JP2023059966A - Head-up display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head-up display reduced in image blurring.

SOLUTION: A head-up display comprises: a display part 2 that emits display light L representing vehicle information; a reflecting part 30 that can reflect the display light L and can rotate with a predetermined rotary shaft P as a center; a protruding part 37 in an arm-piece shape that rotates together with the reflecting part 30 to enable the reflecting part 30 to rotate; an elastic part 40 that energizes the protruding part 37 in a predetermined rotating direction by elastic force; a power transmitting part 70 that contacts the protruding part 37; a power part 80 that moves the power transmitting part 70; and hard structure that holds the reflecting part 30 rotatably and fixes relative positions of the elastic part 40, the power part 80 and the rotary shaft P.

SELECTED DRAWING: Figure 3

COPYRIGHT: (C)2023,JPO&INPIT

Description

The present invention relates to head-up displays.

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

JP 2009-73461 A

With such a configuration, there is a risk of image blurring when the vehicle vibrates greatly due to the meshing of the screw portion and the gear portion included in the drive member (61a). SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a head-up display in which the possibility of image blurring is reduced by paying attention to the above-mentioned problems.

In order to achieve the above object, the head-up display according to the present invention includes:
A head-up display that projects a virtual image by projecting display light onto a reflection-transmitting member of a vehicle,
a display unit that emits the display light representing vehicle information;
a reflector that reflects the display light and is rotatable about a predetermined rotation axis;
an arm-shaped projecting portion that can rotate the reflecting portion by rotating in conjunction with the reflecting portion;
an elastic portion that biases the projecting portion in a predetermined rotational direction with an elastic force;
a power transmission portion that abuts on the projecting portion;
a power unit that moves the power transmission unit;
a rigid structure that rotatably holds the reflecting section and fixes relative positions of the elastic section, the power section, and the rotating shaft;
with
The reflecting part is
a display mode in which the display light is projected onto the reflection-transmission member;
a pause mode in which the display light is not projected onto the reflection-transmission member;
has
The elastic portion is set such that the elastic force is stronger in the display mode.

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

The figure which shows a mode that the head-up display 1 of this indication was mounted in the vehicle C. FIG. 2 is a diagram showing the configuration of a head-up display 1; FIG. The figure which shows a part of head-up display 1 of a parking position. FIG. 4 shows a portion of the head-up display 1 in the toller position; The figure which shows a part of head-up display 1 of a shorter position.

An embodiment and modifications in which a head-up display (HUD) 1 of the present disclosure is mounted on a vehicle C will be described below in the following order with reference to the accompanying drawings.
[First embodiment]
1-1. Description of configuration 1-2. Explanation of modes [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 under a windshield WS provided on a vehicle C. As shown in FIG. The vertical direction of the drawing corresponds to the vertical direction Y of the vehicle C, the horizontal direction corresponds to the front-rear direction Z, and the depth direction corresponds to the horizontal direction X. As shown in FIG.

The HUD 1 displays a virtual image V by projecting display light L representing vehicle information onto a windshield WS (transmissive reflection member) having a free-form curved surface that is inclined forward of the vehicle. The HUD 1 emits the display light L in a diagonally upward direction behind 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 views the display light L reflected by the windshield WS at the viewpoint EP can view the projected virtual image V as a display image floating behind the windshield WS.

The virtual image V includes vehicle information such as speed and engine speed, route guidance displays such as turn-by-turn and maps, and warning displays such as blind spot monitors and speed limit warnings to alert passengers (users). Information that is highly necessary is displayed. This provides a driving environment in which the need for eye movement and eye focal length adjustment is reduced. The display image V includes characters and icons indicating these pieces of information, as well as a background portion, and has, for example, a rectangular shape when viewed from above by the occupant.

Also, the HUD 1 has two major modes. One is a display mode in which the HUD 1 projects the display light L onto the windshield WS as shown in FIG. 1 so that the virtual image V can be visually recognized from the viewpoint EP. The other is a pause mode (parking mode) in which the HUD 1 does not project the display light L onto the windshield WS and the virtual image V cannot be visually recognized from the viewpoint EP. The HUD 1 in the parking mode, which does not project the display light L onto the windshield WS, receives external light (mainly sunlight) incident on the HUD 1 from the direction of the windshield WS based on the principle of backward movement of light rays. It is located at a position where there is no reflection in the direction (the direction in which the display section optically exists). As a result, when the HUD 1 is in the parking mode when the vehicle C is considered to be stopped, the display section is prevented from being exposed to external light and reaching a high temperature.

