Projection lens and projection device

Abstract

To provide a projection optical system that is smaller than conventional systems. [Solution] The projection optical system comprises an element having reflective and transmissive properties positioned on the projection side of the light source panel, and at least one lens positioned between the light source panel and the element, wherein the focal length of the projection optical system, the distance on the optical axis from the projection-side surface of the projection optical system to the display surface of the light source panel, and the maximum effective area of ​​the light-emitting element on the display surface are each appropriately set.

Description

Technical Field

[0001] The present invention relates to a projection lens and a projection device.

Background Art

[0002] Conventionally, a projection optical system is known in which illumination light is made incident on a reflective light valve through a polarization conversion element, the modulated light from the reflective light valve is separated from the optical path of the illumination light by the polarization conversion element, and projected by a projection lens.

Summary of the Invention

Problems to be Solved by the Invention

[0003] In recent years, the development of AR and VR glasses-type devices has advanced, and a small projection optical system that can be arranged within the rim of glasses is desired.

Means for Solving the Problems

[0004] A projection optical system according to one aspect of the present invention includes an element having reflection and transmission characteristics arranged on the projection side from a light source panel, and at least one lens arranged between the light source panel and the element, and when the focal length of the projection optical system is f, the distance on the optical axis from the most projection-side surface of the projection optical system to the display surface of the light source panel is L, and the maximum effective area of the light-emitting element of the display surface is H, 0.10 ≦ L / f ≦ 2.10 0.10 ≦ L / H ≦ 4.50 It is characterized by satisfying the conditional expression.

Brief Description of the Drawings

[0005] [Figure 1] It is a cross-sectional view of the projection optical system of Example 1 at infinite focus. [Figure 2] It is an aberration diagram of the projection optical system of Example 1 at infinite focus. [Figure 3] It is a cross-sectional view of the projection optical system of Example 2 at infinite focus. [Figure 4]This is an aberration diagram of the projection optical system of Example 2 when focused at infinity. [Figure 5] This is a cross-sectional view of the projection optical system of Example 3 when it is in focus at infinity. [Figure 6] This is an aberration diagram of the projection optical system of Example 3 when focused at infinity. [Figure 7] This is a cross-sectional view of the projection optical system of Example 4 when it is in focus at infinity. [Figure 8] This is an aberration diagram of the projection optical system of Example 4 when it is in focus at infinity. [Figure 9] This is a cross-sectional view of the projection optical system of Example 5 when it is in focus at infinity. [Figure 10] This is an aberration diagram of the projection optical system of Example 5 when it is in focus at infinity. [Figure 11] This is a cross-sectional view of the projection optical system of Example 6 when it is in focus at infinity. [Figure 12] This is an aberration diagram of the projection optical system of Example 6 when it is in focus at infinity. [Figure 13] This is a cross-sectional view of the projection optical system of Example 7 when it is in focus at infinity. [Figure 14] This is an aberration diagram of the projection optical system of Example 7 when it is in focus at infinity. [Figure 15] This is a cross-sectional view of the projection optical system of Example 8 when it is in focus at infinity. [Figure 16] This is an aberration diagram of the projection optical system of Example 8 when it is in focus at infinity. [Figure 17] This is a cross-sectional view of the projection optical system of Example 9 when it is in focus at infinity. [Figure 18] This is an aberration diagram of the projection optical system of Example 9 when it is in focus at infinity. [Figure 19] This is a cross-sectional view of the projection optical system of Example 10 when it is in focus at infinity. [Figure 20] This is an aberration diagram of the projection optical system of Example 10 when it is in focus at infinity. [Figure 21] This is an explanatory diagram of a polarization conversion element. [Figure 22] These are schematic diagrams of projection devices having projection optical systems for each embodiment. [Modes for carrying out the invention]

[0006] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same members are denoted by the same reference numerals, and redundant descriptions are omitted.

[0007] FIG. 1, FIG. 3, FIG. 5, FIG. 7, FIG. 9, FIG. 11, FIG. 13, FIG. 15, FIG. 17, and FIG. 19 are cross-sectional views of the projection optical systems 100, 200, 300, 400, 500, 600, 700, 800, 900, and 1000 of Examples 1 to 10, respectively, at infinity focus. The projection optical system of each embodiment projects light from the panel surface (display surface) of a panel (light source panel) to the object side. The panel uses a reflective light valve such as a liquid crystal on silicon (LCOS) or a digital microdevice (DMD), emits image light, and displays an image on a screen. Further, as for AR glass applications, for example, the panel can be used for applications in which image light is incident on the incident portion of a thin glass flat plate (light guide plate), totally reflected and propagated in the light guide plate, and emitted from the emission portion of the light guide plate toward a person's eye to display an image on the retina of the person's eye.

[0008] FIG. 2, FIG. 4, FIG. 6, FIG. 8, FIG. 10, FIG. 12, FIG. 14, FIG. 16, FIG. 18, and FIG. 20 are aberration diagrams of the projection optical systems 100, 200, 300, 400, 500, 600, 700, 800, 900, and 1000, respectively, at infinity focus. In the spherical aberration diagram, Fno is the F-number, and it shows the amount of spherical aberration with respect to the d-line (wavelength 587.6 nm) and the g-line (wavelength 435.8 nm). In the astigmatism diagram, S shows the amount of astigmatism in the sagittal image plane, and M shows the amount of astigmatism in the meridional image plane. The distortion aberration diagram shows the amount of distortion aberration with respect to the d-line. The chromatic aberration diagram shows the amount of chromatic aberration in the g-line. ω is the imaging semi-angle (°).

[0009] Next, the characteristic configurations of the projection optical systems of each embodiment will be described.

[0010] The projection optical system of each embodiment has a polarization beam splitter (PBS), which is an element having a polarization separation surface P and characteristics of reflection and transmission. When the illumination light R1 is incident on the PBS at an angular direction different from the optical axis (in each embodiment, the direction perpendicular to the optical axis), the illumination light R1 is polarization-separated at the polarization separation surface P and reflected toward the panel IM, which is a reflective liquid crystal display element. Here, the vertical direction includes not only the case where it is strictly vertical but also the case where it is substantially vertical (substantially perpendicular).

[0011] The projection optical system of each embodiment has at least one lens disposed between the PBS and the panel IM. Here, the lens refers to an element having a refractive power. The projection optical system may also include an aperture stop (open stop) SP.

[0012] A quarter-wave plate (not shown) is disposed between the lens closest to the panel IM side of the projection optical system and the panel IM. The illumination light becomes linearly polarized at the polarization separation surface P, and the light passing through the quarter-wave plate becomes circularly polarized. After being reflected in a substantially 180° opposite direction by the panel IM, it returns to the quarter-wave plate again. The counterclockwise circularly polarized light returning to the quarter-wave plate becomes linearly polarized light polarized in a direction orthogonal to that when it was first reflected by the polarization separation surface P by the quarter-wave plate, passes through the polarization separation surface P, and is emitted to the projection side of R2. Instead of the quarter-wave plate, a depolarizer may be disposed. As the depolarizer, for example, "Cosmo Shine SRF" of Toyobo Co., Ltd. can be used.

[0013] The polarization separation surface P is, for example, a wire grid polarizer or a reflective polarizer having a configuration of laminated retardation films. At this time, the wire grid formation surface or the retardation film surface functions as a transmission reflection surface. Note that the wire grid polarizer does not necessarily have metal wires aligned. It may have thin metal or dielectric layers at a predetermined interval and function as a polarization selective transmission reflection element. For example, an element in which metal or dielectric layers are aligned by vapor deposition can be used.

[0014] The polarization separation surface P is preferably a surface that separates incident light into reflected light and transmitted light according to its polarization state. Specifically, it is preferable to use a polarization-selective transmission-reflection element. Examples of polarization-selective transmission-reflection elements include "WGF" manufactured by Asahi Kasei Corporation and "IQPE" manufactured by 3M Company. Alternatively, as a polarization-selective transmission-reflection element, an optical element created by forming a grid on the reflective surface during lens molding and then depositing, printing, or lithographing a metal or dielectric material onto it may be used.

[0015] Furthermore, the polarization separation plane P is preferably positioned at approximately 45° with respect to the optical axis. This assumes that the light beam of the illumination optical system is incident on the PBS from a direction perpendicular to the optical axis, and a 45° angle allows for obtaining the desired characteristics on the panel IM side. However, these do not need to be exactly 45°; they should be within ±5° of 45°, more preferably within ±2°, and even more preferably within ±1°.

