GB2255216A - Elapsed event display - Google Patents

Abstract

The display comprises a plurality of indicators, respectively so disposed and configured that any one or more of them may indicate a time elapse since a zero time. A sensor determines a condition which is desired to be monitored substantially continuously, and when the sensed condition is outside predetermined limits, a signal of the existence of such an aberrant condition is sent to an appropriate one or more of said indicators, depending on the time the condition occurred. The signalled one or more indicators become and remain in an indicative condition for a predetermined period after said signal or said zero time. <IMAGE>

Description

ELAPSED EVENT DISPLAY The present invention relates to an elapsed event display.

More particularly, but not exclusively, it relates to such a display where a change in predetermined conditions of whatever sort can be shown and the time when such deviance from normal or ideal occurred is also readily recognisable.

There are devices currently in use for monitoring physical data such as temperature, humidity, or gas levels. For example, there are soft data loggers where the recorded data is displayed by means of a computer. Other systems use graph loggers where recorded data is drawn onto graph paper to leave a record of the conditions. This latter is obviously inconvenient in that the paper must be changed regularly and the level of ink must be checked so that there is no interruption in the recording all the data.

However, it is not always necessary to record the data.

In some circumstances, all that is required is to know whether or not the condition being monitored has exceeded some predetermined limits. In some circumstances, it is also necessary to know only that said limits have been exceeded for a period of time which is itself within acceptable limits.

Examples of this type of monitoring situation are frozen food or part chilled food where the temperature at which the food has been stored is important. Such food must be kept within a predetermined band of temperature and if the temperature exceeds either limit, it is advisable that some warning be given. If the limits are exceeded only temporarily, the food may still be safe to eat, provided that it is eaten immediately rather than re-frozen. To this end, it is important that the time of and duration of any failure in the cooling system is known. If the duration is too long, the food must be wasted. If the instantaneous time of such a failure is too long ago, food again must be wasted.

Other uses of the display system of the present invention are in computer installations which require humidity and temperature to be monitored continuously so that, in the event of a failure of the computer installation, the time and duration of the failure may be known reasonably accurately. Also, grain and fruit and vegetable importers need to monitor the humidity and temperature of the products carried. Also, in many cases, the level of methane emission from a land fill site may need to be monitored so that, if the level exceeds predetermined limits, preventative action may be taken. Other uses include urban pollution monitoring and noise level monitoring in cities. If the pattern of pollution can be established using the display of the present invention, preventative action can be directed more accurately.

Other uses may be foreseen.

It is an object of the present invention to provide a display and system controlling such display which enables such abberrations from a predetermined norm to be monitored and logged.

According to the present invention, there is provided an elapsed event display comprising a plurality of indicators, respectively so disposed and configured that any one or more of them may indicate a time elapse since a zero time, sensor means to determine a condition which is desired to be monitored substantially continuously, means to determine when said sensed condition is outside predetermined limits and signal the existence of such an aberrant condition to an appropriate one or more of said indicators, depending on the time the condition occurred, said one or more indicators becoming and remaining in an indicative condition for a predetermined period after said signal or said zero time.

Preferably, each indicator is an L E D (light emitting diode). Alternatively, it may be a or part of a liquid crystal display (L C D).

The indicators may be arranged in a clock like array or in a digital type display so that indicators in an operative condition show the time at which or over which an aberrant condition occurred.

Preferably, the clocklike array will show any aberrant condition having occurred within twenty four hours of the zero time, but there may optionally be provided memory means to store the condition of the indicators for a time previous to that shown by the current array.

In this case, the system may further comprise means to recall and re-show on demand a previous array.

Further indicator means may be provided to indicate which previous arrays are stored.

Embodiments of the present invention will now be more particularly described by way of example and with reference to the accompanying drawings, in which: FIGURE 1 shows a clocklike L E D display; and FIGURE 2 shows a clocklike L C D display.

