Projection lens and projector

Abstract

This projection lens which is attached to a housing of a projector comprises: a rear lens into which light from the projector enters; a front lens which projects light; a plurality of reflective elements which are disposed between the rear lens and the front lens and which sequentially reflect light transmitted through the rear lens to cause said light to transmit through the front lens; a lens barrel that supports the rear lens, the front lens, and the plurality of reflective elements; and a lens mount that is provided to the lens barrel and that is detachably connected to a body mount provided to the housing of the projector. The optical axis of the rear lens and the optical axis of the front lens are skewed relative to each other.

Description

Projection lens and projector

[0001] The present disclosure relates to a projection lens and a projector that projects image light through the projection lens.

[0002] For example, as a projection lens that is detachably attached to the housing of a projector, there is one described in Patent Document 1. The projection lens described in Patent Document 1 is attached to the front end of the housing of the projector, U-turns the image light emitted from the projector toward the front of the housing, and finally projects it toward the rear of the housing.

[0003] Japanese Patent No. 6836213

[0004] By the way, in the case of the projection lens described in Patent Document 1, if the size of the projector housing in the front-rear direction is large, a part of the housing may be reflected as a shadow in the projection image on the screen. This is caused by the fact that the front lens of the projection lens (the lens that finally emits image light to the outside) is separated from the rear end of the projector housing toward the front end side, and thus a part of the housing exists within the range of the projection angle of the front lens.

[0005] Therefore, an object of the present disclosure is to suppress a part of the projector housing from being reflected as a shadow in the projection image on the screen in a projector to which a projection lens that projects the light emitted from the projector in a direction different from the emission direction is attached.

[0006] To solve the above-mentioned problems, according to one aspect of the present disclosure, a projection lens is provided which is attached to the housing of a projector, comprising: a rear lens into which light from the projector is incident; a front lens for projecting light; a plurality of reflective elements disposed between the rear lens and the front lens, respectively, which sequentially reflect the light that has passed through the rear lens and transmit it to the front lens; a lens barrel supporting the rear lens, the front lens, and the plurality of reflective elements; and a lens mount provided on the lens barrel and detachably connected to a body mount provided on the housing of the projector, wherein the optical axis of the rear lens and the optical axis of the front lens are in a twisted positional relationship with respect to each other.

[0007] Furthermore, according to another aspect of this disclosure, a projector is provided having the above-mentioned projection lens, a housing, and a body mount provided on the housing to which the lens mount of the projection lens is detachably attached.

[0008] According to this disclosure, in a projector equipped with a projection lens that projects light emitted from the projector in a direction different from the direction of emission, it is possible to suppress the appearance of a part of the projector's housing as a shadow on the projected image on the screen.

[0009] Schematic diagram of a projector according to an embodiment of the present disclosure Front perspective view of a projector with a projection lens attached Rear perspective view of a projector with a projection lens attached Front perspective view of a projector with a projection lens removed Front perspective view of the projection lens Rear perspective view of the projection lens Right side view of the projection lens Top view of the projection lens Schematic diagram of the optical system of the projection lens Top view of a projector with a projection lens attached Front perspective view of a deformed projection lens Rear perspective view of a projection lens in a different deformed state

[0010] A projection lens according to one aspect of the present disclosure is a projection lens attached to the housing of a projector, comprising: a rear lens into which light from the projector is incident; a front lens that projects light; a plurality of reflective elements positioned between the rear lens and the front lens, respectively, which sequentially reflect the light that has passed through the rear lens and transmit it to the front lens; a lens barrel that supports the rear lens, the front lens, and the plurality of reflective elements; and a lens mount provided on the lens barrel and detachably connected to a body mount provided on the housing of the projector, wherein the optical axis of the rear lens and the optical axis of the front lens are in a twisted positional relationship with respect to each other.

[0011] In this configuration, in a projector equipped with a projection lens that projects light emitted from the projector in a direction different from the direction of emission, it is possible to suppress the appearance of a part of the projector's housing as a shadow on the projected image on the screen.

