WO2020090462A1

WO2020090462A1 - Head-up display

Info

Publication number: WO2020090462A1
Application number: PCT/JP2019/040606
Authority: WO
Inventors: 典彦牛田
Original assignee: 日本精機株式会社
Priority date: 2018-10-29
Filing date: 2019-10-16
Publication date: 2020-05-07
Also published as: CN112955342A; JP2023059966A; CN112955342B; DE112019005376T5; JP7248035B2; JPWO2020090462A1

Abstract

The present invention provides a head-up display with reduced image blurring. This head-up display is provided with: a display unit 2 that emits display light L indicating vehicle information; a reflection part 30 that reflects the display light L and is capable of rotating about a predetermined rotational axis P; an arm-piece-shaped protruding part 37 that allows the reflection part 30 to rotate by rotating in conjunction with the same; an elastic part 40 that biases the protruding part 37 in a predetermined rotational direction with an elastic force; a power transmission part 70 that comes in contact with a surface in the biasing direction of the elastic part 40; a power unit 80 that rectilinearly moves the power transmission part 70; and a hard structure that rotatably holds the reflection part 30 and fixes the relative positions of the elastic part 40, power unit 80, and rotational axis P.

Description

Head up display

The present invention relates to a head-up display.

As a conventional head-up display, there is disclosed a configuration in which a lead screw (61c) is used to adjust the angle of the concave mirror (41) as shown in Patent Document 1. Specifically, the protrusions (65h, 65i) of the position adjusting means (43) are in point contact with the holding member (42) of the concave mirror (41), and the driving member (61a) is driven, whereby the concave mirror (41). ) Rotates.

JP, 2009-73461, A

With such a configuration, there is a risk that image blur will occur when a large vibration occurs in the vehicle due to the meshing of the screw part and the gear part included in the drive member (61a). Therefore, it is an object of the present invention to provide a head-up display that focuses on the above problems and reduces the risk of image blurring.

In order to achieve the above object, the head-up display according to the present invention,
A head-up display that displays a virtual image by projecting display light onto a reflective / transmissive member of a vehicle,
A display unit that emits the display light representing vehicle information,
A reflecting portion that reflects the display light and is rotatable around a predetermined rotation axis,
An arm-piece-shaped protrusion that can rotate the reflector by rotating in conjunction with the reflector,
An elastic portion that biases the protruding portion in a predetermined rotation direction by an elastic force,
A power transmission portion that comes into contact with a surface of the elastic portion positioned in the biasing direction,
A power unit that linearly moves the power transmission unit,
A rotatably holding the reflecting portion, the elastic portion, the power portion, and a hard structure that fixes the relative position of the rotating shaft,
Equipped with
The reflector is
A display mode for projecting the display light on the reflection / transmission member;
A rest mode in which the display light is not projected on the reflection / transmission member,
Have
The elastic portion is set so that the elastic force becomes stronger in the display mode.

According to the present invention, a head-up display that reduces the risk of image blurring is provided.

The figure which shows a mode that the head-up display 1 of this indication was mounted in the vehicle C. The figure which shows the structure of the head-up display 1. The figure which shows a part of head-up display 1 of a parking position. The figure which shows a part of head-up display 1 of a tolar position. The figure which shows a part of head-up display 1 of a shorter position.

Hereinafter, the head-up display (HUD) 1 of the present disclosure will be described as an example of an embodiment and a modification mounted on the vehicle C, and will be described in the following order with reference to the accompanying drawings.
[First embodiment]
1-1. Description of configuration 1-2. Mode description [Modification]
[Effect example]
[First embodiment]
<1-1. Description of configuration>

As shown in FIG. 1, the HUD 1 of the present disclosure can be assembled below the windshield WS provided in the vehicle C. The vertical direction of the drawing corresponds to the vertical direction Y of the vehicle C, the horizontal direction corresponds to the front-back direction Z, and the depth direction corresponds to the horizontal direction X.

The HUD 1 projects a virtual image V by projecting the display light L representing vehicle information on a windshield WS (reflection / transmission member) that has a free-form surface shape inclined to the front of the vehicle. The HUD 1 emits the display light L in the diagonally upper rear direction of the vehicle. The display light L emitted to the HUD 1 is reflected by the windshield WS. A user (for example, an occupant of the vehicle C) who visually recognizes the display light L reflected by the windshield WS from the viewpoint EP can visually recognize the displayed virtual image V as a display image floating in the back of the windshield WS.