[0016] Now, let's explain the configuration of PBS with reference to Figure 21. Figure 21 is an explanatory diagram of PBS.

[0017] If the element arrangement on the panel IM consists of horizontal size a and vertical size b, the size of the PBS placed on the projection side can be minimized by illuminating this area with a rectangular luminous beam having a ratio of a:b. In Figure 21, a:b ≈ c:d is the configuration that results in the smallest PBS size.

[0018] In the figures for each embodiment, the size of PBS, defined by the length d of one side in the horizontal cross-section, is denoted as PBS2. The angle θP between the optical axis e and the polarization separation plane P in the horizontal cross-section is approximately 45°.

[0019] Furthermore, in each embodiment, the effective range when a light source emitted from the end of the diagonal length H of the panel surface of panel IM passes through PBS is shown as PBS1.

[0020] The projection optical system of each embodiment satisfies the following condition (1).

[0021] 0.10 ≤ L / f ≤ 2.10 (1) Here, f is the focal length of the projection optical system. L is the distance along the optical axis from the projection-side surface of the projection optical system to the panel surface of the light source panel. Note that the projection-side surface of the projection optical system is the surface of the projection optical system closest to the subject, including the PBS and aperture diaphragm SP.

[0022] Conditional equation (1) defines the distance along the optical axis from the projection-side surface of the projection optical system to the panel surface of the panel IM, and the focal length of the projection optical system. Setting the value below the lower limit of conditional equation (1) is advantageous for miniaturization, but it results in a telephoto focal length, making it undesirable as it prevents securing the desired field of view. Setting the value above the upper limit of conditional equation (1) is undesirable because it increases the size of the projection optical system.

[0023] With the above configuration, it is possible to obtain a compact projection optical system even when a PBS with a polarization separation surface is placed.

[0024] Furthermore, it is more preferable that the lower limit of condition (1) be set to 0.12, 0.14, 0.16, 0.18, 0.20, 0.22, 0.24, 0.26, 0.28, or 0.30. The upper limit of condition (1) is more preferable that be set to 2.095, 2.090, 2.085, 2.080, 2.075, 2.070, 2.065, 2.060, 2.055, or 2.050.

[0025] Next, we will describe the configurations that are preferable to satisfy in the projection optical system of each embodiment.

[0026] The projection optical system requires a nearly telecentric configuration to utilize the reflection of illumination light from the panel IM. Furthermore, for use with AR glasses, a light guide plate must be placed on the projection side, and an aperture diaphragm SP must be placed closest to the projection side to direct the projected image. These structures constitute the configuration requirements for the projection optical system.

[0027] The telecentric configuration of the projection optical system means that the effective diameter of the lens positioned closest to the panel IM is approximately the same as the effective display size of the panel surface of the panel IM. Since the light beam emitted from the panel IM travels towards the aperture diaphragm closest to the projection, miniaturization of the projection optical system in the optical axis direction requires that the lens positioned closest to the panel IM bends the light rays with strong refractive power to reach the aperture diaphragm SP on the optical axis. Therefore, the lens positioned closest to the panel IM needs to have a very strong positive refractive power. Bending light rays with strong refractive power causes significant chromatic aberration and field curvature due to the refraction of the light rays. Therefore, the lenses on the projection side of the lens positioned closer to the panel IM need a structure that corrects these aberrations through the optimal arrangement of lens shape, refractive power, and Abbe number.

[0028] Increasing the refractive power usually results in a sharper curvature and a thicker lens. The lens positioned closest to the panel (IM) has a large diameter due to the telecentric conditions, and its size increases with a stronger refractive index. To make it thinner, it is necessary to reduce the curvature by using a high refractive index material. In terms of lens shape, to satisfy the telecentric condition, the panel-side surface of the lens positioned closest to the panel (IM) has a strongly convex shape toward the panel surface, but the curvature can be reduced by using a high refractive index material. In addition, to correct aberrations caused by strong refraction, it is effective to make at least one surface of the lens closest to the light source panel an aspherical lens.

[0029] The projection optical system preferably comprises a first lens with positive refractive power and a second lens with negative refractive power, arranged sequentially from the projection side to the panel IM side. Near the aperture diaphragm, light rays converge, so both the on-axial and off-axial ray beams have approximately the same beam range. By arranging the first and second lenses, aberration correction is effective in simultaneously correcting aberrations. Furthermore, in order to correct aberrations and achieve miniaturization and thinning, the first lens requires a glass material with a high refractive index. Using a high refractive index glass material requires using a material on the high dispersion side within the range of existing glass maps, but this results in significant chromatic aberration. In addition, spherical aberration and coma aberration occur due to the strong refractive power of the first lens. To correct these aberrations generated by the high refractive index, high dispersion positive lens, it is necessary to select a material with even higher dispersion than the first lens for the second lens. By using such glass materials, spherical aberration and coma aberration can be well corrected by optimizing the power distribution of the first and second lenses while correcting chromatic aberration. Furthermore, it is preferable that the projection-side surface of the first lens be convex toward the projection side. This allows for a narrower spacing along the optical axis, enabling miniaturization.

[0030] Furthermore, by adding a positive or negative lens to the three-lens configuration consisting of the first lens, the second lens, and the lens positioned closest to the panel IM, resulting in a total of five or fewer lenses, even higher performance can be achieved.

[0031] Furthermore, miniaturization can be achieved by positioning the PBS closer to the projection side than the lens positioned closest to the panel IM. As mentioned above, the lens positioned closest to the panel IM is nearly telecentric and, in order to achieve miniaturization, refracts the light beam from the panel IM with strong refractive power. Therefore, miniaturization can be achieved by positioning the PBS closer to the projection side. In particular, positioning it between the first lens with positive refractive power, which is positioned closest to the projection side, and the aperture diaphragm allows for the smallest possible size of the PBS.

[0032] Next, we will describe the conditions that the projection optical system of each embodiment preferably satisfies. The projection optical system of each embodiment preferably satisfies one or more of the following conditional equations (2) to (19).

[0033] 0.10 ≤ L / H ≤ 4.50 (2) 0.10 ≤ fP / f ≤ 3.00 (3) 0.10 ≤ ff / f ≤ 3.00 (4) -100000.00≦rr² / f≦-0.50 (5) 0.11 ≤ de / L ≤ 1.00 (6) -100000.00≦rr² / de≦-0.10 (7) 0.10 ≤ fg1 / f ≤ 1.00 (8) -1.00 ≤ fg² / f ≤ -0.10 (9) 0.10 ≤ rs1 / f ≤ 1.20 (10) 0.00 ≤ Sd / L ≤ 0.50 (11) 1.80 ≤ Nd1 ≤ 2.10 (12) 1.50 ≤ Nd² ≤ 1.95 (13) 1.70 ≤ Nde ≤ 1.95 (14) 23.0 ≤ νd1 ≤ 45.0 (15) 18.0 ≤ νd² ≤ 45.0 (16) 30.0 ≤ νde ≤ 55.0 (17) 40 ≤ θP ≤ 50 (18) 0.10 ≤ Sk / f ≤ 0.30 (19) Here, H is the maximum effective area (diagonal length) of the light-emitting element on the panel surface of the panel IM. fP is the total focal length of the lens positioned between the PBS and the panel IM. ff is the focal length of the lens positioned closest to the panel IM. rr2 is the paraxial radius of curvature of the panel IM side surface of the lens positioned closest to the panel IM. de is the thickness of the lens positioned closest to the panel IM (the distance along the optical axis from the projection side surface of the lens to the panel IM side surface). fg1 is the focal length of the positive lens positioned closest to the projection side. fg2 is the focal length of the negative lens positioned closest to the panel IM. rs1 is the radius of curvature of the projection side convex surface (first surface) of the first lens positioned closest to the projection side. Sd is the distance along the optical axis between the aperture diaphragm positioned on the projection side of the first lens positioned closest to the projection side and the projection side surface of the first lens. Nd1 is the refractive index of the first lens positioned closest to the projection side with respect to the d line. Nd1 is the refractive index of the second lens positioned on the panel IM side of the first lens positioned furthest towards the projection side, with respect to the d line. Nde is the refractive power of the lens positioned furthest towards the light source panel, with respect to the d line. νd1 is the Abbe number of the first lens positioned furthest towards the projection side. νd1 is the Abbe number of the second lens positioned on the panel IM side of the first lens positioned furthest towards the projection side, with respect to the νd1. νde is the Abbe number of the lens positioned furthest towards the panel IM. θP[°] is the smaller of the angles of the plane with respect to the optical axis, given that PBS is composed of a plane and the plane has an angle with respect to the optical axis. Sk is the distance along the optical axis from the panel IM side face of the lens positioned furthest towards the light source panel IM to the panel face of the panel IM.

