Optical system, image projection device and imaging device

Abstract

The present disclosure pertains to an optical system which has therein an intermediate image formation position which is conjugate to both an enlargement conjugate point on the enlargement side and a reduction conjugate point on the reduction side, said optical system being equipped with an enlargement optical system located on the enlargement side of the intermediate image formation position and a relay optical system located on the reduction side of the intermediate image formation position, wherein: the relay optical system has a first lens group which is farthest toward the enlargement side, two lens groups which are on the reduction side of the first lens group, and a negative lens group positioned between the two lens groups; and the two lens groups move while the negative lens group remains fixed when zooming occurs.

Description

[Technical field]

[0001] The present disclosure relates to an optical system that forms an intermediate image, and also to an image projection device and an imaging device that use such an optical system. [Background technology]

[0002] Although intermediate imaging optical systems have the advantage of being able to realize wide-angle projection of a large screen with a short focal length, they tend to be long in length, which makes the optical system heavy. If part of the optical system is mounted outside the housing of the image projection device body, the moment acting on the center of gravity may cause the optical system to tilt relative to the device body, resulting in a deterioration of optical performance.

[0003] To reduce the weight of the optical system, it is expected that synthetic resin lenses will be used instead of glass lenses. Compared to glass, synthetic resin has a smaller specific gravity, but a lower thermal conductivity and a higher linear expansion coefficient. Therefore, although it is possible to reduce the weight of the optical system, there is a tendency for localized temperature increases and thermal deformation to occur, increasing optical aberrations, especially chromatic aberrations. This tendency is particularly noticeable in the case of high-brightness projection.

[0004] Patent Document 1 discloses a wide-angle imaging optical system, in which the first lens L1a closest to the magnification conjugate point has the largest aperture. The first lens L1a is aspheric on both sides and has a rather complicated shape, so it is assumed that a synthetic resin lens is used. However, such a complicated aspheric shape is quite sensitive to thermal deformation, and it is expected that the deterioration of optical aberration due to temperature rise will become significant. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-174633 A Summary of the Invention [Problem 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 and reducing the effects of heat, and also provides an image projection device and an imaging device using such an optical system. [Means for solving the problem]

[0007] One aspect of the present disclosure is an optical system having an intermediate image-forming position therein that is conjugate to a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, a magnifying optical system located on the magnifying side of the intermediate image-forming position; a relay optical system located on the reduction side of the intermediate image-forming position, The relay optical system is The first lens group is located on the most magnifying side. two lens groups on the reduction side of the first lens group; a negative lens group disposed between the two lens groups; This is an optical system in which two lens groups move while the negative lens group remains fixed during zooming.

[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 an optical image formed by the optical system and converts it into an electrical image signal. Effect of the Invention

[0010] The optical system according to the present disclosure can reduce the moment acting on the center of gravity and the effect of heat, thereby maintaining stable optical performance when high-intensity light passes through the lens, for example in the case of high-brightness projection. [Brief description of the drawings]

[0011] [Figure 1] Layout diagram showing the optical path of the zoom lens of Example 1 at the wide-angle end when the object distance is 1065.7157 mm. [Diagram 2] Arrangement diagram of the zoom lens of Example 1 at the wide-angle end with an object distance of 1065.7157 mm [Diagram 3] Longitudinal aberration diagram of the zoom lens of Example 1 at an object distance of 1065.7157 mm [Figure 4] Layout diagram showing the optical path of the zoom lens of Example 2 at the wide-angle end when the object distance is 1065.7157 mm. [Diagram 5] Arrangement diagram of the zoom lens of Example 2 at the wide-angle end with an object distance of 1065.7157 mm [Figure 6] Longitudinal aberration diagram of the zoom lens of Example 2 at an object distance of 1065.7157 mm [Figure 7] Layout diagram showing the optical path of the zoom lens of Example 3 at the wide-angle end when the object distance is 1065.7157 mm. [Figure 8] Layout diagram of the zoom lens of Example 3 at the wide-angle end with an object distance of 1065.7157 mm [Figure 9] Longitudinal aberration diagram of the zoom lens of Example 3 at an object distance of 1065.7157 mm [Figure 10] Layout diagram showing the optical path of the zoom lens of Example 4 at the wide-angle end when the object distance is 1065.7157 mm. [Figure 11] Arrangement diagram of the zoom lens of Example 4 at the wide-angle end with an object distance of 1065.7157 mm [Figure 12] Longitudinal aberration diagram of the zoom lens of Example 4 at an object distance of 1065.7157 mm [Figure 13] Layout diagram showing the optical path of the zoom lens of Example 5 at the wide-angle end when the object distance is 1065.7157 mm. [Figure 14] Layout diagram of the zoom lens of Example 5 at the wide-angle end with an object distance of 1065.7157 mm [Figure 15] Longitudinal aberration diagram of the zoom lens of Example 5 at an object distance of 1065.7157 mm [Figure 16] Layout diagram showing the optical path of the zoom lens of Example 6 at the wide-angle end with an object distance of 1065.7157 mm [Figure 17]Arrangement diagram of the zoom lens of Example 6 at the wide-angle end with an object distance of 1065.7157 mm [Figure 18] Longitudinal aberration diagram of the zoom lens of Example 6 at an object distance of 1065.7157 mm [Figure 19] FIG. 1 is a block diagram illustrating an example of an image projection device according to the present disclosure. [Figure 20] FIG. 1 is a block diagram illustrating an example of an imaging device according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

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

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

[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 of the magnification 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) 1 to 15, a first embodiment of the present disclosure will be described below. Here, a zoom lens system will be described as an example of an optical system.

[0017] 1, 4, 7, 10, 13, and 16 are layout diagrams showing the optical paths at the wide-angle end of the zoom lens systems according to Examples 1 to 6 at an object distance of 1065.7157 mm. FIGS. 2, 5, 8, 11, 14, and 17 are layout diagrams at the wide-angle end of the zoom lens systems according to Examples 1 to 6 at an object distance of 1065.7157 mm. FIGS. 2(a), 5(a), 8(a), 11(a), 14(a), and 17(a) show lens layout diagrams at the wide-angle end of the zoom lens systems. FIGS. 2(b), 5(b), 8(b), 11(b), 14(b), and 17(b) show lens layout diagrams at the intermediate position of the zoom lens systems. FIGS. 2(c), 5(c), 8(c), 11(c), 14(c), and 17(c) show lens arrangements at the telephoto end of the zoom lens system.

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

[0019] The zoom lens system according to the first embodiment includes a magnifying optical system Op, a relay optical system Ol, and an optical element P, and the relay optical system Ol includes a first lens group G1 to a fourth lens group G4. The magnifying optical system Op is composed of a first lens element L1 to a twelfth lens element L12, and includes surfaces 1 to 24 (see the numerical examples described later). The relay optical system Ol is composed of a thirteenth lens element L13 to a fifteenth lens element L25, and includes surfaces 25 to 51. The first lens group G1 has a positive power, is composed of a thirteenth lens element L13 to a fifteenth lens element L15, and includes surfaces 25 to 30. The second lens group G2 has a positive power, is composed of a sixteenth lens element L16 to an eighteenth lens element L18, and includes surfaces 31 to 36. The third lens group G3 has a negative power, is composed of a nineteenth lens element L19 to a twenty-second lens element L22, and includes surfaces 37 to 45. The fourth lens group G4 has positive power, is constituted by the twenty-third lens element L23 to the twenty-fifth lens element L25, and includes surfaces 46 to 51. The optical element P includes surfaces 52 to 53.

[0020] The zoom lens system according to the second embodiment includes a magnifying optical system Op, a relay optical system Ol, and an optical element P. The relay optical system Ol includes a first lens group G1 to a second lens group G2. 5 Lens group G 5The magnifying optical system Op is composed of the first lens element L1 to the twelfth lens element L12, and includes surfaces 1 to 24 (see the numerical example described later). The relay optical system Ol is composed of the thirteenth lens element L13 to the fifteenth lens element L25, and includes surfaces 25 to 51. The first lens group G1 has a positive power, is composed of the thirteenth lens element L13 to the fifteenth lens element L15, and includes surfaces 25 to 30. The second lens group G2 has a positive power, is composed of the sixteenth lens element L16 to the eighteenth lens element L18, and includes surfaces 31 to 36. The third lens group G3 has a negative power, is composed of the nineteenth lens element L19 to the twenty-second lens element L22, and includes surfaces 37 to 45. The fourth lens group G4 has a positive power, is composed of the twenty-third lens element L23, and includes surfaces 46 to 47. The fifth lens group G5 has positive power, is composed of the twenty-fourth lens element L24 and the twenty-fifth lens element L25, and includes surfaces 48 to 51. The optical element P includes surfaces 52 to 53.

[0021] The zoom lens system according to the third embodiment includes a magnifying optical system Op, a relay optical system Ol, and an optical element P. The relay optical system Ol includes a first lens group G1 to a second lens group G2. 6 Lens group G 6The magnifying optical system Op is composed of the first lens element L1 to the twelfth lens element L12, and includes surfaces 1 to 24 (see the numerical example described later). The relay optical system Ol is composed of the thirteenth lens element L13 to the fifteenth lens element L25, and includes surfaces 25 to 51. The first lens group G1 has a positive power, is composed of the thirteenth lens element L13 to the fifteenth lens element L15, and includes surfaces 25 to 30. The second lens group G2 has a positive power, is composed of the sixteenth lens element L16 to the eighteenth lens element L18, and includes surfaces 31 to 36. The third lens group G3 has a negative power, is composed of the nineteenth lens element L19 to the twenty-second lens element L22, and includes surfaces 37 to 45. The fourth lens group G4 has a positive power, is composed of the twenty-third lens element L23, and includes surfaces 46 to 47. The fifth lens group G5 has negative power, is formed by the twenty-fourth lens element L24, and includes surfaces 48 to 49. The sixth lens group G6 has positive power, is formed by the twenty-fifth lens element L2, and includes surfaces 50 to 51. The optical element P includes surfaces 52 to 53.

[0022] The zoom lens system according to the fourth embodiment includes a magnifying optical system Op, a relay optical system Ol, and an optical element P. The relay optical system Ol includes a first lens group G1 to a second lens group G2. 6 Lens group G 6The magnifying optical system Op is composed of the first lens element L1 to the twelfth lens element L12, and includes surfaces 1 to 24 (see the numerical example described later). The relay optical system Ol is composed of the thirteenth lens element L13 to the fifteenth lens element L25, and includes surfaces 25 to 51. The first lens group G1 has a positive power, is composed of the thirteenth lens element L13 to the fifteenth lens element L15, and includes surfaces 25 to 30. The second lens group G2 has a positive power, is composed of the sixteenth lens element L16 to the seventeenth lens element L17, and includes surfaces 31 to 34. The third lens group G3 has a positive power, is composed of the eighteenth lens element L18, and includes surfaces 35 to 36. The fourth lens group G4 has a negative power, is composed of the nineteenth lens element L19 to the twenty-second lens element L22, and includes surfaces 37 to 45. The fifth lens group G4 has positive power, is formed by the twenty-third lens element L23, and includes surfaces 46 to 47. The sixth lens group G6 has positive power, is formed by the twenty-fourth lens element L25, and includes surfaces 48 to 51. The optical element P includes surfaces 52 to 53.

