JPH10203199A - Display unit for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control a variation in the sense of distances by adjusting the display position of a virtual image to an upper position to a vehicle front bumper being unsightable from the viewpoint position of a driver so as to make an interval between the tip part of a sightable bonnet or the lower end position of a front window and a virtual image come to the specified one. SOLUTION: In the case where a driver shifts to a higher viewpoint E1 than another viewpoint E0, a vehicle front position being seen from the driver shifts to a contact point Pa1 from P1 on a bonnet 61 as well. In this case, each of coordinates (α1, β10) of the reference position of a combiner and the inclination of an optical axis are all adjusted according to the coordinate of the viewpoint E1 and an overlooking angle, whereby any possible change in an interval between the vehicle front contact point Pa1 seeable from the driver and a virtual image position to be displayed is thus preventable from occurring. In this connection, since a relationship between the combiner's reference position coordinate and the optical axis is always mechanically predetermined, the driver operates an attitude adjusting switch and even in a position of the viewpoint E1, he is merely enough to adjust it so as to make a virtual image 13 sightable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device for a vehicle, and more particularly, to a display device for a vehicle capable of displaying visible information about a vehicle as a virtual image within a limited field of view in front of a driver's seat.

[0002]

2. Description of the Related Art In general, a driver sitting in a driver's seat of a vehicle cannot directly see a front end of the vehicle hidden behind a hood of a vehicle body such as a front bumper. For this reason, in order to drive the front bumper in front of the vehicle so that it does not come into contact with obstacles, for example, on a narrow road or in a garage, the driver must estimate the position of the front bumper. Inexperienced drivers may have difficulty driving around obstacles.

[0003] Therefore, for example, a virtual image is displayed at a position above the front end of the hood that can be visually recognized by the driver, and if the position of the front end of the hood is recognized from the position of the virtual image, the vehicle can be operated. It is possible to prevent a situation in which it comes into contact with an obstacle. As a virtual image display device for displaying such a virtual image, those shown in FIGS. 11 and 12 are known.

In the virtual image display device shown in FIG. 11, light emitted from a light source 201 passes through a display film 203, enters a reflecting mirror 205, is reflected, and further enters a front window glass 207. Next, the light reflected by the front window glass 207 enters the eyes of the driver located at the viewpoint a. Display film 2
When light passes through 03, a specific image is added, so that the driver can visually recognize this image.

As a result, as shown in FIG. 11, the driver sees that a virtual image VI that does not actually exist at that position exists at a certain position above the front bumper.
Thus, the distance from the viewpoint a to the virtual image VI and the viewpoint a
Since the distance from to the display film 203 matches,
By visually recognizing the virtual image VI, there is an advantage that the driver can easily avoid contact between the front bumper and the obstacle.

[0006] Further, as shown in FIG.
However, since the inclination can be adjusted so as to be swingable about the central portion thereof, the direction of the optical path can be adjusted even when the height of the driver's viewpoint changes, so that the virtual image VI can be visually recognized even at the position of the viewpoint b. Have been. As a result, from viewpoint a to viewpoint b
If the driver's viewpoint exists at a position up to
By adjusting the inclination of the virtual image VI, the virtual image VI can be surely visually recognized. FIG.
The virtual image display device shown in FIG. 2 includes a projection device 221 and a translucent member 223 for displaying a virtual image. The light emitted from the projection device 221 is transmitted to the translucent member 2
23, is reflected by the surface, and enters the eyes of the driver located at the viewpoint. Thus, the driver can use the translucent member 2
Through 23, a virtual image displayed near the front bumper can be seen. Also, by adjusting the inclination of the translucent member 223, as in the case shown in FIG. 11, it is considered that the virtual image can be visually recognized even when the height of the driver's viewpoint changes.

