WO2021106335A1 - Optical device for virtual image display, virtual image display system, and moving body - Google Patents

Optical device for virtual image display, virtual image display system, and moving body Download PDF

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Publication number
WO2021106335A1
WO2021106335A1 PCT/JP2020/035620 JP2020035620W WO2021106335A1 WO 2021106335 A1 WO2021106335 A1 WO 2021106335A1 JP 2020035620 W JP2020035620 W JP 2020035620W WO 2021106335 A1 WO2021106335 A1 WO 2021106335A1
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WO
WIPO (PCT)
Prior art keywords
virtual image
image display
curvature
radius
optical device
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PCT/JP2020/035620
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French (fr)
Japanese (ja)
Inventor
智明 宮本
崇人 羽田
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パナソニックＩｐマネジメント株式会社
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Publication of WO2021106335A1 publication Critical patent/WO2021106335A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K35/00—Arrangement of adaptations of instruments
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R11/00—Arrangements for holding or mounting articles, not otherwise provided for
    • B60R11/02—Arrangements for holding or mounting articles, not otherwise provided for for radio sets, television sets, telephones, or the like; Arrangement of controls thereof
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01—Head-up displays

Definitions

  • the present disclosure relates to an optical device for displaying a virtual image, a virtual image display system, and a moving body. More specifically, the present disclosure relates to a virtual image display optical device for displaying a virtual image, a virtual image display system including the virtual image display optical device, and a moving body including the virtual image display system.
  • Patent Document 1 discloses a head-up display device having high visibility of a virtual image.
  • a virtual image display system that displays a virtual image such as the head-up display device described in Patent Document 1, is required to be miniaturized, but there is a problem that the distortion of the virtual image increases with the miniaturization. Further, there is a problem that the light rays passing around the visible visible area of the person observing the virtual image (observer) are blocked by the elements constituting the virtual image display system, and the visible area becomes small.
  • the present disclosure provides a virtual image display optical device, a virtual image display system, and a moving body that can reduce distortion of a virtual image while reducing the size and secure a sufficient visible area that can be visually recognized by an observer.
  • the virtual image display optical device includes a projected member that is displayed by the image display device and on which a displayed image reflected by the reflecting surface of the reflecting member is projected, and is separated from the projected member.
  • a virtual image of the displayed image is displayed at the position.
  • the projected member has a facing surface facing the reflecting surface. The vicinity of the center of the facing surface is formed in a curved surface shape that protrudes in a direction away from the reflecting surface. The vicinity of the center of the reflecting surface is formed in a curved surface shape that protrudes toward the image display device.
  • the minimum value of the first radius of curvature which is the radius of curvature in the left-right direction as seen by the observer observing the virtual image
  • R1 the minimum value of the first radius of curvature
  • R2 the minimum value of the second radius of curvature
  • the virtual image display optical device includes a projected member that is displayed by the image display device and on which a displayed image reflected by the reflecting surface of the reflecting member is projected, and is separated from the projected member.
  • a virtual image of the displayed image is displayed at the position.
  • the projected member has a facing surface facing the reflecting surface. The vicinity of the center of the facing surface is formed in a curved surface shape that protrudes in a direction away from the reflecting surface. The vicinity of the center of the reflecting surface is formed in a curved surface shape that protrudes toward the image display device.
  • the minimum value of the third radius of curvature which is the radius of curvature in the vertical direction as seen by the observer observing the virtual image, is defined as R3.
  • the minimum value of the fourth radius of curvature which is the radius of curvature in the vertical direction, is R4. At this time, the condition of 1.63 ⁇ R4 / R3 ⁇ 6.00 is satisfied.
  • the virtual image display optical device includes a projected member that is displayed by the image display device and on which a displayed image reflected by the reflecting surface of the reflecting member is projected, and is separated from the projected member.
  • a virtual image of the displayed image is displayed at the position.
  • the projected member has a facing surface facing the reflecting surface.
  • the vicinity of the center of the facing surface is formed in a curved surface shape that protrudes in a direction away from the reflecting surface.
  • the vicinity of the center of the reflecting surface is formed in a curved surface shape that protrudes toward the image display device.
  • the width of the visible area in the left-right direction as seen by the observer is defined as EB1.
  • the radius of curvature of the facing surfaces in the left-right direction as seen by the observer is R5. At this time, the condition of 0.1 ⁇ EB1 / R5 ⁇ 0.7 is satisfied.
  • the virtual image display optical device includes a projected member that is displayed by the image display device and on which a displayed image reflected by the reflecting surface of the reflecting member is projected, and is separated from the projected member.
  • a virtual image of the displayed image is displayed at the position.
  • the projected member has a facing surface facing the reflecting surface. At least near the center of the facing surface is formed in a curved surface shape that protrudes in a direction away from the reflecting surface. At least near the center of the reflective surface is formed in a curved surface shape that protrudes toward the image display device.
  • the width of the visible area in the vertical direction as seen by the observer is defined as EB2.
  • the radius of curvature of the facing surfaces in the vertical direction as seen by the observer is R6. At this time, the condition of 0.05 ⁇ EB2 / R6 ⁇ 0.25 is satisfied.
  • the virtual image display system includes the image display device and the virtual image display optical device.
  • the moving body according to one aspect of the present disclosure has a virtual image display system.
  • FIG. 1 is a schematic configuration diagram of a virtual image display optical device, a virtual image display system, and a moving body according to the embodiment of the present disclosure.
  • FIG. 2 is a schematic view of the above-mentioned virtual image display system.
  • FIG. 3 is a schematic configuration diagram of an image display device in the above-mentioned virtual image display system.
  • FIG. 4 is a schematic view showing a cross section of the projected member in the left-right direction in the above-mentioned optical device for displaying a virtual image.
  • FIG. 5 is a schematic view showing a vertical cross section of the projected member in the above-mentioned optical device for displaying a virtual image.
  • FIG. 1 is a schematic configuration diagram of a virtual image display optical device, a virtual image display system, and a moving body according to the embodiment of the present disclosure.
  • FIG. 2 is a schematic view of the above-mentioned virtual image display system.
  • FIG. 3 is a schematic configuration diagram of an image display device in the
  • FIG. 6 is a schematic view showing a cross section of the reflecting member in the left-right direction in the above-mentioned optical device for displaying a virtual image.
  • FIG. 7 is a schematic view showing a vertical cross section of the reflecting member in the above-mentioned optical device for displaying a virtual image.
  • FIG. 8 is an explanatory diagram for explaining the relationship between the numerical embodiment of the above-mentioned virtual image display optical device and the condition 1.
  • FIG. 9 is an explanatory diagram for explaining the relationship between the numerical embodiment of the virtual image display optical device and the condition 2.
  • FIG. 10 is an explanatory diagram for explaining the relationship between the numerical embodiment of the above-mentioned virtual image display optical device and the condition 3.
  • FIG. 11 is an explanatory diagram for explaining the relationship between the numerical embodiment of the above-mentioned virtual image display optical device and the condition 4.
  • the virtual image display optical device 2, the virtual image display system 1, and the moving body 4 according to the embodiment of the present disclosure will be described in detail with reference to the drawings.
  • each figure described in the following embodiment is a schematic view, and the respective ratio of the size and the thickness of each component does not necessarily reflect the actual dimensional ratio.
  • the configuration described in the following embodiments is only an example of the present disclosure.
  • the present disclosure is not limited to the following embodiments, and various changes can be made depending on the design and the like as long as the effects of the present disclosure can be achieved.
  • the virtual image display system 1 (hereinafter, abbreviated as virtual image display system 1) according to the embodiment is a head-up display device mounted on the automobile 4 (see FIGS. 1 and 2).
  • the automobile 4 corresponding to the moving body according to the embodiment includes vehicles such as passenger cars, trucks, buses, motorcycles (motorcycles), and trains.
  • the moving body according to the embodiment may be a vehicle on which a person rides and is driven, for example, a ship navigating on water, an airplane, or the like.
  • the head-up display device (virtual image display system 1) is installed on the dashboard 40 of the automobile 4 (see FIG. 1).
  • the virtual image display system 1 projects a display image on a projected member 20 arranged on the dashboard 40.
  • the virtual image display system may be a so-called far-view electronic rear-view mirror that projects an image of the rear of the vehicle captured by the TV camera onto a projected member arranged at the position of the rear-view mirror in the vehicle.
  • the projected member 20 is formed in a plate shape by at least a material capable of transmitting visible light, for example, a synthetic resin material such as glass or an acrylic resin or a polycarbonate resin.
  • a projected member 20 may be called a combiner.
  • the virtual image display system 1 By projecting the display image onto the projected member 20, the virtual image display system 1 displays the display image at a position in front of the windshield 41 of the automobile 4 (in front of the outside of the automobile 4) as seen from the driver 6 who is the observer. It forms a virtual image 5 of the image (see FIGS. 1 and 2). Therefore, the driver 6 can visually recognize the virtual image 5 of the display image displayed by the virtual image display system 1 through the projected member 20.
  • the alternate long and short dash line in FIG. 1 indicates the central optical path LC, which is an optical path passing through the center of the virtual image 5 and the center of the visual recognition region 60.
  • the central optical path LC of the virtual image 5 is shown by a two-dot dashed line unless otherwise specified.
  • the virtual image display system 1 includes an image display device 3 for displaying a display image on a display surface 30, and a virtual image display optical device 2 (hereinafter, virtual image display optical device 2) according to an embodiment. It is abbreviated as).
  • FIG. 1 shows a part of the structure of the automobile 4 equipped with the virtual image display system 1.
  • FIG. 2 is a schematic view of the virtual image display system 1.
  • the image display device 3 is, for example, a liquid crystal display.
  • the liquid crystal display has a transmissive liquid crystal panel 31 having a display surface 30 for displaying an image, a backlight (not shown) that irradiates the liquid crystal panel 31 with light from the back surface (the surface opposite to the display surface 30) (not shown). (See FIG. 3).
  • the image display device 3 displays, for example, an image showing the speed, navigation information, etc. of the moving automobile 4 controlled by an ECU (Electronic Control Unit) mounted on the automobile 4 on the display surface 30 of the liquid crystal panel 31. It is configured to do.
  • ECU Electronic Control Unit
  • the image displayed on the display surface 30 may be referred to as a display image of the image display device 3.
  • the display surface 30 of the liquid crystal panel 31 may be referred to as the display surface 30 of the image display device 3.
  • the image display device 3 is not limited to the liquid crystal display.
  • the image display device 3 may be an organic EL panel using an organic electroluminescence element.
  • the image display device 3 may be a so-called laser projector that displays an image by scanning the laser beam of the semiconductor laser on the screen.
  • the virtual image display optical device 2 includes a projected member 20.
  • the virtual image display optical device 2 preferably further includes a reflective member 21.
  • the projected member 20 is also called a combiner.
  • the projected member 20 transmits the light from the front view and reflects the light of the display image (light radiated from the display surface 30 of the image display device 3) to superimpose the front view of the automobile 4 and the virtual image 5. It is configured to let you.
  • the projected member 20 is preferably composed of a half mirror having a reflectance of about 50% (transmittance of 50%) in the visible light region.
  • the projected member 20 is a curved plate made of a translucent synthetic resin material such as an acrylic resin or a polycarbonate resin and has a concave surface on the driver 6 side (the facing surface 200 facing the reflecting member 21). It is formed in a shape (see FIGS. 1 and 2).
  • the facing surface 200 of the projected member 20 may be formed in a curved surface (concave surface) shape in which at least the vicinity of the center of the facing surface 200 projects in a direction away from the reflecting member 21.
  • the vicinity of the center of the facing surface 200 is preferably a region including the center and having an area ratio of about 10% when the center of gravity of the facing surface 200 is centered.
  • FIG. 4 shows a cross section of the projected member 20 in the horizontal direction (horizontal direction seen from the driver 6), and is left and right as seen from the driver 6 in the radius of curvature of the facing surface 200 of the projected member 20. It is explanatory drawing for demonstrating the radius of curvature (second radius of curvature Rcx) of a direction.
  • FIG. 4 also illustrates the local coordinate system (xc, yc, zc coordinates) of the projected member 20.
  • FIG. 5 shows a cross section of the projected member 20 in the vertical direction (vertical direction seen from the driver 6), and the curvature in the vertical direction seen from the driver 6 within the radius of curvature of the facing surface 200 of the projected member 20. It is explanatory drawing for demonstrating the radius (fourth radius of curvature Rcy). In addition, FIG. 5 also illustrates the local coordinate system (xc, yc, zc coordinates) of the projected member 20.
  • the reflecting member 21 has a reflecting surface 210 having a reflectance of 80% or more in vertical incident in the visible light region.
  • the reflecting member 21 may be a cold mirror that transmits heat rays such as near infrared rays in order to reduce the heat of sunlight reaching the image display device 3.
  • the reflective member 21 is arranged so that the reflective surface 210 faces the display surface 30 of the image display device 3 (see FIGS. 1 and 2).
  • the reflecting surface 210 is formed in a curved surface shape that protrudes toward the display surface 30 of the image display device 3.
  • the reflective surface 210 of the reflective member 21 may be formed in a curved surface (convex surface) shape in which at least the vicinity of the center of the reflective surface 210 projects toward the display surface 30.
  • the vicinity of the center of the reflecting surface 210 is preferably a region including the center and having an area ratio of about 10% when the center of gravity of the reflecting surface 210 is centered.
  • FIG. 6 shows a cross section of the reflecting member 21 in the horizontal direction (horizontal direction seen from the driver 6), and is the lateral direction seen from the driver 6 within the radius of curvature of the reflecting surface 210 of the reflecting member 21. It is explanatory drawing for demonstrating the radius of curvature (first radius of curvature Rmx). Further, FIG. 6 also illustrates the local coordinate system (xm, ym, zm coordinates) of the reflective member 21.
  • FIG. 7 shows a cross section of the reflective member 21 in the vertical direction (vertical direction seen from the driver 6), and among the radius of curvature of the reflective surface 210 of the reflective member 21, the radius of curvature in the vertical direction seen from the driver 6 ( It is explanatory drawing for demonstrating 3rd radius of curvature Rmy). Further, FIG. 7 also illustrates the local coordinate system (xm, ym, zm coordinates) of the reflective member 21.
  • the first radius of curvature which is the radius of curvature in the left-right direction as seen by the observer (driver 6) who observes the virtual image 5, among the radii of curvature of the reflecting surface 210 of the reflecting member 21.
  • R1 be the minimum value of Rmx.
  • the minimum value of the second radius of curvature Rcx which is the radius of curvature in the left-right direction, among the radii of curvature of the facing surface 200 of the projected member 20 is R2.
  • the virtual image display optical device 2 is configured so that the ratio of the minimum value R2 of the second radius of curvature Rcx to the minimum value R1 of the first radius of curvature Rmx satisfies the following condition (1).
  • the third radius of curvature Rmy which is the radius of curvature in the vertical direction seen from the observer (driver 6) who observes the virtual image 5, among the radius of curvature of the reflecting surface 210 of the reflecting member 21.
