GB1585071A - Electronic display - Google Patents

Description

(54) ELECTRONIC DISPLAY We, WESTERN ENGINEERING LIMITED, a British Company of 23A Arbory Street, Castletown, Isle of Man, do hereby declare the invention, for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to display apparatus operable to display information items provided by sensors on a vehicle.

Information items resulting from the monitoring of the variables in the operation of a vehicle are generally displayed continuously on corresponding separate indicators.

In many cases, however, it is necessary to know the value of only one or two of these variables at any particular instant.

For example, when driving a motor vehicle it is normally necessary for the driver to be aware only of the speed of the vehicle unless any of the other variables being measured are at an abnormal level. This means that much of the displayed information is superfluous for most of the time. In addition, the different variables are displayed on different types of indicator some of which provide the driver with only a rough idea of the value of the variable being measured. The provision of a number of different meters and other indicators leads to data display which is both expensive and untidy.

In accordance with the present invention apparatus to provide a visual display of information items provided by sensors on a vehicle comprises a display matrix of light emissive or reflective devices; means to activate the devices selectively; and means to select which of the items shall be displayed at any instant and to allocate a respective group of the devices to be activated to display the selected item or items, the selection means being operable, when required, to reallocate the devices of the display matrix so that the location of a displayed item within the display matrix and/or the size of display of an item can be changed.

The display matrix may therefore be operated to display, for example, a number of information items at various locations, the items being displayed in characters of equal or unequal sizes, and the locations and character sizes can be continuously selected and varied depending upon the usefulness of the data, at any particular instant, to the driver of the vehicle. If an abnormal condition is sensed, information relating to this condition may be displayed prominently, in preference to other, less important, information.

The display matrix may comprise, for example, a direct current plasma discharge matrix display panel. Such a panel consists of a perforated mask sandwiched between two glass sheets, the matrix being formed by thin transparent parallel strips of tin oxide deposited on the inner surfaces of the glass sheets. The strips on one sheet are perpendicular to the stips on the other sheet and the perforations in the mask coincide with the intersection points. The sheets are brought together and hermetically sealed, the perforations in the mask being filled with ionising gas. By applying suitable "X" and "Y" co-ordinate voltages to the strips on the respective glass sheets, a light dot pattern is obtained due to the gaseous discharge in the perforations in the mask at the selected co-ordinates. The light dot pattern can be used to represent simple alphanumeric data or more advanced graphical data. The resolution of the display will depend on the size and number of the perforations in the mask and the corresponding number of conductive strips on the glass sheets.

An alternating current version of the above-described display panel could alternatively be used. The principal difference between the a.c. and d.c. panels is that the a.c.

panel does not include a mask. Instead, thin sheets of glass sandwich the "X" and "Y" conductors against the outer glass layers.

This insulates the conductors from the ironising gas. Each element of the matrix between the conductor intersections acts as a capacitor, and a pulsed or alternating voltage applied thereto can therefore initiate and sustain an ionised discharge in the element between energised conductors.

Two further possible forms of display matrix are electroluminescent display panels and liquid crystal panels. In an electroluminescent display panel, each cell comprises an X-Y addressed logic transistor, a power tranistor and a storage capacitor. Each power transistor is associated with a respective elec troluminescent element, and power is delivered to the electroluminescent element through the power transistor whenever the logic transistor is correctly addressed.

A liquid crystal panel will include a lightreflective liquid crystal in each cell of the matrix, the crystal being energised through a transistor having its base electrode connected to one of the coordinate lines and its collector electrode connected to the other coordinate line.

One embodiment of the invention as applied to a motor vehicle will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 illustrates diagrammatically the main components of a display apparatus and associated transducers for monitoring the operation of a motor vehicle, and Figure 2 is a block circuit diagram of the apparatus.

Referring to the drawings, the data items for the display are obtained from transducers located at appropriate points within the vehicle.

Transducers 1,2,3,4 and 5, respectively, generate signals representing the fuel level, the road speed, the oil pressure, the coolant temperature, and the engine speed. These signals are fed along transducer input lines 6-10, respectively, to a transducer data input control 11. If necessary, any one of these transducer input lines can be selected by depressing a respective manual data demand control button 11-15 located beneath a display panel 16 shown in Figure 1.

