Image display device and projection optical system

Abstract

A projection optical system for an image display device has a lens system and a concave reflecting surface. The lens system is configured based on a reference axis at a position where generated image light is incident and has a positive refractive power as a whole. The concave reflecting surface is configured based on the reference axis and reflects the image light emitted from the lens system toward an object to be projected. Furthermore, the projection optical system is configured to satisfy the following relationship: 0 < |Δθ(hmax) - Δθ(0.9·hmax)| / θ(hmax) < 0.056, where h is a beam height from the reference axis; θ(h) is an angle between a direction of the beam height and a tangent line of a function Z(h) indicating a shape of the concave reflecting surface according to the beam height h; Δθ(h) is a variation amount of the angle θ(h) at the beam height h; and hmax is the beam height h of a reflection point farthest apart from the reference axis of the concave reflecting surface that reflects the image light.

Description

Technical Field

[0001] This technology relates to image display devices such as projectors and projection optical systems. Background Technology

[0002] In the prior art, projectors are widely known as projection-type image display devices used to display projected images on a screen. Recently, there has been an increasing demand for ultra-wide-angle front projection projectors capable of displaying large screens even in small projection spaces. By using such a projector, large screens can be projected into limited spaces by tilting it relative to the screen and performing projection at a wide angle.

[0003] In the ultra-wide-angle projection projector described in Patent Document 1, screen offset for moving the projected image projected onto the screen can be performed by moving a part of the optical components included in the projection optical system. By using this screen offset, fine adjustments such as image position can be easily made (see paragraphs

[0023] and

[0024] of the specification of Patent Document 1).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 5365155 Summary of the Invention

[0007] The technical problem to be solved by the present invention

[0008] Projectors compatible with ultra-wide-angle lenses will continue to become popular in the future, and technologies that enable high-quality image display will be essential.

[0009] In view of the above, the purpose of this technology is to provide an image display device and projection optical system that are compatible with ultra-wide-angle lenses and can achieve high-quality image display.

[0010] Solution to the problem

[0011] To achieve the above objectives, the image display device according to embodiments of the present technology includes a light source, an image generation unit, and a projection optical system.

[0012] The image generation unit generates image light by modulating the light emitted from the light source.

[0013] A projection optical system includes a lens system and a concave reflective surface.

[0014] The lens system is configured to reference the reference axis at the location where the generated image light is incident and to have positive refractive power as a whole.

[0015] The concave reflective surface is configured with reference axis and reflects the image light emitted from the lens system toward the object to be projected.

[0016] The image display device is configured to satisfy the following relationship:

[0017] 0<|Δθ(hmax)-Δθ(0.9·hmax)| / θ(hmax)<0.056

[0018] in,

[0019] The beam height from the reference axis is denoted as h.

[0020] The angle of the tangent to the function Z(h), which represents the shape of the concave reflecting surface corresponding to the beam height h, with respect to the optical axis height direction, is denoted as θ(h).

[0021] The change in angle θ(h) at beam height h is expressed as Δθ(h), and

[0022] The beam height h of the reflection point furthest from the reference axis of the concave reflecting surface of the reflected image light is denoted as hmax.

[0023] In image display devices, the shape of the concave reflective surface, as described above, is designed to reflect image light toward the projection object. This allows for the display of high-quality images.

[0024] Δθ(h) can be θ(h)-θ(0.98·h).

[0025] If the image light beam included in the region having a reflection point in the direction greater than 0.85·hmax reflected by the concave reflective surface is represented as an edge-side beam, then the projection optical system can be configured such that the propagation directions of the edge-side beams incident on the concave reflective surface are parallel to each other.

[0026] The projection optics system can be configured such that the beam spacing of the edge-side beams incident on the concave reflective surface is equal.

[0027] The lens system may have a first refractive optical system, a first reflective surface, a second reflective surface, and a second reflective surface.

[0028] The first refractive optical system has positive refractive power as a whole and refracts the image light generated by the illumination optical system.

[0029] The first reflective surface reflects the image light refracted by the first refractive optical system back.

[0030] The second reflective surface reflects the image light reflected by the first reflective surface back.

[0031] The second refractive optical system has positive refractive power as a whole and refracts the image light reflected from the second reflective surface to emit it onto the concave reflective surface.

[0032] The image display device can be configured to satisfy the following relationship:

[0033] 0.1 < |Φ2 / Φ1| < 1.2

[0034] in,

[0035] The force on the first reflecting surface is denoted as Φ1, and

[0036] The force on the second reflecting surface is represented by Φ2.

[0037] The image display device can be configured to satisfy the following relationship:

[0038] |Φ2|<|Φ1|.

[0039] In image display devices,

[0040] If we represent the first refractive optical system, the first reflecting surface, and the second reflecting surface as the first optical system, and represent a portion of the edge-side beam of the second refractive optical system as the second optical system,

[0041] The first optical system can then focus the edge-side beam at a predetermined focusing position. This predetermined focusing position can coincide with the front focal point position of the second optical system.

[0042] The image display device can be configured such that the relationship satisfies the following relationship

[0043] 0.8 < |A+B| / C < 1.2

[0044] and

[0045] In edge-side beams, a beam whose height at the reflection point of the concave reflecting surface is at the middle value is represented as an intermediate beam.

[0046] The incident position of the intermediate beam relative to the final lens surface of the second refractive optical system is referred to as the intermediate incident position.

[0047] The optical path length from the image generation unit to the intermediate beam at the predetermined convergence position is denoted as A, and the optical path length from the intermediate incident position to the front focal position is denoted as B.

[0048] The optical path length of the intermediate beam from the image generation unit to the intermediate incident position is denoted as C.

[0049] If the average angle between the travel directions of the edge-side beams incident on the concave reflecting surface and the direction along the reference axis is expressed as the average angle, and...

[0050] The region on which the edge-side beam of the final lens surface of the second refractive optical system is incident is referred to as the edge-side incident region.

[0051] When a parallel beam is incident on the edge-side incident region of the final lens surface from the opposite side along a direction that intersects the direction along the reference axis at an average angle, the front focusing position of the second optical system can be the converging position.

[0052] The optical path length B can be the optical path length of a parallel beam that travels from the middle incident position to the front focal position when it is incident on the edge side of the final lens surface from the opposite side.

[0053] A concave reflective surface can reflect at least a portion of the image light incident on the concave reflective surface in a direction that intersects the direction along the reference axis at an angle of 90 degrees or greater.

[0054] A projection optical system may include a first optical component, wherein a region of the main surface is configured as a first reflective surface and another region of the main surface is configured as a transmissive surface. In this case, the transmissive surface of the first optical component can be used as a second refractive optical system.

[0055] The projection optical system may include a second optical component, wherein a region of the main surface is configured as a second reflective surface and another region of the main surface is configured as a transmissive surface. In this case, the transmissive surface of the second optical component can be used as a first refractive optical system.

[0056] The reference axis can be obtained by extending the optical axis of the lens included in the lens system that is closest to the image generation unit.

[0057] A projection optics system can be configured such that the optical axis of each of all optical components included in the projection optics system is aligned with a predetermined reference axis.

[0058] The concave reflective surface can be configured such that its rotational symmetry axis coincides with the reference axis. In this case, both the first and second reflective surfaces are concave reflective surfaces and are configured such that their rotational symmetry axes coincide with the reference axis.

[0059] Each of the concave reflective surface, the first reflective surface, and the second reflective surface can be configured such that the optical axis is aligned with the reference axis. In this case, at least one of the concave reflective surface, the first reflective surface, or the second reflective surface can be a freely curved surface without an axis of rotational symmetry.

[0060] The object to be projected can be a flat screen or a curved screen.

[0061] The object to be projected can be a screen with a dome shape.

[0062] A projection optical system according to an embodiment of the present technology is used to project image light generated by modulating light emitted from a light source and includes a lens system and a concave reflective surface. Attached Figure Description

[0063] Figure 1 This is a schematic diagram used to illustrate other advantages of LCD projectors compatible with ultra-wide-angle lenses.

[0064] Figure 2 This is a schematic diagram illustrating an example configuration of a projection-type image display device.

[0065] Figure 3 This is a schematic diagram illustrating a configuration example of an image display system according to a first embodiment of the present technology.

[0066] Figure 4 This is a schematic diagram illustrating a configuration example of an image display system according to a first embodiment of the present technology.

[0067] Figure 5 An optical path diagram illustrating a schematic configuration example of a projection optical system according to a first embodiment of the present technology.

[0068] Figure 6 This is an optical path diagram illustrating a schematic configuration example of a projection optical system according to a first embodiment of the present technology.

[0069] Figure 7 This is a schematic diagram showing the optical path of the pixel light (main beam) included in the image light.

[0070] Figure 8 This is a diagram used to describe configuration condition 1.

[0071] Figure 9 This is a schematic diagram used to describe configuration condition 2.

[0072] Figure 10 This is a diagram used to describe configuration condition 5.

[0073] Figure 11 This is a diagram used to describe configuration condition 6.

[0074] Figure 12 This is a diagram used to describe configuration condition 6.

[0075] Figure 13 This is a diagram used to describe configuration condition 6.

[0076] Figure 14 This is a table showing examples of parameters related to image projection.

[0077] Figure 15It is used to describe Figure 14 A schematic diagram of the parameters shown.

[0078] Figure 16 This is a schematic diagram used to describe a high-image, high-emission beam.

[0079] Figure 17 It is the lens data of the image display device.

[0080] Figure 18 This is a table showing examples of the aspherical coefficients of optical components included in a projection optics system.

[0081] Figure 19 It is a graph showing the relationship between beam height h and Δθ(h) / θ(hmax).

[0082] Figure 20 It is a table showing the numerical values ​​of the parameters used by the conditional expressions (1), (2) and (4).

[0083] Figure 21 This is an optical path diagram illustrating an example configuration of a projection optical system according to the second embodiment.

[0084] Figure 22 This is an optical path diagram illustrating an example configuration of a projection optical system according to the second embodiment.

[0085] Figure 23 It is the lens data of the image display device.

[0086] Figure 24 This is a table showing examples of the aspherical coefficients of optical components included in a projection optics system.

[0087] Figure 25 It is a graph showing the relationship between beam height h and Δθ(h) / θ(hmax).

[0088] Figure 26 It is a table showing the numerical values ​​of the parameters used by the conditional expressions (1), (2) and (4).

[0089] Figure 27 This is an optical path diagram illustrating a schematic configuration example of a projection optical system according to a third embodiment.

[0090] Figure 28 This is an optical path diagram illustrating a schematic configuration example of a projection optical system according to a third embodiment.

[0091] Figure 29 This is a table showing examples of parameters related to image projection.

[0092] Figure 30 The lens data of the image display device is shown.

[0093] Figure 31 This is a table showing examples of the aspherical coefficients of the optical elements included in a projection optical system.

[0094] Figure 32 It is a graph showing the relationship between beam height h and Δθ(h) / θ(hmax).

[0095] Figure 33 It is a table showing the numerical values ​​of the parameters used by the conditional expressions (1), (2) and (4).

