JP2007279283A - Visual display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a visual display enabling observation of images that change from directions, as seen from a 360° direction of the periphery, even if a mechanical complex rotation mechanism or the like is not used. <P>SOLUTION: The visual display comprises a reflecting face 2 of positive power obtained by rotating a curved line, including a projection part around a center shaft in the radial direction that is orthogonal to a center shaft 1, in a plane including the center shaft 1 and a ring band-like video display element 3, arranged rotation-symmetrically around the center shaft along the curved image face of the reflecting face 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a visual display device, and more particularly to a visual display device that can be observed from an arbitrary angle and an observation image changes depending on the viewing direction.

Conventionally, when a screen provided with a viewing angle limiting filter is rotated around the central axis, for example, an image of one object viewed from the 360 ° peripheral direction is projected on the screen to observe from an arbitrary direction Patent Documents 1 to 3 are known in which a visual display device in which an observation image changes depending on the viewing direction.
JP 2005-221690 A JP 2006-10852 A JP 2006-11367 A

  However, in the case of the conventional examples known in Patent Documents 1 to 3, a mechanism for mechanically rotating a screen provided with a viewing angle limiting filter is necessary, and observation is performed in that direction when viewed from a specific direction. Possible images can only be seen intermittently.

  The present invention has been made in view of such problems of the prior art, and the object of the present invention is to obtain an image that changes depending on the viewing direction from the surrounding 360 ° direction without using a complicated mechanical rotation mechanism or the like. An observable visual display device is provided.

  The visual display device of the present invention that achieves the above object is a positive power reflecting surface obtained by rotating a curve including a convex portion in a radial direction perpendicular to the central axis in a plane including the central axis around the central axis. And a ring-shaped image display element arranged in a rotationally symmetrical manner around the central axis along the curved image surface of the reflecting surface.

  In this case, it is desirable that the image display element has a three-dimensional display surface that is rotationally symmetric about the central axis.

  Further, it is desirable that the rotational symmetry axis of the reflecting surface and the rotational symmetry axis of the image display element coincide.

  Further, the display surface of the video display element is configured in a cylindrical shape, and the video displayed on the video display element is displayed so that one direction along the central axis is the ground direction at the time of observation, or The display surface of the video display element is configured in a conical shape, and the video displayed on the video display element is displayed along a central axis so that one direction is a ground direction at the time of observation, or the video display element It is desirable that the display surface is configured to have a spherical shape, and the image displayed on the image display element is displayed along the central axis so that one direction is the ground direction at the time of observation.

  The video display element having a three-dimensional display surface rotationally symmetric around the central axis is three-dimensionally configured by rounding a two-dimensional video display element and connecting ends. May be.

  Further, the display surface of the video display element may be formed of a plurality of planar display surfaces arranged in a cylindrical shape, or may be formed of a plurality of planar display surfaces arranged in a conical shape, or may be spherical. You may consist of the several planar display surface arrange | positioned.

  Moreover, it is desirable that the reflection surface has different powers in the meridional section and the sagittal section.

  The reflection surface may have a rotationally symmetric shape formed by rotating an arbitrarily shaped curve having no symmetry surface around a rotational symmetry axis.

  In this case, the reflecting surface may have a rotationally symmetric shape formed by rotating an arbitrarily shaped curve including an odd-order term around a rotational symmetry axis.

When half of the outer diameter of the reflecting surface is Rs,
20 mm <Rs (1)
It is desirable to satisfy the following conditions.

  In addition, an illuminating device that illuminates the entire display surface of the video display element from all directions opposite to the reflective surface side may be provided.

  According to the present invention, there is provided a visual display device capable of observing different desired observation images even when observing from the surrounding 360 ° direction without using a complicated mechanical rotation mechanism or the like. be able to.

  The visual display device of the present invention will be described below.

  First, the principle of the present invention will be described. When the concave mirror is a spherical mirror, the focal plane of the concave mirror is a spherical surface concentric with the concave mirror. Even if the concave mirror is not a perfect spherical mirror but a concave mirror that is rotationally symmetric about the central axis, the focal plane has a three-dimensional curved shape that is rotationally symmetric about the central axis. A real image of the display image of the image display element formed by the concave mirror by disposing an annular image display element arranged rotationally symmetrical around the central axis in the vicinity of the focal plane rotationally symmetrical around the central axis. Alternatively, the virtual image can be observed from any direction around 360 ° around the central axis, and since the image display element is ring-shaped, it can be seen from any direction around 360 ° around the concave mirror. It is possible to observe a real image or a virtual image of a corresponding display image portion of the annular image display element. This is the principle of the visual display device of the present invention.

  Hereinafter, description will be given with reference to the drawings. FIG. 1 is a sectional view (a) taken along the central axis of an optical system of a visual display device according to a first embodiment of the present invention to be described later, and a plane seen in a direction along the central axis showing an optical path in the optical system. FIG. 2 is an enlarged view of the main part of FIG. 1A, and FIG. 3 is an enlarged view of the main part of FIG. Hereinafter, the visual display device of the present invention will be described with reference to FIGS.

