Head-up display

Abstract

In a configuration in which a visually recognizable display image is changed by changing viewpoint in a vertical direction, the present invention generates the display image in an appropriate mode. Disclosed is a head-up display comprising: an emission means for continuously emitting a first laser beam corresponding to a first image for a first viewpoint and a second laser beam corresponding to a second image that is for a second viewpoint and that is away in the vertical direction with respect to the first viewpoint; and a scanning means for scanning the first laser beam in a first scan pattern and scanning the second laser beam in a second scan pattern on a scan surface such that the display image relating to the first image when viewed from the first viewpoint becomes visually recognizable and the display image relating to the second image when viewed from the second viewpoint becomes visually recognizable. The first scan pattern includes a first straight line pattern where the first laser beam continuously enters, for each column, at least one column of optical elements linearly arranged in a first direction. The second scan pattern includes a second straight line pattern that is offset by a predetermined offset amount in a second direction with respect to the first straight line pattern.

Description

[Technical Field]

[0001] The present disclosure relates to head-up displays. [Background technology]

[0002] A technology is known in which laser light is incident on a plurality of optical elements regularly arranged at a predetermined pitch along a plane that forms a scanning surface, and an image that can be seen by the driver is displayed based on the light emitted from the plurality of optical elements. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-225216 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the above-described conventional technology, it is difficult to generate a display image in an appropriate manner in a configuration in which the visible display image changes simply by changing the viewpoint in the vertical direction.

[0005] Therefore, an object of the present disclosure is to generate a display image in an appropriate manner in a configuration in which a visible display image changes simply by changing the viewpoint in the vertical direction. [Means for solving the problem]

[0006] In one aspect, there is provided a head-up display that displays a display image that is visible to an occupant, an emission means for emitting laser light; a plurality of optical elements that are regularly arranged in a plane defined by a first direction and a second direction that are orthogonal to each other and that diffuse the incident laser light; a scanning unit capable of scanning the laser light using the plane as a scanning plane so that the laser light strikes each of the plurality of optical elements with a spot diameter smaller than the size of one of the optical elements, the emission means continuously emits a first laser light corresponding to a first image for a first viewpoint and a second laser light corresponding to a second image for a second viewpoint vertically spaced apart from the first viewpoint, the scanning means scans the first laser light in a first scanning pattern and scans the second laser light in a second scanning pattern on the scanning surface so that the display image related to the first image is visible when viewed from the first viewpoint and the display image related to the second image is visible when viewed from the second viewpoint; the first scanning pattern is a first linear pattern along the first direction, and includes a first linear pattern in which the first laser light is continuously incident on one or more rows of optical elements that are linearly arranged in the first direction among the plurality of optical elements, for each row; the second scanning pattern is a second linear pattern along the first direction, offset by a predetermined offset amount in the second direction from the first linear pattern, and includes a second linear pattern in which the second laser light is continuously incident on the one or more rows of optical elements for each row; the plurality of optical elements are arranged in M ​​rows in the first direction and N rows in the second direction, the one or more rows of optical elements are the N rows of optical elements, The first linear pattern and the second linear pattern are patterns that scan from one end to the other of the M rows. the law of nature, the scanning means starts one scan from a start position of the scan surface, and performs a linear scan from one end side of the first direction to the other end side of the first direction along the first direction while shifting by a constant pitch in the second direction, or a linear scan from the other end side of the first direction to one end side of the first direction along the first direction while shifting by a constant pitch in the second direction, for the N rows, and ends the one scan at an end position of the scan surface; the constant pitch corresponds to the pitch between the N rows in the second direction; a scan pattern for one scan by linear scanning from the other end side in the first direction to the one end side in the first direction is made up of the first linear pattern for each of the N columns, and a scan pattern for one scan subsequent to the scan pattern for the one scan by linear scanning from the one end side in the first direction to the other end side in the first direction is made up of the second linear pattern for each of the N columns; A head-up display is provided. [Effects of the Invention]

[0007] According to the present disclosure, in a configuration in which a visible display image changes simply by changing the viewpoint in the vertical direction, it is possible to generate the display image in an appropriate manner. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram schematically illustrating a state in which a head-up display according to an embodiment is mounted on a vehicle, as viewed from the side of the vehicle. [Figure 2] FIG. 1 is a schematic diagram illustrating a configuration of a head-up display. [Figure 3] FIG. 2 is a schematic diagram showing an example of an arrangement of microlenses that form a screen. [Figure 4] 1A and 1B are explanatory diagrams showing an upper side scanning pattern and a lower side scanning pattern according to one embodiment (embodiment 1). [Figure 5] 10A and 10B are explanatory diagrams illustrating the principle of how two types of display images are generated by an upper side scanning pattern and a lower side scanning pattern. [Figure 6A] 10A and 10B are explanatory diagrams showing an upper side scanning pattern and a lower side scanning pattern according to another embodiment (embodiment 2). [Figure 6B] 10A and 10B are explanatory diagrams showing an upper side scanning pattern and a lower side scanning pattern according to another embodiment (embodiment 2). [Figure 7A] 10A and 10B are explanatory diagrams showing an upper side scanning pattern and a lower side scanning pattern according to another embodiment (embodiment 3). [Figure 7B] 10A and 10B are explanatory diagrams showing an upper side scanning pattern and a lower side scanning pattern according to another embodiment (embodiment 3). [Figure 8A] 10A and 10B are explanatory diagrams showing an upper side scanning pattern and a lower side scanning pattern according to another embodiment (embodiment 4). [Figure 8B] 10A and 10B are explanatory diagrams showing an upper side scanning pattern and a lower side scanning pattern according to another embodiment (embodiment 4). [Figure 8C] 10A and 10B are explanatory diagrams showing an upper side scanning pattern and a lower side scanning pattern according to another embodiment (embodiment 4). [Figure 9] 10A and 10B are explanatory diagrams showing an upper side scanning pattern and a lower side scanning pattern according to another embodiment (embodiment 4). DETAILED DESCRIPTION OF THE INVENTION

