JP2523700Y2 - Display device for vehicles - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention provides a display device which forms a display image by radiance on a dashboard, and displays a display image of the display device in a driver's seat direction by a reflection surface arranged in a field of view in front of the driver's seat. The present invention relates to a vehicular display device of a type generally called a head-up display (HUD), which is reflected so that a display image of the display device can be visually recognized within a field of view of a windshield.

[0002]

2. Description of the Related Art A conventional vehicle display device of this type will be described with reference to FIG. The display device for a vehicle shown in the drawing is configured such that a display image of a display unit 12 composed of a segment type fluorescent display tube is reflected by a concave mirror 13 in a unit case 31 disposed in a dashboard 11, and this reflected image is reflected on the unit case 31. Through the opening 31a of the dashboard 11 and the reflection member 14a which has been subjected to reflection processing on the inner surface of the windshield 14, for example, and is reflected toward the driver's seat side, and viewed from the viewpoint position 15, a virtual image of an enlarged display image. 1
6 is visible in the field of view behind the windshield 14. As a result, the driver can visually recognize the vehicle speed and the like while traveling without removing the line of sight from the field of view of the windshield 14. A connector 17 for inputting an information signal such as a vehicle speed is connected to the display 12.

[0003]

However, in the above-mentioned conventional vehicle display device, when external light such as direct sunlight is incident from outside the windshield 14 in the direction of the arrow, the external light is dashed. The light enters the reflecting mirror 13 through the opening 11 a of the board 11 and the opening 31 a of the unit case 31, is reflected by the concave mirror 13, and finally enters the display 12. In this case, not only the lighting segments but also the non-lighting segments appear to shine due to the external light, so that it is impossible to distinguish between the lighting segments and the non-lighting segments, and so-called washout occurs.

Accordingly, the present invention has been made in view of the above-mentioned conventional problems, and provides a display device for a vehicle which does not cause a display washout even when external light such as direct sunlight is incident on the display. The purpose is to do.

[0005]

In order to solve the above-mentioned problems, a vehicle display device according to the present invention has a reflecting surface in which a display image of a display device arranged on a dashboard is arranged in a field of view in front of a driver's seat. In a vehicle display device in which the display image is reflected in the driver's seat direction so that the display image of the display device can be visually recognized within the field of view of the windshield, the display device becomes transparent when a voltage is applied, and no voltage is applied. comprises a cloudy liquid crystal element having a plurality of display segments cloudy, and a back light source arranged behind the white turbid liquid crystal element when the display
Dark masking the surface of the liquid crystal display element except for the segments
The light incident on the rear surface of the white opaque liquid crystal element from the rear light source is scattered in the white opaque display segment to form a display image, and the light transmitted through the transparent display segment is operated. Disposing the back light source at a position where the light does not enter the eyes of
Before the driver sees through the display segment at
The same portion as the dark mask is provided on the portion behind the liquid crystal display element.
It is characterized by being subjected to dark low-reflection processing .

Further, the display image of the display device arranged on the dashboard is reflected in the direction of the driver's seat by a reflection surface disposed in the field of view in front of the driver's seat, and the display image of the display device is visually recognized in the field of view of the windshield. In the display device for a vehicle, the display device is transparent when a voltage is applied, and has a plurality of white opaque liquid crystal elements having a plurality of display segments that become opaque when no voltage is applied, and is incident on the white opaque liquid crystal element. A back light source that emits light, and a prism disposed between the cloudy liquid crystal element and the back light source, the light incident on the back surface of the cloudy liquid crystal element from the back light source through the prism to a cloudy state. The light is scattered in a certain display segment to form a display image, and the prism surface on which the light from the rear light source is incident and the incident light are transmitted to enter the rear surface of the white opaque liquid crystal element. Association angle between the surface to be, light transmitted through the display segments in the transparent state is characterized in that the angle that does not enter the eyes of the driver.

[0007]

According to the above structure, the liquid crystal table excluding the display segments is provided.
Since the surface of the display element is covered with a dark mask, when no voltage is applied to the display segment of the cloudy liquid crystal element, the display segment becomes cloudy, and light incident on the back of the cloudy liquid crystal element from the back light source is in a cloudy state. A part of the scattered light is scattered in the display segment, and a part of the scattered light travels as a display image in the direction of the optical axis of the cloudy liquid crystal element, and is reflected in the driver's seat direction by a reflection surface arranged in the field of view in front of the driver's seat to form a windshield. The driver can visually recognize the display image within the field of view.