  In the optical system of the visual display device of the present invention, the concave mirror 2 is arranged concentrically with the central axis 1. In this embodiment, the concave mirror 2 is composed of an extended rotational free-form surface obtained by rotating a free curve having an odd-order term convex in the radial direction perpendicular to the central axis 1 around the central axis 1, and has a positive power. It is a concave mirror. The concave mirror 2 is not limited to a single concave mirror having a positive power, but may be a catadioptric system (for example, a Mangin mirror or a back mirror). As a requirement, the concave mirror 2 is positive for a light beam traveling toward the central axis 1. It is reflected by applying power and has a rotationally symmetric shape with respect to the central axis 1.

  An annular image display element 3 is arranged in a rotationally symmetrical manner around the central axis 1 on the eccentric reflection side of the concave mirror 2. The display image inside or outside the annular image display element 3 (in the embodiment shown in FIGS. 1 to 3, the annular image display element 3 has a cylindrical shape and inside thereof) is a concave mirror 2. The image 4 is formed as a rotationally symmetric image 4 around the central axis 1 (in the embodiment shown in FIGS. 1 to 3, formed as a real image), and the image 4 can be observed from a distant observation position (aperture) 5. Therefore, the real image or the virtual image 4 of the display image of the annular image display element 3 can be observed from any direction around 360 ° around the central axis 1, and the image display element 3 has an annular shape. In addition, it is possible to observe the real image or the virtual image 4 of the corresponding display image portion of the annular image display element 3 even if observed from any direction of 360 ° around the concave mirror 2.

  The display image of the video display element 3 may display, for example, a 360 ° panoramic landscape or a 36-view discrete video shot every 10 ° in the periphery.

  Further, as the ring-shaped image display element 3, the image display element 3 arranged in a ring shape on the inner surface or the outer surface of a cylindrical surface, a conical surface, or a spherical surface is used. Instead of the image display element 3 having the central axis 1 as a rotationally symmetric axis and having a continuous display surface on the inner surface or outer surface of the cylindrical surface, conical surface or spherical surface, a ring shape of the inner surface or outer surface of the cylindrical surface, conical surface or spherical surface You may use the image | video display element 3 formed by arrange | positioning a small planar display surface adjacently along an area | region.

  When the image display element is configured with a two-dimensional plane, the display surface is inclined with respect to the principal ray at the center of the image, and thus the observation image is tilted. Are also observed in the air, and the observation diopter changes within the observation image, making observation difficult. Therefore, in order to ensure a wide viewing zone, it is desirable that the image display element 3 has a three-dimensional display surface such as a cylindrical surface, a conical surface, or a spherical surface as described above.

  As described above, it is preferable that the rotational symmetry axis of the concave mirror 2 coincides with the rotational symmetry axis of the image display element 3. If this does not match, the position of the image 4 to be observed is not constant, and the image position fluctuates when observed around the central axis 1 and is difficult to observe.

  More preferably, by arranging the display surface of the image display element 3 in a cylindrical shape, the inclination of the image 4 is reduced particularly when observing from the direction close to the horizontal with the central axis 1 as the vertical direction, and a clear observation is possible. It becomes. It is also important for observing an upright image that the ground direction of the observation image is displayed so that one direction of the central axis 1 of the cylinder is downward.

  More preferably, by arranging the display surface of the image display element 3 in a conical shape, the inclination of the image 4 is reduced when viewed from an obliquely upward direction with the central axis 1 as the vertical direction, and a clear observation is possible. . Also, it is possible to display the observation image so that the ground direction faces the apex of the cone (the reverse when the entire apparatus is turned upside down), that is, when the display surface is expanded, the direction of the fan-shaped key is displayed. It is important to observe erect images.

  More preferably, by arranging the display surface of the video display element 3 in a spherical shape, the inclination of the image 4 is reduced in a wide observation range from horizontal to diagonally upward with the central axis 1 as the vertical direction, and clear observation is possible. It becomes possible. In addition, it is important for observing an erect image to display the observation image so that the ground direction faces the apex (the south pole of the earth) of the sphere (lower half sphere).

  More preferably, for example, on a columnar display surface, the image display element 3 can be formed by rounding a sheet-like display element. Similarly, in the case of a cone, a fan-shaped sheet-like display element is rounded. The video display element 3 can be configured. For example, it is preferable to use a flexible sheet-like organic EL display element or liquid crystal display element as an annular or conical display element because it can be manufactured at low cost.

  More preferably, even when the display surface is cylindrical, conical, or spherical, a plurality of two-dimensional (planar) display surfaces are continuously arranged in a cylindrical, conical, or spherical shape, thereby reducing the size. A plurality of display elements can be used, and a three-dimensional (three-dimensionally arranged) video display element 3 can be realized at low cost.