[0009] Each embodiment will be described in detail below with reference to the accompanying drawings. Note that in Figure 3 and other figures, for ease of viewing, only some of the reference symbols may be assigned to multiple parts or portions with the same attribute.

[0010] [Head-up display configuration] FIG. 1 is a diagram schematically illustrating a head-up display 1 according to an embodiment mounted on a vehicle as viewed from the side of the vehicle. FIG. 2 is a schematic diagram illustrating the configuration of the head-up display 1. FIG. 3 is a schematic diagram illustrating an example of an arrangement of microlenses 41 forming a screen 40. FIG. 2 schematically illustrates a driver's face P1 when the viewpoint is located in a relatively upper eyebox, and a driver's face P2 when the viewpoint is located in a relatively lower eyebox. The upper and lower eyeboxes may be continuous in the vertical direction, or may be separate eyeboxes separated vertically. In FIG. 2, dotted arrows R0 to R4 schematically indicate the flow of electrical signals.

[0011] In the head-up display 1, as shown in FIG. 1, when display light is irradiated onto the windshield WS, a display image (virtual image display) VI obtained by the irradiation is visible to the driver of the vehicle VC in front of the windshield WS. This allows the driver to visually recognize the display image VI superimposed on the scenery ahead. Therefore, the driver can grasp vehicle information, etc. with less eye movement than when looking at meters in the instrument panel 9, improving convenience and safety. In a modified example, a combiner or the like may be used instead of the windshield WS.

[0012] As shown in FIG. 2, the head-up display 1 includes a laser unit 10, a dichroic mirror unit 20, a condenser lens 28, a MEMS (Micro Electro Mechanical Systems) scanner 30, a screen 40 (an example of an optical element), and a control device 50.

[0013] The laser unit 10 includes laser irradiation devices 11, 12, and 13 of red, blue, and green colors. The laser irradiation device 11 emits laser light in the red wavelength range. The laser irradiation device 12 emits laser light in the blue wavelength range. The laser irradiation device 13 emits laser light in the green wavelength range. In this embodiment, since laser light of these three colors can be emitted, a full-color display image VI can be generated. However, in modified examples, the number of displayable colors may be limited.

[0014] The dichroic mirror unit 20 has dichroic mirrors 21, 22, and 23 corresponding to the laser irradiation devices 11, 12, and 13, respectively. The dichroic mirror 21 reflects only light in the red wavelength range. Therefore, the dichroic mirror 21 can reflect only the laser light incident from the laser irradiation device 11 toward the condenser lens 28. The dichroic mirror 22 transmits light in the red wavelength range and reflects light in the blue wavelength range. Therefore, the dichroic mirror 22 can transmit the laser light incident from the dichroic mirror 21 while reflecting the laser light incident from the laser irradiation device 12 toward the condenser lens 28. Similarly, the dichroic mirror 23 transmits light in the red and blue wavelength ranges and reflects light in the green wavelength range. Therefore, the dichroic mirror 23 can transmit the laser light incident from the dichroic mirror 22 while reflecting the laser light incident from the laser irradiation device 13 toward the condenser lens 28.

[0015] The condenser lens 28 condenses the laser light (red, blue, and green laser light) incident from the dichroic mirror unit 20 as described above, and emits the condensed laser light toward the MEMS scanner 30.

[0016] The condenser lens 28 is constructed and arranged so that the laser light incident from the dichroic mirror unit 20 is projected onto the screen 40 with a spot diameter smaller than the size of each of the plurality of microlenses 41 (described later) that form the screen 40. For example, the spot diameter is adapted so that the following relational expression holds: Spot diameter≦Lens pitch / Number of viewpoints, where the lens pitch is the pitch of the arrangement of the plurality of microlenses 41 (described later) (see PT1 and PT2 in FIG. 3), and the number of viewpoints corresponds to the number of ways in which the display image VI can be viewed when the appearance of the display image VI changes depending on the viewpoint, and is "2" in this embodiment.

[0017] The MEMS scanner 30 projects the laser light incident from the condenser lens 28 onto the screen 40. The MEMS scanner 30 is equipped with a MEMS mirror that can rotate around two orthogonal axes. The projection position of the laser light on the screen 40 changes depending on the orientation of the MEMS mirror. Therefore, the MEMS scanner 30 can arbitrarily change the projection position of the laser light on the screen 40.

