JP2018200489A - Lens array, image display device, and movable body - Google Patents

Abstract

To provide a lens array that can increase visibility of an optical image to be formed irrespective of the shapes of lenses.SOLUTION: A microlens array is a lens array in which a plurality of microlenses 881 are individually arranged on a plurality of lattice points (virtual points) having a pitch with periodicity (regularity). The plurality of microlenses each have a length in a Y-direction longer than a length in an X-direction orthogonal to the Y-direction. The apex positions 884 of the plurality of microlenses are shifted from the lattice points on which the microlenses are arranged. The sum total of the amounts of shift in the Y-direction of the apex positions from the lattice points is larger than the sum total of the amounts of shift in the X-direction.SELECTED DRAWING: Figure 13

Description

  The present invention relates to a lens array, an image display device, and a moving body, and more particularly to a lens array including a plurality of lenses, an image display device including the lens array, and a moving body including the image display device.

  Conventionally, a microlens array including a plurality of microlenses is known (see, for example, Patent Document 1).

  Incidentally, the microlens array disclosed in Patent Document 1 has room for improvement in the visibility of an optical image formed by the microlens array, depending on the shape of the microlens.

  The present invention provides a lens array in which a plurality of lenses are individually arranged on a plurality of virtual points having regularity in pitch, and each of the plurality of lenses has a length in a first direction in the first direction. The vertex position of at least one lens among the plurality of lenses is longer than the length in the second direction orthogonal to each other, and is shifted from the virtual point where the lens is disposed, and the vertex position from the virtual point is In the lens array, the sum of the shift amounts in the first direction is larger than the sum of the shift amounts in the second direction.

  According to the present invention, the visibility of an optical image formed by the lens array can be improved regardless of the shape of the lens.

FIG. 1A to FIG. 1C are views (No. 1 to No. 3) for explaining an image display device according to an embodiment of the present invention. FIGS. 2A and 2B are diagrams (No. 1 and No. 2) for explaining the diffusion by the fine convex lens and the generation of coherent noise, respectively. FIGS. 3A to 3C are diagrams (No. 1 to No. 3) for explaining the removal of coherent noise, respectively. FIG. 4A to FIG. 4C are diagrams showing three examples of arrangement forms of the micro-convex lenses. Fig.5 (a)-FIG.5 (e) are figures which show 5 examples of the other example of the arrangement | sequence form of a micro convex lens. FIG. 6A and FIG. 6B are diagrams for explaining an anamorphic microconvex lens. FIGS. 7A and 7B are diagrams illustrating two examples of scanned surface elements. It is a figure which shows one example of the other example of the arrangement | sequence form of a micro convex lens. It is a figure for demonstrating the interference fringe formed on the conventional microlens array. It is a figure for demonstrating a random array lens array. It is a figure for demonstrating the vertex position of each micro lens of a random array lens array. FIG. 12A to FIG. 12C are diagrams for explaining specific examples of the vertically long random array lens array. FIGS. 13A to 13D are diagrams for explaining the apex positions of the vertically long microlenses of Comparative Examples 1 to 4, and FIGS. 13E to 13H are respectively implemented. It is a figure for demonstrating the vertex position of the vertically long microlens of Examples 1-4. FIG. 14A to FIG. 14E are diagrams for explaining the longitudinally long random array lens arrays of Examples 5 to 9, respectively.

Hereinafter, an embodiment will be described.
FIG. 1 is a diagram for explaining an image display apparatus according to an embodiment.

  An image display apparatus 1000 described with reference to FIG. 1 is a head-up display apparatus that displays a two-dimensional color image, and FIG. 1A 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 necessary for maneuvering the moving body via a transmission / reflection member (for example, a windshield) provided on the moving body. (For example, information such as speed and travel distance) is made visible. In the following description, an XYZ three-dimensional orthogonal coordinate system (coordinate system that moves with the moving body) set for the moving body is used as appropriate. The “transmission / reflection member” means a member that transmits a part of incident light and reflects at least a part of the remaining part.

  In FIG. 1A, 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 in the + Z direction.

  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. 1B, semiconductor lasers as light sources denoted by reference signs RS, GS, and BS emit R, G, and B laser beams, respectively. Here, a laser diode (LD) also called an edge emitting laser is used as each semiconductor laser. Note that a surface emitting laser (VCSEL) may be used as the semiconductor laser instead of the edge emitting laser.

  Coupling lenses indicated by reference characters 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.

  Therefore, 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 by the lens 102 into a “parallel beam” having a predetermined light beam diameter.
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 (in accordance with image information (image data)) by an image signal of a “two-dimensional color image” to be displayed. The intensity modulation may be a direct modulation system that directly modulates the semiconductor laser, or an external modulation system 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 is incident on the two-dimensional deflection unit 6 serving as an image forming element 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 deflection means 6 is specifically a MEMS (Micro Electro Mechanical Systems) 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 may be of another configuration, for example, a combination of two micro mirrors that swing around one axis so that the swing directions are orthogonal to each other.

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

The optical action of the concave mirror 7 is to take distortion of the image formed on the reflective surface element 10 by the pixel display beam LC deflected two-dimensionally.
That is, the pixel display beam LC reflected by the concave mirror 7 is incident on the scanned surface element 8 while moving in parallel with the deflection by the two-dimensional deflecting means 6, and scans the scanned surface element 8 two-dimensionally. .

  By this two-dimensional scanning, a “color two-dimensional image” is formed on the scanned surface element 8.

  Of course, what is displayed on the scanned surface element 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.
A “color two-dimensional image” is formed on the scanned surface element 8 as described above, and pixel light, which is light in pixel units (light corresponding to each pixel) of the image information, is incident on the concave mirror 9 and reflected. Is done.

  Although not shown in FIG. 1, the scanned surface element 8 has a “fine convex lens structure” to be described later. The concave mirror 9 constitutes a “virtual image imaging optical system”.

The “virtual image imaging optical system” forms an enlarged virtual image 12 of the “color two-dimensional image”.
A reflective surface element 10 is provided on the near side of the imaging position of the magnified virtual image 12, and the light beam that forms the magnified virtual image 12 is shown as an observer 11 (FIG. 1 (a) shows the eyes of the observer). Reflects to the side. Note that the observer 11 (for example, an operator who controls a moving body) visually recognizes a virtual image from a predetermined observation position on the optical path of the laser light reflected by the reflecting surface element 10 (transmission / reflection member).

  The observer 11 can visually recognize the magnified virtual image 12 by the reflected light.

  As shown in FIG. 1 (a), the vertical direction in the figure is the “Y direction”, and the direction orthogonal to the drawing is the “X direction”.

  In the case shown in FIG. 1A, the Y direction is usually the vertical direction for the observer 11, and this direction is referred to as the “vertical direction”.

  In addition, the X direction is usually the left-right direction for the observer, and this direction is referred to as the “lateral direction”.

As described above, the scanned surface element 8 has a fine convex lens structure.
As will be described later, the micro-convex lens structure is “a plurality of micro-convex lenses are closely arranged at a pitch close to the pixel pitch”.

  Here, the plurality of fine convex lenses are two-dimensionally arranged at a predetermined pitch along a plane (XY plane) orthogonal to the Z direction so that the convex surface becomes the incident surface. Specific arrangement forms include a matrix arrangement in which the X direction is the row direction and the Y direction is the column direction, and a honeycomb arrangement (zigzag arrangement). As an example, the optical axis of each fine convex lens is parallel to the Z axis.

  The planar shape (the shape seen from the Z-axis direction) of each fine convex lens is, for example, a circle, a regular N-gon (N is a natural number of 3 or more), and the like. 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. 1C, reference symbols L <b> 1 to L <b> 4 indicate four pixel display beams incident on the scanned surface element 8.

  These four pixel display beams L1 to L4 are pixel display beams incident on the four corners of the two-dimensional image formed on the scanned surface element 8.

  These four pixel display beams L1 to L4 are converted into beams L11 to L14 after passing through the scanned surface element 8.

  If a quadrilateral light beam having a horizontally long cross section surrounded by the pixel display beams L1 to L4 is incident on the surface element 8 to be scanned, this light beam will be expressed as “four cross sections surrounded by the beams L11 to L14 having a horizontally long side. A divergent luminous flux of shape.

  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 reflecting surface element 10 irradiates a wide area near the eyes of the observer 11”.

  When there is no diffusion function, the light beam reflected by the reflecting surface element 10 irradiates only “a narrow area near the eyes of the observer 11”.

  For this reason, when the observer 11 moves his / her head and the position of the eyes deviates from the “narrow area”, the observer 11 cannot visually recognize the magnified virtual image 12.

  As described above, the light beam reflected by the reflective surface element 10 irradiates a “wide area near the eyes of the observer 11” by diffusing the pixel display beam LC.

  Therefore, even if the observer “moves his head a little”, the magnified virtual image 12 can be reliably recognized.

  As described above, in the present embodiment, the pixel display beam LC incident on the scanned surface element 8 is a parallel beam, but after passing through the scanned surface element 8, it becomes a divergent beam.