[0007]

However, FIG.
Also, in the virtual image display device shown in FIG. 12, when the inclination of the reflecting mirror 205 or the translucent member 223 is adjusted according to the change of the viewpoint position, the inclination of the optical axis connecting the viewpoint and the virtual image changes, or the virtual image The visible position changes. FIG.
When the driver's viewpoint changes from the viewpoint a to the viewpoint b, the contact position at the upper end of the bonnet 225 in contact with the optical axis changes as shown in FIG. The vertical distance between the virtual image and the lower end of the virtual image changes from H1 to H2.

[0008] As described above, there is a possibility that a visual illusion may be given to the driver due to the change in the height of the viewpoint. There is a possibility that the driver may lose his sense of the distance from the virtual image to the virtual image position or the distance from the upper end of the hood to the virtual image position as seen by the driver. As a result, there is a problem that even when the conventional virtual image display device is used to drive on a narrow road or in a garage so as not to contact an obstacle in front of the vehicle, there is a risk of contact with the obstacle. Was.

[0009] The present invention has been made in view of the above, and an object of the present invention is to provide a vehicle display capable of suppressing a change in a sense of distance to a displayed virtual image even when the height of a driver's viewpoint changes. It is to provide a device.

[0010]

According to the first aspect of the present invention, in order to solve the above-mentioned problem, a vehicle can be visually recognized at a position above a bumper in front of a vehicle, which cannot be visually recognized from a viewpoint position above a driver's seat. Adjusting the display position of the virtual image so that an interval between the virtual image and a front end portion of a hood or a lower end position of a front window that can be visually recognized from the viewpoint position and the virtual image are at predetermined intervals. The gist of the present invention is to have adjusting means for performing the adjustment.

In order to solve the above-mentioned problem, it is preferable that the adjusting means adjusts the height of the virtual image display means and the direction of the optical axis in conjunction with each other.

According to a third aspect of the present invention, in order to solve the above-mentioned problem, a viewpoint position detecting means for detecting a viewpoint position of a driver, and a position for obtaining a position of a front end portion of a hood visible from the detected viewpoint position. The gist of the present invention is to have a calculating means.

[0013]

According to the first aspect of the present invention, a visible virtual image is displayed at a position above the bumper in front of the vehicle, which is invisible from the viewpoint position above the driver's seat, and is displayed from the viewpoint position. The display position of the virtual image is adjusted so that the interval between the visible end of the hood or the lower end position of the front window and the virtual image is a predetermined interval, so that the driver changes the height of the viewpoint. Even so, the distance between the virtual image and the tip of the hood visible from the viewpoint does not change, so that the driver's sense of distance to the displayed virtual image can be prevented from changing.

According to the second aspect of the present invention, the height of the virtual image display means and the direction of the optical axis are adjusted in conjunction with each other, so that the driver changes the height of the viewpoint. However, since the distance between the virtual image and the tip of the hood visible from the viewpoint does not change, it is possible to prevent a change in the driver's sense of distance to the displayed virtual image.

According to the third aspect of the present invention, the position of the driver's viewpoint is detected, and the position of the tip of the hood that can be visually recognized from the detected viewpoint is determined. The display position of the virtual image can be automatically adjusted using the position of the tip of the hood, and even if the driver changes the height of the viewpoint, the tip of the hood and the virtual image that are visible from the viewpoint position Since the distance formed by the driver does not change, it is possible to prevent a change in the driver's sense of distance to the displayed virtual image.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a diagram showing a configuration of a virtual image display device 1 according to a first embodiment of the present invention. In FIG. 1, a combiner 3 has a hologram surface on which information of a hologram image is recorded in advance, and is formed of a reflector having semi-light transmittance. The combiner 3 has one end 3
a is fixed to and supported by the device case 5. The light source unit 7 incorporated in the device case 5 is configured by a combination of a light source such as a light bulb or a light emitting diode, a reflector, a lens, and the like. Is configured to emit light close to a point light source by diffusing light through the light source.

