Method and device for minimizing initial surface reflections in a display screen

The present invention relates to a device for minimizing initial surface reflections which can be reflected from the surroundings via the reflecting surface of an electronic display screen in the direction towards a given observation position, whereby the display screen is arranged on a base, preferably mounted on a dashboard of a vehicle, whereby at least a certain region of, or adjoining, the base to which the display screen is intended to be attached, is treated in such manner that a low reflecting surface is obtained.

TECHNICAL FIELD 
The present invention relates to a method and a device for minimizing 
initial surface reflections which can be reflected from the surroundings 
via a reflecting surface of an electronic display screen in a direction 
towards a given observation position. The invention is primarily intended 
to be used to avoid those initial surface reflections which are visible to 
the observer in the glass screen of an electronic display screen mounted 
on the dashboard of a vehicle. 
TECHNICAL PROBLEM 
The use of electronic display screens is continuously increasing. The use 
of such screens in vehicles has until now been relatively limited, though 
it is generally seen to have large potential. Particularly when used in 
vehicles, it is important that the legibility is as good as possible. The 
higher the legibility, the shorter the time that is necessary to 
assimulate the information which is displayed on the screen. Accordingly, 
the shorter the period of distraction, the safer the driver is. One aspect 
which can have a negative effect on the legibility is light reflection on 
the surface of the display screen. This problem has been recognized for a 
long time and a plurality of measures have been suggested for its 
solution, such as glare treatment and matting of the display screen's 
surface. 
BACKGROUND OF THE INVENTION 
A method is known from U.S. Pat. No. 4,521,078 to avoid surface reflections 
which are visible to an observer on the surface of an electronic display 
which is mounted on the dashboard of a vehicle. This known method makes 
use of the fact that the windows of a vehicle are located relatively high 
up in relation to the dashboard and that the light which enters into the 
car can therefore be reflected in small quantities to the observer's 
position if the surface of the display screen is angled such that it forms 
an angle which is less than 90.degree. in relation to the light path from 
the observer's eye to the surface of the information screen and further 
that it forms an angle less than 90.degree. in relation to the 
longitudinal axis of the vehicle. The main part of the reflected light 
path is in such a case reflected to a region which is lower than the 
observation position. This known method accordingly minimizes the majority 
of the direct reflections which could bother the observer. In addition to 
this measure, the outer surface of the electronic display screen is 
provided with a polarizing filter to reduce to a certain extent indirect 
reflections in the display screen. 
A polarizing filter reduces however only a small quantity of the indirect 
reflected light and is accordingly not a perfectly satisfactory solution. 
The risk thus remains that even with such a known device a reflection 
which is disturbing for the driver can arise in the surface of the 
electronic display screen. 
A known method to totally avoid disturbing reflections, even indirect 
reflections, is shown in DE-C-32 25 362. In this method the display is 
placed in a shielded recess sunk into the dashboard. Such a solution is 
however not preferred due to size, difficulties of use and cost reasons. 
The object of the present invention is to provide a method and a device to 
minimize initial surface reflections which can be reflected from the 
surroundings via the reflecting surface of an electronic display screen in 
the direction towards a given observation position in which the display 
screen is arranged above a base, preferably mounted on the dashboard in a 
vehicle. 
SOLUTION 
A further object of the present invention is to provide a device according 
to the invention which is easy to use, demands a limited space and which 
meets certain aesthetic requirements. 
The object is achieved with a method according to the present invention 
which is characterized in that at least a certain region of, or adjoining, 
the base to which the display screen is intended to be arranged is treated 
in such a manner that a low reflecting surface is obtained. 
The object is also achieved by means of a device according to the present 
invention which is characterized in that at least substantial parts of the 
surface in front of and adjoining the display screen have a low reflecting 
structure and/or in the preferred instance that substantial parts of a 
surface belonging to or arranged on the base which can coincide with a 
normal to the reflecting surface have a low reflecting structure.

BEST MODE OF CARRYING OUT THE INVENTION 
FIG. 1 shows a longitudinal schematic cross section through a vehicle which 
is equipped with an electronic display screen 1. The display screen 1 is 
mounted on the dashboard 2 under the rearwardly angled windscreen 3. An 
observer's eye position (not shown) is indicated in principle with the aid 
of two overlapping ellipses 4. Each ellipse indicates for a certain body 
angle the region above and below respectively which 95% of drivers eyes, 
in a sitting position, are located in respect to a tangent which coincides 
with the line of sight to the object, in accordance to SAE J941. The 
schematically shown driver is therefore a borderline case. 
The purpose of the present invention is, in addition to direct reflections, 
to also minimize indirect reflections which can reach the eyes of the 
observer, i.e. the ellipses 4, via the surface 10 of the display screen. 
Figure reference number 5 denotes a light beam which, if it is reflected 
in the upper surface of the dashboard 2 would give an indirect reflection 
via the surface 10 of the display screen to the observer position 4. 
Since, in accordance with the present invention, a certain region 20 of 
the dashboard 2 is provided with a low reflecting surface, it is however 
possible to minimize such an indirect reflection. The figure further shows 
that the display screen's surface 10 in the preferred case forms an acute 
angle .beta. with the vertical and is directed downwardly. Furthermore, in 
the preferred embodiment, the display screen is foldably arranged upwards 
and downwards which will be further explained in the following. 
A preferred embodiment to the invention is shown in FIG. 2 in a folded down 
position. A frame 21 is arranged in a sunken position in the upper surface 
of the dashboard 2. An electronic screen 1 is retractably arranged with 
this frame unit 21. During deployment of the unit, the information screen 
is swung upwardly (manually or automatically) less than 90.degree. to the 
position which is shown in FIG. 3. The display screen is provided with 
means (not shown) for maintaining it in the active position. The means can 
be chosen from a plurality of already known suitable applications, such as 
pivotable support legs, telescopic arms, pinion drive (pinion and electric 
motor), etc. The lower part 20 of the dashboard which is located 
underneath and in front of (in the direction towards the driver) the 
display screen surface 10 has a surface of low reflecting character, in 
accordance with the invention, i.e. a surface which when reflected in the 
display unit's front surface does not worsen the legibility for the driver 
of the information displayed on the screen. 
The low reflecting surface 20 can for example be achieved by means of 
serrations, matt black colouring, low reflecting material, etc. The 
skilled man will recognize that the low reflecting surface 20 can either 
be formed as an integral part of the dashboard in a vehicle, or as a 
separate element intended for subsequent fitting. The skilled man will 
also appreciate that the active position of the display screen 1 in the 
figures is shown by way of example only. Accordingly, the angle formed 
between the low reflecting surface 20 and the electronic display screen 1 
may vary up to 30.degree. when the electronic display screen 1 is in its 
substantially vertical active position as shown in FIG. 1.