JP2006091104A - Head up display for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the external size of a head up display for a vehicle, to display an enlarged image and to prevent a displayed image from wobbling. <P>SOLUTION: An image projector 100 is provided with: a housing 10 which is a storage member, arranged on the rear side of an instrument panel and has an aperture part for emitting image light of an image to the upper part; a display device 20 stored in the housing 10 and capable of emitting the image light of the image to be displayed on a display part 50 of a front window shield WS; a concave mirror 30 stored in the housing 10 and capable of enlarging and reflecting an image made directly incident from the display device 20; and a lens 40 arranged on the aperture part of the housing 10 to close the inside of the housing 10 and capable of enlarging an image made incident from the concave mirror 30 and outputting the enlarged image to the display part 50 of the front window shield WS. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle head-up display including an image projector having a compact outer shape and a reduced optical path length of image light emitted from a light source.

  2. Description of the Related Art Conventionally, a vehicle head-up display is known as a device that makes a driver recognize information related to a vehicle such as vehicle speed and navigation information. 5A and 5B are schematic views of a conventional vehicle head-up display, in which FIG. 5A is a top view of the image projector, and FIG. 5B is a schematic diagram when the vehicle head-up display is used.

  As shown in FIGS. 5A and 5B, the vehicle head-up display includes an image projector 200 that projects image light of an image, and a display unit that displays an image emitted from the image projector 200. 50.

  The image projector 200 includes a housing 11 that forms the outer shape of the image projector 200, a display 20 that includes a light source and a transmissive liquid crystal panel (hereinafter referred to as a liquid crystal panel), and an image emitted from the display 20. A plane mirror MR that reflects light and a concave mirror 30 that magnifies and reflects image light reflected by the plane mirror MR are provided. The display 20, the plane mirror MR, and the concave mirror 30 are housed in the housing 11 and installed in the instrument panel of the vehicle. The concave mirror 30 has a function of enlarging the image by, for example, 4.0 to 5.5 times.

  In addition, a display unit 50 that displays image light emitted from the image projector 200 is provided on the front windshield WS of the vehicle.

  In the vehicle head-up display having the above configuration, the size of the image displayed on the liquid crystal panel of the display device 20 is smaller than the image display size of the display unit 50 of the front windshield WS. For this reason, it is necessary to enlarge and display an image having a size that can be visually recognized by the driver. Therefore, in the above-described in-vehicle head-up display, in addition to the enlargement function of the concave mirror 30, the image size is enlarged by increasing the optical path length of the image light emitted from the display device 20.

  Specifically, as shown in FIG. 5A, the image light emitted from the display 20 through the plane mirror MR is guided to the concave mirror 30. In this way, in addition to the enlargement function of the concave mirror 30, the image emitted from the display device 20 can be enlarged and displayed on the display unit 50 by securing the optical path length from the display device 20 to the concave mirror 30 using the plane mirror MR. It has become. The optical path length from the display 20 to the concave mirror 30 is, for example, 200 to 240 mm.

  In such a vehicle head-up display, the light emitted from the light source in the display device 20 is applied to the liquid crystal panel, and an image displayed on the liquid crystal panel is projected as image light. Then, as shown in FIGS. 5A and 5B, the image light projected from the display device 20 is reflected by the plane mirror MR and the concave mirror 30, and provided on the housing 11 and the upper part of the instrument panel. The light is emitted from an opening (not shown) and imaged on the inner surface of the front windshield WS. Specifically, the concave mirror 30 forms an image of the liquid crystal panel as a virtual image, and forms this virtual image on the inner surface of the front windshield WS. As a result, the driver can visually recognize the image displayed on the display unit 50 of the front windshield WS.

  In recent years, the space in which the image projector 200 of the vehicle head-up display is installed has been reduced due to the components and members provided in the instrument panel. However, in the vehicle head-up display shown in FIG. 5A, the housing 11 itself that forms the outer shape of the image projector 200 is large in order to secure the optical path length of the image light guided from the display device 20 to the concave mirror 30. It has become.

  Further, when the optical path length from the display 20 to the concave mirror 30 is long or when the magnification ratio of the concave mirror 30 is high, the image (display image) displayed on the display unit 50 of the front windshield WS is shaken. This shaking of the display image is caused by the movement of the driver's line of sight. As the image size is increased, the movement amount of the display image and the distortion of the display image change greatly. The visibility of the display image of the driver is deteriorated due to such shaking of the display image.