[0012] For example, if the plurality of reflective elements include a first reflective element, a second reflective element, and a third reflective element, the first reflective element reflects the light transmitted through the rear lens in a first reflection direction intersecting the direction of extension of the optical axis of the rear lens; the second reflective element reflects the light reflected by the first reflective element in a second reflection direction intersecting the first reflection direction; and the third reflective element reflects the light reflected by the second reflective element toward the front lens in a third reflection direction intersecting the second reflection direction and parallel to the direction of extension of the optical axis of the front lens.

[0013] For example, the direction in which the optical axis of the rear lens extends and the second reflection direction may be parallel to each other.

[0014] When the direction in which the optical axis of the rear lens extends and the second reflection direction are parallel to each other, for example, the third reflection direction is a direction that intersects a plane containing the direction in which the optical axis of the rear lens extends and the second reflection direction.

[0015] When the direction in which the optical axis of the rear lens extends and the second reflection direction are parallel to each other, the first reflection direction may be perpendicular to the direction in which the optical axis of the rear lens extends, the second reflection direction may be perpendicular to the first reflection direction, and the distance between the second reflecting element and the third reflecting element may be greater than the distance between the first reflecting element and the lens mount.

[0016] For example, the lens barrel may comprise a first portion including the rear lens and the first reflecting element, a second portion including the second reflecting element, and a third portion including the third reflecting element and the front lens, wherein the first portion supports the second portion so as to be rotatable about a first pivot center line extending in the first reflection direction, and the second portion supports the third portion so as to be rotatable about a second pivot center line extending in the second reflection direction.

[0017] A projector according to another aspect of the present disclosure comprises the above-described projection lens, a housing, and a body mount provided on the housing to which the lens mount of the projection lens is detachably attached.

[0018] In this configuration, in a projector equipped with a projection lens that projects light emitted from the projector in a direction different from the direction of emission, it is possible to suppress the appearance of a part of the projector's housing as a shadow on the projected image on the screen.

[0019] For example, if the housing has a shape that includes front-to-back, left-to-right, and height directions, and the body mount is provided on the front of the housing, and the size of the housing in the left-to-right direction is smaller than that in the front-to-back direction, then the front lens of the projection lens may overlap the housing in the height direction, and the optical axis of the front lens may extend in the left-to-right direction.

[0020] Embodiments of the present disclosure will be described below with reference to the drawings. However, unnecessarily detailed explanations may be omitted. For example, detailed explanations of already well-known matters and redundant explanations of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily verbose and to facilitate understanding by those skilled in the art.

[0021] The attached drawings and the following description are provided for the benefit of those skilled in the art to fully understand this disclosure and are not intended to limit the subject matter described in the claims.

[0022] The projection lens and projector according to the embodiments of this disclosure will be described below with reference to the drawings.

[0023] Figure 1 is a schematic diagram of a projector according to an embodiment of the present disclosure.

[0024] As shown in Figure 1, the projector 10 according to this embodiment has a housing 12. The housing 12 is equipped with a light source 14 and an optical modulation element 16 that modulates the light from the light source 14 to form an image (image light). The optical modulation element 16 is, for example, a transmissive liquid crystal display or a DMD (Digital Micromirror Device). The image light (modulated light) emitted from the optical modulation element 16 is projected onto a screen S or the like via a projection lens 20. Note that the embodiments of this disclosure are not limited to the method of forming the image light incident on the projection lens 20.

[0025] Figures 2 and 3 are front and rear perspective views of a projector with a projection lens attached, according to one embodiment of the present disclosure. Figure 4 is a front perspective view of the projector with the projection lens removed. The X-Y-Z Cartesian coordinate system shown in the figures is intended to facilitate understanding of the embodiments of the present disclosure and does not limit them. The X-axis direction indicates the front-to-back direction of the projector, the Y-axis direction indicates the left-to-right direction, and the Z-axis direction indicates the height direction. The direction in which the projector 10 emits light with the projection lens removed is defined as the "front direction" of the projector 10. Furthermore, "left direction" and "right direction" are the directions when viewing the projector 10 from the front of the projector 10. Furthermore, the "height direction" does not limit the projector's installation position to one where this "height direction" is parallel to the vertical direction.

