズ全長は第1レンズ被写体側面から主レンズ近軸像点までの距離。 
主レンズの焦点距離  4.33mm 
コンバータ倍率      0.70 
[Table 1]
Example 1

Surface number (aspherical surface) R (mm) d (mm) nd νd Effective diameter (mm)
1 15.068 0.80 1.83481 42.7 10.90
2 4.905 3.25 8.14
3 42.025 0.70 1.83400 37.3 7.46
4 11.930 0.20 7.05
5 5.804 2.64 1.67270 32.2 6.91
6 -59.293 1.24 5.95
7 ∞ 0.79 1.51633 64.1 4.15
8 ∞ 1.24 3.51
9 ∞ 0.05 1.80
10 (Aperture) ∞ -0.24 1.80
11 * 1.676 0.63 1.54470 56.2 1.87
12 * -13.857 0.05 1.90
13 * 4.012 0.28 1.63469 23.9 1.92
14 * 1.559 0.57 1.90
15 * -36.876 0.31 1.63469 23.9 2.15
16 * -35.075 0.42 2.46
17 * -6.434 0.86 1.54470 56.2 3.72
18 * -0.965 0.23 4.08
19 * -2.637 0.45 1.53048 55.7 4.59
20 * 1.582 0.64 5.12
21 ∞ 0.30 1.51633 64.1 5.66
22 ∞ 0.40 5.78
image

Aspheric coefficient of main lens
11th surface 12th surface 13th surface 14th surface 15th surface
K -0.025 -29.823 -30.000 -6.295 30.000
A4 5.4737E-03 2.9864E-02 -4.4484E-02 4.7985E-02 -1.2218E-01
A6 1.8802E-03 3.6878E-02 1.4564E-01 5.1872E-02 -2.6536E-02
A8 -3.1928E-03 -4.3208E-02 -1.2728E-01 -1.8852E-02 6.2354E-02
A10 1.7037E-02 -2.3999E-02 -3.2604E-02 -6.3501E-03 2.0372E-02
A12 -2.1868E-02 2.7062E-02 7.7790E-02 -4.1075E-03 -1.8554E-02
A14 8.4210E-03 0.0000E + 00 -1.8876E-02 2.2070E-02 -6.3386E-04

16th surface 17th surface 18th surface 19th surface 20th surface
K 30.000 7.826 -4.059 -30.000 -12.523
A4 -1.0027E-01 -3.7724E-04 -4.3185E-02 -1.4223E-02 -3.6784E-02
A6 3.0627E-03 2.0421E-02 5.1578E-02 -1.5539E-03 7.2592E-03
A8 1.9106E-02 -1.1047E-03 -1.1842E-02 2.1085E-03 -1.4441E-03
A10 1.6054E-02 -1.6207E-03 6.5318E-04 -1.9864E-04 1.4444E-04
A12 -2.2771E-03 2.6445E-04 1.9046E-05 -2.5376E-05 -5.0337E-06
A14 -2.7944E-03 0.0000E + 00 0.0000E + 00 2.8800E-06 3.2341E-08

Values in the combined optical system of the converter lens and main lens
Focal length 3.03mm
F number 2.41
Half angle of view 47.7 °
Image height 3.02mm
Total lens length 15.82mm
Back focus 1.24mm
However, the total lens length is the distance from the side of the first lens subject to the main lens paraxial image point.
Main lens focal length 4.33mm
Converter magnification 0.70
　図３は、実施例１の収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））であるが、収差図はコンバータレンズと主レンズを組み合わせた状態のものである。図４は、主レンズのみの収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））である。球面収差図において、点線はｇ線、実線はｄ線に対する球面収差量をそれぞれ表す。また、非点収差図において、実線Ｓはサジタル面、点線Ｍはメリディオナル面をそれぞれ表す（以下同じ）。 FIG. 3 is an aberration diagram of Example 1 (spherical aberration (a), astigmatism (b), distortion aberration (c)), and the aberration diagram is a combination of the converter lens and the main lens. . FIG. 4 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) of only the main lens. In the spherical aberration diagram, the dotted line represents the amount of spherical aberration with respect to the g line, and the solid line represents the amount of spherical aberration with respect to the d line. In the astigmatism diagram, the solid line S represents the sagittal plane, and the dotted line M represents the meridional plane (the same applies hereinafter).
　実施例１では、第1レンズＬ１物体側面の有効径と、主レンズＭＬの開口絞り径の比が0.17程度と、コンパクトな撮像光学系を実現している。 In Example 1, the ratio of the effective diameter of the object side surface of the first lens L1 to the aperture stop diameter of the main lens ML is about 0.17, thereby realizing a compact imaging optical system.
（実施例２）
　実施例２のレンズデータを表２に示す。図５は、実施例２の撮像光学系の断面図である。図中、ＣＬはコンバータレンズであり、物体側から順に、負の屈折力を有する第１レンズＬ１と、負の屈折力を有する第２レンズＬ２と、正の屈折力を有する第３レンズＬ３から構成される。また、ＭＬは主レンズであり、物体側から順に、第４レンズＬ４，第５レンズＬ５，第６レンズＬ６，第７レンズＬ７，第８レンズＬ８からなる。又、Ｓは、第４レンズＬ４の物体側面の光軸上の位置より像側であって、物体側面の最周辺部より物体側に設けられた開口絞り、ＩＭは撮像装置の撮像面を示す。また、ＣＧは主レンズＭＬのカバーガラスであり、Ｆは光学的ローパスフィルタやＩＲカットフィルタ、固体撮像素子のシールガラス等を想定した平行平板を示す。コンバータレンズＣＬ（面番号１～６）と主レンズＭＬ（面番号７～２２）とで、撮像光学系を構成する。本実施例では、コンバータレンズＣＬは球面レンズのみからなり、主レンズＭＬは非球面レンズを有する。尚、実施例２で用いる主レンズＭＬは、実施例１で用いたものと同じであるため、非球面係数は省略する。 (Example 2)
Table 2 shows lens data of Example 2. FIG. 5 is a sectional view of the image pickup optical system according to the second embodiment. In the figure, CL is a converter lens, and in order from the object side, a first lens L1 having a negative refractive power, a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power. Composed. ML is a main lens, and is composed of a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8 in this order from the object side. S denotes an aperture stop provided on the object side from the position on the optical axis of the object side surface of the fourth lens L4 on the object side from the most peripheral part of the object side surface, and IM denotes an image pickup surface of the image pickup apparatus. . Further, CG is a cover glass of the main lens ML, and F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, and the like. The converter lens CL (surface numbers 1 to 6) and the main lens ML (surface numbers 7 to 22) constitute an imaging optical system. In the present embodiment, the converter lens CL includes only a spherical lens, and the main lens ML includes an aspheric lens. Since the main lens ML used in the second embodiment is the same as that used in the first embodiment, the aspheric coefficient is omitted.
［表２］
実施例２
  
面番号(非球面)    R(mm)   d(mm)   nd         νd     有効径(mm)
1                 14.298  0.80    1.88300     40.8    10.91 
2                 4.966   3.19                        8.21 
3                 36.957  0.70    1.83481     42.7    7.58 
4                 12.156  0.20                        7.18 
5                 5.774   2.84    1.64769     33.8    7.02 
6                -53.069  1.24                        5.97 
7                 ∞      0.79    1.51633     64.1    4.15 
8                 ∞      1.24                        3.51 
9                 ∞      0.05                        1.80 
10(絞り)           ∞     -0.24                        1.80 
11  *             1.676   0.63    1.54470     56.2    1.87 
12  *           -13.857   0.05                        1.90 
13  *             4.012   0.28    1.63469     23.9    1.92 
14  *             1.559   0.57                        1.90 
15  *           -36.876   0.31    1.63469     23.9    2.15 
16  *           -35.075   0.42                        2.46 
17  *            -6.434   0.86    1.54470     56.2    3.73 
18  *            -0.965   0.23                        4.08 
19  *            -2.637   0.45    1.53048     55.7    4.59 
20  *             1.582   0.64                        5.12 
21                ∞      0.30    1.51633     64.1    5.66 
22                ∞      0.40                       5.79 
像  
 
コンバータレンズと主レンズの合成光学系における値 
焦点距離            3.04mm 
Fナンバー           2.41  
半画角              47.4° 
像高                3.02mm 
レンズ全長          15.95mm 
バックフォーカス    1.24mm 
ただし、レンズ全長は第1レンズ被写体側面から主レンズ近軸像点までの距離。 
主レンズの焦点距離  4.33mm   
コンバータ倍率      0.70 
[Table 2]
Example 2

