JP2018072642A - Projection optical system and projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection optical system capable of suppressing an increase in depth dimension of an amusement apparatus while a screen has a desired size.SOLUTION: A projection optical system 30, which projects projection light from a projected plane 20 to a dome-shaped screen 40 from the inside, comprises a reflection mirror 50 for bending an optical path, a positive lens group 60 disposed on the projected plane 20 side of the reflection mirror 50, a negative lens group 70 disposed on the screen 40 side of the reflection mirror 50, and an aperture stop 80 disposed between the positive lens group 60 and the reflection mirror 50.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a projection optical system and a projection apparatus.

2. Description of the Related Art Conventionally, a projection optical system and a projection apparatus that project projection light from a projection surface onto a dome-shaped screen from the inside (hereinafter referred to as a conventional projection optical system and projection apparatus) are known (for example, Patent Document 1). reference.). A conventional projection apparatus is a projection apparatus that projects a projection image formed on a projection surface in accordance with the shape of a dome-shaped screen by a projection optical system, and projects the image on the screen as a projection image. The projected image is generated by a projection image generation unit configured with a liquid crystal panel, a negative / positive film, or the like.
FIG. 10 is a diagram for explaining a conventional projection optical system 930. FIG. 11 is a diagram for explaining a conventional projection apparatus 910. FIG. 12 is a diagram showing an example in which a conventional projection apparatus 910 is incorporated in a thin amusement device 100 (for example, a pachinko device, a slot machine device).

  As shown in FIGS. 10 and 11, the conventional projection optical system 930 is a projection optical system that projects the projection light from the projection surface 920 onto the dome-shaped screen 940 from the inside. A first lens L1 having a positive refractive power, a second lens L2 having a positive refractive power, an aperture stop 980, and a negative lens, which are sequentially arranged from the projection surface 920 side toward the screen 940 side. The third lens L3 having refractive power is configured. The first lens L1 is a biconvex lens with convex surfaces facing the object side and the projection side, the second lens L2 is a positive meniscus lens with convex surfaces facing the object side, and the third lens L3 is facing the projection side. A negative meniscus lens with a concave surface.

  In the conventional projection optical system 930, the third lens L3 is aspheric on both surfaces, includes negative refractive power that increases from the optical axis toward the periphery, and the aperture lens 980 and the third lens L3. The distance between them is smaller than the distance between the aperture stop 980 and the second lens L2. In this specification, “projection side” means “the side in the direction in which projection light travels”, and can also be referred to as “screen side”. Further, “object side” means “side opposite to the direction in which the projection light travels”, and can also be referred to as “projection surface side”.

  In the conventional projection optical system 930, the third lens L3 has a concave surface on the projection side, and the second lens L2 has a convex surface on the object side. For this reason, the projection light collected by both the convex surfaces of the first lens L1 and the convex surface of the second lens L2 passes through the aperture stop 980, and is magnified and projected by the concave surface of the third lens to be connected to the dome-shaped screen. When imaging, spherical aberration and coma can be favorably corrected while generating sufficient distortion. Therefore, according to the conventional projection optical system 930, it is possible to provide a projection device that forms a bright and clear image on a dome-shaped screen while having a compact three-sheet configuration.

  Further, in the conventional projection optical system 930, since the third lens L3 includes negative refractive power that increases from the optical axis toward the periphery, the image is projected so as to form a clearer image along the curved screen. Can project light. Therefore, according to the conventional projection optical system 930, it is possible to project the projection light so that the image of the projection surface is clearly formed even on the hemispherical screen.

JP 2013-97258 A

  By the way, the projector 910 is required to have a configuration that can suppress an increase in the depth dimension of the amusement device 100 while making the screen 940 a desired size.

  Accordingly, an object of the present invention is to provide a projection optical system having a configuration capable of suppressing an increase in the depth dimension of an amusement device while setting a screen to a desired size, and a projection apparatus including such a projection optical system. I will.

[1] A projection optical system of the present invention is a projection optical system that projects projection light from a projection surface onto a dome-shaped screen from the inside, and a reflection member for bending an optical path; A positive lens group disposed on the projection surface side, a negative lens group disposed on the screen side of the reflecting member, and an aperture stop disposed between the positive lens group and the reflecting member; It is characterized by providing.

  According to the projection optical system of the present invention, since the projection light from the projection surface is reflected by the reflecting member and the optical path is bent, the length of the projection optical system along the depth direction as shown in FIG. The length C and the length B of the projection device along the depth direction can be shortened. For this reason, according to the projection optical system of the present invention, an increase in the depth dimension of the amusement device can be suppressed while the screen is set to a desired size.

  According to the projection optical system of the present invention, since the aperture stop is disposed between the positive lens group and the reflecting member, the aperture stop is disposed between the negative lens group and the reflecting member. Compared to the case, the optical path length between the reflecting member and the negative lens group can be shortened, and an increase in the depth dimension of the amusement device can be further suppressed.

  In the projection optical system of the present invention, as will be described later, it is preferable that an aperture stop is disposed at a position where the principal ray of the projection light intersects the optical axis (position along the optical axis). With this configuration, various aberrations can be suitably corrected for the projected image whose field is curved in accordance with the shape of the dome-shaped screen.

[2] In the projection optical system of the present invention, it is preferable that the aperture stop is disposed on a reflecting surface of the reflecting member.

  According to the projection optical system of this aspect, since the position where the aperture stop is arranged can be shared with the position where the reflecting member is arranged, the size of the projection optical system can be reduced.

