JPH11337861A - Onboard headup display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of a distortion in virtual image and to secure a large magnification by making an image forming beam as a virtual image incident on a reflection mirror from a convex lens and enlargingly reflecting it toward a proper place of a front window shield. SOLUTION: When both of the focal point distance of an objective point side focus F1 of the convex lens T and the focal point distance of an image point side focus F2 are made (f), a liquid crystal panel P is arranged between the convex lens T and the objective point side focus F1. The reflection mirror reflects the display beam of the liquid crystal panel P1 image formed as a virtual image by the convex lens T toward the reflection mirror M2. The reflection mirror M2 consists of a sheet of hologram concave mirror having a prescribed magnification K1, and enlarges the reflection beam of the reflection mirror at the magnification K1 to reflects it toward the proper place of the front window shield through an upper wall opening of an instrument panel. That means that the front window shield reflects the reflection beam of the reflection mirror, and image forms the display information of the liquid crystal panel P as the virtual image in the direction of the sight line of a driver.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head-up display for a vehicle.

[0002]

2. Description of the Related Art Conventionally, as this kind of vehicle head-up display, there is one disclosed in, for example, Japanese Patent Application Laid-Open No. 7-84209. In this head-up display, light representing display information emitted from the display device is enlarged and reflected by a single hologram concave mirror toward the front windshield of the vehicle, so that a virtual image is formed forward by the front windshield. The display information on the liquid crystal panel is made visible to the driver.

[0003]

In the above head-up display, in order to make the virtual image formed in front of the front windshield as easy to see as possible, it is necessary to increase the magnification of the hologram magnifying reflector as much as possible. desirable. However, there is naturally a limit in increasing the magnification of the hologram concave mirror, and if the magnification is too large, there is a problem that the virtual image is significantly distorted. Also, using a plurality of concave hologram mirrors complicates the optical path and increases the cost.

In order to cope with the above, the present invention secures a large magnifying power while preventing the generation of a virtual image distortion by combining a convex lens with a reflecting mirror comprising a concave mirror such as a hologram concave mirror. It is an object of the present invention to provide a head-up display for a vehicle which is configured to perform the above.

[0005]

According to the first aspect of the present invention, a head-up display for a vehicle is positioned below a front windshield (W) in a vehicle cabin. A display element (P) disposed on the back side of the instrument panel (I) to emit display information as display light; and a display element (P) disposed on the back side of the instrument panel in front of the display element. A reflection mirror (M2), which is a reflection mirror comprising a concave mirror provided and which receives display light from the display element and expands and reflects toward the appropriate position of the front windshield through the upper wall opening (I1) of the instrument panel. The front windshield reflects the reflected light at an appropriate position and displays the display information ahead as an enlarged virtual image.

Here, the head-up display has a convex lens (T) disposed between the display element and the reflection mirror to enlarge the display light of the display element to the back side and form an image as a virtual image. Then, instead of the display light of the display element, the reflection mirror receives the image forming light as a virtual image from the convex lens, passes through the upper wall opening (I1) of the instrument panel, and expands toward the right position of the front windshield. reflect.

As described above, the convex lens is disposed between the display element and the reflection mirror, and the display light of the display element is enlarged to the back side to form an image as a virtual image. The display information as a virtual image formed in front of the image is an image enlarged by both the convex lens and the reflection mirror at an overall magnification. For this reason, the virtual image is an image having a size that is very easy for the driver to see.