The HUD 1 in the display mode 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 at which the virtual image V can be visually recognized. In the present disclosure, as shown in the drawings, it is possible to change to three types of shorter display light Ls, center display light Lc, and toller display light Lt. As for the shorter display light Ls, in the display mode, the HUD 1 projects the display light L toward a relatively lower portion of the windshield SW to project a virtual image V. As shown in FIG. With the Torah display light Lt, the HUD 1 projects the display light L relatively above the windshield SW to project a virtual image V. As shown in FIG. The center display light Lc projects a virtual image V through the two display optical paths.

The structure of HUD1 is demonstrated using FIG. The directions in the drawing corresponding to the directions of the vehicle C are the same as in FIG. FIG. 2 illustrates a state in which the reflecting portion 30 is at the Toller position Pt where the display light L is reflected as the Toller display light Lt. A coarse broken line Ps indicates the outer shape of the reflecting section 30 when the concave mirror 31 is at the shorter position, and a thin broken line Pp indicates the outer shape when the concave mirror 31 is at the parking position Pp (rest position). In the present disclosure, the parking position is defined as a position where the display light L is not projected onto the windshield WS, particularly a position where the center of the display light L is reflected in the direction B. FIG. Also, at each of the parking position Pp, the toller position Pt, the center position, and the shorter position Ps, the normal to the center of the reflecting surface 31a of the concave mirror 31 (where the center of the display light L is incident) has an angle with respect to the direction B. are, for example, 0°, 18.5°, 19.7°, 21°.

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

The display unit 20 is a member that emits the display light L. As shown in FIG. In the present disclosure, the light is emitted in direction F. As a member for emitting the display light L, for example, a structure using a TFT liquid crystal module, a structure using an organic EL, a projector using a DMD (Digital Micro-mirror Device), or the like can be applied. In a configuration using a TFT liquid crystal module, for example, the display section 20 is configured to have a backlight unit and a liquid crystal display element connected to the control section, respectively, in a fixed state, and a liquid crystal display element for displaying information under the control of the control section. emits display light L when illuminated by illumination light emitted from a backlight unit whose blinking is controlled by the control unit. However, it goes without saying 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 example.

The reflecting portion 30 includes a concave mirror 31, a holder 32, a shaft 33, a locking hole 35 (power point), and a projecting portion 37 (action point).

The concave mirror 31 reflects the display light L while enlarging the display light L according to the free curved surface shape formed on the reflecting surface 31a. The concave mirror 31 can apply a hard synthetic resin or inorganic glass to the base material, and can apply a configuration having a reflecting surface 31a formed by vapor-depositing silver, for example. Further, it is desirable that the reflecting surface 31a has a shape capable of canceling the distortion of the display image V that is expected to occur on the windshield WS due to the free-form surface shape.

The holder 32 is a holding member that fixes the concave mirror 31 by adhesion, screwing, or the like. Hard metals such as magnesium and iron, and hard synthetic resins such as ABS resin can be used as materials. The concave mirror 31 can be held at a position that does not hinder the reflection of the display light L as appropriate. For example, if the holder 32 holds the reflective surface 31a on the back side as shown in the drawing, the holder 32 cannot be seen from the viewpoint EP, and the risk of unintended light (stray light) reaching the viewpoint EP can be reduced.

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 of the holder 32 facing the direction X, for example. The reflection part 30 can be switched between the display mode and the parking mode by rotating around the rotation axis P defined by the axis 33 .

The shaft 33 is held rotatably by a rigid structure (not shown) in a state where the relative position between the fixed end 41 and the power section 80 is fixed. For example, a synthetic resin material such as ABS resin, or a metal such as magnesium can be used as the hard structure. This rigid structure may be a housing that accommodates each member that constitutes the head-up display 1, or may be a part of the vehicle body of the vehicle C. As shown in FIG. In addition, the structure in which the shaft 33 is held by a hard structure can be such that the shaft 33 is placed on a U-shaped guide, and is restrained by a leaf spring or the like with a force that does not hinder rotation. However, the present invention is not limited to this, and any rigid structure capable of holding such that the rotation axis P can be defined may be used.