  More preferably, it is desirable that the rotationally symmetric reflecting surface 2 is configured so that the power differs between the sagittal surface and the tangential surface. This is particularly important in the case of an optical system that observes from 360 ° in all directions as in the present invention. In the case where the optical system is configured by the reflecting surface 2, since the light beam is incident on the optical system with the rotational symmetry axis (center axis) 1 in between, the reflecting surface on the opposite side with the rotational symmetry axis 1 in between is not obstructed. In order to make a light ray incident, it is necessary to make the light ray incident obliquely from above. In other words, it is essential that the light beam be used eccentrically with respect to the reflecting surface 2. Further, in order to widen the observation region (observable position) 5 or to increase the observation image (image height) 3, a large amount of decentration aberration is generated due to decentration. Therefore, in order to correct the decentration aberration caused by such decentration, the decentering aberration can be corrected by forming the reflecting surface 2 with different curvatures on the sagittal surface and the meridional surface.

  More preferably, the reflecting surface 2 has a rotationally symmetric shape formed by rotating an arbitrary-shaped curve having no symmetric surface around the rotational symmetry axis 1, thereby further reducing the occurrence of decentration aberrations. Is possible. In particular, coma generated by decentration can be corrected.

  More preferably, the reflecting surface 2 has a rotationally symmetric shape formed by rotating an arbitrary-shaped curve including an odd-order term around the rotational symmetry axis, so that correction with a higher degree of freedom can be performed. This is preferable in terms of aberration correction.

More preferably, when Rs is half of the outer diameter of the reflecting surface 2 (the outer diameter in the direction perpendicular to the rotational symmetry axis 1),
20 mm <Rs (1)
It is desirable to satisfy the following conditions. If the lower limit of 20 mm is exceeded, the observation image becomes small, and it becomes difficult to make a realistic observation.

More preferably,
50 mm <Rs (1-1)
Satisfying these conditions is preferable for obtaining a sense of reality.

  In addition, Rs of Examples 1-4 described below is as follows.

Example 1 2 3 4
Rs (mm) 25.0 25.0 25.0 25.0
More preferably, the display image displayed on the image display element 3 is preferably a 360 ° panoramic image continuously displayed on the circumference. Accordingly, it is possible to continuously observe a 360 ° panoramic image from an arbitrary viewpoint of 360 °.

  More preferably, it is preferable to display a multi-viewpoint image obtained by photographing an object from a plurality of viewpoints on each display element of the video display element 3 in which a plurality of display elements are arranged adjacent to each other in a ring shape. Thereby, it is possible to observe an image from an arbitrary viewpoint of 360 °.

  Examples 1 to 4 of the optical system of the visual display device of the present invention will be described below. The configuration parameters of these optical systems will be described later. For example, as shown in FIG. 1, the configuration parameters of these embodiments are such that the object plane is the plane of the image 4, the image plane conjugate with the image 4 is the video display device (display plane) 3, and the aperture (observation position) 5 is set. And a ray tracing that passes through a reference plane (the origin of coordinates (X, Y, Z)) that includes the central axis 1 and that travels toward the object plane 4 is reflected by the concave mirror 2 and reaches the image plane 3. Based on the results.

  For example, as shown in FIG. 2, the coordinate system uses the reference plane position projected on the center axis 1 as the origin of the decentered optical surface of the decentered optical system, and the concave mirror 2 with the center axis 1 as shown in FIG. The side direction is the Y-axis positive direction, and the inside of the paper surface of FIG. 2 is the YZ plane. The direction on the reflection position side of the concave mirror 2 in FIG. 2 is the Z axis positive direction, and the Y axis, the Z axis, and the axis constituting the right-handed orthogonal coordinate system are the X axis positive direction.

  For the decentered surface, the amount of decentering from the center of the origin of the optical system in the coordinate system in which the surface is defined (X-axis direction, Y-axis direction, and Z-axis direction are X, Y, and Z, respectively) and the optical system The inclination angles (α, β, γ (°), respectively) of the coordinate system defining each surface centered on the X axis, Y axis, and Z axis of the coordinate system defined at the origin are given. In this case, positive α and β mean counterclockwise rotation with respect to the positive direction of each axis, and positive γ means clockwise rotation with respect to the positive direction of the Z axis. Note that the α, β, and γ rotations of the central axis of the surface are performed by rotating the coordinate system defining each surface counterclockwise around the X axis of the coordinate system defined at the origin of the optical system. Then rotate it around the Y axis of the new rotated coordinate system by β and then rotate it around the Z axis of another rotated new coordinate system by γ. It is.

  Further, among the optical action surfaces constituting the optical system of each embodiment, when a specific surface and a subsequent surface constitute a coaxial optical system, a surface interval is given, in addition, the curvature radius of the surface, The refractive index and Abbe number of the medium are given according to conventional methods.

  The extended rotation free-form surface is a rotationally symmetric surface given by the following definition.

  First, the following curve (d) passing through the origin on the YZ coordinate plane is determined.

