WO2020153475A1

WO2020153475A1 - Head-up display device

Info

Publication number: WO2020153475A1
Application number: PCT/JP2020/002502
Authority: WO
Inventors: 建野口; 雅博渡邉; 大輝船見
Original assignee: 日本精機株式会社
Priority date: 2019-01-25
Filing date: 2020-01-24
Publication date: 2020-07-30
Also published as: DE202020005791U1; CN113330354A; DE112020000507T5; CN113330354B; JPWO2020153475A1; JP7439770B2

Abstract

Provided is a head-up display device (HUD) which is capable of suppressing a driving sound of a motor for driving a reflective mirror. This HUD device 10 displays, as a virtual image, an image in which display light L is shown by emitting, toward a light transmitting member, the display light L reflected from a concave mirror 13. The HUD device 10 is provided with: a motor for rotationally drive the concave mirror 13; a drive control unit and an origin detecting unit which are implemented to serve as a control unit 80; a storage unit 81; and a mass damper D. The drive control unit performs the rotary drive control for the concave mirror 13 by controlling the operation of the motor. The storage unit 81 stores an initial set position within the rotary range of the concave mirror 13. The origin detecting unit detects the origin in the rotary range of the concave mirror 13. The mass damper D has a mass body 70 and suppresses vibrations of the motor.

Description

Head up display device

The present disclosure relates to a head-up display device.

As a conventional head-up display device, for example, a device that rotationally drives a reflecting mirror (for example, a concave mirror) that reflects display light representing an image toward a translucent member (for example, a windshield of a vehicle) by the power of a motor is known. Patent Document 1 discloses.

JP, 2010-230157, A

In the conventional head-up display device, the vibration caused by the motor for driving the reflecting mirror may propagate to the outer case and be amplified, and the driving sound of the motor may be annoying.

The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a head-up display device capable of suppressing the driving sound of the motor for driving the reflecting mirror.

In order to achieve the above object, a head-up display device according to the present disclosure,
A head-up display device for displaying the image represented by the display light as a virtual image by emitting the display light reflected by a reflecting mirror toward a transparent member,
A motor for rotationally driving the reflecting mirror,
By controlling the operation of the motor, a drive control unit that performs rotational drive control of the reflecting mirror,
A storage unit that stores an initial setting position within the rotation range of the reflecting mirror,
An origin detection unit that detects the origin within the rotation range of the reflecting mirror,
A mass damper having a mass body for suppressing vibration of the motor,
After the origin is detected by the origin detector, the drive controller drives the motor at a first drive frequency to move the reflecting mirror to the initial setting position,
The mass of the mass body is determined based on the first driving frequency.

According to the present disclosure, it is possible to suppress the driving sound of the motor for driving the reflecting mirror.

It is a figure which shows the mounting aspect in the vehicle of the head-up display (HUD) apparatus which concerns on one Embodiment of this indication. It is a schematic block diagram of a HUD device. It is a perspective view of a reflecting mirror drive device. It is an exploded perspective view of a reflecting mirror drive device. It is a schematic diagram for demonstrating the positional relationship of a concave mirror and a slide part. It is a figure of a graph which shows the reduction effect of the drive sound of a motor.

An embodiment of the present disclosure will be described with reference to the drawings.

A head-up display (HUD) device 10 according to the present embodiment is arranged, for example, in a dashboard 2 of a vehicle 1 as shown in FIG. The HUD device 10 emits the display light L toward the windshield 3. The display light L reflected by the windshield 3 travels toward the user 4 (mainly the driver of the vehicle 1) and causes the user 4 to visually recognize the image represented by the display light L as a virtual image V. The virtual image V is displayed in front of the vehicle 1 via the windshield 3. As a result, the user 4 can observe the virtual image V by superimposing it on the front landscape. The virtual image V displays various information about the vehicle 1 (hereinafter referred to as vehicle information). The vehicle information includes not only information on the vehicle 1 itself but also external information on the vehicle 1.

As shown in FIG. 2, the HUD device 10 includes a display unit 11, a flat mirror 12, a concave mirror 13, a housing 14, a reflecting mirror driving device 20, and an operating unit 90.

