JPH04255891A - Display device for vehicle - Google Patents

Abstract

PURPOSE:To enable riding persons to view a virtual image formed in front of the vehicle with good visibility without increasing the view load on the riding persons whatever speed the vehicle travels. CONSTITUTION:The vehicle display device which projects a display light image on a reflecting combiner 2 provided on windshield glass 2 to form and display its virtual image in front of the vehicle is provided with an optical system 4 for display light image projection which increases the image formation distance of the above virtual image from the vehicle as the vehicle speed increases. Then the size of the display light image projected on the reflecting combiner 2 by a display light image projecting means 3 is increased with the speed of the vehicle. Consequently, the image formation position of the display virtual image becomes farther as the vehicle speed increases and the display virtual image increases in size simultaneously.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device for a vehicle, and more particularly to a head-up display device used in automobiles and the like.

0002

[Prior Art] Display devices used in vehicles such as automobiles to display vehicle speed and other vehicle status information include CRTs, LCDs with backlights, etc., in addition to reflective combiners such as holograms provided on the front windshield glass. projecting a display light image by means of display light image projection means;
A projection type display device that forms and displays a virtual image of this in front of a vehicle is known, and this is called a head-up display device.

Generally, it is known that the forward visibility of the driver and other passengers physiologically decreases as the vehicle speed increases, and the visible foreground image becomes perceived to be smaller. In view of this, in the above-mentioned head-up display device, the imaging position of the virtual image displayed in front of the vehicle is adjusted to the front windshield glass side, that is, to the front side as seen from the passenger, as the vehicle speed increases. change to
It has already been proposed to improve the visibility of a displayed virtual image by making the displayed virtual image larger and visible to the passenger, and this is disclosed in Japanese Patent Laid-Open No. 183240/1983.

0004

[Problem to be Solved by the Invention] However, the visual field of interest in the forward field of view of the passenger generally becomes a distant view in front of the vehicle as the vehicle speed increases, and therefore the image formation position of the displayed virtual image changes as the vehicle speed increases. When the vehicle changes to the front side as seen from the passenger,
Visual recognition of the foreground and visual recognition of the displayed virtual image are not compatible in the same field of view, which may increase the visual recognition load on the passenger.

The present invention has been made by focusing on the above-mentioned problems in conventional head-up display devices, and the virtual image formed and displayed in front of the vehicle is It is an object of the present invention to provide a projection type display device for a vehicle that displays a virtual image so that it can be visually recognized by a passenger with good visibility without increasing the visual recognition load on a tower passenger.

[0006]

[Means for Solving the Problems] According to the present invention, a display light image is projected onto a reflective combiner provided on the front windshield glass, and a virtual image thereof is formed in front of the vehicle. A vehicle display device for displaying a vehicle includes a vehicle speed detection means for detecting vehicle speed, and an imaging distance adjustable for increasing the imaging distance of the virtual image from the vehicle in accordance with an increase in the vehicle speed detected by the vehicle speed detection means. and a display light image projection means for increasing the size of the display light image projected onto the reflective combiner in accordance with an increase in the vehicle speed detected by the vehicle speed detection means. This is achieved by a vehicle display device characterized by the following.

[0007]

According to the above-described structure, as the vehicle speed increases, the image forming position of the displayed virtual image moves farther in front of the vehicle, and at the same time, the size of the displayed virtual image increases.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a display device for a vehicle according to the present invention. In FIG. 1, reference numeral 1 indicates a front windshield glass of a vehicle, and a sheet-like reflective combiner 2 made of a hologram or the like is adhered to the surface of the front windshield glass on the inside of the vehicle. Inside the vehicle interior, there is a display light image projection device 3 that generates a display light image of vehicle speed, etc. and projects it toward the reflection combiner 2, and a display light image projected by the display light image projection means 3 to the reflection combiner 2. A guiding optical lens device 4 is provided.

The display light image projection device 3 is composed of a CRT, an LCD with a backlight, etc., and the display light image generated is controlled by an external signal, and the size of the display light image can be freely controlled by the external signal. It is configured to be changeable.

The optical lens device 4 includes a relay lens, a Fresnel lens, etc., and variably sets the imaging distance from the vehicle of a virtual image based on the display light image projected from the display light image projection device 3 to the reflection combiner 2. It consists of a motor-driven optical lens system with variable image distance.

The display contents and size of the display light image by the display light image projection device 3 are controlled by a display light image control circuit 5. The display light image control circuit 5 receives a vehicle speed signal indicating the vehicle speed from the vehicle speed sensor 7, and based on this, outputs a display control signal for displaying the current vehicle speed to the display light image projection device 3, and at the same time outputs a display control signal for displaying the current vehicle speed. A display control signal is output to the display light image projection device 3 to increase the size of the display light image in accordance with the increase.

