JP6201339B2 - Head-up display device - Google Patents

Description

  The present invention relates to a head-up display device that displays an image to a driver by projecting the image onto a transparent display member.

  A head-up display device (hereinafter referred to as a head-up display device) that displays various information (vehicle speed, engine speed, etc.) related to vehicle operation to the driver by projecting an image onto a transparent display member called a vehicle front windshield or combiner. Are referred to as HUD devices). In this HUD device, an image showing various types of information is displayed on a transmissive liquid crystal display screen, light is projected from the back side of the liquid crystal display screen, and light transmitted through the liquid crystal display screen is reflected by a reflecting mirror. Thus, an image is projected onto the display member. In this way, the driver appears to be displaying an image over the situation on the other side of the transparent display member (front windshield etc.), so the driver does not move his line of sight greatly while driving, Various information regarding driving can be obtained.

  The HUD device can display various information to the driver by changing the image displayed on the liquid crystal display screen. Therefore, as one of these various types of information, it is also proposed to display important information that is not always displayed, such as information that warns the driver (warning information), on the HUD device. (Patent Document 1).

JP 2004-251881 A

  However, there is a problem that information that is rarely displayed, such as warning information, may not be immediately noticed by the driver just because it is displayed on the HUD device.

  The present invention has been made in view of the above-described problems, and provides a HUD device capable of displaying information that is rarely displayed, such as warning information, in a manner that a driver can immediately recognize. For the purpose.

In order to solve the above-described problems, the head-up display device of the present invention includes a prism mounted between a liquid crystal display unit that displays an image and a reflecting mirror that reflects light from the liquid crystal display unit toward the display member. Thus, the light from the predetermined area provided on the one end side of the liquid crystal display unit passes through the prism, thereby refracting the light from the predetermined area . Further, the prism is mounted in such a direction that the thickness of the prism increases as it approaches the other end side from one end side where the predetermined area of the liquid crystal display unit is provided.
If it carries out like this, the light from the predetermined area | region provided in the one end side of the liquid crystal display part will be refracted by a prism, and the position projected on a display member will move . Therefore, the light from a predetermined area of the liquid crystal display unit, thereby displaying a picture at a position different from the position where the light from the area other than the predetermined area of the liquid crystal display unit displays an image. In addition, the direction in which the prism is mounted is such that the thickness of the prism increases as it approaches the other end from one end where the predetermined area of the liquid crystal display unit is provided. For this reason, the position where the image based on the light passing through the prism is displayed is a position moved away from the position where the image based on the light not passing through the prism is displayed. As a result , even if an image that is rarely displayed is suddenly displayed, the driver can immediately notice that, so even if the information is rarely displayed, such as warning information, the driver Can be recognized immediately.

Further, in the above-described head-up display device of the present invention, a warning display area for displaying an image (warning image) of a warning content for the driver is provided in a part of the liquid crystal display unit, and the warning display area is displayed. It is also possible to refract light from the prism with a prism. The warning display area may be an area where a warning image is displayed, and may be an area where another image is displayed when it is not necessary to display the warning image.
In this way, the warning image is displayed at a position away from the other images. When the warning image is displayed, the driver immediately notices that and can recognize the content of the warning.

Further, in the head-up display device of the present invention in which the liquid crystal display unit is provided with the warning display area, a light shielding plate for preventing light from outside the warning display area from entering the prism is provided on the liquid crystal display unit. It is good also as providing a light-shielding plate between mirrors.
In this way, it is possible to avoid that light from outside the warning display area is refracted by the prism and projected onto the display member, and the image quality of the projected image is deteriorated.

In the above-described head-up display device of the present invention, an achromatic prism may be used. Here, the achromatic prism is a composite prism in which a plurality of prisms having different optical characteristics are combined so as to cancel the difference in refractive index depending on the wavelength of light.
In this way, even when the light passing through the prism includes a plurality of wavelengths, it is possible to avoid the occurrence of chromatic aberration due to the difference in the refractive index depending on the wavelength, so that it is possible to display an image with good image quality. Become.

In the head-up display device of the present invention described above, at least one of the surface of the prism on which light is incident or the surface of the prism on which light is emitted may be formed by a curved surface.
In this way, it is possible to make the driver feel as if the image projected through the prism and projected onto the display member is displayed at a different distance from the normal. For example, if the curved surface is convex, it seems that the image is displayed closer than usual. Conversely, if the curved surface is concave, the image is displayed farther than usual. It feels like For this reason, when an image is displayed, the driver's attention is attracted and the image can be immediately recognized.

In the head-up display device of the present invention described above, the prism may be rotated in a direction in which light incident on the prism is refracted or in a direction opposite to the direction.
In this way, the position of the image projected on the display member through the prism can be moved. For this reason, it is possible to attract the driver's attention by moving the display position according to the image or by moving the display position while displaying the image, so that the image can be recognized immediately. It becomes.

