Head-up-Display

Abstract

In the head-up display device (1), a transparent cover (23) includes an inner surface part (232) arranged on the side of a reflection mirror (22) and an outer surface part (231) arranged on a side opposite to the reflection mirror (22). The display light (L1) guided to an eye point (EP) includes a regular light (L1a) that passes through the transparent cover (23) without being reflected by the inner surface part (232) and the outer surface part (231) of the transparent cover (23) and is guided to the eye point (EP), and an irregular light (L1b) that passes through the transparent cover (23) after being reflected by the inner surface part (232) and the outer surface part (231) of the transparent cover (23) and is guided to the eye point (EP).The inner surface portion (232) of the transparent cover (23) has an incident surface (232b) with an incident angle of 65° or less. The incident angle is an angle at which the irregular light (L1b) enters the incident surface (232b).

Description

Field of invention

[0001] The present invention relates to a head-up display device. State of the art

[0002] As a prior art head-up display device, for example, Patent Literature 1 describes a vehicle head-up display that displays a virtual image in front of a windshield of a vehicle. This vehicle head-up display is mounted on a vehicle instrument panel and includes: a housing having an opening from which image light of an image is emitted; a display instrument housed in the housing and emitting image light of the image; a magnifier housed in the housing and magnifying and reflecting an image directly emitted from the display instrument; and a lens that blocks the opening of the housing and magnifies the image emitted by the magnifier and outputs it to the windshield. Patent literature

[0003] Patent Literature 1: Japanese Patent Application Laid-Open No. 2006-91104 SummaryProblem

[0004] However, in the head-up display device described in Patent Literature 1, there is a risk that a light propagating in the lens is visually perceived as a double image when it is guided to the eye point of an occupant.

[0005] The present invention addresses this problem, and an object of the present invention is to provide a head-up display device that can correctly display a virtual image. Problem solving

[0006] To solve the above-mentioned problem and achieve the object of the invention, a head-up display device according to the present invention comprises: a display unit provided in a vehicle and displaying a virtual image by reflecting a display light emitted to a light-transmitting reflection member to the side of an eye point by means of the reflection member; and a housing having an opening facing the reflection member and on which the display unit is mounted;wherein the display unit comprises a display instrument housed in the housing and emitting the display light, a reflection mirror housed in the housing and reflecting an enlarged display light obtained by magnifying the display light emitted by the display instrument through the opening to the reflection member, and a transparent cover blocking the opening and transmitting the enlarged display light reflected by the reflection mirror; wherein the transparent cover comprises a first surface part located on the side of the reflection mirror and a second surface part located on the side opposite to the reflection mirror;wherein the display light guided to the eye point comprises a regular light that passes through the transparent cover without being reflected by the first surface part and the second surface part of the transparent cover and is guided to the eye point, and an irregular light that passes through the transparent cover after being reflected by the first surface part and the second surface part of the transparent cover and is guided to the eye point; and wherein the first surface part of the transparent cover has an incident surface with an incident angle of 65° or less, the incident angle being the angle at which the irregular light enters the first surface part. Advantageous effects of the invention

[0007] Because the head-up display device according to the present invention can make the luminance of the irregular light directed to the eye point lower than the luminance of the regular light, a passenger can be prevented from visually perceiving a virtual image formed by the irregular light. The head-up display device can therefore prevent a virtual image formed by the irregular light from being visually perceived as a duplicate image and can accordingly correctly display a virtual image formed by the regular light. Brief description of the drawings Fig. 1 is a schematic view showing a configuration example of a head-up display device according to an embodiment. Fig. 2 is a perspective view showing a configuration example of a transparent cover according to the embodiment. Fig. 3 is a schematic view showing a regular light and an irregular light according to the embodiment. Description of embodiments

[0008] An embodiment of the present invention will be described in detail below with reference to the drawings. The present invention is not limited to the embodiment described herein. The components described herein can be implemented by components familiar to those skilled in the art or by substantially identical components. The various configurations described herein can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of configurations may be made without departing from the scope of the invention. [Embodiment]

[0009] A head-up display device 1 according to an embodiment will be described below with reference to the drawings. The head-up display device 1 is provided in a vehicle and displays a virtual image S by reflecting a display light L1 emitted toward a translucent windshield WS on the windshield WS to the side of an eyepoint EP. Here, the windshield WS is an example of a reflection member formed of a transparent glass in a plate shape, arranged in front of the driver's seat, and blocking wind. The head-up display device 1 may be an augmented reality head-up display device (AR-HUD) that displays the virtual image S in alignment with a target object (e.g., a person, an inscription, another vehicle, etc.) located in front of the vehicle.) superimposed, or may be a head-up display (HUD) device that displays the virtual image S without aligning the virtual image S with a target object located in front of the vehicle. The head-up display device 1 is described in detail below.

