Imaging optical system, projection-type display device, and imaging device

Abstract

The invention provides a compact imaging optical system provided with an optical window capable of preventing intrusion of dust and the like, a projection type display device provided with the imaging optical system, and an imaging device provided with the imaging optical system. An image forming optical system capable of forming, on a magnification-side image forming surface, a magnified image obtained by magnifying an image on a reduction-side image forming surface, the image forming optical system including an optical window, a reflective optical system, and a refractive optical system including a plurality of lenses in this order along an optical path from a magnification side to a reduction side, and forming at least two intermediate images. The reflective optical system includes a first reflective surface having a positive refractive power, a second reflective surface having a refractive power, and a third reflective surface having a positive refractive power, in order from an amplification side to a reduction side along an optical path. The center of the enlarged image is positioned at a position displaced in a direction perpendicular to the optical axis with respect to the optical axis of the refractive optical system. The imaging optical system satisfies a preset conditional expression.

Description

Technical Field

[0001] The present invention relates to an imaging optical system, a projection display device, and a camera device. Background Technology

[0002] The following Patent Documents 1 and 2 describe imaging optical systems that can be used in projection display devices and camera devices.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2020-024359

[0004] Patent Document 2: Japanese Patent Application Publication No. 2020-086174 Summary of the Invention

[0005] The present invention provides an imaging optical system having an optical window capable of preventing the intrusion of dust and the like and configured to be small, a projection display device having the imaging optical system, and a camera device having the imaging optical system.

[0006] The first aspect of the present invention is an imaging optical system capable of forming a magnified image on a magnifying side imaging surface, which magnifies an image on a reducing side imaging surface. The system comprises, sequentially along the optical path from the magnifying side to the reducing side, an optical window, a reflecting optical system, and a refractive optical system including multiple lenses. The reflecting optical system, along the optical path from the magnifying side to the reducing side, sequentially includes a first reflecting surface with positive optical power, a second reflecting surface with optical power, and a third reflecting surface with positive optical power. A first intermediate image is formed at a position on the optical path closer to the reducing side than the third reflecting surface and conjugate to the image. A second intermediate image is formed within the reflecting optical system at a position conjugate to the first intermediate image. A magnified image is formed at a position on the optical path closer to the magnifying side than the optical window and conjugate to the second intermediate image. The center of the magnified image is located at a position displaced perpendicular to the optical axis relative to the optical axis of the refractive optical system, and satisfies the following conditions:

[0007] 40°<α<85° (1)

[0008] 0°<θc<35° (2)

[0009] The conditions (1) and (2) are represented.

[0010] Here, the principal ray incident on the center of the magnified image under the condition of maximum displacement is defined as the central principal ray, the incident angle of the central principal ray toward the magnified imaging surface is defined as α, and the incident angle of the central principal ray toward the optical window is defined as θc.

[0011] The second aspect of the present invention, in the imaging optical system of the first aspect, satisfies the condition that the maximum half-angle of the magnification side is set to ω.

[0012] 65°<ω<90° (3)

[0013] The conditional expression (3) is represented.

[0014] In the third aspect of the present invention, in the imaging optical system of the first aspect, the intersection of the central principal ray and the magnified side of the optical window is located on the side of the third reflective surface further away from the second reflective surface than the second reflective surface as a whole in the direction of the optical axis.

[0015] In the fourth aspect of the present invention, in the imaging optical system of the first aspect, the optical window is located further toward the third reflecting surface than the point located on the magnified side of the refractive optical system in the direction of the optical axis.

[0016] The fifth aspect of the present invention, in the imaging optical system of the first aspect, satisfies the following condition: when the distance between the point closest to the optical axis in the optical window and the optical axis is set to hWmin, and the radius of the lens closest to the magnification side of the refractive optical system is set to ra, the following condition is met.

[0017] 0.9 < hWmin / ra < 3 (4)

[0018] The conditional expression (4) is represented.

[0019] In the sixth aspect of the present invention, in the imaging optical system of the first aspect, the optical window is a flat plate. The distance between the point closest to the optical axis on the side of the optical window closest to the reflecting optical system along the optical axis direction and the optical axis is set to hWR. The distance between the point farthest from the optical axis among the points within the effective area of ​​the third reflecting surface and the optical axis is set to hM3. This satisfies...

[0020] 0.5 < hWR / hM3 < 3 (5)

[0021] The conditional expression (5) is represented.

[0022] In the seventh aspect of the present invention, in the imaging optical system of the first aspect, the optical window is a flat plate, and the tilt angle of the optical window relative to the plane perpendicular to the optical axis is set to θwin, which satisfies the following conditions:

[0023] 30°<θwin<85° (6)

[0024] The conditional expression (6) is represented.

[0025] In the eighth aspect of the present invention, in the imaging optical system of the first aspect, the optical window is a flat plate, the distance between the center of the image and the optical axis is set as Δs, the length of the shorter side of the image is set as ImS, the minimum value of V defined by V = Δs / ImS is set as Vmin, the length of the longer side of the rectangle circumscribed by the optical window is set as WL, the distance from the first reflecting surface to the optical axis of the magnified image is set as Dsc, the length of the longer side of the magnified image is set as PrL, and the length of the longer side of the image is set as ImL. When these conditions are met, the following conditions are satisfied:

[0026] 0<(Vmin-0.5)×WL×(Dsc / PrL) / ImL<1.2 (7)

[0027] The conditional expression (7) is represented.

[0028] In the ninth aspect of the present invention, in the imaging optical system of the first aspect, the optical window is a flat plate, and the length of the long side of the rectangle circumscribed with the optical window is set to WL, and the length of the short side of the rectangle is set to WS, which satisfies the following condition:

[0029] 2 < WL / WS < 10 (8)

[0030] The conditional expression (8) is represented.

[0031] In the tenth aspect of the present invention, in the imaging optical system of the first aspect, the optical window is a flat plate, the distance between the center of the image and the optical axis is set as Δs, the length of the shorter side of the image is set as ImS, the minimum value of V defined by V = Δs / ImS is set as Vmin, the length of the longer side of the rectangle circumscribed with the optical window is set as WL, and the length of the shorter side of the rectangle is set as WS, thus satisfying the following conditions:

[0032] 0.5<(Vmin-0.5)×WL / WS<1.5 (9)

[0033] The conditional expression (9) is represented.

[0034] In the eleventh aspect of the present invention, in the imaging optical system of the first aspect, the optical window has curvature in the long side direction of the image.

[0035] In the imaging optical system of the 11th embodiment of the present invention, the 12th embodiment satisfies the following condition: When the length of the long side of the projection of the rectangle circumscribed by the optical window on the plane perpendicular to the direction from the center of curvature toward the origin used in the formula defining the surface of the optical window is set to WpL, and the length of the short side of the projection is set to WpS, the following condition is met:

[0036] 1 < WpL / WpS < 3 (10)

[0037] The conditional expression (10) is represented.

[0038] In the 13th aspect of the present invention, in the imaging optical system of the 11th aspect, the optical window is a cylindrical lens.

[0039] In the imaging optical system of the 13th embodiment, the 14th embodiment of the present invention has a cylindrical surface on the reduced side of the optical window. The length of the long side of the projection of the rectangle circumscribed by the optical window onto the surface perpendicular to the direction from the center of curvature toward the origin used in the formula defining the surface of the optical window is set to WpL. The radius of curvature of the cylindrical surface in the direction perpendicular to the generatrix of the cylindrical surface is set to Rcy. This satisfies...

[0040] 1 < WpL / Rcy < 2 (11)

[0041] The conditional expression (11) is represented.

[0042] In the imaging optical system of the 13th embodiment of the present invention, the 15th embodiment satisfies the following condition: the surface of the reduced-size side of the optical window is cylindrical; the combined focal length of the reflective optical system and the refractive optical system is set to fRL; and the radius of curvature of the cylindrical surface in the direction perpendicular to the generatrix of the cylindrical surface is set to Rcy.

[0043] 0 < fRL / Rcy < 0.1 (12)

[0044] The conditional expression (12) is represented.

[0045] In the imaging optical system of the 11th embodiment of the present invention, the optical window has a complex tortuous surface shape.

[0046] In the imaging optical system of the 11th embodiment of the present invention, the magnifying side surface and the reducing side surface of the optical window are spherical.

[0047] In the 18th aspect of the present invention, in the imaging optical system of the 11th aspect, the optical window has an aspherical shape.

[0048] The 19th aspect of the present invention is a projection-type display device comprising the imaging optical system described in any one of the 1st to 18th aspects.

[0049] The 20th aspect of the present invention is a camera device comprising the imaging optical system described in any one of the 1st to 18th aspects.

[0050] In this specification, "including" and "including" mean that, in addition to the constituent elements listed, it may also include lenses that do not substantially have optical power; optical elements other than lenses such as apertures, masks, filters, cover glass, plane mirrors and prisms; and mechanism parts such as lens flanges, lens barrels, imaging elements and hand shaking correction mechanisms.

[0051] Unless otherwise specified, the sign and surface shape of optical power for aspherical optical components are considered in the paraxial region.

[0052] Invention Effects

[0053] According to the present invention, it is possible to provide an imaging optical system having an optical window capable of preventing the intrusion of dust and the like and configured to be small, a projection display device having the imaging optical system, and a camera device having the imaging optical system. Attached Figure Description

[0054] Figure 1 The imaging optical system corresponding to Embodiment 1 is shown in a cross-sectional view of the structure and beam of the imaging optical system according to one embodiment.

[0055] Figure 2 This is a diagram schematically illustrating the usage state of a projection-type display device according to one embodiment.

[0056] Figure 3 It is a cross-sectional view showing the positional relationship between the imaging optical system, the display surface, and the magnified image.

[0057] Figure 4 It is a diagram showing the positional relationship between the optical axis and the center of the image.

[0058] Figure 5 It is a diagram used to illustrate the notation for each conditional expression.

[0059] Figure 6 It is a diagram used to illustrate the notation for each conditional expression.

[0060] Figure 7 This is a schematic diagram of an imaging optical system including a rectangular and flat optical window.

[0061] Figure 8A This is a diagram showing an example of a beam cross-section and an optical window.

[0062] Figure 8B It means and Figure 8A A diagram of a rectangle circumscribed outside the optical window.

[0063] Figure 9 This is a schematic diagram of an imaging optical system including an optical window with curvature.

[0064] Figure 10 It is a diagram showing the projection of a rectangle tangent to the optical window.

[0065] Figure 11 This is a diagram showing an example of a beam cross-section and an optical window.

[0066] Figure 12A This is a diagram showing an example of a beam cross-section and an optical window.

[0067] Figure 12B It means and Figure 12A A diagram of a rectangle circumscribed outside the optical window.

[0068] Figure 13A This is a diagram showing an example of a beam cross-section and an optical window.

[0069] Figure 13B It means and Figure 13A A diagram of a rectangle circumscribed outside the optical window.

[0070] Figure 14 This is a cross-sectional view showing the structure and beam of the imaging optical system of Embodiment 2.

[0071] Figure 15 This is a cross-sectional view showing the structure and beam of the imaging optical system of Embodiment 3.

[0072] Figure 16 This is a cross-sectional view showing the structure and beam of the imaging optical system of Embodiment 4.

[0073] Figure 17 This is a cross-sectional view showing the structure and beam of the imaging optical system of Embodiment 5.

[0074] Figure 18 This is a cross-sectional view showing the structure and beam of the imaging optical system of Embodiment 6.

[0075] Figure 19 This is a cross-sectional view showing the structure and beam of the imaging optical system of Embodiment 7.

[0076] Figure 20 This is a cross-sectional view showing the structure and beam of the imaging optical system of Embodiment 8.

[0077] Figure 21 This is a cross-sectional view showing the structure and beam of the imaging optical system of Embodiment 9.

[0078] Figure 22 This is a cross-sectional view showing the structure and beam of the imaging optical system of Embodiment 10.

[0079] Figure 23 This is a cross-sectional view showing the structure and beam of the imaging optical system of Embodiment 11.

[0080] Figure 24 This is a cross-sectional view showing the structure and beam of the imaging optical system of Embodiment 12.

[0081] Figure 25 This is a cross-sectional view showing the structure and beam of the imaging optical system of Embodiment 13.

[0082] Figure 26 This is a cross-sectional view showing the structure and beam of the imaging optical system of Embodiment 14.

[0083] Figure 27This is a cross-sectional view showing the structure and beam of the imaging optical system of Embodiment 15.

[0084] Figure 28 This is a cross-sectional view showing a modified example of housing the imaging optical system of Embodiment 15 inside the frame.

[0085] Figure 29 This is a schematic structural diagram of a projection-type display device according to one embodiment.

[0086] Figure 30 This is a schematic structural diagram of a projection-type display device according to another embodiment.

[0087] Figure 31 This is a schematic structural diagram of a projection-type display device according to another embodiment.

[0088] Figure 32 This is a schematic structural diagram of a projection-type display device according to another embodiment.

[0089] Figure 33 This is a perspective view of the front side of a camera device according to one embodiment.

[0090] Figure 34 yes Figure 33 A perspective view of the rear side of the camera device shown.

[0091] Symbol Explanation

[0092] 1-Imaging optical system; 2-Display element; 2a-Display surface; 3-Projection type display device; 4-Image; 4c-Center; 6-Magnified image; 6a-Dot; 6b-Dot; 6c-Center; 9-Frame; 10-Imaging optical system; 11a~11c-Transmissive display element; 12-Dialectical mirror; 13-Dialectical 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-Polarization separation prism; 31a~31c-Reflective display element; 32-Dialectical mirror; 33-Dialectical mirror. 34-Cross-type dichroic prism, 35a~35c-Polarization-separating prism, 38-Total reflection mirror, 41-Light source, 42-Color wheel, 43-Light guiding optical system, 44-DMD element, 45-TIR prism, 46-Imaging optical system, 100-Projection display device, 105-Screen, 200-Projection display device, 205-Screen, 210-Imaging optical system, 215-Light source, 300-Projection display device, 305-Screen, 310-Imaging optical system, 315-Light source, 400-Projection display device, 405-Screen, 800-Camera, 801-Imaging optical system, 820-Interchangeable lens 831-Camera body, 832-Shutter button, 833-Power button, 834-Operation unit, 835-Operation unit, 836-Display unit, 837-Mount, 838-Image sensor, AX-Optical axis, Cray-Central principal ray, Dsc-Distance, GL-Refractive optical system, GR-Reflective optical system, hM3-Distance, hWR-Distance, hWmin-Distance, IC-Image ring, ImL-Length, ImS-Length, L1~L14-Lens, LF1-Beam cross-section, LF2-Beam cross-section, LF3-Beam cross-section, LFa-Beam, LFb-Beam, LFc-Beam, M1-First intermediate image M2 - Second intermediate image, P1 - Intersection point, P2 - Point, PP - Optical component, PrL - Length, R1 - First reflecting surface, R2 - Second reflecting surface, R3 - Third reflecting surface, ra - Radius, RecW1 - Rectangle, RecW3 - Rectangle, RecW4 - Rectangle, Scr - Screen, St - Aperture stop, W - Optical window, W1 - Optical window, W2 - Optical window, W3 - Optical window, W4 - Optical window, W5 - Optical window, W5p - Projection, WL - Length, WpL - Length, WpS - Length, WS - Length, α - Angle of incidence, θc - Angle of incidence, θwin - Tilt angle, Δs - Displacement, ω - Maximum half angle of view. Detailed Implementation

[0093] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0094] Figure 1The diagram shows a cross-sectional view of the structure and beam of an imaging optical system 1 according to an embodiment of the present invention, along a section containing the optical axis AX. Figure 1 The structural example shown corresponds to Embodiment 1 described later.

[0095] In the following description, the direction of the optical axis AX of the imaging optical system 1 is set as the Z-axis direction, and the direction perpendicular to the Z-axis direction is set as follows: Figure 1 The vertical direction is defined as the Y-axis, and the direction perpendicular to both the Z-axis and Y-axis is defined as the X-axis. The X-axis is perpendicular to... Figure 1 The direction perpendicular to the paper. Regarding the Y-axis direction, Figure 1 The upward direction is set to the +Y axis direction, and the downward direction is set to the -Y axis direction.

[0096] The imaging optical system 1 can also be configured as a projection optical system mounted on a projection-type display device and having a display element arranged on the reduced-size imaging surface, or as a camera optical system mounted on a digital camera and having an imaging element arranged on the reduced-size imaging surface. Hereinafter, the imaging optical system 1 will be described as being used as a projection optical system.

[0097] Figure 2 The diagram schematically illustrates the usage state of a projection-type display device 3 according to an embodiment of the present invention. The projection-type display device 3 internally includes an imaging optical system 1 and a display element 2 acting as a light valve. Figure 2 The image optics system 1 and the display element 2 are conceptually shown in the image.

[0098] Display element 2 is an element that outputs an optical image, which is displayed as an image on the display surface 2a of display element 2. As display element 2, for example, a liquid crystal display element or an image display element such as a DMD (Digital Micromirror Device: registered trademark) can be used.

[0099] Imaging optical system 1 magnifies the image on display surface 2a and projects the magnified image 6 onto screen Scr. The image displayed by display element 2 and the magnified image 6 are optically conjugate. Optically, the image displayed by display element 2 can be considered as a reduction-side conjugate image, and the magnified image 6 can be considered as a magnification-side conjugate image. Display surface 2a and screen Scr are located in an optically conjugate position. Display surface 2a is an example of the "reduction-side imaging surface" of the present invention, and screen Scr is an example of the "magnification-side imaging surface" of the present invention.

[0100] In addition, in this specification, "screen" refers to the object on which the projected image formed by the imaging optical system 1 is projected. For example, besides a dedicated screen, a screen can also be the wall, floor, ceiling, or exterior wall of a building.

[0101] exist Figure 2In the magnified image 6, points 6a at the upper corner, 6c at the center, and 6b directly below the center 6c are marked with symbols. Figure 1 In the diagram, the beams with the largest viewing angle, LFa, the beam with the middle viewing angle, LFc, and the beam with the smallest viewing angle are shown. For example... Figure 3 As shown, in magnified image 6, beam LFa converges at point 6a, beam LFc converges at center 6c, and beam LFb converges at point 6b. Figure 3 The diagram shows the structure of the imaging optical system 1, display surface 2a, magnified image 6, and screen Scr on a cross section containing the optical axis AX.

[0102] Figure 1 The imaging optical system 1 includes, from the magnification side to the reduction side along the optical path, an optical window W, a reflective optical system GR, and a refractive optical system GL including multiple lenses.