[0034] Conditional equation (2) defines the maximum effective area (diagonal length) of the light-emitting elements on the panel surface of the panel IM as a function of the distance along the optical axis from the projection-side surface of the projection optical system, including the PBS and aperture diaphragm SP, to the panel surface of the panel IM. If the value falls below the lower limit of conditional equation (2), it is advantageous for miniaturization, but the lens arrangement becomes difficult due to the miniaturization. Also, the focal length becomes a wide-angle focal length, which is undesirable as it is over-specified. If the value exceeds the upper limit of conditional equation (2), the panel IM becomes too small, which restricts the panels that can actually be used, or the projection optical system becomes large, which is undesirable. Also, the focal length becomes a telephoto focal length, which is undesirable as it prevents the desired field of view from being obtained.

[0035] Conditional equation (3) is a conditional equation that defines the focal lengths of all refractive lenses positioned between the PBS and the panel IM with respect to the focal length of the projection optical system. If the value falls below the lower limit of conditional equation (3), the refracting power of the light beam emitted from the light source panel is strong, which is advantageous for miniaturizing the element with reflective and transmitting properties (PBS), but it is undesirable because the strong refractive power causes significant field curvature. On the other hand, if the value exceeds the upper limit of conditional equation (3), the refracting power of the light beam emitted from the light source panel is weak, which is undesirable because the effective area of ​​the element with reflective and transmitting properties (PBS) becomes larger and the element becomes larger.

[0036] Conditional equation (4) specifies the focal length of the lens positioned closest to the panel IM and the focal length of the projection optical system. If the value falls below the lower limit of conditional equation (4), the refracting power of the light beam emitted from the panel IM is strong, which is advantageous for miniaturizing the PBS, but it is undesirable because the strong refractive power causes significant field curvature. If the value exceeds the upper limit of conditional equation (4), the refracting power of the light beam emitted from the panel IM is weak, which is undesirable because it increases the effective area of ​​the PBS and makes it larger.

[0037] Condition (5) specifies the paraxial radius of curvature of the panel IM-side surface of the lens positioned closest to the panel IM and the focal length of the projection optical system. If the value falls below the lower limit of condition (5), the radius of curvature becomes too gentle, causing the angle of incidence of the light rays to deviate from telecentric, which is undesirable as it fails to meet the illumination conditions for the panel IM. If the value exceeds the upper limit of condition (5), the radius of curvature becomes too steep, which is advantageous for achieving a telecentric angle of incidence, but is undesirable as it makes it difficult to correct for field curvature.

[0038] Conditional equation (6) specifies the thickness of the lens positioned closest to the panel IM, relative to the distance along the optical axis from the projection-side surface of the projection optical system to the panel surface of the panel IM. If the value falls below the lower limit of conditional equation (6), the lens thickness becomes too thin, making it impossible to secure sufficient refractive power, and making it difficult to correct for telecentricity, reflective rays, and field curvature, which is undesirable. If the value exceeds the upper limit of conditional equation (6), it is possible to give the final lens strong refractive power, but the lens thickness becomes too thick, resulting in an undesirable size.

[0039] Condition (7) specifies the paraxial radius of curvature of the panel IM-side surface of the lens positioned closest to the panel IM, and the thickness of the lens. If the value falls below the lower limit of condition (7), the lens thickness becomes too thin and the radius of curvature becomes too gentle, causing the angle of incidence of the light rays to deviate from telecentric, which is undesirable as it will no longer satisfy the illumination conditions of the panel IM. If the value exceeds the upper limit of condition (7), the radius of curvature becomes too steep, which is advantageous for achieving a telecentric angle of incidence, but is undesirable as it makes it difficult to correct for field curvature.

[0040] Conditional equation (8) specifies the focal length of the positive lens positioned closest to the projection side relative to the focal length of the projection optical system. If the value falls below the lower limit of conditional equation (8), the refractive power of the positive lens becomes too strong, making spherical aberration and coma aberration more likely to occur and difficult to correct, which is undesirable. If the value exceeds the conditional value of conditional equation (8), the refractive power of the positive lens becomes too weak, making it difficult to correct field curvature, which is also undesirable.

[0041] Conditional equation (9) specifies the focal length of the negative lens positioned on the panel IM side of the lens positioned closest to the projection side, relative to the focal length of the projection optical system. If the value falls below the lower limit of conditional equation (9), the refractive power of the negative lens becomes too strong, making spherical aberration and coma aberration more likely to occur and difficult to correct, which is undesirable. If the value exceeds the conditional value of conditional equation (9), the refractive power of the negative lens becomes too weak, making it difficult to correct field curvature, which is also undesirable.

[0042] Conditional equation (10) defines the radius of curvature of the projection-side surface of the first lens, which is positioned closest to the projection side with respect to the focal length of the projection optical system. If the value falls below the lower limit of conditional equation (10), the refractive power of the first lens becomes too strong, making it easy for under-spherical aberration and coma aberration to occur and difficult to correct, which is undesirable. If the value exceeds the conditional value of conditional equation (10), the refractive power of the first lens becomes too weak, making it difficult to correct over-spherical aberration and field curvature, which is also undesirable.

[0043] Conditional equation (11) defines the distance along the optical axis between the aperture diaphragm SP and the projection-side surface of the first lens, with respect to the distance along the optical axis from the projection-side surface of the projection optical system to the panel surface of panel IM. If the value falls below the lower limit of conditional equation (11), the pupil will be positioned inside the lens, which is undesirable because it will cause interference between the projection optical system and the light guide plate for applications where light is incident into the light guide plate of AR. If the value exceeds the upper limit of conditional equation (11), the outer diameter of the first lens will increase, resulting in a larger projection optical system, which is also undesirable.

[0044] Conditional equation (12) specifies the refractive index of the first lens with respect to the d line. The first lens is positioned near the aperture diaphragm and is highly sensitive to spherical aberration, coma aberration, and field curvature, so a high refractive index is desirable. If it falls below the lower limit of conditional equation (12), spherical aberration, coma aberration, and field curvature will worsen, which is undesirable. If it exceeds the upper limit of conditional equation (12), the Abbe number of the glass material will be on the high dispersion side, making chromatic aberration correction difficult, which is also undesirable.

[0045] Conditional equation (13) specifies the refractive index of the second lens. The second lens has the effect of canceling out spherical aberration, coma aberration, field curvature, and axial chromatic aberration generated by the first lens. If the refractive index falls below the lower limit of conditional equation (13), it becomes difficult to correct the spherical aberration, coma aberration, and field curvature generated by the first lens, which is undesirable. If the refractive index falls above the upper limit of conditional equation (13), the hardening effect of the glass material becomes too strong, and spherical aberration cannot be corrected on the over-correction side, which is also undesirable.

[0046] Conditional equation (14) specifies the refractive index of the lens positioned closest to the panel IM. This lens is intended to ensure telecentricity. If the refractive index falls below the lower limit of conditional equation (14), the lens thickness increases due to the lower refractive index, which is undesirable because it makes the projection optical system larger. If the refractive index exceeds the upper limit of conditional equation (14), the lens becomes thinner and telecentricity is easier to ensure, but the glass material has high dispersion, making it difficult to correct chromatic aberration, which is also undesirable.

[0047] Conditional equation (15) specifies the Abbe number of the first lens. The first lens is positioned near the aperture diaphragm and has a corrective effect on spherical aberration, coma aberration, and field curvature, so it is desirable to set its refractive index high. When setting a high refractive index, the range of the Abbe number is restricted. If it falls below the lower limit of conditional equation (15), the dispersion becomes large and axial chromatic aberration cannot be corrected, which is undesirable. If it exceeds the upper limit of conditional equation (15), it is desirable for correcting chromatic aberration, but it requires setting a low refractive index as the selected glass material, and spherical aberration cannot be corrected, which is undesirable.

[0048] Conditional equation (16) specifies the Abbe number of the second lens. The second lens has the effect of canceling out spherical aberration, coma aberration, field curvature, and axial chromatic aberration generated by the first lens. If the Abbe number falls below the lower limit of conditional equation (16), it is desirable that the axial chromatic aberration generated by the first lens can be corrected, but this direction of Abbe number requires a high refractive index for the glass material, resulting in excessive spherical aberration, which is undesirable. If the Abbe number exceeds the upper limit of conditional equation (16), it is necessary to move the Abbe number of the first lens toward the low dispersion side, but this reduces the refractive power of the first lens, resulting in excessive spherical aberration, which is undesirable.