Surface number (aspherical surface) R (mm) d (mm) nd νd Effective diameter (mm)
1 14.298 0.80 1.88300 40.8 10.91
2 4.966 3.19 8.21
3 36.957 0.70 1.83481 42.7 7.58
4 12.156 0.20 7.18
5 5.774 2.84 1.64769 33.8 7.02
6 -53.069 1.24 5.97
7 ∞ 0.79 1.51633 64.1 4.15
8 ∞ 1.24 3.51
9 ∞ 0.05 1.80
10 (Aperture) ∞ -0.24 1.80
11 * 1.676 0.63 1.54470 56.2 1.87
12 * -13.857 0.05 1.90
13 * 4.012 0.28 1.63469 23.9 1.92
14 * 1.559 0.57 1.90
15 * -36.876 0.31 1.63469 23.9 2.15
16 * -35.075 0.42 2.46
17 * -6.434 0.86 1.54470 56.2 3.73
18 * -0.965 0.23 4.08
19 * -2.637 0.45 1.53048 55.7 4.59
20 * 1.582 0.64 5.12
21 ∞ 0.30 1.51633 64.1 5.66
22 ∞ 0.40 5.79
image

Values in the combined optical system of the converter lens and main lens
Focal length 3.04mm
F number 2.41
Half angle of view 47.4 °
Image height 3.02mm
Total lens length 15.95mm
Back focus 1.24mm
However, the total lens length is the distance from the side of the first lens subject to the main lens paraxial image point.
Main lens focal length 4.33mm
Converter magnification 0.70
　図６は、実施例２の収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））であるが、収差図はコンバータレンズと主レンズを組み合わせた状態のものである。 FIG. 6 is an aberration diagram of Example 2 (spherical aberration (a), astigmatism (b), distortion aberration (c)), and the aberration diagram is a combination of the converter lens and the main lens. .
　実施例２では、第1レンズＬ１物体側面の有効径と、主レンズＭＬの開口絞り径の比が0.17程度と、コンパクトな撮像光学系を実現している。 In Example 2, the ratio of the effective diameter of the object side surface of the first lens L1 to the aperture stop diameter of the main lens ML is about 0.17, thereby realizing a compact imaging optical system.
（実施例３）
　実施例３のレンズデータを表３に示す。図７は、実施例３の撮像光学系の断面図である。図中、ＣＬはコンバータレンズであり、物体側から順に、負の屈折力を有する第１レンズＬ１と、負の屈折力を有する第２レンズＬ２と、正の屈折力を有する第３レンズＬ３から構成される。また、ＭＬは主レンズであり、物体側から順に、第４レンズＬ４，第５レンズＬ５，第６レンズＬ６，第７レンズＬ７，第８レンズＬ８からなる。又、Ｓは、第４レンズＬ４の物体側面の光軸上の位置より像側であって、物体側面の最周辺部より物体側に設けられた開口絞り、ＩＭは撮像装置の撮像面を示す。また、ＣＧは主レンズＭＬのカバーガラスであり、Ｆは光学的ローパスフィルタやＩＲカットフィルタ、固体撮像素子のシールガラス等を想定した平行平板を示す。コンバータレンズＣＬ（面番号１～６）と主レンズＭＬ（面番号７～２２）とで、撮像光学系を構成する。本実施例では、コンバータレンズＣＬは球面レンズのみからなり、主レンズＭＬは非球面レンズを有する。尚、実施例３で用いる主レンズＭＬは、実施例１で用いたものと同じであるため、非球面係数は省略する。 (Example 3)
Table 3 shows lens data of Example 3. FIG. 7 is a cross-sectional view of the image pickup optical system according to the third embodiment. In the figure, CL is a converter lens, and in order from the object side, a first lens L1 having a negative refractive power, a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power. Composed. ML is a main lens, and is composed of a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8 in this order from the object side. S denotes an aperture stop provided on the object side from the position on the optical axis of the object side surface of the fourth lens L4 on the object side from the most peripheral part of the object side surface, and IM denotes an image pickup surface of the image pickup apparatus. . Further, CG is a cover glass of the main lens ML, and F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, and the like. The converter lens CL (surface numbers 1 to 6) and the main lens ML (surface numbers 7 to 22) constitute an imaging optical system. In the present embodiment, the converter lens CL includes only a spherical lens, and the main lens ML includes an aspheric lens. Since the main lens ML used in the third embodiment is the same as that used in the first embodiment, the aspheric coefficient is omitted.
［表３］
実施例３
 
面番号(非球面)    R(mm)   d(mm)   nd         νd     有効径(mm)
1                 11.812  0.80    1.83481     42.7    13.01 
2                 5.747   3.69                        10.01 
3                 21.832  0.70    1.83481     42.7    9.07 
4                 7.327   0.84                        8.18 
5                 6.198   3.29    1.62588     35.7    8.13 
6               -36.168   1.96                        7.11 
7                 ∞      0.79    1.51633     64.1    4.15 
8                 ∞      1.24                        3.52 
9                 ∞      0.05                        1.80 
10(絞り)           ∞     -0.24                        1.80 
11  *             1.676   0.63    1.54470     56.2    1.87 
12  *           -13.857   0.05                        1.90 
13  *             4.012   0.28    1.63469     23.9    1.92 
14  *             1.559   0.57                        1.90 
15  *           -36.876   0.31    1.63469     23.9    2.15 
16  *           -35.075   0.42                        2.46 
17  *            -6.434   0.86    1.54470     56.2    3.71 
18  *            -0.965   0.23                        4.07 
19  *            -2.637   0.45    1.53048     55.7    4.58 
20  *             1.582   0.64                        5.11 
21                ∞      0.30    1.51633     64.1    5.66 
22                ∞      0.40                       5.78 
像  
 
コンバータレンズと主レンズの合成光学系における値 
焦点距離           3.04mm 
Fナンバー          2.41 
半画角              45.9° 
像高                3.02mm 
レンズ全長          18.26mm 
バックフォーカス    1.24mm 
ただし、レンズ全長は第1レンズ被写体側面から主レンズ近軸像点までの距離。
主レンズの焦点距離  4.33mm 
コンバータ倍率      0.70 
[Table 3]
Example 3

Surface number (aspherical surface) R (mm) d (mm) nd νd Effective diameter (mm)
1 11.812 0.80 1.83481 42.7 13.01
2 5.747 3.69 10.01
3 21.832 0.70 1.83481 42.7 9.07
4 7.327 0.84 8.18
5 6.198 3.29 1.62588 35.7 8.13
6 -36.168 1.96 7.11
7 ∞ 0.79 1.51633 64.1 4.15
8 ∞ 1.24 3.52
9 ∞ 0.05 1.80
10 (Aperture) ∞ -0.24 1.80
11 * 1.676 0.63 1.54470 56.2 1.87
12 * -13.857 0.05 1.90
13 * 4.012 0.28 1.63469 23.9 1.92
14 * 1.559 0.57 1.90
15 * -36.876 0.31 1.63469 23.9 2.15
16 * -35.075 0.42 2.46
17 * -6.434 0.86 1.54470 56.2 3.71
18 * -0.965 0.23 4.07
19 * -2.637 0.45 1.53048 55.7 4.58
20 * 1.582 0.64 5.11
21 ∞ 0.30 1.51633 64.1 5.66
22 ∞ 0.40 5.78
image

Values in the combined optical system of the converter lens and main lens
Focal length 3.04mm
F number 2.41
Half angle of view 45.9 °
Image height 3.02mm
Total lens length 18.26mm
Back focus 1.24mm
However, the total lens length is the distance from the side of the first lens subject to the main lens paraxial image point.
Main lens focal length 4.33mm
Converter magnification 0.70
　図８は、実施例３の収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））であるが、収差図はコンバータレンズと主レンズを組み合わせた状態のものである。 FIG. 8 is an aberration diagram of Example 3 (spherical aberration (a), astigmatism (b), distortion aberration (c)), and the aberration diagram is a state where the converter lens and the main lens are combined. .
　実施例３では、第1レンズＬ１物体側面の有効径と、主レンズＭＬの開口絞り径の比が0.14程度と、コンパクトな撮像光学系を実現している。 In Example 3, a compact imaging optical system is realized in which the ratio of the effective diameter of the object side surface of the first lens L1 to the aperture stop diameter of the main lens ML is about 0.14.
（実施例４）
　実施例４のレンズデータを表４に示す。図９は、実施例４の撮像光学系の断面図である。図中、ＣＬはコンバータレンズであり、物体側から順に、負の屈折力を有する第１レンズＬ１と、負の屈折力を有する第２レンズＬ２と、正の屈折力を有する第３レンズＬ３から構成される。また、ＭＬは主レンズであり、物体側から順に、第４レンズＬ４，第５レンズＬ５，第６レンズＬ６，第７レンズＬ７，第８レンズＬ８からなる。又、Ｓは、第４レンズＬ４の物体側面の光軸上の位置より像側であって、物体側面の最周辺部より物体側に設けられた開口絞り、ＩＭは撮像装置の撮像面を示す。また、ＣＧは主レンズＭＬのカバーガラスであり、Ｆは光学的ローパスフィルタやＩＲカットフィルタ、固体撮像素子のシールガラス等を想定した平行平板を示す。コンバータレンズＣＬ（面番号１～６）と主レンズＭＬ（面番号７～２２）とで、撮像光学系を構成する。本実施例では、コンバータレンズＣＬは球面レンズのみからなり、主レンズＭＬは非球面レンズを有する。尚、実施例２で用いる主レンズＭＬは、実施例１で用いたものと同じであるため、非球面係数は省略する。 Example 4
Table 4 shows lens data of Example 4. FIG. 9 is a sectional view of the image pickup optical system according to the fourth embodiment. In the figure, CL is a converter lens, and in order from the object side, a first lens L1 having a negative refractive power, a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power. Composed. ML is a main lens, and is composed of a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8 in this order from the object side. S denotes an aperture stop provided on the object side from the position on the optical axis of the object side surface of the fourth lens L4 on the object side from the most peripheral part of the object side surface, and IM denotes an image pickup surface of the image pickup apparatus. . Further, CG is a cover glass of the main lens ML, and F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, and the like. The converter lens CL (surface numbers 1 to 6) and the main lens ML (surface numbers 7 to 22) constitute an imaging optical system. In the present embodiment, the converter lens CL includes only a spherical lens, and the main lens ML includes an aspheric lens. Since the main lens ML used in the second embodiment is the same as that used in the first embodiment, the aspheric coefficient is omitted.
［表４］
実施例４

