JP6478151B2 - Image display device and object device - Google Patents

Description

  The present invention relates to an image display device and an object device, and more particularly to an image display device that enables a virtual image to be visually recognized through a transmission / reflection member and an object device including the image display device.

  2. Description of the Related Art Conventionally, a head-up display device (image display device) that makes it possible to visually recognize a virtual image through a windshield (transmission / reflection member) of a vehicle is known (see, for example, Patent Document 1).

  In the head-up display device disclosed in Patent Document 1, the visibility of a virtual image cannot be improved without causing an increase in size.

The present invention includes an image forming unit that forms an image with light and emits the light that has formed the image, and a concave mirror that reflects the light from the image forming unit toward a transmissive reflecting member. forming unit forms or the images the image is formed, seen including a transmission member which is curved in a convex shape on the concave mirror side, the light forming the center of the image, other than the center of the concave mirror A part of the light incident on the position and reflected at a position other than the center of the concave mirror is reflected by the transmission / reflection member and is incident on the center of the eye box .

  According to the present invention, the visibility of a virtual image can be improved without increasing the size.

1 is a diagram schematically illustrating a configuration of an image display device according to an embodiment. It is a figure for demonstrating a light source part. FIG. 3A is a diagram showing an optical path from the flat screen to the concave mirror, and FIG. 3B is a graph showing the field curvature of the virtual image when the flat screen is used. FIG. 4A is a diagram showing an optical path from the curved screen to the concave mirror, and FIG. 4B is a graph showing the field curvature of the virtual image when the curved screen is used. It is a figure for demonstrating the diffusion effect | action by a micro convex lens structure. FIG. 6A is a diagram for explaining the merits when the curved screen is a transmission type, and FIG. 6B is a diagram for explaining the demerits when the curved screen is a reflection type. It is a figure for demonstrating the incident position (Xm, Ym) to the concave mirror of the light radiate | emitted from the center of the image formed in the curved screen. FIG. 8A is a diagram showing a virtual image when the light from the curved screen is eccentrically incident on the concave mirror, and FIG. 8B is the case where the light from the flat screen is eccentrically incident on the concave mirror. FIG. 8C is a diagram illustrating a virtual image when light from the curved screen is non-eccentrically incident on the concave mirror, and FIG. 8D is a diagram illustrating light from the flat screen. It is a figure which shows the virtual image at the time of making it enter into a concave mirror non-eccentrically. FIG. 10 is a diagram for explaining an image forming unit according to a second modification. FIG. 10A and FIG. 10B are diagrams for explaining diffusion by the fine convex lens and generation of coherent noise. FIG. 10 is a diagram for explaining an image forming unit according to a first modification. 12A to 12C are views (No. 1 to No. 3) for explaining the shape of the intermediate image formed on the cylindrical curved screen having a curvature in the longitudinal direction. FIGS. 13A to 13C are diagrams (No. 1 to No. 3) for explaining the shape of an intermediate image formed on a toroidal curved screen having a curvature in the longitudinal direction and the lateral direction. . 14A to 14C are views (No. 1 to No. 3) for explaining the shape of the intermediate image formed on the spherical curved screen. FIGS. 15A to 15C are diagrams (No. 1 to No. 3) for explaining the shape of the intermediate image formed on the curved surface having a free-form surface. FIG. 3 is a diagram illustrating field curvature according to the first exemplary embodiment. FIG. 6 is a diagram illustrating curvature of field of Example 2. FIG. 10 is a diagram illustrating curvature of field of Example 3. FIG. 10 is a diagram illustrating the curvature of field of the fourth embodiment. FIG. 10 is a diagram illustrating curvature of field of Example 5. FIG. 10 is a diagram illustrating curvature of field of Example 6. FIG. 10 is a diagram illustrating curvature of field of Example 7. FIG. 10 is a diagram illustrating field curvature in Example 8. FIG. 10 is a diagram illustrating field curvature in Example 9. It is a figure showing the curvature of field of Example 10. FIG. 10 is a diagram illustrating field curvature in Example 11. FIG. 10 is a diagram illustrating the field curvature of Example 12. It is a figure showing the curvature of field of Example 13. It is a figure showing the curvature of field of Example 14. FIG. 20 is a diagram illustrating the curvature of field of Example 15. FIG. 20 is a diagram illustrating the field curvature of Example 16. FIG. 20 is a diagram illustrating the field curvature of Example 17. FIG. 19 is a diagram illustrating curvature of field according to Example 18. FIG. 20 is a diagram illustrating curvature of field of Example 19. FIG. 22 is a diagram illustrating curvature of field of Example 20.

  Hereinafter, an embodiment will be described.

  An image display apparatus 1000 according to an embodiment is a head-up display that displays a two-dimensional color image. FIG. 1 schematically illustrates the entire apparatus.

  As an example, the image display apparatus 1000 is mounted on a moving body such as a vehicle, an aircraft, and a ship, and navigation information (for example, speed) necessary for maneuvering the moving body through the windshield 10 (front windshield) of the moving body. , Information such as travel distance) is made visible. In this case, the windshield 10 also functions as a transmission / reflection member that transmits a part of the incident light and reflects at least a part of the remaining part. In the following description, an abc three-dimensional orthogonal coordinate system (coordinate system that moves with the moving body) set for the moving body is used as appropriate. Here, the a direction is the left-right direction of the moving body (the + a direction is the right direction and the -a direction is the left direction), and the b direction is the up-down direction of the moving body (the + b direction is the upward direction and the -b direction is the downward direction). The c direction is the front-rear direction of the moving body (the -c direction is the forward direction and the + c direction is the backward direction). Hereinafter, an example in which the image display apparatus 1000 is mounted on a vehicle (for example, an automobile) will be described.

  A head-up display as the image display apparatus 1000 includes, for example, a light source unit 100, a two-dimensional deflection unit 6, a concave mirror 7, a curved screen 8, and a concave mirror 9.

  In FIG. 1, a portion denoted by reference numeral 100 is a “light source unit”, and a pixel display beam LC for color image display is emitted from the light source unit 100.

  The pixel display beam LC includes one beam of three colors of red (hereinafter referred to as “R”), green (hereinafter referred to as “G”), and blue (hereinafter referred to as “B”). This is a combined beam.

  That is, the light source unit 100 has a configuration as shown in FIG.

  In FIG. 2, a semiconductor laser as a light source indicated by reference signs RS, GS, and BS emits R, G, and B laser beams, respectively. Here, a laser diode (LD) also called an edge emitting laser is used as each semiconductor laser.

  Coupling lenses indicated by reference numerals RCP, GCP, and BCP suppress the divergence of each laser beam emitted from the semiconductor lasers RS, GS, and BS.

  Each color laser beam whose divergence is suppressed by the coupling lenses RCP, GCP, and BCP is shaped by the aperture RAP, GAP, and BAP (the beam diameter is regulated).

