DE102016200136A1 - Method and device for operating a field of view display device - Google Patents

Abstract

The invention relates to a method for operating a visual field display device (100), the method comprising a step of modifying (1206) in which image information (104) intended for the right eye and / or image information (106) intended for the left eye is changed depending on a ratio or difference between a crosstalk value (140) representing crosstalk between the right-eye and left-eye image information and a threshold value (142).

Description

State of the art

The invention is based on a device or a method according to the preamble of the independent claims. The subject of the present invention is also a computer program.

In a stereoscopic visual field display device, a right-eye image content may be crosstalk-wise to a left-image content for a left eye. A viewer then perceives so-called ghost images or shadows.

Disclosure of the invention

Against this background, with the approach presented here, a method for operating a field of view display device, a device which uses this method, a field of view display device with the device, and finally a corresponding computer program according to the main claims are presented. The measures listed in the dependent claims advantageous refinements and improvements of the independent claim device are possible.

Crosstalk is tolerable up to a threshold. The threshold depends on a contrast of the image content to a background. The image content can be changed until crosstalk is less than the threshold.

A method for operating a field of view display device is presented, the method comprising the following step:
Changing image information intended for the right eye and / or image information intended for the left eye depending on a ratio or difference between a crosstalk value representing crosstalk between the image information intended for the right eye and the left eye, and a threshold.

A field of view display device can be understood as a head-up display. The field of view display device provides individual images for each eye of a viewer to enable spatial vision. The images are also referred to as the image information intended for the right eye and the image information intended for the left eye or also as right image content and left image content. A display can be understood as representing visual information. The display can be referred to as spatial image content. Crosstalk may cause a weakened visibility of the respective other image content as a ghost. There is a ghost image of the right image content in the left image content and vice versa. The threshold may be understood to be a predetermined value. According to one embodiment, the threshold value may be selected from a plurality of predetermined threshold values, for example, depending on the contrast and / or disparity and / or depending on a flatness of the image content.

The method may include a step of determining the crosstalk value. The crosstalk value, also known as the crosstalk value, can be a system variable. A crosstalk value generally does not change in a fully developed, engineered, in-vehicle system. As a result, it is only necessary to measure this value only once in the in-vehicle system. According to one embodiment, it is not necessary to determine this value several times and in particular not as a function of the disparity, the flatness of the image content or the contrast ratios present in a particular situation.

The perception of the effects of the system crosstalk is, according to one embodiment, dependent on the disparity, the flatness of the image content, and the contrast ratios present in a particular situation. The thresholds - perception and tolerance - change with these parameters.

The crosstalk value may be determined using an eye distance value representing an eye distance of a viewer of the display. The closer the two eyes are together, the stronger the crosstalk becomes noticeable. The more area the image content is displayed, the lower the sensitivity of the observer to crosstalk. The lower the disparity, the lower the viewer's sensitivity to crosstalk.

In the step of changing, a brightness of the image information intended for the right eye and / or the image information intended for the left eye can be changed. The brightness can be changed quickly and easily.

The brightness of the image information intended for the right eye and / or the image information intended for the left eye can be reduced if the crosstalk value is greater than the threshold value. The brightness of the right picture content and / or the left picture content can be increased if the crosstalk value is smaller than the threshold value. Due to the reduced brightness of the display, the contrast decreases with the ambient brightness and a higher crosstalk value can be tolerated.

In the step of changing, a flatness of the image information intended for the right eye and / or the image information intended for the left eye can be changed. The flatness can be changed quickly and easily.

The flatness of the image information intended for the right eye and / or the image information intended for the left eye can be increased if the crosstalk value is greater than the threshold value. The flatness of the image information intended for the right eye and / or the image information intended for the left eye can be reduced if the crosstalk value is smaller than the threshold value. Increased surface area allows a higher crosstalk value to be tolerated.

In the step of changing, a disparity between the image information intended for the right eye and the image information intended for the left eye can be changed. The disparity can be changed quickly and easily.

The disparity can be reduced if the crosstalk value is greater than the threshold. The disparity can be increased again if the crosstalk value is less than the threshold. Lower disparity allows a higher crosstalk value to be tolerated.

This method can be implemented, for example, in software or hardware or in a mixed form of software and hardware, for example in a control unit.

Furthermore, an apparatus for operating a field of view display device is presented, the device having the following features:
a changing means for changing image information intended for the right eye and / or image information intended for the left eye depending on a ratio or difference between a crosstalk value which crosstalk between that for the right eye and that for the left eye Image information, and a threshold.

Also by this embodiment of the invention in the form of a device, the object underlying the invention can be solved quickly and efficiently.

For this purpose, the device may comprise at least one computing unit for processing signals or data, at least one memory unit for storing signals or data, at least one interface to a sensor or an actuator for reading sensor signals from the sensor or for outputting data or control signals to the sensor Actuator and / or at least one communication interface for reading or outputting data embedded in a communication protocol. The arithmetic unit may be, for example, a signal processor, a microcontroller or the like, wherein the memory unit may be a flash memory, an EPROM or a magnetic memory unit. The communication interface can be designed to read or output data wirelessly and / or by line, wherein a communication interface that can read or output line-bound data, for example, electrically or optically read this data from a corresponding data transmission line or output to a corresponding data transmission line.