  • R3 be the minimum value of.
  • the minimum value of the fourth radius of curvature Rcy which is the radius of curvature in the vertical direction, is R4.
  • the virtual image display optical device 2 is configured so that the ratio of the minimum value R4 of the fourth radius of curvature Rcy to the minimum value R3 of the third radius of curvature Rmy satisfies the following condition (2).
  • the power (refractive power) of the projected member 20 and the reflecting member 21 are factors in which the ratio R2 / R1 is below the lower limit of the condition (1) or the ratio R4 / R3 is below the lower limit of the condition (2). Each decrease in power is expected.
  • the length of the optical path (optical path length) from the image display device 3 to the projected member 20 via the reflecting member 21 must be increased. As a result, the size of the virtual image display optical device 2 is increased.
  • the power of the projected member 20 becomes too large with respect to the power of the reflecting member 21. If the power of the projected member 20 becomes too large with respect to the power of the reflecting member 21, the following two problems are likely to occur.
  • the first problem is that the external light (sunlight) collected by the projected member 20 through the windshield 41 becomes strong, and the external light hits the display surface 30 of the image display device 3 to cause the image display device 3 to have a problem. The deterioration of the liquid crystal panel 31 is likely to progress.
  • the second problem is that the distance between the projected member 20 and the reflecting member 21 becomes too narrow, so that the light rays from the facing surface 200 of the projected member 20 toward the observer (driver 6) interfere with the reflecting member 21. This means that the visible area 60 tends to be narrowed.
  • the power of the reflecting member 21 becomes too small with respect to the power of the projected member 20. If the power of the reflecting member 21 becomes too small with respect to the power of the projected member 20, the following problems are likely to occur.
  • the problem is that the curvature of field and distortion generated by the positive power of the projected member 20 are not canceled by the negative power of the reflecting member 21, and the curvature of field and distortion tend to worsen.
  • the negative power of the reflective member 21 becomes large as a factor when the ratio R2 / R1 exceeds the upper limit value of the condition (1) or when the ratio R4 / R3 exceeds the upper limit value of the condition (2). Be done.
  • the distance from the observer (driver 6) to the virtual image 5 (also called the viewing distance) is extended, and when the upper limit is exceeded, the viewing distance is near infinity or exceeds infinity, so-called over infinity. It will be in the state. Since a healthy person with sound eyesight cannot clearly see a virtual image having a viewing distance of infinity or over infinity, the visibility of the virtual image deteriorates.
  • the optical path length becomes long, which leads to an increase in the size of the virtual image display optical device 2. Further, when the amount of change in the distance from the observer (driver 6) to the virtual image 5 in the viewing area 60 increases and the observer (driver 6) changes the viewpoint in the viewing area 60. It takes more time to adjust the focus of the eyes.
  • the virtual image display optical device 2 satisfies the condition (1) or the condition (2), preferably the condition (1) and the condition (2) to reduce the size of the virtual image while reducing the distortion (distortion) and the image. It is possible to suppress the occurrence of deterioration of visibility due to curvature of field and viewing distance near infinity.
  • the observer (driver 6) observing the virtual image 5 observes the virtual image 5 within the size of the visible area 60 (also referred to as Eye Box) in which the virtual image 5 can be visually recognized.
  • the width of the visible area 60 in the left-right direction as seen by a person is defined as EB1 (see FIG. 2).
  • the radius of curvature of the facing surfaces 200 in the left-right direction as seen from the observer is defined as R5.
  • the virtual image display optical device 2 is configured so that the ratio of the width EB1 in the left-right direction of the viewing area 60 to the radius of curvature R5 in the left-right direction of the facing surface 200 satisfies the following condition (3).
  • the width be EB2 (see FIG. 2).
  • the radius of curvature of the facing surfaces 200 in the vertical direction as seen from the observer is defined as R6.
  • the virtual image display optical device 2 is configured so that the ratio of the vertical width EB2 of the visible region 60 to the vertical radius of curvature R6 of the facing surface 200 satisfies the following condition (4).
  • the ratio EB1 / R5 exceeds the upper limit value of the condition (3) or the ratio EB2 / R6 exceeds the upper limit value of the condition (4), the power of the facing surface 200 of the projected member 20 becomes large, so that the reflection occurs. It is necessary to reduce the distance from the surface 210. As a result, if the distance between the projected member 20 and the reflecting member 21 becomes too narrow, the light rays from the facing surface 200 of the projected member 20 toward the observer (driver 6) tend to interfere with the reflecting member 21. Further, the light rays from the reflecting member 21 toward the projected member 20 easily interfere with the liquid crystal panel 31 (see FIG. 1). Further, since the external light (sunlight) collected by the projected member 20 becomes stronger, the external light hits the display surface 30 of the image display device 3, and the deterioration of the liquid crystal panel 31 of the image display device 3 progresses. It will be easier.
  • the virtual image display optical device 2 satisfies the condition (3) or the condition (4), preferably the condition (3) and the condition (4), thereby reducing the size of the virtual image (curvature field and distortion). Aberration) can be suppressed.
  • the virtual image display optical device 2 is preferably configured to satisfy the following condition (5).
  • LD represents the length of the first optical path LC1 from the display surface 30 of the image display device 3 to the reflection surface 210 of the reflection member 21 (see FIG. 2).
  • LM represents the length of the second optical path LC2 from the reflecting surface 210 of the reflecting member 21 to the facing surface 200 of the projected member 20 (see FIG. 2).
  • the ratio LM / LD of the length LM of the second optical path LC2 to the length LD of the first optical path LC1 is less than the lower limit of the condition (5), the distance between the projected member 20 and the reflecting member 21 becomes too narrow. The light rays from the facing surface 200 of the projected member 20 toward the observer (driver 6) easily interfere with the reflecting member 21.
  • Another factor below the lower limit of condition (5) is that the distance between the image display device 3 and the reflecting member 21 (length LD of the first optical path LC1) becomes longer, and if it falls below the lower limit, This leads to an increase in the size of the virtual image display optical device 2.
  • the ratio LM / LD of the length LM of the second optical path LC2 to the length LD of the first optical path LC1 exceeds the upper limit of the condition (5), the distance between the image display device 3 and the reflecting member 21 becomes too narrow.
  • the light rays from the reflecting member 21 toward the projected member 20 and the image display device 3 (liquid crystal panel 31) are likely to physically interfere with each other.
  • Another factor that exceeds the upper limit of the condition (5) is that the distance between the reflecting member 21 and the projected member 20 (the length LM of the second optical path LC2) becomes long, and the virtual image display optical device 2 Will lead to an increase in size.
  • the virtual image display optical device 2 By configuring the virtual image display optical device 2 so as to satisfy the condition (5), the virtual image display optical device 2 is compact while suppressing interference between the light rays for displaying the virtual image 5 and the liquid crystal panel 31. Can be achieved.
  • the distance VID (see FIG. 1) from the center of the visible area 60 to the center of the virtual image 5 is preferably 2500 mm or less.
  • the virtual image display optical device 2 further shortens the focus adjustment time from the state in which the observer focuses on the distant view to the focus on the virtual image 5. It is possible to reduce the size.
  • the unit of length in the table is millimeter (mm), and the unit of angle is degree (°).
  • the free curved surface forming the facing surface 200 of the projected member 20 and the reflecting surface 210 of the reflecting member 21 is defined by the following mathematical formulas (A1) and (A2).
  • z is the sag amount at the position of the coordinates (x, y) from the axis that defines the free curved surface.
  • r is the distance from the origin of the axis that defines the free-form surface to the coordinates (x, y).
  • c is the curvature at the origin of the axis that defines the free surface.
  • k is a conic constant.
  • m and n are integers satisfying the mathematical formula (A1).
  • Cj is a coefficient of the xy polynomial.
  • the reference coordinate origin is the center of the display image displayed on the display surface 30, and as shown in FIG. 3, the X-axis, the Y-axis, and the Z-axis are defined.
  • ADE means the amount of rotation from the Z-axis direction to the Y-axis direction about the X-axis.
  • BDE means the amount of rotation from the X-axis direction to the Z-axis direction about the Y-axis.
  • CDE means the amount of rotation from the X-axis direction to the Y-axis direction about the Z-axis.
  • Numerical Example 1 is an example of the virtual image display optical device 2.
  • Table 1 shows the configuration data of the virtual image display optical device 2 of the numerical embodiment 1
  • Table 2 shows the coefficients of the polynomial free-form surface of the virtual image display optical device 2 of the numerical embodiment 1.
  • Numerical Example 2 is an example of the virtual image display optical device 2.
  • Table 3 shows the configuration data of the virtual image display optical device 2 of the numerical embodiment 2
  • Table 4 shows the coefficients of the polynomial free-form surface of the virtual image display optical device 2 of the numerical embodiment 2.
  • Numerical Example 3 is an example of the virtual image display optical device 2.
  • Table 5 shows the configuration data of the virtual image display optical device 2 of the numerical embodiment 3
  • Table 6 shows the coefficients of the polynomial free-form surface of the virtual image display optical device 2 of the numerical example 3.
  • Numerical Example 4 is an example of the virtual image display optical device 2.
  • Table 7 shows the configuration data of the virtual image display optical device 2 of the numerical embodiment 4
  • Table 8 shows the coefficients of the polynomial free-form surface of the virtual image display optical device 2 of the numerical embodiment 4.
  • Numerical Example 5 is an example of the virtual image display optical device 2.
  • Table 9 shows the configuration data of the virtual image display optical device 2 of the numerical embodiment 5, and Table 10 shows the coefficients of the polynomial free-form surface of the virtual image display optical device 2 of the numerical example 5.
  • Numerical Example 6 is an example of the virtual image display optical device 2.
  • Table 11 shows the configuration data of the virtual image display optical device 2 of the numerical embodiment 6
  • Table 12 shows the coefficients of the polynomial free-form surface of the virtual image display optical device 2 of the numerical embodiment 6.
  • Numerical Example 7 is an example of the virtual image display optical device 2.
  • Table 13 shows the configuration data of the virtual image display optical device 2 of the numerical embodiment 7, and
  • Table 14 shows the coefficients of the polynomial free-form surface of the virtual image display optical device 2 of the numerical example 7.
  • Table 15 shows an example of the size of the imaginary image 5, the distance VID from the center of the visible area 60 to the center of the imaginary image 5, and the sizes of the visible area 60 in the horizontal direction (X-axis direction) and the vertical direction (Y-axis direction). Shown. Tables 16 and 17 show the values of the ratio R2 / R1, the ratio R4 / R3, the ratio EB1 / R5, the ratio EB2 / R6, and the ratio LD / LM in all the numerical examples 1-7.
  • FIGS. 8 to 11 the relationship between the above-mentioned seven numerical examples 1-7 and the lower limit value and the upper limit value of the condition 1-4 is shown in FIGS. 8 to 11.
  • “numerical examples” are designated as “examples”.
  • condition 1 is satisfied in all of the numerical examples 1-7.
  • the condition 2 is satisfied in the numerical examples 1 and 5-7.
  • it is below the lower limit value of Condition 2.
  • condition 3 is satisfied in all of the numerical examples 1-7.
  • the minimum value and the maximum value of the ratio EB1 / R5 of each numerical value Example 1-7 are shown.
  • the condition 4 is satisfied in all of the numerical examples 1-7.
  • the minimum value and the maximum value of the ratio EB2 / R6 of each numerical value Example 1-7 are shown.
  • the virtual image display optical device 2 among the seven numerical examples 1-7, the numerical examples 1 and 5-7 satisfying all of the conditions 1 to 5 are preferable.
  • a display image displayed by the image display device (3) and reflected by the reflection surface (210) of the reflection member (21) is projected.
  • the projected member (20) to be projected is provided.
  • the virtual image display optical device (2) according to the first aspect displays the virtual image (5) of the displayed image at a position away from the projected member (20).
  • the projected member (20) has a facing surface (200) facing the reflecting surface (210).
  • the vicinity of the center of the facing surface (200) is formed in a curved surface shape that protrudes in a direction away from the reflecting surface (210).
  • the vicinity of the center of the reflecting surface (210) is formed in a curved surface shape that protrudes toward the image display device (3).
  • the minimum value of the second radius of curvature (Rcx), which is the radius of curvature in the left-right direction is R2.
  • the virtual image display optical device (2) reduces the distortion of the virtual image (curvature of field and distortion) while reducing the size, and sufficiently widens the visible area (60) visible to the observer. Can be secured.
  • a display image displayed by the image display device (3) and reflected by the reflection surface (210) of the reflection member (21) is projected.
  • the projected member (20) to be projected is provided.
  • the virtual image display optical device (2) according to the second aspect displays the virtual image (5) of the displayed image at a position away from the projected member (20).
  • the projected member (20) has a facing surface (200) facing the reflecting surface (210).
  • the vicinity of the center of the facing surface (200) is formed in a curved surface shape that protrudes in a direction away from the reflecting surface (210).
  • the vicinity of the center of the reflecting surface (210) is formed in a curved surface shape that protrudes toward the image display device (3).
  • the minimum value of the fourth radius of curvature (Rcy), which is the radius of curvature in the vertical direction is R4.
  • the virtual image display optical device (2) reduces the distortion of the virtual image (curvature of field and distortion) while reducing the size, and sufficiently widens the visible area (60) visible to the observer. Can be secured.
  • a display image displayed by the image display device (3) and reflected by the reflection surface (210) of the reflection member (21) is projected.
  • the projected member (20) to be projected is provided.
  • the virtual image display optical device (2) according to the third aspect displays the virtual image (5) of the displayed image at a position away from the projected member (20).
  • the projected member (20) has a facing surface (200) facing the reflecting surface (210).
  • the vicinity of the center of the facing surface (200) is formed in a curved surface shape that protrudes in a direction away from the reflecting surface (210).
  • the vicinity of the center of the reflecting surface (210) is formed in a curved surface shape that protrudes toward the image display device (3).
  • EB1 the radius of curvature of the facing surfaces (200) in the left-right direction as seen from the observer is R5.
  • R5 the radius of curvature of the facing surfaces (200) in the left-right direction as seen from the observer.
  • the virtual image display optical device (2) reduces the distortion of the virtual image (curvature of field and distortion) while reducing the size, and sufficiently widens the visible area (60) visible to the observer. Can be secured.
  • a display image displayed by the image display device (3) and reflected by the reflection surface (210) of the reflection member (21) is projected.
  • the projected member (20) to be projected is provided.
  • the virtual image display optical device (2) according to the fourth aspect displays the virtual image (5) of the displayed image at a position away from the projected member (20).
  • the projected member (20) has a facing surface (200) facing the reflecting surface (210). At least near the center of the facing surface (200) is formed in a curved surface shape that projects in a direction away from the reflecting surface (210). At least near the center of the reflecting surface (210) is formed in a curved surface shape that protrudes toward the image display device (3).
  • EB2 the radius of curvature of the facing surfaces (200) in the vertical direction as seen by the observer.