[0026] As shown in Figures 2 to 4, in this embodiment, the housing 12 of the projector 10 has a rectangular shape, and its size in the front-to-back direction (X-axis direction) is larger than its size in the left-to-right direction (Y-axis direction). In addition, a body mount 18 to which the projection lens 20 is detachably attached is provided on the front surface 12a of the housing 12. Furthermore, an air intake port 12c is provided on the right side surface 12b, and an exhaust port 12e is provided on the rear surface 12d.

[0027] The projection lens 20 projects the image light emitted from the projector 10 (in this embodiment, the image light emitted from the light modulation element 16) onto the screen S. Specifically, the projection lens 20 is configured to project the light emitted forward from the projector 10 in another direction (in this embodiment, to the right).

[0028] Figures 5 and 6 are front and rear perspective views of the projection lens. Figure 7 is a right side view of the projection lens. Furthermore, Figure 8 is a top view of the projection lens. And Figure 9 is a schematic diagram of the optical system of the projection lens.

[0029] As shown in Figures 5 to 8, the projection lens 20 has a lens barrel 22. The projection lens 20 also has a rear lens 24 into which image light from the projector 10 enters, and a front lens 26 that projects the image light onto the screen S. The rear lens 24 is located at the proximal end 22a of the lens barrel 22, which is closer to the projector 10 in the optical path, and the front lens 26 is located at the distal end 22b of the lens barrel 22.

[0030] As shown in Figure 4, when the projection lens 20 is attached to the housing 12 of the projector 10, the optical axis C1 of the rear lens 24 coincides with the optical axis C0 of the projector 10. The optical axis C0 of the projector 10 extends in the front-to-back direction (X-axis direction) of the housing 12, that is, it extends in the direction of emission of image light from the projector 10 when the projection lens 20 is not attached. Furthermore, the optical axis C0 is emitted from the projector 10 when the projection lens 20 is not attached and passes through the center of the projected image projected onto a plane perpendicular to the direction of emission.

[0031] As described above and as shown in Figure 4, a body mount 18 is provided on the front surface 12a of the housing 12 of the projector 10. A lens mount 28, which is detachably connected to this body mount 18, is provided on the lens barrel 22 of the projection lens 20. By connecting the lens mount 28 to the body mount 18, the optical axis C1 of the rear lens 24 and the optical axis C0 of the projector 10 coincide (are located on the same straight line). In this embodiment, the connection between the lens mount 28 and the body mount 18 is a bayonet type, in which the connection is completed by bringing the lens mount 28 and the body mount 18 into contact and then rotating the projection lens 20 around the optical axis C0 of the projector 10. However, the embodiments of this disclosure are not limited to a bayonet type for the method of connecting the projection lens 20 and the projector 10.

[0032] As shown in Figures 6 and 9, the rear lens 24 and the front lens 26 are supported by the lens barrel 22 such that the direction of extension of the optical axis C1 of the rear lens 24 and the direction of extension of the optical axis C2 of the front lens 26 are different from each other. In this embodiment, when the projection lens 20 is attached to the housing 12 of the projector 10, the optical axis C1 of the rear lens 24 extends in the front-to-back direction (X-axis direction) of the projector 10, and the optical axis C2 of the front lens 26 extends in the left-to-right direction (Y-axis direction). Therefore, as shown in Figures 7 to 9, the first reflective element 30, the second reflective element 32, and the third reflective element 34 are arranged on the optical path within the lens barrel 22 between the rear lens 24 and the front lens 26.

[0033] In this embodiment, as shown in Figure 9, the optical axis C1 of the rear lens 24 and the optical axis C2 of the front lens 26 are non-parallel and not on the same plane. Furthermore, the optical axis C1 of the rear lens 24 and the optical axis C2 of the front lens 26 do not intersect. That is, the optical axis C1 of the rear lens 24 and the optical axis C2 of the front lens 26 are in a twisted positional relationship with respect to each other. In this positional relationship between the rear lens 24 and the front lens 26, the first to third reflective elements 30, 32, and 34 are provided on the lens barrel 22 in order to transmit the image light that has passed through the rear lens 24 to the front lens 26.