  By the way, in a scanning type image display apparatus that forms an image by scanning a scanned medium (for example, a transmission type or a reflection type screen) with laser light, a virtual image that is visually recognized by strong coherence of laser light that is coherent light is generated. Speckle noise flickers irregularly. Therefore, by using a microlens array (microconvex lens structure) in which a plurality of microlenses (microconvex lenses) are arranged at a pitch close to the beam diameter of the laser beam as a scanned medium in a scanning image display device, speckles are used. The visibility of a virtual image is improved by arbitrarily controlling the divergence angle while reducing the intensity of noise.

  The to-be-scanned surface element 8 in the present invention has a “fine convex lens structure” in which a plurality of fine convex lenses that diffuse the pixel display beam LC are closely arranged at a pitch close to the pixel pitch.

  The fine convex lens is larger than “the beam diameter of the pixel display beam LC”.

  The reason why the fine convex lens is made larger than “the beam diameter of the pixel display beam LC” is to reduce the coherent noise, and this will be described below with reference to FIGS.

In FIG. 2A, reference numeral 802 denotes a scanned surface element.
The scanned surface element 802 has a fine convex lens structure in which fine 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 this 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. 2A, the light beam diameter 807 is drawn equal to the size 806 of the fine convex lens 801, but the light beam diameter 807 does not have to be equal to “the size 806 of the fine convex lens 801”.
It is sufficient that the size 806 of the fine convex lens 801 does not protrude.

  In FIG. 2A, the entire pixel display beam 803 is incident on one fine 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. 2A, there is only one diffused light beam 804 and no interfering light beam, so no coherent noise (speckle 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. 2B, 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 in this portion to generate coherent noise.

  FIG. 3A shows a state in which the pixel display beam 824 is incident across the two fine convex lenses 822 and 823 of the scanned surface element 821.

The beam diameter of the pixel display beam 824 is equal to the size of the fine convex lens 822 and the like.
In this case, the beam portion incident on the fine convex lens 822 becomes a divergent light beam 826, and the beam portion incident on the fine convex lens 823 is diffused as a divergent light beam 827.

  Since divergent light beams 826 and 827 are diffused away from each other, they do not overlap each other, and therefore no coherent noise is generated in this state.

  That is, coherent noise due to the light beam diffused by the fine convex lens is not generated if the beam diameter of the pixel display beam 824 is set to be equal to or smaller than the size of the fine convex lens 822.

  Specific numerical examples of the diameter of the fine convex lens and the beam diameter of the pixel display beam incident on the scanned surface element will be exemplified.

  It is easy to set the beam diameter of the pixel display beam to, for example, about 150 μm.

  In this case, the size of the fine convex lens constituting the fine convex lens structure may be set to the size of 150 μm or more, for example, 160 μm or 200 μm.

  In the scanned surface element 821 shown in FIG. 3A, the fine convex lenses 822, 823,... Are arranged without a gap.

Therefore, the “boundary width (hereinafter also referred to as“ boundary width ”)” of the adjacent fine convex lens surfaces is 0.
Therefore, the divergent light beams generated from the pixel display beam 824 that enters the fine convex lenses 822 and 823 as shown in FIG. 3A are only the divergent light beams 826 and 827.

  However, in the actually formed fine convex lens structure, “the boundary width between adjacent fine convex lenses is not zero”.

  That is, in the actually formed fine convex lens structure as in the scanned surface element 831 shown in FIG. 3B, the boundary portion 835 of the fine convex lenses 833 and 834 is not “width: 0”.

  Microscopically, the boundary portion 835 of the micro convex lenses 833 and 834 is “a curved surface is smoothly continuous” microscopically, and a curved surface is formed at the boundary portion 835.

  The curved surface formed in the boundary portion 835 in this way acts as a “micro lens surface” with respect to the incident light portion when the pixel display beam is incident on this portion.

  Accordingly, the pixel display beam 832 incident across the fine convex lenses 833 and 834 generates a divergent light beam 838 together with the divergent light beams 836 and 837.

  The divergent light beam 838 is generated by the lens action of the curved surface of the boundary portion 835 and overlaps and interferes with the divergent light beams 836 and 837 in the regions 839 and 840 to generate coherent noise.

  FIG. 3C is a diagram for explaining “reduction or prevention of coherent noise” in the fine convex lens structure.

  In the micro-convex lens structure, the curved surface shape of the boundary portion 843 where the lens surfaces of the micro-convex lenses 841 and 842 are gently connected itself forms a “micro lens surface”.

  The curvature radius of the curved surface shape of the boundary portion 843 is “r” as shown in the figure.

  Here, for simplicity of explanation, the pixel display beam incident on the fine convex lens structure is referred to as a “monochromatic laser beam having a wavelength of λ”.

  When the curvature radius r of the boundary portion 843 is larger than the wavelength λ of the pixel display beam (r> λ), the curved surface having the curvature radius r has a lens effect on the incident pixel display beam.

  Therefore, in this case, the beam component passing through the boundary portion 843 is diverged and overlaps and interferes with the light beam diffused by the fine convex lenses 841 and 842 to generate coherent noise.

On the other hand, when the radius of curvature r of the boundary portion 843 is smaller than the wavelength λ of the pixel display beam, the boundary portion 843 has a “sub-wavelength structure” with respect to the pixel display beam.
As is well known, the sub-wavelength structure does not cause a lens action for “light having a wavelength larger than that of the sub-wavelength structure”.
Therefore, the boundary portion 843 having a radius of curvature “r” smaller than the wavelength “λ” does not act as a “lens”, and does not allow the pixel display beam to pass straight through and diverge.

  For this reason, the beam portion transmitted straight through the boundary portion 843 and the divergent light beam diffused by the fine convex lenses 841 and 842 do not overlap with each other, and no coherent noise is generated due to interference.

That is, the size relationship between the beam diameter of the pixel display beam: d, the wavelength: λ, the size of the fine convex lens: D, and the radius of curvature of the surface forming the boundary portion: r is preferably determined as follows.
D> d, λ> r.

When the two-dimensional enlarged virtual image to be displayed is a monochrome image, a pixel display beam is formed by monochromatic coherent light having a wavelength: λ.
Therefore, in this case, coherent noise can be suppressed by setting D, d, r, and λ so as to satisfy the magnitude relationship.

  When displaying a two-dimensional color image (enlarged virtual image) as in the present embodiment, the pixel display beam LC is a combination of R, G, and B beams.

  Assuming that the wavelengths of these three beams are λR (= 640 nm), λG (= 510 nm), and λB (= 445 nm), the magnitude relationship between them is “λR> λG> λB”.

  Therefore, from the viewpoint of preventing coherent noise, the curvature radius r of the surface forming the boundary may be smaller than the shortest wavelength λB, for example, 400 nm.

  However, if a curvature radius: r (for example, 600 nm) smaller than the longest wavelength: λR is set, coherent noise due to the R component of the image display beam can be prevented.

  That is, coherent noise can be effectively reduced.

If “r (for example, 500 nm) <λG”, coherent noise due to the R component and G component light of the image display beam can be prevented.
When the pixel display beam LC is “combined of three color beams of R, G, and B”, coherent noise is generated independently for these three color components.
The “total” of coherent noises of these independent three-color R, G, and B beams is visually recognized coherent noise.
Therefore, if no interference noise is detected even in one of the three colors of interference noise, the visually recognized interference noise is greatly improved, contributing to an improvement in the image quality of the observation image.
Therefore, the effect of preventing coherent noise is effective only with “the longest wavelength R component” of the three colors, and then the “reduction effect” is improved in the order of the G component and the B component.
Therefore, if a radius of curvature: r (for example, 600 nm) smaller than the longest wavelength: λR is set, a certain effect can be achieved in reducing coherent noise.
The visibility of the coherent noise is generally higher in the order of R≈G> B, although the noise intensity varies depending on the wavelength, beam diameter, multi / single mode, and the like.
That is, the light of wavelength λB has low visibility of human eyes, and coherent noise is not noticeable.
Therefore, if the radius of curvature: r (for example, 500 nm) smaller than the wavelength: λG is set, the coherent noise due to the light with relatively high visibility: λR and λG can be reduced.
Even if coherent noise is generated by light having a wavelength of low visibility: λB, it is not so noticeable.
Of course, if the curvature radius: r (for example, 400 nm) smaller than the wavelength: λB is set, the coherent noise can be further effectively reduced as described above.

  The size of each of the plurality of fine convex lenses constituting the fine convex lens structure is on the order of 100 μm as described above, and this can be realized as a normal “micro lens”.

  Further, a fine convex lens structure in which a plurality of fine convex lenses are arranged can be realized as a “microlens array”.

  Therefore, hereinafter, the fine convex lens is also referred to as “micro lens”, and the fine convex lens structure is also referred to as “micro lens array”.

In general, the microlens array is manufactured by manufacturing a mold having a transfer surface of the lens surface array of the microlens array and transferring the mold surface to a resin material using the mold.
As a method for forming a transfer surface in a mold, a method of forming by using cutting or photolithography is known.

  The transfer surface can be transferred to the resin material by, for example, “injection molding”.

Reducing the radius of curvature at the boundary between adjacent microlenses can be achieved by reducing the boundary width.
A small boundary width can be realized by “sharpening” a boundary portion formed by adjacent microlens surfaces.