面番号(非球面)    R(mm)   d(mm)   nd         νd     有効径(mm)
1                 40.045  0.80    1.83481     42.7    10.83 
2                 5.128   2.53                        8.05 
3                 19.828  0.70    1.83481     42.7    7.73 
4                 11.085  0.20                        7.38 
5                 5.906   3.40    1.62588     35.7    7.31 
6               -25.478   1.24                        6.10 
7                 ∞      0.79    1.51633     64.1    4.14 
8                 ∞      1.24                        3.50 
9                 ∞      0.05                        1.80 
10(絞り)           ∞     -0.24                        1.80 
11  *             1.676   0.63    1.54470     56.2    1.87 
12  *           -13.857   0.05                        1.90 
13  *             4.012   0.28    1.63469     23.9    1.92 
14  *             1.559   0.57                        1.90 
15  *           -36.876   0.31    1.63469     23.9    2.15 
16  *           -35.075   0.42                        2.46 
17  *            -6.434   0.86    1.54470     56.2    3.72 
18  *            -0.965   0.23                        4.07 
19  *            -2.637   0.45    1.53048     55.7    4.58 
20  *             1.582   0.64                        5.11 
21                ∞      0.30    1.51633     64.1    5.66 
22                ∞      0.40                       5.78 
像 
  
コンバータレンズと主レンズの合成光学系における値 
焦点距離            2.90mm 
Fナンバー           2.41 
半画角              52.3° 
像高                3.02mm 
レンズ全長          15.86mm 
バックフォーカス    1.24mm 
ただし、レンズ全長は第1レンズ被写体側面から主レンズ近軸像点までの距離。 
主レンズの焦点距離  4.33mm  
コンバータ倍率      0.67 
[Table 4]
Example 4

Surface number (aspherical surface) R (mm) d (mm) nd νd Effective diameter (mm)
1 40.045 0.80 1.83481 42.7 10.83
2 5.128 2.53 8.05
3 19.828 0.70 1.83481 42.7 7.73
4 11.085 0.20 7.38
5 5.906 3.40 1.62588 35.7 7.31
6 -25.478 1.24 6.10
7 ∞ 0.79 1.51633 64.1 4.14
8 ∞ 1.24 3.50
9 ∞ 0.05 1.80
10 (Aperture) ∞ -0.24 1.80
11 * 1.676 0.63 1.54470 56.2 1.87
12 * -13.857 0.05 1.90
13 * 4.012 0.28 1.63469 23.9 1.92
14 * 1.559 0.57 1.90
15 * -36.876 0.31 1.63469 23.9 2.15
16 * -35.075 0.42 2.46
17 * -6.434 0.86 1.54470 56.2 3.72
18 * -0.965 0.23 4.07
19 * -2.637 0.45 1.53048 55.7 4.58
20 * 1.582 0.64 5.11
21 ∞ 0.30 1.51633 64.1 5.66
22 ∞ 0.40 5.78
image

Values in the combined optical system of the converter lens and main lens
Focal length 2.90mm
F number 2.41
Half angle of view 52.3 °
Image height 3.02mm
Total lens length 15.86mm
Back focus 1.24mm
However, the total lens length is the distance from the side of the first lens subject to the main lens paraxial image point.
Main lens focal length 4.33mm
Converter magnification 0.67
　図１０は、実施例４の収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））であるが、収差図はコンバータレンズと主レンズを組み合わせた状態のものである。 FIG. 10 is an aberration diagram of Example 4 (spherical aberration (a), astigmatism (b), distortion aberration (c)). The aberration diagram shows a state in which the converter lens and the main lens are combined. .
　実施例４では、第1レンズＬ１物体側面の有効径と、主レンズＭＬの開口絞り径の比が0.17程度と、コンパクトな撮像光学系を実現している。 In Example 4, the ratio of the effective diameter of the object side surface of the first lens L1 to the aperture stop diameter of the main lens ML is about 0.17, thereby realizing a compact imaging optical system.
（実施例５）
　実施例５のレンズデータを表５に示す。図１１は、実施例５の撮像光学系の断面図である。図中、ＣＬはコンバータレンズであり、物体側から順に、負の屈折力を有する第１レンズＬ１と、負の屈折力を有する第２レンズＬ２と、正の屈折力を有する第３レンズＬ３から構成される。また、ＭＬは主レンズであり、物体側から順に、第４レンズＬ４，第５レンズＬ５，第６レンズＬ６，第７レンズＬ７，第８レンズＬ８からなる。又、Ｓは、第４レンズＬ４の物体側面の光軸上の位置より像側であって、物体側面の最周辺部より物体側に設けられた開口絞り、ＩＭは撮像装置の撮像面を示す。また、ＣＧは主レンズＭＬのカバーガラスであり、Ｆは光学的ローパスフィルタやＩＲカットフィルタ、固体撮像素子のシールガラス等を想定した平行平板を示す。コンバータレンズＣＬ（面番号１～６）と主レンズＭＬ（面番号７～２２）とで、撮像光学系を構成する。本実施例では、コンバータレンズＣＬは球面レンズのみからなり、主レンズＭＬは非球面レンズを有する。尚、実施例５で用いる主レンズＭＬは、実施例１で用いたものと同じであるため、非球面係数は省略する。 (Example 5)
Table 5 shows lens data of Example 5. FIG. 11 is a sectional view of the image pickup optical system according to the fifth embodiment. In the figure, CL is a converter lens, and in order from the object side, a first lens L1 having a negative refractive power, a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power. Composed. ML is a main lens, and is composed of a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8 in this order from the object side. S denotes an aperture stop provided on the object side from the position on the optical axis of the object side surface of the fourth lens L4 on the object side from the most peripheral part of the object side surface, and IM denotes an image pickup surface of the image pickup apparatus. . Further, CG is a cover glass of the main lens ML, and F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, and the like. The converter lens CL (surface numbers 1 to 6) and the main lens ML (surface numbers 7 to 22) constitute an imaging optical system. In the present embodiment, the converter lens CL includes only a spherical lens, and the main lens ML includes an aspheric lens. Since the main lens ML used in the fifth embodiment is the same as that used in the first embodiment, the aspheric coefficient is omitted.
［表５］
実施例５
  
面番号(非球面)    R(mm)   d(mm)   nd         νd     有効径(mm)
1                -30.000  0.75    1.83481     42.7    10.90 
2                 7.671   0.92                        8.92 
3                 10.827  1.95    1.51742     52.2    8.83 
4                 7.184   0.20                        7.86 
5                 6.713   4.50    1.61293     37.0    7.85 
6               -15.723   1.24                        6.28 
7                 ∞      0.79    1.51633     64.1    4.13 
8                 ∞      1.24                        3.50 
9                 ∞      0.05                        1.80 
10(絞り)           ∞     -0.24                        1.80 
11  *             1.676   0.63    1.54470     56.2    1.87 
12  *           -13.857   0.05                        1.90 
13  *             4.012   0.28    1.63469     23.9    1.92 
14  *             1.559   0.57                        1.90 
15  *           -36.876   0.31    1.63469     23.9    2.15 
16  *           -35.075   0.42                        2.47 
17  *            -6.434   0.86    1.54470     56.2    3.77 
18  *            -0.965   0.23                        4.11 
19  *            -2.637   0.45    1.53048     55.7    4.61 
20  *             1.582   0.64                        5.14 
21                ∞      0.30    1.51633     64.1    5.68 
22                ∞      0.40                       5.80 
像 
 
コンバータレンズと主レンズの合成光学系における値 
焦点距離            3.02mm 
Fナンバー           2.41 
半画角              58.9° 
像高                3.02mm 
レンズ全長          16.54mm 
バックフォーカス    1.24mm 
ただし、レンズ全長は第1レンズ被写体側面から主レンズ近軸像点までの距離。                     
主レンズの焦点距離  4.33mm 
コンバータ倍率       0.70  
[Table 5]
Example 5

