DRIVER'S INFORMATION DISPLAY FOR MOTOR VEHICLES

Abstract: An information display for a motor vehicle carries the usual primary information such as vehicle speed and mileage elapsed and in addition carries symbols which light up to indicate cer­ tain secondary functions such as high beam headlamp on, low beam headlamp on, rear fog lamp on. In order to assist the driver, the information display has a button which, when pressed by the driver, causes text to be illuminated adjacent to whatever secondary information symbol is illuminated, which text explains what the symbol means. The display is simple to operate and of value to the inexperienced driver.

Description: DRIVER'S INFORMATION DISPLAY FOR MOTOR VEHICLES This invention relates to a driver's information display for a motor vehicle. Modern displays carry not only primary information such as the speed of the vehicle, the mileage covered, the amount of fuel used, but also a certain amount of secondary information such as whether the headlamps are illuminated and, if so, whether they are on full beam or dipped, whether the heated rear window is illuminated and whether the rear fog lamp is on and so on. The secondary information is usually presented in the form of symbols. Typically the symbols are illuminated at the appropriate time. However an inexperienced driver of the motor vehicle does not always immediately know what any particular symbol means. The invention provides a driver's information display for a motor vehicle having means for producing one or more symbols to indicate certain information, wherein means is provided, operable by a manual control by the driver, to produce explanatory information concerning any symbol. This provides a simple means of immediately identifying any unknown symbol, and therefore enables the driver to give his undivided attention to the road. The explanatory information may be audible, for example in the form of speech synthesis, but is preferably visual and preferably in the form of illuminated text. Conveniently the text appears adjacent the relevant symbol. The display may be arranged to distinguish between when the vehicle is in motion and when it is stationary and to produce more comprehensive explanation in the latter case. For the avoidance of the doubt, the word "symbol1 should be taken to include not only a schematic representation of a quantity (such as the symbol usually used to indicate a heated rear windscreen or a symbol representing fuel level), but also letters or numerals characteristic of some quantity, for example, the temperature outside the vehicle. The invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a block diagram of the electronic circuit of the display; Figure 2 shows the appearance of the display when the vehicle is in motion before the manual control has been operated; Figure 3 shows the appearance of the display when the vehicle is in motion after the manual control has been operated; Figure 4 shows the appearance of the display when the vehicle is stationary; and Figure 5 shows the appearance of the display when the vehicle is stationary after the manual control has been operated. Referring to the drawings an electronic control unit 1 drives a cathode ray tube 2 via an appropriate driving circuit 3. The electronic control unit 1 has five main sets of inputs, namely, a set of main transducers 4, a bank of main electrical loads 5, miscellaneous transducers 6, diagnostics transducers 7 and the actual display controls 8. The main tranducers 4 are for sensing distance, fuel, coolant temperature, ambient temperature and engine speed. The distance transducer is a standard trip computer interface driven from the speedometer cable which gives eight thousand electrical pulses per mile. Road speed and distance travelled can be obtained from this. The fuel transducer is a standard fuel gauge sender unit which gives fuel level information in terms of electrical resistance. The coolant temperature transducer is a thermister located in the engine block. The ambient temperature transducer is a thermister mounted in the vehicle nose so as to read outside air temperature. The engine speed is sensed from the negative terminal of the ignition coil. The bank of main electrical loads are sensed by wires leading to the electronic control unit from side lights, dipped headlights, main beam headlights, heated rear window, right hand and left hand direction indicators, rear fog lamps, and hazard warning lights. Simple switch type transducers are incorporated in the seat belt mechanisms and the hand brake so- that there operation may be sensed by means of the miscellaneous transducers 6. Standard switch type transducers are incorporated to provide diagnostic sensing for the following system failures: coolant level low, screen wash level low, charging system fault, oil pressure low, brake fluid low, brake failure, and worn brake pads. The display control 8 has a bank of six switches to provide various display control functions, namely, selection of imperial or metric units, trip or total odometer selection, trip odometer reset, minutes and hours set for clock function, and manual control button for providing explanatory information The signals from these transducers are converted to digital form in the transducer signal processing unit 9. This process is supervised by a micro-computer 10 and the resulting information is stored in ROM 11 and non-volatile RAM 12 in such a form as to be directly usuable by CRT display control unit 13. The quantitive information, such as speed, fuel level, coolant temperature etc is stored as digital numbers in appropriate memory locations. The on/off information is stored as an array of bits in sucessive memory locations. Non-volatile RAM is used to store the distance travelled. The micro-computer 10 communicates with a standard cathode ray tube display controller 13 to produce the video signals necessary to cause CRT driving circuit 3 to drive the display. Referring to Figure 2, the display shows primary information such as the vehicle speed in the centre and beneath that the distance travelled, above that the revolutions of the engine in thousands of rpm, to the left the fuel tank level and below that the ambient temperature, to the right the engine temperature and below that the time. All these primary pieces of information are illuminated on the cathode ray tube. Above the band indicating revolutions per minute, are shown symbols which each illuminate when their particular function is operated. Obviously, all the symbols would not illuminate at the same time in use of the vehicle, only those for which the appropriate vehicle function is in operation. If an experienced driver was driving the vehicle and one of these secondary symbols illuminated, the driver would press the manual control button to operate the switch in display control 8 and the additional text shown in Figure 3 would result for whatever symbol was illuminated. Thus, if the rear fog lamp symbol was illuminated, the words rear fog underneath the symbol would also be illuminated. Similarly for high beam, low beam, rear demist and service due. Of course the invention is not limited to the particular secondary symbols shown in Figures 2 and 3 thus, for example, other symbols which indicate warnings of various conditions could be displayed, for example a symbol indicating bulb failure. When the manual control button was depressed, the words 'bulb failure' would be read from the display adjacent to the symbol. If desired, the text could be arranged to be displayed for a certain period of time, for example, ten seconds, only, and then disappear. Referring to Figures 4 and 5, this shows the display when the vehicle is stationary and the engine is not turning over. When the ignition switch is turned sufficiently to operate electrical systems, but not sufficiently to turn the engine, a display of the general form shown nun Figure 4 isoproduced. Operation of the manual control button produces the display shown in Figure 5. In the case of Figure 5 all systems, that is, rear demist, low beam, seat belt, light etc are working and the words 'all systems serviceable' appear at the bottom of the page. In the case of Figure 4, these words do not appear because a faults have been noted, namely the oil pressure is low and the windscreen washer is empty. What happens is that the oil can symbol and the word "low" flash on and off in alternation with the word "oil pressure. Similarly the windscreen washer symbol and the word "low1 flashes on and off in alternation with the words "screen washy. Of course if desired further pages of information could be shown, the manual control button enabling the driver to page through them in a simple manner. This pre-start check enables the driver to check for faults, and also to familiarise himself with the symbols, which all appear with text. As an alternative to the pre-start check described with reference to Figures 4 and 5, when the vehicle is stationary and the engine is not running, the act of turning the ignition switch to the position to switch on electrical systems could be arranged to cause any fault condition to be indicated in symbolic form, but again without the primary drivers information. The manual control could then be depressed to obtain textual information on the fault. This time, however, the information could be more detailed than when the vehicle was travelling.

