JP7196762B2 - head-up display device - Google Patents

Description

The present invention relates to a head-up display device that projects a display image based on drawing by laser beam scanning.

2. Description of the Related Art Conventionally, Japanese Patent Laid-Open No. 2002-200000 proposes an optical scanning device for image display that can suppress deterioration in image quality. This optical scanning device comprises an optical scanning system including a light source and a two-dimensional deflection means for deflecting the light from the light source, and a microlens array to which the light is emitted from the optical scanning system. In the lens arrangement of the microlens array, the lens pitch in the Y direction perpendicular to the X direction in the xy plane is changed in the X direction.

In the optical scanning device, interference fringes called moire due to interference between the period of the scanning line and the period of the lens array structure cause image quality deterioration. On the other hand, by arranging the lenses of the microlens array as described above, the lens pitch can be changed so as not to overlap the trajectory of the scanning line spacing in the screen. In other words, the lens pitch of the microlens array can be widened according to the spread of light scanning. This makes it possible to avoid moire.

Japanese Unexamined Patent Application Publication No. 2017-3803

In Japanese Patent Application Laid-Open No. 2002-100003, the interval between adjacent scanning line loci is set as the scanning line interval, and the lens pitch is prevented from overlapping the locus of the scanning line interval. However, as the scanning line spacing, not only the spacing between adjacent scanning line trajectories, but also the spacing between scanning line trajectories that are one apart, the spacing between scanning line trajectories that are two apart, and the spacing between scanning line trajectories that are three apart. There are also spacings between distant scanline trajectories, such as the spacing between . Patent document 1 does not take into account the spacing between such distant scanning line trajectories. In the following description, the interval between adjacent scanning line trajectories is referred to as a basic period because it corresponds to the basic scanning line period. Also, the interval between the scanning line trajectories that are separated by one is twice the basic period at the center of the scan, so it is called a double period. Similarly, the interval between two scanning line trajectories at the center of scanning is three times the basic period, so the interval between three scanning line trajectories is three times the basic period at the scanning center. is four times, it is called a quadruple period.

As described above, in Patent Document 1, although the trajectory of the scanning line spacing in the basic period is considered, the trajectory of the scanning line spacing in the multiplied period such as the double period is not considered. In particular, in an even-numbered cycle such as a double cycle or a quadruple cycle, the scanning line interval has the same value over the entire scanning range. The interval gradually widens, but conversely, when scanning from the scanning end toward the scanning center, the scanning line interval starts from a narrow state. Therefore, if the lens pitch of the microlens array is simply widened in accordance with the spread of the light scanning line interval, the effect of suppressing the moire cannot be properly achieved.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a head-up display device capable of more appropriately suppressing blurred images by considering the scanning line interval of the multiplication period.

In order to achieve the above object, the head-up display device according to claims 1 to 3 includes a laser scanner (10) for outputting laser light for forming a display image, and a laser scanner (10) for reflecting or transmitting the laser light output from the laser scanner. a screen (20) having a plurality of elements (22) arranged in an array to allow the light to flow. In such a configuration, the screen is arranged such that one direction on the scanning surface (21) of the screen is the x-axis direction and the direction perpendicular to the x-axis direction is the y-axis direction, and the laser beam is emitted by the laser scanner in the x-axis direction. When scanning is performed along the scanning line trajectory which is reciprocated in the axial direction and moved in the y-axis direction by a constant amount of movement, a display image is formed on the scanning surface for one scanning period of the laser light. , the length Ly corresponding to the element pitch in the y-axis direction of the plurality of elements is set to a value different from an integral multiple of the scan pitch Ps , and the x-axis constant in direction .
In the head-up display device according to claim 1, the length Ly is set to a value different from a range obtained by adding or subtracting a predetermined value to an integral multiple of the scan pitch Ps. In the head-up display device according to claim 2, the length Ly is set to a value different from the range of 5 μm around the integral multiple of the scan pitch Ps. In the head-up display device according to claim 3, the length Ly is set to a value different from a predetermined range centered on an integer multiple of the scan pitch Ps.

