JP2018010179A - Display unit and head-up display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a reduction in image quality due to moire in an image formed by irradiating with light a micro-lens array constituted by arranging micro-lenses.SOLUTION: A display unit comprises: a light source; an image forming part that forms a plurality of rays of pixel light on the basis of light emitted from the light source; and a micro-lens array that has a plurality of micro-lenses arranged periodically and on which the plurality of rays of pixel light are made incident. The plurality of rays of pixel light are arranged periodically on the micro-lens array; the plurality of micro-lenses are arranged along at least one arrangement direction; the plurality of rays of pixel light are arranged on the micro-lens array along a direction not matching the arrangement direction and shifted by a predetermined angle.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a display device and a head-up display device including the display device.

  The information display device described in Patent Document 1 is a device that scans laser light on a diffusion screen through a scanning system, and diffused light from the diffusion screen is incident on the eyes of an information viewer, and predetermined information is received. Visible. Here, examples of the diffusion screen include a screen in which a plurality of minute lenses are densely spread.

JP-A-7-270711

  However, in an apparatus that displays an image of information by scanning a laser beam on a screen in which a plurality of microlenses are arranged, such as the information display apparatus described in Patent Document 1, the display quality of an image due to the occurrence of moire. There was a risk of lowering. Such moire includes scan moire generated due to scanning of laser light and diffraction moire caused by interference or diffraction of laser light incident on the screen inside the screen.

  Therefore, the present invention provides a display device capable of suppressing a reduction in display quality due to moire in an image formed by irradiating light to a microlens array in which microlenses are arranged, and a head-up display device including the display device. For the purpose.

In order to solve the above problems, a display device according to a first aspect of the present invention includes a light source, an image forming unit that forms a plurality of pixel lights based on light emitted from the light source, and a plurality of pixel lights. And a microlens array in which a plurality of microlenses are periodically arranged. The plurality of pixel lights are periodically arranged on the microlens array, and the plurality of microlenses are arranged along at least one arrangement direction. The plurality of pixel lights are arranged on the microlens array along a direction shifted by a predetermined angle that does not coincide with the arrangement direction.
As a result, the pitch of the moire can be controlled in accordance with the resolution of the eyes of the person viewing the display image, so that the moire can be set at a pitch where it is difficult to visually recognize, thereby suppressing deterioration in display quality due to the moire. It becomes possible.

In the display device according to the first aspect of the present invention, the plurality of microlenses are arranged along at least two arrangement directions, and the predetermined angle corresponds to a direction between two adjacent arrangement directions of the microlenses. It is preferable that
Accordingly, since the pixel light can be arranged in a direction deviated from the arrangement direction of the microlenses, it is difficult for the moire to be visually recognized, thereby suppressing the deterioration in display quality due to the moire.

The display device according to the second aspect of the present invention includes a light source, an image forming unit that forms a plurality of pixel lights based on light emitted from the light source, a plurality of pixel lights incident, and a plurality of microlenses periodically. The plurality of pixel lights are periodically arranged on the microlens array, the plurality of microlenses are arranged at the first pitch Pm, and the plurality of pixel lights are arranged in the microlens array. In the above, it is characterized by being arranged at a second pitch Pp that does not coincide with the first pitch Pm.
Accordingly, since the arrangement of the microlens and the pixel light can be shifted, it is difficult for the moire to be visually recognized, and it is possible to suppress the deterioration of display quality due to the moire.

In the display device according to the first and second aspects of the present invention, the pitch Pm of the plurality of microlenses and the pitch Pp of the plurality of pixel lights on the microlens array are expressed by the following formula (1) or (2): It is preferable to satisfy.
1.5 × Pp ≦ Pm ≦ 1.9 × Pp (1)
0.1 × Pp ≦ Pm ≦ 0.5 × Pp (2)
As a result, the pitch of the moiré can be made lower than the resolution of the person viewing the display image, so that the moiré is less likely to be visually recognized, thereby suppressing the deterioration in display quality due to the moiré.