  • the virtual image display optical device (2) reduces the distortion of the virtual image (curvature of field and distortion) while reducing the size, and sufficiently widens the visible area (60) visible to the observer. Can be secured.
  • the virtual image display optical device (2) according to the fifth aspect of the present disclosure can be realized by combining with any of the first to fourth aspects.
  • the length of the second optical path (LC2) from the reflecting surface (210) to the facing surface (200) is LM, the condition of 1.0 ⁇ LM / LD ⁇ 5.0 is satisfied. Is preferable.
  • the virtual image display optical device (2) according to the fifth aspect can be miniaturized while suppressing interference between the light beam for displaying the virtual image (5) and the image display device (3).
  • the virtual image display optical device (2) according to the sixth aspect of the present disclosure can be realized by combining with any one of the first to fifth aspects.
  • the shortest distance (VID) from the visible area (60) where the observer can see the virtual image (5) to the virtual image (5) is 2500 mm or less. Is preferable.
  • the virtual image display optical device (2) according to the sixth aspect focuses on the virtual image (5) from the state where the observer is focusing on the distant view by setting the distance (VID) to 2500 mm or less. It is possible to further reduce the size while shortening the focus adjustment time.
  • the virtual image display optical device (2) according to the seventh aspect of the present disclosure can be realized by combining with any one of the first to sixth aspects.
  • the virtual image display optical device (2) according to the seventh aspect displays the virtual image (5) when the observer (6) sees the virtual image (5) from the visible area (60) in which the virtual image (5) can be visually recognized.
  • the light rays to be formed it is preferable that the light rays from the projected member (20) toward the viewing region (60) are configured so as not to overlap with the reflecting member (21).
  • the virtual image display optical device (2) according to the seventh aspect can prevent the virtual image (5) from being dispelled by the reflecting member (21) when viewed from the observer.
  • the virtual image display optical device (2) according to the eighth aspect of the present disclosure can be realized by combining with any one of the first to sixth aspects.
  • the virtual image display optical device (2) according to the eighth aspect displays the virtual image (5) when the observer (6) sees the virtual image (5) from the visible area (60) in which the virtual image (5) can be visually recognized.
  • the light rays to be formed it is preferable that the light rays from the image display device (3) toward the reflecting member (21) are configured so as not to overlap with the image display device (3).
  • the virtual image display optical device (2) according to the eighth aspect can prevent the virtual image (5) from being dispelled by the image display device (3) when viewed from the observer.
  • the virtual image display optical device (2) according to the ninth aspect of the present disclosure can be realized by combining with any of the first to eighth aspects.
  • the virtual image display optical device (2) according to the ninth aspect preferably further includes a reflective member (21).
  • the virtual image display optical device (2) according to the ninth aspect can bend light rays by providing the reflective member (21), and can effectively utilize the mounting space.
  • the virtual image display system (1) includes an image display device (3) and an optical device (2) for displaying a virtual image according to any one of the first to ninth aspects.
  • the virtual image display system (1) can suppress the occurrence of distortion of the virtual image (curvature field curvature and distortion) while reducing the size of the virtual image display optical device (2).
  • the moving body (vehicle 4) according to the eleventh aspect of the present disclosure has a virtual image display system (1) according to the tenth aspect.
  • the moving body according to the eleventh aspect can suppress the occurrence of distortion of the virtual image (curvature of field and distortion) while reducing the size of the optical device (2) for displaying the virtual image.

Abstract

The objective of the present invention is to reduce distortion of a virtual image while achieving a reduction in size, and to adequately ensure a visible region that is visually recognizable by an observer. An optical device (2) for virtual image display is provided with a projected member (20) onto which a display image that has been displayed by an image display device (3) and has been reflected by a reflecting surface (210) of a reflecting member (21) is projected, and causes a virtual image (5) of the display image to be displayed in a position separated from the projected member (20). The projected member (20) has a facing surface (200) which faces the reflecting surface (210). An area in the vicinity of the center of the facing surface (200) is formed in the shape of a curved surface which projects in a direction moving away from the reflecting surface (210). An area in the vicinity of the center of the reflecting surface (210) is formed in the shape of a curved surface which projects toward the image display device (3). Let R1 be the minimum value of a first radius of curvature (Rmx) of the reflecting surface (210). Let R2 be the minimum value of a second radius of curvature (Rcx) of the facing surface (200) of the projected member (20). Here, the condition 1.63<R2/R1≤4.50 is satisfied.

Description

虚像表示用光学装置、虚像表示システム及び移動体Virtual image display optical device, virtual image display system and mobile
　本開示は、虚像表示用光学装置、虚像表示システム及び移動体に関する。より詳細には、本開示は、虚像を表示するための虚像表示用光学装置、当該虚像表示用光学装置を備える虚像表示システム、及び当該虚像表示システムを備える移動体に関する。 The present disclosure relates to an optical device for displaying a virtual image, a virtual image display system, and a moving body. More specifically, the present disclosure relates to a virtual image display optical device for displaying a virtual image, a virtual image display system including the virtual image display optical device, and a moving body including the virtual image display system.
　特許文献１は、虚像の視認性が高いヘッドアップディスプレイ装置を開示している。 Patent Document 1 discloses a head-up display device having high visibility of a virtual image.
　特許文献１記載のヘッドアップディスプレイ装置のように虚像を表示する虚像表示システムにおいては、小型化が求められているが、小型化に伴って虚像のひずみが大きくなってしまうという問題があった。さらに、虚像を観察する者（観察者）の視認可能な視認領域の周辺を通る光線が、虚像表示システムを構成する要素によって遮られてしまい、視認領域が小さくなってしまうという問題があった。 A virtual image display system that displays a virtual image, such as the head-up display device described in Patent Document 1, is required to be miniaturized, but there is a problem that the distortion of the virtual image increases with the miniaturization. Further, there is a problem that the light rays passing around the visible visible area of the person observing the virtual image (observer) are blocked by the elements constituting the virtual image display system, and the visible area becomes small.
特開２０１７－１９８８００号公報JP-A-2017-198800
　本開示は、小型化を図りつつ虚像のひずみを低減し、観察者の視認可能な視認領域を十分に確保することができる虚像表示用光学装置、虚像表示システム及び移動体を提供する。 The present disclosure provides a virtual image display optical device, a virtual image display system, and a moving body that can reduce distortion of a virtual image while reducing the size and secure a sufficient visible area that can be visually recognized by an observer.
　本開示の一態様に係る虚像表示用光学装置は、画像表示装置が表示し、かつ、反射部材の反射面で反射された表示画像が投影される被投影部材を備え、前記被投影部材から離れた位置に前記表示画像の虚像を表示させる。前記被投影部材は、前記反射面と対向する対向面を有する。前記対向面の中心付近は、前記反射面から遠ざかる向きに突出する曲面形状に形成されている。前記反射面の中心付近は、前記画像表示装置に向かって突出する曲面形状に形成されている。前記反射面の曲率半径のうちで前記虚像を観察する観察者から見た左右方向の曲率半径である第１曲率半径の最小値をＲ１とする。前記対向面の曲率半径のうちで前記左右方向の曲率半径である第２曲率半径の最小値をＲ２とする。このとき、１．６３＜Ｒ２／Ｒ１≦４．５０の条件を満たす。 The virtual image display optical device according to one aspect of the present disclosure includes a projected member that is displayed by the image display device and on which a displayed image reflected by the reflecting surface of the reflecting member is projected, and is separated from the projected member. A virtual image of the displayed image is displayed at the position. The projected member has a facing surface facing the reflecting surface. The vicinity of the center of the facing surface is formed in a curved surface shape that protrudes in a direction away from the reflecting surface. The vicinity of the center of the reflecting surface is formed in a curved surface shape that protrudes toward the image display device. Of the radius of curvature of the reflecting surface, the minimum value of the first radius of curvature, which is the radius of curvature in the left-right direction as seen by the observer observing the virtual image, is defined as R1. Of the radii of curvature of the facing surfaces, the minimum value of the second radius of curvature, which is the radius of curvature in the left-right direction, is R2. At this time, the condition of 1.63 <R2 / R1 ≦ 4.50 is satisfied.
　本開示の一態様に係る虚像表示用光学装置は、画像表示装置が表示し、かつ、反射部材の反射面で反射された表示画像が投影される被投影部材を備え、前記被投影部材から離れた位置に前記表示画像の虚像を表示させる。前記被投影部材は、前記反射面と対向する対向面を有する。前記対向面の中心付近は、前記反射面から遠ざかる向きに突出する曲面形状に形成されている。前記反射面の中心付近は、前記画像表示装置に向かって突出する曲面形状に形成されている。前記反射面の曲率半径のうちで前記虚像を観察する観察者から見た上下方向の曲率半径である第３曲率半径の最小値をＲ３とする。前記対向面の曲率半径のうちで前記上下方向の曲率半径である第４曲率半径の最小値をＲ４とする。このとき、１．６３＜Ｒ４／Ｒ３＜６．００の条件を満たす。 The virtual image display optical device according to one aspect of the present disclosure includes a projected member that is displayed by the image display device and on which a displayed image reflected by the reflecting surface of the reflecting member is projected, and is separated from the projected member. A virtual image of the displayed image is displayed at the position. The projected member has a facing surface facing the reflecting surface. The vicinity of the center of the facing surface is formed in a curved surface shape that protrudes in a direction away from the reflecting surface. The vicinity of the center of the reflecting surface is formed in a curved surface shape that protrudes toward the image display device. Of the radius of curvature of the reflecting surface, the minimum value of the third radius of curvature, which is the radius of curvature in the vertical direction as seen by the observer observing the virtual image, is defined as R3. Of the radii of curvature of the facing surfaces, the minimum value of the fourth radius of curvature, which is the radius of curvature in the vertical direction, is R4. At this time, the condition of 1.63 <R4 / R3 <6.00 is satisfied.
　本開示の一態様に係る虚像表示用光学装置は、画像表示装置が表示し、かつ、反射部材の反射面で反射された表示画像が投影される被投影部材を備え、前記被投影部材から離れた位置に前記表示画像の虚像を表示させる。前記被投影部材は、前記反射面と対向する対向面を有する。前記対向面の中心付近は、前記反射面から遠ざかる向きに突出する曲面形状に形成されている。前記反射面の中心付近は、前記画像表示装置に向かって突出する曲面形状に形成されている。前記虚像を観察する観察者が前記虚像を視認可能な視認領域の大きさのうちで前記観察者から見た左右方向の前記視認領域の幅をＥＢ１とする。前記対向面の曲率半径のうちで前記観察者から見た左右方向の前記対向面の曲率半径をＲ５とする。このとき、０．１≦ＥＢ１／Ｒ５≦０．７の条件を満たす。 The virtual image display optical device according to one aspect of the present disclosure includes a projected member that is displayed by the image display device and on which a displayed image reflected by the reflecting surface of the reflecting member is projected, and is separated from the projected member. A virtual image of the displayed image is displayed at the position. The projected member has a facing surface facing the reflecting surface. The vicinity of the center of the facing surface is formed in a curved surface shape that protrudes in a direction away from the reflecting surface. The vicinity of the center of the reflecting surface is formed in a curved surface shape that protrudes toward the image display device. Of the size of the visible area in which the observer observing the virtual image can visually recognize the virtual image, the width of the visible area in the left-right direction as seen by the observer is defined as EB1. Of the radii of curvature of the facing surfaces, the radius of curvature of the facing surfaces in the left-right direction as seen by the observer is R5. At this time, the condition of 0.1 ≦ EB1 / R5 ≦ 0.7 is satisfied.
　本開示の一態様に係る虚像表示用光学装置は、画像表示装置が表示し、かつ、反射部材の反射面で反射された表示画像が投影される被投影部材を備え、前記被投影部材から離れた位置に前記表示画像の虚像を表示させる。前記被投影部材は、前記反射面と対向する対向面を有する。前記対向面の少なくとも中心付近は、前記反射面から遠ざかる向きに突出する曲面形状に形成されている。前記反射面の少なくとも中心付近は、前記画像表示装置に向かって突出する曲面形状に形成されている。前記虚像を観察する観察者が前記虚像を視認可能な視認領域の大きさのうちで前記観察者から見た上下方向の前記視認領域の幅をＥＢ２とする。前記対向面の曲率半径のうちで前記観察者から見た上下方向の前記対向面の曲率半径をＲ６とする。このとき、０．０５≦ＥＢ２／Ｒ６≦０．２５の条件を満たす。 The virtual image display optical device according to one aspect of the present disclosure includes a projected member that is displayed by the image display device and on which a displayed image reflected by the reflecting surface of the reflecting member is projected, and is separated from the projected member. A virtual image of the displayed image is displayed at the position. The projected member has a facing surface facing the reflecting surface. At least near the center of the facing surface is formed in a curved surface shape that protrudes in a direction away from the reflecting surface. At least near the center of the reflective surface is formed in a curved surface shape that protrudes toward the image display device. Of the size of the visible area in which the observer observing the virtual image can visually recognize the virtual image, the width of the visible area in the vertical direction as seen by the observer is defined as EB2. Of the radii of curvature of the facing surfaces, the radius of curvature of the facing surfaces in the vertical direction as seen by the observer is R6. At this time, the condition of 0.05 ≦ EB2 / R6 ≦ 0.25 is satisfied.
　本開示の一態様に係る虚像表示システムは、前記画像表示装置と、前記虚像表示用光学装置とを備える。 The virtual image display system according to one aspect of the present disclosure includes the image display device and the virtual image display optical device.
　本開示の一態様に係る移動体は、虚像表示システムを有する。 The moving body according to one aspect of the present disclosure has a virtual image display system.
図１は、本開示の実施形態に係る虚像表示用光学装置、虚像表示システム及び移動体の概略構成図である。FIG. 1 is a schematic configuration diagram of a virtual image display optical device, a virtual image display system, and a moving body according to the embodiment of the present disclosure. 図２は、同上の虚像表示システムの模式図である。FIG. 2 is a schematic view of the above-mentioned virtual image display system. 図３は、同上の虚像表示システムにおける画像表示装置の概略構成図である。FIG. 3 is a schematic configuration diagram of an image display device in the above-mentioned virtual image display system. 図４は、同上の虚像表示用光学装置における被投影部材の左右方向の断面を示す模式図である。FIG. 4 is a schematic view showing a cross section of the projected member in the left-right direction in the above-mentioned optical device for displaying a virtual image. 図５は、同上の虚像表示用光学装置における被投影部材の上下方向の断面を示す模式図である。FIG. 5 is a schematic view showing a vertical cross section of the projected member in the above-mentioned optical device for displaying a virtual image. 図６は、同上の虚像表示用光学装置における反射部材の左右方向の断面を示す模式図である。FIG. 6 is a schematic view showing a cross section of the reflecting member in the left-right direction in the above-mentioned optical device for displaying a virtual image. 図７は、同上の虚像表示用光学装置における反射部材の上下方向の断面を示す模式図である。FIG. 7 is a schematic view showing a vertical cross section of the reflecting member in the above-mentioned optical device for displaying a virtual image. 図８は、同上の虚像表示用光学装置の数値実施例と条件１の関係を説明するための説明図である。FIG. 8 is an explanatory diagram for explaining the relationship between the numerical embodiment of the above-mentioned virtual image display optical device and the condition 1. 図９は、同上の虚像表示用光学装置の数値実施例と条件２の関係を説明するための説明図である。FIG. 9 is an explanatory diagram for explaining the relationship between the numerical embodiment of the virtual image display optical device and the condition 2. 図１０は、同上の虚像表示用光学装置の数値実施例と条件３の関係を説明するための説明図である。FIG. 10 is an explanatory diagram for explaining the relationship between the numerical embodiment of the above-mentioned virtual image display optical device and the condition 3. 図１１は、同上の虚像表示用光学装置の数値実施例と条件４の関係を説明するための説明図である。FIG. 11 is an explanatory diagram for explaining the relationship between the numerical embodiment of the above-mentioned virtual image display optical device and the condition 4.