In this way, the length Ly, which is the element pitch in the y-axis direction in the plurality of elements, is set to a value different from an integral multiple of the scan pitch Ps. As a result, the line indicating the length Ly can be made to intersect only once with the trajectory of the scanning line intervals of the basic period and the multiplication period, and moiré can be appropriately suppressed.

It should be noted that the reference numerals in parentheses attached to each component etc. indicate an example of the correspondence relationship between the component etc. and specific components etc. described in the embodiments described later.

It is the figure which showed the mounting state to the vehicle of the head-up display apparatus concerning 1st Embodiment. 1 is a diagram showing a schematic configuration of a head-up display device; FIG. FIG. 3 is a perspective view of a screen; FIG. 4 is a partial cross-sectional view of the screen; FIG. 4 is a partial front view of the screen; FIG. 4 is a diagram showing the relationship between the intensity of laser light and the beam diameter; FIG. 4 is a diagram showing scanning line trajectories on xy coordinates; FIG. 10 is a diagram illustrating scanning line intervals using scanning line trajectories; FIG. 10 is a diagram showing the relationship between the distance from the scanning center on the x-axis and the change in scanning line spacing; (a) is a diagram schematically showing the relationship between the size of the eyebox in the vertical direction and the length Ly of the element, (b) is an enlarged schematic diagram of the region Ra in (a), (c) is (a ) is an enlarged schematic diagram of a region Rb in FIG.

An embodiment of the present invention will be described below with reference to the drawings. In addition, in each of the following embodiments, portions that are the same or equivalent to each other will be described with the same reference numerals.

(First embodiment)
A head-up display device according to the first embodiment will be described. A head-up display device is applied to a vehicle, and is used to provide information such as display of vehicle speed and direction of travel by a navigation system by allowing a driver to visually recognize a virtual image of a display image.

A head-up display device 100 shown in FIG. 1 is housed, for example, in an instrument panel 1 of a vehicle, and projects a display image onto a projection plane 3 of a windshield 2 so that the driver can visually recognize a virtual image 4 of the display image. make it possible. As for the display image, a virtual image 4 of the display image projected onto the projection surface 3 from the eyebox is made visible by using a rectangular area that is assumed to be the position of the eyes 5 when the driver is seated in the driver's seat. is displayed.

A head-up display device 100 includes a laser scanner 10 , a screen 20 and a concave mirror 30 .

The laser scanner 10 is arranged on one side of the screen 20 and outputs laser light for forming a display image on one side of the screen 20 . Specifically, as shown in FIG. 2, the laser scanner 10 has a controller 11, a light source unit 12, an optical unit 13, and a micro electro mechanical system (hereinafter referred to as MEMS (Micro Electro Mechanical Systems)) mirror unit 14. It is configured.

The controller 11 is configured by a control device configured by a processor or the like, and corresponds to a control section that controls projection of laser light from the light source section 12, optical scanning by the MEMS mirror section 14, and the like. The controller 11 controls projection of laser light from each of the laser projection sections 12a to 12c by transmitting control signals to each of the laser projection sections 12a to 12c, which will be described later.

The light source unit 12 includes three laser projection units 12a to 12c, etc., and projects laser beams by intermittently pulsing the laser beams from the laser projection units 12a to 12c. Each of the laser projection units 12a to 12c projects laser beams of different frequencies, ie, different hues. Specifically, the laser projection units 12a to 12c project red, blue, and green laser beams, respectively. In FIG. 2, red, blue, and green are indicated as R, B, and G, respectively. In this manner, various colors can be reproduced by additively mixing laser beams of different hues.

The optical section 13 has three collimator lenses 13a-13c, dichroic filters 13d-13f and a condenser lens 13g.

