EP2195801A2

EP2195801A2 - Identification and recordal apparatus, and label therefor

Info

Publication number: EP2195801A2
Application number: EP08788552A
Authority: EP
Inventors: Andrew Pollard; Iain Michael Todd; Geoffrey Philip Archer; Gregory James Vincent Powell
Original assignee: Unibyte Ltd
Current assignee: Unibyte Ltd
Priority date: 2007-09-08
Filing date: 2008-09-08
Publication date: 2010-06-16
Also published as: GB0717502D0; WO2009030930A3; WO2009030930A2

Abstract

This invention relates to an identification and recordal apparatus, and in particular to an apparatus which allows the identification of products and the recordal of the expiry or use-by dates of those products. The apparatus comprises a set of labels, each label (10) having a unique machine-readable code (20), and a reader adapted to read the machine-readable code whereby each label can be distinguished from the other labels in the set by the reader, the reader having a memory to store the identity of the label and data associated with the label, each label having a detection zone, the detection zone (18) a pattern of having non-uniform conductivity to a chosen medium such as electricity or electromagnetic radiation whereby the pattern of non-uniform conductivity is detectable to the reader as the machine-readable code. There is also provided a label for use with the apparatus.

Description

IDENTIFICATION AND RECORDAL APPARATUS, AND LABEL THEREFOR

FIELD OF THE INVENTION

This invention relates to an identification and recordal apparatus, and to a label therefor, and in particular to an apparatus and label which allow the identification of products and the recordal of the expiry or use-by dates of those products.

BACKGROUND OF THE INVENTION

Many items which are used domestically and commercially are intended to be used within a certain period of time, i.e. they have a limited shelf life. The shelf life may be determined by the date of supply, for example certain foodstuffs should be consumed within a predetermined period after production or packaging. Alternatively, the shelf life may be determined by opening of the package, for example certain products have a relatively long shelf life until the package is opened, but must be used or consumed within a predetermined period after the package is opened.

Most foodstuffs have a limited shelf life, and much of the following description will relate to such use, but the invention is not limited to foodstuffs, and industrial products such as adhesives and other chemicals have limited shelf lives, some determined by the date of production or packaging, others by the date of opening the package. Also, some medicines, and medical samples, have a limited shelf life.

Products which are packaged and which have a limited shelf life will normally carry aJabel or other marker which indicates to the user the date by which the product must be used, or alternatively (or additionally) the period for which the product can be safely kept after the packaging is opened. To increase the shelf life of certain products it is known to use a refrigerator or freezer, and many items are stored for relatively long periods of time in a freezer. The freezer may be a domestic or commercial freezer which cools products to a few degrees below 0 ⁰C, or it may be a medical or industrial freezer using liquid nitrogen as a refrigerant.

However, whilst a freezer or the like can extend the shelf life of a product it typically cannot extend that shelf life indefinitely, and it is still necessary to use the products by a certain date. A difficulty arises in that the shelf life for products which are stored by the user will often be known only to the user, for example a product manufacturer may determine that a particular product can be safely frozen for a period of three months, but it is often only the consumer who knows when the product was frozen, and therefore when the three-month period will end. Also, only the user will know the use-by date of a product for which the shelf life is determined by the date of opening of the packaging.

As above indicated, many products (or their packaging) carry information concerning the shelf life of the product, and many products also carry a bar code with information about the product. Whilst it would be possible to adapt the bar code to include the shelf life information, that would not enable a user to determine the use-by date for a product once opened, nor necessarily to be able to distinguish between two similar products which were purchased at different times and therefore have different use-by dates.

DESCRIPTION OF THE PRIOR ART

In order to alleviate this problem, it is known to apply labels to products in a freezer to indicate the use-by date. Also, manufacturers have developed re- usable containers (typically of plastic) which can be marked up with the use-by date. One such container has all the months of the year embossed onto a strip and the numbers "1" to "31" embossed onto another strip, with respective sliders which can be moved relative to the strips to define a day and month, so that the user can readily mark the container with the use-by date for the product which is stored in the container.

However, the known systems suffer disadvantages which limit their utility. Labels which are tied to a package can become dislodged in the freezer, particularly as adjacent packages and containers are moved. Also, the sliders of the known container can be moved inadvertently as the container is pushed against other articles in storage, so that the recorded date no longer matches the use-by date.

The use of these known methods and devices also require considerable diligence on the part of the user.

