JP7299199B2 - virtual image display - Google Patents

Description

The disclosure according to this specification relates to a virtual image display device.

2. Description of the Related Art Conventionally, a virtual image display device that displays a virtual image is known. The device disclosed in Patent Document 1 includes a display, a reflector, and a housing. The reflecting mirror divides external light from the outside of the housing into transmitted light and reflected light. The inner wall of the housing is provided with a heat-dissipating member that has sawtooth-shaped unevenness and is coated with a light-absorbing paint. It has become so. The converted heat is radiated out of the device through the outer wall.

JP 2014-191321 A

After the external light is reflected by the reflecting surface of the reflecting mirror, it may enter the surface of the housing, and may be secondarily reflected by the surface to reach the eyes of the viewer of the virtual image. are concerned. When the secondary reflected light of external light reaches the eyes, the visibility of the virtual image is reduced due to its glare. However, in the device of Patent Document 1, sufficient countermeasures are not taken for the reflected light reflected by the reflecting surface of the reflecting mirror.

One of the disclosed objects is to provide a virtual image display device with excellent virtual image visibility.

One of the aspects disclosed herein is a virtual image display device that is mounted on a mobile body and displays a virtual image,
a display (11) that emits display light that is imaged as a virtual image;
a first reflecting mirror ( 21 ) having a first reflecting surface ( 22 ) that reflects display light emitted from the display;
a second reflecting mirror (31) having a second reflecting surface (32) for reflecting display light emitted from the first reflecting mirror;
A housing (51) containing the display , the first reflecting mirror and the second reflecting mirror and having an opening (53) for emitting the display light reflected by the second reflecting mirror to the outside,
In the case, the external light from the outside of the case enters the inside of the case through the opening and is further reflected by the second reflecting surface to arrive at the site (61a) of the surface portion. , a first wall surface (63) facing a first direction (D1) and a second direction (D2) that is different from the first direction and does not directly enter the external light reflected by the second reflecting mirror. having a wall surface structure (62) provided with a second wall surface (64) above the second reflecting mirror in the vertical direction of the moving body;
The wall structure is
Outside light reflected by the second reflecting mirror and reaching the first wall surface is configured to reach the second wall surface when reflected by the first wall surface ,
The ceiling wall (54) is arranged to cover the first reflecting mirror from above and extends in the direction of the opening, and is provided at an exposed portion of the ceiling wall (54).

According to this aspect , in the wall surface structure, external light from the outside of the housing enters the interior through the opening of the surface of the housing, and is further reflected on the reflecting surface of the reflecting mirror. It is formed in the part where it is assumed to reach. Therefore, it is possible to suppress the external light reaching the wall surface structure from reaching the eyes of the viewer of the virtual image secondarily due to the wall surface structure after being reflected by the reflecting surface. At least all secondary reflected light is suppressed from reaching the eye. Therefore, it becomes difficult for the viewer to perceive the glare of the external light.

It should be noted that the reference numerals in parentheses exemplarily indicate the correspondence with the portions of the embodiment described later, and are not intended to limit the technical scope.

It is a figure which shows the mounting state to the vehicle of the HUD apparatus of 1st Embodiment. FIG. 4 is an enlarged view of the wall surface structure of the first embodiment, and is a diagram for explaining an end-based first wall surface angle and an end-based second wall surface angle; It is a figure for demonstrating the visual recognition area 1st critical angle of 1st Embodiment. It is a figure for demonstrating the visual recognition area 2nd critical angle of 1st Embodiment. It is a figure which expands and shows the V section of FIG. FIG. 4 is a diagram for explaining the eyelip first critical angle of the first embodiment; FIG. FIG. 5 is a diagram for explaining the eyelip second critical angle of the first embodiment; It is a figure which expands and shows the VIII section of FIG. It is a figure for demonstrating the definition of an angle, etc. of 1st Embodiment. It is a figure for demonstrating the definition of an angle, etc. of 1st Embodiment. FIG. 6 is a diagram for explaining that external light reflected by the first wall surface reaches the second wall surface in the first embodiment; It is a figure corresponding to FIG. 1 in 2nd Embodiment. It is a figure which expands and shows the wall surface structure of 2nd Embodiment. It is a figure corresponding to FIG. 1 in 3rd Embodiment. FIG. 16 is a sectional view showing the XV-XV section of FIG. 15; FIG. 16 is an enlarged view of the XVI portion of FIG. 15 and is a view for explaining the end-reference first wall surface angle and the end-reference second wall surface angle; FIG. 16 is an enlarged view of the XVII section of FIG. 15 and is a view for explaining the predetermined point-based first wall surface angle and the predetermined point-based second wall surface angle; FIG. 16 is an enlarged view of the XVIII part of FIG. 15 and is a view for explaining the end-reference first wall surface angle and the end-reference second wall surface angle; FIG. 16 is an enlarged view of the XIX part of FIG. 15 and is a view for explaining the predetermined point-based first wall surface angle and the predetermined point-based second wall surface angle; It is a figure which expands and shows the wall surface structure of 4th Embodiment. It is a figure which shows the relationship between the 1st condition establishment area|region and wall surface structure of 5th Embodiment. It is a figure which shows the relationship between the 2nd condition establishment area|region and wall surface structure of 5th Embodiment. FIG. 11 is a diagram showing a specific example of modification 3; FIG. 11 is a diagram showing a specific example of modification 3; FIG. 11 is a diagram showing a specific example of modification 3; FIG. 11 is a diagram showing a specific example of modification 4; FIG. 11 is a diagram showing a specific example of modification 4; FIG. 11 is a diagram showing a specific example of modification 4; FIG. 16 is a diagram showing Modification 6; 4 is a table showing examples of combinations of reflecting mirrors;

A plurality of embodiments will be described below with reference to the drawings. Note that redundant description may be omitted by assigning the same reference numerals to corresponding components in each embodiment. When only a part of the configuration is described in each embodiment, the configurations of other embodiments previously described can be applied to other portions of the configuration. In addition, not only the combinations of the configurations specified in the description of each embodiment, but also the configurations of a plurality of embodiments can be partially combined even if they are not specified unless there is a particular problem with the combination. .