The shaped laser beam of each color enters the beam combining prism 101.
The beam combining prism 101 includes a dichroic film D1 that transmits R color light and reflects G light, and a dichroic film D2 that transmits R and G color light and reflects B color light.

  Accordingly, the R, G, and B color laser beams are combined into one beam and emitted from the beam combining prism 101.

The emitted light beam is converted into a “parallel beam” having a predetermined light beam diameter by the lens 102.
This “parallel beam” is the pixel display beam LC.

  The R, G, and B color laser beams constituting the pixel display beam LC are intensity-modulated (according to image data) by an image signal of a “two-dimensional color image” to be displayed. The intensity modulation may be a direct modulation method that directly modulates a semiconductor laser, or an external modulation method that modulates a laser beam emitted from the semiconductor laser.

  That is, the emission intensity of the semiconductor lasers RS, GS, and BS is modulated by image signals of R, G, and B color components by a driving unit (not shown).

  The pixel display beam LC emitted from the light source unit 100 enters the two-dimensional deflection unit 6 and is two-dimensionally deflected.

  In the present embodiment, the two-dimensional deflecting means 6 is configured to swing a minute mirror with “two axes orthogonal to each other” as a swing axis.

  That is, the two-dimensional deflecting means 6 is specifically a two-dimensional scanner including a MEMS (Micro Electro Mechanical Systems) mirror manufactured as a micro oscillating mirror element by a semiconductor process or the like.

  The two-dimensional deflecting means is not limited to this example, but has another configuration, for example, two micro mirrors (for example, a MEMS mirror or a galvano mirror) that swing around one axis, and the swing directions are orthogonal to each other. It may be a combination.

  The pixel display beam LC deflected two-dimensionally as described above enters the concave mirror 7 and is reflected toward the curved screen 8.

  As an example, the curved screen 8 is a transmission member in which a rectangular plate-like member having the a direction as the longitudinal direction is curved in the longitudinal direction (a direction) (see FIG. 5). The “transmitting member” means a member that transmits at least part of incident light. That is, the curved screen 8 is a curved structure having translucency. The curved screen 8 will be described in detail later.

  The concave mirror 7 is designed to correct the bending of the scanning line (scanning trajectory) generated on the curved screen 8.

  The pixel display beam LC reflected by the concave mirror 7 is incident on the curved screen 8 while being translated along with the deflection by the two-dimensional deflection means 6, and scans the curved screen 8 two-dimensionally. That is, the curved screen 8 is two-dimensionally scanned (for example, raster scan) in the main scanning direction and the sub-scanning direction by the pixel display beam LC.

  By this two-dimensional scanning, a “color image” as an intermediate image is formed on the curved screen 8. Here, an effective scanning region (also referred to as an effective image region) having a shape obtained by curving a rectangle on the curved screen 8 in the longitudinal direction is two-dimensionally scanned, and an intermediate image is formed in the effective scanning region (see FIG. 5).

  That is, an intermediate image forming unit (image forming unit) is configured including the light source unit 100, the two-dimensional deflecting unit 6, the concave mirror 7, and the curved screen 8.

  Of course, what is displayed on the curved screen 8 at each moment is “only the pixel irradiated with the pixel display beam LC at that moment”.

A color two-dimensional image is formed as a “collection of pixels displayed at each moment” by two-dimensional scanning with a pixel display beam LC.
The “color image” is formed on the curved screen 8 as described above, and the pixel display beam LC that forms the color image, that is, the light transmitted through the curved screen 8 is incident on and reflected by the concave mirror 9 (concave mirror).

  Although not shown in FIG. 1, the curved screen 8 has a “fine convex lens structure” that transmits each pixel display beam LC as will be described later. The concave mirror 9 constitutes a “virtual image imaging optical system”.

  As will be described in detail later, the concave mirror 9 has a horizontal line (horizontal line) in a virtual image of a “color image” (intermediate image) formed on the curved screen 8 by the influence of the curved windshield 10 which is inclined with respect to the horizontal plane. It is designed and arranged so as to correct a two-dimensional distortion in which a vertically convex shape and a two-dimensional distortion in which a vertical line (vertical line) has a horizontally convex shape.

The “virtual image imaging optical system” forms an enlarged virtual image I of the “color image”. Hereinafter, the enlarged virtual image I is also simply referred to as “virtual image”.
A windshield 10 is disposed on the front side of the imaging position of the magnified virtual image I, and reflects the light beam that forms the magnified virtual image I toward the viewer. Note that an observer (for example, an operator who controls a moving body) creates a virtual image from the eye box 60 (region near the eyes of the observer) on the optical path of the laser light reflected by the windshield 10 (transmission / reflection member). Visually check. Here, the eye box 60 means a range where a virtual image can be visually recognized without adjusting the position of the viewpoint. Specifically, the eye box 60 is equal to or less than the driver's eye range (JIS D0021).

  With this reflected light, the observer can visually recognize the magnified virtual image I.

  In the case shown in FIG. 1, the direction a is usually the left-right direction for the observer, and this direction is also referred to as the “lateral direction”. A direction orthogonal to the horizontal direction (direction a) is also referred to as a “vertical direction”.

  The curved screen 8 has a convex curved structure on the concave mirror 9 side as a whole. Here, the curved screen 8 is curved with a constant curvature only in the a direction (x direction), that is, in the lateral direction (see FIG. 5). That is, the shape of the curved screen 8 is a cylinder shape. The shape of the curved screen 8 is not limited to the cylinder shape that is curved with a constant curvature only in such a horizontal direction. For example, the shape of the cylinder that is curved with a constant curvature only in the vertical direction, It may be a toroidal shape that is curved with different curvatures in the lateral direction, a spherical shape that is curved with a uniform curvature, a free-form surface shape, or the like.

  Here, the observer places a viewpoint on the eye box 60 and visually recognizes the magnified virtual image I through the windshield 10, but if a flat screen is disposed between the concave mirror 7 and the concave mirror 9, Due to the deflection operation by the two-dimensional deflection means 6 and the magnified reflection by the concave mirror 9, curvature of field (three-dimensional distortion) occurs in the magnified virtual image I.

  Therefore, the curvature of field can be effectively corrected by using a curved screen curved so as to cancel the curvature of field.

  Furthermore, in this embodiment, the curved screen is a “transmission type” as described above. More specifically, when the curved screen is “transmission type”, as shown in FIG. 6A, the scanning line by the two-dimensional deflection means becomes concave on the concave surface side of the curved screen, and the light is collected on the curved screen. The image formed on the curved screen becomes clear.

  On the other hand, when the curved screen is “reflective”, as shown in FIG. 6B, the scanning line by the two-dimensional deflection means becomes convex on the convex surface side of the curved screen, and the light is condensed on the curved screen. The image formed on the curved screen becomes unclear.