In the present case, a device can be understood as meaning an electrical device which processes sensor signals and outputs control and / or data signals in dependence thereon. The device may have an interface, which may be formed in hardware and / or software. In the case of a hardware-based embodiment, the interfaces can be part of a so-called system ASIC, for example, which contains a wide variety of functions of the device. However, it is also possible that the interfaces are their own integrated circuits or at least partially consist of discrete components. At a In terms of software training, the interfaces may be software modules which are present, for example, on a microcontroller in addition to other software modules.

In an advantageous embodiment, the device is used to control a field of view display device.

Also of advantage is a computer program product or computer program with program code which can be stored on a machine-readable carrier or storage medium such as a semiconductor memory, a hard disk memory or an optical memory and for carrying out, implementing and / or controlling the steps of the method according to one of the embodiments described above is used, especially when the program product or program is executed on a computer or a device.

Embodiments of the approach presented here are shown in the drawings and explained in more detail in the following description. It shows:

1 a representation of a vehicle with a field of view display device and an apparatus for operating according to an embodiment;

2 a representation of different virtual image distances;

3 a representation of a beam path of a field of view display device;

4 Representation of a radiation characteristic with resulting crosstalk;

5 a representation of a crosstalk between two images;

6 a representation of an object-dependent crosstalk detection threshold;

7 a representation of a contrast-dependent crosstalk detection threshold;

8th an illustration of changing the surface according to an embodiment;

9 a representation of tolerance bands for crosstalk according to an embodiment;

10 a representation of a reduction of the contrast of a planar object according to an embodiment;

11 a representation of a reduction of the contrast of a linear object according to an embodiment;

12 a flowchart of a method for operating a field of view display device according to an embodiment;

13 a representation of a flow of a method for operating according to an embodiment; and

14 an illustration of changing an image content according to an embodiment.

In the following description of favorable embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and similar acting, wherein a repeated description of these elements is omitted.

1 shows a representation of a vehicle with a field of view display device 100 and a device 102 to operate according to an embodiment. The field of view display device 100 is integrated in the area of a windshield of the vehicle in an instrument panel of the vehicle. The field of view display device 100 is designed to be a right picture 104 and a left picture 106 in a field of view of a viewer 108 to project. This will be the pictures 104 . 106 from an imager 110 of the field of view display device 100 shown. A projection optics 112 of the field of view display device 100 and the windscreen project the pictures 104 . 106 in a left projection area 114 and a right projection area 116 , If the Eyes of the beholder 108 each in their intended projection area 114 . 116 are arranged, the pictures become 104 . 106 displayed in a virtual screen distance. The right picture 104 and the left picture 106 have a disparity in the virtual screen distance, so for the viewer 108 a picture content 118 is arranged in front of the vehicle in a defined by the disparity virtual image distance. The picture content 118 can as the ad 118 of the field of view display device 100 be designated.

Around the projection areas 114 . 116 after supplying is the vehicle with an eye detection device 120 equipped. The eye detection device 120 is on the viewer 108 aligned and adjusts an eye position of the viewer 108 imaging eye position signal 122 ready. In the field of view display device 100 becomes the eye position signal 122 read in and used a position of the pictures 104 . 106 on the imager 110 to track the eye position. Alternatively, the projection optics 112 be changed mechanically to the projection areas 114 . 116 to track the eye position.

The device 102 to operate reads a desired position for the image content 118 and a picture content 118 representing image signal 124 one. In the device 102 become the frames 104 . 106 generated with the position-dependent disparity and for the imager 110 provided.

The device 102 has an optional determination device 126 , an optional detection device 128 and a changer 130 on. The determining device 126 is designed to have a contrast value 132 using an ambient brightness value 134 and a display brightness value 136 to determine. The ambient brightness value represents this 134 a brightness of an environment 138 , The display brightness value 136 represents a brightness of the display 118 of the field of view display device 100 , The contrast value 132 represents a contrast of the display 118 or the contrast between the image content 118 and the environment 138 , The determination device 128 is designed to have a crosstalk value 140 to investigate. The crosstalk value represents this 140 a crosstalk between the right picture 104 and the left picture 106 , The change device 130 is designed to the image content 118 or the right picture 104 and / or the left picture 106 depending on a ratio or a difference between the crosstalk value 140 and a threshold 142 to change. The change device reads this 130 the image signal 124 and gives a right image signal 144 and a left image signal 146 out.

According to one embodiment, the crosstalk value 140 from the investigator 128 determined once for the vehicle and stored for example in a storage device for subsequent use. The change device 130 may be designed in this case to the crosstalk value 140 read from the memory device. Alternatively, the crosstalk value 140 be determined elsewhere and stored in the memory device, so no detection device 128 needs to be provided in the vehicle.