[0096] Figure 34 This is an optical path diagram illustrating an example configuration of a projection optical system according to the fourth embodiment.

[0097] Figure 35 This is an optical path diagram illustrating a schematic configuration example of a projection optical system according to the fourth embodiment.

[0098] Figure 36 This is a table showing examples of parameters related to image projection.

[0099] Figure 37 The lens data of the image display device is shown.

[0100] Figure 38 This is a table showing examples of the aspherical coefficients of the optical elements included in a projection optical system.

[0101] Figure 39 It is a graph showing the relationship between beam height h and Δθ(h) / θ(hmax).

[0102] Figure 40 It is a table showing the numerical values ​​of the parameters used by the conditional expressions (1), (2) and (4).

[0103] Figure 41 This is a schematic diagram illustrating an example configuration of an image display system according to another embodiment.

[0104] Figure 42 This is a schematic diagram illustrating an example configuration of an image display system according to another embodiment. Detailed Implementation

[0105] In the following description, embodiments according to the present technology will be described with reference to the accompanying drawings.

[0106] [Overview of Projection-Type Image Display Devices]

[0107] The outline of a projection-type image display device will be briefly described using a liquid crystal projector as an example.

[0108] Liquid crystal projectors spatially modulate light emitted from a light source to form an optical image (image light) corresponding to a video signal.

[0109] For light modulation, liquid crystal display elements are used as image modulation elements. For example, a three-panel liquid crystal projector uses liquid crystal display elements (liquid crystal panels) that include a panel shape corresponding to each RGB.

[0110] The optical image is magnified, projected, and displayed on the screen by a projection optics system. Here, the projection optics system will be described as compatible with an ultra-wide-angle view having, for example, a half-angle of 70° or greater. It should be understood that this angle is not limited to this angle.

[0111] LCD projectors compatible with ultra-wide-angle projection can display a large screen even in small projection spaces. In other words, it's possible to magnify the projection even when the distance between the LCD projector and the screen is short.

[0112] As a result, the following advantages were observed.

[0113] Because LCD projectors can be positioned close to the screen, the likelihood of light from the LCD projector directly entering the eyes can be significantly reduced, thus achieving a higher level of safety.

[0114] Because the screen does not display shadows of people, it can be presented effectively.

[0115] It offers a high degree of freedom in choosing installation locations and can be easily installed on ceilings, which are narrow installation spaces and contain many obstacles.

[0116] By mounting it on the wall, maintenance such as cable routing is easier compared to mounting it on the ceiling.

[0117] For example, it can increase the flexibility in setting up meeting spaces, classrooms, meeting rooms, etc.

[0118] Figure 1 This is a schematic diagram used to illustrate other advantages of LCD projectors compatible with ultra-wide-angle lenses.

[0119] like Figure 1 As shown, by installing an LCD projector 1 that is compatible with ultra-wide viewing angles on the table, a magnified image 2 can be projected onto the same table.

[0120] This method of use is feasible and can make efficient use of space.

[0121] Recently, with the widespread use of electronic whiteboards (interactive whiteboards) in schools, workplaces, and other settings, the demand for LCD projectors compatible with ultra-wide-angle lenses has been increasing. Furthermore, similar LCD projectors are also used in areas such as digital signage (electronic advertising).

[0122] For example, technologies including liquid crystal displays (LCDs) and plasma display panels (PDPs) can be used as electronic blackboards. In contrast, using LCD projectors compatible with ultra-wide-angle displays can provide a larger screen at a lower cost.

[0123] Note that LCD projectors compatible with ultra-wide-angle lenses are also known as short-throw projectors, ultra-short-throw projectors, etc.

[0124] Figure 2 This is a schematic diagram illustrating an example configuration of a projection-type image display device.

[0125] The image display device 20 includes a light source 5, an illumination optical system 10, and a projection optical system 15.

[0126] The light source 5 is configured to emit a beam of light to the illumination optics system 10.

[0127] As a light source 5, a high-pressure mercury lamp can be used, for example. Alternatively, solid-state light sources such as light-emitting diodes (LEDs) and laser diodes (LDs) can be used.

[0128] The illumination optical system 10 uniformly illuminates the surface of the image modulation element (liquid crystal panel P) used as the main image plane with the light beam emitted from the light source 5.

[0129] In the illumination optical system 10, the light beam from the light source 5 passes sequentially through two compound eye lenses FL, a polarization conversion element PS, and a converging lens L, and is converted into a uniform beam of polarized light.

[0130] The light beam passing through the converging lens L is split into light components for each of the RGB color components by the dichroic mirror DM, which reflects only light within a specific wavelength band.

[0131] Light from each RGB color component is incident on a liquid crystal panel P (image modulation element) corresponding to each RGB color setting via a total reflection mirror M, a lens L, etc. Then, each liquid crystal panel P performs light modulation corresponding to the video signal.

[0132] The optically modulated color components are combined by a dichroic prism PP to generate image light. The generated image light is emitted toward the projection optical system 15.

[0133] The optical components constituting the lighting optical system 10 are not limited, and optical components different from those described above can be used.

[0134] For example, as an image modulation element, a reflective liquid crystal panel or a digital micromirror device (DMD) can be used instead of a transmissive liquid crystal panel P.

[0135] In addition, for example, a polarization beam splitter (PBS), a color composite prism that combines video signals of each RGB color, a total internal reflection (TIR) ​​prism, etc., can be used instead of a dichroic prism (PP).

[0136] In this embodiment, the illumination optical system 10 corresponds to the image generation unit.

[0137] The projection optics system 15 adjusts the image light emitted from the illumination optics system 10, amplifies the image light, and projects it onto the screen, which serves as the secondary image plane. That is, the image information of the primary image plane (liquid crystal panel P) is adjusted by the projection optics system 15, amplified, and projected onto the secondary image plane (screen).

[0138] <First Implementation Method>

[0139] [Image display system]

[0140] Figure 3 and Figure 4 This is a schematic diagram illustrating a configuration example of an image display system according to a first embodiment of the present technology.

[0141] Figure 3 This is a view taken from above the image display system 100.

[0142] Figure 4 This is an illustration viewed from above at an angle on the right front side of the image display system 100.

[0143] The image display system 100 includes a curved screen 30 and two image display devices 20.

[0144] The curved screen 30 includes a screen whose overall shape becomes curved and a screen whose shape at least part becomes curved.

[0145] like Figure 3 and Figure 4 As shown, in this embodiment, a curved screen 30 with a generally arc-shaped shape when viewed from above is used. The curved screen 30 is mounted vertically and extends horizontally.

[0146] The left end 31a and right end 31b of the curved screen 30 are curved forward and are arranged at approximately equal positions in the front-to-back direction. The approximately central part of the curved screen 30 in the left-to-right direction is located at the rearmost side and corresponds to the vertex of the approximately arc shape when viewed from above.

[0147] The shape of the curved screen 30 can also be represented as approximately equal to a portion of the inner surface of a cylinder standing vertically in the vertical direction. Furthermore, the curved screen 30 can be configured by connecting tiny flat areas while changing their angles relative to each other.

[0148] The specific configuration of materials, dimensions, radius of curvature, etc., of the curved screen 30 is unrestricted and can be designed arbitrarily. Furthermore, the curved screen 30 can be achieved by bonding the flexible screen component to the inner surface of a base component that has an arc shape when viewed from above.

[0149] In this embodiment, the curved screen 30 corresponds to the object to be projected.

[0150] The two image display devices 20 include a first image display device 20a and a second image display device 20b.

[0151] The first image display device 20a is mounted approximately at the center of the left end 31a of the curved screen 30 in the vertical direction, so as to project an image toward the rear. The first image display device 20a projects an image (hereinafter referred to as the first image) 21a onto the left side of the curved screen 30, which is bent into an approximately arc shape.

[0152] The second image display device 20b is mounted approximately at the center of the right end 31b of the curved screen 30 in the vertical direction, in a manner that enables it to project an image toward the rear. The second image display device 20b projects an image (hereinafter referred to as the second image) 21b onto the right side of the curved screen 30, which is bent into an approximately arc shape.

[0153] like Figure 3 and Figure 4 As shown, the first image display device 20a and the second image display device 20b project the first image 21a and the second image 21b respectively, such that the first image 21a and the second image 21b overlap each other.

[0154] The holding mechanism (not shown) for holding the first image display device 20a and the second image display device 20b can be designed arbitrarily.

[0155] In this embodiment, each image modulation element (liquid crystal panel P) disposed in the first image display device 20a and the second image display device 20b is made of a rectangular shape having a long side direction and a short side direction. The liquid crystal panel P generates image light to form a rectangular image.

[0156] The first image 21a and the second image 21b are projected as identical rectangular images. The first image 21a and the second image 21b are projected to overlap each other along the long side direction (left-right direction) of the first image 21a and the second image 21b.

[0157] Therefore, an overlap region 22 is generated at approximately the center of the curved screen 30, where the first image 21a and the second image 21b overlap each other.

[0158] In this embodiment, splicing processing is performed in the overlapping region 22 where the first image 21a and the second image 21b overlap.

[0159] Therefore, the first image 21a and the second image 21b are connected and combined into one image. Thus, a large-sized image is displayed over approximately the entire area along the left-right direction of the curved screen 30.

[0160] The specific algorithm for the suturing process is not restricted, and any suturing technique can be used.

[0161] exist Figure 3 The image schematically shows a first image light 23a constituting a first image 21a projected from a first image display device 20a and pixel lights Ca1, Ca2 and Ca3 included in the first image light 23a.

[0162] In addition, Figure 3 The first image light 23b constituting the second image 21b projected from the second image display device 20b and the pixel lights Cb1, Cb2 and Cb3 included in the second image light 23b are schematically shown.

[0163] It should be noted that pixel light is the light used to form each of the multiple pixels contained in a projected image. Typically, the light emitted from each of the multiple pixels included in an image modulation element (liquid crystal panel P) used to generate and emit image light is pixel light. Therefore, image light comprises multiple pixel lights.

[0164] Figure 3 The pixel light Ca1 shown is the pixel light used to form the pixels at the left end of the first image 21a. Therefore, pixel light Ca1 corresponds to the beam at the left end of the first image light 23a.

[0165] Pixel light Ca2 is the pixel light used to form the pixel at the right end of the first image 21a. Therefore, pixel light Ca2 corresponds to the beam at the right end of the first image light 23a.

[0166] Pixel light Ca3 is a pixel light used to form the pixel at the left end of the overlapping region 22 in which the first image 21a and the second image 21b overlap.

[0167] Therefore, among the beams included in the first image light 23a, the beams from pixel lights Ca3 to Ca2 are the image lights constituting the overlapping region 22.

[0168] On the other hand, among the beams included in the first image light 23a, the beams from pixel lights Ca1 to Ca3 are image lights that constitute the area outside the overlapping region 22.

[0169] Figure 3The pixel light Cb1 shown is the pixel light used to form the right-hand portion of the second image 21b. Therefore, pixel light Cb1 corresponds to the beam at the right-hand portion of the second image light 23b.