The present invention will be described by way of reference to a display for conditions relating to chilled food. However, as stated above, many other uses of the display system are envisaged and the present description is given only by way of example.

Chilled food must be stored at a temperature not less than -10C and not greater than 50C. If the temperature at which such food is stored goes outside these limits, the food may be unpalatable or even unhealthy if it is eaten at some later date. What is needed is to know firstly whether or not the temperature range has been breached.

If so, it is useful to know when such an aberrance occurred, and by how much, since in some cases, the error may be rectifiable.

To this end, there is provided, as shown in Figure 1 a clocklike display of forty eight L E D's arranged in a circle of perhaps six inches diameter such that each L E D indicates a time interval of thirty minutes. More or less L E D's may be provided.

A microprocessor is connected to a temperature sensor and if the temperature sensed by that sensor is without the limits over at least a major portion of that half hour of time, or whatever other period may be determined by the number of L E D's, an indication will be sent to the L E D indicating that period of time and this L E D will become illuminated and it will stay so until the display is wiped at the end of a cycle. The information which was displayed during that cycle may be recorded and may be recalled, thus enabling the "out of limit" value to be determined. There may be a number of L E D's, for example six, to show the conditions during the previous six cycles or days. There may also be provided a L C D or L E D display of the predetermined limits, (upper and lower temperature in this case) and means may be provided for re-setting these if that should be desired.

As shown in Figure 2, a similar type of display may be provided using L C D's but may be in a much smaller size, for example two inches square.

One use of the display embodying the present invention is on refrigerated vehicles to ensure that it is known when the goods are delivered that they are in a fit state for consumption, or if they are not, that they may still be sold within a predetermined time limit but with warnings attached. Government health inspectors may also refer to these displays to ensure that the transport is in accordance with regulations set by the appropriate authority.

In this case, there may additionally be provided some audio or visual alarm in the cab of a lorry carrying such goods to alert the driver to the fact that conditions in the storage compartment are not within the predetermined limits.

It is also possible to provide additional memory means capable of recording the acquired data for a period of several weeks, perhaps even eight weeks. This can be useful should any dispute arise following the sale of unfit goods, or goods which are alleged to be unfit.

The apparatus embodied by the invention may also be used in a fixed environment such as a chill cabinet or a supermarket freezer. The customer could be allowed to see the display and know therefrom that the food being purchased had not been stored outside the preset perimeters. Environmental health inspectors would also be able to check, at a glance, that the requisite conditions had been met.

One further use of the apparatus embodied by the present invention lies in the digital thermometer field. Such an apparatus would have the standard facilities of digital thermometers but would also be capable of recording temperatures and displaying the recordings.

Claims (1)

1. An elapsed event display comprising a plurality of indicators, respectively so disposed and configured that any one or more of them may indicate a time elapse since a zero time, sensor means to determine a condition which is desired to be monitored substantially continuously, means to determine when said sensed condition is outside predetermined limits and signal the existence of such an aberrant condition to an appropriate one or more of said indicators, depending on the time the condition occurred, said one or more indicators becoming and remaining in an indicative condition for a predetermined period after said signal or said zero time.

2. A display as claimed in claim 1, wherein each indicator is an L E D (light emitting diode).

3. A display as claimed in claim 1, wherein each indicator is a or a part of a liquid crystal display (L C D).

4. A display as claimed in any one of the preceding claims, wherein the indicators are arranged in a clocklike array or in a digital type display so that indicators in an operative condition show the time at which or over which an aberrant condition occurred.

5. A display as claimed in claim 4, wherein the clocklike array will show any aberrant condition having occurred within twenty four hours of the zero time.

6. A display as claimed in either claim 4 or claim 5, wherein there are provided memory means to store the condition of the indicators for a time previous to that shown by the current array.

further provided means to recall and re-show on demand a previous array.

8. A display as claimed in claim 7, wherein further indicator means are provided to indicate which previous arrays are stored.

9. An elapsed event display substantially as described herein with reference to the accompanying drawings.