Further, the expansion of the display element with respect to the display light is as follows.
Since this is achieved by the optical combination of the reflection mirror and the convex lens T as described above, it is possible to secure a large value of the overall enlargement ratio without complicating the optical path and distorting the virtual image. According to the second aspect of the present invention, the head-up display for a vehicle is disposed on the back side of the instrument panel (I) located below the front windshield (W) in the vehicle interior of the vehicle. A display element (P) for emitting display information as display light, and a reflecting mirror comprising a concave mirror disposed on the back side of the instrument panel and in front of the display element, and A reflection mirror (M2) which receives the display light, passes through the upper wall opening (I1) of the instrument panel, and expands and reflects the display light at an appropriate position on the front windshield.
And a convex lens disposed between the appropriate position of the front windshield and the reflecting mirror, and expands the reflected light of the reflecting mirror to the rear side thereof to form an image as a virtual image, and the image forming light is applied to the appropriate position of the front windshield. The front windshield reflects the image forming light of the convex lens at an appropriate position and displays the display information ahead as an enlarged virtual image.

As described above, unlike the first aspect of the present invention, the convex lens is provided between the proper position of the front windshield and the reflecting mirror so that the reflected light of the reflecting mirror is enlarged toward the back side to form a virtual image. Claim 1
The same operation and effect as the invention described in (1) can be achieved. According to the third aspect of the present invention, the vehicle head-up display is disposed on the back side of the instrument panel (I) located below the front windshield (W) in the vehicle interior of the vehicle. Display element (P), a reflection mirror (M2) composed of a concave mirror, and a convex lens (T).

In addition, the convex lens is arranged so as to form a virtual image on the back side thereof through an optical path connecting the display element and an appropriate position of the front windshield via both the convex lens and the reflection mirror. Further, the display element passes display light representing display information through a reflection mirror under the virtual image forming action of the convex lens, and expands the display light at an overall magnification of both the convex lens and the reflection mirror. At the right place.

Then, the front windshield reflects the incident light at an appropriate position, and displays the display information in the front as an enlarged virtual image. This also achieves the same functions and effects as the first and second aspects of the invention.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of an automotive head-up display according to the present invention. The head-up display includes an instrument panel extending downward from the lower edge of a front windshield W of the automobile to the interior of the vehicle. I is disposed on the back side.

The head-up display includes a light source system L, a convex lens T, a transmission type liquid crystal panel P, and both reflection mirrors M1 and M2. As shown in FIG. 2, the light source system L includes a lamp 10 and a reflector 20, and the lamp 10 and the reflector 20
0.

Specifically, as shown in FIG. 2, the lamp 10 is connected to the through hole 3 of the substrate 30 by the connector 11 thereof.
1 and the lamp portion 12 of this lamp 10
Has a substantially elliptical cross section and protrudes above the board 30 from the connector 11. Here, the lamp section 12 emits light from the entire outer surface thereof. The front part 1 of the lamp part 12
The outer surface of 2a is grained.

As shown in FIGS. 2 and 3, the reflector 20 includes a reflecting wall 20a, and right and left flanges 20b provided integrally on the left and right sides of the reflecting wall 20a.
The reflector 20 is fastened to the left and right rising walls 32 of the substrate 30 by screws 33 at both left and right flanges 20b. As shown in FIGS. 2 and 4, the reflecting wall 20a is integrally formed by a hemispherical wall 21 and a semi-parabolic wall 22.

The semi-parabolic wall 22 constitutes the upper part of the reflecting wall 20a.
2 upper part (hereinafter referred to as the upper part on the back side 12b)
Facing. On the other hand, the hemispherical wall portion 21 is
a constituting a portion other than the semi-parabolic wall portion 22;
The hemispherical wall portion 21 faces the back portion 12c of the back portion of the lamp portion 12 other than the back side upper portion 12b. In the present embodiment, the respective focal points of both the hemispherical wall portion 21 and the semi-parabolic wall portion 22 on the lamp 10 side are located on a common optical axis S (described later) with the lamp 10.

Here, the light emission center of the lamp section 12 is denoted by a symbol a.
If the horizontal axis (hereinafter referred to as the optical axis S) passing through the emission center a is taken, both ends of the hemispherical wall portion 21 in the cross-sectional vertical direction in FIG. Is set at a predetermined angle 2α such that the light emitted from the back portion 12c of the lamp portion 12 can be used effectively.