(First embodiment)
As shown in FIG. 1, the virtual image display device according to the first embodiment of the present disclosure is used in a vehicle 1 as a vehicle or a moving body, and is configured to be accommodated in an instrument panel 2 of the vehicle 1. A head-up display device (hereinafter referred to as HUD device) 10 is provided.

The HUD device 10 projects display light toward the windshield 3 of the vehicle 1 . Thereby, the HUD device 10 displays a virtual image that can be visually recognized by the occupants of the vehicle 1 . That is, the display light reflected by the windshield 3 reaches the visual recognition area EB set in the interior of the vehicle 1 . Accordingly, an occupant sitting on a seat facing the instrument panel 2 and having an eye point EP positioned in the visual recognition area EB perceives a virtual image formed by the display light. Then, the passenger can recognize various information displayed as a virtual image. Various types of information displayed as a virtual image include, for example, information indicating vehicle conditions such as vehicle speed and remaining amount of fuel, or navigation information such as visibility assistance information and road information.

In the following, unless otherwise specified, each direction indicated by front, rear, up, down, left, and right is expressed with reference to the vehicle 1 on a horizontal plane.

A windshield 3 of the vehicle 1 is made of, for example, glass or synthetic resin in the form of a translucent plate, and is arranged above the instrument panel 2 . The windshield 3 is arranged so as to be spaced apart from the instrument panel 2 from the front toward the rear. The windshield 3 has, on the interior side of the vehicle 1, a smooth concave or planar plate surface 3a. Such a windshield 3 functions as a projection section onto which display light is projected from the HUD device 10 .

The visual recognition area EB is a spatial area in which a virtual image displayed by the HUD device 10 can be visually recognized, and is also called an eyebox. The term "visible" as used herein means, for example, a state in which the entire virtual image has a predetermined luminance or higher, and the display content can be recognized. The visual recognition area EB is typically set so as to overlap with the eyelip EL set on the vehicle 1 . The eyelip EL is a virtual space area defined for each vehicle type, and is set in a virtual ellipsoidal shape based on an eye range that statistically represents the spatial distribution of eye points EP of the occupant (JISD0021 : 1998). For example, the eyelip EL is located near the headrest of the seat.

As the eyelip EL, it is preferable to employ an eyelip of the 90th percentile or more and 99th percentile or less, such as a 90th percentile eyelip, a 95th percentile eyelip, or a 99th percentile eyelip. In this embodiment, it is assumed that the 90th percentile eyelip is adopted.

A specific configuration of such a HUD device 10 will be described below with reference to FIGS. The HUD device 10 includes a display 11, a plane mirror 21, a concave mirror 31, a control unit 41, a housing 51, and the like.

The display 11 is, for example, a transmissive liquid crystal display. The display 11 is formed by housing a liquid crystal panel and a backlight in a casing. The display device 11 emits display light that is formed as a virtual image later by illuminating a screen 12 of a liquid crystal panel with a backlight. The display 11 may be a reflective liquid crystal display, an EL display that emits light using electroluminescence, a laser scanner type display, or a DLP (Digital Light Processing) using a DMD (Digital Micromirror Device). (registered trademark) type display or the like can also be adopted. The screen 12 of the display 11 faces upward, for example, and the display light is emitted upward.

The plane mirror 21 and the concave mirror 31 are reflecting mirrors that guide the display light emitted from the display 11 to the windshield 3 . The plane mirror 21 is formed in a rectangular plate shape, for example, from synthetic resin or glass. The plane mirror 21 has a reflecting surface 22 formed by vapor-depositing a metal film such as aluminum on its surface. The reflective surface 22 is formed in a smooth planar shape. The plane mirror 21 is positioned above the display 11, and the reflecting surface 22 faces obliquely forward and backward. The display light incident on the plane mirror 21 from the display device 11 is reflected by the reflecting surface 22 toward the concave mirror 31 .

The concave mirror 31 is made of, for example, synthetic resin or glass and is shaped like a rectangular plate. The concave mirror 31 has a reflecting surface 32 formed by vapor-depositing a metal film such as aluminum on its surface. The reflective surface 32 is formed in a smooth concave shape by curving such that the central portion is concave. The concave mirror 31 is positioned in front of the plane mirror 21, and the reflecting surface 32 faces obliquely upward and backward. The display light incident on the concave mirror 31 from the plane mirror 21 is reflected by the reflecting surface 32 toward the windshield 3 positioned above. Here, the display light is condensed by reflection on the reflecting surface 32, and the virtual image is enlarged.

More specifically, the reflection angle of the display light on the windshield 3 is preferably set in the vicinity of Brewster's angle larger than 45 degrees in consideration of Fresnel's formula. Therefore, the traveling direction of the display light reflected by the reflecting surface 32 of the concave mirror 31 is set in the backward and upward oblique direction. That is, the display optical path OP from the concave mirror 31 to the windshield 3 is constructed so as to linearly progress upward and backward from the concave mirror 31 as a starting point.

The control unit 41 includes an adjustment switch (not shown), a control circuit 42, and the like. The adjustment switch is installed outside the housing 51, for example, on the steering wheel of the vehicle 1, and can be operated by the passenger.

The control circuit 42 is an electronic circuit in which at least one processor, memory device (for example, semiconductor memory), input/output interface, etc. are mounted on a substrate.

A control circuit 42 controls the display 11 . In addition, the control circuit 42 can rotate the concave mirror 31 and its reflecting surface 32 within a predetermined angular range around a rotating shaft 31a extending in the horizontal direction in accordance with the operation of the adjustment switch. . Such rotation adjusts the direction of reflection by the reflecting surface 32 . That is, the direction of the display optical path OP is slightly changed, and the visual recognition area EB and the virtual image are moved up and down.

The housing 51 is made of synthetic resin or metal, for example, and is shaped like a light-shielding hollow box. The housing 51 accommodates the display device 11, the plane mirror 21 and the concave mirror 31 inside. The control circuit 42 is accommodated inside a circuit case 43 that is attached to the housing 51 from below, for example.