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

The projecting portion 37 (point of action) is an arm piece provided integrally with 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 on the same plane as the rotation axis P. As shown in FIG. As a result, the contact surface is perpendicular to the direction Y when the reflecting member 30 is at the toller position Pt. Further, by providing the projecting portion 37 in the center of the holder in the direction X component, the concave mirror 31 can be rotated relatively without distortion. The direction in which the reflecting portion 30 reflects the display light L can be adjusted by displacing the position of the protruding portion 37 by the power transmission portion 70 to be described later. The reflecting portion 30 is held rotatably around the rotation axis P, and is urged in the rotational direction by a torsion spring 40, which will be described later. The angle of the reflecting section 30 can be changed by pushing back the protruding section 37 with a force greater than this bias or pulling it in with a weaker force.

In the present disclosure, protrusion 37 is integrally formed with holder 32 . However, the projecting portion 37 does not necessarily have to be formed integrally with the holder 32 . The projecting portion 37 may be provided on the concave mirror 31 . Furthermore, it is sufficient that the position of the reflecting portion 30 can be adjusted by displacing the projecting portion 37 around a predetermined rotation axis. That is, the rotation of the rotatably provided protrusion may indirectly adjust the angle of reflection 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 rotational direction. A hard metal such as hard steel or stainless steel can be applied as the material. In the present disclosure, shaft 33 serves as a guide rod. Torque can be applied to the load end 42 around the center (rotational axis P) of the shaft 33 that is the guide rod. The torque is determined according to the torque spring constant [N·mm/deg] inherent to the torsion spring 40 and the deflection angle. Further, the fixed end 41 is fixed to the above-described hard structure by means of engagement, adhesion, or the like, and the relative position between the rotating shaft P and the power section 80 is kept constant as described above. One end of the torsion spring 40 is bent toward the direction R, and the load end 42 is locked in the locking hole 35 as described above. That is, it is assembled in the manner shown in FIG.

Also, in the present disclosure, the torsion spring 40 is loaded in the winding direction. That is, it means that the torsion spring 40 is biased clockwise when viewed from the illustrated direction. On the other hand, it means that the protrusion 37 is pushed by the protrusion 71 toward the direction B. As shown in FIG. 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 the parking position is approached.

In addition, even when the parking position is reached, the torsion spring 40 does not return to its own free angle and is configured to continue to flex. This is because the purpose of the biasing of the torsion spring 40 is to provide biasing in any of the parking mode, the display mode, and the transition mode therebetween. By urging with a torque greater than or equal to a predetermined amount, even when torque is generated in the opposite direction due to an impact applied to the HUD 1, the locking hole 35, the reflecting portion 30, the projecting portion 37, the projection 71, the locking hole 35, the reflecting portion 30, the projecting portion 37, the projection 71, When the power transmission section 70 and the power section 80 are energized, image blurring and backlash due to backlash caused by gaps existing inside the power transmission section and the power section 80, even at the connecting portion of the power transmission section and the power section 80, may occur. Therefore, it is possible to reduce the risk of the sound caused by sticking.

Further, as described above, it is preferable to set the positions of both ends of the elastic portion so that the biasing force is stronger in the display mode than in the parking mode. This is because the vehicle C is generally not in a running state in the parking mode, whereas the vehicle C is often in a running state in the display mode. This means that there is a high possibility that a large impact will be applied to the head-up display 1 in the display mode. That is, by setting the positions of both ends of the elastic portion so that the urging force is stronger in the display mode than in the parking mode, it is possible to efficiently reduce the possibility of image blurring.

By the way, due to the above circumstances, the greater the torque spring constant [N·mm/deg] of the torsion spring 40, the greater the resistance to torque in the reverse direction. However, if it is too strong, the concave mirror 31 (reflecting surface 31a) will be distorted. Since this also leads to distortion of the virtual image V, it is necessary to perform sufficient biasing with a spring load that is as small as possible. A configuration according to the setting method will be described in detail later.

