Zoom lens, projection-type display device, and imaging device

Abstract

The invention provides a zoom lens which forms an intermediate image, has high magnification and maintains good optical performance, a projection type display device provided with the zoom lens, and an imaging device provided with the zoom lens. The zoom lens includes a first optical system and a second optical system in this order from a magnification side to a reduction side. The second optical system forms an intermediate image at a position conjugate with the reduction-side imaging plane, and the first optical system reforms the intermediate image on the enlargement-side imaging plane. The lens closest to the magnification side of the second optical system is a positive lens having a convex surface facing the magnification side. The second optical system includes a first moving lens group, a second moving lens group, and a third moving lens group, which move respectively during magnification change, in succession in this order from the most magnification side to the most reduction side. In the entire zoom lens, the lens group that moves during zooming is only the first to third moving lens groups.

Description

Technical Field

[0001] The technology of the present invention relates to a zoom lens, a projection display device, and an imaging device. Background Art

[0002] As a zoom lens applicable to a projection display device or an imaging device, there are known imaging optical systems described in Patent Document 1 and Patent Document 2 below.

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2020-052385

[0004] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2021-026087

[0005] In a zoom lens that forms an intermediate image, it is required to have a high magnification while maintaining good optical performance. These required levels have been increasing year by year. Summary of the Invention

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a zoom lens that has a high magnification while maintaining good optical performance in a zoom lens that forms an intermediate image, a projection display device including the zoom lens, and an imaging device including the zoom lens.

[0007] One aspect of the present invention is a zoom lens that sequentially includes a first optical system and a second optical system along the optical path from the magnifying side to the reducing side. Among them, the second optical system forms an intermediate image at a position conjugate to the reducing-side imaging surface, the first optical system re-images the intermediate image on the magnifying-side imaging surface, the lens closest to the magnifying side of the second optical system is a positive lens with a convex surface facing the magnifying side. When a lens group whose interval in the optical axis direction changes between adjacent groups during zooming is set as one lens group, the second optical system sequentially and continuously includes a first moving lens group with a positive optical power that moves during zooming, a second moving lens group that moves during zooming, and a third moving lens group with a positive optical power that moves during zooming from the closest to the magnifying side to the reducing side along the optical path. In the entire zoom lens, the lens groups that move during zooming are only the first moving lens group, the second moving lens group, and the third moving lens group.

[0008] In the zoom lens of the above aspect, the second optical system preferably includes a fixed lens group that is fixed to the reducing-side imaging surface during zooming at the closest to the reducing side.

[0009] In the zoom lens of the above aspect, the fixed lens group preferably has a positive optical power.

[0010] In the zoom lens of the above aspect, it is preferably configured to be decentered on the reducing side.

[0011] In the zoom lens of the above aspect, the second moving lens group preferably has a negative optical power.

[0012] When the focal length of the zoom lens at the wide-angle end is set to fw and the focal length of the first optical system is set to frl, the zoom lens of the above-described method preferably satisfies the conditional expression (1) represented below:

[0013] 0.8 < fr1 / |fw| < 5 (1).

[0014] In the zoom lens of the above-described method, the first optical system preferably includes a cemented lens formed by sequentially cementing a positive lens, a negative lens, and a positive lens.

[0015] In the zoom lens of the above-described method, the effective diameter of the magnifying-side surface of the second lens from the magnifying side of the first optical system at the wide-angle end is preferably smaller than the effective diameter of the magnifying-side surface of the lens closest to the reducing side of the first optical system at the wide-angle end.

[0016] In the zoom lens of the above-described method, the second moving lens group preferably includes one negative lens and one positive lens.

[0017] When the focal length of the first moving lens group is set to f1, the focal length of the second moving lens group is set to f2, and the focal length of the third moving lens group is set to f3, the zoom lens of the above-described method preferably satisfies the conditional expressions (2) and (3) represented below:

[0018] 0 < |f1 / f2| < 0.75 (2),

[0019] 0 < |f3 / f2| < 0.75 (3),

[0020] More preferably, it satisfies the conditional expressions (2-2) and (3-2) represented below:

[0021] 0 < |f1 / f2| < 0.5 (2-2),

[0022] 0 < |f3 / f2| < 0.5 (3-2).

[0023] When the focal length of the first moving lens group is set to f1 and the focal length of the third moving lens group is set to f3, the zoom lens of the above-described method preferably satisfies the conditional expression (4) represented below:

[0024] 0.5 < f1 / f3 < 2 (4).

[0025] In the zoom lens of the above-described method, it is preferable that: the first moving lens group at the telephoto end is located on the magnifying side with respect to the first moving lens group at the wide-angle end, the second moving lens group at the telephoto end is located on the magnifying side with respect to the second moving lens group at the wide-angle end, and the third moving lens group at the telephoto end is located on the magnifying side with respect to the third moving lens group at the wide-angle end.

[0026] In the zoom lens of the above-described manner, when zooming from the wide-angle end to the telephoto end, it is preferable that the first moving lens group, the second moving lens group, and the third moving lens group always move toward the magnifying side.

[0027] In the zoom lens of the above-described manner, it is preferable that a first optical path bending member for bending the optical path is disposed within the first optical system.

[0028] In the zoom lens of the above-described manner, it is preferable that a second optical path bending member for bending the optical path is disposed on the reducing side with respect to the first optical system.

[0029] In the zoom lens of the above-described manner, it is preferable that: a first optical path bending member for bending the optical path is disposed within the first optical system, and a second optical path bending member for bending the optical path is disposed on the reducing side with respect to the first optical system.

[0030] In the zoom lens of the above-described manner, it is preferable that: the first optical system has a positive optical power and is fixed to the reducing-side imaging surface during zooming, and the second optical system sequentially includes, from the magnifying side to the reducing side along the optical path, a first moving lens group, a second moving lens group, a third moving lens group, and a fixed lens group that is fixed to the reducing-side imaging surface during zooming.

[0031] Another aspect of the present invention is a projection display device including the zoom lens of the above-described manner.

[0032] Still another aspect of the present invention is an imaging device including the zoom lens of the above-described manner.

[0033] In addition, the "including ~" and "including ~ of" in this specification mean that, in addition to the components listed, it may also include: a lens having substantially no optical power; optical components other than lenses such as an aperture, a mask, a filter, a cover glass, a plane mirror, and a prism; and structural parts such as a lens flange, a lens barrel, an imaging element, and a shake correction mechanism.

[0034] The "~ group having a positive optical power" and "the ~ group has a positive optical power" in this specification mean that the entire group has a positive optical power. Similarly, the "~ group having a negative optical power" and "the ~ group has a negative optical power" mean that the entire group has a negative optical power. The "~ lens group" is not limited to a structure including a plurality of lenses, and may also be configured to include only one lens.

[0035] The number of lens elements of the above lens is the number of lens elements that are constituent elements. For example, in a cemented lens formed by cementing multiple singlet lenses made of different materials, the number of lens elements is represented by the number of singlet lenses that make up the cemented lens. However, a compound aspherical lens (a lens in which a lens (e.g., a spherical lens) and an aspherical film formed on the lens are integrated and function as one aspherical lens as a whole) is used as one lens element and is not regarded as a cemented lens. Unless otherwise specified, the sign of the optical power and the surface shape related to a lens including an aspherical surface are the sign of the optical power and the surface shape in the paraxial region.

[0036] The "focal length" used in the conditional expressions is the paraxial focal length. The values used in the conditional expressions are values based on the d-line. The "d-line", "C-line", and "F-line" described in this specification are bright lines. The wavelength of the d-line is regarded as 587.56 nm (nanometers), the wavelength of the C-line is regarded as 656.27 nm (nanometers), and the wavelength of the F-line is regarded as 486.13 nm (nanometers).

[0037] Advantages of the Invention

[0038] According to the present invention, it is possible to provide a zoom lens that has a high magnification while maintaining good optical performance in a zoom lens that forms an intermediate image, a projection display device including the zoom lens, and an imaging device including the zoom lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 The zoom lens corresponding to Embodiment 1 is a cross-sectional view showing the structure and light beam of the zoom lens according to one embodiment.

[0040] Figure 2 It is a cross-sectional view showing the structure and light beam of the zoom lens according to Embodiment 1 in each zoom state.

[0041] Figure 3 It is a cross-sectional view showing the structure and light beam of the first modified example of the zoom lens according to Embodiment 1.

[0042] Figure 4 It is a cross-sectional view showing the structure and light beam of the second modified example of the zoom lens according to Embodiment 1.

[0043] Figure 5 It is a cross-sectional view showing the structure and light beam of the third modified example of the zoom lens according to Embodiment 1.

[0044] Figure 6 They are aberration diagrams of the zoom lens according to Embodiment 1.

[0045] Figure 7 It is a cross-sectional view showing the structure and light beam of the zoom lens according to Embodiment 2.

[0046] Figure 8 It is a cross-sectional view showing the structure and light beam of a modified example of the zoom lens of Example 2.

[0047] Figure 9 They are aberration diagrams of the zoom lens of Example 2.

[0048] Figure 10 It is a cross-sectional view showing the structure and light beam of the zoom lens of Example 3.

[0049] Figure 11 It is a cross-sectional view showing the structure and light beam of a modified example of the zoom lens of Example 3.

[0050] Figure 12 They are aberration diagrams of the zoom lens of Example 3.

[0051] Figure 13 It is a cross-sectional view showing the structure and light beam of the zoom lens of Example 4.

[0052] Figure 14 It is a cross-sectional view showing the structure and light beam of a modified example of the zoom lens of Example 4.

[0053] Figure 15 They are aberration diagrams of the zoom lens of Example 4.

[0054] Figure 16 It is a cross-sectional view showing the structure and light beam of the zoom lens of Example 5.

[0055] Figure 17 It is a cross-sectional view showing the structure and light beam of a modified example of the zoom lens of Example 5.

[0056] Figure 18 They are aberration diagrams of the zoom lens of Example 5.

[0057] Figure 19 It is a cross-sectional view showing the structure and light beam of the zoom lens of Example 6.

[0058] Figure 20 It is a cross-sectional view showing the structure and light beam of a modified example of the zoom lens of Example 6.

[0059] Figure 21 They are aberration diagrams of the zoom lens of Example 6.

[0060] Figure 22 It is a schematic structural diagram of a projection display device according to an embodiment.

[0061] Figure 23 It is a schematic structural diagram of a projection display device according to another embodiment.

[0062] Figure 24This is a schematic structural diagram of a projection display device according to another embodiment.

[0063] Figure 25 This is a perspective view of the front side of a camera device according to an embodiment.

[0064] Figure 26 This is Figure 25 a perspective view of the back side of the camera device shown.

[0065] Symbol Explanation

[0066] 10 - Zoom lens, 11a~11c - Transmissive display element, 12 - Dichroic mirror, 13 - Dichroic mirror, 14 - Cross dichroic prism, 15 - Light source, 16a~16c - Condensing lens, 18a~18c - Total reflection mirror, 21a~21c - DMD element, 24a~24c - TIR prism, 25 - Polarizing beam splitter prism, 31a~31c - Reflective display element, 32 - Dichroic mirror, 33 - Dichroic mirror, 34 - Cross dichroic prism, 35a~35c - Polarizing beam splitter prism, 38 - Total reflection mirror, 41 - Camera body, 42 - Shutter button, 43 - Power button, 44 - Operation unit, 45 - Operation unit, 46 - Display unit, 47 - Bayonet mount, 48 - Interchangeable lens, 49 - Zoom lens, 50 - Imaging element, 100 - Projection display device, 105 - Screen, 200 - Projection display device, 205 - Screen, 210 - Zoom lens, 215 - Light source, 300 - Projection display device, 305 - Screen, 310 - Zoom lens, 315 - Light source, 400 - Camera, G1 - First lens group, G2 - Second lens group, G3 - Third lens group, G4 - Fourth lens group, Gf - Focusing group, Ka - On-axis beam, Kb - Beam with maximum viewing angle, L1~L31 - Lenses, PP - Optical component, R1, R2 - Mirrors, Sim - Image display surface, St - Aperture stop, U1, Ulr - First optical system, U2, U2r - Second optical system, Z - Optical axis. Detailed Embodiment

[0067] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0068] In Figure 1 a cross-sectional view of the structure of the wide-angle end of a zoom lens and the beam according to an embodiment of the present invention is shown. In Figure 1 as the beam, the on-axis beam Ka and the beam Kb with the maximum viewing angle are shown. In Figure 2 a cross-sectional view of the structure and the beam in each zoom state of the zoom lens is shown. In Figure 2In the figure, the wide-angle end state is shown in the upper row marked with "wide-angle end", the intermediate focal length state is shown in the middle row marked with "intermediate", and the telephoto end state is shown in the lower row marked with "telephoto end". Figure 1 and Figure 2 The example shown corresponds to the zoom lens of Embodiment 1 described later. In Figure 1 and Figure 2 the left side is the magnification side and the right side is the reduction side. Hereinafter, mainly with reference to Figure 1 an explanation will be given.