The collimating lenses 13a to 13c are arranged in the projection directions of the laser beams of the laser projection units 12a to 12c, respectively, and generate parallel beams by refracting the laser beams.
The dichroic filters 13d to 13f are arranged in the projection directions of the laser projection sections 12a to 12c with the collimator lenses 13a to 13c interposed therebetween. A dichroic filter 13d arranged in the projection direction of the laser projection unit 12a transmits laser light of a red frequency and reflects laser light of other frequencies. A dichroic filter 13e arranged in the projection direction of the laser projection unit 12b reflects blue-frequency laser light and transmits light of other frequencies. The dichroic filter 13f arranged in the projection direction of the laser projection unit 12c reflects laser light of green frequency and transmits light of other frequencies. Due to the action of the dichroic filters 13d-13f, the laser beams projected from the laser projection units 12a-12c reach the condenser lens 13g.

The condenser lens 13g is a plano-convex lens having a planar entrance surface and a convex exit surface. The condenser lens 13g refracts and converges the laser beam incident on the incident surface. As a result, the laser light that has passed through the condenser lens 13g is reflected by the MEMS mirror section 14 and is irradiated onto the scanning surface 21 of the screen 20, which will be described later.

The MEMS mirror section 14 forms a display image on the screen 20 by scanning the laser light incident from the condenser lens 13g and projecting it toward the screen 20 .

The MEMS mirror unit 14 has a first scanner 14a and a second scanner 14b. The first scanner 14a is arranged with its reflecting surface directed toward the condenser lens 13g and the second scanner 14b, and reflects the laser light incident from the condenser lens 13g toward the second scanner 14b. The second scanner 14b is arranged with its reflective surface facing the first scanner 14a and the screen 20 . The first scanner 14a is supported by the horizontal rotation shaft, and the second scanner 14b is supported by the vertical rotation shaft.

The MEMS mirror section 14 configured in this manner is driven by rotationally displacing the first scanner 14a and the second scanner 14b around respective rotation axes based on drive signals from the controller 11 . By rotationally displacing the first scanner 14a and the second scanner 14b, the direction of the laser light reflected by the MEMS mirror section 14 is scanned along the scanning line SL shown in FIG.

The screen 20 is composed of a reflective screen formed by vapor-depositing aluminum or the like on the surface of a base material such as glass. A display image is formed on 21 . As shown in FIGS. 3A to 3C, the screen 20 has elements 22 each composed of a plurality of minute micromirrors arranged at equal intervals in the x-axis direction along the virtual reference plane and the y-axis direction perpendicular thereto. It is a micromirror array arranged in an array. That is, the structure is such that the elements 22 are continuously and repeatedly arranged at a predetermined element pitch in each of the x-axis direction and the y-axis direction. A surface covered with the elements 22 is used as a scanning surface 21 .

Each element 22 has a convex curved surface that reflects and diffracts the laser light toward the concave mirror 30 while expanding the laser light toward the eyebox. As shown in FIG. 3C, each element 22 has a rectangular upper surface shape. In this embodiment, each element 22 has a length Lx corresponding to the element pitch in the x-axis direction and an element pitch in the y-axis direction. They are squares with the corresponding lengths Ly equal. At least the length Ly of the element 22 is determined from the scan pitch, that is, the relationship with the amount of movement of the laser light in the y-axis direction in one scan period. Assuming that the scan pitch is Ps, the length Ly is, for example, 0.05Ps≦Ly≦0.95Ps, 1.05Ps≦Ly≦1.95Ps, and 2.05Ps≦Ly≦2.95. is set to a value different from an integer multiple of . Furthermore, in consideration of interference noise in which the laser beams reflected by the adjacent elements 22 overlap and interfere with each other, it is preferable to set the length Ly and the length Lx to be equal to or larger than the beam diameter Rb of the laser beam.

As described above, the scanning surface 21 is irradiated with light from the MEMS mirror section 14, and the beam diameter Rb of the laser light upon irradiation, in other words, the diameter of the laser light, is set to about 100 μm, for example. be. As shown in FIG. 4, the beam diameter is defined as a range up to a region where the intensity is 1/e ² or more when the intensity at the central position of the laser beam is 1.