In the display device according to the first and second aspects of the present invention, the diameter of the pixel light on the microlens array is preferably 2/3 or less of the pitch of the microlens.
Thereby, since the generation | occurrence | production of the extra diffraction in a micro lens can be suppressed, the resolution of a display image can be raised.

A head-up display device according to the present invention includes any one of the display devices described above and a projection optical system that projects an intermediate image formed on a microlens array onto a projection target, the projection target being a windshield of a vehicle. Or a combiner disposed inside the windshield.
Thereby, in the image projected in a head up display apparatus, the fall of the display quality by a moire can be suppressed.

  According to the present invention, it is possible to suppress deterioration in display quality due to moire in an image formed by irradiating light to a microlens array in which microlenses are arranged.

It is a side view showing a schematic structure of a head up display device concerning a 1st embodiment of the present invention. It is a block diagram which shows the structure of the head-up display apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows schematic structure of the light source part in 1st Embodiment of this invention. It is a top view which shows the structural example of the micro lens array in 1st Embodiment of this invention. It is the top view which showed the example of arrangement | sequence of the micro lens of a micro lens array, and the pixel light on a micro lens array. It is the top view which showed the example of arrangement | sequence of the micro lens of a micro lens array, and the pixel light on a micro lens array. (A) is a graph showing the relationship between the MLA arrangement angle and the moire frequency when pixel light is applied to the MLA, and (B) is the MLA arrangement angle and Δp when the pixel light is applied to the MLA. It is a graph which shows the relationship. It is the top view which showed the example of arrangement | sequence of the micro lens of the micro lens array which concerns on 2nd Embodiment, and the pixel light on a micro lens array. (A) is a graph showing the relationship between the MLA arrangement angle and the moire frequency when pixel light is applied to the MLA, and (B) is the MLA arrangement angle and Δp when the pixel light is applied to the MLA. It is a graph which shows the relationship.

(First embodiment)
Hereinafter, a display device and a head-up display device according to a first embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a side view showing a schematic configuration of a head-up display device 10 according to the first embodiment of the present invention. FIG. 2 is a block diagram illustrating a configuration of the head-up display device 10 according to the first embodiment. FIG. 3 is a diagram illustrating a schematic configuration of the light source unit 20 in the first embodiment. FIG. 4 is a plan view showing a configuration example of the microlens array 40 in the first embodiment. 1 and 4 show XYZ coordinates as reference coordinates. The X direction is along the optical axis 35c of the lens 35 and the central axis 40x of the entire microlens array 40, and the YZ plane is a plane perpendicular to the X direction. In the following description, the state viewed along the X direction may be referred to as a plan view.

  As shown in FIG. 1, the head-up display device 10 includes a light source unit 20, a scanning mirror 31 and a lens 35 as an image forming unit, a microlens array 40 (hereinafter sometimes referred to as MLA 40), and projection optics. A projection mirror 51 as a system is provided, and a mirror driver 32, a control unit 33, and a memory 34 are provided as shown in FIG. Here, as shown in FIG. 1, the lens 35 and the MLA 40 are arranged in order from the scanning mirror 31 side to the projection mirror 51 side so that the extension lines of the optical axes overlap each other along the X direction. Further, the light source unit 20, the scanning mirror 31, the lens 35, and the MLA 40 in FIG. 1, and the mirror driver 32, the control unit 33, and the memory 34 in FIG. 2 constitute a display device. The memory 34 stores information necessary for control by the control unit 33, data serving as a base for creating image data of an intermediate image, and the like.

  As shown in FIG. 2 or 3, the light source unit 20 includes a laser light source 21 including three laser diodes 21a, 21b, and 21c, a laser driver 22, three collimator lenses 23a, 23b, and 23c, and a mirror 24a. Two dichroic prisms 24b and 24c are provided.