By displaying an image, the display device 11 emits the display light L representing the image toward the plane mirror 12. The display device 11 includes, for example, an LCD (Liquid Crystal Display) and a backlight that illuminates the LCD from behind. The LCD is, for example, a TFT (Thin Film Transistor) type. The backlight includes, for example, an LED (Light Emitting Diode), a light guide member, and the like.

The plane mirror 12 is, for example, a cold mirror, and is arranged so as to be oblique to the optical axis of the display light L emitted from the display unit 11. The plane mirror 12 reflects the display light L from the display device 11 toward the concave mirror 13. The plane mirror 12 is fixed to the housing 14 via a holder (not shown).

The concave mirror 13 is formed, for example, by forming a reflective layer by vapor deposition on a resin substrate made of polycarbonate having a concave surface. The concave mirror 13 expands the display light L from the plane mirror 12 and reflects it toward the windshield 3. As a result, the virtual image V visually recognized by the user 4 is an enlarged image of the image displayed on the display unit 11.

The concave mirror 13 is held by a holder 13a. The holder 13a is made of, for example, a synthetic resin material, and includes a shaft portion 13b and a lever portion 13c. The shaft portion 13b is formed in a substantially columnar shape whose height direction is the direction in which the axis AX extends (the normal direction to the paper surface in FIG. 2). Although a pair of shafts 13b is provided on the holder 13a, only one shaft 13b is shown in FIG. The shaft portion 13b is rotatably supported by a bearing portion (not shown) provided in the housing 14. Thereby, the concave mirror 13 held by the holder 13a is rotatable with respect to the housing 14 about the axis AX. The lever portion 13c has a flat plate shape and is formed so as to project toward the reflecting mirror driving device 20. The reflecting mirror driving device 20 rotationally drives the concave mirror 13 held by the holder 13a around the axis AX by moving the lever portion 13c in parallel in the X-axis direction. The reflector drive device 20 will be described in detail later.

The housing 14 houses each of the display unit 11, the plane mirror 12, the concave mirror 13, and the reflecting mirror drive device 20 at an appropriate position for realizing the above-described functions. The housing 14 is made of synthetic resin or metal and has a light-shielding property and is formed in a box shape. The housing 14 may be composed of a combination of a plurality of members. The housing 14 is provided with an emission port 14a that opens toward the windshield 3. A translucent cover 15 is attached to the housing 14 to close the emission port 14a.

The display light L emitted from the display 11 and reflected by the plane mirror 12 and the concave mirror 13 in this order is emitted from the emission port 14a to the outside of the HUD device 10 and heads for the windshield 3. When the display light L is reflected by the windshield 3, a virtual image V is displayed in front of the windshield 3 when viewed from the user 4.

As shown in FIGS. 3 and 4, the reflector driving device 20 includes a motor 30, a support body 40, a guide shaft G, a slide portion 50, and a circuit board 60. Further, the reflector driving device 20 includes a mass body 70, a control unit 80, and a storage unit 81, which are schematically shown in FIG.

The motor 30 is for driving the concave mirror 13 to rotate, and is composed of, for example, a PM (Permanent Magnet) type stepping motor. The motor 30 is driven by a micro-step drive method by a drive control means described later. The driven motor 30 rotates the rotating shaft 31 extending along the X axis shown in FIG. A spiral thread groove is formed on the peripheral surface of the rotating shaft 31.

The support body 40 mainly supports the motor 30, and is integrally formed of metal, for example. The support body 40 includes a flat plate portion 40a fixed to the bottom portion 14b (see FIG. 2) of the housing 14, and a first wall portion 41 and a second wall portion 42 that face each other in the X-axis direction. In the support body 40, the flat plate portion 40a is fixed to the bottom portion 14b by a fixing means such as a screw. The support 40 may be fixed to the bottom portion 14b via a cushioning member (not shown). The first wall portion 41 is erected from one end portion of the flat plate portion 40a, and the second wall portion 42 is erected from the other end portion of the flat plate portion 40a. The motor 30 is attached to the back surface side of the surface of the first wall portion 41 facing the second wall portion 42. The motor 30 is fixed to the first wall portion 41 by fixing means such as a screw. The rotating shaft 31 extending from the motor 30 is rotatably supported in a bearing hole O2 provided in the second wall portion 42 through an insertion hole O1 provided in the first wall portion 41. Further, the support body 40 supports the mass body 70.