The light emitted from the light source unit 7 enters the reflecting mirror 9 while being reflected by the reflecting mirror 9 and applied to the hologram surface 3b of the combiner 3. The light diffracted by the hologram surface 3b goes to the driver's viewpoint 11, and the virtual image 13 is reproduced so as to be visible at the viewpoint 11. Note that the virtual image 13 shown in FIG. 1 is an image conceptually showing a virtual image viewed from the viewpoint 11. The pedestal 15 supporting the device case 5 is fixed to the vehicle body, and the device case 5
Pedestal 15 via a telescopic device 17 for vertically moving
It is movably supported above. The pins 19a and 19b mounted on the device case 5 are respectively connected to the pedestal 1
5 are engaged with the guide grooves 21 and 23 formed.

The expansion / contraction device 17 has a mechanical structure that supports the device case 5 on the upper surface and changes the inclination of the upper surface in accordance with the height. In particular,
As the height of the device case 5 increases, the device case 5
The inclination changes so that the height on the rear side (viewpoint side) is higher than that on the front side. In addition, the extension device 17
When the device case 5 moves up and down due to
Since a and 3b move along the guide shapes of the guide grooves 21 and 23, the position and inclination of the device case 5 and the combiner 3 in the front-rear direction (X-axis direction) also change with this movement.

The expansion / contraction device 17 is configured to be driven by a motor (not shown). Further, a position adjustment switch (not shown) for instructing ascending, descending, and stopping is disposed at a position operable by the driver.
The motor provided in 7 operates. That is, the position and the inclination of the combiner 3 can be adjusted by operating the manual switch that can be operated by the driver. In addition, since the position adjustment of the position and the inclination of the combiner 3 are linked, the position and the inclination are mechanically determined by operating only one switch.

Light emitted from the light source unit 7 of the virtual image display device 1 enters the reflecting mirror 9, is reflected by the reflecting mirror 9, travels toward the combiner 3, and enters the hologram surface 3 b of the combiner 3. Since predetermined virtual image information is recorded in advance on the hologram surface 3b, the virtual image information is superimposed on the light diffracted by the hologram surface 3b and heads toward the driver's viewpoint 11. In this way, the driver at the viewpoint position can see the virtual image slightly upward from the tip of the hood.

Here, the principle of the hologram will be briefly described with reference to the principle diagram shown in FIG.

As shown in FIG. 1, a laser beam 33 is transmitted through a semi-transmissive reflecting mirror 35 and a reflecting mirror 37 to form a convex lens 3.
9, the laser light 41 emitted from the lens 39 is applied to the entire surface of the object 43. On the other hand, when the laser beam 33 is incident on the convex lens 51 via the semi-transmissive reflecting mirror 35, the reflecting mirror 47, and the reflecting mirror 49, the lens 51
Is emitted to the entire surface of the hologram recording surface 55.

Here, when the laser beam 41 is irradiated on the object 43, the reflected light 45 reflected from the object 43 is reflected.
And the interference fringes generated by the laser beam 33 and the reference beam 53 are recorded on the hologram recording surface 55 in advance. Next, when the hologram recording surface 55 is irradiated with the reference light 53, the object light is reproduced from the hologram recording surface 55. Thus,
A hologram image of the vehicle edge recorded in advance is shown in FIG.
Can be displayed as shown in FIG.

The position of the object recorded on the hologram recording surface 55 is recorded at a position where the hologram image can be seen at a preset position when the driver views the reproduced hologram image. I have. The hologram recording surface 55 thus recorded is attached to the transflective portion of the reflector 3. In the present embodiment, it is assumed that an image for indicating the position of the vehicle end to the driver is recorded on the hologram surface 3 in advance.

Next, the positional relationship among the virtual image display device, the viewpoint, the virtual image, and the like will be described with reference to FIGS. 4 and 5 show planes parallel to the longitudinal section of the vehicle. For convenience of explanation, it is assumed that the X-Y coordinate of the front end position of the front bumper 62 of the vehicle and the X coordinate of the display position of the virtual image 13 are set to 0 for convenience of explanation.