[0018] The screen 40 extends within a plane. In this embodiment, as an example, the screen 40 extends within a horizontal plane, but may be arranged at a slight inclination relative to the horizontal plane. The screen 40 includes a plurality of microlenses 41 regularly arranged within a plane, as shown in FIG. 3 . That is, the screen 40 includes a two-dimensional microlens array. The plurality of microlenses 41 typically have the same shape, and in this embodiment, as an example, they have a rectangular (square) outer shape when viewed in a direction perpendicular to the screen 40, but may have other shapes such as a hexagon. The screen 40 may have an entrance surface that is convex due to the plurality of microlenses 41, and an exit surface that is flat (see FIG. 5 ).

[0019] In the example shown in FIG. 3, the multiple microlenses 41 are arranged in a plane including the X direction (an example of a first direction) and the Y direction (an example of a second direction), and the multiple microlenses 41 are preferably arranged regularly at a constant pitch as shown in FIG. 3. Note that in FIG. 3, the pitches PT1 and PT2 in the X direction and the Y direction are the same, but they may be different. In this embodiment, as an example, the multiple microlenses 41 are arranged in nine rows in the X direction and eight rows in the Y direction, but the number of rows in the X direction and the Y direction is arbitrary. Note that the X direction and the Y direction are also illustrated in FIG. 2 above in association with the screen 40.

[0020] The control device 50 may be realized by a computer such as an ECU (Electronic Control Unit). The control device 50 includes a laser control unit 51 and a scanner control unit 52. In this embodiment, the laser control unit 51 cooperates with the above-described laser unit 10 to form an example of an emission means, and the scanner control unit 52 cooperates with the above-described MEMS scanner 30 to form an example of a scanning means.

[0021] The laser control unit 51 controls the laser unit 10 based on an image signal for generating a display image VI (see arrows R1 to R3 in FIG. 2). In this embodiment, as an example, the image signal includes an upper image signal for generating a display image VI viewable from an upper viewpoint (see P1 in FIG. 2) and a lower image signal for generating a display image VI viewable from a lower viewpoint (see P2 in FIG. 2). Note that the upper image signal and the lower image signal may be generated by an external ECU and provided to the control device 50 (see arrow R0 in FIG. 2), or may be generated by the control device 50 itself.

[0022] In the following, for the sake of convenience, the display image VI visible from an upper viewpoint (see P1 in Figure 2) will also be referred to as "display image VI1," and the display image VI visible from a lower viewpoint (see P2 in Figure 2) will also be referred to as "display image VI2."

[0023] The upper image signal and the lower image signal may be the same signal or different signals. In this embodiment, as an example, the upper image signal and the lower image signal are different signals. In this case, different display images VI1 and VI2 can be formed.

[0024] For example, the display image VI1 may include navigation-related information, and the display image VI2 may include meter-related information. In this case, the driver can selectively view the two types of display images VI1 and VI2 with natural eye movements that conform to the relationship between the general meter position (the meter position in the instrument panel 9) and the display position of the display image VI on the head-up display 1 (see the upper side of FIG. 2).

[0025] The upper image signal is, for example, a signal representing the pixel value (brightness or color) of each pixel of an image of a predetermined size and a predetermined resolution. The lower image signal is, for example, a signal representing the pixel value (brightness or color) of each pixel of an image of a predetermined size and a predetermined resolution. In this case, the predetermined size and the predetermined resolution may be the same for the upper image signal and the lower image signal. Each pixel of the image is associated with each position on the screen 40 (each position on the scanning surface). For example, each pixel of the image may be associated with each position on the screen 40 (each position on the scanning surface) in a one-to-one relationship. Each position on the screen 40 is associated with each orientation of the MEMS mirror of the MEMS scanner 30.

[0026] When controlling the laser unit 10 based on the upper image signal, the laser control unit 51 controls the laser unit 10 based on the pixel value of each pixel included in the upper image signal so that the laser unit 10 emits laser light of a color corresponding to each pixel value at a timing corresponding to each pixel. The same applies to the lower image signal.

[0027] The scanner control unit 52 controls the MEMS scanner 30 (see arrow R4 in FIG. 2). That is, the scanner control unit 52 scans the laser light on the screen 40 by controlling the orientation of the MEMS mirror of the MEMS scanner 30. Herein, "scanning the laser light on the screen 40" refers to changing the projection position of the laser light on the plane of the screen 40 (the projection position when viewed perpendicularly to the plane of the screen 40). Furthermore, hereinafter, the "scanning pattern" refers to the trajectory of the projection position (the trajectory of the projection position of the laser light on the plane of the screen 40). Furthermore, the plane of the screen 40 (i.e., the plane on which the multiple microlenses 41 are arranged) is also referred to as the "scanning plane."

[0028] Specifically, the scanner control unit 52 cooperates with the laser control unit 51 to scan a laser beam (an example of a first laser beam) corresponding to the upper image signal in an upper scanning pattern (an example of a first scanning pattern), and scans a laser beam (an example of a second laser beam) corresponding to the lower image signal in a lower scanning pattern (an example of a second scanning pattern). That is, when operating based on the upper image signal, the scanner control unit 52 controls the MEMS scanner 30 so that laser beams from the laser unit 10 are projected to positions on the scanning surface corresponding to each pixel, based on the pixel values ​​of each pixel included in the upper image signal. The same applies to the lower image signal.

[0029] Next, with reference to FIG. 4 onwards, some preferred examples of upper and lower side scanning patterns will be described.