The housing 51 has an opening 53 that optically opens upward in the direction in which the windshield 3 is positioned, in the ceiling portion 52 opposite to the bottom portion 58 across the internal space. The opening 53 is a part of the ceiling portion 52 of the housing 51 and is provided relatively forward, that is, above the concave mirror 31 . This allows the display light reflected by the concave mirror 31 to pass through the opening 53 and exit the housing 51 . The opening 53 may be closed with a dust-proof sheet formed in the shape of a light-transmitting thin plate.

A ceiling wall 54 is formed behind the opening 53 in the ceiling 52 of the housing 51 so as to cover the plane mirror 21 from above. The ceiling wall 54 extends substantially in parallel with the oblique display optical path OP so as to avoid interference with the display optical path OP.

A surface portion exposed to the inside or the outside is formed in such a housing 51 . A part formed by the ceiling wall 54 of the surface part includes a part 61 a that is exposed to the outside of the housing 51 and faces the windshield 3 .

It is assumed that external light reflected by the reflecting surface 32 of the concave mirror 31 reaches such a portion 61a. For example, in the windshield 3 arranged outside the housing 51, external light such as sunlight is transmitted through the windshield 3 from a position shifted to the rear of the portion where the display light is projected, and is projected forward and downward. can proceed in the diagonal direction of Such outside light enters the interior of the housing 51 through the opening 53 and is reflected by the reflecting surface 32 of the concave mirror 31 . Then, since the reflection angle of the external light on the reflecting surface 32 is smaller than the reflection angle of the display light, the external light can reach the portion 61a slightly shifted downward from the display optical path OP.

If the portion 61a were formed to have a single mirror surface, the external light reaching the portion 61a would be secondarily reflected by the portion 61a, directly or further reflected by the windshield 3, and visually recognized. There is a possibility that it will reach the area EB. Therefore, in this embodiment, as shown in FIG. 2, a wall surface structure 62 capable of controlling the reflection direction is formed in the portion 61a. The wall surface structure 62 has a first wall surface 63 and a second wall surface 64 that are alternately connected one by one along a portion 61a of the surface portion that extends substantially parallel to the display optical path OP in a zigzag (sawtooth shape). to) is formed. It should be noted that alternately connecting means that there are two or more pairs of the first wall surface 63 and the second wall surface 64 .

The multiple first wall surfaces 63 face the common first direction D1. On the other hand, the plurality of second wall surfaces 64 face the common second direction D2, which is different from the first direction D1. Here, the significance of the common orientation may be conceptually common as long as the slopes of the first wall surfaces 63 or the slopes of the second wall surfaces 64 in the same wall structure 62 are strictly matched. does not require you to be. That is, it is sufficient if it can be conceptually understood that each first wall surface 63 faces, for example, the concave mirror 31 side, and each second wall surface 64 faces, for example, the windshield 3 side.

Each of the wall surfaces 63 and 64 extends in a direction intersecting the display optical path OP parallel to the portion 61a, that is, in the horizontal direction, thereby presenting a planar and elongated striped shape. The width of the first wall surface 63 and the width of the second wall surface 64 are set to be sufficiently smaller than the dimensions of the reflecting surface 32 of the concave mirror 31, and in this embodiment are set to, for example, 2 cm or less, more preferably 0.5 mm or less. However, by reducing the number of wall surfaces 63 and 64, it is possible to set the distance to about 10 cm. Furthermore, the widths of the wall surfaces 63 and 64 may be the same width as each other, or may be different as appropriate.

A coating film that absorbs external light is formed on the first wall surface 63 and the second wall surface 64 . Instead of forming a coating film, the first wall surface 63 and the second wall surface 64 may be roughened by texturing or the like.

Here, regarding the angle of each first wall surface 63 and the angle of each second wall surface 64 on a cross section parallel to the longitudinal center plane of the vehicle 1 (the vertical plane passing through the midpoint between the left and right wheels of the vehicle in a straight-ahead attitude) I will explain in detail.

First, an imaginary straight line extending from the upper end 32a of the reflecting surface to a predetermined first wall surface 63 (more specifically, the center of the first wall surface 63 in the width direction) is defined as an edge reference first straight line L1. Next, it is the angle formed by the first wall surface 63 with respect to the first edge-reference straight line L1. It is an angle where the upper side of the first straight line L1 is positive and the lower side is negative (see also FIGS. 9 and 10 for how to determine positive and negative values). Defined as one wall angle αe.

An imaginary straight line extending from the lower end 32b of the reflecting surface to a predetermined second wall surface 64 (more specifically, the center of the second wall surface 64 in the width direction) is defined as an edge reference second straight line L2. Next, it is the angle formed by the second wall surface 64 with respect to the second end-reference straight line L2. It is an angle where the upper side of the second straight line L2 is positive and the lower side is negative (see also FIGS. 9 and 10 for how to determine positive and negative values). Defined as the two-wall angle βe.

Here, since the portion 61a of the surface portion is exposed upward, the portion above the first edge reference straight line L1 or the second edge reference straight line L2 is also referred to as the exposed side of the portion 61a. In addition, since the ceiling wall 54, which is the constituent base material portion of the portion 61a of the surface portion, is arranged on the lower side of the first edge reference straight line L1 or the second edge reference straight line L2, it is also referred to as the opposite side to the exposed side.

Next, an angle θ1 shown in FIG. 3 is defined. It is the angle formed by the first wall surface 63 with respect to the first end-reference straight line L1, and is based on the side of the first end-reference straight line L1 opposite to the upper end 32a of the reflecting surface across the first wall surface 63. An angle where the upper side of L1 is positive and the lower side is negative (see also FIGS. 9 and 10 for how to decide the positive and negative values), and is an angle from the reflective surface upper end 32a along the end reference first straight line L1 to the first wall surface 63 The angle virtually set to the first wall surface 63 so that the incident virtual light ray RB1 reaches the visible area upper end EBa after being reflected by the first wall surface 63 is the visible area first critical angle θ1. Defined.

Also next, an angle .theta.2 shown in FIGS. 4 and 5 is defined. It is the angle formed by the second wall surface 64 with respect to the second end-reference straight line L2, and is based on the side of the second end-reference straight line L2 opposite to the lower end 32b of the reflecting surface across the second wall surface 64. An angle where the upper side of L2 is positive and the lower side is negative (see also FIGS. 9 and 10 for how to decide the positive and negative values), and is an angle from the lower end 32b of the reflecting surface to the second wall surface 64 along the end reference second straight line L2. The angle virtually set to the second wall surface 64 so that the incident virtual light ray RB2 reaches the lower end EBb of the visible area after being reflected by the second wall surface 64 is the second critical angle θ2 of the visible area. Defined.