[0034] The first to third reflective elements 30, 32, and 34 are, for example, mirrors and are supported by the lens barrel 22. The first reflective element 30 reflects the image light transmitted through the rear lens 24 toward the second reflective element 32 in a first reflection direction D1. The first reflection direction D1 is a direction that intersects the direction of extension of the optical axis C1 of the rear lens 24 (X-axis direction) (in this embodiment, the height direction of the projector 10 (Z-axis direction)). That is, the first reflective element 30 and the second reflective element 32 are supported by the lens barrel 22 with a gap between them in the first reflection direction D1.

[0035] The second reflecting element 32 reflects the light reflected by the first reflecting element 30, which is traveling in the first reflection direction D1, toward the third reflecting element 34 in the second reflection direction D2. The second reflection direction D2 is a direction that intersects with the first reflection direction D1. In this embodiment, the second reflection direction D2 is perpendicular to the first reflection direction and parallel to the extending direction (X-axis direction) of the optical axis C1 of the rear lens 24. That is, the second reflecting element 32 and the third reflecting element 34 are supported by the lens barrel 22 with a gap between them in the second reflection direction D2. Therefore, in this embodiment, the image light transmitted through the rear lens 24 makes a U-turn via the first and second reflecting elements 30 and 32.

[0036] The third reflecting element 34 reflects the light reflected by the second reflecting element 32, which is traveling in the second reflection direction D2, toward the front lens 26 in the third reflection direction D3. The third reflection direction D3 intersects the second reflection direction D2 and is parallel to the extending direction (Y-axis direction) of the optical axis C2 of the front lens 26. In this embodiment, the third reflection direction D3 intersects the plane (Z-X plane) that includes the extending direction (X-axis direction) of the optical axis C1 of the rear lens 24 and the second reflection direction D2 (X-axis direction). Also in this embodiment, the third reflection direction D3 is perpendicular to the second reflection direction D2.

[0037] With these first, second, and third reflective elements 30, 32, and 34, even if the optical axis C1 of the rear lens 24 and the optical axis C2 of the front lens 26 are in a twisted positional relationship, the image light from the projector 10 can be propagated from the rear lens 24 to the front lens 26. As a result, the image light emitted from the projector 10 in the front-to-back direction (X-axis direction) is ultimately projected by the projection lens 20 towards the screen S in the left-to-right direction (Y-axis direction) of the projector 10.

[0038] Furthermore, in this embodiment, as shown in Figure 7, the distance L1 between the second reflecting element 32 and the third reflecting element 34 is greater than the distance L2 between the first reflecting element 30 and the lens mount 28. As a result, a portion of the distal end 22b side of the barrel 22 of the projection lens 20 overlaps with the housing 12 of the projector 10.

[0039] Figure 10 is a top view of the projector with the projection lens attached.

[0040] As shown in Figure 10, in this embodiment, the front lens 26 of the projection lens 20 attached to the housing 12 of the projector 10 is located above the upper surface 12f of the housing 12 of the projector 10 and is oriented in the left-right direction (Y-axis direction) of the projector 10 (the optical axis C2 extends in the left-right direction). The reason for this is that, in this embodiment, the size of the housing 12 of the projector 10 in the left-right direction (Y-axis direction) is smaller than the size in the front-back direction (X-axis direction), and also, as shown in Figure 3, an exhaust port 12e is provided on the rear surface 12d of the housing 12.

