CN114730088A

CN114730088A - Head-up display

Info

Publication number: CN114730088A
Application number: CN202080077785.6A
Authority: CN
Inventors: 野本贵之
Original assignee: Nippon Seiki Co Ltd
Current assignee: Nippon Seiki Co Ltd
Priority date: 2019-12-20
Filing date: 2020-12-18
Publication date: 2022-07-08
Also published as: WO2021125330A1; JPWO2021125330A1

Abstract

In a configuration in which a visible display image is changed only by changing a viewpoint in the vertical direction, the display image is generated in an appropriate form. Disclosed is a head-up display wherein an emission mechanism 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 distant from the first viewpoint in the up-down direction, a scanning mechanism scans the first laser light in a first scanning pattern and the second laser light in a second scanning pattern on a scanning surface, the first scanning pattern includes a first linear pattern in which a first laser beam is continuously incident on each of one or more columns of optical elements linearly arranged in a first direction, and the second scanning pattern includes a second linear pattern shifted in a second direction by a predetermined shift amount with respect to the first linear pattern, so that the display image relating to the first image is visually recognized when viewed from a first viewpoint and the display image relating to the second image is visually recognized when viewed from a second viewpoint.

Description

Head-up display

Technical Field

The present disclosure relates to a head-up display.

Background

There is known a technique of displaying a display image visually recognizable by a driver based on light emitted from a plurality of optical elements in which laser light is incident on the plurality of optical elements regularly arranged at a predetermined pitch along a plane forming a scanning surface.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2015-225216

Disclosure of Invention

Problems to be solved by the invention

However, in the conventional technology as described above, in a configuration in which a visible display image is changed only by changing a viewpoint in the vertical direction, it is difficult to generate the display image in an appropriate form.

Therefore, an object of the present disclosure is to generate a display image in an appropriate form in a configuration in which a visible display image is changed only by changing a viewpoint in the vertical direction.

Means for solving the problems

In one aspect, there is provided a head-up display for displaying a display image visually recognizable by an occupant, comprising:

an emission mechanism that emits laser light;

a plurality of optical elements regularly arranged in a plane defined by a first direction and a second direction orthogonal to each other and diffusing the incident laser light; and

a scanning mechanism capable of scanning the laser beam with the plane as a scanning surface so that a spot diameter smaller than the size of one of the optical elements is applied to each of the plurality of optical elements,

wherein the emission mechanism continuously emits a first laser beam corresponding to a first image for a first viewpoint and a second laser beam corresponding to a second image for a second viewpoint which is distant from the first viewpoint in a vertical direction,

the scanning mechanism scans the first laser beam in a first scanning pattern and scans the second laser beam in a second scanning pattern on the scanning surface to visually recognize the display image related to the first image when viewed from the first viewpoint and to visually recognize the display image related to the second image when viewed from the second viewpoint,

the first scan pattern includes a first linear pattern along the first direction, which is a pattern in which the first laser light is continuously incident on each of one or more columns of optical elements linearly arranged in the first direction among the plurality of optical elements,

the second scanning pattern includes a second linear pattern along the first direction, which is a pattern shifted in the second direction by a prescribed shift amount with respect to the first linear pattern, and the second laser light is continuously incident on each column of the optical elements of the one or more columns.

Effects of the invention

According to the present disclosure, in a configuration in which a visible display image is changed only by changing a viewpoint in the vertical direction, the display image can be generated in an appropriate form.

Drawings

Fig. 1 is a view schematically showing a vehicle-mounted state of a head-up display according to an embodiment when viewed from a side of a vehicle.

Fig. 2 is a schematic view showing the structure of the head-up display.

Fig. 3 is a schematic diagram showing an example of arrangement of microlenses forming a screen.

Fig. 4 is an explanatory diagram showing an upper side scanning pattern and a lower side scanning pattern in one embodiment (embodiment 1).

Fig. 5 is an explanatory diagram illustrating a principle of generating two kinds of display images by the upper side scanning pattern and the lower side scanning pattern.

Fig. 6A is an explanatory view showing an upper side scanning pattern and a lower side scanning pattern of another embodiment (embodiment 2).

Fig. 6B is an explanatory diagram showing an upper side scanning pattern and a lower side scanning pattern of another embodiment (embodiment 2).

Fig. 7A is an explanatory view showing an upper side scanning pattern and a lower side scanning pattern of another embodiment (embodiment 3).

Fig. 7B is an explanatory view showing an upper side scanning pattern and a lower side scanning pattern of another embodiment (embodiment 3).