Then, αe>βe is established as a first relationship between the first wall surface 63 and the second wall surface 64 adjacent to each other in the present embodiment. Further, αe>θ1 is established as a second relationship for each first wall surface 63 . Further, βe<θ2 is established as a third relationship for each of the second wall surfaces 64 . By satisfying the first, second, and third relationships at the same time, even if the external light reaching the portion 61a from the reflecting surface 32 of the concave mirror 31 is reflected by the first wall surface 63, the external light reaches the upper end EBa of the visual recognition area. reach. In addition, even if such external light is reflected by the second wall surface 64, it reaches the lower end EBb of the visual recognition area. Therefore, it is possible to suppress the external light reflected by the reflecting surface 32 from reaching the inside of the visible region EB.

Also, an angle φ1 shown in FIG. 6 is defined. It is the angle formed by the first wall surface 63 with respect to the first end-reference straight line L1, and is based on the side of the first end-reference straight line L1 opposite to the upper end 32a of the reflecting surface across the first wall surface 63. An angle where the upper side of L1 is positive and the lower side is negative (see also FIGS. 9 and 10 for how to decide the positive and negative values), and is an angle from the reflective surface upper end 32a along the end reference first straight line L1 to the first wall surface 63 The angle virtually set on the first wall surface 63 so that the incident virtual light ray RL1 reaches the eyelip upper end ELa after being reflected by the first wall surface 63 is defined as the eyelip first critical angle φ1. be.

Then the angle φ2 is defined as shown in FIGS. It is the angle formed by the second wall surface 64 with respect to the second end-reference straight line L2, and is based on the side of the second end-reference straight line L2 opposite to the lower end 32b of the reflecting surface across the second wall surface 64. An angle where the upper side of L2 is positive and the lower side is negative (see also FIGS. 9 and 10 for how to decide the positive and negative values), and is an angle from the lower end 32b of the reflecting surface to the second wall surface 64 along the end reference second straight line L2. The angle virtually set on the second wall surface 64 so that the incident virtual light ray RL2 reaches the eyelip lower end ELb after being reflected by the second wall surface 64 is defined as the eyelip second critical angle φ2. be.

Then, αe>φ1 is established as a fourth relationship for each first wall surface 63 and each second wall surface 64 of the present embodiment. As a fifth relationship, βe<φ2 holds. By satisfying the first, fourth, and fifth relationships at the same time, the external light that reaches the portion 61a from the reflecting surface 33 of the concave mirror 31, even if it is reflected by the first wall surface 63, reaches above the eyelip upper end ELa. do. In addition, even if such external light is reflected by the second wall surface 64, it reaches the lower end of the eyelid line ELb. Therefore, it is possible to suppress the external light reflected by the reflecting surface 32 from reaching the inside of the eyelip EL.

Here, a predetermined point reference first straight line L1f as shown in FIG. 9 is defined separately from the edge reference first straight line L1. The predetermined point reference first straight line L1f is a virtual straight line that extends from a predetermined first predetermined point on the reflecting surface 32 toward a predetermined first wall surface 63 (more specifically, the central portion of the first wall surface 63 in the width direction). . Next, it is the angle formed by the first wall surface 63 with respect to the predetermined point reference first straight line L1f. An angle that is positive above the predetermined point reference first straight line L1f and negative below the predetermined point reference first straight line L1f, and the angle that is currently set on the first wall surface 63 is defined as a predetermined point reference first wall surface angle αf.

Then, there are one or more first predetermined points on the reflecting surface 32 where the angle αf is set within the range represented by the formula of 90°<αf<180° with respect to each of the first wall surfaces 63. . The one or more first predetermined points may exist anywhere on the reflecting surface 32 and may be different for each first wall surface 63 .

In particular, in the present embodiment, the angle αf defined with any point on the reflecting surface 32 as the first predetermined point is set within the range represented by the formula 90°<αf<180°. However, when an arbitrary point is virtually gradually moved from the upper end 32a of the reflecting surface toward the lower end 32b of the reflecting surface, αf does not take discrete values and has no extreme value. It is normal that Therefore, a predetermined point reference first straight line L1f is defined with the upper end 32a of the reflecting surface as the first predetermined point, the angle αf is set within the range represented by the formula of 90°<αf<180°, and the lower end 32b of the reflecting surface is If the first predetermined point reference first straight line L1f is defined as the first predetermined point and the angle αf is set within the range represented by the formula of 90°<αf<180°, the condition can be considered to be satisfied at any point. can.

Here, a predetermined point reference second straight line L2f as shown in FIG. 10 is defined separately from the edge reference second straight line L2. The predetermined point reference second straight line L2f is an imaginary straight line extending from a predetermined second predetermined point on the reflecting surface 32 toward a predetermined second wall surface 64 (more specifically, the central portion of the second wall surface 64 in the width direction). . Next, it is the angle formed by the second wall surface 64 with respect to the predetermined point reference second straight line L2f. An angle that is positive above the predetermined point reference second straight line L2f and negative below the predetermined point reference second straight line L2f, and the angle that is currently set on the second wall surface 64 is defined as a predetermined point reference second wall surface angle βf.

Then, one or more second predetermined points exist on the reflecting surface 32 with respect to each of the second wall surfaces 64, where the angle βf is set within the range represented by the formula −90°<βf<0°. there is The one or more second predetermined points may exist anywhere on the reflecting surface 32 and may be different for each first wall surface 63 .

In particular, in this embodiment, the angle βf defined with any point on the reflecting surface 32 as the second predetermined point is set within the range represented by the formula −90°<βf<0°. However, when an arbitrary point is virtually gradually moved from the upper end 32a of the reflecting surface toward the lower end 32b of the reflecting surface, βf does not take discrete values and has no extreme value. It is normal that Therefore, a predetermined point reference second straight line L2f is defined with the upper end 32a of the reflecting surface as the second predetermined point, the angle βf is set within the range represented by the formula −90°<βf<0°, and the lower end 32b of the reflecting surface is defined as the first predetermined point, and if the angle βf is set in the range indicated by the formula of −90°<βf<0°, the condition is considered to be satisfied at any point. be able to.