The guide shaft G guides the moving direction of the slide portion 50, and extends in the X-axis direction like the rotary shaft 31. The guide shaft G has one end supported by the first wall portion 41 and the other end supported by the second wall portion 42.

The slide portion 50 has a base portion 51 and a sandwiching portion 52 that sandwiches the lever portion 13c of the concave mirror 13. The slide portion 50 is integrally formed of, for example, a synthetic resin material such as polyacetal.

A guide hole 51a into which the guide shaft G is inserted is formed in the base 51. Further, the base portion 51 is provided with a nut portion (not shown) that meshes with the thread groove of the rotary shaft 31, and the nut portion moves the slide portion 50 in the X-axis direction according to the rotation of the rotary shaft 31. .. With such a configuration, the slide portion 50 can slide in the X-axis direction along the guide shaft G according to the rotation of the rotating shaft 31.

The sandwiching portion 52 is provided on the base portion 51, has a pair of wall portions facing each other, and sandwiches the lever portion 13c of the concave mirror 13 between the pair of wall portions. As shown in FIG. 3, one of the pair of wall portions is formed with a protrusion 52a protruding toward the other, and the other is provided with a leaf spring 52b. The sandwiching portion 52 sandwiches the lever portion 13c in a point contact state by pressing the lever portion 13c toward the protrusion 52a by the elastic force of the leaf spring 52b.

The circuit board 60 is a printed circuit board on which various circuits are formed and on which the motor 30, the drive circuit for driving the motor 30, and the switch 61 are mounted. As shown in FIG. 3, the circuit board 60 is fixed to the upper portion of the first wall portion 41 of the support body 40. The switch 61 is provided at a position facing the slide portion 50 in the X-axis direction, and contacts the slide portion 50 as the slide portion 50 moves leftward in FIG. 3, and controls a detection signal indicating the contact. Supply to the part 80. The control unit 80 controls the drive of the concave mirror 13 with the position of the slide unit 50 when the detection signal is acquired as the origin.

The mass body 70 is configured to function as a part of a mass damper D described later, and is provided at an arbitrary position of the support body 40. The mass body 70 is, for example, a weight formed of a metal material such as brass. The material of the mass body 70 is not limited, but it is preferable to select one having a large specific gravity in order to save space and ensure the necessary function of the mass damper D.

In the reflector driving device 20, the mass body 70 and the support body 40 function as a mass damper D (also called a tuned mass damper) schematically shown in FIG. The mass damper D suppresses the resonance phenomenon by adding an auxiliary mass body 70 to the motor 30 that is the object of vibration absorption via the support body 40 that functions as a spring. In this way, the mass damper D suppresses the vibration of the motor 30. The mass of the mass body 70 is determined based on the driving frequency when driving the motor 30, as described later.

The control unit 80 is composed of a microcomputer having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and controls the operation of the reflector driving device 20. The storage unit 81 is a non-volatile memory such as a flash memory and is controlled by the control unit 80 to store an initial setting position of the concave mirror 13 described later. The initial setting position may be stored in the ROM of the control unit 80. For example, the control unit 80 and the storage unit 81 are mounted on a printed circuit board (a board different from the circuit board 60) provided at a predetermined position of the housing 14. In this embodiment, the control unit 80 controls not only the operation of the reflector driving device 20 but also the entire operation of the HUD device 10 and the display operation of the display unit 11. For example, the control unit 80 communicates with a system such as an ECU (Electronic Control Unit) that controls each unit of the vehicle 1 and causes the display 11 to display an image indicating vehicle information.

Further, the control unit 80 controls the rotary drive of the concave mirror 13 by driving the motor 30 by the microstep drive method via the drive circuit of the circuit board 60. That is, the control unit 80 and the drive circuit function as a drive control unit that controls the rotation drive of the concave mirror 13. The drive circuit has a transistor bridge connected to the exciting coil of the motor 30, and is configured to be able to adjust the direction and magnitude of the exciting current flowing in the exciting coil. The drive circuit controls the current supplied to the exciting coil of the motor 30 under the control of the control unit 80. It should be noted that how the drive control unit is configured is arbitrary, and may be mounted on one board, or may be realized by cooperation of each unit mounted on a plurality of boards.