In other words shows 1 a system overview of the autostereoscopic head-up display 100 ,

It will be a facility 102 for situational contrast-dependent adaptation of the image content 124 in an augmented reality application, such as an autostereoscopic head-up display (asHUD) 100 , presented to comply with crosstalk limits.

A field of view display device 100 or Head-up Display (HUD) 100 serves the display of driving-relevant information 118 such as a speedometer, navigation information or warnings in the driver's field of vision 108 , The virtual picture 104 . 106 in which the information 118 will be presented with the real environment 138 superimposed.

Basically, there is a head-up display 100 from a light source, an imager unit 110 and a visual appearance 112 , That the system 100 leaving light falls on the windshield or a mounted behind her combiner disc, is partially reflected by her and enters the eye of the driver 108 that the virtual picture 104 . 106 in one by the optics 112 perceived distance and a likewise determined by this magnification in front of him.

As a light source, for example, light-emitting diodes (LEDs) or laser diodes can be used, the image content 118 providing liquid crystal displays (LCDs) 110 backlighting. Alternatively, different projectors can be used. Overall, the market for head-up displays is growing 100 as novel display concepts in the vehicle strong. In future, the focus will increasingly be on DMD, LCoS or laser technology based miniaturized projectors. The aim is also to realize a contact analog representation. This takes a very large volume of space in biocular design, in which both eyes see the same picture. The binocular variant, in which the two eyes are single, slightly different images 104 . 106 In addition to the additional functionality of stereoscopic depth perception ("3D effect"), it promises great advantages in terms of robustness, installation space and costs.

Using an autostereoscopic head-up display (asHUDs) 100 can drive relevant information 118 be represented spatially, without the driver 108 an additional aid such as a shutter glasses or polarization glasses needed. So the driver 108 also with head movement at any time a perfect picture 104 . 106 sees, has the autostereoscopic head-up display 100 a head tracking system 120 , which is able to control the head and eye position of the driver 108 to analyze, and an appropriate tracking on. An autostereoscopic head-up display 100 allows an augmented reality representation. 1 shows the basic structure of an autostereoscopic head-up display system 100 ,

The imaging optics 112 sets the virtual screen distance (VSD) of the system 100 firmly. By a horizontal offset of the two frames 104 . 106 on the display 110 or on the virtual screen (disp) can be the virtual image distance (VID), in which the driver 108 the picture 118 sees, choose.

It will be an autostereoscopic head-up display 100 with situational, contrast-dependent adaptation of the image content 118 presented for compliance with crosstalk limits for comfortable spatial perception. In the process, the displayed image contents become 118 adjusted the brightness, the flatness of the objects and the used depth levels.

This results in a less impaired spatial perception, a reduction of headache, eye pain, discomfort and a reduction in the risk that the image information 104 . 106 can not be merged. The autostereoscopic head-up display system 100 may have higher crosstalk and may be adjusted at low contrasts according to the proposed method. Furthermore, there is a cost reduction, a reduced development effort, a reduced space, since the tracking can be made less expensive, an increase in security and an increase in comfort.

The approach presented here becomes a facility 102 presented, which allows the displayed image content 118 adapt so that the crosstalk of the system 100 in the given lighting conditions, the one tolerance threshold or perception threshold of the driver 108 does not exceed. It is proposed to use the dependencies of the crosstalk thresholds described in the following figures. The procedure is shown schematically in 13 shown. First, the real existing contrast 132 determined. For this purpose, for example, the light sensor and, alternatively or additionally, the driver assistance camera can be used to determine the ambient brightness. To take into account influences such as headlights switched on, the ambient brightness is ideally at a position close to, but not in the field of view of the head-up display 100 measured. Likewise, the brightness of the display 110 of the head-up display 100 determined. The brightness of the head-up display 110 Depends both on the dimming algorithms used as a function of the ambient brightness and that of the driver 108 adjusted brightness preferences. Are both the brightness of the environment 138 , so the background, as well as the head-up display display 110 known, can the contrast 132 after contrast = luminance of the display by luminance of the background between display 110 and background 138 be calculated. In a storage medium is stored after an initial calibration both stored, what crosstalk value 140 the autostereoscopic head-up display system 100 as well as the dependence of the threshold 142 the crosstalk value 140 for a comfortable viewing situation of the contrast, the flatness of the displayed symbols 118 and disparity. This can be stored, for example, as a look-up table (LUT).

In order to be able to make these adjustments for a specific system, an exact knowledge of its intrinsic crosstalk is necessary. This intrinsic crosstalk is also stored as a look-up table in a storage medium and can be determined, for example, in a calibration routine. Because the crosstalk from the eye relief of the driver 108 depends, the look-up table should also be deposited for different eye distances. The eye relief of the driver can be via the head tracking cameras 120 be measured.