[0010] Here, the direction along the vehicle width direction of the vehicle is called a first direction X, the direction along the entire longitudinal direction of the vehicle is called a second direction Y, and the direction along the up-down direction of the vehicle is called a third direction Z. The second direction Y can also be called a direction along the direct traveling direction in which the vehicle travels straight ahead. The third direction Z can also be called a vertical direction. The first direction X, the second direction Y, and the third direction Z cross each other and are usually orthogonal to each other. In addition, the first direction X and the second direction Y can also be called directions along a horizontal surface that are orthogonal to each other in the vertical direction.

[0011] As in Fig. 1, the head-up display device 1 comprises a housing 10 and a display unit 20.

[0012] The housing 10 is provided on the vehicle, and the display unit 20 is mounted thereon. The housing 10 is box-shaped, and a display instrument 21 and a reflection mirror 22 of the display unit 20, which will be described later, are housed in the housing 10. The housing 10 has an opening 11 that connects the interior to the exterior. The opening 11 is a part facing the windshield WS and can transmit light.

[0013] The display unit 20 displays the virtual image s by reflecting the display light L1 emitted toward the windshield WS on the windshield WS toward the side of the eye point EP. The display unit 20 includes the display instrument 21, the reflection mirror 22, and a transparent cover 23.

[0014] The display instrument 21 emits the display light L1 with an image contained therein and is housed in the housing 10. The display instrument 21 includes, for example, a display and a backlight. The display generates an image and is, for example, a thin-film transistor liquid crystal display (TFT-LCD) or the like. The backlight emits light toward the back surface of the display and includes, for example, a plurality of LEDs. By emitting light toward the display using the backlight, the display instrument 21 emits the display light L1 with an image contained therein from the display to the reflection mirror 22. The display instrument 21 emits the display light L1 directly to the reflection mirror 22, for example, and not via another mirror. That is, no optical component is disposed between the display instrument 21 and the reflection mirror 22.

[0015] Furthermore, in the indicator 21 of this example, a part of the indicator 21 is housed in the housing 10, and another part of the indicator 21 is exposed outside the housing 10. Specifically, an emitting unit (e.g., the display) of the indicator 21 that emits the display light L1 is housed in the housing 10, and the other part (e.g., the backlight) as the emitting unit of the indicator 21 is exposed outside the housing 10.

[0016] The reflection mirror 22 fully reflects light and is housed in the housing 10. The reflection mirror 22 has a reflection surface 221 formed in a concave shape on an aspherical surface. The reflection surface 221 faces the indicator 21 and the transparent cover 23. Through the reflection surface 221, the reflection mirror 22 magnifies the display light L1 (image) emitted from the indicator 21 and reflects the magnified display light L2 obtained through the opening 11 (the transparent cover 23) of the housing 10 to the windshield WS.Specifically, the reflection mirror 22 magnifies the display light L1 emitted directly from the indicator 21 and not through another mirror through the reflection surface 221, and reflects the magnified display light L2 obtained by the magnification L2 through the opening 11 (the transparent cover 23) of the housing 10 to the windshield WS.

[0017] The transparent cover 23 is a cover that blocks the opening 11 of the housing 10 and allows light to pass through. The transparent cover 23 is formed from a transparent resin into a curved plate shape and blocks the opening 11. The transparent cover 23 includes a curved part 230 that is formed into a curved shape toward the interior of a housing 2. The curved part 230 is thus formed into a concave shape toward the interior of the housing 2. As shown in Fig. 2, the curved portion 230 includes an outer surface portion 231 serving as a second surface portion and an inner surface portion 232 serving as a first surface portion.