  In view of the above points, the present invention aims to reduce the outer size of the image projector in the vehicle head-up display and to enlarge the image and to prevent the display image from shaking. The purpose of 2.

  In order to achieve the above object, according to the first aspect of the present invention, an image projector (100) that projects image light of an image and a display unit that is provided in a front windshield (WS) of a vehicle and displays an image. In the vehicle head-up display, the image projector is a storage member and is disposed on the back side of the instrument panel of the vehicle and has an opening that emits image light of the image on the top. A housing (10) having a portion, a display (20) which is housed in the housing and emits image light of an image displayed on the display portion of the front windshield, and is housed in the housing and directly from the display A magnifying glass (30) that magnifies and reflects the incident image, and is disposed in the opening of the housing and closes the inside of the housing. Is characterized in that it comprises a lens (40) for outputting to the display unit of the windshield an enlarged image, a.

  Thus, in the image projector, the image light emitted from the display is directly incident on the magnifier. Thereby, the optical path length from a display to a magnifier can be reduced. Further, the image light is emitted from the magnifying glass to the display unit of the front windshield through the lens. Thereby, an image can be expanded with a magnifier and a lens. At this time, since the magnification of the image can be distributed to the magnifying glass and the lens, the magnifying power of the magnifying glass can be reduced as compared with the conventional case. Therefore, image shaking can be suppressed when the driver's line of sight is moved. In this manner, the housing can be downsized, that is, the image projector can be downsized, and the image can be enlarged and displayed while suppressing the shaking of the displayed image.

  Further, the lens is disposed in the opening of the housing, thereby closing the inside of the housing. Thereby, it is possible to prevent dust and dust from entering the housing. That is, it can be said that the lens has a dustproof function.

  The invention according to claim 2 is characterized in that the lens is at least one of a biconvex lens (41) and a plano-convex lens (42). Thus, a biconvex lens or plano-convex lens having an enlargement function can be employed, and the size of the image can be enlarged.

  According to a third aspect of the present invention, an image projector (100) that projects image light of an image, and a display unit (50) that is provided on a front windshield (WS) of a vehicle and displays an image as an image are provided. In the vehicle head-up display, the image projector is a housing member which is disposed on the back side of the instrument panel of the vehicle and has a housing (10) having an opening for emitting image light of the image on the top. And a display (20) for emitting image light of an image to be displayed on the display unit of the front windshield, and an image stored in the housing and directly incident from the display. And a magnifying mirror (30) that reflects the light, and a function and an image that are disposed in the opening of the housing and close the inside of the housing to enlarge and reduce the image. Has a function of uncorrected, it is characterized in that it comprises a lens (45) for outputting to the display unit of the front windshield image light incident image from magnifier.

  Thus, in the image projector, the image light emitted from the display is directly incident on the magnifier. Thereby, the optical path length from a display to a magnifier can be reduced. The image size can be enlarged to a size that can be visually recognized by the driver by setting the magnification ratio of the magnifier high. Further, the image magnified by the magnifying glass is displayed on the display unit of the front windshield through a lens for correcting distortion. As a result, even if image shaking occurs when the driver moves his / her line of sight, the lens having a distortion correction function can prevent shaking of the image displayed on the display unit. In this way, the housing can be downsized, that is, the image projector can be downsized, and the image can be prevented from shaking while the size of the image is enlarged with a magnifying glass.

  Moreover, the lens has a dustproof function for closing the inside of the housing by being disposed in the opening of the housing. Thereby, it is possible to prevent dust and dust from entering the housing.

  The invention according to claim 4 is characterized in that the lens is at least one of a biconcave lens (46) and a planoconcave lens (47). As described above, a biconcave lens or a plano-concave lens having a distortion correction function can be employed, and shaking of an image displayed on the display unit can be suppressed.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. Hereinafter, the same components as those shown in FIGS. 5A and 5B are denoted by the same reference numerals.

  FIG. 1 is a schematic configuration diagram of a vehicle head-up display according to the first embodiment of the present invention, where (a) is a top view of the image projector 100, and (b) is when the vehicle head-up display is used. FIG. As shown in FIGS. 1A and 1B, the vehicle head-up display includes an image projector 100 that projects image light of an image, and a display unit that displays an image emitted from the image projector 100. 50.

  The image projector 100 emits image light for displaying an image on the display unit 50 of the front windshield WS, and includes a housing 10, a display device 20, a concave mirror 30, and a lens 40. Has been.