[0170] Pixel light Cb2 is the pixel light used to form the pixels at the left end of the second image 21b. Therefore, pixel light Cb2 corresponds to the beam at the left end of the first image light 23a.

[0171] Pixel light Ca3 is the pixel light of the pixel that constitutes the right end of the overlapping region 22.

[0172] Therefore, in the beam of light included in the second image light 23b, the beams from pixel lights Cb3 to Cb2 are the image lights constituting the overlapping region 22.

[0173] On the other hand, in the beam of light included in the second image light 23b, the beams of light from pixel light Cb1 to Cb3 are image lights that constitute the region other than the overlapping region 22.

[0174] like Figure 3 As shown, in this embodiment, the first image display device 20a and the second image display device 20b project the first image 21a and the second image 21b respectively, such that the image lights constituting the region other than the overlapping region 22 where the first image 21a and the second image 21b overlap each other do not intersect each other.

[0175] Therefore, the shadow cast on the user 3, who is standing near the overlapping region 22 generated in the approximate center portion of the curved screen 30, can be sufficiently suppressed. Thus, the user 3 can view the first image 21a and the second image 21b, which are combined into one image, from the inner region of the curved screen 30 (e.g., near the overlapping region 22).

[0176] Therefore, it can provide a considerable sense of immersion in the content and offer users excellent visual effects.

[0177] The direction in which the first image 21a and the second image 21b overlap is unrestricted.

[0178] For example, the first image 21a and the second image 21b can be projected to overlap each other along the short side direction of the first image 21a and the second image 21b.

[0179] For example, in Figure 3 and Figure 4In the configuration example shown, the projection has a first image 21a and a second image 21b with rectangular shapes having the left and right directions as their shorter sides. The first image 21a and the second image 21b can be projected such that the first image 21a and the second image 21b overlap along the shorter sides of the first image 21a and the second image 21b.

[0180] Depending on the shape of the curved screen 30, when an image light that forms a rectangular image is projected, the image can be displayed in a shape different from the rectangular shape.

[0181] In this case, for example, the directions corresponding to the long side and short side of the liquid crystal panel P can be defined as the long side and short side of the image. Multiple images can overlap along either the long side or the short side.

[0182] In this disclosure, the long side direction and short side direction of the liquid crystal panel P can also be represented as the long side direction and short side direction of the image light.

[0183] In this embodiment, image display devices with substantially the same configuration are used as the first image display device 20a and the second image display device 20b.

[0184] The projection optical system 15 of the first image display device 20a and the second image display device 20b will be described below.

[0185] [Projection Optical System]

[0186] Figure 5 and Figure 6 This is an optical path diagram showing a schematic configuration example of the projection optical system 15 according to this embodiment. Figure 6 The image is shown as a portion of a projection optical system 15 and a curved screen S.

[0187] By combination Figure 6 Two configurations that are symmetrical to each other can achieve the following: Figure 3 and Figure 4 The image display system 100 includes the curved screen 30, the first image display device 20a, and the second image display device 20b shown.

[0188] In addition, Figure 5 and Figure 6 The image schematically shows the liquid crystal panel P and the dichroic prism PP of the illumination optical system 10.

[0189] In the following text, the emission direction of the image light emitted from the dichroic prism PP to the projection optical system 15 is set as the Z direction.

[0190] Furthermore, the horizontal direction of the main image plane (liquid crystal panel P) is represented as the X direction, and the vertical direction is represented as the Y direction. The X and Y directions correspond to the horizontal and vertical directions of the image formed by image light.

[0191] Furthermore, for convenience, when viewed from the side of the projection optical system, in each diagram (the direction of image light emission), the Z direction can be described as the left-right direction and the Y direction can be described as the up-down direction.

[0192] It should be understood that in the application of this technology, the emission direction of image light is not limited, and the orientation and posture of the image display device 20, etc., can be arbitrarily set.

[0193] also, Figure 5 and Figure 6 The cross-sectional shapes of the optical surfaces (lens surfaces and reflective surfaces, etc.) of the corresponding optical components included in the projection optical system 15 are shown. On the other hand, for the sake of simplicity, shading and other details representing the cross-sections of each optical component are omitted.

[0194] The projection optical system 15 includes a lens system L and a concave reflective surface Mr3.

[0195] The lens system L is positioned at the point where the image light generated by the illumination optics system 10 is incident, and has positive refractive power overall.

[0196] The lens system L is configured to reference a reference axis extending in the Z direction (hereinafter, the reference axis is described as the optical axis O).

[0197] In this embodiment, the lens system L is configured such that the optical axis of each of one or more optical components included in the lens system L is substantially aligned with the optical axis O, which serves as a reference axis.

[0198] Typically, the optical axis of an optical component is an axis that passes through the center of the optical surface of the optical component. For example, in the case where the optical surface of the optical component has a rotational symmetry axis, the rotational symmetry axis corresponds to the optical axis.

[0199] Only a portion of the optical components can be used, arranged such that its optical axis is aligned with optical axis O, encompassing the effective area of ​​image light incidence. By using this portion of the optical components, the projection optical system 15 can be miniaturized.

[0200] In this embodiment, the optical axis O is an axis obtained by extending the optical axis (rotational symmetry axis) of the lens L11, which is closest to the illumination optical system 10 included in the optical system L. That is, another optical component is provided on the axis obtained by extending the optical axis of the lens L11.

[0201] Note that the image light is emitted from a position offset upwards from the optical axis O. The Z direction along the optical axis O can also be referred to as the direction of light travel in the lens system L.

[0202] like Figure 5 As shown, the lens system L includes a first refractive optical system L1, a first reflective surface Mr1, a second reflective surface Mr2, and a second refractive optical system L2.

[0203] The first refractive optical system L1 has positive refractive power as a whole and refracts the image light generated by the illumination optical system 10.

[0204] In this embodiment, the region from the incident surface F1 to the exit surface F2 functions as the first refractive optical system L1. Image light from the lens L11, located closest to the illumination optical system 10, is incident on the incident surface F1. Image light from the lens L12, located closest to the first reflecting surface Mr1, is emitted from the exit surface F2.

[0205] The first reflecting surface Mr1 is a concave reflecting surface and is a rotationally symmetric aspherical surface, which is configured such that the rotational symmetry axis coincides with the optical axis O.

[0206] The first reflective surface Mr1 is positioned slightly below the optical axis O and reflects the image light refracted by the first refractive optical system L1 back. Specifically, the image light incident from the left is reflected back to the upper left.

[0207] like Figure 5 As shown, in this embodiment, the first optical component R11 is arranged such that the rotational symmetry axis coincides with the optical axis O.

[0208] The first reflective surface Mr1 is disposed in a portion of the region below the rotationally symmetric aspherical surface F3 corresponding to the main surface of the first optical component R11. Conversely, a portion of the region below the rotationally symmetric aspherical surface F3 is disposed as the first reflective surface Mr1.

[0209] In another region of the rotationally symmetric aspherical surface F3 of the first optical component R11, the transmission surface Tr2 is configured.

[0210] The second reflecting surface Mr2 is a concave reflecting surface and a rotationally symmetric sphere, configured such that the rotational symmetry axis coincides with the optical axis O.

[0211] The second reflective surface Mr2 is positioned above the optical axis O and reflects the image light reflected by the first reflective surface Mr1 back towards the second refractive optical system L2. Specifically, the image light incident from the lower right is reflected back to the right.

[0212] like Figure 5As shown, in this embodiment, the second optical component R12 is arranged such that the rotational symmetry axis coincides with the optical axis O.

[0213] The second reflective surface Mr2 is disposed in a portion of the region corresponding to the main surface of the second optical component R12 on the upper side of the rotationally symmetric surface F4. Conversely, a portion of the region on the upper side of the rotationally symmetric surface F4 is disposed as the second reflective surface Mr2.

[0214] In another region of the rotational symmetry plane F4 of the second optical component R12, the transmission surface Tr1 is configured.

[0215] In this embodiment, the transmission surface Tr2 formed on the rotationally symmetric aspherical surface F3 of the first optical component R11 serves as the second refractive optical system L2. The transmission surface Tr1 formed on the rotationally symmetric surface F4 of the second optical component R12 serves as the first refractive optical system L1.

[0216] Therefore, an optical component realizes a first reflective surface Mr1 and an optical surface (transmission surface Tr2) used as a second refractive optical system L2. Furthermore, a second reflective surface Mr2 and an optical surface (transmission surface Tr1) used as a first refractive optical system L1 are also realized.

[0217] Therefore, the projection optical system 15 can be miniaturized. In addition, the assembly accuracy of the projection optical system 15 can be improved.

[0218] The second refractive optical system L2 has a positive refractive index overall, refracts the image light reflected by the second reflecting surface Mr2, and emits it to the concave reflecting surface Mr3.

[0219] In this embodiment, the region from the transmission surface Tr2 formed in the first optical component R11 to the exit surface F5 serves as the second refractive optical system L2. Image light from the lens L21, which is positioned closest to the concave reflective surface Mr3, is emitted from the exit surface F5.

[0220] The exit surface F5 of lens L21 becomes the final lens surface of the second refractive optical system L2. In the following text, the exit surface F5 may be referred to by the same reference numeral as the final lens surface F5.

[0221] The concave reflective surface Mr3 is configured with an optical axis O as a reference axis and reflects the image light emitted from the lens system L toward the curved screen S.

[0222] The concave reflective surface Mr3 is a rotationally symmetric aspherical surface configured such that its rotationally symmetric axis (optical axis) coincides with the optical axis O, and is configured only in the effective area on which image light can be reflected. That is, the entire rotationally symmetric aspherical surface is not arranged, but only the necessary portion of the rotationally symmetric aspherical surface is arranged. As a result, miniaturization of the device can be achieved.

[0223] In this embodiment, a first refractive optical system L1, a first reflective surface Mr1, a second reflective surface Mr2, a second refractive optical system L2, and a concave reflective surface Mr3 are arranged on the common optical axis O.

[0224] Therefore, the first refractive optical system L1, the first reflective surface Mr1, the second reflective surface Mr2, the second refractive optical system L2, and the concave reflective surface Mr3 are configured such that the axis obtained by extending the optical axis (rotational symmetry axis) of the lens L11 closest to the illumination optical system 10 is consistent with each optical axis.

[0225] Therefore, in this embodiment, each optical axis of all optical components included in the projection optical system 15 is configured to coincide with optical axis O.

[0226] This allows for a reduction in size in the Y direction and miniaturization of the device. It is not limited to this, and optical components whose optical axes deviate from the optical axis O can be included in the projection optical system 15.

[0227] Reference Figure 5 and Figure 6 This will describe the light path of the image.

[0228] exist Figure 5 and Figure 6 In the image light emitted from the dichroic prism PP to the projection optical system 15, the optical paths of three pixel lights C1, C2 and C3 are shown.

[0229] Incidentally, pixel light is emitted as diverging light from the pixels of the liquid crystal panel P. The emitted pixel light is imaged onto the curved screen S by the projection optics system 15 and displayed as pixels of a projected image.