[0018] The outer surface part 231 is a surface part located on a side opposite to the reflection mirror 22 and formed with a curvature toward the interior of the housing 2. The outer surface part 231 is a surface part provided on the windshield WS side. The outer surface part 231 reflects external light to an opposing part F. The opposing part F shields light and is installed vertically on the side of the opening 11 opposite to the eye point EP. That is, the opposing part F is a wall part extending along the third direction Z on the side of the transparent cover 23 opposite to the eye point EP. In this example, the opposing part F is slightly inclined toward the side of the transparent cover 23. The outer surface part 231 is formed into a shape that reflects external light emitted from outside the housing 2 to the opposing part F.For example, the shape of the outer surface part 231 is curved in a similar direction to the inner surface part 232 to block external light. Thus, the shape of the outer surface part 231 is curved along the shape of the inner surface part 232. Specifically, the outer surface part 231 has an XZ cross-section along the first direction X and the third direction Z, which is linear and has no curvature. Furthermore, the outer surface part 231 has a YZ cross-section along the second direction Y and the third direction Z, which is curved and has a curvature that can reflect external light to the opposite part F. The outer surface part 231 reflects external light emitted from outside the housing 2 to the opposite part F.

[0019] The inner surface part 232 is a surface part arranged on the side of the reflection mirror 22, which is formed with a curvature towards the interior of the housing 2. The inner surface part 232 is therefore a surface part provided on the side opposite the windshield WS. As shown in Fig. 3, the inner surface part 232 has an incident surface 232b into which the magnified display light L2 reflected by the reflection mirror 22 enters. A free curved surface 232a is formed on the incident surface 232b. The free curved surface 232a is a curved surface that cannot be represented by a simple formula, unlike a sphere, a cylinder, etc. The free curved surface 232a is a curved surface represented by setting a plurality of intersections and a plurality of curvatures in a space and interpolating the intersections by a high-order polynomial. The free curved surface 232a is formed in a shape that corrects aberration of the virtual image S caused by an optical member including the windshield WS, etc.The freely curved surface 232a is formed, for example, with a shape that corrects an aberration of the virtual image S caused by the shape of the windshield WS. With the freely curved surface 232a, the transparent cover 23 performs aberration correction on the magnified display light L2 reflected by the reflection mirror 22. Then, the transparent cover 23 emits the corrected magnified display light L2, on which the aberration correction has been performed by the freely curved surface 232a, toward the windshield WS. The corrected magnified display light L2 emitted toward the windshield WS is reflected by the windshield WS toward the eye point EP side and guided to the eye point EP.

[0020] The display instrument 21 emits as in Fig. 1 by emitting light to the display (e.g., the TFT-LCD) using the backlight, the display light L1 with an image contained therein from the display to the reflection mirror 22. In this case, the display instrument 21 radially emits light (light rays) from individual pixels (dots) of a liquid crystal constituting the display. As shown in Fig.As shown in Figure 3, the display light L1 guided to the eye point EP sometimes includes a regular light 11a and an irregular light 11b different from the regular light L1a. The regular light L1a is a light that transmits through the transparent cover 23 without being reflected by the inner surface part 232 and the outer surface part 231 of the transparent cover 23 and is guided to the eye point EP. That is, the regular light L1a is a light that is guided to the eye point EP without being reflected in the transparent cover 23. The irregular light L1b is a light emitted from pixels (dots) of the same liquid crystal as the regular light L1a, which is transmitted through the transparent cover 23 after being reflected by the inner surface part 232 and the outer surface part 231 of the transparent cover 23 and is guided to the eye point EP.That is, the irregular light L1b is a light emitted from pixels (dots) of the same liquid crystal as the regular light L1a and guided to the eye point EP after being reflected in the transparent cover 23.

[0021] Because the irregular light L1b was conventionally guided to the eye point EP with substantially the same luminance as the regular light L1a, the virtual image S formed by the regular light L1a can be visually perceived, and a virtual image formed by the irregular light L1b is also visually perceived. Thus, the virtual images S are visually perceived as a double image.

