Head-up display

Abstract

To provide a head-up display capable of various different presentations.SOLUTION: In the present embodiment, a head-up display 1 is a head-up display that displays a first image by projecting first display light and displays a second image at a position different from that of the first image by projecting second display light. The head-up display 1 includes a first speaker 41a that outputs first-image audio S1 corresponding to the first image in a first direction when the first image is displayed, and a second speaker 41b that outputs second-image audio S2 corresponding to the second image in a second direction different from the first direction when the second image is displayed.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] A head-up display (HUD) is a type of display that reflects a display light from a reflective member such as a windshield of a vehicle, allowing an image to be viewed from multiple locations inside and outside the vehicle. A sound is also output from a speaker in accordance with the image. [Prior art documents] [Patent documents]

[0003] [Patent Document 2] Patent Publication No. 2021-085990 Summary of the Invention [Problem to be solved by the invention]

[0004] A head-up display can switch the display position of an image between the inside and outside of a vehicle by, for example, changing the arrangement of optical elements to change the focal length of light emitted from a common light source. This allows the head-up display to create a visual presentation that suits the content of the image. For example, during autonomous driving, a character may be displayed as an assistant that provides various information to support the driver. During manual driving, information necessary for driving and warnings may be displayed. In such cases, if the content, type, and position of the display are different but the audio output source and output direction are constant, there is a problem of a lack of realism.

[0005] The present disclosure has been made in consideration of these circumstances, and aims to provide a head-up display capable of producing a variety of effects. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the head-up display of the present disclosure is a head-up display that projects a first display light to display a first image and projects a second display light to display a second image at a position different from the first image, and is equipped with a first speaker that outputs a first image sound corresponding to the first image in a first direction when the first image is displayed, and a second speaker that outputs a second image sound corresponding to the second image in a second direction different from the first direction when the second image is displayed. [Effects of the Invention]

[0007] The head-up display of the present disclosure is capable of producing a variety of effects. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing an example of a system configuration of an embodiment of a HUD according to the present disclosure. [Figure 2] FIG. 1 is a diagram showing an example of a system configuration of an embodiment of a HUD according to the present disclosure. [Figure 3] An overhead view of the HUD to explain the placement of the speakers. [Figure 4] FIG. 1 is an illustration of a HUD particularly showing the placement of the right speaker. [Figure 5] FIG. 1 is an illustration of a HUD particularly showing the placement of the left speaker. [Figure 6] FIG. 10 is an overhead view of a modified HUD that outputs audio for virtual images. [Figure 7] An overhead view of a modified HUD that outputs audio for real images. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of a head-up display (hereinafter referred to as a "HUD") according to the present disclosure will be described with reference to the accompanying drawings. The HUD according to the present disclosure can be applied to HUDs mounted on vehicles such as automobiles, agricultural machinery, and construction machinery.

[0010] FIG. 1 is a diagram showing an example of the system configuration of an embodiment of a HUD according to the present disclosure, and is an explanatory diagram showing the display of a virtual image V. FIG. 2 is a diagram showing an example of the system configuration of an embodiment of the HUD of the present disclosure, and is an explanatory diagram when a real image R is displayed.

[0011] In the following description, "front," "rear," "upper," "lower," "left," and "right" follow the definitions of "Fr.", "Re.", "To.", "Bo.", "L," and "R" in Figures 1 to 7.

[0012] The HUD 1 is mounted, for example, in an instrument panel in front of the front seats of a vehicle. The HUD 1 projects and reflects display lights L1 and L2 from the rear and below onto a windshield 10 (a reflective member) of the vehicle. The HUD 1 displays an aerial image consisting of a virtual image V (first image) associated with the display light L1 (first display light) on the outer surface 10b (front) of the windshield 10, i.e., outside the vehicle, in front of the vehicle, for a viewer 3 (e.g., the driver) who is a passenger in the vehicle to view. The HUD 1 also displays an aerial image consisting of a real image R (second image) associated with the display light L2 (second display light) on the inner surface 10a (rear) of the windshield 10, i.e., inside the vehicle, for a viewer 3 to view. The HUD 1 displays the virtual image V and the real image R at different positions. The HUD 1 forms an eyebox 4, which is an area where the viewer 3's viewpoint is expected to be located, and which is an area where the virtual image V and the real image R are visible. The viewer 3 can view the virtual image V and real image R displayed by the HUD 1 by positioning the viewpoint within the eyebox 4. On the other hand, if the viewer 3 positions the viewpoint outside the eyebox 4, at least a portion of the virtual image V and real image R becomes invisible (difficult to view).