[0069] The zoom lens of the present invention can be mounted on a projection display device as a projection optical system for forming an image projected onto a screen, and can also be mounted on an imaging device as an imaging optical system for forming an image of an object. Hereinafter, a case where the zoom lens is used for the purpose of a projection optical system will be assumed for explanation. And hereinafter, in order to avoid a lengthy explanation, the "zoom lens of the present invention" is sometimes simply referred to as the "zoom lens".

[0070] In Figure 1 an example is shown in which it is assumed that the zoom lens is mounted on a projection display device and the optical components PP and the image display surface Sim of the light valve are arranged on the reduction side of the zoom lens. The optical component PP is a component conceived as a filter, a cover glass, a color synthesis prism, etc. The optical component PP is a component having no optical power, and the structure in which the optical component PP is omitted may also be used. The light valve outputs an optical image, and this optical image is displayed on the image display surface Sim in the form of an image.

[0071] In the projection display device, the light beam given image information on the image display surface Sim enters the zoom lens through the optical component PP and is projected onto a screen (not shown) by the zoom lens. In this case, the image display surface Sim corresponds to the reduction-side imaging surface, and the screen corresponds to the magnification-side imaging surface. In addition, in this specification, the "screen" means an object on which the projection image formed by the zoom lens is projected. As the screen, in addition to a dedicated screen, it may also be a wall surface, a floor surface, a ceiling, an outer wall of a building, etc. of a room.

[0072] And in the description of this specification, the "magnification side" means the screen side on the optical path, and the "reduction side" means the image display surface Sim side on the optical path. In this specification, the "magnification side" and the "reduction side" are defined along the optical path, and this is the same for the case of a zoom lens having a bent optical path. "The most magnification-side ~" means the most magnification-side in the arrangement order on the optical path, and does not mean the closest to the screen in terms of distance. Hereinafter, in order to avoid the explanation from becoming lengthy, "in order along the optical path from the magnification side to the reduction side" is sometimes described as "in order from the magnification side to the reduction side".

[0073] The zoom lens of the present invention includes a first optical system U1 and a second optical system U2 in sequence along the optical path from the magnifying side to the reducing side. The zoom lens of the present invention is configured such that the second optical system U2 forms an intermediate image MI at a position conjugate to the reducing-side imaging surface, and the first optical system U1 re-images the intermediate image MI onto the magnifying-side imaging surface. Hereinafter, the optical system on the magnifying side of the intermediate image MI in the optical system constituting the zoom lens is defined as the first optical system U1, and the optical system on the reducing side of the intermediate image MI is defined as the second optical system U2.

[0074] In the projection display device, the second optical system U2 forms an intermediate image MI of the image displayed on the image display surface Sim, and the first optical system projects the intermediate image MI onto the screen to form a projected image. Thus, by adopting the structure with the intermediate image MI, the zoom lens of the present invention can achieve a wide-angle projection optical system while suppressing the size of the lens system. In Figure 1 only the part of the intermediate image MI below the optical axis Z is schematically shown by a dotted line. Figure 1 The intermediate image MI represents the position in the optical axis direction and does not represent the accurate shape.

[0075] The lens on the magnifying side of the second optical system U2 is a positive lens with its convex surface facing the magnifying side. The lens on the magnifying side of the second optical system U2 is the lens adjacent to the reducing side of the intermediate image MI. By setting this lens as a positive lens with its convex surface facing the magnifying side, even if the interval between the two lens surfaces sandwiching the intermediate image MI is increased, it is beneficial to reduce the size of the zoom lens.

[0076] The second optical system U2 continuously includes, in sequence along the optical path from the magnifying side to the reducing side, a first moving lens group with a positive optical power that moves during zooming, a second moving lens group that moves during zooming, and a third moving lens group with a positive optical power that moves during zooming. By including three lens groups that move during zooming, the second optical system U2 is beneficial for obtaining a high zoom ratio. In order for the second optical system U2 to form the intermediate image MI, the signs of the optical powers of the first moving lens group and the third moving lens group are set to be positive.

[0077] In the entire zoom lens, the lens groups that move during zooming are only the first moving lens group, the second moving lens group, and the third moving lens group. In the entire zoom lens, by only arranging three lens groups that move during zooming, the complication of the zoom mechanism can be avoided. Moreover, by arranging the three lens groups that move during zooming in sequence continuously along the optical path, it is beneficial to shorten the overall optical length.

[0078] In addition, in this specification, a lens group whose interval in the optical axis direction changes between adjacent groups during zooming is regarded as one lens group. That is, the "lens group" in this specification is a component of a zoom lens, which includes at least one lens separated by an air interval that changes during zooming. During zooming, each lens group moves or is fixed as a unit, and the mutual interval between the lenses within each lens group remains unchanged. In addition, the "lens group" may include components other than lenses without optical power, such as an aperture, a mask, a filter, a cover glass, a plane mirror, and a prism, etc.

[0079] As an example, Figure 1 The zoom lens of includes, in order from the magnifying side to the reducing side along the optical path, a first optical system U1 having a positive optical power and a second optical system U2. The first optical system U1 includes lenses L1 to L13 in order from the magnifying side to the reducing side. The second optical system U2 includes a first lens group G1, a second lens group G2, a third lens group G3, and a fourth lens group G4 in order from the magnifying side to the reducing side.

[0080] During zooming, the first lens group G1, the second lens group G2, and the third lens group G3 respectively change the interval between adjacent groups and move along the optical axis Z. During zooming, the first optical system U1 and the fourth lens group G4 are respectively fixed to the reducing-side imaging surface. In Figure 1 , below the lens groups that move during zooming, the approximate movement trajectories of each lens group during zooming from the wide-angle end to the telephoto end are shown by solid arrows.

[0081] As an example, Figure 1 Each lens group of is configured as follows. The first lens group G1 includes one lens, lens L21. The second lens group G2 includes two lenses, lenses L22 to L23, and an aperture stop St in order from the magnifying side to the reducing side. The third lens group G3 includes six lenses, lenses L24 to L29 in order from the magnifying side to the reducing side. The fourth lens group G4 includes one lens, lens L30.

[0082] Figure 1 The zoom lens of includes a focusing group Gf as a group that moves along the optical axis Z during focusing. As an example, Figure 1 In the example of , the focusing group Gf includes two lenses, lenses L4 to L5. In Figure 1 , the symbols Gf below lenses L4 to L5 and two horizontal arrows indicate that lenses L4 to L5 are the focusing group Gf.

[0083] The second optical system U2 preferably includes a fixed lens group that is fixed to the reducing-side imaging surface during zooming at the most reducing side. For example, as in Figure 1As shown in the example, the second optical system U2 can be configured to sequentially include a first moving lens group, a second moving lens group, a third moving lens group, and a fixed lens group along the optical path from the magnification side to the reduction side. By fixing the lens group closest to the reduction side during zooming, it is easy to ensure the telecentricity on the reduction side while maintaining a high zoom ratio.

[0084] The fixed lens group included in the second optical system U2 preferably has a positive optical power. In this case, it is easy to suppress the increase in the diameter of the third moving lens group disposed at a position closer to the magnification side than the fixed lens group.

[0085] The first optical system U1 can be configured to have a positive optical power and be fixed to the reduction-side imaging surface during zooming. In this case, it is beneficial for the miniaturization of the lens system and the simplification of the zoom mechanism.

[0086] The zoom lens of the present invention is preferably configured to be telecentric on the reduction side. In this case, when realizing the function of being able to adjust the position of the projection image on the screen by displacing the projection optical system in a direction perpendicular to the optical axis with respect to the image display element, so-called lens displacement function, it is beneficial to ensure the displacement amount. Strictly speaking, in an optical system configured to be telecentric on the reduction side, the chief ray from the surface closest to the reduction side of the optical system toward the reduction-side imaging surface is parallel to the optical axis Z.

[0087] However, the "telecentric on the reduction side" in the technology of the present invention is not limited to the case where the angle of the chief ray with respect to the optical axis Z is 0 degrees, and includes errors actually allowed in the technical field to which the technology of the present invention belongs. The error can be set, for example, within the range where the angle of the chief ray with respect to the optical axis Z is -3 degrees or more and +3 degrees or less. In addition, in a system that does not include an aperture stop, when observing the light beam in the direction from the magnification side to the reduction side, the bisector of the upper and lower maximum rays in the cross-section of the light beam converging at an arbitrary point on the reduction-side imaging surface, i.e., the image display surface Sim, can be used instead of the chief ray to determine the telecentricity.

[0088] The second moving lens group preferably has a negative optical power. In this case, it is beneficial to suppress the variation of various aberrations accompanying zooming.

[0089] Preferably, the second moving lens group includes one negative lens and one positive lens. In this case, it is beneficial to suppress the generation of field curvature and chromatic aberration.

[0090] The first optical system U1 preferably includes a cemented lens formed by sequentially cementing a positive lens, a negative lens, and a positive lens. In this case, it is beneficial to correct chromatic aberration.

[0091] Preferably, the effective diameter of the magnifying side surface of the second lens from the magnifying side of the first optical system U1 at the wide-angle end is smaller than the effective diameter of the magnifying side surface of the lens closest to the reducing side of the first optical system U1 at the wide-angle end. Generally, in a zoom lens that forms an intermediate image, if wide-angleization is to be achieved, it is likely to result in an increase in the diameter of the lens on the magnifying side. However, in the case of the above structure, an increase in the diameter of the lens on the magnifying side can be suppressed, which is therefore beneficial for weight reduction. By reducing the weight of the zoom lens, for example, in the case of mounting the zoom lens on a projection display device having a lens displacement function, the burden on the displacement mechanism can be reduced.

[0092] In addition, in this specification, for the light rays incident on the lens surface from the magnifying side and exiting toward the reducing side, twice the distance from the intersection of the outermost light ray passing through and the lens surface to the optical axis Z is defined as the "effective diameter" of the lens surface. The "outer side" described here refers to the radially outer side centered on the optical axis Z, that is, the side away from the optical axis Z.

[0093] In the zoom lens of the present invention, preferably, the first moving lens group at the telephoto end is located on the magnifying side relative to the first moving lens group at the wide-angle end. Similarly, preferably, the second moving lens group at the telephoto end is located on the magnifying side relative to the second moving lens group at the wide-angle end. Similarly, preferably, the third moving lens group at the telephoto end is located on the magnifying side relative to the third moving lens group at the wide-angle end. In this case, it is beneficial for simplifying the drive mechanism.

[0094] Moreover, in the zoom lens of the present invention, it is more preferable that when zooming from the wide-angle end to the telephoto end, the first moving lens group, the second moving lens group, and the third moving lens group always move toward the magnifying side respectively. In this case, it becomes beneficial by simplifying the drive mechanism.

[0095] In the zoom lens of the present invention, it can be configured such that a first optical path bending member for bending the optical path is disposed within the first optical system U1.

