Head-up display

Abstract

The present invention generates display images in a suitable form in a configuration in which the visible display image is changed by simply changing the viewpoint in the horizontal direction. Disclosed is a head-up display wherein: an emission means successively emits first laser light corresponding to a first image for a first viewpoint and second laser light corresponding to a second image for a second viewpoint horizontally distanced from the first viewpoint; a scanning means scans the first laser light in a first scanning pattern and scans the second laser light in a second scanning pattern over a scanning surface such that, when viewed from the first viewpoint, a display image for the first image becomes visible and, when viewed from the second viewpoint, a display image for the second image becomes visible; the first scanning pattern includes a first linear pattern in which the first laser light is successively incident to each of one or more columns of optical elements aligned linearly in a first direction; and the second scanning pattern includes a second linear pattern that is offset by a prescribed offset amount in a second direction with respect to the first linear pattern.

Description

Technical Field

[0001] The present disclosure relates to a head-up display.

Background Art

[0002] There is known a technique of causing laser light to be incident on a plurality of optical elements regularly arranged at a predetermined pitch along a plane forming a scanning surface, and displaying a display image visible to a driver based on the light emitted from the plurality of optical elements.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional technology as described above, in a configuration in which the visible display image changes only by changing the viewing point in the horizontal direction, it is difficult to generate the display image in an appropriate manner.

[0005] Therefore, an object of the present disclosure is to generate the display image in an appropriate manner in a configuration in which the visible display image changes only by changing the viewing point in the horizontal direction.

Means for Solving the Problems

[0006] On one side, a head-up display that displays a display image visible to an occupant, an 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 beam 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 a first laser beam corresponding to a first image for a first viewing point and a second laser beam corresponding to a second image for a second viewing point horizontally separated from the first viewing point. The scanning means scans the first laser beam in a first scanning pattern and the second laser beam 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 beam 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, which is 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 beam 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 a single scan from the 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 fixed 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 fixed pitch in the second direction, for the N columns, and ends the single scan at the end position of the scanning surface. The fixed pitch corresponds to the pitch between the N columns in the second direction. The scanning pattern for a certain single scan by the linear scan from the other end side in the first direction to the one end side in the first direction consists of the first linear patterns for each of the N columns, and the scanning pattern for a single scan subsequent to the scanning pattern for the certain single scan, which is a linear scan from the one end side in the first direction to the other end side in the first direction, consists of the second linear patterns for each of the N columns. A head-up display is provided.

Advantages of the Invention

[0007] According to the present disclosure, in a configuration in which the visible display image changes only by changing the viewing point horizontally, it is possible to generate the display image in an appropriate manner.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2A

Figure 2B

Figure 3

Figure 4

Figure 5

Figure 6A

Figure 6B

Figure 7A

Figure 7B

Figure 8A

Figure 8B

Figure 8C

Figure 9

Best Mode for Carrying Out the Invention

[0009] Hereinafter, each embodiment will be described in detail with reference to the accompanying drawings. In FIG. 3 and the like, for the sake of easy viewing, only some of the parts and portions having the same attribute that exist in plurality may be provided with reference numerals.

[0010] [Configuration of Head-up Display] FIG. 1 is a diagram schematically showing the vehicle-mounted state of a head-up display 1 according to an embodiment as viewed from the side of the vehicle. FIG. 2A is a schematic diagram showing the configuration of the head-up display 1. FIG. 2B is a schematic explanatory diagram of the right viewpoint and the left viewpoint. FIG. 3 is a schematic diagram showing an example of the arrangement of the microlenses 41 forming the screen 40. In FIGS. 2A and 2B, the face P1 of the driver when the viewpoint is relatively at the position in the right eye box and the face P2 of the driver when the viewpoint is relatively at the position in the left eye box are schematically shown. Note that the right and left eye boxes may be continuous eye boxes in the horizontal direction or may be separate eye boxes separated into left and right. Also, in FIG. 2A, the dotted arrows R0 to R4 schematically show the flow of the electric signal.

[0011] In the head-up display 1, as shown in FIG. 1, when the display light is irradiated on the windshield WS, for the driver driving the vehicle VC, a display image (virtual image display) VI obtained by the irradiation can be seen in front of the windshield WS. Thereby, the driver can visually recognize the display image VI superimposed on the forward scenery. Therefore, the driver can grasp vehicle information and the like in a mode with less eye movement compared to the case of looking at the meters in the instrument panel 9, and convenience and safety are improved. Note that in a modified example, instead of the windshield WS, a combiner or the like may be used.