In FIG. 1, the virtual image 13 is located on an extension of the optical axis connecting the viewpoint E0 and the combiner 3 of the virtual image display device 1. In the same figure, 61 is a hood of a vehicle, 62 is a front bumper, 63 is an instrument panel, 65 is a front window glass, 67 is a virtual image display unit, and 69 is an adjusting device for adjusting the position of the virtual image display unit 67. It is. That is, the virtual image display unit 6
Reference numeral 7 denotes the device case 5, the light source unit 7, and the reflecting mirror 9 in FIG.
The adjusting device 69 corresponds to the telescopic device 17, the pedestal 15, the pins 210a and 210b, and the guide grooves 21 and 23 in FIG.

In FIG. 4, the viewpoint 11 is set at coordinates E0 (E
x, Ey), and a function representing the shape of the hood 61 is y = f (x). When looking ahead of the host vehicle from the position of the viewpoint E0, the position that can be visually recognized is the position Pa where the line of sight contacts the hood 61. In this case, the line of sight is a function y = f (x) representing the shape of the hood 61. Of the tangents that pass through the viewpoint E0. Therefore, when looking down at the point of contact Pa in front of the host vehicle from the viewpoint E0, the look-down angle is f ′ (a) = (Ey−f (a)) / (Ex−a) from the x coordinate a of the position Pa. Becomes Generally, f ′ (a) is expressed as a slope,
In the present invention, for convenience of explanation, it is assumed that the angle is used.

The virtual image 13 is arranged rearward of a position above the contact point Pa by a predetermined distance Hc in the image in front of the vehicle viewed from the viewpoint E0. In this case, the distance Hc corresponds to the predetermined angle c at the viewpoint E0. Therefore, the lower end of the virtual image 13 may be arranged in the direction in which the look-down angle is f '(a) -c. Assuming that the height of the lower end of the virtual image 13 is m, Ey = (f ′ (a) −c) · Ex + m (2) m = Ey− (f ′ (a) −c) · Ex (3) The straight line corresponding to the line of sight connecting the lower end of the virtual image 13 and the viewpoint E0 is y = (f '(a) -c) .x + m = (f' (a) -c) .x + Ey- (f '(a) −c) · Ex (4)

Here, the reference position (for example, the center) of the combiner 3 must exist on a straight line represented by the following equation (4). Assuming that the coordinates of this reference position are (α, β), the following equation holds. β = (f ′ (a) −c) · α + m (5) The lower end position of the virtual image 13 displayed by the hologram is P0
Then, since x = 0 at the lower end position P0 of the virtual image 13, when the distance L from the reference position of the combiner 3 to the point P0 is obtained,

(Equation 1) Becomes Next, when the coordinates (α, β) are obtained from the third, fifth, and sixth equations,

(Equation 2) Becomes

Therefore, the coordinates (α, β) are
(Y = f (x)) and the viewpoint position (Ex, Ey). Further, the inclination of the combiner 3 may be determined so that the emission direction of the hologram image coincides with (f ′ (a) −c). That is, by adjusting the adjusting device 69,
The coordinate (α, β) of the reference position of the combiner 3 satisfies the relationship of Expression 7, and the emission direction of the hologram image is (f ′ (a)
By adjusting the inclination and the position of the combiner 3 so as to be −c), even when the driver's viewpoint E0 moves up and down,
The virtual image 13 can be displayed at a position on the Y-axis corresponding to a position above a predetermined distance Hc from the contact point Pa in front of the vehicle, which can be directly recognized by the driver. That is, the distance between the hood 61, which is a real image, and the virtual image 13 can be kept constant, so that the sense of distance to the virtual image position can be prevented from changing due to the movement of the viewpoint.

