JP2009222880A - Head-up display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To propose a head-up display device in which a mirror does not get fogged by dew condensation even in a cold winter morning. <P>SOLUTION: In the head-up display device 10, an image displayed on a display panel 21 is enlarged by a mirror optical system 25 constituted of a plurality of mirrors, and the enlarged image is reflected on a windshield 13 of an automobile, to enable a driver of the automobile to view a virtual image of the image. The device includes an LED 22 irradiating the display panel 21 with light from the back and a holding member 30 to which a first plane mirror 27 is attached. The holding member 30 has a function of a heat radiation plate for radiating heat generated by the LED 22. The holding member 30 conducts the heat generated by the LED 22 to the attaching part of the first plane mirror 27, and the first plane mirror 27 is warmed by the conducted heat. Thus, a fogging preventing effect is given to the first plane mirror 27. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a head-up display device for a moving body such as an automobile.

  2. Description of the Related Art Conventionally, a head-up display device is known as a device that displays information such as a traveling speed to a driver such as an automobile. The head-up display device projects a virtual image of an image to be displayed on a windshield, so that a driver can recognize information necessary for driving a car or the like without looking away from the field of view.

Patent Document 1 below describes an image projector for a head-up display that includes a lens that closes an opening and enlarges an image and outputs the enlarged image to a display unit of a windshield. This lens emits image light emitted from the display device and reflected by the concave mirror from the image projector toward the display unit of the windshield, and closes the inside of the image projector to prevent dust from entering.
JP 2006-091104 A

  Even if the inside of the housing is closed to prevent dust from entering as described in the above-mentioned Patent Document 1, the humidity enters. Moisture contained in the air can sometimes condense. For example, on a cold winter morning, the head-up spray device on the dashboard inside the car is also cold. When the head-up display is turned on in such a state, the internal air is warmed by the heat generated by the light source device, and the warmed air touches the cold mirror to cause condensation, causing the mirror to fog up. End up. If the mirror becomes cloudy, it is natural that a clear image cannot be projected.

  In view of the above problems, the present invention proposes a head-up display device in which a mirror does not fog due to condensation even in a cold winter morning.

  A head-up display device according to the present invention enlarges an image displayed on a transmissive liquid crystal display panel by a mirror optical system including a plurality of mirrors, reflects the enlarged image on a windshield of a moving body, and A head-up display device for a moving body that allows an occupant of the moving body to visually recognize a virtual image of the image, a light source device that irradiates light from the back to the transmissive liquid crystal display panel, and at least one of the plurality of mirrors; Is provided with a holding member attached thereto. The holding member serves as a heat radiating plate that radiates heat generated by the light source device. The holding member conducts heat generated by the light source device to the mounting portion of the mirror, warms the mirror by the conducted heat, and imparts an anti-fogging effect to the mirror. The mirror attached to the holding means is preferably a mirror arranged at a position closest to the transmissive liquid crystal display panel among the plurality of mirrors.

  In the head-up display device according to the present invention, the holding member serves as a heat radiating plate of the light source device to reduce the space of the heat radiating member. Absent.

  As shown in FIG. 1, the head-up display device 10 is arranged on a dashboard 12 of an automobile (moving body) 11 and emits an image related to various information such as a value of a speedometer and reflects it on a windshield 13 so that the driver (Crew) A virtual image 15 obtained by enlarging the image is displayed at a few meters ahead. The driver 14 can visually recognize the image enlarged and displayed as the virtual image 15 without greatly moving the viewpoint from the front view even during driving.

  As shown in FIG. 2, the head-up display device 10 includes a transmissive liquid crystal display panel (hereinafter referred to as a display panel) 21 that displays an image inside a housing 20 disposed under the dashboard 12. An LED (light source device) 22 that irradiates light on the back surface of the display panel 21 and an image beam 23 emitted from the display panel 21 are reflected toward the windshield 13 from an emission window 24 provided in the housing 20. A mirror optical system 25 that emits and displays the enlarged image. The mirror optical system 25 includes a first flat mirror 27 that reflects the image light beam 23 emitted from the display panel 21 toward the second flat mirror 26, and a concave mirror 28 that reflects the image light beam 23 from the first flat mirror 27. And a second flat mirror 26 that reflects the image light beam 23 reflected from the concave mirror 28 toward the exit window 24 and the concave mirror 28. The image light beam 23 emitted from the emission window 24 irradiates the windshield 13.

