JPH04264487A - Projection type display device - Google Patents

Abstract

PURPOSE:To perform invariably proper contrast control over a display virtual image corresponding to the brightness and color of the background of the display virtual image in any background state and to eliminate the need for optical components such as a special lens, a reflecting mirror, for detecting the brightness and color of the background of the display virtual image. CONSTITUTION:A hologram combiner 2 is provided with a part which diffracts a light beam from a part, where a display light image from a display light image projector 3 is superimposed as a virtual image except a part diffracting the image to one side of transparent glass 1, to a light quantity detector 5 and a color detector 6 provided on one side of the transparent glass l. The brightness and color of the display light image of the display light image projector 3 are controlled according to the light quantity and color detected by the light quantity detector 5 and color detector 6.

Description

Description: FIELD OF THE INVENTION The present invention relates to a floodlight display device, and more particularly to a floodlight display device used as a head-up display device in automobiles and the like. [0002] As a display device used to display vehicle speed and other vehicle information in vehicles such as automobiles, a combiner such as a hologram provided on the front windshield glass, a CRT, and a backlit LC are used.
2. Description of the Related Art A light projection type display device is known in which a display light image is projected by a display light image projector such as D, and a virtual image of the display light image is formed in front of a combiner, and this is called a head-up display device. A display virtual image formed in front of the combiner, that is, in front of the vehicle, is viewed by a driver or the like in a state in which the foreground in front of the vehicle is superimposed on the background in the vehicle interior. In this case, the display light image projector is adjusted according to the brightness of the part superimposed on the displayed virtual image as a background so that the displayed virtual image can be clearly seen regardless of the brightness of the part superimposed on the virtual image as a background. It has already been proposed to control the brightness of the displayed light image, for example, in
It is shown in the publication No. In addition, the color of the display light image of the display light image projector is adjusted according to the background color so that the display virtual image can be clearly seen regardless of the color of the part superimposed on the display virtual image as a background (background color). In other words, it has already been proposed to control the color of a displayed virtual image, as disclosed in, for example, Japanese Patent Laid-Open No. 2-227340. [0006] Problem to be Solved by the Invention: Control of the brightness of the background of the displayed virtual image and the brightness and color of the displayed virtual image according to the background color so that the displayed virtual image can be clearly seen by a viewer such as a driver. In other words, contrast control is performed depending on the brightness and color of the background on the extension line connecting the viewer's eyes and the displayed virtual image, that is, the spot-like background that is actually superimposed on the displayed virtual image when the viewer visually recognizes the displayed virtual image. It should be done. However, conventionally, the detectors for detecting the background brightness and background color of the displayed virtual image have been placed on the upper edge of the front windshield glass, the upper surface of the installation pad, etc. on the combiner so as not to obstruct the driver's forward view. This means that the brightness and color of the background that is outside the extension line connecting the viewer's eyes and the displayed virtual image is detected. In viewing, it is not possible to accurately detect the brightness and color of a spot-like background that is actually superimposed on the displayed virtual image, and the contrast control of the displayed virtual image based on this cannot necessarily be performed appropriately. Furthermore, if a detector for detecting the background brightness and background color of the displayed virtual image is provided on the upper edge of the front windshield glass, the upper surface of the installation pad, etc.
Optical components such as lenses and reflectors are required to guide light from the background of the displayed virtual image to the detector, and as the number of required components increases, the structure becomes complicated. The present invention has been made by focusing on the above-mentioned problems in conventional floodlight display devices, and provides contrast control of a displayed virtual image according to the brightness and color of the background of the displayed virtual image. A simple light projection method that always works properly under any background condition, and does not require any optical components such as special lenses or reflectors to detect the brightness and color of the background of the displayed virtual image. The purpose is to provide display devices. [Means for Solving the Problems] According to the present invention, the above object is achieved by projecting a display light image from a display light image projector onto a hologram combiner provided on one side of a transparent glass; A virtual image of this is formed in the space on the other side of the transparent glass, and the brightness of the display light image of the display light image projector is controlled according to the brightness of a portion superimposed on the virtual image as a background. In the display device, the hologram combiner sends light rays from a portion superimposed on the virtual image as a background, in addition to a diffractive portion for forming the virtual image, to a light amount detector provided on one side of the transparent glass. A light projection display device having a diffraction portion and configured to control the brightness of the display light image of the display light image projector according to the amount of light detected by the light amount detector;
Alternatively, a display light image is projected from a display light image projector onto a hologram combiner provided on one side of the transparent glass, and a virtual image thereof is formed in the space on the other side of the transparent glass, and the virtual image is In a projection type display device that controls the color of a display light image of the display light image projector according to the color of a portion superimposed as a background, the hologram combiner includes a portion other than a diffraction acting portion for forming a virtual image. It has a portion that diffracts light rays from a portion superimposed on the virtual image as a background to a color detector provided on one side of the transparent glass, and the display light image is adjusted according to the color detected by the color detector. This is accomplished by a floodlight display device, characterized in that it is configured to control the color of a displayed light image of a projector. [Operation] According to the above structure, the hologram combiner performs the original diffraction effect for forming a virtual image of the display light image from the display light image projector, and also superimposes the display light image on the virtual image as a background. A diffraction effect is generated that guides the light rays from the part to the light intensity detector and color detector, and as a result, the light intensity detector and color detector detect the brightness and color of the spot-like background that is actually superimposed on the virtual image in front of the hologram combiner as a background. will be detected. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail by way of embodiments with reference to the accompanying drawings. FIG. 1 shows an embodiment in which a floodlight display device according to the present invention is applied to a head-up display device for an automobile. In FIG. 1, reference numeral 1 indicates a front windshield glass of an automobile, and a hologram combiner 2 is adhered to the surface of the front windshield glass on the inside of the vehicle. Inside the vehicle, there is a display light image projection device 3 that generates a display light image such as vehicle speed and projects it toward the hologram combiner 2, and a display light image projected by the display light image projection means 3 to the hologram combiner 2. A guiding optical lens device 4 is provided. The display light image projection device 3 is composed of a color CRT, a color LCD with a backlight, etc., and the display light image generated is controlled by an external signal, and the color of the display light image can be freely controlled by the external signal. It is structured so that it can change. The optical lens device 4 includes a relay lens, a Fresnel lens, etc., and corrects aberrations of the display light image projected from the display light image projection device 3 to the hologram combiner 2. It is configured to determine the imaging distance of the virtual image D in front of the hologram combiner based on the image. A light amount sensor 5 is installed on the side of the optical lens device 4.
and a chromaticity sensor 6 are attached. Light amount sensor 5
converts the amount of incident light into an amount of electricity, and outputs a light amount signal to the display light image brightness control circuit 7. The chromaticity sensor 6 detects the chromaticity of the incident light beam, and outputs a signal indicating the chromaticity to the display light image color control circuit 8. The display light image brightness control circuit 7 is adapted to increase or decrease the brightness of the display light image of the display light image projection device 3 in accordance with the light amount signal from the light amount sensor 5. The display light image color control circuit 8 is configured to variably control the color of the display light image of the display light image projection device 3 in accordance with the chromaticity signal from the chromaticity sensor 6. The display light image color control circuit 8 controls the color of the display light image of the display light image projection device 3 so that the hue of the display light image is approximately complementary to the hue indicated by the chromaticity signal from the chromaticity sensor 6. It should be done as it should. As shown in FIG. 2, most part 2a of the hologram combiner 2 is tuned to the emission wavelength of the display light image projection device 3 in order to form a virtual image D of the display light image from the display light image projection device 3. It is configured to exhibit high diffraction efficiency for wavelengths, but high transmission efficiency for other wavelengths. Therefore, when viewed from inside the vehicle, the hologram combiner 2 appears almost transparent, and the virtual image D formed in front of the hologram combiner 2, in this case, the vehicle speed display, is visible from the front view of the vehicle, as shown in FIG. The passenger with background B superimposed on
Mainly visible to drivers. A portion 2b of the hologram combiner 2 that is adjacent to the portion 2a for forming a virtual image and does not participate in virtual image formation is subjected to reverse exposure processing, diffracting light rays from the background B superimposed on the virtual image D. This is configured to focus on each of the light amount sensor 5 and chromaticity sensor 6. Here, the above-mentioned portion 2b is referred to as a background light diffraction portion. In this case, the light amount sensor 5 and the chromaticity sensor 6 are provided with a light beam from the background light diffraction portion 2b of the hologram combiner 2, and the background B on the extension line connecting the driver's eyes M and the virtual image D, That is, when the driver visually recognizes the virtual image D, the brightness and color of the spot-like background B that is actually superimposed on the virtual image D is detected. Then, the brightness and color of the display light image of the display light image projection device 3 are set according to the brightness and color of the background B detected by the light amount sensor 5 and the chromaticity sensor 6, and as a result, the brightness and color of the background B are set. The virtual image D is displayed with appropriate contrast and good visibility regardless of brightness or color. FIG. 3 shows another embodiment in which the floodlight display device according to the present invention is applied to a head-up display device for an automobile. In this embodiment, the background light diffraction portion 2b of the hologram combiner 2 has red, green,
In order to perform light color separation of the three primary colors of blue, a red diffraction section 2br and a green diffraction section 2 each individually diffract light beams of each wavelength of red, green, and blue.
bg and a blue diffraction section 2bb. Three light amount sensors 5r, 5g, and 5b such as photosensors are provided on the side of the optical lens device 4. The light amount sensor 5r senses the diffracted light from the red diffraction section 2br, the light amount sensor 5g senses the diffracted light from the green diffraction section 2bg, and the light amount sensor 5b senses the diffracted light from the blue diffraction section 2bb. ing. The output signals of the three light amount sensors 5r, 5g, and 5b are input to a color analysis circuit 9 and a brightness calculation circuit 10, respectively. The color analysis circuit 9 includes light amount sensors 5r, 5g, and 5b.
The color of the background is analyzed based on the amount of light sensed by each sensor, and a signal of the color detected by the analysis is output to the display light image color control circuit 8. The brightness calculation circuit 10 includes a light amount sensor 5r,
Calculate the background brightness from the amount of light detected by each of 5g and 5b,
This signal is output to the display light image brightness control device 7. Therefore, in this case as well, the light rays incident on the background light diffraction portion 2b of the hologram combiner 2, that is, the brightness and color of the spot-like background actually superimposed on the virtual image when the driver visually recognizes the virtual image, are displayed. The brightness and color of the display light image of the light image projection device 3 are set, and as a result, the virtual image D is displayed with appropriate contrast and good visibility regardless of the brightness and color of the background of the virtual image. As can be understood from the above description, according to the projection type display device of the present invention, the hologram combiner for forming a virtual image of the display light image from the display light image projector is capable of forming a virtual image. The light rays from the part superimposed as a background are guided to a light amount detector and a color detector by diffraction, and the light amount detector and color detector detect the brightness of the spot-like background that is actually superimposed as a background on the virtual image in front of the hologram combiner. The color is detected, and the brightness and color of the display light image of the display light image projection device are set accordingly, so the virtual image can be seen with appropriate contrast regardless of the brightness or color of the background of the virtual image. There is no need for optical parts such as special lenses or reflectors to detect the brightness and color of the background of the virtual image, and the structure does not become complicated.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing an embodiment in which a floodlight display device according to the present invention is applied to a head-up display device for an automobile.