In the virtual image V, for example, vehicle information such as speed and engine speed, route guidance display such as turn-by-turn or map, warning display such as blind spot monitor or speed limit warning, etc. are alerted to passengers (users). Information that is highly necessary to be displayed is displayed. This provides a driving environment with reduced need for viewpoint movement and eye focal length adjustment. The display image V includes characters and icons indicating these pieces of information as well as a background portion, and has a rectangular shape, for example, in a plan view from the occupant.

HUD1 also has two major modes. One is a display mode in which the HUD 1 projects the display light L on the windshield WS so that the virtual image V can be visually recognized from the viewpoint EP, as shown in FIG. The other is a rest mode (parking mode) in which the HUD 1 does not project the display light L on the windshield WS and the virtual image V cannot be visually recognized from the viewpoint EP. In the parking mode HUD1 that does not project the display light L onto the windshield WS, the display light L receives the external light (mainly sunlight) incident on the HUD1 from the direction of the windshield WS based on the principle of backward travel of the light rays. This means that it is in a position where there is no reflection in the direction (the direction in which the display section exists optically). As a result, when the HUD 1, which is considered to be in the state where the vehicle C is stopped, is in the parking mode, it is possible to prevent the display unit from being illuminated by external light and becoming a high temperature state.

The display mode HUD 1 can change the optical path of the display light L by a configuration described later in order to adjust the height of the viewpoint EP where the virtual image V can be visually recognized. In the present disclosure, as shown in the drawings, three types of shorter display light Ls, center display light Lc, and toler display light Lt can be changed. As for the shorter display light Ls, in the display mode, the HUD 1 projects the display light L on a relatively lower portion of the windshield SW, and projects the virtual image V. With the toler display light Lt, the HUD 1 projects the display light L onto the windshield SW relatively above and displays a virtual image V. With the center display light Lc, a virtual image V is projected through the two display optical paths described above.

The configuration of HUD1 will be described with reference to FIG. The direction in the drawing corresponding to the direction of the vehicle C is the same as in FIG. FIG. 2 illustrates a state in which the reflector 30 is at the toler position Pt that reflects the display light L as the toler display light Lt. The rough broken line Ps shows the outer shape when the concave mirror 31 of the reflecting section 30 is at the shorter position, and the thin broken line Pp shows the outer shape when the concave mirror 31 is at the parking position Pp (rest position). In the present disclosure, the parking position is a position where the display light L is not projected on the windshield WS, and particularly a position where the center of the display light L is reflected in the direction B. Further, at each of the parking position Pp, the toler position Pt, the center position, and the shorter position Ps, the angle that the normal line of the center of the reflecting surface 31a of the concave mirror 31 (where the center of the display light L is incident) has with respect to the direction B Is 0 °, 18.5 °, 19.7 °, 21 °, for example.

The HUD 1 includes a display unit 20, a reflection unit 30, a torsion spring 40, a control unit 50, a power transmission unit 70, and a power unit 80.

The display unit 20 is a member that emits the display light L. In the present disclosure, the light is emitted in the direction F. As a member that emits the display light L, for example, a configuration using a TFT liquid crystal module, a configuration using an organic EL, a projector using a DMD (Digital Micro-mirror Device), or the like can be applied. In the configuration using the TFT liquid crystal module, for example, the display unit 20 is provided with a backlight unit connected to the control unit and a liquid crystal display element in a fixed state, and a liquid crystal display element that displays information under the control of the control unit. Is illuminated by the illumination light emitted from the backlight unit whose blinking is controlled by the control of the control unit, and emits the display light L. However, it is needless to say that the effects of the configuration of the present disclosure can be exhibited as long as the configuration is capable of emitting display light other than the exemplified ones.

The reflecting portion 30 is provided with a concave mirror 31, a holder 32, a shaft 33, a locking hole 35 (power point), and a protruding portion 37 (point of action).