[0023] The zoom lens system according to the fifth embodiment includes a magnifying optical system Op, a relay optical system Ol, and an optical element P, and the relay optical system O1 includes the first lens group G1 to the eighth lens group G8. The magnifying optical system Op is composed of the first lens element L1 to the twelfth lens element L12, and includes surfaces 1 to 24 (see the numerical examples described later). The relay optical system Ol is composed of the thirteenth lens element L13 to the fifteenth lens element L25, and includes surfaces 25 to 51. The first lens group G1 has a positive power, is composed of the thirteenth lens element L13 to the fifteenth lens element L15, and includes surfaces 25 to 30. The second lens group G2 has a positive power, is composed of the sixteenth lens element L16, and includes surfaces 31 to 32. The third lens group G3 has a negative power, is composed of the seventeenth lens element L17, and includes surfaces 33 to 34. The fourth lens group G4 has positive power, is composed of the 18th lens element L18, and includes surfaces 35 to 36. The fifth lens group G5 has negative power, is composed of the 19th lens element L19 to the 22nd lens element L22, and includes surfaces 37 to 45. The sixth lens group G6 has positive power, is composed of the 23rd lens element L23, and includes surfaces 46 to 47. The seventh lens group G7 has negative power, is composed of the 24th lens element, and includes surfaces 48 to 49. The eighth lens group G8 has positive power, is composed of the 25th lens element L25, and includes surfaces 50 to 51. The optical element P includes surfaces 52 to 53.

[0024] The zoom lens system according to the sixth embodiment includes a magnifying optical system Op, a relay optical system Ol, and an optical element P. The relay optical system Ol includes a first lens group G1 to a second lens group G2. 6 Lens group G 6The magnifying optical system Op is composed of the first lens element L1 to the twelfth lens element L12, and includes surfaces 1 to 24 (see the numerical example described later). The relay optical system Ol is composed of the thirteenth lens element L13 to the fifteenth lens element L25, and includes surfaces 25 to 51. The first lens group G1 has a negative power, is composed of the thirteenth lens element L13 to the fifteenth lens element L15, and includes surfaces 25 to 30. The second lens group G2 has a positive power, is composed of the sixteenth lens element L16 to the eighteenth lens element L18, and includes surfaces 31 to 36. The third lens group G3 has a positive power, is composed of the nineteenth lens element L19, and includes surfaces 37 to 38. The fourth lens group G4 has a negative power, is composed of a stop and the twentieth lens element L20, and includes surfaces 39 to 41. The fifth lens group G5 has negative power, is composed of the twenty-first lens element L21 to the twenty-second lens element L22, and includes surfaces 42 to 45. The sixth lens group G6 has positive power, is composed of the twenty-third lens element L23 to the twenty-fifth lens element L25, and includes surfaces 46 to 51. The optical element P includes surfaces 52 to 53.

[0025] The broken line arrows illustrated between each of (a) and (b) in Figures 2, 5, 8, 11, 14, and 17 are straight lines obtained by connecting the positions of the first lens group G1 to the eighth lens group G8 in each state of the wide-angle end, the intermediate position, and the telephoto end, starting from the top of the figure. The wide-angle end and the intermediate position, and the intermediate position and the telephoto end are simply connected by straight lines, and are different from the actual movements of the lens groups G1 to G8. The symbols (+) and (-) attached to the signs of each of the lens groups G1 to G8 indicate the positive or negative power of each of the lens groups G1 to G8.

[0026] The zoom lens systems according to Examples 1 to 6 may include, as necessary, a focusing adjustment lens group that performs focus adjustment when the object distance changes, and a field curvature correction lens group that corrects field curvature aberration after the focusing adjustment lens group has performed the focus adjustment.

[0027] In each diagram, the image formation position on the enlargement side (i.e., the enlargement conjugate point) is located on the left side, and the image formation position on the reduction side (i.e., the reduction conjugate point) is located on the right side. In each diagram, the straight line drawn on the most reduction side represents the position of the original image S, and the optical element P is located on the enlargement side of the original image S. The optical element P represents an optical element such as a prism for color separation and color synthesis, an optical filter, a parallel plate glass, a quartz low-pass filter, or an infrared cut filter.

[0028] The zoom lens systems according to Examples 1 to 6 have an intermediate imaging position MI therein, which is conjugate with the enlargement conjugate point on the enlargement side and the reduction conjugate point on the reduction side. In each drawing, an enlargement optical system Op is disposed on the enlargement side of the intermediate imaging position MI, and a relay optical system Ol is disposed on the reduction side of the intermediate imaging position MI.

[0029] In the zoom lens systems according to Examples 1 to 6, there are a plurality of air gaps between the first lens element L1 to the twenty-fifth lens element L25 and the optical element P. The magnifying optical system Op has the longest air gap along the optical axis in the magnifying optical system. For example, as shown in Figs. 2, 5, 8, 11, 14, and 17, the longest air gap exists between the ninth lens element L9 and the tenth lens element L10. The magnifying optical system Op includes a front group Opf located on the enlargement side of the longest air gap, and a rear group Opr located on the reduction side of the longest air gap. The front group Opf and the rear group Opr may have a single or a plurality of lens elements.

[0030] 3, 6, 9, 12, 15, and 18 are longitudinal aberration diagrams at an object distance of 1065.7157 mm for the zoom lens systems according to Examples 1 to 6. In each diagram, (a), (b), and (c) show longitudinal aberration diagrams at the wide-angle end, the intermediate position, and the telephoto end of the zoom lens system.

[0031] Each longitudinal aberration diagram shows, from left to right, spherical aberration (SA (mm)), astigmatism (AST (mm)), and distortion (DIS (%)). In each spherical aberration diagram, the vertical axis represents pupil height, with the solid line representing the d-line characteristics, the short dashed line representing the F-line characteristics, and the long dashed line representing the C-line characteristics. In each astigmatism diagram, the vertical axis represents image height, with the solid line representing the sagittal plane characteristics (indicated by s in the diagram), and the dashed line representing the meridional plane characteristics (indicated by m in the diagram). In each distortion diagram, the vertical axis represents image height. Additionally, distortion represents distortion relative to equidistant projection.

[0032] Example 1 1 and 2, the zoom lens system according to the first embodiment includes a magnifying optical system Op and a relay optical system Ol. The magnifying optical system Op is composed of a first lens element L1 to a twelfth lens element L12. The magnifying optical system Op includes a front group Opf and a rear group Opr.

[0033] The front group Opf of the magnification optical system Op is composed of the first lens element L1 to the ninth lens element L9, in order from the magnification side to the reduction side. The first lens element L1 has a negative meniscus shape with a convex surface facing the magnification side. The second lens element L2 has a negative meniscus shape with a convex surface facing the magnification side. The third lens element L3 has a negative meniscus shape with a convex surface facing the magnification side. The fourth lens element L4 has a positive meniscus shape with a convex surface facing the reduction side. 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.

[0034] The rear group Opr of the magnification optical system Op is composed of, from the magnification side to the reduction side, a tenth lens element L10 to a twelfth lens element L12. The tenth lens element L10 has a biconvex shape. The eleventh lens element L11 has a positive meniscus shape with a convex surface facing the magnification side. The twelfth lens element L12 has a negative meniscus shape with a convex surface facing the magnification side.

[0035] 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 positive meniscus shape with a convex surface facing the reduction 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 reduction 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 reduction side. The eighteenth lens element L18 has a biconvex shape. The nineteenth lens element L19 has a positive meniscus shape with a convex surface facing the enlargement side. The twentieth lens element L20 has a negative meniscus shape with a convex surface facing the enlargement side. 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 magnification side. The twenty-fifth lens element L25 has a biconvex shape.

[0036] The relay optical system Ol is composed of, in order from the enlargement side to the reduction side, a first lens group (L13-L15) having positive 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. During zooming, the first lens group and the third lens group are fixed, while the second lens group and the fourth lens group are displaced along the optical axis, and when zooming from the wide-angle end to the telephoto end, the second lens group and the fourth lens group are displaced to the enlargement side.

[0037] In other words, the relay optical system Ol has a first lens group (an example of a first lens group) having positive power on the enlargement side, and a third lens group (an example of a negative lens group) arranged between the second lens group and the fourth lens group (an example of two lens groups) on the reduction side, and during zooming, the second lens group and the fourth lens group move to the enlargement side while the third lens group is fixed.

[0038] An intermediate image position MI is located between the twelfth lens element L12 and the thirteenth lens element L13. In addition, a diaphragm A is located between the nineteenth lens element L19 and the twentieth lens element L20. An optical element P with zero optical power is located on the reduction side of the relay optical system Ol.

[0039] Example 2 4 and 5, the zoom lens system according to the second embodiment includes a magnifying optical system Op and a relay optical system Ol. The magnifying optical system Op is composed of a first lens element L1 to a twelfth lens element L12. The magnifying optical system Op includes a front group Opf and a rear group Opr.

[0040] The front group Opf of the magnification optical system Op is composed of the first lens element L1 to the ninth lens element L9, in order from the magnification side to the reduction side. The first lens element L1 has a negative meniscus shape with a convex surface facing the magnification side. The second lens element L2 has a negative meniscus shape with a convex surface facing the magnification side. The third lens element L3 has a negative meniscus shape with a convex surface facing the magnification side. The fourth lens element L4 has a positive meniscus shape with a convex surface facing the reduction side. 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.

[0041] The rear group Opr of the magnification optical system Op is composed of, from the magnification side to the reduction side, a tenth lens element L10 to a twelfth lens element L12. The tenth lens element L10 has a biconvex shape. The eleventh lens element L11 has a positive meniscus shape with a convex surface facing the magnification side. The twelfth lens element L12 has a negative meniscus shape with a convex surface facing the magnification side.

[0042] 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 positive meniscus shape with a convex surface facing the reduction 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 reduction 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 reduction side. The eighteenth lens element L18 has a biconvex shape. The nineteenth lens element L19 has a positive meniscus shape with a convex surface facing the enlargement side. The twentieth lens element L20 has a negative meniscus shape with a convex surface facing the enlargement side. 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 magnification side. The twenty-fifth lens element L25 has a biconvex shape.

[0043] The relay optical system Ol is composed of, in order from the enlargement side to the reduction side, a first lens group (L13-L15) having positive power, a second lens group (L16-L18) having positive power, a third lens group (L19-L22) having negative power, a fourth lens group (L23) having positive power, and a fifth lens group (L24-L25) having positive power. During zooming, the first lens group, the third lens group, and the fifth lens group are fixed, while the second lens group and the fourth lens group are displaced along the optical axis, and when zooming from the wide-angle end to the telephoto end, the second lens group and the fourth lens group are displaced to the enlargement side.

[0044] In other words, the relay optical system Ol has a first lens group (an example of a first lens group) having positive power on the enlargement side, and a third lens group (an example of a negative lens group) arranged between the second lens group and the fourth lens group (an example of two lens groups) on the reduction side, and during zooming, the second lens group and the fourth lens group move to the enlargement side while the third lens group is fixed.

[0045] An intermediate image position MI is located between the twelfth lens element L12 and the thirteenth lens element L13. In addition, a diaphragm A is located between the nineteenth lens element L19 and the twentieth lens element L20. An optical element P having zero optical power is located on the reduction side of the relay optical system Ol.

[0046] Example 3 7 and 8, the zoom lens system according to the third embodiment includes a magnifying optical system Op and a relay optical system Ol. The magnifying optical system Op is composed of a first lens element L1 to a twelfth lens element L12. The magnifying optical system Op includes a front group Opf and a rear group Opr.

[0047] The front group Opf of the magnification optical system Op is composed of the first lens element L1 to the ninth lens element L9, in order from the magnification side to the reduction side. The first lens element L1 has a negative meniscus shape with a convex surface facing the magnification side. The second lens element L2 has a negative meniscus shape with a convex surface facing the magnification side. The third lens element L3 has a negative meniscus shape with a convex surface facing the magnification side. The fourth lens element L4 has a positive meniscus shape with a convex surface facing the reduction side. 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.

[0048] The rear group Opr of the magnification optical system Op is composed of, from the magnification side to the reduction side, a tenth lens element L10 to a twelfth lens element L12. The tenth lens element L10 has a biconvex shape. The eleventh lens element L11 has a positive meniscus shape with a convex surface facing the magnification side. The twelfth lens element L12 has a negative meniscus shape with a convex surface facing the magnification side.