[0049] Conditional equation (17) specifies the Abbe number of the lens positioned closest to the panel IM. This lens is intended to ensure telecentricity. If the Abbe number falls below the lower limit of conditional equation (17), chromatic aberration cannot be corrected, which is undesirable. If the Abbe number exceeds the upper limit of conditional equation (17), chromatic aberration is easier to correct, which is desirable. However, in this region, the refractive index becomes smaller, which increases the lens thickness and the size of the projection optical system, which is undesirable.

[0050] Conditional equation (18) defines the angle of the polarization separation plane of the PBS with respect to the optical axis. If the angle falls below the lower limit of conditional equation (18), it is undesirable because light rays will not reach the panel IM side. Similarly, if the angle exceeds the upper limit of conditional equation (18), it is also undesirable because light rays will not reach the panel IM side.

[0051] Conditional equation (19) defines the distance along the optical axis from the panel surface of the lens positioned closest to the panel IM to the focal length of the projection optical system. If the distance falls below the lower limit of conditional equation (19), it becomes difficult to place a quarter-wave plate between the lens positioned closest to the panel IM and the panel IM, making it undesirable as the characteristics of the projection optical system cannot be obtained. If the distance exceeds the upper limit of conditional equation (19), it is convenient for placing a quarter-wave plate, but it is undesirable because it increases the size of the projection optical system.

[0052] Furthermore, it is more preferable that the lower limit of condition (2) be set to 0.12, 0.14, 0.16, 0.18, 0.20, 0.22, 0.24, 0.26, 0.28, or 0.30. The upper limit of condition (2) is more preferable to be set to 4.20, 3.90, 3.60, 3.40, 3.20, 3.00, 2.80, 2.60, 2.40, or 2.20.

[0053] Furthermore, it is more preferable that the lower limit of condition (3) be set to 0.15, 0.20, 0.25, 0.30, 0.35, 0.38, 0.41, 0.44, 0.47, or 0.50. It is more preferable that the upper limit of condition (3) be set to 2.80, 2.60, 2.40, 2.20, 2.00, 1.90, 1.80, 1.70, 1.65, or 1.60.

[0054] Furthermore, it is more preferable that the lower limit of conditional expression (4) be set to 0.12, 0.14, 0.16, 0.18, 0.20, 0.22, 0.24, 0.26, 0.28, or 0.30. It is more preferable that the upper limit of conditional expression (4) be set to 2.80, 2.60, 2.40, 2.20, 2.00, 1.90, 1.80, 1.70, 1.65, or 1.60.

[0055] Furthermore, it is more preferable that the lower limit of conditional expression (5) be set to -90000.00, -800000.00, -700000.00, -600000.00, -500000.00, -400000.00, -350000.00, -300000.00, -250000.00, or -200000.00. The upper limit of conditional expression (5) is more preferable to be set to -0.52, -0.54, -0.56, -0.58, -0.60, -0.62, -0.64, -0.66, -0.68, or -0.70.

[0056] Furthermore, it is more preferable that the lower limit of conditional expression (6) be set to 0.113, 0.115, 0.117, 0.119, 0.120, 0.121, 0.122, 0.123, 0.124, or 0.125. It is more preferable that the upper limit of conditional expression (6) be set to 0.90, 0.80, 0.75, 0.70, 0.65, 0.60, 0.55, 0.50, 0.45, or 0.40.

[0057] Furthermore, it is more preferable that the lower limit of conditional expression (7) be set to -90000.00, -800000.00, -700000.00, -600000.00, -550000.00, -500000.00, -450000.00, -400000.00, -350000.00, or -300000.00. The upper limit of conditional expression (7) is more preferable to be set to -0.20, -0.30, -0.40, -0.50, -0.60, -0.70, -0.80, -0.85, -0.90, or -0.95.

[0058] Furthermore, it is more preferable that the lower limit of conditional expression (8) be set to 0.12, 0.14, 0.16, 0.18, 0.20, 0.22, 0.24, 0.26, 0.28, or 0.30. It is more preferable that the upper limit of conditional expression (8) be set to 0.95, 0.90, 0.85, 0.80, 0.75, 0.70, 0.65, 0.60, 0.55, or 0.50.

[0059] Furthermore, it is more preferable that the lower limit of conditional expression (9) be set to -0.95, -0.90, -0.85, -0.80, -0.75, -0.70, -0.65, -0.60, -0.55, or -0.50. It is more preferable that the upper limit of conditional expression (9) be set to -0.105, -0.110, -0.115, -0.120, -0.125, -0.130, -0.135, -0.140, -0.145, or -0.150.

[0060] Furthermore, it is more preferable that the lower limit of condition expression (10) be set to 0.12, 0.14, 0.16, 0.18, 0.20, 0.22, 0.24, 0.26, 0.28, or 0.30. It is more preferable that the upper limit of condition expression (10) be set to 1.15, 1.10, 1.05, 1.02, 1.00, 0.99, 0.98, 0.97, 0.96, or 0.95.

[0061] Furthermore, it is more preferable that the lower limit of condition expression (11) be set to 0.12, 0.14, 0.16, 0.18, 0.20, 0.22, 0.24, 0.26, 0.28, or 0.30. Furthermore, it is more preferable that the upper limit of condition expression (11) be set to 0.48, 0.46, 0.44, 0.42, 0.40, 0.38, 0.36, 0.34, 0.32, or 0.30.

[0062] Furthermore, it is more preferable that the lower limit of condition expression (12) be set to 1.805, 1.810, 1.815, 1.820, 1.825, 1.830, 1.834, 1.836, 1.838, or 1.840. It is more preferable that the upper limit of condition expression (12) be set to 2.095, 2.090, 2.085, 2.080, 2.075, 2.070, 2.067, 2.064, 2.062, or 2.060.

[0063] Furthermore, it is more preferable that the lower limit of condition expression (13) be set to 1.505, 1.510, 1.515, 1.520, 1.525, 1.530, 1.535, 1.540, 1.545, or 1.550. It is more preferable that the upper limit of condition expression (13) be set to 1.900, 1.896, 1.894, 1.892, 1.890, 1.888, 1.886, 1.884, 1.882, or 1.880.

[0064] Furthermore, it is more preferable that the lower limit of condition expression (14) be set to 1.714, 1.718, 1.722, 1.726, 1.730, 1.734, 1.738, 1.742, 1.746, or 1.750. It is more preferable that the upper limit of condition expression (14) be set to 1.945, 1.940, 1.935, 1.930, 1.925, 1.920, 1.915, 1.910, 1.905, or 1.900.

[0065] Furthermore, it is more preferable that the lower limit of condition expression (15) be set to 23.5, 24.0, 24.5, 24.8, 25.0, 25.2, 25.4, 25.6, 25.8, or 26.0. It is more preferable that the upper limit of condition expression (15) be set to 44.6, 44.2, 43.8, 43.4, 43.0, 42.8, 42.6, 42.4, 42.2, or 42.0.

[0066] Furthermore, it is more preferable that the lower limit of condition expression (16) be set to 18.1, 18.2, 18.3, 18.4, 18.5, 18.6, 18.7, 18.8, 18.9, or 19.0. It is more preferable that the upper limit of condition expression (16) be set to 44.8, 44.6, 44.4, 44.2, 44.0, 43.8, 43.6, 43.4, 43.2, or 43.0.

[0067] Furthermore, it is more preferable that the lower limit of condition expression (17) be set to 31.0, 32.0, 33.0, 34.0, 35.0, 35.4, 35.8, 36.2, 36.6, or 37.0. It is more preferable that the upper limit of condition expression (17) be set to 54.8, 54.6, 54.4, 54.2, 54.0, 53.8, 53.6, 53.4, 53.2, or 53.0.

[0068] Furthermore, it is more preferable that the lower limit of condition expression (18) be set to 40.4, 40.8, 41.2, 41.6, 42.0, 42.4, 42.8, 43.2, 43.6, or 44.0. It is more preferable that the upper limit of condition expression (18) be set to 49.6, 49.2, 48.8, 48.4, 48.0, 47.6, 47.2, 46.8, 46.4, or 46.0.

[0069] Furthermore, it is more preferable that the lower limit of conditional expression (19) be set to 0.110, 0.120, 0.130, 0.140, 0.150, 0.160, 0.165, 0.170, 0.175, or 0.180. It is more preferable that the upper limit of conditional expression (19) be set to 0.295, 0.290, 0.285, 0.280, 0.275, 0.270, 0.265, 0.260, 0.255, or 0.250.