[0012] As shown in FIG. 2A, 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 for red, blue, and green laser lights respectively. 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 such three-color laser lights can be emitted, a full-color display image VI can be generated. However, in a modified example, the variations in the displayable colors may be fewer.

[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 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 the red wavelength range and reflects the blue wavelength range. Therefore, the dichroic mirror 22 can reflect the laser light incident from the laser irradiation device 12 toward the condenser lens 28 while transmitting the laser light incident from the dichroic mirror 21. Similarly, the dichroic mirror 23 transmits the red and blue wavelength ranges and reflects the green wavelength range. Therefore, the dichroic mirror 23 can reflect the laser light incident from the laser irradiation device 13 toward the condenser lens 28 while transmitting the laser light incident from the dichroic mirror 22.

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

[0016] The condensing lens 28 is configured and arranged such that the laser light incident from the dichroic mirror unit 20 is projected onto the screen 40 with a spot diameter (diameter) smaller than the size of each of a plurality of microlenses 41 (described later) forming the screen 40. For example, the spot diameter is adapted so that the following relational expression holds. Spot diameter ≦ lens pitch / number of viewpoints Here, the lens pitch is the pitch of the array of the plurality of microlenses 41 (see PT1 and PT2 in FIG. 3) described later, and the number of viewpoints corresponds to the number of ways the display image VI looks when the viewing direction is changed, and in this embodiment, it is "2".

[0017] The MEMS scanner 30 projects the laser light incident from the condensing lens 28 onto the screen 40. The MEMS scanner 30 includes a MEMS mirror that can rotate around two orthogonal axes. The projection position of the laser light on the screen 40 changes according to 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 in a plane. In this embodiment, as an example, the screen 40 extends in a horizontal plane, but it may be arranged at a slight inclination with respect to the horizontal plane. As shown in FIG. 3, the screen 40 includes a plurality of microlenses 41 regularly arranged in a plane. That is, the screen 40 includes a two-dimensional microlens array. The plurality of microlenses 41 typically have the same form, and in this embodiment, as an example, when viewed perpendicular to the screen 40, they have a rectangular (square) outer shape, but they may have other outer shapes such as hexagonal. The screen 40 may have a convex form on the incident surface corresponding to the plurality of microlenses 41 and a flat exit surface (see FIG. 5).

[0019] In the example shown in FIG. 3, the plurality of microlenses 41 are arranged in a plane including the X direction (an example of the first direction) and the Y direction (an example of the second direction), and the plurality of microlenses 41 are preferably regularly arranged at a constant pitch as shown in FIG. 3. In FIG. 3, although each pitch PT1 and PT2 in the X direction and the Y direction are the same, they may be different. In this embodiment, as an example, the plurality of microlenses 41 are arranged in 9 columns in the X direction and 8 columns in the Y direction, but the number of columns in the X direction and the Y direction is arbitrary. Note that the X direction and the Y direction are also illustrated in association with the screen 40 in the above-described FIG. 2A and the like.

[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 emitting unit, and the scanner control unit 52 cooperates with the above-described MEMS scanner 30 to form an example of a scanning unit.

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

[0022] Hereinafter, for the sake of distinction in the description, the display image VI visible from the right viewpoint (see P1 in FIG. 2A) is also referred to as "display image VI1", and the display image VI visible from the left viewpoint (see P2 in FIG. 2A) is also referred to as "display image VI2".

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

[0024] For example, the display image VI1 and the display image VI2 may include meter-related information and may also include navigation-related information. In this case, the driver can selectively view the two types of display images VI1 and VI2 with a natural eye movement according to the relationship between the general meter position (the meter position in the instrument panel 9) and the display position of the navigation display (the center in the vehicle width direction of the instrument panel 9) (see the upper part of FIG. 2). Alternatively, the display image VI1 may include right-side surrounding environment information (such as information about obstacles, etc.), and the display image VI2 may include left-side surrounding environment information (such as information about obstacles, etc.).

[0025] The right image signal is, for example, a signal representing the pixel value (luminance or color) of each pixel of an image with a predetermined size and a predetermined resolution. Also, the left image signal is, for example, a signal representing the pixel value (luminance or color) of each pixel of an image with a predetermined size and a predetermined resolution. In this case, the predetermined size and the predetermined resolution may be the same for the right image signal and the left 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 the laser control unit 51 controls the laser unit 10 based on the right image signal, it controls the laser unit 10 so that laser light of a color corresponding to each pixel value is emitted from the laser unit 10 at a timing corresponding to each pixel based on the pixel value of each pixel included in the right image signal. The same applies to the case of the left image signal.