[0041] To explain in more detail, unlike this embodiment, if the front lens 26 located above the upper surface 12f of the housing 12 of the projector 10 is oriented in the front-to-back direction (X-axis direction) of the projector 10, then a part of the housing 12 will appear as a shadow in the projected image projected onto the screen S from such a front lens 26. This is because the distance from the front lens 26 to the rear surface 12d of the housing 12 is large. In addition, hot air discharged from the exhaust port 12e on the rear surface 12d of the housing 12 flows between the front lens 26 and the screen S, causing the projected image on the screen S to appear blurred. As a result, the projected image on the screen S is not clearly displayed. To address this, it is possible to increase the distance between the front lens 26 and the upper surface 12f of the housing 12, and / or bring the front lens 26 closer to the rear surface 12d of the housing 12, so that no part of the housing 12 of the projector 10 is within the projection angle range of the front lens 26. However, in that case, the projection lens 20 needs to be made larger. Furthermore, the housing 12 of the projector 10 needs to be configured to support the enlarged projection lens 20.

[0042] In contrast, in the case of the present embodiment, the front lens 26 located above the upper surface 12f of the housing 12 of the projector 10 faces in the left - right direction (Y - axis direction) of the projector 10. Since the size in the left - right direction is smaller than the size in the front - rear direction (X - axis direction), the distance L3 from the front lens 26 to the right side surface 12b of the housing 12 is small. As a result, without increasing the size of the projection lens 20, it is possible to suppress a part of the housing 12 of the projector 10 from being imaged as a shadow on the projection image projected on the screen S. Further, since there is no exhaust port provided on the right side surface 12b of the housing 12, the projection image on the screen S does not look blurred. Note that the distance L3 from the front lens 26 to the right side surface 12b of the housing 12 is determined by the required optical path length between the rear lens 24 and the front lens 26.

[0043] Further, since the front lens 26 of the projection lens 20 attached to the housing 12 of the projector 10 overlaps the upper surface 12f of the housing 12 in the height direction (Z - axis direction), the load applied to the body mount 18 that connects and supports the projection lens 20 is reduced.

[0044] Specifically, different from the present embodiment, when the projection lens 20 does not overlap the housing 12 of the projector 10 in the height direction (Z - axis direction) view, the center of gravity of the projection lens 20 exists at a position away from the front surface 12a of the housing 12 of the projector 10. As a result, a large moment is generated in the body mount 18 that connects and supports the projection lens 20. In contrast, in the case of the present embodiment, a part of the projection lens 20 overlaps the housing 12 of the projector 10 in the height direction view. Therefore, the center of gravity of the projection lens 20 approaches or overlaps the housing 12 of the projector 10. Thereby, the moment generated in the body mount 18 that connects and supports the projection lens 20 becomes smaller. As a result, the load applied to the body mount 18 is reduced.

[0045] Furthermore, in the case of the present embodiment, the projection lens 20 is configured to be deformable. That is, the projection lens 20 is configured to be able to change the projection direction of the image light from the front lens 26 of the projection lens 20 attached to the projector 10.

[0046] FIG. 11 is a front perspective view of the projection lens in a deformed state. Also, FIG. 12 is a rear perspective view of the projection lens in a different deformed state.

[0047] As shown in FIGS. 11 and 12, and also as shown in FIGS. 5 to 8, in the case of the present embodiment, the lens barrel 22 of the projection lens 20 is divided into three parts. Specifically, the lens barrel 22 includes a first part 40, a second part 42, and a third part 44.

[0048] The first part 40 of the lens barrel 22 is the part closest to the housing 12 of the projector 10 and includes the proximal end 22a. Also, as shown in FIG. 7, the first part 40 includes the rear lens 24, the first reflection element 30, and the lens mount 28.

[0049] The second part 42 of the lens barrel 22 is the middle part of the lens barrel 22 and includes the second reflection element 32 as shown in FIG. 7.

[0050] The third part 44 of the lens barrel 22 is the part farthest from the housing 12 of the projector 10 and includes the distal end 22b. Also, as shown in FIG. 8, the third part 44 includes the third reflection element 34 and the front lens 26.