  As a result, when a reflective curved screen is used, it is necessary to correct the scanning line with a free curved lens so that the scanning line matches the screen shape, but when a transmissive curved screen is used, it is corrected with a free curved lens. There is no need.

  As shown in FIG. 3A, when a flat screen is used, variation in the optical path length of light emitted from the flat screen and incident on the concave mirror increases. That is, the optical path length difference between the center light and the end light is increased. As a result, the field curvature increases (see FIG. 3B). FIG. 3B shows the MTF (Modulation Transfer Function) / defocus characteristic when the viewpoint is placed at the left end of the eye box 60.

  On the other hand, as shown in FIG. 4A, when a convex curved screen is used on the concave mirror side, the variation in the optical path length of light emitted from the curved screen and incident on the concave mirror is reduced. That is, the optical path length difference between the center light and the end light is reduced. As a result, field curvature is reduced (see FIG. 4B). FIG. 4B shows the MTF / defocus characteristic when the viewpoint is placed at the left end of the eye box 60.

  As a result, field curvature can be effectively suppressed by using a curved screen.

The curved screen 8 has a fine convex lens structure as described above.
As will be described later, the micro-convex lens structure is “a plurality of micro-convex lenses (micro lenses) arranged closely in a three-dimensional manner at a pitch close to the pixel pitch so as to form the above“ curved structure ”as a whole”. . That is, the curved screen 8 is a microlens array that is curved as a whole.

  Here, the plurality of fine convex lenses are three-dimensionally arranged at a predetermined pitch along a virtual curved surface convex toward the concave mirror 9 so that the convex surface becomes a surface on the incident side. As a specific arrangement form, for example, a matrix-like arrangement in which a direction (x direction) is a row direction and one direction (y direction) orthogonal to the a direction in the virtual curve is a column direction, or a honeycomb shape (A zigzag array).

  The planar shape of each micro-convex lens is, for example, a circle or a regular N-gon (N is a natural number of 3 or more). Here, each of the fine convex lenses has the same curvature (curvature radius).

  Each fine convex lens has a function of isotropically diffusing the pixel display beam LC. That is, each fine convex lens has an even diffusion power in all directions. The “diffusion function” will be briefly described below.

  In FIG. 5, reference numerals L <b> 1 to L <b> 4 indicate four pixel display beams incident on the curved screen 8.

  These four pixel display beams L <b> 1 to L <b> 4 are pixel display beams incident on the four corners of the image formed on the curved screen 8.

  When these four pixel display beams L1 to L4 pass through the curved screen 8, they are converted into beams L11 to L14.

  If a light beam having a laterally long quadrilateral shape surrounded by the pixel display beams L1 to L4 is incident on the curved screen 8, this light beam is expressed as “a cross-sectional shape surrounded by the beams L11 to L14 has a horizontally long quadrilateral shape. "Divergent luminous flux".

  This function of the micro-convex lens is a “diffusion function”.

  The “divergent light beam surrounded by the beams L11 to L14” is a result of temporally collecting the pixel display beams thus converted into the divergent light beam.

  The pixel display beam is diffused so that “the light beam reflected by the windshield 10 irradiates a wide area near the eyes of the observer”.

  In the absence of the diffusing function, the light beam reflected by the windshield 10 irradiates only the “narrow region near the eyes of the observer”.

  For this reason, when the observer moves his / her head and the position of the eyes deviates from the “narrow area”, the observer cannot visually recognize the magnified virtual image I.

  As described above, the light beam reflected by the windshield 10 irradiates a “wide area near the eyes of the observer” by diffusing the pixel display beam LC. That is, the eye box 60 can be enlarged.

  Therefore, even if the observer “moves his head a little”, the magnified virtual image I can be reliably recognized.

  Hereinafter, a microlens array used as the curved screen 8 will be described with reference to FIGS. 10A and 10B. Here, for convenience, a plurality of fine convex lenses (microlenses) are provided on a virtual plane. An example of a microlens array arranged two-dimensionally will be described.

In FIG. 10A, reference numeral 802 denotes a microlens array. The micro lens array 802 has a micro convex lens structure in which micro convex lenses 801 are arranged. The beam diameter 807 of the “pixel display beam” indicated by reference numeral 803 is smaller than the size of the fine convex lens 801. That is, the size 806 of the fine convex lens 801 is larger than the beam diameter 807. In the present embodiment, the pixel display beam 803 is a laser beam, and forms a Gaussian light intensity distribution around the center of the beam. Therefore, the light beam diameter 807 is a distance in the radial direction of the light beam at which the light intensity in the light intensity distribution decreases to “1 / e ² ”.

In FIG. 10A, the beam diameter 807 is drawn equal to the size 806 of the fine convex lens 801, but the beam diameter 807 does not have to be equal to the “size 806 of the fine convex lens 801”.
The size 806 of the fine convex lens 801 may not be taken out.
In FIG. 10A, the entire pixel display beam 803 is incident on one minute convex lens 801 and converted into a diffused light beam 804 having a divergence angle 805. The “divergence angle” may be referred to as “diffusion angle” below.

  In the state of FIG. 10A, since there is one diffused light beam 804 and no light beam that interferes, no coherent noise is generated. The size of the divergence angle 805 can be set as appropriate depending on the shape of the fine convex lens 801.

  In FIG. 10B, the pixel display beam 811 has a light beam diameter that is twice the arrangement pitch 812 of the fine convex lenses, and is incident across the two fine convex lenses 813 and 814. In this case, the pixel display beam 811 is diffused as two divergent light beams 815 and 816 by the two incident micro convex lenses 813 and 814. The two divergent light beams 815 and 816 overlap in a region 817 and interfere with each other at this portion to generate coherent noise (speckle noise).

  Here, as described above, when the windshield 10 is inclined and curved with respect to the horizontal plane, the magnified virtual image I has an asymmetrical distortion (two-dimensional distortion, hereinafter simply referred to as “distortion”). Occurs.

  Therefore, in this embodiment, in order to effectively correct this distortion, that is, to generate a distortion opposite to the distortion caused by the windshield 10, the reflecting surface (concave surface) has a curvature as the concave mirror 9. A free-form curved mirror with a distribution is used.

  More specifically, the reflecting surface of the concave mirror 9 is expressed by a high-order XY polynomial in the Z coordinate in the three-dimensional orthogonal coordinates (X, Y, Z) with the center coordinate being (0, 0, 0). . The X direction is the horizontal direction, and the Y direction is the vertical direction.

  Here, the XY polynomial of the concave mirror 9 is designed so that distortion can be corrected according to the inclination and curvature of the windshield 10 (see Tables 1 to 5). Tables 1 to 5 describe coefficients for each degree of the XY polynomial in each example of the present embodiment.

  The XY polynomial of the concave mirror 9 increases the distortion correction effect as the distance from the center of the concave mirror 9 increases.