  The laser diodes 21 a, 21 b, and 21 c are light sources that emit laser light in the visible region, and emit light having an intensity corresponding to the amount of current supplied from the laser driver 22. This light has a point-like cross section perpendicular to the traveling direction, and the modulation of amplitude and the amount of current supplied from the laser driver 22 are controlled by the control unit 33. Accordingly, laser light is emitted from the laser diodes 21a, 21b, and 21c at a predetermined time interval.

  The laser diode 21a emits red laser light, for example, and the laser light emitted from the laser diode 21a is collimated by the collimator lens 23a and reflected by the mirror 24a toward the dichroic prism 24b.

  The laser diode 21b emits green laser light, for example, and the laser light emitted from the laser diode 21b is collimated by the collimator lens 23b and reflected by the dichroic prism 24b toward the dichroic prism 24c. The dichroic prism 24b reflects the green light emitted from the collimator lens 23b and transmits the red light reflected by the mirror 24a to the dichroic prism 24c side.

The laser diode 21c emits, for example, blue laser light, and the laser light emitted from the laser diode 21c is collimated by the collimator lens 23c and reflected by the dichroic prism 24c to the scanning mirror 31 side. The dichroic prism 24c reflects the blue light emitted from the collimator lens 23c, and transmits the combined light of red light and green light emitted from the dichroic prism 24b to the scanning mirror 31 side.
The laser light source 21 may be composed of a monochromatic laser diode.

  The scanning mirror 31 is, for example, a galvanometer mirror, and as a two-dimensional scanner, the reflection surface 31r is rotated about two rotation axes by a mirror driver 32. The laser light emitted from the light source unit 20 is emitted as scanning light by being reflected by the rotating reflecting surface 31r. In this scanning, first, light for one line is irradiated onto the lens 35 by rotation about a first rotation axis (not shown) along the Z direction. Next, after a predetermined amount of rotation about a second rotation axis (not shown) along the Y direction, rotation about the first rotation axis is performed again to perform the next 1 The light for the line is irradiated to the lower side in the Z direction, and by repeating these, the light for one frame periodically arranged in the vertical and horizontal directions is irradiated onto the lens 35. The rotation direction and rotation speed of the scanning mirror 31 are controlled by the control unit 33, and the mirror driver 32 rotates the scanning mirror 31 in accordance with a control signal from the control unit 33. The second rotation axis of the scanning mirror 31 is disposed on an extension line of the central axis 40x of the entire MLA 40.

  The lens 35 is a lens having a positive refractive power, and emits the reflected light from the scanning mirror 31 to the MLA 40 side in parallel with the central axis 40x of the entire MLA 40. Light emitted from the lens 35 is incident as a plurality of pixel lights so as to be periodically arranged on the MLA 40, thereby forming an intermediate image on the MLA 40 frame by frame.

  As shown in FIG. 4, the microlens array (MLA) 40 has a rectangular planar shape as a whole, and has a configuration in which a plurality of microlenses 40a having the same shape are periodically arranged so as to be in close contact with each other. Yes. Each of the microlenses 40a has a regular hexagonal shape in plan view, and each side is in contact with one side of the adjacent microlens 40a, whereby the MLA 40 forms a hexagonal array. FIG. 4 shows a state in which the vertical and horizontal sides of the MLA 40 are arranged along the Z direction and the Y direction, respectively, and in this state, the plurality of microlenses 40a includes a first direction D11 parallel to the Y direction, The second direction D12 is inclined 60 degrees clockwise in plan view with respect to the first direction D11, and the third direction D13 is inclined 60 degrees counterclockwise in plan view with respect to the first direction D11. Are lined up. As shown in FIG. 1, each microlens 40 a protrudes hemispherically along the X direction toward the lens 35, and each optical axis extends parallel to the central axis 40 x of the entire MLA 40. Each of the microlenses 40a diffracts incident light from the lens 35, and emits a plurality of diffracted lights having different emission angles and phases to the projection mirror 51 side. The MLA 40 is formed, for example, by resin molding.