2 shows a representation of different virtual image distances 200 , The virtual image distances 200 are shown using the example of a field of view display device, such as in 1 is shown. Here are a right eye 202 and a left eye 204 shown by the viewer. In the virtual screen distance 206 are the right picture 104 and the left picture 106 with divergence 208 shown. In the first example shown is the right image 104 right next to the left picture 106 arranged. This will cause the image content to appear 118 in a virtual image distance 200 that is larger than the virtual canvas distance 206 is.

In the second example is the right picture 104 to the left of the left picture 106 arranged. This will cause the image content to appear 118 in a virtual image distance 200 which is smaller than the virtual screen distance 206 is.

In 2 is the principle of stereoscopic spatial vision with indication of the sizes virtual screen distance (VSD) 206 and virtual image distance (VID) 200 presented for the crossed and uncrossed visual situation.

The parameters Virtual Canvas Distance 206 and virtual image distance 200 are in 2 presented for the crossed and the uncrossed visual situation. The virtual screen distance 200 is over

where A is the driver's interpupillary eye relief. The sign in the denominator or the disparity 208 determines if the picture 118 in front of or behind the virtual screen distance 206 lies. The system is able to adapt to the interpupillary distance or can determine the eye relief of the driver and in the calculation of the realization of a specific virtual image distance 200 necessary disparity 208 take into account, so that the driver the picture information 118 can perceive at the desired distance.

The greater the amount of disparity 208 the farther the virtual image distance 200 from the virtual canvas distance 206 away. If the crosstalk value of the system is higher than the threshold given for the existing contrast, the image content becomes 118 customized. This adaptation consists of a reduction of the image brightness used, the absolute disparities used 208 or a more planar representation of the elements or a combination thereof. How strong the brightness, the disparity 208 or the flatness is adjusted, can from the displayed image content 118 depend.

In the stereoscopic system, the depth becomes 200 of the picture content 118 , so the virtual image distance 200 by adjusting the disparity 208 varied. One of the features that characterizes the autostereoscopic head-up display is that several depth levels can be occupied simultaneously. The different depth levels can extend over the complete comfort zone. The from the virtual screen 206 Far away deep levels require a high absolute disparity 208 , In a high-contrast visual situation, this can cause the system's crosstalk to be disruptive. Here it is proposed, in such a case, the image planes closer to the virtual screen 206 to lay, so the absolute disparities 208 to reduce. In extreme cases, a pure 2D representation in the virtual screen distance 206 respectively. In this situation, stereoscopic crosstalk is not relevant anyway.

3 shows a representation of a beam path 300 a field of view display device 100 , the field of view display device 100 is essentially the same as in 1 displayed field of view display device. The field of view display device 100 projects the right image into the right projection area 114 and the left image in the left projection area 116 , Here are the projection areas 114 . 116 laterally staggered areas in which the eyes 202 . 204 the viewer 108 should be arranged to see the images in the virtual screen distance sharply. The projection areas 114 . 116 have a small lateral width. The projection areas 114 . 116 have a much larger dimension vertically than lateral.

In 3 is an optical design of a head-up display 100 shown. For right and left eye 202 . 204 becomes a narrow eyebox 114 . 116 realized. The two eyeboxes 114 . 116 are in the driver's field of vision 108 to recognize.

4 shows a representation of a right projection area 114 and a left projection area 116 a field of view display device. The projection areas 114 . 116 are essentially the same as in the 1 and 3 shown projection areas. Here is a right brightness distribution 400 of the right projection area 114 and a left brightness distribution 402 of the left projection area 116 shown in a first diagram. The diagram has a lateral distance in millimeters on its abscissa. On the ordinate a normalized brightness in percent is plotted. Both brightness distributions 400 . 402 correspond to a bell curve with low slope. The brightness distributions 400 . 402 to overlap with something. As a result, in the area of the overlap, both in the right-hand projection area 114 shown right image as well as the left projection area 116 displayed left image visible. This simultaneous visibility is referred to as crosstalk.

Below the first diagram is in a second diagram the crosstalk 404 shown in percent. The second diagram also has the lateral distances of millimeters on the abscissa. On the ordinate here the crosstalk in percent is shown. It can be seen that already near the middle of the right projection area 114 the crosstalk 404 already above an average threshold of perception 406 lies. Likewise, the crosstalk lies 404 near the middle of the left projection area 116 above the threshold of perception 406 , At the respective other projection area facing edge of the projection areas 114 . 116 is the crosstalk 404 above a tolerance threshold 408 ,

In 4 For example, in the upper graph, exemplary Gaussian radiation characteristics are shown 400 . 402 the two eyeboxes 114 . 116 shown. In the lower graph is in black the resulting crosstalk 404 applied.

For spatial representations, two separate and narrow (about 2 cm) Eyeboxes (EB) 114 . 116 generated. Crosstalk of right and left image information may be referred to as crosstalk (CT). In the situation virtual image distance * virtual screen distance, there is a disparity between right and left images. For example, in an ideal spatial system, the left eye sees nothing of the image information intended for the right. In a real system, however, there may well be a crosstalk here.