[0103] In addition, in this specification, "magnification side" refers to the screen Scr side in the optical path, and "reduction side" refers to the display surface 2a side in the optical path. In this specification, "magnification side" and "reduction side" are defined along the optical path. For example, in an imaging optical system forming a curved optical path, "reflecting surface A is located on the magnification side closer than reflecting surface B" has the same meaning as "reflecting surface A is located on the optical path on the magnification side closer than reflecting surface B." In an imaging optical system forming a curved optical path, "closest to the magnification side" indicates the side closest to the magnification side as arranged in the optical path, not the side closest to the screen Scr in distance. Hereinafter, to avoid lengthy explanations, "in sequence along the optical path from the magnification side to the reduction side" will sometimes be written as "in sequence from the magnification side to the reduction side."

[0104] The reflective optical system GR includes, along the optical path from the magnification side to the reduction side, a first reflecting surface R1 with positive optical power, a second reflecting surface R2 with optical power, and a third reflecting surface R3 with positive optical power.

[0105] Since the reflecting surface itself does not produce chromatic aberration, by arranging three reflecting surfaces on the magnification side within the imaging optical system 1, chromatic aberration throughout the optical system can be reduced. Furthermore, since the optical path length is easily ensured through three reflections, a wide-angle and compact design can be achieved, thereby reducing the optical power of each optical component. As a result, the burden associated with aberration correction in the refractive optical system GL can be reduced, thus reducing the number of lenses in the refractive optical system GL and contributing to miniaturization.

[0106] The first reflecting surface R1 and the third reflecting surface R3 can also be formed in the same component and have the same surface shape. In this case, the time and labor required for relative alignment of the reflecting surfaces during manufacturing can be reduced, thus helping to reduce costs. Furthermore, performance degradation caused by relative positional misalignment of the reflecting surfaces during manufacturing can be suppressed, thus helping to ensure performance.

[0107] Furthermore, "formed in the same component and having the same surface shape" refers to continuous surfaces that have shapes formed based on the same design data. "The same design data" means that, in the case of a spherical shape, the radius of curvature is the same; in the case of an aspherical shape, the aspherical type and aspherical coefficient are the same; and in the case of a freeform surface shape, the freeform type and freeform coefficient are the same.

[0108] As an example, Figure 1 The first reflecting surface R1, the second reflecting surface R2, and the third reflecting surface R3 are composed of reflecting mirrors. As an example, Figure 1 The refractive optical system GL, from the magnification side to the reduction side, includes lenses L1 to L8, aperture stop St, and lenses L9 to L14. Figure 1 The aperture stop St shown does not represent its size or shape, but rather its position along the optical axis. As an example, Figure 1 The refractive optical system GL and the reflective optical system GR share a common optical axis AX. This coaxial system structure is easier to assemble compared to structures that are not coaxial. Furthermore, when the optical surfaces of the optical components have a rotational symmetry axis, that rotational symmetry axis corresponds to the optical axis AX.

[0109] exist Figure 1 The diagram shows an example of a display surface 2a in which an optical component PP and a display element 2 are arranged on a smaller side than the imaging optical system 1. The optical component PP is assumed to include a filter, cover glass, and color-combining prism, etc. The optical component PP is a component without optical power, or its structure may be omitted. Figure 2 The illustration of the optical component PP is omitted.

[0110] exist Figure 1 In the imaging optical system 1, a light beam from the display surface 2a toward the magnification side passes through the optical component PP and the refractive optical system GL, and then connects to the first intermediate image M1. The beam then strikes and is reflected by the third reflecting surface R3, strikes and is reflected by the second reflecting surface R2, and then connects to the second intermediate image M2. Finally, the beam strikes and is reflected by the first reflecting surface R1, passes through the optical window W, and is projected onto the screen Scr (…). Figure 1 A projected image is formed on (not shown in the figure).

[0111] Imaging optical system 1 has a curved optical path that reflects the beam three times, therefore, as Figure 1 As shown, the light beam becomes dense. For example, if we assume a plane perpendicular to the optical axis AX passing through the first intermediate image M1, the beam passes through this plane four times. If dust or other contaminants enter this optical path, the intense light may encounter the dust, potentially causing problems. Therefore, in the imaging optical system 1, the optical window W is configured to be positioned on the side closest to the magnification.

[0112] The optical window W comprises a refractive material that is translucent. Translucency, for example, refers to a transmittance of 80% or more of the wavelength of a light beam. The optical window W differs from a simple opening that is open to the outside. By arranging a refractive material that functions as a window on the magnification side of the imaging optical system 1, the intrusion of dust and other contaminants from the outside can be prevented. Furthermore, the area referred to as the "optical window" in this invention is the area through which light can pass, excluding mechanical components such as window frames.

[0113] As an example, Figure 1 In the example, the optical window W is a flat plate with a rectangular shape. However, the optical window of the present invention is not limited to this. Figure 1 Examples can be made in various ways. The detailed structure of the optical window of this invention will be described in detail later.

[0114] In the imaging optical system 1, at least two intermediate images, a first intermediate image M1 and a second intermediate image M2, are formed as conjugate images to the image displayed on the display surface 2a. By forming intermediate images, the focal length of the imaging optical system 1 can be shortened, making it suitable for wide-angle viewing. Furthermore, forming at least two intermediate images facilitates the realization of an ultra-wide-angle optical system. Figure 1 In the diagram, the first intermediate image M1 and the second intermediate image M2 are conceptually represented by thick dashed lines. Figure 1 The shapes of the first intermediate image M1 and the second intermediate image M2 shown are not necessarily accurate.

[0115] The first intermediate image M1 is formed on the optical path closer to the reduction side than the third reflecting surface R3 and is conjugate to the image plane on the reduction side. Preferably, the first intermediate image M1 is formed on the optical path between the third reflecting surface R3 and the refractive optical system GL. In this way, if the first intermediate image M1 is not formed within the refractive optical system GL, the projection of lens scratches and / or dust can be suppressed, thus facilitating the formation of a good projected image.

[0116] The second intermediate image M2 is formed within the reflective optical system GR and at a position conjugate to the first intermediate image M1. Furthermore, the magnified image 6 is formed at a position conjugate to the second intermediate image M2. "Within the reflective optical system GR" refers to the optical path from the surface of the reflective optical system GR closest to the magnification side to the surface of the reflective optical system GR closest to the reduction side. By forming the second intermediate image M2 within the reflective optical system GR, it is possible to suppress the projection of lens scratches and / or dust, thus facilitating the formation of a good projected image.

[0117] The second intermediate image M2 is preferably formed in the optical path between the first reflecting surface R1 and the second reflecting surface R2. In this case, scratches and / or dust on the reflecting surfaces can be suppressed from being projected, thus facilitating the formation of a good projected image.

[0118] The intermediate images formed on the magnification side, which is closer to the refracting optical system GL, are preferably only two: the first intermediate image M1 and the second intermediate image M2. In this case, it is advantageous to realize a wide-angle optical system and to make it compact. Furthermore, for the purpose of miniaturization, the intermediate images formed by the imaging optical system 1 can also be configured to be only two: the first intermediate image M1 and the second intermediate image M2.

[0119] Alternatively, the device can be configured such that no refractive element is disposed in the optical path between the first reflecting surface R1 and the second reflecting surface R2. When a refractive element is disposed in the optical path between the first reflecting surface R1 and the second reflecting surface R2, it may result in scratches and / or dust from the refractive element being projected, but this problem can be avoided by not disposing of the refractive element. Furthermore, this simplifies the device structure. Similarly, the device can also be configured such that no refractive element is disposed in the optical path between the second reflecting surface R2 and the third reflecting surface R3.

[0120] In this example, the center of the image displayed on display surface 2a is not located on the optical axis AX, but is located at a position that is displaced relative to the optical axis AX in a direction perpendicular to the optical axis AX, i.e., the -Y axis direction. Figure 4 The diagram shows the approximate positional relationship between the optical axis AX on the image ring IC on the reduced side of the imaging optical system 1 and the image 4 displayed on the display surface 2a. In this example, the long side direction of the image 4 is the X-axis direction, and the short side direction is the Y-axis direction. Hereinafter, the displacement amount, i.e., the distance between the center 4c of the image 4 and the optical axis AX, will be referred to as the displacement amount Δs. For example, when the imaging optical system 1 and the display element 2 are configured to be able to move relative to each other in a direction perpendicular to the optical axis AX, the displacement amount Δs can be variable.

[0121] In the state where the center 4c of image 4 is located at a position displaced from the optical axis AX towards the -Y axis, as shown... Figure 3As shown, the center 6c of the magnified image 6 projected onto the screen Scr is not located on the optical axis AX of the imaging optical system 1, but rather at a position displaced relative to the optical axis AX in a direction perpendicular to the optical axis AX, i.e., the +Y axis direction. This structure allows the magnified image 6 to be positioned higher than the imaging optical system 1. This is effective, for example, when the projection display device 3 is placed on the floor and the projected image is projected onto a screen higher than the floor.

[0122] Furthermore, the center of the image displayed on display surface 2a is the intersection of the diagonals of the rectangle when the image is rectangular, the center of the circle when the image is circular, and the intersection of the diagonals of the trapezoid when the image is trapezoidal. Similarly, the center of the magnified image, which is a projected image, is the intersection of the diagonals of the rectangle when the magnified image is rectangular, the center of the circle when the magnified image is circular, and the intersection of the diagonals of the trapezoid when the magnified image is trapezoidal.

[0123] Hereinafter, the principal ray incident on the center 6c of the magnified image 6 under the condition that the displacement Δs is at its maximum is called the central principal ray Cray. The central principal ray Cray is the ray contained in the beam LFc. As an example, in Figure 3 and Figure 5 The central principal ray (Cray) is shown in the image. Figure 5 The middle shows Figure 1 The structure on the cross section containing the optical axis AX of the imaging optical system 1. Figure 5 In, with Figure 1 In comparison, the illustration omits some symbols.

[0124] like Figure 5 As shown, the intersection point P1 of the central principal ray Cray and the magnified side of the optical window W is preferably located on the side of the third reflecting surface R3, which is closer to the second reflecting surface R2 than the second reflecting surface R2 as a whole, in the direction of the optical axis AX. In this case, it is beneficial to the miniaturization of the optical window W.

[0125] Furthermore, in order to miniaturize the optical window W, such as Figure 6 As shown, the preferred optical window W is located closer to the third reflecting surface R3 than point P2, which is located on the magnified side of the refractive optical system GL in the direction of the optical axis AX. Figure 6 The middle shows Figure 1 The structure on the cross section containing the optical axis AX of the imaging optical system 1. Figure 6 In order to facilitate understanding, and Figure 1 Compared to the illustrations that omit some symbols and the illustrations of beams. Additionally, in Figure 6In the example, since the surface of the refractive optical system GL that is closest to the magnification side is convex, the vertex of this convex surface (the point on the optical axis AX of the convex surface) becomes point P2. However, if the surface of the refractive optical system GL that is closest to the magnification side is concave, then it is not the point on the optical axis AX, but rather a point on the periphery of the concave surface that can become point P2 located on the closest side of the refractive optical system GL.

[0126] Next, preferred and possible structures related to the conditional expressions of the imaging optical system of the present invention will be described. Hereinafter, to avoid lengthy explanations, "the imaging optical system of the present invention" will sometimes be simply referred to as "imaging optical system". Furthermore, in the descriptions related to the following conditional expressions, to avoid lengthy explanations, the same notations will be used for the same definitions, and repeated explanations of the notations will be omitted.

[0127] When the incident angle of the central principal ray Cray toward the magnified imaging surface is set to α, the imaging optical system preferably satisfies the following condition (1). In this example, the screen Scr corresponds to the magnified imaging surface. As an example, in Figure 3 The above-mentioned incident angle α is shown in the figure. Figure 3 In the diagram, the plane perpendicular to the screen Scr is represented by a dashed line. In this example, the incident angle α is the angle formed between the central principal ray Cray and the plane perpendicular to the magnified imaging plane. By ensuring that the corresponding value of condition (1) is not below the lower limit, it is beneficial to widen the field of view of the imaging optical system. By ensuring that the corresponding value of condition (1) is not above the upper limit, it is beneficial to project the image onto the plane without distortion.

[0128] 40°<|α|<85° (1)

[0129] To obtain better properties, the lower limit of condition (1) is more preferably set to 50°, and even more preferably to 60°. To obtain better properties, the upper limit of condition (1) is more preferably set to 80°.

[0130] When the incident angle of the central principal ray Cray onto the optical window W is set to θc, the imaging optical system preferably satisfies the following condition (2). As an example, in Figure 5 The above incident angle θc is shown in the figure. Figure 5 In the diagram, the plane perpendicular to the optical window W is represented by a dashed line. Regarding the lower limit of condition (2), since |θc| is an absolute value, it is 0° < |θc|. By ensuring that the corresponding value of condition (2) does not exceed the upper limit, it is possible to suppress the enlargement of the optical window W, especially to suppress the excessive length of the short side of the optical window W.

[0131] 0°<|θc|<35° (2)

[0132] To obtain better properties, the upper limit of condition (2) is more preferably set to 30°, and even more preferably set to 25°.

[0133] When the maximum half-angle of the magnification side is set to ω, the imaging optical system preferably satisfies the following condition (3). ω is the largest angle among the angles formed by the principal ray from the surface closest to the magnification side of the imaging optical system toward the imaging surface on the magnification side and the optical axis AX. In this example, it corresponds to the angle formed by the principal ray of the beam LFa and the optical axis AX. As an example, in Figure 5 The maximum half-angle view ω is shown above. By ensuring that the corresponding value of condition (3) is not below the lower limit, a wide-angle optical system can be achieved. By ensuring that the corresponding value of condition (3) is not above the upper limit, light blocking caused by the relatively fine unevenness of the wall surface of the screen Scr can be suppressed.

[0134] 65°<ω<90° (3)

[0135] To obtain better properties, the lower limit of condition (3) is more preferably set to 70°, and even more preferably to 75°.

[0136] The imaging optical system preferably satisfies the following condition (4). Here, the distance between the point closest to the optical axis AX in the optical window W and the optical axis AX is set as hWmin. The radius of the lens on the magnifying side of the refractive optical system GL is set as ra. As an example, in Figure 6 The distance hWmin and radius ra are shown above. In addition, when the shape of the lens is not circular, the maximum value of the lens radius is set as ra. By ensuring that the corresponding value of condition (4) is not below the lower limit, interference between the optical window W and the refractive optical system GL can be easily prevented. By ensuring that the corresponding value of condition (4) is not above the upper limit, it is beneficial to miniaturize the optical window W.

[0137] 0.9 < hWmin / ra < 3 (4)

[0138] To obtain better properties, the lower limit of condition (4) is more preferably set to 1. To obtain better properties, the upper limit of condition (4) is more preferably set to 2.7, and even more preferably set to 2.5.

[0139] The optical window of the present invention can also be configured as a flat plate. In this case, manufacturing becomes easier and it is advantageous for reducing costs.

[0140] When the optical window is a flat plate, the imaging optical system preferably satisfies the following condition (5). Here, the distance between the point closest to the optical axis AX and the optical axis AX at the point on the side of the optical window closest to the optical system GR in the direction of the optical axis AX is defined as hWR. The distance between the point farthest from the optical axis AX and the optical axis AX in the effective area of ​​the third reflecting surface R3 is defined as hM3. Here, "effective area" refers to the mirror surface and is a region with a reflectivity of 80% or more for the wavelength of the light beam. As an example, in Figure 6 The distances hWR and hM3 mentioned above are shown in the figure. By ensuring that the corresponding value of condition (5) is not below the lower limit, it is easy to prevent interference between the beam toward the third reflecting surface R3 and the optical window W. By ensuring that the corresponding value of condition (5) is not above the upper limit, it is beneficial to miniaturize the optical window W.

[0141] 0.5 < hWR / hM3 < 3 (5)

[0142] To obtain better properties, the lower limit of condition (5) is more preferably set to 0.7. To obtain better properties, the upper limit of condition (5) is more preferably set to 2, and even more preferably set to 1.5.

[0143] When the optical window is a flat plate, the imaging optical system preferably satisfies the following condition (6). Here, the tilt angle of the optical window relative to the plane perpendicular to the optical axis AX is set as θwin. As an example, in Figure 6 The tilt angle 0win mentioned above is shown in the figure. Figure 6 In the diagram, the plane perpendicular to the optical axis AX is represented by a dashed line. By ensuring that the corresponding value of condition (6) is not below the lower limit, it is easy to construct a structure capable of handling beams with high viewing angles and to achieve miniaturization of the optical window W. By ensuring that the corresponding value of condition (6) is not above the upper limit, it is easy to construct a structure capable of handling beams with low viewing angles and to achieve miniaturization of the optical window W.

[0144] 30°<θwin<85° (6)

[0145] To obtain better properties, the lower limit of condition (6) is more preferably set to 40°, and even more preferably to 50°. To obtain better properties, the upper limit of condition (6) is more preferably set to 82°, and even more preferably to 80°.

[0146] When the optical window is a flat plate, the imaging optical system preferably satisfies the following condition (7). Here, the distance, i.e., the displacement, between the center 4c of image 4 and the optical axis AX is set as Δs. The length of the short side of image 4 is set as ImS. The minimum value of V, defined by V = Δs / ImS, is set as Vmin. The length of the long side of the rectangle circumscribed with the optical window is set as WL. The distance from the first reflecting surface R1 to the optical axis AX of magnified image 6 is set as Dsc. The length of the long side of magnified image 6 is set as PrL. The length of the long side of image 4 is set as ImmL. As described above, for example, when the imaging optical system 1 and the display element 2 are configured to be able to move relative to each other in a direction perpendicular to the optical axis AX, the displacement Δs is variable, and therefore V is also variable. Vmin is the minimum value among the possible values ​​of V. By satisfying condition (7), it is beneficial to miniaturize the optical window.

[0147] 0<(Vmin-0.5)×WL×(Dsc / PrL) / ImL<1.2 (7)

[0148] To obtain better properties, the upper limit of condition (7) is more preferably set to 1, and even more preferably set to 0.8.

[0149] Furthermore, when the optical window is rectangular, the length of the longer side of the rectangle is WL. When the image displayed on the display surface 2a is not a rectangle, the length of the shorter side of the rectangle tangent to the image is set to ImS, and the length of the longer side is set to ImL. When the magnified image projected onto the screen is not a rectangle, the length of the longer side of the rectangle tangent to the magnified image is set to PrL.

[0150] As an example, in Figure 4 The displacement Δs, length ImS, and length ImL are shown above. As an example, in... Figure 3 The distance Dsc mentioned above is shown in the figure. Figure 2 The above length PrL is shown in the figure. Figure 7 The length WL mentioned above is shown in the figure.

