JPH03200445A - Head up display device - Google Patents

Abstract

PURPOSE:To prevent reflection of leakage light and improve visibility by arranging an optical axis correcting prism and a visual field selecting filter on the upper face of a Fresnel lens for displaying image, and providing a combiner along the inner face of a front glass. CONSTITUTION:An electronic shutter LCD 1 is provided as an image display device, and a light source 2 is provided under the device. A combiner 5 is provided along the inner side of a front glass 4, a Fresnel lens 3 and the optical axis correcting prism 10 are arranged on the upper face of a device box body 6, and an optical axis 13 is introduced to the eye E of a driver. Meters 7 and a light source 8 are arranged inside the device box body 6, and the optical axis 14 is introduced to the eye E of the driver through the Fresnel lens 3. Further leakage light 12 passing through the Fresnel lens 3 is reflected on the upper end part of the front glass 4 by action of a visual field selecting filter 11, not to reach the eye E of the driver. Hereby, visibility of a head up display device is further improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a head-up display installed on the dash board of a vehicle such as a car or a vehicle.The conventional head-up display (hereinafter referred to as HUD) is For example, in the cockpit of an airplane, the pilot can check necessary information without having to turn his/her line of sight from the flight direction to the dash board.
No. 212 (1973) and U.S. Patent No. 42181
Although it is known from Specification No. 1 (1980), the one shown in Figure 3 is one that appeared for automobiles. The combiner 24 can be attached to the inner surface of the windshield 25. However, some of these systems use a prism to refract the optical axis. However, the optical system containing them is complicated and expensive, and the one shown in FIG. Convoluted electronic shutter LCD
A light source 34 is projected below 31. A combiner 39 is an electronic shutter L installed separately inside the windshield 40.
An enlarged virtual image 41 of the CD 31 is created in front of the windshield 40.4 -
Fresnel lens 3 for the meter is installed on the side facing the operator.
8 is installed, and an enlarged virtual image 42 of the meters 36 is created below and in front of the dash board 33. According to this configuration, the optical axis of the upper Fresnel lens 32 from the electronic shutter LCD 31, and the meter Fresnel lens light from the meters 36. The axes are orthogonal to each other inside the HUD housing 35, and they share an internal space, allowing for space-saving mounting.However, in this case, the leaked light from the meters 36 passes through the upper Fresnel lens 32 and passes through the windshield. There is a drawback that the reflection from the inner surface of the 40 reaches the operator's eyes.