Here are exemplary gaussian radiation characteristics 400 . 402 the two eyeboxes 116 . 114 shown. In the lower graph is in black the resulting crosstalk 404 applied. The crosstalk 404 is calculated as follows:

Where L is _{the background} for the luminance of the background. L _{other eye} is the proportion of luminance of the image information intended for the other eye, which enters the target eye. L _soll-Auge is the proportion of the luminance of the image information intended for the target eye, which also reaches it.

Too high a crosstalk value is perceived as disturbing and can lead to impaired spatial perception, headache, nausea, etc.

Any kind of physical malady, as well as the loss of perception of the driving-related information displayed by means of the autostereoscopic head-up display can pose a risk in road traffic and endanger both the safety of the driver and all other road users. In addition, reduced comfort means a lack of sales argument.

Autostereoscopic head-up displays produce narrow projection areas 114 . 116 so that the crosstalk is as low as possible. However, the projection areas are allowed 114 . 116 also not be too narrow, otherwise the driver immediately loses his head movement. Although there is a tracking unit that tracks the system during head movements, latency times, uncertainties in eye detection, resulting homogeneity fluctuations and the step size of the tracking must be taken into account here. Thus, a real autostereoscopic head-up display always has a certain crosstalk value.

5 shows a representation of a crosstalk of two image contents. The first image content is a dash. The second image content is an arrow. The image contents are each as a right picture 104 for the right eye and as a left picture 106 shown for the left eye. The pictures 104 . 106 are displayed with a disparity, so that the image content is spatially perceived by a viewer. If the right picture 104 on the left picture 106 the left eye takes the right picture 104 as a ghost 500 true. Likewise, the right eye takes the left picture 106 as a ghost 500 true, if the left picture 106 on the right picture 104 about talks. When linking the pictures 104 . 106 In the mind of the beholder, the viewer thus takes a ghost image to the right and left of the image content 500 true.

In other words shows 5 a perception of crosstalk. Here is the phenomenon Crosstalk or crosstalk for two different objects, line and arrow outlined. In the first line is in each case the image perceived by the left eye 106 , in the second line the image perceived by the right eye 104 shown. The first column shows a spatial line without crosstalk. Since a spatial impression is to emerge, a disparity exists between the right and the left image. This is recognizable by the fact that the line is in the picture 106 for the left eye to the left of the dashed center line drawn as an orientation, while the line in the image 104 for the right eye to the right of the midline. In perception, the brain assembles these two images in the middle to form an object that appears at a certain distance behind the virtual screen distance. In a real spatial head-up display, it may be that the image information 104 , which is actually intended for the right eye, in a weakened form 500 is also perceived by the left eye. This is shown in the second column. In this case, the system is subject to crosstalk. If the crosstalk is low, the brain can use the image information 104 . 106 still merge into a line, however, the image information intended for the other eye 500 perceived as weak additional images ("ghosting") to the right and left of the actual image. If the crosstalk is too strong, the fusion may also be impossible. On the right side the described situation is again shown for a green arrow object. An autostereoscopic head-up display produces two narrow eyeboxes. The profile of these eyeboxes depends on the image generating unit (PGU) used and the components used in it, such as scattering surfaces, microlens arrays or holograms.

6 shows a representation of an object-dependent crosstalk detection threshold. This is a first perception threshold 600 for a line and a second threshold of perception 602 for an arrow in a diagram, which has plotted on its abscissa an object type and on its ordinate a value of the perception threshold. The first threshold of perception 600 the line is lower than the second threshold of perception 602 of the arrow.

It is an average of the threshold of perception 600 . 602 shown as a function of the displayed object type. The crosstalk threshold (perception) can be increased from 2% to 3% by a two-dimensional display. The tolerance band for larger objects is shifted towards higher contrast values.

7 shows a representation of a contrast-dependent perception threshold 700 for a crosstalk. The contrast-dependent perception threshold 700 is plotted on a graph. The contrast-dependent perception threshold 700 rises with falling contrast. This is the threshold of perception 700 at a contrast between 1 and 1000 in the single-digit percentage range.

It is an average of the threshold of perception 700 depending on the contrast. The contrast is plotted on the x-axis. The crosstalk in percent is plotted on the y-axis.

Both the threshold of perception 700 as well as the tolerance threshold of crosstalk strongly depends on the contrast. Exemplary is in 7 the course of the mean value of the perception threshold 700 of the crosstalk were shown. The graph shows examples of the mean values of the perception threshold 700 shown. These should illustrate the order of magnitude. However, the mean values of the tolerance threshold could also be used. Alternatively, it is also possible to use the corresponding quartiles. The course is similar in all these cases. It turns out that with increasing contrast the threshold drops significantly.

The contrast in head-up displays varies greatly depending on the environmental conditions. It ranges from about two to one a day in the sunshine to several hundred to one on a night drive on a very dark country road. Accordingly, it is advantageous if an autostereoscopic head-up display system has a very low crosstalk value so that the threshold is not exceeded under all conditions. However, since the very high contrasts also occur only in certain situations, a method is proposed here that allows even autostereoscopic head-up display systems with higher crosstalk values to provide a satisfactory spatial perception.