[0013] The display light L1 relates to images that are displayed, for example, during manual driving of the vehicle, to provide information necessary for driving, such as driving speed, engine RPM, blind spot indicator, warning information such as speed limit exceeding warning, route guidance information, etc. The display light L2 relates to images (contents) that are displayed, for example, during automatic driving of the vehicle or when the vehicle is stopped, to provide characters (assistants, agents) that provide various information to support the driver as the viewer 3, and to provide entertainment (videos, music) to the viewer 3.

[0014] The HUD 1 includes an image generating unit 21, a first mirror 31, a second mirror 32, a third mirror 33, a speaker 41 (see FIG. 3), and a housing 35.

[0015] The image generation unit 21 generates a display light L1 associated with the virtual image V and a display light L2 associated with the real image R. The image generation unit 21 includes a light source 22, a display element 23, a switching element 24, and a control unit 25.

[0016] The light source 22 is, for example, a light emitting diode (LED) that emits light in the visible wavelength range and is mounted on a wiring board. The light emitted from the light source 22 is homogenized by passing through optical members such as a condenser lens, a lenticular lens, and a diffusion plate, and is then emitted to the display element 23.

[0017] The display element 23 is, for example, a TFT (Thin Film Transistor) liquid crystal display element. The display element 23 generates light that becomes display light L1 related to the virtual image V and display light L2 related to the real image R, using light emitted from the optical member as backlight.

[0018] The switching element 24 extracts S-polarized or P-polarized light as a specific polarization from the light emitted from the display element 23. Specifically, the switching element 24 switches the extracted light between an S-polarized component and a P-polarized component, and passes only one of the polarization components. The switching element 24 switches the polarization component to pass by electrical control based on whether or not a current is applied. Here, the S-polarized component of the display light emitted from the display element 23 is designated as display light L1, and the P-polarized component is designated as display light L2.

[0019] The control unit 25 controls the lighting of the light source 22. The control unit 25 also controls the display element 23 to generate required display light. Furthermore, the control unit 25 controls the switching element 24 so that the switching element 24 switches the display light that it emits.

[0020] The first mirror 31, the second mirror 32, and the third mirror 33 are flat or curved mirrors. The first mirror 31 reflects the display light L1, which is an S-polarized component, and transmits the display light L2, which is a P-polarized component. The second mirror 32 reflects the display light L2 that passes through the first mirror 31. As shown in FIG. 2, since the first mirror 31 is a mirror that transmits the display light L2, the display light L2 reflected by the second mirror 32 naturally passes from the back side to the front side of the first mirror 31. Therefore, the display light L2 reflected by the second mirror 32 passes through the first mirror 31 again and is guided to the third mirror 33. This allows the second mirror 32 to be disposed close to the first mirror 31, thereby preventing the housing 35 from becoming large.

[0021] The display lights L1 and L2 reflected by the first mirror 31 and the second mirror 32 are guided to the third mirror 33. The third mirror 33 reflects the display lights L1 and L2 toward the windshield 10. The third mirror 33 also has a drive unit (not shown) that is driven based on the control of the control unit 25, and rotates around a rotation axis 34. This allows the third mirror 33 to change the reflection direction of the incident light.

[0022] When a virtual image V and a real image R are displayed, the speaker 41 outputs a virtual image sound S1 (first image sound) corresponding to the virtual image V and a real image sound S2 (second image sound) corresponding to the real image R. Here, FIG. 3 is an overhead view of the HUD 1 to particularly explain the arrangement of the speakers 41. FIG. 4 is an explanatory diagram of the HUD 1 particularly showing the arrangement of the right speaker 41a. FIG. 5 is an explanatory diagram of the HUD 1 particularly showing the arrangement of the left speaker 41b.

[0023] The speaker 41 is, for example, a parametric speaker that uses ultrasonic waves. Because a parametric speaker has high directivity, it can selectively output sound to a viewer 3 (for example, a driver) in a specific narrow range. The speaker 41 has, for example, a right speaker 41a (first speaker) and a left speaker 41b (second speaker).

