Optical system, image projection device, and imaging device

Abstract

The present disclosure is an optical system that includes, internally, an intermediate image forming position that is a conjugate of each of an enlargement conjugate point on an enlargement side and a reduction conjugate point on a reduction side. The optical system comprises: an enlargement optical system that includes a plurality of lens elements and that is positioned more to the enlargement side than the intermediate image forming position; and a relay optical system that includes a plurality of lens elements and that is positioned more to the reduction side than the intermediate image forming position. A plurality of air gaps exists among the lens elements, and the enlargement optical system includes: an enlargement optical system front group that is positioned more to the enlargement side than a longest air gap along an optical axis in the enlargement optical system; and an enlargement optical system rear group that is positioned more to the reduction side than the the longest air gap. The following conditions (1) and (2) are satisfied: (1): 7 < |TS / fw| < 15 (2): 2 < |Tpr / fw| < 7

Description

Technical Field

[0001] The present disclosure relates to an optical system that forms an intermediate image. The present disclosure also relates to an image projection apparatus and an imaging apparatus using such an optical system.

Background Art

[0002] An optical system using an intermediate imaging method has an advantage that it can achieve wide-angle projection with a short focal length and a large screen, but the overall length of the optical system tends to be large. Therefore, the optical system becomes heavy, and when a part of the optical system is mounted outside the housing of the image projection apparatus main body, the optical system may tilt with respect to the apparatus main body due to the moment acting on the center of gravity, and the optical performance may deteriorate.

[0003] To reduce the weight of the optical system, the use of synthetic resin lenses is assumed as an alternative to glass lenses. Synthetic resin has a smaller specific gravity than glass, but has a smaller thermal conductivity and a larger linear expansion coefficient. Therefore, although the weight of the optical system can be reduced, local temperature rise and thermal deformation occur, and optical aberrations, particularly chromatic aberration, tend to increase. Such a tendency becomes particularly prominent in the case of high-brightness projection.

[0004] Patent Document 1 discloses a wide-angle imaging optical system, and the first lens L1a closest to the enlarged conjugate point has the largest aperture. Since both surfaces of the first lens L1a are aspherical and have a rather complex shape, the use of a synthetic resin lens is presumed. However, such a complex aspherical shape is quite sensitive to thermal deformation, and it is expected that the deterioration of optical aberration due to temperature rise will become prominent.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present disclosure provides an optical system capable of reducing the moment acting on the center of gravity. The present disclosure also provides an image projection device and an imaging device using such an optical system.

Means for Solving the Problems

[0007] One aspect of the present disclosure is an optical system having an intermediate imaging position conjugate to an enlarged conjugate point on the enlargement side and a reduced conjugate point on the reduction side, respectively, inside, having a plurality of lens elements, an enlargement optical system located on the enlargement side of the intermediate imaging position, having a plurality of lens elements, and a relay optical system located on the reduction side of the intermediate imaging position, Between the lens elements, along the optical axis within the optical system a plurality of air spaces exist, The plurality of air gaps have a longest first air gap within the magnifying optical system, a longest second air gap within the relay optical system, and a third air gap where the intermediate imaging position is arranged, and the third air gap is shorter than the first air gap and the second air gap. The enlargement optical system the first includes an enlargement optical system front group located on the enlargement side of the air space and the First enlargement optical system rear group located on the reduction side of the air space, satisfies the following conditions (1) and (2). 7 < |Ts / fw| < 15 …(1) 2 < |Tpr / fw| < 7 …(2) Here, Ts: the First air space fw: the focal length of the entire system at the wide-angle end Tpr: the distance from the enlargement-side surface of the enlargement optical system rear group to the intermediate imaging position position is.

[0008] An image projection device according to the present disclosure includes the above optical system and an image forming element that generates an image to be projected onto a screen via the optical system.

[0009] An imaging device according to the present disclosure includes the above optical system and an imaging element that receives the optical image formed by the optical system and converts it into an electrical image signal.

Advantages of the Invention

[0010] According to the optical system according to the present disclosure, the moment acting on the center of gravity can be reduced. Therefore, the optical system can be stably mounted on the apparatus main body.

Brief Description of the Drawings

[0011]

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Mode for Carrying Out the Invention

[0012] Hereinafter, embodiments will be described in detail with appropriate reference to the drawings. However, a more detailed description than necessary may be omitted. For example, a detailed description of well-known matters or a redundant description of substantially the same configuration may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate the understanding of those skilled in the art.

[0013] The applicant provides the accompanying drawings and the following description for those skilled in the art to fully understand the present disclosure, and does not intend to limit the subject matter described in the claims thereby.

[0014] Hereinafter, each embodiment of the optical system according to the present disclosure will be described. In each embodiment, a case where the optical system is used in a projector (an example of an image projection device) that projects image light of an original image S obtained by spatially modulating incident light with an image forming element such as a liquid crystal or a DMD (Digital Micromirror Device) based on an image signal will be described. That is, the optical system according to the present disclosure can be used to project the original image S on the image forming element arranged on the reduction side onto a screen by arranging a screen (not shown) on the extension line on the enlargement side and enlarging it.

[0015] In addition, the optical system according to the present disclosure can also be used to collect light emitted from an object located on the extension line on the enlargement side and form an optical image of the object on the imaging surface of an imaging element arranged on the reduction side.

[0016] (Embodiment 1) Hereinafter, Embodiment 1 of the present disclosure will be described with reference to FIGS. 1 to 21. Here, a zoom lens system will be described as an example of the optical system.

[0017] FIGS. 1, 4, 7, 10, 13, 16, and 19 are layout diagrams showing the optical paths at the wide-angle end when the object distance is 1066 mm for the zoom lens systems according to Examples 1 to 7. FIGS. 2, 5, 8, 11, 14, 17, and 20 are layout diagrams at the wide-angle end when the object distance is 1066 mm for the zoom lens systems according to Examples 1 to 7. FIGS. 2(a), 5(a), 8(a), 11(a), 14(a), 17(a), and 20(a) show lens layout diagrams at the wide-angle end of the zoom lens system. FIGS. 2(b), 5(b), 8(b), 11(b), 14(b), 17(b), and 20(b) show lens layout diagrams at the intermediate position of the zoom lens system. FIGS. 2(c), 5(c), 8(c), 11(c), 14(c), 17(c), and 20(c) show lens layout diagrams at the telephoto end of the zoom lens system.

[0018] The wide-angle end is in the shortest focal length state where the entire system has the shortest focal length fw. The intermediate position is in the intermediate focal length state between the wide-angle end and the telephoto end. The telephoto end is in the longest focal length state where the entire system has the longest focal length ft. Based on the focal length fw of the wide-angle end and the focal length ft of the telephoto end, the focal length fm of the intermediate position is defined as fm = √(fw × ft).

[0019] The zoom lens system according to Embodiment 1 includes a first lens group G1 to a fourth lens group G4 and an optical element P. The first lens group G1 has a positive power and is composed of a first lens element L1 to a fifteenth lens element L15, including surfaces 1 to 30 (refer to the numerical examples described later). The second lens group G2 has a positive power and is composed of a sixteenth lens element L16 to an eighteenth lens element L18, including surfaces 31 to 36. The third lens group G3 has a negative power and is composed of a nineteenth lens element L19 to a twenty-second lens element L22, including surfaces 37 to 45. The fourth lens group G4 has a positive power and is composed of a twenty-third lens element L23 to a twenty-fifth lens element L25, including surfaces 46 to 51. The optical element P includes surfaces 52 to 53.

[0020] The zoom lens system according to Embodiment 2 includes a first lens group G1 to a fourth lens group G4 and an optical element P, which is the same as Embodiment 1, so duplicate explanations are omitted.

[0021] The zoom lens system according to Embodiment 3 includes a first lens group G1 to a fourth lens group G4 and an optical element P. The first lens group G1 has a positive power and is composed of a first lens element L1 to a sixteenth lens element L16, including surfaces 1 to 32 (refer to the numerical examples described later). The second lens group G2 has a positive power and is composed of a seventeenth lens element L17 to a nineteenth lens element L19, including surfaces 33 to 38. The third lens group G3 has a negative power and is composed of a twentieth lens element L20 to a twenty-third lens element L23, including surfaces 39 to 47. The fourth lens group G4 has a positive power and is composed of a twenty-fourth lens element L24 to a twenty-sixth lens element L26, including surfaces 48 to 53. The optical element P includes surfaces 54 to 55.

[0022] The broken-line arrows shown between each figure (a) and each figure (b) are straight lines obtained by connecting the positions of the first lens group G1 to the fourth lens group G4 in each state of the wide-angle end, the intermediate position, and the telephoto end in order from the top in the figure. Between the wide-angle end and the intermediate position, and between the intermediate position and the telephoto end, they are simply connected by straight lines, which is different from the actual movement of each lens group G1 to G4. Also, the symbols (+) and (-) attached to the signs of each lens group G1 to G4 indicate the positive and negative of the power of each lens group G1 to G4.

[0023] The zoom lens systems according to Embodiments 1 to 7 may include, if necessary, a focusing adjustment lens group that performs focusing adjustment when the object distance changes, and an image curvature correction lens group that corrects image curvature aberration after the focusing adjustment lens group performs focusing adjustment.

[0024] In each figure, the imaging position on the magnifying side (i.e., the magnified conjugate point) is located on the left side, and the imaging position on the reducing side (i.e., the reduced conjugate point) is located on the right side. Also, in each figure, the straight line described on the most reduced side represents the position of the original image S, and the optical element P is located on the magnifying side of the original image S. The optical element P represents optical elements such as a prism for color separation and color synthesis, an optical filter, a parallel plate glass, a quartz low-pass filter, and an infrared cut filter.

[0025] The zoom lens systems according to Embodiments 1 to 7 have an intermediate imaging position MI inside that is conjugate to the magnified conjugate point on the magnifying side and the reduced conjugate point on the reducing side, respectively. Also, in each figure, an enlarging optical system Op is arranged on the magnifying side of the intermediate imaging position MI, and a relay optical system Ol is arranged on the reducing side of the intermediate imaging position MI.

[0026] In the zoom lens systems according to Embodiments 1 to 7, there are a plurality of air spaces between the first lens element L1 and the 25th lens element L25 (26th lens element L26) and the optical element P. The magnifying optical system Op has the longest air space along the optical axis within the magnifying optical system. For example, in Embodiments 1 and 2, as shown in FIGS. 2 and 5, the longest air space exists between the 10th lens element L10 and the 11th lens element L11. In Embodiment 3, as shown in FIG. 8, the longest air space exists between the 11th lens element L11 and the 12th lens element L12. The magnifying optical system Op includes a front group Opf located on the magnifying side from the longest air space and a rear group Opr located on the reducing side from the longest air space. The front group Opf and the rear group Opr may have a single or a plurality of lens elements.

[0027] FIGS. 3, 6, 9, 12, 15, 18, and 21 are longitudinal aberration diagrams of the zoom lens systems according to Embodiments 1 to 7 at an object distance of 1066 mm. (a), (b), and (c) in each figure show longitudinal aberration diagrams at the wide-angle end, the intermediate position, and the telephoto end of the zoom lens system.

[0028] Each longitudinal aberration diagram shows, in order from the left, spherical aberration (SA (mm)), astigmatism (AST (mm)), and distortion (DIS (%)). In the spherical aberration diagram, the vertical axis represents the pupil height, the solid line represents the characteristics of the d-line, the short dashed line represents the F-line, and the long dashed line represents the C-line. In the astigmatism diagram, the vertical axis represents the image height, the solid line represents the sagittal plane (indicated by s in the figure), and the dashed line represents the meridional plane (indicated by m in the figure). In the distortion diagram, the vertical axis represents the image height. Also, the distortion represents the distortion with respect to equidistant projection.

[0029] (Embodiment 1) As shown in FIGS. 1 and 2, the zoom lens system according to Embodiment 1 includes a magnifying optical system Op and a relay optical system Ol. The magnifying optical system Op is composed of the first lens element L1 to the 12th lens element L12. The magnifying optical system Op includes a front group Opf and a rear group Opr.

[0030] The front group Opf of the magnifying optical system Op is composed of the first lens element L1 to the tenth lens element L10 in order from the magnifying side to the reducing side. The first lens element L1 has a negative meniscus shape with a convex surface facing the magnifying side. The second lens element L2 has a negative meniscus shape with a convex surface facing the magnifying side. The third lens element L3 has a negative meniscus shape with a convex surface facing the magnifying side. The fourth lens element L4 has a biconcave shape. The fifth lens element L5 has a negative meniscus shape with a convex surface facing the reducing side. The sixth lens element L6 has a positive meniscus shape with a convex surface facing the reducing side. The seventh lens element L7 has a negative meniscus shape with a convex surface facing the reducing side. The eighth lens element L8 has a positive meniscus shape with a convex surface facing the reducing side. The ninth lens element L9 has a positive meniscus shape with a convex surface facing the reducing side. The tenth lens element L10 has a positive meniscus shape with a convex surface facing the reducing side.