  Various methods are known for reducing the size of the “border width between adjacent microlenses” to the order of wavelengths in a mold for a microlens array.

  For example, Japanese Patent No. 4200283 discloses a method of increasing the radius of curvature of each microlens by anisotropic etching and ion processing to remove the non-lens portion at the boundary.

  Japanese Patent No. 5010445 discloses a method of removing a flat surface between adjacent microlenses by using isotropic dry etching.

For example, by using these known methods, it is possible to produce a microlens array in which the radius of curvature of the surface forming the boundary between adjacent microlenses is sufficiently small.
That is, the scanned surface element described above can be configured as a microlens array having a structure in which a plurality of microlenses are arranged close to each other.
By forming the radius of curvature of the surface forming the boundary between adjacent microlenses as a microlens array having r smaller than 640 nm, coherent noise of R component light can be prevented.
Further, if the curvature radius r is formed as a microlens array smaller than 510 nm, coherent noise due to R component light and G component light can be prevented.
If the radius of curvature of the surface forming the boundary between adjacent microlenses is formed as a microlens array having r smaller than 445 nm, coherent noise of R, G, and B component light can be prevented.

  The image display device (head-up display device) shown in FIG. 1 has been described above.

The concave mirror 7 shown in FIG. 1 has “a function of taking distortion of an image formed on the reflecting surface element 10 by a two-dimensionally deflected pixel display beam LC”.
That is, the concave mirror 7 functions as a “deflection range regulating means for regulating the scanning range of the scanned surface element by adjusting the deflection range of the two-dimensionally deflected pixel display beam”.

  Such a deflection range restricting means can be omitted when the deflection angle of the pixel display beam deflected two-dimensionally by the two-dimensional deflecting means 6 is not so large.

  The conditions for the fine convex lens structure (microlens array) and the fine convex lens (microlens) are as described above.

  That is, “a plurality of fine convex lenses larger than the beam diameter of the pixel display beam are closely arranged at a pitch close to the pixel pitch to form a fine convex lens structure”.

FIG. 4 shows three specific examples of microlens arrays that satisfy these conditions.
4A is a microlens array 87 in which square-shaped microlenses 8711, 8712,... Are arranged in a square matrix.

  The number of pixels of the two-dimensional image (enlarged virtual image) displayed in the head-up display device is determined by the arrangement period of the microlenses in the microlens array.

  In the case of the arrangement shown in FIG. 4A, the distance between the centers of the microlenses 8711 and 8712 adjacent in the X-axis direction is X1.

  In the drawing, the distance between the centers of the microlenses 8711 and 8721 adjacent in the Y-axis direction is Y1. These X1 and Y1 can be regarded as “effective size of one pixel”.

  The “effective size of one pixel” is hereinafter also referred to as “effective pitch of one pixel” or “effective pixel pitch”.

  4B is a microlens array 88 in which regular hexagonal microlenses 8811, 8821,... Are densely arranged.

  In the arrangement of the microlenses in this case, the arranged microlenses 8811 and the like do not have sides parallel to the X-axis direction.

  That is, since the upper and lower sides of the microlenses arranged in the X-axis direction are “zigzag”, such an arrangement is called “zigzag type arrangement”.

  The microlens array 89 shown in FIG. 4 (c) is an example in which regular hexagonal microlenses 8911, 8921,... Are densely arranged.

  In the arrangement of microlenses in this case, the arranged microlenses 8911 and the like have sides parallel to the X-axis direction. This arrangement is called an “armchair arrangement”.

  The zigzag array and the armchair array are collectively referred to as a “honeycomb array”.

The armchair arrangement shown in FIG. 4C is an arrangement obtained by rotating the zigzag arrangement shown in FIG. 4B by 90 degrees.
In the zigzag type array, in the microlens array, X2 shown in the figure can be regarded as “an effective pixel pitch in the X-axis direction” and Y2 can be regarded as an “effective pixel pitch in the Y-axis direction”.

  In the armchair type arrangement, X3 shown in the figure can be regarded as “an effective pixel pitch in the X-axis direction”, and Y3 can be regarded as an “effective pixel pitch in the Y-axis direction”.

  In FIG. 4B, the effective pixel pitch Y2 is the distance between the center of the microlens 8821 and the midpoint of the right side of the microlens 8811.

  In FIG. 4C, the effective pixel pitch: X3 is the distance between the midpoint of the sides of the two microlenses that are in contact with the right side of the microlens 8911 and the center of the microlens 8911.

  In the zigzag type array, since the effective pixel pitch X2 in the X-axis direction is small, the resolution in the X-axis direction in image display can be improved.

  In the armchair type arrangement, the resolution in the Y-axis direction can be improved.

  In this way, by arranging the microlenses in a honeycomb shape, pixels smaller than the actual lens diameter can be effectively expressed, and the number of effective pixels can be improved.

  As described above, in the fine convex lens structure (microlens array) of the surface element to be scanned, the boundary between adjacent microlenses has a radius of curvature: r.

  The radius of curvature r is smaller than the wavelength R of the R component of the pixel display beam, for example.

  Therefore, as described above, “coherent noise due to interference of R component coherent light” is prevented.

  However, if the radius of curvature r is greater than the wavelength of the G component light: λG and the wavelength of the B component light of the pixel display beam: λB, these lights are diffused at the boundary and interfere with each other.

  Therefore, coherent noise due to this interference is generated.

  In this case, in the case of the “square matrix-like arrangement” in FIG. 4A, divergence (diffusion) at the boundary portion occurs in two directions of the Xa direction and the Ya direction in the figure, and each causes the coherent noise. It becomes.

  On the other hand, in the arrangement of FIG. 4B, divergence at the boundary portion occurs in three directions 8A, 8B, and 8C. Further, in the case of FIG. 4C, diffusion is performed in three directions 9A, 9B, and 9C.

  That is, the divergence at the boundary portion occurs in two directions in the square matrix arrangement and in three directions in the honeycomb arrangement.

  Therefore, the generation of coherent noise occurs in two directions in a square matrix arrangement and in three directions in a honeycomb arrangement.

  That is, the generated coherent noise is “dispersed in two directions” in the square matrix arrangement, whereas “coherent noise is distributed in three directions” in the honeycomb arrangement.

The maximum intensity of coherent light that causes coherent noise is constant.
Therefore, the greater the number of dispersed elements, the weaker the “contrast of the generated coherent noise” becomes, and the more difficult it is to be visually recognized (not noticeable).

  Therefore, in the case where the generation of “coherent noise due to a component having a wavelength smaller than r at the boundary radius of curvature: r” is allowed, the arrangement of the microlenses is preferably a “honeycomb arrangement”.

  When the boundary width is larger than the wavelength: λR, coherent noise due to R component coherent light is also generated.

  However, the “boundary width between lens surfaces” of adjacent micro-convex lenses is very small, and the optical energy of coherent light incident on the portion having the very small boundary width is small.

Therefore, light energy that generates coherent noise is not large.
Therefore, even if coherent noise occurs, in the case of the honeycomb arrangement, the contrast is weakened by being dispersed in three directions as described above.

  Accordingly, the visibility of the coherent noise is effectively reduced.

  As described with reference to FIG. 1A, the virtual image imaging optical system that forms the two-dimensional enlarged virtual image 12 is configured by the concave mirror 9.

That is, the magnified virtual image 12 is a set of pixel images formed by the concave mirror 9.
If the microlens that is a micro-convex lens has an “anamorphic function”, the diffusion function of the micro-convex lens can be made different in directions orthogonal to each other.

6 (a) and 6 (b), reference numeral 80 in FIGS. 6 (a) and 6 (b) denotes an individual microlens (fine convex lens) densely formed on the surface element 8 to be scanned. Is shown as an explanatory diagram. In the example of FIG. 6A, the fine convex lenses are vertically long ellipses and are arranged in a “matrix arrangement”.
In the example of FIG. 6B, the fine convex lenses 80 are vertically long hexagons having sides parallel to the X-axis direction, and are arranged in an “armchair arrangement”.
The micro-convex lens 80 has different curvature radii between the X-axis direction and the Y-axis direction, and the curvature radius Rx in the X-axis direction is smaller than the curvature radius Ry in the Y-axis direction. That is, the micro convex lens 80 has a curvature in the X-axis direction that is larger than a curvature in the Y-axis direction.

Accordingly, the power (diffusion power) in the X-axis direction of the fine convex lens 80 is larger than the power (diffusion power) in the Y-axis direction.
Further, since the curvature is given to both the X-axis direction and the Y-axis direction of the lens surface, as shown in FIG. 6B, the fine convex lens can be formed into a hexagonal shape. "Visibility" can be weakened.
6A and 6B show a case where the pixel display beam LC is incident on one fine convex lens 80. FIG. In FIG. 6A and FIG. 6B, the width of each fine convex lens 80 in the Y-axis direction is longer than the width in the X-axis direction.

Further, as shown in FIG. 6A, the beam diameter of the pixel display beam LC is “ellipse shape long in the Y-axis direction”, and the light beam diameter in the Y-axis direction is the diameter of the fine convex lens 80 in the Y-axis direction. Make it smaller.
In this way, the pixel display beam LC can be “incident without straddling the lens boundary”, and the cross-sectional shape of the emitted divergent light beam is an elliptical shape that is long in the X-axis direction (horizontally long). Become.