The control unit 50 is provided with a storage unit such as ROM and RAM (not shown) used for storage of a predetermined program and various data and a storage area for calculation, a CPU for performing arithmetic processing according to the predetermined program, an input/output interface, and the like. A 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 lighting means based on the vehicle information received from the vehicle-mounted equipment 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 driving of the power unit 80 .

The power section 80 is a power section that causes a power transmission section 70 described later to perform linear motion along a direction non-parallel to the rotation axis P. As shown in FIG. The present disclosure provides for linear motion in direction Z, for example. As described above, it is electrically connected to the control unit 50 and its operation is controlled.

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

The power transmission part 70 can be made of, for example, a hard and rigid resin material, performs linear motion by the power of the power part 80, and adjusts the angle of the reflection member 30 by pushing the protrusion 37 via the protrusion 71 provided on itself. can do. When the power unit 80 has the aforementioned configuration using a lead screw, it is fixed to the nut portion, and the nut portion abuts against the guide portion via the fixed power transmission portion 70, thereby suppressing its own rotation. You can
<1-2. Explanation of modes>

The state of biasing in each mode will be described with reference to FIGS. 3, 4, and 5. FIG.
FIG. 3 shows the state of biasing when the concave mirror 31 is at the parking position Pp. Tp indicates the torque applied to the reflecting member 30 by the torsion spring 40 at the parking position Pp. Fp indicates the force with which the protrusion 37 contacts the protrusion 71 . The contact force Fp is generated perpendicularly to the contact surface of the protruding portion 37 . fp indicates the Z-direction component force (holding component force) in Fp. By increasing the holding component force fp, it is possible to prevent rattling of the power section 80 even when a stronger impact is applied. This is because the direction of linear motion of the power section 80 and the power transmission section 70 coincides with the direction Z. FIG. Tx, Fx, and fx (x is t or s) in FIGS. 4 and 5 indicate the torque, force, or holding component force at the Toller position Pt or Shorter position Ps.

Here, the angle formed by the contact force Fp and the holding component 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 Z direction. In other words, it can be said that the angle (abutment angle) at which the protrusion 37 contacts the power transmission portion 70 is 18.5°. In addition, the holding component force fp is the contact force Fp multiplied by the cosine value 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 cosine of 2.5°. That is, when the contact angle is closer to 0°, the holding component force f can be applied more efficiently.

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

Therefore, as shown in the present disclosure, if the display mode is configured so that the contact angle is near 0° from the parking position Pp, stress dispersion is reduced as much as possible, and a head-up display with reduced image blur is provided. can.

Furthermore, in a configuration where the angle of contact is at right angles between the toller position and the shorter position, whichever is closer to the parking position, at least one position in the display mode will have no stress distribution. , image blurring can be reduced more efficiently.

More preferably, the torque spring constant is k [N·mm/deg], the angle as a variable is θ [deg], the contact angle of one of the toller position and the shorter position closer to the parking is θt [deg], and the other is θt [deg]. is the angle of contact at θs (that is, the angle obtained by adding the angle θt when the reflector is rotated from one position to the other position in the display mode) [deg], θ・k・cos θ is It is desirable to set θt so that the absolute value when integrated from θt to θs is maximized. According to this, it is possible to further reduce stress dispersion and efficiently reduce image blurring.

Thus, a head-up display that reduces the risk of image blur is provided.

Although the head-up display of the present invention has been described with the configuration of the above-described embodiment as an example, the present invention is not limited to this, and other configurations may also deviate from the gist of the present invention. It goes without saying that various improvements and display changes are possible within the scope of this invention. For example, in the present disclosure, a configuration using a holder is shown as a reflective portion in addition to the reflective surface and the projecting portion. However, it is sufficient that the holder is not provided and at least the reflecting surface 31a and the projecting portion move in conjunction with each other.

Moreover, it was set as the structure using the torsion spring as an elastic part. However, other structures than the torsion spring may be used as long as the elastic part can urge the reflecting part in the rotational direction. For example, it may be a coil spring in which the expansion and contraction direction connecting the fixed end and the elastic end (moving end) is at a twisted position with respect to the rotating shaft. If the expansion/contraction direction is not at the twisted position, torque cannot be generated with respect to the rotating shaft, and as a result, biasing cannot be performed. However, in the torsion position, if the moving end is stopped at the reflecting portion while the relative positions of the fixed end, the rotating shaft, and the power portion are kept constant as described above, torque is generated, Biasing can be performed.