[0030] [Example 1] FIG. 4 is an explanatory diagram showing an upper side scanning pattern and a lower side scanning pattern according to one embodiment (embodiment 1), and is a diagram showing a screen 40 in a plan view. FIG. 5 is an explanatory diagram showing the principle by which display images VI1 and VI2 are generated by the upper side scanning pattern and the lower side scanning pattern. In FIG. 4 (as well as FIG. 6A and the like described later), X1 and X2 sides in the X direction are defined, and Y1 and Y2 sides in the Y direction are defined. In FIG. 5, the screen 40 is shown in a cross-sectional view, with only three microlenses 41 arranged in the Y direction. The Y direction corresponds to the fore-and-aft direction of the vehicle when the screen 40 is located in a horizontal plane. In this case, the X direction corresponds to the lateral direction of the vehicle (vehicle width direction). In FIG. 5, the direction perpendicular to the paper surface is the X direction.

[0031] 4, one scan by the scanner control unit 52 and the MEMS scanner 30 starts from a start position S4 of the scan plane, performs linear scanning back and forth along the X direction while shifting alternately in the Y direction by predetermined pitches PT41 and PT42, for each column (column in the Y direction), and ends at an end position E4 of the scan plane. Note that the scanner control unit 52 and the MEMS scanner 30 can maintain the output states of the display images VI1 and VI2 by repeatedly performing such one scan continuously in time.

[0032] 4, the linear scan going back and forth along the X direction is made up of an outgoing scan L401 and a returning scan L402. The outgoing scan L401 and the returning scan L402 pass through each microlens 41 and are offset from each other by a predetermined offset amount (=α+β) in the Y direction. In other words, the outgoing scan L401 is offset by a predetermined amount α toward the Y1 direction with respect to the center O of each microlens 41, and the returning scan L402 is offset by a predetermined amount β toward the Y2 direction with respect to the center O of each microlens 41.

[0033] The predetermined pitch PT41 is the pitch when transitioning from the forward scan L401 to the backward scan L402, and is equal to a predetermined offset amount (=α+β). The predetermined pitch PT42 is the pitch when transitioning from the backward scan L402 to the forward scan L401, and is the length obtained by subtracting the predetermined offset amount (=α+β) from the size of the microlens 41 in the Y direction (=Y direction pitch PT2) (hereinafter also referred to as the "difference offset amount"). The position of the start position S4 in the Y direction is a position shifted by a predetermined amount α toward the Y1 direction Y1 from the center O of the microlens 41.

[0034] In this case, the upper scanning pattern consists of a straight line pattern (an example of a first straight line pattern) along the X direction by the outgoing scanning L401, and the lower scanning pattern consists of a straight line pattern (an example of a second straight line pattern) along the X direction by the returning scanning L402.

[0035] According to such an upper scanning pattern and a lower scanning pattern, a display image VI1 can be generated by laser light scanned with the upper scanning pattern (laser light corresponding to an upper image signal), and a display image VI2 can be generated by laser light scanned with the lower scanning pattern (laser light corresponding to a lower image signal).

[0036] More specifically, as shown in FIG. 5, the laser light scanned with the upper scan pattern (laser light corresponding to the upper image signal) is incident on a position shifted by a predetermined amount α toward the Y1 direction from the center O of the microlens 41 (see arrow R51). In this case, the laser light is emitted from the microlens 41 in a direction corresponding to the shape (spherical shape) of the incident surface of the microlens 41 (see arrow R511). On the other hand, as shown in FIG. 5, the laser light scanned with the lower scan pattern (laser light corresponding to the lower image signal) is incident on a position shifted by a predetermined amount β toward the Y2 direction from the center O of the microlens 41 (see arrow R52). In this case, the laser light is emitted from the microlens 41 in a direction corresponding to the shape (spherical shape) of the incident surface of the microlens 41 (see arrow R521). At this time, the incident position (spot position) of one microlens 41, which is the incident position of the laser light scanned with the upper-side scanning pattern (laser light corresponding to the upper-side image signal), and the incident position of the laser light scanned with the lower-side scanning pattern (laser light corresponding to the lower-side image signal), are located on opposite sides in the Y direction across the center O of the microlens 41. Therefore, the emission direction (see arrow R511) of the laser light scanned with the upper-side scanning pattern (laser light corresponding to the upper-side image signal) and the emission direction (see arrow R521) of the laser light scanned with the lower-side scanning pattern (laser light corresponding to the lower-side image signal) are inclined (non-parallel) to each other, as schematically shown in FIG. That is, the region R510 of the windshield WS onto which the laser light from the microlenses 41 is incident, which corresponds to the laser light scanned with the upper scanning pattern (the laser light corresponding to the upper image signal), and the region R520 of the laser light scanned with the lower scanning pattern (the laser light corresponding to the lower image signal), are spaced apart from each other. Specifically, the regions R510 and R520 are offset in the vertical direction on the windshield WS. As a result, as shown schematically in FIG. 2, the laser light can be projected toward the driver from the vertically offset regions R510 and R520, thereby generating the display images VI1 and VI2. Note that the predetermined offset amount correlates with the distance between the upper viewpoint (the viewpoint from which the display image VI1 is seen) and the lower viewpoint (the viewpoint from which the display image VI2 is seen) in the vertical direction.The predetermined amounts α and β may be adapted according to the desired positions of the regions R510 and R520 (and thus the desired positions of the displayed images VI1 and VI2).

