JP2013174667A - Display device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device for a vehicle capable of controlling display luminance in accordance with the fineness of the background in addition to the brightness of the background at the position where the display is superimposed.
SOLUTION: Background luminance estimation means 15 estimates the luminance of a plurality of points in the front landscape and estimates the background luminance distribution. The background spatial frequency estimation means 16 estimates the spatial frequency of a plurality of areas in the front landscape and estimates the background spatial frequency distribution. The control means 19 controls the display luminance based on the estimated value of the background luminance distribution and the estimated value of the background spatial frequency distribution. The background luminance estimation means 15 and the background spatial frequency estimation means 16 calculate an estimated value for each region M divided by a predetermined size.
[Selection] Figure 1

Description

  The present invention relates to a vehicle display device that displays visual information within a driver's forward visual field.

  A conventional vehicle display device is disclosed in Patent Document 1, for example. The vehicle display device mainly includes visual information display means that can superimpose and display visual information on the scenery in the driver's front vision, background luminance estimation means that estimates the brightness of the background of the superimposed display, and the background. Image information control means for controlling the brightness of the visual information display means based on the brightness distribution estimated from the brightness estimation means, and the visibility of the visual information deteriorates due to a change in brightness of the background displaying the visual information. Is to prevent.

JP 2008-11182 A

However, the vehicular display device described in Patent Document 1 controls the display luminance only with respect to the brightness of an area having a certain size with respect to the background of the superimposed display position. When a structure near the road such as a guardrail is used as a background, it cannot cope with a change in the appearance of the superimposed display due to the fineness or roughness of the background. For example, in the case of superimposing display in which a guard rail column installed on the road side is the background, there is a problem in that the display becomes difficult to see due to the fine pattern of the column as the background.
The present invention has been made in view of this problem, and provides a display device for a vehicle that can control display luminance in accordance with the fineness of the background in addition to the brightness of the background at the position where the display is superimposed.

  According to the first aspect of the present invention, background luminance estimating means for estimating the luminance of a plurality of points in the front scene and estimating the background luminance distribution, and estimating the spatial frequency of a plurality of areas of the front scene to determine the background spatial frequency distribution And a control means for controlling the display luminance based on the estimated value of the background luminance distribution and the estimated value of the background spatial frequency distribution.

  According to a second aspect of the present invention, the background luminance estimation means and the background spatial frequency estimation means calculate the estimated value for each region divided by a predetermined size.

  Further, according to the present invention, as described in claim 3, the control means changes the control value of the adjacent regions in a continuous or stepwise manner.

  According to the first aspect of the present invention, when visual information is superimposed and displayed on the landscape in the driver's forward visual field, the display luminance is controlled based on the background luminance and spatial frequency of the superimposed display. On the other hand, it is possible to avoid the state where the display is too dark to see and the situation where it is difficult to distinguish the display from the display due to the fact that the background is dense, and the visibility of the superimposed display is improved. Can do.

  According to the second aspect of the present invention, since the background luminance and the background spatial frequency around the position to be superimposed are calculated for each fixed region, the troublesomeness caused by the small change in luminance can be avoided, so that the display is not bothersome and easy to see. Yes. In addition, the amount of calculation can be reduced.

  According to the invention of claim 3, by changing the control value continuously or stepwise in the display brightness of adjacent areas, it is possible to avoid bothersomeness and unsightlyness such as a sudden change in brightness. Can be displayed easily.

The block diagram which shows embodiment of this invention. The general-view figure which shows embodiment same as the above. Explanatory drawing of front image data which shows embodiment same as the above. Explanatory drawing of the superimposition front image data which shows embodiment same as the above. Explanatory drawing of the frame display image which shows embodiment same as the above. Explanatory drawing of the estimation analysis area | region which shows embodiment same as the above.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. The vehicle information display device 10 projects the display light L onto the windshield W of the vehicle and displays a virtual image V. The vehicle information display apparatus 10 includes a background information acquisition unit 11, a storage unit 12, a vehicle exterior environment acquisition unit 13, a host vehicle state acquisition unit 14, a background luminance estimation unit 15, a background spatial frequency estimation unit 16, Driver viewpoint position estimating means 17, display image control means 18, screen control means 19, and display means 20 are provided.