It is explanatory drawing which shows the structure of the head-up display apparatus of a present Example. It is explanatory drawing which illustrated the image which the head-up display apparatus of a present Example displays with respect to a driver | operator. It is explanatory drawing which shows the function of the prism provided in the head-up display apparatus of a present Example. It is explanatory drawing which showed the correspondence of the image displayed with the liquid crystal display device, and the image displayed on a front windshield. It is explanatory drawing which illustrated the 1st modification provided with a light-shielding plate between a liquid crystal display device and a prism. It is explanatory drawing which illustrated the 2nd modification using an achromatic prism. It is explanatory drawing which illustrated the 3rd modification using the prism whose entrance surface is a curved surface. It is explanatory drawing which illustrated the 4th modification provided with the prism so that rotation was possible.

Hereinafter, examples will be described in order to clarify the contents of the present invention described above.
As shown in FIG. 1, the head-up display device (hereinafter referred to as the HUD device 100) of this embodiment is mounted inside the instrument panel 300 of the vehicle 1 and projects an image onto the front windshield 200. Thus, various information is displayed to the driver.
The HUD device 100 includes a transmissive liquid crystal display device 110, a light source 120 that projects light from the back surface of the liquid crystal display device 110, and a concave mirror 130 that reflects the light transmitted through the liquid crystal display device 110 toward the front windshield 200. And a prism 140 provided between the liquid crystal display device 110 and the concave mirror 130. In this embodiment, the transmissive liquid crystal display device 110 is used. However, if an image can be displayed and light can be emitted, other types of display devices such as a reflective liquid crystal display device can be used. Is also possible.
When an image showing various information is displayed on the liquid crystal display device 110 and projected from the light source 120, the image displayed on the liquid crystal display device 110 is reflected by the concave mirror 130 and projected onto the front windshield 200. For this reason, it seems to the driver 10 that an image is displayed on the other side of the front windshield 200, so that the image of the liquid crystal display device 110 can be confirmed without moving the line of sight greatly during driving. .

In the HUD device 100 of this embodiment, a prism 140 is provided between the liquid crystal display device 110 and the concave mirror 130. Therefore, a part of the image projected from the liquid crystal display device 110 passes through the prism 140, is reflected by the concave mirror 130, and is projected on the front windshield 200.
The liquid crystal display device 110 of this embodiment corresponds to the “liquid crystal display unit” in the present invention. Further, the front windshield 200 of this embodiment corresponds to a “display member” in the present invention. Furthermore, the concave mirror 130 of this embodiment corresponds to a “reflecting mirror” in the present invention.

FIG. 2 illustrates an image displayed for the driver 10 by the HUD device 100 of the present embodiment. As shown in the figure, an image indicating various information necessary for driving such as the vehicle speed and engine rotation speed of the vehicle 1 is displayed in a range slightly lower than the front of the driver 10 (display range 400a). In addition, a display range 400b is provided at a position slightly lower than the display range 400a, and the display range 400b is not displayed normally during the display as in the warning image for the driver 10, but is important. An image with the correct content is displayed.
Here, the image displayed in the display range 400b is an image projected through the prism 140 onto the front windshield 200. As shown in FIG. 2, the distance between the display range 400 a and the display range 400 b is a position projected on the front windshield 200 because light is refracted when passing through the prism 140. Is to move. Hereinafter, this point will be described in detail.

FIG. 3 shows an optical path of light projected from the liquid crystal display device 110. First, an optical path of light projected on the display range 400a will be described with reference to FIG. As indicated by hatching in the drawing, the light transmitted from the region 110 a of the liquid crystal display device 110 is reflected by the concave mirror 130 and projected onto the front windshield 200. Then, the light reflected by the front windshield 200 enters the eyes of the driver 10 and is recognized as an image.
However, since the driver 10 does not know that the light has entered the eye through such an optical path, the virtual image 410a exists beyond the display range 400a, and the light from the virtual image 410a enters the eye. It will feel as if it were.

Next, an optical path of light projected on the display range 400b will be described with reference to FIG. The fact that an image is displayed in the display range 400b means that the driver 10 feels as if the light from the virtual image 410b existing beyond the display range 400b has entered the eyes. Of course, the light projected on the front windshield 200 is actually reflected and enters the eyes, and the light projected on the front windshield 200 is the light reflected by the concave mirror 130.
As shown in FIG. 3B, there is a gap between the virtual image 410a in the display range 400a and the virtual image 410b in the display range 400b. Therefore, the optical path of light projected on the display range 400b (shown with hatched lines in FIG. 3B) is the optical path of light projected on the display range 400a (shown with diagonal lines in FIG. 3A). Pass through a position distant from the display. However, since the prism 140 refracts light, as shown in FIG. 3B, the light path of the light in the display range 400b approaches the light path of the light in the display range 400a on the upstream side of the prism 140. As a result, the region 110b of the liquid crystal display device 110 is reached. That is, after the light from the region 110b is refracted by the prism 140, there is an optical path that is reflected by the concave mirror 130 and projected onto the display range 400b to reach the eyes of the driver 10. The image displayed in the area 110b of the display device 110 can be displayed as a virtual image 410b on the other side of the display range 400b.