[0230] In this disclosure, the component light emitted along the optical axis O (along the Z direction) of each pixel light is used as the main beam. Each pixel light is imaged at the position where the main beam is incident on the curved screen S.

[0231] exist Figure 5 In the image, the main beam and the maximum diverging beams at the top and bottom are shown as each pixel light.

[0232] Pixel light C1 corresponds to the pixel light emitted from the pixel at the center of the liquid crystal panel P.

[0233] Pixel light C2 corresponds to the pixel light emitted from the pixel closest to the optical axis O at the center of the liquid crystal panel P.

[0234] Pixel light C3 corresponds to the pixel light emitted from the pixel furthest from the optical axis O at the center of the liquid crystal panel P.

[0235] That is, in this embodiment, pixel light C2 corresponds to pixel light emitted from the pixel closest to the optical axis O of the liquid crystal panel P. Furthermore, pixel light C3 corresponds to pixel light emitted from the pixel furthest from the optical axis O, which is located on the straight line connecting the pixel closest to the optical axis O to the pixel at the center of the liquid crystal panel P.

[0236] like Figure 5 As shown, the image light emitted from a position offset upward from the optical axis O to the projection optical system 15 intersects the optical axis O in the first refractive optical system L1, travels to the lower side, and is incident on the first reflective surface Mr1.

[0237] The image light incident on the first reflecting surface Mr1 is reflected back by the first reflecting surface Mr1, intersects the optical axis O again, travels to the upper side, and is incident on the second reflecting surface Mr2.

[0238] The image light incident on the second reflective surface Mr2 is reflected back by the second reflective surface Mr2 and incident on the second refractive optical system L2.

[0239] Within the second refractive optical system L2, the image light intersects the optical axis O again, travels to the lower side, and is emitted toward the concave reflective surface Mr3.

[0240] Image light emitted from the second refractive optical system L1 is reflected upwards through the concave reflective surface Mr3, intersecting the optical axis O again, and projected toward the curved screen S.

[0241] As described above, in this embodiment, the optical path of the image light is configured to intersect with the optical axis O. Therefore, the optical path of the image light can be configured to the concave reflective surface Mr3 near the optical axis O. Thus, the size of the device in the Y direction can be reduced, and the device can be miniaturized.

[0242] Furthermore, the image light is reflected back through each of the first reflecting surface Mr1 and the second reflecting surface Mr2. Therefore, the optical path length of the image light can be sufficiently ensured. Consequently, the size of the device in the X direction can be reduced, and the device can be miniaturized.

[0243] Furthermore, in the projection optical system 15 according to this embodiment, a plurality of intermediate images (not shown) are imaged between the dichroic prism PP included in the illumination optical system 10 and the concave reflective surface Mr3. The intermediate images are intermediate images of the image formed by the image light.

[0244] This allows for the projection of images with an ultra-wide angle. For example, a large screen can be displayed even when the distance between the projector and the screen is short.

[0245] In order to image a high-precision image on the screen through the concave reflective surface Mr3, the image generated by the illumination optics system 10 must be optically properly corrected and guided to the concave reflective surface Mr3.

[0246] In this embodiment, because the optical path length of the image light can be sufficiently ensured by the first reflective surface Mr1 and the second reflective surface Mr2, the optical correction of the image can be performed accurately. That is, a suitable intermediate image can be generated, and a high-precision image can be easily formed on the screen.

[0247] Furthermore, by ensuring sufficient optical path length, the optical load required to generate a proper intermediate image can be suppressed, and the optical power of each optical component included in the projection optical system 15 can be suppressed. As a result, each optical component can be miniaturized, and the entire device can be miniaturized.

[0248] Furthermore, because multiple intermediate images are formed in the projection optical system 15, an optimal intermediate image can be generated with high precision. Therefore, a high-precision image can be displayed on the screen via the concave reflective surface Mr3. As described above, by using the projection optical system 15 according to this embodiment, the performance of the device can be enhanced.

[0249] like Figure 5 and Figure 6 As shown, in this embodiment, at least a portion of the image light beam incident on the concave reflective surface Mr3 is reflected in a direction that intersects the direction along the optical axis O, which serves as a reference axis, at an angle of 90 degrees or greater.

[0250] It should be noted that the cross angle between the direction of travel of the image light contained in the concave reflective surface Mr3 and the direction along the optical axis O is defined as follows.

[0251] First, calculate the intersection point of the straight line extending along the optical axis O and the straight line extending along the direction of light travel reflected by the concave reflective surface Mr3.

[0252] The straight line extending from the intersection point to the P side of the LCD panel rotates relative to the intersection point on the direction of the beam's travel.

[0253] At this point, the rotation angle at which the straight line extending to the P side of the liquid crystal panel coincides with the straight line extending along the direction of the beam's travel is defined as the intersection angle between the direction of the beam's travel and the direction along the optical axis O in the image light contained in the image light reflected by the concave reflective surface Mr3.

[0254] In this embodiment, the concave reflective surface Mr3 is designed such that the cross angle of at least a portion of the image light contained in the concave reflective surface Mr3, as defined above, is 90 degrees or greater.

[0255] exist Figure 5 In the example shown, pixel light C3, included in the image light, is reflected in a direction that intersects the direction along the optical axis O at an angle greater than 90 degrees. The intersection angle R1 of image light C3 is the maximum intersection angle. That is, pixel light C3 is the beam with the largest intersection angle. Other beams are reflected in directions that intersect the direction along the optical axis O at an angle smaller than the intersection angle R1.

[0256] Here, pixel light is used as an example, referring to a beam of light included in the image light. It is not limited to this; at least a portion of the beam (such as another portion of the beam included in the pixel light) may be reflected from directions intersecting at an angle of 90 degrees or greater along the optical axis O.

[0257] include Figure 5 and Figure 6 The image display device 20 of the projection optical system 15 shown is mounted such that the concave reflective surface Mr3 is arranged at a position corresponding to the shape of the curved screen S.

[0258] By designing a concave reflective surface Mr3 to increase the cross angle, high-quality image display corresponding to a curved screen S can be achieved.

[0259] The inventors have focused on the main beam of each pixel light included in the image light of an image display using the concave reflective surface Mr3, and have repeatedly studied the behavior of the main beam. Then, the following configuration conditions of the projection optics system 15 were newly discovered.

[0260] Figure 7 This is a schematic diagram showing the optical path of the pixel light (main beam) included in the image light. Although Figure 7 The projection optical system 15 shown is Figure 5 Although they are different, the behavior of the pixel light (main beam) is similar.

[0261] In the following text, for the purpose of describing the results under consideration, it is assumed that "beam" means "pixel light". Furthermore, "beam" and "pixel light" are intended to refer to the main beam of "pixel light".

[0262] For example, descriptions of the beam (pixel light)'s direction of travel, incident position, reflection point of the beam (pixel light) reflected by the reflective surface, reflection angle of the beam (pixel light) reflected by the reflective surface, and beam height (pixel light) indicate the main beam's direction of travel, incident position, reflection point, reflection angle, and height.

[0263] (Configuration Condition 1)

[0264] Figure 8 This is a diagram used to describe configuration condition 1.

[0265] like Figure 8 As shown, the beam height from the optical axis O, which serves as the reference axis, is denoted as h.

[0266] The angle of the tangent of the function Z(h), which represents the shape of the concave reflecting surface Mr3 corresponding to the beam height h, relative to the optical axis height direction, is denoted as θ(h).

[0267] like Figure 8 As shown, the optical axis height direction is perpendicular to the optical axis O (Y direction). The slope of the tangent to the function Z(h) can be calculated using the differential function Z'(h), which is obtained by differentiating the function Z(h) from the beam height h. Using the differential function Z'(h), the angle θ(h) can be calculated.

[0268] The change in angle θ(h) at beam height h is expressed as Δθ(h).

[0269] The beam height h of the reflection point RPmax, which is the farthest point from the optical axis O of the concave reflective surface Mr3 used to reflect image light, is denoted as hmax. The beam height hmax is the beam height h of the reflection point of the light incident on the concave reflective surface Mr3 that is the farthest point from the optical axis O.

[0270] In this case, the projection optics system 15 is configured to satisfy the following relationship.

[0271] (1)0<|Δθ(hmax)-Δθ(0.9·hmax)| / θ(hmax)<0.056

[0272] Conditional expression (1) defines the amount of shape change in the region with a large beam height h on the concave reflecting surface Mr3 (hereinafter referred to as the edge-side region). More specifically, it defines the amount of shape change in the region from the region axis height hmax to the optical axis height 0.9·hmax.

[0273] The light beam reflected from the edge region of the concave reflective surface Mr3 constitutes the edge region of the image projected onto the curved screen S.

[0274] If |Δθ(hmax)-Δθ(0.9·hmax)| / θ(hmax) exceeds the upper limit defined in the conditional expression (1), the change in shape of the edge region of the concave reflective surface Mr3 increases, and the uniformity of brightness (brightness) and magnification of the edge region of the projected image decreases.

[0275] If |Δθ(hmax)-Δθ(0.9·hmax)| / θ(hmax) exceeds the lower limit defined in the conditional expression (1), that is, if the change in shape of the edge side region of the concave reflective surface Mr3 is 0, then the uniformity of brightness and magnification of the edge side region of the projected image also decreases.

[0276] The concave reflective surface Mr3 is configured to satisfy conditional expression (1). That is, for light beams reflected by the concave reflective surface Mr3, the reflection point includes the light beam within the range from the optical axis height hmax to 0.9·hmax, and the shape change of the concave reflective surface Mr3 is designed to be gradual. Therefore, the uniformity of brightness and magnification in the edge region of the projected image can be improved, and high-quality image display can be achieved.

[0277] like Figure 8 As shown, in this embodiment, Δθ(h) is θ(h) - θ(0.98·h). It should be understood that, not limited to this, other parameters representing the change in angle θ(h) at beam height h can be used.

[0278] (Configuration Condition 2)

[0279] Figure 9 This is a schematic diagram used to describe configuration condition 2.

[0280] like Figure 9 As shown, the beam of image light in the region of the reflection point of the concave reflective surface Mr3 with a reflection of greater than 0.85·hmax is represented as the edge-side beam CE.

[0281] The projection optical system 15 is configured such that the travel directions of the edge-side beams CE incident on the concave reflective surface Mr3 are parallel to each other. That is, the projection optical system 15 is configured such that the edge-side beams CE incident on the concave reflective surface Mr3 are parallel beams.

[0282] Therefore, it can improve the uniformity of brightness and magnification of the edge regions of the projected image.

[0283] (Configuration Condition 3)

[0284] The projection optics system 15 is configured such that the beam spacing of the edge-side beams CE incident on the concave reflective surface Mr3 is equal. This can be described as the reflection points of the corresponding edge-side beams CE on the concave reflective surface Mr3 being arranged at equal intervals.

[0285] Therefore, it can improve the uniformity of brightness and magnification of the edge regions of the projected image.

[0286] (Configuration Condition 4)

[0287] The force on the first reflecting surface Mr1 is represented by Φ1.

[0288] The force on the second reflecting surface Mr2 is represented by Φ2.