  The background information acquisition unit 11 includes an imaging device such as a camera installed in the vehicle, and captures a landscape image in front of the driver. The background information acquisition unit 11 may be a communication device for acquiring a landscape image ahead of the driver from a unit other than the vehicle information display device.

  The storage unit 12 includes a storage device such as a RAM (Random Access Memory), and stores the image information from the background information acquisition unit 11, the background luminance estimation unit 15, and the processing results of the background spatial frequency estimation unit 16. . The outside environment acquisition means 13 acquires information on the outside environment surrounding the own vehicle from the position information, map information, time information, etc. of the own vehicle, and stores various data in the storage means 12.

  The own vehicle status acquisition unit 14 acquires the traveling state information of the own vehicle such as the traveling direction, the horizontal position, and the speed of the own vehicle, and stores various data in the storage unit 12. Based on the data stored in the storage unit 12, the background luminance estimation unit 15 divides an area centering on the display superimposed on the front into a plurality of parts, and calculates an average estimated luminance value of each of the divided areas. The average estimated brightness value obtained by the background brightness estimating means 15 is stored in the storage means 12.

  Based on the data stored in the storage unit 12, the background spatial frequency estimation unit 16 divides the region centered on the display superimposed on the front into a plurality of regions, and calculates an estimated value of the spatial frequency of each of the divided regions. To do. The spatial frequency estimation value obtained by the background spatial frequency estimation means 16 is stored in the storage means 12. The driver viewpoint position estimation means 17 images the face and eyes with an imaging device such as a camera installed in the vehicle, and estimates the position coordinates of the driver's viewpoint from the obtained image. The viewpoint position coordinates obtained by the driver viewpoint position estimating means 17 are stored in the storage means 12. As a viewpoint position estimation method, a position detection device such as a microwave radar may be used.

  The display image control means 18 is based on the information from the background information acquisition means 11, the vehicle exterior environment acquisition means 13, the vehicle status acquisition means 14, and the driver viewpoint position estimation means 17 stored in the storage means 12. A display image and display configuration information to be superimposed on the front landscape are generated. The display configuration information means various information for displaying the display position, the center coordinates of the display image, the shape, the color, the size, and the like. As the display position, a position that matches the front scenery is calculated from the front scenery image and the viewpoint position coordinates from the driver viewpoint position estimation means 17.

  The screen control unit 19 controls display luminance of the display image and display on / off from the display image information, the average estimated luminance value, and the spatial frequency estimated value stored in the storage unit 12. . The display unit 20 includes a display device such as a head-up display, a projector, a transparent liquid crystal, and an LED, projects a display on the windshield W of the host vehicle under the control of the screen control unit 19, and provides visual information at a position overlapping the front landscape. Is superimposed.

  Next, when the preceding vehicle is closer than the safe inter-vehicle distance, the operation of the vehicle information display device 10 will be described by taking as an example a case where a frame display for instructing the presence of the preceding vehicle is superimposed and displayed near the preceding preceding vehicle. explain.

  The background information acquisition unit 11 always captures a landscape in front and stores the captured front image data in the storage unit 12. FIG. 3 shows an example of an image of a front landscape photographed by the background information acquisition unit 11. At the same time, the inter-vehicle distance value with the preceding vehicle is measured by the vehicle exterior environment acquisition unit 13 and stored in the storage unit 12. Further, the position coordinates of the driver's viewpoint are estimated by the driver viewpoint position estimation means 17 and stored in the storage means 12.

  Next, the display image control means 18 reads the front image data P1 and the inter-vehicle distance value stored in the storage means 12. When it is determined that the inter-vehicle distance value is shorter than the safe inter-vehicle distance value, a frame display image surrounding the preceding vehicle is generated.

  When the frame display image P3 is generated, the front image data P1 is coordinate-transformed and processed into the superimposition front image data P2 so that the display area on the display unit 20 and the scenery of the front image data P1 coincide (FIG. 4). By drawing a display to be superimposed based on the superimposing front image data P2, it is possible to display a frame display image P3 that appears to surround the actual preceding vehicle for the driver (see FIG. 5).

  When the forward image data P1 is coordinate-transformed, the driver's viewpoint position estimating means 17 performs correction based on the driver's viewpoint position stored in the storage means 12, so that the front landscape can be seen even when the driver's viewpoint changes. Can be displayed.