Fig. 8A is an explanatory view showing an upper side scanning pattern and a lower side scanning pattern of another embodiment (embodiment 4).

Fig. 8B is an explanatory view showing an upper side scanning pattern and a lower side scanning pattern of another embodiment (embodiment 4).

Fig. 8C is an explanatory view showing an upper side scanning pattern and a lower side scanning pattern of another embodiment (embodiment 4).

Fig. 9 is an explanatory view showing an upper side scanning pattern and a lower side scanning pattern of another embodiment (embodiment 4).

Detailed Description

Hereinafter, each embodiment will be described in detail with reference to the drawings. In fig. 3 and the like, for the sake of easy observation, a plurality of existing parts or portions having the same attribute may be denoted by only a part of reference numerals.

[ Structure of head-up display ]

Fig. 1 is a view schematically showing a vehicle-mounted state of a head-up display 1 according to an embodiment when viewed from a side of a vehicle. Fig. 2 is a schematic diagram showing the structure of head-up display 1. Fig. 3 is a schematic diagram showing an example of the arrangement of the microlenses 41 forming the screen 40. Fig. 2 schematically shows the driver's face P1 when the viewpoint is located in the eye movement range on the relatively upper side, and the driver's face P2 when the viewpoint is located in the eye movement range on the relatively lower side. The upper and lower eye movement ranges may be vertically continuous eye movement ranges or other vertically separated eye movement ranges. Further, in fig. 2, arrows R0 to R4 of broken lines schematically show the flow of the electrical signals.

In the head-up display 1, as shown in fig. 1, when display light is irradiated on the windshield WS, a display image (virtual image display) VI obtained by the irradiation is observed in front of the windshield WS for a driver driving the vehicle VC. This allows the driver to visually recognize the display image VI superimposed on the forward scenery. Therefore, the driver can grasp the vehicle information and the like with less line of sight movement than the case of observing the meter inside the instrument panel 9, and convenience and safety are improved. In addition, in the modification, a combiner or the like may be used instead of the windshield WS.

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 (one example of an optical element), and a control device 50.

The laser unit 10 includes

laser irradiation devices

11, 12, 13 of respective colors of red, blue, green. The laser irradiation device 11 emits laser light in a wavelength region of red. The laser irradiation device 12 emits laser light in the blue wavelength range. The laser irradiation device 13 emits laser light in a green wavelength region. In addition, in this embodiment, since the laser light of the three colors can be emitted, a full-color display image VI can be generated. However, in the modification, the change in the displayable color may be small.

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 wavelength region of red. Therefore, the dichroic mirror 21 can reflect only the laser light to be incident from the laser irradiation device 11 toward the condenser lens 28. The dichroic mirror 22 transmits a wavelength region of red and reflects a wavelength region of blue. Therefore, the dichroic mirror 22 can transmit the laser light incident from the dichroic mirror 21 and reflect the laser light incident from the laser irradiation device 12 toward the condenser lens 28. Similarly, the dichroic mirror 23 transmits the wavelength regions of red and blue, and reflects the wavelength region of green. Therefore, the dichroic mirror 23 can transmit the laser light incident from the dichroic mirror 22 and reflect the laser light incident from the laser irradiation device 13 toward the condenser lens 28.

As described above, the condenser lens 28 condenses the laser light (laser light of each color of red, blue, and green) incident from the dichroic mirror unit 20 and emits the condensed laser light toward the MEMS scanner 30.

The condenser 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 adjusted so that the following relational expression holds.

The diameter of the light spot is less than or equal to the distance between the lenses/the number of viewpoints

In the formula, the lens pitch is a pitch of arrangement 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 visual expressions of the display image VI when the visual expressions of the display image VI are changed by changing the viewpoint, and is "2" in the present embodiment.

The MEMS scanner 30 projects the laser light incident from the condenser lens 28 onto the screen 40. The MEMS scanner 30 is provided with a MEMS mirror that can rotate about two orthogonal axes. The projection position of the laser light on the screen 40 varies 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.

The screen 40 extends in a plane. In the present embodiment, the screen 40 extends in a horizontal plane as an example, but may be arranged in an orientation slightly inclined 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 shape, and in the present embodiment, as an example, have a rectangular (square) outer shape when viewed from a direction perpendicular to the screen 40, but may have another outer shape such as a hexagonal shape. The incident surface of the screen 40 may have a convex shape with respect to the plurality of microlenses 41, and the exit surface may be a flat surface (see fig. 5).