Furthermore, as shown in FIG. 5, the HUD housing 35 having the above structure is combined with a combiner 44 in which a translucent reflective thin film is deposited on the inner surface of the windshield 43.
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This invention attempts to solve the problem that when mounted with the optical axes of the meters aligned, the meters 36 appear normal, but on the other hand, the leaked light can be seen either directly through the upper Fresnel lens 32 or reflected on the windshield 43. Problem A: When implementing a HUD that allows for space-saving mounting by making the HUD part and meters coexist, as seen in the conventional example, in a car with a design where the windshield combiner slope is extremely large. The present invention is intended to solve the problem that meters cannot be seen or leakage light from meters can be seen when the display image is adjusted to the display image. A prism for correcting the HUD optical axis is placed on the upper surface of the upper Fresnel lens that forms an optical image of the HUD optical axis.It refracts the HUD optical axis uniformly toward the operator, and for example, it is transparent between ±26.5 degrees in the vertical direction.Diagonal direction 26 .5 to 58.5 degrees, insert a frosted glass-like opaque field selection filter between the upper Fresnel lens and the optical axis correction prism to prevent diagonal leakage light from the meters from reaching the windshield combiner. The HUD is characterized by preventing reflections from entering the pilot's eyes.The HUD is a space-sharing HUD that aligns the optical axis of the operating meters with the pilot's line of sight, and the HUD optical axis is orthogonal to the optical axis of the meters. By using an optical axis correction prism to refract the HUD optical axis to align with the combiner's optical axis, it is possible to align the combiner's reflected optical axis with the operator's line of sight. , HUD
Insert the upper Fresnel lens and the HUD light D optical axis correction prism field selection filter to make it opaque to the diagonal leakage light from the Km internal meters that is transparent to the HUD light pongee.
It can be improved so that unnecessary light does not reach the pilot's eyes. Here, if the material of the Fresnel lens is acrylic and is not flame retardant, A
For the HUD optical axis correction prism, choosing a flame-retardant material such as lead glass will help improve safety.At the same time, dust and other adhesion can be easily removed compared to exposed uneven surfaces on the Fresnel lens surface. Advantages and Practical Example An example in which the present invention is applied to an automobile HUD,
The explanations will be made using the first to second figures. Figure 1 is an explanatory diagram of the use of the first HUD optical axis correction prism and visual field selection filter 11 (including the integrated visual field selection optical axis correction plate) in this embodiment. DeMo Electronic shutter LCD 1 is used as an image display device, a light source 2 is placed below it, and a combiner 5 formed by pasting an anti-transparent reflective material on the inner surface of the windshield 4 and the upper surface of the display screen forming the light source image. The Fresnel lens 3 is equipped with a HUD optical axis correction prism lO on its upper surface, and its optical axis 13 is refracted by θ degrees, so that the optical axis just reflected by the combiner 5 reaches the operator's eye E. On the other hand, meters 7 made of a translucent material and a light source 8 are installed on the back panel of the HUD housing 6, and there is a meter that enlarges the meters 7 on the driver's side of the HUD housing 6. Although the optical axis 14 of the Fresnel lens 9 is designed to reach the operator's eyes E, leakage light 121 passes through the Fresnel lens 3 on the upper surface of the meters 7;
Optical axis optical axis correction prism l integrated visual field selection filter 1
1 is placed on the upper surface of the upper Fresnel lens 3 and is designed so that it will not be reflected off the upper end of the windshield 4 and reach the driver's eyes. The transparent optical axis region 17 and frosted glass-like opaque region 16 of the visual field selection filter 11 shown in FIG.
Effects of the Invention As mentioned above, according to the present invention, in a HUD that uses the inner surface of the windshield as a semi-transparent reflector, the HUD can share space with meters. Taking advantage of the advantage of space-saving mounting by orthogonally intersecting each other, the design of the car has an extremely slanted windshield.
D and meters can be seen correctly, and the reflection of leaked light from the meters can also be eliminated.

[Brief explanation of drawings]

Figure 1 shows the configuration of a head-up display according to an embodiment of the present invention. Figure 2 shows the operation of the head-up display. Figure 3 shows the configuration of a conventional head-up display. Figure 4 shows the configuration of a conventional head-up display. FIG. 5 is an explanatory diagram of the problems of the head-up display shown in FIG. 4. 1.Electronic shutter LCD, 2. Light #3.・Top Fresnel Len fS 4..Includes front glass 5..Combiner, 6..HUD housing 7..Meter iL8.
・Light! ! i 9... Fresnel lens for meter, (10
・・To HUD optical axis correction priz 81・・Field of view selection filter 12・・Leaked light 13・・HUD ray 14・・Meter type ray θ・・HUD optical axis refraction 9

Claims (3)

[Claims] (1) A Fresnel lens on which an image is displayed, a combiner formed by pasting a translucent reflective material on the inner surface of the windshield, an optical axis correction prism placed on the top surface of the Fresnel lens, and an image on the Fresnel lens. A head-up display device characterized in that a forming optical axis is refracted with respect to the inclination of a windshield combiner to align it with a driver's line of sight. (2) A first Fresnel lens arranged on the top surface of the housing for image display, a second Fresnel lens arranged on the side surface of the housing, and a translucent reflective material adhered to the inner surface of the windshield. a combiner, and a field selection filter disposed on the upper surface of the first Fresnel lens that forms an optical image of a displayed image, and the leakage light from the meters provided in the housing passes through the first Fresnel lens through the windshield. A head-up display device that prevents reflections from entering the operator's eyes. (3) The head-up display device according to claim 2, wherein an optical axis correction prism is superimposed on the visual field selection filter.