Further, as is apparent from the above description, when the prism 140 is used, the liquid crystal display device 110 displays the images of the regions 110a and 110b provided adjacent to each other on the front windshield 200 at a display range 400a at a distant position. And it becomes possible to display on the display range 400b.
That is, as illustrated in FIG. 4A, an image indicating the vehicle speed, the engine rotation speed, and the like is displayed in the area 110a of the liquid crystal display device 110. In addition, an image (warning image) having a warning content for the driver 10 is displayed in a region 110b adjacent to the region 110a. As described above, even if the two regions 110a and 110b are adjacent to each other in the liquid crystal display device 110, if the light from the region 110b is refracted by the prism 140 and projected onto the front windshield 200, on the front windshield 200, Images can be displayed in the display range 400a and the display range 400b that are separated from each other.
It should be noted that the area 110b of the present embodiment displaying the warning image corresponds to the “warning display area” in the present invention.

If an image is to be displayed in the display range 400a and the display range 400b that are separated from each other on the front windshield 200 without using the prism 140, the liquid crystal display device 110 displays the image as shown in FIG. In addition, it is necessary to provide the region 110a and the region 110b apart from each other. Then, as shown by hatching in FIG. 4B, an area where no image is displayed (non-display area) is generated, and the display efficiency of the liquid crystal display device 110 is lowered. Further, when the area of the region 110a and the region 110b is to be secured, the liquid crystal display device 110 is increased by the amount corresponding to the non-display region.
On the other hand, in the HUD device 100 of the present embodiment, the display range 400b can be moved away from the display range 400a by using the prism 140, so that the display efficiency of the liquid crystal display device 110 is reduced or the liquid crystal display is displayed. The device 110 does not become large. Furthermore, since the prism 140 is installed between the liquid crystal display device 110 and the concave mirror 130, the provision of the prism 140 does not increase the size of the HUD device 100.

In the HUD device 100 of the present embodiment, an image indicating various information necessary for driving such as the vehicle speed is displayed in the display range 400a, and a warning image or the like is displayed in the display range 400b far from the display range 400a. Thus, an image that is not normally displayed can be displayed.
In this way, when a warning image or the like is displayed, the image is displayed at a position (display range 400b) away from the display range 400a where the image is normally displayed. You can immediately notice that it is displayed. For this reason, it becomes possible for the driver to quickly recognize important information that is not normally displayed, such as a warning, using the HUD device 100.

  There are several variations of the HUD device 100 of the present embodiment described above. In the following, these modified examples will be described focusing on differences from the present embodiment. Note that, in the modification described below, the same reference numerals are given to the same configurations as those of the above-described embodiment, and the detailed description is omitted.

[First Modification]:
In the HUD device 100 of the above-described embodiment, a member for preventing light from a region other than the region 110b (for example, the region 110a) from entering the prism 140 may be provided.
FIG. 5 illustrates a first modified example in which a light shielding plate 142 is provided between the liquid crystal display device 110 and the prism 140.
In such a first modification, the light from the region other than the region 110 b is not incident on the prism 140 by being blocked by the light shielding plate 142. For this reason, since the light that passes through the prism 140 and is projected onto the display range 400b is exclusively light from the region 110b, a clear image can be displayed in the display range 400b.

[Second Modification]:
In the above-described embodiments and modifications, the prism 140 has been described as being formed of a single optically homogeneous material. However, a combination prism (so-called achromatic prism) that cancels out the difference in refractive index depending on the wavelength of light by combining a plurality of prisms having different optical characteristics may be used.

  FIG. 6 illustrates a second modification using the achromatic prism 144. The illustrated achromatic prism 144 can cancel out the difference in refractive index due to the difference in the wavelength of light by using a combination of two prisms 144a and 144b formed of a single material. For this reason, it is possible to avoid the image displayed in the display range 400b from becoming unclear due to chromatic aberration.

[Third Modification]:
Further, in the above-described embodiments and modifications, it has been described that the surface on which light enters the prism 140 (incident surface) and the surface from which light exits from the prism 140 (exit surface) are both flat. However, at least one of the entrance surface and the exit surface may be configured by a curved surface.