  Regardless of the length in the Y-axis direction and the length in the X-axis direction of the fine convex lens, if the curvature in the X-axis direction is larger than the curvature in the Y-axis direction, the beam cross section FX of the divergent beam emitted from each fine convex lens Is longer in the X-axis direction than in the Y-axis direction. That is, it becomes horizontally long.

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

In this case, the reflecting surface element 10 is an automobile windshield.
In this case, for example, a “navigation image” can be displayed as a magnified virtual image 12 in front of the windshield, and the driver who is the observer 11 can observe the image from the front of the windshield with little movement while staying in the driver's seat. .

  In such a case, as described above, the displayed enlarged virtual image is a “landscape image as viewed from the driver”, that is, the image formed on the microlens and the enlarged virtual image have an angle of view in the X-axis direction. It is generally preferable that the image is large.

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 (X-axis direction) of the enlarged virtual image than in the lateral direction (Y-axis direction).

  Therefore, the micro convex lens of the surface element to be scanned is an anamorphic lens having a larger curvature in the longitudinal direction than the short direction of the image formed on the micro lens or the magnified virtual image, and has a diffusion angle for diffusing the pixel display beam. It is preferable that “the horizontal direction of the two-dimensional 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 field angle of the head-up display device, improve the light use efficiency, and improve the brightness of the display image.

Of course, it is also possible to use “isotropic diffusion” in which the diffusion angles are equal in the vertical direction and the horizontal direction, instead of the “isotropic diffusion” as described above.
However, in the case of a head-up display device 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 two-dimensional 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.

  Each micro convex lens (micro lens) in the micro convex lens structure (micro lens array) shown in FIGS. 4A to 4C was a square or a regular hexagon.

  The shape of the micro-convex lens does not have to be a regular polygon in this way, and may be a shape obtained by extending the micro lens shape shown in FIGS. 4A to 4C in one direction.

  In this case, a square shape is a “rectangular shape”, and a regular hexagonal shape is an elongated deformed hexagon.

The effective pixel pitch of the fine convex lens structure was X1 to X3 in the X-axis direction and Y1 to Y3 in the Y-axis direction in the arrangements of FIGS. 4 (a) to 4 (c).
When the effective pixel pitch in the X-axis direction thus determined is generally “SX” and the effective pixel pitch in the Y-axis direction is generally “SY”, the ratio between the two: SY / SX is referred to as “aspect ratio”.

  In the case of FIG. 4A, the aspect ratio is “Y1 / X1”, and X1 = Y1, so the aspect ratio is 1.

  In the case of FIG. 4B, the aspect ratio is “Y2 / X2”, and Y2> X1, so the aspect ratio is greater than 1.

  In the case of FIG. 4C, the aspect ratio is “Y3 / X3”, and Y3 <X3. Therefore, the aspect ratio is smaller than 1.

  In the fine convex lens structures of the microlens arrays 91 to 95 shown in FIGS. 5A to 5E, the effective pixel pitch is determined as follows in the same manner as in FIG.

  That is, the effective pixel pitches in the X-axis direction and the Y-axis direction are “X11, Y11”, “X12, Y12”, and “X13, Y13” in FIG.

  The micro-convex lens structure of FIG. 5A is an array of rectangular micro-convex lenses 9111, 9112,... 9121,.

  In the microlens arrays 92 to 95 shown in FIGS. 5B to 5E, the fine convex lens structure is a honeycomb type array.

  In the honeycomb array shown in FIGS. 5B, 5D, and 5E, the aspect ratios “Y12 / X12” and “Y13 / X13” are both greater than 1.

  In each of the five examples of the fine convex lens structure shown in FIGS. 5A to 5E, the “fine convex lens” has a length in the Y-axis direction larger than a length in the X-axis direction.

  Thus, in the case of “a fine convex lens whose length in the Y-axis direction is larger than the length in the X-axis direction”, it is easy to make the curvature in the X-axis direction larger than the curvature in the Y-axis direction as the shape of the fine convex lens. is there.

  Therefore, it is easy to realize the “anamorphic optical function in which the power in the X-axis direction is larger than the power in the Y-axis direction”.

  For example, in the case of the example shown in FIG. 5A, specific examples include X11 = 150 μm, Y11 = 200 μm, and aspect ratio = 200/150 = 4/3> 1.

  Of course, in this case, the beam diameter of the pixel display beam is less than 150 μm in the X-axis direction and less than 200 μm in the Y-axis direction.

  The arrangement of the micro-convex lenses shown in FIGS. 5B to 5D is a honeycomb type array, and each micro-convex lens has a “long shape in the Y-axis direction”.

  The arrangement in FIG. 5B is a “zigzag type”, and the arrangements in FIGS. 5C to 5E are all “armchair types”.

  It is a matter of course that both the “zigzag-type vertically elongated honeycomb array” in FIG. 5B and the “armchair-shaped vertically honeycomb array” in FIG. 5C can be used.

  However, the arrangement example in FIG. 5C has the following advantages over the arrangement example in FIG.

  That is, in the arrangement of FIG. 5C, the “difference in size between the X-axis direction and the Y-axis direction” in the micro-convex lens is smaller than in the arrangement of FIG. The “difference” becomes smaller.

List specific dimensions.
For example, in FIG. 5B, the lens diameter in the X-axis direction of the fine convex lenses 9211 and 9212: R2x = 100 μm, and the lens diameter in the Y-axis direction: R2y = 200 μm.

  At this time, the effective pixel pitch (= X12) in the X-axis direction is 50 μm, and the effective pixel pitch (= Y12) in the Y-axis direction is 150 μm.

  Similarly, in FIG. 5C, the lens diameter in the X-axis direction: R3x = 100 μm and the lens diameter in the Y-axis direction: R3y = 200 μm for the fine convex lenses 9311 and 9312 and the like.

In addition, the length of the upper and lower sides of the hexagonal shape such as the fine convex lens 9311 is 50 μm.
At this time, the effective pixel pitch in the X-axis direction (= X13) is 75 μm, and the effective pixel pitch in the Y-axis direction (= Y13) = 100 μm.

  Therefore, the “effective pixel pitch in the X and Y axis directions” is “a value closer to each other” in the arrangement (75 μm and 100 μm) in FIG. 5C than in the arrangement (50 μm and 100 μm) in FIG. become.

In FIGS. 5C, 5D, and 5E, the effective pixel pitch in the X-axis direction is X13, and the effective pixel pitch in the Y-axis direction is Y13.
This is because the pixel pitch in the X-axis direction and the pixel pitch in the Y-axis direction are defined in the same way in the honeycomb type arrangement (armchair type honeycomb arrangement) of FIGS. 5 (c) to 5 (e). by.
In FIG. 5D, the fine convex lenses 9411 and 9421 have short upper and lower sides parallel to the X-axis direction and long oblique sides.
In FIG. 5E, the fine convex lenses 9511 and 9521 have short upper and lower sides parallel to the X-axis direction and long oblique sides.
As shown in these figures, the pixel pitch: X13 in the X-axis direction and the pixel pitch: Y13 in the Y-axis direction can be adjusted by deforming the hexagonal shape of the fine convex lens.

As in the case of FIG. 5C, in the arrangements shown in FIGS. 5D and 5E, the “effective pixel pitch in the X and Y axis directions is obtained because the“ fine convex lens structure is a vertically long structure ”. Equalization ”is possible.
For example, the microlenses 9611 and 9621 of the microlens array 96 shown in FIG. 8 have a vertically long hexagonal shape similar to the microlens array 95 shown in FIG.
The arrangement of the microlenses 9611 and the like shown in FIG. 8 is an “armchair-type vertically long honeycomb arrangement” similar to FIG.
The hexagonal shape of the microlens 9611 or the like is set so that the effective pixel pitch X14 in the X-axis direction is completely equal to the effective pixel pitch Y14 in the Y-axis direction.
Thus, the aspect ratio can be set to 1 in the armchair-type vertically long honeycomb arrangement. In the case of a fine convex lens larger than the beam diameter of the pixel display beam or a fine convex lens having the same size as the beam diameter of the pixel display beam, if the aspect ratio of the effective pixel pitch is 1, image data projected as a virtual image On the other hand, reproducibility by a virtual image increases. The microlens of image data projected as a virtual image by matching the effective pixel pitch with the effective pixel pitch on the microlens array of the image data projected as a virtual image or compared with other effective pixel pitches This is because the pixel pitch of the image data on the array can be approached.
In the above description, the vertical direction is described as “vertical direction” and the horizontal direction as “horizontal direction”, but this is for convenience of description.
Which direction is the vertical direction in the actual space depends on the direction in which the microlens array is attached to the image display device and the direction in which the image display device is attached to a moving body such as a vehicle.
The two-dimensional deflection means 6 performs reciprocal oscillation (oscillation of the second axis) a plurality of times while performing reciprocal oscillation (oscillation of the first axis) about one axis. However, in many cases, the X-axis direction, which is the longitudinal direction of the enlarged virtual image, is set as the scanning direction of the pixel display beam LC with respect to the microlens array by the oscillation of the second axis. Accordingly, the upper and lower sides of the “armchair-type” hexagonal microlens parallel to the X-axis direction are substantially parallel to the scanning direction of the pixel display beam LC with respect to the microlens array, An interval between two sides that are closest to the scanning direction of the square-shaped pixel display beam with respect to the microlens array, in other words, a side that is closest to the scanning direction of the pixel display beam with respect to the microlens array and an opposite side thereof The shape in which the distance between the two is extended in a direction perpendicular to these two sides is an “armchair-type vertically long honeycomb structure”.