　本開示の実施形態に係る虚像表示用光学装置２、虚像表示システム１及び移動体４について、図面を参照して詳細に説明する。ただし、下記の実施形態において説明する各図は模式的な図であり、各構成要素の大きさ及び厚さのそれぞれの比が必ずしも実際の寸法比を反映しているとは限らない。なお、以下の実施形態で説明する構成は本開示の一例にすぎない。本開示は、以下の実施形態に限定されず、本開示の効果を奏することができれば、設計等に応じて種々の変更が可能である。 The virtual image display optical device 2, the virtual image display system 1, and the moving body 4 according to the embodiment of the present disclosure will be described in detail with reference to the drawings. However, each figure described in the following embodiment is a schematic view, and the respective ratio of the size and the thickness of each component does not necessarily reflect the actual dimensional ratio. The configuration described in the following embodiments is only an example of the present disclosure. The present disclosure is not limited to the following embodiments, and various changes can be made depending on the design and the like as long as the effects of the present disclosure can be achieved.
　（１．実施形態に係る虚像表示ステム及び移動体の説明）
　実施形態に係る虚像表示システム１（以下、虚像表示システム１と略す。）は、自動車４に搭載されるヘッドアップディスプレイ装置である（図１及び図２参照）。実施形態に係る移動体に相当する自動車４は、乗用車、トラック、バス、オートバイ（自動二輪車）、電車などの車両を含む。ただし、実施形態に係る移動体は、人が乗車して運転する乗り物、例えば、水上を航行する船、あるいは飛行機などであってもかまわない。 (1. Description of the virtual image display stem and the moving body according to the embodiment)
The virtual image display system 1 (hereinafter, abbreviated as virtual image display system 1) according to the embodiment is a head-up display device mounted on the automobile 4 (see FIGS. 1 and 2). The automobile 4 corresponding to the moving body according to the embodiment includes vehicles such as passenger cars, trucks, buses, motorcycles (motorcycles), and trains. However, the moving body according to the embodiment may be a vehicle on which a person rides and is driven, for example, a ship navigating on water, an airplane, or the like.
　ヘッドアップディスプレイ装置（虚像表示システム１）は、自動車４のダッシュボード４０に設置される（図１参照）。虚像表示システム１は、ダッシュボード４０上に配置された被投影部材２０に表示画像を投影する。ただし、虚像表示システムは、テレビカメラで撮像した自車の後方の画像を、車内のルームミラーの位置に配置された被投影部材に投影させる、いわゆる遠視点電子ルームミラーであってもかまわない。 The head-up display device (virtual image display system 1) is installed on the dashboard 40 of the automobile 4 (see FIG. 1). The virtual image display system 1 projects a display image on a projected member 20 arranged on the dashboard 40. However, the virtual image display system may be a so-called far-view electronic rear-view mirror that projects an image of the rear of the vehicle captured by the TV camera onto a projected member arranged at the position of the rear-view mirror in the vehicle.
　被投影部材２０は、少なくとも可視光を透過可能な材料、例えば、ガラスや、アクリル樹脂又はポリカーボネート樹脂などの合成樹脂材料によって板状に形成されている。なお、このような被投影部材２０は、コンバイナと称される場合がある。 The projected member 20 is formed in a plate shape by at least a material capable of transmitting visible light, for example, a synthetic resin material such as glass or an acrylic resin or a polycarbonate resin. In addition, such a projected member 20 may be called a combiner.
　虚像表示システム１は、被投影部材２０に表示画像を投影することにより、観察者である運転者６から見て、自動車４のウインドシールド４１よりも前方（自動車４の車外前方）の位置に表示画像の虚像５を形成する（図１及び図２参照）。したがって、運転者６は、虚像表示システム１によって表示される表示画像の虚像５を、被投影部材２０を通して視認可能となる。ここで、図１における二点鎖線は、虚像５の中心と、視認領域６０の中心を通る光路である、中心光路ＬＣを示している。なお、図１以外の図面においても、特に断りのない限り、虚像５の中心光路ＬＣを二点破線で示している。 By projecting the display image onto the projected member 20, the virtual image display system 1 displays the display image at a position in front of the windshield 41 of the automobile 4 (in front of the outside of the automobile 4) as seen from the driver 6 who is the observer. It forms a virtual image 5 of the image (see FIGS. 1 and 2). Therefore, the driver 6 can visually recognize the virtual image 5 of the display image displayed by the virtual image display system 1 through the projected member 20. Here, the alternate long and short dash line in FIG. 1 indicates the central optical path LC, which is an optical path passing through the center of the virtual image 5 and the center of the visual recognition region 60. In drawings other than FIG. 1, the central optical path LC of the virtual image 5 is shown by a two-dot dashed line unless otherwise specified.
　（１－１．虚像表示システムの構成）
　虚像表示システム１は、図１及び図２に示すように、表示面３０に表示画像を表示させる画像表示装置３と、実施形態に係る虚像表示用光学装置２（以下、虚像表示用光学装置２と略す。）とを備える。なお、図１は、虚像表示システム１を搭載した自動車４の一部の構造を示している。また、図２は、虚像表示システム１の模式図である。 (1-1. Configuration of virtual image display system)
As shown in FIGS. 1 and 2, the virtual image display system 1 includes an image display device 3 for displaying a display image on a display surface 30, and a virtual image display optical device 2 (hereinafter, virtual image display optical device 2) according to an embodiment. It is abbreviated as). Note that FIG. 1 shows a part of the structure of the automobile 4 equipped with the virtual image display system 1. Further, FIG. 2 is a schematic view of the virtual image display system 1.
　（１－１－１．画像表示装置）
　画像表示装置３は、例えば、液晶ディスプレイである。液晶ディスプレイは、画像を表示する表示面３０を有する透過型の液晶パネル３１、液晶パネル３１に裏面（表示面３０の反対側の面）から光を照射するバックライト（不図示）などを有する（図３参照）。画像表示装置３は、例えば、自動車４に搭載されているＥＣＵ（Electronic Control Unit）に制御されて走行中の自動車４の速度、ナビゲーション情報などを表した画像を液晶パネル３１の表示面３０に表示するように構成されている。 (1-1-1. Image display device)
The image display device 3 is, for example, a liquid crystal display. The liquid crystal display has a transmissive liquid crystal panel 31 having a display surface 30 for displaying an image, a backlight (not shown) that irradiates the liquid crystal panel 31 with light from the back surface (the surface opposite to the display surface 30) (not shown). (See FIG. 3). The image display device 3 displays, for example, an image showing the speed, navigation information, etc. of the moving automobile 4 controlled by an ECU (Electronic Control Unit) mounted on the automobile 4 on the display surface 30 of the liquid crystal panel 31. It is configured to do.
　以下の説明では、表示面３０に表示される画像を、画像表示装置３の表示画像と呼ぶ場合がある。また、液晶パネル３１の表示面３０を、画像表示装置３の表示面３０と呼ぶ場合がある。ただし、画像表示装置３は液晶ディスプレイに限定されない。画像表示装置３は、有機エレクトロルミネッセンス素子を用いた有機ＥＬパネルであってもかまわない。あるいは、画像表示装置３は、半導体レーザのレーザ光をスクリーン上に走査して画像を表示する、いわゆるレーザプロジェクタであってもかまわない。 In the following description, the image displayed on the display surface 30 may be referred to as a display image of the image display device 3. Further, the display surface 30 of the liquid crystal panel 31 may be referred to as the display surface 30 of the image display device 3. However, the image display device 3 is not limited to the liquid crystal display. The image display device 3 may be an organic EL panel using an organic electroluminescence element. Alternatively, the image display device 3 may be a so-called laser projector that displays an image by scanning the laser beam of the semiconductor laser on the screen.
　（１－２．実施形態に係る虚像表示用光学装置の説明）
　虚像表示用光学装置２は、被投影部材２０を備える。なお、虚像表示用光学装置２は、反射部材２１を更に備えることが好ましい。 (1-2. Description of the virtual image display optical device according to the embodiment)
The virtual image display optical device 2 includes a projected member 20. The virtual image display optical device 2 preferably further includes a reflective member 21.
　（１－２－１．被投影部材）
　被投影部材２０は、コンバイナとも呼ばれる。被投影部材２０は、前方景色からの光を透過し、表示画像の光（画像表示装置３の表示面３０から放射される光）を反射することにより、自動車４の前方景色と虚像５を重畳させるように構成されている。例えば、被投影部材２０は、可視光領域における反射率が５０％（透過率が５０％）程度のハーフミラーで構成されることが好ましい。 (1-2-1. Projected member)
The projected member 20 is also called a combiner. The projected member 20 transmits the light from the front view and reflects the light of the display image (light radiated from the display surface 30 of the image display device 3) to superimpose the front view of the automobile 4 and the virtual image 5. It is configured to let you. For example, the projected member 20 is preferably composed of a half mirror having a reflectance of about 50% (transmittance of 50%) in the visible light region.
　また、被投影部材２０は、アクリル樹脂又はポリカーボネート樹脂などの透光性を有する合成樹脂材料により、運転者６側の表面（反射部材２１と対向する対向面２００）を凹面とする曲面形状の板状に形成されている（図１及び図２参照）。ただし、被投影部材２０の対向面２００は、少なくとも対向面２００の中心付近が反射部材２１から遠ざかる向きに突出する曲面（凹面）形状に形成されていればよい。なお、対向面２００の中心付近とは、対向面２００の図心を中心としたときに、中心を含み、かつ面積比を１０％程度とした領域であることが好ましい。 Further, the projected member 20 is a curved plate made of a translucent synthetic resin material such as an acrylic resin or a polycarbonate resin and has a concave surface on the driver 6 side (the facing surface 200 facing the reflecting member 21). It is formed in a shape (see FIGS. 1 and 2). However, the facing surface 200 of the projected member 20 may be formed in a curved surface (concave surface) shape in which at least the vicinity of the center of the facing surface 200 projects in a direction away from the reflecting member 21. The vicinity of the center of the facing surface 200 is preferably a region including the center and having an area ratio of about 10% when the center of gravity of the facing surface 200 is centered.
　ここで、図４は、被投影部材２０の水平方向（運転者６から見た左右方向）の断面を示し、被投影部材２０の対向面２００の曲率半径のうちで運転者６から見た左右方向の曲率半径（第２曲率半径Ｒｃｘ）を説明するための説明図である。また、図４には、被投影部材２０のローカル座標系（ｘｃ、ｙｃ、ｚｃ座標）も図示している。 Here, FIG. 4 shows a cross section of the projected member 20 in the horizontal direction (horizontal direction seen from the driver 6), and is left and right as seen from the driver 6 in the radius of curvature of the facing surface 200 of the projected member 20. It is explanatory drawing for demonstrating the radius of curvature (second radius of curvature Rcx) of a direction. In addition, FIG. 4 also illustrates the local coordinate system (xc, yc, zc coordinates) of the projected member 20.
　図５は、被投影部材２０の鉛直方向（運転者６から見た上下方向）の断面を示し、被投影部材２０の対向面２００の曲率半径のうちで運転者６から見た上下方向の曲率半径（第４曲率半径Ｒｃｙ）を説明するための説明図である。また、図５には、被投影部材２０のローカル座標系（ｘｃ、ｙｃ、ｚｃ座標）も図示している。 FIG. 5 shows a cross section of the projected member 20 in the vertical direction (vertical direction seen from the driver 6), and the curvature in the vertical direction seen from the driver 6 within the radius of curvature of the facing surface 200 of the projected member 20. It is explanatory drawing for demonstrating the radius (fourth radius of curvature Rcy). In addition, FIG. 5 also illustrates the local coordinate system (xc, yc, zc coordinates) of the projected member 20.
　（１－２－２．反射部材）
　反射部材２１は、可視光領域の垂直入射における反射率が８０％以上の反射面２１０を有する。反射部材２１は、画像表示装置３へ到達する太陽光の熱を低減させるための、近赤外線等の熱線を透過させるコールドミラーであってもよい。反射部材２１は、画像表示装置３の表示面３０に反射面２１０を対向させるように配置される（図１及び図２参照）。反射面２１０は、画像表示装置３の表示面３０に向かって突出する曲面形状に形成されている。ただし、反射部材２１の反射面２１０は、少なくとも反射面２１０の中心付近が表示面３０に向かって突出する曲面（凸面）形状に形成されていればよい。なお、反射面２１０の中心付近とは、反射面２１０の図心を中心としたとき、中心を含み、かつ面積比を１０％程度とした領域であることが好ましい。 (1-2-2. Reflective member)
The reflecting member 21 has a reflecting surface 210 having a reflectance of 80% or more in vertical incident in the visible light region. The reflecting member 21 may be a cold mirror that transmits heat rays such as near infrared rays in order to reduce the heat of sunlight reaching the image display device 3. The reflective member 21 is arranged so that the reflective surface 210 faces the display surface 30 of the image display device 3 (see FIGS. 1 and 2). The reflecting surface 210 is formed in a curved surface shape that protrudes toward the display surface 30 of the image display device 3. However, the reflective surface 210 of the reflective member 21 may be formed in a curved surface (convex surface) shape in which at least the vicinity of the center of the reflective surface 210 projects toward the display surface 30. The vicinity of the center of the reflecting surface 210 is preferably a region including the center and having an area ratio of about 10% when the center of gravity of the reflecting surface 210 is centered.
　ここで、図６は、反射部材２１の水平方向（運転者６から見た左右方向）の断面を示し、反射部材２１の反射面２１０の曲率半径のうちで運転者６から見た左右方向の曲率半径（第１曲率半径Ｒｍｘ）を説明するための説明図である。また、図６には、反射部材２１のローカル座標系（ｘｍ、ｙｍ、ｚｍ座標）も図示している。 Here, FIG. 6 shows a cross section of the reflecting member 21 in the horizontal direction (horizontal direction seen from the driver 6), and is the lateral direction seen from the driver 6 within the radius of curvature of the reflecting surface 210 of the reflecting member 21. It is explanatory drawing for demonstrating the radius of curvature (first radius of curvature Rmx). Further, FIG. 6 also illustrates the local coordinate system (xm, ym, zm coordinates) of the reflective member 21.