[0151] exist Figure 7 The text shows from Figure 1 Observing from above downwards along the normal direction of the optical window W Figure 1 A schematic structural diagram of the imaging optical system, optical component PP, and display element 2. Figure 7 The diagram schematically shows the reflective optical system GR, the refractive optical system GL, the optical component PP, and the display element 2. Figure 7 The long side of the optical window W is in the same X-axis direction as the long side of the image displayed by the display element 2. Figure 7 The figure shows the length of the long side WL and the length of the short side WS of the optical window W.

[0152] exist Figure 7 In the diagram, the imaging of the surface of the optical window W is represented by the cross section of the beam, i.e., the beam cross section LF1, marked with a slash. Hereinafter, for ease of explanation, the cross section of the beam used for imaging the surface of the optical window will be referred to as the "beam cross section". Figure 7 The optical window W is a rectangle containing the size of the beam cross section LF1.

[0153] However, in the technology of this invention, the shape of the optical window is not limited to a rectangle and can be arbitrarily set. For example, for Figure 7 The beam cross section LF1 can also be used. Figure 8A The trapezoidal optical window W1 is shown. Figure 8A The beam cross section LF1 and Figure 7 The beam cross-section LF1 has the same shape. Figure 8B In the diagram, a dashed line represents the rectangle RecW1 circumscribed by the optical window W1. The dashed line also represents the length of the longer side WL and the length of the shorter side WS of rectangle RecW1. Figure 7 Compared to the optical window W, Figure 8A The optical window W1 is beneficial for miniaturization and weight reduction of the optical window, and also helps to block stray light from the outside.

[0154] When the optical window is a flat plate, the imaging optical system preferably satisfies the following condition (8). Here, the length of the short side of the rectangle circumscribed with the optical window is set as WS. By ensuring that the corresponding value of condition (8) is not below the lower limit, it is beneficial to widen the angle of the imaging optical system. By ensuring that the corresponding value of condition (8) is not above the upper limit, it is beneficial to miniaturize the long side of the optical window.

[0155] 2 < WL / WS < 10 (8)

[0156] To obtain better properties, the lower limit of condition (8) is more preferably set to 3, and even more preferably set to 4. To obtain better properties, the upper limit of condition (8) is more preferably set to 9, and even more preferably set to 8.

[0157] When the optical window is a flat plate, the imaging optical system preferably satisfies the following condition (9). By ensuring that the corresponding value of condition (9) is not below the lower limit, it is beneficial to widen the angle of the imaging optical system. By ensuring that the corresponding value of condition (9) is not above the upper limit, it is beneficial to miniaturize the long side of the optical window.

[0158] 0.5<(Vmin-0.5)×WL / WS<1.5 (9)

[0159] To obtain better properties, the lower limit of condition (9) is more preferably set to 0.6, and even more preferably to 0.7. To obtain better properties, the upper limit of condition (9) is more preferably set to 1.3, and even more preferably to 1.1.

[0160] The optical window of the present invention can also be configured to have curvature. If the optical window is configured to have curvature, it can help to miniaturize the optical window. For example, if the optical window is configured to have curvature in the long side direction of the image displayed on the display element 2, miniaturization in the long side direction of the optical window can be achieved. As an example, in Figure 9 The diagram shows a perspective view of the structure of an imaging optical system using an optical window W5 with curvature along the long side of the image displayed by display element 2. Figure 9 In this context, the direction of the longer side of the above image is defined as the X direction. Figure 9 The diagram illustrates each of the constituent elements.

[0161] When the optical window has curvature along the long side of the image displayed by display element 2, the imaging optical system preferably satisfies the following conditional expression (10). Here, the length of the long side of the projection of the rectangle circumscribed by the optical window on the plane perpendicular to the direction from the center of the curvature of the optical window toward the origin used in the expression that defines the surface of the optical window is set as WpL, and the length of the short side of the projection is set as WpS. In addition, when the magnification side and the reduction side of the optical window have curvature, WpL and WpS are set to values ​​related to the magnification side of the optical window. By ensuring that the corresponding value of conditional expression (10) is not below the lower limit value, it is beneficial to widen the angle of the imaging optical system. By ensuring that the corresponding value of conditional expression (10) is not above the upper limit value, it is beneficial to miniaturize the long side of the optical window.

[0162] 1 < WpL / WpS < 3 (10)

[0163] To obtain better properties, the lower limit of condition (10) is more preferably set to 1.2, and even more preferably to 1.5. To obtain better properties, the upper limit of condition (10) is more preferably set to 2.8, and even more preferably to 2.5.

[0164] As an example, in Figure 10 The diagram shows an optical window W5 with curvature, the aforementioned projection W5p, the aforementioned length WpL, and the aforementioned length WpS. In Figure 10 In the equation, a double-dotted line represents the direction from the center of the curvature of the optical window W5 toward the origin used in the equation that defines the surface of the optical window W5.

[0165] When the optical window has curvature, it can also be configured to include a cylindrical lens. Even if the optical window is configured with curvature along the short side of the image, the miniaturization effect is relatively small; however, if it is configured with curvature along the long side of the image, miniaturization can be effectively achieved. Furthermore, a structure with curvature in only one of the short or long side directions is easier to manufacture than a structure with curvature in both the short and long side directions. Therefore, by configuring the optical window as a cylindrical shape, mass production is ensured, and miniaturization is effectively achieved.

[0166] When the optical window is a cylindrical lens and the narrowing side of the optical window is cylindrical, the imaging optical system preferably satisfies the following condition (11). Here, the radius of curvature of the cylindrical surface in the direction perpendicular to the generatrix of the cylindrical surface is defined as Rcy. The direction perpendicular to the generatrix of the cylindrical surface is the direction with curvature. In the sign of Rcy, the sign of the shape convex to the magnification side is set to positive, and the sign of the shape convex to the narrowing side is set to negative. By ensuring that the corresponding value of condition (11) is not below the lower limit value, it is beneficial to miniaturize the optical window in the direction with curvature. By ensuring that the corresponding value of condition (11) is not above the upper limit value, it is preferable to configure it as a cylindrical lens.

[0167] 1 < WpL / Rcy < 2 (11)

[0168] To obtain better properties, the lower limit of condition (11) is more preferably set to 1.2, and even more preferably set to 1.5.

[0169] When the optical window is a cylindrical lens and the narrowed side of the optical window is cylindrical, the imaging optical system preferably satisfies the following condition (12). Here, the combined focal length of the reflective optical system GR and the refractive optical system GL included in the imaging optical system is set to fRL. By ensuring that the corresponding value of condition (12) is not below the lower limit, it is beneficial to miniaturize the optical window in the direction of curvature. By ensuring that the corresponding value of condition (12) is not above the upper limit, it is beneficial to miniaturize the imaging optical system.

[0170] 0 < fRL / Rcy < 0.1 (12)

[0171] To obtain better properties, the upper limit of condition (12) is more preferably set to 0.08, and even more preferably set to 0.06.

[0172] When the optical window has curvature, it can also be configured to have a complex surface shape. In this case, miniaturization can be easily achieved according to the aspect ratio of the image.

[0173] When the optical window has curvature, it can be configured such that both the magnifying side and the reducing side of the optical window are spherical. In this case, in addition to miniaturization, it also enables the optical window to have aberration correction capabilities. Furthermore, since it can be manufactured in the same way as a spherical lens, high costs can be suppressed.

[0174] When the optical window has curvature, it can also be configured to have an aspherical shape. In this case, in addition to the effect of miniaturization, it is also possible to obtain an optical window with better aberration correction capabilities.

[0175] When the optical window has curvature, the beam cross-section varies depending on that curvature. When the optical window has curvature, the "beam cross-section" refers to the cross-section of the imaging beam on the cross-section of the optical window at the center of the magnifying side of the optical window. Figure 11 , Figure 12A , Figure 12B , Figure 13A and Figure 13B The diagram schematically illustrates an example of a beam cross-section and an optical window.

[0176] exist Figure 11 The image shows the beam cross-section LF2 and the rectangular optical window W2. Figure 11 In the diagram, the beam cross section LF2 is marked with a slanted line. Figure 11 The left-right direction is the X-axis direction, which is the direction of the long side of the image displayed by the display element. The beam cross-section LF2 is, for example, an example of a case where a cylindrical optical window is used.

[0177] for Figure 11 The beam cross section LF2 can also be used. Figure 12A The trapezoidal optical window W3 is shown. Figure 12A The beam cross section LF2 and Figure 11 The beam cross-section LF2 has the same shape. Figure 12B In the diagram, a dashed line represents the rectangle RecW3 circumscribed by the optical window W3. The dashed line also represents the length of the longer side WL and the length of the shorter side WS of rectangle RecW3. Figure 11 Compared to the optical window W2, Figure 12A The W3 optical window is beneficial for miniaturization and weight reduction of optical windows, and also helps to block stray light from the outside.

[0178] exist Figure 13A The image shows the beam cross-section LF3 and the optical window W4, which forms part of a roughly circular ring. Figure 13A In the diagram, the beam cross section LF3 is marked with a slanted line. Figure 13AThe left-right direction is the X-axis direction, which is the direction of the long side of the image displayed by the display element. The beam cross-section LF3 is, for example, an example of an aspherical optical window using a magnifying side surface and a reducing side surface. In Figure 13B In the diagram, a rectangle RecW4, which is circumscribed by the optical window W4, is represented by a dashed line. The length of the long side WL and the length of the short side WS of the rectangle RecW4 are also represented by dashed lines.

[0179] in addition, Figure 7 , Figure 8B , Figure 11 , Figure 12B and Figure 13B The symbol WL is used to indicate the same concept and does not necessarily mean that they have the same value. Similarly, Figure 7 , Figure 8B , Figure 11 , Figure 12B and Figure 13B The symbol WS is used to represent the same concept and does not necessarily mean that it has the same value.

[0180] Including structures related to conditional expressions, the above-mentioned preferred structures and possible structures can be combined arbitrarily within a non-contradictory range, and are preferably adopted selectively and appropriately according to the required specifications. Various modifications can be made without departing from the spirit of the invention.

[0181] For example, in the technology of this invention, the number of lenses and the number of reflecting surfaces included in the imaging optical system can be related to... Figure 1 The examples differ. A reflective optical system GR can be configured to include the three reflecting surfaces mentioned above, or it can include optical components other than the three reflecting surfaces. The reflecting surface is not limited to a mirror surface; for example, it can be a surface formed on the surface of a lens or a surface formed on the surface of a prism. A refractive optical system GL can include optical components other than lenses. For example, a refractive optical system GL can include a plane mirror. An imaging optical system can include a light path bending component that does not have optical power for bending the light path. As a light path bending component, for example, the reflecting surface of a plane mirror or a prism can be used.

[0182] As an example, a preferred embodiment of the imaging optical system of the present invention is an imaging optical system 1, which is capable of forming a magnified image 6 on the magnification side imaging surface after magnifying the image 4 on the reduction side imaging surface. The system comprises, from the magnification side to the reduction side along the optical path, an optical window W, a reflective optical system GR, and a refractive optical system GL including multiple lenses. The reflective optical system GR, from the magnification side to the reduction side along the optical path, comprises, in sequence, a first reflective surface R1 with positive optical power, a second reflective surface R2 with optical power, and a third reflective surface R3 with positive optical power. The third reflective surface R3... The first intermediate image M1 is formed at a position on the optical path closer to the shrinking side and conjugate with the image. The second intermediate image M2 is formed at a position on the optical path closer to the shrinking side and conjugate with the first intermediate image M1 within the reflective optical system GR. The magnified image is formed at a position on the optical path closer to the magnification side than the optical window W and conjugate with the second intermediate image M2. The center of the magnified image is located at a position that is displaced relative to the optical axis AX of the refractive optical system GL in a direction perpendicular to the optical axis AX. When the principal ray incident on the center of the magnified image at the maximum displacement is set as the central principal ray Cray, the above conditions (1) and (2) are satisfied.

[0183] Next, embodiments of the imaging optical system of the present invention will be described with reference to the accompanying drawings. Furthermore, the reference numerals used to denote the constituent elements of the imaging optical system in the cross-sectional views of each embodiment are used independently in each embodiment to avoid complicating the description and drawings due to an increase in the number of digits in the reference numerals. Therefore, even if the same reference numerals are used in the drawings of different embodiments, the structures are not necessarily the same.

[0184] [Example 1]

[0185] The structure and cross-sectional view of the imaging optical system of Example 1 are shown in the figure. Figure 1 The diagrammatic method and structure are as described above, so some repeated explanations are omitted here.

[0186] The imaging optical system of Example 1, from the magnification side to the reduction side along the optical path, includes an optical window W, a reflective optical system GR, and a refractive optical system GL. The reflective optical system GR, from the magnification side to the reduction side along the optical path, includes a first reflective surface R1 with positive optical power, a second reflective surface R2 with optical power, and a third reflective surface R3 with positive optical power. The first reflective surface R1 and the third reflective surface R3 are formed in the same component and have the same surface shape. The refractive optical system GL, from the magnification side to the reduction side, includes lenses L1 to L8, an aperture stop St, and lenses L9 to L14. A first intermediate image M1 is formed in the optical path between the refractive optical system GL and the third reflective surface R3. A second intermediate image M2 is formed in the optical path between the second reflective surface R2 and the first reflective surface R1.

[0187] Data for the imaging optical system of Example 1 are shown in Tables 1 to 4. Table 1 shows the structures of the optical window W. Table 2 shows the structural data of the reflective optical system GR, the refractive optical system GL, and the optical component PP. Table 3 shows the specifications of the composite optical system formed by combining the reflective optical system GR and the refractive optical system GL. Table 4 shows the aspheric coefficients of each aspheric surface.

[0188] In Table 1, "Center Position" refers to the center position of the optical window W with the intersection of the first reflecting surface R1 and the optical axis AX as the reference. "Normal Direction" refers to the normal direction at the center position of the optical window W. "Dimensions" refers to the dimensions when viewed from the normal direction of the optical window W. The X-axis direction is set as the long side direction. "Center Thickness" refers to the center thickness in the normal direction. "Refractive Index" is the refractive index relative to the d-line. "Abbe Number" is the Abbe number based on the d-line. The wavelength of the d-line is set to 587.56 nm (nanometers).

[0189] The structural data in Table 2 are recorded as follows. The Sn column shows the surface numbering, with the surface closest to the magnification side as surface 1 and the numbering increasing sequentially towards the reduction side. The R column shows the radius of curvature of each surface. The D column shows the surface spacing along the optical axis AX between each surface and the surface adjacent to its reduction side. The Nd column shows the refractive index of each component relative to the d-line. The vd column shows the Abbe number of each component based on the d-line. The "Reflecting Surface" is entered in the Nd column of the row corresponding to each reflecting surface.

[0190] In the structural data table, the sign of the radius of curvature of the convex shape facing the magnification side is set to positive, and the sign of the radius of curvature of the convex shape facing the reduction side is set to negative. The column corresponding to the surface number of the aperture stop St records the surface number and the statement (St). The bottom column of column D of the table contains the interval between the surface closest to the reduction side and the display surface 2a.

[0191] Table 3 shows the focal length f, the back focal length Bf (at air equivalent distance), the F-number FNo., and the maximum full angle of view 2ω for the above-mentioned synthetic optical system, with the d-line as the reference. The [°] in the 2ω column indicates the unit as degrees.

[0192] In the structural data, the surface numbers of aspherical surfaces are marked with an asterisk (*), and the paraxial radius of curvature is recorded in the column for the radius of curvature of the aspherical surface. In Table 4, the surface number of the aspherical surface is shown in row Sn, and the values ​​of the aspherical coefficients for each aspherical surface are shown in rows KA and Am. Furthermore, m in Am is an integer greater than or equal to 3, varying depending on the surface. For example, on the first surface of Example 1, m = 3, 4, 5, ... 20. The values ​​of the aspherical coefficients in Table 4, "E±n" (n: integer), represent "×10⁻¹⁰". ±n KA and Am are the aspheric coefficients in the aspheric formula expressed below.

[0193] Zd=C×h 2 / {1+(1-KA×C 2 ×h 2 ) 1 / 2}+∑Am×h m

[0194] in,

[0195] Zd: Aspherical depth (the length of the perpendicular line from a point on the aspherical surface at height h to a plane tangent to the vertex of the aspherical surface and perpendicular to the optical axis AX).

[0196] h: Height (distance from the optical axis AX to the lens surface)

[0197] C: The reciprocal of the paraxial radius of curvature

[0198] KA, Am: Aspheric coefficients

[0199] In aspherical form, ∑ represents the sum of all terms with respect to m.

[0200] In the data in each table, degrees are used as the unit of angle and millimeters (mm) are used as the unit of length. However, optical systems can also use different units depending on whether they are magnified or reduced. Furthermore, the values ​​shown in the tables below are rounded to the specified number of decimal places.