^{Z = (Y 2 / RY)} / [1+ {1- (C 1 +1) Y 2 / RY 2} 1/2]
C ₂ Y + C ₃ Y ² + C ₄ Y ³ + C ₅ Y ⁴ + C ₆ Y ⁵ + C ₇ Y ⁶
+ ··· + C ₂₁ Y ²⁰ + ··· + C _{n + 1} Y ⁿ + ····
... (d)
Next, a curve F (Y) obtained by rotating the curve (d) in the positive direction of the X axis and turning it counterclockwise to be positive is determined. This curve F (Y) also passes through the origin on the YZ coordinate plane.

  The curve F (Y) is translated in the positive Z direction by a distance R (or negative Z direction if negative), and then the rotationally symmetric surface formed by rotating the translated curve around the Y axis is expanded and rotated. Let it be a free-form surface.

  As a result, the extended rotation free-form surface becomes a free-form surface (free-form curve) in the YZ plane and a circle with a radius | R | in the XZ plane.

  From this definition, the Y-axis becomes the axis of the extended rotation free-form surface (rotation symmetry axis).

Where RY is the radius of curvature of the spherical term in the YZ section, C ₁ is the conic constant, C ₂ , C ₃ , C ₄ , C ₅ . Aspheric coefficient.

A conical surface having an axis parallel to the Y axis as a central axis is given as one of the extended rotation free-form surfaces, and RY = ∞, C ₁ , C ₂ , C ₃ , C ₄ , C ₅ ,. , Θ = (conical surface inclination angle), R = (radius of bottom surface in XZ plane).

  In addition, a term relating to an aspheric surface for which no data is described in the constituent parameters described later is zero. The refractive index and the Abbe number are shown for the d-line (wavelength 587.56 nm). The unit of length is mm. As described above, the eccentricity of each surface is expressed by the amount of eccentricity from the reference surface.

  FIG. 1 is a cross-sectional view taken along the central axis 1 of the optical system of the visual display device of Example 1 and a plan view (b) seen in the direction along the central axis 1 showing the optical path in the optical system. FIG. 2 is an enlarged view of the main part of FIG. 1 (a), and FIG. 3 is an enlarged view of the main part of FIG. 1 (b). Further, FIG. 4 shows a lateral aberration diagram of the entire optical system of this example. In this lateral aberration diagram, the angle shown at the center indicates (horizontal field angle, vertical field angle), and the lateral aberrations in the Y direction (meridional direction) and X direction (sagittal direction) at that field angle. Show. Note that a negative field angle means a clockwise angle in the Y-axis positive direction for the horizontal field angle, and a clockwise angle in the X-axis positive direction for the vertical field angle. same as below.

  In this embodiment, the concave mirror 2 is composed of an extended rotation free-form surface obtained by rotating a free curve having an odd-order term convex in the radial direction perpendicular to the central axis 1 around the central axis 1 and has a positive power. is there. An annular and cylindrical image display element 3 is arranged coaxially with the central axis 1 of the concave mirror 2, and the inside of the cylindrical image display element 3 constitutes a display surface, and the display surface is In this embodiment, the emitted light beam is reflected by the concave mirror 2, and an image 4 is formed as a real image at a cylindrical position conjugate with the display surface and having the central axis 1 as the central axis. Therefore, when the central axis 1 is a vertical axis, when an observer sees the obliquely lower side through the central axis 1 through the obliquely upper observation position (aperture) 5 around the central axis 1, an image display corresponding to that direction is displayed. An aerial image 4 of the display image on the display surface of the element 3 can be seen. Therefore, even if the observer looks obliquely downward from any position around the central axis 1 obliquely above the central axis 1, an aerial real image of the display image portion of the display surface of the video display element 3 corresponding to that direction. Therefore, even if the observer observes from any direction of 360 ° around the central axis 1, a display image portion corresponding to that direction of the annular display element arranged on the image plane 3 The image 4 can be observed.

The specification of this Example 1 is
Pupil diameter φ100.00mm
Display size X9.09mm x Y9.98mm
Image size □ 6mm × 6mm
It is.

  FIG. 5 is a cross-sectional view (a) taken along the central axis 1 of the optical system of the visual display device of Example 2 and a plan view (b) seen in the direction along the central axis 1 showing the optical path in the optical system. FIG. 6 is an enlarged view of the main part of FIG. 5 (a), and FIG. 7 is an enlarged view of the main part of FIG. 5 (b). Further, FIG. 8 shows a lateral aberration diagram of the entire optical system of this example.

  In this embodiment, the concave mirror 2 is composed of an extended rotation free-form surface obtained by rotating a free curve having an odd-order term convex in the radial direction perpendicular to the central axis 1 around the central axis 1 and has a positive power. is there. An annular and cylindrical image display element 3 is arranged coaxially with the central axis 1 of the concave mirror 2, and the outside of the cylindrical image display element 3 constitutes a display surface. In this embodiment, the emitted light is reflected by the concave mirror 2 and an image 4 enlarged as a real image is formed at a cylindrical position conjugate with the display surface and having the central axis 1 as the central axis. Therefore, when the central axis 1 is a vertical axis, when an observer sees the obliquely lower side through the central axis 1 through the obliquely upper observation position (aperture) 5 around the central axis 1, an image display corresponding to that direction is displayed. A magnified aerial image 4 of the display image on the display surface of the element 3 can be seen. Therefore, even if the observer looks obliquely downward from any position around the central axis 1 obliquely above the central axis 1, the display image portion of the display surface of the video display element 3 corresponding to that direction is enlarged. A real aerial image can be seen, and therefore, even if the observer observes from any direction of 360 ° around the central axis 1, it corresponds to that direction of the annular display element arranged on the image plane 3. An enlarged image 4 of the display image portion can be observed.