[0031] The rear group Opr of the magnifying optical system Op is composed of the eleventh lens element L11 to the twelfth lens element L12 in order from the magnifying side to the reducing side. The eleventh lens element L11 has a biconvex shape. The twelfth lens element L12 has a positive meniscus shape with a convex surface facing the magnifying side.

[0032] The relay optical system Ol is composed of the thirteenth lens element L13 to the twenty-fifth lens element L25 in order from the magnifying side to the reducing side. The thirteenth lens element L13 has a biconcave shape. The fourteenth lens element L14 has a biconcave shape. The fifteenth lens element L15 has a positive meniscus shape with a convex surface facing the reducing side. The sixteenth lens element L16 has a biconvex shape. The seventeenth lens element L17 has a negative meniscus shape with a convex surface facing the reducing side. The eighteenth lens element L18 has a biconvex shape. The nineteenth lens element L19 has a biconvex shape. The twentieth lens element L20 has a biconcave shape. The twenty-first lens element L21 has a biconcave shape. The twenty-second lens element L22 has a biconvex shape. The twenty-third lens element L23 has a biconvex shape. The twenty-fourth lens element L24 has a negative meniscus shape with a convex surface facing the magnifying side. The twenty-fifth lens element L25 has a biconvex shape.

[0033] The relay optical system Ol is composed of, in order from the wide-angle side to the telephoto side, a first lens group (L13 to L15) having negative power, a second lens group (L16 to L18) having positive power, a third lens group (L19 to L22) having negative power, and a fourth lens group (L23 to L25) having positive power. During zooming, the first lens group and the third lens group are fixed, and the second lens group and the fourth lens group are displaced along the optical axis.

[0034] As an example, the first lens element L1 corresponds to the first lens element of the claims.

[0035] There is an intermediate imaging position MI between the 12th lens element L12 and the 13th lens element L13. Also, a diaphragm A is disposed between the 19th lens element L19 and the 20th lens element L20. An optical element P having zero optical power is disposed on the telephoto side of the relay optical system Ol.

[0036] (Example 2) As shown in FIGS. 4 and 5, the zoom lens system according to Example 2 includes an expansion optical system Op and a relay optical system Ol. The expansion optical system Op is composed of a first lens element L1 to a 12th lens element L12. The expansion optical system Op includes a front group Opf and a rear group Opr.

[0037] The front group Opf of the expansion optical system Op is composed of a first lens element L1 to a 10th lens element L10 in order from the wide-angle side to the telephoto side. The first lens element L1 has a negative meniscus shape with a convex surface facing the wide-angle side. The second lens element L2 has a negative meniscus shape with a convex surface facing the wide-angle side. The third lens element L3 has a negative meniscus shape with a convex surface facing the wide-angle side. The fourth lens element L4 has a biconvex shape. The fifth lens element L5 has a positive meniscus shape with a convex surface facing the telephoto side. The sixth lens element L6 has a positive meniscus shape with a convex surface facing the telephoto side. The seventh lens element L7 has a negative meniscus shape with a convex surface facing the telephoto side. The eighth lens element L8 has a positive meniscus shape with a convex surface facing the telephoto side. The ninth lens element L9 has a positive meniscus shape with a convex surface facing the telephoto side. The 10th lens element L10 has a biconvex shape.

[0038] The rear group Opr of the magnifying optical system Op is composed of an 11th lens element L11 and a 12th lens element L12 in order from the magnifying side to the reducing side. The 11th lens element L11 has a biconvex shape. The 12th lens element L12 has a positive meniscus shape with a convex surface facing the magnifying side.

[0039] The relay optical system Ol is composed of a 13th lens element L13 to a 25th lens element L25 in order from the magnifying side to the reducing side. The 13th lens element L13 has a biconcave shape. The 14th lens element L14 has a biconcave shape. The 15th lens element L15 has a biconvex shape. The 16th lens element L16 has a biconvex shape. The 17th lens element L17 has a biconcave shape. The 18th lens element L18 has a biconvex shape. The 19th lens element L19 has a positive meniscus shape with a convex surface facing the magnifying side. The 20th lens element L20 has a negative meniscus shape with a convex surface facing the magnifying side. The 21st lens element L21 has a biconcave shape. The 22nd lens element L22 has a biconvex shape. The 23rd lens element L23 has a biconvex shape. The 24th lens element L24 has a negative meniscus shape with a convex surface facing the magnifying side. The 25th lens element L25 has a biconvex shape.

[0040] The relay optical system Ol is composed of a first lens group (L13 to L15) having a negative power, a second lens group (L16 to L18) having a positive power, a third lens group (L19 to L22) having a negative power, and a fourth lens group (L23 to L25) having a positive power in order from the magnifying side to the reducing side. During zooming, the first lens group and the third lens group are fixed, and the second lens group and the fourth lens group are displaced along the optical axis.

[0041] As an example, the 1st lens element L1 corresponds to the 1st lens element of the claims.

[0042] There is an intermediate imaging position MI between the 12th lens element L12 and the 13th lens element L13. Also, a diaphragm A is disposed between the 19th lens element L19 and the 20th lens element L20. An optical element P with zero optical power is disposed on the reducing side of the relay optical system Ol.

[0043] (Embodiment 3) As shown in FIGS. 7 and 8, the zoom lens system according to Embodiment 3 includes an enlargement optical system Op and a relay optical system Ol. The enlargement optical system Op is composed of a 1st lens element L1 to a 13th lens element L13. The enlargement optical system Op includes a front group Opf and a rear group Opr.

[0044] The front group Opf of the enlargement optical system Op is composed of a 1st lens element L1 to an 11th lens element L11 in order from the enlargement side to the reducing side. The 1st lens element L1 has a negative meniscus shape with a convex surface facing the enlargement side. The 2nd lens element L2 has a negative meniscus shape with a convex surface facing the enlargement side. The 3rd lens element L3 has a negative meniscus shape with a convex surface facing the enlargement side. The 4th lens element L4 has a biconcave shape. The 5th lens element L5 has a biconvex shape. The 6th lens element L6 has a biconcave shape. The 7th lens element L7 has a biconvex shape. The 8th lens element L8 has a negative meniscus shape with a convex surface facing the reducing side. The 9th lens element L9 has a positive meniscus shape with a convex surface facing the reducing side. The 10th lens element L10 has a positive meniscus shape with a convex surface facing the reducing side. The 11th lens element L11 has a biconvex shape.

[0045] The rear group Opr of the enlargement optical system Op is composed of a 12th lens element L12 to a 13th lens element L13 in order from the enlargement side to the reducing side. The 12th lens element L12 has a biconvex shape. The 13th lens element L13 has a positive meniscus shape with a convex surface facing the enlargement side.

[0046] The relay optical system Ol is composed of the 14th lens element L14 to the 26th lens element L26 in order from the magnification side to the reduction side. The 14th lens element L14 has a biconcave shape. The 15th lens element L15 has a biconcave shape. The 16th lens element L16 has a positive meniscus shape with the convex surface facing the reduction side. The 17th lens element L17 has a negative meniscus shape with the convex surface facing the magnification side. The 18th lens element L18 has a biconvex shape. The 19th lens element L19 has a biconvex shape. The 20th lens element L20 has a biconvex shape. The 21st lens element L21 has a biconcave shape. The 22nd lens element L22 has a biconcave shape. The 23rd lens element L23 has a biconvex shape. The 24th lens element L24 has a biconvex shape. The 25th lens element L25 has a negative meniscus shape with the convex surface facing the magnification side. The 26th lens element L26 has a biconvex shape.

[0047] The relay optical system Ol consists of a first lens group (L14 to L16) having negative power, a second lens group (L17 to L19) having positive power, a third lens group (L20 to L23) having negative power, and a fourth lens group (L24 to L26) having positive power in order from the magnification side to the reduction side. During zooming, the first lens group and the third lens group are fixed, and the second lens group and the fourth lens group are displaced along the optical axis.

[0048] As an example, the first lens element L1 corresponds to the first lens element of the claim.

[0049] There is an intermediate imaging position MI between the 13th lens element L13 and the 14th lens element L14. Also, a diaphragm A is disposed between the 19th lens element L19 and the 20th lens element L20. An optical element P having zero optical power is disposed on the reduction side of the relay optical system Ol.

[0050] (Example 4) As shown in FIGS. 10 and 11, the zoom lens system according to Example 4 includes an enlargement optical system Op and a relay optical system Ol. The enlargement optical system Op is composed of a first lens element L1 to a twelfth lens element L12. The enlargement optical system Op includes a front group Opf and a rear group Opr.

[0051] The front group Opf of the enlargement optical system Op is composed of a first lens element L1 to a tenth lens element L10 in order from the enlargement side to the reduction side. The first lens element L1 has a negative meniscus shape with a convex surface facing the enlargement side. The second lens element L2 has a negative meniscus shape with a convex surface facing the enlargement side. The third lens element L3 has a negative meniscus shape with a convex surface facing the enlargement side. The fourth lens element L4 has a biconcave shape. The fifth lens element L5 has a positive meniscus shape with a convex surface facing the reduction side. The sixth lens element L6 has a positive meniscus shape with a convex surface facing the reduction side. The seventh lens element L7 has a negative meniscus shape with a convex surface facing the reduction side. The eighth lens element L8 has a positive meniscus shape with a convex surface facing the reduction side. The ninth lens element L9 has a positive meniscus shape with a convex surface facing the reduction side. The tenth lens element L10 has a positive meniscus shape with a convex surface facing the reduction side.

[0052] The rear group Opr of the enlargement optical system Op is composed of an eleventh lens element L11 to a twelfth lens element L12 in order from the enlargement side to the reduction side. The eleventh lens element L11 has a biconvex shape. The twelfth lens element L12 has a positive meniscus shape with a convex surface facing the enlargement side.

[0053] The relay optical system Ol is composed of a thirteenth lens element L13 to a twenty-fifth lens element L25 in order from the enlargement side to the reduction side. The thirteenth lens element L13 has a biconcave shape. The 14th lens element L14 has a biconcave shape. The 15th lens element L15 has a positive meniscus shape with the convex surface facing the reduction side. The 16th lens element L16 has a positive meniscus shape with the convex surface facing the reduction side. The 17th lens element L17 has a negative meniscus shape with the convex surface facing the reduction side. The 18th lens element L18 has a biconvex shape. The 19th lens element L19 has a biconvex shape. The 20th lens element L20 has a biconcave shape. The 21st lens element L21 has a biconcave shape. The 22nd lens element L22 has a biconvex shape. The 23rd lens element L23 has a biconvex shape. The 24th lens element L24 has a negative meniscus shape with the convex surface facing the enlargement side. The 25th lens element L25 has a biconvex shape.

[0054] The relay optical system Ol consists of a first lens group (L13 - L15) having negative power, a second lens group (L16 - L18) having positive power, a third lens group (L19 - L22) having negative power, and a fourth lens group (L23 - L25) having positive power, in order from the enlargement side to the reduction side. During zooming, the first lens group and the third lens group are fixed, and the second lens group and the fourth lens group are displaced along the optical axis.

[0055] As an example, the first lens element L1 corresponds to the first lens element of the claims.

[0056] There is an intermediate imaging position MI between the 12th lens element L12 and the 13th lens element L13. Also, a diaphragm A is disposed between the 19th lens element L19 and the 20th lens element L20. An optical element P with zero optical power is disposed on the reduction side of the relay optical system Ol.

[0057] (Example 5) As shown in FIGS. 13 and 14, the zoom lens system according to Example 5 includes an enlargement optical system Op and a relay optical system Ol. The enlargement optical system Op is composed of the first lens element L1 to the 12th lens element L12. The enlargement optical system Op includes a front group Opf and a rear group Opr.

[0058] The front group Opf of the magnifying optical system Op is composed of a first lens element L1 to a tenth lens element L10 in order from the magnifying side to the reducing side. The first lens element L1 has a negative meniscus shape with a convex surface facing the magnifying side. The second lens element L2 has a negative meniscus shape with a convex surface facing the magnifying side. The third lens element L3 has a negative meniscus shape with a convex surface facing the magnifying side. The fourth lens element L4 has a positive meniscus shape with a convex surface facing the reducing side. The fifth lens element L5 has a negative meniscus shape with a convex surface facing the reducing side. The sixth lens element L6 has a positive meniscus shape with a convex surface facing the reducing side. The seventh lens element L7 has a biconcave shape. The eighth lens element L8 has a biconvex shape. The ninth lens element L9 has a positive meniscus shape with a convex surface facing the reducing side. The tenth lens element L10 has a biconvex shape.