Therefore, the armchair-type vertically elongated honeycomb arrangement can reduce the difference in effective pixel pitch between the X-axis direction (horizontal direction) and the Y-axis direction (vertical direction) in addition to the improvement in luminance and the number of effective pixels.
The “shape of the fine convex lens” as shown in FIGS. 5C to 5E can be arbitrarily selected, for example, for controlling the divergence angle of the divergent light beam.

  In the head-up display device shown in FIG. 1A, the pixel display beam LC is orthogonally incident on the fine convex lens structure of the scanned surface element 8.

  However, the incident form of the pixel display beam to the scanned surface element is not limited to such “orthogonal incidence”.

  For example, in order to make the head-up display device compact by devising the arrangement of the optical elements from the light source unit to the reflective surface element, an incident form as shown in FIG.

  That is, in the example of FIG. 7A, the pixel display beam LC is incident on the scan surface element 8 with an inclination.

  When the lens surface of the fine convex lens is an “aspherical surface”, the pixel display beam LC is incident with an inclination relative to the optical axis of the aspherical surface, and the aspherical function may not be utilized.

  In such a case, as in the scanned surface element 8a in FIG. 7B, the lens surface optical axis AX of the fine convex lens ML is inclined from the orthogonal direction with respect to the reference surface of the scanned surface element 8a. good.

  In this way, the lens surface optical axis AX can be made parallel to or close to the incident direction of the pixel display beam LC.

  The reference surface of the scanned surface element 8a is a surface on which the micro convex lenses ML are arrayed.

  By doing so, the optical system can be downsized and the light utilization efficiency can be improved, and the “direction of divergence of the pixel display beam by the fine convex lens” can be made uniform.

  The head-up display device described above can be mounted not only on the above-described automobile but also on various types of steerable moving bodies such as trains, ships, helicopters, and airplanes. For example, a windshield of a motorcycle can be used as a transmission reflection member.

  In this case, the windshield in front of the cockpit may be used as a reflective surface element.

  Of course, it goes without saying that the head-up display device can be implemented as, for example, an “image display device for watching movies”.

  The micro-convex lens having the micro-convex lens structure diffuses the pixel display beam as described above. However, it may be considered that only one of the X and Y directions is diffused.

  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 head-up display device described above can be used, for example, for in-vehicle use such as an automobile, and the X direction is “horizontal when viewed from the driver's seat” and the Y direction is “vertical”.

In this case, the reflecting surface element 10 is an automobile windshield.
In this case, for example, a “navigation image” can be displayed as a magnified virtual image 12 in front of the windshield, and the driver who is the observer 11 can observe the image from the front of the windshield with little movement while staying in the driver's seat. .

  In such a case, as described above, the displayed enlarged virtual image is a “landscape image viewed from the driver”, that is, the image formed on the microlens and the enlarged virtual image have an angle of view in the X direction. A large image, that is, a horizontally long image is generally preferable.

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

  The lens surface of the fine 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.

  By the way, when a microlens array having a periodic lens arrangement is used as a surface element to be scanned (for example, a transmissive screen or a reflective screen) of an optical apparatus such as a head-up display device, It is known that interference patterns (interference fringes) such as diffraction patterns and moire fringes due to strengthened diffracted light are visually recognized. When such an interference pattern is generated, the visibility of an image or virtual image formed by the microlens array is degraded.

  Here, “a microlens array having a periodic lens arrangement” means a pitch of apex positions of a plurality of microlenses (hereinafter also referred to as a lens pitch), that is, an interval between apexes of two adjacent microlenses is periodic. It means a (for example, constant) microlens array (hereinafter also referred to as a periodic array lens array).

  Note that “the position of the apex of the microlens” means the position of the apex of the lens surface of the microlens in the XY plane. “A vertex of the lens surface of the microlens” means a point where the lens surface of the microlens and the optical axis (here, parallel to the Z axis) intersect.

  As a specific example of the periodic array lens array, for example, the vertex position of each microlens coincides with the center position of the microlens, the pitch (lens pitch) of the vertex position (center position) is constant, and the lens diameter (lens (Size) is mentioned. Here, the optical axis of each microlens passes through the center position of the microlens. In this case, the interference pattern is visually recognized as a stripe pattern having a uniform stripe direction and pitch.

  The “center position of the microlens” means a position in the XY plane of the center of the microlens.

  For example, in a periodic array lens array in which a plurality of microlenses having the same planar shape and the same size have a constant lens pitch, stripes in two vertical and horizontal directions are visually recognized. Further, for example, in a periodic array lens array in which a plurality of microlenses having the same size and having a hexagonal honeycomb shape are arranged so as to have a constant lens pitch, it is visually recognized as a six-fold symmetric three-way stripe.

  FIG. 9 shows a schematic diagram when interference occurs in the horizontal direction of the periodic array lens array and the diffraction pattern is displayed as vertical stripes 851 and 852. Since the stripe direction 853 and the pitch 854 are uniform in the plane, this diffraction pattern is visually recognized.

  Summarizing the above discussion, the microlens array in which lens diameter> beam diameter is used to suppress the interference of diverging beams from two adjacent microlenses, but the minute interference due to the spread of the base of the beam still remains. The minute interference remains and is visually recognized as a highly visible interference fringe because the direction and pitch of the fringes are aligned.

  In order to reduce the generation of the interference fringes, it is necessary to eliminate the periodicity of the interference fringes and lower the visibility.

  As described above, in the periodic array lens array, periodic interference fringes with uniform pitch and direction are generated due to the periodicity of the lens array. Therefore, generation of interference fringes can be reduced by eliminating the periodicity of the lens arrangement of the microlens array, that is, by randomizing (non-periodic) the lens pitch.

  FIG. 10 shows a microlens array in which the lens pitch is randomized (hereinafter also referred to as “random array lens array”). In this random array lens array, the optical axis of each microlens of the periodic array lens array in which the apex position of each microlens coincides with the center position of the microlens is randomly shifted in a direction perpendicular to the optical axis (Z axis). (Offset) structure, that is, the lens pitch is irregular. In this case, the optical axis of each microlens passes through the apex of the microlens but does not pass through the center. Note that the center position of each macro lens of the random array lens array shown in FIG. 10 may be, for example, the center of the circumscribed circle of the micro lens or the center of the inscribed circle of the micro lens. .

  For example, as shown in FIG. 10, in the case of a microlens array in which the lens pitch and the lens boundary direction are randomized (non-periodic), two adjacent microlenses are disposed between two adjacent microlenses 861 and 862. Interference fringes generated between 862 and 863 have different directions and pitches, and are not visually recognized as interference fringes with uniform directions and pitches. That is, the generation of interference fringes is reduced by randomizing the lens pitch, and the interference intensity of diverging beams from two adjacent microlenses (hereinafter also referred to as adjacent diverging beams) is dispersed by randomizing the lens boundary direction. The

  In the random array lens array shown in FIG. 10, for example, the lens pitches p1 to p29 may all be different, or some of them may be the same and the rest may be different. In short, the lens pitch is irregular. I just need it. In addition, the black circle in FIG. 10 shows the vertex position of each micro lens. A black square in FIG. 10 indicates the center position of each microlens.

  In particular, the lens pitches in the lens arrangement direction (... p4, p9, p11 ...), (... p23, p24, p25 ...), (... p8, p12, p20 ...) are irregular ( It is preferable that there is no periodicity.

  Hereinafter, randomization of the lens pitch and the lens boundary direction will be described.

  First, it will be described that the microlens array of the present embodiment is different from a normal diffuser plate used for reducing speckle noise. In ordinary diffuser plates, many uneven structures with different sizes are formed on the surface.For example, if there is unevenness that is extremely smaller than the beam diameter, the interference between reflected light becomes strong at that part, and interference fringes are generated. End up.

  Therefore, in this embodiment, a random array lens array having a lens diameter (lens size) equal to or larger than a predetermined value on the entire surface is proposed.

  This random array lens array has a structure based on a periodic array lens array in which a plurality of square microlenses are arrayed at a constant lens pitch, for example, as indicated by broken grid lines in FIG.

  In this periodic array lens array, the center position of each microlens is each lattice point 899 (virtual point) of a square lattice. In the periodic array lens array, the apex position of each microlens coincides with the lattice point 899 that is the center position of the microlens.

  In addition, in each microlens of the periodic array lens array, the lens diameter is larger than the incident beam diameter (above the predetermined value or more) in order to suppress interference of diverging beams (also referred to as adjacent diverging beams) from two adjacent microlenses. Lens diameter).