  Therefore, in the present embodiment, the light emitted from the center of the intermediate image (image) formed on the curved screen 8, that is, the light that forms the center of the intermediate image (light that is visually recognized as the center of the enlarged virtual image I) is a concave mirror. The positional relationship between the curved screen 8 and the concave mirror 9 is set so as to be incident (eccentric incident) at positions (Xm, Ym) other than the center (0, 0) of 9 (see FIG. 7). It should be noted that the light emitted from the center of the intermediate image and reflected at a position other than the center of the concave mirror 9 is reflected by the windshield 10 and is incident on the center of the eyebox 60. An image forming unit and a concave mirror 9 are laid out. That is, the center of the eye box 60 corresponds to the center of the enlarged virtual image I that is the virtual image at the center of the intermediate image.

  Here, the intermediate image has a shape obtained by curving a rectangle in the longitudinal direction, and the center of the intermediate image means an intersection of diagonal lines of the intermediate image.

  As a result, in the present embodiment, it is possible to effectively correct the distortion as compared with a case where light emitted from the center of the intermediate image is incident on the center of the concave mirror 9 (non-eccentric incidence).

  Tables 1 to 5 show the incident positions (Xm, Ym) of the light emitted from the center of the intermediate image (light incident on the center of the eye box 60) on the concave mirror 9 in Examples 1 to 20 of the present embodiment. Specific examples of these are shown. In each example, it can be seen that (Xm, Ym) is not (0, 0) but an eccentric incidence.

  8A to 8D show specific examples of virtual image distortion. The lattice points in each figure are ideal virtual images without distortion, and the solid lines are virtual images obtained by simulation.

  FIG. 8A shows a virtual image when the light from the curved screen 8 is eccentrically incident on the concave mirror 9. From FIG. 8A, it can be seen that the distortion is small for both the vertical and horizontal lines.

  FIG. 8B shows a virtual image when light from the flat screen is incident eccentrically on the concave mirror 9. FIG. 8B shows that the distortion of the vertical line is small, but the distortion of the horizontal line is large.

  FIG. 8C shows a virtual image when the light from the curved screen 8 is incident on the concave mirror 9 non-eccentrically. It can be seen from FIG. 8C that the vertical line distortion is large and the horizontal line distortion is small.

  FIG. 8D shows a virtual image when light from the flat screen is incident on the concave mirror 9 non-eccentrically. From FIG. 8D, it can be seen that the distortion is large for both the vertical and horizontal lines.

  As a result, the curved screen 8 is used as a screen on which the intermediate image is formed, and the light that forms the center of the intermediate image is incident on a position other than the center of the concave mirror 9, thereby effectively reducing the curvature of field and distortion. Can be corrected.

In the present embodiment, it is preferable that the following expression (1) is satisfied.
0.15 ≦ R / L ≦ 2.0 (1)
However, the optical path length from the center of the intermediate image of the light emitted from the center of the intermediate image formed on the curved screen 8 and incident on the concave mirror 9 to the concave mirror 9 is L,
When the curved screen 8 has a cylindrical shape having a curvature in the longitudinal direction or the short direction, the curvature radius in the longitudinal direction or the short direction of the curved screen 8 is R,
When the curved screen 8 has a toroidal shape having a curvature in the longitudinal direction, the radius of curvature of the curved screen 8 in the longitudinal direction is R,
When the curved screen 8 has a spherical shape with a uniform curvature, the radius of curvature of the curved screen 8 is R.

  The above equation (1) is a conditional equation for appropriately determining the radius of curvature of the curved screen 8. If R / L exceeds the upper limit (2.0) of the above equation (1), the curvature radius of the curved screen 8 becomes too large (the curvature is too small), so that the field curvature cannot be corrected.

  On the other hand, if R / L falls below the lower limit (0.15) of the above equation (1), the radius of curvature of the curved screen 8 is too small (the curvature is too large) and the curvature of field cannot be corrected. The distance between 8 and the concave mirror 9 becomes too large, which is disadvantageous for miniaturization.

In the present embodiment, it is preferable that the following expression (2) is satisfied.
0.01 ≦ β / R ≦ 0.7 (2)
However, a value obtained by dividing (dividing) the length in the a direction (lateral direction) of the virtual image visually recognized through the windshield 10 by the length in the a direction (lateral direction) of the intermediate image (image) is β,
When the curved screen 8 has a cylinder shape having a curvature in the longitudinal direction or the short direction, the curvature radius in the longitudinal direction or the short direction of the curved screen 8 is R [mm],
When the curved screen 8 has a toroidal shape having a curvature in the longitudinal direction, the curvature radius in the longitudinal direction of the curved screen 8 is R [mm]
When the curved screen 8 has a spherical shape with a uniform curvature, the radius of curvature of the curved screen 8 is R [mm].

  The above expression (2) is a conditional expression for appropriately setting the lateral magnification of the projection optical system including the curved screen 8 and the concave mirror 9.

  If β / R exceeds the upper limit (0.7) of the above equation (2), the magnification in the a direction (lateral direction) of the projection optical system becomes too high, and distortion is likely to occur.

  On the other hand, if β / R falls below the lower limit (0.01) of the above equation (2), the magnification in the a direction (lateral direction) of the projection optical system becomes too low, which is disadvantageous for miniaturization.

In the present embodiment, it is preferable that the following expression (3) is satisfied.
0.01 ≦ α / R ≦ 0.7 (3)
However, a value obtained by dividing (dividing) the length in the b direction (vertical direction) of the virtual image visually recognized through the windshield 10 by the length in the b direction (vertical direction) of the intermediate image (image) is α,
When the curved screen 8 has a cylinder shape having a curvature in the longitudinal direction or the short direction, the curvature radius in the longitudinal direction or the short direction of the curved screen 8 is R [mm],
When the curved screen 8 has a toroidal shape having a curvature in the longitudinal direction, the curvature radius in the longitudinal direction of the curved screen 8 is R [mm]
When the curved screen 8 has a spherical shape with a uniform curvature, the radius of curvature of the curved screen 8 is R [mm].

  The above expression (3) is a conditional expression for appropriately setting the vertical magnification of the projection optical system including the curved screen 8 and the concave mirror 9.

  If α / R exceeds the upper limit (0.7) of the above expression (3), the magnification in the b direction (vertical direction) of the projection optical system becomes too high, and distortion is likely to occur, which is not preferable.

  On the other hand, if α / R falls below the lower limit (0.01) of the above formula (3), the magnification in the b direction (vertical direction) of the projection optical system becomes too low, which is not preferable because it is disadvantageous for miniaturization.