  In the projection optical system of this aspect, it is preferable to arrange the reflecting member at a position where the principal ray intersects the optical axis as shown in FIG. With this configuration, the reflecting member can be downsized.

[3] In the projection optical system according to the aspect of the invention, it is preferable that the aperture stop is disposed closer to the positive lens group than the reflecting member.

  According to the projection optical system of this aspect, as shown in FIG. 2 to be described later, the positive lens group can be further reduced in size as compared with the case of the projection optical system described in [2] above. Various aberrations can be easily corrected while generating curvature of field in accordance with the shape of the dome-shaped screen.

[4] In the projection optical system of the present invention, among the lenses included in the positive lens group, the lens disposed closest to the object side is a positive first meniscus lens having a convex surface facing the object side, The concave surface of the first meniscus lens is preferably a curved surface whose curvature decreases from the optical axis toward the periphery.

  According to the projection optical system of this aspect, the concave surface of the first meniscus lens arranged closest to the object among the lenses included in the positive lens group is a curved surface whose curvature decreases from the optical axis toward the periphery. Therefore, it is possible to appropriately generate a field curvature that matches the shape of the dome-shaped screen in the projected image.

[5] In the projection optical system of this aspect, it is preferable that the concave surface of the first meniscus lens has an inflection point that becomes a convex surface in the peripheral portion.

  According to the projection optical system of this aspect, since the concave surface of the first meniscus lens has an inflection point that becomes a convex surface in the peripheral portion, it is possible to optimize the field curvature generated in the projection image.

[6] In the projection optical system of the present aspect, when the sag amount at the radial position separated by a predetermined distance r from the optical axis toward the periphery on the concave surface of the first meniscus lens is Sag (r), It is preferable to satisfy the formula (1).

−0.1 ≦ (Sag (r ₁ ) −Sag (0.9r ₁ )) / (Sag (0.6r ₁ ) −Sag (0.5r ₁ )) ≦ 0.4 (1)

In equation (1), the symbol “r ₁ ” is the effective radius of the first meniscus lens, and the symbol “Sag (r ₁ )” is the sag amount at the radial position of the effective radius r ₁ of the first meniscus lens. , and the symbol "sag (0.9r _1)" is a sag amount at 90% radius position of the effective radius r ₁ of the first meniscus lens, reference numeral "sag (0.6r _1)" is the first meniscus lens The sag amount at the 60% radius position of the effective radius r ₁ , and the sign “Sag (0.5r ₁ )” is the sag amount at the 50% radius position of the effective radius r ₁ of the first meniscus lens.

  According to the projection optical system of this aspect, by satisfying the condition of the above formula (1), it is possible to optimize the field curvature generated in the projection image in accordance with the shape of the dome-shaped screen. When the value of the above formula (1) is smaller than −0.1, the sag amount of the meniscus surface is small, and the power on the peripheral side of the meniscus surface of the first meniscus lens is more positive than that on the central side. And the curvature of field of the projected image tends to be excessive. When the value of the above formula (1) is larger than 0.4, the power on the peripheral side of the meniscus surface of the first meniscus lens is weakened as a whole, and it is difficult to generate field curvature in the projected image. .

[7] In the projection optical system of the present invention, it is preferable that the positive lens group includes a first lens group on the object side and a second lens group on the projection side.

  According to the projection optical system of this aspect, the refractive power is dispersed between the first lens group and the second lens group, so that the spherical aberration of the projected image can be reduced, and the image plane is matched to the shape of the dome-shaped screen. The curve can be optimized.

[8] In the projection optical system according to this aspect, the first lens group includes a positive first meniscus lens having a convex surface facing the object side, and the second lens group is a positive lens having the convex surface facing the object side. The second meniscus lens is preferably used.

  According to the projection optical system of this aspect, the first lens group is composed of a positive first meniscus lens having a convex surface facing the object side, and the second lens group is a positive second meniscus having a convex surface facing the object side. Since it consists of lenses, the refractive power is dispersed between the first lens and the second lens, and the spherical aberration of the projected image can be reduced.

[9] In the projection optical system according to this aspect, it is preferable that a light shielding member for shielding light around the luminous flux of the projection light is disposed between the first lens group and the second lens group. .

  According to the projection optical system of this aspect, since the light shielding member that shields the light around the luminous flux of the projection light is disposed between the first lens group and the second lens group, the generation of flare is prevented. Can be suppressed. In addition, the diameter of the second lens group of the first lens group and the second lens group can be reduced, and the projection optical system can be reduced in size.

[10] In the projection optical system of the present invention, the lens arranged closest to the projection side among the lenses included in the negative lens group is a negative third meniscus lens having a convex surface directed toward the projection side, The convex surface of the third meniscus lens is preferably a curved surface having a curvature that decreases from the optical axis toward the periphery.

  According to the projection optical system of this aspect, the convex surface of the third meniscus lens arranged closest to the projection side among the lenses included in the negative lens group is a curved surface whose curvature decreases from the optical axis toward the periphery. For this reason, the distortion generated in the positive lens group can be set to an appropriate value.

[11] In the projection optical system according to this aspect, it is preferable that the convex surface of the third meniscus lens has an inflection point that becomes a concave surface in the peripheral portion.

  According to the projection optical system of this aspect, since the convex surface of the third meniscus lens has an inflection point that becomes a concave surface in the peripheral portion, it is possible to optimize the distortion aberration generated in the positive lens group.