[0049] 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 positive meniscus shape with a convex surface facing the reduction 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 reduction 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 reduction side. The eighteenth lens element L18 has a biconvex shape. The nineteenth lens element L19 has a positive meniscus shape with a convex surface facing the enlargement side. The twentieth lens element L20 has a negative meniscus shape with a convex surface facing the enlargement side. 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 magnification side. The twenty-fifth lens element L25 has a biconvex shape.

[0050] The relay optical system Ol is composed of, in order from the enlargement side to the reduction side, a first lens group (L13-L15) having positive power, a second lens group (L16-L18) having positive power, a third lens group (L19-L22) having negative power, a fourth lens group (L23) having positive power, a fifth lens group (L24) having negative power, and a sixth lens group (L25) having positive power. During zooming, the first lens group, the third lens group, and the sixth lens group are fixed, and the second lens group, the fourth lens group, and the fifth lens group are displaced along the optical axis, and when zooming from the wide-angle end to the telephoto end, the second lens group, the fourth lens group, and the fifth lens group are displaced to the enlargement side.

[0051] That is, the relay optical system Ol has a first lens group (an example of a first lens group) having positive power on the enlargement side, and a third lens group (an example of a negative lens group) disposed between the second and fourth lens groups (an example of two lens groups) on the reduction side, and during zooming, the second and fourth lens groups move to the enlargement side while the third lens group is fixed. The relay optical system Ol further has a fifth lens group (an example of another negative lens group), and the third lens group has a smaller negative power than the fifth lens group.

[0052] An intermediate image position MI is located between the twelfth lens element L12 and the thirteenth lens element L13. In addition, a diaphragm A is located between the nineteenth lens element L19 and the twentieth lens element L20. An optical element P with zero optical power is located on the reduction side of the relay optical system Ol.

[0053] Example 4 10 and 11, the zoom lens system according to Example 4 includes a magnifying optical system Op and a relay optical system Ol. The magnifying optical system Op is composed of a first lens element L1 to a twelfth lens element L12. The magnifying optical system Op includes a front group Opf and a rear group Opr.

[0054] The front group Opf of the magnification optical system Op is composed of the first lens element L1 to the ninth lens element L9, in order from the magnification side to the reduction side. The first lens element L1 has a negative meniscus shape with a convex surface facing the magnification side. The second lens element L2 has a negative meniscus shape with a convex surface facing the magnification side. The third lens element L3 has a negative meniscus shape with a convex surface facing the magnification side. The fourth lens element L4 has a positive meniscus shape with a convex surface facing the reduction side. 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 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 reduction side.

[0055] The rear group Opr of the magnification optical system Op is composed of, from the magnification side to the reduction side, a tenth lens element L10 to a twelfth lens element L12. The tenth lens element L10 has a biconvex shape. The eleventh lens element L11 has a positive meniscus shape with a convex surface facing the magnification side. The twelfth lens element L12 has a negative meniscus shape with a convex surface facing the magnification side.

[0056] 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 positive meniscus shape with a convex surface facing the reduction 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 reduction 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 reduction side. The eighteenth lens element L18 has a biconvex shape. The nineteenth lens element L19 has a positive meniscus shape with a convex surface facing the enlargement side. The twentieth lens element L20 has a negative meniscus shape with a convex surface facing the enlargement side. 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 magnification side. The twenty-fifth lens element L25 has a biconvex shape.

[0057] The relay optical system Ol is composed of, in order from the enlargement side to the reduction side, a first lens group (L13-L15) having positive power, a second lens group (L16-L17) having positive power, a third lens group (L18) having positive power, a fourth lens group (L19-L22) having negative power, a fifth lens group (L23) having positive power, and a sixth lens group (L24-L25) having positive power. During zooming, the first lens group, the fourth lens group, and the sixth lens group are fixed, and the second lens group, the third lens group, and the fifth lens group are displaced along the optical axis, and when zooming from the wide-angle end to the telephoto end, the second lens group, the third lens group, and the fifth lens group are displaced to the enlargement side.

[0058] In other words, the relay optical system Ol has a first lens group (an example of a first lens group) having positive power on the enlargement side, and a fourth lens group (an example of a negative lens group) arranged between the third lens group and the fifth lens group (an example of two lens groups) on the reduction side, and during zooming, the third lens group and the fifth lens group move to the enlargement side while the fourth lens group is fixed.

[0059] An intermediate image position MI is located between the twelfth lens element L12 and the thirteenth lens element L13. In addition, a diaphragm A is located between the nineteenth lens element L19 and the twentieth lens element L20. An optical element P with zero optical power is located on the reduction side of the relay optical system Ol.

[0060] Example 5 13 and 14, the zoom lens system according to Example 5 includes a magnifying optical system Op and a relay optical system Ol. The magnifying optical system Op is composed of a first lens element L1 to a twelfth lens element L12. The magnifying optical system Op includes a front group Opf and a rear group Opr.

[0061] The front group Opf of the magnification optical system Op is composed of the first lens element L1 to the ninth lens element L9, in order from the magnification side to the reduction side. The first lens element L1 has a negative meniscus shape with a convex surface facing the magnification side. The second lens element L2 has a negative meniscus shape with a convex surface facing the magnification side. The third lens element L3 has a negative meniscus shape with a convex surface facing the magnification side. The fourth lens element L4 has a positive meniscus shape with a convex surface facing the reduction side. 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 biconcave shape. 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 biconvex shape.

[0062] The rear group Opr of the magnification optical system Op is composed of, from the magnification side to the reduction side, a tenth lens element L10 to a twelfth lens element L12. The tenth lens element L10 has a biconvex shape. The eleventh lens element L11 has a positive meniscus shape with a convex surface facing the magnification side. The twelfth lens element L12 has a negative meniscus shape with a convex surface facing the magnification side.

[0063] 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 positive meniscus shape with a convex surface facing the reduction 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 reduction 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 reduction side. The eighteenth lens element L18 has a biconvex shape. The nineteenth lens element L19 has a positive meniscus shape with a convex surface facing the enlargement side. The twentieth lens element L20 has a negative meniscus shape with a convex surface facing the enlargement side. 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 magnification side. The twenty-fifth lens element L25 has a biconvex shape.

[0064] The relay optical system Ol is composed of, in order from the enlargement side to the reduction side, a first lens group (L13-L15) having positive power, a second lens group (L16) having positive power, a third lens group (L17) having negative power, a fourth lens group (L18) having positive power, a fifth lens group (L19-L22) having negative power, a sixth lens group (L23) having positive power, a seventh lens group (L24) having negative power, and an eighth lens group (L25) having positive power. During zooming, the first lens group, the fifth lens group, and the eighth lens group are fixed, and the second lens group, the third lens group, the fourth lens group, the sixth lens group, and the seventh lens group are displaced along the optical axis, and during zooming from the wide-angle end to the telephoto end, the second lens group, the third lens group, the fourth lens group, the sixth lens group, and the seventh lens group are displaced to the enlargement side.

[0065] That is, the relay optical system Ol has a first lens group (an example of a first lens group) having positive power on the enlargement side, and a fifth lens group (an example of a negative lens group) disposed between the fourth lens group and the sixth lens group (an example of two lens groups) on the reduction side, and during zooming, the fourth lens group and the sixth lens group move to the enlargement side while the fifth lens group is fixed. The relay optical system Ol further has a third lens group and a seventh lens group (an example of another negative lens group), and the fifth lens group has a negative power smaller than that of the third lens group and the seventh lens group.

[0066] An intermediate image position MI is located between the twelfth lens element L12 and the thirteenth lens element L13. In addition, a diaphragm A is located between the nineteenth lens element L19 and the twentieth lens element L20. An optical element P having zero optical power is located on the reduction side of the relay optical system Ol.

[0067] Example 6 16 and 17, the zoom lens system according to Example 6 includes a magnifying optical system Op and a relay optical system Ol. The magnifying optical system Op is composed of a first lens element L1 to a twelfth lens element L12. The magnifying optical system Op includes a front group Opf and a rear group Opr.

[0068] The front group Opf of the magnification optical system Op is composed of the first lens element L1 to the ninth lens element L9, in order from the magnification side to the reduction side. The first lens element L1 has a negative meniscus shape with a convex surface facing the magnification side. The second lens element L2 has a negative meniscus shape with a convex surface facing the magnification side. The third lens element L3 has a negative meniscus shape with a convex surface facing the magnification side. The fourth lens element L4 has a positive meniscus shape with a convex surface facing the reduction side. 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 biconcave shape. 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 biconvex shape.

[0069] The rear group Opr of the magnification optical system Op is composed of, from the magnification side to the reduction side, a tenth lens element L10 to a twelfth lens element L12. The tenth lens element L10 has a biconvex shape. The eleventh lens element L11 has a positive meniscus shape with a convex surface facing the magnification side. The twelfth lens element L12 has a negative meniscus shape with a convex surface facing the magnification side.

[0070] 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 positive meniscus shape with a convex surface facing the reduction 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 reduction 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 reduction side. The eighteenth lens element L18 has a biconvex shape. The nineteenth lens element L19 has a positive meniscus shape with a convex surface facing the enlargement side. The twentieth lens element L20 has a negative meniscus shape with a convex surface facing the enlargement side. 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 magnification side. The twenty-fifth lens element L25 has a biconvex shape.

[0071] The relay optical system Ol is composed of, in order from the enlargement side to the reduction side, a first lens group (L13-L15) having negative power, a second lens group (L16-L18) having positive power, a third lens group (L19) having positive power, a fourth lens group (L20) having negative power, a fifth lens group (L21-L22) having negative power, and a sixth lens group (L23-L25) having positive power. During zooming, the first lens group and the fourth lens group are fixed, and the second lens group, the third lens group, the fifth lens group, and the sixth lens group are displaced along the optical axis, and during zooming from the wide-angle end to the telephoto end, the second lens group, the fifth lens group, and the sixth lens group are displaced toward the enlargement side, and the third group is displaced toward the reduction side.

[0072] That is, the relay optical system Ol has a first lens group (an example of a first lens group) having negative power on the enlargement side, and a fourth lens group (an example of a negative lens group) disposed between the third lens group and the fifth lens group (an example of two lens groups) on the reduction side, and during zooming, while the fourth lens group is fixed, the third lens group moves to the reduction side and the fifth lens group moves to the enlargement side. The relay optical system Ol further has a fourth lens group and a fifth lens group (an example of another negative lens group), and the fourth lens group has a smaller negative power than the fifth lens group.

[0073] An intermediate image position MI is located between the twelfth lens element L12 and the thirteenth lens element L13. In addition, a diaphragm A is located between the nineteenth lens element L19 and the twentieth lens element L20. An optical element P with zero optical power is located on the reduction side of the relay optical system Ol.

[0074] The zoom lens systems according to Examples 1 to 6 may include not only lens elements having optical power, but also elements whose optical power is zero or substantially zero, such as optical elements such as mirrors, diaphragms, masks, cover glasses, filters, prisms, wave plates, and polarizing elements.

[0075] Next, conditions that can be satisfied by the zoom lens system according to the present embodiment will be described. Note that, although a number of conditions are specified for the zoom lens system according to each embodiment, it is possible to obtain the corresponding effect by satisfying all of these conditions or by satisfying each individual condition.

[0076] The zoom lens systems according to Examples 1 to 6 are optical systems having an intermediate imaging position therein that is conjugate to a magnification conjugate point on the enlargement side and a reduction conjugate point on the reduction side, and include an enlargement optical system located on the enlargement side of the intermediate imaging position, and a relay optical system located on the reduction side of the intermediate imaging position, and the relay optical system has a first lens group having positive power closest to the enlargement side, two lens groups on the reduction side of the first lens group, and a negative lens group disposed between the two lens groups, and the two lens groups move while the negative lens group is fixed during zooming.

[0077] With this configuration, even if the lens is made wider angle, the effective diameter of the lens can be made smaller, the lens weight can be reduced, and the zoom operation mechanism can be simply configured, so that the weight of the mechanical parts can be reduced, and the weight of the entire lens can be reduced.