[0096] By bending the optical path, a compact structure can be achieved, which is therefore beneficial for miniaturization. In the case of mounting a zoom lens having a structure that bends the optical path once on a projection display device, it can be considered to accommodate the portion closer to the reducing side than the bending portion in the housing of the device main body, and accommodate the portion closer to the magnifying side than the bending portion in the protruding portion protruding from the housing. In this case, by disposing the optical path bending member within the first optical system U1 on the magnifying side, the length from the lens closest to the magnifying side to the bending portion can be shortened, which is therefore beneficial for miniaturization of the protruding portion. Also, by rotating the bending portion, the lens closest to the magnifying side can be positioned in any direction, so that projection can be performed in various directions. As the first optical path bending member, for example, a prism and a mirror having a reflecting surface can be used.

[0097] As Figure 1 a first modification example of the zoom lens, an example of a zoom lens having a first optical path bending member is shown in Figure 3 . The zoom lens of Figure 3 includes a first optical system U1r and a second optical system U2 in order along the optical path from the telephoto side to the wide-angle side. Figure 3 The difference between the zoom lens of Figure 1 and the zoom lens of Figure 1 is that a mirror R1 is disposed inside the first optical system Ulr, and the optical path is bent by the mirror R1. The structures of the other lenses are the same as those in the example of Figure 3 . The mirror R1 corresponds to the first optical path bending member of the present invention. In

[0098] In the zoom lens of the present invention, it can be configured that a second optical path bending member for bending the optical path is disposed on the wide-angle side of the first optical system U1. By bending the optical path, a compact structure can be achieved, which is beneficial to miniaturization. Although the total length of the optical system having the intermediate image MI is often long, by bending the optical path on the wide-angle side of the first optical system U1, the elongation of the optical system in one direction can be suppressed. And by rotating the bending portion, the lens closest to the telephoto side can be located in an arbitrary direction, so that projection can be performed in various directions. As the second optical path bending member, for example, a prism and a mirror having a reflecting surface can be used.

[0099] As Figure 1 a second modification example of the zoom lens, an example of a zoom lens having a second optical path bending member is shown in Figure 4 . The zoom lens of Figure 4 includes a first optical system U1 and a second optical system U2r in order along the optical path from the telephoto side to the wide-angle side. Figure 4 The difference between the zoom lens of Figure 1 and the zoom lens of Figure 1 is that a mirror R2 is disposed on the telephoto side of the second optical system U2r, and the optical path is bent by the mirror R2. The structures of the other lenses are the same as those in the example of Figure 4 . The mirror R2 corresponds to the second optical path bending member of the present invention. In

[0100] In the zoom lens of the present invention, it can be configured such that a first optical path bending member for bending the optical path is disposed within the first optical system U1, and a second optical path bending member for bending the optical path is disposed on the reduction side with respect to the first optical system U1. By bending the optical path twice, a more compact structure can be achieved, which is more conducive to miniaturization. When a zoom lens having a structure that bends the optical path twice is mounted on a projection display device, by rotating the two bending portions respectively, the lens closest to the magnification side can be positioned in any direction, so that projection can be performed in various directions.

[0101] As Figure 1 a third modification of the zoom lens, in Figure 5 it shows an example of a zoom lens having two optical path bending members and bending the optical path twice. Figure 5 The zoom lens of Figure 5 from the magnification side to the reduction side includes the first optical system U1r and the second optical system U2r in sequence along the optical path. Figure 3 The first optical system U1r of Figure 5 is the same as the first optical system Ulr of Figure 4 and the second optical system U2r of Figure 5 is the same as the second optical system U2r of

[0102] The angle at which the optical path bending member bends the optical path can be set arbitrarily. For example, it can be set to 90 degrees. By setting the bending angle to 90 degrees, a structure that is easy to manufacture can be obtained. In addition, this "90 degrees" includes the errors actually allowed in the technical field to which the technology of the present invention belongs. The error can be set to ±5 degrees, for example.

[0103] Next, a preferred structure related to the conditional expressions of the zoom lens of the present invention will be described. In addition, in the following description related to the conditional expressions, in order to avoid redundant descriptions, the same notations are used for the parts with the same definitions, and the repeated descriptions of the notations are omitted.

[0104] When the focal length of the zoom lens at the wide-angle end is set to fw and the focal length of the first optical system U1 is set to fr1, the zoom lens preferably satisfies the following conditional expression (1). In addition, fw is the value in a state where the projection distance is 0.97 m (meter). The projection distance is the distance on the optical axis from the imaging surface on the magnification side to the lens surface closest to the magnification side. By preventing the corresponding value of conditional expression (1) from becoming less than the lower limit value, the optical power of the first optical system U1 does not become too strong, so it is beneficial for correcting various aberrations. By preventing the corresponding value of conditional expression (1) from becoming greater than the upper limit value, the optical power of the first optical system U1 does not become too weak, so it is beneficial for wide-angleization. In order to obtain better characteristics, the zoom lens more preferably satisfies the following conditional expression (1-1), and even more preferably satisfies the following conditional expression (1-2).

[0105] 0.8 < fr1 / |fw| < 5 (1)

[0106] 1 < fr1 / |fw| < 3 (1-1)

[0107] 1.5 < fr1 / |fw| < 2.5 (1-2)

[0108] When the focal length of the first moving lens group is set to f1 and the focal length of the second moving lens group is set to f2, the zoom lens preferably satisfies the following conditional expression (2). Regarding the lower limit of conditional expression (2), since f1 / f2 is an absolute value, it is 0 < f1 / f2. By preventing the corresponding value of conditional expression (2) from becoming greater than the upper limit value, the optical power of the second moving lens group does not become too strong, and the balance of the optical powers of the first moving lens group and the second moving lens group can be maintained well, so it is beneficial for suppressing the generation of various aberrations. In order to obtain better characteristics, the zoom lens more preferably satisfies the following conditional expression (2-1), and even more preferably satisfies the following conditional expression (2-2).

[0109] 0 < |f1 / f2| < 0.75 (2)

[0110] 0 < |f1 / f2| < 0.6 (2-1)

[0111] 0 < |f1 / f2| < 0.5 (2-2)

[0112] When the focal length of the third moving lens group is set to f3, the zoom lens preferably satisfies the following conditional expression (3). Regarding the lower limit of conditional expression (3), since |f3 / f2| is an absolute value, 0 < |f3 / f2|. By preventing the corresponding value of conditional expression (3) from becoming greater than or equal to the upper limit value, the optical power of the second moving lens group does not become too strong, and the balance of the optical powers of the second moving lens group and the third moving lens group can be maintained well. Therefore, it is beneficial to suppress the generation of various aberrations. To obtain better characteristics, the zoom lens more preferably satisfies the following conditional expression (3-1), and even more preferably satisfies the following conditional expression (3-2).

[0113] 0 < |f3 / f2| < 0.75 (3)

[0114] 0 < |f3 / f2| < 0.6 (3-1)

[0115] 0 < |f3 / f2| < 0.5 (3-2)

[0116] The zoom lens preferably satisfies the following conditional expression (4). By preventing the corresponding value of conditional expression (4) from becoming less than or equal to the lower limit value, the optical power of the first moving lens group does not become too strong. Therefore, it is beneficial to suppress the generation of various aberrations accompanying zooming. By preventing the corresponding value of conditional expression (4) from becoming greater than or equal to the upper limit value, the optical power of the third moving lens group does not become too strong. Therefore, it is beneficial to suppress the generation of various aberrations accompanying zooming. To obtain better characteristics, the zoom lens more preferably satisfies the following conditional expression (4-1), and even more preferably satisfies the following conditional expression (4-2).

[0117] 0.5 < f1 / f3 < 2 (4)

[0118] 0.6 < f1 / f3 < 1.67 (4-1)

[0119] 0.7 < f1 / f3 < 1.43 (4-2)

[0120] Including the structures related to the conditional expressions, the above-mentioned preferred structures and the structures that can be realized can be combined arbitrarily, and it is preferably selectively adopted appropriately according to the required specifications.

[0121] Next, embodiments and modified examples of the zoom lens of the present invention will be described with reference to the drawings. In addition, the reference signs marked in the cross-sectional views of the respective embodiments and modified examples are used independently for each embodiment and modified example to avoid complication of the description and the drawings caused by an increase in the number of digits of the reference signs. Therefore, even if the same reference sign is marked in the drawings of different embodiments and modified examples, it is not necessarily the same structure.

[0122] [Embodiment 1]

[0123] The cross-sectional views of the structure of the zoom lens of Example 1 and the light beam are shown in Figure 1 and Figure 2 , and the illustration method and structure are as described above, so a part of the repeated description is omitted here.

[0124] The zoom lens of Example 1 includes a first optical system U1 and a second optical system U2 having positive optical powers in order from the wide-angle side to the telephoto side. The first optical system U1 includes lenses L1 to L13 in order from the wide-angle side to the telephoto side. The second optical system U2 includes a first lens group G1, a second lens group G2, a third lens group G3, and a fourth lens group G4 in order from the wide-angle side to the telephoto side. The first lens group G1 includes a lens L21. The second lens group G2 includes lenses L22 to L23 and an aperture stop St in order from the wide-angle side to the telephoto side. The third lens group G3 includes lenses L24 to L29 in order from the wide-angle side to the telephoto side. The fourth lens group G4 includes a lens L30.

[0125] During zooming, the first lens group G1, the second lens group G2, and the third lens group G3 change the intervals between them and the adjacent groups and move along the optical axis Z, respectively. During zooming, the first optical system U1 and the fourth lens group G4 are fixed to the imaging surface on the telephoto side, respectively. The focusing group Gf includes lenses L4 to L5.

[0126] Regarding the zoom lens of Example 1, the basic lens data are shown in Tables 1A and 1B, the specifications and variable surface intervals are shown in Table 2, and the aspherical coefficients are shown in Table 3. Here, in order to prevent one table from becoming too long, the basic lens data are shown in two tables, Table 1A and Table 1B. The first optical system U1 is shown in Table 1A, and the second optical system U2 and the optical component PP are shown in Table 1B.

[0127] The basic lens data table is recorded as follows. In the "Sn" column, the surface numbers are shown when the surface closest to the wide-angle side is the first surface and the numbers increase one by one toward the telephoto side. In the "R" column, the curvature radii of the respective surfaces are shown. In the "D" column, the surface intervals on the optical axis between each surface and the surface adjacent to it on the telephoto side are shown. In the "Nd" column, the refractive indices of the respective components with respect to the d line are shown. In the "v d" column, the Abbe numbers of the respective components based on the d line are shown. In the "ED" column, the effective diameter in the diameter is shown. ED only shows the wide-angle side surface of the second lens from the wide-angle side of the first optical system U1 and the wide-angle side surface of the lens closest to the telephoto side of the first optical system U1, and the column description is omitted in Table 1B.

[0128] In the basic lens data table, the sign of the radius of curvature of the surface with the convex shape facing the magnification side is set to positive, and the sign of the radius of curvature of the surface with the convex shape facing the reduction side is set to negative. In the surface number column of the surface corresponding to the aperture stop St, the surface number and the term (St) are recorded. The value in the bottommost column of column D in Table 1B is the distance between the surface closest to the reduction side in the table and the image display surface Sim. In the basic lens data table, the notation DD[] is used for the variable surface interval during zooming, and the surface number on the magnification side of this interval is marked in [] and entered in column D.

[0129] In Table 2, the zoom magnification Zr, the absolute value of the focal length |f|, the F-number FNo., the maximum full angle of view 2ω, and the variable surface interval are shown based on the d-line reference. The [°] in the 2ω column indicates that the unit is degrees. The values shown in Table 1 and Table 2 are the values in the state where the projection distance is set to 0.97 m (meter). In Table 2, the values at the wide-angle end are shown in the "Wide-angle end" column, the values in the state of the intermediate focal length are shown in the "Intermediate" column, and the values at the telephoto end are shown in the "Telephoto end" column.

[0130] In the basic lens data, an asterisk (*) is marked on the surface number of the aspherical surface, and the value of the paraxial radius of curvature is recorded in the radius of curvature column of the aspherical surface. In Table 3, the surface numbers of the aspherical surfaces are shown in the Sn row, and the numerical values of the aspherical coefficients for each aspherical surface are shown in the KA and Am (m = 3, 4, 5,..., 20) rows. The "E±n" (n: integer) of the numerical values of the aspherical coefficients in Table 3 represents "×10 ±n ". KA and Am are the aspherical coefficients in the aspherical formula represented by the following formula.