The concave mirror 31 reflects the display light L while expanding the display light L according to the free-form surface shape formed on the reflecting surface 31a. For the concave mirror 31, a hard synthetic resin or an inorganic glass can be applied to the base material, and for example, a configuration having a reflecting surface 31a formed by depositing silver can be applied. Further, it is desirable that the reflection surface 31a has a shape that can cancel the distortion of the display image V that is supposed to occur in the windshield WS due to the free-form surface shape.

The holder 32 is a holding member that fixes the concave mirror 31 by bonding or screwing. As a material, a hard metal such as magnesium or iron or a hard synthetic resin such as ABS resin can be applied. The concave mirror 31 can be held at a position that does not interfere with the reflection of the display light L. For example, when the holder 32 holds the reflection surface 31a on the back surface as illustrated, it is possible to reduce the possibility that the holder 32 cannot be seen from the viewpoint EP and that unintended light (stray light) reaches the viewpoint EP.

The shaft 33 is formed integrally with the holder 32, for example. In order to define the rotation axis P along the direction X, it is desirable to provide one shaft 33 on each side surface of the holder 32 facing the direction X, for example. When the reflection unit 30 rotates about the rotation axis P defined by the shaft 33, the display mode and the parking mode can be switched.

The shaft 33 is rotatably held by a hard structure (not shown) such that the rotary shaft P is fixed in a relative position between a fixed end 41 (described later) and the power unit 80. As the hard structure, for example, a synthetic resin material such as ABS resin or a metal such as magnesium can be applied. The hard structure may be a housing that houses each member that constitutes the head-up display 1, or may be a part of the vehicle body of the vehicle C. Further, in the structure in which the hard structure holds the shaft 33, the shaft 33 can be placed in the U-shaped guide and restrained by a leaf spring or the like with a force that does not hinder the rotation. However, the present invention is not limited to this, and any hard structure that holds the rotation axis P can be used.

The locking hole 35 (power point) is a portion provided in the reflecting portion 30 for connecting the elastic portion. In the present disclosure, for example, the holes are provided near the axis. By locking the load end 42 of the torsion spring 40, which is an example of the elastic portion, which is described below, the reaction force of the elastic portion can be transmitted to this hole.

The protrusion 37 (point of action) is an arm piece that is integrally provided on the holder 32. For example, in the present disclosure, it has a flat plate shape protruding from the holder 32. The contact surface that contacts the protrusion 71 is inclined by 18.5 ° with respect to the center of the concave mirror 31 in the rotational direction component, and is present on the same plane as the rotation axis P. Thereby, when the reflecting member 30 is at the toler position Pt, the contact surface is perpendicular to the direction Y. Further, by providing the protrusion 37 in the center of the holder in the direction X component, the concave mirror 31 can be rotated relatively without distortion. The power transmission unit 70, which will be described later, displaces the position of the protrusion 37, so that the direction in which the reflection unit 30 reflects the display light L can be adjusted. The reflecting portion 30 is held rotatably around the rotation axis P, and is biased in the rotation direction by a torsion spring 40 described later. The angle of the reflection part 30 can be changed by pushing the protrusion 37 back with a force larger than this bias or pulling it in with a weak force.

In the present disclosure, the protrusion 37 is formed integrally with the holder 32. However, the protrusion 37 does not necessarily have to be formed integrally with the holder 32. The protrusion 37 may be provided on the concave mirror 31. Furthermore, the position of the reflection part 30 may be adjusted by displacing the position of the protrusion 37 around a predetermined rotation axis. That is, the rotation of the rotatably provided protrusion may indirectly adjust the reflection angle via, for example, at least one gear.

The torsion spring 40 (elastic portion) is an elastic member that biases the reflecting portion 30 in the rotation direction. The material can be hard metal such as hard steel or stainless steel. In the present disclosure, the shaft 33 functions as a guide rod. A torque can be applied to the load end 42 about the center of the shaft 33 (rotating shaft P) which is a guide rod. The torque is determined according to the torque spring constant [N · mm / deg] peculiar to the torsion spring 40 and the deflection angle. Further, the fixed end 41 is fixed to the above-mentioned hard structure by means such as locking or adhesion, and the relative position between the rotating shaft P and the power unit 80 is kept constant as described above. The load end 42 has one end of the torsion spring 40 bent in the direction R and is locked in the locking hole 35 as described above. That is, it is assembled as shown in FIG.