　図７は、反射部材２１の鉛直方向（運転者６から見た上下方向）の断面を示し、反射部材２１の反射面２１０の曲率半径のうちで運転者６から見た上下方向の曲率半径（第３曲率半径Ｒｍｙ）を説明するための説明図である。また、図７には、反射部材２１のローカル座標系（ｘｍ、ｙｍ、ｚｍ座標）も図示している。 FIG. 7 shows a cross section of the reflective member 21 in the vertical direction (vertical direction seen from the driver 6), and among the radius of curvature of the reflective surface 210 of the reflective member 21, the radius of curvature in the vertical direction seen from the driver 6 ( It is explanatory drawing for demonstrating 3rd radius of curvature Rmy). Further, FIG. 7 also illustrates the local coordinate system (xm, ym, zm coordinates) of the reflective member 21.
　（２．条件及び効果）
　ここで、虚像表示用光学装置２において、反射部材２１の反射面２１０の曲率半径のうちで虚像５を観察する観察者（運転者６）から見た左右方向の曲率半径である第１曲率半径Ｒｍｘの最小値をＲ１とする。また、被投影部材２０の対向面２００の曲率半径のうちで左右方向の曲率半径である第２曲率半径Ｒｃｘの最小値をＲ２とする。このとき、虚像表示用光学装置２は、第１曲率半径Ｒｍｘの最小値Ｒ１に対する第２曲率半径Ｒｃｘの最小値Ｒ２の比が、下記の条件（１）を満たすように構成される。 (2. Conditions and effects)
Here, in the virtual image display optical device 2, the first radius of curvature, which is the radius of curvature in the left-right direction as seen by the observer (driver 6) who observes the virtual image 5, among the radii of curvature of the reflecting surface 210 of the reflecting member 21. Let R1 be the minimum value of Rmx. Further, the minimum value of the second radius of curvature Rcx, which is the radius of curvature in the left-right direction, among the radii of curvature of the facing surface 200 of the projected member 20 is R2. At this time, the virtual image display optical device 2 is configured so that the ratio of the minimum value R2 of the second radius of curvature Rcx to the minimum value R1 of the first radius of curvature Rmx satisfies the following condition (1).
　１．６３＜Ｒ２／Ｒ１≦４．５０…（１）
　また、虚像表示用光学装置２において、反射部材２１の反射面２１０の曲率半径のうちで虚像５を観察する観察者（運転者６）から見た上下方向の曲率半径である第３曲率半径Ｒｍｙの最小値をＲ３とする。被投影部材２０の対向面２００の曲率半径のうちで上下方向の曲率半径である第４曲率半径Ｒｃｙの最小値をＲ４とする。このとき、虚像表示用光学装置２は、第３曲率半径Ｒｍｙの最小値Ｒ３に対する第４曲率半径Ｒｃｙの最小値Ｒ４の比が、下記の条件（２）を満たすように構成される。 1.63 <R2 / R1 ≤ 4.50 ... (1)
Further, in the virtual image display optical device 2, the third radius of curvature Rmy, which is the radius of curvature in the vertical direction seen from the observer (driver 6) who observes the virtual image 5, among the radius of curvature of the reflecting surface 210 of the reflecting member 21. Let R3 be the minimum value of. Of the radii of curvature of the facing surface 200 of the projected member 20, the minimum value of the fourth radius of curvature Rcy, which is the radius of curvature in the vertical direction, is R4. At this time, the virtual image display optical device 2 is configured so that the ratio of the minimum value R4 of the fourth radius of curvature Rcy to the minimum value R3 of the third radius of curvature Rmy satisfies the following condition (2).
　１．６３＜Ｒ４／Ｒ３＜６．００…（２）
　ここで、比Ｒ２／Ｒ１が条件（１）の下限値を下回る要因又は比Ｒ４／Ｒ３が条件（２）の下限値を下回る要因として、被投影部材２０のパワー（屈折力）及び反射部材２１のパワーのそれぞれの低下が想定される。被投影部材２０のパワー及び反射部材２１のパワーが双方とも低下した場合、画像表示装置３から反射部材２１を経て被投影部材２０に至る光路の長さ（光路長）を長くしなければならない。その結果、虚像表示用光学装置２の大型化を招いてしまう。 1.63 <R4 / R3 <6.00 ... (2)
Here, the power (refractive power) of the projected member 20 and the reflecting member 21 are factors in which the ratio R2 / R1 is below the lower limit of the condition (1) or the ratio R4 / R3 is below the lower limit of the condition (2). Each decrease in power is expected. When both the power of the projected member 20 and the power of the reflecting member 21 are reduced, the length of the optical path (optical path length) from the image display device 3 to the projected member 20 via the reflecting member 21 must be increased. As a result, the size of the virtual image display optical device 2 is increased.
　また、別の要因として、被投影部材２０のパワーが反射部材２１のパワーに対して相対的に大きくなり過ぎることが想定される。被投影部材２０のパワーが反射部材２１のパワーに対して相対的に大きくなり過ぎた場合、以下の二つの不具合が生じる可能性が高くなる。一つめの不具合は、ウインドシールド４１を通して被投影部材２０で集光される外光（太陽光）が強くなるため、当該外光が画像表示装置３の表示面３０に当たることによって画像表示装置３の液晶パネル３１の劣化が進行しやすくなることである。二つめの不具合は、被投影部材２０と反射部材２１の間隔が狭くなり過ぎてしまうため、被投影部材２０の対向面２００から観察者（運転者６）に向かう光線が反射部材２１と干渉しやすくなり、視認領域６０が狭くなりやすくなることである。 As another factor, it is assumed that the power of the projected member 20 becomes too large with respect to the power of the reflecting member 21. If the power of the projected member 20 becomes too large with respect to the power of the reflecting member 21, the following two problems are likely to occur. The first problem is that the external light (sunlight) collected by the projected member 20 through the windshield 41 becomes strong, and the external light hits the display surface 30 of the image display device 3 to cause the image display device 3 to have a problem. The deterioration of the liquid crystal panel 31 is likely to progress. The second problem is that the distance between the projected member 20 and the reflecting member 21 becomes too narrow, so that the light rays from the facing surface 200 of the projected member 20 toward the observer (driver 6) interfere with the reflecting member 21. This means that the visible area 60 tends to be narrowed.
　さらに、別の要因として、反射部材２１のパワーが被投影部材２０のパワーに対して相対的に小さくなり過ぎることが想定される。被投影部材２０のパワーに対して反射部材２１のパワーが相対的に小さくなり過ぎた場合、以下のような不具合が生じる可能性が高くなる。当該不具合は、被投影部材２０の正のパワーで発生する像面湾曲及び歪曲収差が反射部材２１の負のパワーで打ち消されず、像面湾曲及び歪曲収差が悪化しやすくなることである。 Further, as another factor, it is assumed that the power of the reflecting member 21 becomes too small with respect to the power of the projected member 20. If the power of the reflecting member 21 becomes too small with respect to the power of the projected member 20, the following problems are likely to occur. The problem is that the curvature of field and distortion generated by the positive power of the projected member 20 are not canceled by the negative power of the reflecting member 21, and the curvature of field and distortion tend to worsen.
　一方、比Ｒ２／Ｒ１が条件（１）の上限値を上回る場合又は比Ｒ４／Ｒ３が条件（２）の上限値を上回る場合の要因として、反射部材２１の負のパワーが大きくなることが考えられる。この場合、観察者（運転者６）から虚像５までの距離（視距離とも呼ばれる。）が伸びてしまい、上限値を上回ると、視距離が無限遠近傍か無限遠を超えた、いわゆるオーバー無限という状態になってしまう。健全な視力を持つ健常者が、視距離が無限遠やオーバー無限にある虚像を鮮明に視認することはできないため、虚像の視認性が悪くなってしまう。また、視距離が長くなると、光路長が長くなって虚像表示用光学装置２の大型化を招いてしまう。さらに、観察者（運転者６）から虚像５までの距離の、視認領域６０内での変化量が増大してしまい、観察者（運転者６）が視認領域６０内で視点を変えた際に目のピント調節に要する時間が増えてしまう。 On the other hand, it is considered that the negative power of the reflective member 21 becomes large as a factor when the ratio R2 / R1 exceeds the upper limit value of the condition (1) or when the ratio R4 / R3 exceeds the upper limit value of the condition (2). Be done. In this case, the distance from the observer (driver 6) to the virtual image 5 (also called the viewing distance) is extended, and when the upper limit is exceeded, the viewing distance is near infinity or exceeds infinity, so-called over infinity. It will be in the state. Since a healthy person with sound eyesight cannot clearly see a virtual image having a viewing distance of infinity or over infinity, the visibility of the virtual image deteriorates. Further, when the viewing distance becomes long, the optical path length becomes long, which leads to an increase in the size of the virtual image display optical device 2. Further, when the amount of change in the distance from the observer (driver 6) to the virtual image 5 in the viewing area 60 increases and the observer (driver 6) changes the viewpoint in the viewing area 60. It takes more time to adjust the focus of the eyes.
　ゆえに、虚像表示用光学装置２は、条件（１）又は条件（２）、望ましくは条件（１）及び条件（２）を満たすことにより、小型化を図りつつ虚像のひずみ（歪曲収差）及び像面湾曲や視距離が無限遠近傍になることによる視認性の低下の発生を抑制することができる。 Therefore, the virtual image display optical device 2 satisfies the condition (1) or the condition (2), preferably the condition (1) and the condition (2) to reduce the size of the virtual image while reducing the distortion (distortion) and the image. It is possible to suppress the occurrence of deterioration of visibility due to curvature of field and viewing distance near infinity.
　ここで、虚像表示用光学装置２において、虚像５を観察する観察者（運転者６）が虚像５を視認可能な視認領域６０（アイボックス：Eye Boxとも呼ばれる。）の大きさのうちで観察者から見た左右方向の視認領域６０の幅をＥＢ１とする（図２参照）。また、対向面２００の曲率半径のうちで観察者から見た左右方向の対向面２００の曲率半径をＲ５とする。このとき、虚像表示用光学装置２は、対向面２００の左右方向の曲率半径Ｒ５に対する視認領域６０の左右方向の幅ＥＢ１の比が、下記の条件（３）を満たすように構成される。 Here, in the virtual image display optical device 2, the observer (driver 6) observing the virtual image 5 observes the virtual image 5 within the size of the visible area 60 (also referred to as Eye Box) in which the virtual image 5 can be visually recognized. The width of the visible area 60 in the left-right direction as seen by a person is defined as EB1 (see FIG. 2). Further, among the radii of curvature of the facing surfaces 200, the radius of curvature of the facing surfaces 200 in the left-right direction as seen from the observer is defined as R5. At this time, the virtual image display optical device 2 is configured so that the ratio of the width EB1 in the left-right direction of the viewing area 60 to the radius of curvature R5 in the left-right direction of the facing surface 200 satisfies the following condition (3).
　０．１≦ＥＢ１／Ｒ５≦０．７…（３）
　また、虚像表示用光学装置２において、虚像５を観察する観察者（運転者６）が虚像５を視認可能な視認領域６０の大きさのうちで観察者から見た上下方向の視認領域６０の幅をＥＢ２とする（図２参照）。また、対向面２００の曲率半径のうちで観察者から見た上下方向の対向面２００の曲率半径をＲ６とする。このとき、虚像表示用光学装置２は、対向面２００の上下方向の曲率半径Ｒ６に対する視認領域６０の上下方向の幅ＥＢ２の比が、下記の条件（４）を満たすように構成される。 0.1 ≤ EB1 / R5 ≤ 0.7 ... (3)
Further, in the virtual image display optical device 2, the vertical viewing area 60 seen by the observer within the size of the viewing area 60 in which the observer (driver 6) observing the virtual image 5 can see the virtual image 5. Let the width be EB2 (see FIG. 2). Further, among the radii of curvature of the facing surfaces 200, the radius of curvature of the facing surfaces 200 in the vertical direction as seen from the observer is defined as R6. At this time, the virtual image display optical device 2 is configured so that the ratio of the vertical width EB2 of the visible region 60 to the vertical radius of curvature R6 of the facing surface 200 satisfies the following condition (4).
　０．０５≦ＥＢ２／Ｒ６≦０．２５…（４）
　ここで、比ＥＢ１／Ｒ５が条件（３）の下限値を下回る場合又は比ＥＢ２／Ｒ６が条件（４）の下限値を下回る場合、反射面２１０のパワーが低下して反射部材２１の反射面２１０が平面に近付くため、光路長が長くなって虚像表示用光学装置２の大型化を招いてしまう。 0.05 ≦ EB2 / R6 ≦ 0.25 ... (4)
Here, when the ratio EB1 / R5 is lower than the lower limit value of the condition (3) or the ratio EB2 / R6 is lower than the lower limit value of the condition (4), the power of the reflective surface 210 is reduced and the reflective surface of the reflective member 21 is reduced. Since the 210 approaches a flat surface, the optical path length becomes long, which leads to an increase in the size of the virtual image display optical device 2.
　一方、比ＥＢ１／Ｒ５が条件（３）の上限値を上回る場合又は比ＥＢ２／Ｒ６が条件（４）の上限値を上回る場合、被投影部材２０の対向面２００のパワーが大きくなるため、反射面２１０との間隔を狭くする必要がある。その結果、被投影部材２０と反射部材２１の間隔が狭くなり過ぎてしまうと、被投影部材２０の対向面２００から観察者（運転者６）に向かう光線が反射部材２１と干渉しやすくなる。また、反射部材２１から被投影部材２０に向かう光線が液晶パネル３１と干渉しやすくなる（図１参照）。さらに、被投影部材２０で集光される外光（太陽光）が強くなるため、当該外光が画像表示装置３の表示面３０に当たることによって画像表示装置３の液晶パネル３１の劣化が進行しやすくなる。 On the other hand, when the ratio EB1 / R5 exceeds the upper limit value of the condition (3) or the ratio EB2 / R6 exceeds the upper limit value of the condition (4), the power of the facing surface 200 of the projected member 20 becomes large, so that the reflection occurs. It is necessary to reduce the distance from the surface 210. As a result, if the distance between the projected member 20 and the reflecting member 21 becomes too narrow, the light rays from the facing surface 200 of the projected member 20 toward the observer (driver 6) tend to interfere with the reflecting member 21. Further, the light rays from the reflecting member 21 toward the projected member 20 easily interfere with the liquid crystal panel 31 (see FIG. 1). Further, since the external light (sunlight) collected by the projected member 20 becomes stronger, the external light hits the display surface 30 of the image display device 3, and the deterioration of the liquid crystal panel 31 of the image display device 3 progresses. It will be easier.
　ゆえに、虚像表示用光学装置２は、条件（３）又は条件（４）、望ましくは条件（３）及び条件（４）を満たすことにより、小型化を図りつつ虚像のひずみ（像面湾曲及び歪曲収差）の発生を抑制することができる。 Therefore, the virtual image display optical device 2 satisfies the condition (3) or the condition (4), preferably the condition (3) and the condition (4), thereby reducing the size of the virtual image (curvature field and distortion). Aberration) can be suppressed.