In the present embodiment, it is preferable that the following expression (4) is satisfied.
0.005 ≦ R / Limg ≦ 0.15 (4)
However, the distance from the viewpoint of the observer who observes the virtual image of the intermediate image formed on the curved screen 8 through the windshield 10 to the virtual image is Limg,
When the curved screen 8 has a cylindrical shape having a curvature in the longitudinal direction or the short direction, the curvature radius in the longitudinal direction or the short direction of the curved screen 8 is R,
When the curved screen 8 has a toroidal shape having a curvature in the longitudinal direction, the radius of curvature of the curved screen 8 in the longitudinal direction is R,
When the curved screen 8 has a spherical shape with a uniform curvature, the radius of curvature of the curved screen 8 is R.

  The above expression (4) is a conditional expression for appropriately determining the radius of curvature of the curved screen 8 and the distance between the viewpoint virtual images.

  If R / Limg exceeds the upper limit (0.15) of the above equation (4), the radius of curvature of the curved screen 8 becomes too large, and the effect of correcting field curvature is reduced, which is not desirable.

  On the other hand, if R / Limg is below the lower limit (0.005) of the above equation (4), the radius of curvature of the curved screen 8 becomes too small, and the field curvature is overcorrected, which is not desirable.

In the present embodiment, it is preferable that the following expression (5) is satisfied.
0.8 ≦ R / R ′ ≦ 2.2 (5)
However, when the curved screen 8 has a toroidal shape having different curvatures in the longitudinal direction and the short direction, the curvature radius in the longitudinal direction of the curved screen 8 is R and the curvature radius R ′ in the short direction.

  By making the curved screen 8 a toroidal shape having different curvatures in the longitudinal direction and the lateral direction, it is possible to effectively correct field curvature in the horizontal direction and the vertical direction of the virtual image.

  The above formula (5) is a condition for appropriately determining the curvature radius in the longitudinal direction and the short direction of the curved screen 8 when the curved screen 8 has a toroidal shape.

  If R / R ′ exceeds the upper limit (2.2) of the above equation (5), the curvature radius in the longitudinal direction of the curved screen 8 becomes too large to correct the curvature of field.

  On the other hand, if R / R ′ falls below the lower limit (0.8) of the above equation (5), the curvature radius in the short direction of the curved screen 8 becomes too large to correct the curvature of field.

  Here, when the concave mirror 7 that corrects the bending of the scanning line (scanning trajectory) is not disposed between the two-dimensional deflecting unit 6 and the curved screen 8 as in the image forming unit of Modification 1 shown in FIG. The light from the light source unit is scanned in an arc shape by the two-dimensional deflection means 6.

  Therefore, if the curved clean 8 is arranged so as to match the scanning line scanned in an arc shape, an optical member such as a free-form surface lens and a concave mirror 7 is arranged on the optical path between the two-dimensional deflection means 6 and the curved screen 8. Thus, there is no need to correct the scanning line (there is no need to make the scanning surface flat), and it is possible to reduce the number of parts and the sensitivity of tolerance.

  Table 1 shown below shows optical setting values in Examples 1 to 4. Table 2 shows optical setting values in Examples 5 to 8. Table 3 shows optical setting values in Examples 9 to 12. Table 4 shows optical setting values in Examples 13 to 16. Table 5 shows optical setting values in Examples 17 to 20. In Table 6, R / L, β / R [1 / mm], α / R [1 / mm], R / Limg, and R / R ′ in each example are listed to the third decimal place.

  In Tables 1 to 5, the xyw coordinate system set for the curved screen 8 (transmission member) (the x direction is the horizontal direction, the y direction is the vertical direction, and the w direction is orthogonal to both the x direction and the y direction). , See FIG. 5), and the XY coordinate system set for the concave mirror 9 is used. R is the radius of curvature of the curved screen 8. However, when the shape of the curved screen 8 is a cylinder shape having a curvature in the longitudinal direction or the short direction, the curvature radius in the longitudinal direction or the short direction of the curved screen 8 is R, and the shape of the curved screen 8 is a curvature in the longitudinal direction. In the case of a toroidal shape having R, the radius of curvature of the curved screen 8 in the longitudinal direction is R, the radius of curvature in the short direction is R ′, and the shape of the curved screen 8 is a spherical shape having a uniform curvature. Let R be the radius of curvature.

The concave mirror 9 which is a free-form curved mirror is defined by the following equation (a). Here, z is the sag amount of the surface parallel to the Z axis, c is the curvature of the surface vertex (that is, the radius of curvature is 1 / c), r is the vertical distance from the central axis of the concave mirror 9, k is the conic constant, and Cj is It is a coefficient of an XY polynomial.

  12A to 15C show specific examples of intermediate images formed on the curved screen 8 (transmission member).

  In Examples 1 to 10, the curved screen 8 has a cylindrical shape having a curvature in the longitudinal direction (lateral direction) (see FIGS. 12A to 12C). 16 to 25 show MTF / defocus characteristics representing field curvature in Examples 1 to 10, respectively.

  In Examples 11 to 15, the shape of the curved screen 8 is a toroidal shape having different curvatures in the longitudinal direction (lateral direction) and the short direction (vertical direction) (see FIGS. 13A to 13C). ). 26 to 30 show MTF / defocus characteristics representing field curvature in Examples 11 to 15, respectively.

  In Examples 16 to 18, the curved screen 8 has a spherical shape (see FIGS. 14A to 14C). 31 to 33 show MTF / defocus characteristics representing the curvature of field in Examples 16 to 18, respectively.

  In Examples 19 and 20, the shape of the curved screen 8 is a free-form surface. 34 and 35 show MTF / defocus characteristics representing the curvature of field in Examples 19 and 20, respectively.

  In any of the examples, it can be seen that the curvature of field is suppressed by using the curved screen 8.

  As described above, the head-up display described above can be used for in-vehicle use such as an automobile, for example. The a direction is “lateral direction when viewed from the driver's seat” and the b direction is “vertical direction”.

  In this case, for example, a “navigation image” can be displayed as an enlarged virtual image I in front of the windshield 10 of an automobile or the like, and the driver who is an observer moves his / her line of sight almost from the front of the windshield 10 while staying in the driver seat. Without observing.

  In such a case, as described above, the magnified virtual image I to be displayed is a “horizontal image as viewed from the driver”, that is, the image (intermediate image) formed on the microlens array and the magnified virtual image I are It is generally preferable that the image has a large angle of view in the a direction.

In addition, as described above, when the driver who is an observer looks at the display image from the left and right oblique directions, the horizontal direction has a “large viewing angle compared to the vertical direction” so that the display can be recognized. Required.
For this reason, a larger diffusion angle (isotropic diffusion) is required in the longitudinal direction (a direction) of the magnified virtual image I than in the lateral direction (b direction).

  Therefore, each micro-convex lens (micro-lens) of the micro-convex lens structure (micro-lens array) has an anamorphic lens in which the curvature in the longitudinal direction is larger than the short direction of the intermediate image or magnified virtual image I formed on the curved screen 8. It is preferable that the diffusion angle for diffusing the pixel display beam is “the horizontal direction of the intermediate image is wider than the vertical direction”.