[0022] In contrast, according to one embodiment, the inner surface portion 232 of the transparent cover 23 has the incident surface 232b with an incident angle θ of 65° or less. The incident angle θ is an angle at which the irregular light L1b enters the incident surface 232b. That is, the inner surface portion 232 of the transparent cover 23 is provided such that the incident angle θ at which the irregular light L1b enters the incident surface 232b is 65° or less. And because the outer surface part 231 of the transparent cover 23 is curved along the shape of the inner surface part 232, the incident angle at which the irregular light L1b enters an incident surface of the outer surface part 231 becomes approximately equal to the incident angle θ of the inner surface part 232. The incident angle θ is an angle with respect to a normal line N.Here, by setting the above-described incident angle θ to 65° or less, the head-up display device 1 can provide a relatively smaller reflectance with which the irregular light L1b is reflected in the transparent cover 23, and thus can set the luminance of the irregular light L1b with respect to the luminance of the regular light L1a to 2% or less. Because the luminance of the irregular light L1b with respect to the luminance of the regular light L1a becomes 2% or less in this way, the head-up display device 1 can prevent a virtual image formed by the irregular light L1b from being visually perceived even when the irregular light L1b is guided to the eye point EP.In addition, when setting the luminance of the irregular light L1b with respect to the luminance of the regular light L1a to 2% or less, the head-up display device 1 takes into account the material of the transparent cover 23, the reflectance of the inner surface part 232 and the outer surface part 231, etc.

[0023] As described above, the head-up display device 1 according to an embodiment includes the display unit 20 and the housing 10. The display unit 20 is provided in a vehicle and displays the virtual image S by reflecting the display light L1 emitted toward the translucent windshield WS toward the eyepoint EP side. The housing 10 has the opening 11 facing the windshield WS, and the display unit 20 is attached thereto. The above-described display unit 20 includes the meter 21, the reflection mirror 22, and a transparent cover 23. The meter 21 is housed in the housing 10 and emits the display light L1. The reflection mirror 22 is housed in the housing 10 and reflects the enlarged display light L2 obtained by magnifying the display light L1 emitted from the meter 11 toward the windshield WS through the opening 11.The transparent cover 23 blocks the opening 11 and transmits the magnified display light L2 reflected by the reflection mirror 22. The above-described transparent cover 23 includes the inner surface part 232 located on the reflection mirror 22 side and the outer surface part 231 located on the opposite side to the reflection mirror 22. Here, the display light L1 guided to the eye point EP includes the regular light L1a that passes through the transparent cover 23 without being reflected by the inner surface part 232 and the outer surface part 231 of the transparent cover 23 and is guided to the eye point EP, and the irregular light L1b that passes through the transparent cover 23 after being reflected by the inner surface part 232 and the outer surface part 231 of the transparent cover 23 and is guided to the eye point EP.The inner surface portion 232 of the transparent cover 23 has the incident surface 232b with an incident angle θ of 65°C or less. The incident angle θ is an angle at which the irregular light L1b enters the incident surface 232b. In other words, the inner surface portion 232 of the transparent cover 23 has the incident surface 232b into which the irregular light L1b enters at an angle that sets the luminance of the irregular light L1b to 2% or less with respect to the luminance of the regular light L1a.

[0024] With this configuration, because the head-up display device 1 can make the luminance of the irregular light L1b to be guided to the eye point EP smaller than the luminance of the regular light L1a, an occupant can be prevented from visually perceiving the virtual image S formed by the irregular light L1b. The head-up display device 1 can thereby prevent a virtual image formed by the irregular light L1b from being visually perceived as a duplicate image, and thus can correctly display the virtual image S formed by the regular light L1a.

[0025] In the head-up display device 1, the freely curved surface 232a, which performs aberration correction on the magnified display light L2 reflected by the reflection mirror 22, is formed on the incident surface 232b. With this configuration, the head-up display device 1 can correct the aberration of the virtual image S caused by an optical member including the windshield WS, etc., by means of the freely curved surface 232a of the transparent cover 23. And by the division of duties provided by assigning the aberration correction function mainly to the transparent cover 23 and assigning a magnification function to the reflection mirror 22, the head-up display device 1 can improve the accuracy of aberration correction and increase a magnification factor.Because the head-up display device 1 can reduce the number of parameter coefficients through task division, the head-up display device 1 can be manufactured easily and the tolerance can be reduced. Because the transparent cover 23 blocking the opening 11 of the housing 10 also has the function of aberration correction, the head-up display device 1 can avoid a larger number of components and thus an increase in the size of the optical system. Consequently, the head-up display device 1 can accurately display the virtual image S.