On the other hand, the angle formed by both ends of the semi-parabolic wall 22 in the vertical direction in the sectional view of FIG.
The predetermined angle β is set so that light emitted from the upper rear portion 12b of the lamp portion 12 can be effectively used. In the present embodiment, the predetermined angle β is a value within a range from 20 degrees to 35 degrees. However, without being limited to this, the predetermined angle β
May be set so that the light emitted from the upper rear portion 12b of the lamp portion 12a can be reflected by the semi-parabolic wall portion 22 without leakage. The predetermined angle α is a value obtained by subtracting the predetermined angle β from approximately 90 degrees. The hemispherical wall 21
Each of the inner surfaces of the semi-parabolic wall portions 22 is subjected to a treatment such as application of a diffuse reflection paint.

In the reflector 20 configured as described above, the hemispherical wall portion 21 is provided on the back portion 1 of the lamp portion 12.
The light emitted from 2c is reflected forward and toward the optical axis S as shown by the arrow in FIG. The semi-parabolic wall 22 reflects the light emitted from the upper part 12b on the back side of the lamp part 12 forward and toward the optical axis S as shown by the arrow in FIG.

Further, as shown in FIG. 2, the light source system L includes a convex lens 30 and a heat ray absorbing filter 40, and the convex lens 30 and the heat ray absorbing filter 40
The casing 6 together with the liquid crystal panel P via the support member 50
It is assembled in 0. The convex lens 30 is supported coaxially with the optical axis S in the through hole 51 of the support member 50, and the convex lens 30 faces the opening 61 of the casing 60 at its entrance surface 31. Left and right ends 3
2 (see FIGS. 5 and 6), which are fixed to the left and right ends of the through hole 51.

The convex lens 30 has a plano-convex lens section 33, and the exit surface 34 of the plano-convex lens section 33 is a paraboloid having a convex shape on the side opposite to the incident surface 31. However, the object point side focal point F (see FIG. 5) of the plano-convex lens section 33 is located on the lamp 10 side. The convex lens 30 configured as described above receives the direct light from the lamp 10 and the reflected light from the reflector 20 through the opening 61 of the casing 60 on the incident surface 31, and the incident light is reflected by the plano-convex lens unit 33. The light is converted into parallel light and emitted from the emission surface 34.

The plate-like heat ray absorbing filter 40 is a convex lens 3
The bottom surface of the support member 50 is fixed to a portion of the bottom wall of the support member 50 so as to face the light exit surface 34 of the first lens 30. This heat ray absorbing filter 40 absorbs infrared rays in the parallel light from the convex lens 30. By doing so, the temperature rise of the liquid crystal panel P is suppressed. The liquid crystal panel P is supported by a part of the support member 50 in front of the heat ray absorbing filter 40. The liquid crystal panel P receives parallel light from the convex lens 30 via the heat ray absorbing filter 40, and receives vehicle information. Is emitted through the opening 62 of the casing 60 as display light indicating
Note that the liquid crystal panel P is supported to be inclined with respect to the optical axis S as shown in FIG.

The convex lens T is connected to the opening 6 of the casing 60.
The convex lens T is attached to the substrate 30 at the front side of the optical element 2, and is arranged so that its optical center O coincides with the optical axis S and is orthogonal to the optical axis S. This convex lens T
Has a square front shape as shown in FIG. 7. The convex lens T receives display light from the liquid crystal panel P through the opening 62 of the casing 60, and At the rear, a virtual image P1 at a predetermined magnification K
(See FIG. 8).

More specifically, the specifications of the convex lens T and the positional relationship between the convex lens T and the liquid crystal panel P are set as follows.
As shown in FIG. 8, assuming that the focal length of the object-side focal point F1 and the focal length of the image-point-side focal point F2 of the convex lens T are both f, the liquid crystal panel P is located between the convex lens T and the object-side focal point F1. It is arranged.