For example, as shown in FIG. 5, when the driver moves to the viewpoint E1 higher than the viewpoint E0, the position in front of the vehicle seen by the driver is the contact point Pa on the hood 61.
To Pa1. In this case, by adjusting the coordinates (α1, β1) of the reference position of the combiner 3 and the inclination of the optical axis in accordance with the coordinates of the viewpoint E1 and the above-described relational expression, the contact point Pa1 in front of the vehicle as seen by the driver is displayed. It is possible to prevent the distance Hc from the virtual image position from changing. In the virtual image display device 1 shown in FIG. 1, the relationship between the reference position coordinates (α1, β1) of the combiner 3 and the inclination of the optical axis is mechanically predetermined so as to always satisfy the above-mentioned relational expression. Therefore, the driver only has to operate the attitude adjustment switch to adjust the virtual image 13 so that the virtual image 13 can be visually recognized even at the position of the viewpoint E1.

(Second Embodiment) FIG. 6 shows a second embodiment of the present invention.
It is a figure showing composition of virtual image display 71 concerning an embodiment. The feature of the virtual image display device 71 shown in the figure is that the telescopic device 17, the guide grooves 21 and 23, and the pins 19a and 19b of the virtual image display device 1 shown in FIG. That is, the lifting mechanisms 73 and 75 are provided. In addition, about the part which is not demonstrated in this Embodiment and the element shown with the same code | symbol,
It is the same as that shown in FIG.

The elevation mechanisms 73 and 75 can freely change the position of the combiner 3 and the inclination of the optical axis by adjusting the heights of the mechanisms themselves. The lifting mechanisms 73 and 75 are respectively provided with motors 8 shown in FIG.
1 and 83. The motor 81 has a position sensor 85 for detecting the height of the lifting mechanism 73.
However, the motor 83 is provided with a position sensor 87 for detecting the height of the lifting mechanism 75.

FIG. 7 shows an elevating mechanism 73 of the virtual image display device 71.
FIG. 7 is a diagram showing a configuration example of an electric circuit for controlling the power supply and the power supply 75; As shown in the figure, a microcomputer 77 for controlling the attitude of the virtual image display device 71 is provided. The switches SW1 and SW2 connected to the input of the microcomputer 77 are arranged at positions where the driver can operate them. The switch SW1 is used to instruct the elevating mechanisms 73 and 75 to rise, and the switch SW2 is used to instruct the descending. The microcomputer 77 includes a switch SW1, which is provided by the driver.
In response to the operation of SW2, the motors 81 and 83 are driven via the driver 79, and the heights of the lifting mechanisms 73 and 75 are automatically adjusted. When positioning these, the position information output from the position sensors 85 and 87 is referred to. Further, on a memory built in the microcomputer 77, data indicating a correlation between the height of the lifting mechanism 73 and the height of the lifting mechanism 75 is stored in the table 89 in advance.

Next, the operation of the virtual image display device 71 will be described with reference to the flowchart shown in FIG. This flowchart controls the entire virtual image display device 71 according to a control program stored in the internal ROM of the microcomputer 77. First, in step S10, the microcomputer 77 performs an initialization process on the device 77.
That is, the motors 81 and 83 are driven, and the lifting mechanisms 73 and 7 are driven.
The heights 5 are respectively positioned at predetermined initial positions.

Next, in step S20, the switch SW
The contact state of No. 1 is checked to determine whether or not the driver has given an ascending instruction. If the switch SW1 is on, the process proceeds to step S40, and if it is off, the process proceeds to step S30. Next, in step S30, the contact state of the switch SW2 is checked to determine whether or not the driver has given a descending instruction. If the switch SW2 is on, the process proceeds to step S40, and if it is off, the process returns to step S20. Next, in step S40,
If the switch in the ON state is SW1,
2 to determine the driving direction of the motor.