[0131] Zd = C × h 2 / {1+(1 - KA × C 2 × h 2 ) 1 / 2}+ ∑Am × h m

[0132] where,

[0133] Zd: Aspherical depth (the length of the perpendicular line dropped from the point on the aspherical surface at height h to the plane tangent to the vertex of the aspherical surface and perpendicular to the optical axis Z)

[0134] h: Height (the distance from the optical axis Z to the lens surface)

[0135] C: Reciprocal of the paraxial radius of curvature

[0136] KA, Am: Aspherical coefficients, and ∑ in the aspherical formula represents the sum related to m.

[0137] In the data of each table, degrees are used as the unit of angle and mm (millimeters) are used as the unit of length. The optical system can be used with an enlarged scale or a reduced scale, so other appropriate units can also be used. Also, the values rounded to a specified number of digits are recorded in each of the tables shown below.

[0138] [Table 1A]

[0139] Example 1

[0140] Sn R D Nd v d ED *1 106.8168 5.0200 1.53638 56.09 *2 67.2451 10.1900 3 54.0823 1.4200 1.83481 42.72 49.73 4 18.5861 5.5230 5 40.4187 1.0500 1.86966 20.02 6 14.1571 15.1000 7 15.4041 4.8500 1.48749 70.44 8 124.2882 2.0155 9 29.9406 5.3100 1.80420 46.50 10 23.0974 3.0700 11 181.9978 3.1400 1.80809 22.76 12 85.1490 12.6900 13 90.1357 6.6300 1.59282 68.62 14 -60.4140 39.5000 15 63.7297 9.2600 1.49700 81.61 16 -26.3132 1.3800 1.92286 20.88 17 35.4623 5.6300 1.60311 60.64 18 121.4384 0.2000 19 97.1293 12.3500 1.49700 81.61 20 30.4975 0.3000 *21 666.6656 4.1000 1.51633 64.06 *22 98.8447 35.5400 23 63.5148 8.3800 1.84661 23.88 56.62 24 DD

[24]

[0141] [Table 1B]

[0142] Example 1

[0143] Sn R D Nd v d 25 42.2252 3.9400 1.65160 58.54 26 284.6768 DD

[26] 27 126.4576 0.8000 1.94595 17.98 28 29.6768 1.2229 29 58.0168 3.3400 1.83481 42.72 30 147.6677 8.7300 31(St) DD

[31] 32 65.5246 3.4300 1.92286 20.88 33 65.5246 1.4400 34 58.5357 0.8500 1.83481 42.72 35 31.5548 0.0247 36 31.8622 10.9800 1.48749 70.44 37 -19.0114 0.0420 38 -18.8679 1.0200 1.83481 42.72 39 37.9471 6.7400 1.49700 81.61 40 -45.9868 0.2000 41 105.9732 8.3200 1.51680 64.20 42 26.6617 DD

[42] 43 2.5700 1.94595 17.98 44 120.7806 14.5000 45 23.0000 1.51680 64.20 46 1.0000 47 3.0000 1.48749 70.44 48 4.1255

[0144] [Table 2]

[0145] Example 1

[0146] Wide-angle end Middle Telephoto end Zr 1.00 1.15 1.33 |f| 6.68 7.68 8.88 FNo. 2.19 2.28 2.41 2ω[°] 126.4 119.6 112.2 DD

[24] 94.6045 84.9517 75.2795 DD

[26] 8.1100 10.5404 12.1608 DD

[31] 11.6600 12.7878 12.2818 DD

[42] 4.2400 10.3345 18.8925

[0147] [Table 3]

[0148] Example 1

[0149] Sn 1 2 21 22 KA 2.4954715E+00 -2.4999450E+00 1.0000000E+00 1.0000000E+00 A3 -4.7558748E-04 -1.8888411E-04 0.0000000E+00 0.0000000E+00 A4 1.7148940E-04 8.1800326E-05 8.7328534E-06 9.7216509E-06 A5 -1.0797125E-05 3.9323057E-06 -1.9108283E-06 1.0219914E-06 A6 4.5042978E-08 -1.0434428E—06 2.8743336E-07 -3.2936771E-07 A7 3.5211036E-08 3.5036012E-08 -3.3795273E-08 1.1822850E-08 A8 -1.8128331E-09 3.7325394E-09 1.1881814E-09 3.7919069E-09 A9 -2.5553700E-11 -2.9092999E-10 2.6173408E-10 -3.5471843E-10 A10 5.1026685E-12 -4.3642188E-12 -3.5447612E-11 -1.4659173E-11 A11 -9.1397670E-14 9.5564303E-13 3.6567770E-13 2.5872694E-12 A12 -5.7869831E-15 -9.3315372E-15 1.8023617E-13 -1.7607274E-15 A13 2.1879639E-16 -1.6522588E-15 -7.9299634E-15 -8.6874400E-15 A14 2.3283682E-18 3.6382858E-17 -3.4657738E-16 1.4763919E-16 A15 -1.9699700E-19 1.5851165E-18 2.6442882E-17 1.5139506E-17 A16 6.7286714E-22 -4.7931798E-20 1.2928030E-19 -3.8742790E-19 A17 8.2652855E-23 -7.9637833E-22 -3.6373516E-20 -1.3343527E-20 A18 -8.2532057E-25 2.9545294E-23 3.6195614E-22 4.1324747E-22 A19 -1.3476262E-26 1.6290989E-25 1.8483825E-23 4.7170243E-24 A20 1.8462690E-28 -7.1591810E-27 -3.2891336E-25 -1.6418867E-25

[0150] In Figure 6 are shown the aberration diagrams of the zoom lens of Example 1 in a state where the projection distance is set to 0.97 m (meters). In Figure 6 , spherical aberration, astigmatism, distortion aberration, and longitudinal chromatic aberration are shown in order from the left. In Figure 6 , the aberration diagrams at the wide-angle end are shown in the upper row marked with "Wide-angle end", the aberration diagrams in the state of the intermediate focal length are shown in the middle row marked with "Intermediate", and the aberration diagrams at the telephoto end are shown in the lower row marked with "Telephoto end". In the spherical aberration diagram, the aberrations related to the d-line, C-line, and F-line are shown by solid lines, long dashed lines, and short dashed lines, respectively. In the astigmatism diagram, the aberration related to the d-line in the sagittal direction is shown by a solid line, and the aberration related to the d-line in the meridional direction is shown by a short dashed line. In the distortion aberration diagram, the aberration related to the d-line is shown by a solid line. In the longitudinal chromatic aberration diagram, the aberrations related to the C-line and F-line are shown by long dashed lines and short dashed lines, respectively. In the spherical aberration diagram, the value of the F-number is shown after "FNo. =". In the other aberration diagrams, the value of the maximum semi-field angle is shown after "ω =".

[0151] In Figure 3 , Figure 4 and Figure 5Cross-sectional views showing the structures of the first, second, and third modified examples of the zoom lens of Example 1 are respectively shown. Figures 3 - 5 Since the structure of the example is as described above, repeated description is omitted here.

[0152] Regarding the notations, meanings, description methods, and illustration methods of the respective data related to the above-described Example 1 and the modified examples, unless otherwise specified, they are basically the same in the following examples, and thus repeated description is omitted below.

[0153] [Example 2]

[0154] A cross-sectional view of the structure of the wide-angle end of the zoom lens of Example 2 and the light beam is shown in Figure 7 . The zoom lens of Example 2 sequentially includes a first optical system U1 and a second optical system U2 having positive optical powers from the magnifying side to the reducing side. The first optical system U1 sequentially includes lenses L1 to L12 from the magnifying side to the reducing side. The second optical system U2 sequentially includes a first lens group G1, a second lens group G2, a third lens group G3, and a fourth lens group G4 from the magnifying side to the reducing side. The first lens group G1 includes a lens L21. The second lens group G2 sequentially includes lenses L22 to L23 and an aperture stop St from the magnifying side to the reducing side. The third lens group G3 sequentially includes lenses L24 to L29 from the magnifying side to the reducing side. The fourth lens group G4 includes a lens L30.

[0155] During zooming, the first lens group G1, the second lens group G2, and the third lens group G3 respectively change the intervals with the adjacent groups and move along the optical axis Z. During zooming, the first optical system U1 and the fourth lens group G4 are respectively fixed to the reducing-side imaging surface. The focusing group Gf includes lenses L4 to L5.

[0156] Regarding the zoom lens of Example 2, the basic lens data are shown in Tables 4A and 4B, the specifications and variable surface intervals are shown in Table 5, the aspherical coefficients are shown in Table 6, and the respective aberration diagrams are shown in Figure 9 . The basic lens data, specifications, and respective aberration diagrams are data in a state where the projection distance is 0.97 m (meters).

[0157] [Table 4A]

[0158] Example 2

[0159] Sn R D Nd v d ED *1 102.4443 5.1838 1.53638 56.09 *2 83.0560 9.7253 3 37.5145 1.9996 1.83481 42.72 41.32 4 19.3773 6.8865 5 59.2624 1.0503 1.86966 20.02 6 13.6979 14.2718 7 14.9099 4.3971 1.48749 70.44 8 142.7042 1.9343 9 28.5648 5.6051 1.77250 49.62 10 21.8287 2.9292 11 217.4138 4.3606 1.86966 20.02 12 95.8652 11.4358 13 90.2819 6.2174 1.59282 68.62 14 -57.2604 39.5000 15 78.1200 10.8425 1.48749 70.44 16 -26.3158 1.3801 1.86966 20.02 17 35.3884 14.9031 1.55032 75.50 18 -31.1160 0.4662 *19 240.3695 4.0993 1.58913 61.15 *20 86.1137 36.4776 21 63.3059 8.5243 1.84661 23.88 56.88 22 DD

[22]

[0160] [Table 4B]

[0161] Example 2

[0162] Sn R D Nd v d 23 43.2250 3.9702 1.65160 58.54 24 290.7590 DD

[24] 25 62.5723 0.8000 1.94595 17.98 26 26.8699 1.3245 27 53.7281 4.3081 1.69680 55.53 28 133.5394 6.4331 29(St) DD

[29] 30 61.8466 3.5066 1.94595 17.98 31 65.0745 0.0308 32 63.3312 0.8500 2.00100 29.13 33 52.7241 1.9999 34 126.9242 6.1289 1.48749 70.44 35 -18.9229 1.0200 1.80420 46.50 36 34.9829 6.0744 1.49700 81.61 37 -48.6871 0.2000 38 87.9651 8.4259 1.51680 64.20 39 -26.9971 DD

[39] 40 2.5007 1.94595 17.98 41 121.9908 14.5000 42 23.0000 1.51680 64.20 43 1.0000 44 3.0000 1.48749 70.44 45 4.0895

[0163] [Table 5]

[0164] Example 2

[0165] Wide-angle end Middle Telephoto end Zr 1.00 1.15 1.33 |f| 6.70 7.70 8.91 FNo. 2.19 2.29 2.41 2ω[°] 126.2 119.4 112.0 DD

[22] 96.8902 87.4592 77.6902 DD

[24] 8.4929 11.3022 13.2080 DD

[29] 13.5545 14.4309 13.8989 DD

[39] 6.2148 11.9581 20.3557

[0166] [Table 6]