The specification of Example 2 is
Pupil diameter φ65.00mm
Display size X 2.18mm x Y 2.20mm
Image size □ 6mm × 6mm
It is.

  FIG. 9 is a cross-sectional view (a) taken along the central axis 1 of the optical system of the visual display device of Example 3 and a plan view (b) seen in the direction along the central axis 1 showing the optical path in the optical system. FIG. 10 is an enlarged view of the main part of FIG. 9A, and FIG. 11 is an enlarged view of the main part of FIG. 9B. Further, FIG. 12 shows a lateral aberration diagram of the entire optical system of this example.

  In this embodiment, the concave mirror 2 is composed of an extended rotation free-form surface obtained by rotating a free curve having an odd-order term convex in the radial direction perpendicular to the central axis 1 around the central axis 1 and has a positive power. is there. An annular and conical image display element 3 is arranged coaxially with the central axis 1 of the concave mirror 2, and the outside of the conical image display element 3 constitutes a display surface, and the display surface is In this embodiment, the emitted light is reflected by the concave mirror 2 and an image 4 enlarged as a real image is formed at a cylindrical position conjugate with the display surface and having the central axis 1 as the central axis. Therefore, when the central axis 1 is a vertical axis, when an observer sees the obliquely lower side through the central axis 1 through the obliquely upper observation position (aperture) 5 around the central axis 1, an image display corresponding to that direction is displayed. A magnified aerial image 4 of the display image on the display surface of the element 3 can be seen. Therefore, even if the observer looks obliquely downward from any position around the central axis 1 obliquely above the central axis 1, the display image portion of the display surface of the video display element 3 corresponding to that direction is enlarged. A real aerial image can be seen, and therefore, even if the observer observes from any direction of 360 ° around the central axis 1, it corresponds to that direction of the annular display element arranged on the image plane 3. An enlarged image 4 of the display image portion can be observed.

The specification of this Example 3 is
Pupil diameter φ65.00mm
Display size X 2.45mm x Y 2.47mm
Image size □ 6mm × 6mm
It is.
.

  FIG. 13 is a cross-sectional view (a) taken along the central axis 1 of the optical system of the visual display device of Example 4 and a plan view (b) seen in the direction along the central axis 1 showing the optical path in the optical system. FIG. 14 is an enlarged view of the main part of FIG. 13 (a), and FIG. 15 is an enlarged view of the main part of FIG. 13 (b). Further, FIG. 16 shows a lateral aberration diagram of the entire optical system of this example.

  In this embodiment, the concave mirror 2 is composed of an extended rotation free-form surface obtained by rotating a free curve having an odd-order term convex in the radial direction perpendicular to the central axis 1 around the central axis 1 and has a positive power. is there. An annular and cylindrical image display element 3 is arranged coaxially with the central axis 1 of the concave mirror 2, and the outside of the cylindrical image display element 3 constitutes a display surface. In this embodiment, the emitted light beam is reflected by the concave mirror 2 and an image 4 enlarged as a virtual image is formed at a cylindrical position conjugate with the display surface and having the central axis 1 as the central axis. Therefore, when the central axis 1 is a vertical axis, when an observer sees the obliquely lower side through the central axis 1 through the obliquely upper observation position (aperture) 5 around the central axis 1, an image display corresponding to that direction is displayed. An enlarged virtual image 4 of the display image on the display surface of the element 3 can be seen. Therefore, even if the observer looks obliquely downward from any position around the central axis 1 obliquely above the central axis 1, the display image portion of the display surface of the video display element 3 corresponding to that direction is enlarged. Therefore, even if the observer observes from any direction of 360 ° around the central axis 1, it corresponds to the direction of the annular display element arranged on the image plane 3. An enlarged image 4 of the display image portion can be observed.

The specification of this Example 4 is
Pupil diameter 32.50mm
Display size X2.03mm × Y2.06mm
Image size □ 6mm × 6mm
It is.

  The configuration parameters of Examples 1 to 4 are shown below. In the table below, “ERFS” indicates an extended rotation free-form surface, and “RS” indicates a reflective surface.