[0070] The projection optical systems of each embodiment will be described below. In each embodiment, the light emitted from the panel IM is equivalent to being projected at infinity.

[0071] The projection optical system 100 of Embodiment 1 comprises an aperture diaphragm SP, a PBS, and first to fifth lenses 101, 102, 103, 104, and 105 with positive, negative, positive, negative, and positive refractive powers, arranged in order from the projection side to the panel IM side.

[0072] The projection optical system 200 of Embodiment 2 comprises an aperture diaphragm SP, first and second lenses 201 and 202 with positive and negative refractive powers, PBS, and third to fifth lenses 203, 204, and 205 with positive, negative, and positive refractive powers, arranged in order from the projection side to the panel IM side.

[0073] The projection optical system 300 of Embodiment 3 comprises an aperture diaphragm SP, first to fourth lenses 301, 302, 303, and 304 with positive, negative, positive, and negative refractive powers, a PBS, and a fifth lens 305 with positive refractive power, arranged in order from the projection side to the panel IM side.

[0074] The projection optical system 400 of Embodiment 4 comprises an aperture diaphragm SP, PBS, and first to fifth lenses 401, 402, 403, 404, and 405 with positive, negative, positive, negative, and positive refractive powers, arranged in order from the projection side to the panel IM side.

[0075] The projection optical system 500 of Embodiment 5 comprises an aperture diaphragm SP, first to fourth lenses 501, 502, 503, 504 with positive, negative, negative, and positive refractive powers, PBS, and a fifth lens 505 with positive refractive power, arranged in order from the projection side to the panel IM side.

[0076] The projection optical system 600 of Embodiment 6 comprises an aperture diaphragm SP, first and second lenses 601 and 602 with positive and negative refractive powers, PBS, and a third lens 603 with positive refractive power, arranged in order from the projection side to the panel IM side.

[0077] The projection optical system 700 of Embodiment 7 comprises an aperture diaphragm SP, first and second lenses 701 and 702 with positive and negative refractive powers, PBS, and a third lens 703 with positive refractive power, arranged in order from the projection side to the panel IM side.

[0078] The projection optical system 800 of Embodiment 8 comprises an aperture diaphragm SP, first and second lenses 801 and 802 with positive and negative refractive powers, PBS, and a third lens 803 with positive refractive power, arranged in order from the projection side to the panel IM side.

[0079] The projection optical system 900 of Embodiment 9 comprises an aperture diaphragm SP, a PBS, and first to fifth lenses 901, 902, 903, 904, and 905 with positive, negative, positive, negative, and positive refractive powers, arranged in order from the projection side to the panel IM side.

[0080] The projection optical system 1000 of Example 10 comprises an aperture diaphragm SP, a PBS, and first to fifth lenses 1001, 1002, 1003, 1004, and 1005 with positive, negative, positive, negative, and positive refractive powers, arranged in order from the projection side to the panel IM side.

[0081] The following shows the numerical examples 1 to 10 corresponding to each of the numerical examples. In the surface data of each numerical example, r represents the radius of curvature of each optical surface, and d (mm) represents the on-axial spacing (distance on the optical axis) between the m-th surface and the (m+1)-th surface. Here, m is the surface number counted from the light incident side. Also, nd represents the refractive index of each optical element with respect to the d line, and νd represents the Abbe number of the optical element with respect to the d line. Note that the Abbe number νd of a certain material is given by Nd, NF, and NC, respectively, when the refractive indices at the Fraunhofer lines d line (587.6 nm), F line (486.1 nm), and C line (656.3 nm) are Nd, NF, and NC. νd = (Nd-1) / (NF-NC) It is represented as follows.

[0082] In each numerical example, d, focal length (mm), F-number, and half-angle of view (°) are all values ​​when the projection optical system of each example is focused on an object at infinity. "Back focus" is the distance along the optical axis from the lens surface closest to the panel IM to the paraxial image plane (panel surface), expressed in terms of air equivalent length. "Total lens length" is the length obtained by adding the air equivalent back focus to the distance along the optical axis from the lens surface closest to the projection side to the lens surface closest to the panel IM. "Lens group" includes not only cases where it is composed of multiple lenses, but also cases where it is composed of a single lens.

[0083] Furthermore, if the optical surface is aspherical, the symbol "*" is added to the right of the surface number. The aspherical shape is expressed by the following formula, where X is the displacement from the surface vertex in the direction of the optical axis, h is the height from the optical axis perpendicular to the optical axis, R is the radius of paraxial curvature, K is the cone constant, and A4, A6, A8, and A10 are the aspherical coefficients of their respective orders.

[0084] X=(h2 / R) / [1+{1-(1+K)(h / R)2}1 / 2]+A4×h4+A6×h6+A8×h8+A10×h10 Note that "e±XX" in each aspherical coefficient means "×10±XX".