  In the state shown in FIG. 4, the microlenses 40a are arranged at a pitch Ph in the horizontal direction (Y direction) in plan view, and are arranged at a pitch Pv in the vertical direction (Z direction). These pitches Ph and Pv are intervals between the centers of the hexagonal microlenses 40a in plan view.

  The projection mirror 51 is a concave mirror (magnifying mirror) having a reflecting surface 51r. Projection light including an intermediate image formed by the MLA 40 is magnified and reflected by the projection mirror 51. This reflected light is projected onto a display area of the windshield W of the vehicle or a combiner installed in front of the windshield W. Since the windshield W or combiner functions as a semi-reflective surface, the incident image light is reflected toward the driver, and a virtual image V is formed at a position in front of the windshield W or combiner. By visually observing the virtual image V in front of the windshield W or the combiner, it appears to the driver's eyes E that various types of information are displayed in front of the steering wheel.

  FIGS. 5 and 6 are plan views showing an example of the arrangement of the microlenses 40 a of the microlens array 40 and the pixel light on the microlens array 40. FIG. 5 shows a state in which the vertical and horizontal sides of the MLA 40 are arranged along the Z direction and the Y direction, respectively, as in FIG. 4, and a part of the MLA 40 is shown in an enlarged manner. On the other hand, FIG. 6 shows a state in which the MLA 40 is inclined 15 degrees clockwise in plan view with respect to the state of FIG.

  In the head-up display device 10 of the first embodiment, the center positions of the plurality of pixel lights incident on the MLA 40 from the lens 35 and the center positions of the plurality of microlenses 40a of the MLA 40 do not coincide with each other. For example, as shown in FIG. 6, the arrangement direction of the plurality of pixel lights on the MLA 40 and the arrangement direction of the plurality of microlenses 40a of the MLA 40 are shifted by a predetermined angle. Hereinafter, a more specific description will be given with reference to FIGS. 5 and 6.

  As shown in FIG. 5 or FIG. 6, the laser light emitted from the lens 35 is given to the MLA 40 as a plurality of pixel lights 41. In the example shown in FIG. 5 and FIG. The first direction D11, the second direction D12, and the third direction D13 are periodically arranged. The pixel light 41 is arranged at a pitch Ph in the horizontal direction (Y direction) in a plan view and at a pitch Pv in the vertical direction (Z direction), like the microlens 40a of the MLA 40 in the state shown in FIG. It is arranged. These pitches Ph and Pv are intervals between the centers of the pixel lights 41 having a circular shape in plan view. With such an arrangement, in the state shown in FIG. 5, the plurality of pixel lights 41 are arranged so that the center positions thereof coincide with the plurality of microlenses 40a.

  The state shown in FIG. 6 is a state in which the MLA 40 is inclined 15 degrees clockwise in the YZ plane without changing the arrangement of the pixel lights 41 with respect to the state shown in FIG. As shown in FIG. 6, the microlenses 40a are arranged along arrangement directions D21, D22, and D23, which are deviated by 15 degrees from the first direction D11, the second direction D12, and the third direction D13, respectively. For this reason, the pitches Ph and Pv of the microlens 40a both change, and there is a deviation between the center position of the pixel light 41 and the center position of the microlens 40a.

  7A and 7B, as shown in FIG. 4, the arrangement angle (MLA angle (unit: degree)) of the MLA 40 in which a plurality of microlenses 40a are arranged in a hexagon and pixel light is given to the MLA 40 8 is a graph showing the relationship with the moire frequency (unit: mm / cycle) (FIG. 7A) or pitch difference Δp (unit: mm) (FIG. 7B). In these graphs, a “Horizontal” curve indicated by a solid line indicates a change in the pitch Ph of the microlens 40a in the Y direction, and a “Vertical” curve indicated by a broken line indicates a change in the pitch Pv in the Z direction. Show.