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 as shown in fig. 3, the plurality of microlenses 41 are preferably regularly arranged at a constant pitch. In fig. 3, the pitches PT1 and PT2 in the X direction and the Y direction are the same, but may be different. In the present embodiment, as an example, the plurality of 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. In addition, the X direction and the Y direction are also illustrated in correspondence with the screen 40 in fig. 2 described above.

The Control device 50 may be implemented by a computer such as an ECU (Electronic Control Unit). The control device 50 includes a laser control section 51 and a scanner control section 52. In the present embodiment, the laser control unit 51 forms an example of the emission mechanism in cooperation with the laser unit 10, and the scanner control unit 52 forms an example of the scanning mechanism in cooperation with the MEMS scanner 30.

The laser control section 51 controls the laser unit 10 based on the image signal for generating the display image VI (see arrows R1 to R3 in fig. 2). In the present embodiment, the image signal includes, as an example, an upper image signal for generating the display image VI visually recognizable from an upper viewpoint (see P1 in fig. 2) and a lower image signal for generating the display image VI visually recognizable from a lower viewpoint (see P2 in fig. 2). The upper image signal and the lower image signal may be generated by an external ECU and supplied to the control device 50 (see arrow R0 in fig. 2), or may be generated by the control device 50 itself.

Hereinafter, for the sake of explanation, the display image VI visually recognizable from the upper viewpoint (see P1 in fig. 2) is also referred to as "display image VI 1", and the display image VI visually recognizable from the lower viewpoint (see P2 in fig. 2) is also referred to as "display image VI 2".

The upper image signal and the lower image signal may be the same signal or different signals. In the present embodiment, as an example, the upper side image signal and the lower side image signal are different signals. In this case, the display image VI1 and the display image VI2 can be formed to be different from each other.

For example, display view VI1 may include navigation-related information and display view VI2 may include meter-related information. In this case, the driver can selectively observe the two types of display images VI1 and VI2 (see the upper side of fig. 2) by a natural line-of-sight operation that matches the relationship between the general instrument position (the instrument position in the instrument panel 9) and the display position of the display image VI on the head-up display 1.

The upper image signal is, for example, a signal indicating a pixel value (luminance, color) of each pixel of an image of a predetermined size and a predetermined resolution. The lower image signal is a signal indicating, for example, a pixel value (luminance, color) of each pixel of an image of a predetermined size and a predetermined resolution. In this case, the prescribed size and the prescribed resolution may be the same in the upper image signal and the lower image signal. In addition, each pixel of the image corresponds to each position (each position on the scanning surface) of the screen 40. For example, each pixel of the image may correspond to each position of the screen 40 (each position on the scanning surface) in a one-to-one relationship. In addition, the positions of the screen 40 correspond to the orientations of the MEMS mirrors of the MEMS scanner 30.

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 laser light of a color corresponding to each pixel value is emitted from the laser unit 10 at a time corresponding to each pixel. The same applies to the lower image signal.

The scanner control section 52 controls the MEMS scanner 30 (refer to an arrow R4 of fig. 2). That is, the scanner control section 52 scans the laser light on the screen 40 by controlling the orientation of the MEMS mirror of the MEMS scanner 30. Here, "scanning the laser light on the screen 40" means changing the projection position of the laser light on the plane related to the screen 40 (the projection position when the plane related to the screen 40 is vertically observed). Further, the "scanning pattern" hereinafter refers to a trajectory of the projection position (a trajectory of the projection position of the laser light on a plane related to the screen 40). Further, a plane related to the screen 40 (i.e., a plane in which the plurality of microlenses 41 are arranged) is also referred to as a "scanning plane".

Specifically, the scanner control unit 52 scans the laser light (an example of the first laser light) corresponding to the upper image signal with the upper scanning pattern (an example of the first scanning pattern) and scans the laser light (an example of the second laser light) corresponding to the lower image signal with the lower scanning pattern (an example of the second scanning pattern) in cooperation with the laser control unit 51. That is, when operating based on the upper image signal, the scanner control unit 52 controls the MEMS scanner 30 based on the pixel value of each pixel included in the upper image signal so that the laser light from the laser unit 10 is projected to each position on the scanning surface corresponding to each pixel. The same applies to the lower image signal.

Next, a preferred embodiment of the upper scanning pattern and the lower scanning pattern will be described with reference to fig. 4 and subsequent drawings.

