FR2488555A1 - Infinite focus windscreen head=up display for motor vehicle - uses reflection from windscreen within two zones either side of steering wheel to provide information from pushbutton selected instruments - Google Patents

Abstract

The display uses reflection from the inside surface of the front windscreen to obtain an image lying in the normal field of vision of the driver. The illuminated display is controlled by a microprocessor and is connected to the dashboard instrumentation. The layout of the display is such that is is reflected from the inside of the windscreen within two zones lying either side of the steering wheel, preventing the view directly ahead from being impeded. Pref. the dashboard incorporates a number of standard instruments viewed through the steering wheel, together with a number of warning lights, the head-up display incorporating the same warning indication and pref. duplicating some of the other instrumentionation with push-button programming keys for the microprocessor incorporated in the dashboard for selecting the information for the head-up display.

Description

 The present invention relates to the presentation of information, indicator lights and alarms, for the attention of the driver of an automobile, by the reflection of these on the windshield, in the field of vision, without him having need to tilt your head.

 The dashboards of current classic automobiles contain the following devices: a / Electronic speedometer, b / Total and partial odometer, c / Radiator water temperature indicator, d / Oil pressure indication, e / Battery charge indicator, t} Fuel level indicator, g / Electronic engine tachometer, h / Quartz watch ...

There are also a dozen indicator lights or alarms, which signal to the driver: l / High beam headlights, 2 / Critical temperature of the radiator cool down, 3 / Parking and parking lights, 4 / Direction change signals , 5 / The fuel reserve 6 / The discharging of the battery, 7 / The choke, 8 / The critical limit of wear of the brake pads, 9 / The 8 hand brake blocked or the critical level of the liquid in the
brake system ...

 For many years the instruments on the dashboard were precision mechanical equipment, just like those on the dashboards of aircraft cockpits. For ten years, with the swelling advances of electronics and also those of data processing, micro-data processing, certain automobile manufacturers even offer microcomputers to calculate the fuel consumption, to program the speed, and it is difficult to stop the progress of microcomputing on board future automobiles.

 Current dashboards have too much information, too many instruents that drivers cannot watch while driving, on the road or in town: a driver spends only 1 to 2 * of his time looking at the instruments on the dashboard : when starting up, when he is alone on a long straight journey, when he sees a petrol station, ... and when an abnormal noise awakens his attention.

 Some car manufacturers have sometimes placed warning lights on the back of the steering wheel, in an area where a normally seated driver cannot see them. A systematic check of all dashboards in 1980 model cars shows that more than half of the instruments and lights are difficult to see while driving. It is only at low speed that a driver can better examine his instruments; at 100 km / h he must have his eyes fixed on his route.

 The presentation of information according to the invention resembles that introduced over the past ten years in aviation: the HUD (Head Ut Display), that is to say the presentation by reflection on the front window, before the eyes of the pilots , light signals during the critical phases of ILS (Instruments Landing System) blind landing, or critical phases of flight during military missions. When the eyes of a pilot are fixed to look at infinity, they can also read luminous signs which are reflected on the windshield, without excessive fatigue. To check dials and indications located less than a meter away, the fatigue of adjusting the sight is very great. This procedure for controlling the instrument panel is often done when the autopilot is connected.

 The presentation of information such as speed, tachometer, fuel tank level, exact time, according to the invention, makes it possible to avoid the disadvantage of the lack of control mentioned above, since a motorist driving or overtaking another vehicle more than 120 kn / h, cannot take his eyes off the road, cannot bow his head to examine an instrument located 70 or 80 cm from his eyes. It is preferable to present information to him by reflection on his front window, not in the field of vision of his route, but rather in that where he sees the top of the hood of his engine, on both sides of his steering wheel. With the progress of electronics, microcomputing and especially with the so-called electronic components of OPTOELECTRONICS, fluorescent @ DISPLAYS, light-emitting diodes, alarms, it is now relatively easy to install, in parallel with existing instru- ments and indicators, light displays whose essential information will be reflected on the bottom of the windshield, in front of the driver and on each side of the steering wheel.

 The construction of a new automobile model, study, prototype, test, manufacturing tool, launch requires approximately four to five years; the construction of display devices according to the intention requires only 9 to 12 months of work for the adaptation to a model of automobile: it is therefore desirable, after a constructive criticism of the dashboard of a model car, to remedy the lack of visibility of the information, by its presentation by means of display by reflection on the windshield.

 Another advantage of the invention is that the rather timid introduction of microcomputing on the dashboards will allow the elimination of conventional iDstrunents & cadrsne @ and their replacement by electronic displays, and above all, by the presentation , in better safety conditions, by reflection on the front window.

 Another advantage of the invention is to partially mask the ugliness of the wiper blades of many European cars, because by tinting the bottom of the windshield slightly to facilitate the reflection of light information, in all weathers, we see less black and unpleasant brooms.