[12] In the projection optical system of the present aspect, when the sag amount at the radial position separated by a predetermined distance r from the optical axis toward the periphery on the convex surface of the third meniscus lens is Sag (r), It is preferable to satisfy the formula (2).

Sag (0.7r ₂ ) / Sag (r ₂ ) ≧ 0.7 (2)

In Equation (2), the symbol “r ₂ ” is the effective radius of the third meniscus lens, and the symbol “Sag (0.7r ₂ )” is the 70% radius position of the effective radius r ₂ of the third meniscus lens. The symbol “Sag (r ₂ )” is the sag amount at the radial position of the effective radius r ₂ of the third meniscus lens.

According to the projection optical system of this aspect, the performance of the optical system (optimization of the field curvature of the projection image generated in accordance with the shape of the dome-shaped screen, miniaturization, etc., while satisfying the condition of the above formula (2) ) Can be improved. When “Sag (0.7r ₂ ) / Sag (r ₂ )” is smaller than 0.7, it is not possible to appropriately generate a field curvature in accordance with the shape of the dome-shaped screen in the projected image. .

[13] In the projection optical system of the present invention, when the effective diameter of the negative lens group is D, and the distance from the optical axis in the portion most distant from the optical axis of the projection surface is I, It is preferable to satisfy the formula (3).

3.0 ≧ D / (2 · I) ≧ 2.0 (3)

  According to the projection optical system of this aspect, the spherical aberration of the projected image can be appropriately corrected by satisfying the condition of the above formula (3). That is, when “D / (2 · I)” is smaller than 2.0, it is not preferable because the spherical aberration of the projected image cannot be sufficiently corrected. Further, when “D / (2 · I)” is larger than 3.0, the optical path length between the reflecting member and the negative lens group becomes long, leading to an increase in the depth dimension of the amusement device. In addition, since the outer diameter of the negative lens group is increased, the projection optical system is increased in size.

[14] In the projection optical system of the present invention, a composite focal length of the positive lens group and f _1, when the combined focal length of the projection optical system and the f _2, satisfies the following formula (4) It is preferable.

1.1 ≦ f ₁ / f ₂ ≦ 1.9 (4)

    According to the projection optical system of this aspect, by satisfying the condition of the above formula (4), it is possible to easily correct various aberrations while suppressing an increase in the size of the projection optical system.

[15] A projection apparatus of the present invention is a projection apparatus including a projection optical system and a dome-shaped screen, wherein the projection optical system is the projection optical system of the present invention.

  According to the projection device of the present invention, as described above, since the projection light from the projection surface is reflected by the reflecting member and the optical path is bent, the projection along the depth direction is performed as shown in FIG. It is possible to shorten the length C of the optical system and the length B of the projection device along the depth direction. For this reason, according to the projection device of the present invention, it is possible to suppress an increase in the depth dimension of the amusement device while making the screen a desired size.

  According to the projection device of the present invention, the aperture stop is disposed between the positive lens group and the reflecting member, and therefore the aperture stop is disposed between the negative lens group and the reflecting member. As compared with the above, the optical path length between the reflecting member and the negative lens group can be shortened, and the increase in the depth dimension of the amusement device can be further suppressed.

It is a figure shown in order to demonstrate the projection apparatus 10 which concerns on Embodiment 1, and the projection apparatus 11 which concerns on a comparative example. However, the aperture stop 80 and the light shielding member 90 are not shown. It is a figure shown in order to demonstrate the projection optical system 30 which concerns on Embodiment 1. FIG. It is a figure shown in order to demonstrate the conditions of Formula (1). It is a figure shown in order to demonstrate the conditions of Formula (2). It is a figure shown in order to demonstrate the conditions of Formula (3). 1 is a diagram illustrating an example in which a projection device 10 according to Embodiment 1 is incorporated into a thin amusement device 100. FIG. It is a figure shown in order to demonstrate the projector 10a which concerns on Embodiment 2. FIG. However, the aperture stop 80a and the light shielding member 90a are not shown. It is a figure shown in order to demonstrate the projection optical system 30a which concerns on Embodiment 2. FIG. It is a figure which shows the example which incorporated the projection apparatus 10b which concerns on a modification in the thin amusement apparatus 100. FIG. It is a figure shown in order to demonstrate the conventional projection optical system 930. FIG. It is a figure shown in order to demonstrate the conventional projector 910. FIG. It is a figure which shows the example which incorporated the conventional projector 910 in the thin amusement apparatus 100. FIG.

  Hereinafter, a projection optical system and a projection apparatus of the present invention will be described based on the embodiments shown in the drawings.

[Embodiment 1]
1. Configuration of Embodiment 1 FIG. 1 is a diagram illustrating a projection apparatus 10 according to Embodiment 1 and a projection apparatus 11 according to a comparative example. FIG. 2 is a diagram for explaining the projection optical system 30 according to the first embodiment. FIG. 3 is a diagram for explaining the condition of the expression (1). FIG. 4 is a diagram for explaining the condition of the expression (2). FIG. 5 is a diagram for explaining the condition of the expression (3). FIG. 6 is a diagram illustrating an example in which the projector 10 according to the first embodiment is incorporated in a thin amusement device 100.

  In FIG. 1, the projection surface 20, the projection image generation unit 21, the screen 40, and the light rays in the projection device 10 according to the first embodiment are indicated by solid lines, and the projection surface 22 and the projection image in the projection device 11 according to the comparative example. The generation unit 23, the screen 41, and light rays are indicated by broken lines. That is, the projection apparatus 10 according to the first embodiment has the projection surface 20 disposed on the negative lens group 70 side with respect to the optical axis Ax, and is on the opposite side of the negative lens group 70 with respect to the optical axis Ax. The projection apparatus 11 according to the comparative example is provided with the projection surface 22.