Therefore, for example, when the scan pitch Ps is 50 μm, the length Ly of the element 22 in the y-axis direction is set to 102.5 μm or more, which is 100+α μm.

The concave mirror 30 is arranged, for example, in the horizontal direction of the screen 20 as shown in FIG. doing. The concave mirror 30 has a concave surface with a concave central portion, the concave surface serves as a reflecting surface, and is arranged facing the screen 20 side.

The head-up display device 100 is configured as described above. Next, the operation of the head-up display device 100 and the effect of suppressing moire will be described.

As described above, based on the control signal from the controller 11, the laser beams are appropriately projected from the three laser projection units 12a to 12c of the light source unit 12. The laser beams pass through the collimator lenses 13a to 13c and the like, and then the condenser lens 13g. and condensed. Further, based on the drive signal from the controller 11, the first scanner 14a and the second scanner 14b are rotationally displaced, and the direction of the laser light from the condenser lens 13g is scanned like the scanning line SL shown in FIG. be done. As a result, the light projected onto the scanning surface 21 of the screen 20 is imaged to form a display image. Specifically, a display image is drawn on the scanning surface 21 of the screen 20 by assembling and forming an image of the point-like light emission as one pixel by scanning the point-like light emission by the projected laser light. . A display image drawn on the screen 20 is reflected by a concave mirror 30 and projected onto the projection plane 3 . Therefore, it is possible for the driver to visually recognize the virtual image of the display image, and information can be provided by the head-up display device 100 .

In providing information by means of a display image in this manner, the scanning line interval, which is the interval between the scanning line loci, and the element pitch, which is the arrangement interval of the elements 22, are set so as to suppress moire. This will be described with reference to FIGS. 5, 6 and 7. FIG.

FIG. 5 is a diagram showing scanning line trajectories and scanning line intervals on the scanning surface 21 by xy coordinates. FIG. 6 illustrates the scanning line spacing using the scanning line trajectory of FIG. FIG. 7 shows the relationship between the distance from the scanning center, which is the central position of the scanning line trajectory in the x-axis direction, and the change in the scanning line interval.

As shown in FIG. 5, the scanning line SL traces a scanning line trajectory in which it moves in the y-axis direction at a constant moving amount, in other words, at a constant moving speed while reciprocating in the x-axis direction. Here, as shown in FIG. 6, one scanning period is defined as a basic period, and the scanning line interval between adjacent scanning line trajectories in the basic period is called a basic period interval W1.

In FIG. 7, lines L1a and L1b represent changes in the basic period interval W1 with respect to the distance from the scanning center. For example, after passing through the left scanning end (hereinafter referred to as the left end) in the x-axis direction from point A in FIG. Assume again the fundamental period leading to point C in the middle of the scan.

In that case, the interval between point A and point B at the center of scanning is Ps/2, which is half the scanning pitch Ps. Then, when reaching the leftmost point D from the point A, the fundamental period interval W1 is the distance between the leftmost point D and the leftmost point E in the previous fundamental period. Therefore, from point A to point D, the basic period interval W1 gradually increases from Ps/2, reaching Ps at the left end. Similarly, from point B to point F, it gradually increases from Ps/2 and reaches Ps at the right end. Therefore, the change in the basic period interval W1 between them is indicated by the locus L1a in FIG.

However, the basic periodic interval W1 does not gradually increase from the point D to the point B and from the point F to the point C as described above. Regarding this, looking at the change in the basic period interval W1 from point F on the right end to point C, the basic period interval W1 at this time corresponds to the scanning line locus from point B to point F. It is the distance from the scanning line trajectory from point F to point C. Therefore, at point F, the fundamental period interval is 0, and from point F to point C it gradually increases to Ps/2. Therefore, the change in the basic period interval W1 between them is indicated by the locus L1b in FIG.

In addition to the basic period, the loci of the scanning line intervals of the multiplied period such as the double period, the triple period, and the quadruple period are as follows.