The characteristics and advantages of the information presentation device, indicator lights and alarms, For the attention of car drivers, by the reflection of these on the windshield, in the normal field of vision, emerge even better from descriptions which follow, by way of examples, with reference to the appended drawings in which: - The Wig.l schematically shows the position and the vision ehawp
of a driver driving an auto-bile.

- Fig. 2 is a front view of a classic dashboard with
A steering wheel.

- Fig. 3 is a view of a dashboard where a lot of information
are practically hidden by the steering wheel.

- Fig. 4 shows how this table can be completed by presenting
reflected information on the windshield.

- Lig. 6 is an enlarged view of Pig.l, also more detailed.

- Fig.5 shows a classic dashboard disassembled with,
Checked in parallel, an information display device.

- Fig. 7 shows that the letters and numbers of the display device
are displayed upside down.

-LB Fig.8 shows the position of the display device and its reflection-
xion on the windshield.

- Fig. 9 presents a miero-processe'cr for controlling the device
information display.

As shown in summary, the display device of nfor-
reflective mations can have many variations and
give a single piece of information, the speed of the automobile, or davan
tage of information, two, three, four, and above all present a
or several warning lights, when necessary.

The advantage of a device with microcomputer is to present
the driver with essential and timely information
in my field of vision. It is desirable that gradually,
the amount of information in the dashboard is increasing
reduced, and the role of the on-board microcomputer takes over
to simplify driving, both on and off the road
city.

Fig. 1 schematically shows a driver 1 in a car
2 of medium category, looking at His road in front of him, To infinity
), that is to say at about 300 m, or at a shorter distance L = 30m.

This is the most frequent case of adaptation of the view of the conduc
ters, they watch 98% of their time on the road in front of the hood 5
and at most 2 b of their time looking at dashboard 4,
or the mirrors. The dashboard is only at a distance of
60 to 80 cm and its examination requires lowering the eyes and getting
adapt to a reduced viewing distance. LB visual fatigue
the higher the conductor frequency
of the dashboard is repeated often and its lighting differs
of the road. Best to present information
by display-reflection on the windshield 3.

Fig. 2 presents a dashboard 4 partially masked by the
steering wheel 6, the number of masked information and their
importance depend at all times on the position of the body of the
driver, position and distance from his eyes to the board
edge, even even, the position of his hands on the steering wheel.

On a car, I could see that warning lights 7 of various alarms A, B, C, D, S, X, G, E, I, J, were difficult to see, because the central part of the steering wheel was too important; when you drive very often the steering wheel isn’t with its horizontal bars, nie very often slightly tilted, and constantly you have to correct the position of the steering wheel: in short, you hardly see the warning lights, and you realizes that one of them is on when the car breaks down.

The inatruzents of dial 8 are essential for the smooth running of the engine, but many drivers analyze the information they provide very poorly, since energy savings and consumption per 100 kM depend very much on this.

Tachometer 2 and the odometers are checked the most frequently because sometimes it is the passenger who notices too high a speed. De = ie the number of revolutions per minute 10 and the acceleration are mainly felt by the passengers. When very often the automobile is used for home-work trips, one is essential. Unfortunately when you are driving very fast so as not to be late, this watch is not very efficient.

There are two zones 12 and 13 on each side of the steering wheel, on which the reflection of light displays of information and indicators seems an excellent idea, visible reflection in all lighting conditions, because the light intensity can be regulated by a photo-cell, automatically.

 In Fig. 3 is presented a very aesthetic dashboard; the advertising brochure presents very nice photos, but when you are behind the wheel, the disappointment is very great: many of the indicator lights 7 are invisible and too many of them often flash at the same time. The instruments 8 are partially hidden by the steering wheel 6 and only the dials 2 and 10 are clearly visible. What's the use of adding an optional microcomputer to calculate fuel consumption indices? Better would be to use the MPU, the ROMs and RAM of this microcomputer to present as in Fig.4, the main information by display reflection on the windshield 3, in zones 12 and 13, two warning lights 14 and 15 sufficient to attract the driver's attention.

 Fig.5 is an exploded view of a very compact dashboard but which unfortunately is quite difficult to read, especially that of the warning lights 7. The anti-reflection visor 16, the window 17, the ideogram 18 , the seal 19 assembled on a case 20 have a tachometer 9, a classic watch 11, instruments 8, instruments connected to a printed circuit 21. The invention consists in modifying this current printed circuit 21 to connect in parallel, a device d display 27, controlled by a microcomputer 23 by means of cables 22, 24 and 2S. Each car before its particular electrical circuits, the microcomputer 23 can be adapted to each model by a different programmable ROM or EPROM.