Surface number (aspherical surface) R (mm) d (mm) nd νd Effective diameter (mm)
1 -30.000 0.75 1.83481 42.7 10.90
2 7.671 0.92 8.92
3 10.827 1.95 1.51742 52.2 8.83
4 7.184 0.20 7.86
5 6.713 4.50 1.61293 37.0 7.85
6 -15.723 1.24 6.28
7 ∞ 0.79 1.51633 64.1 4.13
8 ∞ 1.24 3.50
9 ∞ 0.05 1.80
10 (Aperture) ∞ -0.24 1.80
11 * 1.676 0.63 1.54470 56.2 1.87
12 * -13.857 0.05 1.90
13 * 4.012 0.28 1.63469 23.9 1.92
14 * 1.559 0.57 1.90
15 * -36.876 0.31 1.63469 23.9 2.15
16 * -35.075 0.42 2.47
17 * -6.434 0.86 1.54470 56.2 3.77
18 * -0.965 0.23 4.11
19 * -2.637 0.45 1.53048 55.7 4.61
20 * 1.582 0.64 5.14
21 ∞ 0.30 1.51633 64.1 5.68
22 ∞ 0.40 5.80
image

Values in the combined optical system of the converter lens and main lens
Focal length 3.02mm
F number 2.41
Half angle of view 58.9 °
Image height 3.02mm
Total lens length 16.54mm
Back focus 1.24mm
However, the total lens length is the distance from the side of the first lens subject to the main lens paraxial image point.
Main lens focal length 4.33mm
Converter magnification 0.70
　図１２は、実施例５の収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））であるが、収差図はコンバータレンズと主レンズを組み合わせた状態のものである。 FIG. 12 is an aberration diagram of Example 5 (spherical aberration (a), astigmatism (b), distortion aberration (c)), and the aberration diagram is a state where the converter lens and the main lens are combined. .
　実施例５では、第1レンズＬ１物体側面の有効径と、主レンズＭＬの開口絞り径の比が0.17程度と、コンパクトな撮像光学系を実現している。 Example 5 realizes a compact imaging optical system in which the ratio of the effective diameter of the object side surface of the first lens L1 to the aperture stop diameter of the main lens ML is about 0.17.
（実施例６）
　実施例６のレンズデータを表６に示す。図１３は、実施例６の撮像光学系の断面図である。図中、ＣＬはコンバータレンズであり、物体側から順に、負の屈折力を有する第１レンズＬ１と、負の屈折力を有する第２レンズＬ２と、正の屈折力を有する第３レンズＬ３から構成される。また、ＭＬは主レンズであり、物体側から順に、第４レンズＬ４，第５レンズＬ５，第６レンズＬ６，第７レンズＬ７，第８レンズＬ８からなる。又、Ｓは、第４レンズＬ４の物体側面の光軸上の位置より像側であって、物体側面の最周辺部より物体側に設けられた開口絞り、ＩＭは撮像装置の撮像面を示す。また、ＣＧは主レンズＭＬのカバーガラスであり、Ｆは光学的ローパスフィルタやＩＲカットフィルタ、固体撮像素子のシールガラス等を想定した平行平板を示す。コンバータレンズＣＬ（面番号１～６）と主レンズＭＬ（面番号７～２２）とで、撮像光学系を構成する。本実施例では、コンバータレンズＣＬは球面レンズのみからなり、主レンズＭＬは非球面レンズを有する。尚、実施例６で用いる主レンズＭＬは、実施例１で用いたものと同じであるため、非球面係数は省略する。 (Example 6)
Table 6 shows lens data of Example 6. FIG. 13 is a sectional view of the image pickup optical system according to the sixth embodiment. In the figure, CL is a converter lens, and in order from the object side, a first lens L1 having a negative refractive power, a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power. Composed. ML is a main lens, and is composed of a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8 in this order from the object side. S denotes an aperture stop provided on the object side from the position on the optical axis of the object side surface of the fourth lens L4 on the object side from the most peripheral part of the object side surface, and IM denotes an image pickup surface of the image pickup apparatus. . Further, CG is a cover glass of the main lens ML, and F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, and the like. The converter lens CL (surface numbers 1 to 6) and the main lens ML (surface numbers 7 to 22) constitute an imaging optical system. In the present embodiment, the converter lens CL includes only a spherical lens, and the main lens ML includes an aspheric lens. Since the main lens ML used in the sixth embodiment is the same as that used in the first embodiment, the aspheric coefficient is omitted.
［表６］
実施例６
  
面番号(非球面)    R(mm)   d(mm)   nd         νd     有効径(mm)
1               -32.917   0.75    1.88300     40.8    10.89 
2                 7.522   0.93                        8.90 
3                10.606   2.08    1.48749     70.4    8.81 
4                 7.025   0.20                        7.83 
5                 6.645   4.50    1.62004     36.3    7.83 
6               -15.644   1.24                        6.28 
7                 ∞      0.79    1.51633     64.1    4.13 
8                 ∞      1.24                        3.50 
9                 ∞      0.05                        1.80 
10(絞り)           ∞     -0.24                        1.80 
11  *             1.676   0.63    1.54470     56.2    1.87 
12  *           -13.857   0.05                        1.90 
13  *             4.012   0.28    1.63469     23.9    1.92 
14  *             1.559   0.57                        1.90 
15  *           -36.876   0.31    1.63469     23.9    2.15 
16  *           -35.075   0.42                        2.47 
17  *            -6.434   0.86    1.54470     56.2    3.77 
18  *            -0.965   0.23                        4.11 
19  *            -2.637   0.45    1.53048     55.7    4.61 
20  *             1.582   0.64                        5.14 
21                ∞      0.30    1.51633     64.1    5.68 
22                ∞      0.40                       5.80 
像 
 
コンバータレンズと主レンズの合成光学系における値 
焦点距離            2.94mm 
Fナンバー           2.41 
半画角              61.2° 
像高                3.02mm  
レンズ全長          16.68mm 
バックフォーカス    1.24mm 
ただし、レンズ全長は第1レンズ被写体側面から主レンズ近軸像点までの距離。 
主レンズの焦点距離  4.33mm 
コンバータ倍率      0.68 
[Table 6]
Example 6

Surface number (aspherical surface) R (mm) d (mm) nd νd Effective diameter (mm)
1 -32.917 0.75 1.88300 40.8 10.89
2 7.522 0.93 8.90
3 10.606 2.08 1.48749 70.4 8.81
4 7.025 0.20 7.83
5 6.645 4.50 1.62004 36.3 7.83
6 -15.644 1.24 6.28
7 ∞ 0.79 1.51633 64.1 4.13
8 ∞ 1.24 3.50
9 ∞ 0.05 1.80
10 (Aperture) ∞ -0.24 1.80
11 * 1.676 0.63 1.54470 56.2 1.87
12 * -13.857 0.05 1.90
13 * 4.012 0.28 1.63469 23.9 1.92
14 * 1.559 0.57 1.90
15 * -36.876 0.31 1.63469 23.9 2.15
16 * -35.075 0.42 2.47
17 * -6.434 0.86 1.54470 56.2 3.77
18 * -0.965 0.23 4.11
19 * -2.637 0.45 1.53048 55.7 4.61
20 * 1.582 0.64 5.14
21 ∞ 0.30 1.51633 64.1 5.68
22 ∞ 0.40 5.80
image

Values in the combined optical system of the converter lens and main lens
Focal length 2.94mm
F number 2.41
Half angle of view 61.2 °
Image height 3.02mm
Total lens length 16.68mm
Back focus 1.24mm
However, the total lens length is the distance from the side of the first lens subject to the main lens paraxial image point.
Main lens focal length 4.33mm
Converter magnification 0.68
　図１４は、実施例６の収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））であるが、収差図はコンバータレンズと主レンズを組み合わせた状態のものである。 FIG. 14 is an aberration diagram of Example 6 (spherical aberration (a), astigmatism (b), distortion aberration (c)), and the aberration diagram is a state where the converter lens and the main lens are combined. .
　実施例６では、第1レンズＬ１物体側面の有効径と、主レンズＭＬの開口絞り径の比が0.17程度と、コンパクトな撮像光学系を実現している。 In Example 6, the ratio of the effective diameter of the object side surface of the first lens L1 to the aperture stop diameter of the main lens ML is about 0.17, thereby realizing a compact imaging optical system.
（実施例７）
　実施例７のレンズデータを表７に示す。図１５は、実施例７の撮像光学系の断面図である。図中、ＣＬはコンバータレンズであり、物体側から順に、負の屈折力を有する第１レンズＬ１と、負の屈折力を有する第２レンズＬ２と、正の屈折力を有する第３レンズＬ３から構成される。また、ＭＬは主レンズであり、物体側から順に、第４レンズＬ４，第５レンズＬ５，第６レンズＬ６，第７レンズＬ７，第８レンズＬ８からなる。又、Ｓは、第４レンズＬ４の物体側面の光軸上の位置より像側であって、物体側面の最周辺部より物体側に設けられた開口絞り、ＩＭは撮像装置の撮像面を示す。また、ＣＧは主レンズＭＬのカバーガラスであり、Ｆは光学的ローパスフィルタやＩＲカットフィルタ、固体撮像素子のシールガラス等を想定した平行平板を示す。コンバータレンズＣＬ（面番号１～６）と主レンズＭＬ（面番号７～２２）とで、撮像光学系を構成する。本実施例では、コンバータレンズＣＬは、第１レンズＬ１が非球面レンズであり、それ以外は球面レンズであり、主レンズＭＬは非球面レンズを有する。尚、実施例７で用いる主レンズＭＬは、実施例１で用いたものと同じであるため、非球面係数は省略する。 (Example 7)
Table 7 shows lens data of Example 7. FIG. 15 is a sectional view of the image pickup optical system according to the seventh embodiment. In the figure, CL is a converter lens, and in order from the object side, a first lens L1 having a negative refractive power, a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power. Composed. ML is a main lens, and is composed of a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8 in this order from the object side. S denotes an aperture stop provided on the object side from the position on the optical axis of the object side surface of the fourth lens L4 on the object side from the most peripheral part of the object side surface, and IM denotes an image pickup surface of the image pickup apparatus. . Further, CG is a cover glass of the main lens ML, and F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, and the like. The converter lens CL (surface numbers 1 to 6) and the main lens ML (surface numbers 7 to 22) constitute an imaging optical system. In the present embodiment, in the converter lens CL, the first lens L1 is an aspheric lens, the other lenses are spherical lenses, and the main lens ML has an aspheric lens. Since the main lens ML used in the seventh embodiment is the same as that used in the first embodiment, the aspheric coefficient is omitted.
［表７］
実施例７
  