[0027] The scanner control unit 52 controls the MEMS scanner 30 (see arrow R4 in FIG. 2A). That is, the scanner control unit 52 controls the direction of the MEMS mirror of the MEMS scanner 30 to scan the laser beam on the screen 40. Here, "scanning the laser beam on the screen 40" means changing the projection position of the laser beam on the plane related to the screen 40 (the projection position when viewed perpendicular to the plane related to the screen 40). Also, hereinafter, the "scanning pattern" refers to the locus of the projection position (the locus of the projection position of the laser beam on the plane related to the screen 40). Also, the plane related to the screen 40 (that is, the plane on which the plurality of 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 the laser beam corresponding to the right image signal (an example of the first laser beam) in the right-side scanning pattern (an example of the first scanning pattern), and scan the laser beam corresponding to the left image signal (an example of the second laser beam) in the left-side scanning pattern (an example of the second scanning pattern). That is, when operating based on the right image signal, the scanner control unit 52 controls the MEMS scanner 30 so that the laser beam from the laser unit 10 is projected onto each position on the scanning plane corresponding to each pixel based on the pixel value of each pixel included in the right image signal. The same applies to the case of the left image signal.

[0029] Next, with reference to FIGS. 4 and later, several preferred embodiments of the right-side scanning pattern and the left-side scanning pattern will be described.

[0030] [Embodiment 1] FIG. 4 is an explanatory diagram showing a scanning pattern for the right side and a scanning pattern for the left side according to an embodiment (Embodiment 1), and is a diagram showing the screen 40 in a plan view. FIG. 5 is an explanatory diagram of the principle by which display images VI1 and VI2 are generated by the scanning pattern for the right side and the scanning pattern for the left side. In FIG. 4 (the same applies to FIGS. 6A and the like to be described later), an X1 side and an X2 side in the X direction are defined, and a Y1 side and a Y2 side in the Y direction are defined. In FIG. 5, for the screen 40, only three microlenses 41 arranged in the Y direction are taken out and shown in a cross-sectional view. The Y direction corresponds to the vehicle width direction when the screen 40 is located in the horizontal plane. At this time, the X direction corresponds to the vehicle longitudinal direction. In FIG. 5, the direction perpendicular to the paper surface is the X direction.

[0031] In the example shown in FIG. 4, one scan by the scanner control unit 52 and the MEMS scanner 30 starts from the start position S4 of the scanning surface, and performs a linear scan that reciprocates along the X direction while being alternately shifted by predetermined pitches PT41 and PT42 in the Y direction for each column (column in the Y direction), and ends at the end position E4 of the scanning surface. 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 continuously in time.

[0032] In FIG. 4, the linear scan that reciprocates along the X direction consists of an outward scan L401 and a return scan L402. The outward scan L401 and the return 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 outward scan L401 is offset by a predetermined amount α to the Y1 side in the Y direction with respect to the center O of each microlens 41, and the return scan L402 is offset by a predetermined amount β to the Y2 side in the Y direction with respect to the center O of each microlens 41.

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

[0034] In this case, the scanning pattern for the right side consists of a linear pattern along the X direction by the forward scan L401 (an example of the first linear pattern), and the scanning pattern for the left side consists of a linear pattern along the X direction by the return scan L402 (an example of the second linear pattern).

[0035] According to such a scanning pattern for the right side and the scanning pattern for the left side, the display image VI1 can be generated by the laser beam scanned by the scanning pattern for the right side (the laser beam corresponding to the right side image signal), and the display image VI2 can be generated by the laser beam scanned by the scanning pattern for the left side (the laser beam corresponding to the left side image signal).