[0289] In this case, the projection optics system 15 is configured to satisfy the following relationship.

[0290] (2) 0.1 < |Φ2 / Φ1| < 1.2

[0291] Conditional expression (2) defines the relationship between the power Φ1 of the first reflecting surface Mr1 and the power Φ2 of the second reflecting surface Mr2.

[0292] If |Φ2 / Φ1| exceeds the upper limit defined in conditional expression (2), the beam reflected by the first reflecting surface Mr1 and the beam reflected by the second reflecting surface Mr2 interfere.

[0293] If |Φ2 / Φ1| exceeds the lower limit defined in conditional expression (2), then the light beam reflected by the second reflecting surface Mr2 is not properly incident on the second refractive optical system L2. That is, the light beam reflected by the second reflecting surface Mr2 is not properly incident on the transmission surface Tr2 of the first optical component R11.

[0294] By configuring the first reflective surface Mr1 and the second reflective surface Mr2 to satisfy conditional expression (2), image light can be properly guided to the concave reflective surface Mr3. This enables high-quality image display.

[0295] (Configuration Condition 5)

[0296] Figure 10 This is a diagram used to describe configuration condition 5.

[0297] The projection optics system 15 is configured to satisfy the following relationship.

[0298] (3)|Φ2|<|Φ1|

[0299] like Figure 10 As shown, in order to satisfy the above (configuration condition 2), in the second refractive optical system L2, it is necessary to apply a large refractive force to the beam with increased beam height h (specifically, the beam with beam height hmax).

[0300] If condition expression (3) is not satisfied, i.e., |Φ2|≥|Φ1|, then in order to apply a larger refractive force to the beam with beam height hmax, it is conceivable to design a large distance between the second reflecting surface Mr2 and the second refractive optical system L2, for example, such as Figure 10As shown in A. However, if the distance between the second reflective surface Mr2 and the second refractive optical system L2 is increased, the projection optical system 15 has a large size.

[0301] Alternatively, such as Figure 10 As shown in B, it is also conceivable to increase the force of the second refractive optical system L2. However, if the force of the second refractive optical system L2 is increased, aberrations may occur in the projected image, and the image quality may be reduced.

[0302] like Figure 10 As shown in C, the first reflecting surface Mr1 and the second reflecting surface Mr2 are configured to satisfy the conditional expression (2).

[0303] This allows a beam with a beam height hmax to be greatly reflected upwards. Therefore, a beam with a beam height hmax can be emitted from the second reflecting surface Mr2 at an angle from the top towards the second refractive optical system L2. Consequently, a large refractive force can be applied to a beam with a beam height hmax.

[0304] Therefore, miniaturization of the device and aberration suppression can be achieved while satisfying (configuration condition 2). Conversely, (configuration condition 2) can be satisfied without increasing the projection optical system 15 or generating aberrations in the projected image.

[0305] (Configuration condition 6-1)

[0306] Figures 11 to 13 This is a diagram used to describe configuration condition 6.

[0307] The first optical system LL1 includes a first refractive optical system L1, a first reflecting surface Mr1, and a second reflecting surface Mr2. That is, the first optical system LL1 extends from the incident surface F1 of the lens L11 to the second reflecting surface Mr2.

[0308] The second optical system LL2 is the portion of the edge-side beam acting on the second refractive optical system L2. That is, if the portion of the edge-side beam CE traveling in the second refractive optical system L2 is considered as an optical system, then that optical system is the second optical system LL2.

[0309] The projection optical system 15 is configured such that the first optical system L1 converges the edge-side beam CE to a predetermined convergence position 35. Furthermore, the projection optical system 15 is configured such that the convergence position 35 coincides with the front focal point position 36 of the second optical system LL2.

[0310] That is, the projection optical system 15 is configured such that the first optical system LL1 focuses the edge-side beam CE onto the front focal position 36 of the second optical system LL2.

[0311] Reference Figure 12 The front focal position 36 of the second optical system LL2 will be described.

[0312] The average angle between each travel direction (the direction of incidence on the concave reflective surface Mr3) of the edge-side beam CE incident on the concave reflective surface Mr3 and the direction along the optical axis O is expressed as the average angle θ1.

[0313] The area on which the edge-side beam CE of the final lens surface F5 of the second refractive optical system L2 is incident is denoted as the edge-side incident area 37.

[0314] like Figure 12 As shown, the front focal position 36 of the second optical system LL2 is the convergence position when the parallel beam 38 is incident from the opposite side onto the edge-side incident region 37 of the final lens surface F5 along a direction that intersects with the direction along the optical axis O at an average angle θ1.

[0315] (Configuration condition 6-2)

[0316] As an equivalent condition to (Configuration Condition 6-1), (Configuration Condition 6-2) will be described.

[0317] like Figure 11 and Figure 13 As shown, in the edge-side beam CE, the beam with an intermediate beam height h at the reflection point reflected by the concave reflecting surface Mr3 is represented as the intermediate beam 40. Figure 11 and Figure 13 In the middle, the central beam 40 is indicated by a thick arrow.

[0318] The incident position of the intermediate beam 40 relative to the final lens surface F5 of the second refractive optical system L2 is referred to as the intermediate incident position 41.

[0319] The optical path length of the intermediate light 40 from the illumination optics system 10 to the converging position 35 is denoted as A. Specifically, as... Figure 13 As shown, the optical path length from the image modulation element (liquid crystal panel P) to the convergence position 35 is denoted as optical path length A.

[0320] The optical path length from the intermediate incident position 41 to the front focal position 36 is denoted as B. For example... Figure 12 As shown, the optical path length B is the length of the beam from the middle incident position 41 to the front focal position 36 when the parallel beam 38 is incident from the opposite side onto the edge-side incident area 37 of the final lens surface F5. Figure 12 The optical path length (the thick arrow in the image).

[0321] The optical path length of the intermediate light 40 from the illumination optical system 10 to the intermediate incident position 41 is denoted as C. Specifically, as... Figure 13As shown, the optical path length from the image modulation element (liquid crystal panel P) to the middle incident position 41 is denoted as optical path length C.

[0322] In this case, the projection optics system 15 is configured to satisfy the following relationship.

[0323] (4) 0.8 < |A+B| / C < 1.2

[0324] That is, in this disclosure, if the range satisfies the condition expression (4), then the convergence position 35 is consistent with the front focus position 36 and satisfies (configuration condition 6-1).

[0325] If |A+B| / C exceeds the upper limit defined by the conditional expression (4), the edge-side beam CE emitted from the second refractive optical system L2 diverges and remains a parallel beam.

[0326] If |A+B| / C exceeds the lower limit defined by the conditional expression (4), the edge-side beam CE emitted from the second refractive optical system L2 converges and remains a parallel beam.

[0327] The projection optical system 15 is configured to satisfy condition expression (4). That is, the projection optical system 15 is configured such that the convergence position 35 coincides with the front focal position 36. Therefore, (configuration condition 2) can be satisfied, and the uniformity of brightness and magnification of the edge region of the projected image can be improved.

[0328] In the projection optical system 15 of this embodiment, the first intermediate image is imaged between the dichroic prism PP included in the illumination optical system 10 and the first reflective surface Mr1.

[0329] The second intermediate image is imaged between the first reflective surface Mr1 and the second reflective surface Mr2.

[0330] Furthermore, the third intermediate image is imaged between the second refractive optical system L2 and the concave reflective surface Mr3.

[0331] The image is projected onto the screen through the concave reflective surface Mr3.

[0332] The first optical system LL1 can also be represented as a pre-stage optical system with the second intermediate image as its boundary. The second optical system LL2 can also be a post-stage optical system that captures the second intermediate image as its boundary.

[0333] It should be understood that the application of this technology is not limited to the imaging of intermediate images.

[0334] In this embodiment, the edge-side beam CE is emitted from the liquid crystal panel P along the optical axis O. Therefore, the convergence position 35 on which the first optical system LL1 converges the edge-side beam CE can also be represented as the back-focusing position of the first optical system LL1.

[0335] Therefore, in this embodiment, for (configuration condition 6-1) and (configuration condition 6-2), the convergence position 35 can also be referred to as the back focal position of the first optical system LL1.

[0336] When configuring the projection optical system 15 according to the present invention, not all of the configuration conditions listed above may be satisfied. If at least one of the above configuration conditions is satisfied, it can be used as an implementation of the projection optical system according to the present invention. High-quality image display can be achieved.

[0337] It should be understood that all configuration conditions can be satisfied. Alternatively, the projection optical system 15 can be configured to satisfy any two or more configuration conditions.

[0338] The lower and upper limits of each of the conditional expressions (1), (2), and (4) are not limited to the values ​​described above. For example, the values ​​can be appropriately changed according to the configuration of the illumination optical system 10, the projection optical system 15, etc. For example, any value included in the above range can be selected as the lower and upper limit values, and can be set to the optimal range again.

[0339] For example, the conditional expression (1) can be set to the following range.

[0340] 0.01<|Δθ(hmax)-Δθ(0.9·hmax)| / θ(hmax)<0.06

[0341] 0.02<|Δθ(hmax)-Δθ(0.9·hmax)| / θ(hmax)<0.05

[0342] 0.03<|Δθ(hmax)-Δθ(0.9·hmax)| / θ(hmax)<0.04

[0343] For example, the conditional expression (2) can be set to the following range.

[0344] 0.05 < |Φ2 / Φ1| < 1.3

[0345] 0.15 < |Φ2 / Φ1| < 1.15

[0346] 0.2 < |Φ2 / Φ1| < 1.1

[0347] For example, the conditional expression (4) can be set to the following range.

[0348] 0.7 < |Φ2 / Φ1| < 1.3

[0349] 0.9 < |Φ2 / Φ1| < 1.15

[0350] 1.0 < |Φ2 / Φ1| < 1.1

[0351] The projection optical system 15 configured as described above will be briefly described with reference to specific numerical examples.

[0352] Figure 14 This is a table showing examples of parameters related to image projection.

[0353] Figure 15 It is used to describe Figure 14 A schematic diagram of the parameters shown.

[0354] The numerical aperture NA of the projection optics system 15 on the main image plane side is 0.127.

[0355] The image modulation element (liquid crystal panel P) has lengths of 15.6 mm in the left-right direction and 8.7 mm in the up-down direction (H×VSp).

[0356] The center position (Chp) of the image modulation element is 5.6 mm above the optical axis O.

[0357] The image circle (imc) on the side of the main image plane is

[0358] like Figure 15 As shown, Figure 5 The pixel light C1 shown is emitted from the center pixel (referred to as pixel C1 by the same reference numeral) of the liquid crystal panel P.

[0359] Pixel light C2 (referred to as pixel C2 using the same reference numerals) is emitted from the pixel on the optical axis O closest to the center of the LCD panel P.

[0360] Pixel light C3 (referred to as pixel C3 using the same reference numerals) is emitted from the pixel on the optical axis O furthest from the center of the LCD panel P.

[0361] For the configuration conditions of edge-side beams CE, similar configuration conditions can be applied to beams defined using image circles (imc).