When a voltage is applied to the display segment of the opaque liquid crystal element, the display segment becomes transparent, and the back light source prevents light transmitted through the display segment from entering the driver's eyes when the display segment is in a transparent state. Display segment placed in a transparent position
Behind the liquid crystal display element that the driver sees through
Since it subjected to the same dark low reflection treatment and the dark color mask, the light from the back light source, without entering the eyes of the driver through the display segments in the transparent state and Toru
Excess parts have a background similar to the mask around the display segment
Become.

[0009] Even when external light enters the display,
The external light does not pass through the display segment in the transparent state and is not reflected. In the display segment in the cloudy state, the external light is scattered, so that the display does not wash out.

When the display segment of the opaque liquid crystal element is in the opaque state, the light incident on the back of the opaque liquid crystal element from the back light source via the prism is scattered in the display segment and a part of the scattered light. Is reflected by the reflection surface, and the driver can visually recognize the display image on the display.

When the display segment is in a transparent state, the angle of association between the surface of the prism on which the light from the rear light source is incident and the surface of the prism that transmits the incident light and impinges on the rear surface of the opaque liquid crystal element is as follows: Since the light transmitted through the display segment is at such an angle that the light does not enter the driver's eyes, the light from the rear light source does not pass through the display segment and enter the driver's eyes.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. In these figures, the same reference numerals are given to the same portions as those of the conventional device described above with reference to FIG. 7, and the detailed description thereof will be omitted.

In FIG. 1, a white opaque LCD (white opaque liquid crystal element) 2 for displaying a display image such as a vehicle speed is fixed in a unit case 31 provided in a dashboard 11 at a position facing the concave mirror 13. Behind the cloudy LCD 2, a lamp 18 for illuminating the cloudy LCD 2 is fixed. The unit case 31, the cloudy LCD 2 and the lamp 18 constitute the display 1.

As shown in FIG. 2, the white turbid LCD 2
For example, the three-digit number display portion 2a is composed of two segments for the hundreds digit, seven digits for the tens digit, and seven segments for the first digit, and a display segment representing the unit symbol km / h of the vehicle speed. It has a unit display section 2b and a warning display section 2c composed of segments representing warning displays. As shown in FIG. 3, the transparent LCD 22 has a transparent electrode 22a formed corresponding to the shape of each display segment constituting the display portions 2a, 2b, and 2c, and a transparent electrode 22b opposed to the transparent electrode 22a. In this structure, two transparent plastic sheets or glasses 23a and 23b are bonded together with a liquid crystal group 24 disposed between the transparent electrodes 22a and 22b. The transparent electrode 22
An electronic circuit 19 for inputting an information signal such as a speed via the connector 7 and applying an AC voltage to a portion to be made transparent is connected to the terminals a and 22b.

When no electric field is applied between the transparent electrodes 22a and 22b, the liquid crystal 24a has an orientation that is not restricted by the interface in each liquid crystal group 24, and the alignment direction is irregular in each liquid crystal group 24. And the incident light (arrow in the figure) is scattered. That is, the cloudy LCD 2 becomes cloudy.

When an AC voltage is applied between the transparent electrodes 22a and 22b by the electronic circuit 19 and a predetermined electric field is applied, the liquid crystals 24a of each liquid crystal group 24 are oriented in one direction regulated by the electric field. Incident light is transmitted. That is, the cloudy LCD 2 is in a transparent state.

Note that the display unit 2 is provided on the white turbid LCD 2.
Except for a, 2b and 2c, the mask 25 is applied by dark printing, for example, black printing. Further, instead of applying the mask 25 by printing, a dark plate having a window hole corresponding to the shape of the display units 2a, 2b and 2c is used as a mask.
It is also possible to use Te.

The lamp 18 is fixed at a position on the unit case 31 such that the emitted light is transmitted and does not enter the concave mirror 13 when the display segment is transparent.

An opaque LCD in the unit case 31
2, on the inner wall of the room A in which the lamp 18 and the electronic circuit 19 are housed, especially on the portion directly behind the cloudy LCD 2,
2 is in a transparent state so as to be visually recognized as the same black as the background. Also, in order to suppress the reflection of light from the lamp 18 and external light, a low reflection treatment such as a black matte suede-like coating and electrostatic flocking is performed. Is given.

According to the above configuration, when an AC voltage is not applied to the display segments constituting the display sections 2a, 2b and 2c by the electronic circuit 19, the display segments become cloudy and the light emitted from the lamp 18 is scattered by the display segments. Part of this scattered light travels in the direction of the optical axis L of the cloudy LCD 2 as a display image of the cloudy LCD 2, is reflected by the concave mirror 13, passes through the opening 31 a of the unit case 31, and passes through the opening 11 a of the dashboard 11, The reflected image is reflected by the reflecting member 14 a, and the virtual image 16 of the enlarged display image can be visually recognized in the field of view of the windshield 14 when viewed from the viewpoint position 15.