 Fig.6 shows a driver 1 at the wheel 6 of a normal car 2, looking at a distance L = = # or about 200 to 300 n. To look at the warning lights 7, his eyes must rotate by an angle of approximately: # + γ + ss = 11 to 12. If he wants to look at his dials 8,9,10 he must lower his eyes by an angle of: α + ss + γ + # = 19 to 20.

Above all, fatigue comes from the need to accommodate from the eyes, at a distance about a hundred times less, at a different luminance, at a frequent repetition of attention forwards, backwards, instruments and alarms.

It is much less tiring to look at the road and to see, if the microcomputer 23 controls a light display XY, the reflection of the points X 'and Y' on the front windshield 3. In such a case, the driver's eyes only have to turn at an angle of: # + = 4 to 7 maximum, and make a much less accommodation effort.

 The wiper blades 26 occupy an area where it is easy to tint the windshield very slightly, to facilitate the reflection of a quantified light formation, or of a luminous alarm indicator, this dyeing being only limited to the surfaces of reflection and not in the observation area of the road. This drawing shows the dashboard shown in exploded view in Fig. 5. In future automobiles, it is possible that the elements of the dashboard 7,8,9,10,16,20,21, the microcomputer 23 and the displays 27 are combined together in the same equipment, simpler and also very improved reliability.

This figure allows us to guess how much progress can be made on future cars, by introducing microcomputing and eliminating the dials of classic instrumentation.

 Fig.7 shows that the reflection of the light displays on the windshield glass requires that the signs, letters and numbers be presented as if by a glass, on the contrary, to be read.

One of the characteristics of electronic circuits, of the devices for controlling DISPLAY displays, is the need to present inverted signs, and also, inclined to the left, not unlike those of conventional fluorescent displays. For this it is necessary to modify the ROM of the microcomputer controlling the displays.

In order for visibility to be perfect in all lighting conditions of the environment, an automatic photocell like camera must be able to automatically adjust the light intensity, so that the reflected information is clearly visible. The position thereof is recommended at 28 in the light display device 27 which can be seen more schematically in FIG. 8.
in Fig. 7 above the Z'Z axis we see the speed indication on the left, for example 158 km / h, with the time below, 22.35 and on the right the number of engine revolutions, 4750 rpm, and the amount of fuel in the tank, 35 liters. The two circles symbolize the location of the green signal if everything is working well, and of a red ALARM light, if an indicator on the panel lights up.

 These are a display esesple among many other possible embodiments of the invention.

The displays called "Fluorescent Displav Panels" have a number of digits from 1 to 32, an author from 4.5 mm to 7.6 mm, a number of segments of 7, 8, 14 or 16, or a number of 5 @ 7 points for each letter or number. The tests to which they are subjected allow them to be used in problems for a hundred nilliers of hours, as long as an automobile.

 Fig. 8 shows how a letter XY from device 27 is reflected on the windshield 3 and presents in X'Y 'this to the driver: the view AA is what he sees, the view BB is what a driver would see looking at the device 27. The XY points must not be seen directly, hence the Y shape of the device and also the location of the photocell system 28 for automatic adjustment of the light intensity of the displays, according to the ambient light , day or night, in town or on the road, with the possibility of adjustment according to the driver's view.

 The Pig. 9 schematically represents the display display part 2t and the corner microcomputer part 23 which includes numerous integrated circuits, XPU, ROM, RAM, EPROM, etc.

Claims (6)

 steering wheel, and does not obscure the view of the road in front of the automobile.  te on the windshield in two zones 1 and 13 on each side of the  linked to dashboard instruments 4, display that reflects  control actuator 23 of a light display assembly 27, re  of the driver, characterized by the installation of a micro-computer  by reflection on the windshield 2 in the normal field of vision  nes luminous, for the driver of an automobile 2,  R E V E N D I C A T I O N S 1. Information display, indicator and warning devices 2. Devices according to claim 1 characterized by the present  normal information 8, e, 10, 11 on normal dials,  alarm lights 7 on the dashboard 4 panel  part masked by the steering wheel 6, and the simultaneous presentation and  parallel of this same information by thinking about the two  windshield zones 12 and 13 3. 3. Devices according to claims 1 and 2 characterized by  the display by reflection on the parebzise Z of the essential data  for the smooth running of the automobile, select display  operated by the microcomputer 23 or by the conductor 1, the  alarm lights 14 and 15 remaining priority. 4. Devices according to claims 1 to 3 characterized by  a photocell 28 for automatic intensity regulation  display 27, depending on conditions  ambient lighting.  reflection zones of light displays.  a weak transparent dye from the bottom of the windshield 3, in the  5. Devices according to claims 1 to 4 characterized by 6. Devices according to claims 1 to 5 characterized by the  grouping under the control of a microcomputer 23 of all  the information presented on the dashboard and by reflection  xion on the windshield of the automobile, information that can  be selected by the driver or by the manufacturer at  by means of REPRO @ integrated circuits of the microcomputer.