[0059] The rear group Opr of the magnifying optical system Op is composed of an eleventh lens element L11 to a twelfth lens element L12 in order from the magnifying side to the reducing side. The eleventh lens element L11 has a biconvex shape. The twelfth lens element L12 has a positive meniscus shape with a convex surface facing the magnifying side.

[0060] The relay optical system Ol is composed of a thirteenth lens element L13 to a twenty-fifth lens element L25 in order from the magnifying side to the reducing side. The thirteenth lens element L13 has a negative meniscus shape with a convex surface facing the magnifying side. The fourteenth lens element L14 has a biconcave shape. The fifteenth lens element L15 has a positive meniscus shape with a convex surface facing the reducing side. The sixteenth lens element L16 has a biconvex shape. The seventeenth lens element L17 has a negative meniscus shape with a convex surface facing the reducing side. The eighteenth lens element L18 has a biconvex shape. The nineteenth lens element L19 has a biconvex shape. The twentieth lens element L20 has a biconcave shape. The twenty-first lens element L21 has a biconcave shape. The twenty-second lens element L22 has a biconvex shape. The twenty-third lens element L23 has a biconvex shape. The twenty-fourth lens element L24 has a negative meniscus shape with a convex surface facing the magnifying side. The twenty-fifth lens element L25 has a biconvex shape.

[0061] The relay optical system Ol is composed of, in order from the wide-angle side to the telephoto side, a first lens group (L13 to L15) having negative power, a second lens group (L16 to L18) having positive power, a third lens group (L19 to L22) having negative power, and a fourth lens group (L23 to L25) having positive power. During zooming, the first lens group and the third lens group are fixed, and the second lens group and the fourth lens group are displaced along the optical axis.

[0062] As an example, the first lens element L1 corresponds to the first lens element of the claims.

[0063] There is an intermediate imaging position MI between the 12th lens element L12 and the 13th lens element L13. Also, a diaphragm A is disposed between the 19th lens element L19 and the 20th lens element L20. An optical element P having zero optical power is disposed on the telephoto side of the relay optical system Ol.

[0064] (Example 6) As shown in FIGS. 16 and 17, the zoom lens system according to Example 6 includes an expansion optical system Op and a relay optical system Ol. The expansion optical system Op is composed of the first lens element L1 to the 12th lens element L12. The expansion optical system Op includes a front group Opf and a rear group Opr.

[0065] The front group Opf of the magnifying optical system Op is composed of the first lens element L1 to the tenth lens element L10 in order from the magnifying side to the reducing side. The first lens element L1 has a negative meniscus shape with a convex surface facing the magnifying side. The second lens element L2 has a negative meniscus shape with a convex surface facing the magnifying side. The third lens element L3 has a negative meniscus shape with a convex surface facing the magnifying side. The fourth lens element L4 has a negative meniscus shape with a convex surface facing the reducing side. The fifth lens element L5 has a negative meniscus shape with a convex surface facing the reducing side. The sixth lens element L6 has a positive meniscus shape with a convex surface facing the reducing side. The seventh lens element L7 has a negative meniscus shape with a convex surface facing the reducing side. The eighth lens element L8 has a positive meniscus shape with a convex surface facing the reducing side. The ninth lens element L9 has a positive meniscus shape with a convex surface facing the reducing side. The tenth lens element L10 has a biconvex shape.

[0066] The rear group Opr of the magnifying optical system Op is composed of the eleventh lens element L11 to the twelfth lens element L12 in order from the magnifying side to the reducing side. The eleventh lens element L11 has a biconvex shape. The twelfth lens element L12 has a positive meniscus shape with a convex surface facing the magnifying side.

[0067] The relay optical system Ol is composed of the thirteenth lens element L13 to the twenty-fifth lens element L25 in order from the magnifying side to the reducing side. The thirteenth lens element L13 has a negative meniscus shape with a convex surface facing the magnifying side. The fourteenth lens element L14 has a biconcave shape. The fifteenth lens element L15 has a positive meniscus shape with a convex surface facing the reducing side. The sixteenth lens element L16 has a positive meniscus shape with a convex surface facing the reducing side. The seventeenth lens element L17 has a negative meniscus shape with a convex surface facing the reducing side. The eighteenth lens element L18 has a biconvex shape. The nineteenth lens element L19 has a biconvex shape. The twentieth lens element L20 has a biconcave shape. The twenty-first lens element L21 has a biconcave shape. The twenty-second lens element L22 has a biconvex shape. The twenty-third lens element L23 has a biconvex shape. The twenty-fourth lens element L24 has a negative meniscus shape with a convex surface facing the magnifying side. The twenty-fifth lens element L25 has a biconvex shape.

[0068] The relay optical system Ol is composed of a first lens group (L13 to L15) having negative power, a second lens group (L16 to L18) having positive power, a third lens group (L19 to L22) having negative power, and a fourth lens group (L23 to L25) having positive power, in order from the magnification side to the reduction side. During zooming, the first lens group and the third lens group are fixed, and the second lens group and the fourth lens group are displaced along the optical axis.

[0069] As an example, the first lens element L1 corresponds to the first lens element of the claims.

[0070] There is an intermediate imaging position MI between the 12th lens element L12 and the 13th lens element L13. Also, a diaphragm A is disposed between the 19th lens element L19 and the 20th lens element L20. An optical element P having zero optical power is disposed on the reduction side of the relay optical system Ol.

[0071] (Example 7) As shown in FIGS. 19 and 20, the zoom lens system according to Example 7 includes an expansion optical system Op and a relay optical system Ol. The expansion optical system Op is composed of a first lens element L1 to a 12th lens element L12. The expansion optical system Op includes a front group Opf and a rear group Opr.

[0072] The front group Opf of the magnifying optical system Op is composed of a first lens element L1 to a tenth lens element L10 in order from the magnifying side to the reducing side. The first lens element L1 has a negative meniscus shape with a convex surface facing the magnifying side. The second lens element L2 has a negative meniscus shape with a convex surface facing the magnifying side. The third lens element L3 has a negative meniscus shape with a convex surface facing the magnifying side. The fourth lens element L4 has a negative meniscus shape with a convex surface facing the reducing side. The fifth lens element L5 has a negative meniscus shape with a convex surface facing the reducing side. The sixth lens element L6 has a positive meniscus shape with a convex surface facing the reducing side. The seventh lens element L7 has a biconcave shape. The eighth lens element L8 has a positive meniscus shape with a convex surface facing the reducing side. The ninth lens element L9 has a positive meniscus shape with a convex surface facing the reducing side. The tenth lens element L10 has a biconvex shape.

[0073] The rear group Opr of the magnifying optical system Op is composed of an eleventh lens element L11 to a twelfth lens element L12 in order from the magnifying side to the reducing side. The eleventh lens element L11 has a biconvex shape. The twelfth lens element L12 has a positive meniscus shape with a convex surface facing the magnifying side.

[0074] The relay optical system Ol is composed of a thirteenth lens element L13 to a twenty-fifth lens element L25 in order from the magnifying side to the reducing side. The thirteenth lens element L13 has a negative meniscus shape with a convex surface facing the magnifying side. The fourteenth lens element L14 has a biconcave shape. The fifteenth lens element L15 has a positive meniscus shape with a convex surface facing the reducing side. The sixteenth lens element L16 has a positive meniscus shape with a convex surface facing the reducing side. The seventeenth lens element L17 has a negative meniscus shape with a convex surface facing the reducing side. The eighteenth lens element L18 has a biconvex shape. The nineteenth lens element L19 has a biconvex shape. The twentieth lens element L20 has a biconcave shape. The twenty-first lens element L21 has a biconcave shape. The twenty-second lens element L22 has a biconvex shape. The twenty-third lens element L23 has a biconvex shape. The twenty-fourth lens element L24 has a negative meniscus shape with a convex surface facing the magnifying side. The twenty-fifth lens element L25 has a biconvex shape.

[0075] The relay optical system Ol consists of, in order from the wide-angle side to the telephoto side, a first lens group (L13 to L15) having negative power, a second lens group (L16 to L18) having positive power, a third lens group (L19 to L22) having negative power, and a fourth lens group (L23 to L25) having positive power. During zooming, the first lens group and the third lens group are fixed, and the second lens group and the fourth lens group are displaced along the optical axis.

[0076] As an example, the first lens element L1 corresponds to the first lens element of the claims.

[0077] There is an intermediate imaging position MI between the 12th lens element L12 and the 13th lens element L13. Also, a diaphragm A is disposed between the 19th lens element L19 and the 20th lens element L20. An optical element P having zero optical power is disposed on the telephoto side of the relay optical system Ol.

[0078] Note that the zoom lens systems according to Embodiments 1 to 7 may include not only lens elements having optical power but also elements having zero or substantially zero optical power, such as optical elements such as mirrors, diaphragms, masks, cover glasses, filters, prisms, wave plates, and polarizing elements.

[0079] Next, the conditions that the zoom lens system according to the present embodiment can satisfy will be described. Note that a plurality of conditions are defined for the zoom lens systems according to the respective embodiments, and all of these plurality of conditions may be satisfied, or by satisfying individual conditions, the corresponding effects can be obtained.

[0080] The zoom lens systems according to Embodiments 1 to 7 are optical systems having an intermediate imaging position that is conjugate to the wide-angle conjugate point on the wide-angle side and the telephoto conjugate point on the telephoto side, respectively, inside, having a plurality of lens elements, a wide-angle optical system located on the wide-angle side of the intermediate imaging position, having a plurality of lens elements, and a relay optical system located on the telephoto side of the intermediate imaging position, and are provided with, There are a plurality of air intervals between the lens elements. The magnifying optical system includes a front group of the magnifying optical system located on the magnifying side with respect to the longest air interval along the optical axis within the magnifying optical system, and a rear group of the magnifying optical system located on the reducing side with respect to the longest air interval. It satisfies the following conditions (1) and (2). 7 < |Ts / fw| < 15 …(1) 2 < |Tpr / fw| < 7 …(2) Here, Ts: The longest air interval fw: The focal length of the entire system at the wide-angle end Tpr: The distance from the magnifying-side surface of the rear group of the magnifying optical system to the intermediate imaging is.

[0081] Condition (1) is a conditional expression that defines the relationship between the longest air interval and the focal length of the entire system at the wide-angle end. By satisfying condition (1), the optical system can be widened. If it is below the lower limit of condition (1), the lenses of the front group of the magnifying optical system become heavy. If it exceeds the upper limit of condition (1), the center of gravity of the entire optical system moves to the magnifying side. Also, condition (2) is a conditional expression that defines the relationship between the distance from the magnifying-side surface of the rear group of the magnifying optical system to the intermediate imaging and the focal length of the entire system at the wide-angle end. By satisfying condition (2), the effect of condition (1) can be exerted.

[0082] In addition to conditions (1) and (2), by further satisfying at least one of the following conditions (1A) and (2A), more advantageous effects can be obtained. 7 < |Ts / fw| < 12 …(1A) 4 < |Tpr / fw| < 6 …(2A)

[0083] The zoom lens systems according to Examples 1 to 7 may satisfy the following conditional expression (3). 0.8 < Tp / Tr < 1.3 …(3) Here, Tp: The distance from the most magnifying-side surface of the magnifying optical system to the intermediate imaging position Tr: From the intermediate imaging position at the wide-angle end to the mostreduction Distance to the side surface is as follows.

[0084] Condition (3) is a conditional expression that defines the relationship between the distance from the most magnifying side surface of the magnifying optical system to the intermediate imaging position and the distance from the intermediate imaging position at the wide-angle end to the most reduction side surface of the relay optical system. Exceeding the upper limit of condition (3) makes it difficult to correct field curvature. Falling below the lower limit of condition (3) causes the center of gravity to shift toward the magnifying side.

[0085] The zoom lens systems according to Examples 1 to 7 may satisfy the following conditional expression (4). 0.3 < fp / fr < 1.1 …(4) Here, fp: Focal length of the magnifying optical system fr: Focal length of the relay optical system at the wide-angle end is as follows.

[0086] Condition (4) is a conditional expression for defining the relationship between the combined focal length of the magnifying optical system and the relay optical system. By satisfying this, an optical system that is wide-angle and has a small lens diameter can be realized. If the lower limit value of the conditional expression (4) is fallen below, it is on the magnifying side of the intermediate imaging position, and the effective diameter of the positive power lens element closest to the intermediate imaging position becomes too large, making the lens heavy. Conversely, if the upper limit value is exceeded, the effective diameter of the lens on the most magnifying side becomes too large, making the lens heavy.

[0087] The zoom lens systems according to Examples 1 to 7 may satisfy the following conditional expression (5). 2 < |fpr / fw| < 10 …(5) Here, fpr: Focal length of the rear group of the magnifying optical system is as follows.