  As shown in FIGS. 1 and 2, the projection optical system 30 according to the first embodiment is a projection optical system that projects projection light from the projection surface 20 onto the dome-shaped screen 40 from the inside. Then, the reflecting mirror 50 as a reflecting member for bending the optical path, the positive lens group 60 disposed on the projection surface 20 side of the reflecting mirror 50, and the negative lens group disposed on the screen 40 side of the reflecting mirror 50. 70, and an aperture stop 80 disposed between the positive lens group 60 and the reflection mirror 50.

  In the projection optical system 30 according to the first embodiment, the aperture stop 80 is disposed closer to the positive lens group 60 than the reflection mirror 50.

  The positive lens group 60 includes a positive first meniscus lens 61 as a first lens group and a positive second meniscus lens 62 as a second lens group. Among the lenses included in the positive lens group 60, the lens disposed closest to the object side is a first meniscus lens 61. The first meniscus lens 61 includes a convex surface R1 having a convex surface facing the object side, and a projection. It has a concave surface R2 facing the concave surface to the side. The concave surface R2 of the first meniscus lens 61 is a curved surface whose curvature decreases from the optical axis Ax toward the periphery. Among the lenses included in the positive lens group 60, the lens arranged closest to the projection side is the second meniscus lens 62. The second meniscus lens 62 includes a convex surface R3 having a convex surface facing the object side, and a projection side. Has a concave surface R4 facing the concave surface.

  The projection surface 20 is a display surface on which an image of the projection image generation unit 21 is formed. The projection image generation unit 21 can be configured by a liquid crystal display element, a negative film, a positive film, or the like. The projection surface 20 is disposed closer to the lens group 70 than the optical axis Ax. In other words, the projection surface 20 includes a plane that includes the optical axis Ax of the positive lens group 60 and intersects the optical axis Ax of the negative lens group 70 with the intersection line with the reflection surface of the reflecting mirror 50 (hereinafter referred to as an axial plane). It is arranged on the negative lens group 70 side. In other words, the emission position of the projection light from the projection surface 20 is on the negative lens group 70 side with respect to the axial plane.

  In the projection optical system 30 according to Embodiment 1, the concave surface R2 of the first meniscus lens 61 has an inflection point that becomes a convex surface in the peripheral portion.

In the projection optical system 30 according to the first embodiment, as shown in FIG. 3, the sag amount at the radial position separated from the optical axis toward the periphery by a predetermined distance r on the concave surface R2 of the first meniscus lens 61 is Sag. When (r) is satisfied, the following expression (1) is satisfied.

−0.1 ≦ (Sag (r ₁ ) −Sag (0.9r ₁ )) / (Sag (0.6r ₁ ) −Sag (0.5r ₁ )) ≦ 0.4 (1)

In the equation (1), the symbol “r ₁ ” is the effective radius of the first meniscus lens 61, and the symbol “Sag (r ₁ )” is the sag amount at the radial position of the effective radius r ₁ of the first meniscus lens 61. , and the symbol "sag (0.9r _1)" is a sag amount at 90% radius position of the effective radius r ₁ of the first meniscus lens 61, the code "sag (0.6r _1)" is the first meniscus lens 61 The sag amount at the 60% radius position of the effective radius r ₁ , and the sign “Sag (0.5r ₁ )” is the sag amount at the 50% radius position of the effective radius r ₁ of the first meniscus lens 61.

  In the projection optical system 30 according to the first embodiment, a light shielding member 90 that shields light around the luminous flux of the projection light is disposed between the first meniscus lens 61 and the second meniscus lens 62.

  In the projection optical system 30 according to the first embodiment, the negative lens group 70 includes a negative third meniscus lens 71 as a third lens group. The third meniscus lens 71 has a concave surface R5 with a concave surface facing the object side and a convex surface R6 with a convex surface facing the projection side. The convex surface R6 is a curved surface whose curvature decreases from the optical axis Ax toward the periphery. In the projection optical system 30 according to the first embodiment, the convex surface R6 of the third meniscus lens 71 has an inflection point that becomes a concave surface in the peripheral portion.

In the projection optical system 30 according to the first embodiment, as shown in FIG. 4, the sag amount at the radial position separated from the optical axis Ax toward the periphery by a predetermined distance r on the convex surface R6 of the third meniscus lens 71 is obtained. When Sag (r) is satisfied, the following expression (2) is satisfied.

Sag (0.7r ₂ ) / Sag (r ₂ ) ≧ 0.7 (2)

In Equation (2), the symbol “r ₂ ” is the effective radius of the third meniscus lens 71, and the symbol “Sag (0.7r ₂ )” is the 70% radius position of the effective radius r ₂ of the third meniscus lens 71. The symbol “Sag (r ₂ )” is the sag amount at the radial position of the effective radius r ₂ of the third meniscus lens 71.

In the projection optical system 30 according to the first embodiment, as shown in FIG. 5, the effective diameter of the third meniscus lens 71 is D, and the distance from the optical axis Ax in the portion farthest from the optical axis Ax of the projection surface 20. When the distance is I, the following formula (3) is satisfied.

3.0 ≧ D / (2 · I) ≧ 2.0 (3)

In the projection optical system 30 according to Embodiment 1, when the combined focal length of the positive lens group 60 is f ₁ and the combined focal length of the projection optical system 30 is f ₂ , the following expression (4) is satisfied. .