[0201] [Table 1]

[0202] Example 1

[0203] Central position 31mm along the Y-axis and 67mm along the Z-axis Normal direction The direction of rotation of the optical axis AX by 60° with the X-axis as the rotation axis. shape rectangular flat plate size Long side 235mm, short side 56mm Center thickness 1mm Refractive index 1.51680 Abbe number 64.20

[0204] [Table 2]

[0205] Example 1

[0206] Sn R D Nd vd *1 62.5759 78.1800 Reflective surface *2 227.4726 -78.1800 Reflective surface *3 62.5759 91.1864 Reflective surface *4 ∞ 1.0400 1.72916 54.68 5 18.6285 7.2166 6 -41.7154 0.8100 1.92286 20.88 7 111.2286 0.2000 *8 25.5205 8.5400 1.51742 52.43 9 -27.9500 0.3400 *10 56.7987 2.7100 1.80518 25.46 11 158.5181 12.6619 12 27.4224 0.8000 1.90043 37.37 13 11.1730 4.9500 1.67270 32.10 14 -75.7140 0.4682 15 -34.0677 6.9600 1.90043 37.37 16 14.0954 4.9100 1.80809 22.76 17 406.7297 0.1200 18(St) ∞ 0.5800 19 22.6285 5.8800 1.51742 52.43 *20 -30.5443 0.6900 21 ∞ 0.9000 1.95375 32.32 22 18.8698 8.8300 1.48749 70.44 23 -18.8698 0.2000 24 -23.0909 0.9300 2.00069 25.46 25 -101.7220 5.1400 1.48749 70.44 26 -18.1195 0.2000 27 47.2808 4.6000 1.60311 60.64 28 -59.5384 12.0000 29 ∞ 24.5000 1.51680 64.20 30 ∞ 0.2009

[0207] [Table 3]

[0208] Example 1

[0209] f 2.12 Bf 28.34 FNo. 1.80 2ω[°] 158.0

[0210] [Table 4]

[0211] Example 1

[0212] Sn 1 2 3 KA 4.9484650E-01 2.1016143E+01 4.9484650E-01 A3 2.0670685E-05 1.7408582E-04 2.0670685E-05 A4 -3.3224988E-06 -7.1080471E-05 -3.3224988E-06 A5 1.7181164E-07 8.1664560E-06 1.7181164E-07 A6 1.3803767E-09 -2.3589031E-07 1.3803767E-09 A7 -4.0534139E-10 -1.4905223E-08 -4.0534139E-10 A8 9.2215574E-12 9.2981646E-10 9.2215574E-12 A9 2.0375333E-13 6.2385263E-12 2.0375333E-13 A10 -1.0060937E-14 -1.3352700E-12 -1.0060937E-14 A11 1.6697234E-17 8.6845273E-15 1.6697234E-17 A12 4.3017226E-18 1.1360941E-15 4.3017226E-18 A13 -4.5208445E-20 -1.5481642E-17 -4.5208445E-20 A14 -8.4810951E-22 -6.3250099E-19 -8.4810951E-22 A15 1.5641416E-23 1.2890556E-20 1.5641416E-23 A16 5.2893627E-26 1.8957439E-22 5.2893627E-26 A17 -2.3072995E-27 -5.9555061E-24 -2.3072995E-27 A18 5.6058850E-30 -4.4733331E-27 5.6058850E-30 A19 1.2937950E-31 1.1394564E-27 1.2937950E-31 A20 -7.1642091E-34 -8.2026634E-30 -7.1642091E-34

[0213] Sn 4 8 10 20 KA 1.0000000E+00 1.0000000E+00 1.0000000E+00 1.0000000E+00 A3 0.0000000E+00 0.0000000E+00 0.0000000E+00 0.0000000E+00 A4 1.1890529E-04 -5.3626389E-05 -1.4081630E-05 3.9779385E-05 A5 -8.8687390E-06 9.3189604E-06 4.2814060E-06 -8.5327356E-07 A6 1.6137207E-07 -6.3984935E-07 -1.0094215E-06 7.6658191E-08 A7 3.6831937E-08 -1.4050469E-08 9.0958580E-08 -4.8679958E-09 A8 -2.1602541E-09 3.3884215E-09 -1.0583872E-09 -2.9616178E-10 A9 -2.7392546E-11 -1.0920277E-10 -3.0223454E-10 8.5785377E-12 A10 3.0791861E-12 -1.0565732E-13 1.3070503E-11 4.0225722E-13

[0214] The notation, meaning, recording method, and illustration method of the data related to Embodiment 1 described above are basically the same in the following embodiments unless otherwise specified, therefore repeated descriptions are omitted below. The X-axis, Y-axis, and Z-axis directions in the following embodiments are also determined in the same way as in Embodiment 1. In all the following embodiments, the shape of the optical window W as viewed from the normal direction of the optical window W is rectangular, and the long side of the rectangle is in the X-axis direction. In the following embodiments, in the embodiment having an optical window W with curvature, the values ​​related to the magnified side surface of the optical window W are recorded in the table representing the various structures of the optical window W.

[0215] [Example 2]

[0216] The structure and cross-sectional view of the imaging optical system of Example 2 are shown in the figure. Figure 14 The imaging optical system of Example 2, from the magnification side to the reduction side along the optical path, includes an optical window W, a reflective optical system GR, and a refractive optical system GL. The reflective optical system GR, from the magnification side to the reduction side along the optical path, includes a first reflective surface R1 with positive optical power, a second reflective surface R2 with optical power, and a third reflective surface R3 with positive optical power. The first reflective surface R1 and the third reflective surface R3 are formed in the same component and have the same surface shape. The refractive optical system GL, from the magnification side to the reduction side, includes lenses L1 to L8, an aperture stop St, and lenses L9 to L14. A first intermediate image M1 is formed in the optical path between the refractive optical system GL and the third reflective surface R3. A second intermediate image M2 is formed in the optical path between the second reflective surface R2 and the first reflective surface R1.

[0217] Data for the imaging optical system of Example 2 are shown in Tables 5 to 8. Table 5 shows the structures of the optical window W. Table 6 shows the structural data of the reflective optical system GR, the refractive optical system GL, and the optical component PP. Table 7 shows the specifications of the composite optical system formed by combining the reflective optical system GR and the refractive optical system GL. Table 8 shows the aspheric coefficients of each aspheric surface.

[0218] [Table 5]

[0219] Example 2

[0220] Central position 35mm in the Y-axis direction and 68mm in the Z-axis direction Normal direction The direction of rotation of the optical axis AX by 60° with the X-axis as the rotation axis. shape Cylindrical shape, radius of curvature in the X-axis direction 50mm size Long side 90mm, short side 46mm Center thickness 1mm Refractive index 1.51680 Abbe number 64.20

[0221] [Table 6]

[0222] Example 2

[0223] Sn R D Nd vd *1 62.5759 78.1800 Reflective surface *2 227.4726 -78.1800 Reflective surface *3 62.5759 91.1864 Reflective surface *4 ∞ 1.0400 1.72916 54.68 5 18.6285 7.2166 6 -41.7154 0.8100 1.92286 20.88 7 111.2286 0.2000 *8 25.5205 8.5400 1.51742 52.43 9 -27.9500 0.3400 *10 56.7987 2.7100 1.80518 25.46 11 158.5181 12.6619 12 27.4224 0.8000 1.90043 37.37 13 11.1730 4.9500 1.67270 32.10 14 -75.7140 0.4682 15 -34.0677 6.9600 1.90043 37.37 16 14.0954 4.9100 1.80809 22.76 17 406.7297 0.1200 18 (St) ∞ 0.5800 19 22.6285 5.8800 1.51742 52.43 *20 -30.5443 0.6900 21 ∞ 0.9000 1.95375 32.32 22 18.8698 8.8300 1.48749 70.44 23 -18.8698 0.2000 24 -23.0909 0.9300 2.00069 25.46 25 -101.7220 5.1400 1.48749 70.44 26 -18.1195 0.2000 27 47.2808 4.6000 1.60311 60.64 28 -59.5384 12.0000 29 ∞ 24.5000 1.51680 64.20 30 ∞ 0.2009

[0224] [Table 7]

[0225] Example 2

[0226] f 2.12 Bf 28.34 FNo. 1.80 2ω[°] 158.0

[0227] [Table 8]

[0228] Example 2

[0229] Sn 1 2 3 KA 4.9484650E-01 2.1016143E+01 4.9484650E-01 A3 2.0670685E-05 1.7408582E-04 2.0670685E-05 A4 -3.3224988E-06 -7.1080471E-05 -3.3224988E-06 A5 1.7181164E-07 8.1664560E-06 1.7181164E-07 A6 1.3803767E-09 -2.3589031E-07 1.3803767E-09 A7 -4.0534139E-10 -1.4905223E-08 -4.0534139E-10 A8 9.2215574E-12 9.2981646E-10 9.2215574E-12 A9 2.0375333E-13 6.2385263E-12 2.0375333E-13 A10 -1.0060937E-14 -1.3352700E-12 -1.0060937E-14 A11 1.6697234E-17 8.6845273E-15 1.6697234E-17 A12 4.3017226E-18 1.1360941E-15 4.3017226E-18 A13 -4.5208445E-20 -1.5481642E-17 -4.5208445E-20 A14 -8.4810951E-22 -6.3250099E-19 -8.4810951E-22 A15 1.5641416E-23 1.2890556E-20 1.5641416E-23 A16 5.2893627E-26 1.8957439E-22 5.2893627E-26 A17 -2.3072995E-27 -5.9555061E-24 -2.3072995E-27 A18 5.6058850E-30 -4.4733331E-27 5.6058850E-30 A19 1.2937950E-31 1.1394564E-27 1.2937950E-31 A20 -7.1642091E-34 -8.2026634E-30 -7.1642091E-34

[0230] Sn 4 8 10 20 KA 1.0000000E+00 1.0000000E+00 1.0000000E+00 1.0000000E+00 A3 0.0000000E+00 0.0000000E+00 0.0000000E+00 0.0000000E+00 A4 1.1890529E-04 -5.3626389E-05 -1.4081630E-05 3.9779385E-05 A5 -8.8687390E-06 9.3189604E-06 4.2814060E-06 -8.5327356E-07 A6 1.6137207E-07 -6.3984935E-07 -1.0094215E-06 7.6658191E-08 A7 3.6831937E-08 -1.4050469E-08 9.0958580E-08 -4.8679958E-09 A8 -2.1602541E-09 3.3884215E-09 -1.0583872E-09 -2.9616178E-10 A9 -2.7392546E-11 -1.0920277E-10 -3.0223454E-10 8.5785377E-12 A10 3.0791861E-12 -1.0565732E 13 1.3070503E-11 4.0225722E-13

[0231] [Example 3]

[0232] The structure and cross-sectional view of the imaging optical system of Example 3 are shown in the figure. Figure 15 The imaging optical system of Example 3, from the magnification side to the reduction side along the optical path, includes an optical window W, a reflective optical system GR, and a refractive optical system GL. The reflective optical system GR, from the magnification side to the reduction side along the optical path, includes a first reflecting surface R1 with positive optical power, a second reflecting surface R2 with optical power, and a third reflecting surface R3 with positive optical power. The refractive optical system GL, from the magnification side to the reduction side, includes lenses L1 to L7, an aperture stop St, and lenses L8 to L12. A first intermediate image M1 is formed in the optical path between the refractive optical system GL and the third reflecting surface R3. A second intermediate image M2 is formed in the optical path between the second reflecting surface R2 and the first reflecting surface R1.

[0233] Data for the imaging optical system of Example 3 are shown in Tables 9 to 12. Table 9 shows the structures of the optical window W. Table 10 shows the structural data of the reflective optical system GR, the refractive optical system GL, and the optical component PP. Table 11 shows the specifications of the composite optical system formed by combining the reflective optical system GR and the refractive optical system GL. Table 12 shows the aspheric coefficients of each aspheric surface.

[0234] [Table 9]

[0235] Example 3

[0236] Central position 42mm along the Y-axis and 107mm along the Z-axis. Normal direction The direction of rotation of the optical axis AX by 70° about the X-axis. shape rectangular flat plate size Long side 580mm, short side 78mm Center thickness 1mm Refractive index 1.51680 Abbe number 64.20

[0237] [Table 10]

[0238] Example 3

[0239] Sn R D Nd vd *1 90.3999 121.6454 Reflective surface *2 147.9247 -117.7919 Reflective surface *3 83.6336 127.3182 Reflective surface 4 161.5284 5.2820 1.75500 52.32 5 -158.2707 4.6188 *6 -37.0785 4.2572 1.58913 61.15 7 47.2005 8.2408 8 -67.8403 13.0733 1.49700 81.61 9 -39.3828 27.1171 10 27.3006 9.7896 1.51742 52.43 11 30.1540 4.5544 12 194.0087 0.9991 1.80420 46.50 13 29.5222 0.1006 14 30.7206 4.0792 1.48749 70.44 15 -81.7275 6.1880 16 59.5507 10.0009 1.59270 35.31 17 (St) -559.2067 14.6255 18 317.6939 7.6158 1.49700 81.61 19 -22.7918 0.1000 20 -22.3867 6.0009 1.87070 40.73 21 -61.9365 5.8124 22 88.5399 6.8078 1.59282 68.62 23 -32.2014 0.0995 24 -31.6224 3.9317 1.87070 40.73 25 -126.1715 0.0291 26 200.3045 6.2791 1.51633 64.06 *27 -32.1675 17.0500 28 ∞ 29.1000 1.51680 64.20 29 ∞ 0.0523

[0240] [Table 11]

[0241] Example 3

[0242] f 2.01 Bf 36.28 FNo. 2.00 2ω[°] 143.6

[0243] [Table 12]

[0244] Example 3

[0245] Sn 1 2 3 KA 6.6097081E-01 3.4475110E+00 -2.5498209E-01 A3 1.4123225E-06 -2.4574371E-05 5.4566756E-07 A4 -1.4271660E-07 9.3390310E-08 -3.8473499E-07 A5 7.5994413E-09 4.7407434E-08 1.9700320E-08 A6 -1.5905247E-10 -4.1397122E-09 -3.6362011E-10 A7 -1.4947711E-12 4.2113414E-11 -5.4581013E-12 A8 6.6594229E-14 1.6688648E-12 2.8765080E-13 A9 -1.3019224E-16 -2.9297527E-14 -1.8871006E-15 A10 -9.1849160E-18 -2.4212041E-16 -5.3233532E-17 A11 4.4173419E-20 6.5208664E-18 7.6224954E-19 A12 5.5661837E-22 8.2453988E-21 2.3293230E-21 A13 -3.1808508E-24 -6.3278346E-22 -8.5305630E-23 A14 -1.4369072E-26 9.7658860E-25 1.9762226E-25 A15 7.3121202E-29 2.2788453E-26 3.1406445E-27 A16 1.0706006E-31 -6.4523411E-29 -1.4462391E-29

[0246]

[0247] [Example 4]

[0248] The structure and cross-sectional view of the imaging optical system of Example 4 are shown in the figure. Figure 16 The imaging optical system of Example 4, from the magnification side to the reduction side along the optical path, includes an optical window W, a reflective optical system GR, and a refractive optical system GL. The reflective optical system GR, from the magnification side to the reduction side along the optical path, includes a first reflecting surface R1 with positive optical power, a second reflecting surface R2 with optical power, and a third reflecting surface R3 with positive optical power. The refractive optical system GL, from the magnification side to the reduction side, includes lenses L1 to L7, an aperture stop St, and lenses L8 to L12. A first intermediate image M1 is formed in the optical path between the refractive optical system GL and the third reflecting surface R3. A second intermediate image M2 is formed in the optical path between the second reflecting surface R2 and the first reflecting surface R1.

[0249] Data for the imaging optical system of Example 4 are shown in Tables 13 to 16. Table 13 shows the structures of the optical window W. Table 14 shows the structural data of the reflective optical system GR, the refractive optical system GL, and the optical component PP. Table 15 shows the specifications of the composite optical system formed by combining the reflective optical system GR and the refractive optical system GL. Table 16 shows the aspheric coefficients of each aspheric surface.

[0250] [Table 13]

[0251] Example 4

[0252] Central position 50.2mm in the Y-axis direction and 102.6mm in the Z-axis direction. Normal direction Rotating the optical axis AX by 55° with the X-axis as the rotation axis shape Cylindrical shape, radius of curvature in the X-axis direction: 62mm size Long side 122mm, short side 68mm Center thickness 1mm Refractive index 1.51680 Abbe number 64.20

[0253] [Table 14]

[0254] Example 4

[0255] Sn R D Nd vd *1 90.3999 121.6454 Reflective surface *2 147.9247 -117.7919 Reflective surface *3 83.6336 127.3182 Reflective surface 4 161.5284 5.2820 1.75500 52.32 5 -158.2707 4.6188 *6 -37.0785 4.2572 1.58913 61.15 7 47.2005 8.2408 8 -67.8403 13.0733 1.49700 81.61 9 -39.3828 27.1171 10 27.3006 9.7896 1.51742 52.43 11 30.1540 4.5544 12 194.0087 0.9991 1.80420 46.50 13 29.5222 0.1006 14 30.7206 4.0792 1.48749 70.44 15 -81.7275 6.1880 16 59.5507 10.0009 1.59270 35.31 17 (St) -559.2067 14.6255 18 317.6939 7.6158 1.49700 81.61 19 -22.7918 0.1000 20 -22.3867 6.0009 1.87070 40.73 21 -61.9365 5.8124 22 88.5399 6.8078 1.59282 68.62 23 -32.2014 0.0995 24 -31.6224 3.9317 1.87070 40.73 25 -126.1715 0.0291 26 200.3045 6.2791 1.51633 64.06 *27 -32.1675 17.0500 28 ∞ 29.1000 1.51680 64.20 29 ∞ 0.0523

[0256] [Table 15]

[0257] Example 4

[0258] f 2.01 Bf 36.28 FNo. 2.00 2ω[°] 143.6

[0259] [Table 16]

[0260] Example 4

[0261] Sn 1 2 3 KA 6.6097081E-01 3.4475110E+00 -2.5498209E-01 A3 1.4123225E-06 -2.4574371E-05 5.4566756E-07 A4 -1.4271660E-07 9.3390310E-08 -3.8473499E-07 A5 7.5994413E-09 4.7407434E-08 1.9700320E-08 A6 -1.5905247E-10 -4.1397122E-09 -3.6362011E-10 A7 -1.4947711E-12 4.2113414E-11 -5.4581013E-12 A8 6.6594229E--14 1.6688648E-12 2.8765080E-13 A9 -1.3019224E-16 -2.9297527E-14 -1.8871006E-15 A10 -9.1849160E-18 -2.4212041E-16 -5.3233532E-17 A11 4.4173419E-20 6.5208664E-18 7.6224954E-19 A12 5.5661837E-22 8.2453988E-21 2.3293230E-21 A13 -3.1808508E-24 -6.3278346E-22 -8.5305630E-23 A14 -1.4369072E-26 9.7658860E-25 1.9762226E-25 A15 7.3121202E-29 2.2788453E-26 3.1406445E-27 A16 1.0706006E-31 -6.4523411E-29 -1.4462391E-29

[0262]

[0263] [Example 5]

[0264] The structure and cross-sectional view of the imaging optical system of Example 5 are shown in the figure. Figure 17 The imaging optical system of Example 5, from the magnification side to the reduction side along the optical path, includes an optical window W, a reflective optical system GR, and a refractive optical system GL. The reflective optical system GR, from the magnification side to the reduction side along the optical path, includes a first reflecting surface R1 with positive optical power, a second reflecting surface R2 with optical power, and a third reflecting surface R3 with positive optical power. The refractive optical system GL, from the magnification side to the reduction side, includes lenses L1 to L6, an aperture stop St, and lenses L7 to L11. A first intermediate image M1 is formed in the optical path between the refractive optical system GL and the third reflecting surface R3. A second intermediate image M2 is formed in the optical path between the second reflecting surface R2 and the first reflecting surface R1.

[0265] Data for the imaging optical system of Example 5 are shown in Tables 17 to 20. Table 17 shows the structures of the optical window W. Table 18 shows the structural data of the reflective optical system GR, the refractive optical system GL, and the optical component PP. Table 19 shows the specifications of the composite optical system formed by combining the reflective optical system GR and the refractive optical system GL. Table 20 shows the aspheric coefficients of each aspheric surface.