[0088] Condition (5) is a conditional expression that defines the relationship between the focal length of the rear group of the telephoto optical system and the focal length of the entire system at the wide-angle end. If the upper limit of condition (5) is exceeded, the aperture of the rear group of the telephoto optical system becomes too large, and the lens becomes heavy. If the lower limit of condition (5) is not met, the aperture of the front group of the telephoto optical system becomes too large, and the lens becomes heavy.

[0089] In addition to condition (5), more advantageous effects can be obtained by further satisfying the following condition (5A). |fpr / fw| < 9 …(5A)

[0090] The zoom lens system according to Examples 1 to 7 may satisfy the following conditional expression (6). 2 < |fpf / fw| < 5 …(6) Here, fpf: the focal length of the front group of the telephoto optical system is.

[0091] Condition (6) is a conditional expression that defines the relationship between the focal length of the front group of the telephoto optical system and the focal length of the entire system at the wide-angle end. If the upper limit of condition (6) is exceeded, the aperture of the front group of the telephoto optical system becomes too large, and the lens becomes heavy. If the lower limit of condition (6) is not met, the aperture of the rear group of the telephoto optical system becomes too large, and the lens becomes heavy.

[0092] In addition to condition (6), more advantageous effects can be obtained by further satisfying the following condition (6A). |fpf / fw| < 4 …(6A)

[0093] Also, in the zoom lens system according to Examples 1 to 7, during zooming, the telephoto optical system may be fixed, and part or all of the lens elements of the relay optical system may be displaced along the optical axis.

[0094] According to such a configuration, by arranging the zoom mechanism on the reduction side from the intermediate imaging position, a zoom operation mechanism, for example, a cam, a motor, etc. can be mounted on the reduction side. Therefore, the center of gravity of the lens barrel can be shifted toward the reduction side.

[0095] Also, in the zoom lens system according to Embodiments 1 to 7, the relay optical system includes, in order from the wide-angle side to the telephoto side, a first lens group having a negative power, a second lens group having a positive power, a third lens group having a negative power, and a fourth lens group having a positive power. During zooming, the first lens group and the third lens group may be fixed, and the second lens group and the fourth lens group may be displaced along the optical axis.

[0096] According to such a configuration, it is possible to reduce the lens diameter of the relay optical system and lighten the weight of the relay optical system while maintaining high optical performance throughout the zoom range.

[0097] Also, the zoom lens system according to Embodiments 1 to 7 may satisfy the following conditional expression (7). 3 < |T12 / fw| < 10 …(7) Here, T12: The air interval between the first lens group and the second lens group at the wide-angle end is.

[0098] Condition (7) is a conditional expression that defines the relationship between the air interval between the first lens group and the second lens group at the wide-angle end and the focal length of the entire system at the wide-angle end. If the upper limit of condition (7) is exceeded, the aperture of the rear group of the magnifying optical system becomes too large and the lens becomes heavy. If the lower limit of condition (7) is not met, it becomes difficult to correct field curvature.

[0099] In addition to condition (7), more advantageous effects can be obtained by further satisfying the following condition (7A). 4 < |T12 / fw| …(7A)

[0100] Also, the zoom lens system according to Embodiments 1 to 7 may satisfy the following conditional expression (8). 10 < fr1 / fw < 30 …(8) Here, fr1: The focal length of the first lens group is.

[0101] Condition (8) is a conditional expression that defines the relationship between the focal length of the first lens group and the focal length of the entire system at the wide-angle end. If the upper limit of condition (8) is exceeded, the aperture of the first lens group becomes too large and the lens becomes heavy. If the lower limit of condition (8) is not met, the aperture of the rear group of the magnifying optical system becomes too large and the lens becomes heavy.

[0102] In addition to condition (8), more advantageous effects can be obtained by further satisfying the following condition (8A). 14 < fr1 / fw < 26 …(8A)

[0103] Also, the zoom lens system according to Examples 1 to 7 may satisfy the following conditional expression (9). 5 < |fr2 / fw| < 30 …(9) Here, fr2: the focal length of the second lens group is.

[0104] Condition (9) is a conditional expression that defines the relationship between the focal length of the second lens group and the focal length of the entire system at the wide-angle end. If the upper limit of condition (9) is exceeded, the variation of axial chromatic aberration during zooming becomes large, and it becomes difficult to correct axial chromatic aberration well throughout the zoom range. If the lower limit of condition (9) is not met, the sensitivity of aberration to eccentricity increases and manufacturing becomes difficult.

[0105] In addition to condition (9), more advantageous effects can be obtained by further satisfying the following condition (9A). 11 < |fr2 / fw| < 15 …(9A)

[0106] Also, the zoom lens system according to Examples 1 to 7 may satisfy the following conditional expression (10). 5 < fr3 / fw < 50 …(10) Here, fr3: the focal length of the third lens group is.

[0107] Condition (10) is a conditional expression that defines the relationship between the focal length of the third lens group and the focal length of the entire system at the wide-angle end. If the upper limit of condition (10) is exceeded, the aperture of the third lens group becomes too large, and the lens becomes heavy. If the lower limit of condition (10) is not met, the aperture of the fourth lens group becomes too large, and the lens becomes heavy.

[0108] In addition to condition (10), by further satisfying the following condition (10A), more advantageous effects can be obtained. 10 < fr3 / fw < 15 …(10A)

[0109] Also, the zoom lens system according to Examples 1 to 7 may satisfy the following conditional expression (11). 3 < |fr4 / fw| < 9 …(11) Here, fr4: The focal length of the fourth lens group is.

[0110] Condition (11) is a conditional expression that defines the relationship between the focal length of the third lens group and the focal length of the entire system at the wide-angle end. If the upper limit of condition (11) is exceeded, the variation of the field curvature during zooming becomes large, and it becomes difficult to correct the field curvature well throughout the zoom range. If the lower limit of condition (11) is not met, the sensitivity of the aberration to decentration becomes high, and manufacturing becomes difficult.

[0111] In addition to condition (11), by further satisfying the following condition (11A), more advantageous effects can be obtained. 6 < |fr4 / fw| < 7 …(11A)

[0112] Also, in the zoom lens system according to Examples 1 to 7, the first lens element and the second lens element are arranged in order from the magnifying side to the reducing side of the magnifying optical system, and the following conditional expression (12) may be satisfied. 1 < |T1 / fw| < 6 …(12) Here, T1: The air interval between the first lens element and the second lens element is.

[0113] Condition (12) is a conditional expression that defines the relationship between the air interval between the first lens element and the second lens element and the focal length of the entire system at the wide-angle end. If the upper limit of condition (12) is exceeded, the first lens element becomes too heavy, increasing the weight of the entire optical system. If the lower limit of condition (12) is not met, the second lens element becomes too heavy, increasing the weight of the entire optical system.

[0114] In addition to condition (12), more advantageous effects can be obtained by further satisfying the following condition (12A). |T1 / fw| < 4 …(12A)

[0115] Also, the zoom lens system according to Embodiments 1 to 7 may satisfy the following conditional expression (13). 1 < |Tm / fw| < 9 …(13) Here, Tm: The distance from the reduced-side surface of the magnifying optical system to the magnifying-side surface of the relay optical system is.

[0116] Condition (13) is a conditional expression that defines the relationship between the distance from the reduced-side surface of the magnifying optical system to the magnifying-side surface of the relay optical system and the focal length of the entire system at the wide-angle end. If the upper limit of condition (13) is exceeded, the overall length of the optical system becomes longer and the center of gravity moves toward the magnifying side. If the lower limit of condition (13) is not met, when foreign matter adheres to the lens near the intermediate imaging, the reflection into the image tends to be prominent.

[0117] In addition to condition (13), more advantageous effects can be obtained by further satisfying the following condition (13A). 2 < |Tm / fw| < 5 …(13A)

[0118] Also, in the zoom lens system according to Embodiments 1 to 7, the first lens element is arranged on the most magnifying side of the magnifying optical system, and the first lens element has an aspherical first lens magnifying-side surface facing the magnifying side and an aspherical first lens reducing-side surface facing the reducing side. The first lens enlarged side surface and the first lens reduced side surface may satisfy the following condition (14) within the effective diameter when r > 0. dZ(r) / dr > 0 …(14) Here, r: Distance from the vertex of the surface along the plane perpendicular to the optical axis of the optical system (r > 0) Z(r): Sag amount of the surface (assuming Z = 0 at the vertex (r = 0), with the displacement on the reduced side with respect to the vertex having a positive sign and the displacement on the enlarged side having a negative sign) is.

[0119] Condition (14) is a conditional expression that defines that the first derivative dZ(r) / dr of the sag amount Z(r) of the surface is positive. By satisfying condition (14), even when local heat is generated in the first lens element, the shape changes due to thermal expansion will cause the enlarged side surface and the reduced side surface of the first lens to change in the same way. As a result, the occurrence of field curvature and astigmatism can be suppressed.

[0120] Also, in the zoom lens system according to Embodiments 1 to 7, the first lens element may be made of synthetic resin.

[0121] According to such a configuration, since the first lens element is likely to have a large diameter, the lens can be lightened by making it of synthetic resin.

[0122] Also, in the zoom lens system according to Embodiments 1 to 7, among the plurality of lens elements, all the lens elements that satisfy condition (15) may satisfy condition (16), and one of the plurality of lens elements does not necessarily need to satisfy both conditions (15) and (16). |ym / (fw·tan(ωm))| < 3.0 …(15) Tg > 300°C …(16) Here, ωm: Maximum half field angle at the wide-angle end ym: Height at which the outermost chief ray at the telephoto end passes through the lens surface Tg: Glass transition point of the lens material is.

[0123] Condition (15) is a conditional expression that defines the relationship between the height at which the outermost principal ray passes through the lens surface at the telephoto end, the focal length of the entire system at the wide-angle end, and the maximum semi-field angle at the wide-angle end. Condition (16) is a conditional expression that defines the glass transition point of the lens material. By satisfying both conditions (15) and (16), it is possible to prevent deterioration of the lens when high-intensity light passes through the lens. Here, ym is calculated based on the surface with the lower height passing through the surfaces on the magnifying side and the reducing side of the lens.

[0124] Also, the zoom lens system according to Embodiments 1 to 7 may satisfy the following conditional expression (17). ωm>65° …(17) Here, ωm: The maximum semi-field angle at the wide-angle end is.

[0125] Condition (17) is a conditional expression that defines the maximum semi-field angle at the wide-angle end. By satisfying condition (17), it becomes possible to shorten the working distance.

[0126] As described above, several embodiments have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and is also applicable to embodiments in which appropriate changes, replacements, additions, omissions, etc. are made.

[0127] Hereinafter, numerical examples of the zoom lens system according to Embodiments 1 to 7 will be described. In each numerical example, the unit of length in the table is all "mm", and the unit of the field angle is all "°". Also, in each numerical example, r is the radius of curvature, d is the surface interval, nd is the refractive index with respect to the d-line, and vd is the Abbe number with respect to the d-line. Also, in each numerical example, the surface marked with an asterisk is an aspherical surface, and the aspherical shape is defined by the following equation.

[0128]

Number

[0129] Here, Z: The distance from a point on the aspherical surface at a height h from the optical axis to the tangent plane at the vertex of the aspherical surface, h: The height from the optical axis, r: The vertex curvature radius, κ: The conic constant, An: The aspherical coefficient of the nth order is as follows.

[0130] (Numerical Example 1) For the zoom lens system of Numerical Example 1 (corresponding to Example 1), the surface data is shown in Table 1, various data is shown in Table 2, single lens data is shown in Table 3, and zoom lens group data is shown in Table 4 (unit: mm).