  In this way, it is possible to diverge light within the minimum necessary range that satisfies the required angle of view of the head-up display, improve the light utilization efficiency, and improve the brightness of the display image.

Of course, it is possible to use “isotropic diffusion” in which the diffusion angles are equal in the vertical direction and the horizontal direction, instead of the above-mentioned “isotropic diffusion”.
However, in the case of a head-up display used for in-vehicle use such as an automobile, it is not easy for the driver to observe the display image from a vertical position.
Therefore, in such a case, as described above, it is preferable from the viewpoint of light utilization efficiency that the diffusion angle for diffusing the pixel display beam is “wider the horizontal direction of the intermediate image than the vertical direction”.

  It has been conventionally known that a micro-convex lens (micro lens) can be formed as an “aspherical surface”.

  The anamorphic lens surface described immediately above is also “aspherical”, but the lens surface of the micro-convex lens can be formed as a more general aspherical surface, and aberration correction can also be performed.

  It is also possible to reduce “diffuse intensity unevenness” by correcting aberrations.

  The micro-convex lens having the micro-convex lens structure diffuses the pixel display beam as described above. However, it may be possible to diffuse only one of the two directions of the x direction and the y direction.

  In such a case, a “fine convex cylinder surface” can be used as the lens surface of the fine convex lens.

  It has been conventionally known that the shape of the micro-convex lens is a hexagonal shape and the arrangement thereof is a honeycomb type in relation to the method of manufacturing the microlens array.

  The image display apparatus 1000 (head-up display) according to the present embodiment described above forms an intermediate image (image) with light, emits light that forms the image, and light from the image forming unit. And a concave mirror 9 that reflects the light toward the windshield 10 (transmission / reflection member), and the image forming unit is a transmission member (curved screen 8) curved in a convex shape on the concave mirror 9 side on which an image is formed. including.

  In this case, it is possible to suppress the curvature of field of the virtual image without increasing the number of parts.

  As a result, according to the image display apparatus 1000, the visibility of a virtual image can be improved without causing an increase in the size of the apparatus.

  On the other hand, an optical member (lens, mirror, etc.) for suppressing curvature of field of the virtual image may be provided (added) separately from the curved screen (or flat screen), but in this case, the number of parts increases. Resulting in. As a result, the influence of the manufacturing error and installation error of each component on the visibility of the virtual image is increased, and the size of the apparatus is increased.

  Moreover, when the shape of the curved screen 8 is a cylinder shape having a curvature in the longitudinal direction or the lateral direction, it is possible to suppress the curvature of field in the longitudinal direction or the lateral direction of the virtual image. Therefore, it is preferable that the curved screen 8 has a curvature in a direction in which field curvature is likely to occur in the longitudinal direction and the short direction of the virtual image.

  Further, when the curved screen 8 has a cylindrical shape having a curvature in the longitudinal direction, it is possible to effectively correct the curvature of the virtual image in the longitudinal direction, which increases due to the large angle of view.

  Moreover, when the shape of the curved screen 8 is a toroidal shape having a curvature in the longitudinal direction and the lateral direction, it is possible to suppress the curvature of field in the longitudinal direction and the lateral direction of the virtual image.

  Moreover, when the shape of the curved screen 8 is a spherical shape, it is possible to suppress field curvature in the longitudinal direction and the short direction of the virtual image.

  Moreover, when the shape of the curved screen 8 is a free-form surface shape, it is possible to suppress the field curvature of the entire virtual image.

  Further, the windshield 10 is inclined and curved with respect to the horizontal plane, and the light emitted from the center of the intermediate image is incident on a portion other than the center of the concave mirror 9.

  In this case, the distortion of the virtual image due to the inclination and curvature of the windshield 10 can be effectively corrected.

  Note that the inclination and shape of the windshield 10 vary depending on the vehicle type, and some of them have a very small inclination or very large degree of inclination and curvature. In either case, the image display device In 1000, the distortion of the virtual image can be suppressed by designing the concave mirror 9 and adjusting the incident position of the light forming the center of the intermediate image on the concave mirror 9 (which can be finely decentered).

  Thus, in a moving body (for example, a vehicle) on which the image display device 1000 is mounted, the operator can quickly and reliably visually recognize the information (virtual image) displayed by the image display device without stress.

  In the above-described embodiment, a color image is formed using a plurality of light sources. However, a single light source is used as in the image forming units of Modifications 1 and 2 shown in FIGS. A monochrome image may be formed. Note that in the image forming unit of Modification 1 shown in FIG. 11, a light source unit corresponding to a color image similar to that of the light source unit 100 of the above-described embodiment may be provided.

  Moreover, in the said embodiment and each modification, although the curved convex micro convex lens structure (micro lens array) is used as a curved screen as a whole, it is not restricted to this, For example, the curved permeation | transmission board, the curved reflection A plate, a curved diffusion plate, or the like may be used.

  However, the curved screen is preferably “transmissive” rather than “reflective”.

  In the microlens array of the above embodiment and each modification, a plurality of microlenses are arranged three-dimensionally along the virtual curved surface. Instead, they are arranged two-dimensionally along the virtual curved line. May be.

  In the above-described embodiment and each modification, an image is formed by two-dimensional scanning using a two-dimensional deflection unit on the screen. For example, a one-dimensional deflection unit including a MEMS mirror, a galvanometer mirror, a polygon mirror, or the like. A one-dimensional scan may be used to form an image.

  Moreover, in the said embodiment and each modification, although LD (edge-emitting laser) is used as a light source, it is not restricted to this, VCSEL (surface emitting laser), LED (light emitting diode), an organic EL element, a lamp, Lasers other than semiconductor lasers may be used. Further, the optical system for guiding the light from the light source to the curved screen 8 can be changed as appropriate.

  Moreover, in the said embodiment and the modification 2, you may provide a plane mirror instead of the concave mirror 7. FIG.

  Moreover, in the said embodiment and each modification, although the image formation part is comprised including the light source part, the two-dimensional deflection | deviation means 6, and the curved screen 8 (curved transmission member), it is not restricted to this. For example, as a third modification, an image forming element (imaging device) such as a transmissive liquid crystal panel, a reflective liquid crystal panel, or a DMD (digital micromirror device) panel, and a light source may be included. That is, the image forming element may be a transmissive type or a reflective type. Here, examples of the light source include a cold cathode fluorescent tube, a lamp, an LED (light emitting diode), an organic EL element, a semiconductor laser (LD or VCSEL), a laser other than a semiconductor laser, and the like. The imaging device may form either a color image or a monochrome image.