1.0 ≦ f ₁ / f ₂ ≦ 1.9 (4)

  The projection apparatus 10 according to the first embodiment is a projection apparatus that includes a projection optical system and a dome-shaped screen 40. In the projection device 10 according to the first embodiment, the projection optical system is the projection optical system 30 according to the first embodiment.

2. Operation / Effect of First Embodiment According to the projection optical system 30 according to the first embodiment, since the projection light from the projection surface 20 is reflected by the reflection mirror 50 and the optical path is bent, as shown in FIG. The length C of the projection optical system along the depth direction and the length B of the projection apparatus along the depth direction can be shortened. For this reason, according to the projection optical system 30 which concerns on Embodiment 1, the increase in the depth dimension of an amusement apparatus can be suppressed, making a screen a desired magnitude | size.

  In addition, according to the projection optical system 30 according to the first embodiment, the aperture stop 80 is disposed between the positive lens group 60 and the reflection mirror 50, and thus, between the negative lens group 70 and the reflection mirror 50. The optical path length between the reflecting mirror 50 and the negative lens group 70 can be shortened, and the increase in the depth dimension of the amusement device 100 can be further suppressed as compared with the case where an aperture stop is disposed at the center.

  Further, according to the projection optical system 30 according to the first embodiment, since the aperture stop 80 is disposed on the positive lens group 60 side with respect to the reflection mirror 50, as shown in FIG. As compared with the case of the projection optical system 30a according to No. 2, the positive lens group 60 can be further reduced in size and various aberrations can be generated while generating curvature of field in accordance with the shape of the dome-shaped screen. It becomes easy to correct.

  In addition, according to the projection optical system 30 according to the first embodiment, the concave surface R2 of the first meniscus lens 61 arranged closest to the object side among the lenses included in the positive lens group 60 is located on the periphery from the optical axis Ax. Since the curved surface has a curvature that decreases as it goes, it is possible to appropriately generate a field curvature in accordance with the shape of the dome-shaped screen 40 in the projected image.

  Further, according to the projection optical system 30 according to the first embodiment, the concave surface R2 of the first meniscus lens 61 has an inflection point that becomes a convex surface in the peripheral portion, so that the field curvature generated in the projection image is optimized. Can be achieved.

Further, according to the projection optical system 30 according to the first embodiment, the sag amount at the radial position separated from the optical axis Ax by the predetermined distance r on the concave surface R2 of the first meniscus lens 61 is represented by Sag (r). Since the following expression (1) is satisfied, it is possible to optimize the field curvature generated in the projected image in accordance with the shape of the dome-shaped screen 40.

−0.1 ≦ (Sag (r ₁ ) −Sag (0.9r ₁ )) / (Sag (0.6r ₁ ) −Sag (0.5r ₁ )) ≦ 0.4 (1)

When the value of the above formula (1) is smaller than −0.1, the sag amount of the meniscus surface is small, so that the power on the peripheral side of the meniscus surface of the first meniscus lens 61 is larger than that on the central side. It becomes larger on the positive side, and the field curvature of the projected image tends to be excessive. When the value of the above formula (1) is larger than 0.4, the power on the peripheral side of the meniscus surface of the first meniscus lens 61 is weakened as a whole, and it is difficult to generate field curvature in the projected image. Become.

  In the projection optical system 30 according to the first embodiment, the positive lens group 60 includes the first meniscus lens 61 on the object side and the second meniscus lens 62 on the projection side. The refractive power is dispersed between the second meniscus lens 62 and the spherical aberration of the projected image can be reduced, and the field curvature can be optimized in accordance with the shape of the dome-shaped screen 40.

  Further, according to the projection optical system 30 according to the first embodiment, the positive lens group 60 includes the positive first meniscus lens 61 with the convex surface facing the object side and the positive second meniscus with the convex surface facing the object side. Since the lens 62 is included, the refractive power is dispersed between the first meniscus lens 61 and the second meniscus lens 62, and the spherical aberration of the projected image can be reduced.

  Further, according to the projection optical system 30 according to the first embodiment, the light shielding member 90 that shields light around the luminous flux of the projection light is disposed between the first meniscus lens 61 and the second meniscus lens 62. Therefore, the occurrence of flare can be suppressed. In addition, the diameter of the second meniscus lens 62 of the first meniscus lens 61 and the second meniscus lens 62 can be reduced, and the projection optical system 30 can be reduced in size. Further, by reducing the diameter of the second meniscus lens 62, the second meniscus lens 62 interferes with the projection light reflected by the reflection mirror 50 even if the interval between the reflection mirror 50 and the third meniscus lens 71 is narrowed. It becomes difficult to do.

  In addition, according to the projection optical system 30 according to the first embodiment, the lens arranged closest to the projection side among the lenses included in the negative lens group 70 is a negative third meniscus lens having a convex surface directed toward the projection side. 71, and the convex surface R6 of the third meniscus lens 71 is a curved surface whose curvature decreases from the optical axis Ax toward the periphery, so that the distortion generated in the positive lens group can be set to an appropriate value. it can.

  Further, according to the projection optical system 30 according to the first embodiment, the convex surface R6 of the third meniscus lens 71 has an inflection point that becomes a concave surface in the peripheral portion, so that the distortion aberration generated in the positive lens group is optimal. Can be achieved.