As shown in FIG. 11, the first wall surface 63 and the second wall surface 64 are joined to form an acute angle γ in the valley on the exposed side (in other words, the outer side of the housing 51). Then, in the wall surface structure 62 provided in the portion 61a, when the external light reflected by the reflecting surface 32 of the concave mirror 31 and reaching the first wall surface 63 is further reflected by the first wall surface 63, the external light is , reaches the second wall surface 64 adjacent to the reflecting surface 32 and forming an acute angle γ with the first wall surface 63 . In addition, by setting the range of βf as described above, the external light reflected by the reflecting surface 32 does not directly enter the second wall surface 64 .

In the wall surface structure 62, each first wall surface 63 is formed with substantially the same slope, and each second wall surface 64 is formed with substantially the same slope. In addition, the physical quantity described as "slope" in this embodiment is defined as the degree of inclination of each of the wall surfaces 63 and 64 in a coordinate system with the vehicle 1 having a horizontal plane as a reference.

On the other hand, physical quantities such as αe, αf, βe, θ1, θ2, φ1, φ2, etc. described as “angles” correspond to the relative positions of the respective first wall surfaces 63 and the respective second wall surfaces 64 with respect to the reflecting surface 32. , the edge-reference first straight line L1 or the edge-reference second straight line L2 having different definitions is used as a reference. Therefore, even if the same angle αe is applied to each of the first wall surfaces 63, the reference lines for the angles corresponding to the respective first wall surfaces 63 are different, so it should be noted that the slopes will not be the same. The same applies to the application of the angle βe to the second wall surface 64 .

Further, in this embodiment, the upper end 32a of the reflecting surface corresponds to "one end of the reflecting surface", and the lower end 32b of the reflecting surface corresponds to "the other end of the reflecting surface". “One end of the reflecting surface” and “the other end of the reflecting surface” are arranged to face each other with the reflecting surface interposed therebetween. If the mirror-like reflecting surface 32 is formed up to the edge of the concave mirror 31 , the reflecting surface upper end 32 a and the reflecting surface lower end 32 b substantially coincide with the upper and lower ends of the concave mirror 31 . If the mirror-like reflecting surface 32 is surrounded by an outer frame made of, for example, a light-shielding synthetic resin, the upper end of the mirror-like portion excluding the outer frame is the reflecting surface upper end 32a. The lower end is the reflecting surface lower end 32b.

Further, in the present embodiment, the visible area upper end EBa corresponds to "one end of the visible area", and the visible area lower end EBb corresponds to "the other end of the visible area". “One end of the visible region” and “the other end of the visible region” are arranged to face each other with the visible region interposed therebetween.

In addition, in the present embodiment, the eyelip upper end ELa corresponds to "one end of the eyelip", and the eyelip lower end ELb corresponds to "the other end of the eyelip". The “one end of the eyelip” and the “other end of the eyelip” are arranged to face each other with the eyelip interposed therebetween.

(Effect)
The effects of the first embodiment described above will be described again below.

According to the first embodiment, the housing 51 is provided with the wall surface structure 62 in which the first wall surfaces 63 and the second wall surfaces 64 are alternately connected one by one. In this wall surface structure 62, outside light from the outside of the housing 51 enters the interior through the opening 53 of the surface portion of the housing 51, and is further reflected to the reflecting surface 32 of the concave mirror 31 to reach it. It is formed at the site 61a where it is assumed that Therefore, the wall surface structure 62 can suppress the external light reaching the wall surface structure 62 after being reflected by the reflecting surface 32 from reaching the eyes of the viewer of the virtual image secondarily. Specifically, since the first wall surface 63 and the second wall surface 64 face different directions D1 and D2, external light is reflected in different directions by the first wall surface 63 and the second wall surface 64, so that at least All secondary reflected light is suppressed from reaching the eye. Therefore, it becomes difficult for the viewer to perceive the glare of the external light.

The first wall surface 63 and the second wall surface 64 are arranged along the surface of the housing 51 . Therefore, it is suppressed that the top portion of the structure 62 protrudes greatly and obstructs the display optical path OP of the display light from the display device 11 . By suppressing the obstruction of the display optical path OP, the display light satisfactorily reaches the eyes of the viewer and is formed as a virtual image. As described above, it is possible to provide the HUD device 10 having excellent virtual image visibility.

Further, according to the first embodiment, the edge reference first wall surface angle αe is larger than the edge reference second wall surface angle βe, and the edge reference first wall surface angle αe is larger than the visual recognition area first critical angle θ1. Moreover, the end reference second wall surface angle βe is smaller than the visual recognition area second critical angle θ2. By satisfying these conditions, it becomes difficult for reflected light due to external light reaching the wall surface structure 62 from the reflecting surface 32 and being reflected to reach the inside of the visual recognition area EB. Secondary reflected light of external light is suppressed from reaching the eyes. Therefore, when viewing the virtual image, the viewer is less likely to feel the glare of the external light, and the visibility of the virtual image is enhanced.

Further, according to the first embodiment, the edge-based first wall surface angle αe is greater than the edge-based second wall surface angle βe, and the edge-based first wall surface angle αe is greater than the eyelip first critical angle φ1, In addition, the edge reference second wall surface angle βe is smaller than the eyelip second critical angle φ2. By satisfying these conditions, it becomes difficult for the reflected light due to the external light reaching the wall surface structure 62 from the reflecting surface 32 to be reflected to reach the inside of the eyelip EL. At the eye point EP, secondary reflected light of external light is suppressed from reaching the eye. Therefore, it becomes difficult for the viewer to perceive the glare of the external light, and the visibility of the virtual image is enhanced.

Further, according to the first embodiment, the predetermined point reference first wall surface angle αf is set to be larger than +90 degrees and smaller than +180 degrees. In this way, even if the external light reflected by the reflective surface 32 is reflected by the first wall surface 63, it is more likely to be reflected toward the second wall surface 64, so that it does not reach the eyes of the viewer. can be suppressed.