[0078] In the zoom lens systems according to Examples 1 to 6, the first lens group and the magnifying optical system are fixed during zooming.

[0079] With this configuration, by disposing the zoom mechanism on the reduction side from the intermediate imaging position, the zoom operation mechanism, such as a cam and a motor, can be mounted on the reduction side, so that the center of gravity of the lens barrel can be moved closer to the reduction side.

[0080] In the zoom lens systems according to Examples 1 to 6, the relay optical system further includes another negative lens group, and the negative lens group has a smaller negative power than the other negative lens group.

[0081] With this configuration, it is possible to reduce aberration fluctuations during zooming, and good performance can be obtained over the entire zoom range.

[0082] In the zoom lens systems according to Examples 1 to 6, the negative lens unit has a diaphragm.

[0083] With this configuration, it is possible to reduce aberration fluctuations during zooming, and good performance can be obtained over the entire zoom range.

[0084] In the zoom lens systems according to Examples 1 to 6, the lens on the most reduction side of the enlarging optical system is a negative lens.

[0085] With this configuration, the effective diameter of the lens close to the intermediate image can be made small, and the lens can be made lighter.

[0086] In the zoom lens systems according to Examples 1 to 6, the lens on the most enlargement side of the relay optical system is a positive lens.

[0087] With this configuration, the effective diameter of the lens close to the intermediate image can be made small, and the lens can be made lighter.

[0088] The zoom lens systems according to Examples 1 to 6 may also satisfy the condition (1). 0.1 <fp / fr<0.5 ···(1) Where: fp: focal length of magnifying optical system fr: focal length of relay optical system at wide-angle end It is.

[0089] Condition (1) is a conditional expression that specifies the relationship between the composite focal length of the magnification optical system and the relay optical system. By satisfying this, an optical system that is wide-angle yet has a small lens diameter can be realized. If the lower limit of conditional expression (1) is exceeded, the effective diameter of the lens element with positive power that is located on the magnification side of the intermediate image formation position and is second closest to the intermediate image formation position on the magnification side becomes too large, making the lens heavy. Conversely, if the upper limit is exceeded, the effective diameter of the lens element located furthest on the magnification side becomes too large, making the lens heavy.

[0090] Furthermore, a more advantageous effect can be obtained by satisfying the following condition (1A) in addition to the condition (1). 0.15 <fp / fr<0.30 …(1A)

[0091] The zoom lens systems according to Examples 1 to 6 may also satisfy the condition (2). 100<|fr1 / fw|<1000 ···(2) Where: fr1: focal length of the first lens group fw: focal length of the entire system at the wide-angle end It is.

[0092] Condition (2) is a conditional expression that sets forth the relationship between the focal length of the first lens group and the focal length of the entire system at the wide-angle end. By satisfying this condition, an optical system with a small lens diameter despite being wide-angle can be realized. If the upper limit of condition (2) is exceeded, the aperture of the first lens group becomes too large, and the lens becomes heavy. Conversely, if the lower limit is exceeded, the aperture of the rear group of the magnification optical system becomes too large, and the lens becomes heavy.

[0093] Furthermore, a more advantageous effect can be obtained by satisfying the following condition (2A) in addition to the condition (2): 150<|fr1 / fw|<700 ···(2A)

[0094] The zoom lens systems according to Examples 1 to 6 may also satisfy the condition (3). 5 <frn / fw<50 ···(3) Where: frn: focal length of negative lens group fw: focal length of the entire system at the wide-angle end It is.

[0095] Condition (3) is a conditional expression that specifies the relationship between the focal length of the negative lens group and the focal length of the entire system at the wide-angle end. By satisfying this condition, an optical system that is wide-angle yet has a small lens diameter can be realized. If the upper limit of condition (3) is exceeded, the aperture of the negative lens group becomes too large, and the lens becomes heavy. Conversely, if the lower limit is exceeded, the aperture of the group on the reduction side of the negative lens group becomes too large, and the lens becomes heavy.

[0096] Furthermore, a more advantageous effect can be obtained by satisfying the following condition (3A) in addition to the condition (3): 8 <frn / fw<30 ···(3A)

[0097] In the zoom lens systems according to Examples 1 to 6, the magnification optical system has the longest air space, and the magnification optical system includes a front group of magnification optical systems on the magnification side and a rear group of magnification optical systems on the reduction side, with the longest air space as a boundary, and the zoom lens systems may satisfy conditions (4) and (5). 6.5<|Ts / fw|<12.0 ···(4) 3.0<|Tpr / fw|<8.0 ···(5) Where: Ts: The maximum air gap of the magnifying optical system fw: focal length of the entire system Tpr: Distance from the surface of the rear group of the magnifying optical system that is closest to the magnifying side to the intermediate image It is.

[0098] Condition (4) is a conditional expression that specifies the relationship between the longest air gap in the magnifying optical system and the focal length of the entire system at the wide-angle end. By satisfying condition (4), the optical system can be made wider-angle. If the lower limit of condition (4) is not met, the lenses in the front group of the magnifying optical system will become heavy. If the upper limit of condition (4) is exceeded, the center of gravity of the entire optical system will move toward the magnifying side. In addition, condition (5) is a conditional expression that specifies the relationship between the distance from the magnifying-side surface of the rear group of the magnifying optical system to the intermediate image and the focal length of the entire system at the wide-angle end. By satisfying condition (5), the effect of condition (4) can be achieved.

[0099] Furthermore, more advantageous effects can be obtained by satisfying at least one of the following conditions (4A) and (5A) in addition to the conditions (4) and (5). 6.5<|Ts / fw|<10.0 …(4A) 5.0<|Tpr / fw|<6.5 …(5A)

[0100] The zoom lens systems according to Examples 1 to 6 may satisfy the following conditional expression (6). 0.8 <Tp / Tr<1.0 …(6) Where: Tp: the distance from the most enlarged surface of the enlargement optical system to the intermediate image position Tr: the distance from the intermediate image-forming position at the wide-angle end to the surface on the most reduced side of the relay optical system It is.

[0101] Condition (6) regulates the relationship between the distance from the most enlargement surface of the magnification optical system to the intermediate image position and the distance from the intermediate image position at the wide-angle end to the most reduction surface of the relay optical system. If the upper limit of condition (6) is exceeded, it becomes difficult to correct the curvature of field. If the lower limit of condition (6) is not met, the center of gravity shifts to the enlargement side.

[0102] Furthermore, a more advantageous effect can be obtained by satisfying the following condition (6A) in addition to the condition (6): 0.9 <Tp / Tr<1.0 …(6A)

[0103] In the zoom lens systems according to Examples 1 to 6, the magnification optical system has the longest air space, and may include a magnification optical system front group on the magnification side and a magnification optical system rear group on the reduction side, with the longest air space as a boundary, and may satisfy the following conditional expression (7): 7<|fpr / fw|<12 …(7) Where: fpr: focal length of the rear group of the magnifying optical system It is.

[0104] Condition (7) sets forth the relationship between the focal length of the rear group of the magnifying optical system 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, making the lens heavy. If the lower limit of condition (7) is exceeded, the aperture of the front group of the magnifying optical system becomes too large, making the lens heavy.

[0105] Furthermore, a more advantageous effect can be obtained by satisfying the following condition (7A) in addition to condition (7): 9<|fpr / fw|<10 …(7A)

[0106] In the zoom lens systems according to Examples 1 to 6, the magnification optical system has the longest air space, and includes a magnification optical system front group on the magnification side and a magnification optical system rear group on the reduction side across the longest air space, and may satisfy the following conditional expression (8): 2<|fpf / fw|<5 …(8) Where: fpf: focal length of the front group of the magnifying optical system It is.

[0107] Condition (8) sets forth the relationship between the focal length of the front group of the magnifying optical system 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 front group of the magnifying optical system becomes too large, making the lens heavy. If the lower limit of condition (8) is exceeded, the aperture of the rear group of the magnifying optical system becomes too large, making the lens heavy.

[0108] Furthermore, a more advantageous effect can be obtained by satisfying the following condition (8A) in addition to condition (8): 3<|fpf / fw|<4 …(8A)

[0109] In the zoom lens systems according to Examples 1 to 6, a first lens element is disposed on the most enlargement side of the enlargement optical system, and the first lens element has an aspheric first lens enlargement side surface facing the enlargement side and an aspheric first lens reduction side surface facing the reduction side, The first lens enlargement side surface and the first lens reduction side surface may satisfy the following condition (9) within an effective diameter range from r>0: dZ(r) / dr>0 …(9) Where: r: Distance from the vertex of the surface along a plane perpendicular to the optical axis of the optical system (r>0) Z(r): Amount of sag of the surface (Z=0 at the vertex (r=0), the contraction displacement with respect to the vertex has a + sign, and the expansion displacement has a - sign) It is.

[0110] Condition (9) is a conditional expression that stipulates that the first derivative dZ(r) / dr of the surface sag amount Z(r) must be positive. By satisfying condition (9), even if localized heat is generated in the first lens element, the shape change due to thermal expansion will occur in the same manner on the enlargement side and reduction side of the first lens. As a result, the occurrence of field curvature and astigmatism can be suppressed.

[0111] In the zoom lens systems according to Examples 1 to 6, the first lens element may be made of a synthetic resin.

[0112] With this configuration, the first lens element can be easily made large in diameter, and by making it from a synthetic resin, the lens can be made lighter.

[0113] In the zoom lens systems according to Examples 1 to 6, all of the lens elements that satisfy the condition (10) may also satisfy the condition (11), and one lens element among the lens elements does not have to satisfy both the conditions (10) and (11). |ym / (fw·tan(ωm))|<3.0 …(10) Tg>300℃ …(11) Where: ωm: Maximum half angle at the wide-angle end ym: Height at which the most off-axis chief ray passes through the lens surface at the telephoto end Tg: glass transition temperature of the lens material It is.

[0114] Condition (10) is a conditional expression that specifies the relationship between the height at which the most off-axis chief 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 half angle of view at the wide-angle end. Condition (11) is a conditional expression that specifies the glass transition point of the lens material. By satisfying both conditions (10) and (11), lens deterioration can be prevented when high-intensity light passes through the lens. Note that ym is calculated for the surface that passes through the surface on the enlargement side and the reduction side of the lens at a lower height. In addition, in the region that does not satisfy (10), in order to widen the range of glass materials to be selected that are less susceptible to heat, it is possible to select a material that does not satisfy the glass transition point Tg of the lens material. This allows the selection of a material with a low glass transition point Tg, such as a resin, and thus reduces the weight.

[0115] Moreover, the zoom lens systems according to Examples 1 to 6 may satisfy the following conditional expression (12). ωm>65° …(12) Where: ωm: Maximum half angle at the wide-angle end It is.

[0116] Condition (12) sets forth the maximum half angle of view at the wide-angle limit. By satisfying condition (12), it becomes possible to shorten the working distance.

[0117] Moreover, the zoom lens systems according to Examples 1 to 6 may satisfy the following conditional expression (13). -1.5<(L1R1+L1R2) / (L1R2-L1R1)<-0.9 …(13) Where: L1R1: The central curvature radius of the most magnifying lens side L1R2: The radius of curvature of the center of the lens on the most magnifying side It is.

[0118] Condition (13) is a conditional expression that prescribes the shaping factor of the first lens element located at the most enlargement side in the magnification optical system. By satisfying condition (13), the effective diameter of the lens can be made small while correcting curvature of field and distortion. If the lower limit of condition (13) is not met, correction of curvature of field and distortion becomes insufficient. If the upper limit is exceeded, the effective diameter of the lens located at the reduction side becomes large.