  The moiré frequency shown on the vertical axis in FIG. 7A is obtained by taking an image projected on the windshield W by the projection mirror 51, and in the shaded moiré pattern appearing in this photographed image, one adjacent shade. The moiré image is shown as one cycle, and the width (unit: mm) per cycle is shown.

  The pitch difference Δp shown on the vertical axis in FIG. 7B is the difference between the pitch of the micro lenses 40a of the MLA 40 and the pitch of the pixel light on the MLA 40. The pitch difference Δp is the absolute value of the difference between the average value of the pitch Ph of the microlens 40a and the average value of the pixel light pitch in the Y direction for “Horizontal” indicated by a solid line, and “Vertical” indicated by a broken line. Is the absolute value of the difference between the average value of the pitches Ph of the microlenses 40a in the Z direction and the average value of the pitches of the pixel lights.

  The MLA angle shown on the horizontal axis in FIGS. 7A and 7B is zero when the arrangement shown in FIG. 4 or FIG. 5 is used (unit deg (degrees)), and the MLA 40 is tilted clockwise in plan view. Shows the angle. Therefore, the state tilted by 15 degrees corresponds to FIG. Here, since the micro lens 40a of the MLA 40 has a regular hexagonal planar shape, the pitch in the Y direction of the micro lens 40a is the same when the MLA angle is 0 degree and when it is 60 degrees. Similarly, the pitch of the micro lenses 40a in the Z direction is the same when the MLA angle is 0 degree and when it is 60 degrees. For this reason, in the pitch difference Δp shown in FIG. 7B, the pitch difference Δp becomes the same every time the MLA angle changes by 60 degrees in both the “Horizontal” and “Vertical” curves. In addition, the “Horizontal” and “Vertical” curves in FIG. 7B are convex upward curves, and the MLA angle at which the pitch difference Δp is the minimum in each curve is used as a reference. The pitch difference Δp is maximum at a position of 30 degrees. For example, the MLA angle corresponding to the minimum value of the pitch difference Δp of the “Vertical” curve is 0 degree and 60 degrees, and the pitch difference Δp takes the maximum value at the middle 30 degrees.

  The moire frequency shown in FIG. 7A changes so that the unevenness is opposite to the change in the pitch difference Δp shown in FIG. 7B. That is, in both the “Horizontal” and “Vertical” curves, the moire frequency is the same every time the MLA angle changes by 60 degrees, and both curves are curved downward. . Then, with the MLA angle corresponding to the maximum value of each curve as a reference, the moire frequency is minimum at a position shifted by 30 degrees with respect to this. For example, the MLA angle corresponding to the maximum value of the moire frequency of the “Vertical” curve is 0 degree and 60 degrees, and the moire frequency takes the minimum value at the middle 30 degrees.

  As shown in FIG. 7A, in the two ranges of MLA angles R11 and R12, the moiré frequency is 0.4 or less in both “Horizontal” and “Vertical”. In these ranges, the moiré stripes are very fine, so it is difficult for the eyes of those who see the image projected on the windshield W to recognize the moiré, and the display quality deteriorates due to the moiré. Is suppressed. Here, the ranges R11 and R12 correspond to a state in which the MLA 40 is inclined along a direction that does not coincide with the arrangement directions D11, D12, and D13 (MLA angles) of the micro lenses 40a of the MLA 40, and two adjacent arrangements The angle range is in the middle of the direction and in the vicinity thereof. In the example shown in FIG. 7A, the moiré frequency is 0.4 or less in the ranges R11 and R12. However, the setting of these ranges is an example, and the brightness and other characteristics of the projected image and the brightness around the vehicle It can be set arbitrarily according to the speed of the automobile and other driving conditions.