8th FIG. 12 is an illustration of changing the surface according to an embodiment. FIG. Changing the surface is the example of an arrow 800 shown. In a first illustration is the arrow 800 shown as a thin outline. The thin line has a low crosstalk detection threshold. That is, a viewer is the ghost of the arrow 800 already perceives at a very low brightness of the ghosting. To counter this is the arrow 800 represented in a second representation with a thick outline. The thick outline has a higher crosstalk detection threshold than the thin outline. In a third illustration is the arrow 800 filled shown. This representation has the highest perception threshold for crosstalk.

In a fourth illustration is the arrow 800 shown as thin and filled. The thin arrow 800 again has a low crosstalk detection threshold. To raise the threshold of perception, the arrow can 800 as widened in a fifth presentation.

In a sixth illustration the arrow 800 shown thick and filled. To further increase the threshold of perception, the arrow is shown in the seventh representation with a blurred contour. This representation has the highest perception threshold for crosstalk.

In addition, it can be exploited that the threshold of the crosstalk value not only depends on the contrast, but also on other parameters. One parameter is the flatness of the displayed objects. The larger the objects are, the higher the crosstalk threshold. Exemplary is in 6 the average of the crosstalk detection threshold for a line and an arrow is shown. The disparity also has an influence on the crosstalk threshold. The greater the disparity, the lower the crosstalk threshold.

The negative influence of crosstalk can be reduced in high-contrast situations by making the symbols used in the display less filigree and instead more flat. For example, you can switch from an outline drawing to a flat icon. Even a representation with less sharp, rather blurred edges defuses the perception of crosstalk. In order to avoid overloading the display during such adjustments of the picture content, its content can be reduced.

In other words, examples 800 for the adjustment of the flatness of picture objects. An outline representation can be increased in its line width and converted into a flat representation. The surface area of the displayed objects can be increased. It can deliberately introduce a blur, this blurring is shown here for the entire image. In contrast, the blur can be applied only in the horizontal direction.

9 shows a representation of tolerance bands 900 . 902 for crosstalk according to an embodiment. The tolerance bands 900 . 902 are shown in a diagram which has a logarithmically increasing contrast on its abscissa and a perceptual threshold in percent on its ordinate. Here are a first tolerance band 900 for flat objects and a second tolerance band 902 shown for line-like objects. The tolerance bands 900 . 902 are similar. As in 7 have the tolerance bands 900 . 902 higher values at low contrast than at high contrast. The perception threshold for flat objects over the entire contrast range shown is higher than the perception threshold for line-like objects. The tolerance bands 900 . 902 However, most of them overlap.

There are possible exemplary tolerance bands 900 . 902 for a permissible crosstalk depending on the contrast. The lower limit here is the perception threshold. As upper the tolerance threshold. The tolerance bands 900 . 902 are represented for two flat objects as line object and as flat object.

In the following exemplary embodiments, an adaptation takes place with regard to the perception threshold of crosstalk. But it can also be made an adjustment in terms of tolerance threshold.

In one embodiment, the brightness of the display is adjusted. The brightness of a head-up display is adjusted to the ambient brightness to make the display readable in the light and to prevent dazzling the driver in the dark. Also a manual adjustment of the brightness may be possible. Usually, a head-up display display is as bright as possible, so bright that the driver just does not feel uncomfortable. This maximum brightness ensures a clear and clearly recognizable image content and is appealing. Here, this brightness is lowered with regard to the perception of crosstalk in critical situations in order to reduce the contrast and thus the influence of crosstalk. For example, the brightness may be according to the curve 900 be adjusted. These stored values can be determined from examinations. In this case, the dependency of the perception or tolerance of crosstalk from various parameters is precisely determined.

For example, there is a contrast of 100: 1 and, according to the look-up table, the system has an intrinsic crosstalk of 1.5%. This value is above the threshold 900 , Therefore, the brightness is reduced so much that the contrast is only 70: 1. At this contrast lies the threshold of perception 900 above the intrinsic crosstalk value of the system and the driver is no longer disturbed by the crosstalk or can no longer perceive it.

They are exemplary areas 900 . 902 , so-called tolerance bands, shown in which the contrast and thus dependent on the ambient lighting, the image brightness may move. The lower limit used here is the perception threshold. Of course, the perception threshold can also be significantly higher than the crosstalk of the system, but if a reduction of the image brightness is necessary, then this should only as far as necessary, so for example to increase the perception threshold on the crosstalk value of the system, performed. The upper limit is the acceptance threshold. Likewise, 20% smaller values than the acceptance threshold can be used as the upper limit of the tolerance band.