In addition, it is necessary for the user to open the storage area (e.g. the freezer) and inspect the labels periodically in order to ensure that products are used by their respective use-by dates. It is understood that only the most diligent of householders will undertake regular inspections of their freezer for example. In order to inspect the labels or the recorded dates the user must normally move the containers and packages within the storage area, increasing the likelihood of a label becoming dislodged or a slider being moved inadvertently.

Furthermore, opening a freezer door in order to undergo regular inspections of the contents causes a rise in temperature in the freezer, which both increases the usage of energy and can reduce the shelf-life of products stored therein.

Whilst the problems identified in the preceding paragraph apply mostly to products stored within freezers, they also apply to other chilled cabinets or refrigerators.

Many products which are stored at room temperature also have a shelf-life and require regular inspection if they are not to pass their use-by date, and certain of the previously-described problems relate also to these products.

Another known prior device is that sold under the trade name "Timestrip" by Timestrip PIc, of Gregans House, 34 Bedford Road, Hitchin, SG5 1 HP, England. This device is in the form of a label which can be attached to a product to be stored. The label is activated by the user and thereafter provides an indication of the period since activation, so that the device allows the user to monitor the period of time for which the product has been stored. The labels are not reusable, and the indication is temperature dependent, so that a different label is required for storage at room temperature, in a refrigerator, and in a freezer, for example. Also, the user still needs to undertake regular inspections of the storage area to check the indication provided by the device(s) therein.

Our European patent application 1 792 237 discloses an apparatus for storing use-by data, the apparatus comprising a set of labels which can be applied to chosen items, each label having a unique identifier which can be recognised by a reader, the reader storing the use-by date information for the item and the unique identifier, and thereby being able to alert the user that the item is approaching or has passed its use-by date.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an apparatus which facilitates the machine-reading of labels.

According to the invention there is provided an identification and recordal apparatus comprising: a set of labels, each label in the set being adapted for use with an item, each label having a unique machine-readable code, and a reader adapted to read the machine-readable code whereby each label can be distinguished from the other labels in the set by the reader, the reader having a memory to store the identity of the label and data associated with the label, each label having a detection zone, the detection zone having non-uniform conductivity to a chosen medium whereby the pattern of non-uniform conductivity is detectable to the reader as the machine-readable code. The chosen medium can be electricity, in which case the detection zone can have a pattern of electrically-conductive ink. Alternatively the chosen medium can be visible light in which case the detection zone can have a pattern of holes through which the light can pass within a generally opaque body. Alternatively again the chosen medium can be electromagnetic radiation from the visible or non-visible part of the spectrum, and the detection zone can have regions which conduct the radiation and regions which do not conduct the radiation (or regions which conduct better than others).

In the embodiments utilising electromagnetic radiation, it will be understood that the general term "conduct" (and derivatives thereof) embraces the more commonly used term "transmit" (and derivatives).

The label can initially be separate from the item and designed for attachment to the item by the user, or it can be an integral part of the item, for example being printed directly onto the item. The item may be a product itself, or the package or container in which a product is stored.

Preferably, the reader has a timer whereby time periods associated with the item can be monitored.

Preferably, the reader also has a data-entry element whereby the user can enter data associated with the label and/or the package. The data-entry element can be a keyboard so that the user can enter the desired data such as the identification of an article and/or its location. In a preferred embodiment the reader has a visual display unit and is adapted to ask a series of questions by way of the VDU; the data-entry element of such an embodiment can be simplified in line with the simplified inputs required. In another embodiment the data-entry element includes a microphone by which the reader can store data in the form of an audio file which can be replayed when the label is subsequently read.

Desirably, the reader has a processor whereby data related to the item can be processed or modified. The data can for example be a use-by date. Preferably, the label also carries a visual code and the reader has a record of the visual code and the machine-readable code for each label.

In embodiments in which the labels are initially separate from the item, the labels may be self-adhesive, and preferably reusable, or they may be formed as reusable clips which can be temporarily secured to the item.

Preferably, the reader includes a display which can carry information for the benefit of the user. Such information will typically include the data which is being entered (so that the user is aware that the correct data has been entered), and also alerts the user to the labels which are carried by or affixed to items approaching their use-by date. The reader can have an alarm, and can be configured to issue an alarm signal at a predetermined time before a use-by date, thereby alerting the user that a use-by date is approaching and advising the user of the label in question. Since the reader can display the visual code of the label in question the user can quickly identify the label and therefore the item.

The visual code is preferably a colour and/or letter and/or number combination.