  In the random array lens array, the vertex position of each microlens of the periodic array lens array is displaced from the center position within a virtual area 897 (area within a circular broken line) including the center position (lattice point 899) of the microlens ( It has an eccentric structure. That is, in the random array lens array, the apex position of each microlens is eccentric.

  In other words, the plurality of microlenses of the random array lens array are individually disposed on the plurality of lattice points 899 having a constant array pitch, and the apex position of each microlens is determined from the lattice point 899 where the microlenses are disposed. It's off.

  On the other hand, the plurality of microlenses of the periodic array lens array are individually disposed on a plurality of lattice points having a constant array pitch, and the vertex positions of the microlenses coincide with the lattice points where the microlenses are disposed.

  Further, in the random array lens array, the deviation of the apex positions of the plurality of microlenses from the center position of the microlenses is irregular, and as a result, the lens pitch is irregular.

  Further, the lens boundary direction of the random array lens array (directions of the solid lines 893, 894, 895, and 896 in FIG. 11) is the lens boundary direction of the periodic array lens array (direction of the lattice lines (broken lines) in FIG. 11). On the other hand, it is shifted randomly (irregularly).

  In this case, interference fringes in different directions are generated in each microlens. As a result, since the directions of the interference fringes are not aligned macroscopically, the visibility of the interference fringes decreases.

  In the random array lens array configured as described above, since the lens diameter (lens size) is kept substantially constant, the protrusion of the incident beam from the lens is prevented, and the diverging beam from two adjacent microlenses is prevented. Interference can be suppressed. Further, since the lens pitch is random, the interference intensity is reduced and the generation of interference fringes is suppressed. Further, since the lens boundary direction is random, the direction of the interference fringes generated is randomized. As a result, the visibility of interference fringes can be greatly reduced. Therefore, the visibility of an image (optical image) formed by the random array lens array can be improved.

  Here, when the microlens array is scanned with laser light, it is preferable to use a microlens array including a vertically long microlens. Specifically, since the effective cross section of the laser beam from the LD is generally an elliptical shape instead of a circular diameter, the lens diameter (lens size) is determined as incident beam diameter <microlens diameter as described above. In this case, it is desirable to select an aspect ratio (for example, vertically long) corresponding to the shape (elliptical shape) of the effective cross section of the laser light. This makes it possible to suppress speckle noise and interference fringes with the minimum necessary lens diameter. The “effective cross section” means a portion having a relative intensity of 20% to 80% in the cross section of the laser beam.

  12A to 12C show specific examples of a random array lens array (hereinafter, also referred to as a vertically long random array lens array) including vertically long microlenses.

  The vertically long random array lens array shown in FIG. 12A has a structure based on a periodic array lens array in which a plurality of rectangular microlenses are arranged in a matrix. Each microlens of this periodic array lens array has a vertically long aspect ratio, and y> x is established.

  The vertically long random array lens array shown in FIG. 12B has a structure based on a periodic array lens array in which a plurality of vertically long hexagonal microlenses are arranged in a zigzag shape.

  The vertically long random array lens array shown in FIG. 12C has a structure based on a periodic array lens array in which a plurality of vertically long hexagonal microlenses are arranged in an armchair shape.

  Also in the vertically long random array lens array shown in FIGS. 12A to 12C, the lens pitch and the lens boundary direction are randomized, and the generation of interference fringes with uniform pitches can be suppressed.

  FIGS. 13A to 13D show the vertically long random array lens arrays of Comparative Examples 1 to 4, respectively. FIGS. 13 (e) to 13 (h) show the vertically long random array lens arrays of Examples 1 to 4, respectively. In each figure, “dashed line” indicates the virtual boundary, “small black square” indicates the center position of the microlens, and “+” indicates the apex position of the microlens.

  In the longitudinally random array lens array of Comparative Example 1 shown in FIG. 13A, the apex position 884 of each longitudinally rectangular microlens 881 is a circular virtual provided at the same distance from the center position 882 of the microlens 881. It is set to a random point selected with equal probability within the boundary 883. That is, the vertex position 884 of each microlens is randomly eccentric within the virtual boundary 883. In this case, it is possible to disperse the vertex positions while determining the maximum value of the deviation amount from the center position 882 of the vertex position of each microlens. Hereinafter, a region (virtual region) within the virtual boundary is also referred to as an “eccentric region”.

  In the longitudinally long random array lens array of Comparative Example 2 shown in FIG. 13B, a square virtual boundary 887 is provided. Also in this case, the vertex positions can be dispersed while determining the maximum value of the deviation amount from the center position 886 of the vertex position 888 of each of the vertically long microlenses.

  However, in Comparative Examples 1 and 2, since the microlens is not considered to be vertically long, the relative random eccentricity in the horizontal direction with respect to the horizontal length of the microlens (hereinafter referred to as the random in the horizontal direction). There is a high probability that the eccentricity ratio (also referred to as eccentricity ratio) is larger than the random amount of vertical eccentricity with respect to the vertical length of the microlens (hereinafter also referred to as vertical random eccentricity ratio). In this case, variation occurs in the effect of random eccentricity in the vertical direction and the horizontal direction.

  Here, the larger the random eccentricity ratio, the higher the interference fringe reduction effect. However, when the microlens array is visually recognized, the surface has a graininess similar to that of a diffuser plate, and appears rough. End up. For this reason, it is desired to appropriately control the random eccentric ratio in the vertical direction and the horizontal direction to control the graininess. For example, when the amount of random eccentricity in the vertical direction and the horizontal direction is the same, the random eccentricity ratio in the horizontal direction is larger than the random eccentricity ratio in the vertical direction.

  Therefore, in Examples 1 and 2 shown in FIGS. 13 (e) and 13 (f) respectively, the vertical virtual boundaries 890 and 892, that is, the vertical eccentric region (hereinafter, referred to as the vertical eccentric lens) , Also referred to as a vertically long eccentric region). In this case, the amount of random eccentricity in the vertical and horizontal directions can be controlled independently.

  In the longitudinally long random array lens array, the vertex positions of the microlenses are selected equidistantly within the longitudinally decentered region (random eccentricity). As a result, the amount of eccentricity in the Y direction (center) of the vertex positions of all the microlenses The sum of the deviation amounts from the position) is larger than the sum of the eccentric amounts (deviation amounts from the center position) in the X direction of the vertex positions of all the microlenses. In this case, “sum” may be replaced with “average”. This “average” may be an “arithmetic average” or a “synergistic average”.

  That is, in the vertically long and randomly arrayed lens array, the number of microlenses in which the amount of eccentricity in the Y direction at the vertex position is larger than the amount of eccentricity in the X direction is the number of microlenses in which the amount of eccentricity in the X direction is larger More than the number of lenses (including 0).

  In the vertically long random array lens array, the maximum value of the shift amount in the Y direction is less than ½ of the length of the micro lens in the Y direction, and the maximum value of the shift amount in the X direction is X of the micro lens. The length is preferably less than ½ of the length in the direction.

  Further, the length in the Y direction (vertical direction) of the vertically long eccentric region is set to, for example, 4/5 or less of the length of the micro lens in the Y direction, and the length of the vertically long eccentric region in the X direction (horizontal direction). Is preferably set to, for example, 4/5 or less of the length of the microlens in the X direction. This is because, when the vertically long eccentric region becomes too large with respect to the microlens, the graininess increases as described above.

  The size of the vertically decentered region may be set according to the curvature (divergence angle) of the microlens. Specifically, the longitudinally decentered region may be increased as the curvature (divergence angle) of the microlens increases.

  Further, it is preferable that the vertically long eccentric region does not protrude from the microlens. That is, the length of the longitudinally eccentric region in the Y direction is less than the length of the microlens in the Y direction, and the length of the longitudinally eccentric region in the X direction is less than the length of the microlens in the X direction. Is preferred.

  In addition, the area of the vertically long eccentric region is a circle whose diameter is the maximum length in the X direction of the vertically long microlens (see the two-dot chain line in FIGS. 13E to 13H). It is preferably less than or equal to the area of the circumscribed regular n-gon (n is an integer of 3 or more). In other words, the area of the vertically eccentric region is preferably equal to or less than the area of the maximum positive n-gonal (n is an integer of 3 or more) eccentric region that can be set in the vertically long microlens. A typical example of the regular n-gon is a square or a regular hexagon.

  In this case, the area of the vertically long eccentric region can suppress the amount of random random eccentricity in comparison with a regular n-square (n is an integer of 3 or more) eccentric region having the same area as that of the vertically long eccentric region. Can be suppressed.

  Furthermore, the area of the vertically long eccentric region is more preferably equal to or less than the area of a circle whose diameter is the maximum length among the lengths of the vertically long microlenses in the X direction. In other words, the area of the vertically long eccentric region is preferably equal to or smaller than the area of the largest circular eccentric region that can be set for the vertically long microlens. In this case, compared to a circular eccentric region having the same area as the vertically long eccentric region, the amount of lateral random eccentricity can be suppressed, and an increase in graininess can be suppressed. In this case, it goes without saying that the area of the vertically decentered region is equal to or smaller than the area of the decentered region of the maximum regular n-gon (where n is an integer of 3 or more) that can be set for the vertically long microlens.