[0119] A more advantageous effect can be obtained by satisfying the following condition (13A) in addition to condition (13): -1.2<(L1R1+L1R2) / (L1R2-L1R1)<-1.07 …(13A)

[0120] In the zoom optical systems according to the first to sixth embodiments, the rear group located closest to the enlargement side may have positive power and may move to the enlargement side when zooming from the wide-angle end to the telephoto end.

[0121] With this configuration, it is possible to reduce aberration fluctuations during zooming.

[0122] The zoom optical systems according to the first to sixth embodiments are beforeThe group adjacent to the group on the magnifying side may have positive power and the group adjacent to the reducing side may have positive power.

[0123] With this configuration, it is possible to reduce aberration fluctuations during zooming.

[0124] As described above, several examples have been described as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited to these examples, and may be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made as appropriate.

[0125] Numerical examples of the zoom lens system according to Examples 1 to 6 will be described below. In each numerical example, all lengths in the table are in "mm" and all angles of view are in "°". In each numerical example, r is the radius of curvature, d is the surface spacing, nd is the refractive index for the d-line, and vd is the Abbe number for the d-line. In each numerical example, the surfaces marked with an * are aspheric, and the aspheric shape is defined by the following formula.

[0126]

number

[0127] Where: Z: The distance from a point on the aspheric surface whose height from the optical axis is h to the tangent plane of the vertex of the aspheric surface. h: distance from the optical axis, r: apex curvature radius, κ: conic constant, An: n-th order aspheric coefficient It is.

[0128] (Numerical Example 1) For the zoom lens system of Numerical Example 1 (corresponding to Example 1), surface data is shown in Table 1, various data is shown in Table 2, and single lens data is shown in Table 3 (unit: mm).

[0129] [Table 1] Surface Data Surface number rd nd vd Object plane∞ 1* 1559.72740 10.00000 1.50940 56.5 2* 49.93020 21.30460 3 62.81020 3.50000 1.80420 46.5 4 34.70010 8.90130 5 56.73020 2.50000 1.80420 46.5 6 26.07540 23.46460 7 -45.65000 9.58260 1.80420 46.5 8 -43.96980 10.59440 9* -26.79370 9.98320 1.51633 64.1 10* -17.01960 0.20000 11 -48.20740 6.63870 1.49700 81.6 12 -23.22440 0.20000 13 -24.11240 2.50000 1.86966 20.0 14 -390.21520 0.27550 15 -310.33810 10.92670 1.49700 81.6 16 -32.54250 3.54050 17 -327.98450 12.31470 1.49700 81.6 18 -44.92820 52.72720 19 112.99220 12.93660 1.92286 20.9 20 -242.56180 1.07700 21 34.64080 10.20050 1.92286 20.9 22 47.22600 7.87550 23 175.26870 2.64100 1.80420 46.5 24 40.67200 17.69210 25 -99.40430 5.09720 1.73800 32.3 26 -58.46020 1.18700 27 -48.52090 4.00000 1.75500 52.3 28 112.52870 24.31600 29 -103.32630 9.73590 1.86966 20.0 30 -46.35090 Variable 31 628.18950 14.57510 1.59282 68.6 32 -52.01000 1.93020 33 -50.20170 1.50000 1.59270 35.4 34 -118.85930 0.20000 35 119.34120 4.06280 1.49700 81.6 36 -609.80110 Variable 37 39.15350 4.63700 1.59270 35.4 38 78.94450 7.47190 39(Aperture) ∞ 5.06950 40 83.20610 1.50000 1.51680 64.2 41 25.33360 19.56830 42 -35.31920 1.50000 1.73800 32.3 43 314.02180 0.23590 44 317.72160 6.90320 1.43700 95.1 45 -39.10950 Variable 46 77.92810 10.14880 1.49700 81.6 47 -66.68800 4.58920 48 52.73130 2.50000 1.67300 38.3 49 38.05440 2.43570 50 43.58200 13.94890 1.43700 95.1 51 -89.60580 Variable 52 ∞ 41.77900 1.51680 64.2 53 ∞ BF Image plane∞ Aspheric surface Page 1 K= 0.00000E+00, A3= 1.28353E-04, A4=-2.64195E-07, A5=-6.74969E-08 A6= 1.81712E-09, A7=-1.58164E-11, A8=-6.22311E-14, A9= 2.06740E-15 A10=-1.04375E-17 Page 2 K=-8.26520E-01, A3= 1.67017E-04, A4=-3.90151E-06, A5= 4.01101E-09 A6= 8.36718E-11, A7=-1.92652E-12, A8= 3.11135E-14, A9= 6.71471E-16 A10=-8.69102E-18 Page 9 K= 0.00000E+00, A3= 0.00000E+00, A4=-2.79259E-05, A5= 0.00000E+00 A6=-9.86305E-08, A7= 0.00000E+00, A8=-4.35015E-11, A9= 0.00000E+00 A10=-3.54848E-12 Page 10 K= 0.00000E+00, A3= 0.00000E+00, A4= 6.83358E-06, A5= 0.00000E+00 A6= 5.05887E-09, A7= 0.00000E+00, A8= 4.34142E-12, A9= 0.00000E+00 A10 = 0.00000E+00

[0130] [Table 2] Various データ ズームratio 1.07169 Wide Angle Mid-Telephoto Focal length -7.2471 -7.4853 -7.7666 F-number -1.89825 -1.89923 -1.90119 Angle of view -66.7864 -66.1339 -65.3643 Image height 17.2650 17.2650 17.2650 Lens total length 531.0070 531.0195 531.0251 BF 1.00700 1.01971 1.02522 d30 79.3276 76.2376 72.7297 d36 2.0000 5.0899 8.5979 d45 2.8841 2.8449 2.7430 d51 15.3200 15.3591 15.4610 Entrance pupil position 39.4726 39.4868 39.5064 Exit pupil position -629.6533 -622.9628 -606.2384 Front principal point position 32.1422 31.9117 31.6404 Back principal point position 538.2065 538.4541 538.7371

[0131] [Table 3] Single lens data Lens starting surface focal length 1 1 -101.4864 2 3 -102.0782 3 5 -62.2680 4 7 419.3768 5 9 67.0430 6 11 82.8595 7 13 -29.6464 8 15 72.2058 9 17 103.2565 10 19 85.0120 11 21 101.4077 12 23 -66.4382 13 25 182.6611 14 27 -44.4293 15 29 89.5395 16 31 81.6757 17 33 -147.8329 18 35 201.1947 19 37 125.6127 20 40 -71.1068 21 42 -42.9411 22 44 80.1579 23 46 74.0303 24 48 -218.0976 25 50 69.3032

[0132] (Numerical Example 2) For the zoom lens system of Numerical Example 2 (corresponding to Example 2), surface data is shown in Table 4, various data is shown in Table 5, and single lens data is shown in Table 6. 6 (unit: mm)

[0133] [Table 4] Surface Data Surface number rd nd vd object surface ∞ 1* 1285.52270 10.00000 1.50940 56.5 2* 49.83060 21.21070 3 62.02650 3.50000 1.80420 46.5 4 35.06940 9.10900 5 58.54560 2.50000 1.80420 46.5 6 26.12090 23.74190 7 -46.72130 9.61280 1.80420 46.5 8 -44.15830 10.24780 9* -26.01750 9.90630 1.51633 64.1 10* -16.98380 0.20000 11 -50.16140 6.68810 1.49700 81.6 12 -23.53440 0.20000 13 -24.64730 2.50000 1.86966 20.0 14 -585.53890 0.31100 15 -393.42380 10.84330 1.49700 81.6 16 -33.35970 3.25760 17 -343.11560 12.47360 1.49700 81.6 18 -44.66860 52.40130 19 112.65940 13.18500 1.92286 20.9 20 -240.04370 1.20910 21 34.70690 10.27630 1.92286 20.9 22 47.35520 7.94350 23 175.99540 2.70280 1.80420 46.5 24 40.79770 17.83980 25 -100.33770 4.78040 1.73800 32.3 26 -61.87190 1.14400 27 -51.03120 4.00000 1.75500 52.3 28 106.39920 25.02820 29 -107.82800 9.69950 1.86966 20.0 30 -46.86680 Variable 31 980.24220 13.42940 1.59282 68.6 32 -49.21610 1.38190 33 -47.83950 1.50000 1.59270 35.4 34 -112.14390 0.20000 35 114.93620 4.06190 1.49700 81.6 36 -836.92110 Variable 37 39.04630 4.71460 1.59270 35.4 38 80.21340 6.84850 39(Aperture) ∞ 4.96320 40 87.23480 1.50000 1.51680 64.2 41 25.40700 20.30400 42 -35.83100 1.50000 1.73800 32.3 43 333.80130 0.62340 44 184.10960 7.84820 1.43700 95.1 45 -39.54110 Variable 46 78.61340 10.04780 1.49700 81.6 47 -72.77470 Variable 48 53.01230 2.50000 1.67300 38.3 49 36.50730 2.16040 50 40.36680 13.98580 1.43700 95.1 51 -111.29940 15.32000 52 ∞ 41.77900 1.51680 64.2 53∞BF Image plane ∞ Aspheric Data Front page K= 0.00000E+00, A3= 1.28839E-04, A4=-3.08330E-07, A5=-6.71661E-08 A6= 1.82141E-09, A7=-1.58537E-11, A8=-6.25886E-14, A9= 2.06822E-15 A10=-1.04113E-17 2nd side K=-8.31900E-01, A3= 1.67819E-04, A4=-3.91209E-06, A5= 3.98957E-09 A6= 8.43543E-11, A7=-1.91614E-12, A8= 3.12599E-14, A9= 6.71655E-16 A10=-8.70014E-18 9th page K= 0.00000E+00, A3= 0.00000E+00, A4=-2.77656E-05, A5= 0.00000E+00 A6=-1.04848E-07, A7= 0.00000E+00, A8=-1.16343E-11, A9= 0.00000E+00 A10=-3.81206E-12 Side 10 K= 0.00000E+00, A3= 0.00000E+00, A4= 6.68590E-06, A5= 0.00000E+00 A6= 4.30475E-09, A7= 0.00000E+00, A8= 5.04148E-12, A9= 0.00000E+00 A10= 0.00000E+00

[0134] [Table 5] Various data Zoom ratio 1.07164 Wide Angle Mid-Telephoto Focal length -7.2472 -7.4856 -7.7664 F-number -1.89804 -1.89866 -1.90299 Angle of view -66.7815 -66.1287 -65.3536 Image height 17.2650 17.2650 17.2650 Lens total length 531.0056 531.0189 531.0223 BF 1.00567 1.01918 1.02245 d30 79.4673 76.3678 73.0056 d36 2.0000 5.0994 8.4617 d45 2.9239 2.9156 2.7065 d47 4.4286 4.4368 4.6460 Entrance pupil position 39.6338 39.6469 39.6642 Exit pupil position -629.4376 -628.4604 -604.9882 Front principal point position 32.3032 32.0722 31.7983 Back principal point position 538.2053 538.4538 538.7342

[0135] [Table 6] Single lens data Lens starting surface focal length 1 1 -102.0460 2 3 -106.5025 3 5 -60.7339 4 7 374.6402 5 9 68.9777 6 11 82.3402 7 13 -29.6481 8 15 72.6153 9 17 101.9147 10 19 84.6010 11 21 101.3027 12 23 -66.6334 13 25 207.7268 14 27 -45.1874 15 29 88.7533 16 31 79.4364 17 33 -141.9943 18 35 203.6251 19 37 123.1158 20 40 -69.9428 21 42 -43.7696 22 44 75.2891 23 46 77.7513 24 48 -185.5362 25 50 69.7427

[0136] (Numerical Example 3) For the zoom lens system of Numerical Example 3 (corresponding to Example 3), surface data is shown in Table 7, various data is shown in Table 8, and single lens data is shown in Table 9 (unit: mm).