[0037] In this embodiment, as described above, one scan is realized by a scan pattern that combines an upper-side scan pattern and a lower-side scan pattern, so that the display images VI1 and VI2 can be generated substantially simultaneously. Therefore, the driver can continuously view the display images VI1 and VI2 simply by moving the viewpoint up or down, for example, to view the display image VI1, the driver moves the viewpoint relatively upward, and to view the display image VI2, the driver moves the viewpoint relatively downward. In this way, according to this embodiment, in a configuration in which the visible display images VI1 and VI2 change simply by changing the viewpoint up or down, the display images VI1 and VI2 can be generated in an appropriate manner.

[0038] Furthermore, in this embodiment, the display images VI1 and VI2 are generated substantially simultaneously regardless of the driver's current viewpoint without detecting the driver's viewpoint with a camera, etc. Therefore, even if the driver's viewpoint changes, the driver can view the display images VI1 or VI2 without delay.

[0039] [Example 2] 6A and 6B are explanatory diagrams showing an upper side scanning pattern and a lower side scanning pattern according to another embodiment (embodiment 2).

[0040] 6A and 6B, one scan by the scanner control unit 52 and the MEMS scanner 30 starts from a start position S6A or S6B of the scan plane, executes a linear scan back and forth along the X direction while shifting in the Y direction by a constant pitch PT2 (= the Y-direction pitch of the array of microlenses 41) for each column (column in the Y direction), and ends at an end position E6A or E6B of the scan plane. Note that the scanner control unit 52 and the MEMS scanner 30 can maintain the output states of the display images VI1 and VI2 by repeatedly executing such one scan shown in FIG. 6A and one scan shown in FIG. 6B consecutively in time.

[0041] 6A and 6B, start position S6A and start position S6B are offset from each other in the Y direction by a predetermined offset amount (=α+β). Specifically, the position of start position S6A in the Y direction is shifted by a predetermined amount α toward the Y1 side in the Y direction from the center O of microlens 41, and the position of start position S6B in the Y direction is shifted by a predetermined amount β toward the Y2 side in the Y direction from the center O of microlens 41.

[0042] In this case, the upper-side scanning pattern is a linear pattern (an example of a first linear pattern) along the X direction by scan L601 shown in FIG. 6A, and the lower-side scanning pattern is a linear pattern (an example of a second linear pattern) along the X direction by scan L602 shown in FIG. 6A. In this case, the laser light scanned by the upper-side scanning pattern (laser light corresponding to the upper-side image signal) is incident on the microlens 41 at a position shifted by a predetermined amount α toward the Y1 direction from the center O of the microlens 41, as shown in FIG. 5 (see arrow R51). In this case, the laser light is emitted from the microlens 41 in a direction corresponding to the shape (spherical shape) of the incident surface of the microlens 41 (see arrow R511). On the other hand, the laser light scanned by the lower-side scanning pattern (laser light corresponding to the lower-side image signal) is incident on the microlens 41 at a position shifted by a predetermined amount β toward the Y2 direction from the center O of the microlens 41, as shown in FIG. 5 (see arrow R52).

[0043] Therefore, according to the upper scanning pattern and the lower scanning pattern shown in Figures 6A and 6B, a display image VI1 can be generated by laser light scanned with the upper scanning pattern (laser light corresponding to an upper image signal), and a display image VI2 can be generated by laser light scanned with the lower scanning pattern (laser light corresponding to a lower image signal).

[0044] Here, in this embodiment, as described above, one scan is composed of only an upper-side scan pattern or a lower-side scan pattern, unlike a scan pattern that combines an upper-side scan pattern and a lower-side scan pattern, and therefore the pitch in the Y direction in one scan can be set to a relatively large constant pitch PT2. This makes it possible to relatively reduce the resolution of the change in orientation of the MEMS scanner 30 required to achieve such scanning (resolution of the change in orientation related to the pitch in the Y direction), making it relatively easy to control the MEMS scanner 30.

[0045] In this embodiment, too, by performing one scan shown in Fig. 6A and one scan shown in Fig. 6B close in time, the display images VI1 and VI2 can be generated substantially simultaneously. Therefore, the driver can continuously view the display images VI1 and VI2 simply by moving the viewpoint up or down, for example, to view the display image VI1, by moving the viewpoint relatively upward, and to view the display image VI2, by moving the viewpoint relatively downward. In this way, according to this embodiment, in a configuration in which the visible display images VI1 and VI2 change simply by changing the viewpoint up or down, the display images VI1 and VI2 can be generated in an appropriate manner.

[0046] In this embodiment, one scan shown in FIG. 6A and one scan shown in FIG. 6B are performed alternately, but if the time for one scan is sufficiently short, they may be performed alternately multiple times.

[0047] [Example 3] 7A and 7B are explanatory diagrams showing an upper side scanning pattern and a lower side scanning pattern according to still another embodiment (embodiment 3).