[0266] [Table 17]

[0267] Example 5

[0268] Central position 40mm along the Y-axis and 72.5mm along the Z-axis Normal direction Rotating the optical axis AX by 56° with the X-axis as the rotation axis shape rectangular flat plate size Long side 404mm, short side 54mm Center thickness 1mm Refractive index 1.51633 Abbe number 64.14

[0269] [Table 18]

[0270] Example 5

[0271] Sn R D Nd vd *1 69.0780 97.1646 Reflective surface *2 115.9484 -84.9678 Reflective surface *3 58.6129 94.4289 Reflective surface 4 500.0000 2.8950 1.84666 23.78 5 -139.4545 3.3854 *6 -24.3818 6.3211 1.76450 49.10 7 42.2369 5.6093 8 -266.2675 11.1087 1.43700 95.10 9 -24.7687 23.6794 10 67.8589 4.7408 1.86966 20.02 11 113.6408 2.8196 12 27.2473 0.8010 1.80420 46.50 13 16.9347 0.0502 14 17.1536 3.2380 1.48749 70.44 15 (St) 1808.4665 10.4373 16 -30.0619 12.7814 1.48749 70.44 17 -13.7698 0.9997 1.87070 40.73 18 -25.2899 0.0991 19 118.0186 5.6815 1.59282 68.62 20 -26.2489 0.7999 1.80420 46.50 21 -129.1262 0.2000 *22 83.0722 7.5283 1.49700 81.61 *23 -20.3892 12.2900 24 ∞ 30.0900 1.51680 64.20 25 ∞ 0.0508

[0272] [Table 19]

[0273] Example 5

[0274] f 1.15 Bf 32.17 FNo. 2.19 2ω[°] 169.6

[0275] [Table 20]

[0276] Example 5

[0277] Sn 1 2 3 KA 6.2310280E-01 3.9038253E+00 3.8038492E-02 A3 -2.2274506E-05 -6.2177818E-05 2.7490561E-06 A4 8.2698572E-07 5.9669729E-07 -9.4493186E-07 A5 3.2754170E-08 2.4483807E-07 3.5676281E-08 A6 -1.4811608E-09 -2.1588202E-08 -6.7746513E-10 A7 -9.5882579E-12 2.2095803E-10 -1.5529893E-11 A8 7.4398296E-13 1.6600439E-11 1.0087852E-12 A9 -8.3754329E-16 -3.4884722E-13 -9.5309283E-15 A10 -1.6238548E-16 -4.5955809E-15 -2.7924079E-16 A11 5.9982361E-19 1.5182851E-16 5.5956379E-18 A12 1.7300642E-20 3.0055912E-19 1.4137729E-20 A13 -7.3584090E-23 -2.8170896E-20 -9.3274233E-22 A14 -8.7601003E-25 6.5904201E-23 3.2991391E-24 A15 2.8415104E-27 1.9240193E-24 5.1232084E-26 A16 1.6503742E-29 -8.2710970E-27 -3.1686037E-28

[0278]

[0279] [Example 6]

[0280] The structure and cross-sectional view of the imaging optical system of Example 6 are shown in the figure. Figure 18 The imaging optical system of Example 6, from the magnification side to the reduction side along the optical path, includes an optical window W, a reflective optical system GR, and a refractive optical system GL. The reflective optical system GR, from the magnification side to the reduction side along the optical path, includes a first reflecting surface R1 with positive optical power, a second reflecting surface R2 with optical power, and a third reflecting surface R3 with positive optical power. The refractive optical system GL, from the magnification side to the reduction side, includes lenses L1 to L6, an aperture stop St, and lenses L7 to L11. A first intermediate image M1 is formed in the optical path between the refractive optical system GL and the third reflecting surface R3. A second intermediate image M2 is formed in the optical path between the second reflecting surface R2 and the first reflecting surface R1.

[0281] Data for the imaging optical system of Example 6 are shown in Tables 21 to 24. Table 21 shows the structures of the optical window W. Table 22 shows the structural data of the reflective optical system GR, the refractive optical system GL, and the optical component PP. Table 23 shows the specifications of the composite optical system formed by combining the reflective optical system GR and the refractive optical system GL. Table 24 shows the aspheric coefficients of each aspheric surface.

[0282] [Table 21]

[0283] Example 6

[0284] Central position 47.8mm in the Y-axis direction and 75.8mm in the Z-axis direction. Normal direction The direction of rotation of the optical axis AX by 72° about the X-axis. shape Cylindrical shape, radius of curvature in the X-axis direction 55mm size Long side 108mm, short side 50mm Center thickness 0.5mm Refractive index 1.53638 Abbe number 56.09

[0285] [Table 22]

[0286] Example 6

[0287] Sn R D Nd vd *1 69.0780 97.1646 Reflective surface *2 115.9484 -84.9678 Reflective surface *3 58.6129 94.4289 Reflective surface 4 500.0000 2.8950 1.84666 23.78 5 -139.4545 3.3854 - *6 -24.3818 6.3211 1.76450 49.10 7 42.2369 5.6093 8 -266.2675 11.1087 1.43700 95.10 9 -24.7687 23.6794 10 67.8589 4.7408 1.86966 20.02 11 113.6408 2.8196 12 27.2473 0.8010 1.80420 46.50 13 16.9347 0.0502 14 17.1536 3.2380 1.48749 70.44 15 (St) 1808.4665 10.4373 16 -30.0619 12.7814 1.48749 70.44 17 -13.7698 0.9997 1.87070 40.73 18 -25.2899 0.0991 19 118.0186 5.6815 1.59282 68.62 20 -26.2489 0.7999 1.80420 46.50 21 -129.1262 0.2000 *22 83.0722 7.5283 1.49700 81.61 *23 -20.3892 12.2900 24 ∞ 30.0900 1.51680 64.20 25 ∞ 0.0508

[0288] [Table 23]

[0289] Example 6

[0290] f 1.15 Bf 32.17 FNo. 2.19 2ω[°] 169.6

[0291] [Table 24]

[0292] Example 6

[0293] Sn 1 2 3 KA 6.2310280E-01 3.9038253E+00 3.8038492E-02 A3 -2.2274506E-05 -6.2177818E-05 2.7490561E-06 A4 8.2698572E-07 5.9669729E-07 -9.4493186E-07 A5 3.2754170E-08 2.4483807E-07 3.5676281E-08 A6 -1.4811608E-09 -2.1588202E-08 -6.7746513E-10 A7 -9.5882579E-12 2.2095803E-10 -1.5529893E-11 A8 7.4398296E-13 1.6600439E-11 1.0087852E-12 A9 -8.3754329E-16 -3.4884722E-13 -9.5309283E-15 A10 -1.6238548E-16 -4.5955809E-15 -2.7924079E-16 A11 5.9982361E-19 1.5182851E-16 5.5956379E-18 A12 1.7300642E-20 3.0055912E-19 1.4137729E-20 A13 -7.3584090E-23 -2.8170896E-20 -9.3274233E-22 A14 -8.7601003E-25 6.5904201E-23 3.2991391E-24 A15 2.8415104E-27 1.9240193E-24 5.1232084E-26 A16 1.6503742E-29 -8.2710970E-27 -3.1686037E-28

[0294]

[0295] [Example 7]

[0296] The structure and cross-sectional view of the imaging optical system of Example 7 are shown in the figure. Figure 19The imaging optical system of Example 7, from the magnification side to the reduction side along the optical path, includes an optical window W, a reflective optical system GR, and a refractive optical system GL. The reflective optical system GR, from the magnification side to the reduction side along the optical path, includes a first reflecting surface R1 with positive optical power, a second reflecting surface R2 with optical power, and a third reflecting surface R3 with positive optical power. The refractive optical system GL, from the magnification side to the reduction side, includes lenses L1 to L6, an aperture stop St, and lenses L7 to L11. A first intermediate image M1 is formed in the optical path between the refractive optical system GL and the third reflecting surface R3. A second intermediate image M2 is formed in the optical path between the second reflecting surface R2 and the first reflecting surface R1.

[0297] Data for the imaging optical system of Example 7 are shown in Tables 25 to 28. Table 25 shows the various structures of the optical window W. The "Origin of the Formulation of the Surface" in Table 25 refers to the origin used in the formula defining the surface of the optical window W, and Table 25 shows the position of this origin with the intersection of the first reflecting surface R1 and the optical axis AX as a reference. The "Long Side Direction" and "Short Side Direction" in the "Shape" column of Table 25 refer to the directions when viewing the optical window W from the normal direction. Table 26 shows the structural data of the reflective optical system GR, the refractive optical system GL, and the optical component PP. Table 27 shows the specifications of the composite optical system formed by combining the reflective optical system GR and the refractive optical system GL. Table 28 shows the aspheric coefficients of each aspheric surface.

[0298] [Table 25]

[0299] Example 7

[0300] Central position 51.2mm in the Y-axis direction and 76.7mm in the Z-axis direction. The origin of the form of the curved surface 50mm in the Y-axis direction and 80mm in the Z-axis direction Normal direction The direction of rotation of the optical axis AX by 70° about the X-axis. shape The complex surface has a radius of curvature of 55 mm along its long side and 150 mm along its short side. size Long side 109mm, short side 50mm Center thickness 1mm Refractive index 1.51633 Abbe number 64.14

[0301] [Table 26]

[0302] Example 7

[0303] Sn R D Nd vd *1 69.0780 97.1646 Reflective surface *2 115.9484 -84.9678 Reflective surface *3 58.6129 94.4289 Reflective surface 4 500.0000 2.8950 1.84666 23.78 5 -139.4545 3.3854 *6 -24.3818 6.3211 1.76450 49.10 7 42.2369 5.6093 8 -266.2675 11.1087 1.43700 95.10 9 -24.7687 23.6794 10 67.8589 4.7408 1.86966 20.02 11 113.6408 2.8196 12 27.2473 0.8010 1.80420 46.50 13 16.9347 0.0502 14 17.1536 3.2380 1.48749 70.44 15 (St) 1808.4665 10.4373 16 -30.0619 12.7814 1.48749 70.44 17 -13.7698 0.9997 1.87070 40.73 18 -25.2899 0.0991 19 118.0186 5.6815 1.59282 68.62 20 -26.2489 0.7999 1.80420 46.50 21 -129.1262 0.2000 *22 83.0722 7.5283 1.49700 81.61 *23 -20.3892 12.2900 24 ∞ 30.0900 1.51680 64.20 25 ∞ 0.0508

[0304] [Table 27]

[0305] Example 7

[0306] f 1.16 Bf 32.17 FNo. 2.19 2ω[°] 169.6

[0307] [Table 28]

[0308] Example 7

[0309] Sn 1 2 3 KA 6.2310280E-01 3.9038253E+00 3.8038492E-02 A3 -2.2274506E-05 -6.2177818E-05 2.7490561E-06 A4 8.2698572E-07 5.9669729E-07 -9.4493186E-07 A5 3.2754170E-08 2.4483807E-07 3.5676281E-08 A6 -1.4811608E-09 -2.1588202E-08 -6.7746513E-10 A7 -9.5882579E-12 2.2095803E-10 -1.5529893E-11 A8 7.4398296E-13 1.6600439E-11 1.0087852E-12 A9 -8.3754329E-16 -3.4884722E-13 -9.5309283E-15 A10 -1.6238548E-16 -4.5955809E-15 -2.7924079E-16 A11 5.9982361E-19 1.5182851E-16 5.5956379E-18 A12 1.7300642E-20 3.0055912E-19 1.4137729E-20 A13 -7.3584090E-23 -2.8170896E-20 -9.3274233E-22 A14 -8.7601003E-25 6.5904201E-23 3.2991391E-24 A15 2.8415104E-27 1.9240193E-24 5.1232084E-26 A16 1.6503742E-29 -8.2710970E-27 -3.1686037E-28

[0310]

[0311] [Example 8]

[0312] The structure and cross-sectional view of the imaging optical system of Example 8 are shown in the figure. Figure 20 The imaging optical system of Example 8, from the magnification side to the reduction side along the optical path, includes an optical window W, a reflective optical system GR, and a refractive optical system GL. The reflective optical system GR, from the magnification side to the reduction side along the optical path, includes a first reflecting surface R1 with positive optical power, a second reflecting surface R2 with optical power, and a third reflecting surface R3 with positive optical power. The refractive optical system GL includes lenses L1 to L6, an aperture stop St, and lenses L7 to L12. A first intermediate image M1 is formed in the optical path between the refractive optical system GL and the third reflecting surface R3. A second intermediate image M2 is formed in the optical path between the second reflecting surface R2 and the first reflecting surface R1.

[0313] Data for the imaging optical system of Example 8 are shown in Tables 29 to 32. Table 29 shows the structures of the optical window W. Table 30 shows the structural data of the reflective optical system GR, the refractive optical system GL, and the optical component PP. Table 31 shows the specifications of the composite optical system formed by combining the reflective optical system GR and the refractive optical system GL. Table 32 shows the aspheric coefficients of each aspheric surface.

[0314] [Table 29]

[0315] Example 8

[0316] Central position 32.1mm in the Y-axis direction and 61.6mm in the Z-axis direction. Normal direction The direction of rotation of the optical axis AX by 70° about the X-axis. shape rectangular flat plate size Long side 240mm, short side 46mm Center thickness 3mm Refractive index 1.51680 Abbe number 64.20

[0317] [Table 30]

[0318] Example 8

[0319] Sn R D Nd vd *1 32.0680 79.7500 Reflective surface *2 80.6818 -82.4741 Reflective surface *3 88.6891 87.4742 Reflective surface *4 -403.0262 5.7045 1.51007 56.24 *5 -25.5927 10.9735 6 -42.1526 1.2000 1.60738 56.82 7 -289.1760 3.2086 8 -925.8158 10.2775 1.51742 52.43 9 -33.9505 0.6883 10 -98.2644 1.2004 1.80400 46.53 11 80.3752 6.9581 12 -91.8902 6.8783 1.65844 50.88 13 -34.0606 45.4956 14 32.2189 5.4094 1.48749 70.44 15 -105.2785 5.9301 16 (St) ∞ -2.0098 17 27.8787 1.2006 1.80400 46.53 18 18.8050 1.4514 19 27.2323 6.6969 1.51742 52.43 20 -24.1411 0.1207 21 -23.4680 1.2007 1.80440 39.58 22 57.7071 15.9036 23 153.4166 1.2009 1.79952 42.24 24 32.2895 7.9675 1.58913 61.13 25 -51.7150 0.2000 26 52.3743 7.4921 1.53775 74.70 27 -43.0537 11.5000 28 ∞ 32.1500 1.51680 64.20 29 ∞ 0.1597

[0320] [Table 31]

[0321] Example 8

[0322] f 2.53 Bf 32.84 FNo. 1.68 2ω[°] 156.0

[0323] [Table 32]

[0324] Example 8

[0325] Sn 1 2 3 KA 2.7440972E-01 8.0209624E+00 -1.0828293E+00 A3 0.0000000E+00 0.0000000E+00 0.0000000E+00 A4 -1.5727758E-06 -6.7444778E-05 2.8107038E-07 A5 -1.5475182E-07 6.1020501E-06 1.1521027E-08 A6 7.0219118E-09 2.5265943E-08 -1.0007724E-09 A7 -1.2329329E-11 -3.9549098E-08 3.8248985E-11 A8 -5.7046655E-12 1.5376586E-09 -4.8599481E-13 A9 1.0247085E-13 8.6071456E-11 -1.0659642E-14 A10 1.3991962E-15 -7.5624153E-12 3.9922946E-16 A11 -5.3804736E-17 8.3059010E-14 -2.0046954E-18 A12 1.4802709E-19 9.8785387E-15 -7.9573484E-20 A13 8.3939391E-21 -4.3651349E-16 1.3430506E-21 A14 -7.3107825E-23 5.8950622E-18 -6.4363051E-24

[0326] Sn 4 5 KA -1.0000000E+01 -1.0000000E+01 A3 0.0000000E+00 0.0000000E+00 A4 3.9829966E-04 3.1878299E-04 A5 -4.1819476E-05 -2.0498026E-05 A6 2.1584398E-07 -1.4788913E-06 A7 1.9612557E-07 1.5862761E-07 A8 -1.0765950E-08 1.7232633E-09 A9 -1.9338022E-10 -6.0910377E-10 A10 2.9293499E-1 1 9.2284534E-12 A11 -1.5586060E-13 1.1122429E-12 A12 -3.4968563E-14 -3.0281862E-14 A13 6.2335940E-16 -7.7271077E-16 A14 3.2155229E-18 2.5797054E-17

[0327] [Example 9]

[0328] The structure and cross-sectional view of the imaging optical system of Example 9 are shown in the figure. Figure 21The imaging optical system of Example 9, from the magnification side to the reduction side along the optical path, includes an optical window W, a reflective optical system GR, and a refractive optical system GL. The reflective optical system GR, from the magnification side to the reduction side along the optical path, includes a first reflecting surface R1 with positive optical power, a second reflecting surface R2 with optical power, and a third reflecting surface R3 with positive optical power. The refractive optical system GL, from the magnification side to the reduction side, includes lenses L1 to L6, an aperture stop St, and lenses L7 to L12. A first intermediate image M1 is formed in the optical path between the refractive optical system GL and the third reflecting surface R3. A second intermediate image M2 is formed in the optical path between the second reflecting surface R2 and the first reflecting surface R1.

[0329] Data for the imaging optical system of Example 9 are shown in Tables 33 to 36. Table 33 shows the structures of the optical window W. Table 34 shows the structural data of the reflective optical system GR, the refractive optical system GL, and the optical component PP. Table 35 shows the specifications of the composite optical system formed by combining the reflective optical system GR and the refractive optical system GL. Table 36 shows the aspheric coefficients of each aspheric surface.