Further, in the ranges R11 and R12, the pitch Pm of the microlenses 40a is sufficiently larger than the pitch Pp of the pixel light on the MLA 40 as compared with the MLA angles before and after the ranges. Here, the pitch Pm of the microlens 40a is an average value of the pitch in the Y direction and the pitch in the Z direction of the microlens 40a, and the pitch Pp of the pixel light is the pitch in the Y direction of the pixel light on the MLA 40 and the Z direction. It is the average value of the pitch. Furthermore, it is preferable that the pitch Pm of the microlens 40a and the pitch Pp of the pixel light satisfy the following expression (1). By satisfying this condition, the moire can be made finer, and the projection image can be reduced to a resolution lower than that of the eyes of the viewer. It is possible to suppress a decrease in display quality.
1.5 × Pp ≦ Pm ≦ 1.9 × Pp (1)

Here, it is preferable that the beam diameter of laser light as pixel light incident from the lens 35 with respect to the microlens 40a is 2/3 or less for both the pitches Ph and Pv. If the beam diameter is set in this way, the light emitted from the lens 35 is likely to be incident on the center of each microlens 40a, thereby suppressing the occurrence of extra diffraction, so that the intermediate image can be suppressed. Can increase the resolution.
Furthermore, it is preferable to set the beam diameter of the laser light incident from the lens 35 to 3/5 or less of the pitch P because not only generation of diffraction can be suppressed but also the resolution of the image can be increased.

With the configuration as described above, the following effects are achieved according to the first embodiment.
On the microlens array 40, the pixel light is arranged along a direction shifted by a predetermined angle that does not coincide with the arrangement direction of the microlens 40a, so that the pitch of the moire corresponding to the resolution of the eyes of the viewer of the displayed image. Therefore, it is possible to set the pitch so that the moiré is not easily recognized, thereby suppressing the deterioration in display quality due to the moiré. Furthermore, since the arrangement direction of the pixel light on the MLA 40 is a direction between two adjacent arrangement directions of the microlenses 40a, it is difficult for the moire to be visually recognized, thereby suppressing the deterioration in display quality due to the moire. It becomes.

A modification will be described below.
4 to 6 exemplify the case where the arrangement directions of the microlenses 40a corresponding to the pitch are three directions, the present invention can be similarly applied to cases where the arrangement directions are one direction, two directions, or four directions or more.
In the first embodiment, the pitch of the microlenses 40a and the pitch of the pixel light are the same in the state shown in FIG. 5, but the present invention is not limited to this.
In the first embodiment, the pitch difference Δp is changed by rotating the MLA 40. Instead of this, or in addition to this, on the image forming unit side, for example, by changing the direction of the scanning mirror 31. The pitch difference Δp may be changed by tilting the arrangement direction of the pixel light.
Further, the change in the pitch difference Δp does not tilt the arrangement direction of the micro lenses 40a of the MLA 40 or tilt the arrangement direction of the image light on the MLA 40, but changes the image light on the MLA 40 and / or MLA 40 in the Z direction and / or Alternatively, it can be realized by shifting in the Y direction.

(Second Embodiment)
FIG. 8 is a plan view showing an arrangement example of the microlens 140a of the microlens array 140 according to the second embodiment and the pixel light on the microlens array 40. FIG. FIG. 8 shows a state in which the vertical and horizontal sides of the MLA 140 are arranged along the Z direction and the Y direction, respectively, as in FIG. 5, and a part of the microlens 140a is enlarged.