[0051] The first portion 40 of the lens barrel 22 supports the second portion 42 so as to be rotatable about a first rotation centerline R1 that extends in the first reflection direction D1 (Z-axis direction). Figure 11 shows the state in which the projection lens 20 has been deformed from the state shown in Figures 2, 3, 5, and 10 so that the second portion 42 rotates 180 degrees relative to the first portion 40 about the first rotation centerline R1. In the deformed state shown in Figure 11, a portion of the projection lens 20 is not above the upper surface 12f of the housing 12 of the projector 10. Since a portion of the projection lens 20 is not above the upper surface 12f of the housing 12, it becomes possible to rotate the projection lens 20 relative to the housing 12 about the optical axis C0 of the projector 10. That is, even when rotated, the projection lens 20 does not collide with the housing 12. Therefore, the lens mount 28 of the projection lens 20 and the body mount 18 of the projector 10, which are connected by a bayonet mount, can be rotated relative to each other to attach and detach them.

[0052] The second portion 42 of the lens barrel 22 supports the third portion 44 so as to be rotatable about a second rotation centerline R2 that extends in the second reflection direction D2. Figure 12 shows the projection lens 20 modified from the state shown in Figures 2, 3, 6, and 10 so that the third portion 44 rotates 180 degrees relative to the second portion 42 about the second rotation centerline R2. This rotation of the third portion 44 relative to the second portion 42 allows the front lens 26 to be directed toward the right side 12b of the housing 12, as shown in Figure 10, and also toward the opposite direction (i.e., the left side 12g).

[0053] Furthermore, the deformable projection lens 20 allows the projection direction of the front lens 26 to be changed in various directions. That is, the direction of extension of the optical axis C2 of the front lens 26 can be changed with respect to the direction of extension of the optical axis C1 of the rear lens 24 (optical axis C0 of the projector 10). Therefore, even with multiple types of projectors with different housing shapes, it is possible to suppress the appearance of a part of the housing as a shadow in the projected image projected from the projection lens 20 onto the screen S by appropriately deforming the projection lens 20.

[0054] According to this embodiment, in a projector 10 equipped with a projection lens 20 that projects light emitted from the projector 10 in a direction different from the direction of emission, it is possible to suppress the appearance of a part of the housing 12 of the projector 10 as a shadow in the projected image on the screen S.

[0055] The present disclosure has been described above with reference to the embodiments described above, but the embodiments of the present disclosure are not limited to these.

[0056] For example, in the above-described embodiment, as shown in Figures 5 and 11, the second portion 42 of the lens barrel 22 of the projection lens 20 is rotatable relative to the first portion 40. This allows the lens mount 28 of the projection lens 20 and the body mount 18 of the housing 12 of the projector 10, which are connected in a bayonet-type manner, to be rotated relative to each other for attachment and detachment. However, the embodiments of this disclosure are not limited to this. When the projection lens 20 and the housing 12 of the projector 10 are connected in a manner other than the bayonet type, that is, when it is not necessary to rotate them relative to each other during connection (for example, in the case of a plug-in type), the second portion 42 may be fixed so as not to rotate relative to the first portion 40 (it may be integrated with the first portion 40).

[0057] Furthermore, in the above-described embodiment, as shown in Figures 6 and 12, the third portion 44 of the barrel 22 of the projection lens 20 is rotatable relative to the second portion 42. However, the embodiments of this disclosure are not limited thereto. The third portion 44 may be fixed so as not to rotate relative to the second portion 42 (it may be integrated with the second portion 42).

[0058] Furthermore, in the above-described embodiment, the projection lens 20 includes, as optical elements, a rear lens 24, a front lens 26, a first reflecting element 30, a second reflecting element 32, and a third reflecting element 34. However, the projection lens 20 may include other optical elements besides these five. For example, other optical elements such as lenses and filters may be arranged in the optical path between the rear lens 24 and the first reflecting element 30.

[0059] Furthermore, in the above-described embodiment, in the projection lens 20, the image light that has passed through the rear lens 24 passes through the front lens 26 via three reflective elements 30, 32, and 34. However, the embodiments of this disclosure are not limited to this. In a rear lens 24 and a front lens 26 whose respective optical axes are in a twisted positional relationship, the number of reflective elements is not limited to three, as long as the image light that has passed through the rear lens 24 can ultimately pass through the front lens 26.