  The housing 10 forms the outer shape of the image projector 100. The housing 10 accommodates a display 20 and a concave mirror 30 described later, and is disposed on the back side of the instrument panel of the vehicle.

  The display 20 emits image light corresponding to the content displayed on the display unit 50 of the front windshield WS. Such a display device 20 includes a light source, a liquid crystal panel for displaying an image, and a case (not shown).

  The light source is a well-known one that emits light and functions as a backlight of a liquid crystal panel. As such a light source, for example, an LED (light emitting diode) is employed.

  In the liquid crystal panel, liquid crystal is injected between two glass plates to form element patterns, that is, dots (pixels) segmented by wiring, and each pixel is controlled by a thin film transistor (TFT) to display an image. This is a known image display device. The liquid crystal panel is electrically connected to an external ECU or the like, and an image signal is input from the external ECU or the like, and an image corresponding to the image signal is displayed.

  As shown in FIG. 1A, the display device 20 as described above is disposed at a position where the optical axis of the image light does not enter perpendicularly to the mirror surface of the concave mirror 30. That is, in the display device 20, the optical axis and the liquid crystal panel are accommodated in the housing 10 so as to be off-axis. The case forms the outer shape of the box-shaped display 20 and is a storage member that stores a light source and a liquid crystal panel. One side surface of the case is provided with an opening for emitting image light of an image displayed on the liquid crystal panel.

  In the display device 20 having the above configuration, when light is emitted from a light source and an image signal is input from an external ECU or the like to the liquid crystal panel, the image light is emitted from the liquid crystal panel and the image light is emitted. Is ejected from the opening of the case.

  The concave mirror 30 enlarges an image directly incident from the display 20 and guides image light of the enlarged image to the front windshield WS through a lens 40 described later. Such a concave mirror 30 enlarges the size of the image, for example, by a factor of two. The concave mirror 30 corresponds to the magnifying glass of the present invention.

  The lens 40 is a transparent body that enlarges an incident image by utilizing the refractive action of light. 2A and 2B are diagrams showing the cross-sectional shape of the lens 40. FIG. 2A is a cross-sectional view of the biconvex lens 41, and FIG.

  Each of the lenses 40 shown in FIGS. 2A and 2B enlarges and emits an image, and the magnification is, for example, 3 times. In the present embodiment, a biconvex lens 41 shown in FIG. Then, the size of the image emitted from the display device 20 is doubled by the concave mirror 30 and tripled by the biconvex lens 41 in FIG. Become. In this way, the magnification for enlarging the image is distributed between the concave mirror 30 and the lens 40.

  As shown in FIG. 1B, the lens 40 is fixed to an opening provided in the upper part of the housing 10. In other words, the lens 40 is installed in the opening of the housing 10, thereby fulfilling a dustproof function for preventing dust and dust from entering the housing 10. Then, the lens 40 enlarges the image light reflected by the concave mirror 30 and guides it to the display unit 50 of the front windshield WS.

  The display unit 50 forms an image of the image light emitted from the image projector 100 and displays it as an image, and is an image display area (so-called combiner) provided on the inner surface of the front windshield WS. Although not limited, the display unit 50 of the front windshield WS includes vehicle information such as vehicle speed and navigation (arrows, shape of intersection, distance to intersection), and the front of the vehicle photographed by an infrared camera at night. Is displayed. The above is the configuration of the vehicle head-up display.

  In the configuration of the image projector 100, the optical path length from the display 20 to the concave mirror 30 is 80 to 100 mm, and this optical path length is about half that of the conventional one. Therefore, since the size of the housing 10 can be designed according to the optical path length, the outer size of the housing 10, that is, the outer size of the image projector 100 can be reduced.

  Next, image display of the vehicle head-up display will be described. First, when light is emitted from the light source of the display 20 in the image projector 100, the light is irradiated onto the liquid crystal panel, and image light of an image displayed on the liquid crystal panel is projected from the opening of the display 20. The image light emitted from the display device 20 is directly incident on the concave mirror 30.

  Subsequently, the image light of the image magnified by the concave mirror 30 is emitted through the lens 40 fixed to the upper part of the housing 10. At this time, the image is enlarged according to the enlargement ratio of the lens 40. The image light of the image thus enlarged and emitted is imaged on the inner surface of the front windshield WS. Specifically, the image of the liquid crystal panel is formed as a virtual image in the concave mirror 30, and this virtual image is formed on the inner surface of the front windshield WS. In this way, an image is displayed on the display unit 50 of the front windshield WS.