Next, in step S50, the target position is determined by referring to the data of the variable allocated on the internal memory corresponding to the front elevating mechanism 73. Next, in step S60, a predetermined small increment is added to or subtracted from the target position of the front lifting mechanism 73 input in step S50 (determined according to the driving direction), and the target position is updated.

Next, in step S70, the target position of the front elevating mechanism 73 updated in the immediately preceding step S60 is used as a variable to refer to the contents stored in the table 89 on the memory, and is associated. The target position data of the lifting mechanism 75 on the side is input, and the target position of the lifting mechanism 75 on the rear side is determined. Next, in step S80, the current position data output from the front position sensor 85 is input.
Next, in step S90, the current position data output from the rear position sensor 87 is input. Next, in step S100, the motor 81 is driven to automatically adjust the height of the front elevating mechanism 73 so that the target position determined in step S60 matches the current position detected in step S80. Adjust to At the same time, the motor 83 is driven to automatically adjust the height of the rear lifting mechanism 75 so that the target position determined in step S70 matches the current position detected in step S90.

As described above, the heights of the lifting mechanisms 73 and 75 are determined with reference to the table 89 on the memory, and the heights of the virtual image display units are adjusted using the lifting mechanisms 73 and 75, and at the same time, the optical axis is adjusted. Can be adjusted (tilt adjustment), and the distance (corresponding to the angle c) between the position of the leading end of the hood 61 and the virtual image that can be visually recognized by the driver in front of the vehicle can be suppressed.

(Third Embodiment) A virtual image display device according to a second embodiment of the present invention has the same configuration as that shown in FIG. 6, and the electric circuit shown in FIG. The viewpoint detection device 91 is added to the device shown in FIG. In FIG. 9, the viewpoint detection device 91 includes a video camera that captures a driver's face, and an image recognition device that recognizes regions of various parts of the face from image signals obtained by capturing the driver. The eye position coordinates (Ex, Ey) are output. The microcomputer 93 automatically adjusts the position of the virtual image display unit and the direction (tilt) of the optical axis based on the eye position coordinates (Ex, Ey) detected by the viewpoint detection device 91.

The coordinates of the driver's eyes (Ex, E, E) are stored in a memory built in the microcomputer 93.
A table is provided in which data indicating the correspondence between y) and the heights of the lifting mechanisms 73 and 75 is stored in advance. The contents of this table correspond to numerical data calculated based on the above-described calculation formula.

Next, the operation of the virtual image display device 71 will be described with reference to the flowchart shown in FIG. This flowchart controls the entire virtual image display device 71 in accordance with a control program stored in the internal ROM of the microcomputer 93. First, in step S210,
The microcomputer 77 performs an initialization process on the device 77. That is, the motors 81 and 83 are driven to
The heights of 3, 75 are respectively positioned at predetermined initial positions.

Next, in step S220, the position coordinates (Ex, E) of the driver's eyes output from the viewpoint detection device 91 are output.
Enter y). Next, in step S230, the eye position coordinates (Ex, Ey) input in step S220 are
It is compared with the previously detected eye position coordinates to determine whether or not the eye position has changed. When there is a change in the eye position, the process proceeds to step S240, and when there is no change, the process returns to step S220. Next, in step S240, the current position coordinates (Ex, Ey) of the eyes input in step S220 are used as variables, and the table 95 is referred to and the target of the front lifting mechanism 73 associated with the position coordinates of the eyes. The position and the target position of the lifting mechanism 75 on the rear side are input and determined as the target position.

Next, in step S250, position data output from the front position sensor 85 is input. Next, in step S260, the position data output from the rear position sensor 87 is input. Next, step S2
In step 70, the target positions of the front and rear elevating mechanisms 73 and 75 determined in step S240 and step S25
0, the motors 81 and 83 are driven so that the position data detected in S260 coincide with the position data respectively.
Automatically adjust the height of 3,75. Next, step S
Returning to 220, the process is repeated.