Further, the control unit 80 stores the point where the slide unit 50 comes into contact with the switch 61 as the origin in the RAM of the control unit 80, and counts the number of driving steps of the motor 30 being driven with the origin stored in the RAM as a reference. Specifies where the concave mirror 13 is currently located.

The control unit 80 drives the motor 30 via the drive circuit to move the slide unit 50 in the X-axis direction within the range between the first wall portion 41 and the second wall portion 42 of the support body 40. , Controls the rotational position of the concave mirror 13. In addition, the control unit 80 adjusts the position of the concave mirror 13 within the rotation range of the concave mirror 13 that allows the virtual image V to be displayed according to the input operation by the user 4 from the operation unit 90, so that the user 4 can see. The display position of the virtual image V in the vertical direction is adjusted. Then, the control unit 80 sets the position of the concave mirror 13 adjusted by the operation of the user 4 as a new initial setting position, and overwrites (updates) the initial setting position stored in the storage unit 81.

The operation unit 90 receives an input operation by the user 4, is configured by a known input device such as a push button and a touch panel, and supplies a signal indicating the operation content to the control unit 80 according to the input operation. To do. As the operation unit 90, for example, a steering switch provided on the vehicle 1 can be used.

Here, the positional relationship between the concave mirror 13 and the slide portion 50 will be described with reference to FIG. FIG. 5 schematically shows the relationship between the rotation position of the concave mirror 13 and the slide position of the slide portion 50. In practice, the axis AX, which is the rotation center of the concave mirror 13, does not move in the X-axis direction. Needless to say. The rotation range of the concave mirror 13 in which the display light L reflected by the concave mirror 13 does not reach the windshield 3 and the virtual image V cannot be displayed is defined as a non-display range R1. Further, the rotation range of the concave mirror 13 where the display light L reflected by the concave mirror 13 reaches the windshield 3 and the virtual image V can be displayed is a display range R2. In the non-display range R1, the rotation position of the concave mirror 13 at the position X1 where the slide portion 50 comes into contact with the switch 61 is defined as the first position P1. Further, the initial setting position of the concave mirror 13 in the display range R2 (the position set by the adjustment by the user 4) is the second position P2. Further, the position closest to the non-display range R1 in the display range R2, that is, the position of the concave mirror 13 when the virtual image V is switched from the non-display state to the display state is defined as the specific position Ps. In such a case, in the sliding range of the slide part 50, the position X1, the position Xs of the slide part 50 with the concave mirror 13 as the specific position Ps, and the slide part 50 with the concave mirror 13 as the second position P2 are arranged in order from the switch 61. It becomes the position X2.

When the ignition of the vehicle 1 is turned on and the operating power is supplied to the HUD device 10, the control unit 80 drives the motor 30 via the drive circuit to bring the slide unit 50 into contact with the switch 61, and determine the contact point. Remember as the origin. In this way, the control unit 80 functions as an origin detection unit that detects the origin. After storing the origin, the control unit 80 moves the slide unit 50 from the position X1 to the position X2 to move the concave mirror 13 from the position P1, which is the origin of the non-display range R1, to the initial setting position within the display range R2. Is rotated to the position P2 stored as. When the concave mirror 13 is positioned at the position P2, the control unit 80 controls the operation of the display device 11 and controls the display of the virtual image V.

In this embodiment, when rotating the concave mirror 13 from the position P1 (origin) to the position P2 (initial setting position), the control unit 80 sets the rotation speed of the concave mirror 13 in the non-display range R1 to the concave mirror in the display range R2. The rotation speed is set higher than that of 13, and the time until the display of the virtual image V is started is shortened. Specifically, the control unit 80 drives the motor 30 at the first drive frequency when moving the concave mirror 13 from the position P1 (origin) in the non-display range R1 to the position P2 (initial setting position) in the display range R2. To do. In addition, when the control unit 80 moves the concave mirror 13 to the position P2 (initial setting position) and then adjusts the position of the concave mirror 13 within the display range R2 according to the input from the operation unit 90, The motor 30 is driven at the second drive frequency lower than the drive frequency. At this time, the control unit 80 drives the motor 30 at a driving frequency of about 2500 pps (pulse per second) (for example, 2496 pps) as the first driving frequency in order to realize the rotation speed of the concave mirror 13 in the non-display range R1. To do. Then, if no measures are taken, a driving sound in the 2.5 kHz band may be generated corresponding to the driving frequency, and may be annoying to the user 4.