[0036] More specifically, as shown in FIG. 5, the laser light scanned by the right-side scanning pattern (laser light corresponding to the right-side image signal) is incident on a position shifted by a predetermined amount α toward the Y1 side in the Y direction from the center O of the microlens 41 (see arrow R51). In this case, the microlens 41 emits light in a direction corresponding to the shape of the incident surface of the microlens 41 (spherical shape) (see arrow R511). On the other hand, the laser light scanned by the left-side scanning pattern (laser light corresponding to the left-side image signal) is incident on a position shifted by a predetermined amount β toward the Y2 side in the Y direction from the center O of the microlens 41, as shown in FIG. 5 (see arrow R52). In this case, the microlens 41 emits light in a direction corresponding to the shape of the incident surface of the microlens 41 (spherical shape) (see arrow R521). At this time, the incident positions (spot positions) in one microlens 41, that is, the incident position related to the laser light scanned by the right-side scanning pattern (laser light corresponding to the right-side image signal) and the incident position related to the laser light scanned by the left-side scanning pattern (laser light corresponding to the left-side image signal) are located on the opposite sides in the Y direction with the center O of the same microlens 41 interposed therebetween. For this reason, the emission directions of the laser light from the microlens 41, that is, the emission direction related to the laser light scanned by the right-side scanning pattern (laser light corresponding to the right-side image signal) (see arrow R511) and the emission direction related to the laser light scanned by the left-side scanning pattern (laser light corresponding to the left-side image signal) (see arrow R521) are inclined (non-parallel) with respect to each other, as schematically shown in FIG. 5. That is, the region R510 related to the laser light scanned by the right-side scanning pattern (laser light corresponding to the right-side image signal) and the region R520 related to the laser light scanned by the left-side scanning pattern (laser light corresponding to the left-side image signal), which are regions where the laser light from the microlens 41 in the windshield WS is incident, are spaced apart from each other. Specifically, the regions R510 and R520 are offset in the horizontal direction in the windshield WS. As a result, as schematically shown in FIG. 2A, since the laser light can be projected from the horizontally offset regions R510 and R520 toward the driver side, the display images VI1 and VI2 can be generated. Note that the predetermined offset amount correlates with the distance between the right viewing point (the viewing point from which the display image VI1 can be seen) and the left viewing point (the viewing point from which the display image VI2 can be seen) in the horizontal direction.The quantified amounts α and β may be adapted according to desired positions in regions R510 and R520 (and thus desired positions of display images VI1 and VI2).

[0037] Here, in this embodiment, as described above, since one scan is realized with a scan pattern that combines a right-side scan pattern and a left-side scan pattern, display images VI1 and VI2 can be generated substantially simultaneously. Therefore, when the driver wants to view display image VI1, the driver can move the viewpoint relatively to the right, and when the driver wants to view display image VI2, the driver can move the viewpoint relatively to the left. In this way, the driver can continuously view display images VI1 and VI2 simply by moving the viewpoint horizontally. Thus, according to this embodiment, in a configuration where display images VI1 and VI2 that can be viewed by simply changing the viewpoint horizontally change, it is possible to generate the display images VI1 and VI2 in an appropriate manner.

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

[0039] [Embodiment 2] FIGS. 6A and 6B are explanatory diagrams showing a right-side scan pattern and a left-side scan pattern according to another embodiment (Embodiment 2).

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

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

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

[0043] Therefore, according to the scanning pattern for the right side and the scanning pattern for the left side shown in FIGS. 6A and 6B, the display image VI1 can be generated by the laser light scanned by the scanning pattern for the right side (laser light corresponding to the right image signal), and the display image VI2 can be generated by the laser light scanned by the scanning pattern for the left side (laser light corresponding to the left image signal).

[0044] Here, in this embodiment, as described above, unlike the scanning pattern that combines the right-side scanning pattern and the left-side scanning pattern in one scan, one scan consists of only the right-side scanning pattern or the left-side scanning pattern. Therefore, the pitch in the Y direction in one scan can be set to a relatively large constant pitch PT2. As a result, the resolution of the change in the orientation of the MEMS scanner 30 required to realize such scanning (the resolution of the change in orientation with respect to the pitch in the Y direction) can be made relatively small, and thus the control of the MEMS scanner 30 becomes relatively easy.

[0045] In this embodiment as well, by executing one scan shown in FIG. 6A and one scan shown in FIG. 6B in close temporal proximity, the display images VI1 and VI2 can be generated substantially simultaneously. Therefore, when the driver wants to view the display image VI1, the driver can move the viewpoint relatively to the right, and when the driver wants to view the display image VI2, the driver can move the viewpoint relatively to the left. In this way, the driver can continuously view the display images VI1 and VI2 only by moving the viewpoint horizontally. In this manner, according to this embodiment, in a configuration where the display images VI1 and VI2 that can be viewed only by changing the viewpoint horizontally change, 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 alternately executed once each. However, when the one-scan time is sufficiently short, they may be alternately executed multiple times each.