[0167] Example 2

[0168] Sn 1 2 19 20 KA 2.4999950E+00 -1.5486737E+00 1.0000000E+00 1.0000000E+00 A3 -4.8629957E-04 —3.1584518E-04 0.0000000E+00 0.0000000E+00 A4 1.6282277E-04 1.0502595E-04 —1.1736800E-06 —6.1958851E-06 A5 —7.2229312E-06 4.2923205E—06 —7.7298344E—07 3.3593082E—06 A6 —2.5489547E-07 —1.1241371E-06 2.2808442E-07 —5.4693176E—07 A7 2.8345976E-08 1.9440268E-08 -5.4403562E-08 1.4716824E-08 A8 —2.6166951E-11 4.1362214E-09 4.0330037E-09 3.7838844E-09 A9 -6.0683702E-11 -1.5179442E-10 2.3223162E-10 -2.9462920E-10 A10 1.1883698E-12 -7.5431939E-12 -4.6134878E-11 -8.6017360E-12 A11 6.8602601E-14 3.8722107E-13 8.1661106E-13 1.4695508E-12 A12 -2.2736308E-15 6.9280777E-15 1.7239927E-13 -6.3229517E-15 A13 -4.3661080E-17 -4.9882069E-16 -7.5681180E-15 -3.5356988E-15 A14 2.1450802E-18 -2.5998874E-18 -2.6874743E-16 6.2801792E-17 A15 1.6536019E-20 3.4939733E-19 1.9723460E-17 4.5370905E-18 A16 -1.2041188E-21 -4.0641175E-22 8.8935240E-20 -1.1317153E-19 A17 -3.6760356E-24 -1.2684592E-22 -2.2614451E-20 -2.9940556E-21 A18 3.9673877E-25 6.0617118E-25 1.9057002E-22 8.7733680E-23 A19 3.5966742E-28 1.8702511E-26 9.8192075E-24 8.0113560E-25 A20 -5.9179795E-29 -1.3129697E-28 -1.5091598E-25 -2.5720537E-26

[0169] In Figure 8 is shown the structure and light beam of the wide-angle end of the zoom lens as a modified example of Example 2. Figure 8 The zoom lens of Figure 8 has two light-path bending members and bends the light path twice. Figure 8 The zoom lens of Figure 8 sequentially includes a first optical system U1r and a second optical system U2r along the light path from the magnifying side to the reducing side. Figure 8 The difference between the first optical system U1r of Figure 8 and the first optical system U1 of Example 2 is that a mirror R1 is disposed inside the first optical system U1r, and the light path is bent by the mirror R1. Figure 8 The difference between the second optical system U2r of Figure 8 and the second optical system U2 of Example 2 is that a mirror R2 is disposed closest to the magnifying side in the second optical system U2r, and the light path is bent by the mirror R2. Figure 8 The other structure of the zoom lens of Figure 8 is the same as that of the zoom lens of Example 2.

[0170] [Example 3]

[0171] The cross-sectional view of the structure and light beam of the wide-angle end of the zoom lens of Example 3 is shown in Figure 10 . The zoom lens of Example 3 sequentially includes a first optical system U1 with a positive optical power and a second optical system U2 from the magnifying side to the reducing side. The first optical system U1 sequentially includes lenses L1 to L13 from the magnifying side to the reducing side. The second optical system U2 sequentially includes a first lens group G1, a second lens group G2, a third lens group G3, and a fourth lens group G4 from the magnifying side to the reducing side. The first lens group G1 includes a lens L21. The second lens group G2 sequentially includes lenses L22 to L23 and an aperture stop St from the magnifying side to the reducing side. The third lens group G3 sequentially includes lenses L24 to L29 from the magnifying side to the reducing side. The fourth lens group G4 includes a lens L30.

[0172] During zooming, the first lens group G1, the second lens group G2, and the third lens group G3 respectively change the interval between adjacent groups and move along the optical axis Z. During zooming, the first optical system U1 and the fourth lens group G4 are respectively fixed to the reducing-side imaging surface. The focusing group Gf includes lenses L4 to L5.

[0173] Regarding the zoom lens of Embodiment 3, the basic lens data is shown in Tables 7A and 7B, the specifications and variable surface intervals are shown in Table 8, the aspherical coefficients are shown in Table 9, and the aberration diagrams are shown in Figure 12 . The basic lens data, specifications, and aberration diagrams are the data in the state where the projection distance is 0.97 m (meter).

[0174] [Table 7A]

[0175] Embodiment 3

[0176] Sn R D Nd v d ED *1 -30.0477 4.6997 1.53638 56.09 *2 -78.4526 3.4481 3 55.3437 4.4930 1.83481 42.72 50.03 4 20.3962 6.9550 5 58.5090 1.8088 1.86966 20.02 6 14.5154 15.3183 7 -15.5243 2.6323 1.49700 81.61 8 -123.8964 1.7713 9 -33.1837 7.4421 1.80420 46.50 10 -24.1638 3.1819 11 148.4440 3.5433 1.80518 25.46 12 -72.6066 17.2707 13 433.2747 3.3369 1.59282 68.62 14 -54.1797 40.0000 15 52.6666 10.4771 1.49700 81.61 16 -32.9366 1.2500 1.92286 20.88 17 32.2862 8.7461 1.60311 60.64 18 ∞ 0.2008 19 154.9251 11.0873 1.49700 81.61 20 -32.3856 0.2000 *21 -523.7012 3.0000 1.51633 64.06 *22 -170.6891 33.5926 23 61.6522 8.5021 1.84666 23.78 56.54 24 ∞ DD

[24]

[0177] [Table 7B]

[0178] Embodiment 3

[0179] Sn R D Nd v d 25 39.0595 4.1225 1.65160 58.54 26 -290.8319 DD

[26] 27 ∞ 0.8000 1.94595 17.98 28 32.1112 1.0571 29 58.4784 3.3899 1.83481 42.72 30 -99.0675 9.8061 31(St) ∞ DD

[31] 32 52.2549 5.0166 1.92286 20.88 33 -52.2549 1.6542 34 -42.6652 0.9000 1.83481 42.72 35 20.9000 0.0819 36 21.3669 17.9999 1.49700 81.61 37 -20.5137 0.0846 38 -20.1701 1.0000 1.83481 42.72 39 49.4688 5.7158 1.49700 81.61 40 -49.4688 0.2000 41 155.0372 8.4256 1.51680 64.20 42 -25.2924 DD

[42] 43 ∞ 2.6290 1.94595 17.98 44 -111.1907 14.5000 45 ∞ 23.0000 1.51680 64.20 46 ∞ 1.0000 47 ∞ 2.0000 1.52300 58.76 48 ∞ 3.5800 49 ∞ 1.1000 1.50997 61.61 50 ∞ 0.4959

[0180] [Table 8]

[0181] Embodiment 3

[0182] Wide-angle end Middle Telephoto end Zr 1.00 1.15 1.33 |f| 6.66 7.66 8.85 FNo. 2.18 2.28 2.41 2ω[°] 126.6 119.8 112.4 DD

[24] 94.8687 85.5168 76.2936 DD

[26] 5.6435 7.4428 8.6252 DD

[31] 4.8859 6.3726 6.1135 DD

[42] 4.8431 10.9060 19.2097

[0183] [Table 9]

[0184] Embodiment 3

[0185] Sn 1 2 21 22 KA -6.3100148E-02 1.7647061E+00 1.0000000E+00 1.0000000E+00 A3 -4.1262880E-05 3.6116503E-04 0.0000000E+00 0.0000000E+00 A4 2.3323245E-04 1.0960858E-04 -1.0037781E-05 —1.2126314E-05 A5 —1.5824531E-05 9.9953060E-07 3.0124928E-08 4.6141873E-06 A6 —6.8011684E-08 —8.3545147E-07 8.3784037E-07 4.0499758E-08 A7 5.6682868E-08 1.0953691E-08 —1.2702191E-07 —8.6251997E-08 A8 —2.0464789E-09 2.8646074E-09 —1.3689307E-09 4.2372119E-09 A9 -6.9995137E-11 —3.1548151E-11 1.3860786E-09 5.7028167E-10 A10 6.5680278E-12 —7.9274538E-12 -5.4064496E-11 4.5445117E-11 A11 -5.6047448E-14 5.4376158E-14 -5.8313551E-12 -1.7225663E-12 A12 -8.3254126E-15 1.5577479E-14 3.9549424E-13 2.0167460E-13 A13 2.3275548E-16 -5.4541745E-17 1.0023566E-14 2.4705734E-15 A14 4.2133373E-18 -2.0676038E-17 -1.1686807E-15 -4.8293247E-16 A15 -2.4007236E-19 3.0462267E-20 -1.3109310E-18 -1.2535261E-18 A16 2.5850059E-22 1.7395503E-20 1.6577512E-18 6.6434774E-19 A17 1.0941265E-22 -7.6096779E-24 -1.5480638E-20 -5.2298303E-22 A18 -9.9779945E-25 -8.3378159E-24 -1.0190733E-21 -5.0128259E-22 A19 -1.9056780E-26 1.5876715E-28 1.2975974E-23 5.6638051E-25 A20 2.5903023E-28 1.7346216E-27 1.4566400E-25 1.6240563E-25

[0186] In Figure 11 the structure and light beam of the wide-angle end of the zoom lens as a modified example of Embodiment 3 are shown. Figure 11 The zoom lens of Figure 11 has two optical path bending components and bends the optical path twice. Figure 11 The first optical system Ulr of Figure 11 is different from the first optical system U1 of Embodiment 3 in that a mirror R1 is disposed inside the first optical system Ulr and the optical path is bent by the mirror R1. Figure 11 The second optical system U2r of

[0187] [Embodiment 4]

[0188] The cross-sectional view of the structure and light beam of the wide-angle end of the zoom lens of Embodiment 4 is shown in Figure 13The zoom lens of Example 4 includes, in order from the telephoto side to the wide-angle side, a first optical system U1 and a second optical system U2 having positive optical powers. The first optical system U1 includes lenses L1 to L13 in order from the telephoto side to the wide-angle side. The second optical system U2 includes a first lens group G1, a second lens group G2, a third lens group G3, and a fourth lens group G4 in order from the telephoto side to the wide-angle side. The first lens group G1 includes a lens L21. The second lens group G2 includes lenses L22 to L23 and an aperture stop St in order from the telephoto side to the wide-angle side. The third lens group G3 includes lenses L24 to L29 in order from the telephoto side to the wide-angle side. The fourth lens group G4 includes a lens L30.

[0189] During zooming, the first lens group G1, the second lens group G2, and the third lens group G3 move along the optical axis Z by changing the intervals between adjacent groups, respectively. During zooming, the first optical system U1 and the fourth lens group G4 are fixed to the imaging surface on the wide-angle side, respectively. The focusing group Gf includes lenses L4 to L5.

[0190] Regarding the zoom lens of Example 4, the basic lens data are shown in Tables 10A and 10B, the specifications and variable surface intervals are shown in Table 11, the aspherical coefficients are shown in Table 12, and the aberration diagrams are shown in Figure 15 . The basic lens data, specifications, and aberration diagrams are the data in the state where the projection distance is 0.97 m (meter).