[ example 1]

Fig. 4 is an explanatory diagram showing an upper side scanning pattern and a lower side scanning pattern of an embodiment (embodiment 1), and is a diagram showing the screen 40 in a plan view. Fig. 5 is an explanatory diagram illustrating a principle of generating the display images VI1, VI2 by the upper side scanning pattern and the lower side scanning pattern. In fig. 4 (the same applies to fig. 6A and the like 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, with respect to the screen 40, only three microlenses 41 arranged in the Y direction are taken out and shown in a cross-sectional state. The Y direction corresponds to the vehicle front-rear direction when the screen 40 is located in the horizontal plane. In this case, the X direction corresponds to the vehicle lateral direction (vehicle width direction). In fig. 5, a direction perpendicular to the paper surface is the X direction.

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 scan surface, and for each column (Y-direction column), a linear scan is performed while alternately shifting the predetermined pitches PT41 and PT42 in the Y direction, and the linear scan is repeated in the X direction, and ends at the end position E4 of the scan surface. In addition, the scanner control unit 52 and the MEMS scanner 30 can maintain the output state of the display images VI1 and VI2 by repeating such one scan continuously over time.

In fig. 4, the linear scan reciprocating in the X direction is composed of an outward path side scan L401 and a return path side scan L402. The outward-path-side scan L401 and the return-path-side scan L402 pass through the microlenses 41 and are offset from each other by a predetermined offset amount (α + β) in the Y direction. In other words, the forward-side scan L401 is shifted by a predetermined amount α toward the Y1 with respect to the center O of each microlens 41, and the return-side scan L402 is shifted by a predetermined amount β toward the Y2 with respect to the center O of each microlens 41.

The predetermined pitch PT41 is a pitch at the time of transition from the outward scanning line L401 to the return scanning line L402, and matches a predetermined offset amount (═ α + β). The predetermined pitch PT42 is a pitch at the time of transition from the circuit-side scan L402 to the forward-side scan L401, and is a length (hereinafter, also referred to as "differential shift amount") obtained by subtracting a predetermined shift amount (═ α + β) from the size of the microlens 41 in the Y direction (═ Y-direction pitch PT 2). The position in the Y direction of the start position S4 is shifted by a predetermined amount α toward the Y1 side from the center O of the microlens 41.

In this case, the upper-side scan pattern is composed of a straight line pattern in the X direction (an example of a first straight line pattern) by the outward-route-side scan L401, and the lower-side scan pattern is composed of a straight line pattern in the X direction (an example of a second straight line pattern) by the return-route-side scan L402.

According to the upper scanning pattern and the lower scanning pattern, the display image VI1 can be generated by the laser light (laser light corresponding to the upper image signal) scanned by the upper scanning pattern, and the display image VI2 can be generated by the laser light (laser light corresponding to the lower image signal) scanned by the lower scanning pattern.

More specifically, as shown in fig. 5, the laser light (laser light corresponding to the upper image signal) scanned in the upper scanning pattern enters a position shifted by a predetermined amount α in the Y direction Y1 side from the center O of the microlens 41 (see arrow R51). In this case, the 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 (laser light corresponding to the lower image signal) scanned by the lower scanning pattern enters a position shifted by a predetermined amount β from the center O of the microlens 41 toward the Y2 (see arrow R52). In this case, the 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 an arrow R521). At this time, the incident position (spot position) of one microlens 41, that is, the incident position of the laser light scanned in the upper scanning pattern (laser light corresponding to the upper image signal) and the incident position of the laser light scanned in the lower scanning pattern (laser light corresponding to the lower image signal) are located on the opposite side in the Y direction with respect to the center O of the microlens 41. Therefore, the emission direction of the laser light from the microlens 41, that is, the emission direction (refer to an 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 (refer to an arrow R521) of the laser light scanned with the lower side scanning pattern (laser light corresponding to the lower side image signal) are inclined (not parallel) to each other as schematically shown in fig. 5. That is, in the windshield WS, a region where the laser light from the microlens 41 enters, that is, a region R510 relating to the laser light scanned with the upper scanning pattern (laser light corresponding to the upper image signal) and a region R520 relating to the laser light scanned with the lower scanning pattern (laser light corresponding to the lower image signal) are separated from each other. Specifically, the regions R510, R520 are offset in the vertical direction in the windshield WS. As a result, as schematically shown in fig. 2, laser light can be projected toward the driver from the regions R510, R520 shifted in the vertical direction, and therefore, display images VI1, VI2 can be generated. The predetermined offset amount is related to a vertical distance between an upper viewpoint (a viewpoint from which the display image VI1 can be seen) and a lower viewpoint (a viewpoint from which the display image VI2 can be seen). The predetermined amounts α and β can be adjusted according to desired positions of the regions R510 and R520 (and thus desired positions of the display images VI1 and VI 2).