  The display panel 21 is a small display panel such as a 0.8 type, for example, and displays values of various instruments such as a tachometer, a water temperature gauge, and a fuel gauge in addition to a speedometer. Since the display panel 21 is small in size, the displayed image is small, and therefore the image is magnified by the concave mirror 28. The concave mirror 28 corrects not only the enlargement of the image but also distortion caused by the windshield 13, so that the concave mirror The image by the reflected light 28 becomes a distorted image as it is, but it appears as a normal image through reflection by the curved surface of the windshield 13. The mirror optical system 25 is configured such that the image light beam 23 is reflected twice by the second flat mirror 26, thereby making the whole compact and reducing the size of the head-up display device 10.

  The LED 22 is attached to one end side of a holding member 30 fixed to the housing 20. The holding member 30 is formed of a material having a high thermal conductivity such as aluminum, for example, and serves as a heat radiating plate that conducts heat generated by the LED 22 to the entire holding member 30 and cools the LED 22. The first flat mirror 27 attached to the other end of the holding member 30 is warmed by the heat generated by the LED 22.

  Next, the operation of the above embodiment will be described. Moisture contained in the air can sometimes condense. For example, even in the cold winter morning, even the head-up display device 10 housed in the dashboard 12 in the automobile 11 is cold. When the power of the head-up display device 10 is turned on, the LED 22 generates heat, and the air around the LED 22 is heated by the heat, and the entire air in the housing 20 is gradually heated. Since the first plane mirror 27 is disposed at a position closest to the LED 22 among the plurality of mirrors, it is affected first. The heat generated by the LED 22 is absorbed by the holding member 30 faster than the surrounding air is warmed, and the entire holding member 30 becomes warm. The heated holding member 30 warms the first flat mirror 27 attached to the other end. Thus, since the 1st plane mirror 27 is warmed earlier than the surrounding air, the 1st plane mirror 27 does not become cloudy. Accordingly, the head-up display device 10 can display a clear image without fogging the mirror even in a cold morning.

  Next, although another embodiment will be described, the holding member 30 in the above-described embodiment is replaced with a holding member 31 having a different shape, and the other members are all the same, so the same symbols are used, and those members are also used. The explanation is also omitted. As shown in FIG. 3, the holding member 31 has the LED 22 attached to one end side and the second flat mirror 26 attached to the other end side. By arranging in this way, the second plane mirror 26 can be prevented from being fogged.

  In the above embodiment, the three mirrors forming the mirror optical system 25 are composed of two plane mirrors and one concave mirror. However, the configuration of the mirror is not limited to this. For example, the second plane mirror 26 Instead of this, another concave mirror may be used.

  Moreover, although LED was used for the light source, LED of what color may be sufficient and the light source of a desired color may be used. For example, white, red, green, blue, or other single color LEDs may be used, or an image may be displayed in a desired color by combining some of these single color LEDs. Furthermore, not only LEDs but also other known lamps may be used.

  In the embodiment described above, the automobile 11 is used as a moving body on which the head-up display device 10 is mounted. However, the moving body is not limited to a vehicle such as the automobile 11, and may be a flying body such as an airplane. Or a ship.

It is a schematic diagram of the driver's seat of the motor vehicle carrying the head up display apparatus which implemented this invention. It is a figure which shows the structure of a head-up display apparatus. It is a figure which shows the structure of another embodiment.

Explanation of symbols

10 Head-up display device 11 Car (moving body)
12 Dashboard 13 Windshield 14 Driver (Crew)
15 Virtual image 21 Display panel (Transmission type liquid crystal display panel)
22 LED (light source device)
23 Image beam 24 Exit window 25 Mirror optical system 26 Second plane mirror 27 First plane mirror 28 Concave mirror 30, 31 Holding member

Claims (2)

The image displayed on the transmissive liquid crystal display panel is magnified by a mirror optical system composed of a plurality of mirrors, the magnified image is reflected by the windshield of the moving body, and a virtual image of the image is transmitted to the occupant of the moving body In a head-up display device for a moving body that visually recognizes
A light source device for irradiating light from the back to the transmissive liquid crystal display panel;
At least one of the plurality of mirrors and the light source device are attached to conduct heat generated by the light source device, and to hold the mirror by the conducted heat,
A head-up display device comprising: The head-up display device according to claim 1, wherein the mirror attached to the holding member is disposed at a position closest to the transmissive liquid crystal display panel among the plurality of mirrors.

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