  In general, in order to adjust the random eccentric ratio in the vertical direction and the horizontal direction to an appropriate value, it is preferable to set the aspect ratio of the vertically eccentric region based on the aspect ratio of the microlens (here, vertically long). .

  That is, the ratio ly / lx between the length ly in the Y direction and the length lx in the X direction of the longitudinally eccentric region is based on the ratio Ly / Lx between the length Ly in the Y direction and the length Lx in the X direction of the microlens. Are preferably set. Specifically, ly / lx may be equal to Ly / Lx, or ly / lx may be slightly larger or slightly smaller than Lx / Ly.

  In this case, the amount of random random eccentricity in the horizontal direction can be limited more than the amount of random eccentricity in the vertical direction, and surface graininess and roughness when viewed on the microlens array can be suppressed.

  Specific examples of the virtual boundary (eccentric region) include, for example, the vertically long oval shape of the first embodiment shown in FIG. 13E and the vertically long rectangular shape of the second embodiment shown in FIG. As long as the shape is vertically long, the same effect can be expected with other shapes.

  In Comparative Examples 1 and 2 and Examples 1 and 2, a vertically long rectangular microlens has been described as an example, but the same discussion is shown in FIGS. 13C and 13D, for example. Vertical hexagonal microlenses 901 and 905 as in Comparative Examples 3 and 4 and vertical hexagonal shapes as in Examples 3 and 4 shown in FIGS. 13 (g) and 13 (h), respectively. The same applies to the microlenses 909 and 911.

  Compared to Comparative Examples 3 and 4, in Examples 3 and 4, the random eccentric amount in the horizontal direction is limited rather than the random eccentric amount in the vertical direction, and graininess and roughness can be suppressed.

  Further, in Comparative Examples 3 and 4, due to random eccentricity, the lateral shape change from the periodic array lens array including a plurality of vertically long hexagonal microlenses as a base becomes large. On the other hand, in Examples 3 and 4, it is possible to suppress the shape change from the periodic array lens array as a base.

  Note that the vertically long eccentric region (virtual region) is not limited to a vertically long ellipse and a vertically long rectangle, but may be other vertically long shapes. In either case, it is possible to adjust the amount of random eccentricity and the interference intensity according to the interference intensity of adjacent divergent beams. Moreover, you may give a difference in the probability distribution inside a vertically long eccentric area | region. For example, the distribution density of the vertex positions may be locally increased or decreased within the vertically long eccentric region.

  From the first viewpoint, the microlens array (longitudinal random array lens array) of the present embodiment described above has a plurality of microlenses on a plurality of lattice points (virtual points) having periodicity (regularity) in pitch. Are individually arranged lens arrays, and each of the plurality of microlenses has a length in the Y direction that is longer than a length in the X direction orthogonal to the Y direction. The total deviation amount in the Y direction from the lattice point at the vertex position is larger than the total deviation amount in the X direction.

  Further, the microlens array (longitudinal random array lens array) of the present embodiment includes a plurality of microlenses having periodicity (regularity) in the pitch of the center position (lattice point) from the second viewpoint. Each of the plurality of microlenses has a length in the Y direction that is longer than a length in the X direction orthogonal to the Y direction, and the vertex positions of the plurality of microlenses are shifted from the center position of the lens, The sum of the deviation amounts in the Y direction from the center position of the vertex position is larger than the sum of the deviation amounts in the X direction.

  Further, from the third viewpoint, the microlens array (longitudinal random array lens array) of the present embodiment has a plurality of microlenses on a plurality of lattice points (virtual points) having periodicity (regularity) in pitch. Each of the plurality of microlenses has a length in the Y direction that is longer than a length in the X direction perpendicular to the Y direction. Is located in a vertically decentered region (virtual region) whose length in the Y direction is longer than the length in the X direction with the lattice point as the center.

  In addition, from the fourth viewpoint, the microlens array (longitudinal random array lens array) of the present embodiment includes a plurality of microlenses having periodicity (regularity) at the center position (lattice point) pitch. Each of the plurality of microlenses has a length in the Y direction that is longer than a length in the X direction orthogonal to the Y direction, and the vertex positions of the plurality of microlenses are shifted from the center position of the lens, It is located in a vertically long eccentric region (virtual region) having the center position as the center and the length in the Y direction being longer than the length in the X direction.

  In the microlens array of the present embodiment configured as described above, regardless of the ratio of the length in the Y direction and the length in the X direction of each microlens, the corresponding lattice point (center position) of the apex position of the microlens ) In the Y direction and the X direction can be appropriately controlled, and an increase in graininess can be suppressed while suppressing generation of interference fringes on the microlens array.

  As a result, the visibility of an image (optical image) formed by the microlens array can be improved regardless of the shape of each microlens.

  In the microlens array (longitudinal random array lens array) of this embodiment, the length Ly in the Y direction is slightly longer than the length Lx in the X direction, and is substantially equal to the microlens with Ly≈Lx. The same effect can be obtained. That is, for example, the random array lens array shown in FIG. 10 may be regarded as a vertically long random array lens array.

  In addition, it can be said that the vertically long random array lens arrays in the first and third aspects have a configuration that does not necessarily depend on the periodic array lens array.

  On the other hand, in Patent Document 1 (Japanese Patent Laid-Open No. 2003-004907), a plurality of microlenses are mutually connected for the purpose of solving problems such as the influence of diffracted light peculiar to the regular arrangement of microlenses and the occurrence of moire fringes. Disclosed is a microlens array (random array lens array) that is formed irregularly or with established distribution regularity so as to be different from a basic pattern in which the vertex intervals of adjacent microlenses are all equal intervals L Yes.

  In the microlens array disclosed in Patent Document 1, selectable lens shapes are significantly limited. That is, in Patent Document 1, there is a limitation that the lens pitch is arranged at an equal interval L, which is limited to a random array lens array based on a periodic array lens array including regular hexagonal (or square) microlenses. . That is, it is not applicable to a vertically long random array lens array.

  Moreover, in Patent Document 1, since the eccentric region of the microlens of the periodic array lens array is set in a circle centered on the apex position of the microlens, the periodic array lens array including a vertically long microlens is assumed. When the vertex position is randomly eccentric within the circle (eccentric region), the random eccentric ratio in the horizontal direction becomes relatively larger than the random eccentric ratio in the vertical direction, and graininess and Become visible. That is, in Patent Document 1, there is room for improvement in the visibility of an optical image formed by the microlens array depending on the shape of the microlens.

  In the present embodiment, a longitudinally decentered region is provided for each longitudinally long microlens of the periodic array lens array, and the apex position of the microlens is randomly decentered in the vertically decentered region. Random eccentricity can be adjusted independently. Therefore, by reducing the amount of random eccentricity in the horizontal direction relatively less than the amount of random eccentricity in the vertical direction, it is possible to reduce the graininess on the microlens array caused by random eccentricity.

  Further, the microlens array of the present embodiment is used as a scanned surface element of the above-described head-up display device. In this case, a high-quality image (virtual image) can be displayed.

  In the above embodiment, the lens boundary direction of the vertically long random array lens array is random, but may have periodicity. That is, in the vertically long random array lens array, only the deviation of the apex position of each microlens from the corresponding lattice point (the center position of the microlens) may be random.

  For example, FIG. 14A to FIG. 14E respectively show a vertically long random array lens array having periodicity in the lens boundary direction of Examples 5 to 9 and periodicity in the pitch of the center position of the microlens. It is shown. In each figure, “+” indicates the vertex position of the lens.

  The vertically long random array lens array of Example 5 shown in FIG. 14A is a vertically long rectangular array, and y> x is established. The longitudinally random array lens array of Example 6 shown in FIG. 14B is a longitudinally hexagonal zigzag array. The vertically long random array lens array of Example 7 shown in FIG. 14C is a vertically long hexagonal armchair array. The vertically long randomly arrayed lens array of Example 8 shown in FIG. 14D has a rhombus-like structure in which the upper and lower sides are short and the oblique sides are long. The longitudinally long random array lens array of Example 9 shown in FIG. 14E has a structure close to a rectangle with the upper and lower sides being long and the hypotenuse being short.

  Also in the vertically long random array lens arrays of Examples 5 to 9, the vertex positions are randomly decentered, and the generation of interference fringes with uniform pitches can be suppressed.

  In Examples 5 to 9, if the shape of each microlens matches, for example, the spot shape of the incident beam (the shape of the effective cross section), the protrusion of the beam from the microlens can be suppressed. It is possible to weaken the interference fringe intensity itself.

  As can be seen from the above description, the occurrence of interference fringes with uniform pitches can be suppressed by randomly decentering the apex position of any periodic array lens array.

  In the above-described embodiment, an example in which the lens pitch is constant has been described as the case where the lens pitch has periodicity. However, the present invention is not limited to this, and the case where the lens pitch changes, for example, in an arithmetic progression, It can be said that the lens pitch also has periodicity when it changes in a geometric progression. It can also be said that there is periodicity when there are a plurality of repeating units in which the lens pitch changes in the lens arrangement direction, for example, in an arithmetic progression or geometric progression.