[0085] (Numerical Example 1) Unit: mm Surface data Face number rd nd νd Effective diameter 1 (aperture) ∞ 0.00 1.27 2 ∞ 2.50 2.00100 29.1 1.27 3 ∞ 0.30 2.36 4 3.688 1.15 2.00100 29.1 2.93 5 16.823 0.50 1.80810 22.8 2.89 6 2.636 0.79 2.86 7* 5.936 1.74 1.88202 37.2 4.11 8* -9.268 0.40 4.30 9 -5.256 0.60 1.80810 22.8 4.30 10 7.880 2.36 4.85 11* 20.227 3.23 1.88202 37.2 9.71 12* -9.467 (variable) 10.02 Image plane ∞ Aspherical data Side 7 K = 0.00000e+00 A 4=-2.04769e-04 A 6= 4.14667e-04 A 8=-1.57795e-05 Side 8 K = 0.00000e+00 A 4= 2.95488e-04 A 6= 1.48283e-04 Page 11 K = 0.00000e+00 A 4=-4.90803e-04 A 6= 2.84211e-05 A 8=-1.75674e-07 Side 12 K = 0.00000e+00 A 4=-2.94312e-04 A 6=-3.05013e-06 A 8= 7.95497e-07 Various data Zoom ratio 1.00 Focal length 10.19 F-number 8.00 Half-angle (°): 24.97 Image height 4.74 Lens length: 16.00 BF 2.43 d12 2.43 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 10.19 13.57 7.87 -7.76 Single lens data Lens starting plane, focal length 1 1 0.00 2 4 4.52 3 5 -3.93 4 7 4.34 5 9 -3.82 6 11 7.70 (Numerical Example 2) Unit: mm Surface data Face number rd nd vd Effective diameter 1 (aperture) ∞ 0.50 1.29 2 3.861 1.17 2.00100 29.1 1.88 3 -22.115 0.50 1.80810 22.8 2.04 4 2.813 0.77 2.15 5 ∞ 3.00 2.00100 29.1 2.88 6 ∞ 0.15 4.58 7* 6.667 1.33 1.88202 37.2 5.41 8* 70.551 1.40 5.43 9 -5.040 0.60 1.80810 22.8 5.53 10 17.945 0.94 6.64 11* 9.781 3.65 1.88202 37.2 9.15 12 -7.713 (variable) 10.06 Image plane ∞ Aspherical data Side 7 K = 0.00000e+00 A 4=-7.33908e-03 A 6= 9.60556e-04 A 8=-2.39833e-05 Side 8 K = 0.00000e+00 A 4=-9.74705e-03 A 6= 8.90716e-04 Page 11 K = 0.00000e+00 A 4=-3.09581e-03 A 6= 1.17792e-04 A 8=-1.93166e-06 Various data Zoom ratio 1.00 Focal length 10.34 F-number 8.00 Half-angle (°): 24.64 Image height 4.74 Lens length: 16.00 BF 2.00 d12 2.00 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 10.34 14.00 10.24 -8.35 Single lens data Lens starting plane, focal length 1 1 3.36 2 3 -3.06 3 5 0.00 4 7 8.27 5 9 -4.81 6 11 5.42 (Numerical Example 3) Unit: mm Surface data Face number rd nd νd Effective diameter 1 (aperture) ∞ 0.50 1.30 2 4.216 1.26 2.05090 26.9 1.87 3 -5.704 0.50 1.80810 22.8 2.04 4 3.590 0.77 2.14 5* -5.646 1.22 1.85135 40.1 2.52 6 -1.863 0.50 1.72825 28.5 3.00 7 -25.475 1.77 3.79 8 ∞ 5.00 2.00100 29.1 5.84 9 ∞ 0.49 8.35 10 21.220 2.51 1.75500 52.3 9.50 11 -12.415 (variable) 9.82 Image plane ∞ Aspherical data 5th page K = 8.99977e+00 A 4=-1.14776e-03 A 6=-2.79821e-04 Various data Zoom ratio 1.00 Focal length 10.44 F-number 8.00 Half-angle (°): 24.44 Image height 4.74 Lens length: 16.51 BF 1.99 d11 1.99 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 10.44 14.53 8.23 ​​-8.45 Single lens data Lens starting plane, focal length 1 1 2.47 2 3 -2.66 3 5 2.84 4 6 -2.78 5 8 0.00 6 10 10.72 (Numerical Example 4) Unit: mm Surface data Face number rd nd νd Effective diameter 1 (aperture) ∞ 0.00 2.49 2 ∞ 4.50 2.00100 29.1 2.49 3 ∞ 0.30 4.45 4* 6.066 3.09 1.85135 40.1 5.27 5 -4.847 0.50 1.69895 30.1 5.30 6 4.522 1.23 5.09 7* 8.880 2.57 1.88202 37.2 5.90 8* -11.104 0.23 6.39 9 -4.774 0.60 1.72151 29.2 6.34 10 8.049 1.09 7.05 11* 6.604 3.50 1.88202 37.2 8.90 12* -218.168 (variable) 10.45 Image plane ∞ Aspherical data Side 4 K = 0.00000e+00 A 4=-2.54184e-04 A 6=-3.72153e-05 A 8=-9.70155e-08 Side 7 K = 0.00000e+00 A 4=-2.82099e-03 A 6= 1.38297e-04 A 8=-9.60193e-06 Side 8 K = 0.00000e+00 A 4=-8.53484e-03 A 6= 5.24045e-04 A 8=-1.98150e-05 Page 11 K = 0.00000e+00 A 4=-5.56968e-03 A 6= 1.64187e-04 A 8=-2.76987e-06 Side 12 K = 0.00000e+00 A 4=-4.10966e-03 A 6= 1.38996e-04 A 8=-2.73062e-06 Various data Zoom ratio 1.00 Focal length 9.95 F-number 4.00 Half-angle (°): 25.49 Image height 4.74 Lens length: 19.43 BF 1.83 d12 1.83 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 9.95 17.60 5.12 -8.12 Single lens data Lens starting plane, focal length 1 1 0.00 2 4 3.64 3 5 -3.27 4 7 5.95 5 9 -4.07 6 11 7.32 (Numerical Example 5) Unit: mm Surface data Face number rd nd νd Effective diameter 1 (aperture) ∞ 0.50 2.55 2* 5.494 2.16 1.85135 40.1 3.25 3 -4.718 0.50 1.56732 42.8 3.50 4 4.624 1.64 3.55 5 -3.362 0.50 1.86966 20.0 3.94 6 23.973 3.11 1.88202 37.2 5.17 7* -4.701 0.29 6.88 8 ∞ 5.50 2.00100 29.1 8.01 9 ∞ 0.55 10.03 10* -217.877 2.54 1.76802 49.2 10.85 11* -11.318 (variable) 10.87 Image plane ∞ Aspherical data 2nd side K = 0.00000e+00 A 4=-5.88878e-04 A 6=-6.07032e-05 A 8= 7.52593e-06 Side 7 K = 0.00000e+00 A 4= 1.49852e-03 A 6= 2.14620e-05 A 8= 3.97762e-06 Side 10 K = 0.00000e+00 A 4= 6.54121e-04 A 6=-4.73508e-07 A 8= 2.78549e-08 Page 11 K = 0.00000e+00 A 4=-1.30192e-04 A 6= 1.70564e-05 A 8=-8.95080e-08 Various data Zoom ratio 1.00 Focal length 10.21 F-number 4.00 Half-angle (°): 24.92 Image height 4.74 Lens length: 19.51 BF 2.22 d11 2.22 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 10.21 17.29 11.01 -7.99 Single lens data Lens starting plane, focal length 1 1 3.30 2 3 -4.04 3 5 -3.36 4 6 4.70 5 8 0.00 6 10 15.46 (Numerical Example 6) Unit: mm Surface data Face number rd nd νd Effective diameter 1 (aperture) ∞ 0.00 2.57 2* 9.399 3.59 1.85135 40.1 2.64 3* -2.679 0.56 3.77 4* -3.170 0.50 1.82115 24.1 3.40 5* 3.314 0.65 3.85 6 ∞ 5.50 2.00100 29.1 4.21 7 ∞ 0.37 8.06 8* 8.999 4.31 1.76802 49.2 10.90 9* -9.635 (variable) 11.16 Image plane ∞ Aspherical data 2nd side