Also, in the present disclosure, the torsion spring 40 has a load applied in the winding direction. That is, it means that the torsion spring 40 is biased in the clockwise direction when viewed from the illustrated direction. On the other hand, the protrusion 37 means that the protrusion 71 is pushed in the direction B. This bias increases as the reflecting surface 31a of the reflecting portion 30 faces the direction U, in other words, as it approaches the shorter position. On the other hand, this bias becomes smaller as it approaches the parking position.

Also, when the parking position is reached, the torsion spring 40 does not return to its free angle, but has a structure that allows it to continue to flex. This is because the purpose of biasing the torsion spring 40 is to bias the parking mode, the display mode, and the transition mode therebetween. By energizing with a torque of a predetermined value or more, even when a torque in the opposite direction is generated due to an impact applied to the HUD 1, the locking hole 35, the reflecting portion 30, the protruding portion 37, the protrusion 71, in the desired direction, When the power transmission unit 70 and the power 80 are energized, even if the connection between the power transmission unit and the power unit 80 and the gap existing in the power unit 80 that may cause backlash, an image blur or rattling due to rattling Therefore, it is possible to reduce the possibility that a sound caused by the movement will be generated.

Also, as mentioned above, it is recommended to set the positions of both ends of the elastic part so that the bias in the display mode is stronger than in the parking mode. This is because the vehicle C is generally not in the traveling state in the parking mode, whereas the vehicle C is often in the traveling state in the display mode. This means that the head-up display 1 is likely to be heavily impacted in the display mode. That is, by setting the positions of both ends of the elastic portion so that the bias in the display mode is stronger than that in the parking mode, it is possible to effectively reduce the risk of image blur.

By the way, due to the above-mentioned circumstances, the larger the torque spring constant [N · mm / deg] of the torsion spring 40, the more resistant it is to torque in the opposite direction. However, if it is made too strong, the concave mirror 31 (reflection surface 31a) will be distorted. Since this also leads to distortion of the virtual image V, it is necessary to perform sufficient urging with a spring load as small as possible. The configuration according to the setting method will be described in detail later.

The control unit 50 is provided with a storage unit such as a ROM and a RAM (not shown) used as a storage area for storing a predetermined program and various data and a calculation, a CPU for performing a calculation process according to the predetermined program, an input / output interface and the like. Microcomputer can be applied. The control unit 50 generates an image to be displayed on the display unit 20, controls the display of the display unit, and controls the illuminance of the illumination unit based on the vehicle information received from the vehicle-mounted device outside the HUD 1. The control unit 50 is electrically connected to the display unit 20, the power unit 80, and electronic devices outside the HUD 1, and also controls the driving of the power unit 80.

The power unit 80 is a power unit that causes the power transmission unit 70, which will be described later, to perform a linear motion along a direction that is not parallel to the rotation axis P. In the present disclosure, for example, linear movement is performed in the direction Z. As described above, it is electrically connected to the control unit 50 and its operation is controlled.

The configuration using a lead screw, for example, can be applied to the power unit 80. Specifically, a drive unit such as a motor that rotates a rotating shaft in response to an input signal, a screw shaft that rotates in response to the rotation, a ring-shaped nut unit that is screwed onto the screw shaft, and a guide that suppresses rotation of the nut unit. And a power transmission unit 70 described later is fixed to the nut. The nut part whose rotation is suppressed by the guide part can perform linear motion along the axial direction of the screw shaft rotated by the drive part.

The power transmission unit 70 can be made of, for example, a hard and rigid resin material, performs linear motion by the power of the power unit 80, and pushes the protrusion 37 through the protrusion 71 provided on itself to adjust the angle of the reflection member 30. can do. When the power unit 80 has the above-mentioned configuration using the lead screw, it is fixed to the nut unit, and the nut unit contacts the guide unit via the fixed power transmission unit 70 to suppress the rotation of itself. You may.
<1-2. Mode description>

The mode of energization in each mode will be described with reference to FIGS. 3, 4, and 5.
FIG. 3 shows how the concave mirror 31 is urged when it is at the parking position Pp. Tp represents the torque applied to the reflecting member 30 by the torsion spring 40 at the parking position Pp. Fp represents the force with which the protrusion 37 abuts the protrusion 71. The contact force Fp is generated perpendicularly to the contact surface of the protrusion 37. fp represents a component force in the Z direction (holding component force) of Fp. By increasing the holding component force fp, rattling of the power unit 80 can be prevented even when a stronger impact is applied. This is because the linear motion directions of the power unit 80 and the power transmission unit 70 coincide with the direction Z. Tx, Fx, and fx (x is t or s) in FIGS. 4 and 5 indicate torque or force or holding component force at the toler position Pt or the shorter position Ps.