Claims: CLAIMS 1 A driver's information display for a motor vehicle having means for producing one or more symbols to indicate certain information, wherein means is provided, operable by a manual control by the driver, to produce explanatory information concerning any symbol. 2 A display as claimed in claim 1, wherein the explanatory information is provided in audible form. 3 A display as claimed in claim 1, wherein the explanatory information is provided in visual form. 4 A display as claimed in claim 3, wherein visual text is provided as explanatory information. ¯¯¯ 5 A display as claimed in claim 4, wherein the text appears adjacent the relevant symbol when the manual control is operated. 6 A display as claimed in any one of claims 1 to 5, wherein the explanatory information is more detailed if the vehicle is stationary and the engine is not running. 7 A display as claimed in any one of claims 1 to 5, if the vehicle is stationary and the engine is not running, the display produces a first page of information on the vehicle systems, and the manual control is operable to produce a second page of information on the vehicle systems. 8 A display as claimed in any one of claims 1 to 7, wherein the display is a cathode ray tube. 9 A driver's information display substantially as hereinbefore described with reference to the accompanying drawings. 10 A motor vehicle incorporating a display as claimed in any one of claims 1 to 9.

Inventors: MACKIE, CARMICHAEL, WILLIAMS, MALCOLM
Applicants: GAYDON TECHNOLOGY LIMITED
Application year: 1984
Main classification: B60K37
IPC codes: G08B5, B60K37, G08B3