Further, in the present disclosure, the positions of the reflecting portion 30 are, in order from the parking position, the parking position Pp, the toller position Pt, the center position, and the shorter position Ps. However, if the parking position is designed so that the reflective surface 31a faces the direction F, which is the traveling direction of the vehicle, the position of the reflective portion in the display mode closest to the parking position is the shorter position. In such a case, if the contact angle is set to 0° at the shorter position close to the parking position, the head-up display can efficiently reduce the possibility of image blurring.
[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 display light L onto a reflection-transmission member WS of a vehicle C,
a display unit 2 that emits display light L representing vehicle information;
a reflector 30 that reflects the display light L and is rotatable about a predetermined rotation axis P;
an arm-like projecting portion 37 that can rotate the reflecting portion 30 by rotating in conjunction with the reflecting portion 30;
an elastic portion 40 that biases the protruding portion 37 in a predetermined rotational direction with an elastic force;
a power transmission portion 70 that contacts a surface of the elastic portion 40 located in the biasing direction;
a power unit 80 that linearly moves the power transmission unit 70;
a hard structure that rotatably holds the reflecting part 30 and fixes the relative positions of the elastic part 40, the power part 80, and the rotation axis P;
with
The reflector 30 is
a display mode in which the display light L is projected onto the transmissive member WS;
a parking mode in which the display light L is not projected onto the reflection-transmission member WS;
has
The elastic part 40 is a head-up display whose elastic force is set to be stronger in the display mode.
According to this configuration, it is possible to provide a head-up display that can efficiently reduce image blur to a minimum when the vehicle C is in a state where the head-up display 1 is likely to be subjected to shock.

Second, the head-up display 1 is
The projecting portion 37 is
always in contact with the power transmission unit 70 in the rotational direction in plan view from the rotation axis P,
The contact angle between the direction of contact and the direction of linear motion Z is
The head-up display is smaller in display mode than in parking mode.
According to this configuration, it is possible to provide a head-up display that can prevent image blurring relatively efficiently.

Thirdly, the head-up display 1 is
The reflector 30 is
Can be displaced to multiple display positions (Toller position Pt and Shorter position Ps) in display mode,
In the parking mode, it can be displaced to the parking position Pp,
The contact angle is
This is a head-up display that becomes 0° when the reflecting part 30 is at at least one display position among the display positions in the display mode.
According to this configuration, it is possible to provide a head-up display that has a display position in which stress dispersion does not occur in at least one position and that effectively reduces the possibility of image blurring.

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 a 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 (Effort Point)
37 protrusion (point of action)
40 torsion spring (elastic part)
41 load end 42 fixed end 70 power transmission section 71 projection 80 power section

P Rotational axis (fulcrum)

Claims (4)

A head-up display that projects a virtual image by projecting display light onto a reflection-transmitting member of a vehicle,
a display unit that emits the display light representing vehicle information;
a reflector that reflects the display light and is rotatable about a predetermined rotation axis;
a protruding portion capable of rotating the reflecting portion by rotating in conjunction with the reflecting portion;
an elastic portion that biases the projecting portion in a predetermined rotational direction with an elastic force;
a power transmission portion that abuts on the projecting portion;
a power unit that moves the power transmission unit;
a rigid structure that rotatably holds the reflecting section and fixes relative positions of the elastic section, the power section, and the rotating shaft;
with
The reflecting part is
a display mode in which the display light is projected onto the reflection-transmission member;
a pause mode in which the display light is not projected onto the reflection-transmission member;
has
The elastic part is set so that the elastic force is stronger in the display mode,
head-up display. The protrusion is
always in contact with the power transmission portion in the rotational direction in a plan view from the rotating shaft,
The angle of contact between the direction of contact and the direction of movement is
2. A head-up display according to claim 1, wherein the display mode is smaller than the rest mode. The reflecting part is
Displaceable to a plurality of display positions in the display mode,
Displaceable to a rest position in the rest mode,
The contact angle is
3. The head-up display according to claim 2, wherein the angle is 0[deg.] when the reflecting portion is at at least one of the display positions. The contact angle is
4. 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[deg.].

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