面番号(非球面)    R(mm)   d(mm)   nd         νd     有効径(mm)
1   *             25.425  0.75    1.88202     37.2    10.95 
2   *              5.973  2.59                        8.48 
3               -114.874  0.70    1.78590     43.9    7.99 
4                 11.710  0.20                        7.62 
5                  7.342  4.34    1.64769     33.8    7.65 
6                -11.799  1.24                        6.46 
7                  ∞     0.79    1.51633     64.1    4.13 
8                  ∞     1.24                        3.50 
9                  ∞     0.05                        1.80 
10(絞り)            ∞    -0.24                        1.80 
11  *             1.676   0.63    1.54470     56.2    1.87 
12  *           -13.857   0.05                        1.90 
13  *             4.012   0.28    1.63469     23.9    1.92 
14  *             1.559   0.57                        1.90 
15  *           -36.876   0.31    1.63469     23.9    2.15 
16  *           -35.075   0.42                        2.46 
17  *            -6.434   0.86    1.54470     56.2    3.74 
18  *            -0.965   0.23                        4.09 
19  *            -2.637   0.45    1.53048     55.7    4.60 
20  *             1.582   0.64                        5.13 
21                ∞      0.30    1.51633     64.1    5.67 
22                ∞      0.40                       5.80 
像 
 
コンバータレンズの非球面係数 
     第1面       第2面 
K    0.000        0.000  
A4  -7.2151E-04  -5.8463E-04 
A6   4.1528E-06   2.1826E-06  
A8   2.2788E-07  -8.4479E-07 
A10 -3.5985E-09   6.4026E-08  

コンバータレンズと主レンズの合成光学系における値 
焦点距離            2.72mm 
Fナンバー           2.41 
半画角              70.8° 
像高                3.02mm 
レンズ全長          16.80mm 
バックフォーカス    1.24mm  
ただし、レンズ全長は第1レンズ被写体側面から主レンズ近軸像点までの距離。
主レンズの焦点距離  4.33mm 
コンバータ倍率      0.63  
[Table 7]
Example 7

Surface number (aspherical surface) R (mm) d (mm) nd νd Effective diameter (mm)
1 * 25.425 0.75 1.88202 37.2 10.95
2 * 5.973 2.59 8.48
3 -114.874 0.70 1.78590 43.9 7.99
4 11.710 0.20 7.62
5 7.342 4.34 1.64769 33.8 7.65
6 -11.799 1.24 6.46
7 ∞ 0.79 1.51633 64.1 4.13
8 ∞ 1.24 3.50
9 ∞ 0.05 1.80
10 (Aperture) ∞ -0.24 1.80
11 * 1.676 0.63 1.54470 56.2 1.87
12 * -13.857 0.05 1.90
13 * 4.012 0.28 1.63469 23.9 1.92
14 * 1.559 0.57 1.90
15 * -36.876 0.31 1.63469 23.9 2.15
16 * -35.075 0.42 2.46
17 * -6.434 0.86 1.54470 56.2 3.74
18 * -0.965 0.23 4.09
19 * -2.637 0.45 1.53048 55.7 4.60
20 * 1.582 0.64 5.13
21 ∞ 0.30 1.51633 64.1 5.67
22 ∞ 0.40 5.80
image

Aspheric coefficient of converter lens
First side Second side
K 0.000 0.000
A4 -7.2151E-04 -5.8463E-04
A6 4.1528E-06 2.1826E-06
A8 2.2788E-07 -8.4479E-07
A10 -3.5985E-09 6.4026E-08

Values in the combined optical system of the converter lens and main lens
Focal length 2.72mm
F number 2.41
Half angle of view 70.8 °
Image height 3.02mm
Total lens length 16.80mm
Back focus 1.24mm
However, the total lens length is the distance from the side of the first lens subject to the main lens paraxial image point.
Main lens focal length 4.33mm
Converter magnification 0.63
　図１６は、実施例７の収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））であるが、収差図はコンバータレンズと主レンズを組み合わせた状態のものである。 FIG. 16 is an aberration diagram of Example 7 (spherical aberration (a), astigmatism (b), distortion aberration (c)), and the aberration diagram shows a state in which the converter lens and the main lens are combined. .
　実施例７では、第1レンズＬ１物体側面の有効径と、主レンズＭＬの開口絞り径の比が0.16程度と、コンパクトな撮像光学系を実現している。 Example 7 realizes a compact imaging optical system in which the ratio of the effective diameter of the object side surface of the first lens L1 to the aperture stop diameter of the main lens ML is about 0.16.
（実施例８）
　実施例８のレンズデータを表８に示す。図１７は、実施例８の撮像光学系の断面図である。図中、ＣＬはコンバータレンズであり、物体側から順に、負の屈折力を有する第１レンズＬ１と、負の屈折力を有する第２レンズＬ２と、正の屈折力を有する第３レンズＬ３から構成される。また、ＭＬは主レンズであり、物体側から順に、第４レンズＬ４，第５レンズＬ５，第６レンズＬ６，第７レンズＬ７，第８レンズＬ８からなる。又、Ｓは、第４レンズＬ４の物体側面の光軸上の位置より像側であって、物体側面の最周辺部より物体側に設けられた開口絞り、ＩＭは撮像装置の撮像面を示す。また、ＣＧは主レンズＭＬのカバーガラスであり、Ｆは光学的ローパスフィルタやＩＲカットフィルタ、固体撮像素子のシールガラス等を想定した平行平板を示す。コンバータレンズＣＬ（面番号１～６）と主レンズＭＬ（面番号７～２２）とで、撮像光学系を構成する。本実施例では、コンバータレンズＣＬは、第１レンズＬ１が非球面レンズであり、それ以外は球面レンズであり、主レンズＭＬは非球面レンズを有する。尚、実施例８で用いる主レンズＭＬは、実施例１で用いたものと同じであるため、非球面係数は省略する。 (Example 8)
Table 8 shows lens data of Example 8. FIG. 17 is a cross-sectional view of the image pickup optical system according to the eighth embodiment. In the figure, CL is a converter lens, and in order from the object side, a first lens L1 having a negative refractive power, a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power. Composed. ML is a main lens, and is composed of a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8 in this order from the object side. S denotes an aperture stop provided on the object side from the position on the optical axis of the object side surface of the fourth lens L4 on the object side from the most peripheral part of the object side surface, and IM denotes an image pickup surface of the image pickup apparatus. . Further, CG is a cover glass of the main lens ML, and F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, and the like. The converter lens CL (surface numbers 1 to 6) and the main lens ML (surface numbers 7 to 22) constitute an imaging optical system. In the present embodiment, in the converter lens CL, the first lens L1 is an aspheric lens, the other lenses are spherical lenses, and the main lens ML has an aspheric lens. Since the main lens ML used in the eighth embodiment is the same as that used in the first embodiment, the aspheric coefficient is omitted.
［表８］
実施例８

面番号(非球面)    R(mm)   d(mm)   nd         νd      有効径(mm)
1   *             30.226  0.75    1.88202     37.2    10.96 
2   *             6.282   2.58                        8.48 
3              -117.270   0.70    1.78590     43.9    7.98 
4                11.258   0.20                        7.60 
5                 7.256   4.34    1.64769     33.8    7.65 
6               -11.702   1.24                        6.46 
7                 ∞      0.79    1.51633     64.1    4.13 
8                 ∞      1.24                        3.50 
9                 ∞      0.05                        1.80 
10(絞り)           ∞     -0.24                        1.80 
11  *             1.676   0.63    1.54470     56.2    1.87 
12  *           -13.857   0.05                        1.90 
13  *             4.012   0.28    1.63469     23.9    1.92 
14  *             1.559   0.57                        1.90 
15  *           -36.876   0.31    1.63469     23.9    2.15 
16  *           -35.075   0.42                        2.46 
17  *            -6.434   0.86    1.54470     56.2    3.74 
18  *            -0.965   0.23                        4.09 
19  *            -2.637   0.45    1.53048     55.7    4.60 
20  *             1.582   0.64                        5.13 
21                ∞      0.30    1.51633     64.1    5.67 
22                ∞      0.40                       5.79 
像 
 
