Head-up display device

Abstract

To provide a head-up display device capable of appropriately displaying a virtual image.SOLUTION: A head-up display device 1 comprises a housing 10 and a display unit 20. The housing 10 has an opening 11 facing a windshield WS, and the display unit 20 is attached to the housing. The display unit 20 is configured to include a display 21, a reflection mirror 22, and a transparent cover 23. The display 21 is housed in the interior of the housing 10 and emits display light L1. The reflection mirror 22 is housed in the interior of the housing 10, and reflects, toward the windshield WS through the opening 11, enlarged display light L2 resulting from enlarging the display light L1 emitted from the display 21. The transparent cover 23 is a cover sealing the opening 11 and transmitting light and has a freeform surface 232a correcting distortion of the enlarged display light L2 reflected by the reflection mirror 22.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a head-up display device. [Background technology]

[0002] As a conventional head-up display device, for example, Patent Document 1 describes a vehicle head-up display that displays a virtual image through the front windshield of the vehicle. This vehicle head-up display includes a housing that is disposed on the instrument panel of the vehicle and has an opening for emitting image light of an image, a display that is housed in the housing and emits image light of the image, a magnifying mirror that is housed in the housing and magnifies and reflects an image directly incident from the display, and a lens that closes the opening of the housing and magnifies the image incident from the magnifying mirror and outputs it to the front windshield. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-91104 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the vehicle head-up display described in the above-mentioned Patent Document 1, for example, when displaying a larger virtual image, it is difficult to correct the aberration of the virtual image using only a magnifying glass, and there is room for further improvement in this regard.

[0005] Therefore, the present invention has been made in consideration of the above, and has an object to provide a head-up display device that can properly display a virtual image. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the head-up display device of the present invention comprises a display unit that is installed in a vehicle and displays a virtual image by reflecting display light emitted toward a light-transmitting reflective member toward the eye point side by the reflective member, and a housing having an opening facing the reflective member and in which the display unit is assembled, wherein the display unit includes a display that is housed inside the housing and emits the display light, a reflective mirror that is housed inside the housing and reflects enlarged display light, which is an enlarged display light emitted from the display, toward the reflective member through the opening, and a transparent cover that closes the opening and transmits light, and has a free-form surface that performs aberration correction on the enlarged display light reflected by the reflective mirror. Effect of the Invention

[0007] The head-up display device according to the present invention can correct the aberration of the virtual image caused by the optical members including the reflecting member by using the free-form surface of the transparent cover. The head-up display device can properly perform the aberration correction and the enlargement process of the virtual image by dividing the roles such that the aberration correction function is mainly performed by the transparent cover and the enlargement function is mainly performed by the reflecting mirror. As a result, the head-up display device can properly display the virtual image. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing an example of the configuration of a head-up display device according to an embodiment. [Diagram 2] FIG. 2 is a perspective view showing an example of the configuration of a transparent cover according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The form (embodiment) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiment. Furthermore, the components described below include those that a person skilled in the art can easily imagine and those that are substantially the same. Furthermore, the configurations described below can be appropriately combined. Furthermore, various omissions, substitutions, or modifications of the configurations can be made without departing from the gist of the present invention.

[0010] [Embodiment] A head-up display device 1 according to an embodiment will be described with reference to the drawings. The head-up display device 1 is provided in a vehicle, and displays a virtual image S by reflecting display light L1 emitted toward a light-transmitting windshield WS toward an eye point EP by the windshield WS. Here, the windshield WS is an example of a reflecting member, and is a member formed in a plate shape from transparent glass, and is provided in front of the driver's seat to block wind. The head-up display device 1 may be an AR-HUD device that matches and superimposes a virtual image S on an object (e.g., a person, a sign, another vehicle, etc.) in front of the vehicle, or may be a HUD device that displays a virtual image S without matching the virtual image S with an object in front of the vehicle. The head-up display device 1 will be described in detail below.

[0011] Here, the direction along the width direction of the vehicle is referred to as the first direction X, the direction along the overall length direction of the vehicle is referred to as the second direction Y, and the direction along the up-down direction of the vehicle is referred to as the third direction Z. The second direction Y can also be said to be a direction along the straight-line direction in which the vehicle travels straight. The third direction Z can also be said to be a direction along the vertical direction. The first direction X, the second direction Y, and the third direction Z intersect with each other and are typically perpendicular to each other. The first direction X and the second direction Y can also be said to be directions along a horizontal plane perpendicular to the vertical direction.

[0012] The head-up display device 1 includes a housing 10 and a display unit 20, as shown in FIG.

[0013] The housing 10 is provided in a vehicle and has a display unit 20 attached thereto. The housing 10 is formed in a box shape, and houses a display 21 and a reflecting mirror 22 of the display unit 20, which will be described later, inside the housing 10. The housing 10 has an opening 11 that communicates between the inside and the outside. The opening 11 is provided opposite the windshield WS, and is a portion that is capable of transmitting light.

[0014] The display unit 20 displays a virtual image S by reflecting display light L1 emitted toward a windshield WS toward an eye point EP by the windshield WS. The display unit 20 includes a display 21, a reflecting mirror 22, and a transparent cover 23.