[0024] The right speaker 41a is disposed to the right of the cover 36 inside the housing 35, and outputs the virtual image sound S1 in a first direction. Specifically, the right speaker 41a outputs the virtual image sound S1 in a direction that is substantially the same as the direction in which the third mirror 33 emits the display light L1 toward the windshield 10, and in which the sound is reflected by the windshield 10 and heads toward the viewer 3.

[0025] The left speaker 41b is disposed to the left of the cover 36 inside the housing 35, and outputs the real image sound S2 in a second direction different from the first direction. Specifically, the left speaker 41b outputs the real image sound S2 in a direction directly toward the viewer 3. The left speaker 41b is preferably disposed particularly below the display position of the real image R (for example, at a position equal in the front-to-back direction).

[0026] The housing 35 supports and houses the image generating unit 21, the first mirror 31, the second mirror 32, the third mirror 33, and the speaker 41. The housing 35 has an opening above the third mirror 33, through which the display lights L1 and L2 reflected by the third mirror 33 are emitted to the outside of the housing 35. The opening is covered with a cover 36 to prevent dust and other particles from entering the housing 35. The housing 35 also has a hole 37 above the speaker 41 that emits sound from the speaker 41 to the outside.

[0027] Next, the operation of the HUD 1 in this embodiment when displaying an aerial image will be described.

[0028] When the HUD 1 displays an aerial image consisting of a virtual image V, the image generation unit 21 emits display light L1 related to the virtual image V, as shown in FIG. 1 . That is, under the control of the control unit 25, the image generation unit 21 causes the display element 23 to generate an image using light emitted from the light source 22 to display the virtual image V, and further causes the switching element 24 to emit display light L1 consisting of the S-polarized component of the display light. The display light L1 is reflected sequentially by the first mirror 31 and the third mirror 33, and is emitted from the opening (cover 36). The emitted display light L1 is reflected by the windshield 10 toward the viewer 3 and is viewed by the viewer 3.

[0029] Here, when the first mirror 31, the third mirror 33, and the windshield 10 are considered to be a single imaging optical system, by arranging the image generating unit 21 sufficiently close to the first mirror 31, the composite focus F1 of the imaging optical system is located in front of the light source 22 (on the side where the light travels). By setting the position of the composite focus F1 in this way, the HUD 1 causes the virtual image V to be visible on the outer surface 10b side of the windshield 10, i.e., in front of the vehicle.

[0030] On the other hand, when the HUD 1 displays an aerial image consisting of a real image R, the image generation unit 21 emits display light L2 corresponding to the real image R, as shown in Fig. 2. That is, in the image generation unit 21, under the control of the control unit 25, the display element 23 generates an image using light emitted from the light source 22 to display the real image R, and the switching element 24 further emits display light L2 consisting of a P-polarized component of the display light. The display light L2 passes through the first mirror 31, is reflected sequentially by the second mirror 32 and the third mirror 33, and is emitted from the opening (cover 36). The emitted display light L2 is reflected by the windshield 10 toward the viewer 3 and is viewed by the viewer 3.

[0031] Here, when the second mirror 32, the third mirror 33, and the windshield 10 are considered to be a single imaging optical system, by arranging the image generating unit 21 at a position sufficiently far from the second mirror 32, the composite focus F2 of the imaging optical system is positioned after the light source 22. By setting the position of the composite focus F2 in this way, the HUD 1 allows the real image R to be viewed on the inner surface 10a side of the windshield 10, i.e., inside the vehicle.

[0032] In this way, the HUD 1 projects and reflects display light L1 made of S-polarized light onto the windshield 10 from the inner surface 10a of the windshield 10, causing a virtual image V made of S-polarized light to be viewed on the outer surface 10b of the windshield 10. The HUD 1 also projects and reflects display light L2 made of P-polarized light onto the windshield 10 from the inner surface 10a of the windshield 10, causing a real image R to be viewed on the inner surface 10a of the windshield 10. The HUD 1 displays the virtual image V during manual driving and the real image R during automatic driving or when the vehicle is stopped, for example, based on control by a vehicle ECU that comprehensively controls the vehicle.