コンバータレンズの非球面係数  
     第1面       第2面 
K    0.000        0.000 
A4  -4.7093E-04  -2.5021E-04 
A6  -6.2283E-06  -1.1760E-06 
A8   4.6488E-07  -1.0778E-06 
A10 -5.7998E-09   8.0612E-08  
  
コンバータレンズと主レンズの合成光学系における値  
焦点距離            2.72mm 
Fナンバー           2.41 
半画角              70.8°  
像高                3.02mm 
レンズ全長          16.79mm 
バックフォーカス    1.24mm 
ただし、レンズ全長は第1レンズ被写体側面から主レンズ近軸像点までの距離。
主レンズの焦点距離  4.33mm 
コンバータ倍率      0.63  
[Table 8]
Example 8

Surface number (aspherical surface) R (mm) d (mm) nd νd Effective diameter (mm)
1 * 30.226 0.75 1.88202 37.2 10.96
2 * 6.282 2.58 8.48
3 -117.270 0.70 1.78590 43.9 7.98
4 11.258 0.20 7.60
5 7.256 4.34 1.64769 33.8 7.65
6 -11.702 1.24 6.46
7 ∞ 0.79 1.51633 64.1 4.13
8 ∞ 1.24 3.50
9 ∞ 0.05 1.80
10 (Aperture) ∞ -0.24 1.80
11 * 1.676 0.63 1.54470 56.2 1.87
12 * -13.857 0.05 1.90
13 * 4.012 0.28 1.63469 23.9 1.92
14 * 1.559 0.57 1.90
15 * -36.876 0.31 1.63469 23.9 2.15
16 * -35.075 0.42 2.46
17 * -6.434 0.86 1.54470 56.2 3.74
18 * -0.965 0.23 4.09
19 * -2.637 0.45 1.53048 55.7 4.60
20 * 1.582 0.64 5.13
21 ∞ 0.30 1.51633 64.1 5.67
22 ∞ 0.40 5.79
image

Aspheric coefficient of converter lens
First side Second side
K 0.000 0.000
A4 -4.7093E-04 -2.5021E-04
A6 -6.2283E-06 -1.1760E-06
A8 4.6488E-07 -1.0778E-06
A10 -5.7998E-09 8.0612E-08

Values in the combined optical system of the converter lens and main lens
Focal length 2.72mm
F number 2.41
Half angle of view 70.8 °
Image height 3.02mm
Total lens length 16.79mm
Back focus 1.24mm
However, the total lens length is the distance from the side of the first lens subject to the main lens paraxial image point.
Main lens focal length 4.33mm
Converter magnification 0.63
　図１８は、実施例８の収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））であるが、収差図はコンバータレンズと主レンズを組み合わせた状態のものである。 FIG. 18 is an aberration diagram of Example 8 (spherical aberration (a), astigmatism (b), distortion aberration (c)), and the aberration diagram shows a state in which the converter lens and the main lens are combined. .
　実施例８では、第1レンズＬ１物体側面の有効径と、主レンズＭＬの開口絞り径の比が0.16程度と、コンパクトな撮像光学系を実現している。 In Example 8, the ratio of the effective diameter of the object side surface of the first lens L1 to the aperture stop diameter of the main lens ML is about 0.16, thereby realizing a compact imaging optical system.
（実施例９）
　実施例９のレンズデータを表９に示す。図１９は、実施例９の撮像光学系の断面図である。図中、ＣＬはコンバータレンズであり、物体側から順に、負の屈折力を有する第１レンズＬ１と、負の屈折力を有する第２レンズＬ２と、正の屈折力を有する第３レンズＬ３から構成される。また、ＭＬは主レンズであり、物体側から順に、第４レンズＬ４，第５レンズＬ５，第６レンズＬ６，第７レンズＬ７，第８レンズＬ８からなる。又、Ｓは、第４レンズＬ４の物体側面の光軸上の位置より像側であって、物体側面の最周辺部より物体側に設けられた開口絞り、ＩＭは撮像装置の撮像面を示す。また、ＣＧは主レンズＭＬのカバーガラスであり、Ｆは光学的ローパスフィルタやＩＲカットフィルタ、固体撮像素子のシールガラス等を想定した平行平板を示す。コンバータレンズＣＬ（面番号１～６）と主レンズＭＬ（面番号７～２２）とで、撮像光学系を構成する。本実施例では、コンバータレンズＣＬは、第１レンズＬ１が非球面レンズであり、それ以外は球面レンズであり、主レンズＭＬは非球面レンズを有する。尚、実施例９で用いる主レンズＭＬは、実施例１で用いたものと同じであるため、非球面係数は省略する。 Example 9
Table 9 shows lens data of Example 9. FIG. 19 is a cross-sectional view of the image pickup optical system according to the ninth embodiment. In the figure, CL is a converter lens, and in order from the object side, a first lens L1 having a negative refractive power, a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power. Composed. ML is a main lens, and is composed of a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8 in this order from the object side. S denotes an aperture stop provided on the object side from the position on the optical axis of the object side surface of the fourth lens L4 on the object side from the most peripheral part of the object side surface, and IM denotes an image pickup surface of the image pickup apparatus. . Further, CG is a cover glass of the main lens ML, and F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, and the like. The converter lens CL (surface numbers 1 to 6) and the main lens ML (surface numbers 7 to 22) constitute an imaging optical system. In the present embodiment, in the converter lens CL, the first lens L1 is an aspheric lens, the other lenses are spherical lenses, and the main lens ML has an aspheric lens. Since the main lens ML used in the ninth embodiment is the same as that used in the first embodiment, the aspheric coefficient is omitted.
［表９］
実施例９
 
面番号(非球面)    R(mm)   d(mm)   nd         νd      有効径(mm)
1   *             15.980  0.75    1.88202     37.2    10.97 
2   *              5.172  2.67                        8.48 
3               -163.709  0.70    1.78590     43.9    7.99 
4                 11.289  0.20                        7.61 
5                  7.267  4.34    1.64769     33.8    7.65 
6                -11.787  1.24                        6.46 
7                  ∞     0.79    1.51633     64.1    4.13 
8                  ∞     1.24                        3.50 
9                  ∞     0.05                        1.80 
10(絞り)            ∞    -0.24                        1.80 
11  *             1.676   0.63    1.54470     56.2    1.87 
12  *           -13.857   0.05                        1.90 
13  *             4.012   0.28    1.63469     23.9    1.92 
14  *             1.559   0.57                        1.90 
15  *           -36.876   0.31    1.63469     23.9    2.15 
16  *           -35.075   0.42                        2.46 
17  *            -6.434   0.86    1.54470     56.2    3.74 
18  *            -0.965   0.23                        4.09 
19  *            -2.637   0.45    1.53048     55.7    4.60 
20  *             1.582   0.64                        5.13 
21                ∞      0.30    1.51633     64.1    5.67 
22                ∞      0.40                       5.80 
像 
 
コンバータレンズの非球面係数 
     第1面       第2面  
K    0.000        0.000  
A4  -1.4947E-03  -1.6461E-03 
A6   3.0552E-05   1.5199E-06 
A8  -2.9350E-07   1.9499E-08 
A10  9.5095E-10   6.7781E-09  
 
コンバータレンズと主レンズの合成光学系における値 
焦点距離            2.72mm  
Fナンバー           2.41  
半画角              70.8° 
像高                3.02mm 
レンズ全長          16.88mm 
バックフォーカス    1.24mm 
ただし、レンズ全長は第1レンズ被写体側面から主レンズ近軸像点までの距離。
主レンズの焦点距離  4.33mm  
コンバータ倍率      0.63 
[Table 9]
Example 9

Surface number (aspherical surface) R (mm) d (mm) nd νd Effective diameter (mm)
1 * 15.980 0.75 1.88202 37.2 10.97
2 * 5.172 2.67 8.48
3 -163.709 0.70 1.78590 43.9 7.99
4 11.289 0.20 7.61
5 7.267 4.34 1.64769 33.8 7.65
6 -11.787 1.24 6.46
7 ∞ 0.79 1.51633 64.1 4.13
8 ∞ 1.24 3.50
9 ∞ 0.05 1.80
10 (Aperture) ∞ -0.24 1.80
11 * 1.676 0.63 1.54470 56.2 1.87
12 * -13.857 0.05 1.90
13 * 4.012 0.28 1.63469 23.9 1.92
14 * 1.559 0.57 1.90
15 * -36.876 0.31 1.63469 23.9 2.15
16 * -35.075 0.42 2.46
17 * -6.434 0.86 1.54470 56.2 3.74
18 * -0.965 0.23 4.09
19 * -2.637 0.45 1.53048 55.7 4.60
20 * 1.582 0.64 5.13
21 ∞ 0.30 1.51633 64.1 5.67
22 ∞ 0.40 5.80
image