[0015] The display 21 emits display light L1 including an image, and is housed inside the housing 10. The display 21 includes, for example, a display and a backlight. The display forms an image, and is, for example, a TFT-LCD (Thin Film Transistor-Liquid Crystal Display). The backlight irradiates light onto the back of the display, and is, for example, a plurality of LEDs (light-emitting diodes). The display 21 emits display light L1 including an image from the display toward the reflecting mirror 22 by irradiating light onto the display using the backlight. The display 21 emits the display light L1 directly to the reflecting mirror 22, for example, without passing through another mirror. That is, no optical components are interposed between the display 21 and the reflecting mirror 22.

[0016] In this example, a part of the display 21 is accommodated inside the housing 10, and another part of the display 21 is exposed to the outside of the housing 10. Specifically, the display 21 has an emission part (e.g., a display) that emits display light L1 accommodated inside the housing 10, and a part of the display 21 other than the emission part (e.g., a backlight) is exposed to the outside of the housing 10.

[0017] The reflecting mirror 22 totally reflects light and is housed inside the housing 10. The reflecting mirror 22 has a reflecting surface 221 formed to be concave and aspherical. The reflecting surface 221 is disposed opposite the display 21 and opposite the transparent cover 23. The reflecting mirror 22 magnifies the display light L1 (image) emitted from the display 21 by the reflecting surface 221, and reflects the magnified magnified display light L2 toward the windshield WS through the opening 11 (transparent cover 23) of the housing 10. Specifically, the reflecting mirror 22 magnifies the display light L1 emitted directly from the display 21 without passing through another mirror by the reflecting surface 221, and reflects the magnified magnified display light L2 toward the windshield WS through the opening 11 (transparent cover 23) of the housing 10.

[0018] The transparent cover 23 is a cover that closes the opening 11 of the housing 10 and transmits light. The transparent cover 23 is formed in a curved plate shape using transparent resin, and closes the opening 11. The transparent cover 23 has a curved portion 230 that is curved toward the inside of the housing 2. That is, the curved portion 230 is formed in a concave shape toward the inside of the housing 2. As shown in FIG. 2, the curved portion 230 has an outer surface portion 231 as a second surface portion and an inner surface portion 232 as a first surface portion.

[0019] The outer surface portion 231 is a surface portion located on the opposite side to the reflecting mirror 22 side and curved toward the inside of the housing 2. That is, the outer surface portion 231 is a surface portion provided on the window shield WS side. The outer surface portion 231 reflects external light toward the inside back portion F. Here, the inside back portion F shields light and is erected on the opposite side of the eye point EP side of the opening 11. That is, the inside back portion F is a wall portion provided on the opposite side of the eye point EP side of the transparent cover 23 and extending along the third direction Z. In this example, the inside back portion F is provided at a slight incline toward the transparent cover 23 side. The outer surface portion 231 is formed in a shape that reflects external light incident from the outside of the housing 2 toward the inside back portion F. Specifically, the XZ cross section of the outer surface portion 231 cut along the first direction X and the third direction Z is formed in a straight line without being curved. Further, the outer side surface portion 231 has a YZ cross section cut along the second direction Y and the third direction Z formed in a curved shape with a curvature capable of reflecting external light toward the end cover portion F. The outer side surface portion 231 reflects external light incident from outside the housing 2 toward the end cover portion F.

[0020] The inner side surface portion 232 is located on the reflecting mirror 22 side, and is a surface portion formed to be curved toward the inside of the housing 2. In other words, the inner side surface portion 232 is a surface portion provided on the side opposite to the windshield WS side. The inner side surface portion 232 has a free-form surface 232a. The free-form surface 232a is a curved surface that cannot be expressed by a simple mathematical formula, such as a sphere or a cylinder. inThe free-form surface 232a is a curved surface expressed by, for example, setting a plurality of intersections and curvatures in space and interpolating the respective intersections with a high-order polynomial. The free-form surface 232a is formed in a shape that corrects the aberration of the virtual image S caused by optical members including the window shield WS. The free-form surface 232a is formed in a shape that corrects the aberration of the virtual image S caused by, for example, the shape of the window shield WS. The transparent cover 23 performs aberration correction on the enlarged display light L2 reflected by the reflecting mirror 22 with the free-form surface 232a. Then, the transparent cover 23 emits the enlarged display light L2 after the aberration correction by the free-form surface 232a toward the window shield WS. The enlarged display light L2 after the correction emitted toward the window shield WS is reflected by the window shield WS toward the eye point EP and is guided to the eye point EP.

[0021] As described above, the head-up display device 1 according to the embodiment includes a housing 10 and a display unit 20. The housing 10 has an opening 11 facing a windshield WS, and the display unit 20 is attached to the housing 10. The display unit 20 is provided in a vehicle and displays a virtual image S by reflecting the display light L1 emitted toward the light-transmitting windshield WS toward the eye point EP by the windshield WS. The display unit 20 includes a display 21, a reflecting mirror 22, and a transparent cover 23. The display 21 is accommodated inside the housing 10 and emits the display light L1. The reflecting mirror 22 is accommodated inside the housing 10 and reflects the enlarged display light L2, which is an enlarged version of the display light L1 emitted from the display 21, toward the windshield WS through the opening 11. The transparent cover 23 is a cover that closes the opening 11 and transmits light, and has a free-form surface 232a that performs aberration correction on the enlarged display light L2 reflected by the reflecting mirror 22.