  When such an image forming element is used instead of the screen, the liquid crystal panel or the DMD panel may be flat as a whole. However, as with the curved screen 8 of the above embodiment and each modification, It is preferable that the DMD panel has a curved structure convex toward the concave mirror 9 as a whole. The image forming element having this curved structure has, for example, the same shape as that of the curved screen 8 as a whole, and is arranged such that the longitudinal direction coincides with the lateral direction and the lateral direction coincides with the longitudinal direction.

  In other words, the image forming element has an image display panel (for example, a virtual curved surface) arranged such that a plurality of display units (for example, liquid crystal) corresponding to a plurality of pixels of image data form a curved structure as a whole. A liquid crystal panel). The image forming element is a digital micromirror device (DMD panel) in which a plurality of micromirrors corresponding to a plurality of pixels of image data are arranged (along the virtual curved surface) so as to form a curved structure as a whole. There may be. When the image forming element has a curved structure, the “transmission type” is preferable to the “reflection type” as in the case of the curved screen described above.

  Even when an image forming element having a curved structure is used instead of a curved screen, the above expression (1) is preferably satisfied. Also in this case, the same effects as those in the above embodiment and the first and second modifications can be obtained. However, the optical path length from the center of the image to the concave mirror 9 of the light emitted from the center of the image on the image forming element and incident on the concave mirror 9 is L, and the image forming element has a curvature in the longitudinal direction or the short side direction. In the case of the cylinder shape, the radius of curvature in the longitudinal direction or the short side direction of the image forming element is R, and when the image forming element is a toroidal shape having a curvature in the longitudinal direction, the radius of curvature in the longitudinal direction of the image forming element is Let R be the radius of curvature of the image forming element when the image forming element has a spherical shape with a uniform curvature.

  In addition, when the curved image forming element is used instead of the curved screen, the above expression (2) is preferably satisfied. Also in this case, the same effects as those in the above embodiment and the first and second modifications can be obtained. However, a value obtained by dividing (dividing) the length in the a direction (lateral direction) of the virtual image visually recognized through the windshield 10 by the length in the a direction (lateral direction) of the intermediate image (image) is β, When the image forming element has a cylindrical shape having a curvature in the longitudinal direction or the short direction, the radius of curvature in the longitudinal direction or the short direction of the image forming element is R [mm], and the image forming element has a curvature in the longitudinal direction. In the case of a toroidal shape, the radius of curvature of the image forming element in the longitudinal direction is R [mm], and when the image forming element is a spherical shape having a uniform curvature, the radius of curvature of the image forming element is R [mm]. .

  Further, when the curved image forming element is used instead of the curved screen, it is preferable that the above expression (3) is satisfied. Also in this case, the same effects as those in the above embodiment and the first and second modifications can be obtained. However, a value obtained by dividing (dividing) the length in the b direction (vertical direction) of the virtual image visually recognized through the windshield 10 by the length in the b direction (vertical direction) of the intermediate image (image) is α, When the image forming element has a cylindrical shape having a curvature in the longitudinal direction or the short direction, the radius of curvature in the longitudinal direction or the short direction of the image forming element is R [mm], and the image forming element has a curvature in the longitudinal direction. In the case of a toroidal shape, the radius of curvature of the image forming element in the longitudinal direction is R [mm], and when the image forming element is a spherical shape having a uniform curvature, the radius of curvature of the image forming element is R [mm]. .

  In addition, when the curved image forming element is used instead of the curved screen, the above expression (4) is preferably satisfied. Also in this case, the same effects as those in the above embodiment and the first and second modifications can be obtained. However, the distance from the viewpoint of the observer who observes the virtual image of the intermediate image formed on the image forming element through the windshield 10 to the virtual image is Limg, and the image forming element has a curvature in the longitudinal direction or the lateral direction. In the case of the shape, the radius of curvature in the longitudinal direction or the short side direction of the image forming element is R, and in the case where the image forming element has a toroidal shape having a curvature in the longitudinal direction, the radius of curvature in the longitudinal direction of the image forming element is R. When the image forming element has a spherical shape having a uniform curvature, R is the radius of curvature of the image forming element.

  Further, when the curved image forming element is used in place of the curved screen, it is preferable that the expression (5) is satisfied. Also in this case, the same effects as those in the above embodiment and the first and second modifications can be obtained. However, when the image forming element has a toroidal shape having different curvatures in the longitudinal direction and the short direction, the curvature radius in the longitudinal direction of the image forming element is R, and the curvature radius R ′ in the short direction.

  When the image forming element is used instead of the screen, the light emitted from the center of the image on the image forming element may be incident (eccentric incident) at a position other than the center of the concave mirror 9. In this case, the image forming element can correct distortion even if the overall shape is flat (flat), but if the liquid crystal panel or DMD panel has a curved structure convex toward the concave mirror 9, the curvature of field and Both distortions can be corrected.

  Moreover, in the said embodiment and each modification, although the light radiate | emitted from the center of the image on a curved structure (a curved screen or a curved imaging device) is incident on positions other than the center of the concave mirror 9, it is concave. You may make it inject into the center of the mirror 9 (non-eccentric incidence).

  Moreover, in the said embodiment and each modification, although the intermediate image on a curved structure is the shape which curved the rectangle, it is not restricted to this, For example, the shape which curved circular or ellipse, rectangles, such as a square A shape obtained by curving a parallelogram other than the above, or a shape obtained by curving a pentagon or more regular polygon.

  Moreover, in the said embodiment and each modification, when making it enter into the concave-surface mirror 9 eccentrically, it may replace with a curved screen and may use a flat screen. The flat screen may be a transmission type or a reflection type, and specifically includes a flat microlens array, a flat transmission plate, a flat reflection plate, a flat diffusion plate, and the like.

  Further, in the above-described embodiment and each modified example, in the case where the incident light is incident on the concave mirror 9, R / L may be a value that deviates from the range of the above expression (1).

  Further, in the above-described embodiment and each modification, in the case where the incident light is eccentrically incident on the concave mirror 9, β / R may be a value that deviates from the range of the above expression (2).

  Further, in the above embodiment and each modified example, in the case where the incident light is incident on the concave mirror 9, α / R may be a value that deviates from the range of the above expression (3).

  Further, in the above-described embodiment and each modified example, in the case where the light is incident on the concave mirror 9 eccentrically, R / Limg may be a value that deviates from the range of the above expression (4).

  Further, in the above-described embodiment and each modification, in the case where the incident light is eccentrically incident on the concave mirror 9, R / R ′ may be a value that deviates from the range of the above expression (5).

  Moreover, in the said embodiment and each modification, although the free-form surface mirror with curvature distribution is used as the concave mirror 9, you may use a concave mirror with a constant curvature.

  In addition, the transmission / reflection member is not limited to the windshield of the moving body, but for example, a passenger of the moving body such as a side glass and a rear glass (for example, a pilot, a navigator, a crew member, a passenger) can visually recognize the outside of the moving body. Other window members may be used. Further, the transmission / reflection member is not limited to glass but may be made of resin, for example.