Further, according to the projection optical system 30 according to the first embodiment, the sag amount at the radial position separated from the optical axis Ax by the predetermined distance r on the convex surface R6 of the third meniscus lens 71 is represented by Sag (r). Since the following expression (2) is satisfied, the performance of the optical system (optimization of the field curvature of the projection image generated in accordance with the shape of the dome-shaped screen, miniaturization, etc.) is improved. be able to.

Sag (0.7r ₂ ) / Sag (r ₂ ) ≧ 0.7 (2)

When “Sag (0.7r ₂ ) / Sag (r ₂ )” is smaller than 0.7, it is not possible to appropriately generate a field curvature in accordance with the shape of the dome-shaped screen in the projected image. .

According to the projection optical system 30 according to the first embodiment, when the effective diameter of the third meniscus lens 71 is D, and the distance from the optical axis Ax in the portion farthest from the optical axis Ax of the projection surface 20 is I. Since the following expression (3) is satisfied, the spherical aberration of the projected image can be corrected appropriately. When “D / (2 · I)” is smaller than 2.0, it is not preferable because the spherical aberration of the projected image cannot be sufficiently corrected. When “D / (2 · I)” is larger than 3.0, the optical path length between the reflecting mirror 50 and the negative lens group 70 becomes long, and the depth dimension of the amusement device 100 increases. Invite. Further, since the outer diameter of the negative lens group 70 is increased, the projection optical system 30 is increased in size.

3.0 ≧ D / (2 · I) ≧ 2.0 (3)

Further, according to the projection optical system 30 according to the first embodiment, the composite focal length of the positive lens group 60 and f _1, when the combined focal length of the projection optical system 30 and the f _2, the following equation (4) Therefore, it is possible to easily correct various aberrations while suppressing an increase in the size of the projection optical system 30.

1.1 ≦ f ₁ / f ₂ ≦ 1.9 (4)

  The projection apparatus 10 according to the first embodiment is a projection apparatus including a projection optical system and a dome-shaped screen 40, and the projection optical system is the projection optical system 30 according to the first embodiment. In addition, since the projection light from the projection surface 20 is reflected by the reflection mirror 50 and the optical path is bent, as shown in FIG. 1, the length C of the projection optical system along the depth direction, and the depth direction The length B of the projection device along the line can be shortened. For this reason, according to the projection apparatus 10 which concerns on Embodiment 1, the increase in the depth dimension of an amusement apparatus can be suppressed, making a screen a desired magnitude | size.

  Further, according to the projection device 10 according to the first embodiment, the aperture stop 80 is disposed between the positive lens group 60 and the reflection mirror 50, and therefore, between the negative lens group 70 and the reflection mirror 50. Compared with the case where the aperture stop is arranged, the optical path length between the reflection mirror 50 and the negative lens group 60 can be shortened, and the increase in the depth dimension of the amusement device 100 can be further suppressed.

Moreover, according to the projection apparatus 10 which concerns on Embodiment 1, the increase in the height dimension of the amusement apparatus 100 can also be suppressed for the following reasons.
That is, when the projection surface 22 is disposed on the opposite side of the negative lens group 70 from the optical axis Ax (axial plane) of the positive lens group 60 as in the projection device 11 according to the comparative example. The reflected light is reflected by the reflecting mirror 50 toward the side opposite to the positive lens group 60 with respect to the optical axis Ax of the negative lens group 70 (see FIG. 1).
On the other hand, as in the projection apparatus 10 according to the first embodiment, the projection surface 20 has a negative lens group 70 side (the optical axis Ax is greater than the optical axis Ax (axial plane) of the positive lens group 60. When arranged on the bent side), the projection light is reflected by the reflection mirror 50 toward the positive lens group 60 side with respect to the optical axis Ax of the negative lens group 70.

Therefore, the following can be said about the dimensions of the projection apparatus 10 in the optical axis Ax direction of the positive lens group 60. That is, the dimension E (see FIG. 1) of the projection apparatus (projection apparatus 10 according to Embodiment 1) when the projection surface 20 is arranged on the negative lens group 70 side with respect to the optical axis Ax is the projection surface 20. Is shorter than the dimension F (see FIG. 1) of the projection apparatus (projection apparatus 11 according to the comparative example) in the case where is disposed on the opposite side of the negative lens group 70 from the optical axis Ax.
As a result, according to the projection apparatus 10 according to the first embodiment, by arranging the projection surface 20 on the negative lens group 70 side with respect to the optical axis Ax, it is possible to suppress an increase in the height dimension of the amusement device 100. it can.

Moreover, according to the projection apparatus 10 which concerns on Embodiment 1, the increase in the height dimension of the amusement apparatus 100 can be suppressed also for the following reasons.
That is, in the projection apparatus 10 according to the first embodiment, the projection surface 20 is illuminated behind the projection surface 20 (projection image generation unit 21) (in the direction opposite to the side where the reflection mirror 50 is disposed). Light source (not shown) and the like. For this reason, when the projection device 10 is arranged on the upper part of the amusement device 100 (see FIG. 6), the projection surface 20 is arranged on the negative lens group 70 side with respect to the optical axis Ax, whereby the light source or the like is arranged. Can be arranged below the projection surface 20. Therefore, the projection optical system does not protrude above the amusement device 100, and an increase in the height dimension of the amusement device 100 can be suppressed.