  Next, display configuration information of the frame display image P3 of the preceding vehicle is stored in the storage unit 12 based on the superimposition front image data P3. The display configuration information is information for generating image data. When the frame display image P3 is rectangular, the display configuration information includes four corner coordinates, frame line thickness, and display color information.

  Next, estimation of the luminance distribution of the front scenery by the background luminance estimation means 15 will be described. First, the display configuration information and superimposition front image data P2 stored in the storage unit 12 are read. Then, the display center coordinates and the frame size of the frame display image P3 are calculated from the display configuration information read from the storage means 12, and the estimated analysis region S is set (see FIG. 6).

  The estimated analysis region S is determined by dividing the region sufficient to include the frame display image P3 around the display center position coordinates by a matrix-like small region M having a number of divisions of 3 × 3 or more and the vertex coordinates thereof. . Among the regions divided by the vertex coordinates, the luminance value of the superimposing front image data is estimated from the gradation value of the image, and the region average luminance value of each small region M is calculated by averaging them. The calculated area average luminance value is stored in the storage unit 12.

  Next, estimation of the spatial frequency distribution of the front scenery by the background spatial frequency estimation means 16 will be described. Similar to the background luminance estimation means 15, the estimated analysis region S and its vertex coordinates are determined. A spatial frequency analysis is performed in each region divided by these vertex coordinates, and a region spatial frequency value of each region is calculated. The calculated region spatial frequency value is stored in the storage unit 12.

  Next, display luminance control by the screen control means 19 will be described. First, the area average luminance value in each small area M, the area spatial frequency value in each small area M, and the display configuration information stored in the storage unit 12 are read. A region center control value in each small region M is determined from the region average luminance value and the region spatial frequency value of each small region M.

  Here, the region center control value is determined by multiplying the region average luminance value and the region spatial frequency value in each small region M by independent constants and taking the sum thereof. Note that the storage unit 12 may have a table value corresponding to the combination of the region average luminance value and the region spatial frequency value, and the table center value may be read to determine the region center control value.

  Up to this point, the region center control value of each small region has been calculated. Further, brightness control distribution data having a continuous change or an intermittent change in fine steps between the center coordinates of the small areas M is created. Based on the brightness control distribution data, image data in which the display gradation of the frame display image P3 is changed based on the display configuration information is generated. As a method for controlling the display luminance, a method for controlling a laser current value at the time of scanning drawing with a laser beam may be used in addition to the above-described display gradation.

  Finally, the display image generated by the screen control means 19 is displayed by superimposing the frame display image P3 on the front landscape by the display means 20 constituted by a head-up display. By this display, a frame display image P3 is displayed so as to surround an actual preceding vehicle existing ahead of the driver, and the frame display image P3 is displayed in a state in which the luminance is controlled according to the brightness and fineness of the background. The

  In this embodiment, the frame display image P3 in which the preceding vehicle is surrounded by a frame line is given as an example of the rear-end collision warning display, but this can be applied to all displays superimposed on the scenery in front of the driver. Examples of display include navigation display to the destination, detection of pedestrians in front of the vehicle, and night vision display.

DESCRIPTION OF SYMBOLS 11 Background information acquisition means 12 Storage means 13 Outside vehicle environment acquisition means 14 Own vehicle condition acquisition means 15 Background luminance estimation means 16 Background spatial frequency estimation means 17 Driver viewpoint position estimation means 18 Display image control means 19 Screen control means (control means)
20 Display means

Claims (3)

  A background luminance estimating means for estimating a luminance of a plurality of points in the forward landscape and estimating a background luminance distribution; a background spatial frequency estimating means for estimating a spatial frequency of a plurality of areas of the forward landscape and estimating a background spatial frequency distribution; and the background luminance And a control means for controlling display luminance based on the estimated distribution value and the estimated background spatial frequency distribution.   The vehicle display device according to claim 1, wherein the background luminance estimation unit and the background spatial frequency estimation unit calculate the estimation value for each region divided by a predetermined size.   The vehicle display device according to claim 2, wherein the control unit changes the control value of the adjacent regions in a continuous or stepwise manner.

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