The angle formed by the contact force Fp and the holding force fp is 18.5 °. This can be seen from the fact that the projection 37 forms an angle of 18.5 ° with the concave mirror 31, and the concave mirror 31 is perpendicular to the direction Z. In other words, it can be said that the angle (contact angle) at which the protrusion 37 contacts the power transmission unit 70 is 18.5 °. In addition, the holding component force fp has a magnitude obtained by multiplying the contact force Fp by the value of the cosine of 18.5 °.

Similarly, the holding component force ft is equal to the contact force Ft, and the holding component force fs is the contact force Fs multiplied by the value of the cosine of 2.5 °. That is, the holding component force f can be efficiently applied when the contact angle is closer to 0 °.

Generally, the angle when the concave mirror of HUD rotates from the shorter position to the toler position is within 3 °. Further, of the shorter position and the toler position, the angle required to rotate from the position close to the parking position to the parking position is 10 ° or more. Therefore, when the contact angle reaches 0 degrees when the reflector is near the parking position, the contact angle deviates from 0 ° when the reflector reaches the display mode thereafter. If the stress is dispersed in this way, even if the contact force Fx is large, the holding component force fx cannot be efficiently applied and becomes small.

Therefore, as shown in the present disclosure, in the display mode, if the contact angle is closer to 0 ° than at the parking position Pp, the stress dispersion is reduced as much as possible and the image blur is reduced. it can.

Furthermore, in the configuration in which the contact angle is a right angle closer to the parking position of the toller position and the shorter position, a position without stress dispersion is set in at least one position of the display mode. Further, the image blur can be reduced more efficiently.

More desirably, the torque spring constant is k [N · mm / deg], the angle as a variable is θ [deg], the contact angle of one of the toler position and the shorter position near parking is θt [deg], and the other is θt [deg]. Where θ is the contact angle at θ (that is, the angle when the reflection part is rotated from one position to the other position in the display mode is added to θt) [deg], then θ · k · cos θ is It is desirable to set θt so that the absolute value when integrating from θt to θs becomes maximum. According to this, the stress dispersion can be further reduced, and the image blur can be efficiently reduced.

In this way, we have provided a head-up display that reduces the risk of image blurring.

Although the head-up display of the present invention has been described by taking the configuration of the above-mentioned embodiment as an example, the present invention is not limited to this, and other configurations deviate from the gist of the present invention. It goes without saying that various improvements and display changes can be made within the range not covered. For example, in the present disclosure, a configuration using a holder as the reflecting portion in addition to the reflecting surface and the protruding portion is shown. However, it suffices that at least the reflecting surface 31a and the protruding portion move in conjunction with each other without providing the holder.

Also, a torsion spring is used as the elastic part. However, other than the torsion spring, another structure may be used as long as it is an elastic portion that can bias the reflecting portion in the rotation direction. For example, the coil spring may be configured such that the expanding and contracting direction connecting the fixed end and the elastic end (moving end) with respect to the rotating shaft is in a twisted position. If the direction of expansion and contraction is not in the twisted position, torque cannot be generated on the rotating shaft, and as a result, bias cannot be performed. However, at the twisted position, with the relative position of the fixed end, the rotating shaft, and the power unit kept constant by the hard structure as described above, if the moving end is stopped at the reflecting unit, torque is generated, Biasing can be done.