Example 1
Surface number Curvature radius Surface spacing Eccentricity Refractive index Abbe number Object surface Cylindrical surface [1] Eccentricity (1)
1 ∞ (diaphragm surface) Eccentricity (2)
2 ∞ (reference plane)
3 ERFS [1] (RS) Eccentricity (3)
Image plane Cylindrical surface [2] Eccentricity (4)
Cylindrical surface [1]
X direction radius of curvature -5.00
Y direction radius of curvature ∞
Cylindrical surface [2]
X direction radius of curvature 7.55
Y direction radius of curvature ∞
ERFS [1]
RY -28.04
θ 0.00
R 25.00
C ₄ 1.0484 × 10 ^-4
C ₅ -7.1424 × 10 ^-8
Eccentricity (1)
X 0.00 Y 0.00 Z 5.00
α 0.00 β 0.00 γ 0.00
Eccentricity (2)
X 0.00 Y 109.00 Z -300.00
α 0.00 β 0.00 γ 0.00
Eccentricity (3)
X 0.00 Y -7.15 Z 0.00
α 0.00 β 0.00 γ 0.00
Eccentricity (4)
X 0.00 Y -18.78 Z -7.55
α 0.00 β 0.00 γ 0.00.

Example 2
Surface number Curvature radius Surface spacing Eccentricity Refractive index Abbe number Object surface Cylindrical surface [1] Eccentricity (1)
1 ∞ (diaphragm surface) Eccentricity (2)
2 ∞ (reference plane)
3 ERFS [1] (RS) Eccentricity (3)
Image plane Cylindrical surface [2] Eccentricity (4)
Cylindrical surface [1]
X direction radius of curvature 20.00
Y direction radius of curvature ∞
Cylindrical surface [2]
X direction radius of curvature -8.27
Y direction radius of curvature ∞
ERFS [1]
RY -28.41
θ 0.00
R 25.00
C ₄ 1.7888 × 10 ^-4
C ₅ -2.1802 × 10 ^-7
Eccentricity (1)
X 0.00 Y 0.00 Z -20.00
α 0.00 β 0.00 γ 0.00
Eccentricity (2)
X 0.00 Y 109.00 Z -300.00
α 0.00 β 0.00 γ 0.00
Eccentricity (3)
X 0.00 Y -17.52 Z 0.00
α 0.00 β 0.00 γ 0.00
Eccentricity (4)
X 0.00 Y -24.03 Z 8.27
α 0.00 β 0.00 γ 0.00.

Example 3
Surface number Curvature radius Surface spacing Eccentricity Refractive index Abbe number Object surface Cylindrical surface [1] Eccentricity (1)
1 ∞ (diaphragm surface) Eccentricity (2)
2 ∞ (reference plane)
3 ERFS [1] (RS) Eccentricity (3)
Image surface ERFS [2] Eccentricity (4)
Cylindrical surface [1]
X direction radius of curvature 25.00
Y direction radius of curvature ∞
ERFS [1]
RY -32.11
θ -33.00
R 25.00
C ₄ -7.5923 × 10 ^-5
C ₅ 1.5229 × 10 ^-6
ERFS [2]
RY ∞
θ -54.01
R 10.91
Eccentricity (1)
X 0.00 Y 0.00 Z -25.00
α 0.00 β 0.00 γ 0.00
Eccentricity (2)
X 0.00 Y 100.00 Z -300.00
α 0.00 β 0.00 γ 0.00
Eccentricity (3)
X 0.00 Y -14.55 Z 0.00
α 0.00 β 0.00 γ 0.00
Eccentricity (4)
X 0.00 Y 2.11 Z 0.00
α 0.00 β 0.00 γ 0.00.

Example 4
Surface number Curvature radius Surface spacing Eccentricity Refractive index Abbe number Object surface Cylindrical surface [1] Eccentricity (1)
1 ∞ (diaphragm surface) Eccentricity (2)
2 ∞ (reference plane)
3 ERFS [1] (RS) Eccentricity (3)
Image plane Cylindrical surface [2] Eccentricity (4)
Cylindrical surface [1]
X direction radius of curvature -50.00
Y direction radius of curvature ∞
Cylindrical surface [2]
X direction radius of curvature -16.78
Y direction radius of curvature ∞
ERFS [1]
RY -31.27
θ 0.00
R 25.00
C ₄ 4.0864 × 10 ^-4
C ₅ -8.9244 × 10 ^-6
Eccentricity (1)
X 0.00 Y 0.00 Z 50.00
α 0.00 β 0.00 γ 0.00
Eccentricity (2)
X 0.00 Y 100.00 Z -150.00
α 0.00 β 0.00 γ 0.00
Eccentricity (3)
X 0.00 Y 12.50 Z 0.00
α 0.00 β 0.00 γ 0.00
Eccentricity (4)
X 0.00 Y 8.39 Z 16.78
α 0.00 β 0.00 γ 0.00.

  In the optical system of the visual display device of the present invention, the concave mirror 2 that is rotationally symmetric about the central axis 1 is used as it is, so that the annular image display element 3 can be viewed from all directions around 360 ° around the concave mirror 2. A real image or a virtual image 4 of the display image can be observed, but the concave mirror 2 is cut by a section including the central axis 1 to make it half, one third, two thirds, etc. Of course, the enlarged virtual image may be observed in the surrounding angular range of 180 °, 120 °, 240 °, or the like.