Here, in the present embodiment, as described above, since one scan is realized by a scan pattern in which the upper side scan pattern and the lower side scan pattern are combined, the display images VI1 and VI2 can be generated substantially simultaneously. Therefore, the driver can continuously view the display images VI1 and VI2 by moving the viewpoint in the vertical direction only such that the viewpoint is relatively moved upward when he wants to view the display image VI1 and downward when he wants to view the display image VI 2. As described above, according to the present embodiment, the display images VI1 and VI2 can be generated in an appropriate form in a configuration in which the visually recognizable display images VI1 and VI2 are changed only by changing the viewpoint in the vertical direction.

In the present embodiment, the viewpoint of the driver is not detected by a camera or the like, and the display images VI1 and VI2 are generated substantially simultaneously regardless of the current viewpoint of the driver. Therefore, even when the viewpoint of the driver changes, the driver can visually recognize the display image VI1 or VI2 without delay.

[ example 2]

Fig. 6A and 6B are explanatory views showing an upper side scanning pattern and a lower side scanning pattern of another embodiment (embodiment 2).

In the example shown in fig. 6A and 6B, one scan by the scanner control unit 52 and the MEMS scanner 30 starts from the start position S6A or S6B of the scan surface, and a linear scan is performed on each column (Y-direction column) while reciprocating in the X direction at a constant pitch PT2 (equal to the pitch in the Y direction of the arrangement of the microlenses 41) in the Y direction, and ends at the end position E6A or E6B of the scan surface. The scanner control unit 52 and the MEMS scanner 30 can maintain the output state of the display images VI1 and VI2 by repeating such one scan shown in fig. 6A and one scan shown in fig. 6B continuously in time.

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

In this case, the upper-side scanning pattern is composed of a straight line pattern in the X direction (an example of a first straight line pattern) based on the scanning L601 shown in fig. 6A, and the lower-side scanning pattern is composed of a straight line pattern in the X direction (an example of a second straight line pattern) based on the scanning L602 shown in fig. 6A. In this case as well, as shown in fig. 5, the laser light (laser light corresponding to the upper image signal) scanned in the upper scanning pattern enters a position shifted by a predetermined amount α in the Y direction Y1 side from the center O of the microlens 41 (see arrow R51). In this case, the 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 (laser light corresponding to the lower image signal) scanned by the lower scanning pattern enters a position shifted by a predetermined amount β from the center O of the microlens 41 toward the Y2 (see arrow R52).

Therefore, according to the upper side scanning pattern and the lower side scanning pattern shown in fig. 6A and 6B, the display image VI1 can be generated by the laser light (laser light corresponding to the upper side image signal) scanned by the upper side scanning pattern, and the display image VI2 can be generated by the laser light (laser light corresponding to the lower side image signal) scanned by the lower side scanning pattern.

Here, in the present embodiment, as described above, since the single scan is composed of only the upper side scan pattern or the lower side scan pattern, unlike the scan pattern in which the upper side scan pattern and the lower side scan pattern are combined, the pitch in the Y direction in the single scan can be set to the constant pitch PT2 which is relatively large. This makes it possible to reduce the resolution of the change in the orientation of the MEMS scanner 30 (the resolution of the change in the orientation with respect to the pitch in the Y direction) required to achieve such scanning, and therefore, the control of the MEMS scanner 30 becomes relatively easy.

In addition, in the present embodiment, the display images VI1 and VI2 can be generated substantially simultaneously by performing the one-time scanning shown in fig. 6A and the one-time scanning shown in fig. 6B in close temporal proximity. Therefore, the driver can continuously view the display images VI1 and VI2 by moving the viewpoint in the vertical direction only such that the viewpoint is relatively moved upward when he wants to view the display image VI1 and downward when he wants to view the display image VI 2. As described above, according to the present embodiment, the display images VI1 and VI2 can be generated in an appropriate form in a configuration in which the visible display images VI1 and VI2 are changed only by changing the viewpoint in the vertical direction.

In the present embodiment, the one-time scanning shown in fig. 6A and the one-time scanning shown in fig. 6B are alternately performed every time, and may be alternately performed every several times when the one-time scanning time is sufficiently short.

[ example 3]

Fig. 7A and 7B are explanatory views showing an upper side scanning pattern and a lower side scanning pattern of still another embodiment (embodiment 3).