[0047] [Embodiment 3] FIGS. 7A and 7B are explanatory diagrams showing a right-side scanning pattern and a left-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 the start position S7A of the scanning surface, and while shifting by a predetermined pitch PT2 in the Y direction, a linear scan from one end side (X1 side) to the other end side (X2 side) along the X direction is performed for each column (column in the Y direction), and ends at the end position E7A of the scanning surface. Further, in the example shown in FIG. 7B, one scan by the scanner control unit 52 and the MEMS scanner 30 starts from the start position S7B of the scanning surface, and while shifting by a predetermined pitch PT2 in the Y direction, a linear scan from the other end side (X2 side) to the one end side (X1 side) along the X direction is performed for each column (column in the Y direction), and ends at the end position E7B of the scanning surface. 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. 7A and one scan shown in FIG. 7B continuously in time.

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

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

[0051] Therefore, according to the scanning patterns for the right side and the left side shown in FIGS. 7A and 7B, the display image VI1 can be generated by the laser light scanned by the scanning pattern for the right side (laser light corresponding to the right image signal), and the display image VI2 can be generated by the laser light scanned by the scanning pattern for the left side (laser light corresponding to the left image signal).

[0052] Note that in this embodiment, the control content of the MEMS scanner 30 for realizing the scans shown in FIGS. 7A and 7B can be the same as the example shown in FIG. 4. In this case, only the control for the laser unit 10 is different. In other words, if the scan shown in FIG. 4 is a "progressive method", the scans shown in FIGS. 7A and 7B can be called an "interlace method".

[0053] Here, in this embodiment, as described above, unlike the scanning pattern that combines the right-side scanning pattern and the left-side scanning pattern in one scan, one scan consists of only the right-side scanning pattern or the left-side scanning pattern. Therefore, the pitch in the Y direction in one scan can be set to a relatively large constant pitch PT2. Also, since the control content of the MEMS scanner 30 itself is the same for the one scan shown in FIG. 7A and the one scan shown in FIG. 7B (only the control for 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] Note that also in this embodiment, by executing the one scan shown in FIG. 7A and the one scan shown in FIG. 7B in close temporal proximity, 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 horizontally moving the viewpoint, such as moving the viewpoint relatively to the right when wanting to view the display image VI1 and moving the viewpoint relatively to the left when wanting to view the display image VI2. In this way, according to this embodiment, in a configuration where the display images VI1 and VI2 that can be viewed by simply changing the viewpoint horizontally change, it becomes possible to generate the display images VI1 and VI2 in an appropriate manner.

[0055] Note that in this embodiment, the one scan shown in FIG. 7A and the one scan shown in FIG. 7B are alternately executed once each time, but when the one scan time is sufficiently short, they may be alternately executed every plurality of times.

[0056] Also, in this embodiment, although the control content of the MEMS scanner 30 itself is the same for one scan shown in FIG. 7A and one scan shown in FIG. 7B, it is not limited to this. For example, the start position of one scan shown in FIG. 7B may be the start position S6B shown in FIG. 6B. In this case, one scan starts from the start position S6B of the scan plane and performs a linear scan 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 for each column (column in the Y direction), and ends at the end position E7B' (see FIG. 7B) of the scan plane.

[0057] [Embodiment 4] FIGS. 8A to 8C and FIG. 9 are explanatory diagrams showing a scanning pattern for the right side and a scanning pattern for the left side according to still another embodiment (Embodiment 4).

[0058] In the example shown in FIGS. 8A to 8C, one scan by the scanner control unit 52 and the MEMS scanner 30 starts from the start position S8A, S8B, or S8C of the scan plane and performs a linear scan that reciprocates along the X direction while shifting by a predetermined pitch PT8A or PT8B in the Y direction for some columns (columns in the Y direction), and ends at the 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 executing such one scan shown in FIG. 8A, one scan shown in FIG. 8B, and one scan shown in FIG. 8C continuously in time (see FIG. 9).

[0059] The predetermined pitch PT8A is larger than the pitch PT2 (= the pitch in the Y direction of the array of the microlenses 41), and is equal 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 array of the microlenses 41), and is equal to the length obtained by adding the differential offset amount to the pitch PT2. The differential offset amount is, as described above, the length obtained by subtracting the predetermined offset amount (= α + β) from the size in the Y direction of the microlens 41 (= 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 in the Y direction of the microlens 41 (= the pitch PT2 in the Y direction).