[0330] [Table 33]

[0331] Example 9

[0332] Central position 36.6mm in the Y-axis direction and 42.3mm in the Z-axis direction. Normal direction Rotating the optical axis AX by 65° with the X-axis as the rotation axis shape Cylindrical shape, radius of curvature in the X-axis direction 50mm size Long side 95mm, short side 36mm Center thickness 2mm Refractive index 1.51680 Abbe number 64.20

[0333] [Table 34]

[0334] Example 9

[0335] Sn R D Nd vd *1 32.0680 79.7500 Reflective surface *2 80.6818 -82.4741 Reflective surface *3 88.6891 87.4742 Reflective surface *4 -403.0262 5.7045 1.51007 56.24 *5 -25.5927 10.9735 6 -42.1526 1.2000 1.60738 56.82 7 -289.1760 3.2086 8 -925.8158 10.2775 1.51742 52.43 9 -33.9505 0.6883 10 -98.2644 1.2004 1.80400 46.53 11 80.3752 6.9581 12 -91.8902 6.8783 1.65844 50.88 13 -34.0606 45.4956 14 32.2189 5.4094 1.48749 70.44 15 -105.2785 5.9301 16 (St) ∞ -2.0098 17 27.8787 1.2006 1.80400 46.53 18 18.8050 1.4514 19 27.2323 6.6969 1.51742 52.43 20 -24.1411 0.1207 21 -23.4680 1.2007 1.80440 39.58 22 57.7071 15.9036 23 153.4166 1.2009 1.79952 42.24 24 32.2895 7.9675 1.58913 61.13 25 -51.7150 0.2000 26 52.3743 7.4921 1.53775 74.70 27 -43.0537 11.5000 28 ∞ 32.1500 1.51680 64.20 29 ∞ 0.1597

[0336] [Table 35]

[0337] Example 9

[0338] f 2.53 Bf 32.84 FNo. 1.68 2ω[°] 156.0

[0339] [Table 36]

[0340] Example 9

[0341] Sn 1 2 3 KA 2.7440972E-01 8.0209624E+00 -1.0828293E+00 A3 0.0000000E+00 0.0000000E+00 0.0000000E+00 A4 -1.5727758E-06 -6.7444778E-05 2.8107038E-07 A5 -1.5475182E-07 6.1020501E-06 1.1521027E-08 A6 7.0219118E-09 2.5265943E-08 -1.0007724E-09 A7 -1.2329329E-11 -3.9549098E-08 3.8248985E-11 A8 -5.7046655E-12 1.5376586E-09 -4.8599481E-13 A9 1.0247085E-13 8.6071456E-11 -1.0659642E-14 A10 1.3991962E-15 -7.5624153E-12 3.9922946E-16 A11 -5.3804736E-17 8.3059010E-14 -2.0046954E-18 A12 1.4802709E-19 9.8785387E-15 -7.9573484E-20 A13 8.3939391E-21 -4.3651349E-16 1.3430506E-21 A14 -7.3107825E-23 5.8950622E-18 -6.4363051E-24

[0342] Sn 4 5 KA -1.0000000E+01 -1.0000000E+01 A3 0.0000000E+00 0.0000000E+00 A4 3.9829966E-04 3.1878299E-04 A5 -4.1819476E-05 -2.0498026E-05 A6 2.1584398E-07 -1.4788913E-06 A7 1.9612557E-07 1.5862761E-07 A8 -1.0765950E-08 1.7232633E-09 A9 -1.9338022E-10 -6.0910377E-10 A10 2.9293499E-1 1 9.2284534E-12 A11 -1.5586060E-13 1.1122429E-12 A12 -3.4968563E-14 -3.0281862E-14 A13 6.2335940E-16 -7.7271077E-16 A14 3.2155229E-18 2.5797054E-17

[0343] [Example 10]

[0344] The structure and cross-sectional view of the imaging optical system of Example 10 are shown in the figure. Figure 22The imaging optical system of Example 10, from the magnification side to the reduction side along the optical path, includes an optical window W, a reflective optical system GR, and a refractive optical system GL. The reflective optical system GR, from the magnification side to the reduction side along the optical path, includes a first reflecting surface R1 with positive optical power, a second reflecting surface R2 with optical power, and a third reflecting surface R3 with positive optical power. The refractive optical system GL, from the magnification side to the reduction side, includes lenses L1-L2, an aperture stop St, and lenses L3-L6. A first intermediate image M1 is formed in the optical path between the refractive optical system GL and the third reflecting surface R3. A second intermediate image M2 is formed in the optical path between the second reflecting surface R2 and the first reflecting surface R1.

[0345] Data for the imaging optical system of Example 10 are shown in Tables 37 to 40. Table 37 shows the structures of the optical window W. Table 38 shows the structural data of the reflective optical system GR, the refractive optical system GL, and the optical component PP. Table 39 shows the specifications of the composite optical system formed by combining the reflective optical system GR and the refractive optical system GL. Table 40 shows the aspheric coefficients of each aspheric surface.

[0346] [Table 37]

[0347] Example 10

[0348] Central position 11mm in the Y-axis direction and 25mm in the Z-axis direction Normal direction The direction of rotation of the optical axis AX by 60° with the X-axis as the rotation axis. shape rectangular flat plate size 46mm long side, 14mm short side Center thickness 1mm Refractive index 1.51680 Abbe number 64.20

[0349] [Table 38]

[0350] Example 10

[0351] Sn R D Nd vd *1 19.7221 29.7898 Reflective surface *2 26.6528 -23.4282 Reflective surface *3 18.5347 28.7425 Reflective surface *4 33.9837 2.5143 1.80610 40.73 *5 8.4813 2.4972 6 14.1369 1.9148 1.51742 52.15 7 -17.8042 0.5189 8 (St) ∞ 5.3607 9 23.8650 1.5900 1.56883 56.04 10 -138.3622 1.1545 11 18.4597 2.9560 1.49700 81.61 12 -10.1051 1.0782 1.84666 23.78 13 -24.5577 0.2009 14 13.5944 2.8007 1.55397 71.76 15 -181.6933 2.0008 16 ∞ 2.0000 1.51680 64.20 17 ∞ 0.8000 18 ∞ 11.2000 1.72342 37.95 19 ∞ 0.2000 20 ∞ 1.1000 1.48749 70.44 21 ∞ 0.0475

[0352] [Table 39]

[0353] Example 10

[0354] f 0.85 Bf 11.60 FNo. 2.00 2ω[°] 160.6

[0355] [Table 40]

[0356] Example 10

[0357] Sn 1 2 3 KA 3.0254917E-01 5.1850683E+00 -1.8105802E-01 A3 -9.5031709E-04 2.0105494E-03 -4.9273974E-04 A4 1.4950563E-04 -1.7074575E-03 2.4339883E-04 A5 -1.8907199E-06 5.4263026E-04 -5.5543976E-05 A6 -4.9759823E-07 -7.9836465E-05 5.8496337E-06 A7 -1.0287458E-08 -1.6804738E-06 -7.9297237E-09 A8 2.1940240E-09 1.9289363E-06 -5.4324034E-08 A9 6.7227745E-11 -1.6244194E-07 3.5686820E-09 A10 -7.4972837E-12 -1.1674184E-08 1.1525899E-10 A11 -8.9394184E-14 2.3030681E-09 -1.8924245E-11 A12 1.2624994E-14 -2.7508297E-11 2.2396707E-13 A13 2.4630130E-18 -1.1822177E-11 3.6962211E-14 A14 -9.3301580E-18 4.8485752E-13 -1.0545036E-15 A15 3.9711889E-20 2.1098666E-14 -2.3934104E-17 A16 2.2377226E-21 -1.2257663E-15 9.2618167E-19

[0358] Sn 4 5 KA 1.0000000E+00 1.0000000E+00 A3 0.0000000E+00 1.1297561E-18 A4 1.1400003E-04 6.4470365E-04 A5 3.9438050E-04 -2.4327474E-04 A6 -6.8380971E-05 2.8039901E-05 A7 -5.0676829E-05 -1.8367005E-08 A8 1.4369124E-05 -1.5961557E-07 A9 1.1109095E-06 -4.2072390E-09 A10 -4.6856118E-07 1.3036972E-10

[0359] [Example 11]

[0360] The structure and cross-sectional view of the imaging optical system of Example 11 are shown in the figure. Figure 23The imaging optical system of Example 11, from the magnification side to the reduction side along the optical path, includes an optical window W, a reflective optical system GR, and a refractive optical system GL. The reflective optical system GR, from the magnification side to the reduction side along the optical path, includes a first reflecting surface R1 with positive optical power, a second reflecting surface R2 with optical power, and a third reflecting surface R3 with positive optical power. The refractive optical system GL, from the magnification side to the reduction side, includes lenses L1-L2, an aperture stop St, and lenses L3-L6. A first intermediate image M1 is formed in the optical path between the refractive optical system GL and the third reflecting surface R3. A second intermediate image M2 is formed in the optical path between the second reflecting surface R2 and the first reflecting surface R1.

[0361] Data for the imaging optical system of Example 11 are shown in Tables 41 to 44. Table 41 shows the structures of the optical window W. Table 42 shows the structural data of the reflective optical system GR, the refractive optical system GL, and the optical component PP. Table 43 shows the specifications of the composite optical system formed by combining the reflective optical system GR and the refractive optical system GL. Table 44 shows the aspheric coefficients of each aspheric surface.

[0362] [Table 41]

[0363] Example 11

[0364] Central position 24mm in the Y-axis direction and 50.5mm in the Z-axis direction. Normal direction The direction of rotation of the optical axis AX by 60° with the X-axis as the rotation axis. shape Cylindrical shape, radius of curvature in the X-axis direction 20mm size 31mm long side, 15mm short side Center thickness 2mm Refractive index 1.51680 Abbe number 64.20

[0365] [Table 42]

[0366] Example 11

[0367] Sn R D Nd vd *1 19.7221 29.7898 Reflective surface *2 26.6528 -23.4282 Reflective surface *3 18.5347 28.7425 Reflective surface *4 33.9837 2.5143 1.80610 40.73 *5 8.4813 2.4972 6 14.1369 1.9148 1.51742 52.15 7 -17.8042 0.5189 8 (St) ∞ 5.3607 9 23.8650 1.5900 1.56883 56.04 10 -138.3622 1.1545 11 18.4597 2.9560 1.49700 81.61 12 -10.1051 1.0782 1.84666 23.78 13 -24.5577 0.2009 14 13.5944 2.8007 1.55397 71.76 15 -181.6933 2.0008 16 ∞ 2.0000 1.51680 64.20 17 ∞ 0.8000 18 ∞ 11.2000 1.72342 37.95 19 ∞ 0.3000 20 ∞ 1.1000 1.48749 70.44 21 ∞ 0.0475

[0368] [Table 43]

[0369] Example 11

[0370] f 0.85 Bf 11.60 FNo. 2.00 2ω[°] 160.6

[0371] [Table 44]

[0372] Example 11

[0373] Sn 1 2 3 KA 3.0254917E-01 5.1850683E+00 -1.8105802E-01 A3 -9.5031709E-04 2.0105494E-03 -4.9273974E-04 A4 1.4950563E-04 -1.7074575E-03 2.4339883E-04 A5 -1.8907199E-06 5.4263026E-04 -5.5543976E-05 A6 -4.9759823E-07 -7.9836465E-05 5.8496337E-06 A7 -1.0287458E-08 -1.6804738E-06 -7.9297237E-09 A8 2.1940240E-09 1.9289363E-06 -5.4324034E-08 A9 6.7227745E-11 -1.6244194E-07 3.5686820E-09 A10 -7.4972837E-12 -1.1674184E-08 1.1525899E-10 A11 -8.9394184E-14 2.3030681E-09 -1.8924245E-11 A12 1.2624994E-14 -2.7508297E-11 2.2396707E-13 A13 2.4630130E-18 -1.1822177E-11 3.6962211E-14 A14 -9.3301580E-18 4.8485752E-13 -1.0545036E-15 A15 3.9711889E-20 2.1098666E-14 -2.3934104E-17 A16 2.2377226E-21 -1.2257663E-15 9.2618167E-19

[0374] Sn 4 5 KA 1.0000000E+00 1.0000000E+00 A3 0.0000000E+00 1.1297561E-18 A4 1.1400003E-04 6.4470365E-04 A5 3.9438050E-04 -2.4327474E-04 A6 -6.8380971E-05 2.8039901E-05 A7 -5.0676829E-05 -1.8367005E-08 A8 1.4369124E-05 -1.5961557E-07 A9 1.1109095E-06 -4.2072390E-09 A10 -4.6856118E-07 1.3036972E-10

[0375] [Example 12]

[0376] The structure and cross-sectional view of the imaging optical system of Example 12 are shown in the figure. Figure 24The imaging optical system of Example 12, from the magnification side to the reduction side along the optical path, includes an optical window W, a reflective optical system GR, and a refractive optical system GL. The reflective optical system GR, from the magnification side to the reduction side along the optical path, includes a first reflective surface R1 with positive optical power, a second reflective surface R2 with optical power, and a third reflective surface R3 with positive optical power. The first reflective surface R1 and the third reflective surface R3 are formed in the same component and have the same surface shape. The refractive optical system GL, from the magnification side to the reduction side, includes lenses L1-L2, an aperture stop St, and lenses L3-L5. A first intermediate image M1 is formed in the optical path between the refractive optical system GL and the third reflective surface R3. A second intermediate image M2 is formed in the optical path between the second reflective surface R2 and the first reflective surface R1.

[0377] Data for the imaging optical system of Example 12 are shown in Tables 45 to 48. Table 45 shows the structures of the optical window W. Table 46 shows the structural data of the reflective optical system GR, the refractive optical system GL, and the optical component PP. Table 47 shows the specifications of the composite optical system formed by combining the reflective optical system GR and the refractive optical system GL. Table 48 shows the aspheric coefficients of each aspheric surface.

[0378] [Table 45]

[0379] Example 12

[0380] Central position 10.5mm in the Y-axis direction and 29.5mm in the Z-axis direction. Normal direction Rotating the optical axis AX by 45° with the X-axis as the rotation axis shape rectangular flat plate size 38mm long side, 16mm short side Center thickness 1mm Refractive index 1.51680 Abbe number 64.20

[0381] [Table 46]

[0382] Example 12

[0383] Sn R D Nd vd *1 22.3197 26.5656 Reflective surface *2 29.7141 -26.5656 Reflective surface *3 22.3197 32.8262 Reflective surface *4 -57.5824 1.0000 1.50864 56.51 *5 49.1968 2.4914 6 17.5672 1.4885 1.63854 55.38 7 -27.8774 1.7795 8 (St) ∞ 7.5041 9 16.3721 3.0901 1.49700 81.61 10 -10.4746 0.7005 1.84666 23.78 11 -24.7630 0.3239 12 16.2770 2.3784 1.69680 55.53 13 -108.0215 2.0000 14 ∞ 2.0000 1.51680 64.20 15 ∞ 0.8000 16 ∞ 11.2000 1.72342 37.95 17 ∞ 0.3000 18 ∞ 1.1000 1.48749 70.44 19 ∞ 0.1044

[0384] [Table 47]

[0385] Example 12

[0386] f 1.69 Bf 11.75 FNo. 2.00 2ω[°] 142.0

[0387] [Table 48]

[0388] Example 12

[0389] Sn 1 2 3 KA 3.3245959E-01 6.9916921E+00 3.3245959E-01 A3 -1.2869058E-04 3.1651003E-03 -1.2869058E-04 A4 4.7538657E-05 -2.6861172E-03 4.7538657E-05 A5 -7.9560576E-06 9.7601981E-04 -7.9560576E-06 A6 6.6207097E-07 -1.5493818E-04 6.6207097E-07 A7 -8.1793480E-09 -4.2908113E-06 -8.1793480E-09 A8 -2.7107505E-09 4.6387933E-06 -2.7107505E-09 A9 1.5652630E-10 -4.0387463E-07 1.5652630E-10 A10 2.0202953E-12 -3.7238409E-08 2.0202953E-12 A11 -3.7657515E-13 7.0519472E-09 -3.7657515E-13 A12 4.6826058E-15 -3.4995688E-11 4.6826058E-15 A13 3.4876909E-16 -4.4381837E-11 3.4876909E-16 A14 -8.1563597E-18 1.6271035E-12 -8.1563597E-18 A15 -1.0846076E-19 9.7946851E-14 -1.0846076E-19 A16 3.3978515E-21 -5.2184497E-15 3.3978515E-21

[0390] Sn 4 5 KA 1.0000000E+00 1.0000000E+00 A3 0.0000000E+00 7.8797743E-19 A4 1.9552233E-03 2.9311693E-03 A5 1.0443443E-04 -8.2239302E-04 A6 -1.2374104E-04 1.3796017E-04 A7 7.6441311E-06 3.1728021E-05 A8 4.5734892E-06 -1.4431884E-05 A9 -5.2880164E-07 1.0867290E-07 A10 -6.0249175E-08 2.7636340E-07

[0391] [Example 13]

[0392] The structure and cross-sectional view of the imaging optical system of Example 13 are shown in the figure. Figure 25The imaging optical system of Example 13, from the magnification side to the reduction side along the optical path, includes an optical window W, a reflective optical system GR, and a refractive optical system GL. The reflective optical system GR, from the magnification side to the reduction side along the optical path, includes a first reflective surface R1 with positive optical power, a second reflective surface R2 with optical power, and a third reflective surface R3 with positive optical power. The first reflective surface R1 and the third reflective surface R3 are formed in the same component and have the same surface shape. The refractive optical system GL, from the magnification side to the reduction side, includes lenses L1-L2, an aperture stop St, and lenses L3-L5. A first intermediate image M1 is formed in the optical path between the refractive optical system GL and the third reflective surface R3. A second intermediate image M2 is formed in the optical path between the second reflective surface R2 and the first reflective surface R1.

[0393] Data for the imaging optical system of Example 13 are shown in Tables 49 to 52. Table 49 shows the structures of the optical window W. Table 50 shows the structural data for the reflective optical system GR, the refractive optical system GL, and the optical component PP. Table 51 shows the specifications of the composite optical system formed by combining the reflective optical system GR and the refractive optical system GL. Table 52 shows the aspheric coefficients of each aspheric surface.