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 a linear scan is performed for each column (column in the Y direction) from one end side (X1 side) to the other end side (X2 side) in the X direction while shifting the predetermined pitch PT2 in the Y direction, and ends at the end position E7A of the scanning surface. In the example shown in fig. 7B, the scanning of each column (Y-direction column) is performed linearly from the other end side (X2 side) to the one end side (X1 side) in the X direction with a shift of the predetermined pitch PT2 in the Y direction from the start position S7B of the scanning surface to the end position E7B of the scanning surface, while one scanning by the scanner control unit 52 and the MEMS scanner 30 is started from the start position S7B of the scanning surface. The scanner control unit 52 and the MEMS scanner 30 can maintain the output state of the display images VI1 and VI2 by repeating such one scan shown in fig. 7A and one scan shown in fig. 7B continuously in time.

In the example shown in fig. 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 located on opposite sides in the X direction. Specifically, the start position S7A is located on the X-direction X1 side, and the Y-direction position thereof is shifted by a predetermined amount α from the center O of the microlens 41 toward the Y1 side in the Y direction. On the other hand, the start position S7B is located on the X-direction X2 side, and the Y-direction position thereof is shifted by a predetermined amount β from the center O of the microlens 41 toward the Y2 side in the Y direction.

In this case, the upper-side scanning pattern is realized by one scan shown in fig. 7A, and is composed of a straight line pattern (one example of the first straight line pattern) in the X direction based on the scan L701. Further, the lower-side scanning pattern is realized by one scan shown in fig. 7B, and is composed of a straight line pattern (one example of a second straight line pattern) in the X direction based on the scan L702. In this case as well, as shown in fig. 5, the laser light (laser light corresponding to the upper image signal) scanned in the upper scanning pattern enters a position shifted by a predetermined amount α in the Y direction Y1 side from the center O of the microlens 41 (see arrow R51). In this case, the 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 (laser light corresponding to the lower image signal) scanned by the lower scanning pattern enters a position shifted by a predetermined amount β from the center O of the microlens 41 toward the Y2 (see arrow R52).

Therefore, according to the upper side scanning pattern and the lower side scanning pattern shown in fig. 7A and 7B, the display image VI1 can be generated by the laser light (laser light corresponding to the upper side image signal) scanned by the upper side scanning pattern, and the display image VI2 can be generated by the laser light (laser light corresponding to the lower side image signal) scanned by the lower side scanning pattern.

In addition, in the present embodiment, the control contents of the MEMS scanner 30 for realizing the scanning shown in fig. 7A and 7B can be set to be the same as the example shown in fig. 4. In this case, only the control of the laser unit 10 is different. In addition, if the scanning shown in fig. 4 is the "progressive scanning method", the scanning shown in fig. 7A and 7B can be referred to as the "interlace scanning method".

Here, in the present embodiment, as described above, since the single scan is composed of only the upper side scan pattern or the lower side scan pattern, unlike the scan pattern in which the upper side scan pattern and the lower side scan pattern are combined, the pitch in the Y direction in the single scan can be set to the constant pitch PT2 which is relatively large. Further, since the one-time scanning shown in fig. 7A and the one-time scanning shown in fig. 7B are the same as the control content of the MEMS scanner 30 itself (only the control of the laser unit 10 is different), the control content of the MEMS scanner 30 (i.e., the pattern of the movement of the MEMS scanner 30) does not need to be switched every time of scanning, and the processing load can be reduced.

In addition, in the present embodiment, the display images VI1 and VI2 can be generated substantially simultaneously by performing the one-time scanning shown in fig. 7A and the one-time scanning shown in fig. 7B in close temporal proximity. Therefore, the driver can continuously view the display images VI1 and VI2 by moving the viewpoint in the vertical direction only such that the viewpoint is relatively moved upward when he wants to view the display image VI1 and downward when he wants to view the display image VI 2. As described above, according to the present embodiment, the display images VI1 and VI2 can be generated in an appropriate form in a configuration in which the visible display images VI1 and VI2 are changed only by changing the viewpoint in the vertical direction.

In this embodiment, the one-time scanning shown in fig. 7A and the one-time scanning shown in fig. 7B are alternately performed every time, and may be alternately performed every several times when the one-time scanning time is sufficiently short.

In the present embodiment, the control contents of the MEMS scanner 30 of one scan shown in fig. 7A and one scan shown in fig. 7B are the same, but the present invention is not limited thereto. For example, the start position of one scan shown in fig. 7B may be set to the start position S6B shown in fig. 6B. In this case, one scan starts from the start position S6B of the scanning surface, and a linear scan is performed on each column (column in the Y direction) from one end side (X1 side) to the other end side (X2 side) in the X direction while shifting the predetermined pitch PT2 in the Y direction, and ends at the end position E7B' (see fig. 7B) of the scanning surface.