[0362] For example, such as Figure 16 As shown, the image circle (0.74imc) with 74% image height is defined relative to the image circle (imc) with the maximum image height.

[0363] A beam emitted from the region from the image circle at 74% of the image height to the image circle at the maximum image height (imc) (the area shown in gray in the figure) is called a high-image-height emission beam.

[0364] For high-image, high-emission beams, the following configuration conditions are shown.

[0365] The projection optical system 15 is configured such that the high-image high-emission beam is incident as a parallel beam on the concave reflective surface Mr3 (the condition corresponding to configuration condition 2).

[0366] The projection optical system 15 is configured such that high-image, high-emission beams are incident on the concave reflective surface Mr3 at equal beam intervals (the condition corresponding to configuration condition 3).

[0367] In the portion of the first optical system LL1 and the second refractive optical system L2 that act on the high-image, high-emission beam, such as Figure 13 As shown, the convergence position 35 is consistent with the front focal position 36 (corresponding to the condition in configuration condition 6-1).

[0368] In the portion of the high-image, high-emission beam that acts on the first optical system LL1 and the second refractive optical system L2, condition expression (4) is satisfied (the condition corresponding to configuration condition 6-2).

[0369] By configuring the projection optics system 15 to meet the configuration conditions related to high image emission beams, similar effects as described above are achieved. That is, the uniformity of brightness and magnification in the edge regions of the projected image can be improved, and high-quality image display can be achieved.

[0370] Note that the high-image, high-emission beam group and the edge-side beam group can be the same beam group or they can be different beam groups.

[0371] Figure 17 It is the lens data of the image display device.

[0372] Figure 17 Data are shown on 1 to 33 optical components (lens surfaces) arranged from the main image plane (P) side to the secondary image plane (S) side and the curved screen S.

[0373] For each of the optical components (lens surfaces), the data describes the radius of curvature (mm), core thickness d (mm), refractive index nd (587.56 nm) in the d-line, and Abbe number νd in the d-line. For the curved screen S, the radius of curvature (mm) is described.

[0374] Note that optical components with aspherical surfaces follow the following expression.

[0375] [Mathematical Expression 1]

[0376]

[0377] Figure 18This is a table showing examples of the aspherical coefficients of optical components included in a projection optics system.

[0378] Figure 18 The aspherical coefficients of the various aspherical optical components 19, 20, 21, 23, 24, and 33 are shown. Figure 17 The aspherical coefficients in this example correspond to the expressions above (Expression 1).

[0379] In this embodiment, the expression (expression 1) corresponds to the function Z(h) which represents the shape of the concave reflective surface Mr3 corresponding to the beam height.

[0380] In expression (Expression 1), the sag amount Z at the light height h is used as a parameter representing the shape of the concave reflecting surface Mr3 according to the beam height. It should be noted that the "sag amount" represents the distance between a point on the lens surface in the optical axis direction when a plane perpendicular to the optical axis is formed by passing through the vertex of the plane.

[0381] The derivative Z'(h) (=dZ / dh), obtained by differentiating the function Z(h) with respect to the beam height, is expressed by the following expression.

[0382] [Mathematical Expression 2]

[0383]

[0384] This expression allows us to calculate the slope of the line tangent to the concave reflecting surface Mr3 at beam height h. In other words, it allows us to calculate the angle θ(h) in the optical axis height direction relative to the tangent of the function Z(h).

[0385] Figure 19 It is a graph showing the relationship between beam height h and Δθ(h) / θ(hmax).

[0386] In addition, the beam height h is calculated after standardizing it by setting the optical height h of the optical axis O to 0 and the beam height hmax1.

[0387] Δθ(h) / θ(hmax) gradually changes from 0.9 to 1.00 of the beam height away from the optical axis O.

[0388] This means that the shape change on the edge side region of the concave reflective surface Mr3 is gradual as the beam height increases from (0.9·hmax) to (hmax). In other words, it means that the shape change of the reflective surface is gradual relative to a beam with a reflection point from (0.9·hmax) to (hmax).

[0389] Therefore, it can improve the brightness and magnification uniformity of the edge areas of the projected image and achieve high-quality image display.

[0390] It should be noted that in the conditional expression (1), |Δθ(hmax)-Δθ(0.9·hmax)| / θ(hmax) is Figure 19 The curve shown represents the difference between the light height value of 1.00 and the beam height value of 0.9.

[0391] Figure 20 This is a table showing the values ​​of the parameters used in the above conditional expressions (1), (2) and (4) in this embodiment.

[0392] |Z'(1.0·hmax)-Z'(0.9·hmax)|0.001

[0393] |Φ2 / Φ1|0.370

[0394] |A+B| / C 1.004

[0395] The results show that conditional expressions (1), (2), and (4) are satisfied. Conditional expression (3) is also satisfied.

[0396] In this embodiment, all configuration conditions 1 to 6 are satisfied.

[0397] In this embodiment, the beam emitted from the region from the image circle with 59% image height to the image circle (imc) with the maximum image height satisfies conditional expression (4). Therefore, the beam can also be defined as a high-image-height emission beam.

[0398] As described above, in the image display device 20 according to this embodiment, the shape of the concave reflective surface Mr3, designed to reflect image light toward the object to be projected, is as described above. This enables high-quality image display.

[0399] Furthermore, in the image display device 20 according to this embodiment, at least a portion of the image light beam is reflected along the optical axis O via the concave reflective surface Mr3, serving as a reference in the projection optical system 15, and is also reflected in directions intersecting at angles of 90 degrees or more. Therefore, for example, it is possible to correspond to the projection of an image onto a curved screen S or the like and achieve high-quality image display.

[0400] For example, considering the same image light projected onto a flat screen and a curved screen respectively, the images displayed on the flat screen and the curved screen will naturally have different shapes. Taking the image displayed on the flat screen as a reference, the image displayed on the curved screen is a distorted image.

[0401] Therefore, in order to properly display images on a curved screen, electrical correction processing should be performed on the image signal. The correction amount is usually large, depending on the shape of the curved screen, and there is a possibility of degrading image quality.

[0402] Furthermore, in order to display images over the wide area of ​​a curved screen, the image display device must be installed at a position far from the curved screen. As a result, the presence of the image display device protrudes from the user viewing the image, impairing the immersion of the content. In addition, because the area where the user's shadow appears becomes larger, the area where the user can move is smaller. Consequently, it becomes difficult to provide a superior viewing environment.

[0403] In the image display system 100 according to this embodiment, the range that can be reflected by the concave reflective surface Mr3 is extensively designed to be 90 degrees or greater relative to the optical axis O used as a reference. Therefore, distortion of the image optically displayed on the curved screen S can be suppressed. This allows for sufficient suppression of the electrical correction amount of the image signal. As a result, an image with high image quality can be displayed.

[0404] In addition, such as Figure 3 As shown, because images can be projected from a position close to the curved screen S over a wide area of ​​the curved screen S, the presence of the first image display device 20a and the second image display device 20b effectively suppresses the user 3's immersion in the content. Furthermore, since the area where the user 3's shadow appears can be reduced, the area where the user 3 can move can be enlarged. As a result, a very superior viewing environment can be provided.

[0405] <Second Implementation Method>

[0406] A second embodiment of an image display system according to the present technology will be described. In the following description, descriptions of configurations and operations identical to those of the image display system 100 and image display device 20 described in the above embodiments will be omitted or simplified.

[0407] Figure 21 and Figure 22 This is an optical path diagram showing a schematic configuration example of the projection optical system 215 according to the second embodiment.

[0408] Figure 23 The lens data of the image display device is shown.

[0409] Figure 24 This is a table showing examples of the aspherical coefficients of optical components included in a projection optics system.

[0410] Figure 25 It is a graph showing the relationship between beam height h and Δθ(h) / θ(hmax).

[0411] It should be noted that the parameters related to image projection are similar to those in the first embodiment, and have the characteristics of... Figure 14 The values ​​shown.

[0412] Furthermore, in the projection optical system 215 according to this embodiment, the concave reflective surface Mr3 (at least a portion of the light beam included in the image light incident on the concave reflective surface Mr3) is reflected in a direction that intersects the direction along the optical axis O, which serves as a reference axis, at an angle of 90 degrees or more.

[0413] Therefore, high-quality image display corresponding to the curved screen S can be achieved.

[0414] Figure 26 This is a table showing the values ​​of the parameters used in the above conditional expressions (1), (2) and (4) in this embodiment.

[0415] |Z'(1.0·hmax)-Z'(0.9·hmax)|0.003

[0416] |Φ2 / Φ1|0.356

[0417] |A+B| / C 1.003

[0418] The results show that conditional expressions (1), (2), and (4) are satisfied. Conditional expression (3) is also satisfied.

[0419] In the projection optical system 215 according to this embodiment, all configuration conditions 1 to 6 are satisfied.

[0420] Therefore, it can improve the brightness and magnification uniformity of the edge areas of the projected image and achieve high-quality image display.

[0421] In this embodiment, the beam emitted from the region from the image circle with 59% image height to the image circle (imc) with the maximum image height satisfies conditional expression (4). Therefore, the beam can also be defined as a high-image-height emission beam.

[0422] <Third Implementation Method>

[0423] Figure 27 and Figure 28 This is an optical path diagram illustrating a schematic configuration example of the projection optical system 315 according to the third embodiment.

[0424] Figure 29 This is a table showing examples of parameters related to image projection.

[0425] Figure 30 The lens data of the image display device is shown.

[0426] Figure 31This is a table showing examples of the aspherical coefficients of the optical elements included in a projection optical system.

[0427] Figure 32 It is a graph showing the relationship between beam height h and Δθ(h) / θ(hmax).

[0428] In this embodiment, image light is projected onto a flat screen S'.

[0429] The concave reflective surface Mr3 of the projection optical system 315 reflects the beam of image light incident on the concave reflective surface Mr3 in a direction that intersects the direction along the optical axis O at an angle of less than 90 degrees.

[0430] This technology is also applicable to this image display device.

[0431] Figure 33 This is a table showing the values ​​of the parameters used in the above conditional expressions (1), (2) and (4) in this embodiment.

[0432] |Z'(1.0·hmax)-Z'(0.9·hmax)|0.002

[0433] |Φ2 / Φ1|0.455

[0434] |A+B| / C 0.972

[0435] The results show that conditional expressions (1), (2), and (4) are satisfied. Conditional expression (3) is also satisfied.

[0436] In the projection optical system 315 according to this embodiment, all configuration conditions 1 to 6 are satisfied.

[0437] Therefore, it can improve the brightness and magnification uniformity of the edge areas of the projected image and achieve high-quality image display.

[0438] In this embodiment, for a light beam that includes a region with a reflection point greater than 0.82·hmax reflected by the concave reflective surface Mr3, condition expression (4) is satisfied. Therefore, the light beam can also be defined as a high-image, high-emission light beam.

[0439] In this embodiment, the beam emitted from the region from the image circle with 71% image height to the image circle (imc) with the maximum image height satisfies conditional expression (4). Therefore, the beam can also be defined as a high-image-height emission beam.