  Further, as described above, the lens 40 having an enlargement function is fixed to the opening of the housing 10 that emits the image light to the passenger compartment. Therefore, the lens 40 blocks the vehicle interior and the space in the housing 10.

  As described above, in the present embodiment, the image light emitted from the display device 20 in the image projector 100 is directly reflected on the concave mirror 30 and the image light reflected on the concave mirror 30 via the lens 40 is displayed. Leading to part 50. In this way, the optical path length from the display 20 to the concave mirror 30 can be reduced by directly entering the image light emitted from the display 20 into the concave mirror 30. Furthermore, since the image light is emitted from the concave mirror 30 to the display unit 50 of the front windshield WS via the lens 40, the image can be enlarged by the concave mirror 30 and the lens 40. Thus, the housing 10 can be downsized, that is, the image projector 100 can be downsized, and an image can be enlarged and displayed.

  Further, the image emitted from the display 20 is enlarged by the concave mirror 30 and the lens 40. Thereby, the magnification of the image can be dispersed in the concave mirror 30 and the lens 40, and the magnification of the concave mirror 30 can be lowered as compared with the conventional case. Thereby, the high image magnification of the concave mirror 30 can suppress image shaking that occurs when the driver's line of sight moves.

  As such a lens 40, as shown in FIGS. 2A and 2B, the biconvex lens 41 or the plano-convex lens 42 having an enlargement function can be used to enlarge the size of the image.

  The lens 40 is disposed at the opening of the housing 10 and closes the inside of the housing 10. Thereby, since the lens 40 functions as a dustproof lens, it is possible to prevent dust and dust from entering the housing 10.

(Second Embodiment)
In the present embodiment, only different parts from the first embodiment will be described. This embodiment is different from the first embodiment in that the magnification of the concave mirror is higher than that in the first embodiment, and the lens has a concave surface on both sides or one side. In addition, the same code | symbol is described about the same thing as the component shown by FIG.

  FIG. 3 is a schematic diagram of a vehicle head-up display according to the second embodiment of the present invention. As shown in this figure, the vehicle head-up display includes an image projector 100 that emits image light of an image, and a display unit 50 that displays the image light emitted from the image projector 100. It is configured.

  Similar to the first embodiment, the image projector 100 includes a housing 10, a display device 20, a concave mirror 30, and a lens 45. The housing 10, the display device 20, and the display unit 50 are the same as those in the first embodiment.

  The concave mirror 30 enlarges an image directly incident from the display device 20 as in the first embodiment. In the present embodiment, the magnification of the concave mirror 30 is higher than that of the first embodiment, for example, 6 times.

  The lens 45 is a transparent body having a function of enlarging / reducing an image and a function of correcting distortion of the image. 3A and 3B are diagrams showing the cross-sectional shape of the lens 45, where FIG. 3A is a cross-sectional view of the biconcave lens 46, and FIG. Each of the lenses 45 shown in FIGS. 3A and 3B performs light distortion correction, and the magnification is, for example, −2. Here, distortion refers to the meaning that the display position of an image is shaken. Further, the distortion correction refers to a function for preventing the shaking of the image display position. In the present embodiment, the biconcave lens 46 shown in FIG. The above is the configuration of the vehicle head-up display of this embodiment.

  Next, image display of the vehicle head-up display will be described. Similar to the first embodiment, the image projector 100 directly irradiates image light onto the concave mirror 30 from the display 20, and the concave mirror 30 enlarges the size of the image. Thereby, the optical path length from the display 20 to the concave mirror 30 can be reduced. In addition, the size of the image can be enlarged to a size that can be visually recognized by the driver by setting the magnification of the concave mirror 30 high.

  Subsequently, the image light of the image magnified by the concave mirror 30 is emitted to the display unit 50 through the lens 45 fixed to the upper part of the housing 10. The image light of the image thus enlarged and emitted is imaged on the inner surface of the front windshield WS, and the image is displayed on the display unit 50 of the front windshield WS.

  When the driver's line of sight movement occurs when an image is displayed on the display unit 50 in this way, the image light emitted from the concave mirror 30 is shaken, and the display position of the image displayed on the display unit 50 is shaken. However, in this embodiment, even if the optical axis of the image light emitted from the display device 20 is shaken due to the shaking of the housing 10, the shaking of the optical axis is suppressed by the distortion preventing function of the lens 45, so It is possible to prevent the display position of the displayed image from changing greatly.