[0033] Here, when the HUD 1 displays the virtual image V and the real image R, the HUD 1 outputs sound from the speaker 41 as described above. Specifically, the right speaker 41a outputs the virtual image sound S1 corresponding to the virtual image V when it is displayed. At this time, the virtual image sound S1 is emitted, for example, from the opening (hole 37) of the HUD 1 to the outside of the housing 35, similar to the optical path of the display light L1, and is then reflected by the windshield 10 to reach the viewer 3 of the virtual image V. Therefore, the viewer 3 perceives the virtual image sound S1 as being emitted from a virtual point Z on an extension line of the virtual image sound S1 reflected by the windshield 10 in a direction toward the outer surface 10b of the windshield 10, and has the illusion that the sound is emanating from the virtual image V.

[0034] Furthermore, the left speaker 41b outputs a real image sound S2 corresponding to the real image R when the real image R is displayed. At this time, the real image sound S2 is emitted from, for example, an opening (hole 37) of the HUD 1 to the outside of the housing 35, and then reaches the viewer 3 of the real image R directly. Furthermore, as shown in FIG. 5, the left speaker 41b is disposed below the display position of the real image R in the left-right view, and emits the real image sound S2. The viewer 3 hears the real image sound S2 from below the real image R, and therefore has the illusion that the sound is emanating from the real image R.

[0035] Therefore, the HUD 1 of this embodiment varies the output position of the sound corresponding to the image depending on the display position of the image, and the sound is emitted from near the display position, allowing for a variety of effects. Also, the HUD 1 is designed so that the output direction of the sound from the speaker 41 (the arrangement of the speaker 41) is such that the sound appears to be emitted from the display position of the image, so that the output of the sound corresponding to the image can have a sense of realism.

[0036] Although the speaker 41 has been described using an example in which it has a right speaker 41a for the virtual image V and a left speaker 41b for the real image R, it may have two speakers, one for the right ear and one for the left ear of the viewer 3. Fig. 6 is an overhead view of a modified HUD 1 that outputs sound S1 for a virtual image. Fig. 7 is an overhead view of a modified HUD 1 that outputs sound S2 for a real image.

[0037] The speaker 41 includes a right speaker 41c and a left speaker 41d, which are disposed on the right and left sides, respectively, within the housing 35. The speaker 41 is a parametric speaker that uses ultrasonic waves, and its directivity can be varied by controlling the ultrasonic waves. Alternatively, the speaker 41 itself may have a rotation mechanism, and its directivity can be varied by controlling the rotation of the speaker 41. The right speaker 41c and the left speaker 41d simultaneously output sounds when an image is displayed. In other words, the right speaker 41c and the left speaker 41d also serve as speakers for the virtual image sound S1 and the virtual image sound S2 (the first speaker also serves as the second speaker).

[0038] When the virtual image sound S1 is output, the right speaker 41c serves as a right-ear speaker that outputs right-ear sound S1R directed to the right ear of the viewer 3. The left speaker 41d serves as a left-ear speaker that outputs left-ear sound S1L directed to the left ear of the viewer 3. That is, the right speaker 41c and the left speaker 41d serve as speakers (first speakers) that output the virtual image sound S1. Specifically, the right speaker 41c and the left speaker 41d reflect the virtual image sound S1 off the windshield 10, and output the reflected right-ear sound S1R and left-ear sound S1L in a direction (first direction) where extensions of the reflected right-ear sound S1R and left-ear sound S1L toward the outer surface 10b of the windshield 10 intersect at the display position of the virtual image V.

[0039] Furthermore, when the real image sound S2 is output, the right speaker 41c serves as a left-ear speaker that outputs left-ear sound S2L directed to the left ear of the viewer 3. The left speaker 41d serves as a right-ear speaker that outputs right-ear sound S2R directed to the right ear of the viewer 3. That is, the right speaker 41c and the left speaker 41d serve as speakers (second speakers) that output the virtual image sound S2. Specifically, the right speaker 41c and the left speaker 41d reflect the real image sound S2 from the windshield 10, and output the reflected right-ear sound S2R and left-ear sound S2L in a direction (second direction) toward the viewer 3, crossing each other. At this time, it is preferable that the right-ear sound S2R and left-ear sound S2L cross each other at positions where they overlap substantially in the front-rear and left-right directions with respect to the display position of the real image R, as shown in FIG. 7.

[0040] This modified HUD1 can create the illusion that the sound is coming from a position closer to the image, which gives the sound corresponding to the image a more realistic feel. Therefore, the modified HUD1 can be used in a wider variety of ways and can improve its marketability.