[0394] [Table 49]

[0395] Example 13

[0396] Central position 8.2mm in the Y-axis direction and 31.8mm in the Z-axis direction. Normal direction Rotating the optical axis AX by 45° with the X-axis as the rotation axis shape rectangular flat plate size Long side 34mm, short side 10.5mm Center thickness 1mm Refractive index 1.51680 Abbe number 64.20

[0397] [Table 50]

[0398] Example 13

[0399] Sn R D Nd vd *1 23.5859 26.2199 Reflective surface *2 28.6473 -26.2199 Reflective surface *3 23.5859 32.7872 Reflective surface *4 -15.2692 1.0001 1.50864 56.51 *5 -22.2217 2.5429 6 14.5278 1.5144 1.63854 55.38 7 -55.2713 1.7800 8 (St) ∞ 7.3297 9 18.9962 3.0504 1.49700 81.61 10 -9.3189 0.9299 1.84666 23.78 11 -19.3178 0.2005 12 16.7503 2.4094 1.69680 55.53 13 -93.9504 2.0000 14 ∞ 2.0000 1.51680 64.20 15 ∞ 0.8000 16 ∞ 11.2000 1.72342 37.95 17 ∞ 0.3000 18 ∞ 1.1000 1.48749 70.44 19 ∞ 0.1015

[0400] [Table 51]

[0401] Example 13

[0402] f 2.22 Bf 11.74 FNo. 2.00 2ω[°] 131.6

[0403] [Table 52]

[0404] Example 13

[0405] Sn 1 2 3 KA 3.3702552E-01 7.1687261E+00 3.3702552E-01 A3 -4.9037924E-05 1.7139537E-03 -4.9037924E-05 A4 2.4068093E-05 -1.7091855E-03 2.4068093E-05 A5 -4.6785568E-06 6.5676892E-04 -4.6785568E-06 A6 4.7025303E-07 -1.3226955E-04 4.7025303E-07 A7 -1.3072687E-08 4.0553947E-06 -1.3072687E-08 A8 -1.3660298E-09 3.1213325E-06 -1.3660298E-09 A9 1.1123180E-10 -4.3985151E-07 1.1123180E-10 A10 -2.7769370E-13 -1.3376801E-08 -2.7769370E-13 A11 -2.1809600E-13 6.2350192E-09 -2.1809600E-13 A12 4.8858587E-15 -1.8346614E-10 4.8858587E-15 A13 1.6908917E-16 -3.5146085E-11 1.6908917E-16 A14 -5.8451536E-18 1.9054678E-12 -5.8451536E-18 A15 -4.2505699E-20 7.1184732E-14 -4.2505699E-20 A16 2.1101974E-21 -4.9230017E-15 2.1101974E-21

[0406] Sn 4 5 KA 1.0000000E+00 1.0000000E+00 A3 3.3023407E-19 -1.3680521E-18 A4 2.9278577E-03 2.7458408E-03 A5 5.8209807E-05 -3.0278925E-05 A6 -9.9526469E-05 -3.5868086E-05 A7 9.9230568E-06 7.5897362E-06 A8 2.8371012E-06 -6.9618044E-07 A9 -3.4215183E-07 1.8525111E-08 A10 -4.2289918E-08 2.0606431E-08

[0407] [Example 14]

[0408] The structure and cross-sectional view of the imaging optical system of Example 14 are shown in the figure. Figure 26The imaging optical system of Example 14, from the magnification side to the reduction side along the optical path, includes an optical window W, a reflective optical system GR, and a refractive optical system GL. The reflective optical system GR, from the magnification side to the reduction side along the optical path, includes a first reflective surface R1 with positive optical power, a second reflective surface R2 with optical power, and a third reflective surface R3 with positive optical power. The first reflective surface R1 and the third reflective surface R3 are formed in the same component and have the same surface shape. The refractive optical system GL, from the magnification side to the reduction side, includes lenses L1 to L5, an aperture stop St, and lenses L6 to L10. A first intermediate image M1 is formed in the optical path between the refractive optical system GL and the third reflective surface R3. A second intermediate image M2 is formed in the optical path between the second reflective surface R2 and the first reflective surface R1.

[0409] Data for the imaging optical system of Example 14 are shown in Tables 53 to 56. Table 53 shows the various structures of the optical window W. The "Origin of the Surface Formula" in Table 53 refers to the origin used in the formula defining the surface of the optical window W; Table 53 shows the position of this origin with the intersection of the first reflecting surface R1 and the optical axis AX as a reference. The "Normal Direction" in Table 53 shows the normal direction of the center of curvature of the magnified side surface of the optical window W. Table 54 shows the structural data of the imaging optical system, including the optical window W, and the optical component PP. Table 55 shows the specifications of the imaging optical system, including the optical window W. Table 56 shows the aspheric coefficients of each aspheric surface.

[0410] [Table 53]

[0411] Example 14

[0412] Central position 35.3mm in the Y-axis direction and 87.1mm in the Z-axis direction. The origin of the form of the curved surface 20mm along the Y-axis and 100mm along the Z-axis. Normal direction The direction of rotation of the optical axis AX by 40° with the X-axis as the rotation axis. shape The magnified side and the reduced side are spherical. size Long side 124mm, short side 44mm Center thickness 1mm Refractive index 1.51680 Abbe number 64.20

[0413] [Table 54]

[0414] Example 14

[0415] Sn R D Nd vd 1 -95.3000 -1.0000 1.51680 64.20 2 -92.0000 -99.0000 *3 68.4344 90.4401 Reflective surface *4 124.9403 -90.4401 Reflective surface *5 68.4344 95.3479 Reflective surface *6 -41.4856 7.9989 1.69350 53.18 7 18.7543 2.6281 8 25.0592 12.0008 1.69895 30.13 9 -54.8102 2.3371 10 -16.6107 5.1325 1.48749 70.44 11 -18.8938 0.9345 12 -103.6085 8.0005 1.77250 49.62 13 21.4501 0.0511 14 17.3458 3.9095 1.48749 70.44 15 (St) -23.7551 2.2322 16 107.9483 12.4152 1.48749 70.44 17 -10.0745 5.9999 1.83481 42.72 18 -99.6193 1.0479 19 68.4501 0.8821 1.80420 46.50 20 35.1266 0.1960 21 37.2551 8.7072 1.59282 68.62 22 -22.1688 0.0300 23 43.1546 3.9884 1.51633 64.06 *24 -108.3105 12.2900 25 ∞ 30.0900 1.51680 64.20 26 ∞ 0.0511

[0416] [Table 55]

[0417] Example 14

[0418] f 1.84 Bf 32.17 FNo. 2.00 2ω[°] 162.2

[0419] [Table 56]

[0420] Example 14

[0421] Sn 3 4 5 KA 5.9549660E-01 7.0407163E+00 5.9549660E-01 A3 -2.8186123E-07 -1.0526407E-04 -2.8186123E-07 A4 2.7050203E-07 1.5627378E-05 2.7050203E-07 A5 -1.7925325E-08 8.8542095E-08 -1.7925325E-08 A6 -3.0297673E-11 -6.9581033E-08 -3.0297673E-11 A7 9.7275184E-12 1.6760577E-09 9.7275184E-12 A8 -4.1700097E-14 5.4517477E-11 -4.1700097E-14 A9 -3.1189692E-15 -2.2682310E-12 -3.1189692E-15 A10 2.6112870E-17 -9.2155994E-15 2.6112870E-17 A11 4.8944073E-19 1.1742342E-15 4.8944073E-19 A12 -5.3587450E-21 -5.5018990E-18 -5.3587450E-21 A13 -3.5635322E-23 -2.7383535E-19 -3.5635322E-23 A14 4.5777099E-25 2.4109042E-21 4.5777099E-25 A15 9.7533588E-28 2.3994848E-23 9.7533588E-28 A16 -1.4012626E-29 -2.6656661E-25 -1.4012626E-29

[0422]

[0423] [Example 15]

[0424] The structure and cross-sectional view of the imaging optical system of Example 15 are shown in the figure. Figure 27 The imaging optical system of Example 15, from the magnification side to the reduction side along the optical path, includes an optical window W, a reflective optical system GR, and a refractive optical system GL. The reflective optical system GR, from the magnification side to the reduction side along the optical path, includes a first reflective surface R1 with positive optical power, a second reflective surface R2 with optical power, and a third reflective surface R3 with positive optical power. The first reflective surface R1 and the third reflective surface R3 are formed in the same component and have the same surface shape. The refractive optical system GL, from the magnification side to the reduction side, includes lenses L1 to L7, an aperture stop St, and lenses L8 to L11. A first intermediate image M1 is formed in the optical path between the refractive optical system GL and the third reflective surface R3. A second intermediate image M2 is formed in the optical path between the second reflective surface R2 and the first reflective surface R1.

[0425] Data for the imaging optical system of Example 15 are shown in Tables 57 to 60. Table 57 shows the various structures of the optical window W. The "Origin of the Formulation for the Surface" in Table 57 refers to the origin used in the formula defining the surface of the optical window W; Table 57 shows the position of this origin with the intersection of the first reflecting surface R1 and the optical axis AX as a reference. The "Normal Direction" in Table 57 shows the normal direction of the center of curvature of the magnified side surface of the optical window W. Table 58 shows the structural data of the imaging optical system including the optical window W and the optical component PP. Table 59 shows the specifications of the imaging optical system including the optical window W. Table 60 shows the aspheric coefficients of each aspheric surface.

[0426] [Table 57]

[0427] Example 15

[0428] Central position 40mm along the Y-axis and 78.55mm along the Z-axis The origin of the form of the curved surface 0mm on the Y-axis and 86.84mm on the Z-axis. Normal direction The direction of the optical axis AX shape The magnified side and the reduced side are aspherical surfaces. size Long side 120mm, short side 52mm Center thickness 4mm Refractive index 1.53638 Abbe number 56.09

[0429] [Table 58]

[0430] Example 15

[0431] Sn R D Nd vd *1 -137.0303 -4.0010 1.53638 56.09 *2 -9994.8919 -82.8362 *3 62.0058 87.8502 Reflective surface *4 569.2204 -87.8502 Reflective surface *5 62.0058 94.7530 Reflective surface *6 -15.6732 4.7847 1.53638 56.09 *7 -62.9889 4.9187 8 -25.1224 0.8000 1.84666 23.78 9 41.7609 0.4087 10 46.1400 7.1405 1.59551 39.24 11 -27.3716 0.0304 12 118.0968 3.8005 1.84666 23.78 13 -64.6260 6.7326 14 18.7644 4.8346 1.59551 39.24 15 759.2139 8.9423 16 -26.7791 0.9991 1.83481 42.72 17 14.1118 0.0308 18 11.5546 3.3679 1.48749 70.44 19 -21.0959 0.5727 20(St) ∞ 3.3982 21 36.6114 4.4440 1.48749 70.44 22 -7.6779 6.0008 1.83481 42.72 23 371.3311 0.0308 24 52.6456 5.9573 1.59282 68.62 25 -24.9938 1.9590 26 210.3683 6.9994 1.58913 61.15 *27 -15.1885 3.2000 28 ∞ 2.0000 1.51680 64.20 29 ∞ 1.0000 30 ∞ 20.0000 1.72342 37.95 31 ∞ 0.4000 32 ∞ 1.2000 1.48749 70.44 33 ∞ 0.0520

[0432] [Table 59]

[0433] Example 15

[0434] f 2.08 Bf 18.37 FNo. 2.00 2ω[°] 154.6

[0435] [Table 60]

[0436] Example 15

[0437] Sn 1 2 27 KA 1.0000000E+00 1.0000000E+00 1.0000000E+00 A4 6.4125122E-07 -1.6359149E-06 6.5017661E-05 A6 -5.9382937E-10 1.2851549E-10 -1.0778638E-08 A8 7.7963296E-14 -9.9141959E-14 4.0140517E-10 A10 -3.9688769E-18 1.3392686E-17 1.6921998E-12

[0438] Sn 3 4 5 KA -3.0432803E-01 9.9999994E+00 -3.0432803E-01 A3 6.5716337E-06 2.6591735E-05 6.5716337E-06 A4 -1.6096295E-06 -1.1026928E-05 -1.6096295E-06 A5 1.2155657E-07 4.5528822E-07 1.2155657E-07 A6 -2.0943836E-09 -4.9394515E-09 -2.0943836E-09 A7 -9.1130495E-11 -2.4464201E-10 -9.1130495E-11 A8 4.4409331E-12 7.4763917E-12 4.4409331E-12 A9 -2.9796044E-14 2.6011524E-14 -2.9796044E-14 A10 -1.7818583E-15 -3.0279917E-15 -1.7818583E-15 A11 3.4737411E-17 1.0212139E-17 3.4737411E-17 A12 1.4932812E-19 5.9534306E-19 1.4932812E-19 A13 -8.6689727E-21 -2.7785886E-21 -8.6689727E-21 A14 3.6789973E-23 -5.9788071E-23 3.6789973E-23 A15 6.8947524E-25 1.9074439E-25 6.8947524E-25 A16 -5.3969606E-27 2.5254284E-27 -5.3969606E-27

[0439] Sn 6 7 KA 1.0000000E+00 1.0000000E+00 A4 2.4768996E-04 1.2733445E-04 A6 -1.5671169E-06 -9.9484243E-07 A8 1.1066272E-08 4.0558252E-09 A10 -5.9100749E-11 -3.3511669E-12 A12 2.4083898E-13 -8.8053517E-14 A14 -6.3192178E-16 5.3022179E-16 A16 8.9595305E-19 -9.9536979E-19

[0440] [Variation Example]

[0441] exist Figure 28 shown in the Figure 27 The imaging optical system of Embodiment 15 shown is a modified example housed inside the frame 9.

[0442] Table 61 shows various data related to the images displayed on display surface 2a in Examples 1-15. In all embodiments, the long side direction is the X-axis direction, and the short side direction is the Y-axis direction. In Table 61, the diagonal length of the image is shown in inches in the "Inch Dimensions" row. "ImL", "ImS", "Δs", and "V" are used in the above conditional expressions. "[mm]" indicates that the unit is millimeters. The diagonal length of the projected magnified image is shown in inches in the "Projection Dimensions" row. In Examples 1-4 and Examples 8-15, the relative position of the imaging optical system 1 and the display element 2 is fixed, but in Examples 5-7, the imaging optical system 1 and the display element 2 are configured to be movable relative to each other in a direction perpendicular to the optical axis AX.

[0443] [Table 61]

[0444] Example 1 Example 2 Example 3 Example 4 Example 5 Inch size 0.61″ 0.61″ 0.78″ 0.78″ 0.61″ ImL[mm] 13.44 13.44 17.28 17.28 13.44 ImS[mm] 7.56 7.56 9.72 9.72 7.56 Aspect Ratio 16∶9 16∶9 16∶9 16∶9 16∶9 Projection size 80″ 80″ 150″ 150″ 120″ Δs[mm] 5.065 5.065 5.832 5.832 4.778～6.161 V 0.67 0.67 0.60 0.60 0.632～0.815

[0445] Example 6 Example 7 Example 8 Example 9 Example 10 Inch size 0.61″ 0.61″ 0.61″ 0.61″ 0.23″ ImL[mm] 13.44 13.44 13.44 13.44 5.184 ImS[mm] 7.56 7.56 7.56 7.56 2.916 Aspect Ratio 16∶9 16∶9 16∶9 16∶9 16∶9 Projection size 120″ 120″ 100″ 100″ 70″ Δs[mm] 4.778～6.161 4.778～6.161 5.292 5.292 2.624 V 0.632～0.815 0.632～0.815 0.70 0.70 0.90

[0446] Example 11 Example 12 Example 13 Example 14 Example 15 Inch size 0.23″ 0.23″ 0.23″ 0.61″ 0.47″ ImL[mm] 5.184 5.184 5.184 13.44 10.368 ImS[mm] 2.916 2.916 2.916 7.56 5.832 Aspect Ratio 16∶9 16∶9 16∶9 16∶9 16∶9 Projection size 70″ 35″ 35″ 100″ 90″ Δs[mm] 2.624 2.624 2.624 4.914 4.43 V 0.90 0.90 0.90 0.65 0.76

[0447] Tables 62 to 66 show the corresponding values ​​of conditional expressions (1) to (12) for the imaging optical systems of Examples 1 to 15. Below the corresponding values ​​of conditional expressions (4), (5), (7), and (10) in Tables 62 to 66, the values ​​used to calculate the corresponding values ​​are shown. The units of length shown in Tables 62 to 66 are all mm (millimeters). The corresponding values ​​of the embodiments shown in Tables 62 to 66 can also be used as upper or lower limits of the conditional expressions to set the preferred range of the conditional expressions.

[0448] [Table 62]

[0449]

[0450] [Table 63]

[0451]

[0452] [Table 64]

[0453]

[0454] [Table 65]

[0455]

[0456] [Table 66]

[0457]

[0458] Next, the projection display device according to the embodiments of the present invention will be described. Figure 29 This is a schematic structural diagram of a projection-type display device according to an embodiment of the present invention. Figure 29 The projection display device 100 shown includes the imaging optical system 10, light source 15, and transmissive display elements 11a-11c that act as light valves and output optical images corresponding to each color of light, as described in the embodiments of the present invention. Furthermore, the projection display device 100 includes dichroic mirrors 12 and 13 for color separation, a cross-shaped dichroic prism 14 for color synthesis, condenser lenses 16a-16c, and total internal reflection mirrors 18a-18c for deflecting the light path. Additionally, in... Figure 29 The imaging optical system 10 is schematically illustrated. Furthermore, an integrator is positioned between the light source 15 and the dichroic mirror 12, but... Figure 29 Its illustration is omitted.

[0459] White light from light source 15 is split into beams of three colors (green, blue, and red) in dichroic mirrors 12 and 13. These beams are then modulated by condenser lenses 16a-16c and incident on transmissive display elements 11a-11c, which correspond to the beams of each color. After color synthesis by cross-shaped dichroic prism 14, the light is incident on imaging optical system 10. Imaging optical system 10 projects an optical image based on the modulated light from transmissive display elements 11a-11c onto screen 105.

[0460] Figure 30 This is a schematic structural diagram of a projection-type display device according to another embodiment of the present invention. Figure 30 The projection display device 200 shown includes the imaging optical system 210, light source 215, and DMD (Digital Micromirror Device) elements 21a-21c, which act as light valves and output optical images corresponding to each color of light, as described in the embodiments of the present invention. Furthermore, the projection display device 200 includes TIR (Total Internal Reflection) prisms 24a-24c for color separation and color synthesis, and a polarizing light separating prism 25 for separating illumination light and projection light. Additionally, in Figure 30The imaging optical system 210 is schematically illustrated. Furthermore, an integrator is disposed between the light source 215 and the polarization-separating prism 25, but... Figure 30 Its illustration is omitted.

[0461] White light from light source 215 is reflected by the reflective surface inside polarization-splitting prism 25 and then decomposed into beams of three colors (green, blue, and red) by TIR prisms 24a-24c. Each decomposed color beam is modulated by its corresponding DMD element 21a-21c, and then undergoes color synthesis again in the opposite direction within the TIR prisms 24a-24c before being transmitted through polarization-splitting prism 25 and incident on imaging optical system 210. Imaging optical system 210 projects an optical image based on the modulated light from DMD elements 21a-21c onto screen 205.