  The MLA 140 shown in FIG. 8 has a configuration in which a plurality of microlenses 140a having the same square shape in plan view are periodically arranged so as to be in close contact with each other. The micro lens 140a is in contact with one side of the adjacent micro lens 140a, and each vertex is also in contact with one vertex of the adjacent micro lens 140a. FIG. 8 shows a state in which the horizontal and vertical sides of the MLA 140 are arranged along the Z direction and the Y direction, respectively. In this state, the plurality of microlenses 140a includes a first direction D31 parallel to the Y direction, The second direction D32 inclined 45 degrees clockwise in plan view with respect to the first direction D31, the third direction D33 inclined 45 degrees relative to the second direction D32, and inclined 45 degrees relative to the third direction D33 Are aligned along the fourth direction D34. Each microlens 140a is arranged so as to protrude hemispherically toward the lens 35 side along the X direction in the same manner as the microlens 40a in the first embodiment, and each optical axis is the whole of the MLA 140. Extending parallel to the central axis, the incident light from the lens 35 is diffracted, and a plurality of diffracted lights having different emission angles and phases are emitted to the projection mirror 51 side. The microlenses 140a are arranged at a pitch Ph in the horizontal direction in plan view and at a pitch Pv in the vertical direction. These pitches Ph and Pv are intervals between the centers of the square microlenses 140a in plan view, and the pitch Ph and the pitch Ph are equal when the MLA 140 is not tilted as shown in FIG.

  The laser light emitted from the lens 35 is given to the MLA 140 as a plurality of pixel lights 141, and on the MLA 140, the period is along the first direction D31, the second direction D32, the third direction D33, and the fourth direction D34. Ordered. In the example shown in FIG. 8, the pixel light 141 is arranged at a pitch Ph in the horizontal direction in plan view and at a pitch Pv in the vertical direction, like the microlens 40a of the MLA 140. 141 are arranged so that the center positions thereof coincide with the plurality of 140a.

  9A and 9B show the arrangement angle of the MLA 140 and the moire frequency when the pixel light is given to the MLA 140 (unit: mm / cycle) (FIGS. 7A and 7B). FIG. 9A is a graph showing a relationship with a pitch difference Δp (unit: mm) (FIG. 9B). In these figures, the “Horizontal” and “Vertical” curves overlap each other.

  The MLA angle shown on the horizontal axis of FIGS. 9A and 9B is an angle obtained by inclining the MLA 140 clockwise in a plan view when the arrangement shown in FIG. 8 is set to zero (unit deg (degree)). Yes. Here, since the micro lens 140a of the MLA 140 has a square planar shape, the pitch in the Y direction of the micro lens 140a is the same when the MLA angle is 0 degree and when it is 90 degrees. Similarly, the pitch of the micro lenses 140a in the Z direction is the same when the MLA angle is 0 degree and when it is 90 degrees. Therefore, in the pitch difference Δp shown in FIG. 9B, the pitch difference Δp takes the same value every time the MLA angle changes by 90 degrees in both the “Horizontal” and “Vertical” curves. The curves of “Horizontal” and “Vertical” are maximum when the MLA angle is 0 degree and 90 degrees, and are also maximum when the MLA angle is 45 degrees. On the other hand, it is minimal in the vicinity of 35 degrees between 0 and 45 degrees and in the vicinity of 55 degrees between 45 and 90 degrees.

The moire frequency shown in FIG. 9 (A) changes so that the unevenness is opposite to the change in the pitch difference Δp shown in FIG. 9 (B).
As shown in FIG. 9A, in the two ranges of MLA angles R21 and R22, the moiré frequency is larger than 0.4 in both “Horizontal” and “Vertical”, and in particular, the MLA angle is around 35 degrees. And around 55 degrees, it is about 10. Of these ranges R21 and R22, especially in the vicinity of 35 degrees and 55 degrees, the width of the moiré stripes is very large. Is difficult to recognize moire, and display quality deterioration due to moire is suppressed. Here, the ranges R21 and R22 correspond to a state in which the MLA 40 is inclined along a direction that does not coincide with the arrangement direction D31, D32, D33, and D34 of the 140a of the MLA 140, and between the two adjacent arrangement directions. Angle range. In the example shown in FIG. 9A, the moiré frequency is 0.4 or more in the ranges R11 and R12. However, the setting of this range is an example, and the brightness and other characteristics of the projected image and the brightness around the vehicle It can be set arbitrarily according to the speed of the automobile and other driving conditions.