FIG. 2 is a plan view showing an example of a hologram combiner used in a floodlight display device according to the present invention.

FIG. 3 is a schematic perspective view showing another embodiment in which the floodlight display device according to the present invention is applied to a head-up display device for an automobile.

[Explanation of symbols]

1 Front windshield glass 2 Hologram combiner 3 Display light image projection device 4 Optical lens device 5 Light amount sensor 6 Chromaticity sensor 7 Light image brightness control circuit 8 Display light image color control circuit 9 Color analysis circuit 10 Brightness calculation circuit D Virtual image B Background M Driver's eyes

Claims (2)

[Claims] 1. Projecting a display light image from a display light image projector onto a hologram combiner provided on one side of the transparent glass, and forming a virtual image thereof in a space on the other side of the transparent glass, In a projection type display device that controls the brightness of a display light image of the display light image projector according to the brightness of a portion superimposed on the virtual image as a background, the hologram combiner is configured to perform diffraction for forming the virtual image. In addition to the active part, there is a part that diffracts light rays from a part superimposed on the virtual image as a background to a light quantity detector provided on one side of the transparent glass, and the light quantity is adjusted according to the light quantity detected by the light quantity detector. A light projection display device, characterized in that it is configured to control the brightness of a display light image of the display light image projector. 2. Projecting a display light image from a display light image projector onto a hologram combiner provided on one side of the transparent glass, and forming a virtual image thereof in a space on the other side of the transparent glass, In a projection type display device that controls the color of the display light image of the display light image projector according to the color of a portion superimposed on the virtual image as a background, the hologram combiner has a diffraction effect for forming the virtual image. In addition to the portion, there is a portion that diffracts light rays from the portion superimposed on the virtual image as a background to a color detector provided on one side of the transparent glass, and the A light projecting display device configured to control the color of a display light image of a display light image projector.