Aspheric coefficient of converter lens
First side Second side
K 0.000 0.000
A4 -1.4947E-03 -1.6461E-03
A6 3.0552E-05 1.5199E-06
A8 -2.9350E-07 1.9499E-08
A10 9.5095E-10 6.7781E-09

Values in the combined optical system of the converter lens and main lens
Focal length 2.72mm
F number 2.41
Half angle of view 70.8 °
Image height 3.02mm
Total lens length 16.88mm
Back focus 1.24mm
However, the total lens length is the distance from the side of the first lens subject to the main lens paraxial image point.
Main lens focal length 4.33mm
Converter magnification 0.63
　図２０は、実施例９の収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））であるが、収差図はコンバータレンズと主レンズを組み合わせた状態のものである。 FIG. 20 is an aberration diagram of Example 9 (spherical aberration (a), astigmatism (b), distortion aberration (c)), and the aberration diagram is a state where the converter lens and the main lens are combined. .
　実施例９では、第1レンズＬ１物体側面の有効径と、主レンズＭＬの開口絞り径の比が0.16程度と、コンパクトな撮像光学系を実現している。 In the ninth embodiment, the ratio of the effective diameter of the object side surface of the first lens L1 to the aperture stop diameter of the main lens ML is about 0.16, thereby realizing a compact imaging optical system.
（実施例１０）
　実施例１０のレンズデータを表１０に示す。図２１は、実施例１０の撮像光学系の断面図である。図中、ＣＬはコンバータレンズであり、物体側から順に、負の屈折力を有する第１レンズＬ１と、負の屈折力を有する第２レンズＬ２と、正の屈折力を有する第３レンズＬ３から構成される。また、ＭＬは主レンズであり、物体側から順に、第４レンズＬ４，第５レンズＬ５，第６レンズＬ６，第７レンズＬ７，第８レンズＬ８からなる。又、Ｓは、第４レンズＬ４の物体側面の光軸上の位置より像側であって、物体側面の最周辺部より物体側に設けられた開口絞り、ＩＭは撮像装置の撮像面を示す。また、ＣＧは主レンズＭＬのカバーガラスであり、Ｆは光学的ローパスフィルタやＩＲカットフィルタ、固体撮像素子のシールガラス等を想定した平行平板を示す。コンバータレンズＣＬ（面番号１～６）と主レンズＭＬ（面番号７～２２）とで、撮像光学系を構成する。本実施例では、コンバータレンズＣＬは、第１レンズＬ１の物体側面が非球面であり、それ以外は球面であり、主レンズＭＬは非球面レンズを有する。尚、実施例１０で用いる主レンズＭＬは、実施例１で用いたものと同じであるため、非球面係数は省略する。 (Example 10)
Table 10 shows lens data of Example 10. FIG. 21 is a sectional view of the image pickup optical system according to the tenth embodiment. In the figure, CL is a converter lens, and in order from the object side, a first lens L1 having a negative refractive power, a second lens L2 having a negative refractive power, and a third lens L3 having a positive refractive power. Composed. ML is a main lens, and is composed of a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8 in this order from the object side. S denotes an aperture stop provided on the object side from the position on the optical axis of the object side surface of the fourth lens L4 on the object side from the most peripheral part of the object side surface, and IM denotes an image pickup surface of the image pickup apparatus. . Further, CG is a cover glass of the main lens ML, and F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, and the like. The converter lens CL (surface numbers 1 to 6) and the main lens ML (surface numbers 7 to 22) constitute an imaging optical system. In the present embodiment, the converter lens CL has an aspheric object side surface of the first lens L1 and a spherical surface other than that, and the main lens ML has an aspheric lens. Since the main lens ML used in the tenth embodiment is the same as that used in the first embodiment, the aspheric coefficient is omitted.
［表１０］
実施例１０
 
面番号(非球面)    R(mm)   d(mm)   nd         νd     有効径(mm)
1   *             30.284  0.75    1.88202     37.2    10.94 
2                 5.990   2.76                        8.41 
3               -57.165   0.70    1.78590     43.9    7.92 
4                14.450   0.20                        7.61 
5                 7.692   4.17    1.64769     33.8    7.61 
6               -11.791   1.24                        6.46 
7                 ∞      0.79    1.51633     64.1    4.13 
8                 ∞      1.24                        3.50 
9                 ∞      0.05                        1.80 
10(絞り)           ∞     -0.24                        1.80 
11  *             1.676   0.63    1.54470     56.2    1.87 
12  *           -13.857   0.05                        1.90 
13  *             4.012   0.28    1.63469     23.9    1.92 
14  *             1.559   0.57                        1.90 
15  *           -36.876   0.31    1.63469     23.9    2.15 
16  *           -35.075   0.42                        2.47 
17  *            -6.434   0.86    1.54470     56.2    3.78 
18  *            -0.965   0.23                        4.12 
19  *            -2.637   0.45    1.53048     55.7    4.62 
20  *             1.582   0.64                        5.14 
21                ∞      0.30    1.51633     64.1    5.68 
22                ∞      0.40                       5.80 
像 
 
コンバータレンズの非球面係数 
     第1面  
K    0.000 
A4  -2.1950E-04  
A6  -7.4033E-06 
A8   2.4743E-07  
A10 -2.8930E-09 
 
コンバータレンズと主レンズの合成光学系における値 
焦点距離            2.66mm 
Fナンバー           2.41  
半画角              70.7°  
像高                3.02mm  
レンズ全長          16.80mm 
バックフォーカス    1.24mm 
ただし、レンズ全長は第1レンズ被写体側面から主レンズ近軸像点までの距離。 
主レンズの焦点距離  4.33mm 
コンバータ倍率      0.61 
[Table 10]
Example 10

Surface number (aspherical surface) R (mm) d (mm) nd νd Effective diameter (mm)
1 * 30.284 0.75 1.88202 37.2 10.94
2 5.990 2.76 8.41
3 -57.165 0.70 1.78590 43.9 7.92
4 14.450 0.20 7.61
5 7.692 4.17 1.64769 33.8 7.61
6 -11.791 1.24 6.46
7 ∞ 0.79 1.51633 64.1 4.13
8 ∞ 1.24 3.50
9 ∞ 0.05 1.80
10 (Aperture) ∞ -0.24 1.80
11 * 1.676 0.63 1.54470 56.2 1.87
12 * -13.857 0.05 1.90
13 * 4.012 0.28 1.63469 23.9 1.92
14 * 1.559 0.57 1.90
15 * -36.876 0.31 1.63469 23.9 2.15
16 * -35.075 0.42 2.47
17 * -6.434 0.86 1.54470 56.2 3.78
18 * -0.965 0.23 4.12
19 * -2.637 0.45 1.53048 55.7 4.62
20 * 1.582 0.64 5.14
21 ∞ 0.30 1.51633 64.1 5.68
22 ∞ 0.40 5.80
image

Aspheric coefficient of converter lens
First side
K 0.000
A4 -2.1950E-04
A6 -7.4033E-06
A8 2.4743E-07
A10 -2.8930E-09

Values in the combined optical system of the converter lens and main lens
Focal length 2.66mm
F number 2.41
Half angle of view 70.7 °
Image height 3.02mm
Total lens length 16.80mm
Back focus 1.24mm
However, the total lens length is the distance from the side of the first lens subject to the main lens paraxial image point.
Main lens focal length 4.33mm
Converter magnification 0.61
　図２２は、実施例１０の収差図（球面収差（ａ）、非点収差（ｂ）、歪曲収差（ｃ））であるが、収差図はコンバータレンズと主レンズを組み合わせた状態のものである。 FIG. 22 is an aberration diagram of Example 10 (spherical aberration (a), astigmatism (b), distortion aberration (c)), and the aberration diagram shows a state in which the converter lens and the main lens are combined. .
　実施例１０では、第1レンズＬ１物体側面の有効径と、主レンズＭＬの開口絞り径の比が0.16程度と、コンパクトな撮像光学系を実現している。 Example 10 realizes a compact imaging optical system in which the ratio of the effective diameter of the object side surface of the first lens L1 to the aperture stop diameter of the main lens ML is about 0.16.
　各条件式に対応する各実施例の値を表１１に示す。 Table 11 shows values of each example corresponding to each conditional expression.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　本発明は、明細書に記載の実施形態、実施例に限定されるものではなく、他の実施形態・実施例・変形例を含むことは、本明細書に記載された実施形態や実施例や技術思想から本分野の当業者にとって明らかである。例えば、実質的にパワーを持たないダミーレンズを更に付与した場合でも本発明の適用範囲内である。 The present invention is not limited to the embodiments and examples described in the specification, and includes other embodiments, examples, and modified examples. It will be apparent to those skilled in the art from the technical idea. For example, even when a dummy lens having substantially no power is further provided, it is within the scope of the present invention.
ＢＤ　　ボディ
HLD　　鏡筒
ＣＬ　　コンバータレンズ
ＭＬ　　主レンズ
ＳＦ　　携帯端末
Ｌ１～Ｌ８　　レンズ BD body
HLD Lens CL Converter lens ML Main lens SF Mobile terminal L1-L8 Lens