[0131] [Table 1] Surface data Surface number r d nd vd Object surface ∞ 1* 97.69350 10.00000 1.50940 56.5 2* 31.36770 22.18050 3 54.45170 3.50000 1.80420 46.5 4 36.74110 10.22980 5 60.03940 2.50000 1.74330 49.2 6 26.09880 16.03710 7 -348.06090 27.99020 1.59270 35.4 8 1289.14890 2.72020 9* -16.44190 3.13670 1.58699 59.5 10* -17.87810 0.20000 11 -348.97530 9.49740 1.49700 81.6 12 -18.76270 0.20000 13 -23.12320 2.50000 1.86966 20.0 14 -732.20040 0.41780 15 -346.16980 10.45900 1.49700 81.6 16 -31.22520 0.20000 17 -192.12440 7.03440 1.48749 70.2 18 -59.47230 0.20000 19 -876.82590 10.00000 1.49700 81.6 20 -61.25280 63.22670 21 151.52720 11.91050 1.92286 20.9 22 -375.29900 0.20000 23 45.77140 12.92810 1.92286 20.9 24 65.14770 29.26890 25 -367.22620 3.00000 1.77250 49.6 26 50.66420 9.98110 27 -205.48240 2.50000 1.69680 55.5 28 98.55830 19.30500 29 -209.63120 7.75900 1.86966 20.0 30 -55.21680 Variable 31 1308.78740 5.01580 1.69680 55.5 32 -53.85000 0.20000 33 -54.57770 1.50000 1.73800 32.3 34 -127.98930 8.99160 35 204.58150 3.58200 1.59282 68.6 36 -192.87060 Variable 37 27.84990 8.37540 1.59270 35.4 38 -188.22480 0.20000 39 (Diaphragm) ∞ 0.74080 40 -206.46080 2.00000 1.67300 38.3 41 24.12340 11.45950 42 -31.56750 2.00000 1.67300 38.3 43 64.18200 0.52060 44 80.45210 6.46490 1.43700 95.1 45 -33.71550 variable 46 83.09620 9.68650 1.49700 81.6 47 -63.78080 3.05650 48 45.51150 2.50000 1.62299 58.1 49 37.00910 5.33620 50 44.31030 12.35130 1.43700 95.1 51 -149.35890 variable 52 ∞ 41.75000 1.51680 64.2 53 ∞ BF Image plane ∞ Aspherical data First surface K = 0.00000E+00, A3=-7.25014E-06, A4=-1.15220E-06, A5= 2.72823E-08 A6=-4.98172E-11, A7=-3.06439E-12, A8= 5.81613E-15, A9= 4.07487E-16 A10=-2.69504E-18 Second surface K=-1.22715E+00, A3= 1.40108E-05, A4=-2.62157E-06, A5= 7.38521E-09 A6= 2.80400E-10, A7= 2.43598E-14, A8=-1.40378E-14, A9=-2.03884E-16 A10= 1.80622E-18 Ninth surface K = 0.00000E+00, A3 = 0.00000E+00, A4 = 2.14919E-05, A5 = 0.00000E+00 A6 = 2.07809E-07, A7 = 0.00000E+00, A8 = -7.30054E-10, A9 = 0.00000E+00 A10 = 8.85358E-13 The 10th surface K = 0.00000E+00, A3 = 0.00000E+00, A4 = 2.81203E-05, A5 = 0.00000E+00 A6 = 1.62721E-07, A7 = 0.00000E+00, A8 = 0.00000E+00, A9 = 0.00000E+00 A10 = 0.00000E+00

[0132] [Table 2] Various data Zoom ratio 1.07128 Wide angle Middle Telephoto Focal length -7.2355 -7.4717 -7.7512 F-number -1.91298 -1.91566 -1.91968 Angle of view -66.8135 -66.1719 -65.4059 Image height 17.2650 17.2650 17.2650 Overall lens length 520.0129 520.0218 520.0245 BF 1.01329 1.02242 1.02517 d30 64.3935 61.5954 58.4105 d36 2.0000 4.7981 7.9829 d45 12.4726 12.3440 12.1423 d51 15.3200 15.4484 15.6501 Entrance pupil position 42.2840 42.2972 42.3159 Exit pupil position -595.1149 -576.1453 -548.7901 Front principal point position: 34.9607, 34.7287, 34.4554 Rear principal point position: 527.2011, 527.4432, 527.7214

[0133] [Table 3] Single lens data Lens starting surface, focal length 1 1 -95.5628 2 3 -154.0331 3 5 -64.1256 4 7 -459.4756 5 9 -1814.3228 6 11 39.5198 7 13 -27.5009 8 15 68.3037 9 17 173.6739 10 19 131.9648 11 21 118.2505 12 23 126.3105 13 25 -57.4536 14 27 -95.2714 15 29 84.2276 16 31 74.3399 17 33 -130.0626 18 35 168.0277 19 37 41.5307 20 40 -31.9830 21 42 -31.1794 22 44 55.3204 23 46 74.2297 24 48 -358.4389 25 50 79.7441

[0134] [Table 4] Zoom lens group data Group, starting surface, focal length, lens configuration length, front principal point position, rear principal point position 1 1 17.89892, 299.08240, 61.92894, 188.87067 2 31 88.42608 19.28940 9.02057 12.67491 3 37 -84.47818 31.76120 30.16528 30.25589 4 46 47.05259 32.93050 10.59383 16.63543 Zoom lens group magnification Group starting surface Wide-angle Intermediate Telephoto 1 1 -0.01613 -0.01613 -0.01613 2 31 -1.14821 -1.19150 -1.24493 3 37 -1.26654 -1.24728 -1.21956 4 46 -0.27843 -0.28135 -0.28570

[0135] (Numerical Example 2) Regarding the zoom lens system of Numerical Example 2 (corresponding to Example 2), the surface data is shown in Table 5, various data is shown in Table 6, single lens data is shown in Table 7, and zoom lens group data is shown in Table 8 (unit: mm).

[0136] [Table 5] Surface data Surface number r d nd vd Object surface ∞ 1* 165.06600 10.00000 1.50940 56.5 2* 37.26640 28.66350 3 59.92230 3.00000 1.83400 37.3 4 30.05740 6.06970 5 40.76120 2.00000 1.80420 46.5 6 23.47790 24.51010 7 169.52580 4.45090 1.49700 81.6 8 -232.47350 2.21550 9* -21.41670 2.48360 1.58699 59.5 10* -21.40060 0.20000 11 -49.10900 7.08080 1.49700 81.6 12 -16.94060 0.20000 13 -22.49620 2.50000 1.86966 20.0 14 -441.93320 0.49480 15 -218.68930 10.07060 1.49700 81.6 16 -27.20590 0.20000 17 -181.89320 7.52360 1.48749 70.2 18 -50.60870 4.98130 19 212.13330 10.00000 1.49700 81.6 20 -103.26610 53.33790 21 89.06370 14.00000 1.80420 46.5 22 -3267.89360 0.20000 23 43.66420 13.03580 1.92286 20.9 24 68.22500 24.37490 25 -126.59430 3.00000 1.77250 49.6 26 46.11280 12.92370 27 -46.42300 2.50000 1.62041 60.3 28 153.22030 14.38260 29 4963.70420 17.00000 1.80420 46.5 30 -51.43220 Variable 31 92.95090 6.03150 1.72916 54.7 32 -730.31630 31.25490 33* -31.49100 13.92770 1.58699 59.5 34* 594.70610 0.20000 35 63.95900 10.36090 1.43700 95.1 36 -34.56770 Variable 37 29.89280 7.05260 1.59270 35.4 38 1341.86370 0.20000 39 (Aperture) ∞ 0.21320 40 757.66530 2.00000 1.65844 50.9 41 25.51370 19.33080 42 -37.71970 2.00000 1.67300 38.3 43 74.95530 0.31620 44 79.99120 8.20600 1.43700 95.1 45 -37.31670 Variable 46 63.06970 9.91920 1.49700 81.6 47 -99.17320 0.20000 48 55.94260 2.50000 1.58144 40.7 49 36.03770 4.83460 50 43.09730 14.70570 1.43700 95.1 51 -89.04820 Variable 52 ∞ 41.75000 1.51680 64.2 53 ∞ BF Image plane ∞ Aspherical data First surface K = 0.00000E+00, A3 = -2.65067E-06, A4 = 4.62668E-07, A5 = 1.02356E-09 A6 = -5.81330E-11, A7 = 8.20273E-14, A8 = 6.76604E-15, A9 = 2.18048E-17 A10 = -5.71783E-19 Second surface K = -9.55907E-01, A3 = 0.00000E+00, A4 = -1.80425E-06, A5 = 0.00000E+00 A6 = 9.34430E-11, A7 = 0.00000E+00, A8 = 9.19265E-15, A9 = 0.00000E+00 A10 = -1.18438E-18 Face 9 K = 0.00000E+00, A3 = 0.00000E+00, A4 = 4.18656E-06, A5 = 0.00000E+00 A6 = 4.74295E-08, A7 = 0.00000E+00, A8 = -1.07013E-09, A9 = 0.00000E+00 A10 = 0.00000E+00 Face 10 K = 0.00000E+00, A3 = 0.00000E+00, A4 = 2.35037E-05, A5 = 0.00000E+00 A6 = 7.58692E-08, A7 = 0.00000E+00, A8 = -4.25680E-10, A9 = 0.00000E+00 A10 = 0.00000E+00 Face 33 K = 0.00000E+00, A3 = 0.00000E+00, A4 = 9.60708E-06, A5 = 0.00000E+00 A6 = -8.51152E-09, A7 = 0.00000E+00, A8 = 4.75793E-12, A9 = 0.00000E+00 A10 = 0.00000E+00 Face 34 K = 0.00000E+00, A3 = 0.00000E+00, A4 = 9.30721E-06, A5 = 0.00000E+00 A6 = -5.66264E-09, A7 = 0.00000E+00, A8 = 2.36850E-12, A9 = 0.00000E+00 A10 = 0.00000E+00

[0137] [Table 6] Various data Zoom ratio 1.07524 Wide angle, middle, telephoto Focal length -7.2781 -7.5294 -7.8257 F-number -1.89960 -1.90067 -1.90235 Field angle -66.7419 -66.1476 -65.4354 Image height 17.2650 17.2650 17.2650 Overall lens length 520.0163 520.0156 520.0152 BF 1.01640 1.01584 1.01552 d30 38.9837 35.3568 31.2138 d36 2.0000 5.6269 9.7698 d45 6.2936 6.2335 6.1191 d51 15.3200 15.3800 15.4944 Entrance pupil position 40.7256 40.7551 40.7942 Exit pupil position -616.7026 -607.9230 -591.9016 Front principal point position 33.3618 33.1326 32.8652 Rear principal point position 527.2465 527.4938 527.7856

[0138] [Table 7] Single lens data Lens, starting surface, focal length 1 1 -97.0535 2 3 -75.7737 3 5 -72.5965 4 7 197.9836 5 9 835.3507 6 11 48.4926 7 13 -27.3309 8 15 61.4452 9 17 141.1827 10 19 141.2367 11 21 108.0110 12 23 104.7466 13 25 -43.4262 14 27 -57.1531 15 29 63.3946 16 31 113.4344 17 33 -50.5350 18 35 53.0458 19 37 51.4808 20 40 -40.1428 21 42 -37.0201 22 44 59.4941 23 46 79.1774 24 48 -182.6283 25 50 68.7848

[0139] [Table 8] Zoom lens group data Group Starting surface Focal length Lens configuration length Front principal point position Rear principal point position 1 1 20.36658 281.39930 62.67798 133.51296 2 31 106.43172 61.77500 41.99245 33.45401 3 37 -103.98710 39.31880 29.38709 30.25682 4 46 49.83733 32.15950 10.71081 17.31236 Zoom lens group magnification Group Starting surface Wide angle Medium Telephoto 1 1 -0.01838 -0.01838 -0.01838 2 31 -1.04663 -1.08534 -1.13322 3 37 -1.92102 -1.90368 -1.87104 4 46 -0.17801 -0.17920 -0.18149

[0140] (Numerical Example 3) Regarding the zoom lens system of Numerical Example 3 (corresponding to Example 3), surface data is shown in Table 9, various data is shown in Table 10, single lens data is shown in Table 11, and zoom lens group data is shown in Table 12 (unit: mm).