  By the way, as the annular image display element 3 having a three-dimensional display surface of the present invention, the image display element 3 having a continuous display surface on the inner surface or outer surface of a cylindrical surface, a conical surface, or a spherical surface is used. it can. In FIG. 17A, when the outer surface of the cylindrical image display element 3 is used as in the second embodiment, the display surface 15 of the image display element 3 is configured by a display element having a continuous cylindrical surface. It is a figure which shows a case. Instead, as described above, in this example, as shown in FIG. 17 (b), a small planar display surface 16 is disposed adjacent to the annular zone on the outer surface of the cylindrical surface. The video display element 3 may be configured.

  In addition, it is desirable to arrange a light shielding member in a region where the light beam of the rotationally symmetric optical system of the visual display device of the present invention does not pass. FIG. 18 is a cross-sectional view taken along the central axis 1 of the example, and is an example in which an illuminating device for illuminating the image display element 3 from the back surface (cylindrical outer surface) in all directions is arranged in the configuration of the first embodiment. . In this case, a linear light source 12 is disposed on the central axis 1, and has a positive power in a sectional view including the central axis 1 as a condensing optical system around it. 13 is arranged, and the illumination light emitted from the line light source 12 is reflected again toward the central axis 1 by the ring-shaped condenser mirror 13, and the cylindrical image display element 3 is arranged in the reflected light path, The illumination device of the visual display device of Example 1 is configured. With such a configuration, the illumination light is limited within the meridional cross section including the central axis 1 and can illuminate the video display element 3, and an image with good contrast can be observed.

  In this example, the light blocking member 11 that restricts the display light from the concave mirror 2 made of a rotationally symmetric reflecting mirror, and the illumination light that reaches the image display element 3 from the line light source 12 via the ring-shaped condensing mirror 13 are used. The light shielding member 11 ′ to be restricted is arranged symmetrically about the central axis 1 as shown in the figure.

  FIG. 19 is a cross-sectional view taken along the central axis 1 of an example in which an illuminating device that illuminates the image display element 3 in all directions from the back surface (cylindrical inner surface) is arranged in the configuration of the second embodiment. Also in this case, the linear light source 12 is disposed on the central axis 1 and has an eccentric power which has a positive power in the sectional view including the central axis 1 as a condensing optical system around the central axis 1 and is rotationally symmetric around the central axis 1. The ring-shaped condensing lens 14 is arranged, and the illumination light emitted from one point of the line light source 12 passes through the ring-shaped condensing lens 14 and becomes substantially parallel in the cross-sectional view including the central axis 1. It is a Koehler illumination, and it has a uniform illumination. In addition, the illumination light emitted from the line light source 12 is limited only within the cross section including the central axis 1 and there is no light of the sagittal cross section, so there is no light that causes flare. Therefore, an enlarged image with little unevenness and good contrast can be observed. Also in this embodiment, the same light shielding members 11 and 11 'as those in FIG. 18 are arranged.

  FIG. 20 is a cross-sectional view taken along the central axis 1 of an example in which an illuminating device that illuminates the image display element 3 in all directions from the back surface (the inner surface of the cone) is arranged in the configuration of the third embodiment. Also in this case, a line light source 12 is arranged on the central axis 1, and has a positive power in a sectional view including the central axis 1 as a condensing optical system around the linear light source 12, and a rotationally symmetric ring shape around the central axis 1. A condensing Fresnel lens system 17 is disposed, and the illumination light emitted from one point of the line light source 12 passes through the ring-shaped condensing Fresnel lens system 17 and becomes substantially parallel in the cross-sectional view including the central axis 1. No. 3 is illuminated and is Koehler illumination, providing uniform illumination. In addition, the illumination light emitted from the line light source 12 is limited only within the cross section including the central axis 1 and there is no light of the sagittal cross section, so there is no light that causes flare. Therefore, an enlarged image with little unevenness and good contrast can be observed. Also in this embodiment, the same light shielding members 11 and 11 'as those in FIG. 18 are arranged.

  FIG. 21 is a cross-sectional view taken along the central axis 1 of an example in which another illuminating device that illuminates the image display element 3 in all directions from the back surface (conical inner surface) is arranged in the configuration of the third embodiment. As a lighting device in this case, a ring-shaped ring-shaped light emitter 18 centering on the central axis 1 is used, and the illumination light emitted from the ring-shaped light emitter 18 is displayed within the cross section including the central axis 1. FIG. 6 is a diagram showing an example in which a ring-shaped reflecting mirror 19 that condenses in a direction is arranged inside a ring-shaped light emitter 18 with a central axis 1 as the center, and the conical image display element 3 is condensed and illuminated from the inside. In this configuration, in order to increase the contrast of the observation image, a means such as a viewing angle limiting filter or a louver 20 is connected to the ring so as to limit the light emitted from the image display element 3 within the cross section including the central axis 1. It is preferable to dispose between the light emitter 18 and the image display element 3.