Therefore, in this embodiment, in order to suppress the drive sound generated as described above, the mass of the mass body 70 in the mass damper D is determined based on the drive frequency 2500 pps of the motor 30. The mass of the mass body 70 can be obtained by a theory, for example, by solving an equation of motion in a linear spring-mass system, but by the time the driving sound reaches the user's ear, the reflector driving device 20 and the HUD device 10 are driven. Since there are complex factors such as the configuration and the mounting mode of the HUD device 10 in the vehicle 1, it is actually obtained by an experiment or a combination of theory and experiment. For the same reason, it is preferable that the location of the mass body 70 on the support body 40 for effectively suppressing the driving sound is also determined by an experiment or a combination of theory and experiment.

FIG. 6 shows the effect of reducing the driving sound of the motor 30 by the mass damper D. The solid line graph 5 is the measurement result of the drive sound when the mass of the mass body 70 of the mass damper D is determined based on the drive frequency of 2496 pps in the reflecting mirror drive device 20 described above. On the other hand, the broken line graph 6 is the measurement result of the driving sound of the reflecting mirror driving device in which the mass damper D is not provided. Referring to FIG. 6, it can be seen that when the mass damper D is provided, the driving sound in the 2.5 kHz band is significantly reduced as compared with the case where the mass damper D is not provided.

(1) The HUD device 10 described above emits the display light L reflected by the concave mirror 13 (an example of a reflecting mirror) toward the windshield 3 (an example of a light-transmissive member) to display an image represented by the display light L. Is displayed as a virtual image V. The HUD device 10 includes a motor 30 for rotationally driving the concave mirror 13, a drive control unit and an origin detection unit realized as a function of the control unit 80, a storage unit 81, and a mass damper D. The drive control unit controls the drive of the concave mirror 13 by controlling the operation of the motor 30. The storage unit 81 stores the initial setting position (position P2) within the rotation range of the concave mirror 13. The origin detector detects the origin (position P1) within the rotation range of the concave mirror 13. The mass damper D has a mass body 70 and suppresses vibration of the motor 30.
With this configuration, as described above, the driving sound of the motor 30 for driving the reflecting mirror can be suppressed.

(2) Specifically, the origin (position P1) is within the rotation range (non-display range R1) of the concave mirror 13 that makes it impossible to display the virtual image V. In addition, the initial setting position (position P2) is within the rotation range (display range R2) of the concave mirror 13 that allows the virtual image V to be displayed.
With this configuration, it is possible to suppress the driving sound of the motor 30 when the reflecting mirror is rotated from the origin in the non-display range R1 to the initial setting position in the display range R2.

(3) Further, the HUD device 10 includes the operation unit 90. Then, the drive control unit moves the concave mirror 13 to the initial setting position, and then drives the motor 30 at the second drive frequency lower than the first drive frequency in response to the input from the operation unit 90 to display the virtual image V. The position of the reflecting mirror is moved within the rotation range (R2 within the display range) of the concave mirror 13 that enables the movement.
With this configuration, it is possible to effectively reduce the driving sound at the first driving frequency that is significantly generated, compared to the driving sound at the second driving frequency according to the adjustment operation of the user 4. As a result, for example, the period until the HUD device 10 is activated and the concave mirror 13 is moved to the initial setting position (that is, when the vehicle 1 has not yet started traveling, there is no road noise, and the driving sound is annoying). It is possible to effectively reduce the driving sound during the expected period).

The present disclosure is not limited to the above embodiments and drawings. Modifications (including deletion of constituent elements) can be appropriately added without changing the gist of the present disclosure.

A plane mirror other than the plane mirror 12 may be provided in the optical path of the display light L connecting the plane mirror 12 and the concave mirror 13. Further, a free-form curved mirror may be provided instead of the plane mirror 12. In the HUD device 10, how many mirrors are used and how the optical path of the display light L is turned back can be appropriately changed according to the design.

Although the example in which the reflecting mirror driving device 20 rotationally moves the concave mirror 13 has been described above, the reflecting mirror driving device 20 may also rotate and move a flat mirror or a free-form curved mirror (another example of the reflecting mirror). Good. The configuration of the reflecting mirror drive device 20 is arbitrary as long as it uses the power of the motor 30 to drive the reflecting mirror to rotate.