That is, as in the projection device 11 according to the comparative example, if the projection surface 22 is configured to be disposed on the opposite side of the negative lens group 70 across the optical axis Ax, the positive lens group 60 The projection surface 22 and the light source (not shown) are arranged inside the amusement device 100 in the order of the positive lens group 60, the projection surface 22 and the light source (not shown) from below to above. Become. That is, it is necessary to extend the amusement device 100 upward.
On the other hand, when the projection surface 20 is arranged on the negative lens group 70 side with the optical axis Ax interposed therebetween as in the projection apparatus 10 according to the first embodiment, the positive lens group 60 is arranged. The projection surface 20 and the light source (not shown) are arranged inside the amusement device 100 in the order of the light source (not shown), the projection surface 20 and the positive lens group 60 from below to above. Become. That is, it is not necessary to lengthen the amusement device 100 upward.

  As a result, according to the projection device 10 according to the first embodiment, it is possible to suppress an increase in the height dimension of the amusement device 100 even for such a reason.

  Moreover, according to the projection storage 10 which concerns on Embodiment 1, the following effects are also acquired. That is, when the projection surface 22 is arranged on the opposite side of the negative lens group 70 across the optical axis Ax as in the projection device 11 according to the comparative example, the reflection mirror 50 is provided with the third meniscus. It is necessary to lengthen the lens 71 side. On the other hand, when the projection surface 20 is arranged on the negative lens group 70 side with the optical axis Ax interposed therebetween as in the projection apparatus 10 according to the first embodiment, the reflection mirror 50 is the first mirror. There is no need to increase the length to the 3 meniscus lens 71 side. As a result, according to the projection storage 10 concerning Embodiment 1, the magnitude | size of a reflective mirror can be made small compared with the case of the projection apparatus 11 which concerns on a comparative example.

[Embodiment 2]
FIG. 7 is a diagram for explaining the projection apparatus 10a according to the second embodiment. FIG. 8 is a diagram for explaining the projection optical system 30a according to the second embodiment.

As shown in FIGS. 7 and 8, the projection optical system 30a according to the second embodiment projects the projection light from the projection surface 20 onto the dome-shaped screen 40 from the inside.
The positive lens group 60a includes a first lens group on the object side and a second lens group on the projection side. The first lens group includes a positive first meniscus lens 61a having a convex surface R1 with the convex surface facing the object side. The concave surface R2 of the first meniscus lens 61a has a curvature that decreases from the optical axis Ax toward the periphery. It is a curved surface. The second lens group includes a biconvex positive lens 62a having a convex surface R3 and a convex surface R4 with the convex surfaces facing the object side and the projection side. The positive lens 62a has an inflection point that becomes a concave surface at the periphery of the convex surface R4.

The negative lens group 70a includes a third meniscus lens 71a as a third lens group. The third meniscus lens 71a has a concave surface R5 with the concave surface facing the object side and a convex surface R6 with the convex surface facing the projection side. The convex surface R6 is a curved surface whose curvature decreases from the optical axis Ax toward the periphery.
Between the first meniscus lens 61a and the positive lens 62a, a light shielding member 90a that shields light around the luminous flux of the projection light is disposed.

  The projection optical system 30a according to the second embodiment is different from the projection optical system 30 according to the first embodiment in the position of the aperture stop. That is, in the projection optical system 30a according to Embodiment 2, as shown in FIG. 8, the aperture stop 80a is disposed on the reflection surface of the reflection mirror 50a.

  As described above, the projection optical system 30a according to the second embodiment differs from the projection optical system 30 according to the first embodiment in the position of the aperture stop, but the projection light from the projection surface 20 is reflected by the reflection mirror 50a. Therefore, as in the case of the projection optical system 30 according to the first embodiment, the length C of the projection optical system along the depth direction and the length B of the projection apparatus along the depth direction can be shortened. (See FIG. 7). As a result, similarly to the projection optical system 30 according to the first embodiment, the projection optical system 30a according to the second embodiment can suppress an increase in the depth dimension of the amusement device while making the screen a desired size.

  Further, according to the projection optical system 30a according to the second embodiment, the aperture stop 80a is disposed between the positive lens group 60a and the reflection mirror 50a, and therefore, between the negative lens group 70a and the reflection mirror 50a. As compared with the case where the aperture stop is disposed at the center, the optical path length between the reflection mirror 50a and the negative lens group 60a can be shortened, and the increase in the depth dimension of the amusement device 100 can be further suppressed.

  Further, according to the projection optical system 30a according to the second embodiment, since the aperture stop 80a is disposed on the reflection surface of the reflection mirror 50a, the position at which the aperture stop 80a is disposed is the position at which the reflection mirror 50a is disposed. And the size of the projection optical system 30a can be reduced.

  When the aperture stop 80a is arranged on the reflection surface of the reflection mirror 50a, it is preferable to arrange the reflection surface of the reflection mirror 50a at a position where the principal ray intersects the optical axis Ax. With this configuration, the reflecting mirror 50a can be downsized.

  As mentioned above, although this invention was demonstrated based on said embodiment, this invention is not limited to said embodiment. The present invention can be implemented within a range that does not depart from the gist, and for example, the following modifications are possible.

(1) The number, material, shape, position, size, and the like of the constituent elements described in each of the above-described embodiments are examples, and can be changed within a range not impairing the effects of the present invention.

(2) In each of the embodiments described above, the reflection mirrors 50 and 50a are used as the reflection member, but the present invention is not limited to this. An optical element such as a right-angle reflecting prism can also be used as the reflecting member.

(3) In each of the above-described embodiments, the projected image is arranged on the side of the negative lens group 70, 70a with respect to the optical axis Ax, and a quadrispherical screen is used as the dome-shaped screen 40. Is not limited to this. FIG. 9 is a diagram illustrating an example in which the projector 10b according to the modification is applied to a thin amusement device 100. As shown in FIG. 9, the projected image is arranged so as to extend from the negative lens group 70, 70 a side to the opposite side across the optical axis Ax, and a hemispherical screen may be used as the dome-shaped screen 40. Good.