  In the present embodiment, the magnification of the lens 45 is negative, but the size of the image displayed on the display unit 50 of the front windshield WS is secured by covering the magnification with the magnification of the concave mirror 30. is doing. As in the first embodiment, the lens 45 serves as a dustproof cover.

  As described above, in the present embodiment, the image magnified by the concave mirror 30 is displayed on the display unit 50 of the front windshield WS via the lens 45 that corrects distortion. Thereby, even if the optical axis of the image light emitted from the display device 20 vibrates due to the movement of the line of sight of the driver, it is possible to prevent the image displayed on the display unit 50 from being shaken by the lens 45 having the distortion correction function. it can. In this way, the housing 10 can be downsized, that is, the image projector 100 can be downsized and an image can be enlarged and displayed, and image shaking can also be suppressed.

  Further, by adopting the biconcave lens 46 or the plano-concave lens 47 shown in FIGS. 4A and 4B as the lens 45 having the distortion correction function, the shaking of the image displayed on the display unit 50 is suppressed. be able to. Such a lens 45 has a dustproof function of closing the inside of the housing 10 by being disposed in the opening of the housing 10. Therefore, dust and dust can be prevented from entering the housing 0.

(Other embodiments)
The configuration of the vehicle head-up display shown in the first and second embodiments is an example, and is not limited thereto.

  In the first and second embodiments, the lenses 40 and 45 are used alone. However, for example, a plurality of lenses 40 and 45 may be combined and fixed to the housing 10.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the head-up display for vehicles which concerns on 1st Embodiment of this invention, (a) is a top view of an image projector, (b) is a schematic diagram at the time of use of the head-up display for vehicles. . It is the figure which showed the cross-sectional shape of the lens in 1st Embodiment, (a) is a biconvex lens, (b) is sectional drawing of a plano-convex lens. It is a schematic diagram at the time of use of the head-up display for vehicles which concerns on 2nd Embodiment of this invention. It is the figure which showed the cross-sectional shape of the lens in 2nd Embodiment, (a) is a biconcave lens, (b) is sectional drawing of a plano-concave lens. It is the figure which showed the schematic block diagram of the conventional head-up display for vehicles, (a) is a top view of an image projector, (b) is a schematic diagram at the time of use of the head-up display for vehicles.

Explanation of symbols

100, 200 ... Image projector, 10 ... Housing, 20 ... Display, 30 ... Concave mirror,
40, 45 ... lens, 41 ... biconvex lens, 42 ... plano-convex lens, 46 ... biconcave lens,
47: Plano-concave lens, 50: Display unit, WS: Front windshield.

Claims (4)

In a vehicle head-up display comprising: an image projector (100) that projects image light of an image; and a display unit (50) that is provided on a front windshield (WS) of the vehicle and displays the image.
The image projector is
A housing (10) which is a storage member and is disposed on the back side of the instrument panel of the vehicle and has an opening for emitting image light of the image at the top;
A display (20) that is housed in the housing and emits image light of the image displayed on the display unit of the front windshield;
A magnifying glass (30) that is housed in the housing and that magnifies and reflects the image directly incident from the display;
A lens (40) disposed in the opening of the housing, closing the inside of the housing, enlarging the image incident from the magnifying glass, and outputting the enlarged image to the display unit of the front windshield. A vehicle head-up display. The vehicle head-up display according to claim 1, wherein the lens is at least one of a biconvex lens (41) and a plano-convex lens (42). In a vehicle head-up display comprising: an image projector (100) that projects image light of an image; and a display unit (50) that is provided on a front windshield (WS) of the vehicle and displays the image.
The image projector is
A housing (10) which is a storage member and is disposed on the back side of the instrument panel of the vehicle and has an opening for emitting image light of the image at the top;
A display (20) that is housed in the housing and emits image light of the image displayed on the display unit of the front windshield;
A magnifying glass (30) that is housed in the housing and magnifies and reflects the image directly incident from the display;
The housing is disposed in the opening and closes the inside of the housing, and has a function of enlarging / reducing the image and a function of correcting distortion of the image. A vehicle head-up display, comprising: a lens (45) that outputs image light to the display unit of the front windshield. The vehicle head-up display according to claim 3, wherein the lens is at least one of a biconcave lens (46) and a planoconcave lens (47).

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