[ example 4]

Fig. 8A to 8C and fig. 9 are explanatory views showing an upper side scanning pattern and a lower side scanning pattern of still another embodiment (embodiment 4).

In the example shown in fig. 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 surface, and a linear scan reciprocating in the X direction while shifting the predetermined pitch PT8A or PT8B in the Y direction is performed on a part of the columns (columns in the Y direction), and ends at the end position E8A, E8B, or E8C of the scan surface. The scanner control unit 52 and the MEMS scanner 30 can maintain the output states of the display images VI1 and VI2 by repeating 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).

The predetermined pitch PT8A is larger than the pitch PT2 (the pitch in the Y direction of the arrangement of the microlenses 41), and matches the length obtained by adding a predetermined offset amount (α + β) to the pitch PT 2. The predetermined pitch PT8B is larger than the pitch PT2 (i.e., the pitch in the Y direction of the arrangement of the microlenses 41), and matches the pitch PT2 plus a differential offset. As described above, the differential offset amount is a length obtained by subtracting a predetermined offset amount (α + β) from the size of the microlens 41 in the Y direction (i.e., the pitch PT2 in the Y direction). Therefore, the predetermined pitch PT8B is a length obtained by subtracting a predetermined offset amount (α + β) from twice the size of the microlens 41 in the Y direction (the pitch PT2 in the Y direction).

In the example shown in fig. 8A to 8C, the start positions S8A, S8B, and S8C are all located on the X direction X1 side, and the position in the Y direction of the start position S8A is shifted by a predetermined amount α to the Y direction Y1 side from the center O of the microlens 41. The start position S8B is shifted from the start position S8A toward the Y2 side by a predetermined shift amount (═ α + β). The start position S8C is shifted toward the Y direction Y2 side by the differential shift amount with respect to the start position S8B.

In this case, the scanning pattern for the upper side is composed of a straight line pattern (one example of a first straight line pattern) in the X direction based on the scanning L801 shown in fig. 8A to 8C, and the scanning pattern for the lower side is composed of a straight line pattern (one example of a second straight line pattern) in the X direction based on the scanning L802 shown in fig. 8A to 8C. That is, the upper side scanning pattern and the lower side scanning pattern are realized by the cooperation of the three scans shown in fig. 8A to 8C. In this case as well, as shown in fig. 5, the laser light (laser light corresponding to the upper image signal) scanned in the upper scanning pattern enters a position shifted by a predetermined amount α in the Y direction Y1 side from the center O of the microlens 41 (see arrow R51). In this case, the 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 (laser light corresponding to the lower image signal) scanned by the lower scanning pattern enters a position shifted by a predetermined amount β from the center O of the microlens 41 toward the Y2 in the Y direction (see arrow R52).

Therefore, according to the upper side scanning pattern and the lower side scanning pattern shown in fig. 8A to 8C, the display image VI1 can be generated by the laser light (laser light corresponding to the upper side image signal) scanned by the upper side scanning pattern, and the display image VI2 can be generated by the laser light (laser light corresponding to the lower side image signal) scanned by the lower side scanning pattern.

Here, in the present embodiment, since three scans are performed to generate the display images VI1 and VI2 corresponding to 1 frame as described above, the pitches in the Y direction in one scan can be set to the relatively large predetermined pitches PT8A and PT 8B. This makes it possible to reduce the resolution of the change in the orientation of the MEMS scanner 30 required to realize such scanning, and therefore, the control of the MEMS scanner 30 becomes relatively easy.

In the present embodiment, as described above, three scans are performed to generate the display images VI1 and VI2 corresponding to 1 frame, but four or more scans may be performed to generate the display images VI1 and VI2 corresponding to 1 frame.

While the embodiments have been described in detail, the present invention is not limited to the specific embodiments, and various modifications and changes can be made within the scope of the claims. All or a plurality of the constituent elements of the above-described embodiments may be combined.