[0141] [Table 9] Surface Data Surface Number r d nd vd Object Surface ∞ 1* 89.99630 8.59390 1.50940 56.5 2* 29.83290 25.73990 3 73.68090 4.00000 1.72916 54.7 4 37.62120 11.07470 5 68.67760 2.50000 1.72916 54.7 6 26.46670 24.87000 7 -82.72950 3.00000 1.48749 70.2 8 193.27580 0.20000 9 55.40140 13.86720 1.49700 81.6 10 -38.61260 0.90070 11 -23.10810 2.99370 1.73800 32.3 12 338.09410 0.20000 13 243.79390 5.98230 1.49700 81.6 14 -22.38130 0.20000 15 -33.81890 2.50000 1.86966 20.0 16 -3046.30550 1.00820 17 -129.36060 6.90580 1.49700 81.6 18 -29.32500 0.20000 19 -157.80220 5.57540 1.72916 54.7 20 -52.92660 0.20000 21 137.68250 9.08670 1.49700 81.6 22 -82.27180 70.03820 23 144.33300 9.45410 1.92286 20.9 24 -743.83350 0.20000 25 46.39800 10.82830 1.92286 20.9 26 67.85260 31.36930 27 -134.17810 3.49510 1.59349 67.0 28 58.02470 26.84610 29 -174.53030 4.00000 1.48749 70.2 30 113.99230 4.75960 31 -224.81500 8.24670 1.86966 20.0 32 -58.15140 Variable 33 146.52380 3.00000 1.73800 32.3 34 74.42940 1.69100 35 142.73740 4.65510 1.72916 54.7 36 -204.20580 36.12080 37 255.70130 4.77470 1.59282 68.6 38 -76.13990 Variable 39 (Aperture) ∞ 0.00000 40 27.70880 8.38830 1.59270 35.4 41 -171.98430 0.20530 42 -246.11820 2.00000 1.65844 50.9 43 23.65710 12.47240 44 -30.41040 2.00000 1.73800 32.3 45 64.94710 0.44100 46 76.95830 6.79230 1.43700 95.1 47 -31.53450 Variable 48 78.74410 11.63740 1.49700 81.6 49 -64.61500 0.20000 50 48.33940 2.50000 1.67300 38.3 51 36.05770 3.25360 52 40.85850 14.87760 1.43700 95.1 53 -117.53200 Variable 54 ∞ 41.75000 1.51680 64.2 55 ∞ BF Image plane ∞ Aspherical data First surface K = 0.00000E+00, A3=-4.98082E-05, A4= 1.02415E-06, A5=-2.94689E-08 A6= 7.04235E-10, A7=-6.53517E-12, A8=-1.32511E-14, A9= 4.97035E-16 A10=-1.16266E-18, A11= 1.10076E-22, A12=-1.04222E-23, A13=-7.34121E-26 A14=-1.19521E-26, A15= 5.84967E-29, A16=-1.36553E-32, A17=-1.81844E-33 A18=-1.06538E-35, A19=-2.13620E-37, A20=-9.95976E-39 Second surface K=-9.54170E-01, A3=-1.48327E-05, A4=-2.41212E-06, A5=-5.68248E-10 A6= 1.08199E-10, A7=-3.03274E-13, A8= 3.45630E-15, A9= 9.09825E-17 A10 = 4.23242E-18, A11 = -4.76060E-21, A12 = -5.81989E-22, A13 = -8.46992E-24 A14 = 8.97671E-26, A15 = -4.55046E-28, A16 = -3.81800E-30, A17 = 1.48597E-32 A18 = 1.41251E-33, A19 = 3.80980E-35, A20 = -4.85676E-37

[0142] [Table 10] Various data Zoom ratio 1.07159 Wide angle, middle, telephoto Focal length -7.2461 -7.4838 -7.7648 F-number -1.97041 -1.97181 -1.97429 Angle of view -66.7864 -66.1701 -65.4248 Image height 17.2650 17.2650 17.2650 Overall lens length 520.0186 520.0315 520.0365 BF 1.01858 1.03157 1.03656 d32 34.3954 31.8072 28.8643 d38 2.0000 4.5882 7.5311 d47 11.6892 11.6283 11.4986 d53 15.3200 15.3808 15.5105 Entrance pupil position 41.5035 41.5161 41.5337 Exit pupil position -3602.6235 -3265.6740 -2723.7680 Front principal point position 34.2428 34.0151 33.7467 Rear principal point position 527.2172 527.4647 527.7469

[0143] [Table 11] Single lens data Lens starting surface, focal length 1 1 -92.0424 2 3 -110.5981 3 5 -60.5692 4 7 -118.4160 5 9 48.1403 6 11 -29.2058 7 13 41.5565 8 15 -39.3391 9 17 74.5917 10 19 106.8222 11 21 105.0609 12 23 131.6545 13 25 127.9993 14 27 -67.7935 15 29 -140.8095 16 31 88.1681 17 33 -208.6590 18 35 115.8747 19 37 99.4996 20 40 40.9024 21 42 -32.6823 22 44 -27.8176 23 46 52.1803 24 48 73.3900 25 50 -229.6827 26 52 71.4189

[0144] [Table 12] Zoom lens group data Group, starting surface, focal length, lens configuration length, front principal point position, rear principal point position 1 1 16.36167 298.83590 59.39221 196.90868 2 33 80.54203 50.24160 37.19334 37.42587 3 39 -74.04702 32.29930 27.69110 28.51657 4 48 45.95013 32.46860 9.73608 17.61383 Zoom lens group magnification Group starting surface Wide-angle Intermediate Telephoto 1 1 -0.01476 -0.01476 -0.01476 2 33 -1.05462 -1.09161 -1.13696 3 39 -1.51335 -1.50134 -1.48004 4 48 -0.27787 -0.27948 -0.28241

[0145] (Numerical Example 4) Regarding the zoom lens system of Numerical Example 4 (corresponding to Example 4), the surface data is shown in Table 13, various data is shown in Table 14, single lens data is shown in Table 15, and zoom lens group data is shown in Table 16 (unit: mm).

[0146] [Table 13] Surface data Surface number r d nd vd Object surface ∞ 1* 102.89670 10.00000 1.50940 56.5 2* 31.58350 20.90230 3 52.49390 3.50000 1.80420 46.5 4 38.06810 11.11230 5 66.62750 2.50000 1.74330 49.2 6 25.91550 14.61510 7 -476.15420 29.73760 1.59270 35.4 8 1818.52440 2.87470 9* -17.79050 3.51460 1.58699 59.5 10* -18.79510 0.20000 11 -596.56580 10.03480 1.49700 81.6 12 -18.35160 0.20000 13 -21.74040 2.50000 1.86966 20.0 14 -618.61420 0.43790 15 -312.69370 10.55520 1.49700 81.6 16 -31.49520 0.20000 17 -196.16590 7.17640 1.48749 70.2 18 -60.18670 1.95440 19 -346.58290 10.00000 1.49700 81.6 20 -59.55810 54.34820 21 167.48040 12.82620 1.92286 20.9 22 -331.21280 8.17680 23 45.65930 12.99900 1.92286 20.9 24 66.26060 29.76290 25 -248.95030 3.00000 1.77250 49.6 26 54.43690 7.78420 27 -159.54610 2.50000 1.69680 55.5 28 100.51300 17.58570 29 -240.94020 8.61860 1.86966 20.0 30 -53.28050 variable 31 -5306.70620 4.91380 1.69680 55.5 32 -53.10680 0.20000 33 -53.99280 1.50000 1.73800 32.3 34 -111.83480 2.73900 35 150.54590 3.50470 1.59282 68.6 36 -331.21000 variable 37 27.97490 8.32580 1.59270 35.4 38 -188.82190 0.20000 39 (Aperture) ∞ 0.73020 40 -210.55990 2.00000 1.67300 38.3 41 24.31650 11.54170 42 -31.47630 2.00000 1.67300 38.3 43 63.67160 0.52010 44 79.82010 6.41460 1.43700 95.1 45 -33.74870 Variable 46 81.76500 9.78730 1.49700 81.6 47 -63.07500 1.71080 48 46.02820 2.50000 1.62299 58.1 49 36.59500 5.98390 50 43.99590 12.49800 1.43700 95.1 51 -142.71420 Variable 52 ∞ 41.75000 1.51680 64.2 53 ∞ BF Image plane ∞ Aspherical data First surface K = 0.00000E+00, A3=-5.32341E-06, A4=-1.08236E-06, A5= 2.61031E-08 A6=-4.27853E-11, A7=-3.00834E-12, A8= 5.23078E-15, A9= 4.08999E-16 A10=-2.64786E-18 Second surface K=-1.22711E+00, A3= 1.51511E-05, A4=-2.64143E-06, A5= 7.26941E-09 A6 = 2.79585E-10, A7 = 3.15970E-14, A8 = -1.39833E-14, A9 = -1.99424E-16 A10 = 1.77284E-18 The 9th surface K = 0.00000E+00, A3 = 0.00000E+00, A4 = 1.92717E-05, A5 = 0.00000E+00 A6 = 1.99778E-07, A7 = 0.00000E+00, A8 = -7.68502E-10, A9 = 0.00000E+00 A10 = -1.41298E-13 The 10th surface K = 0.00000E+00, A3 = 0.00000E+00, A4 = 2.60433E-05, A5 = 0.00000E+00 A6 = 1.52935E-07, A7 = 0.00000E+00, A8 = 0.00000E+00, A9 = 0.00000E+00 A10 = 0.00000E+00

[0147] [Table 14] Various data Zoom ratio 1.07110 Wide angle Middle Telephoto Focal length -7.2477 -7.4838 -7.7630 F-number -1.91302 -1.91539 -1.91898 Angle of view -66.7797 -66.1429 -65.3812 Image height 17.2650 17.2650 17.2650 Overall lens length 520.0143 520.0225 520.0253 BF 1.01429 1.02263 1.02545 d30 70.7792 68.0418 64.9273 d36 2.0407 4.7781 7.8926 d45 12.4233 12.3107 12.1307 d51 15.3200 15.4325 15.6125 Entrance pupil position 41.8940 41.9048 41.9207 Exit pupil position -595.3865 -578.5443 -553.5762 Front principal point position 34.5582 34.3244 34.0490 Rear principal point position 527.2145 527.4558 527.7340

[0148] [Table 15] Single lens data Lens Starting surface Focal length 1 1 -93.9052 2 3 -193.1403 3 5 -58.5935 4 7 -633.6045 5 9 1928.6388 6 11 37.8786 7 13 -25.9598 8 15 69.6014 9 17 175.0808 10 19 143.0474 11 21 122.0383 12 23 122.1421 13 25 -57.5761 14 27 -88.1486 15 29 77.0151 16 31 76.9559 17 33 -143.0283 18 35 175.0641 19 37 41.7044 20 40 -32.2803 21 42 -31.0355 22 44 55.2271 23 46 73.2885 24 48 -319.0770 25 50 78.5527

[0149] [Table 16] Zoom lens group data Group starting surface Focal length Lens configuration length Front principal point position Rear principal point position 1 1 18.06918 299.61690 61.80676 194.14445 2 31 86.72560 12.85750 5.51839 9.42898 3 37 -84.26874 31.73240 30.14098 30.24312 4 46 46.86150 32.48000 10.50105 16.64953 Zoom lens group magnification Group starting surface Wide angle Medium Telephoto 1 1 -0.01629 -0.01629 -0.01629 2 31 -1.13099 -1.17286 -1.22443 3 37 -1.29779 -1.28017 -1.25429 4 46 -0.27375 -0.27633 -0.28023

[0150] (Numerical Example 5) For the zoom lens system of Numerical Example 5 (corresponding to Example 5), the surface data is shown in Table 17, various data is shown in Table 18, single lens data is shown in Table 19, and zoom lens group data is shown in Table 20 (unit: mm).

[0151] [Table 17] Surface data Surface number r d nd vd Object surface ∞ 1* 88.43730 10.00000 1.50940 56.5 2* 30.98810 21.95040 3 56.04410 3.50000 1.80420 46.5 4 36.62330 9.14040 5 55.73150 2.50000 1.74330 49.2 6 26.55220 16.25210 7 -105.61520 23.28420 1.59270 35.4 8 -97.65610 10.06170 9* -15.12600 3.96900 1.58699 59.5 10* -17.25600 0.20000 11 -104.21250 8.36620 1.49700 81.6 12 -20.24120 0.20000 13 -28.55900 2.50000 1.86966 20.0 14 848.41580 0.23680 15 1747.45800 10.90330 1.49700 81.6 16 -31.06140 1.59470 17 -104.66030 5.94050 1.48749 70.2 18 -52.63830 4.37260 19 1915.34720 9.6134 1.49700 81.6 20 -70.73170 66.78710 21 137.36750 11.53820 1.92286 20.9 22 -372.10820 0.20000 23 40.92760 12.35270 1.92286 20.9 24 59.35410 20.43020 25 669.30860 3.02760 1.77250 49.6 26 36.71060 13.21340 27 -371.44310 2.50000 1.69680 55.5 28 102.03360 22.62050 29 -159.43290 7.07750 1.86966 20.0 30 -57.60810 variable 31 466.10450 7.88750 1.69680 55.5 32 -53.93730 0.20000 33 -54.28910 1.50000 1.73800 32.3 34 -143.19360 13.95850 35 354.82120 3.58320 1.59282 68.6 36 -138.11420 Variable 37 27.98990 8.45390 1.59270 35.4 38 -196.94770 0.20000 39 (Diaphragm) ∞ 0.69920 40 -223.46150 2.00000 1.67300 38.3 41 23.80580 10.22400 42 -32.31480 2.00000 1.67300 38.3 43 63.33780 0.49290 44 77.01980 7.22850 1.43700 95.1 45 -33.87480 Variable 46 78.21220 9.28860 1.49700 81.6 47 -70.36380 4.75950 48 43.61550 2.50000 1.62299 58.1 49 36.62400 6.12930 50 45.69070 12.00850 1.43700 95.1 51 -149.98300 Variable 52 ∞ 41.75000 1.51680 64.2 53 ∞ BF Image plane ∞ Aspherical data First surface K = 0.00000E+00, A3=-1.80686E-05, A4=-1.24260E-06, A5= 2.82728E-08 A6 = -4.68886E-11, A7 = -3.14281E-12, A8 = 3.69704E-15, A9 = 4.05487E-16 A10 = -2.70992E-18 Second surface K = -1.29848E+00, A3 = 9.60558E-06, A4 = -2.58551E-06, A5 = 8.15356E-09 A6 = 2.89291E-10, A7 = 7.31407E-14, A8 = -1.40654E-14, A9 = -2.05740E-16 A10 = 1.87867E-18 Ninth surface K = 0.00000E+00, A3 = 0.00000E+00, A4 = 2.17129E-05, A5 = 0.00000E+00 A6 = 2.20039E-07, A7 = 0.00000E+00, A8 = -6.23863E-10, A9 = 0.00000E+00 A10 = 1.23212E-12 Tenth surface K = 0.00000E+00, A3 = 0.00000E+00, A4 = 2.79313E-05, A5 = 0.00000E+00 A6 = 1.44206E-07, A7 = 0.00000E+00, A8 = 0.00000E+00, A9 = 0.00000E+00 A10 = 0.00000E+00