Normally, however, the selection of a particular input is under the control of a central processor 17 which automatically selects the data of use to the driver at any particular instant. For example, immediately after starting the engine, the processor 17 might select the inputs from the oil pressure transducer 3 and from the fuel level transducer 1 so that these values would be displayed on the display panel. During normal running, on the other hand, the processor 17 might select only the input from the road speed transducer 2. In addition, the processor might respond to any one of the inputs exceeding a predetermined threshold level, so that the driver would be immediately warned of any abnormal conditions by appearance of the relevant date on the display.

The output from the processor 17 energises selected generators in a character generator unit 18 and also feeds a signal to an address control circuit 19 to determine the location at which the selected character is to be displayed matrix 20. The unit 18 feeds signals to X and Y matrix address logic circuits 21 and 22 which energise the X and Y conductors appropriate to the characters to be displayed. The logic circuits 21 and 22 can each be manufactured as an Uncommitted Logic Array, which is a large number of densely packed resistor/ transistor logic elements on a ceramic substrate. These arrays are manufactured up to a final masking and deposition stage without being connected to one another, so that the final deposition dictates their function.

In operation, the sensed road speed may be displayed over substantially the whole area of the matrix 20 when this is the only variable being displayed. On the other hand, as soon as the processor 17 detects the need to display one or more other variables, the road speed reading can be made to occupy a different location on the matrix to make room for the displaying of the other variable or variables.

The speedometer reading might, for example, be reduced in size whilst still occupying the central area of the matrix.

The apparatus can also include a transponder 23 which reacts to the start and finish of speed restriction areas. This transponder is used in conjunction with transmitters which would be fixed to the speed restriction signs at the side of the road in such a manner that the vehicle has to pass through a transmitted beam each time it enters or leaves a restricted area. The beam switches on the transponder 23, and the transponder feeds a signal representing the speed limit, via n input memory 24, to the processor 17. The processor compares the actual road speed with the limit speed, and if the road speed is above the limit, this is indicated on the display matrix as a flashing signal.

A flashing signal can also be used to attract the driver's attention to other abnormal conditions, for example when the fuel level drops to a predetermined lower limit value of, say, one gallon. The fuel level might also be displayed continuously for a brief period before this lower limit value is reached, for example as the level drops from two gallons to one gallon.

The apparatus can also be adapted to provide critical information if the vehicle is involved in a crash. This is achieved by an ultrasonic transceiver 25 located in the front of the vehicle. The ultrasonic waves emitted from the transceiver are bounced back from any obstacle in front of the vehicle and are detected at the transceiver. The frequency of the received signal varies with the rate of change of distance from the obstacle. Hence, if a vehicle is closing on another in front of it, the closing speed can be monitored and, if this speed (which is measurable from the rate of frequency change) exceeds a set limit, a command is fed to the processor in the rear vehicle to record the events. At the same time a warning is flashed on the display in the rear vehicle. Whether the vehicles impact or not, a record of the important parameters such as speed, distance and rate of deceleration can be made in response to the "record" command. This can be subsequently read out of the processor by the use of, say, a key switch under the display panel, which switch can be operated only by the police. This forms the subject of our Patent Application No.8000319, (Serial No.1585072) which is divided out of the present application.

Because the apparatus can respond to signals from outside the vehicle, it can be made responsive to police instructions or information, such as a "slow down" instruction, or an accident warning, and can be made to display corresponding information on the matrix.

Similar apparatus can be used for monitoring the operation of a heavy goods vehicle, an aircraft, a train, a hovercraft, a ship or other vehicle.

Each train on a system might be fitted with apparatus responsive to shock. The apparatus could then transmit a signal whenever a preset shock limit is exceeded, and this signal could be detected by the antennas transponder input of any other trains in the area, and a signal flashed on the displays in those trains, giving a warning of possible danger.

A mixture of types of devices might be used in the matrix, so that indications displayed in different regions of the matrix could be in different colours.

WHAT I CLAIM IS: 1. Apparatus to provide a visual display of information items provided by sensors on a vehicle, the apparatus comprising a display matrix of light emissive or reflective devices; means to activate the devices selectively; and means to select which of the items shall be displayed at any instant and to allocate a respective group of the devices to be achieved to display the selected item or items, the selection means being operable, when required, to re-allocate the devices of the display matrix so that the location of a displayed item within the display matrix and/or the size of display of an item can be changed.

2. Apparatus as claimed in Claim 1, where- in the selection means is operable to select a plurality of the information items for display in sequence.