　また、虚像表示用光学装置２は、以下の条件（５）を満たすように構成されることが好ましい。 Further, the virtual image display optical device 2 is preferably configured to satisfy the following condition (5).
　１．０≦ＬＭ／ＬＤ≦５．０…（５）
　ここで、ＬＤは、画像表示装置３の表示面３０から反射部材２１の反射面２１０までの第１光路ＬＣ１の長さを表している（図２参照）。ＬＭは、反射部材２１の反射面２１０から被投影部材２０の対向面２００までの第２光路ＬＣ２の長さを表している（図２参照）。 1.0 ≤ LM / LD ≤ 5.0 ... (5)
Here, LD represents the length of the first optical path LC1 from the display surface 30 of the image display device 3 to the reflection surface 210 of the reflection member 21 (see FIG. 2). LM represents the length of the second optical path LC2 from the reflecting surface 210 of the reflecting member 21 to the facing surface 200 of the projected member 20 (see FIG. 2).
　第１光路ＬＣ１の長さＬＤに対する第２光路ＬＣ２の長さＬＭの比ＬＭ／ＬＤが条件（５）の下限値を下回ると、被投影部材２０と反射部材２１の間隔が狭くなりすぎてしまい、被投影部材２０の対向面２００から観察者（運転者６）に向かう光線が反射部材２１と干渉しやすくなる。また、条件（５）の下限値を下回る他の要因として、画像表示装置３と反射部材２１の間隔（第１光路ＬＣ１の長さＬＤ）が長くなることが挙げられ、下限値を下回る場合、虚像表示用光学装置２の大型化を招いてしまう。 If the ratio LM / LD of the length LM of the second optical path LC2 to the length LD of the first optical path LC1 is less than the lower limit of the condition (5), the distance between the projected member 20 and the reflecting member 21 becomes too narrow. The light rays from the facing surface 200 of the projected member 20 toward the observer (driver 6) easily interfere with the reflecting member 21. Another factor below the lower limit of condition (5) is that the distance between the image display device 3 and the reflecting member 21 (length LD of the first optical path LC1) becomes longer, and if it falls below the lower limit, This leads to an increase in the size of the virtual image display optical device 2.
　第１光路ＬＣ１の長さＬＤに対する第２光路ＬＣ２の長さＬＭの比ＬＭ／ＬＤが条件（５）の上限値を上回ると、画像表示装置３と反射部材２１の間隔が狭くなりすぎてしまい、反射部材２１から被投影部材２０へ向かう光線と画像表示装置３（液晶パネル３１）が物理的に干渉しやすくなる。また、条件（５）の上限値を上回る他の要因として、反射部材２１と被投影部材２０の間隔（第２光路ＬＣ２の長さＬＭ）が長くなることが挙げられ、虚像表示用光学装置２の大型化を招いてしまう。 If the ratio LM / LD of the length LM of the second optical path LC2 to the length LD of the first optical path LC1 exceeds the upper limit of the condition (5), the distance between the image display device 3 and the reflecting member 21 becomes too narrow. The light rays from the reflecting member 21 toward the projected member 20 and the image display device 3 (liquid crystal panel 31) are likely to physically interfere with each other. Another factor that exceeds the upper limit of the condition (5) is that the distance between the reflecting member 21 and the projected member 20 (the length LM of the second optical path LC2) becomes long, and the virtual image display optical device 2 Will lead to an increase in size.
　しかして、虚像表示用光学装置２は、条件（５）を満たすように構成されることによって、虚像５を表示するための光線と液晶パネル３１の干渉を抑えつつ虚像表示用光学装置２の小型化を図ることができる。 By configuring the virtual image display optical device 2 so as to satisfy the condition (5), the virtual image display optical device 2 is compact while suppressing interference between the light rays for displaying the virtual image 5 and the liquid crystal panel 31. Can be achieved.
　ここで、視認領域６０の中心から虚像５の中心までの距離ＶＩＤ（図１参照）は、２５００ｍｍ以下であることが好ましい。虚像表示用光学装置２は、距離ＶＩＤを２５００ｍｍ以下とすることにより、観察者が遠方景色にピントを合わせている状態から、虚像５にピントを合わせるまでのピント調整時間を短縮したまま、更なる小型化を図ることができる。 Here, the distance VID (see FIG. 1) from the center of the visible area 60 to the center of the virtual image 5 is preferably 2500 mm or less. By setting the distance VID to 2500 mm or less, the virtual image display optical device 2 further shortens the focus adjustment time from the state in which the observer focuses on the distant view to the focus on the virtual image 5. It is possible to reduce the size.
　（３．数値実施例）
　以下、本開示の実施形態に係る虚像表示用光学装置２について、具体的な数値実施例を説明する。なお、以下に説明する複数の数値実施例の各々において、表中の長さの単位はミリメートル（ｍｍ）であり、角度の単位は度（°）である。また、被投影部材２０の対向面２００及び反射部材２１の反射面２１０を形成する自由曲面は、次の数式（Ａ１）、（Ａ２）で定義される。 (3. Numerical example)
Hereinafter, specific numerical examples of the virtual image display optical device 2 according to the embodiment of the present disclosure will be described. In each of the plurality of numerical examples described below, the unit of length in the table is millimeter (mm), and the unit of angle is degree (°). Further, the free curved surface forming the facing surface 200 of the projected member 20 and the reflecting surface 210 of the reflecting member 21 is defined by the following mathematical formulas (A1) and (A2).
Figure JPOXMLDOC01-appb-M000001
Figure JPOXMLDOC01-appb-M000001
Figure JPOXMLDOC01-appb-M000002
Figure JPOXMLDOC01-appb-M000002
　ここで、数式（Ａ１）において、ｚは自由曲面を定義する軸から座標（ｘ，ｙ）の位置におけるサグ量である。ｒは、自由曲面を定義する軸の原点から座標（ｘ，ｙ）までの距離である。ｃは、自由曲面を定義する軸の原点における曲率である。ｋは、コーニック定数である。ｍ及びｎは、数式（Ａ１）を満たす整数である。Ｃｊは、ｘｙ多項式の係数である。 Here, in the mathematical formula (A1), z is the sag amount at the position of the coordinates (x, y) from the axis that defines the free curved surface. r is the distance from the origin of the axis that defines the free-form surface to the coordinates (x, y). c is the curvature at the origin of the axis that defines the free surface. k is a conic constant. m and n are integers satisfying the mathematical formula (A1). Cj is a coefficient of the xy polynomial.
　また、各数値実施例において、基準となる座標原点は、表示面３０に表示される表示画像の中心であり、図３に示すように、Ｘ軸、Ｙ軸、Ｚ軸を定義している。 Further, in each numerical example, the reference coordinate origin is the center of the display image displayed on the display surface 30, and as shown in FIG. 3, the X-axis, the Y-axis, and the Z-axis are defined.
　さらに、各数値実施例中の偏心データにおいて、ＡＤＥは、Ｘ軸を中心にＺ軸方向からＹ軸方向に回転した量を意味する。ＢＤＥは、Ｙ軸を中心にＸ軸方向からＺ軸方向に回転した量を意味する。ＣＤＥは、Ｚ軸を中心にＸ軸方向からＹ軸方向に回転した量を意味する。 Further, in the eccentricity data in each numerical example, ADE means the amount of rotation from the Z-axis direction to the Y-axis direction about the X-axis. BDE means the amount of rotation from the X-axis direction to the Z-axis direction about the Y-axis. CDE means the amount of rotation from the X-axis direction to the Y-axis direction about the Z-axis.
　（３－１．数値実施例１）
　数値実施例１は、虚像表示用光学装置２の一例である。数値実施例１の虚像表示用光学装置２の構成データを表１に示し、数値実施例１の虚像表示用光学装置２の多項式自由曲面の係数を表２に示す。 (3-1. Numerical Example 1)
Numerical Example 1 is an example of the virtual image display optical device 2. Table 1 shows the configuration data of the virtual image display optical device 2 of the numerical embodiment 1, and Table 2 shows the coefficients of the polynomial free-form surface of the virtual image display optical device 2 of the numerical embodiment 1.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
　（３－２．数値実施例２）
　数値実施例２は、虚像表示用光学装置２の一例である。数値実施例２の虚像表示用光学装置２の構成データを表３に示し、数値実施例２の虚像表示用光学装置２の多項式自由曲面の係数を表４に示す。 (3-2. Numerical Example 2)
Numerical Example 2 is an example of the virtual image display optical device 2. Table 3 shows the configuration data of the virtual image display optical device 2 of the numerical embodiment 2, and Table 4 shows the coefficients of the polynomial free-form surface of the virtual image display optical device 2 of the numerical embodiment 2.
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006
　（３－３．数値実施例３）
　数値実施例３は、虚像表示用光学装置２の一例である。数値実施例３の虚像表示用光学装置２の構成データを表５に示し、数値実施例３の虚像表示用光学装置２の多項式自由曲面の係数を表６に示す。 (3-3. Numerical Example 3)
Numerical Example 3 is an example of the virtual image display optical device 2. Table 5 shows the configuration data of the virtual image display optical device 2 of the numerical embodiment 3, and Table 6 shows the coefficients of the polynomial free-form surface of the virtual image display optical device 2 of the numerical example 3.
Figure JPOXMLDOC01-appb-T000007
Figure JPOXMLDOC01-appb-T000007
Figure JPOXMLDOC01-appb-T000008
Figure JPOXMLDOC01-appb-T000008
　（３－４．数値実施例４）
　数値実施例４は、虚像表示用光学装置２の一例である。数値実施例４の虚像表示用光学装置２の構成データを表７に示し、数値実施例４の虚像表示用光学装置２の多項式自由曲面の係数を表８に示す。 (3-4. Numerical Example 4)
Numerical Example 4 is an example of the virtual image display optical device 2. Table 7 shows the configuration data of the virtual image display optical device 2 of the numerical embodiment 4, and Table 8 shows the coefficients of the polynomial free-form surface of the virtual image display optical device 2 of the numerical embodiment 4.
Figure JPOXMLDOC01-appb-T000009
Figure JPOXMLDOC01-appb-T000009
Figure JPOXMLDOC01-appb-T000010
Figure JPOXMLDOC01-appb-T000010
　（３－５．数値実施例５）
　数値実施例５は、虚像表示用光学装置２の一例である。数値実施例５の虚像表示用光学装置２の構成データを表９に示し、数値実施例５の虚像表示用光学装置２の多項式自由曲面の係数を表１０に示す。 (3-5. Numerical Example 5)
Numerical Example 5 is an example of the virtual image display optical device 2. Table 9 shows the configuration data of the virtual image display optical device 2 of the numerical embodiment 5, and Table 10 shows the coefficients of the polynomial free-form surface of the virtual image display optical device 2 of the numerical example 5.
Figure JPOXMLDOC01-appb-T000011
Figure JPOXMLDOC01-appb-T000011
Figure JPOXMLDOC01-appb-T000012
Figure JPOXMLDOC01-appb-T000012
　（３－６．数値実施例６）
　数値実施例６は、虚像表示用光学装置２の一例である。数値実施例６の虚像表示用光学装置２の構成データを表１１に示し、数値実施例６の虚像表示用光学装置２の多項式自由曲面の係数を表１２に示す。 (3-6. Numerical Example 6)
Numerical Example 6 is an example of the virtual image display optical device 2. Table 11 shows the configuration data of the virtual image display optical device 2 of the numerical embodiment 6, and Table 12 shows the coefficients of the polynomial free-form surface of the virtual image display optical device 2 of the numerical embodiment 6.
Figure JPOXMLDOC01-appb-T000013
Figure JPOXMLDOC01-appb-T000013
Figure JPOXMLDOC01-appb-T000014
Figure JPOXMLDOC01-appb-T000014
　（３－７．数値実施例７）
　数値実施例７は、虚像表示用光学装置２の一例である。数値実施例７の虚像表示用光学装置２の構成データを表１３に示し、数値実施例７の虚像表示用光学装置２の多項式自由曲面の係数を表１４に示す。 (3-7. Numerical Example 7)
Numerical Example 7 is an example of the virtual image display optical device 2. Table 13 shows the configuration data of the virtual image display optical device 2 of the numerical embodiment 7, and Table 14 shows the coefficients of the polynomial free-form surface of the virtual image display optical device 2 of the numerical example 7.
Figure JPOXMLDOC01-appb-T000015
Figure JPOXMLDOC01-appb-T000015
Figure JPOXMLDOC01-appb-T000016
Figure JPOXMLDOC01-appb-T000016
　（４．数値実施例のまとめ）
　表１５は、虚像５のサイズ、視認領域６０の中心から虚像５の中心までの距離ＶＩＤ、視認領域６０の左右方向（Ｘ軸方向）及び上下方向（Ｙ軸方向）のサイズのそれぞれの一例を示している。また、表１６及び表１７は、すべての数値実施例１－７における比Ｒ２／Ｒ１、比Ｒ４／Ｒ３、比ＥＢ１／Ｒ５、比ＥＢ２／Ｒ６及び比ＬＤ／ＬＭの値を示している。 (4. Summary of numerical examples)
Table 15 shows an example of the size of the imaginary image 5, the distance VID from the center of the visible area 60 to the center of the imaginary image 5, and the sizes of the visible area 60 in the horizontal direction (X-axis direction) and the vertical direction (Y-axis direction). Shown. Tables 16 and 17 show the values of the ratio R2 / R1, the ratio R4 / R3, the ratio EB1 / R5, the ratio EB2 / R6, and the ratio LD / LM in all the numerical examples 1-7.
Figure JPOXMLDOC01-appb-T000017
Figure JPOXMLDOC01-appb-T000017
Figure JPOXMLDOC01-appb-T000018
Figure JPOXMLDOC01-appb-T000018
Figure JPOXMLDOC01-appb-T000019
Figure JPOXMLDOC01-appb-T000019
　ここで、上述した七つの数値実施例１－７と条件１－４の下限値及び上限値の関係を図８－図１１に示す。ただし、図８－図１１においては、「数値実施例」を「実施例」と標記している。図８に示すように、数値実施例１－７のすべてにおいて、条件１が満たされている。また、図９に示すように、数値実施例１、５－７において、条件２が満たされている。ただし、数値実施例２－４では、条件２の下限値を下回っている。図１０に示すように、数値実施例１－７のすべてにおいて、条件３が満たされている。ただし、図１０において、各数値実施例１－７の比ＥＢ１／Ｒ５の最小値と最大値を示している。図１１に示すように、数値実施例１－７のすべてにおいて、条件４が満たされている。ただし、図１１において、各数値実施例１－７の比ＥＢ２／Ｒ６の最小値と最大値を示している。 Here, the relationship between the above-mentioned seven numerical examples 1-7 and the lower limit value and the upper limit value of the condition 1-4 is shown in FIGS. 8 to 11. However, in FIGS. 8 to 11, "numerical examples" are designated as "examples". As shown in FIG. 8, condition 1 is satisfied in all of the numerical examples 1-7. Further, as shown in FIG. 9, the condition 2 is satisfied in the numerical examples 1 and 5-7. However, in Numerical Example 2-4, it is below the lower limit value of Condition 2. As shown in FIG. 10, condition 3 is satisfied in all of the numerical examples 1-7. However, in FIG. 10, the minimum value and the maximum value of the ratio EB1 / R5 of each numerical value Example 1-7 are shown. As shown in FIG. 11, the condition 4 is satisfied in all of the numerical examples 1-7. However, in FIG. 11, the minimum value and the maximum value of the ratio EB2 / R6 of each numerical value Example 1-7 are shown.