Regarding the scanning line interval in the double period (hereinafter referred to as the double period interval), for example, the scanning line trajectory from point A to the leftmost point D, and the scanning line locus from point C to the leftmost point G in the next period. This is the interval between the scanning line trajectories that are one apart, such as the scanning line spacing between the scanning line trajectories of . The scanning line trajectory from point A to point D and the scanning line trajectory from point C to point G move a certain distance in the y-axis direction but are the same trajectory. becomes constant at Ps. Therefore, there is no change in the double period interval, and Ps becomes a constant value as indicated by locus L2 in FIG.

As for the scanning line interval in the triple period (hereinafter referred to as "triple period interval"), for example, the scanning line trajectory from point A to point D at the left end and the scanning line trajectory from point G to point H at the center of scanning. It is the interval between the scanning line trajectories that are two apart, such as the scanning line interval between . This triple period interval is a value obtained by adding Ps to the basic period interval W1. Therefore, changes in the triple period interval are indicated by loci L3a and L3b in FIG.

Furthermore, the scanning line interval in the quadruple cycle (hereinafter referred to as the quadruple cycle interval) is, for example, the scanning line locus from point A to the leftmost point D, and the scanning line locus from the point J in the second cycle to the leftmost point K. This is the interval between the scanning line trajectories that are three away from each other, such as the scanning line spacing between the scanning line trajectories up to . The scanning line trajectory from point A to point D and the scanning line trajectory from point J to point K move a certain distance in the y-axis direction but are the same trajectory. It becomes constant at 2Ps. Therefore, the quadruple period interval does not change, and becomes a constant value at 2Ps as indicated by locus L4 in FIG.

Here, when the lens pitch of the microlens array in the y-axis direction increases as the distance from the scanning center in the x-axis direction increases, as in the prior art disclosed in Patent Document 1, the change in the pitch is represented by the curve Lj is indicated by This curve Lj is distant from the trajectory L1a indicating the change in the fundamental period interval. However, it overlaps with both the trajectories L2 and L3b indicating changes in the double periodic interval and the triple periodic interval, which are other than the basic periodic interval.

In such a state, although the trajectory L1a in the basic period interval is taken into consideration, the trajectory of the scanning line interval in the multiplied period such as the double period is not taken into consideration, and the effect of suppressing the moire is appropriately obtained. cannot play.

In contrast, in the present embodiment, the length Ly, which is the element pitch in the y-axis direction, is set to a value different from an integer multiple of the scan pitch Ps. For this reason, as shown in FIG. 7 as an example in which the length Ly is 130 μm, straight lines indicating the length Ly, which is the element pitch in the y-axis direction, are traces L1a, L1b, L2, L3a, L3b, and L4. only intersect once. As a result, it is possible to appropriately exhibit the effect of suppressing moire.

The present inventors conducted intensive studies based on experiments and the like on the range in which the effect of suppressing moiré can be obtained. It was found necessary to consider the trajectory of the periodic scan line spacing. However, it is not necessary to not intersect the trajectories L1a and L1b of the change in the basic period interval and the trajectory of the scanning line interval of the multiplication period at all, and it is allowed to intersect once, and at least within a range visible to the naked eye. , it was confirmed that an effect of suppressing moire was obtained.

Therefore, in the present embodiment, the length Ly, which is the element pitch in the y-axis direction, is set to a value different from an integral multiple of the scan pitch Ps, and the straight lines indicating the length Ly are loci L1a, L1b, L2, L3a, L3b, and L4. I try to cross only once. By doing so, it is possible to appropriately suppress moire.

In order to obtain the effect of suppressing moiré appropriately, the length Ly, which is the element pitch in the y-axis direction, should be set to a value different from an integral multiple of the scan pitch Ps. However, based on experiments and the like, even if the length Ly, which is the element pitch in the y-axis direction, is a value different from an integral multiple of the scan pitch Ps, if the value is close to that value, moire may occur slightly. is confirmed.