[0191] [Table 10A]

[0192] Example 4

[0193] Sn R D Nd v d ED *1 26.6529 5.6998 1.53638 56.09 *2 76.1620 6.9483 3 54.5684 1.7839 1.80518 25.46 41.64 4 18.6434 6.6755 5 72.0863 1.0657 1.68893 31.07 6 14.2069 14.2961 7 16.4644 3.5944 1.49700 81.61 8 267.5781 1.5644 9 37.9885 5.9389 1.80420 46.50 10 25.3715 1.5664 11 174.7017 6.0009 1.80518 25.46 12 67.7440 16.5440 13 221.0695 4.0930 1.59282 68.62 14 47.2036 38.4827 15 55.0252 8.7874 1.49700 81.61 16 -31.7874 1.2000 1.92286 20.88 17 27.7970 8.3000 1.60311 60.64 18 142.6925 0.1008 19 66.1343 14.5921 1.49700 81.61 20 31.3826 4.7145 *21 584.1365 5.0819 1.51633 64.06 *22 155.2865 25.7614 23 86.6404 8.9318 1.84666 23.78 58.29 24 165.9083 DD

[24]

[0194] [Table 10B]

[0195] Example 4

[0196] Sn R D Nd v d 25 45.2472 3.2182 1.69680 55.46 26 199.3141 DD

[26] 27 215.1467 0.8000 1.94595 17.98 28 33.2404 1.0672 29 77.3436 2.6750 1.83481 42.72 30 107.9454 DD

[30] 31(St) 6.5339 32 62.0961 3.6124 1.92286 20.88 33 82.8788 0.2102 34 65.3386 0.9008 1.83481 42.72 35 32.5876 2.3576 36 26.1515 15.4150 1.49700 81.61 37 58.6052 0.1010 38 -55.2811 1.0963 1.83481 42.72 39 30.4253 0.3239 40 33.4543 11.1344 1.49700 81.61 41 -71.9896 1.7185 42 77.3957 6.1595 1.51680 64.20 43 51.2127 DD

[43] 44 707.1473 2.6698 1.94595 17.98 45 95.0801 14.5050 46 23.0000 1.51680 64.20 47 1.0000 48 2.0000 1.52300 58.76 49 3.5800 50 1.1000 1.50997 61.61 51 0.5129

[0197] [Table 11]

[0198] Example 4

[0199] Wide-angle end Middle Telephoto end Zr 1.00 1.15 1.33 |f| 6.66 7.66 8.83 FNo. 2.21 2.31 2.45 2ω[°] 126.4 119.6 112.4 DD

[24] 96.0330 86.9090 78.0208 DD

[26] 4.3178 6.1756 7.4956 DD

[30] 11.1668 12.5317 12.0496 DD

[43] 2.3984 8.2993 16.3502

[0200] [Table 12]

[0201] Example 4

[0202] Sn 1 2 21 22 KA 3.1181324E-01 1.4836360E+00 1.0000000E+00 1.0000000E+00 A3 —2.4902654E-05 1.6094785E-04 0.0000000E+00 0.0000000E+00 A4 1.6133420E-04 9.0630262E-05 —5.6482967E-06 8.1425149E-06 A5 —6.2492399E-06 3.3059833E-06 —2.1663989E-06 —4.8280638E-06 A6 —2.8692150E-07 —8.2855476E-07 7.7295658E-07 1.3000477E-06 A7 2.4044959E-08 2.1604716E-08 —5.6625551E-08 —8.1853458E-08 A8 9.3452703E-11 1.9485071E-09 —4.5088396E-09 —8.5961737E-09 A9 -4.7606987E-i1 -1.1136864E-10 6.1374807E-10 1.1910821E-09 A10 7.4404097E-13 -1.9909358E-12 3.5567792E-12 -8.0484144E-12 A11 4.7235518E-14 2.5037889E-13 -2.6849205E-12 -5.1173580E-12 A12 -1.3714310E-15 -6.5719116E-16 4.6338738E-14 2.1415857E-13 A13 -2.2429533E-17 -3.0666279E-16 6.2692095E-15 7.6513754E-15 A14 1.0743289E-18 3.5576663E-18 -1.8484551E-16 -6.9243402E-16 A15 3.0289124E-21 2.1416398E-19 -8.2096745E-18 4.0899538E-18 A16 -4.2681698E-22 -3.4628848E-21 3.1156993E-19 8.4942130E-19 A17 1.1771636E-24 -8.0418789E-23 5.6947346E-21 -2.1943629E-20 A18 8.0830282E-26 1.4876346E-24 -2.5601476E-22 -2.3501077E-22 A19 -3.3944757E-28 1.2619771E-26 -1.6303355E-24 1.5917235E-23 A20 -5.2001826E-30 -2.4625994E-28 8.3872303E-26 -1.7514063E-25

[0203] In Figure 14 the structure and light beam at the wide-angle end of the zoom lens as a modified example of Example 4 are shown. Figure 14 The zoom lens has two optical path bending members and bends the optical path twice.Figure 14 The zoom lens includes a first optical system Ulr and a second optical system U2r in sequence along the optical path from the telephoto side to the wide-angle side. Figure 14 The difference between the first optical system Ulr of and the first optical system U1 of Embodiment 4 is that a mirror R1 is disposed inside the first optical system Ulr, and the optical path is bent by the mirror R1. Figure 14 The difference between the second optical system U2r of and the second optical system U2 of Embodiment 4 is that a mirror R2 is disposed on the most telephoto side of the second optical system U2r, and the optical path is bent by the mirror R2. Figure 14 Other structures of the zoom lens of are the same as those of the zoom lens of Embodiment 4.

[0204] [Embodiment 5]

[0205] The structure of the wide-angle end of the zoom lens of Embodiment 5 and a cross-sectional view of the light beam are shown in Figure 16 . The zoom lens of Embodiment 5 includes a first optical system U1 with a positive optical power and a second optical system U2 in sequence from the telephoto side to the wide-angle side. The first optical system U1 includes lenses L1 to L13 in sequence from the telephoto side to the wide-angle side. The second optical system U2 includes a first lens group G1, a second lens group G2, a third lens group G3, and a fourth lens group G4 in sequence from the telephoto side to the wide-angle side. The first lens group G1 includes a lens L21. The second lens group G2 includes lenses L22 to L23 and an aperture stop St in sequence from the telephoto side to the wide-angle side. The third lens group G3 includes lenses L24 to L29 in sequence from the telephoto side to the wide-angle side. The fourth lens group G4 includes a lens L30.

[0206] During zooming, the first lens group G1, the second lens group G2, and the third lens group G3 move along the optical axis Z by changing the intervals between adjacent groups respectively. During zooming, the first optical system U1 and the fourth lens group G4 are fixed to the imaging surface on the wide-angle side respectively. The focusing group Gf includes lenses L4 to L5.

[0207] Regarding the zoom lens of Embodiment 5, the basic lens data is shown in Tables 13A and 13B, the specifications and variable surface intervals are shown in Table 14, the aspherical coefficients are shown in Table 15, and the aberration diagrams are shown in Figure 18 . The basic lens data, specifications, and aberration diagrams are the data in the state where the projection distance is 0.97 m (meter).

[0208] [Table 13A]

[0209] Embodiment 5

[0210] Sn R D Nd v d ED *1 30.5974 6.1506 1.53097 55.66 *2 133.6602 5.5376 3 39.6197 1.9999 1.92286 20.88 43.67 4 19.2083 7.5628 5 58.4623 0.7991 1.75500 52.32 6 14.0497 16.1887 7 17.6429 0.9667 1.49700 81.61 8 221.7347 2.6094 9 49.3203 5.8092 1.84666 23.78 10 28.5710 1.2964 11 283.0708 2-7994 1.87070 40.73 12 77.4008 13.1280 13 318.0722 3.3585 1.59282 68.62 14 -42.0369 35.3903 15 46.2458 9.3493 1.49700 81.61 16 -35.4974 1.2009 1.92286 20.88 17 27.9061 12.8165 1.55052 75.50 18 67.1251 0.0294 19 94.5500 15.0000 1.49700 81.61 20 33.5302 2.6110 *21 57.1498 4.7148 1.51633 64.06 *22 200.0007 24.6418 23 87.8087 10.5012 1.84666 23.78 59.81 24 192.5737 DD

[24]

[0211] [Table 13B]

[0212] Embodiment 5

[0213] Sn R D Nd v d 25 97.6584 3.2705 1.59282 68.62 26 79.6246 DD

[26] 27 252.4864 0.8010 1.92286 20.88 28 48.1528 1.0116 29 38.0586 3.9073 1.75500 52.32 30 146.2989 DD

[30] 31(St) 3.8897 32 78.1403 2.8688 1.92286 20.88 33 66.3501 1.2735 34 31.5778 0.7993 1.87070 40.73 35 39.5191 6.9165 36 29.7407 6.7212 1.49700 81.61 37 28.7314 6.4829 38 -20.7585 0.8000 1.69680 55.46 39 55.5518 1.4016 40 210.6301 5.6168 1.49700 81.61 41 -30.6256 0.0298 42 101.8635 6.9360 1.49700 81.61 43 33.6986 DD

[43] 44 1479.8255 2.6116 1.94595 17.98 45 115.9308 15.7284 46 30.6464 1.51633 64.14 47 0.0000

[0214] [Table 14]

[0215] Example 5

[0216] Wide-angle end Middle Telephoto end Zr 1.00 1.15 1.33 |f| 6.66 7.66 8.85 FNo. 2.13 2.27 2.46 2ω[°] 126.4 119.6 112.2 DD

[24] 96.1903 85.5297 75.0513 DD

[26] 1.4997 5.2259 6.0281 DD

[30] 15.0328 15.8256 17.3766 DD

[43] 9.6740 15.8155 23.9408

[0217] [Table 15]

[0218] Example 5

[0219] Sn 1 2 21 22 KA -6.8154789E-02 1.0000090E+00 1.0000000E+00 1.0000000E+00 A3 1.2552791E-04 5.3708771E-04 0.0000000E+00 0.0000000E+00 A4 9.3624713E-05 —2.8974385E-05 —4.7586440E-05 —3.2332070E-05 A5 —1.1005330E-06 1.1429637E-05 7.7013605E-06 5.1389845E-06 A6 —3.1810833E-07 —4.1418990E-07 —1.2434843E-07 3.2824931E-07 A7 9.1398870E-09 —4.6557386E-08 -1.2124328E-07 —1.3673139E-07 A8 5.8911721E-lO 2.0751758E-09 9.2337332E-09 5.1368346E-09 A9 -2.8483981E-11 1.4183687E-10 4.8888258E-10 9.0720630E-10 A10 -3.8993822E-13 -7.1249023E-12 -7.3872867E-11 -6.9270150E-11 A11 3.9032933E-14 -2.4295555E-13 2.1363790E-13 -2.1621970E-12 A12 -1.0462616E-16 1.4039895E-14 2.6469854E-13 3.3580012E-13 A13 -2.8675382E-17 2.4526185E-16 -7.1813846E-15 -1.8846324E-15 A14 3.0866308E-19 -1.6588248E-17 -4.6944769E-16 -7.9848002E-16 A15 1.1834398E-20 -1.3980941E-19 2.2713909E-17 2.0577653E-17 A16 -1.8793391E-22 1.1580881E-20 3.0480777E-19 8.4504501E-19 A17 -2.5933787E-24 3.9597032E-23 -3.1077864E-20 -3.9565975E-20 A18 5.1138446E-26 -4.3950551E-24 1.8416798E-22 -8.8503153E-23 A19 2.3509553E-28 -3.8788823E-27 1.6407105E-23 2.5538741E-23 A20 -5.4041684E-30 6.9851371E-28 -2.6673433E-25 -3.3436631E-25

[0220] In Figure 17 is shown the structure and the light beam of the wide-angle end of the zoom lens as a modified example of Example 5. Figure 17 The zoom lens of has two optical path bending members and bends the optical path twice. Figure 17 The zoom lens of includes, in order along the optical path from the magnifying side to the reducing side, a first optical system Ulr and a second optical system U2r. Figure 17 The first optical system Ulr of is different from the first optical system U1 of Example 5 in that a mirror R1 is disposed inside the first optical system Ulr and the optical path is bent by the mirror R1. Figure 17 The second optical system U2r of is different from the second optical system U2 of Example 5 in that a mirror R2 is disposed closest to the magnifying side in the second optical system U2r and the optical path is bent by the mirror R2. Figure 17 The other structure of the zoom lens of is the same as that of the zoom lens of Example 5.

[0221] [Example 6]

[0222] A cross-sectional view of the structure and the light beam of the wide-angle end of the zoom lens of Example 6 is shown in Figure 19 . The zoom lens of Example 6 includes, in order from the magnifying side to the reducing side, a first optical system U1 having a positive optical power and a second optical system U2. The first optical system U1 includes, in order from the magnifying side to the reducing side, lenses L1 to L14. The second optical system U2 includes, in order from the magnifying side to the reducing side, a first lens group G1, a second lens group G2, a third lens group G3, and a fourth lens group G4. The first lens group G1 includes a lens L21. The second lens group G2 includes, in order from the magnifying side to the reducing side, lenses L22 to L23 and an aperture stop St. The third lens group G3 includes, in order from the magnifying side to the reducing side, lenses L24 to L30. The fourth lens group G4 includes a lens L31.

[0223] Upon variable magnification, the first lens group G1, the second lens group G2, and the third lens group G3 move along the optical axis Z by changing the intervals between the adjacent groups respectively. Upon variable magnification, the first optical system U1 and the fourth lens group G4 are fixed to the imaging surface on the reduction side respectively. The focusing group Gf includes lenses L4 to L5.