As described above, by determining the heights of the elevating mechanisms 73 and 75 with reference to the table, the height of the virtual image display unit is adjusted, and at the same time, the direction of the optical axis is adjusted (tilt adjustment). As a result, it is possible to suppress a change in the interval (corresponding to the angle c) between the position of the front end of the hood and the virtual image that can be visually recognized by the driver.

In the present embodiment, the position of the virtual image display device is determined in accordance with the bonnet shape of the host vehicle and the driver's viewpoint, but the present invention is not limited to such a configuration. For example, in the case of a vehicle such as a one-box vehicle in which the hood is not visible to the driver, the position of the virtual image display device is determined based on the lower end position of the front window and the viewpoint position. In this case, it is preferable that a portion closest to the displayed virtual image among the front end portions of the bonnet visible to the driver is set as the reference position.

In this embodiment, a case has been described in which a virtual image is displayed near the front end of the hood in front of the vehicle. However, the present invention is not limited to such a case. A virtual image may be displayed behind the vehicle in order to make the driver aware of the position of the part. In this case, for example, a virtual image display device is provided based on the trunk shape behind the vehicle, the position of the lower end of the rear glass, and the driver's viewpoint. May be determined. Further, in the present embodiment,
In forming the virtual image display device, the light source unit 7 and the reflecting mirror 9 are used.
Although the case where the hologram recording surface is used has been described, the present invention is not limited to the use of such a hologram virtual image, and displays a real image by combining a plurality of lenses, or displays a virtual image using a display film. It may be configured as follows.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a virtual image display device 1 according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining the principle of a hologram.

FIG. 3 is a diagram showing a virtual image displayed using a hologram.

FIG. 4 is a side view illustrating a positional relationship between a virtual image displayed by the vehicular display device 1 according to the first embodiment of the present invention and a viewpoint.

FIG. 5 is a side view showing a positional relationship between a virtual image displayed by the vehicular display device 1 according to the first embodiment of the present invention and a new viewpoint.

FIG. 6 is a diagram illustrating a configuration of a virtual image display device 71 according to a second embodiment of the present invention.

7 is a diagram showing a configuration example of an electric circuit for controlling the elevating mechanisms 73 and 75 of the virtual image display device 71. FIG.

FIG. 8 is a flowchart for explaining the operation of the virtual image display device 71.

9 is a block diagram showing that a viewpoint detection device 91 is added to the electric circuit shown in FIG. 7;

FIG. 10 is a flowchart for explaining the operation of the virtual image display device 71.

FIG. 11 is a side view showing a positional relationship between a virtual image displayed by a conventional vehicle display device and a viewpoint.

FIG. 12 is a side view showing a positional relationship between a virtual image displayed by a conventional vehicle display device and a viewpoint.

[Explanation of symbols]

 Reference Signs List 3 Combiner 5 Device case 7 Light source unit 9 Reflector 11 Driver's viewpoint 13 Virtual image seen from viewpoint 11 Base 17 Expansion device 19a, 19b Pin 21, 23 Guide groove 73, 75 Elevating mechanism 77, 93 Microcomputer 81, 83 Motor 85, 87 position sensor 91 viewpoint detection device SW1, SW2 switch

Claims (3)

[Claims] 1. A virtual image display means for displaying a visible virtual image at a position above a bumper in front of a vehicle which is invisible from a viewpoint position above a driver's seat, and a tip of a hood visible from the viewpoint position. A display device for a vehicle, comprising: adjusting means for adjusting a display position of the virtual image so that an interval between a lower end position of a part or a front window and the virtual image is a predetermined interval. 2. The vehicle display device according to claim 1, wherein said adjusting means adjusts the height of said virtual image display means and the direction of an optical axis in conjunction with each other. 3. The apparatus according to claim 1, further comprising: viewpoint position detecting means for detecting a viewpoint position of the driver; and position calculating means for calculating a position of a front end portion of the bonnet which can be visually recognized from the detected viewpoint position. The display device for a vehicle as described in the above.