When an AC voltage is applied by the electronic circuit 19 to each of the display segments constituting the display sections 2a, 2b and 2c, the display segments become transparent, and the lamp 18 emits light so that the display segments become transparent. , The light from the lamp 18 is transmitted through the display segment and does not enter the concave mirror 13, so that the white turbidity L
The driver does not see the image of CD2. Each display segment of the display portions 2a, 2b and 2c of the cloudy LCD 2 can be set to a very high transmission state because no polarizing plate is used.

Further, even when external light such as direct sunlight is incident on the unit case 31 and is reflected by the concave mirror 13 and is incident on the transparent display segment of the white opaque LCD 2, this display segment is also displayed. Is in a very high transmission state, and the unit case 31 is subjected to a low reflection process, so that incident light is transmitted and is not reflected, and external light is not reflected in a display segment in a cloudy state. Since the light is scattered, washout of the display does not occur.

As shown in FIG. 4, by forming a wall 31b around the lamp 18 and providing a convex lens 41 in the optical path of the lamp 18, the light emitted from the lamp 18 can be effectively applied to the cloudy LCD 2. Can also be collected.

In the first embodiment, the inner surface of the case is blackened so that the transparent display segment looks the same black as the background, and the light of the lamp 18 transmitted through the transparent display segment is transmitted to the driver. The lamp is arranged close to the corner inside the case 31 so as not to be seen, but this is changed as in the second embodiment described below with reference to FIGS. 5 and 6. Is also possible. In FIGS. 5 and 6, the same parts as those of the related art described above with reference to FIGS. 1 and 7 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 1, a display 1 includes a unit case 31 provided in a dashboard 11 and a right-angle prism 51 having a slope 51a fixed in the unit case 31 toward a reflection member 14a. , The cloudy LCD 2 fixed to the slope 51a, and the face 5 associated with the slope 51a.
1b, and a lamp 18 for emitting light incident on the lamp 1b.
On the third surface 51c of the right-angle prism 51, a black anti-reflection coating surface 51d is formed.

With this configuration, the surface 51 of the prism 51
The light of the lamp 18 that has entered b is transmitted through the prism 51 and is incident on the back surface of the cloudy LCD 2, whereby it is scattered in the cloudy display segment to form a display image. This display image is reflected by the reflection member 14a,
The driver visually recognizes the reflected image. A surface 51b of the prism 51 on which the light from the back light source 18 is incident, and a slope 51a that transmits the incident light and impinges on the rear surface of the cloudy LCD 2;
That is, the association angle θ with the surface on which the cloudy LCD 2 is arranged
₁ is set at an angle such that light transmitted through the display segment in the transparent state does not enter the eyes of the driver.

More specifically, as shown in FIG. 6, the external light is transmitted from the inclined surface 51a of the prism 51 to the prism 51 at an angle within θ ₂ which is the angle range (total reflection angle range) where the external light is incident in FIG. When the light is refracted and enters the inside of the prism 51, the incident light is totally reflected by the surface 51b in the prism 51.
A prism apex angle θ _1, which is an association angle between the inclined surface 51 a and the surface 51 b of the prism 51, is set. The prism apex angle θ ₁ is set so that the total reflection angle range θ ₂ includes an angle range in which light from the display 1 goes to the reflection member 14 a. Then, a small angular range than the critical angle of total reflection has a transmission angular range theta _3.

With the above configuration, when the display segment of the cloudy LCD 2 is in the cloudy state, the light incident from the lamp 18 via the prism 51 is scattered in the display segment, and a part of the scattered light is used as a display image. The light travels in the direction of the reflection member 14a, is reflected by the reflection member 14a, advances in the direction of the viewpoint position 15, and the virtual image 16 of the display image can be visually recognized in the field of view of the windshield 14.

When the display segment is in a transparent state, the light from the lamp 18 is not visually recognized by the driver, and is totally reflected by the second interface 51b of the prism 51, so that a black non-reflective coating process is performed. The surface 51d is visually recognized and looks the same black as the background, and the virtual image 16 of the display image is visually recognized in such a background, and the contrast is improved.

Further, even if external light enters the prism 51,
External light is more scattered in display segments that are opaque,
In the display segment in the transparent state, the black non-reflective coating processing surface 51 is formed by total reflection on the surface 51b of the prism 51.
d is visually recognized and looks the same black as the background, and no display washout occurs.

If a color filter is arranged in front of the lamp 18, the fashionability due to a change in color can be improved.