Here, the distance between the optical center O of the convex lens T and the center in the width direction of the liquid crystal panel P on the optical axis S is defined as m, and the center of the liquid crystal panel P in the width direction and the optical axis of the virtual image P1 of the liquid crystal panel. Assuming that the distance from the center in the S upper width direction is n, the predetermined enlargement factor K is obtained as (n / m) in the proportional processing in FIG. The reflection mirror M1 reflects the display light of the liquid crystal panel P1 formed as a virtual image by the convex lens T on the reflection mirror M1.
Reflects toward 2.

The reflection mirror M2 is composed of a single hologram concave mirror having a predetermined magnification K1, and this reflection mirror M2 enlarges the reflected light of the reflection mirror M1 at the magnification K1 to form an instrument panel. I upper wall opening I
1, the light is reflected toward the right position of the front windshield W. This means that the front windshield W
Reflects the reflected light of the reflection mirror M1, and forms the display information of the liquid crystal panel P as a virtual image W1 in front of the driver Q through a proper place of the front windshield W in the line of sight of the driver Q. Means

In the present embodiment configured as described above,
When the lamp 10 of the light source system L is emitted from the entire outer surface of the lamp portion 12, the emitted light from the front portion 12a of the lamp portion 12 of the emitted light passes through the opening 61 of the casing 60 and is incident on the convex lens 30 at the incident surface. It enters from 31. Here, the reflector 20 is, as described above, a hemispherical wall portion 21.
And a semi-parabolic wall 22. For this reason, outgoing light of the lamp portion 12 from the back of the lamp portion 12 is incident on each of the reflecting surfaces of the hemispherical wall portion 21 and the semi-parabolic wall portion 22 of the reflector 20 and is reflected therefrom.
The light enters the convex lens 30 from the entrance surface 31 through the opening 61 of the zero.

Further, as described above, the upper and lower ends of the cross section of the hemispherical wall portion 21 have the optical axis S around the light emission center a.
Is set as the predetermined angle 2α. In the semi-parabolic wall 22, the angle formed by the upper and lower ends of the cross section with respect to the emission center a is the angle of the lamp 1.
The predetermined angle β is set so that the light emitted from the upper part on the back side of the second 2 can be effectively used.

For this reason, the back part 12c of the lamp part 12
Is reflected by the hemispherical wall portion 21 and is incident on the convex lens 30.
Almost all of the light emitted from b is reflected by the reflecting surface of the semi-parabolic wall 22 and enters the convex lens 30. Thus, the lamp 1 including the light emitted from the front portion 12a of the lamp 10
Almost all outgoing light of 0 enters the convex lens 30. As a result, light emitted from the lamp 10 can be used as light to be incident on the liquid crystal panel P via the convex lens 30 without leakage, and the utilization rate of light emitted from the lamp 10 can be significantly improved.

As described above, when the direct light from the lamp 10 and the reflected light from the reflector 20 are incident on the convex lens 30, the convex lens 30 converts the incident light into parallel light at the plano-convex lens section 33 and absorbs heat rays. The light enters the liquid crystal panel P through the filter 40. The plano-convex lens portion 33 of the convex lens 30 has the above-described shape (FIGS. 2, 5, and 6).
), The incident surface 3 of the convex lens 30
All of the light incident on 1 can be efficiently converted into parallel light and incident on the liquid crystal panel P.

Next, when the liquid crystal panel P emits the incident light as display light, the emitted display light is
The light is incident on the convex lens T through the opening 62 of zero. Here, as described above, the liquid crystal panel P is located between the optical center O of the convex lens T and the object point side focal point F1 at a position that provides the magnification K. Therefore, the convex lens T transmits the display light from the liquid crystal panel P behind the liquid crystal panel P to the virtual image P of the magnification K.
An image is formed as 1. This means that, instead of the liquid crystal panel P, display light from the liquid crystal panel as a virtual image with the magnification K is incident on the reflection mirror M2 via the reflection mirror M1 by the convex lens T.