[0152] [Table 18] Various data Zoom ratio 1.07174 Wide angle, medium, telephoto Focal length -7.2510 -7.4894 -7.7712 F-number -1.91320 -1.91666 -1.92171 Angle of view -66.7701 -66.1350 -65.3775 Image height 17.2650 17.2650 17.2650 Overall lens length 520.0113 520.0208 520.0231 BF 1.01163 1.02116 1.02339 d30 49.7749 46.9581 43.7513 d36 2.0000 4.8168 8.0236 d45 12.7087 12.5347 12.2749 d51 15.3200 15.4939 15.7538 Entrance pupil position 43.3307 43.3465 43.3682 Exit pupil position -594.6793 -570.5253 -538.0230 Front principal point position 35.9915 35.7590 35.4849 Rear principal point position 527.2149 527.4596 527.7398

[0153] [Table 19] Single lens data Lens Starting surface Focal length 1 1 -99.4905 2 3 -142.8978 3 5 -70.8149 4 7 1046.7742 5 9 -671.7381 6 11 48.9258 7 13 -31.7277 8 15 61.5319 9 17 209.3991 10 19 137.4705 11 21 109.9108 12 23 108.0791 13 25 -50.3847 14 27 -114.6269 15 29 100.4704 16 31 69.8133 17 33 -119.3380 18 35 168.1546 19 37 41.9344 20 40 -31.8635 21 42 -31.5293 22 44 54.9265 23 46 76.1079 24 48 -425.0804 25 50 81.6652

[0154] [Table 20] Zoom lens group data Group Starting surface Focal length Lens configuration length Front principal point position Rear principal point position 1 1 17.35441 304.33250 62.31153 187.32213 2 31 88.53910 27.12920 13.11252 17.33570 3 37 -86.17768 31.29850 27.74377 28.59629 4 46 48.19888 34.68590 11.58527 16.86729 Zoom lens group magnification Group Starting surface Wide angle Medium Telephoto 1 1 -0.01563 -0.01563 -0.01563 2 31 -1.20081 -1.24850 -1.30763 3 37 -1.24638 -1.22154 -1.18740 4 46 -0.27960 -0.28341 -0.28884

[0155] (Numerical Example 6) For the zoom lens system of Numerical Example 6 (corresponding to Example 6), the surface data is shown in Table 21, various data is shown in Table 22, single lens data is shown in Table 23, and zoom lens group data is shown in Table 24 (unit: mm).

[0156] [Table 21] Surface data Surface number r d nd vd Object surface ∞ 1* 99.66580 10.00000 1.50940 56.5 2* 31.15430 21.16210 3 57.06200 3.50000 1.80420 46.5 4 36.93080 7.73380 5 50.81200 2.50000 1.74330 49.2 6 27.51500 15.31740 7 -205.41930 28.15950 1.59270 35.4 8 -642.59470 6.06970 9* -16.11230 3.67340 1.58699 59.5 10* -18.27770 0.20000 11 -302.65750 10.86660 1.49700 81.6 12 -20.29530 0.20000 13 -27.24440 2.50000 1.86966 20.0 14 -3012.85830 0.48370 15 -539.62060 11.67900 1.49700 81.6 16 -33.64020 0.20000 17 -180.36270 7.17790 1.48749 70.2 18 -62.86680 0.20000 19 456.34570 10.00000 1.49700 81.6 20 -87.38400 69.03230 21 143.62540 12.97490 1.92286 20.9 22 -438.58710 0.20000 23 44.62770 13.58550 1.92286 20.9 24 62.77010 25.96680 25 1119.09760 3.00000 1.77250 49.6 26 38.04470 11.59990 27 -248.66770 2.50000 1.69680 55.5 28 143.52430 19.89390 29 -149.66720 6.44170 1.86966 20.0 30 -56.09200 variable 31 -663.22970 4.75210 1.69680 55.5 32 -52.42210 0.20000 33 -54.07600 1.50000 1.73800 32.3 34 -100.66200 0.20000 35 120.83860 3.54940 1.59282 68.6 36 -594.16750 variable 37 27.69060 8.19560 1.59270 35.4 38 -222.25250 0.20000 39 (aperture) ∞ 0.59300 40 -283.00080 2.00000 1.67300 38.3 41 23.87620 10.74910 42 -32.12210 2.00000 1.67300 38.3 43 62.94480 0.60160 44 83.73990 6.33940 1.43700 95.1 45 -34.32250 variable 46 80.53540 9.61270 1.49700 81.6 47 -63.58790 1.57030 48 44.32190 2.50000 1.62299 58.1 49 36.50970 7.88690 50 46.15500 12.12990 1.43700 95.1 51 -138.83570 variable 52 ∞ 41.75000 1.51680 64.2 53 ∞ BF Image plane ∞ Aspherical data First surface K = 0.00000E+00, A3=-1.74067E-05, A4=-8.55706E-07, A5 = 2.47548E-08 A6=-5.71120E-11, A7=-2.95249E-12, A8 = 6.30469E-15, A9 = 4.04186E-16 A10=-2.73602E-18 Second surface K=-1.29979E+00, A3 = 3.56842E-06, A4=-2.46793E-06, A5 = 9.34818E-09 A6 = 2.89223E-10, A7=-1.38298E-13, A8=-1.85781E-14, A9=-2.48923E-16 A10 = 2.68573E-18 Ninth surface K = 0.00000E+00, A3 = 0.00000E+00, A4 = 2.51303E-05, A5 = 0.00000E+00 A6 = 1.94136E-07, A7 = 0.00000E+00, A8=-4.58227E-10, A9 = 0.00000E+00 A10 = 4.69317E-13 Tenth surface K = 0.00000E+00, A3 = 0.00000E+00, A4 = 2.81131E-05, A5 = 0.00000E+00 A6 = 1.45179E-07, A7 = 0.00000E+00, A8 = 0.00000E+00, A9 = 0.00000E+00 A10 = 0.00000E+00

[0157] [Table 22] Various data Zoom ratio 1.07125 Wide-angle mid-telephoto Focal length -7.2308 -7.4669 -7.7460 F-number -1.91327 -1.91616 -1.92042 Angle of view -66.8273 -66.1800 -65.4092 Image height 17.2650 17.2650 17.2650 Overall lens length 520.0160 520.0238 520.0243 BF 1.01594 1.02379 1.02437 d30 65.7460 63.0911 60.0737 d36 2.2088 4.8638 7.8811 d45 12.5772 12.4452 12.2397 d51 15.3200 15.4518 15.6573 Entrance pupil position 41.3329 41.3427 41.3572 Exit pupil position -595.0768 -575.7057 -548.0188 Front principal point position 34.0143 33.7791 33.5018 Rear principal point position 527.1996 527.4403 527.7161

[0158] [Table 23] Single lens data Lens Starting surface Focal length 1 1 -93.5797 2 3 -141.1025 3 5 -84.6081 4 7 -521.9422 5 9 -621.9251 6 11 43.2188 7 13 -31.6257 8 15 71.6381 9 17 194.0754 10 19 148.4734 11 21 118.5059 12 23 123.0784 13 25 -51.0437 14 27 -130.2570 15 29 99.9603 16 31 81.4290 17 33 -160.5229 18 35 169.7001 19 37 42.0565 20 40 -32.6314 21 42 -31.3371 22 44 56.6327 23 46 73.1136 24 48 -379.0439 25 50 80.8789

[0159] [Table 24] Zoom lens group data Group Starting surface Focal length Lens configuration length Front principal point position Rear principal point position 1 1 17.56673 306.81810 60.72090 201.50830 2 31 84.37000 10.20150 4.28026 8.19655 3 37 -82.72585 30.67870 28.45123 28.97178 4 46 47.12030 33.69980 11.38892 16.93941 Zoom lens group magnification Group Starting surface Wide angle Medium Telephoto 1 1 -0.01584 -0.01584 -0.01584 2 31 -1.15384 -1.19731 -1.25088 3 37 -1.24721 -1.22845 -1.20166 4 46 -0.28652 -0.28949 -0.29386

[0160] (Numerical Example 7) For the zoom lens system of Numerical Example 7 (corresponding to Example 7), the surface data is shown in Table 25, various data is shown in Table 26, single lens data is shown in Table 27, and zoom lens group data is shown in Table 28 (unit: mm).

[0161] [Table 25] Surface data Surface number r d nd vd Object surface ∞ 1* 94.83650 8.00000 1.50940 56.5 2* 32.65770 9.89290 3 61.26280 4.00000 1.80420 46.5 4 45.77930 20.08130 5 79.19320 2.66040 1.74330 49.2 6 29.23810 22.00300 7 -115.06770 14.29440 1.59270 35.4 8 -125.93070 14.25190 9* -15.41130 3.48450 1.58699 59.5 10* -17.51970 0.20000 11 -154.21760 9.42060 1.49700 81.6 12 -20.48120 0.20000 13 -27.55080 2.50000 1.86966 20.0 14 2376.06500 0.62580 15 -1176.16180 11.72110 1.49700 81.6 16 -37.11450 0.50060 17 -155.74230 7.86250 1.48749 70.2 18 -54.47480 0.20000 19 869.16730 10.00000 1.49700 81.6 20 -77.39740 80.24410 21 136.35560 13.12770 1.92286 20.9 22 -534.37280 0.20000 23 45.70790 14.00000 1.92286 20.9 24 65.18520 23.73660 25 383.53820 3.50000 1.77250 49.6 26 38.19620 11.98520 27 -272.93710 2.50000 1.69680 55.5 28 103.79030 19.81240 29 -215.45580 6.46750 1.86966 20.0 30 -61.70410 Variable 31 -564.66740 4.81810 1.69680 55.5 32 -56.30910 0.20000 33 -58.46110 1.57040 1.73800 32.3 34 -97.51240 3.96420 35 123.37100 3.46770 1.59282 68.6 36 -494.17440 Variable 37 27.47700 8.07910 1.59270 35.4 38 -193.85750 0.20000 39 (Aperture) ∞ 0.63890 40 -234.45360 2.00000 1.67300 38.3 41 23.51640 8.71820 42 -32.12530 2.00000 1.67300 38.3 43 65.03560 0.67300 44 94.76020 6.39860 1.43700 95.1 45 -33.49250 Variable 46 81.67170 14.24010 1.49700 81.6 47 -62.18810 0.27720 48 44.33880 2.50000 1.62299 58.1 49 36.77280 6.81730 50 45.41700 12.12120 1.43700 95.1 51 -147.50210 variable 52 ∞ 41.75000 1.51680 64.2 53 ∞ BF Image plane ∞ Aspherical data First surface K = 0.00000E+00, A3=-1.52651E-05, A4=-9.94232E-07, A5 = 2.44429E-08 A6=-1.95730E-11, A7=-3.08842E-12, A8 = 2.25161E-15, A9 = 4.13973E-16 A10=-2.55437E-18 Second surface K=-1.34729E+00, A3 = 9.87687E-06, A4=-2.47222E-06, A5 = 9.33782E-09 A6 = 2.90162E-10, A7=-1.04007E-13, A8=-1.82010E-14, A9=-2.48249E-16 A10 = 2.59959E-18 Ninth surface K = 0.00000E+00, A3 = 0.00000E+00, A4 = 2.53409E-05, A5 = 0.00000E+00 A6 = 2.16366E-07, A7 = 0.00000E+00, A8=-3.24181E-10, A9 = 0.00000E+00 A10 = 1.24182E-13 Tenth surface K = 0.00000E+00, A3 = 0.00000E+00, A4 = 2.70872E-05, A5 = 0.00000E+00 A6 = 1.50922E-07, A7 = 0.00000E+00, A8 = 0.00000E+00, A9 = 0.00000E+00 A10 = 0.00000E+00