[0224] Regarding the zoom lens of Embodiment 6, the basic lens data are shown in Tables 16A and 16B, the specifications and the variable surface intervals are shown in Table 17, the aspherical coefficients are shown in Table 18, and the respective aberration diagrams are shown in Figure 21 . The basic lens data, the specifications, and the respective aberration diagrams are the data in the state where the projection distance is 0.97 m (meter).

[0225] [Table 16A]

[0226] Embodiment 6

[0227] Sn R D Nd v d ED *1 29.0532 5.3386 1.53638 56.09 *2 79.9394 5.0871 3 52.7063 2.4343 1.83481 42.72 46.16 4 20.2314 6.9098 5 57.3614 1.1007 1.86966 20.02 6 14.8512 16.6200 7 15.7458 3.5291 1.48749 70.44 8 124.5580 1.8729 9 32.7482 6.3565 1.80420 46.50 10 24.0632 3.3660 11 154.1897 4.9705 1.80518 25.46 12 75.3289 20.3881 13 587.9725 3.5313 1.59282 68.62 14 53.4359 40.0000 15 53.7341 11.1444 1.49700 81.61 16 -37.8455 0.1243 17 36.8788 0.7991 1.94595 17.98 18 4533.0001 0.2606 19 -806.6420 6.9544 1.59282 68.62 20 43.2670 0.0100 21 43.1716 4.0288 1.94595 17.98 22 1931.1970 0.2009 23 223.8074 11.3535 1.49700 81.61 24 33.6608 1.9130 *25 598.7779 3.7787 1.51633 64.06 *26 175.6697 33.5459 27 63.0622 8.9981 1.84666 23.78 56.55 28 DD

[28]

[0228] [Table 16B]

[0229] Embodiment 6

[0230] Sn R D Nd v d 29 39.7690 4.5132 1.60311 60.64 30 273.4720 DD

[30] 31 559.3311 4.1529 1.94595 17.98 32 35.0507 1.1785 33 63.3478 7.3954 1.83481 42.72 34 117.6016 12.6957 35(St) DD

[35] 36 50.4868 4.4027 1.92286 20.88 37 53.8113 0.6495 38 46.9648 0.9000 1.83481 42.72 39 21.0283 0.0333 40 21.1827 12.1814 1.48749 70.44 41 -4929.4525 0.7267 42 601.3870 5.0210 1.49700 81.61 43 -20.3710 0.0690 44 -20.1254 0.7991 1.83481 42.72 45 57.4921 0.0301 46 58.5221 4.9447 1.49700 81.61 47 63.3450 0.2000 48 170.1351 8.2335 1.51680 64.20 49 25.6462 DD

[49] 50 2.4995 1.94595 17.98 51 115.0806 14.5000 52 23.0000 1.51680 64.20 53 1.0000 54 2.0000 1.52300 58.76 55 3.5800 56 1.1000 1.50997 61.61 57 0.5669

[0231] [Table 17]

[0232] Embodiment 6

[0233] Wide-angle end Middle Telephoto end Zr 1.00 1.15 1.33 |f| 6.69 7.67 8.89 FNo. 2.17 2.28 2.41 2ω[°] 126.4 119.6 112.2 DD

[28] 98.6603 88.6687 78.3892 DD

[30] 2.3269 3.9415 4.8224 DD

[35] 9.1898 11.1858 11.6034 DD

[49] 7.3491 13.7222 22.7122

[0234] [Table 18]

[0235] Embodiment 6

[0236] Sn 1 2 25 26 KA -9.5888388E-02 -3.0482600E-01 1.0000000E+00 1.0000000E+00 A3 -4.7632367E-04 —3.1760027E-04 0.0000000E+00 0.0000000E+00 A4 2.4698954E-04 1.7053489E-04 1.2247879E-05 2.1385171E-05 A5 -1.3741619E-05 1.1236045E-07 —3.8922985E-06 —3.2756236E-06 A6 —2.2580655E-07 —1.4373052E-06 4.3425218E-07 2.4472909E-07 A7 5.2710518E-08 6.6422618E-08 —2.8430189E-11 1.9832580E-08 A8 —1.1350545E-09 4.9346498E-09 -3.5943946E-09 -3.2398550E-09 A9 -8.7137274E-11 -4.2035870E-10 1.2975001E-10 -5.8174091E-11 A10 4.1620473E-12 —7.1951451E-12 1.2252871E-11 1.7982035E-11 A11 4.6469450E-14 1.3060374E-12 -5.3884480E-13 2.0792801E-13 A12 -5.7498202E-15 -5.1804032E-15 -2.7515254E-14 -6.8480875E-14 A13 3.5713607E-17 -2.2597509E-15 7.9852379E-16 -5.8668308E-16 A14 3.9377808E-18 3.3646610E-17 6.1305412E-17 1.7685949E-16 A15 -5.8627388E-20 2.2081976E-18 -2.3414850E-19 7.7020917E-19 A16 -1.3183591E-21 -4.7932263E-20 -1.1558627E-19 -2.7939140E-19 A17 2.7568845E-23 -1.1369962E-21 -4.5238790E-22 -2.8264463E-22 A18 1.6998554E-25 3.0247534E-23 1.2363841E-22 2.3859057E-22 A19 -4.4914096E-27 2.3926214E-25 3.0730935E-25 -1.0327253E-25 A20 -5.8678447E-31 -7.3208456E-27 -5.2494263E-26 -8.4118127E-26

[0237] In Figure 20 the structure and the light beam at the wide-angle end of the zoom lens as a modification of Embodiment 6 are shown. Figure 20 The zoom lens of Figure 20 has two light path bending members and bends the light path twice. The zoom lens of Figure 20 includes the first optical system Ulr and the second optical system U2r in sequence along the light path from the magnification side to the reduction side. The difference between the first optical system Ulr of Figure 20 and the first optical system U1 of Embodiment 6 is that a mirror R1 is disposed inside the first optical system Ulr and the light path is bent by the mirror R1. The difference between the second optical system U2r of Figure 20 and the second optical system U2 of Embodiment 6 is that a mirror R2 is disposed on the most magnification side of the second optical system U2r and the light path is bent by the mirror R2. The other structures of the zoom lens of

[0238] In the above, regarding Embodiments 2 to 6, an example in which the optical path is bent twice is shown as a modification. However, regarding Embodiments 2 to 6, as the optical path bending member, there may also be a modification having only the first optical path bending member and a modification having only the second optical path bending member.

[0239] Table 19 shows the corresponding values of conditional expressions (1) to (4) of the zoom lenses of Embodiments 1 to 6. The corresponding values of the embodiments shown in Table 19 can also be used as the upper limit or the lower limit of the conditional expression to set the preferred range of the conditional expression.

[0240] [Table 19]

[0241] Equation number Conditional equation Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 (1) fr1 / |fw| 1.86 1.86 1.88 1.88 1.93 1.89 (2) |f1 / f2| 0.21 0.08 0.32 0.27 0.20 0.24 (3) |f3 / f2| 0.25 0.10 0.43 0.37 0.19 0.32 (4) f1 / f3 0.85 0.80 0.74 0.72 1.04 0.77

[0242] The zoom ratios of the zoom lenses of Embodiments 1 to 6 are 1.2 times or more and have a high magnification. The full viewing angles of the zoom lenses of Embodiments 1 to 6 at the wide-angle end are 105 degrees or more and have a wide viewing angle. Also, the aberration variation during zooming of the zoom lenses of Embodiments 1 to 6 is suppressed, and each aberration is well corrected, thereby achieving high optical performance.

[0243] Next, a projection display device according to an embodiment of the present invention will be described. Figure 22 It is a schematic configuration diagram of a projection display device according to an embodiment of the present invention. Figure 22 The projection display device 100 shown has: a zoom lens 10 according to an embodiment of the present invention; a light source 15; and transmissive display elements 11a to 11c as light valves, which output an optical image corresponding to light of each color. Further, the projection display device 100 has dichroic mirrors 12 and 13 for color separation, a cross dichroic prism 14 for color synthesis, condenser lenses 16a to 16c, and total reflection mirrors 18a to 18c for deflecting the optical path. In addition, Figure 22 the zoom lens 10 is schematically illustrated. Also, an integrator is disposed between the light source 15 and the dichroic mirror 12, but its illustration is omitted in Figure 22 this figure.

[0244] The white light from the light source 15 is decomposed into three-color light beams (blue light, green light, and red light) by the dichroic mirrors 12 and 13, and then respectively passes through the condenser lenses 16a to 16c and is incident on the transmissive display elements 11a to 11c corresponding to the light beams of each color and is modulated. After color synthesis by the cross dichroic prism 14, it is incident on the zoom lens 10. The zoom lens 10 projects an optical image based on the modulated light modulated by the transmissive display elements 11a to 11c onto the screen 105.

[0245] Figure 23 This is a schematic structural diagram of a projection display device according to another embodiment of the present invention. Figure 23 The shown projection display device 200 has: a zoom lens 210 according to an embodiment of the present invention; a light source 215; and DMD (Digital Micromirror Device (registered trademark)) elements 21a to 21c as light valves, which output optical images corresponding to lights of respective colors. And, the projection display device 200 has TIR (Total Internal Reflection) prisms 24a to 24c for color separation and color synthesis and a polarization beam splitter prism 25 for separating illumination light and projection light. In addition, Figure 23 a zoom lens 210 is schematically illustrated. And, an integrator is disposed between the light source 215 and the polarization beam splitter prism 25, but its illustration is omitted in Figure 23 this figure.

[0246] After the white light from the light source 215 is reflected by the reflection surface inside the polarization beam splitter prism 25, it is decomposed into three-color light beams (blue light, green light, and red light) by the TIR prisms 24a to 24c. Each decomposed color light beam is incident on the corresponding DMD element 21a to 21c and is modulated, and then travels in the opposite direction again in the TIR prisms 24a to 24c for color synthesis, and then transmits through the polarization beam splitter prism 25 and is incident on the zoom lens 210. The zoom lens 210 projects an optical image based on the modulated light modulated by the DMD elements 21a to 21c onto the screen 205.

[0247] Figure 24 This is a schematic structural diagram of a projection display device according to still another embodiment of the present invention. Figure 24 The shown projection display device 300 has: a zoom lens 310 according to an embodiment of the present invention; a light source 315; and reflective display elements 31a to 31c as light valves, which output optical images corresponding to lights of respective colors. And, the projection display device 300 has color separation mirrors 32 and 33 for color separation, a cross color separation prism 34 for color synthesis, a total reflection mirror 38 for deflecting an optical path, and polarization beam splitter prisms 35a to 35c. In addition, Figure 24 a zoom lens 310 is schematically illustrated. And, an integrator is disposed between the light source 315 and the color separation mirror 32, but its illustration is omitted in Figure 24 this figure.

[0248] The white light from the light source 315 is decomposed into three-color light beams (blue light, green light, and red light) by the dichroic mirrors 32 and 33. Each decomposed color light beam passes through the polarization beam split prisms 35a to 35c, is incident on the reflective display elements 31a to 31c corresponding to the light beams of each color and is modulated, and after color synthesis by the cross dichroic prism 34, is incident on the zoom lens 310. The zoom lens 310 projects an optical image based on the modulated light modulated by the reflective display elements 31a to 31c onto the screen 305.

[0249] Figure 25 and Figure 26 are external views of a camera 400, which is an imaging device according to an embodiment of the present invention. Figure 25 shows a perspective view of the camera 400 observed from the front side, Figure 26 shows a perspective view of the camera 400 observed from the back side. The camera 400 is detachably mounted with an interchangeable lens 48 and is a mirrorless single-lens digital camera. The interchangeable lens 48 houses a zoom lens 49 according to an embodiment of the present invention in the lens barrel.

[0250] The camera 400 includes a camera body 41, and a shutter button 42 and a power button 43 are provided on the upper surface of the camera body 41. Further, an operation unit 44, an operation unit 45, and a display unit 46 are provided on the back surface of the camera body 41. The display unit 46 displays the captured image and the image existing within the perspective before shooting.

[0251] A photographic aperture for the light from the photographic subject to enter is provided at the center of the front surface of the camera body 41, and a bayonet 47 is provided at a position corresponding to the photographic aperture. The interchangeable lens 48 is mounted on the camera body 41 via the bayonet 47.