Then, the display light from the convex lens T is enlarged and reflected by the reflection mirror M2 at the enlargement factor K1, and the upper wall opening I1 of the instrument panel I is reflected.
Through the front windshield W and is reflected toward the right place. Accordingly, the front windshield W reflects light from the reflection mirror M2 to form the display information as a virtual image W1. Thereby, the driver Q visually recognizes the display information on the liquid crystal panel P as the virtual image W1.

In this case, as described above, the display light of the liquid crystal panel P is enlarged by the convex lens T at the enlargement factor K, and the light from the convex lens T is enlarged by the reflection mirror M2 at the enlargement factor K1. The virtual image W1 in front of the windshield W is an image enlarged by the product of both magnifications K and K1. For this reason, the virtual image W1 is an image having a size that is very easy for the driver Q to see.

Further, since the enlargement of the liquid crystal panel P with respect to the display light is achieved by the optical combination of one reflection mirror M2 and one convex lens T as described above, the optical path becomes complicated and the virtual image W1 is distorted. It is possible to obtain a virtual image W1 that is very easy to see for the driver Q, as well as to secure a large magnification that is the product of the two magnifications K and K1 without accompanying.

Since the light emitted from the lamp 10 is used as incident light to the liquid crystal panel P without leakage as described above, the display brightness of the liquid crystal panel P is very high. Therefore,
As a virtual image formed in front of the front windshield W via the two reflection mirrors M1 and M2, the luminance of the display information of the liquid crystal panel P becomes very high. That is, as described above, the reflector 20 is configured to have the hemispherical wall portion 21 and the hemispherical wall portion 21 and the convex lens T is provided so that the driver Q
Can visually recognize the virtual image W1 in an easy-to-see size with no distortion in light luminance regardless of day or night.

In implementing the present invention, the convex lens T
Is not limited to the one described in the above embodiment, and may be any convex lens having a magnification ratio K. For example,
A Fresnel lens having an enlargement factor K may be used. Further, in the embodiment of the present invention, the reflection mirror M2 is not limited to a hologram concave mirror, but may be any concave mirror as long as it has a magnification K1.

In implementing the present invention, unlike the above embodiment, a convex lens T is disposed between the two reflecting mirrors M1 and M2, and the object-side focal point F of the convex lens T is set.
A reflection mirror M1 may be provided in the unit 1 instead of the liquid crystal panel P. In this case, the convex lens T enlarges the reflected light of the reflection mirror M1 at the magnification K, and the virtual image reflection mirror M
The convex lens T and the reflecting mirror M1
Set the placement relationship between

In implementing the present invention, unlike the above-described embodiment, the convex lens T is disposed between a proper position of the front windshield W and the reflection mirror M2,
A reflection mirror M2 may be provided in place of the liquid crystal panel P in the object-side focal point F1 of the convex lens T. In this case, the positional relationship between the convex lens T and the reflection mirror M2 is set so that the convex lens T enlarges the enlarged reflected light of the reflection mirror M2 at the magnification K and forms an image as the virtual image reflection mirror M2.

In implementing the present invention, the reflection mirror M1 may be omitted. Also, in implementing the present invention,
The light source system L may be only the lamp 10, and
The lamp 10 may be various light source elements such as an incandescent lamp, a xenon lamp, a halogen lamp, a cold cathode tube, and a light emitting diode. In implementing the present invention, the light from the lamp 10 and the reflector 20 is sufficient for the liquid crystal panel P.
In the case where the display brightness can be ensured, the convex lens 30 may be omitted to implement.

In practicing the present invention, the reflector 20 has a hemispherical wall portion 21 as described in the above embodiment.
Instead of the semi-parabolic wall 22, the semi-spherical wall 21 and the semi-parabolic wall 22 may be configured to have an arc-shaped spherical wall and a parabolic wall. Also,
The reflector 20 may have a hemispherical reflecting wall that exposes the upper rear portion 12b of the lamp 20 to the outside.