[0162] [Table 26] Various data Zoom ratio 1.07093 Wide-angle Middle Telephoto Focal length -7.2295 -7.4654 -7.7423 F-number -1.91923 -1.92230 -1.92676 Field angle -66.8342 -66.1810 -65.4093 Image height 17.2650 17.2650 17.2650 Overall lens length 530.0173 530.0245 530.0243 BF 1.01775 1.02488 1.02469 d30 60.9650 58.3362 55.3677 d36 2.1970 4.8259 7.7943 d45 12.6019 12.4620 12.2498 d51 15.3292 15.4690 15.6813 Entrance pupil position 41.5519 41.5637 41.5806 Exit pupil position -594.4349 -573.6290 -544.7992 Front principal point position 34.2345 34.0013 33.7285 Rear principal point position 537.1997 537.4395 537.7124

[0163] [Table 27] Single lens data Lens Starting surface Focal length 1 1 -102.2211 2 3 -254.5452 3 5 -63.8070 4 7 -4410.2316 5 9 -561.2435 6 11 46.4351 7 13 -31.3016 8 15 76.8482 9 17 167.5923 10 19 143.4998 11 21 118.8321 12 23 123.2428 13 25 -55.1573 14 27 -107.6219 15 29 97.5183 16 31 89.4138 17 33 -201.2403 18 35 166.8811 19 37 41.1628 20 40 -31.6586 21 42 -31.6891 22 44 57.4995 23 46 73.4509 24 48 -396.1540 25 50 81.0098

[0164] [Table 28] Zoom lens group data Group Starting surface Focal length Lens configuration length Front principal point position Rear principal point position 1 1 17.67884 317.47250 61.08007 212.01761 2 31 83.48585 14.02040 6.33935 10.23768 3 37 -82.35184 28.70780 25.69887 26.84023 4 46 46.71049 35.95580 12.56350 19.78117 Zoom lens group magnification Group Starting surface Wide angle Medium Telephoto 1 1 -0.01594 -0.01594 -0.01594 2 31 -1.17070 -1.21551 -1.27041 3 37 -1.22561 -1.20566 -1.17781 4 46 -0.28551 -0.28865 -0.29319

[0165] Table 29 below shows the corresponding values of each conditional expression (1) to (17) in each numerical example.

[0166] [Table 29] TIFF0007702617000002.tif125155

[0167] Table 30 below shows the values of the variables of each conditional expression (1) to (17) in each numerical example.

[0168] [Table 30] TIFF0007702617000003.tif145155Ts: Longest air gap Tp: Distance from the most magnified side surface of the magnifying optical system to the intermediate imaging position Tr: From the intermediate imaging position at the wide-angle end to the most reduction side surface of the relay optical system Tpr: Distance from the magnified side surface of the rear group of the magnifying optical system to the intermediate imaging T12: Air gap at the wide-angle end between the first lens group and the second lens group T1: Air gap between the first lens element and the second lens element Tm: Distance between the reduced side surface of the magnifying optical system and the magnified side surface of the relay optical system fw: Focal length of the entire system at the wide-angle end fp: Focal length of the magnifying optical system fr: Focal length of the relay optical system at the wide-angle end fpr: Focal length of the rear group of the magnifying optical system fpf: Focal length of the front group of the magnifying optical system fr1: Focal length of the first lens group fr2: Focal length of the second lens group fr3: Focal length of the third lens group fr4: Focal length of the fourth lens group ωm: Maximum half angle at the wide-angle end ym: Height at which the outermost chief ray passing through the surface at the telephoto end passes through the lens surface

[0169] Table 31 and Table 32 below show the values of |ym / (fw·tan(ωm))| in conditional expression (15) and Tg in conditional expression (16) for each numerical example. Note that the lens material Z330R is the product name of a cycloolefin polymer (COP) (manufactured by Zeon Corporation). The lens element L1 can be made of various synthetic resins, thereby achieving weight reduction. Weight reduction can also be achieved for the remaining lens elements L2 to L26 by manufacturing them with various synthetic resins.

[0170] [Table 31] TIFF0007702617000004.tif176155

[0171] [Table 32] TIFF0007702617000005.tif160155

[0172] (Embodiment 2) Hereinafter, Embodiment 2 of the present disclosure will be described with reference to FIG. 22. FIG. 22 is a block diagram showing an example of an image projection apparatus according to the present disclosure. The image projection apparatus 100 includes the optical system 1 disclosed in Embodiment 1, an image forming element 101, a light source 102, a control unit 110, and the like. The image forming element 101 is composed of liquid crystal, DMD, etc., and generates an image to be projected onto the screen SR via the optical system 1. The light source 102 is composed of an LED (light emitting diode), a laser, etc., and supplies light to the image forming element 101. The control unit 110 is composed of a CPU or an MPU, etc., and controls the entire apparatus and each component. The optical system 1 may be configured as an interchangeable lens that can be detachably attached to the image projection apparatus 100. In this case, an apparatus obtained by removing the optical system 1 from the image projection apparatus 100 is an example of a main body apparatus.

[0173] The above image projection device 100 can reduce the moment acting on the center of gravity of the optical system 1 by the optical system 1 according to Embodiment 1, and can realize a wide-angle zoom function while reducing the influence of heat.

[0174] (Embodiment 3) Hereinafter, Embodiment 3 of the present disclosure will be described with reference to FIG. 23. FIG. 23 is a block diagram showing an example of an imaging device according to the present disclosure. The imaging device 200 includes the optical system 1 disclosed in Embodiment 1, an imaging element 201, a control unit 210, and the like. The imaging element 201 is composed of a CCD (charge-coupled device) image sensor, a CMOS image sensor, or the like, and receives the optical image of the object OBJ formed by the optical system 1 and converts it into an electrical image signal. The control unit 110 is composed of a CPU, an MPU, or the like, and controls the entire device and each component. The optical system 1 may be configured as an interchangeable lens that can be detachably attached to the imaging device 200. In this case, a device obtained by removing the optical system 1 from the imaging device 200 is an example of a main body device.

[0175] The above imaging device 200 can reduce the moment acting on the center of gravity of the optical system 1 by the optical system 1 according to Embodiment 1, and can realize a wide-angle zoom function while reducing the influence of heat.

[0176] As described above, the embodiments have been described as the disclosure of the technology in the present disclosure. For this purpose, the accompanying drawings and detailed descriptions have been provided.

[0177] Therefore, among the components described in the accompanying drawings and the detailed description, there may be not only the components essential for solving the problems, but also the components not essential for solving the problems for exemplifying the above technology. Therefore, just because those non-essential components are described in the accompanying drawings or the detailed description, it should not be immediately determined that those non-essential components are essential.

[0178] In addition, since the above-described embodiments are for exemplifying the technology in the present disclosure, various changes, substitutions, additions, omissions, etc. can be made within the scope of the claims or the equivalent scope thereof.

Industrial Applicability

[0179] The present disclosure is applicable to image projection devices such as projectors and head-up displays, and imaging devices such as digital still cameras, digital video cameras, surveillance cameras in surveillance systems, web cameras, and in-vehicle cameras. In particular, the present disclosure is applicable to optical systems that require high image quality, such as projectors, digital still camera systems, and digital video camera systems.

Claims

1. An optical system having an intermediate imaging position conjugate to an enlarged conjugate point on the enlargement side and a reduced conjugate point on the reduction side respectively inside, having a plurality of lens elements, an enlargement optical system located on the enlargement side from the intermediate imaging position, having a plurality of lens elements, a relay optical system located on the reduction side from the intermediate imaging position, and comprising: There are a plurality of air intervals along the optical axis in the optical system between the lens elements. The plurality of air intervals include the longest first air interval in the enlargement optical system, the longest second air interval in the relay optical system, and a third air interval where the intermediate imaging position is arranged. The third air interval is shorter than the first air interval and the second air interval. The enlargement optical system includes an enlargement optical system front group located on the enlargement side from the first air interval and an enlargement optical system rear group located on the reduction side from the first air interval. An optical system satisfying the following conditions (1) and (2). 7 < |Ts / fw| < 15... (1) 2 < |Tpr / fw| < 7... (2) Here, Ts: The first air interval fw: The focal length of the entire system at the wide-angle end Tpr: The distance from the enlargement-side surface of the rear group of the enlargement optical system to the intermediate imaging position is.

2. The optical system according to claim 1, satisfying the following conditional formula (3). 0.8 < Tp / Tr < 1.3... (3) Here, Tp: The distance from the most enlargement-side surface of the enlargement optical system to the intermediate imaging position Tr: The distance from the intermediate imaging position at the wide-angle end to the most reduction-side surface of the relay optical system is.

3. The optical system according to claim 1, satisfying the following conditional formula (4). 0.3 < fp / fr < 1.1... (4) Here, fp: The focal length of the enlargement optical system fr: The focal length of the relay optical system at the wide-angle end is.

4. The optical system according to claim 1, satisfying the following conditional formula (5). 2 < |fpr / fw| < 10... (5) Here, fpr: The focal length of the rear group of the enlargement optical system is.

5. The optical system according to claim 1, satisfying the following conditional formula (6). 2 < |fpf / fw| < 5... (6) Here, fpf: The focal length of the front group of the enlargement optical system is.

6. The optical system according to claim 1, wherein the enlargement optical system is fixed during zooming, and part or all of the lens elements of the relay optical system are displaced along the optical axis.

7. The relay optical system consists of, in order from the wide-angle side to the telephoto side, a first lens group having a negative power, a second lens group having a positive power, a third lens group having a negative power, and a fourth lens group having a positive power. The optical system according to claim 6, wherein, during the zooming, the first lens group and the third lens group are fixed, and the second lens group and the fourth lens group are displaced along the optical axis.

8. The optical system according to claim 7, satisfying the following conditional expression (7). 3 < |T12 / fw| < 10... (7) Here, T12: The air interval between the first lens group and the second lens group at the wide-angle end is.

9. The optical system according to claim 7, satisfying the following conditional expression (8). 10 < fr1 / fw < 30... (8) Here, fr1: The focal length of the first lens group is.

10. The optical system according to claim 7, satisfying the following conditional expression (9). 5 < |fr2 / fw| < 30... (9) Here, fr2: The focal length of the second lens group is.

11. The optical system according to claim 7, satisfying the following conditional expression (10). 5 < fr3 / fw < 50... (10) Here, fr3: The focal length of the third lens group is.

12. The optical system according to claim 7, satisfying the following conditional expression (11). 3 < |fr4 / fw| < 9... (11) Here, fr4: The focal length of the fourth lens group is.

13. The first lens element and the second lens element are arranged in order from the wide-angle side to the telephoto side of the magnifying optical system, and the optical system according to claim 1, satisfying the following conditional expression (12). 1 < |T1 / fw| < 6... (12) Here, T1: The air interval between the first lens element and the second lens element is.

14. The optical system according to claim 1, satisfying the following conditional expression (13). 1 < |Tm / fw| < 9... (13) Here, Tm: The interval from the surface on the telephoto side of the magnifying optical system to the surface on the wide-angle side of the relay optical system is.

15. The first lens element is arranged on the most wide-angle side of the magnifying optical system, and the first lens element has an aspherical first lens wide-angle side facing the wide-angle side and an aspherical first lens telephoto side facing the telephoto side. The optical system according to claim 1, wherein the first lens wide-angle side and the first lens telephoto side satisfy the following condition (14) within the effective diameter from r > 0. dZ(r) / dr > 0... (14) Here, r: Distance from the vertex of the surface along a plane perpendicular to the optical axis of the optical system (r > 0) Z(r): Sag amount of the surface (assuming Z = 0 at the vertex (r = 0), with the displacement on the reducing side with respect to the vertex having a positive sign and the displacement on the enlarging side having a negative sign) is as follows.

16. The optical system according to claim 15, wherein the first lens element is made of synthetic resin.

17. In the plurality of lens elements, all lens elements satisfying condition (15) satisfy condition (16), and among the plurality of lens elements, one lens element does not satisfy both conditions (15) and (16). The optical system according to claim 1. |ym / (fw · tan(ωm))| < 3.0 …(15) Tg > 300°C …(16) Here, ωm: Maximum half field angle at the wide-angle end ym: Height at which the outermost chief ray at the telephoto end passes through the lens surface Tg: Glass transition point of the lens material is as follows.

18. The optical system according to claim 1, which satisfies the following conditional expression (17). ωm > 65° …(17) Here, ωm: Maximum half field angle at the wide-angle end is as follows.

19. An image projection apparatus comprising the optical system according to any one of claims 1 to 18, and an image forming element that generates an image projected onto a screen via the optical system.

20. An imaging apparatus comprising the optical system according to any one of claims 1 to 18, and an imaging element that receives the optical image formed by the optical system and converts it into an electrical image signal.

Images