It is sectional drawing (a) taken along the central axis of the optical system of the visual display apparatus of Example 1 of this invention, and the top view (b) seen in the direction along the central axis which shows the optical path in the optical system. . It is an enlarged view of the principal part of Fig.1 (a). It is an enlarged view of the principal part of FIG.1 (b). 2 is a transverse aberration diagram for the whole optical system of Example 1. FIG. It is a figure similar to FIG. 1 of the optical system of the visual display apparatus of Example 2 of this invention. It is an enlarged view of the principal part of Fig.5 (a). It is an enlarged view of the principal part of FIG.5 (b). FIG. 6 is a transverse aberration diagram for the whole optical system of Example 2. It is a figure similar to FIG. 1 of the optical system of the visual display apparatus of Example 3 of this invention. It is an enlarged view of the principal part of Fig.9 (a). It is an enlarged view of the principal part of FIG.9 (b). 5 is a lateral aberration diagram for the whole optical system of Example 3. FIG. It is a figure similar to FIG. 1 of the optical system of the visual display apparatus of Example 4 of this invention. It is an enlarged view of the principal part of Fig.13 (a). It is an enlarged view of the principal part of FIG.13 (b). 10 is a transverse aberration diagram for the whole optical system of Example 4. FIG. It is a figure which shows the case where (a) comprised a cylindrical video display element by the display element which has a continuous cylindrical surface, and the case (b) comprised by arrange | positioning a planar small display surface adjacently. It is a figure which shows the example which has arrange | positioned the illuminating device which illuminates a video display element in all directions from a back surface in the structure of Example 1. FIG. It is a figure which shows the example which has arrange | positioned the illuminating device which illuminates a video display element in all directions from a back surface in the structure of Example 2. FIG. It is a figure which shows the example which has arrange | positioned the illuminating device which illuminates a video display element in all directions from a back surface in the structure of Example 3. FIG. It is a figure which shows the example which has arrange | positioned another illuminating device which illuminates a video display element in all directions from a back surface in the structure of Example 3. FIG.

Explanation of symbols

1 ... center axis 2 ... concave mirror (reflecting surface)
3. Image display element 4. Display image (real image, virtual image)
5 ... Observation position, observation area (aperture)
DESCRIPTION OF SYMBOLS 11, 11 '... Shading member 12 ... Line light source 13 ... Ring-shaped condensing mirror 14 ... Ring-shaped condensing lens 15 ... Display surface 16 ... Planar small display surface 17 ... Ring-shaped condensing Fresnel lens system 18 ... Ring shape Luminescent body 19 ... Ring-shaped reflector 20 ... Viewing angle limiting filter (louver)

Claims (15)

A positive power reflecting surface obtained by rotating a curved line including a convex portion in a radial direction perpendicular to the central axis in a plane including the central axis, along a curved image surface of the reflecting surface. What is claimed is: 1. A visual display device comprising: a ring-shaped image display element arranged rotationally symmetrically about a central axis. 2. The visual display device according to claim 1, wherein the image display element has a three-dimensional display surface rotationally symmetric about a central axis. 3. The visual display device according to claim 1, wherein a rotational symmetry axis of the reflecting surface coincides with a rotational symmetry axis of the video display element. A display surface of the video display element is formed in a cylindrical shape, and an image displayed on the video display element is displayed along a central axis so that one direction is a ground direction at the time of observation. The visual display device according to claim 1. The display surface of the image display element is configured in a conical shape, and an image displayed on the image display element is displayed along a central axis so that one direction is a ground direction at the time of observation. The visual display device according to claim 1. The display surface of the image display element is formed in a spherical shape, and an image displayed on the image display element is displayed along the central axis so that one direction is a ground direction at the time of observation. The visual display device according to claim 1. The video display element having a three-dimensional display surface rotationally symmetric about the central axis is three-dimensionally configured by rounding a two-dimensional video display element and connecting ends. The visual display device according to any one of claims 2, 4, and 5. The visual display device according to claim 4, wherein the display surface of the video display element includes a plurality of planar display surfaces arranged in a cylindrical shape. 6. The visual display device according to claim 5, wherein the display surface of the video display element is composed of a plurality of flat display surfaces arranged in a conical shape. The visual display device according to claim 6, wherein the display surface of the video display element includes a plurality of planar display surfaces arranged in a spherical shape. The visual display device according to claim 1, wherein the reflective surface has different powers in a meridional section and a sagittal section. 12. The reflection surface according to claim 1, wherein the reflection surface has a rotationally symmetric shape formed by rotating an arbitrarily shaped curve having no symmetry surface around a rotational symmetry axis. Visual display device. The visual display device according to claim 12, wherein the reflection surface has a rotationally symmetric shape formed by rotating an arbitrarily shaped curve including an odd-order term around a rotational symmetry axis. When half of the outer diameter of the reflecting surface is Rs,
20 mm <Rs (1)
The visual display device according to claim 1, wherein the following condition is satisfied. The visual display device according to claim 1, further comprising an illumination device that illuminates the entire display surface of the video display element from all directions opposite to the reflection surface side.

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