Further, according to the first embodiment, the predetermined point reference second wall surface angle βf is set to be larger than -90 degrees and smaller than 0 degrees. By doing so, the external light reflected by the reflecting surface 32 is suppressed from reaching the second wall surface 64 directly.

Further, according to the first embodiment, the wall surface structure 62 is configured such that the external light reflected by the reflecting surface 32 and reaching the first wall surface 63 reaches the second wall surface 64 when the external light is further reflected by the first wall surface 63 . is configured to Every time the external light is reflected, the intensity of the external light decreases due to absorption by the material of the housing 51 or diffusion at the surface, etc. Light intensity can be reduced cumulatively. Therefore, when viewing the virtual image, the viewer is less likely to feel the glare of the external light, and the visibility of the virtual image is enhanced.

Further, according to the first embodiment, the wall surface structure 62 is provided at a portion 61a facing the windshield 3 in the surface portion. By controlling the direction of reflection by the wall surface structure 62 at such a portion 61a, secondary reflected light is suppressed from entering the windshield 3, and by extension, the secondary reflected light from the windshield 3 reaches the eyes of the viewer. It is possible to suppress the arrival of the reflected light.

Further, according to the first embodiment, the wall surface structure 62 is provided in the portion 61 a that is exposed to the outside of the housing 51 and faces the windshield 3 . Since the wall surface structure 62 is along the surface portion, not only does secondary reflected light reach the eye, but the housing 51 outside the housing 51 interferes with the display optical path OP. can be suppressed. That is, since the degree of freedom in designing the display optical path OP of the display light emitted from the opening 53 to the outside is improved, it is possible to easily realize high visibility of the virtual image.

(Second embodiment)
As shown in FIGS. 12 and 13, the second embodiment is a modification of the first embodiment. The second embodiment will be described with a focus on points different from the first embodiment.

The control circuit 242 of the control unit 241 of the second embodiment is accommodated inside the housing 251 and arranged in the space formed between the display 11 and the concave mirror 31, as shown in FIG.

Correspondingly, the housing 251 of the second embodiment has a partitioning portion 55 that partitions the control circuit 242 and the concave mirror 31 inside thereof. The partition part 55 has a partition plate 56 formed in a substantially plate shape.

The partition plate 56 has a parallel portion 56a and a bent portion 56b. The parallel portion 56 a extends substantially parallel to the display optical path OP below the display optical path OP between the plane mirror 21 and the concave mirror 31 . The bent portion 56b is arranged at the forefront of the partition plate 56 and is formed by bending downward with respect to the parallel portion 56a.

A portion of the surface formed by the partition plate 56 is exposed upward from the parallel portion 56a, a portion 261a facing the windshield 3 through the opening 53, and a concave mirror exposed rearward from the bent portion 56b. 31, and includes a portion 261b facing.

It is assumed that external light reflected by the reflecting surface 32 of the concave mirror 31 reaches the portions 261a and 261b. For example, in the windshield 3 arranged outside the housing 251, external light such as sunlight is transmitted through the windshield 3 from a position slightly forward of the portion where the display light is projected, and downward. can proceed. Such outside light enters the inside of the housing 251 through the opening 53 and is reflected by the reflecting surface 32 of the concave mirror 31 . Then, since the angle of reflection of the external light on the reflecting surface 32 is larger than the angle of reflection of the display light, the external light is projected onto the portions 261a and 261b slightly downwardly shifted from the display optical path OP between the plane mirror 21 and the concave mirror 31. can be reached.

Therefore, in the second embodiment, as shown in FIG. 13, a portion 261a is provided with a wall surface structure 262a for controlling the reflection direction, and a portion 261b is provided with another wall surface structure 262b for controlling the reflection direction. In each wall surface structure 262a, 262b, the angles of the first wall surface 63 and the second wall surface 64 are set so as to satisfy the same relationship as in the first and second embodiments. However, since the relative position with respect to the concave mirror 31 is different between the wall surface structure 262a and the wall surface structure 262b, the specific shape thereof may be observed differently.

According to the second embodiment described above, the wall surface structure 262a is provided at the portion 261a facing the windshield 3 through the opening 53 inside the housing 251 . Since the wall surface structure 262a is along the surface portion, not only does secondary reflected light reach the eyes, but also the case 251 inside the case 251 interferes with the display optical path OP. can be suppressed. That is, since the degree of freedom in arranging members such as the display device 11 and the concave mirror 31 inside the housing 251 is improved, high visibility of the virtual image can be easily realized.

(Third Embodiment)
As shown in FIGS. 14-19, the third embodiment is a modification of the second embodiment. The third embodiment will be described with a focus on points different from the second embodiment.

In the third embodiment, the wall surface structure 362 in which the first wall surface 63 and the second wall surface 64 are alternately connected one by one is a portion of the surface portion that is exposed inside the housing 351 so as to face the left side. , are provided in a portion 361 a formed by the side wall portion 57 of the housing 351 .

As shown in FIGS. 14 and 15 , the side wall portion 57 is formed in a plate shape that stands substantially perpendicular to the bottom portion 58 or the ceiling portion 52 . Further, the portion 361 a extends in a direction oblique to the reflecting surface 22 of the plane mirror 21 and is arranged at a position adjacent to the plane mirror 21 . Particularly in this embodiment, the portions 361a are arranged on both sides of the plane mirror 21 on both sides.

It is assumed that external light reflected by the reflecting surface 32 of the concave mirror 31 reaches such a portion 361a. For example, outside light such as sunlight that obliquely enters the vehicle 1 in the early morning or evening enters the housing 351 through the opening 53 and is reflected by the reflecting surface 32 of the concave mirror 31 . Then, the part 361a may be reached. The external light is reflected by the portion 361a, reflected by the plane mirror 21, further reflected by the concave mirror 31, and reflected by the windshield 3, thereby reaching the visual recognition area EB or the eyelip EL in some cases.