This is believed to be due to the light that forms the moiré entering the pupil of the eye. As a result of examining the influence, when the line indicating the length Ly overlaps a range obtained by adding or subtracting a predetermined value to or from the trajectories L1a, L1b, L2, L3a, L3b, and L4, for example, a range of about ±2.5 μm However, it has been found that some moiré may occur. Therefore, as described above, it is preferable that the line indicating the length Ly does not overlap the area within the range of ±2.5 μm, which is an integral multiple of the scan pitch Ps.

Here, the numerical range described above defines the range in which the light forming the moire enters the pupil of the eye. Hereinafter, an example of numerical values will be given to explain the reasons for the numerical ranges described above.
Numerical values described here are merely examples, and may vary depending on the dimensions of each part of the head-up display device 100 and the like.

FIG. 8(a) shows the relationship when, for example, the eyebox size in the vertical direction is set to 140 mm and the length Ly of the element 22 is set to 100 μm. As shown in FIG. 8, there is a corresponding relationship between the length Ly of each element 22 and the eyebox size.

The pupil size shown in FIG. 8B is 2 mm at minimum and 6 to 7 mm at maximum in humans. Considering that light that forms moire affects only light that enters the pupil, it is possible to assume a range that can be affected by moire from the size of the pupil. Specifically, if the maximum pupil size is 7 mm, 7 mm on the eyebox corresponds to 5 μm on the screen 20 as shown in FIG. 8(c). Therefore, the range of 5 μm around the scan pinch Ps is considered to be the range that can be affected by moire. Therefore, when the scan pitch Ps is 50 μm, the range is expressed as 2.05Ps≦Ly≦2.95, excluding an integral multiple of the scan pitch Ps ±5%.

Here, when the pupil size is assumed to be the maximum, the range that may be affected by moiré is assumed. However, when the size assumed as the pupil size is changed, the range can be assumed to be small.

Also, here, if the eyebox size in the vertical direction is 140 mm, the length Ly of the element 22 is 100 μm, and the pupil size is 7 m, moire can be affected in the range of 5 μm. However, these numerical values only show an example. That is, the range that can be affected by moire can be set according to the size of the eyebox in the vertical direction, the length Ly of the element 22, and the expected size of the pupil.

For example, let L _box be the eyebox size in the vertical direction, L _{eye be the size obtained by cutting out a part of the eye box expected as the pupil size, and Ls be the size of the part of the element 22 corresponding to the cut out size L eye .} In that case, using the length size Ly of the element 22, Equation 1 holds.

(Number 1)
L _box : L _eye = Ly: Ls

From this formula, Ls=L _eye ·Ly/L _box is derived. Therefore, the range of Ls can be determined according to the expected pupil size. For example, assuming that the minimum pupil size is L _eye(min) and the maximum pupil size is L _eye(max) , the size Ls of the part of the element 22 corresponding to the pupil size is expressed by Equation (2).

(Number 2)
L _{eye (min)} · Ly / L _box ≤ Ls ≤ L _{eye (max)} · Ly / L _box

Therefore, an arbitrary predetermined value within the range shown by the above formula 2 is set as the width of the range that can be affected by moire, and the length Ly is set around the integral multiple of the scan pinch Ps, excluding the range corresponding to that width. By designing, it becomes possible to suppress the influence of moire.

(Other embodiments)
The present invention is not limited to the above-described embodiments, and can be appropriately modified within the scope of the claims.

For example, in the above embodiment, the case where the length Ly, which is the element pitch in the y-axis direction, is set to a constant value has been described as an example. can be Even in that case, if the line indicating the length Ly intersects the trajectories L1a, L1b, L2, L3a, L3b, and L4 only once, the effect of suppressing moiré can be preferably achieved.

In the above-described embodiment, the element 22 forming the screen 20 has been described as having a rectangular shape. It's okay to be.

In the above-described embodiment, the case where the screen 20 is configured with a reflective screen has been described. good. In that case, the head-up display device may be configured such that the laser light is transmitted through the screen 20 and the transmitted light is used to display the display image.