In addition, in the present disclosure, the position of the reflecting portion 30 is the parking position Pp, the toler position Pt, the center position, and the shorter position Ps in order from the parking position. However, if the parking position is designed such that the reflecting surface 31a faces the direction F and the traveling direction of the vehicle, the position of the reflecting portion in the display mode closest to the parking position is the shorter position. In such a case, if the contact angle is 0 ° at the shorter position close to the parking position, the head-up display can efficiently reduce the possibility of image blur.
[Effect example]

First, the head-up display 1 of the present disclosure is a head-up display 1 that displays a virtual image V by projecting the display light L on the reflection / transmission member WS of the vehicle C.
A display unit 2 for emitting display light L representing vehicle information;
A reflecting portion 30 that reflects the display light L and is rotatable around a predetermined rotation axis P;
An arm-piece-shaped protrusion 37 that can rotate the reflector 30 by rotating in conjunction with the reflector 30;
An elastic portion 40 for urging the protruding portion 37 in a predetermined rotation direction by an elastic force,
A power transmission portion 70 that comes into contact with a surface of the elastic portion 40 located in the urging direction;
A power unit 80 that linearly moves the power transmission unit 70,
A rigid structure that rotatably holds the reflection part 30 and fixes the relative position of the elastic part 40, the power part 80, and the rotation axis P;
Equipped with
The reflector 30 is
A display mode for projecting the display light L onto the reflection / transmission member WS;
A parking mode in which the display light L is not projected onto the reflection / transmission member WS;
Have
The elastic section 40 is a head-up display in which the elastic force is set to be stronger in the display mode.
With this configuration, it is possible to provide a head-up display that can easily reduce the image blur when the vehicle C is in a travelable state and that is easily subject to impact.

Second, the head-up display 1
The protrusion 37 is
When in plan view from the rotation axis P, the power transmission section 70 always comes into contact with the power transmission section 70 in a point contact in the rotation direction,
The contact angle formed by the contact direction and the direction Z of the linear motion is
The head-up display is smaller in the display mode than in the parking mode.
With this configuration, it is possible to provide a head-up display that can prevent image blur relatively efficiently.

Third, the head-up display 1
The reflector 30 is
In display mode, you can move to multiple display positions (Toler position Pt and Shorter position Ps)
In the parking mode, it can be displaced to the parking position Pp,
The contact angle is
The head-up display is 0 ° when the reflecting section 30 is in at least one display position among the display positions in the display mode.
With this configuration, it is possible to provide a head-up display that has a display position where stress dispersion does not occur in at least one place and efficiently reduces the risk of image blur.

Fourthly, the head-up display 1 is a head-up display in which the contact angle is 0 ° at the display position closest to the parking position among the plurality of display positions.

C Vehicle 1 Head-up display (HUD)
WS Windshield (Reflecting and transmitting material)
V virtual image EP viewpoint L display light
2 display part 3 reflecting part 31 concave mirror 31a reflecting surface 32 holder 33 shaft 35 locking hole (power point)
37 Projection (point of action)
40 torsion spring (elastic part)
41 load end 42 fixed end 70 power transmission part 71 projection 80 power part
P rotation axis (fulcrum)

Claims

A head-up display that displays a virtual image by projecting display light onto a reflective / transmissive member of a vehicle,
A display unit that emits the display light representing vehicle information,
A reflecting portion that reflects the display light and is rotatable around a predetermined rotation axis,
A protrusion that can rotate the reflector by rotating in conjunction with the reflector;
An elastic portion that biases the protruding portion in a predetermined rotation direction by an elastic force,
A power transmission portion that comes into contact with a surface of the elastic portion positioned in the biasing direction,
A power unit that linearly moves the power transmission unit,
A rotatably holding the reflecting portion, the elastic portion, the power portion, and a hard structure that fixes the relative position of the rotating shaft,
Equipped with
The reflector is
A display mode for projecting the display light on the reflection / transmission member;
A rest mode in which the display light is not projected on the reflection / transmission member,
Have
The elastic portion is set so that the elastic force becomes stronger in the display mode,
Head-up display.
The protrusion is
In a plan view from the rotation shaft, the power transmission portion is always in point contact with the power transmission portion in abutting contact,
The contact angle formed by the contact direction and the linear movement direction is
The head-up display according to claim 1, wherein the head-up display is smaller in the display mode than in the sleep mode.
The reflector is
Can be displaced to multiple display positions in the display mode,
In the rest mode, it can be displaced to the rest position,
The contact angle is
The head-up display according to claim 2, wherein the angle is 0 ° when the reflecting portion is in at least one display position among the display positions.
The contact angle is
The head-up display according to claim 3, wherein the display position closest to the rest position among the plurality of display positions is 0 °.