[0440] <Fourth Implementation Method>

[0441] Figure 34 and Figure 35This is an optical path diagram illustrating a schematic configuration example of the projection optical system 415 according to the fourth embodiment.

[0442] Figure 36 This is a table showing examples of parameters related to image projection.

[0443] Figure 37 The lens data of the image display device is shown.

[0444] Figure 38 This is a table showing examples of the aspherical coefficients of the optical elements included in a projection optical system.

[0445] Figure 39 It is a graph showing the relationship between beam height h and Δθ(h) / θ(hmax).

[0446] Furthermore, in this embodiment, the image light is projected onto the flat screen S'.

[0447] The concave reflective surface Mr3 of the projection optical system 415 reflects the beam of image light incident on the concave reflective surface Mr3 in a direction that intersects the direction along the optical axis O at an angle of less than 90 degrees.

[0448] Figure 40 This is a table showing the values ​​of the parameters used in the above conditional expressions (1), (2) and (4) in this embodiment.

[0449] |Z'(1.0·hmax)-Z'(0.9·hmax)|0.004

[0450] |Φ2 / Φ1|0.701

[0451] |A+B| / C 1.0388

[0452] The results show that conditional expressions (1), (2), and (4) are satisfied. Conditional expression (3) is also satisfied.

[0453] In the projection optical system 315 according to this embodiment, all configuration conditions 1 to 6 are satisfied.

[0454] Therefore, it can improve the brightness and magnification uniformity of the edge areas of the projected image and achieve high-quality image display.

[0455] In this embodiment, for a light beam that includes a region in which the reflection point of the concave reflective surface Mr3 is greater than 0.78hmax, conditional expression (4) is satisfied. Therefore, the light beam can also be defined as a high-image, high-emission light beam.

[0456] <Other Implementation Methods>

[0457] This technology is not limited to the above-described embodiments and can be implemented in various other ways.

[0458] Figure 41 and Figure 42 Each of these is a schematic diagram illustrating an example configuration of an image display system according to another embodiment.

[0459] exist Figure 41 The image display system 500 shown uses a curved screen S with a dome shape. Note that the dome shape is not limited to a hemispherical shape, but includes any shape that can cover the upper part of about 360 degrees.

[0460] A curved screen S with an arched shape can also be called an arched screen.

[0461] like Figure 41 As shown in A to C, the first image display device 520a and the second image display device 520b are arranged below the dome-shaped curved screen S, facing each other along the right and left directions.

[0462] The first image display device 520a and the second image display device 520b are mounted such that the first image 521a and the second image 521b can be projected upwards.

[0463] The first image 521a and the second image 521b are projected to overlap each other along the long side direction (left-right direction).

[0464] Therefore, an overlap region 522 is generated at the vertex portion of the curved screen S, where the first image 521a and the second image 521b overlap each other. A stitching process is performed based on the overlap region 522, and an image with a larger size is displayed.

[0465] By using the image display devices according to this technology as the first image display device 520a and the second image display device 520b, high-quality image display corresponding to the dome shape can be achieved, and an excellent viewing environment can be provided.

[0466] exist Figure 42 In the image display system 600 shown in A and B, the first image display device 620a to the third image display device 620b are arranged at equal intervals along the circumference below the dome-shaped curved screen S.

[0467] The first to third image display devices 620a to 620c are installed so that the first to third images 621a to 621c can be projected upwards.

[0468] like Figure 42 As shown in B, the image light projected to form a rectangular image is used as the first image 621a to the third image 621c.

[0469] like Figure 42 As shown in B, each of the first images 621a to the third image 621c is schematically shown in a rectangular shape, but the shape displayed on the curved screen S is different from the rectangular shape.

[0470] The first image 621a to the third image 621b are projected to overlap each other at positions symmetrical about the vertices of the curved screen S. Then, a stitching process is performed on the overlapping regions 622a to 622c, and a single image with a larger size is displayed.

[0471] By using the image display device described above according to the present technology as the first to third image display devices 620a to 620c, high-quality image display corresponding to the dome shape can be achieved, and an excellent viewing environment can be provided.

[0472] As mentioned above, this technology is applicable even when using three or more image display devices.

[0473] As a concave reflective surface used to reflect image light on a screen, a freely curved surface without a rotational axis of symmetry can be used.

[0474] In this case, for example, the optical axis of the concave reflective surface (e.g., the axis passing through the center of the optical surface) is aligned with the reference axis used as a reference for the lens system. Thus, the same effect as described above can be achieved.

[0475] Furthermore, for each of the first and second reflective surfaces, a freely curved surface without an axis of rotational symmetry can be used. That is, at least one of the concave reflective surface, the first reflective surface, or the second reflective surface can be a freely curved surface without an axis of rotational symmetry.

[0476] The object to be projected is not limited to curved screens. This technology can be applied to image display on any object to be projected (such as a table, a wall, a building, etc.). In particular, it can achieve high-quality image display corresponding to objects with curved shapes.

[0477] The image display system, image display device, projection optical system, concave reflective surface, screen, etc., described with reference to the accompanying drawings are merely one embodiment and can be modified arbitrarily without departing from the scope of the present technology. In other words, for example, any other configuration or algorithm for implementing the present technology can be employed.

[0478] When the term “approximate” is used in this disclosure, it is only for the purpose of facilitating the understanding of the description, and the use / non-use of the term “approximate” is not particularly meaningful.

[0479] That is, in this disclosure, the concepts of shape, size, contrast relationship, positional relationship, state, etc., such as "center," "central," "uniform," "consistent," "equal," "identical," "orthogonal," "parallel," "extended," "axial," "cylindrical," "cylindrical," "ring-shaped," "wheel-shaped," etc., include the following concepts:

[0480] "Basically centered", "Basically central", "Basically uniform", "Basically consistent", "Basically equal", "Basically identical", "Basically orthogonal", "Basically parallel", "Basically extended", "Basically axial", "Basically cylindrical", "Basically columnar", "Basically ring-shaped", "Basically wheel-shaped", etc.

[0481] For example, based on "perfect center", "perfect center", "perfect uniformity", "perfect consistency", "perfect equality", "perfect sameness", "perfect orthogonality", "perfect parallelism", "perfect extension", "perfect axial direction", "perfect cylinder", "perfect column", "perfect ring", "perfect wheel", etc., it also includes states contained within a predetermined range (e.g., ±10%).

[0482] Therefore, even without adding the word "approximate," the concept expressed by adding the so-called "approximate" can be included. Conversely, for states indicated by the addition of "approximate," the complete state is not excluded.

[0483] In this disclosure, the use of expressions such as "greater than A" and "smaller than A" comprehensively includes both expressions that express equivalence to A and expressions that express non-equivalence to A. For example, "greater than A" is not limited to cases excluding equivalents to A, but includes "greater than A or equal to A". "smaller than A" is not limited to "smaller than A", but includes "smaller than A or equal to A".

[0484] When implementing this technology, specific settings can be appropriately adopted from the concepts included in "larger than A" and "smaller than A" to achieve the above-mentioned effects.

[0485] At least two of the features of this technology described above can also be combined. In other words, regardless of the implementation method, the various features described in the various implementations can be combined arbitrarily. Furthermore, the various effects described above are not limiting, but merely exemplary, and may provide other effects.

[0486] It should be noted that this technology can also be configured as follows.

[0487] (1) An image display device, comprising:

[0488] light source;

[0489] An image generation unit is used to generate image light by modulating light emitted from a light source; and

[0490] The projection optical system has the following features:

[0491] The lens system is configured to reference a reference axis at the location where the generated image light is incident, and has positive refractive power overall.

[0492] A concave reflective surface, configured with reference to a reference axis, reflects image light emitted from the lens system toward the object to be projected.

[0493] Among them, the following relationship is satisfied:

[0494] 0<|Δθ(hmax)-Δθ(0.9·hmax)| / θ(hmax)<0.056,

[0495] in,

[0496] The beam height from the reference axis is denoted as h.

[0497] The angle of the tangent to the function Z(h), which represents the shape of the concave reflecting surface corresponding to the beam height h, with respect to the optical axis height direction, is denoted as θ(h).

[0498] The change in angle θ(h) at beam height h is expressed as Δθ(h), and

[0499] The beam height h of the reflection point furthest from the reference axis of the concave reflective surface used to reflect image light is denoted as hmax.

[0500] (2) The image display device according to (1), wherein,

[0501] Δθ(h) is θ(h)-θ(0.98·h).

[0502] (3) The image display device according to (1) or (2), wherein,

[0503] If the light beam in the image is included in the region where the reflection point of the reflected light from the concave reflective surface is greater than 0.85·hmax, it is represented as an edge-side beam.

[0504] The projection optical system is then configured such that the travel directions of the edge-side beams incident on the concave reflective surface are parallel to each other.

[0505] (4) The image display device according to (3), wherein,

[0506] The projection optics system is configured such that the beam spacing of the edge-side beams incident on the concave reflective surface is equal.

[0507] (5) An image display device according to any one of (1) to (4), wherein

[0508] The lens system has:

[0509] The first refractive optical system has a positive refractive force as a whole and refracts the generated image light.

[0510] A first reflective surface is used to reflect the image light refracted by the first refractive optical system back;

[0511] A second reflective surface is used to reflect the image light reflected by the first reflective surface back; and

[0512] The second refractive optical system, having positive refractive power overall, refracts image light reflected from the second reflecting surface to emit it onto the concave reflecting surface, wherein the following relationship is satisfied:

[0513] 0.1 < |Φ2 / Φ1| < 1.2

[0514] in,

[0515] The force on the first reflecting surface is denoted as Φ1, and

[0516] The force on the second reflecting surface is represented by Φ2.

[0517] (6) The image display device according to (5), wherein,

[0518] |Φ2|<|Φ1|

[0519] satisfy.

[0520] (7) The image display device according to (5) or (6), wherein,

[0521] If the first refractive optical system, the first reflecting surface, and the second reflecting surface are referred to as the first optical system, and the portion of the edge-side beam acting on the second refractive optical system is referred to as the second optical system,

[0522] The first optical system then focuses the edge-side beam at a predetermined convergence position, and

[0523] The predetermined convergence position coincides with the front focal point position of the second optical system.

[0524] (8) The image display device according to (7), wherein the following relationship is satisfied:

[0525] 0.8 < |A+B| / C < 1.2

[0526] in,

[0527] In edge-side beams, a beam whose beam height at the reflection point of the concave reflecting surface is an intermediate value is referred to as an intermediate beam.

[0528] The incident position of the intermediate beam relative to the final lens surface of the second refractive optical system is referred to as the intermediate incident position.

[0529] The optical path length from the image generation unit to the intermediate beam at the predetermined convergence position is denoted as A, and the optical path length from the intermediate incident position to the front focal position is denoted as B.

[0530] The optical path length of the intermediate beam from the image generation unit to the intermediate incident position is denoted as C.

[0531] (9) The image display device according to (8), wherein,

[0532] If the average angle between the travel directions of the edge-side beams incident on the concave reflecting surface and the direction along the reference axis is expressed as the average angle, and...