In the wall surface structure 362 provided in such a portion 361a, as shown in FIGS. 16 to 19, the first wall surface 63 and the second wall surface 64 are vertically elongated stripes. Since the extending direction is different from that of the first embodiment, the definitions of angles such as αe, αf, βe, βf, θ1, θ2, φ1, φ2 are also made on the horizontal plane from the cross section parallel to the longitudinal center plane of the vehicle 1. can be understood as a replacement. In addition, the “upper end 32a” and “above” of the first embodiment are changed to the “left end 32c” and “leftward” of the first embodiment, and the “lower end 32b” and “downward” of the first embodiment are changed to “right end 32d” and “rightward”. , can be understood by replacing each other. Depending on the relationship with the reflection direction of the external light, it can be understood by reversing left and right. In this way, the cross section in which the angle is defined is not limited to the vertical plane, and can be understood as a cross section including the continuous direction of the first wall surface 63 and the second wall surface 64 .

According to the third embodiment described above, the wall surface structure 362 is provided in the portion 361a formed by the side wall portion 57 in the surface portion. By controlling the direction of reflection at the portion 361a, the effect of suppressing secondary reflected light from reaching the viewer's eyes is relatively enhanced.

(Fourth embodiment)
As shown in FIG. 20, the fourth embodiment is a modification of the first embodiment. The fourth embodiment will be described with a focus on the differences from the first embodiment.

At least one of the gradient of the first wall surface 63 and the gradient of the second wall surface 64 in the wall surface structure 462 provided in the portion 61a of the fourth embodiment extends from one end 65a of the wall surface structure 462 to the other along the connecting direction SD. It changes gradually toward the end 65b. The connecting direction SD is the direction in which the first wall surfaces 63 and the second wall surfaces 64 are alternately connected one by one. In addition, the gradual change referred to here includes a stepwise change for each area described below as well as a slope-like change that changes little by little for each wall surface.

Particularly in this embodiment, the wall surface structure 462 has a plurality of different gradient areas A1 and A2 with different gradient settings. A plurality of different gradient regions A1 and A2 are set so as to be mutually shifted in the direction SD so as to divide the wall surface structure 462 in the direction SD. In this embodiment, both the gradient of the first wall surface 63 and the gradient of the second wall surface 64 are set to be different between the different gradient regions A1 and A2.

According to the fourth embodiment described above, it is possible to more appropriately set the gradient between the different gradient regions A1 and A2. Therefore, even if the portion 61a where the wall surface structure 462 is provided is in close proximity to the reflective surface 32 or the dimension of the connection direction SD of the portion 61a is large, it is more appropriate depending on the relative relationship with the reflective surface 32. By setting the slope of the first wall surface 63 or the slope of the second wall surface 64, the effect of suppressing secondary reflected light from reaching the viewer's eyes can be easily enhanced.

(Fifth embodiment)
As shown in FIGS. 21 and 22, the fifth embodiment is a modification of the first embodiment. The fifth embodiment will be described with a focus on points different from the fifth embodiment.

In the wall surface structure 562 provided in the portion 61a of the fifth embodiment, the first wall surface 63 and the second wall surface 64 adjacent to each other have an angular relationship slightly different from that of the first embodiment.

Specifically, the reflecting surface 32 of the concave mirror 31 is virtually divided into two areas, a first condition satisfying area B1 and a second condition satisfying area B2. The first condition satisfaction region B1 and the second condition satisfaction region B2 may be set in common for all the first wall surfaces 63 and the second wall surfaces 64 that constitute the wall surface structure 562 . Alternatively, for each pair of the first wall surface 63 and the second wall surface 64 adjacent to each other, the boundaries of the first condition satisfying region B1 and the second condition satisfying region B2 may be set differently.

For example, the first condition satisfied area B1 is located closer to the lower end 32b of the reflecting surface 32 than the second condition satisfied area B2, and the second condition satisfied area B2 is located closer to the first condition satisfied area B2 of the reflecting surface 32 than the second condition satisfied area B2. It is arranged on the reflecting surface upper end 32a side of B1. The entire reflecting surface 32 is occupied by the two regions B1 and B2.

Here, for one pair of the first wall surface 63 and the second wall surface 64 adjacent to each other, the angle of each first wall surface 63 and the angle of each second wall surface 64 on a cross section parallel to the longitudinal center plane of the vehicle 1 are I will explain in detail.

First, as shown in FIG. 21, an imaginary straight line extending from the upper end B1a of the first condition satisfying region toward the first wall surface 63 (more specifically, the center of the first wall surface 63 in the width direction) is the edge reference first straight line L1. Defined. Next, it is the angle formed by the first wall surface 63 with respect to the first edge-reference straight line L1. It is an angle where the upper side of the first straight line L1 is positive and the lower side is negative (see also FIGS. 9 and 10 for how to determine positive and negative values). Defined as one wall angle αe.

An imaginary straight line extending from the lower end B1b of the first condition satisfying region to the second wall surface 64 (more specifically, the center of the second wall surface 64 in the width direction) is defined as the edge reference second straight line L2. Next, it is the angle formed by the second wall surface 64 with respect to the second end-reference straight line L2. It is an angle where the upper side of the second straight line L2 is positive and the lower side is negative (see also FIGS. 9 and 10 for how to determine positive and negative values). Defined as the two-wall angle βe.

Then, based on the straight lines L1 and L2 defined just now, as in the first embodiment, the visual recognition area first critical angle θ1, the visual recognition area second critical angle θ2, the eyelip first critical angle φ1, and the eyelip second critical angle φ2 are defined respectively.

Then, αe>βe holds, αe>θ1 and βe<θ2 hold, and αe>φ1 and βe<φ2 hold. That is, for the first condition satisfying area B1, which is a part of the reflecting surface 32, the angle is set to suppress the external light reflected by the area B1 from reaching at least one of the visual recognition area and the eyelip. .

Further, as shown in FIG. 22, a predetermined point reference first straight line L1f is defined separately from the edge reference first straight line L1. The predetermined point reference first straight line L1f is a virtual straight line extending from a predetermined first predetermined point on the second condition satisfied region B2 toward a predetermined first wall surface 63 (more specifically, the central portion of the first wall surface 63 in the width direction). Straight line. A predetermined point reference first wall surface angle αf is also defined for the straight line L1f defined now, as in the first embodiment.

Then, of the first wall surface 63 and the second wall surface 64 adjacent to each other, the first wall surface 63 has a predetermined point reference first wall surface angle defined with an arbitrary point on the second condition satisfying region B2 as the first predetermined point. αf is set to be larger than +90 degrees and smaller than +180 degrees. That is, the predetermined point reference first wall surface angle αf establishes the above relationship for all points on the second condition satisfaction region B2.