[0048] In the example shown in FIG. 7A, one scan by the scanner control unit 52 and the MEMS scanner 30 starts from a start position S7A of the scan plane, performs a linear scan along the X direction from one end (X1 side) to the other end (X2 side) for each column (column in the Y direction) while shifting by a predetermined pitch PT2 in the Y direction, and ends at an end position E7A of the scan plane. Also, in the example shown in FIG. 7B, one scan by the scanner control unit 52 and the MEMS scanner 30 starts from a start position S7B of the scan plane, performs a linear scan along the X direction from the other end (X2 side) to one end (X1 side) for each column (column in the Y direction) while shifting by a predetermined pitch PT2 in the Y direction, and ends at an end position E7B of the scan plane. The scanner control unit 52 and the MEMS scanner 30 can maintain the output states of the display images VI1 and VI2 by repeatedly and continuously executing one scan shown in FIG. 7A and one scan shown in FIG. 7B.

[0049] 7A and 7B, start position S7A and start position S7B are offset from each other in the Y direction by a predetermined offset amount (=α+β) and are on opposite sides in the X direction. Specifically, start position S7A is located on the X1 side in the X direction, and its position in the Y direction is shifted by a predetermined amount α toward the Y1 side in the Y direction from the center O of microlens 41. On the other hand, start position S7B is located on the X2 side in the X direction, and its position in the Y direction is shifted by a predetermined amount β toward the Y2 side in the Y direction from the center O of microlens 41.

[0050] In this case, the upper-side scanning pattern is realized by one scan as shown in FIG. 7A and is a linear pattern (an example of a first linear pattern) along the X direction by scan L701. The lower-side scanning pattern is realized by one scan as shown in FIG. 7B and is a linear pattern (an example of a second linear pattern) along the X direction by scan L702. In this case, the laser light scanned by the upper-side scanning pattern (laser light corresponding to the upper-side image signal) is incident on a position shifted by a predetermined amount α toward the Y1 direction from the center O of the microlens 41, as shown in FIG. 5 (see arrow R51). In this case, the laser light is emitted from the microlens 41 in a direction corresponding to the shape (spherical shape) of the incident surface of the microlens 41 (see arrow R511). On the other hand, the laser light scanned by the lower-side scanning pattern (laser light corresponding to the lower-side image signal) is incident on a position shifted by a predetermined amount β toward the Y2 direction from the center O of the microlens 41, as shown in FIG. 5 (see arrow R52).

[0051] Therefore, according to the upper scanning pattern and the lower scanning pattern shown in Figures 7A and 7B, a display image VI1 can be generated by laser light scanned with the upper scanning pattern (laser light corresponding to an upper image signal), and a display image VI2 can be generated by laser light scanned with the lower scanning pattern (laser light corresponding to a lower image signal).

[0052] In this embodiment, the control content of the MEMS scanner 30 for realizing the scanning shown in Figures 7A and 7B can be the same as that in the example shown in Figure 4. In this case, only the control over the laser unit 10 is different. If the scanning shown in Figure 4 is a "progressive method," then the scanning shown in Figures 7A and 7B can be said to be an "interlaced method."

[0053] Here, in this embodiment, as described above, one scan is composed of only an upper-side scan pattern or a lower-side scan pattern, unlike a scan pattern that combines an upper-side scan pattern and a lower-side scan pattern, and therefore the pitch in the Y direction in one scan can be set to a relatively large constant pitch PT2. Furthermore, since the control content of the MEMS scanner 30 is the same for one scan shown in Fig. 7A and one scan shown in Fig. 7B (only the control over the laser unit 10 is different), there is no need to switch the control content of the MEMS scanner 30 (i.e., the movement pattern of the MEMS scanner 30) for each scan, and the processing load can be reduced.

[0054] In this embodiment, too, by performing one scan shown in Fig. 7A and one scan shown in Fig. 7B close in time, the display images VI1 and VI2 can be generated substantially simultaneously. Therefore, the driver can continuously view the display images VI1 and VI2 simply by moving the viewpoint up or down, for example, to view the display image VI1, by moving the viewpoint relatively upward, and to view the display image VI2, by moving the viewpoint relatively downward. In this way, according to this embodiment, in a configuration in which the visible display images VI1 and VI2 change simply by changing the viewpoint up or down, the display images VI1 and VI2 can be generated in an appropriate manner.

[0055] In this embodiment, one scan shown in FIG. 7A and one scan shown in FIG. 7B are performed alternately, but if the time for one scan is sufficiently short, they may be performed alternately multiple times.

[0056] 7A and 7B are the same, but this is not limiting. For example, the start position of the scan shown in Fig. 7B may be the start position S6B shown in Fig. 6B. In this case, the scan starts from the start position S6B of the scan plane, and linear scanning is performed for each row (row in the Y direction) from one end side (X1 side) to the other end side (X2 side) along the X direction while shifting by a predetermined pitch PT2 in the Y direction, and ends at the end position E7B' of the scan plane (see Fig. 7B).

[0057] [Example 4] 8A to 8C and 9 are explanatory diagrams showing upper and lower scanning patterns according to still another embodiment (embodiment 4).

[0058] 8A to 8C, one scan by the scanner control unit 52 and the MEMS scanner 30 starts from a start position S8A, S8B, or S8C of the scan plane, performs a linear scan back and forth along the X direction while shifting in the Y direction by a predetermined pitch PT8A or PT8B, on some columns (columns in the Y direction), and ends at an end position E8A, E8B, or E8C of the scan plane. Note that the scanner control unit 52 and the MEMS scanner 30 can maintain the output states of the display images VI1 and VI2 by repeatedly and sequentially executing one scan shown in FIG. 8A, one scan shown in FIG. 8B, and one scan shown in FIG. 8C (see FIG. 9).