The same effect can be obtained even if the prism 51 is not a right-angle prism.

[0033]

As described above, according to the present invention, when no voltage is applied to the display segment of the cloudy liquid crystal element, the display segment becomes cloudy and the light incident on the back of the cloudy liquid crystal element from the rear light source becomes cloudy. The light is scattered in the display segment in the state, and a part of the scattered light travels in the direction of the optical axis of the cloudy liquid crystal element, so that the driver can visually recognize the display image on the display. Also, when a voltage is applied to the display segment of the white turbid liquid crystal element, the display segment becomes transparent, and the back light source is arranged at a position such that light transmitted through the display segment does not enter the reflecting mirror when the display segment is in a transparent state. Through the transparent display segment
In the first place, the color behind the liquid crystal display element seen by the driver is dark
Since the dark low-reflection treatment similar to that of the mask is applied , the light from the rear light source passes through the display segment in the transparent state and does not enter the reflecting mirror, and the transmitted portion is not visible.
The background is the same as the mask around the indicated segment. Furthermore, even when external light is incident on the display, the external light passes through the transparent display segment and is not reflected, and the external light is scattered in the white opaque display segment. Does not occur, and the display image of the cloudy liquid crystal element can be clearly recognized within the field of view of the windshield.

When the display segment of the opaque liquid crystal element is in the opaque state, the light incident on the back surface of the opaque liquid crystal element from the back light source via the prism is scattered in the display segment and a part of the scattered light. Is reflected by the reflection surface, and the driver can visually recognize the display image on the display.
When the display segment is in a transparent state, the angle of association between the surface of the prism on which the light from the rear light source is incident and the surface of the prism that transmits the incident light and impinges on the rear surface of the opaque liquid crystal element is determined by the display segment. Since the transmitted light is at an angle so as not to enter the driver's eyes, the light from the rear light source does not pass through the display segment and enter the driver's eyes, thereby washing out the display. Will not occur.

[Brief description of the drawings]

FIG. 1 is a view showing a first embodiment of a vehicle display device according to the present invention.

FIG. 2 is a front view of the cloudy LCD in FIG.

FIG. 3 is an explanatory view showing the principle of the cloudy LCD in FIG.

4 is a diagram showing the vehicle display device of FIG. 1 in which light emitted by a lamp is effectively condensed on a cloudy LCD.

FIG. 5 is a view showing a second embodiment of the vehicle display device according to the present invention.

FIG. 6 is an explanatory diagram of a function of a prism in FIG. 5;

FIG. 7 is a diagram illustrating an example of a conventional vehicle display device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Display 11 Dashboard 14 Windshield 14a Reflection member (reflection surface) 2 Cloudy LCD (cloudy liquid crystal element) 18 Lamp (back light source) 25 Mask 51 Prism 51a Slope 51b Surface θ1 Prism angle (association angle)

Claims (2)

(57) [Scope of request for utility model registration] 1. A display image of a display device arranged on a dashboard is reflected toward a driver's seat by a reflection surface disposed in a field of view in front of a driver's seat, and the display image of the display device is visually recognized in a field of view of a windshield. In the display device for a vehicle, the display device is transparent when a voltage is applied, and has a plurality of display segments that are opaque when a voltage is not applied. And a rear light source disposed on the liquid crystal display element.
Covered with a color mask, the light incident on the back of the cloudy liquid crystal element from the back light source is scattered in the display segment in the cloudy state,
The back light source is arranged at a position where a display image is formed and light transmitted through the transparent display segment does not enter the eyes of a driver.
And the display segment in the transparent state
The part behind the liquid crystal display element which the driver sees through
To the same low-reflection treatment as in the dark mask described above.
Vehicle display device characterized by that. 2. A display image of a display device provided on a dashboard is reflected in a driver's seat direction by a reflection surface disposed in a field of view in front of a driver's seat, and a display image of the display device is visually recognized in a field of view of a windshield. In a display device for a vehicle, the display is transparent when a voltage is applied,
A cloudy liquid crystal element having a plurality of display segments that become cloudy when no voltage is applied, a back light source that emits light incident on the cloudy liquid crystal element, and a prism disposed between the cloudy liquid crystal element and the back light source. And scatters light incident on the back surface of the cloudy liquid crystal element from the back light source through the prism in the display segment in a cloudy state,
A display image is formed, and an association angle between a surface of the prism on which light from the back light source is incident and a surface of the prism that transmits the incident light and is incident on the rear surface of the white opaque liquid crystal element is in a transparent state. A vehicle display device, wherein an angle is set so that light transmitted through a display segment does not enter a driver's eyes.