　しかして、虚像表示用光学装置２としては、七つの数値実施例１－７のうち、条件１－条件５のすべてを満たす数値実施例１、５－７が好ましい。 Therefore, as the virtual image display optical device 2, among the seven numerical examples 1-7, the numerical examples 1 and 5-7 satisfying all of the conditions 1 to 5 are preferable.
　（５．まとめ）
　本開示の第１の態様に係る虚像表示用光学装置（２）は、画像表示装置（３）が表示し、かつ、反射部材（２１）の反射面（２１０）で反射された表示画像が投影される被投影部材（２０）を備える。第１の態様に係る虚像表示用光学装置（２）は、被投影部材（２０）から離れた位置に表示画像の虚像（５）を表示させる。被投影部材（２０）は、反射面（２１０）と対向する対向面（２００）を有する。対向面（２００）の中心付近は、反射面（２１０）から遠ざかる向きに突出する曲面形状に形成されている。反射面（２１０）の中心付近は、画像表示装置（３）に向かって突出する曲面形状に形成されている。反射面（２１０）の曲率半径のうちで虚像（５）を観察する観察者（運転者６）から見た左右方向の曲率半径である第１曲率半径（Ｒｍｘ）の最小値をＲ１とする。被投影部材（２０）の対向面（２００）の曲率半径のうちで左右方向の曲率半径である第２曲率半径（Ｒｃｘ）の最小値をＲ２とする。このとき、１．６３＜Ｒ２／Ｒ１≦４．５０の条件を満たす。 (5. Summary)
In the virtual image display optical device (2) according to the first aspect of the present disclosure, a display image displayed by the image display device (3) and reflected by the reflection surface (210) of the reflection member (21) is projected. The projected member (20) to be projected is provided. The virtual image display optical device (2) according to the first aspect displays the virtual image (5) of the displayed image at a position away from the projected member (20). The projected member (20) has a facing surface (200) facing the reflecting surface (210). The vicinity of the center of the facing surface (200) is formed in a curved surface shape that protrudes in a direction away from the reflecting surface (210). The vicinity of the center of the reflecting surface (210) is formed in a curved surface shape that protrudes toward the image display device (3). Of the radii of curvature of the reflecting surface (210), the minimum value of the first radius of curvature (Rmx), which is the radius of curvature in the left-right direction as seen by the observer (driver 6) observing the virtual image (5), is R1. Of the radii of curvature of the facing surface (200) of the projected member (20), the minimum value of the second radius of curvature (Rcx), which is the radius of curvature in the left-right direction, is R2. At this time, the condition of 1.63 <R2 / R1 ≦ 4.50 is satisfied.
　第１の態様に係る虚像表示用光学装置（２）は、小型化を図りつつ虚像のひずみ（像面湾曲及び歪曲収差）を低減し、観察者の視認可能な視認領域（６０）を十分に確保することができる。 The virtual image display optical device (2) according to the first aspect reduces the distortion of the virtual image (curvature of field and distortion) while reducing the size, and sufficiently widens the visible area (60) visible to the observer. Can be secured.
　本開示の第２の態様に係る虚像表示用光学装置（２）は、画像表示装置（３）が表示し、かつ、反射部材（２１）の反射面（２１０）で反射された表示画像が投影される被投影部材（２０）を備える。第２の態様に係る虚像表示用光学装置（２）は、被投影部材（２０）から離れた位置に表示画像の虚像（５）を表示させる。被投影部材（２０）は、反射面（２１０）と対向する対向面（２００）を有する。対向面（２００）の中心付近は、反射面（２１０）から遠ざかる向きに突出する曲面形状に形成されている。反射面（２１０）の中心付近は、画像表示装置（３）に向かって突出する曲面形状に形成されている。反射面（２１０）の曲率半径のうちで虚像（５）を観察する観察者（運転者６）から見た上下方向の曲率半径である第３曲率半径（Ｒｍｙ）の最小値をＲ３とする。被投影部材（２０）の対向面（２００）の曲率半径のうちで上下方向の曲率半径である第４曲率半径（Ｒｃｙ）の最小値をＲ４とする。このとき、１．６３＜Ｒ４／Ｒ３＜６．００の条件を満たす。 In the virtual image display optical device (2) according to the second aspect of the present disclosure, a display image displayed by the image display device (3) and reflected by the reflection surface (210) of the reflection member (21) is projected. The projected member (20) to be projected is provided. The virtual image display optical device (2) according to the second aspect displays the virtual image (5) of the displayed image at a position away from the projected member (20). The projected member (20) has a facing surface (200) facing the reflecting surface (210). The vicinity of the center of the facing surface (200) is formed in a curved surface shape that protrudes in a direction away from the reflecting surface (210). The vicinity of the center of the reflecting surface (210) is formed in a curved surface shape that protrudes toward the image display device (3). Of the radii of curvature of the reflecting surface (210), the minimum value of the third radius of curvature (Rmy), which is the radius of curvature in the vertical direction as seen by the observer (driver 6) observing the virtual image (5), is R3. Of the radii of curvature of the facing surface (200) of the projected member (20), the minimum value of the fourth radius of curvature (Rcy), which is the radius of curvature in the vertical direction, is R4. At this time, the condition of 1.63 <R4 / R3 <6.00 is satisfied.
　第２の態様に係る虚像表示用光学装置（２）は、小型化を図りつつ虚像のひずみ（像面湾曲及び歪曲収差）を低減し、観察者の視認可能な視認領域（６０）を十分に確保することができる。 The virtual image display optical device (2) according to the second aspect reduces the distortion of the virtual image (curvature of field and distortion) while reducing the size, and sufficiently widens the visible area (60) visible to the observer. Can be secured.
　本開示の第３の態様に係る虚像表示用光学装置（２）は、画像表示装置（３）が表示し、かつ、反射部材（２１）の反射面（２１０）で反射された表示画像が投影される被投影部材（２０）を備える。第３の態様に係る虚像表示用光学装置（２）は、被投影部材（２０）から離れた位置に表示画像の虚像（５）を表示させる。被投影部材（２０）は、反射面（２１０）と対向する対向面（２００）を有する。対向面（２００）の中心付近は、反射面（２１０）から遠ざかる向きに突出する曲面形状に形成されている。反射面（２１０）の中心付近は、画像表示装置（３）に向かって突出する曲面形状に形成されている。虚像（５）を観察する観察者（運転者６）が虚像（５）を視認可能な視認領域（６０）の大きさのうちで観察者から見た左右方向の視認領域（６０）の幅をＥＢ１とする。対向面（２００）の曲率半径のうちで観察者から見た左右方向の対向面（２００）の曲率半径をＲ５とする。このとき、０．１≦ＥＢ１／Ｒ５≦０．７の条件を満たす。 In the virtual image display optical device (2) according to the third aspect of the present disclosure, a display image displayed by the image display device (3) and reflected by the reflection surface (210) of the reflection member (21) is projected. The projected member (20) to be projected is provided. The virtual image display optical device (2) according to the third aspect displays the virtual image (5) of the displayed image at a position away from the projected member (20). The projected member (20) has a facing surface (200) facing the reflecting surface (210). The vicinity of the center of the facing surface (200) is formed in a curved surface shape that protrudes in a direction away from the reflecting surface (210). The vicinity of the center of the reflecting surface (210) is formed in a curved surface shape that protrudes toward the image display device (3). The width of the visible area (60) in the left-right direction as seen by the observer within the size of the visible area (60) in which the observer (driver 6) observing the virtual image (5) can visually recognize the virtual image (5). Let it be EB1. Of the radii of curvature of the facing surfaces (200), the radius of curvature of the facing surfaces (200) in the left-right direction as seen from the observer is R5. At this time, the condition of 0.1 ≦ EB1 / R5 ≦ 0.7 is satisfied.
　第３の態様に係る虚像表示用光学装置（２）は、小型化を図りつつ虚像のひずみ（像面湾曲及び歪曲収差）を低減し、観察者の視認可能な視認領域（６０）を十分に確保することができる。 The virtual image display optical device (2) according to the third aspect reduces the distortion of the virtual image (curvature of field and distortion) while reducing the size, and sufficiently widens the visible area (60) visible to the observer. Can be secured.
　本開示の第４の態様に係る虚像表示用光学装置（２）は、画像表示装置（３）が表示し、かつ、反射部材（２１）の反射面（２１０）で反射された表示画像が投影される被投影部材（２０）を備える。第４の態様に係る虚像表示用光学装置（２）は、被投影部材（２０）から離れた位置に表示画像の虚像（５）を表示させる。被投影部材（２０）は、反射面（２１０）と対向する対向面（２００）を有する。対向面（２００）の少なくとも中心付近は、反射面（２１０）から遠ざかる向きに突出する曲面形状に形成されている。反射面（２１０）の少なくとも中心付近は、画像表示装置（３）に向かって突出する曲面形状に形成されている。虚像（５）を観察する観察者（運転者６）が虚像（５）を視認可能な視認領域（６０）の大きさのうちで観察者から見た上下方向の視認領域（６０）の幅をＥＢ２とする。対向面（２００）の曲率半径のうちで観察者から見た上下方向の対向面（２００）の曲率半径をＲ６とする。このとき、０．０５≦ＥＢ２／Ｒ６≦０．２５の条件を満たす。 In the virtual image display optical device (2) according to the fourth aspect of the present disclosure, a display image displayed by the image display device (3) and reflected by the reflection surface (210) of the reflection member (21) is projected. The projected member (20) to be projected is provided. The virtual image display optical device (2) according to the fourth aspect displays the virtual image (5) of the displayed image at a position away from the projected member (20). The projected member (20) has a facing surface (200) facing the reflecting surface (210). At least near the center of the facing surface (200) is formed in a curved surface shape that projects in a direction away from the reflecting surface (210). At least near the center of the reflecting surface (210) is formed in a curved surface shape that protrudes toward the image display device (3). The width of the vertical viewing area (60) seen by the observer within the size of the viewing area (60) in which the observer (driver 6) observing the virtual image (5) can see the virtual image (5). Let it be EB2. Of the radii of curvature of the facing surfaces (200), the radius of curvature of the facing surfaces (200) in the vertical direction as seen by the observer is R6. At this time, the condition of 0.05 ≦ EB2 / R6 ≦ 0.25 is satisfied.
　第４の態様に係る虚像表示用光学装置（２）は、小型化を図りつつ虚像のひずみ（像面湾曲及び歪曲収差）を低減し、観察者の視認可能な視認領域（６０）を十分に確保することができる。 The virtual image display optical device (2) according to the fourth aspect reduces the distortion of the virtual image (curvature of field and distortion) while reducing the size, and sufficiently widens the visible area (60) visible to the observer. Can be secured.
　本開示の第５の態様に係る虚像表示用光学装置（２）は、第１－第４の態様のいずれかとの組合せにより実現され得る。第５の態様に係る虚像表示用光学装置（２）において、画像表示装置（３）において表示画像が表示される表示面（３０）から反射面（２１０）までの第１光路（ＬＣ１）の長さをＬＤとし、反射面（２１０）から対向面（２００）までの第２光路（ＬＣ２）の長さをＬＭとしたときに、１．０≦ＬＭ／ＬＤ≦５．０の条件を満たすことが好ましい。 The virtual image display optical device (2) according to the fifth aspect of the present disclosure can be realized by combining with any of the first to fourth aspects. In the virtual image display optical device (2) according to the fifth aspect, the length of the first optical path (LC1) from the display surface (30) to the reflection surface (210) on which the display image is displayed in the image display device (3). When the length of the second optical path (LC2) from the reflecting surface (210) to the facing surface (200) is LM, the condition of 1.0 ≦ LM / LD ≦ 5.0 is satisfied. Is preferable.
　第５の態様に係る虚像表示用光学装置（２）は、虚像（５）を表示するための光線と画像表示装置（３）の干渉を抑えつつ小型化を図ることができる。 The virtual image display optical device (2) according to the fifth aspect can be miniaturized while suppressing interference between the light beam for displaying the virtual image (5) and the image display device (3).
　本開示の第６の態様に係る虚像表示用光学装置（２）は、第１－第５の態様のいずれかとの組合せにより実現され得る。第６の態様に係る虚像表示用光学装置（２）において、観察者が虚像（５）を視認可能な視認領域（６０）から虚像（５）までの最短の距離（ＶＩＤ）が２５００ｍｍ以下であることが好ましい。 The virtual image display optical device (2) according to the sixth aspect of the present disclosure can be realized by combining with any one of the first to fifth aspects. In the virtual image display optical device (2) according to the sixth aspect, the shortest distance (VID) from the visible area (60) where the observer can see the virtual image (5) to the virtual image (5) is 2500 mm or less. Is preferable.
　第６の態様に係る虚像表示用光学装置（２）は、距離（ＶＩＤ）を２５００ｍｍ以下とすることにより、観察者が遠方景色にピントを合わせている状態から、虚像（５）にピントを合わせるまでのピント調整時間を短縮したまま、更なる小型化を図ることができる。 The virtual image display optical device (2) according to the sixth aspect focuses on the virtual image (5) from the state where the observer is focusing on the distant view by setting the distance (VID) to 2500 mm or less. It is possible to further reduce the size while shortening the focus adjustment time.
　本開示の第７の態様に係る虚像表示用光学装置（２）は、第１－第６の態様のいずれかとの組合せにより実現され得る。第７の態様に係る虚像表示用光学装置（２）は、観察者（６）が虚像（５）を視認可能な視認領域（６０）から虚像（５）を見たときに虚像（５）を形成する光線のうちで、被投影部材（２０）から視認領域（６０）に向かう光線が反射部材（２１）と重ならないように構成されていることが好ましい。 The virtual image display optical device (2) according to the seventh aspect of the present disclosure can be realized by combining with any one of the first to sixth aspects. The virtual image display optical device (2) according to the seventh aspect displays the virtual image (5) when the observer (6) sees the virtual image (5) from the visible area (60) in which the virtual image (5) can be visually recognized. Among the light rays to be formed, it is preferable that the light rays from the projected member (20) toward the viewing region (60) are configured so as not to overlap with the reflecting member (21).
　第７の態様に係る虚像表示用光学装置（２）は、観察者から見て虚像（５）が反射部材（２１）でけられることを防ぐことができる。 The virtual image display optical device (2) according to the seventh aspect can prevent the virtual image (5) from being dispelled by the reflecting member (21) when viewed from the observer.