[0026] In the head-up display device 1, the display instrument 21 emits the display light L1 directly to the reflection mirror 22. The reflection mirror 22 reflects the magnified display light L2 obtained by magnifying the display light L1 emitted directly from the display instrument 21 to the windshield WS through the transparent cover 23. With this configuration, since the display instrument 21 of the head-up display device 1 emits the display light L1 directly to the reflection mirror 22 rather than through another mirror, the device can be downsized.

[0027] In the above, an example in which the free curved surface 232a performing aberration correction is formed on the incident surface 232b has been described, but the invention is not limited thereto and the free curved surface 232a need not be formed for aberration correction.

[0028] An example has been described in which the display instrument 21 emits the display light L1 directly to the reflection mirror 22 rather than via another mirror, but the invention is not limited thereto, and the display instrument 21 may also emit the display light L1 indirectly to the reflection mirror 22 via another mirror.

[0029] An example has been described in which the freely curved surface 232a is formed on the reflection mirror 22 side of the transparent cover 23 (ie, on the inner surface part 232), but the invention is not limited to this, and the freely curved surface 232a may also be formed on the opposite side of the transparent cover 23 to the reflection mirror 22.

[0030] In addition to the function of correcting aberration of the virtual image S by the freely curved surface 232a, the transparent cover 23 may have a function of magnifying the magnified display light L2 (image). In this case, the transparent cover 23 magnifies the magnified display light L2 (image) at a magnification factor smaller than the magnification factor of the reflection mirror 22. For example, the transparent cover 23 magnifies the magnified display light L2 (image) at a magnification factor of approximately 1 / 10 of the magnification factor of the reflection mirror 22.

[0031] In addition to the function of magnifying the display light L1 (image) through the reflection surface 221, the reflection mirror 22 may have a function of correcting an aberration of the virtual image S. In this case, the reflection mirror 22 corrects an aberration of the virtual image S by an aberration correction amount smaller than that of the transparent cover 23. For example, the reflection mirror 22 corrects an aberration of the virtual image S by an aberration correction amount of approximately 1 / 10 of an aberration correction amount of the transparent cover 23.

[0032] An example has been described in which the reflection element is the windshield WS, but the reflection element is not limited to this and can also be, for example, a combiner or similar. List of reference symbols 10 housings 11 Opening 20 display unit 21 Display instrument 22 reflection mirrors 23 transparent cover 231 Outer surface part (second surface part) 232 Inner surface part (first surface part) 232a freely curved surface 232b Incident surface EP Eyepoint L1 Indicator light L2 enlarged indicator light L1a regular light L1b irregular light S virtual image WS windshield (reflective element) QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2006-91104

[0003]

Claims

[1] Head-up display device, comprising: a display unit provided in a vehicle and displaying a virtual image by reflecting a display light emitted to a light-transmitting reflection member to the side of an eye point through the reflection member, and a housing with an opening facing the reflective element, to which the display unit is mounted, wherein the display unit comprises: a display instrument housed in the housing and emitting the display light, a reflection mirror accommodated in the housing and reflecting an enlarged display light obtained by magnifying the display light emitted from the display instrument through the opening to the reflection member, and a transparent cover that blocks the opening and allows the magnified display light reflected by the reflection mirror to pass through, wherein the transparent cover comprises a first surface part arranged on the side of the reflection mirror and a second surface part arranged on the side opposite to the reflection mirror, wherein the display light guided to the eye point comprises a regular light that is transmitted through the transparent cover without being reflected by the first surface part and the second surface part of the transparent cover and is guided to the eye point, and an irregular light that is transmitted through the transparent cover after being reflected by the first surface part and the second surface part of the transparent cover and is guided to the eye point, and wherein the first surface part of the transparent cover has an incident surface with an incident angle of 65° or less, the incident angle being an angle at which the irregular light enters the first surface part. [2] The head-up display device according to claim 1, wherein a freely curved surface that performs aberration correction on the magnified display light reflected by the reflection mirror is formed on the incident surface. [3] A head-up display device according to claim 1 or 2, wherein: the indicating instrument emits the display light directly to the reflection mirror, and the reflection mirror reflects the magnified display light obtained by magnifying the display light emitted directly from the display instrument through the transparent cover to the reflection member.

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