The imaging distance control by the optical lens device 4 is performed by an imaging distance control device 6. The imaging distance control device 6 is provided with a vehicle speed signal indicating the vehicle speed from the vehicle speed sensor 7, and based on this, the imaging distance control device 6 sends an imaging distance control signal to the motor drive device of the optical lens device 4 to increase the imaging distance in accordance with an increase in the vehicle speed. 4a.

According to the above configuration, the display light image generated by the display light image projection device 3 is projected onto the reflection combiner 2 while the imaging distance is adjusted by the optical lens device 4, and a virtual image thereof is projected in front of the vehicle. The image is formed and displayed as a visible image. In this case, the imaging distance by the optical lens device 4 increases as the vehicle speed increases, and the display light image generated by the display light image projection device 3 increases in size as the vehicle speed increases. As a result, the image formation position of the displayed virtual image moves farther in front of the vehicle, for example from position A to position B in FIG. 1, as the vehicle speed increases, and the size of the displayed virtual image increases from Sa to Sb. Become.

If the size of the displayed light image does not change only by a change in the imaging distance, the viewing angle of the displayed virtual image will become α smaller than β due to the change in the imaging position from the A position to the B position, and the displayed virtual image will change. However, when the size of the displayed virtual image increases from Sa to Sb as the imaging position changes from position A to position B, its viewing angle does not change and it is visible to passengers on board. The size of the displayed virtual image will not change. The relationship between the imaging distance in this case, the size of the displayed light image by the display light image projection device 3, and the size of the displayed virtual image visually recognized by the passenger is shown by a solid line in FIG.

[0016] As a result, the virtual image formed and displayed in front of the vehicle can be visually recognized by the occupants with good visibility, without increasing the visual burden on the tower occupants, regardless of the speed at which the vehicle is traveling.

The size of the displayed virtual image visually recognized by the passenger may be increased as the imaging distance increases, in other words, as the vehicle speed increases; in this case, the display light image by the display light image projection device 3 It is only necessary that the magnification of the magnitude of the vehicle speed is increased from that in the above embodiment. The relationship between the imaging distance in this case, the size of the displayed light image by the display light image projection device 3, and the size of the displayed virtual image visually recognized by the passenger is shown by a broken line in FIG.

In FIG. 2, the dashed line indicates the imaging distance and the size of the displayed light image by the display light image projection device 3 when the size of the displayed light image is constant regardless of the increase in the imaging distance. It shows the relationship between the size of the displayed virtual image and the size of the displayed virtual image that is visually recognized by the passenger.

Furthermore, in the vehicle display device according to the present invention, the imaging distance and size of the displayed virtual image are controlled according to the vehicle speed in order to avoid sudden or frequent changes in the imaging position. The vehicle speed may be smoothed within a predetermined period of time with a certain delay in response to the change.

[0020]

As can be understood from the above explanation, according to the vehicle display device according to the present invention, as the vehicle speed increases, the image formation position of the displayed virtual image moves farther in front of the vehicle. Since the size of the displayed virtual image becomes larger, the virtual image formed and displayed in front of the vehicle will not increase the visual burden on the tower occupants no matter what speed the vehicle is traveling at.
It can be seen with good visibility by passengers.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of a vehicle display device according to the present invention.

FIG. 2 is a graph showing the relationship between the imaging distance, the size of a display light image by a display light image projection device, and the size of a display virtual image visually recognized by a passenger, under various conditions.

[Explanation of symbols]

1 Front windshield glass 2 Reflection combiner 3 Display light image projection means 4 Optical lens device 5 Display light image control circuit 6 Imaging distance control device 7 Vehicle speed sensor

Claims (1)

[Claims] Claim 1: A vehicle speed detection device for detecting vehicle speed in a vehicle display device that projects a display light image onto a reflective combiner provided on a front windshield glass and forms and displays a virtual image of this in front of the vehicle. means, a display light image projection optical system capable of adjusting an imaging distance that increases the imaging distance of the virtual image from the vehicle in accordance with an increase in the vehicle speed detected by the vehicle speed detection means, and a display light image projection optical system that is adjustable in imaging distance from the vehicle in accordance with an increase in the vehicle speed detected by the vehicle speed detection means; 1. A display device for a vehicle, comprising display light image projecting means for increasing the size of a display light image projected onto the reflective combiner in accordance with an increase in vehicle speed.