　本開示の第８の態様に係る虚像表示用光学装置（２）は、第１－第６の態様のいずれかとの組合せにより実現され得る。第８の態様に係る虚像表示用光学装置（２）は、観察者（６）が虚像（５）を視認可能な視認領域（６０）から虚像（５）を見たときに虚像（５）を形成する光線のうちで、画像表示装置（３）から反射部材（２１）へ向かう光線が画像表示装置（３）と重ならないように構成されていることが好ましい。 The virtual image display optical device (2) according to the eighth aspect of the present disclosure can be realized by combining with any one of the first to sixth aspects. The virtual image display optical device (2) according to the eighth aspect displays the virtual image (5) when the observer (6) sees the virtual image (5) from the visible area (60) in which the virtual image (5) can be visually recognized. Among the light rays to be formed, it is preferable that the light rays from the image display device (3) toward the reflecting member (21) are configured so as not to overlap with the image display device (3).
　第８の態様に係る虚像表示用光学装置（２）は、観察者から見て虚像（５）が画像表示装置（３）でけられることを防ぐことができる。 The virtual image display optical device (2) according to the eighth aspect can prevent the virtual image (5) from being dispelled by the image display device (3) when viewed from the observer.
　本開示の第９の態様に係る虚像表示用光学装置（２）は、第１－第８の態様のいずれかとの組合せにより実現され得る。第９の態様に係る虚像表示用光学装置（２）は、反射部材（２１）を更に備えることが好ましい。 The virtual image display optical device (2) according to the ninth aspect of the present disclosure can be realized by combining with any of the first to eighth aspects. The virtual image display optical device (2) according to the ninth aspect preferably further includes a reflective member (21).
　第９の態様に係る虚像表示用光学装置（２）は、反射部材（２１）を備えることで光線を折り曲げることができ、搭載スペースの有効活用を図ることができる。 The virtual image display optical device (2) according to the ninth aspect can bend light rays by providing the reflective member (21), and can effectively utilize the mounting space.
　本開示の第１０の態様に係る虚像表示システム（１）は、画像表示装置（３）と、第１－第９の態様のいずれかの虚像表示用光学装置（２）とを備える。 The virtual image display system (1) according to the tenth aspect of the present disclosure includes an image display device (3) and an optical device (2) for displaying a virtual image according to any one of the first to ninth aspects.
　第１０の態様に係る虚像表示システム（１）は、虚像表示用光学装置（２）の小型化を図りつつ虚像のひずみ（像面湾曲及び歪曲収差）の発生を抑制することができる。 The virtual image display system (1) according to the tenth aspect can suppress the occurrence of distortion of the virtual image (curvature field curvature and distortion) while reducing the size of the virtual image display optical device (2).
　本開示の第１１の態様に係る移動体（自動車４）は、第１０の態様に係る虚像表示システム（１）を有する。 The moving body (vehicle 4) according to the eleventh aspect of the present disclosure has a virtual image display system (1) according to the tenth aspect.
　第１１の態様に係る移動体は、虚像表示用光学装置（２）の小型化を図りつつ虚像のひずみ（像面湾曲及び歪曲収差）の発生を抑制することができる。 The moving body according to the eleventh aspect can suppress the occurrence of distortion of the virtual image (curvature of field and distortion) while reducing the size of the optical device (2) for displaying the virtual image.
　１　虚像表示システム
　２　虚像表示用光学装置
　３　画像表示装置
　４　自動車（移動体）
　５　虚像
　６　運転者（観察者）
　２０　被投影部材
　２１　反射部材
　３０　表示面
　６０　視認領域
　２００　対向面
　２１０　反射面
　Ｒｍｘ　第１曲率半径
　Ｒ１　第１曲率半径の最小値
　Ｒｃｘ　第２曲率半径
　Ｒ２　第２曲率半径の最小値
　Ｒｍｙ　第３曲率半径
　Ｒ３　第３曲率半径の最小値
　Ｒｃｙ　第４曲率半径
　Ｒ４　第４曲率半径の最小値
　Ｒ５　左右方向の対向面の曲率半径
　Ｒ６　上下方向の対向面の曲率半径
　ＬＣ１　第１光路
　ＬＤ　第１光路の長さ
　ＬＣ２　第２光路
　ＬＭ　第２光路の長さ 1 Virtual image display system 2 Optical device for virtual image display 3 Image display device 4 Automobile (moving body)
5 Virtual image 6 Driver (observer)
20 Projected member 21 Reflective member 30 Display surface 60 Visible area 200 Facing surface 210 Reflective surface Rmx First radius of curvature R1 Minimum value of first radius of curvature Rcx Second radius of curvature R2 Minimum value of second radius of curvature Rmy Third radius of curvature R3 Minimum value of the third radius of curvature Rcy Fourth radius of curvature R4 Minimum value of the fourth radius of curvature R5 Radius of curvature of the opposing surfaces in the left-right direction R6 Radius of curvature of the opposing surfaces in the vertical direction LC1 First optical path LD Length of the first optical path LC2 2nd light path LM 2nd light path length

Claims (11)

  1. 　画像表示装置が表示し、かつ、反射部材の反射面で反射された表示画像が投影される被投影部材を備え、前記被投影部材から離れた位置に前記表示画像の虚像を表示させるための虚像表示用光学装置であって、
    　前記被投影部材は、前記反射面と対向する対向面を有し、かつ、前記対向面の中心付近が前記反射面から遠ざかる向きに突出する曲面形状に形成されており、
    　前記反射面の中心付近は、前記画像表示装置に向かって突出する曲面形状に形成されており、
    　前記反射面の曲率半径のうちで前記虚像を観察する観察者から見た左右方向の曲率半径である第１曲率半径の最小値をＲ１とし、前記対向面の曲率半径のうちで前記左右方向の曲率半径である第２曲率半径の最小値をＲ２としたときに、
    　１．６３＜Ｒ２／Ｒ１≦４．５０
    の条件を満たす、
    虚像表示用光学装置。     A virtual image for displaying a virtual image of the displayed image at a position away from the projected member, which is provided with a projected member which is displayed by the image display device and on which the displayed image reflected by the reflecting surface of the reflecting member is projected. An optical device for display
    The projected member has a facing surface facing the reflecting surface, and is formed in a curved surface shape in which the vicinity of the center of the facing surface projects in a direction away from the reflecting surface.
    The vicinity of the center of the reflective surface is formed in a curved surface shape that protrudes toward the image display device.
    Of the radius of curvature of the reflecting surface, the minimum value of the first radius of curvature, which is the radius of curvature in the left-right direction as seen by the observer observing the virtual image, is R1, and the radius of curvature of the facing surface in the left-right direction When the minimum value of the second radius of curvature, which is the radius of curvature, is R2,
    1.63 <R2 / R1 ≤ 4.50
    Satisfy the conditions of
    Optical device for displaying virtual images.
  2. 　画像表示装置が表示し、かつ、反射部材の反射面で反射された表示画像が投影される被投影部材を備え、前記被投影部材から離れた位置に前記表示画像の虚像を表示させるための虚像表示用光学装置であって、
    　前記被投影部材は、前記反射面と対向する対向面を有し、かつ、前記対向面の中心付近が前記反射面から遠ざかる向きに突出する曲面形状に形成されており、
    　前記反射面の中心付近は、前記画像表示装置に向かって突出する曲面形状に形成されており、
    　前記反射面の曲率半径のうちで前記虚像を観察する観察者から見た上下方向の曲率半径である第３曲率半径の最小値をＲ３とし、前記対向面の曲率半径のうちで前記上下方向の曲率半径である第４曲率半径の最小値をＲ４としたときに、
    　１．６３＜Ｒ４／Ｒ３＜６．００
    の条件を満たす、
    虚像表示用光学装置。     A virtual image for displaying a virtual image of the displayed image at a position away from the projected member, which is provided with a projected member which is displayed by the image display device and on which the displayed image reflected by the reflecting surface of the reflecting member is projected. An optical device for display
    The projected member has a facing surface facing the reflecting surface, and is formed in a curved surface shape in which the vicinity of the center of the facing surface projects in a direction away from the reflecting surface.
    The vicinity of the center of the reflective surface is formed in a curved surface shape that protrudes toward the image display device.
    Of the radius of curvature of the reflecting surface, the minimum value of the third radius of curvature, which is the radius of curvature in the vertical direction as seen by the observer observing the virtual image, is R3, and the radius of curvature of the facing surface in the vertical direction is defined as R3. When the minimum value of the fourth radius of curvature, which is the radius of curvature, is R4,
    1.63 <R4 / R3 <6.00
    Satisfy the conditions of
    Optical device for displaying virtual images.
  3. 　画像表示装置が表示し、かつ、反射部材の反射面で反射された表示画像が投影される被投影部材を備え、前記被投影部材から離れた位置に前記表示画像の虚像を表示させるための虚像表示用光学装置であって、
    　前記被投影部材は、前記反射面と対向する対向面を有し、かつ、前記対向面の中心付近が前記反射面から遠ざかる向きに突出する曲面形状に形成されており、
    　前記反射面の中心付近は、前記画像表示装置に向かって突出する曲面形状に形成されており、
    　前記虚像を観察する観察者が前記虚像を視認可能な視認領域の大きさのうちで前記観察者から見た左右方向の前記視認領域の幅をＥＢ１とし、前記対向面の曲率半径のうちで前記観察者から見た左右方向の前記対向面の曲率半径をＲ５としたときに、
    　０．１≦ＥＢ１／Ｒ５≦０．７
    の条件を満たす、
    虚像表示用光学装置。     A virtual image for displaying a virtual image of the displayed image at a position away from the projected member, which is provided with a projected member which is displayed by the image display device and on which the displayed image reflected by the reflecting surface of the reflecting member is projected. An optical device for display
    The projected member has a facing surface facing the reflecting surface, and is formed in a curved surface shape in which the vicinity of the center of the facing surface projects in a direction away from the reflecting surface.
    The vicinity of the center of the reflective surface is formed in a curved surface shape that protrudes toward the image display device.
    Of the size of the visible area in which the observer observing the imaginary image can see the imaginary image, the width of the visible area in the left-right direction as seen by the observer is EB1, and the radius of curvature of the facing surface is the same. When the radius of curvature of the facing surface in the left-right direction as seen from the observer is R5,
    0.1 ≤ EB1 / R5 ≤ 0.7
    Satisfy the conditions of
    Optical device for displaying virtual images.
  4. 　画像表示装置が表示し、かつ、反射部材の反射面で反射された表示画像が投影される被投影部材を備え、前記被投影部材から離れた位置に前記表示画像の虚像を表示させるための虚像表示用光学装置であって、
    　前記被投影部材は、前記反射面と対向する対向面を有し、かつ、前記対向面の少なくとも中心付近が前記反射面から遠ざかる向きに突出する曲面形状に形成されており、
    　前記反射面の少なくとも中心付近は、前記画像表示装置に向かって突出する曲面形状に形成されており、
    　前記虚像を観察する観察者が前記虚像を視認可能な視認領域の大きさのうちで前記観察者から見た上下方向の前記視認領域の幅をＥＢ２とし、前記対向面の曲率半径のうちで前記観察者から見た上下方向の前記対向面の曲率半径をＲ６としたときに、
    　０．０５≦ＥＢ２／Ｒ６≦０．２５
    の条件を満たす、
    虚像表示用光学装置。     A virtual image for displaying a virtual image of the displayed image at a position away from the projected member, which is provided with a projected member which is displayed by the image display device and on which the displayed image reflected by the reflecting surface of the reflecting member is projected. An optical device for display
    The projected member has a facing surface facing the reflecting surface, and is formed in a curved surface shape in which at least the vicinity of the center of the facing surface projects in a direction away from the reflecting surface.
    At least near the center of the reflective surface is formed in a curved surface shape that protrudes toward the image display device.
    Of the size of the visible area in which the observer observing the virtual image can see the virtual image, the width of the visible area in the vertical direction as seen by the observer is EB2, and the radius of curvature of the facing surface is the same. When the radius of curvature of the facing surface in the vertical direction as seen from the observer is R6,
    0.05 ≤ EB2 / R6 ≤ 0.25
    Satisfy the conditions of
    Optical device for displaying virtual images.
  5. 　前記画像表示装置において前記表示画像が表示される表示面から前記反射面までの第１光路の長さをＬＤとし、前記反射面から前記対向面までの第２光路の長さをＬＭとしたきに、
    　１．０≦ＬＭ／ＬＤ≦５．０
    の条件を満たす、
    請求項１－４のいずれか１項に記載の虚像表示用光学装置。     In the image display device, the length of the first optical path from the display surface on which the display image is displayed to the reflection surface is defined as LD, and the length of the second optical path from the reflection surface to the facing surface is defined as LM. To,
    1.0 ≤ LM / LD ≤ 5.0
    Satisfy the conditions of
    The optical device for displaying a virtual image according to any one of claims 1-4.
  6. 　前記観察者が前記虚像を視認可能な視認領域から前記虚像までの最短の距離が２５００ｍｍ以下である、
    請求項１－５のいずれか１項に記載の虚像表示用光学装置。     The shortest distance from the visible area where the observer can see the virtual image to the virtual image is 2500 mm or less.
    The optical device for displaying a virtual image according to any one of claims 1-5.
  7. 　前記観察者が前記虚像を視認可能な視認領域から前記虚像を見たときに前記虚像を形成する光線のうちで、前記被投影部材から前記視認領域に向かう光線が前記反射部材と重ならないように構成されている、請求項１－６のいずれか１項に記載の虚像表示用光学装置。 Among the light rays forming the virtual image when the observer sees the virtual image from a visible area where the virtual image can be visually recognized, the light rays from the projected member toward the visible area do not overlap with the reflective member. The virtual image display optical device according to any one of claims 1 to 6, which is configured.
  8. 　前記観察者が前記虚像を視認可能な視認領域から前記虚像を見たときに前記虚像を形成する光線のうちで、前記画像表示装置から前記反射部材へ向かう光線が前記画像表示装置と重ならないように構成されている、
    請求項１－６のいずれか１項に記載の虚像表示用光学装置。     Among the light rays forming the virtual image when the observer sees the virtual image from a visible area where the virtual image can be visually recognized, the light rays from the image display device toward the reflection member do not overlap with the image display device. Is composed of,
    The optical device for displaying a virtual image according to any one of claims 1-6.
  9. 　前記反射部材を更に備える、
    請求項１－８のいずれか１項に記載の虚像表示用光学装置。     The reflective member is further provided.
    The optical device for displaying a virtual image according to any one of claims 1-8.
  10. 　前記画像表示装置と、請求項１－９のいずれかの虚像表示用光学装置とを備える、
    虚像表示システム。     An image display device and an optical device for displaying a virtual image according to any one of claims 1-9.
    Virtual image display system.
  11. 　請求項１０の虚像表示システムを有する、
    移動体。     The virtual image display system of claim 10 is provided.
    Mobile body.
PCT/JP2020/035620 2019-11-26 2020-09-18 Optical device for virtual image display, virtual image display system, and moving body WO2021106335A1 (en)

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