Claims (11)

  1. 　主レンズより物体側に装着され、前記主レンズの撮影画角を広角側に変換するコンバータレンズにおいて、
    　前記コンバータレンズは物体側から順に、負の屈折力を有する第１レンズと、負の屈折力を有する第２レンズと、正の屈折力を有する第３レンズから構成され、
    　以下の条件式を満たすことを特徴とするコンバータレンズ。
    　０．０４＜ｄ４／ｄ５＜０．３　　　　　　　　　　　　　（１）
    　０．１＜（Ｒ６＋Ｒ５）／（Ｒ６－Ｒ５）＜２．０　　　（２）
    ただし、
    ｄ４：前記第２レンズと前記第３レンズの軸上空気間隔
    ｄ５：前記第３レンズの軸上厚
    Ｒ５：前記第３レンズの物体側面の曲率半径
    Ｒ６：前記第３レンズの像側面の曲率半径     In the converter lens that is mounted on the object side from the main lens and converts the shooting angle of view of the main lens to the wide angle side,
    The converter lens includes, in order from the object side, a first lens having negative refractive power, a second lens having negative refractive power, and a third lens having positive refractive power,
    A converter lens characterized by satisfying the following conditional expression:
    0.04 <d4 / d5 <0.3 (1)
    0.1 <(R6 + R5) / (R6-R5) <2.0 (2)
    However,
    d4: On-axis air space between the second lens and the third lens d5: On-axis thickness of the third lens R5: Curvature radius of the object side surface of the third lens R6: Radius of curvature of the image side surface of the third lens
  2. 　以下の条件式を満たすことを特徴とする請求項１に記載のコンバータレンズ。
    　ｎ１＞１．７　　　　　　　　　　　　　　　　　　　（３）
    ただし、
    ｎ１：前記第１レンズの屈折率     The converter lens according to claim 1, wherein the following conditional expression is satisfied.
    n1> 1.7 (3)
    However,
    n1: Refractive index of the first lens
  3. 　以下の条件式を満たすことを特徴とする請求項１又は２に記載のコンバータレンズ。
    　３０＜ν１＜５０　　　　　　　　　　　　　　　　　（４）
    ただし
    ν１：前記第１レンズのアッベ数     The converter lens according to claim 1, wherein the following conditional expression is satisfied.
    30 <ν1 <50 (4)
    Where ν1: Abbe number of the first lens
  4. 　以下の条件式を満たすことを特徴とする請求項１から３のいずれか一項に記載のコンバータレンズ。
    　２５＜ν３＜５０　　　　　　　　　　　　　　　　　（５）
    ただし、
    ν３：前記第３レンズのアッベ数     The converter lens according to any one of claims 1 to 3, wherein the following conditional expression is satisfied.
    25 <ν3 <50 (5)
    However,
    ν3: Abbe number of the third lens
  5. 　以下の条件式を満たすことを特徴とする請求項１から４のいずれか一項に記載のコンバータレンズ。
    　０．０５＜ｄ２／ｄ３５＜２．０　　　　　　　　　　（６）
    ただし、
    ｄ２：前記第１レンズと前記第２レンズの軸上空気間隔
    ｄ３５：前記第２レンズの物体側面から前記第３レンズの像側面までの軸上距離     The converter lens according to claim 1, wherein the following conditional expression is satisfied.
    0.05 <d2 / d35 <2.0 (6)
    However,
    d2: axial air space between the first lens and the second lens d35: axial distance from the object side surface of the second lens to the image side surface of the third lens
  6. 　以下の条件式を満たすことを特徴とする請求項１から５のいずれか一項に記載のコンバータレンズ。
    　０．５＜ｆ２／ｆ１＜１０　　　　　　　　　　　　（７）
    ただし、
    ｆ１：前記第１レンズの焦点距離
    ｆ２：前記第２レンズの焦点距離     The converter lens according to claim 1, wherein the following conditional expression is satisfied.
    0.5 <f2 / f1 <10 (7)
    However,
    f1: Focal length of the first lens f2: Focal length of the second lens
  7. 　前記第１レンズは少なくとも物体側面に非球面を有し、以下の条件式を満たすことを特徴とする請求項１から６のいずれか一項に記載のコンバータレンズ。
    　－２５＜ＡＰＥ１／ＡＳＰ１＜－５　　　　　　　（８）
    ただし、
    ＡＰＥ１：前記第１レンズの物体側面の有効半径
    ＡＳＰ１：前記第１レンズの物体側面の有効半径における非球面量     The converter lens according to claim 1, wherein the first lens has an aspheric surface at least on the object side surface, and satisfies the following conditional expression.
    -25 <APE1 / ASP1 <-5 (8)
    However,
    APE1: Effective radius of the object side surface of the first lens ASP1: Aspheric amount at an effective radius of the object side surface of the first lens
  8. 　前記第１レンズは少なくとも像側面に非球面を有し、以下の条件式を満たすことを特徴とする請求項１から７のいずれか一項に記載のコンバータレンズ。
    　－９０＜ＡＰＥ２／ＡＳＰ２＜－５　　　　　　　　　（９）
    ただし、
    ＡＰＥ１：前記第１レンズの像側面の有効半径
    ＡＳＰ１：前記第１レンズの像面の有効半径における非球面量     The converter lens according to claim 1, wherein the first lens has an aspheric surface at least on an image side surface, and satisfies the following conditional expression.
    -90 <APE2 / ASP2 <-5 (9)
    However,
    APE1: Effective radius of the image side surface of the first lens ASP1: Aspheric amount at an effective radius of the image surface of the first lens
  9. 　前記第１レンズは物体側面と像側面何れにも非球面を有し、以下の条件式を満たすことを特徴とする請求項１から８のいずれか一項に記載のコンバータレンズ。
    　１＜ＡＳＰ１／ＡＳＰ２＜８　　　　　　　（１０）
    ただし、
    ＡＳＰ１：前記第１レンズの物体側面の有効半径における非球面量
    ＡＳＰ２：前記第１レンズの像側面の有効半径における非球面量     The converter lens according to claim 1, wherein the first lens has an aspheric surface on both the object side surface and the image side surface, and satisfies the following conditional expression.
    1 <ASP1 / ASP2 <8 (10)
    However,
    ASP1: Aspheric amount at effective radius of object side surface of first lens ASP2: Aspheric amount at effective radius of image side surface of first lens
  10. 　請求項１から９のいずれか一項に記載のコンバータレンズと、前記主レンズとからなり、前記主レンズは、前記主レンズの物体側から２番目のレンズより物体側に開口絞りが設けられていることを特徴とする撮像光学系。 A converter lens according to any one of claims 1 to 9 and the main lens, wherein the main lens is provided with an aperture stop closer to the object side than the second lens from the object side of the main lens. An imaging optical system characterized by comprising:
  11. 　前記主レンズと撮像素子を本体内に内蔵し、請求項１から９のいずれか一項に記載のコンバータレンズが装着可能となされたことを特徴とする携帯端末。 10. A portable terminal comprising the main lens and an image sensor incorporated in a main body, wherein the converter lens according to claim 1 can be attached.
PCT/JP2014/062792 2013-06-11 2014-05-14 Converter lens, image capture optical assembly, and portable terminal WO2014199766A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112154364A (en) * 2019-09-23 2020-12-29 深圳市大疆创新科技有限公司 Optical system and imaging device

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Publication number Priority date Publication date Assignee Title
JPH03260609A (en) * 1990-03-09 1991-11-20 Canon Inc Wide converter lens
JP2001272599A (en) * 2000-03-28 2001-10-05 Canon Inc Converter lens and optical system using the same
JP2003241094A (en) * 2002-02-15 2003-08-27 Nikon Corp Lens system and wide converter lens
US20110085245A1 (en) * 2009-10-13 2011-04-14 Samsung Electronics Co., Ltd. Wide converter lens
JP2014048590A (en) * 2012-09-03 2014-03-17 Ricoh Co Ltd Wide converter lens

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03260609A (en) * 1990-03-09 1991-11-20 Canon Inc Wide converter lens
JP2001272599A (en) * 2000-03-28 2001-10-05 Canon Inc Converter lens and optical system using the same
JP2003241094A (en) * 2002-02-15 2003-08-27 Nikon Corp Lens system and wide converter lens
US20110085245A1 (en) * 2009-10-13 2011-04-14 Samsung Electronics Co., Ltd. Wide converter lens
JP2014048590A (en) * 2012-09-03 2014-03-17 Ricoh Co Ltd Wide converter lens

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112154364A (en) * 2019-09-23 2020-12-29 深圳市大疆创新科技有限公司 Optical system and imaging device

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