K = 0.00000e+00 A 4=-4.01618e-03 A 6=-5.82449e-04 A 8=-3.15619e-04 3rd page K = 0.00000e+00 A 4= 2.01331e-02 A 6=-4.18165e-03 A 8= 5.07560e-04 Side 4 K = 0.00000e+00 A 4= 1.91156e-02 A 6=-7.17524e-03 A 8= 7.18816e-04 5th page K = 0.00000e+00 A 4=-1.53152e-02 A 6= 1.68949e-03 A 8=-2.36274e-04 Side 8 K = 0.00000e+00 A 4=-1.84398e-03 A 6= 6.79051e-05 A 8=-1.12079e-06 A10= 5.47956e-09 9th page K = 0.00000e+00 A 4=-1.24483e-03 A 6= 5.15010e-05 A 8=-1.87985e-07 A10=-6.15924e-09 Various data Zoom ratio 1.00 Focal length 10.30 F-number 4.00 Half-angle (°): 24.74 Image height 4.74 Lens length: 17.50 BF 2.03 d 9 2.03 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 10.30 15.48 10.08 -8.27 Single lens data Lens starting plane, focal length 1 1 2.84 2 4 -1.91 3 6 0.00 4 8 6.74 (Numerical Example 7) Unit: mm Surface data Face number rd nd νd Effective diameter 1 (aperture) ∞ 0.20 1.85 2* 8.477 2.38 1.85135 40.1 2.10 3* -2.572 0.57 3.00 4* -2.688 0.50 1.82115 24.1 2.74 5* 3.609 0.62 3.17 6 ∞ 4.20 2.00100 29.1 3.83 7 ∞ 0.46 7.16 8* 9.832 4.31 1.77250 49.5 10.10 9* -8.033 (variable) 10.75 Image plane ∞ Aspherical data 2nd side K = 0.00000e+00 A 4=-1.20299e-02 A 6=-2.89247e-03 A 8=-2.03119e-03 3rd page K = 0.00000e+00 A 4= 1.17182e-03 A 6=-2.05174e-03 A 8= 2.29022e-04 Side 4 K = 0.00000e+00 A 4=-8.44527e-03 A 6= 5.40542e-03 A 8=-1.41129e-03 5th page K = 0.00000e+00 A 4=-1.42779e-02 A 6= 5.33857e-03 A 8=-1.03329e-03 Side 8 K = 0.00000e+00 A 4=-1.60601e-03 A 6= 4.76104e-05 A 8=-6.08478e-07 9th page K = 0.00000e+00 A 4=-7.21862e-04 A 6= 3.00727e-05 A 8=-2.08441e-07 Various data Zoom ratio 1.00 Focal length 9.26 F-number 5.00 Half-angle (°): 27.12 Image height 4.74 Lens length: 15.22 BF 1.97 d 9 1.97 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 9.26 13.25 8.50 -7.29 Single lens data Lens starting plane, focal length 1 1 2.57 2 4 -1.81 3 6 0.00 4 8 6.40 (Numerical Example 8) Unit: mm Surface data Face number rd nd νd Effective diameter 1 (aperture) ∞ 0.20 1.16 2* 4.966 1.33 1.85135 40.1 1.41 3* -3.106 0.56 1.88 4* -1.973 0.50 1.82115 24.1 1.80 5* 6.274 0.50 2.25 6 ∞ 3.50 2.00100 29.1 3.07 7 ∞ 0.98 5.87 8* 13.751 3.96 1.77250 49.5 9.36 9* -7.530 (variable) 10.20 Image plane ∞ Aspherical data 2nd side K = 0.00000e+00 A 4=-3.49151e-02 A 6=-1.35035e-02 A 8=-2.81167e-02 3rd page K = 0.00000e+00 A 4=-7.12764e-02 A 6=-1.26847e-02 A 8= 2.72938e-03 Side 4 K = 0.00000e+00 A 4=-7.72211e-02 A 6= 1.03401e-02 A 8= 1.91746e-03 5th page K = 0.00000e+00 A 4= 4.42236e-03 A 6= 1.78362e-02 A 8=-7.09203e-03 Side 8 K = 0.00000e+00 A 4=-8.91613e-04 A 6= 2.90378e-05 A 8=-4.63684e-07 9th page K = 0.00000e+00 A 4=-6.36489e-04 A 6= 2.82396e-05 A 8=-2.64180e-07 Various data Zoom ratio 1.00 Focal length 9.29 F-number 8.00 Half-angle (°): 27.05 Image height 4.74 Lens length: 13.51 BF 1.99 d 9 1.99 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 9.29 11.52 7.40 -7.30 Single lens data Lens starting plane, focal length 1 1 2.43 2 4 -1.78 3 6 0.00 4 8 6.86 (Numerical Example 9) Unit: mm Surface data Face number rd nd νd Effective diameter 1 (aperture) ∞ 0.00 1.29 2 ∞ 2.80 1.51633 64.1 1.29 3 ∞ 0.30 2.92 4 4.095 1.27 2.00100 29.1 3.59 5 21.121 0.50 1.80810 22.8 3.49 6 2.884 0.53 3.39 7* 5.627 1.85 1.88202 37.2 4.24 8* -10.079 0.66 4.39 9 -4.144 0.60 1.80810 22.8 4.36 10 8.997 1.67 5.13 11* 23.603 3.76 1.88202 37.2 9.76 12* -7.584 (variable) 10.50 Image plane ∞ Aspherical data Side 7 K = 0.00000e+00 A 4= 1.15923e-03 A 6= 1.06550e-04 A 8= 1.50786e-05 Side 8 K = 0.00000e+00 A 4= 1.73635e-03 A 6=-1.12369e-04 Page 11 K = 0.00000e+00 A 4=-2.58160e-05 A 6= 1.05985e-05 A 8=-1.00765e-07 Side 12 K = 0.00000e+00 A 4=-3.46891e-05 A 6= 6.06894e-06 A 8= 3.74591e-07 Various data Zoom ratio 1.00 Focal length 10.35 F-number 8.00 Half-angle (°): 24.64 Image height 4.74 Lens length: 16.50 BF 2.55 d12 2.55 Zoom lens group data Group starting plane Focal length Lens length Front principal point position Rear principal point position 1 1 10.35 13.95 8.53 -7.79 Single lens data Lens starting plane, focal length 1 1 0.00 2 4 4.89 3 5 -4.18 4 7 4.33 5 9 -3.44 6 11 6.90 (Numerical Example 10) Unit: mm Surface data Face number rd nd νd Effective diameter 1 (aperture) ∞ 0.00 2.49 2 ∞ 5.20 1.51633 64.1 2.49 3 ∞ 0.30 5.52 4 6.691 2.72 2.00330 28.3 6.63 5 -12.544 0.50 1.86966 20.0 6.35 6 5.599 0.88 5.91 7* 8.638 2.67 1.88202 37.2 6.20 8 -5.055 0.60 1.68948 31.0 6.53 9* 4.251 1.67 6.97 10* 7.828 3.42 1.88202 37.2 9.71 11* -100000.000 (variable) 10.57 Image plane ∞ Aspherical data Side 7 K = 0.00000e+00 A 4=-2.37121e-03 A 6= 1.04910e-04 A 8=-9.88031e-06 9th page K = 0.00000e+00 A 4=-5.67587e-03 A 6= 2.95842e-04 A 8=-1.56163e-05 Side 10 K = 0.00000e+00 A 4=-2.63780e-03 A 6= 6.11691e-05 A 8=-8.03526e-07 Page 11 K = 0.00000e+00 A 4=-2.37278e-03 A 6= 4.48444e-05 A 8=-5.75915e-07 Various data Zoom ratio 1.00 Focal length 9.95 F-number 4.00 Half-angle (°): 25.50 Image height 4.74 Overall lens length 20.30 BF 2.33 d11 2.33 Zoom lens group data Group Starting surface Focal length Lens configuration length Front principal point position Rear principal point position 1 1 9.95 17.97 6.36 -7.61 Single lens data Lens Starting surface Focal length 1 1 0.00 2 4 4.68 3 5 -4.40 4 7 3.98 5 8 -3.26 6 10 8.87 The various values in each numerical example are summarized in Table 1 below.