Further, in the ranges R21 and R22, the pitch Pm of the microlenses 140a is sufficiently smaller than the pitch Pp of the pixel light on the MLA 140 as compared with the MLA angles before and after the ranges. Here, the pitch Pm of the microlens 140a is an average value of the pitch in the Y direction and the pitch in the Z direction of the microlens 140a, and the pitch Pp of the pixel light is the pitch in the Y direction of the pixel light on the MLA 140 and the Z direction. It is the average value of the pitch. Furthermore, it is preferable that the pitch Pm of the microlenses 140a and the pitch Pp of the pixel light satisfy the following formula (2). By satisfying this condition, the moire can be made coarse and the resolution of the eyes of the viewer of the image can be reduced. Therefore, it is difficult for the person who sees the projection image to recognize the moire, thereby It is possible to suppress a decrease in display quality.
0.1 × Pp ≦ Pm ≦ 0.5 × Pp (2)
Other operations, effects, and modifications are the same as those in the first embodiment.
Although the present invention has been described with reference to the above embodiment, the present invention is not limited to the above embodiment, and can be improved or changed within the scope of the purpose of the improvement or the idea of the present invention.

  As described above, the display device and the head-up display device according to the present invention can suppress deterioration in display quality due to moire in an image formed by irradiating light to a microlens array in which microlenses are arranged. It is useful in.

DESCRIPTION OF SYMBOLS 10 Head-up display apparatus 20 Light source part 21 Laser light source 21a, 21b, 21c Laser diode 22 Laser driver 23a, 23b, 23c Collimator lens 24a Mirror 24b, 24c Dichroic prism 31 Scanning mirror 31r Reflective surface 32 Mirror driver 33 Control part 34 Memory 35 Lens 40, 140 Micro lens array (MLA)
40a, 140a Microlens 40x Central axis of the entire microlens array 41, 141 Pixel light 51 Projection mirror 51r Reflecting surface D11, D12, D13, D21, D22, D23, D31, D32, D33 Arrangement direction Ph, Pm, Pp, Pv pitch R11, R12, R21, R22 Range W Windshield V Virtual image

Claims (6)

A light source;
An image forming unit that forms a plurality of pixel lights based on light emitted from the light source;
The plurality of pixel lights are incident and a microlens array in which a plurality of microlenses are periodically arranged,
The plurality of pixel lights are periodically arranged on the microlens array,
The plurality of microlenses are arranged along at least one arrangement direction,
The display device, wherein the plurality of pixel lights are arranged on the microlens array along a direction shifted by a predetermined angle that does not coincide with the arrangement direction. The plurality of microlenses are arranged along at least two arrangement directions,
The display device according to claim 1, wherein the predetermined angle is an angle corresponding to a direction between two adjacent arrangement directions of the microlenses. A light source;
An image forming unit that forms a plurality of pixel lights based on light emitted from the light source;
The plurality of pixel lights are incident and a microlens array in which a plurality of microlenses are periodically arranged,
The plurality of pixel lights are periodically arranged on the microlens array,
The plurality of microlenses are arranged at a first pitch Pm,
The display device, wherein the plurality of pixel lights are arranged at a second pitch Pp that does not coincide with the first pitch Pm on the microlens array. The pitch Pm of the plurality of microlenses and the pitch Pp of the plurality of pixel lights on the microlens array satisfy the following formula (1) or the following formula (2): The display device according to any one of claims 1 to 3.
1.5 × Pp ≦ Pm ≦ 1.9 × Pp (1)
0.1 × Pp ≦ Pm ≦ 0.5 × Pp (2)   The display device according to claim 1, wherein a diameter of the pixel light on the microlens array is 2/3 or less of a pitch of the microlens. A display device according to any one of claims 1 to 5,
A projection optical system that projects an intermediate image formed on the microlens array onto a projection object;
The head-up display device, wherein the projection target is a windshield of a vehicle or a combiner disposed inside the windshield.

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