[0059] The predetermined pitch PT8A is larger than the pitch PT2 (= the pitch in the Y direction of the arrangement of the microlenses 41) and corresponds to the length obtained by adding a predetermined offset amount (= α + β) to the pitch PT2. The predetermined pitch PT8B is larger than the pitch PT2 (= the pitch in the Y direction of the arrangement of the microlenses 41) and corresponds to the length obtained by adding the pitch PT2 to the differential offset amount. As described above, the differential offset amount is the length obtained by subtracting the predetermined offset amount (= α + β) from the size of the microlenses 41 in the Y direction (= the pitch PT2 in the Y direction). Therefore, the predetermined pitch PT8B is the length obtained by subtracting the predetermined offset amount (= α + β) from twice the size of the microlenses 41 in the Y direction (= the pitch PT2 in the Y direction).

[0060] 8A to 8C, start positions S8A, S8B, and S8C are all located on the X1 side in the X direction, and the position of start position S8A in the Y direction is shifted by a predetermined amount α toward the Y1 side in the Y direction from the center O of microlens 41. Start position S8B is offset by a predetermined offset amount (=α+β) toward the Y2 side in the Y direction from start position S8A. Also, start position S8C is offset by a differential offset amount toward the Y2 side in the Y direction from start position S8B.

[0061] In this case, the upper-side scanning pattern is composed of a linear pattern (an example of a first linear pattern) along the X direction by scan L801 shown in FIGS. 8A to 8C, and the lower-side scanning pattern is composed of a linear pattern (an example of a second linear pattern) along the X direction by scan L802 shown in FIGS. 8A to 8C. That is, the upper-side scanning pattern and the lower-side scanning pattern are both realized by the three scans shown in FIGS. 8A to 8C in cooperation with each other. In this case, the laser light scanned by the upper-side scanning pattern (laser light corresponding to the upper image signal) is incident on the microlens 41 at a position shifted by a predetermined amount α toward the Y1 direction from the center O of the microlens 41, as shown in FIG. 5 (see arrow R51). In this case, the laser light is emitted from the microlens 41 in a direction corresponding to the shape (spherical shape) of the incident surface of the microlens 41 (see arrow R511). On the other hand, the laser light scanned with the lower scanning pattern (laser light corresponding to the lower image signal) is incident on a position shifted by a predetermined amount β toward the Y direction Y2 from the center O of the microlens 41, as shown in Figure 5 (see arrow R52).

[0062] Therefore, according to the upper scanning pattern and the lower scanning pattern shown in Figures 8A to 8C, a display image VI1 can be generated by laser light scanned with the upper scanning pattern (laser light corresponding to an upper image signal), and a display image VI2 can be generated by laser light scanned with the lower scanning pattern (laser light corresponding to a lower image signal).

[0063] In this embodiment, as described above, three scans are performed to generate display images VI1 and VI2 corresponding to one frame, and therefore the pitch in the Y direction in one scan can be set to relatively large predetermined pitches PT8A and PT8B. This allows the resolution of the change in orientation of the MEMS scanner 30 required to achieve such scanning to be relatively small, making it relatively easy to control the MEMS scanner 30.

[0064] In this embodiment, as described above, three scans are performed to generate display images VI1 and VI2 corresponding to one frame, but four or more scans may be performed to generate display images VI1 and VI2 corresponding to one frame.

[0065] Although each embodiment has been described in detail above, it is not limited to the specific embodiment, and various modifications and changes are possible within the scope of the claims. It is also possible to combine all or a plurality of components of the above-described embodiments.

[0066] For example, in each of the above-described embodiments, the display images VI1 and VI2 are each generated using all of the microlenses 41 that form the screen 40. Therefore, this embodiment is advantageous in that it can generate relatively large display images VI1 and VI2 compared to when display images VI1 and VI2 are generated using only a portion of the microlenses 41 that form the screen 40 (or, if the display images VI1 and VI2 have the same size, it can increase the resolution of the display images VI1 and VI2). However, in a modified example, the display images VI1 and / or VI2 may be generated using only a portion of the microlenses 41 that form the screen 40. For example, both the upper-side scanning pattern and the lower-side scanning pattern may be patterns that scan only a portion of the rows of the microlenses 41 in the Y direction. Similarly, both the upper-side scanning pattern and / or the lower-side scanning pattern may be patterns that scan only a portion of the rows of the microlenses 41 in the X direction.

[0067] In addition, in each of the above-described embodiments, different display images VI1 and VI2 can be viewed from two viewpoints offset in the vertical direction, but this is not limiting. For example, a configuration in which different display images can be viewed from three or more different viewpoints along the vertical direction may be realized.

[0068] Furthermore, although the above-described embodiments have a simple configuration in which feedback control is not performed on the projection position of the laser light on the screen 40, the present invention is not limited to this. For example, as disclosed in Patent Document 1, a scanning position detection plate on which light receiving elements are arranged may be provided, and feedback control may be performed on the projection position of the laser light on the screen 40.