[0022] With this configuration, the head-up display device 1 can correct the aberration of the virtual image S caused by optical members including the windshield WS, etc., by the free-form surface 232a of the transparent cover 23. The head-up display device 1 can improve the accuracy of the aberration correction and the magnification rate by dividing the roles by mainly assigning the aberration correction function to the transparent cover 23 and mainly assigning the magnification function to the reflection mirror 22. The head-up display device 1 can be easily manufactured because the parameter coefficients can be reduced by dividing the roles, and thus the tolerance can be reduced. In the head-up display device 1, the transparent cover 23 that closes the opening 11 of the housing 10 also serves the function of aberration correction, so that the number of parts can be suppressed and the size of the optical system can be suppressed. As a result, the head-up display device 1 can properly display the virtual image S.

[0023] In the head-up display device 1, the display 21 directly emits display light L1 to the reflecting mirror 22. The reflecting mirror 22 reflects magnified display light L2, which is the display light L1 directly emitted from the display 21, to the windshield WS via the transparent cover 23. With this configuration, the head-up display device 1 can be made compact because the display 21 directly emits the display light L1 to the reflecting mirror 22 without passing through another mirror.

[0024] In the head-up display device 1, the free curved surface 232a is formed on the reflective mirror 22 side of the transparent cover 23. With this configuration, the head-up display device 1 can appropriately reflect external light toward the facing portion F by the outer surface portion 231 on the opposite side of the transparent cover 23 from the reflective mirror 22 side.

[0025] In the above description, an example has been described in which the display 21 directly emits the display light L1 to the reflecting mirror 22 without passing through another mirror, but this is not limited to this, and the display light L1 may be indirectly emitted to the reflecting mirror 22 via another mirror.

[0026] Although the example in which the free curved surface 232a is formed on the reflection mirror 22 side of the transparent cover 23 has been described, the present invention is not limited to this, and the free curved surface 232a may be formed on the side of the transparent cover 23 opposite to the reflection mirror 22 side.

[0027] The transparent cover 23 may have a function of magnifying the magnified display light L2 (image) in addition to the function of correcting the aberration of the virtual image S by the free curved surface 232a. In this case, the transparent cover 23 magnifies the magnified display light L2 (image) at a magnification ratio smaller than that of the reflecting mirror 22. For example, the transparent cover 23 magnifies the magnified display light L2 (image) at a magnification ratio of about 1 / 10 of that of the reflecting mirror 22.

[0028] The reflecting mirror 22 may have a function of correcting the aberration of the virtual image S, in addition to the function of magnifying the display light L1 (image) by the reflecting surface 221. In this case, the reflecting mirror 22 corrects the aberration of the virtual image S with an aberration correction amount smaller than that of the transparent cover 23. For example, the reflecting mirror 22 corrects the aberration of the virtual image S with an aberration correction amount that is about 1 / 10 of the aberration correction amount of the transparent cover 23.

[0029] Although an example in which the reflective member is a windshield WS has been described, the reflective member is not limited to this and may be, for example, a combiner or the like. [Explanation of symbols]

[0030] 10. Chassis 11 Opening 20 Display unit 21 Display 22 Reflective mirror 23 Transparent cover 232a Free-form surface EP Eyepoint L1 display light L2 Enlarged display light S Virtual Image WS Window Shield (Reflective Material)

Claims

1. a display unit provided in the vehicle, the display unit emitting display light toward a light-transmitting reflective member and reflecting the display light toward an eye point by the reflective member, thereby displaying a virtual image; a housing having an opening facing the reflective member and in which the display unit is assembled; The display unit includes a display device that is accommodated in the housing and emits the display light; a reflecting mirror that is accommodated inside the housing and that reflects magnified display light obtained by magnifying the display light emitted from the display unit toward the reflecting member through the opening; a transparent cover that closes the opening and transmits light, the transparent cover having a free-form surface that performs aberration correction on the enlarged display light reflected by the reflection mirror, the transparent cover has a function of further magnifying the magnified display light by the free-form surface, magnifying the magnified display light at a magnification ratio smaller than that of the reflection mirror, being formed in a concave shape toward the inside of the housing, and having an outer surface portion and an inner surface portion; the reflecting mirror has a function of correcting the aberration of the virtual image, and corrects the aberration of the virtual image with an amount of aberration correction smaller than that of the transparent cover; The inner surface portion has the free curved surface. Head-up display device.

2. The display device directly emits the display light to the reflection mirror, The head-up display device according to claim 1 , wherein the reflection mirror reflects the magnified display light, which is obtained by magnifying the display light directly emitted from the display, to the reflection member via the transparent cover.

3. The head-up display device according to claim 1 or 2, wherein the free-form surface is formed on the transparent cover on a side facing the reflecting mirror.

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