10 shows a representation of a reduction of the contrast K1 of a planar object 1000 according to an embodiment. The reduction is based on the in 9 illustrated tolerance bands 900 . 902 shown. The contrast K1 is a current contrast of a display of a field of view display device, such as in 1 is shown. The contrast K1 is the crosstalk value 140 above the tolerance band 900 for flat objects. To enter the tolerance band 900 to get either properties of the object 1000 can be changed or the contrast of the display can be reduced. Here the contrast is reduced from K1 to K2. This is the crosstalk value 140 within the tolerance band 900 ,

Here an exemplary crosstalk value of the system "CT_System" and two contrast values K1 and K2 are drawn in black. The arrow pointing to the left illustrates the lowering of the contrast that is at least necessary so that the crosstalk value of the system is within the tolerance band 900 for flat objects 1000 lies. The lowering of the contrast can be achieved by reducing the luminance of the image content.

Has a flat icon 1000 the system representing the registered crosstalk value and a contrast K1 occurs, the crosstalk is above the upper limit of the tolerance band 900 , If the luminance of the image content is lowered so far that the contrast is at most K2, the crosstalk lies within the tolerance band 900 for flat objects 1000 ,

11 shows a representation of a reduction of the contrast of a linear object 1100 according to an embodiment. The reduction is based on the in 9 illustrated tolerance bands 900 . 902 shown. As in 10 is the crosstalk value 140 determined by properties of the system. Again, the crosstalk value 140 above the tolerance band 902 for linear objects. In contrast to 10 The reduction of the contrast from K1 to K2 is not enough within the tolerance band 902 to lie. Here the contrast is lowered to K3. This is the crosstalk value 140 also here within the tolerance band 902 ,

Here, an exemplary crosstalk value of the system "CT_System" and three contrast values K1, K2 and K3 are shown in black. The arrow pointing to the left illustrates the lowering of the contrast that is at least necessary so that the crosstalk value of the system is within the tolerance band 902 for filigree objects 1100 lies. The arrow pointing to the left illustrates the lowering of the contrast that is at least necessary so that the crosstalk value of the system is within the tolerance band 900 lies for flat objects. The lowering of the contrast can be achieved by reducing the luminance of the image content.

Shall now be a filigree object 1100 can be displayed, the contrast can be further lowered. Has a filigree object 1100 the system representing the registered crosstalk value and a contrast K1 occurs, the crosstalk is above the upper limit of the tolerance band 902 for filigree Objects. If the luminance of the image content is lowered so far that the contrast is at most K3, the crosstalk lies within the tolerance band 903 for filigree objects. Alternatively, the representation of the image content can be made more flat. Then, the luminance only has to be lowered so far that the contrast is at most K2, because then the crosstalk lies within the tolerance band 900 for flat objects.

12 shows a flowchart of a method 1200 for operating a field of view display device according to an embodiment. The procedure 1200 indicates an optional step 1202 determining, an optional step 1204 determining and a step 1206 of changing. In step 1202 determining, a contrast value representing a contrast of a display of the field of view display device is determined using an ambient brightness value representing a brightness of an environment and a display brightness value representing a brightness of the display. In step 1204 the determination determines a crosstalk value representing a crosstalk between a right image content of the display and a left image content of the display. In step 1206 of changing, the right image content and / or the left image content is changed depending on a ratio between the crosstalk value and a threshold value.

In one embodiment, a high-frequency adjustment of the image content, which could possibly have a disturbing effect, is prevented by not responding instantaneously to short-term influences, such as passing headlights. If the influence is strong enough and, alternatively or in addition, persists long enough, the corresponding change signal with respect to the image content is output to the image content generating unit. This can be realized for example by a hysteresis.

In one embodiment, the reduction of the image brightness does not aim at an upper edge of the tolerance band, but at the center to avoid frequent readjustment.

In one embodiment, alternatively or in addition to the embodiments described above, the system is manually adapted by the driver to his present sensation. In this case, an operator interface can be designed differently. For example, the input can be made via a button, voice or gesture control.

In one exemplary embodiment, a personalized calibration of the system to a personal perception of the crosstalk depending on the abovementioned parameters is initially performed once. The results of this calibration replace the general settings in the storage medium. This system is specially adapted to personal needs. Such an individualization is advantageous because the perception of crosstalk and the point at which it no longer seems acceptable are just as individually different as the spatial perception in stereoscopic systems in general.

In one embodiment, the system is designed as a learning system as an alternative or in addition to the embodiments described above. It learns how the respective driver perceives crosstalk as a function of the above-mentioned parameters and alternatively or additionally as a function of other variables such as driving time, time of day, driving situation, such as city or motorway, and takes these individual fluctuations into account. In addition, the camera that captures the eye position data for tracking can be used to record gaze direction data and blinking behavior.

From this conclusions about the current perception of the driver's display and his well-being can be drawn.

13 shows a representation of a sequence of a method 1200 to operate according to an embodiment. The procedure 1200 corresponds essentially to the method in 12 , In addition, the method points 1200 one step 1300 measuring and another step 1302 of determining. In step 1300 When measuring, an ambient brightness is measured and mapped in the ambient brightness value. In the next step 1302 In determining, a brightness of the display of the field of view display device is determined and mapped in the display brightness value.