[0069] Furthermore, in each of the above-described embodiments, the viewer of the display image is the driver of the vehicle, but the display image may be formed so that other occupants (for example, passengers in the passenger seat or rear seat) are the viewers. [Explanation of symbols]

[0070] 1 Head-up display 10 Laser unit 11 Laser irradiation device 12 Laser irradiation device 13 Laser irradiation device 20 Dichroic mirror unit 21 Dichroic mirror 22 Dichroic mirror 23 Dichroic mirror 28 Condenser Lens 30 MEMS scanner 40 screens 41 Microlens 50 Control device 51 Laser control unit 52 Scanner control unit

Claims

1. A head-up display that displays a display image visible to an occupant, comprising: emitting means for emitting laser light; a plurality of optical elements regularly arranged in a plane defined by orthogonal first and second directions and diffusing the incident laser light; scanning means capable of scanning the laser light with the plane as a scanning surface so as to hit each of the plurality of optical elements with a spot diameter smaller than the size of one of the optical elements; the emitting means continuously emits first laser light corresponding to a first image for a first viewing point and second laser light corresponding to a second image for a second viewing point vertically separated from the first viewing point; the scanning means scans the first laser light in a first scanning pattern and the second laser light in a second scanning pattern on the scanning surface so that the display image related to the first image is visible when viewed from the first viewing point and the display image related to the second image is visible when viewed from the second viewing point; the first scanning pattern is a first linear pattern along the first direction, and includes a first linear pattern in which the first laser light continuously enters, column by column, one or more columns of optical elements arranged linearly in the first direction among the plurality of optical elements; the second scanning pattern is a second linear pattern along the first direction, offset from the first linear pattern by a predetermined offset amount in the second direction, and includes a second linear pattern in which the second laser light continuously enters, column by column, the one or more columns of optical elements; the plurality of optical elements are arranged in M columns in the first direction and N columns in the second direction; the one or more columns of optical elements are the N columns of optical elements; the first linear pattern and the second linear pattern are patterns that scan from end to end of the M columns; the scanning means starts one scan from a start position of the scanning surface, and performs a linear scan from one end side in the first direction to the other end side in the first direction along the first direction while shifting by a constant pitch in the second direction, or a linear scan from the other end side in the first direction to the one end side in the first direction along the first direction while shifting by a constant pitch in the second direction, for the N columns, and ends the one scan at an end position of the scanning surface; the constant pitch corresponds to the pitch between the N columns in the second direction; The scanning pattern for a certain one scanning by linear scanning from the other end side in the first direction to the one end side in the first direction is composed of the first linear patterns for each of the N columns. One scanning following the scanning pattern for the certain one scanning, which is linear scanning from the one end side in the first direction to the other end side in the first direction, the scanning pattern for the scanning is composed of the second linear patterns for each of the N columns, Head-up display.

2. The scanning means includes a scanner whose orientation can be electronically controlled. The movement of the scanner is the same for the certain one scanning and the one scanning following the scanning pattern for the certain one scanning. The head-up display according to Claim 1.

3. A head-up display that displays a display image visible to an occupant, Emitting means for emitting laser light, A plurality of optical elements regularly arranged in a plane defined by orthogonal first and second directions and diffusing the incident laser light, Scanning means capable of scanning the laser light with the plane as a scanning surface so as to hit each of the plurality of optical elements with a spot diameter smaller than the size of one of the optical elements, The emitting means continuously emits first laser light corresponding to a first image for a first viewing point and second laser light corresponding to a second image for a second viewing point vertically separated from the first viewing point. The scanning means scans the first laser light in a first scanning pattern and the second laser light in a second scanning pattern on the scanning surface so that the display image related to the first image is visible when viewed from the first viewing point and the display image related to the second image is visible when viewed from the second viewing point. The first scanning pattern is a first linear pattern along the first direction, and includes a first linear pattern in which the first laser light continuously enters each column of one or more columns of optical elements arranged linearly in the first direction among the plurality of optical elements. The second scanning pattern is a second linear pattern along the first direction, offset by a predetermined offset amount in the second direction with respect to the first linear pattern, and includes a second linear pattern in which the second laser light continuously enters each column of the one or more columns of optical elements. The plurality of optical elements are arranged in M columns in the first direction and N columns in the second direction. The above one or more columns of optical elements are the N columns of optical elements, The first linear pattern and the second linear pattern are patterns that scan from end to end of the M columns, The scanning means starts one scan from the start position of the scanning surface, and executes a linear scan that reciprocates along the first direction while shifting by a predetermined pitch in the second direction for a part of the N columns of the scanning surface, and ends the one scan at the end position of the scanning surface, The predetermined pitch varies between a length obtained by adding the predetermined offset amount to the pitch between the N columns in the second direction and a length obtained by subtracting the predetermined offset amount from twice the pitch between the N columns in the second direction, The start position changes in the second direction by the predetermined offset amount or a length obtained by subtracting the predetermined offset amount from the pitch between the N columns in the second direction for each one scan, A scanning pattern related to three consecutive scans consists of the first linear pattern for each of the N columns and the second linear pattern for each of the N columns, a head-up display.

4. The head-up display according to any one of claims 1 to 3, wherein the predetermined offset amount correlates with the distance between the first viewpoint and the second viewpoint in the vertical direction.

Images