  In the above-described embodiment, the case where the lens pitch in the periodic array lens array has periodicity has been described. In short, it is sufficient that the lens pitch in the periodic array lens array has some regularity. Specifically, there may be a plurality of repeating units in which the lens pitch changes in the lens arrangement direction, for example, in an arithmetic progression or geometric progression.

  Further, in the above embodiment, the vertically long random array lens array is arranged so that the longitudinal direction of the vertically long microlens array is the Y direction (vertical direction) and the short direction is the X direction (lateral direction). However, the present invention is not limited to this, and can be appropriately changed according to, for example, the layout of the optical system.

  In the above embodiment, one point in the vertically decentered region is selected at random (randomly) as the apex position of the microlens, but the point is that the lattice point corresponding to the apex position of each microlens (the microlens) The deviation (eccentricity) from the lens center position) may be random (irregular). That is, it is sufficient that at least one of the “deviation amount” and “deviation direction” of the deviation is random. That is, only the shift amount may be random, only the shift direction may be random, or both the shift amount and the shift direction may be random.

  Further, in the above embodiment, when determining the vertex position of each microlens in the vertically long random array lens array, a vertically long eccentric area is set, and one point in the vertically long eccentric area is randomly extracted. In short, the point is that the point where the sum of the deviation amounts in the Y direction from the corresponding lattice point of the apex position of each microlens is larger than the sum of the deviation amounts in the X direction may be selected. That is, the vertically long eccentric region does not necessarily have to be set.

  In the above embodiment, the vertex positions of all the microlenses in the vertically long random array lens are randomly shifted from the corresponding lattice points. However, the present invention is not limited to this, and the point is that the lens pitch (vertex interval) may be irregular. It suffices if the vertex position of at least one microlens is shifted from the corresponding lattice point. For example, the vertex positions of some microlenses may deviate from the corresponding lattice points, and the vertex positions of the remaining microlenses may coincide with the corresponding lattice points.

  In the above embodiment, as a vertex position of each microlens in the vertically long random array lens array, one point in the vertically decentered area is selected randomly (randomly). For example, in the vertically decentered area, Y Only a point where the amount of eccentricity (deviation amount) in the direction is larger than the amount of eccentricity (deviation amount) in the X direction may be selected. In this case, the selection may be made within the vertically long eccentric region, or may be made without providing the vertically long eccentric region. In any case, the sum of the eccentric amounts in the Y direction at the apex positions of all the microlenses is larger than the sum of the eccentric amounts in the X direction.

  In the above embodiment, the sum of the eccentric amounts in the Y direction at the apex positions of all the microlenses (the former) is larger than the sum of the eccentric amounts in the X direction (the latter), but vice versa (the latter is the former). It may be larger) or both may be equal. In short, it is only necessary that the apex position of each microlens is located in the vertically long eccentric area set in the microlens, and the apex position of at least one microlens is randomly decentered in the vertically eccentric area. preferable.

  In the above-described embodiment, a plurality of microlenses are adjacent to each other in the vertically long random array lens array. However, the present invention is not limited to this, and the microlenses may be separated from each other. For example, a region between two adjacent microlenses may be a non-lens region.

  In the above embodiment, the shape of each microlens of the vertically long random array lens array is exemplified by a rectangle or a hexagon. However, the present invention is not limited to this, and is essentially an N-gon (N is an integer of 3 or more). Preferably, it may be oval. Also in these cases, the lens boundary direction is preferably random.

  In the above embodiment, the optical axis of each microlens of the vertically long random array lens array is offset in the direction perpendicular to the Z axis to shift the apex position of the microlens from the center position. The optical axis of each microlens may be inclined with respect to the Z axis, and the apex position of the microlens (the position of the apex on the optical axis in the XY plane) may be shifted from the center position. In this case, the optical axis of each microlens may or may not pass through the center position of the microlens.

  In the microlens array of the above embodiment, a plurality of microlenses are two-dimensionally arranged, but instead of this, a one-dimensional array or a three-dimensional array may be arranged.

  In the above embodiment, the microlens array is two-dimensionally scanned using a two-dimensional deflecting unit (scanning unit) to form a two-dimensional image. For example, the microlens array includes a MEMS mirror, a galvanometer mirror, a polygon mirror, and the like. A one-dimensional image may be formed by one-dimensional scanning using a one-dimensional deflection unit.

  In the above embodiment, a color image is formed, but a monochrome image may be formed.

  Further, the transmissive reflecting member as the reflecting surface element 10 is configured by a member different from the windshield of the moving body, for example, a so-called combiner, and is disposed in front of the windshield as viewed from the observer. Also good.

  In addition, the transmission / reflection member is not limited to the windshield of the moving body, and may be, for example, a side glass, a rear glass, and the like. Any window member that allows the operator to visually recognize the outside of the moving body may be used.

  The target person whose virtual image can be visually recognized by the image display device is not limited to the driver of the moving body, and may be, for example, a navigator or a passenger who rides on the moving body.

  The image display device of the present invention can be applied not only to a head-up display device mounted on a moving body, but also to a head-mounted display that arrives at the observer's head or a projector, for example.

  That is, the present invention can be applied to all image display apparatuses including a microlens array irradiated with laser light.

  8... Scanned surface element (microlens array), 10... Reflective surface element (transmission and reflection member).

JP 2013-4907 A

The present invention provides a lens array in which a plurality of lenses are individually arranged on a plurality of virtual points having regularity in pitch, and each of the plurality of lenses has a length in a first direction in the first direction. longer than the length in a second direction perpendicular, the vertex position of at least one lens of the plurality of lenses are offset from the imaginary point of the lens is placed, the vertex position in the said lens array the sum of the shift amount of the first direction from the virtual point is the much larger than the second direction displacement amount of the sum, said plurality of lenses each, diffusion angle of the first direction, wherein The lens array is different from the diffusion angle in the second direction .

Claims (15)

In a lens array in which a plurality of lenses are individually arranged on a plurality of virtual points having regularity in pitch,
Each of the plurality of lenses has a length in a first direction longer than a length in a second direction orthogonal to the first direction,
The vertex position of at least one lens among the plurality of lenses is deviated from the virtual point where the lens is disposed,
2. The lens array according to claim 1, wherein a sum of deviation amounts in the first direction from the virtual point at the vertex position is larger than a sum of deviation amounts in the second direction. In a lens array including a plurality of lenses having regularity in the central position pitch,
Each of the plurality of lenses has a length in a first direction longer than a length in a second direction orthogonal to the first direction,
The vertex position of at least one lens among the plurality of lenses is deviated from the center position of the lens,
2. The lens array according to claim 1, wherein a sum of deviation amounts in the first direction from the center position of the vertex position is larger than a sum of deviation amounts in the second direction. The maximum deviation amount in the first direction is less than half of the length of the lens in the first direction;
3. The lens array according to claim 1, wherein a maximum value of the shift amount in the second direction is less than ½ of a length of the lens in the second direction. The vertex position of each of the plurality of lenses is located in a virtual region in which the length in the first direction is longer than the length in the second direction,
The lens array according to claim 3, wherein an area of the virtual region is equal to or less than an area of a circle whose diameter is the length of the lens in the second direction.   The ratio of the lengths of the virtual region in the first and second directions is set based on the ratio of the lengths of the lenses in the first and second directions. The lens array described in 1. In a lens array in which a plurality of lenses are individually arranged on a plurality of virtual points having regularity in pitch,
Each of the plurality of lenses has a length in a first direction longer than a length in a second direction orthogonal to the first direction,
The vertex position of at least one lens among the plurality of lenses is deviated from the virtual point where the lens is disposed,
The vertex position of each of the plurality of lenses is located in a virtual region in which the length in the first direction is longer than the length in the second direction, with the virtual point where the lens is disposed as the center. Characteristic lens array. In a lens array including a plurality of lenses having regularity in the central position pitch,
Each of the plurality of lenses has a length in a first direction longer than a length in a second direction orthogonal to the first direction,
The vertex position of at least one lens among the plurality of lenses is deviated from the center position of the lens,
The vertex position of each of the plurality of lenses is located in a virtual region in which the length in the first direction is longer than the length in the second direction, with the center position of the lens as the center. array. A length of the virtual region in the first direction is less than a length of the lens in the first direction;
The lens array according to claim 6 or 7, wherein a length of the virtual region in the second direction is less than a length of the lens in the second direction.   9. The lens array according to claim 8, wherein the area of the virtual region is equal to or less than an area of a circle whose diameter is the length of the lens in the second direction.   9. The ratio of the length of the virtual region in the first and second directions is set based on the ratio of the length of the lens in the first and second directions. Or the lens array according to 9.   11. The lens array according to claim 1, wherein pitches of apex positions of the plurality of lenses are irregular. The planar shape of each of the plurality of lenses is an N-gon (N is an integer of 3 or more),
The lens array according to claim 1, wherein the boundary direction between two adjacent lenses is irregular. The plurality of lenses are irradiated with laser light,
The lens array according to any one of claims 1 to 12, wherein each of the plurality of lenses is larger than an effective cross section of the irradiated laser beam.   An image display device that displays an image by irradiating the lens array according to any one of claims 1 to 13 with laser light. An image display device according to claim 14,
A moving body in which a transmission / reflection member is disposed on an optical path of laser light through the lens array.

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