In one embodiment, the method 1200 another step 1304 of measuring. In the next step 1304 In measuring, an eye distance of a viewer of the field of view display device is measured and mapped to an eye distance value. The eye distance value is in the step 1204 used to determine crosstalk value.

In one embodiment, the method 1200 one step 1306 of retrieving. In step 1306 When retrieving, the crosstalk value is read from a table. From the table, the threshold value can also be read out depending on other factors, such as a disparity between the right-hand image content and the left-hand image content and a flatness of the image content. The table can be multi-dimensional.

The step 1206 of changing, the right image content and / or the left image content is changed if the crosstalk value is greater than the threshold value.

If the crosstalk value is greater than the threshold, in one step 1308 adjusting the brightness of the right picture content and / or the left picture content. For example, while the brightness using the in 7 adjusted perception threshold are adjusted.

If the crosstalk value is greater than the threshold, in a further step 1310 adjusting the surface area of the right picture content and / or the left picture content. The image content can be as in 8th be adapted from an outline to a flat representation. Furthermore, an area of the image contents can be increased. Likewise, the image content can be displayed blurred.

If the crosstalk value is greater than the threshold, in a further step 1312 adjusting the disparity of the right picture content and the left picture content. The maximum absolute disparity can be reduced. Furthermore, a number of depth levels can be reduced. Without disparity can be switched to a two-dimensional representation.

If the crosstalk value is less than the threshold, in one step 1314 of not fitting no adjustment of the picture content. If previously in the steps 1308 . 1310 . 1312 Measures have been taken, these can be withdrawn.

14 shows a representation of an image content adjustment according to an embodiment. The adjustment takes place as in the 12 and 13 in step 1206 of changing. First, the step takes place 1202 determining the contrast value. It will be in the step 1306 retrieving the crosstalk value and depending on the contrast value, the areal content of the image content and the disparity of the threshold value from the table. In step 1206 changing is the image content 124 displayed normally, if the crosstalk value is not greater than the threshold value. If the crosstalk value is greater than the threshold, the image content becomes 124 adjusted in terms of its brightness, flatness and / or disparity.

If an exemplary embodiment comprises a "and / or" link between a first feature and a second feature, then this is to be read so that the embodiment according to one embodiment, both the first feature and the second feature and according to another embodiment either only first feature or only the second feature.

Claims (13)

Procedure ( 1200 ) for operating a field of view display device ( 100 ), the process ( 1200 ) comprises the following step: changing ( 1206 ) image information intended for the right eye ( 104 ) and / or image information intended for the left eye ( 106 ) depending on a ratio or difference between a crosstalk value ( 140 ) representing crosstalk between image information intended for the right eye and left eye, and a threshold ( 142 ). Procedure ( 1200 ) according to claim 1, with a step ( 1204 ) of determining the crosstalk value ( 140 ). Procedure ( 1200 ) according to claim 2, wherein in step ( 1204 ) of determining the crosstalk value ( 140 ) using an eye relief of an observer ( 108 ) of the ad ( 118 ) representing eye distance value ( 122 ) is determined. Procedure ( 1200 ) according to one of the preceding claims, wherein in step ( 1206 ) of changing a brightness of the image information intended for the right eye ( 104 ) and / or the image information intended for the left eye ( 106 ) is changed. Procedure ( 1200 ) according to claim 4, wherein in step ( 1206 ) of changing the brightness of the image information intended for the right eye ( 104 ) and / or the image information intended for the left eye ( 106 ) is reduced when the crosstalk value ( 140 ) greater than the threshold ( 142 ). Procedure ( 1200 ) according to one of the preceding claims, wherein in step ( 1206 ) of changing a surface of the image information intended for the right eye ( 104 ) and / or the image information intended for the left eye ( 106 ) is changed. Procedure ( 1200 ) according to claim 6, wherein in step ( 1206 ) of changing the flatness of the image information intended for the right eye ( 104 ) and / or the image information intended for the left eye ( 106 ) is increased when the crosstalk value ( 140 ) greater than the threshold ( 142 ). Procedure ( 1200 ) according to one of the preceding claims, wherein in step ( 1206 ) of changing a disparity ( 208 ) between the image information intended for the right eye ( 104 ) and the image information intended for the left eye ( 106 ) is changed. Method according to claim 8, wherein in step ( 1206 ) of changing the disparity ( 208 ) is reduced when the crosstalk value ( 140 ) greater than the threshold ( 142 ). Contraption ( 102 ) for operating a field of view display device ( 100 ), the device ( 102 ) has the following feature: a changing device ( 130 ) for changing image information intended for the right eye ( 104 ) and / or image information intended for the left eye ( 106 ) depending on a ratio or a difference between the crosstalk value ( 140 ) representing crosstalk between image information intended for the right eye and left eye, and a threshold ( 142 ). Field of View Display ( 100 ) with a device ( 102 ) according to claim 10. Computer program adapted to carry out the method according to one of the preceding claims. A machine readable storage medium storing the computer program of claim 12.

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