  The transmission / reflection member is formed of a member different from the window member (for example, the windshield) of the moving body, for example, a so-called combiner, and is disposed in front of the window member as viewed from the observer. Also good. Also in this case, the design of the concave mirror 9 according to the shape and inclination of the transmission / reflection member, the eccentric incidence to the concave mirror 9, the setting of the curvature radius of the screen, the setting of the positional relationship between the screen and the concave mirror 9 and the like are performed. Is preferred.

  In addition, the transmission / reflection member is only required to satisfy at least one of being inclined and curved with respect to the horizontal plane. For example, the transmission / reflection member may be a flat member inclined with respect to the horizontal plane, or may be a curved member perpendicular to the horizontal plane.

  Moreover, in the said embodiment and each modification, although the image display apparatus demonstrated as an example what was mounted in moving bodies, such as a vehicle, an aircraft, a ship, etc., the point will be as long as it is mounted in an object. good. Also in this case, an object device including an object and an image forming apparatus mounted on the object can obtain the same effects as those of the above-described embodiment and each modification. In this case, the image display apparatus may or may not include a transmission / reflection member as a component. Note that the “object” includes, in addition to a moving object, a permanently installed object and a transportable object.

  Further, the image display device of the present invention is not limited to the one mounted on the object, but can be applied to, for example, a device installed alone or a device that can be attached to a human body (for example, a head mounted display). For example, it can be implemented as an image display device for movie appreciation.

  LC: pixel display beam (light based on image data), 6: two-dimensional deflection means (deflection means, part of image forming unit), 7 ... concave mirror (part of image forming unit), 8 ... curved screen (curved) , A transparent mirror, 10 a concave mirror, 10 a windshield (transmission reflection member), 100 a light source part (a part of the image forming part), 1000 an image display device.

Japanese Patent No. 5370427

Claims (16)

An image forming unit that forms an image with light and emits light that has formed the image;
A concave mirror that reflects the light from the image forming unit toward the transmission / reflection member,
The image forming unit forms or the images the image is formed, seen including a transmission member which is curved in a convex shape on the concave mirror side, the light forming the center of the image, the center of the concave mirror Part of the light that is incident on a position other than the center of the concave mirror and reflected at a position other than the center of the concave mirror is reflected by the transmissive reflecting member and is incident on the center of the eye box .   The image display device according to claim 1, wherein the transmissive member has a cylindrical shape having a curvature in a longitudinal direction or a lateral direction.   The image display device according to claim 1, wherein a shape of the transmissive member is a toroidal shape having a curvature in a longitudinal direction.   The image display apparatus according to claim 1, wherein a shape of the transmissive member is a spherical shape.   The image display device according to claim 1, wherein the shape of the transmissive member is a free-form surface. 0.15 ≦ R / L ≦ 2.0
The image display apparatus according to claim 1, wherein: is satisfied.
However, the optical path length from the center of the intermediate image of the light emitted from the center of the intermediate image formed on the transmission member and incident on the concave mirror to the concave mirror is L,
When the transmission member has a cylindrical shape having a curvature in the longitudinal direction or the short direction, the radius of curvature in the longitudinal direction or the short direction of the transmission member is R,
When the transmission member has a toroidal shape having a curvature in the longitudinal direction, the curvature radius in the longitudinal direction of the transmission member is R,
Let R be the radius of curvature of the transmitting member when the transmitting member has a spherical shape with a uniform curvature. 0.01 ≦ β / R ≦ 0.7
The image display device according to claim 1, wherein: is satisfied.
However, a value obtained by dividing the horizontal length of the virtual image visually recognized through the transmission and reflection member by the horizontal length of the image is β,
When the transmission member has a cylindrical shape having a curvature in the longitudinal direction or the short direction, the curvature radius in the longitudinal direction or the short direction of the transmission member is R [mm],
When the transmissive member has a toroidal shape having a curvature in the longitudinal direction, the radius of curvature in the longitudinal direction of the transmissive member is R [mm],
When the transmissive member has a spherical shape with a uniform curvature, the radius of curvature of the transmissive member is R [mm]. 0.01 ≦ α / R ≦ 0.7
The image display apparatus according to claim 1, wherein: is satisfied.
However, a value obtained by dividing the vertical length of the virtual image visually recognized through the transmission and reflection member by the vertical length of the image is α,
When the transmission member has a cylindrical shape having a curvature in the longitudinal direction or the short direction, the curvature radius in the longitudinal direction or the short direction of the transmission member is R [mm],
When the transmissive member has a toroidal shape having a curvature in the longitudinal direction, the radius of curvature in the longitudinal direction of the transmissive member is R [mm],
When the transmissive member has a spherical shape with a uniform curvature, the radius of curvature of the transmissive member is R [mm]. 0.005 ≦ R / Limg ≦ 0.15
Is satisfied, The image display apparatus as described in any one of Claims 1-8 characterized by the above-mentioned.
However, the distance from the viewpoint of the observer who observes the virtual image of the image through the transmission / reflection member to the virtual image is Limg,
When the transmission member has a cylindrical shape having a curvature in the longitudinal direction or the short direction, the radius of curvature in the longitudinal direction or the short direction of the transmission member is R,
When the transmission member has a toroidal shape having a curvature in the longitudinal direction, the curvature radius in the longitudinal direction of the transmission member is R,
Let R be the radius of curvature of the transmitting member when the transmitting member has a spherical shape with a uniform curvature.   10. The image display device according to claim 2, wherein when the transmission member has a cylindrical shape, the transmission member has a curvature in a longitudinal direction. When the transmissive member has a toroidal shape, the transmissive member has a curvature in the short direction, the radius of curvature in the longitudinal direction of the transmissive member is R, and the radius of curvature R ′ in the short direction.
The image display device according to claim 6, wherein 0.8 ≦ R / R ′ ≦ 2.2 is satisfied.   The image display device according to claim 1, wherein the transmission member is a microlens array. The image forming unit includes:
A light source that emits light based on image data;
A scanning optical system having a deflection unit that scans the transmission member with light from the light source unit, and
The image display apparatus according to any one of claims 1 to 12, characterized in that does not include the optical member between the transparent member and the deflecting means. An image forming unit that forms an image with light and emits light that has formed the image;
A concave mirror that reflects the light from the image forming unit toward the transmission / reflection member,
The light that forms the center of the image is incident on a position other than the center of the concave mirror, and a part of the light reflected at a position other than the center of the concave mirror is reflected by the transmissive reflecting member and reflected by the eye box. An image display device that enters the center . The transmissive reflecting member, an image display apparatus according to any one of claims 1 to 14, characterized in that a window member of the moving body. The image display device according to any one of claims 1 to 15 ,
And an object on which the image display device is mounted.

Images