In practicing the present invention, instead of the liquid crystal panel P, a self-luminous display element such as an electroluminescence panel which emits display information as display light, or a CR.
A display device such as a T television may be employed. In addition,
The light source system L becomes unnecessary. In the above embodiment, the light source system L has been described as a concept different from the liquid crystal panel P.
Instead, the light source system L may be included in the liquid crystal panel P to serve as a display element.

In the above embodiment, an example in which the present invention is applied to a head-up display for an automobile has been described. However, the present invention is not limited to this, and is generally applied to a head-up display for various vehicles. May be.

[Brief description of the drawings]

FIG. 1 is a schematic overall configuration diagram showing an embodiment of an automotive head-up display according to the present invention.

FIG. 2 is an enlarged schematic side view of the light source system of FIG.

FIG. 3 is a partial plan view of the light source system of FIG. 2;

FIG. 4 is an enlarged view showing a side surface of a lamp and a cross section of a reflector in the light source system of FIG. 2;

FIG. 5 is a side view of the convex lens 30 of FIG.

FIG. 6 is a plan view of the convex lens 30 of FIG.

FIG. 7 is a front view of the convex lens T of FIG. 2;

FIG. 8 is a schematic diagram showing an optical arrangement relationship between a convex lens T and a liquid crystal panel P.

[Explanation of symbols]

I: Instrument panel, I1: Upper wall opening, L:
Light source system, M2: reflection mirror, W: front windshield, P: liquid crystal panel, T: convex lens.

Claims (3)

[Claims] 1. A display element disposed on a back side of an instrument panel (I) located below a front windshield (W) in a vehicle interior of a vehicle, and emits display information as display light. A display element (P), a reflection mirror comprising a concave mirror disposed on the back side of the instrument panel and in front of the display element, wherein display light is incident from the display element and the display element is above the instrument panel. A reflection mirror (M2) that expands and reflects toward the right place of the front windshield through the wall opening (I1), and the front windshield reflects the reflected light at the right place to reflect the display information. A head-up display for a vehicle, which is displayed as an enlarged virtual image in a forward direction, wherein the head-up display is disposed between the display element and the reflection mirror. A convex lens (T) for enlarging display light of the display element to the back side thereof and forming an image as a virtual image, wherein the reflection mirror substitutes the display light of the display element with image light as a virtual image from the convex lens. A head-up display for a vehicle, which is made incident and is reflected through the upper wall opening (I1) of the instrument panel toward an appropriate position of the front windshield. 2. A display element disposed on the back side of an instrument panel (I) located below a front windshield (W) in a vehicle interior of a vehicle, and emits display information as display light. A display element (P), a reflection mirror comprising a concave mirror disposed on the back side of the instrument panel and in front of the display element, wherein display light is incident from the display element and the display element is above the instrument panel. A reflecting mirror (M2) that expands and reflects toward a proper position of the front windshield through a wall opening (I1); and a convex lens disposed between the proper position of the front windshield and the reflecting mirror. The reflected light of the reflecting mirror is enlarged to the back side to form an image as a virtual image, and the formed light is made to enter a proper place of the front windshield. And a lens (T), the front windshield for a vehicle head-up display which is adapted to display in front of the display information to reflect imaging light of the convex lens at its place as an enlarged virtual image. 3. A reflecting mirror (M2) comprising a display element (P) disposed on the back side of an instrument panel (I) located below a front windshield (W) in a cabin of a vehicle, and a concave mirror. ) And a convex lens (T) such that the convex lens forms a virtual image on the back side of the convex lens through an optical path connecting the display element and an appropriate position of the front windshield via both the convex lens and the reflection mirror. The display element is arranged such that display light representing display information passes through the reflection mirror under a virtual image forming effect of the convex lens, and is enlarged at an overall magnification of both the convex lens and the reflection mirror. In this state, the light is incident on the right place of the front windshield, and the front windshield reflects the incident light at the right place and displays the display. A head-up display for a vehicle in which information is displayed forward as an enlarged virtual image.