[0041] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the claims. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the inventions described in the claims and their equivalents.

[0042] For example, although the example has been described in which the first polarized light is S-polarized and the second polarized light is P-polarized, the first polarized light may be P-polarized and the second polarized light may be S-polarized. Furthermore, the first polarized light and the second polarized light are not limited to S-polarized and P-polarized light, as long as the polarization angles of the first polarized light and the second polarized light are different. In this case, for example, it is preferable that the difference in polarization angle between the first polarized light and the second polarized light is 22.5 degrees or more. Furthermore, the present invention is not limited to a method of switching between the real image R and the virtual image V by changing the polarization.

[0043] The placement of the two speakers is merely an example and is not limited thereto. For example, the speaker outputting the virtual image sound S1 may be placed on the left, and the speaker outputting the real image sound S2 may be placed on the right, or they may be placed in a front-to-back relationship. The speaker may be a single speaker that serves as both the first speaker and the second speaker, and the sound emission direction may be mechanically or electrically variable when outputting the virtual image sound and when outputting the real image sound. The at least two images displayed may be virtual images or real images as long as they are displayed at different positions, and the method of generating the images is not limited. For example, the images may be floating images displayed by passing through a microlens array.

[0044] The speaker is not limited to being located inside the housing, but may also be located outside the housing. [Explanation of symbols]

[0045] 1 Head-up display (HUD) 3. Viewer 4 Eye Box 10 Windshield 10a Inner surface 10b External surface 21 Image Generation Unit 22 Light source 23 Display element 24 Switching element 25 Control Unit 25 Optical Components 31 First Mirror 32 Second Mirror 33 Third Mirror 34 Rotation axis 35 cabinet 36 Cover 41 Speaker 41a, 41c Right speaker 41b, 41d left speaker 42 Light distribution control section F1, F2 composite focus L1, L2 display light R real image V Virtual Image S1 Virtual Image Sound S2 Real Image Audio S1L, S2L Left ear audio S1R, S2R Right ear audio Z virtual point

Claims

1. A head-up display that projects a first display light to display a first image and projects a second display light to display a second image at a position different from the first image, a first speaker that outputs a first image sound corresponding to the first image in a first direction when the first image is displayed; a second speaker that outputs a second image sound corresponding to the second image in a second direction different from the first direction when the second image is displayed.

2. The head-up display of claim 1 , wherein the first image is a virtual image and the second image is a real image.

3. the first indication light and the second indication light are projected onto a windshield having an inner surface and an outer surface; The virtual image is viewed from the outer surface side, The real image is viewed from the inner surface side, the first direction is a direction in which the first image sound is reflected by the windshield and directed toward a viewer of the virtual image; 3. The head-up display according to claim 2, wherein the second direction is a direction in which the second image sound is directed directly to the viewer or reflected by the windshield toward the viewer of the real image.

4. The head-up display according to claim 3 , wherein the second speaker is disposed below a display position of the real image.

5. the first speaker includes a right-ear speaker that outputs right-ear sound directed to the right ear and a left-ear speaker that outputs left-ear sound directed to the left ear, 4. The head-up display according to claim 3, wherein the first direction is a direction in which an extension line of the sound for the right ear and the sound for the left ear reflected by the windshield toward the outer surface of the windshield intersects at the display position of the virtual image.

6. the second speaker includes a right-ear speaker that outputs right-ear sound directed to the right ear and a left-ear speaker that outputs left-ear sound directed to the left ear, The head-up display according to claim 3 , wherein the second direction is a direction in which the sound for the right ear and the sound for the left ear reflected by the windshield intersect and head toward the viewer.

7. The head-up display according to claim 5 , wherein the right-ear sound and the left-ear sound intersect at an overlapping position in approximately the front-rear and left-right directions with respect to the display position of the real image.

8. The head-up display of claim 1 , wherein the first speaker and the second speaker are parametric speakers.

9. The head-up display according to claim 1 , wherein the first speaker also serves as the second speaker, has a rotation mechanism, and is capable of changing the direction in which sound is emitted.

10. 2. The head-up display according to claim 1, wherein the first speaker is a parametric speaker that also functions as the second speaker, and the sound emission direction of the first speaker is electrically variable.

Images