A predetermined point reference second straight line L2f is defined separately from the edge reference second straight line L2. The predetermined point reference second straight line L2f is a virtual straight line extending from a predetermined second predetermined point on the second condition satisfied region B2 toward a predetermined second wall surface 64 (more specifically, the central portion of the second wall surface 64 in the width direction). Straight line. A predetermined point reference second wall surface angle βf is also defined for the straight line L2f defined now, as in the first embodiment.

Then, of the first wall surface 63 and the second wall surface 64 adjacent to each other, the second wall surface 64 is defined as a first predetermined point, which is an arbitrary point on the second condition satisfying region B2. βf is set to be larger than +90 degrees and smaller than +180 degrees.

Therefore, even if the external light reflected by the area B2 is reflected by the first wall surface 63, the second wall surface 64 is An angle setting that is highly likely to be reflected toward is established. In addition, for the second condition satisfying region B2 excluding the first condition satisfying region B1 on the reflecting surface 32, there is an angle setting that makes it difficult for the external light reflected in the region B2 to directly reach the second wall surface 64. established.

According to the fifth embodiment described above, the reflective surface 32 is divided into two regions B1 and B2, and the angle conditions are set so that the viewer is less likely to feel the glare of the external light with different effects. It is established in each area B1, B2. Therefore, regardless of the area of the reflecting surface 32, it is possible to easily realize an increase in the visibility of the virtual image.

(Other embodiments)
Although a plurality of embodiments have been described above, the present disclosure is not to be construed as being limited to those embodiments, and can be applied to various embodiments and combinations within the scope of the present disclosure. can be done.

Specifically, as a modification 1 of the first, fourth, and fifth embodiments, a wall surface structure 62 is provided at a portion of the bottom surface portion 58 of the housing 51 that is exposed upward and faces the windshield 3 through the opening 53. may be formed.

As a modified example 2, a combiner provided separately from the vehicle 1 may be employed as a projection unit on which display light is projected.

As a modification 3, the wall surface structure 62 can be applied to various shaped portions of the housing 51 . As shown in FIG. 23, the wall structure 62 can be placed on the surface of the convex curved plate. As shown in FIG. 24, the wall structure 62 can be placed on the surface of the concave curved plate. As shown in FIG. 25, the wall structure 62 can be placed on the surface of a concave bend corner.

As a modification 4, at least one of the first wall surface 63 and the second wall surface 64 can be formed in a curved shape instead of a planar shape. In the example of FIG. 26, the second wall surface 64 is formed in a planar shape, while the first wall surface 63 is formed in a concavely curved cylindrical surface shape. In the example of FIG. 27, the first wall surface 63 is formed in a planar shape, while the second wall surface 64 is formed in a concavely curved cylindrical surface shape. In the example of FIG. 28, the first wall surface 63 is formed in the shape of a concavely curved cylindrical surface, and the second wall surface 64 is formed in the shape of a convexly curved cylindrical surface.

As a modification 5, the wall surface structure 62 may be provided on a surface portion where it is assumed that external light is reflected by the reflecting surface 22 of the plane mirror 21 and reaches it.

As a modification 6, three or more reflecting mirrors 91 may be provided as shown in FIG. When the reflecting mirrors are numbered from the opening 53 side of the display optical path OP as the first mirror 91a, the second mirror 91b, and the third mirror 91c, various combinations shown in FIG. 30 can be adopted.

As a modification example 7, the angles αe and βe are adjusted so as to satisfy the first, second and third relationships among the first to fifth relationships shown in the first embodiment, but not to satisfy the fourth and fifth relationships. may be set. Also, the angles αe and βe may be set so as to satisfy the first, fourth and fifth relationships but not to satisfy the second and third relationships.

As a modified example 8, the first wall surface 63 and the second wall surface 64 may continue to form an obtuse angle with the exposed valley portion of the surface portion.

As a ninth modification, the virtual image display device can be applied to various vehicles such as an aircraft, a ship, or a non-moving vehicle (for example, a game cabinet).

10 HUD device, 11 display, 31 reflector (concave mirror), 32 reflective surface, 51 housing, 53 opening, 61a, 261a, 261b, 361a portion, 62, 262a, 262b, 362, 462 wall structure, 63 second 1 wall surface, 64 2nd wall surface, D1 1st direction, D2 2nd direction

Claims (3)

A virtual image display device that is mounted on a moving body and displays a virtual image,
a display device (11) emitting display light formed as the virtual image;
a first reflecting mirror ( 21 ) having a first reflecting surface ( 22 ) that reflects the display light emitted from the display;
a second reflecting mirror (31) having a second reflecting surface (32) that reflects the display light emitted from the first reflecting mirror;
A housing (51) containing the display , the first reflecting mirror and the second reflecting mirror and having an opening (53) for emitting the display light reflected by the second reflecting mirror to the outside. and
The housing has a surface portion where it is assumed that external light from the outside of the housing enters the interior of the housing through the opening and is reflected by the second reflective surface to reach the surface. In the portion (61a), a first wall surface (63) facing the first direction (D1) and a first wall surface (63) different from the first direction and not directly incident on the external light reflected by the second reflecting mirror. a wall surface structure (62) provided with a second wall surface (64) facing two directions (D2) above the second reflecting mirror in the vertical direction of the moving body;
The wall structure is
Outside light reflected by the second reflecting mirror and reaching the first wall surface is configured to reach the second wall surface when reflected by the first wall surface ,
A virtual image display device provided in a part exposed to the outside of a ceiling wall (54) arranged to cover the first reflecting mirror from above and extending in the direction of the opening. An angle (αf) formed by the first wall surface with respect to a first straight line (L1f) extending from a predetermined point on the second reflecting surface to the first wall surface is positive above the first straight line. 2, the virtual image display device according to claim 1, wherein the angle is greater than 90 degrees. A virtual image display device that projects display light onto the windshield (3) of the moving body,
3. The virtual image display device according to claim 1, wherein the portion provided with the wall surface structure includes a portion exposed to the outside of the housing and facing the windshield.

Images