[0137] [Table 7] Surface Data Surface number rd nd vd object surface ∞ 1* 1542.85870 10.00000 1.50940 56.5 2* 49.55880 20.91510 3 61.91000 3.50000 1.80420 46.5 4 35.40450 8.98610 5 58.86560 2.50000 1.80420 46.5 6 26.15990 23.55990 7 -48.39100 9.60620 1.80420 46.5 8 -45.50060 10.68200 9* -24.82700 9.90660 1.51633 64.1 10* -17.27930 0.20000 11 -60.90260 7.18860 1.49700 81.6 12 -24.17250 0.20000 13 -25.60320 2.50000 1.86966 20.0 14 -12790.35690 0.38630 15 -810.61200 10.98140 1.49700 81.6 16 -34.93840 2.31620 17 -470.05300 12.87300 1.49700 81.6 18 -45.09980 52.14650 19 112.57610 13.51480 1.92286 20.9 20 -235.92950 1.04610 21 34.81750 10.34860 ​​1.92286 20.9 22 46.77120 7.98380 23 167.00960 2.74570 1.80420 46.5 24 40.71110 17.82940 25 -99.89220 4.66260 1.73800 32.3 26 -63.60960 1.09750 27 -52.56980 4.00000 1.75500 52.3 28 104.66390 25.76170 29 -110.86560 9.51860 1.86966 20.0 30 -47.59640 Variable 31 1141.93590 12.21660 1.59282 68.6 32 -49.36050 1.41000 33 -47.97660 1.50000 1.59270 35.4 34 -114.67330 0.20000 35 112.51030 4.14990 1.49700 81.6 36 -772.27450 Variable 37 39.35990 4.81790 1.59270 35.4 38 84.40660 6.27310 39(Aperture) ∞ 4.75130 40 91.49710 1.50000 1.51680 64.2 41 25.98720 19.85740 42 -38.54720 1.50000 1.73800 32.3 43 190.47750 0.81730 44 123.82590 8.05450 1.43700 95.1 45 -41.18570 Variable 46 75.00430 8.96430 1.49700 81.6 47 -89.90820 Can change 48 49.67100 2.50000 1.67300 38.3 49 36.65610 Can change 50 43.77010 13.46000 1.43700 95.1 51 -103.12930 15.32000 52 ∞ 41.77900 1.51680 64.2 53 ∞ BF Image plane∞ Aspheric surface Page 1 K= 0.00000E+00, A3= 1.27352E-04, A4=-2.46395E-07, A5=-6.78194E-08 A6= 1.82353E-09, A7=-1.58698E-11, A8=-6.23368E-14, A9= 2.06906E-15 A10=-1.04258E-17 Page 2 K=-8.34168E-01, A3= 1.66154E-04, A4=-3.92942E-06, A5= 3.98305E-09 A6= 8.75484E-11, A7=-1.87356E-12, A8= 3.13986E-14, A9= 6.69332E-16 A10=-8.78444E-18 Page 9 K= 0.00000E+00, A3= 0.00000E+00, A4=-2.59408E-05, A5= 0.00000E+00 A6=-1.01204E-07, A7= 0.00000E+00, A8= 1.03376E-11, A9= 0.00000E+00 A10=-3.68227E-12 Page 10 K= 0.00000E+00, A3= 0.00000E+00, A4= 6.01465E-06, A5= 0.00000E+00 A6= 4.28522E-09, A7= 0.00000E+00, A8= 4.82571E-12, A9= 0.00000E+00 A10= 0.00000E+00

[0138] [Table 8] Various data Zoom ratio 1.07195 Wide Angle Mid-Telephoto Focal length -7.2462 -7.4855 -7.7676 F-number -1.89833 -1.89996 -1.90470 Angle of view -66.7849 -66.1367 -65.3666 Image height 17.2650 17.2650 17.2650 Lens total length 531.0064 531.0187 531.0213 BF 1.00665 1.01903 1.02147 d30 80.2537 77.1802 73.8099 d36 2.0130 5.0864 8.4567 d45 3.0000 2.9143 2.6517 d47 4.3983 4.3721 4.5535 d49 4.3068 4.4187 4.5000 Entrance pupil position 39.3613 39.3735 39.3900 Exit pupil position -624.4664 -620.0128 -597.7090 Front principal point position 32.0311 31.7978 31.5217 Back principal point position 538.2052 538.4535 538.7343

[0139] [Table 9] Single lens data Lens starting surface focal length 1 1 -100.7454 2 3 -109.2611 3 5 -60.6131 4 7 381.7367 5 9 76.0781 6 11 75.7254 7 13 -29.5021 8 15 73.1217 9 17 99.3757 10 19 84.1477 11 21 104.2867 12 23 -67.5962 13 25 225.0220 14 27 -45.8473 15 29 89.6298 16 31 80.1192 17 33 -140.3461 18 35 197.9015 19 37 119.6685 20 40 -70.7848 21 42 -43.3203 22 44 71.7887 23 46 83.7890 24 48 -225.2782 25 50 72.3320

[0140] (Numerical Example 4) For the zoom lens system of Numerical Example 4 (corresponding to Example 4), surface data is shown in Table 10, various data is shown in Table 11, and single lens data is shown in Table 12 (unit: mm).

[0141] [Table 10] Surface Data Surface number rd nd vd object surface ∞ 1* 853.38660 10.00000 1.50940 56.5 2* 48.21640 20.70550 3 60.33030 3.50000 1.80420 46.5 4 35.47130 9.18140 5 59.13110 2.50000 1.80420 46.5 6 26.22800 21.79970 7 -52.13020 9.56340 1.80420 46.5 8 -50.05870 12.81450 9* -24.44800 9.66160 1.51633 64.1 10* -18.38320 0.20000 11 -86.40890 8.16710 1.49700 81.6 12 -24.81670 0.20000 13 -27.15970 2.50000 1.86966 20.0 14 547.94120 0.56170 15 16222.81880 11.25620 1.49700 81.6 16 -37.40970 0.96000 17 -1502.05520 13.82660 1.49700 81.6 18 -46.36270 51.66830 19 114.83090 13.86910 1.92286 20.9 20 -243.40280 2.17470 21 34.79770 10.67800 1.92286 20.9 22 46.85510 8.21000 23 161.92410 2.91920 1.80420 46.5 24 40.25020 17.86250 25 -104.95000 4.80810 1.73800 32.3 26 -63.25580 0.87980 27 -54.39110 4.00000 1.75500 52.3 28 95.33210 26.73890 29 -112.94140 8.84110 1.86966 20.0 30 -48.78270 Variable 31 884.85040 8.40570 1.59282 68.6 32 -49.78970 1.34100 33 -48.57320 1.50000 1.59270 35.4 34 -118.65630 Variable 35 124.78890 4.21320 1.49700 81.6 36 -452.70770 Variable 37 37.96760 5.04490 1.59270 35.4 38 82.24760 4.80510 39(Aperture) ∞ 5.85310 40 75.39660 1.50000 1.51680 64.2 41 24.99980 18.91870 42 -39.01370 1.50000 1.73800 32.3 43 127.29270 0.70010 44 120.82030 7.63430 1.43700 95.1 45 -41.82490 Variable 46 68.42550 9.25900 1.49700 81.6 47 -93.00100 Variable 48 54.80590 2.50000 1.67300 38.3 49 37.59050 3.35980 50 44.24510 14.52660 1.43700 95.1 51 -76.05600 15.32000 52 ∞ 41.77900 1.51680 64.2 53∞BF Image plane ∞ Aspheric Data Front page K= 0.00000E+00, A3= 1.23207E-04, A4=-2.64346E-07, A5=-6.70631E-08 A6= 1.82466E-09, A7=-1.59622E-11, A8=-6.20200E-14, A9= 2.06858E-15 A10=-1.04117E-17 Page 2 K=-8.53791E-01, A3= 1.65320E-04, A4=-4.01450E-06, A5= 4.12521E-09 A6= 9.64433E-11, A7=-1.78094E-12, A8= 3.16260E-14, A9= 6.61916E-16 A10=-8.92584E-18 Page 9 K= 0.00000E+00, A3= 0.00000E+00, A4=-2.10717E-05, A5= 0.00000E+00 A6=-6.55977E-08, A7= 0.00000E+00, A8=-1.66719E-11, A9= 0.00000E+00 A10=-2.25629E-12 Page 10 K= 0.00000E+00, A3= 0.00000E+00, A4= 4.94270E-06, A5= 0.00000E+00 A6= 4.28518E-09, A7= 0.00000E+00, A8= 1.37239E-11, A9= 0.00000E+00 A10 = 0.00000E+00

[0142] [Table 11] Various データ ズームratio 1.07176 View from the middle of Kok Kok Focus distance -7.2505 -7.4890 -7.7708 Fナンバー-1.89769 -1.89966 -1.90218 Angle of view -66.7723 -66.1145 -65.3417 Image height 17.2650 17.2650 17.2650 Lens total length 531.0044 531.0164 531.0251 BF 1.00464 1.01668 1.02526 d30 80.1300 77.1041 73.7905 d34 2.4064 2.3383 2.0000 d36 2.0000 5.0939 8.7459 d45 2.9859 2.9042 2.7968 d47 4.2696 4.3513 4.4587 Entrance pupil position 39.5645 39.5759 39.5918 Exit pupil position -634.2339 -625.3536 -614.0913 Front principal point position 32.2313 31.9973 31.7228 Back principal point position 538.2074 538.4547 538.7412

[0143] [Table 12] Single lens data Lens starting surface focal length 1 1 -100.7441 2 3 -114.2125 3 5 -60.6659 4 7 512.2830 5 9 93.0480 6 11 67.0985 7 13 -29.6952 8 15 75.1155 9 17 95.9541 10 19 86.1445 11 21 102.8235 12 23 -67.3269 13 25 205.6785 14 27 -45.3490 15 29 92.7964 16 31 79.7802 17 33 -139.8653 18 35 197.3075 19 37 114.1453 20 40 -73.1124 21 42 -40.3084 22 44 72.1265 23 46 80.8587 24 48 -188.8490 25 50 66.4500

[0144] (Numerical Example 5) For the zoom lens system of Numerical Example 5 (corresponding to Example 5), surface data is shown in Table 13, various data is shown in Table 14, and single lens data is shown in Table 15 (unit: mm).