[0462] Figure 31 This is a schematic structural diagram of a projection-type display device according to another embodiment of the present invention. Figure 31 The projection display device 300 shown includes the imaging optical system 310, light source 315, reflective display elements 31a-31c that act as light valves corresponding to each color of light, dichroic mirrors 32 and 33 for color separation, a cross dichroic prism 34 for color synthesis, a total reflection mirror 38 for deflecting the light path, and polarization separation prisms 35a-35c. Furthermore, in Figure 31 The imaging optical system 310 is schematically illustrated. Furthermore, an integrator is positioned between the light source 315 and the dichroic mirror 32, but... Figure 31 Its illustration is omitted.

[0463] White light from light source 315 is split into beams of three colors (green, blue, and red) by dichroic mirrors 32 and 33. Each beam of light is then passed through polarization-separating prisms 35a-35c and modulated by reflective display elements 31a-31c corresponding to their respective colors. After color synthesis by a cross-shaped dichroic prism 34, the light is incident on imaging optical system 310. Imaging optical system 310 projects an optical image based on the modulated light from reflective display elements 31a-31c onto screen 305.

[0464] Figure 32 This is a schematic structural diagram of a projection-type display device according to another embodiment of the present invention. Figure 32The projection display device 400 shown includes an imaging optical system 46, a light source 41, and a DMD element 44 acting as a light valve to output an optical image corresponding to each color of light, as described in the embodiments of the present invention. Furthermore, the projection display device 400 includes a color wheel 42, a light-guiding optical system 43, and a TIR prism 45. Additionally, in Figure 32 The image optical system 46 is schematically illustrated in the figure.

[0465] Color wheel 42 has filters of three colors—green, blue, and red—arranged on its circumference. As color wheel 42 rotates, filters of each color are inserted sequentially into the light path. White light from light source 41 is incident on the rotating color wheel 42 and split into beams of three colors (green, blue, and red) in time. After passing through light guide optical system 43 and TIR prism 45, the time-splitting beams of each color are incident on DMD element 44 and modulated, then pass through TIR prism 45 again before being incident on imaging optical system 46. Imaging optical system 46 projects an optical image based on the modulated light from DMD element 44 onto screen 405.

[0466] Figure 33 and Figure 34 This is an external view of a camera 800, a camera device according to one embodiment of the present invention. Figure 33 This is a stereoscopic view of the camera 800 as seen from the front side. Figure 34 This is a perspective view of the camera 800 as seen from the rear side. The camera 800 is a so-called mirrorless digital camera, capable of mounting and removing an interchangeable lens 820. The interchangeable lens 820 is configured to include an imaging optical system 801 according to an embodiment of the present invention, housed within a lens barrel.

[0467] The camera 800 includes a camera body 831. A shutter button 832 and a power button 833 are provided on the upper surface of the camera body 831. Furthermore, an operation unit 834, an operation unit 835, and a display unit 836 are provided on the back of the camera body 831. The display unit 836 displays the captured image and an image that existed within the field of view before the image was captured.

[0468] A camera aperture for light from the subject is provided at the center of the front surface of the camera body 831. A bayonet 837 is provided at the position corresponding to the camera aperture, and an interchangeable lens 820 is mounted on the camera body 831 via the bayonet 837.

[0469] An image sensor 838 is provided within the camera body 831. The image sensor 838 outputs an image signal corresponding to the image of the subject formed by the interchangeable lens 820. For example, a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) can be used as the image sensor 838. A signal processing circuit (not shown) and a recording medium (not shown) are provided within the camera body 831. The signal processing circuit processes the image signal output from the image sensor 838 to generate an image. The recording medium is used to record the generated image. In the camera 800, still images or moving images can be captured by pressing the shutter button 832, and the image data obtained by this capture is recorded in the aforementioned recording medium.

[0470] The above description, through examples and embodiments, illustrates the technology of the present invention. However, the technology of the present invention is not limited to the above examples and embodiments, and various modifications are possible. The radius of curvature of each reflecting surface, as well as the radius of curvature, surface spacing, refractive index, Abbe number, and aspherical coefficient of each lens, are not limited to the values ​​shown in the above embodiments and may take other values.

[0471] Furthermore, the projection display device involved in the technology of this invention is not limited to the structure described above. For example, the optical components and light valves used in beam splitting or beam combining can be modified in various ways. The light valve is not limited to the method of spatially modulating light from a light source through an image display element to output an optical image based on image data; it can also be the method of outputting an optical image based on image data from the light itself output from a self-emissive image display element. Examples of self-emissive image display elements include, for example, image display elements composed of two-dimensionally arranged light-emitting elements such as LEDs (Light Emitting Diodes) or OLEDs (Organic Light Emitting Diodes).

[0472] Furthermore, the imaging device involved in the technology of the present invention is not limited to the above-described structure. For example, it can be configured as a camera other than a mirrorless type, a film camera, a video camera, a security camera, and a movie camera, etc.

[0473] The following notes further disclose the above-described implementation methods and embodiments.

[0474] [Postscript 1]

[0475] An imaging optical system is capable of forming a magnified image on a magnifying side imaging plane, which magnifies an image on a reducing side imaging plane, wherein...

[0476] Along the optical path from the magnifying side to the reducing side, it sequentially includes an optical window, a reflective optical system, and a refractive optical system comprising multiple lenses.

[0477] The reflective optical system, from the magnification side to the reduction side along the optical path, sequentially includes a first reflecting surface with positive optical power, a second reflecting surface with optical power, and a third reflecting surface with positive optical power.

[0478] A first intermediate image is formed at a position on the optical path that is closer to the reduced side than the third reflecting surface and is conjugate with the image.

[0479] A second intermediate image is formed within the reflective optical system at a position conjugate to the first intermediate image.

[0480] The magnified image is formed at a position on the optical path that is further away from the magnification side than the optical window and is conjugate with the second intermediate image.

[0481] The center of the magnified image is located at a position that is displaced in a direction perpendicular to the optical axis relative to the optical axis of the refractive optical system.

[0482] The principal ray incident on the center of the magnified image under the condition of maximum displacement is taken as the central principal ray.

[0483] Let α be the angle of incidence of the central principal ray toward the magnified imaging surface.

[0484] When the incident angle of the central principal ray toward the optical window is set to θc, the following conditions are met:

[0485] 40°<|α|<85° (1)

[0486] 0°<|θc|<35° (2)

[0487] The conditions (1) and (2) are represented.

[0488] [Postscript 2]

[0489] According to the imaging optical system described in Appendix 1, wherein,

[0490] When the maximum half-angle of the magnified side is set to ω, the following conditions are met:

[0491] 65°<ω<90° (3)

[0492] The conditional expression (3) is represented.

[0493] [Postscript 3]

[0494] According to the imaging optical system described in Appendix 1 or Appendix 2, the intersection of the central principal ray and the magnified side of the optical window is located on the optical axis further from the third reflecting surface than the second reflecting surface as a whole.

[0495] [Postscript 4]

[0496] According to any one of Annexes 1 to 3, the imaging optical system wherein the optical window is located generally closer to the third reflecting surface than the point located on the magnified side of the refractive optical system in the direction of the optical axis.

[0497] [Postscript 5]

[0498] The imaging optical system according to any one of Annexes 1 to 4, wherein,

[0499] Let hWmin be the distance between the point in the optical window closest to the optical axis and the optical axis.

[0500] When the radius of the lens closest to the magnification side of the refractive optical system is set to ra, the following conditions are met:

[0501] 0.9 < hWmin / ra < 3 (4)

[0502] The conditional expression (4) is represented.

[0503] [Postscript 6]

[0504] According to the imaging optical system described in any one of Annexes 1 to 5, wherein,

[0505] The optical window is a flat plate.

[0506] Let hWR be the distance between the point closest to the optical axis and the optical axis located on the side of the optical window closest to the reflective optical system along the optical axis.

[0507] When the distance between the point farthest from the optical axis within the effective area of ​​the third reflecting surface and the optical axis is set to hM3, the following conditions are met:

[0508] 0.5 < hWR / hM3 < 3 (5)

[0509] The conditional expression (5) is represented.

[0510] [Postscript 7]

[0511] The imaging optical system according to any one of Annexes 1 to 6, wherein,

[0512] The optical window is a flat plate.

[0513] When the tilt angle of the optical window relative to the plane perpendicular to the optical axis is set to θwin, the following conditions are met:

[0514] 30°<θwin<85° (6)

[0515] The conditional expression (6) is represented.

[0516] [Postscript 8]

[0517] The imaging optical system according to any one of Annexes 1 to 7, wherein,

[0518] The optical window is a flat plate.

[0519] Let Δs be the distance between the center of the image and the optical axis.

[0520] Let the length of the shorter side of the image be ImS.

[0521] Let the minimum value of V, defined by V = Δs / ImS, be Vmin.

[0522] Let the length of the longer side of the rectangle circumscribed with the optical window be WL.

[0523] Let Dsc be the distance from the first reflecting surface to the optical axis of the magnified image.

[0524] Let the length of the long side of the magnified image be PrL.

[0525] When the length of the longer side of the image is set to ImL, it satisfies

[0526] 0<(Vmin-0.5)×WL×(Dsc / PrL) / ImL<1.2 (7)

[0527] The conditional expression (7) is represented.

[0528] [Postscript 9]

[0529] The imaging optical system according to any one of Annexes 1 to 8, wherein,

[0530] The optical window is a flat plate.

[0531] Let the length of the longer side of the rectangle circumscribed with the optical window be WL.

[0532] When the length of the shorter side of the rectangle is set to WS, the following conditions are met:

[0533] 2 < WL / WS < 10 (8)

[0534] The conditional expression (8) is represented.

[0535] [Postscript 10]

[0536] The imaging optical system according to any one of Annexes 1 to 9, wherein...

[0537] The optical window is a flat plate.

[0538] Let Δs be the distance between the center of the image and the optical axis.

[0539] Let the length of the shorter side of the image be ImS.

[0540] Let the minimum value of V, defined by V = Δs / ImS, be Vmin.

[0541] Let the length of the longer side of the rectangle circumscribed with the optical window be WL.

[0542] When the length of the shorter side of the rectangle is set to WS, the following conditions are met:

[0543] 0.5<(Vmin-0.5)×WL / WS<1.5 (9)

[0544] The conditional expression (9) is represented.

[0545] [Postscript 11]

[0546] The imaging optical system according to any one of Annexes 1 to 5, wherein the optical window has curvature in the long side direction of the image.

[0547] [Postscript 12]

[0548] According to the imaging optical system described in Appendix 11, wherein,

[0549] Let WpL be the length of the long side of the projection of the rectangle circumscribed by the optical window onto the plane perpendicular to the direction from the center of the curvature toward the origin used in the formula defining the surface of the optical window.

[0550] When the length of the shorter side of the projection is set to WpS, the following conditions are met:

[0551] 1 < WpL / WpS < 3 (10)

[0552] The conditional expression (10) is represented.

[0553] [Postscript 13]

[0554] The imaging optical system according to Appendix 11 or Appendix 12, wherein the optical window is a cylindrical lens.

[0555] [Postscript 14]

[0556] According to the imaging optical system described in Appendix 13, wherein,

[0557] The narrowed side of the optical window is cylindrical.

[0558] Let WpL be the length of the long side of the projection of the rectangle circumscribed by the optical window onto the plane perpendicular to the direction from the center of the curvature toward the origin used in the formula defining the surface of the optical window.

[0559] When the radius of curvature of the cylinder in the direction perpendicular to the generatrix of the cylinder is set to Rcy, the following condition is met:

[0560] 1 < WpL / Rcy < 2 (11)

[0561] The conditional expression (11) is represented.

[0562] [Postscript 15]

[0563] According to the imaging optical system described in Appendix 13 or Appendix 14, wherein,

[0564] The narrowed side of the optical window is cylindrical.

[0565] The combined focal length of the reflective optical system and the refractive optical system is set to fRL.

[0566] When the radius of curvature of the cylinder in the direction perpendicular to the generatrix of the cylinder is set to Rcy, the following condition is met:

[0567] 0 < fRL / Rcy < 0.1 (12)

[0568] The conditional expression (12) is represented.

[0569] [Postscript 16]

[0570] The imaging optical system according to Appendix 11 or Appendix 12, wherein the optical window has a complex tortuous surface shape.

[0571] [Postscript 17]

[0572] According to the imaging optical system described in Appendix 11 or Appendix 12, the magnifying side surface and the reducing side surface of the optical window are spherical.

[0573] [Postscript 18]

[0574] The imaging optical system according to Appendix 11 or Appendix 12, wherein the optical window has an aspherical shape.

[0575] [Postscript 19]

[0576] A projection display device comprising an imaging optical system as described in any one of Annex 1 to Annex 18.

[0577] [Postscript 20]

[0578] A camera device comprising an imaging optical system as described in any one of Annex 1 to Annex 18.

Claims

1. An imaging optical system capable of forming a magnified image on a magnifying side imaging plane, which magnifies an image on a reducing side imaging plane, wherein, Along the optical path from the magnifying side to the reducing side, it sequentially includes an optical window, a reflective optical system, and a refractive optical system comprising multiple lenses. The reflective optical system, from the magnification side to the reduction side along the optical path, sequentially includes a first reflecting surface with positive optical power, a second reflecting surface with optical power, and a third reflecting surface with positive optical power. A first intermediate image is formed at a position on the optical path that is closer to the reduced side than the third reflecting surface and is conjugate with the image. A second intermediate image is formed within the reflective optical system at a position conjugate to the first intermediate image. The magnified image is formed at a position on the optical path that is further away from the magnification side than the optical window and is conjugate with the second intermediate image. The center of the magnified image is located at a position that is displaced in a direction perpendicular to the optical axis relative to the optical axis of the refractive optical system. The principal ray incident on the center of the magnified image under the condition of maximum displacement is taken as the central principal ray. Let α be the angle of incidence of the central principal ray toward the magnified imaging surface. When the incident angle of the central principal ray toward the optical window is set to θc, the following conditions are met: 40°＜|α|＜85° (1) 0°<|θc|<35° (2) The conditions (1) and (2) are represented.

2. The imaging optical system according to claim 1, wherein, When the maximum half-angle of the magnified side is set to ω, the following conditions are met: 65°<ω<90° (3) The conditional expression (3) is represented.

3. The imaging optical system according to claim 1 or 2, wherein, The intersection of the central principal ray and the magnified side of the optical window is located on the optical axis further from the third reflective surface than the second reflective surface as a whole.

4. The imaging optical system according to claim 1 or 2, wherein, The optical window is located closer to the third reflecting surface than the point on the magnified side of the refractive optical system in the direction of the optical axis.

5. The imaging optical system according to claim 1 or 2, wherein, Let hWmin be the distance between the point in the optical window closest to the optical axis and the optical axis. When the radius of the lens closest to the magnification side of the refractive optical system is set to ra, the following conditions are met: 0.9 < hWmin / ra < 3 (4) The conditional expression (4) is represented.

6. The imaging optical system according to claim 1 or 2, wherein, The optical window is a flat plate. Let hWR be the distance between the point closest to the optical axis and the optical axis located on the side of the optical window closest to the reflective optical system along the optical axis. When the distance between the point farthest from the optical axis within the effective area of ​​the third reflecting surface and the optical axis is set to hM3, the following conditions are met: 0.5 < hWR / hM3 < 3 (5) The conditional expression (5) is represented.

7. The imaging optical system according to claim 1 or 2, wherein, The optical window is a flat plate. When the tilt angle of the optical window relative to the plane perpendicular to the optical axis is set to θwin, the following conditions are met: 30°<θwin<85° (6) The conditional expression (6) is represented.

8. The imaging optical system according to claim 1 or 2, wherein, The optical window is a flat plate. Let Δs be the distance between the center of the image and the optical axis. Let the length of the shorter side of the image be ImS. Let the minimum value of V, defined by V = Δs / ImS, be Vmin. Let the length of the longer side of the rectangle circumscribed with the optical window be WL. Let Dsc be the distance from the first reflecting surface to the optical axis of the magnified image. Let the length of the long side of the magnified image be PrL. When the length of the longer side of the image is set to ImL, it satisfies 0<(Vmin-0.5)×WL×(Dsc / PrL) / ImL<1.2 (7) The conditional expression (7) is represented.

9. The imaging optical system according to claim 1 or 2, wherein, The optical window is a flat plate. Let the length of the longer side of the rectangle circumscribed with the optical window be WL. When the length of the shorter side of the rectangle is set to WS, the following conditions are met: 2 < WL / WS < 10 (8) The conditional expression (8) is represented.

10. The imaging optical system according to claim 1 or 2, wherein, The optical window is a flat plate. Let Δs be the distance between the center of the image and the optical axis. Let the length of the shorter side of the image be ImS. Let the minimum value of V, defined by V = Δs / ImS, be Vmin. Let the length of the longer side of the rectangle circumscribed with the optical window be WL. When the length of the shorter side of the rectangle is set to WS, the following conditions are met: 0.5<(Vmin-0.5)×WL / WS<1.5 (9) The conditional expression (9) is represented.

11. The imaging optical system according to claim 1 or 2, wherein, The optical window has curvature along the long side of the image.

12. The imaging optical system according to claim 11, wherein, Let WpL be the length of the long side of the projection of the rectangle circumscribed by the optical window onto the plane perpendicular to the direction from the center of the curvature toward the origin used in the formula defining the surface of the optical window. When the length of the shorter side of the projection is set to WpS, the following conditions are met: 1 < WpL / WpS < 3 (10) The conditional expression (10) is represented.

13. The imaging optical system according to claim 11, wherein, The optical window is a cylindrical lens.

14. The imaging optical system according to claim 13, wherein, The narrowed side of the optical window is cylindrical. Let WpL be the length of the long side of the projection of the rectangle circumscribed by the optical window onto the plane perpendicular to the direction from the center of the curvature toward the origin used in the formula defining the surface of the optical window. When the radius of curvature of the cylinder in the direction perpendicular to the generatrix of the cylinder is set to Rcy, the following condition is met: 1 < WpL / Rcy < 2 (11) The conditional expression (11) is represented.

15. The imaging optical system according to claim 13, wherein, The narrowed side of the optical window is cylindrical. The combined focal length of the reflective optical system and the refractive optical system is set to fRL. When the radius of curvature of the cylinder in the direction perpendicular to the generatrix of the cylinder is set to Rcy, the following condition is met: 0 < fRL / Rcy < 0.1 (12) The conditional expression (12) is represented.

16. The imaging optical system according to claim 11, wherein, The optical window has a tortuous surface shape.

17. The imaging optical system according to claim 11, wherein, The magnified side and the reduced side of the optical window are spherical.

18. The imaging optical system according to claim 11, wherein, The optical window has an aspherical shape.

19. A projection display device comprising the imaging optical system according to any one of claims 1 to 18.

20. A camera device comprising the imaging optical system according to any one of claims 1 to 18.

Images