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

[0061] In this case, the scanning pattern for the right side consists of a linear pattern (an example of a first linear pattern) along the X direction by the scanning L801 shown in FIGS. 8A to 8C, and the scanning pattern for the left side consists of a linear pattern (an example of a second linear pattern) along the X direction by the scanning L802 shown in FIGS. 8A to 8C. That is, both the scanning pattern for the right side and the scanning pattern for the left side are cooperatively realized by the three scans shown in FIGS. 8A to 8C. Also in this case, the laser light scanned by the scanning pattern for the right side (laser light corresponding to the right image signal) is incident on a position shifted by a predetermined amount α to the Y1 side in the Y direction from the center O of the microlens 41 as shown in FIG. 5 (see arrow R51). In this case, the microlens 41 emits light in a direction corresponding to the form of the incident surface of the microlens 41 (spherical form) (see arrow R511). On the other hand, the laser light scanned by the scanning pattern for the left side (laser light corresponding to the left image signal) is incident on a position shifted by a predetermined amount β to the Y2 side in the Y direction from the center O of the microlens 41 as shown in FIG. 5 (see arrow R52).

[0062] Therefore, according to the scanning pattern for the right side and the scanning pattern for the left side shown in FIGS. 8A to 8C, the display image VI1 can be generated by the laser light scanned by the scanning pattern for the right side (laser light corresponding to the right image signal), and the display image VI2 can be generated by the laser light scanned by the scanning pattern for the left side (laser light corresponding to the left image signal).

[0063] Here, in this embodiment, as described above, since three scans are executed to generate the display images VI1 and VI2 corresponding to one frame, the pitch in the Y direction in one scan can be set to relatively large predetermined pitches PT8A and PT8B. Thereby, the resolution of the change in the orientation of the MEMS scanner 30 required to realize such scanning can be made relatively small, and the control of the MEMS scanner 30 becomes relatively easy.

[0064] In this embodiment, as described above, three scans are performed to generate display images VI1 and VI2 corresponding to one frame. However, 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 a specific embodiment, and various modifications and changes are possible within the scope described in the claims. Also, it is possible to combine all or a plurality of the components of the foregoing embodiments.

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

[0067] Also, in each of the above-described embodiments, the configuration is such that different display images VI1 and VI2 are visible at two viewpoints offset in the horizontal direction, but it is not limited to this. For example, a configuration may be realized in which different display images are visible at three or more different viewpoints along the horizontal direction.

[0068] In addition, in each of the above-described embodiments, the two horizontally offset viewpoints may be viewpoints that cause a parallax (i.e., binocular parallax) due to the driver's left and right eyes. That is, the two horizontally offset viewpoints may be a viewpoint corresponding to the position of the left eye and a viewpoint corresponding to the position of the right eye. In this case, both the right-side image and the left-side image are formed as stereoscopic images. In this case, since the display images VI1 and VI2 can be visually recognized in stereoscopy when viewed simultaneously with the right eye and the left eye, vehicle information and the like can be provided with a new feeling. Since the display images VI1 and VI2 can be visually recognized in stereoscopy, the display images VI1 and VI2 may display map information in the navigation information, for example, in stereoscopy.

[0069] In addition, in each of the above-described embodiments, a simple configuration is adopted in which feedback control is not performed on the projection position of the laser beam on the screen 40, but 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 beam on the screen 40. In addition, in each of the above-described embodiments, the viewer of the display image is the driver of the vehicle, but a configuration may be adopted in which the display image is formed so that other passengers (for example, passengers in the passenger seat or the rear seat) become the viewers.

Explanation of Reference Numerals

[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 Condensing lens 30 MEMS scanner 40 Screen 41 Microlens 50 Control device 51 Laser control unit 52 Scanner control unit

Claims

1. A head-up display for displaying 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 horizontally 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 consists of the first linear patterns for each of the N columns. A subsequent scanning to the scanning pattern for the certain one scanning, which is a 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 consists of the second linear patterns for each of the N columns. A 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 subsequent one scanning to 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 horizontally 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-described 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 being shifted by a predetermined pitch in the second direction for a part of the N columns, 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 scan. A head-up display in which the scanning patterns related to three consecutive scans are composed of the first linear pattern for each of the N columns and the second linear pattern for each of the N columns.

4. A head-up display that displays a display image visible to an occupant, Emitting means for emitting laser light, A plurality of optical elements that are regularly arranged in a plane defined by orthogonal first and second directions and diffract 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 horizontally 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 of one or more columns of optical elements linearly arranged in the first direction among the plurality of optical elements, column by column. The second scanning pattern is a second linear pattern along the first direction, which is 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 is continuously incident on each 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 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 first image and the second image are stereoscopic images that utilize the parallax between the first viewpoint and the second viewpoint. The predetermined offset amount is a head-up display that correlates with the distance between the first viewpoint and the second viewpoint in the horizontal direction.

Images