3. Apparatus as claimed in Claim 1 or Claim 2, wherein the selection means includes manually operable means for selecting one or more information items for display on demand.

4. Apparatus as claimed in any preceding claim, wherein the selection means includes means responsive to the sensing of abnormal operation of the vehicle to cause information indicating the abnormality to be displayed.

5. Apparatus as claimed in any preceding claim, wherein the devices of the display matrix are of any of the following types: gas plasma discharge devices, fluorescent devices, light emitting diodes, electroluminescent devices, or liquid crystals.

6. Apparatus as claimed in any preceding claim, wherein the selection means is also responsive to radio transmissions received from outside the vehicle to allocate devices of the display matrix to be activated to display information obtained from the transmissions.

7. Apparatus as claimed in Claim 6, wherein the selection means is responsive to radio transmissions representing speed limits imposed upon the vehicle, and is operative to allocate said devices if the vehicle speed is ouside the imposed speed limit.

8. Apparatus as claimed in Claiml and substantially as hereinbefore described with reference to the accompanying drawings.

9. A vehicle including apparatus as claimed in any preceding claim, and further including a plurality of said sensors.

10.A vehicle as claimed in Claim 9, wherein the sensors are respectively effective to monitor vehicle operating parameters selected from vehicle speed, engine operating temperature, fuel level, lubrication pressure, and engine speed.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (10)

**WARNING** start of CLMS field may overlap end of DESC **. vehicle. Whether the vehicles impact or not, a record of the important parameters such as speed, distance and rate of deceleration can be made in response to the "record" command. This can be subsequently read out of the processor by the use of, say, a key switch under the display panel, which switch can be operated only by the police. This forms the subject of our Patent Application No.8000319, (Serial No.1585072) which is divided out of the present application. Because the apparatus can respond to signals from outside the vehicle, it can be made responsive to police instructions or information, such as a "slow down" instruction, or an accident warning, and can be made to display corresponding information on the matrix. Similar apparatus can be used for monitoring the operation of a heavy goods vehicle, an aircraft, a train, a hovercraft, a ship or other vehicle. Each train on a system might be fitted with apparatus responsive to shock. The apparatus could then transmit a signal whenever a preset shock limit is exceeded, and this signal could be detected by the antennas transponder input of any other trains in the area, and a signal flashed on the displays in those trains, giving a warning of possible danger. A mixture of types of devices might be used in the matrix, so that indications displayed in different regions of the matrix could be in different colours. WHAT I CLAIM IS:

1. Apparatus to provide a visual display of information items provided by sensors on a vehicle, the apparatus comprising a display matrix of light emissive or reflective devices; means to activate the devices selectively; and means to select which of the items shall be displayed at any instant and to allocate a respective group of the devices to be achieved to display the selected item or items, the selection means being operable, when required, to re-allocate the devices of the display matrix so that the location of a displayed item within the display matrix and/or the size of display of an item can be changed.

2. Apparatus as claimed in Claim 1, where- in the selection means is operable to select a plurality of the information items for display in sequence.

3. Apparatus as claimed in Claim 1 or Claim 2, wherein the selection means includes manually operable means for selecting one or more information items for display on demand.

4. Apparatus as claimed in any preceding claim, wherein the selection means includes means responsive to the sensing of abnormal operation of the vehicle to cause information indicating the abnormality to be displayed.

5. Apparatus as claimed in any preceding claim, wherein the devices of the display matrix are of any of the following types: gas plasma discharge devices, fluorescent devices, light emitting diodes, electroluminescent devices, or liquid crystals.

6. Apparatus as claimed in any preceding claim, wherein the selection means is also responsive to radio transmissions received from outside the vehicle to allocate devices of the display matrix to be activated to display information obtained from the transmissions.

7. Apparatus as claimed in Claim 6, wherein the selection means is responsive to radio transmissions representing speed limits imposed upon the vehicle, and is operative to allocate said devices if the vehicle speed is ouside the imposed speed limit.

8. Apparatus as claimed in Claiml and substantially as hereinbefore described with reference to the accompanying drawings.

9. A vehicle including apparatus as claimed in any preceding claim, and further including a plurality of said sensors.

10.A vehicle as claimed in Claim 9, wherein the sensors are respectively effective to monitor vehicle operating parameters selected from vehicle speed, engine operating temperature, fuel level, lubrication pressure, and engine speed.