REFERENCE SIGNS LIST 10 laser scanner 20 screen 21 scanning surface 22 element 100 head-up display device

Claims (5)

A head-up display device for displaying a display image,
a laser scanner (10) that outputs a laser beam that forms the display image;
a screen (20) in which a plurality of elements (22) for reflecting or transmitting the laser beam output from the laser scanner are arranged in an array;
The screen is
The laser beam is caused to reciprocate in the x-axis direction by the laser scanner, with one direction on the scanning surface (21) of the screen as the x-axis direction and the direction perpendicular to the x-axis direction as the y-axis direction. forming the display image on the scanning plane when scanned with a scanning line trajectory that is moved by a constant movement amount in the y-axis direction while being moved;
Assuming that the amount of movement of the laser light in the y-axis direction in one scanning cycle of the laser light is a scan pitch Ps, the length Ly corresponding to the element pitch in the y-axis direction in the plurality of elements is the scanning pitch. is set to a value different from an integral multiple of the pitch Ps and is constant in the x-axis direction;
2. The head-up display device according to claim 1, wherein said length Ly is set to a value different from a range obtained by adding or subtracting a predetermined value to an integral multiple of said scan pitch Ps. A head-up display device for displaying a display image,
a laser scanner (10) that outputs a laser beam that forms the display image;
a screen (20) in which a plurality of elements (22) for reflecting or transmitting the laser beam output from the laser scanner are arranged in an array;
The screen is
The laser beam is caused to reciprocate in the x-axis direction by the laser scanner, with one direction on the scanning surface (21) of the screen as the x-axis direction and the direction perpendicular to the x-axis direction as the y-axis direction. forming the display image on the scanning plane when scanned with a scanning line trajectory that is moved by a constant movement amount in the y-axis direction while being moved;
Assuming that the amount of movement of the laser light in the y-axis direction in one scanning cycle of the laser light is a scan pitch Ps, the length Ly corresponding to the element pitch in the y-axis direction in the plurality of elements is the scanning pitch. is set to a value different from an integral multiple of the pitch Ps and is constant in the x-axis direction;
2. The head-up display device according to claim 1, wherein said length Ly is set to a value different from a range of 5 [mu]m centered on integral multiples of said scan pitch Ps. A head-up display device for displaying a display image,
a laser scanner (10) that outputs a laser beam that forms the display image;
a screen (20) in which a plurality of elements (22) for reflecting or transmitting the laser beam output from the laser scanner are arranged in an array;
The screen is
The laser beam is caused to reciprocate in the x-axis direction by the laser scanner, with one direction on the scanning surface (21) of the screen as the x-axis direction and the direction perpendicular to the x-axis direction as the y-axis direction. forming the display image on the scanning plane when scanned with a scanning line trajectory that is moved by a constant movement amount in the y-axis direction while being moved;
Assuming that the amount of movement of the laser light in the y-axis direction in one scanning cycle of the laser light is a scan pitch Ps, the length Ly corresponding to the element pitch in the y-axis direction in the plurality of elements is the scanning pitch. is set to a value different from an integral multiple of the pitch Ps and is constant in the x-axis direction ;
The head-up display device, wherein the length Ly is set to a value different from a predetermined range centered on integral multiples of the scan pitch Ps. L _box is the vertical size of the eye box, which is a rectangular area defined as the position of the driver's eye (5), and L _{eye (min)} and L are the minimum and maximum pupil sizes of the eyes, respectively. _eye(max) , Ls being the size corresponding to the pupil size on the screen,
L _{eye (min)} · Ly / L _box ≤ Ls ≤ L _{eye (max)} · Ly / L _box As the width of the predetermined range, the length Ly is the width 4. The head-up display device according to claim 3 , which is set to a value different from the predetermined range set by . The element has a curved convex surface, and has a rectangular upper surface shape,
5. The head-up display according to any one of claims 1 to 4 , wherein the length Ly corresponding to the element pitch in the y-axis direction is the length in the y-axis direction of the quadrangles forming the elements. Device.

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