[0086] [Table 1] [ [

[0087] [Projection device] FIG. 22 is a configuration diagram of AR glasses, which is an example of a projection device having a projection optical system for each embodiment. As a light modulation element (display element) 38 of the AR glasses, a panel such as an LCOS or a DMD is used. In FIG. 22, 31 is a light source device, 32 is a reflection mirror, 33 is an illumination optical system, 35 is a polarization conversion element (PBS), 34 is a polarization separation surface, 36 is a projection lens, 37 is a wavelength plate, 39 is an aperture stop, and 42 including these is a projection optical system which is any one of the projection optical systems of each embodiment.

[0088] The light emitted by the light emitting panel (light source device 31) travels in the direction of the arrow in the figure and projects an image on the subject side of the projection optical system 42. The projected image is reflected by the reflection surface 40 in the light guide plate 41 for AR glasses and travels through the light guide plate 41 by total reflection. Note that an LD or an LED light source may be used as the light source device 31.

[0089] Each embodiment disclosed includes the following configuration: (Composition 1) A projection optical system comprising an element having reflective and transmissive properties positioned on the projection side of the light source panel, and at least one lens positioned between the light source panel and the element, When the focal length of the projection optical system is f, the distance along the optical axis from the projection-side surface of the projection optical system to the display surface of the light source panel is L, and the maximum effective area of ​​the light-emitting element on the display surface is H, 0.10 ≤ L / f ≤ 2.10 0.10 ≤ L / H ≤ 4.50 A projection optical system characterized by satisfying the following conditional equation. (Configuration 2) When fP is the total focal length of the lens arranged between the light source panel and the element, 0.10 ≤ fP / f ≤ 3.00 The projection optical system according to configuration 1, characterized in that it satisfies the following conditional equation. (Composition 3) When the focal length of the lens positioned closest to the light source panel is ff, 0.10 ≤ ff / f ≤ 3.00 A projection optical system according to configuration 1 or 2, characterized by satisfying the following conditional expression. (Composition 4) When the paraxial radius of curvature of the surface of the lens positioned closest to the light source panel is rr2, -100000.00≦rr² / f≦-0.50 A projection optical system according to any one of configurations 1 to 3, characterized by satisfying the following conditional expression. (Composition 5) When de is the distance along the optical axis from the side of the element of the lens positioned closest to the light source panel to the side of the light source panel, 0.11 ≤ de / L ≤ 1.00 A projection optical system according to any one of configurations 1 to 4, characterized in that it satisfies the following conditional expression. (Composition 6) When the paraxial radius of curvature of the surface of the lens located closest to the light source panel is rr2, and the distance along the optical axis from the projection-side surface of the lens located closest to the light source panel to the surface of the light source panel is de, -100000.00≦rr2 / de≦-0.10 A projection optical system according to any one of configurations 1 to 5, characterized by satisfying the following conditional expression. (Composition 7) A projection optical system according to any one of configurations 1 to 6, characterized by including five or fewer lenses. (Composition 8) When the focal length of the positive lens positioned closest to the projection side is fg1, 0.10 ≤ fg1 / f ≤ 1.00 A projection optical system according to any one of configurations 1 to 7, characterized by satisfying the following conditional expression. (Composition 9) When the focal length of the negative lens positioned on the light source panel side of the lens positioned closest to the projection side is fg2, -1.00 ≤ fg² / f ≤ -0.10 A projection optical system according to any one of configurations 1 to 8, characterized by satisfying the following conditional expression. (Composition 10) A projection optical system according to any one of configurations 1 to 9, characterized in that the projection-side surface of the first lens positioned closest to the projection side is convex toward the projection side. (Composition 11) When rs1 is the radius of curvature of the projection-side surface of the first lens, which is positioned closest to the projection side, 0.10 ≤ rs1 / f ≤ 1.20 A projection optical system according to any one of configurations 1 to 10, characterized by satisfying the following conditional expression. (Composition 12) It further includes an aperture diaphragm located on the projection side of the first lens, which is positioned closest to the projection side. When Sd is the distance along the optical axis between the aperture diaphragm and the projection-side surface of the first lens, 0.00 ≤ Sd / L ≤ 0.50 The projection optical system according to any one of Configurations 1 to 11, characterized by satisfying the following conditional expression. (Configuration 13) When the refractive power of the first lens disposed on the most projection side with respect to the d-line is Nd1, 1.80 ≦ Nd1 ≦ 2.10 The projection optical system according to any one of Configurations 1 to 12, characterized by satisfying the following conditional expression. (Configuration 14) When the refractive index of the second lens disposed on the side of the light source panel of the first lens disposed on the most projection side with respect to the d-line is Nd2, 1.50 ≦ Nd2 ≦ 1.95 The projection optical system according to any one of Configurations 1 to 13, characterized by satisfying the following conditional expression. (Configuration 15) When the refractive power of the lens disposed on the side of the light source panel with respect to the d-line is Nde, 1.70 ≦ Nde ≦ 1.95 The projection optical system according to any one of Configurations 1 to 14, characterized by satisfying the following conditional expression. (Configuration 16) When the Abbe number of the first lens disposed on the most projection side is νd1, 23.0 ≦ νd1 ≦ 45.0 The projection optical system according to any one of Configurations 1 to 15, characterized by satisfying the following conditional expression. (Configuration 17) When the Abbe number of the second lens disposed on the side of the light source panel of the first lens disposed on the most projection side is νd2, 18.0 ≦ νd2 ≦ 45.0 The projection optical system according to any one of Configurations 1 to 16, characterized by satisfying the following conditional expression. (Configuration 18) When the Abbe number of the lens disposed on the side of the light source panel is νde, 30.0 ≦ νde ≦ 55.0 The projection optical system according to any one of Configurations 1 to 17, characterized by satisfying the following conditional expression. (Composition 19) The projection optical system according to any one of configurations 1 to 18, characterized in that the element is composed of a plane. (Composition 20) The aforementioned element is composed of a plane, The aforementioned plane has an angle with respect to the optical axis, When the smaller of the angles of the plane with respect to the optical axis is denoted as θP[°], 40 ≤ θP ≤ 50 A projection optical system according to any one of configurations 1 to 19, characterized by satisfying the following conditional expression. (Composition 21) When Sk is the distance along the optical axis from the surface of the lens positioned closest to the light source panel to the display surface, 0.10 ≤ Sk / f ≤ 0.30 A projection optical system according to any one of configurations 1 to 20, characterized by satisfying the following conditional expression. (Composition 22) A projection optical system according to any one of configurations 1 to 21, further comprising a quarter-wave plate disposed between a lens positioned closest to the light source panel and the display surface. (Composition 23) A projection optical system according to any one of configurations 1 to 22, characterized in that illumination light is incident on the element from a direction perpendicular to the optical axis, reflected by a surface of the element having reflective and transmissive properties toward the light source panel, reflected by the light source panel toward the projection side, passes through at least one lens, passes the surface toward the projection side, and is emitted toward the projection side. (Composition 24) A projection optical system comprising an element having reflective and transmissive properties positioned on the projection side of the light source panel, and at least one lens positioned between the light source panel and the element, When the focal length of the projection optical system is f, and the distance along the optical axis from the projection-side surface of the projection optical system to the display surface of the light source panel is L, 0.10 ≤ L / f ≤ 2.10 A projection optical system characterized by satisfying the following conditional equation. (Composition 25) A projection device characterized by having a projection optical system described in any one of configurations 1 to 24, and a display element.

[0090] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of its gist. [Explanation of Symbols]

[0091] 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000 projection field PBS polarization conversion element (element) IM Panel (Light Source Panel)

Claims

1. A projection optical system comprising an element having reflective and transmissive properties positioned on the projection side of the light source panel, and at least one lens positioned between the light source panel and the element, When the focal length of the projection optical system is f, the distance along the optical axis from the projection-side surface of the projection optical system to the display surface of the light source panel is L, and the maximum effective area of ​​the light-emitting element on the display surface is H, 0.10 ≤ L / f ≤ 2.10 0.10 ≤ L / H ≤ 4.50 A projection optical system characterized by satisfying the following conditional equation.

2. When fP is the total focal length of the lens arranged between the light source panel and the element, 0.10 ≤ fP / f ≤ 3.00 The projection optical system according to claim 1, characterized in that it satisfies the following condition.

3. When the focal length of the lens positioned closest to the light source panel is ff, 0.10 ≤ ff / f ≤ 3.00 The projection optical system according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

4. When the paraxial radius of curvature of the surface of the lens positioned closest to the light source panel is rr2, -100000.00 ≤ rr² / f ≤ -0.50 The projection optical system according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

5. When de is the distance along the optical axis from the surface of the lens located closest to the light source panel to the surface of the light source panel, 0.11 ≤ de / L ≤ 1.00 The projection optical system according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

6. When rr2 is the paraxial radius of curvature of the surface of the lens located closest to the light source panel, and de is the distance along the optical axis from the projection-side surface of the lens located closest to the light source panel to the surface of the light source panel, -100000.00 ≤ rr² / de ≤ -0.10 The projection optical system according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

7. The projection optical system according to claim 1 or 2, characterized by including five or fewer lenses.

8. When the focal length of the positive lens positioned closest to the projection side is fg1, 0.10 ≤ fg ≤ 1 / f ≤ 1.00 The projection optical system according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

9. When the focal length of the negative lens positioned on the light source panel side of the lens positioned closest to the projection side is fg2, -1.00 ≤ fg² / f ≤ -0.10 The projection optical system according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

10. The projection optical system according to claim 1 or 2, characterized in that the projection-side surface of the first lens positioned closest to the projection side is convex toward the projection side.

11. When rs1 is the radius of curvature of the projection-side surface of the first lens, which is positioned closest to the projection side, 0.10 ≤ rs1 / f ≤ 1.20 The projection optical system according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

12. It further includes an aperture diaphragm located on the projection side of the first lens, which is positioned closest to the projection side. When Sd is the distance along the optical axis between the aperture diaphragm and the projection-side surface of the first lens, 0.00 ≤ Sd / L ≤ 0.50 The projection optical system according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

13. When the refractive power of the first lens positioned closest to the projection side with respect to the d line is Nd1, 1.80 ≤ Nd1 ≤ 2.10 The projection optical system according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

14. When the refractive index of the second lens positioned on the side of the light source panel to the first lens positioned closest to the projection side is Nd2, 1.50 ≤ Nd2 ≤ 1.95 The projection optical system according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

15. When Nde is the refractive power of the lens positioned closest to the light source panel with respect to the d-line, 1.70 ≤ Nde ≤ 1.95 The projection optical system according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

16. When the Abbe number of the first lens positioned closest to the projection side is νd1, 23.0 ≤ νd1 ≤ 45.0 The projection optical system according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

17. When the Abbe number of the second lens positioned on the side of the light source panel to the first lens positioned closest to the projection side is νd2, 18.0 ≤ νd² ≤ 45.0 The projection optical system according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

18. When the Abbe number of the lens positioned closest to the light source panel is νde, 30.0 ≤ νde ≤ 55.0 The projection optical system according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

19. The projection optical system according to claim 1 or 2, characterized in that the element is composed of a plane.

20. The aforementioned element is composed of a plane, The aforementioned plane has an angle with respect to the optical axis, When the smaller of the angles of the plane with respect to the optical axis is denoted as θP [°], 40 ≤ θP ≤ 50 The projection optical system according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

21. When Sk is the distance along the optical axis from the surface of the lens positioned closest to the light source panel to the display surface, 0.10 ≤ Sk / f ≤ 0.30 The projection optical system according to claim 1 or 2, characterized in that it satisfies the following conditional expression.

22. The projection optical system according to claim 1 or 2, further comprising a quarter-wave plate disposed between the lens positioned closest to the light source panel and the display surface.

23. The projection optical system according to claim 1 or 2, characterized in that illumination light is incident on the element from a direction perpendicular to the optical axis, reflected by a surface of the element having reflective and transmissive properties toward the light source panel, reflected by the light source panel toward the projection side, passes through the at least one lens, passes the surface toward the projection side, and is emitted toward the projection side.

24. A projection optical system comprising an element having reflective and transmissive properties positioned on the projection side of the light source panel, and at least one lens positioned between the light source panel and the element, When the focal length of the projection optical system is f, and the distance along the optical axis from the projection-side surface of the projection optical system to the display surface of the light source panel is L, 0.10 ≤ L / f ≤ 2.10 A projection optical system characterized by satisfying the following conditional equation.

25. A projection device characterized by having a projection optical system according to claim 1 or 2 and a display element.

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