For example, in the above-described embodiments, the display images VI1, VI2 are generated by all the microlenses 41 forming the screen 40, respectively. Therefore, the present embodiment is advantageous in that the display images VI1, VI2 having a relatively large size can be generated (or the resolution of the display images VI1, VI2 can be increased if the display images VI1, VI2 have the same size) as compared with the case where the display images are generated by using a part of the microlenses 41 forming the screen 40. However, in the modification, the display image VI1 and/or the display image VI2 may be generated by a part of the microlenses 41 forming the screen 40. For example, each of the upper-side scanning pattern and the lower-side scanning pattern may be a pattern for scanning only a part of the rows in the Y direction of the microlenses 41. Similarly, each of the upper scanning pattern and the lower scanning pattern may be a pattern for scanning only a part of the rows of the microlenses 41 in the X direction.

In the above embodiments, the different display images VI1 and VI2 are visible from two viewpoints shifted in the vertical direction, but the present invention is not limited to this. For example, a configuration may be adopted in which different display images are visually recognized at three or more different viewpoints in the vertical direction.

In addition, in the above-described embodiments, the feedback control is not performed on the projection position of the laser light 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 in which light receiving elements are arranged may be provided to perform feedback control on the projection position of the laser light on the screen 40.

In 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 another passenger (e.g., a passenger in a passenger seat or a rear seat) can be viewed.

Description of the symbols

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 Screen

41 micro lens

50 control device

51 laser control part

52 scanner control part

Claims

1. A head-up display for displaying a display image visually recognizable to an occupant, comprising:

an emission mechanism that emits laser light;

a plurality of optical elements regularly arranged in a plane defined by orthogonal first and second directions, diffusing the incident laser light; and

2. The heads-up display of claim 1,

the plurality of optical elements are arranged in M columns in the first direction and arranged in N columns in the second direction,

the optical elements of more than one column are the optical elements of the N columns,

the first and second linear patterns are patterns scanned from one end to the other end of the M columns.

3. The heads-up display of claim 2 wherein,

the scanning mechanism starts scanning once from a start position of the scanning surface, performs linear scanning reciprocating in the first direction while shifting each of the N rows by a predetermined pitch in the second direction, and ends the scanning once at an end position of the scanning surface,

the predetermined pitch varies between the predetermined offset amount and a length obtained by subtracting the predetermined offset amount from the pitch between the N columns in the second direction,

a scanning pattern related to the one-time scanning is composed of the first straight line pattern for each of the N columns and a second straight line pattern for each of the N columns.

4. The heads-up display of claim 2,

the scanning mechanism starts scanning once from a start position of the scanning surface, performs linear scanning reciprocating in the first direction while shifting each of the N rows by a certain pitch in the second direction, and ends the scanning once at an end position of the scanning surface,

the certain pitch corresponds to a pitch between the N columns in the second direction,

the scanning pattern relating to a certain scanning is composed of the first straight line pattern for each of the N columns, and the scanning pattern relating to a scanning, which follows the scanning pattern relating to the certain scanning and in which the start position changes by the prescribed offset amount in the second direction, is composed of the second straight line pattern for each of the N columns.

5. The heads-up display of claim 2 wherein,

the scanning mechanism starts scanning once from a start position of the scanning surface, performs scanning of a straight line from one end side of the first direction to the other end side of the first direction along the first direction with a shift of a certain pitch in the second direction or performs scanning of a straight line from the other end side of the first direction to one end side of the first direction along the first direction with a shift of a certain pitch in the second direction, on the N columns, and ends the scanning once at an end position of the scanning surface,

the certain pitch corresponds to a pitch between the N columns of the second direction,

a scan pattern related to a certain one of the scans based on the linear scan from the other end side of the first direction toward the one end side of the first direction is composed of the first linear pattern for each of the N columns, and a scan pattern related to a scan based on a linear one of the scans from the one end side of the first direction toward the other end side of the first direction immediately after the scan pattern related to the one of the scans is composed of the second linear pattern for each of the N columns.

6. The heads-up display of claim 5,

the scanning mechanism includes a scanner capable of electronic control of orientation,

the movement of the scanner is the same as the one scan shown and the one scan immediately following the scan pattern associated with the one scan.

7. The heads-up display of claim 2 wherein,

the scanning mechanism starts scanning once from a start position of the scanning surface, performs linear scanning reciprocating in the first direction while shifting a portion of the N rows by a predetermined pitch in the second direction, and ends the scanning once at an 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 is changed by the predetermined offset amount in the second direction or by a length obtained by subtracting the predetermined offset amount from the pitch between the N columns in the second direction every time scanning is performed,

a scanning pattern related to consecutive three-time scanning is composed of the first straight line pattern for each of the N columns and a second straight line pattern for each of the N columns.

8. The head-up display according to any one of claims 1 to 7,

the predetermined offset amount is related to a distance in an up-down direction between the first viewpoint and the second viewpoint.