[0252] An imaging element 50 is provided in the camera body 41. The imaging element 50 outputs a captured image signal corresponding to the subject image formed by the interchangeable lens 48. As the imaging element 50, for example, a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) can be used. In the camera body 41, a signal processing circuit (not shown) and a recording medium (not shown) are provided. The signal processing circuit processes the captured image signal output from the imaging element 50 to generate an image. The recording medium is used to record the generated image. In the camera 400, by pressing the shutter button 42, a still image or a moving image can be captured, and the image data obtained by the shooting is recorded in the above recording medium.

[0253] As described above, the technology of the present invention has been described by way of embodiments and examples. However, the technology of the present invention is not limited to the above-described embodiments and examples, and various modifications can be made. For example, the radius of curvature, surface interval, refractive index, Abbe number, aspherical coefficient, etc. of each lens are not limited to the values shown in the above examples, and other values can be adopted.

[0254] Moreover, the projection display device related to the technology of the present invention is not limited to the above structure. For example, the optical components and the light valve for beam separation or beam combination can be changed in various ways. The light valve is not limited to the mode in which the light from the light source is spatially modulated by the image display element and output as an optical image based on the image data. It can also be a mode in which the light itself output from the self-luminous image display element is output as an optical image based on the image data. As the self-luminous image display element, for example, an image display element formed by two-dimensionally arranging light-emitting elements such as LEDs (Light Emitting Diodes) or OLEDs (Organic Light Emitting Diodes) can be cited.

[0255] Furthermore, the imaging device related to the technology of the present invention is not limited to the above structure. For example, it can be configured in various ways such as cameras other than mirrorless cameras, film cameras, video cameras, security cameras, and movie cameras.

[0256] Regarding the above embodiments and examples, the following supplementary notes are further disclosed.

[0257] [Supplementary Note 1]

[0258] A zoom lens that sequentially includes a first optical system and a second optical system along the optical path from the telephoto side to the wide-angle side, wherein

[0259] the second optical system forms an intermediate image at a position conjugate to the wide-angle side imaging surface, and the first optical system re-images the intermediate image on the telephoto side imaging surface,

[0260] the lens of the second optical system closest to the telephoto side is a positive lens with a convex surface facing the telephoto side,

[0261] when a group in which the interval in the optical axis direction between adjacent groups changes during zooming is set as one lens group,

[0262] the second optical system sequentially and continuously includes, along the optical path from the telephoto side to the wide-angle side, a first moving lens group with a positive optical power that moves during zooming, a second moving lens group that moves during zooming, and a third moving lens group with a positive optical power that moves during zooming,

[0263] In the entire zoom lens, the lens groups that move during zooming are only the first moving lens group, the second moving lens group, and the third moving lens group.

[0264] [Supplementary Note 2]

[0265] The zoom lens according to Supplementary Note 1, wherein

[0266] The second optical system includes a fixed lens group that is fixed to the reduction-side imaging surface during zooming on the most reduction side.

[0267] [Supplementary Note 3]

[0268] The zoom lens according to Supplementary Note 2, wherein

[0269] The fixed lens group has a positive optical power.

[0270] [Supplementary Note 4]

[0271] The zoom lens according to Supplementary Note 2 or Supplementary Note 3, wherein

[0272] It is configured to be decentered on the reduction side.

[0273] [Supplementary Note 5]

[0274] The zoom lens according to any one of Supplementary Notes 1 to 4, wherein

[0275] The second moving lens group has a negative optical power.

[0276] [Supplementary Note 6]

[0277] The zoom lens according to any one of Supplementary Notes 1 to 5, wherein

[0278] When the focal length of the zoom lens at the wide-angle end is set to fw,

[0279] and the focal length of the first optical system is set to fr1,

[0280] the following conditional expression (1) is satisfied:

[0281] 0.8 < fr1 / |fw| < 5 (1).

[0282] [Supplementary Note 7]

[0283] The zoom lens according to any one of Supplementary Notes 1 to 6, wherein

[0284] The first optical system includes a cemented lens formed by sequentially cementing a positive lens, a negative lens, and a positive lens.

[0285] [Supplementary Note 8]

[0286] The zoom lens according to any one of Appendices 1 to 7, wherein

[0287] The effective diameter of the magnifying side surface of the second lens from the magnifying side of the first optical system at the wide-angle end is smaller than the effective diameter of the magnifying side surface of the lens closest to the reducing side of the first optical system at the wide-angle end.

[0288] [Appendix 9]

[0289] The zoom lens according to any one of Appendices 1 to 8, wherein

[0290] The second moving lens group includes one negative lens and one positive lens.

[0291] [Appendix 10]

[0292] The zoom lens according to any one of Appendices 1 to 9, wherein

[0293] When the focal length of the first moving lens group is set as f1,

[0294] the focal length of the second moving lens group is set as f2,

[0295] and the focal length of the third moving lens group is set as f3,

[0296] the following conditional expressions (2) and (3) are satisfied:

[0297] 0 < f1 / f2 < 0.75 (2),

[0298] 0 < f3 / f2 < 0.75 (3).

[0299] [Appendix 11]

[0300] The zoom lens according to Appendix 10 satisfies the following conditional expressions (2-2) and (3-2):

[0301] 0 < f1 / f2 < 0.5 (2-2),

[0302] 0 < f3 / f2 < 0.5 (3-2).

[0303] [Appendix 12]

[0304] The zoom lens according to any one of Appendices 1 to 11, wherein

[0305] When the focal length of the first moving lens group is set as f1,

[0306] and the focal length of the third moving lens group is set as f3,

[0307] the following conditional expression (4) is satisfied:

[0308] 0.5 < f1 / f3 < 2 (4).

[0309] [Supplementary Note 13]

[0310] The zoom lens according to any one of Supplementary Notes 1 to 12, wherein

[0311] The first moving lens group at the telephoto end is located on the magnification side relative to the first moving lens group at the wide-angle end.

[0312] The second moving lens group at the telephoto end is located on the magnification side relative to the second moving lens group at the wide-angle end.

[0313] The third moving lens group at the telephoto end is located on the magnification side relative to the third moving lens group at the wide-angle end.

[0314] [Supplementary Note 14]

[0315] The zoom lens according to Supplementary Note 13, wherein

[0316] When zooming from the wide-angle end to the telephoto end, the first moving lens group, the second moving lens group, and the third moving lens group always move toward the magnification side respectively.

[0317] [Supplementary Note 15]

[0318] The zoom lens according to any one of Supplementary Notes 1 to 14, wherein

[0319] A first optical path bending member for bending the optical path is disposed in the first optical system.

[0320] [Supplementary Note 16]

[0321] The zoom lens according to any one of Supplementary Notes 1 to 14, wherein

[0322] A second optical path bending member for bending the optical path is disposed on the reduction side relative to the first optical system.

[0323] [Supplementary Note 17]

[0324] The zoom lens according to any one of Supplementary Notes 1 to 14, wherein

[0325] A first optical path bending member for bending the optical path is disposed in the first optical system.

[0326] A second optical path bending member for bending the optical path is disposed on the reduction side relative to the first optical system.

[0327] [Supplementary Note 18]

[0328] The zoom lens according to any one of Appendices 1 to 17, wherein

[0329] the first optical system has a positive optical power and is fixed to the reduced-side imaging surface during zooming,

[0330] the second optical system sequentially includes, along the optical path from the enlarged side to the reduced side, the first moving lens group, the second moving lens group, the third moving lens group, and a fixed lens group that is fixed to the reduced-side imaging surface during zooming.

[0331] [Appendix 19]

[0332] A projection display device including the zoom lens according to any one of Appendices 1 to 18.

[0333] [Appendix 20]

[0334] An imaging device including the zoom lens according to any one of Appendices 1 to 18.

Claims

1. A zoom lens, comprising a first optical system and a second optical system in order from a magnification side to a reduction side along an optical path, wherein: The second optical system forms an intermediate image at a position conjugate with the image plane on the reduction side, and the first optical system re-images the intermediate image on the image plane on the magnification side. The lens closest to the magnification side of the second optical system is a positive lens with a convex surface facing the magnification side. When the interval between the adjacent lens groups in the optical axis direction changes during zooming is set as one lens group, The second optical system includes, in sequence from the magnification side to the reduction side, a first movable lens group with positive optical power that moves when changing magnification, a second movable lens group that moves when changing magnification, and a third movable lens group with positive optical power that moves when changing magnification. In the entire zoom lens, the lens groups that move when changing magnification are only the first moving lens group, the second moving lens group, and the third moving lens group.

2. The zoom lens according to claim 1, wherein: The second optical system includes, on the most reduction side, a fixed lens group fixed to the reduction side imaging surface during magnification change.

3. The zoom lens according to claim 2, wherein: The fixed lens group has positive optical power.

4. The zoom lens according to claim 2 or claim 3, wherein: The reduced side is configured telecentrically.

5. The zoom lens according to claim 1 or claim 2, wherein: The second movable lens group has negative optical power.

6. The zoom lens according to claim 1 or claim 2, wherein: When the focal length of the zoom lens at the wide angle end is set to fw, When the focal length of the first optical system is set to frl, The following condition (1) is satisfied: 0.8<fr1 / |fw|<5 (1).

7. The zoom lens according to claim 1 or claim 2, wherein: The first optical system includes a cemented lens in which a positive lens, a negative lens, and a positive lens are cemented in sequence.

8. The zoom lens according to claim 1 or claim 2, wherein: The effective diameter of the magnification-side surface of the second lens from the magnification side of the first optical system at the wide angle end is smaller than the effective diameter of the magnification-side surface of the lens closest to the reduction side of the first optical system at the wide angle end.

9. The zoom lens according to claim 1 or claim 2, wherein: The second movable lens group includes a negative lens and a positive lens.

10. The zoom lens according to claim 1 or claim 2, wherein: When the focal length of the first movable lens group is set to f1, The focal length of the second movable lens group is set to f2, When the focal length of the third movable lens group is set to f3, The following conditions (2) and (3) are satisfied: 0<|f1 / f2|<0.75 (2), 0<|f3 / f2|<0.75 (3).

11. The zoom lens according to claim 10, which satisfies the following conditional expressions (2-2) and (3-2): 0<|f1 / f2|<0.5 (2-2), 0<|f3 / f2|<0.5 (3-2).

12. The zoom lens according to claim 1 or claim 2, wherein: When the focal length of the first movable lens group is set to f1, When the focal length of the third movable lens group is set to f3, The following condition (4) is satisfied: 0.5 <f1 / f3<2 (4)。 13. The zoom lens according to claim 1 or claim 2, wherein: The first movable lens group at the telephoto end is located closer to the magnification side than the first movable lens group at the wide-angle end. The second movable lens group at the telephoto end is located closer to the magnification side than the second movable lens group at the wide-angle end. The third movable lens group at the telephoto end is located closer to the magnification side than the third movable lens group at the wide-angle end.

14. The zoom lens according to claim 13, wherein: When zooming from the wide-angle end to the telephoto end, the first movable lens group, the second movable lens group, and the third movable lens group are always moved toward the magnification side.

15. The zoom lens according to claim 1 or claim 2, wherein: A first optical path bending component for bending the optical path is arranged in the first optical system.

16. The zoom lens according to claim 1 or claim 2, wherein: A second optical path bending member for bending the optical path is arranged on the reduction side of the first optical system.

17. The zoom lens according to claim 1 or claim 2, wherein: A first optical path bending component for bending the optical path is arranged in the first optical system. A second optical path bending member for bending the optical path is arranged on the reduction side of the first optical system.

18. The zoom lens according to claim 1 or claim 2, wherein: The first optical system has positive refractive power and is fixed to the image plane on the reduction side during magnification change. The second optical system includes, in order from the magnification side to the reduction side along the optical path, the first movable lens group, the second movable lens group, the third movable lens group and a fixed lens group fixed to the imaging surface on the reduction side when changing the magnification. 19 . A projection display device comprising the zoom lens according to claim 1 . 20 . An imaging device comprising the zoom lens according to claim 1 .

Images