[0533] The region where the light beam is incident on the edge side of the final lens surface of the second refractive optical system is denoted as the edge side incident region.

[0534] The front focal position of the second optical system is the convergence position when a parallel beam is incident from the opposite side onto the edge-side incident region of the final lens surface along a direction that intersects with the direction along the reference axis at an average angle.

[0535] (10) The image display device according to (9), wherein,

[0536] The optical path length B is the optical path length of a parallel beam traveling from the middle incident position to the front focal position when it is incident on the edge side of the final lens surface from the opposite side.

[0537] (11) An image display device according to any one of (1) to (10), wherein

[0538] A concave reflective surface will reflect at least a portion of the beam of image light incident on the concave reflective surface in a direction that intersects the direction along the reference axis at an angle of 90 degrees or more.

[0539] (12) An image display device according to any one of (1) to (11), wherein

[0540] The projection optical system includes a first optical component, wherein a region of the main surface is configured as a first reflective surface and another region of the main surface is configured as a transmissive surface, and

[0541] The transmission surface of the first optical component is used as the second refractive optical system.

[0542] (13) The image display device according to any one of (1) to (12), wherein

[0543] The projection optical system includes a second optical component, wherein a region of the main surface is configured as a second reflective surface and another region of the main surface is configured as a transmissive surface, and

[0544] The transmission surface of the second optical component is used as the first refractive optical system.

[0545] (14) The image display device according to any one of (1) to (13), wherein

[0546] The reference axis is obtained by extending the optical axis of the lens that is closest to the image generating unit included in the lens system.

[0547] (15) An image display device according to any one of (1) to (14), wherein

[0548] The projection optics system is configured such that the optical axis of each optical component in all the optical components contained in the projection optics system is aligned with a predetermined reference axis.

[0549] (16) The image display device according to any one of (1) to (15), wherein

[0550] The concave reflective surface is configured such that the axis of rotational symmetry coincides with the reference axis, and

[0551] Each of the first and second reflective surfaces is a concave reflective surface and is configured such that the axis of rotational symmetry coincides with the reference axis.

[0552] (17) An image display device according to any one of (1) to (15), wherein

[0553] Each of the concave reflective surface, the first reflective surface, and the second reflective surface is configured such that the optical axis is aligned with the reference axis, and

[0554] At least one of the concave reflective surface, the first reflective surface, and the second reflective surface is a free-bending surface without an axis of rotational symmetry.

[0555] (18) An image display device according to any one of (1) to (17), wherein

[0556] The object to be projected is a flat screen or a curved screen.

[0557] (19) An image display system according to any one of (1) to (17), wherein,

[0558] The object to be projected is a screen with a dome shape.

[0559] (20) A projection optical system for projecting image light generated by modulating light emitted from a light source, the projection optical system comprising:

[0560] The lens system is configured to reference a reference axis at the location where the generated image light is incident, and has positive refractive power overall; and

[0561] A concave reflective surface is configured as a reference axis and reflects the image light emitted from the lens system toward the object to be projected.

[0562] Among them, the following relationship is satisfied:

[0563] 0<|Δθ(hmax)-Δθ(0.9·hmax)| / θ(hmax)<0.056,

[0564] in,

[0565] The beam height from the reference axis is denoted as h.

[0566] The angle of the tangent to the function Z(h), which represents the shape of the concave reflecting surface corresponding to the beam height h, with respect to the optical axis height direction, is denoted as θ(h).

[0567] The change in angle θ(h) at beam height h is expressed as Δθ(h), and

[0568] The beam height h of the reflection point furthest from the reference axis of the concave reflective surface used to reflect image light is denoted as hmax.

[0569] Reference number list

[0570] CE edge side beam

[0571] C1 to C3 pixel light

[0572] F5 Final Lens Surface

[0573] L1 First Refractive Optical System

[0574] L2 Second Refractive Optical System

[0575] LL1 First Optical System

[0576] LL2 Second Optical System

[0577] Mr1 First Reflective Surface

[0578] Mr2 Second Reflective Surface

[0579] Mr3 concave reflective surface

[0580] O optical axis

[0581] S' flat screen

[0582] 1 LCD projector

[0583] 5. Light source

[0584] 10 Illumination Optical System

[0585] 15, 215, 315, 415 Projection Optical Systems

[0586] 20, 520, 620 image display devices

[0587] 30 Curved Screen

[0588] 35 Convergence Location

[0589] 36. Foreground focus position

[0590] 37. Edge-side incident area

[0591] 38 parallel beams

[0592] 40 Intermediate Beam

[0593] 41. Intermediate incident position

[0594] 100, 500, 600 image display systems.

Claims

1. An image display device, comprising: light source; An image generation unit is used to generate image light by modulating light emitted from the light source; as well as The projection optical system has the following features: The lens system is configured such that the optical axis is aligned with the reference axis at the point of incidence of the generated image light, and has positive refractive power overall. A concave reflective surface is configured such that its rotational symmetry axis coincides with the reference axis, and reflects the image light emitted from the lens system toward the object to be projected. Among them, the following relationship is satisfied: 0<|Δθ(hmax)-Δθ(0.9 hmax)| / θ(hmax)<0.056, in, The height of the beam from the reference axis is denoted as h. The angle of the tangent to the function Z(h), which represents the shape of the concave reflective surface corresponding to the beam height h, relative to the optical axis height direction, is denoted as θ(h). The change in angle θ(h) at the beam height h is expressed as Δθ(h), and The beam height h of the reflection point furthest from the reference axis of the concave reflective surface used to reflect the image light is denoted as hmax.

2. The image display device according to claim 1, wherein, The Δθ(h) is θ(h)-θ(0.98 h).

3. The image display device according to claim 1, wherein, If the image light includes a reflection point greater than 0.85 reflected by the concave reflective surface. The beams in the hmax region are represented as edge-side beams. The projection optical system is then configured such that the respective travel directions of the edge-side beams incident on the concave reflective surface are parallel to each other.

4. The image display device according to claim 3, wherein, The projection optical system is configured such that the beam spacing of the edge-side beams incident on the concave reflective surface is equal.

5. The image display device according to claim 1, wherein, The lens system has: The first refractive optical system has a positive refractive force as a whole and refracts the generated image light. A first reflective surface is used to reflect the image light refracted by the first refractive optical system back; A second reflective surface is used to reflect the image light reflected by the first reflective surface back; as well as The second refractive optical system, having positive refractive power overall, refracts the image light reflected by the second reflective surface to emit it onto the concave reflective surface, wherein the following relationship is satisfied: 0.1 < |Φ2 / Φ1| < 1.2, in, The force on the first reflective surface is denoted as Φ1, and The force on the second reflective surface is denoted as Φ2.

6. The image display device according to claim 5, wherein, The following relationship must be satisfied: |Φ2|<|Φ1|.

7. The image display device according to claim 5, wherein, If the first refractive optical system, the first reflective surface, and the second reflective surface are represented as a first optical system, and the portion of the edge-side beam from the second refractive optical system is represented as a second optical system, The first optical system then focuses the edge-side beam at a predetermined focusing position, and The predetermined convergence position coincides with the front focal point position of the second optical system.

8. The image display device according to claim 7, wherein, The following relationship must be satisfied: 0.8 < |A+B| / C < 1.2 in, In the edge-side beam, the beam whose height at the reflection point reflected by the concave reflective surface is an intermediate value is represented as an intermediate beam. The incident position of the intermediate beam relative to the final lens surface of the second refractive optical system is referred to as the intermediate incident position. The optical path length of the intermediate beam from the image generation unit to the predetermined convergence position is denoted as A. The optical path length from the intermediate incident position to the front focal position is denoted as B, and The optical path length of the intermediate beam from the image generation unit to the intermediate incident position is denoted as C.

9. The image display device according to claim 8, wherein, If the average value of the angles at which the respective travel directions of the edge-side beams incident on the concave reflecting surface intersect with the direction along the reference axis is expressed as the average angle, and The region on the edge side of the final lens surface of the second refractive optical system where the beam is incident is referred to as the edge side incident region. The front focal position of the second optical system is the convergence position when a parallel beam is incident from the opposite side onto the edge-side incident region of the final lens surface along a direction that intersects with the direction along the reference axis at the average angle.

10. The image display device according to claim 9, wherein The optical path length B is the optical path length of the beam traveling from the intermediate incident position to the front focal position when the parallel beam is incident on the edge-side incident area of ​​the final lens surface from the opposite side.

11. The image display device according to claim 1, wherein, The concave reflective surface will reflect at least a portion of the light beam, including the image light incident on the concave reflective surface, in a direction that intersects the direction along the reference axis at an angle of 90 degrees or more.

12. The image display device according to claim 1, wherein, The projection optical system includes a first optical component, wherein a region of the main surface is configured as a first reflective surface and another region of the main surface is configured as a transmissive surface, and The transmission surface of the first optical component serves as a second refractive optical system.

13. The image display device according to claim 1, wherein, The projection optical system includes a second optical component, wherein a region of the main surface is configured as a second reflective surface and another region of the main surface is configured as a transmissive surface, and The transmission surface of the second optical component serves as the first refractive optical system.

14. The image display device according to claim 1, wherein, The reference axis is obtained by extending the optical axis of the lens that is closest to the image generating unit included in the lens system.

15. The image display device according to claim 1, wherein, The projection optics system is configured such that the optical axis of each of all optical components included in the projection optics system is aligned with a predetermined reference axis.

16. The image display device according to claim 5, wherein, The concave reflective surface is configured such that its rotational symmetry axis coincides with the reference axis, and Each of the first and second reflective surfaces is a concave reflective surface and is configured such that the axis of rotational symmetry is aligned with the reference axis.

17. The image display device according to claim 5, wherein Each of the concave reflective surface, the first reflective surface, and the second reflective surface is configured such that the optical axis is aligned with the reference axis, and At least one of the concave reflective surface, the first reflective surface, and the second reflective surface is a free-bending surface without a rotational symmetry axis.

18. The image display device according to claim 1, wherein The object to be projected is a flat screen or a curved screen.

19. The image display device according to claim 1, wherein, The object to be projected is a screen with a dome shape.

20. A projection optical system for projecting image light generated by modulating light emitted from a light source, the projection optical system comprising: The lens system is configured such that the optical axis is aligned with the reference axis at the point of incidence of the generated image light, and has positive refractive power overall; as well as A concave reflective surface is configured such that its rotational symmetry axis coincides with the reference axis, and reflects the image light emitted from the lens system toward the object to be projected. Among them, the following relationship is satisfied: 0<|Δθ(hmax)-Δθ(0.9 hmax)| / θ(hmax)<0.056, in, The height of the beam from the reference axis is denoted as h. The angle of the tangent to the function Z(h), which represents the shape of the concave reflective surface corresponding to the beam height h, relative to the optical axis height direction, is denoted as θ(h). The change in angle θ(h) at the beam height h is expressed as Δθ(h), and The beam height h of the reflection point furthest from the reference axis of the concave reflective surface used to reflect the image light is denoted as hmax.

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