In the above, an example in which the mass body 70 is provided on the support body 40 has been shown, but a configuration in which the mass body 70 is attached to the motor 30 or the support body 40 via an elastic member may be adopted.

In the above, the mass of the mass body 70 is determined based on the drive frequency of the motor 30 when the concave mirror 13 is rotationally driven in the non-display range R1, but the drive of the motor 30 when the concave mirror 13 is rotationally driven in the display range R2. The mass of the mass body 70 may be determined based on the frequency. Further, the frequency band of the drive sound to be suppressed is also arbitrary, and may be higher or lower than the 2.5 kHz band. For example, the frequency band that the user 4 feels uncomfortable may be any frequency band within the range of 1 kHz to 5 kHz. If the mass body is made lighter than the mass body 70 of the mass damper D that suppresses the 2.5 kHz band of the driving sound, any frequency band higher than the 2.5 kHz band can be reduced, and if the mass body is made heavier. , Any frequency band lower than the 2.5 kHz band can be reduced.

In the above, an example in which the support 40 is fixed to the bottom portion 14b of the housing 14 has been shown, but the present invention is not limited to this. If the reflecting mirror can be rotationally moved, how to fix the support body 40 of the reflecting mirror driving device 20 to the housing 14 is arbitrary.

Also, the display device 11 is not limited to one using an LCD, and may use one using an OLED (Organic Light-Emitting Diode). Further, the display device 11 may use a reflective display device such as DMD (Digital Micromirror Device) or LCOS (Liquid Crystal On Silicon), for example.

Further, the translucent member which is the projection target of the display light L is not limited to the windshield 3 of the vehicle 1, and may be a combiner composed of a plate-shaped half mirror, a hologram element, or the like.

Also, the type of the vehicle 1 in which the HUD device 10 is mounted is not limited, and it can be applied to various vehicles such as a motorcycle and a motorcycle. In addition, the HUD device 10 may be mounted on a vehicle other than the vehicle 1, such as an aircraft, a ship, and a snowmobile.

In the above description, in order to facilitate understanding of the present disclosure, description of well-known technical matters has been appropriately omitted.

1... Vehicle, 2... Dashboard, 3... Windshield, 4... User L... Display light, V... Virtual image 10... Head-up display (HUD) device 11... Indicator 12... Plane mirror 13... Concave mirror (an example of a reflector)
R1... Non-display range, R2... Display range P1... First position, P2... Second position, Ps... Specific position 13a... Holder, 13b... Shaft portion, 13c... Lever portion, AX... Axis line 14... Housing, 14a... Ejection port, 14b... Bottom part 20... Reflector driving device 30... Motor, 31... Rotating shaft 40... Support, 40a... Flat plate part, 41... First wall part, 42... Second wall part G... Guide shaft 50 ...Sliding part, 51... Base part, 52... Clamping part 60... Circuit board, 61... Switch 70... Mass body, D... Mass damper 80... Control part, 81... Storage part 90... Operation part

Claims

A head-up display device for displaying the image represented by the display light as a virtual image by emitting the display light reflected by a reflecting mirror toward a transparent member,
A motor for rotationally driving the reflecting mirror,
By controlling the operation of the motor, a drive control unit that performs rotational drive control of the reflecting mirror,
A storage unit that stores an initial setting position within the rotation range of the reflecting mirror,
An origin detection unit that detects the origin within the rotation range of the reflecting mirror,
A mass damper having a mass body for suppressing vibration of the motor,
After the origin is detected by the origin detector, the drive controller drives the motor at a first drive frequency to move the reflecting mirror to the initial setting position,
The mass of the mass body is determined based on the first driving frequency,
Head-up display device.
The origin is in the rotation range of the reflecting mirror that makes it impossible to display the virtual image,
The initial setting position is within the rotation range of the reflecting mirror that enables the virtual image to be displayed,
The head-up display device according to claim 1.
Equipped with an operation unit,
The drive control unit, after moving the reflecting mirror to the initial setting position, drives the motor at a second drive frequency lower than the first drive frequency in response to an input from the operation unit to drive the virtual image. The position of the reflecting mirror is moved within the rotation range of the reflecting mirror that enables the display of
The head-up display device according to claim 2.