[0145] [Table 13] Surface Data Surface number rd nd vd object surface ∞ 1* 689.85100 10.00000 1.50940 56.5 2* 47.67700 21.86350 3 64.31700 3.50000 1.80420 46.5 4 34.75590 8.13040 5 53.64940 2.50000 1.80420 46.5 6 26.31140 22.13420 7 -51.65890 9.56070 1.80420 46.5 8 -49.64180 12.98510 9* -26.25180 9.33550 1.51633 64.1 10* -18.86710 0.20000 11 -72.14340 8.82740 1.49700 81.6 12 -23.27540 0.20000 13 -26.11700 2.50000 1.86966 20.0 14 778.49390 0.61230 15 -1722.01300 11.44520 1.49700 81.6 16 -37.94710 0.20000 17 3317.56040 14.48620 1.49700 81.6 18 -48.06360 50.74300 19 120.75180 14.00000 1.92286 20.9 20 -239.77770 3.13130 21 35.09390 11.02300 1.92286 20.9 22 47.26840 8.37230 23 157.56200 3.14730 1.80420 46.5 24 39.82520 16.97740 25 -103.58400 4.82360 1.73800 32.3 26 -63.27830 0.70490 27 -56.53210 4.00000 1.75500 52.3 28 89.06880 27.26760 29 -117.80840 9.17600 1.86966 20.0 30 -49.09390 Variable 31 450.02090 7.92050 1.59282 68.6 32 -55.86800 Variable 33 -54.84200 1.50000 1.59270 35.4 34 -154.22020 Variable 35 154.83850 4.19470 1.49700 81.6 36 -218.56910 Variable 37 34.89000 5.42970 1.59270 35.4 38 91.06230 2.30800 39(Aperture) ∞ 5.54400 40 93.13560 1.50000 1.51680 64.2 41 23.67250 16.44500 42 -35.51570 1.50000 1.73800 32.3 43 120.09350 0.22440 44 122.77130 7.34710 1.43700 95.1 45 -37.72510 Variable 46 65.47640 11.04450 1.49700 81.6 47 -86.74310 Variable 48 53.44180 2.50000 1.67300 38.3 49 37.63000 Variable 50 46.31700 14.75210 1.43700 95.1 51 -67.97830 15.32000 52 ∞ 41.77900 1.51680 64.2 53∞BF Image plane ∞ Aspheric Data Front page K= 0.00000E+00, A3= 1.17463E-04, A4=-2.31628E-07, A5=-6.59395E-08 A6= 1.81310E-09, A7=-1.60936E-11, A8=-6.10381E-14, A9= 2.09440E-15 A10=-1.06332E-17 2nd side K=-8.25922E-01, A3= 1.59536E-04, A4=-4.03112E-06, A5= 5.08423E-09 A6= 1.00553E-10, A7=-1.90015E-12, A8= 2.91500E-14, A9= 6.51056E-16 A10=-8.49456E-18 9th page K= 0.00000E+00, A3= 0.00000E+00, A4=-2.18898E-05, A5= 0.00000E+00 A6=-7.41292E-08, A7= 0.00000E+00, A8= 4.43382E-11, A9= 0.00000E+00 A10=-2.46623E-12 Side 10 K= 0.00000E+00, A3= 0.00000E+00, A4= 3.98821E-06, A5= 0.00000E+00 A6= 2.26149E-09, A7= 0.00000E+00, A8= 2.47661E-13, A9= 0.00000E+00 A10= 0.00000E+00

[0146] [Table 14] Various data Zoom ratio 1.07178 Wide Angle Mid-Telephoto Focal length -7.2794 -7.5189 -7.8019 F-number -1.89789 -1.89986 -1.90209 Angle of view -66.7679 -66.1108 -65.3409 Image height 17.2650 17.2650 17.2650 Lens total length 531.0025 531.0103 531.0183 BF 1.00289 1.01065 1.01871 d30 79.7849 76.8891 73.7081 d32 2.3452 2.1673 2.0000 d34 3.0465 2.6569 2.0000 d36 2.0000 5.4633 9.4686 d45 3.1570 3.0692 2.9663 d47 4.5101 4.5175 4.5349 d49 4.0000 4.0804 4.1658 Entrance pupil position 39.6022 39.6132 39.6290 Exit pupil position -636.8964 -630.5474 -622.9057 Front principal point position 32.2397 32.0048 31.7296 Back principal point position 538.2340 538.4780 538.7651

[0147] [Table 15] Single lens data Lens starting surface focal length 1 1 -101.0747 2 3 -99.2699 3 5 -66.9349 4 7 507.8820 5 9 90.8085 6 11 65.2261 7 13 -29.0145 8 15 77.8974 9 17 95.4633 10 19 88.6740 11 21 102.9202 12 23 -67.0718 13 25 209.6995 14 27 -45.2696 15 29 91.1241 16 31 84.3243 17 33 -144.4018 18 35 183.0431 19 37 92.1154 20 40 -61.8717 21 42 -36.9891 22 44 66.9681 23 46 76.9281 24 48 -201.8175 25 50 65.6130

[0148] (Numerical Example 6) For the zoom lens system of Numerical Example 6 (corresponding to Example 6), surface data is shown in Table 16, various data is shown in Table 17, and single lens data is shown in Table 18 (unit: mm). [Table 16] Surface Data Surface number rd nd vd object surface ∞ 1* 470.37890 10.00000 1.50940 56.5 2* 46.40080 22.24280 3 62.86240 3.50000 1.80420 46.5 4 35.04850 8.23400 5 54.25150 2.50000 1.80420 46.5 6 26.46800 20.45790 7 -58.23820 9.59530 1.80420 46.5 8 -54.97430 13.48880 9* -21.83380 8.92100 1.51633 64.1 10* -19.16310 0.20000 11 -170.52590 8.82520 1.49700 81.6 12 -25.34350 0.20000 13 -27.52730 2.50000 1.86966 20.0 14 547.77300 0.66240 15 -2910.64330 12.01970 1.49700 81.6 16 -34.94790 0.20000 17 569.05770 13.00120 1.49700 81.6 18 -54.03350 52.43390 19 113.08890 14.00000 1.92286 20.9 20 -255.91160 0.20000 21 35.51020 11.53020 1.92286 20.9 22 48.89210 8.57230 23 149.63270 3.11540 1.80420 46.5 24 39.72700 18.68680 25 -81.98070 4.41450 1.73800 32.3 26 -58.08410 0.47880 27 -54.41030 4.00000 1.75500 52.3 28 102.14640 28.87440 29 -123.11250 8.14390 1.86966 20.0 30 -51.51400 Variable 31 459.44430 6.60460 1.59282 68.6 32 -51.60860 0.20000 33 -52.25720 1.50000 1.59270 35.4 34 -166.77410 0.20000 35 131.99520 4.04930 1.49700 81.6 36 -805.29130 Variable 37 35.88770 5.95330 1.59270 35.4 38 87.80370 Variable 39(Aperture) ∞ 2.91650 40 64.62000 1.50000 1.51680 64.2 41 25.27360 Variable 42 -37.75460 1.50000 1.73800 32.3 43 79.16160 0.45350 44 91.44850 7.76440 1.43700 95.1 45 -42.41670 Variable 46 70.67940 9.55270 1.49700 81.6 47 -80.50330 8.02360 48 57.64490 2.50000 1.67300 38.3 49 38.89870 1.10570 50 42.03140 14.81530 1.43700 95.1 51 -78.93860 Can change 52 ∞ 41.77900 1.51680 64.2 53 ∞ BF Image plane∞ Aspheric surface Page 1 K= 0.00000E+00, A3= 1.21277E-04, A4=-5.82244E-07, A5=-5.95006E-08 A6= 1.77842E-09, A7=-1.63746E-11, A8=-5.85060E-14, A9= 2.11902E-15 A10=-1.08872E-17 Page 2 K=-8.11394E-01, A3= 1.65003E-04, A4=-4.20440E-06, A5= 3.97809E-09 A6= 1.14779E-10, A7=-1.71713E-12, A8= 2.91519E-14, A9= 6.24786E-16 A10=-8.50847E-18 Page 9 K= 0.00000E+00, A3= 0.00000E+00, A4=-1.13910E-05, A5= 0.00000E+00 A6=-2.46711E-08, A7= 0.00000E+00, A8=-1.20244E-11, A9= 0.00000E+00 A10=-1.67140E-12 Page 10 K= 0.00000E+00, A3= 0.00000E+00, A4= 5.61069E-06, A5= 0.00000E+00 A6= 9.40124E-09, A7= 0.00000E+00, A8= 3.22652E-11, A9= 0.00000E+00 A10= 0.00000E+00 [Table 17] Various data Zoom ratio 1.07206 Wide Angle Mid-Telephoto Focal length -7.2526 -7.4921 -7.7752 F-number -1.89660 -1.89323 -1.89545 Angle of view -66.7640 -66.1128 -65.3466 Image height 17.2650 17.2650 17.2650 Lens total length 531.0076 531.0105 531.0083 BF 1.00778 1.01095 1.00847 d30 80.0082 76.0752 71.4986 d36 2.0000 6.0639 10.7992 d38 5.2896 5.1586 5.0000 d41 23.0156 22.5850 21.9978 d45 2.9500 2.8961 2.8254 d51 15.3200 15.8044 16.4624 Entrance pupil position 40.2672 40.2788 40.2965 Exit pupil position -723.7475 -660.0698 -589.7112 Front principal point position 32.9420 32.7017 32.4189 Back principal point position 538.2126 538.4519 538.7288 [Table 18] Single lens data Lens starting surface focal length 1 1 -101.8693 2 3 -104.3530 3 5 -66.9515 4 7 527.9376 5 9 141.9555 6 11 58.7099 7 13 -30.0775 8 15 71.0740 9 17 99.9845 10 19 86.5622 11 21 99.4565 12 23 -68.1163 13 25 250.3683 14 27 -46.5091 15 29 96.7347 16 31 78.6425 17 33 -129.0298 18 35 228.5115 19 37 98.2136 20 40 -81.3741 21 42 -34.4504 22 44 67.4982 23 46 77.3496 24 48 -187.8082 25 50 65.1909 Table 19 below shows the corresponding values ​​of each conditional expression in each numerical example.

[0149] [Table 19] TIFF0007664544000002.tif89145

[0150] Table 20 below shows the variable values ​​of each of the conditional expressions (1) to (13) and the focal length of each group in each numerical example. [Table 20] TIFF0007664544000003.tif136144fp: Focal length of magnifying optical system fr: focal length of relay optical system at wide-angle end fw: The entire system at the wide-angle end Focal length fr1: focal length of the first lens group frn: focal length of negative lens group Ts: The maximum air gap of the magnifying optical system Tpr: Distance from the surface of the rear group of the magnifying optical system that is closest to the magnifying side to the intermediate image Tp: Distance from the most magnifying surface of the magnifying optical system to the intermediate image Tr: Distance from the intermediate image at the wide-angle end to the surface on the most reduced side of the relay optical system fpr: focal length of rear group of magnifying optical system fpf: focal length of the front group of the magnifying optical system ωm: Maximum half angle at the wide-angle end ym: The height at which the most off-axis chief ray passes through the lens surface at the telephoto end L1R1: The central curvature radius of the most magnifying lens side L1R2: The radius of curvature of the center of the lens on the most magnifying side fr2: focal length of the second lens group fr3: focal length of the third lens group fr4: focal length of the fourth lens group fr5: focal length of the fifth lens group fr6: focal length of the sixth lens group fr7: focal length of the seventh lens group fr8: focal length of the 8th lens group

[0151] Tables 21 and 22 below show the values ​​of |ym / (fw tan(ωm))| in conditional formula (10) and the Tg in conditional formula (11) in each numerical example. The lens material Z330R is the product name of cycloolefin polymer (COP) (Zeon Corporation). The lens element L1 can be made of various synthetic resins, which reduces the weight. The remaining lens elements L2 to L25 can also be made of various synthetic resins, which reduces the weight. [Table 21] TIFF0007664544000004.tif154170[Table 22] TIFF0007664544000005.tif152170

[0152] (Embodiment 2) Hereinafter, the second embodiment of the present disclosure will be described with reference to FIG. 19. FIG. 19 is a block diagram showing an example of an image projection device according to the present disclosure. The image projection device 100 includes the optical system 1 disclosed in the first embodiment, an image forming element 101, a light source 102, a control unit 110, and the like. The image forming element 101 is composed of a liquid crystal, a DMD, and the like, and generates an image to be projected on a screen SR via the optical system 1. The light source 102 is composed of an LED (light emitting diode), a laser, and the like, and supplies light to the image forming element 101. The control unit 110 is composed of a CPU or an MPU, and 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 image projection device 100. In this case, the device from which the optical system 1 is removed from the image projection device 100 is an example of a main body device.

[0153] The image projection device 100 described above can reduce the moment acting on the center of gravity of the optical system 1 by using the optical system 1 according to the first embodiment, and can achieve a wide-angle zoom function while reducing the effects of heat.

[0154] (Embodiment 3) Hereinafter, the third embodiment of the present disclosure will be described with reference to FIG. 20. FIG. 20 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 the first embodiment, 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 an optical image of an 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 or 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, the device from which the optical system 1 is removed from the imaging device 200 is an example of a main body device.

[0155] The imaging device 200 described above can reduce the moment acting on the center of gravity of the optical system 1 by using the optical system 1 according to the first embodiment, and can achieve a wide-angle zoom function while reducing the influence of heat.

[0156] As described above, the embodiments have been described as disclosure of the technology in the present disclosure, and the accompanying drawings and detailed description have been provided for this purpose.