[0060] In other words, the embodiments of the present disclosure, in a broad sense, are projection lenses attached to the housing of a projector, comprising: a rear lens into which light from the projector is incident; a front lens that projects light; a plurality of reflective elements positioned between the rear lens and the front lens, respectively, which sequentially reflect the light that has passed through the rear lens and transmit it to the front lens; a lens barrel that supports the rear lens, the front lens, and the plurality of reflective elements; and a lens mount provided on the lens barrel and detachably connected to a body mount provided on the housing of the projector, wherein the optical axis of the rear lens and the optical axis of the front lens are in a twisted positional relationship with respect to each other.

[0061] As described above, the embodiments described in this disclosure have been explained as examples of the technology. For this purpose, drawings and a detailed description are provided. Therefore, among the components described in the drawings and detailed description, there may be not only components that are essential for solving the problem, but also components that are not essential for solving the problem, in order to illustrate the technology described above. For this reason, the mere fact that these non-essential components are described in the drawings and detailed description should not be immediately assumed to be essential.

[0062] Furthermore, since the embodiments described above are for illustrative purposes of the technology described herein, various modifications, substitutions, additions, omissions, etc., can be made within the scope of the claims or equivalents thereof.

[0063] This disclosure is applicable to projectors equipped with projection lenses.

Claims

1. A projection lens to be attached to the housing of a projector, comprising: a rear lens into which light from the projector is incident; a front lens for projecting light; a plurality of reflective elements positioned between the rear lens and the front lens, respectively, to sequentially reflect the light that has passed through the rear lens and transmit it to the front lens; a lens barrel supporting the rear lens, the front lens, and the plurality of reflective elements; and a lens mount provided on the lens barrel and detachably connected to a body mount provided on the housing of the projector, wherein the optical axis of the rear lens and the optical axis of the front lens are in a twisted positional relationship with respect to each other.

2. The projection lens according to claim 1, wherein the plurality of reflective elements include a first reflective element, a second reflective element, and a third reflective element, the first reflective element reflects light transmitted through the rear lens in a first reflection direction intersecting the extending direction of the optical axis of the rear lens, the second reflective element reflects the light reflected by the first reflective element in a second reflection direction intersecting the first reflection direction, and the third reflective element reflects the light reflected by the second reflective element toward the front lens in a third reflection direction intersecting the second reflection direction and parallel to the extending direction of the optical axis of the front lens.

3. The projection lens according to claim 2, wherein the direction of extension of the optical axis of the rear lens and the second reflection direction are parallel to each other.

4. The projection lens according to claim 3, wherein the third reflection direction is a direction that intersects a plane containing the extending direction of the optical axis of the rear lens and the second reflection direction.

5. The projection lens according to claim 3, wherein the first reflection direction is perpendicular to the direction of extension of the optical axis of the rear lens, the second reflection direction is perpendicular to the first reflection direction, and the distance between the second reflecting element and the third reflecting element is greater than the distance between the first reflecting element and the lens mount.

6. The projection lens according to claim 2, wherein the lens barrel comprises a first portion including the rear lens and the first reflecting element, a second portion including the second reflecting element, and a third portion including the third reflecting element and the front lens, wherein the first portion supports the second portion so as to be rotatable about a first pivot center line extending in the first reflection direction, and the second portion supports the third portion so as to be rotatable about a second pivot center line extending in the second reflection direction.

7. A projector comprising: a projection lens according to any one of claims 1 to 6; a housing; and a body mount provided on the housing, to which the lens mount of the projection lens is detachably attached.

8. The projector according to claim 7, wherein the housing has a shape that includes a front-to-back direction, a left-to-right direction, and a height direction, the body mount is provided on the front of the housing, the size of the housing in the left-to-right direction is smaller than that in the front-to-back direction, the front lens of the projection lens overlaps with the housing in the height direction, and the optical axis of the front lens extends in the left-to-right direction.

Images