DESCRIPTION OF SYMBOLS 1 ... Viewer 10, 10, 10a, 10b, 11, 910 ... Projection apparatus, 20, 22 ... Projection surface, 21, 23 ... Projection image generation part, 30, 30a, 930 ... Projection optical system, 40, 41 ... Dome Shaped screen, 50, 50a ... reflecting mirror, 60, 60a ... positive lens group, 61, 61a ... first meniscus lens, 62, 62a ... second meniscus lens, 70, 70a ... negative lens group, 71, 71a ... 3rd meniscus lens, 80, 80a ... Aperture stop, 90, 90a ... Light-shielding member

Claims (15)

A projection optical system that projects projection light from a projection surface onto a dome-shaped screen from the inside,
A reflecting member for bending the optical path;
A positive lens group disposed on the projection surface side of the reflecting member;
A negative lens group disposed on the screen side of the reflecting member;
A projection optical system comprising: an aperture stop disposed between the positive lens group and the reflecting member. The projection optical system according to claim 1,
The projection optical system according to claim 1, wherein the aperture stop is disposed on a reflecting surface of the reflecting member. The projection optical system according to claim 1,
The projection optical system according to claim 1, wherein the aperture stop is disposed closer to the positive lens group than the reflecting member. In the projection optical system according to any one of claims 1 to 3,
Among the lenses included in the positive lens group, the lens disposed closest to the object side includes a positive first meniscus lens having a convex surface facing the object side,
The projection optical system according to claim 1, wherein the concave surface of the first meniscus lens is a curved surface whose curvature decreases from the optical axis toward the periphery. In the projection optical system according to claim 4,
The projection optical system according to claim 1, wherein the concave surface of the first meniscus lens has an inflection point that becomes a convex surface at a peripheral portion. In the projection optical system according to claim 4 or 5,
When the sag amount on the concave surface of the first meniscus lens at a radial position spaced from the optical axis toward the periphery by a predetermined distance r is Sag (r), the following expression (1) is satisfied. Projection optical system.

−0.1 ≦ (Sag (r ₁ ) −Sag (0.9r ₁ )) / (Sag (0.6r ₁ ) −Sag (0.5r ₁ )) ≦ 0.4 (1)

In equation (1), the symbol “r ₁ ” is the effective radius of the first meniscus lens, and the symbol “Sag (r ₁ )” is the sag amount at the radial position of the effective radius r ₁ of the first meniscus lens. , and the symbol "sag (0.9r _1)" is a sag amount at 90% radius position of the effective radius r ₁ of the first meniscus lens, reference numeral "sag (0.6r _1)" is the first meniscus lens The sag amount at the 60% radius position of the effective radius r ₁ , and the sign “Sag (0.5r ₁ )” is the sag amount at the 50% radius position of the effective radius r ₁ of the first meniscus lens. In the projection optical system according to any one of claims 1 to 3,
The positive lens group includes a first lens group on the object side and a second lens group on the projection side. In the projection optical system according to claim 7,
The first lens group includes a positive first meniscus lens having a convex surface facing the object side,
The projection optical system, wherein the second lens group includes a positive second meniscus lens having a convex surface directed toward the object side. In the projection optical system according to claim 7 or 8,
A projection optical system characterized in that a light shielding member for shielding light around the luminous flux of the projection light is disposed between the first lens group and the second lens group. In the projection optical system according to any one of claims 1 to 9,
Among the lenses included in the negative lens group, the lens arranged closest to the projection side includes a negative third meniscus lens having a convex surface facing the projection side,
The projection optical system according to claim 1, wherein the convex surface of the third meniscus lens is a curved surface whose curvature decreases from the optical axis toward the periphery. The projection optical system according to claim 10, wherein
The projection optical system according to claim 1, wherein the convex surface of the third meniscus lens has an inflection point that becomes a concave surface in a peripheral portion. The projection optical system according to claim 10 or 11,
When the sag amount on the convex surface of the third meniscus lens at a radial position separated from the optical axis by a predetermined distance r toward the periphery is Sag (r), the following expression (2) is satisfied. Projection optical system.

Sag (0.7r ₂ ) / Sag (r ₂ ) ≧ 0.7 (2)

In Equation (2), the symbol “r ₂ ” is the effective radius of the third meniscus lens, and the symbol “Sag (0.7r ₂ )” is the 70% radius position of the effective radius r ₂ of the third meniscus lens. The symbol “Sag (r ₂ )” is the sag amount at the radial position of the effective radius r ₂ of the third meniscus lens. In the projection optical system according to any one of claims 1 to 12,
The following expression (3) is satisfied, where D is the effective diameter of the negative lens group, and I is the distance from the optical axis at the portion of the projection surface farthest from the optical axis. Projection optical system.

3.0 ≧ D / (2 · I) ≧ 2.0 (3)
In the projection optical system according to any one of claims 1 to 13,
A projection optical system satisfying the following expression (4), where f ₁ is a combined focal length of the positive lens group and f ₂ is a combined focal length of the projection optical system.

1.1 ≦ f ₁ / f ₂ ≦ 1.9 (4)
A projection optical system;
A projection device comprising a dome-shaped screen,
The projection optical system according to claim 1, wherein the projection optical system is a projection optical system according to claim 1.

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