[0157] Therefore, among the components described in the accompanying drawings and the detailed description, not only components essential for solving the problem but also components that are not essential for solving the problem in order to illustrate the above technology may be included. Therefore, just because those non-essential components are described in the accompanying drawings or the detailed description, it should not be immediately recognized that those non-essential components are essential.

[0158] Furthermore, since the above-described embodiments are intended to illustrate the technology in the present disclosure, various modifications, substitutions, additions, omissions, and the like can be made within the scope of the claims or their equivalents. [Industrial Applicability]

[0159] 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, vehicle-mounted cameras, etc. 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 including a plurality of lens elements and having an intermediate image forming position therein that is conjugate to a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, a magnifying optical system including a lens element located on the magnifying side from the intermediate image-forming position among the plurality of lens elements; a relay optical system including a lens element located on the reduction side from the intermediate image-forming position among the plurality of lens elements; Equipped with The relay optical system includes: a first lens group located on the most enlargement side; two lens groups disposed on the reduction side of the first lens group, the distance between adjacent lens groups changing during zooming; a negative lens group disposed between the two lens groups; An optical system in which the two lens groups move while the negative lens group remains fixed during zooming.

2. An optical system having an intermediate image-forming position therein that is conjugate to a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, a magnifying optical system located on the magnifying side of the intermediate image-forming position; a relay optical system located on the reduction side of the intermediate image-forming position; Equipped with The relay optical system includes: a first lens group located on the most enlargement side; two lens groups disposed on the reduction side of the first lens group, the distance between adjacent lens groups changing during zooming; a negative lens group disposed between the two lens groups; During zooming, the negative lens unit is fixed and the two lens units are moved, the first lens group has a positive power, The optical system, wherein the first lens group and the magnifying optical system are fixed during zooming.

3. An optical system having an intermediate image-forming position therein that is conjugate to a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, a magnifying optical system located on the magnifying side of the intermediate image-forming position; a relay optical system located on the reduction side of the intermediate image-forming position; Equipped with The relay optical system includes: a first lens group located on the most enlargement side; two lens groups disposed on the reduction side of the first lens group, the distance between adjacent lens groups changing during zooming; a negative lens group disposed between the two lens groups; During zooming, the negative lens unit is fixed and the two lens units are moved, the relay optical system further includes another negative lens group, The negative lens group has a smaller negative power than the other negative lens groups.

4. The optical system according to claim 1 , wherein the negative lens group comprises a stop.

5. An optical system having an intermediate image-forming position therein that is conjugate to a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, a magnifying optical system located on the magnifying side of the intermediate image-forming position; a relay optical system located on the reduction side of the intermediate image-forming position; Equipped with The relay optical system includes: a first lens group located on the most enlargement side; two lens groups disposed on the reduction side of the first lens group, the distance between adjacent lens groups changing during zooming; a negative lens group disposed between the two lens groups; During zooming, the negative lens unit is fixed and the two lens units are moved, An optical system, wherein the lens on the most reducing side of the magnifying optical system is a negative lens.

6. An optical system having an intermediate image-forming position therein that is conjugate to a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, a magnifying optical system located on the magnifying side of the intermediate image-forming position; a relay optical system located on the reduction side of the intermediate image-forming position; Equipped with The relay optical system includes: a first lens group located on the most enlargement side; two lens groups disposed on the reduction side of the first lens group, the distance between adjacent lens groups changing during zooming; a negative lens group disposed between the two lens groups; During zooming, the negative lens unit is fixed and the two lens units are moved, an optical system in which the lens on the most enlargement side of the relay optical system is a positive lens.

7. An optical system having an intermediate image-forming position therein that is conjugate to a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, a magnifying optical system located on the magnifying side of the intermediate image-forming position; a relay optical system located on the reduction side of the intermediate image-forming position; Equipped with The relay optical system includes: a first lens group located on the most enlargement side; two lens groups disposed on the reduction side of the first lens group, the distance between adjacent lens groups changing during zooming; a negative lens group disposed between the two lens groups; During zooming, the negative lens unit is fixed and the two lens units are moved, An optical system that satisfies the following condition (1): 0.1<fp / fr<0.5...(1) Where: fp: focal length of the magnifying optical system fr: focal length of the relay optical system at the wide-angle end It is.

8. An optical system having an intermediate image-forming position therein that is conjugate to a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, a magnifying optical system located on the magnifying side of the intermediate image-forming position; a relay optical system located on the reduction side of the intermediate image-forming position; Equipped with The relay optical system includes: a first lens group located on the most enlargement side; two lens groups disposed on the reduction side of the first lens group, the distance between adjacent lens groups changing during zooming; a negative lens group disposed between the two lens groups; During zooming, the negative lens unit is fixed and the two lens units are moved, An optical system that satisfies the following condition (2): 100<fr1 / fw<1000...(2) Where: fr1: focal length of the first lens group fw: focal length of the entire system at the wide-angle end It is.

9. 2. The optical system according to claim 1, which satisfies the following condition (3): 5<frn / fw<50...(3) Where: frn: focal length of the negative lens group fw: focal length of the entire system at the wide-angle end It is.

10. An optical system having an intermediate image-forming position therein that is conjugate to a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, a magnifying optical system located on the magnifying side of the intermediate image-forming position; a relay optical system located on the reduction side of the intermediate image-forming position; Equipped with The relay optical system includes: a first lens group located on the most enlargement side; two lens groups disposed on the reduction side of the first lens group, the distance between adjacent lens groups changing during zooming; a negative lens group disposed between the two lens groups; During zooming, the negative lens unit is fixed and the two lens units are moved, an optical system in which the magnification optical system has the longest air space, and which includes a magnification optical system front group on the magnification side and a magnification optical system rear group on the reduction side, with the longest air space as a boundary, and which satisfies the following conditions (4) and (5): 6.5<|Ts / fw|<12.0...(4) 3.0<|Tpr / fw|<8.0...(5) Where: Ts: the longest air gap in the magnifying optical system fw: focal length of the entire system at the wide-angle end Tpr: the distance from the surface of the rear group of the magnifying optical system on the most magnifying side to the intermediate image It is.

11. An optical system having an intermediate image-forming position therein that is conjugate to a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, a magnifying optical system located on the magnifying side of the intermediate image-forming position; a relay optical system located on the reduction side of the intermediate image-forming position; Equipped with The relay optical system includes: a first lens group located on the most enlargement side; two lens groups disposed on the reduction side of the first lens group, the distance between adjacent lens groups changing during zooming; a negative lens group disposed between the two lens groups; During zooming, the negative lens unit is fixed and the two lens units are moved, An optical system that satisfies the following condition (6): 0.8<Tp / Tr<1.0...(6) Where: Tp: distance from the most enlarged surface of the enlargement optical system to the intermediate image position Tr: the distance from the intermediate image-forming position at the wide-angle end to the surface on the most reduced side of the relay optical system It is.

12. An optical system having an intermediate image-forming position therein that is conjugate to a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, a magnifying optical system located on the magnifying side of the intermediate image-forming position; a relay optical system located on the reduction side of the intermediate image-forming position; Equipped with The relay optical system includes: a first lens group located on the most enlargement side; two lens groups disposed on the reduction side of the first lens group, the distance between adjacent lens groups changing during zooming; a negative lens group disposed between the two lens groups; During zooming, the negative lens unit is fixed and the two lens units are moved, an optical system having a maximum air gap, the optical system including a front group of the magnification optical system on the magnification side and a rear group of the magnification optical system on the reduction side, the front group being separated by the maximum air gap, and the optical system satisfying the following condition (7): 7<|fpr / fw|<12...(7) Where: fpr: focal length of the rear group of the magnifying optical system fw: focal length of the entire system at the wide-angle end It is.

13. An optical system having an intermediate image-forming position therein that is conjugate to a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, a magnifying optical system located on the magnifying side of the intermediate image-forming position; a relay optical system located on the reduction side of the intermediate image-forming position; Equipped with The relay optical system includes: a first lens group located on the most enlargement side; two lens groups disposed on the reduction side of the first lens group, the distance between adjacent lens groups changing during zooming; a negative lens group disposed between the two lens groups; During zooming, the negative lens unit is fixed and the two lens units are moved, an optical system having a maximum air gap, the optical system including a front group of an optical system on the enlargement side and a rear group of an optical system on the reduction side, the front group being separated by the maximum air gap, and the optical system satisfying the following condition (8): 2<|fpf / fw|<5...(8) Where: fpf: focal length of the front group of the magnifying optical system fw: focal length of the entire system at the wide-angle end It is.

14. An optical system having an intermediate image-forming position therein that is conjugate to a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, a magnifying optical system located on the magnifying side of the intermediate image-forming position; a relay optical system located on the reduction side of the intermediate image-forming position; Equipped with The relay optical system includes: a first lens group located on the most enlargement side; two lens groups disposed on the reduction side of the first lens group, the distance between adjacent lens groups changing during zooming; a negative lens group disposed between the two lens groups; During zooming, the negative lens unit is fixed and the two lens units are moved, a first lens element is disposed on the most enlargement side of the magnification optical system, the first lens element having an aspheric first lens enlargement side surface facing the magnification side and an aspheric first lens reduction side surface facing the reduction side; an optical system, wherein the first lens enlargement side surface and the first lens reduction side surface satisfy the following condition (9) within an effective diameter from r>0: dZ(r) / dr>0 (9) Where: r: Distance from the vertex of the surface along a plane perpendicular to the optical axis of the optical system (r>0) Z(r): Amount of sag of the surface (Z=0 at the vertex (r=0), the contraction displacement with respect to the vertex is indicated by the sign +, and the expansion displacement is indicated by the sign -) It is.

15. An optical system having an intermediate image-forming position therein that is conjugate to a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, a magnifying optical system located on the magnifying side of the intermediate image-forming position; a relay optical system located on the reduction side of the intermediate image-forming position; Equipped with The relay optical system includes: a first lens group located on the most enlargement side; two lens groups disposed on the reduction side of the first lens group, the distance between adjacent lens groups changing during zooming; a negative lens group disposed between the two lens groups; During zooming, the negative lens unit is fixed and the two lens units are moved, An optical system, wherein a first lens element is disposed on the most magnifying side of the magnifying optical system, and the first lens element is made of a synthetic resin.

16. 2. The optical system according to claim 1, wherein, among the plurality of lens elements, all lens elements that satisfy condition (10) also satisfy condition (11), and one lens element among the plurality of lens elements does not satisfy both conditions (10) and (11). |ym / (fw・tan(ωm))|<3.0...(10) Tg>300℃...(11) Where: ωm: Maximum half angle of view at the wide-angle end ym: Height at which the most off-axis chief ray passes through the lens surface at the telephoto end fw: focal length of the entire system at the wide-angle end Tg: glass transition temperature of the lens material It is.

17. 2. The optical system according to claim 1, which satisfies the following condition (12): ωm>65°…(12) Where: ωm: Maximum half angle of view at the wide-angle end It is.

18. An optical system having an intermediate image-forming position therein that is conjugate to a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, a magnifying optical system located on the magnifying side of the intermediate image-forming position; a relay optical system located on the reduction side of the intermediate image-forming position; Equipped with The relay optical system includes: a first lens group located on the most enlargement side; two lens groups disposed on the reduction side of the first lens group, the distance between adjacent lens groups changing during zooming; a negative lens group disposed between the two lens groups; During zooming, the negative lens unit is fixed and the two lens units are moved, An optical system that satisfies the following condition (13): -1.5<(L1R1+L1R2) / (L1R2-L1R1)<-0.9...(13) Where: L1R1: Radius of curvature of the center of the lens on the most magnifying side L1R2: The radius of curvature of the center of the lens on the most enlarged side It is.

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

20. An optical system according to any one of claims 1 to 18; and an image sensor that receives an optical image formed by the optical system and converts it into an electrical image signal.

Images