FIG. 7 illustrates a third modification using the prism 146 having such a curved surface. In the illustrated prism 146, the entrance surface is formed by a convex curved surface, but the exit surface may be a convex curved surface, and furthermore, the entrance surface and the exit surface may be formed by a convex curved surface. Also good. The curved surface is not necessarily limited to the convex shape, and may be a concave curved surface.
As illustrated in FIG. 7, if at least one of the entrance surface and the exit surface is formed by a convex curved surface, the light passing through the prism 146 tries to form an image in front of the light not passing through the prism 146. . Therefore, the driver 10 feels that the image in the display range 400b is displayed in front of the image displayed in the display range 400a. Conversely, if at least one of the incident surface and the exit surface of the prism 146 is formed by a concave curved surface, the image in the display range 400b can be felt as being displayed farther than the image in the display range 400a.
For this reason, the image of the display range 400b can be displayed not only at a position distant from the display range 400a but also displayed at a different distance from the image of the display range 400a. 10 can be immediately noticed.

[Fourth Modification]:
In the above-described embodiments and modifications, the prisms 140, 144, and 146 have been described as being fixed at a predetermined position between the liquid crystal display device 110 and the concave mirror 130. However, the prisms 140, 144, and 146 may be provided in a rotatable manner.

FIG. 8 illustrates a fourth modification in which the prism 140 is rotatably provided. In the example shown in FIG. 8, the prism 140 is supported by a shaft from the lateral direction (that is, a direction parallel to both the entrance surface and the exit surface of the prism 140), and this shaft is rotated by the rotation of the stepping motor 150. Connected to the shaft. Therefore, when the stepping motor 150 is driven, the display range 400b on which the light that has passed through the prism 140 is projected can be moved in the vertical direction as viewed from the driver 10.
Therefore, for example, the position of the display range 400b can be changed by rotating the stepping motor 150 to a predetermined angle in accordance with the content of the image displayed in the region 110b of the liquid crystal display device 110. When various information used by the driver 10 for driving is displayed in the area 110b, the stepping motor 150 may be rotated so that the display range 400b is positioned adjacent to the display range 400a.
Furthermore, if the stepping motor 150 is rotated finely alternately in the clockwise direction and in the counterclockwise direction, the position of the display range 400b can be vibrated in the vertical direction as viewed from the driver 10. If the image is displayed in such a manner, the driver's 10 attention is strongly attracted, so that the driver 10 can immediately recognize that the image has been displayed.
The stepping motor 150 of the fourth modified example corresponds to “rotating means” in the present invention.

As mentioned above, although the present Example and the modification were demonstrated, this invention is not restricted to said Example and a modification, It can implement in a various aspect in the range which does not deviate from the summary.
For example, in the above-described embodiments and modifications, the prisms 140, 144, and 146 have been described as being provided on the upper side of the liquid crystal display device 110. However, the present invention is not limited to this, and the prisms 140, 144, and 146 may be provided below the liquid crystal display device 110, or may be provided on the right side or the left side of the liquid crystal display device 110.

DESCRIPTION OF SYMBOLS 1 ... Vehicle, 100 ... HUD apparatus, 110 ... Liquid crystal display device,
110a, b ... area, 120 ... light source, 130 ... concave mirror,
140 ... Prism, 142 ... Shading plate, 144 ... Achromatic prism,
146 ... Prism, 150 ... Stepping motor,
200: front windshield, 400a, b ... display range.

Claims (6)

A head-up display device that displays an image by projecting the image onto a transparent display member,
A liquid crystal display for displaying the image;
A light source that projects light onto the liquid crystal display unit;
A reflecting mirror that reflects light from the liquid crystal display unit toward the display member;
A prism mounted between the liquid crystal display unit and the reflecting mirror and refracting light from a predetermined region provided on one end side of the liquid crystal display unit ;
The prism is mounted in such a direction that the thickness of the prism increases as it approaches the other end side from one end side where the predetermined region of the liquid crystal display unit is provided.
Head-up display device you wherein a. The head-up display device according to claim 1,
The predetermined area is a warning display area in which a warning image is displayed on the liquid crystal display unit ,
The head-up display device, wherein the prism is a prism that refracts light from the warning display area. The head-up display device according to claim 2,
A head-up display device provided with a light-shielding plate that prevents light from outside the warning display area from entering the prism between the liquid crystal display unit and the prism. The head-up display device according to any one of claims 1 to 3,
A head-up display device in which the prism is an achromatic prism. The head-up display device according to any one of claims 1 to 4,
The head-up display device, wherein the prism is a prism in which at least one of the light incident surface and the light exiting surface is a curved surface. The head-up display device according to any one of claims 1 to 5,
A head-up display device comprising rotation means for rotating the prism in a direction in which light incident on the prism is refracted or in the opposite direction.

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