The number of labels in a set can be relatively small, and therefore the number of visual and machine-readable codes can be similarly small. Thus, it is recognised that the visual code and machine-readable code only need to be unique within the set of labels and the apparatus sold to one user can be identical to that sold to another user.

In embodiments using electricity as the chosen medium the apparatus relies upon contact between the reader and the detection zone in order that the reader can determine the machine-readable code. It is relatively easy to ensure that the correct contact has been made. Embodiments using electromagnetic radiation as the chosen medium, however, do not necessarily require the reader to contact the detection zone. In embodiments utilising electrically-conductive ink to form the machine-readable code, the label carries a chosen number of terminals and a chosen number of sensor contacts, with each sensor contact connected to one or other of the terminals by way of a conductive (or resistive) track. In the simplest embodiments the label has two terminals and the conductive tracks all have the same conductivity, so that there are two states for each sensor contact, i.e. connected to the first terminal or connected to the second terminal. The maximum number of unique labels in such a set is therefore 2", where n is the number of sensor contacts. In a more complex arrangement the conductive track can have a first known conductivity (or resistivity) or a second known conductivity (or resistivity), so that for a label with two terminals each sensor contact can be in one of four states, namely {i} connected to the first terminal by a low conductivity track, {ii} connected to the first terminal by a high conductivity track, {Hi} connected to the second terminal by a low conductivity track, and {iv} connected to the second terminal by a high conductivity track. The maximum number of unique labels in such a set is therefore 4", where n is the number of sensor contacts.

Preferably, in such embodiments the reader has a reader head carrying electrically-conductive pins configured to match the arrangement of terminals and sensor contacts on the label. Ideally, the pin which is to be connected to the first terminal is connected to an electrical voltage different to the pin which is to be connected to the second terminal. The reader is configured to measure the voltage at each of the sensor contacts and can thereby determine whether each sensor contact is connected to the first terminal or to the second terminal, and also the conductivity of the connection therebetween.

Preferably, the label and the reader head have location means, desirably in the form of complementary formations to ensure that the reader head is correctly applied to the label. Thus, even in contact-less embodiments it will be preferable to ensure that the reader and label are correctly positioned relative to one another for the machine-readable code to be correctly read. Ideally, the label has a recess and the reader head carries a projection which can fit snugly into the recess.

In embodiments relying upon contact between the reader and the detection zone, the label preferably has additional points of reference, and the reader head has corresponding additional pins, defining control contacts which are effective to ensure that correct electrical contact has been made between the reader head and the label, and that the label has not become damaged.

For labels encoded by use of a detection zone having areas with varying conductivity (transparency) to electromagnetic radiation, the variation of conductivity may for example be achieved by providing a detection zone which is generally opaque to the electromagnetic radiation in the applicable part of the spectrum, and creating a pattern of physical holes in the detection zone, the reader being able to read the pattern of holes by detecting the positions at which the radiation passes through the detection zone.

Alternatively, the detection zone can be generally transparent to the electromagnetic radiation in the applicable part of the spectrum, and the machine- readable code created by regions which block the transmission of the radiation, the reader being able to read the pattern of blocking regions by detecting the positions at which the radiation does not pass through the detection zone.

It can be convenient to mould a pattern of dimpled hollows in a generally transparent detection zone, and selectively print the hollows with an opaque ink to create the machine-readable code.

In each case when using electromagnetic radiation as the chosen medium, the labels are preferably inserted into an apparatus arranged with an electromagnetic radiation source or sources to one side of the label and electromagnetic radiation sensitive receptors to the other side. When the label is inserted and registered in the correct position, the source or sources are activated and the response at each receptor is measured. If there are six receptors each with two possible states then there may be 2⁶ combinations providing 64 distinct label identities.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention will now be described in more detail, by way of example, with reference to the accompanying schematic drawings, in which:

Fig.1 shows a label of an apparatus according to a first embodiment of the invention;

Fig.2 shows a view of the reader of the apparatus of Fig.1 ;

Fig.3 shows a detailed view of the reader head of the reader of Fig.2;

Fig.4 shows a view of a reader and inserted label of an apparatus according to a second embodiment of the invention; and

Fig.5 shows a view of a label of the apparatus of Fig.4.

DETAILED DESCRIPTION

The apparatus of the first embodiment of the invention comprises a set of labels (of which one label 10 is shown in Fig.1) and a reader 12 as shown in Fig.2.

The label 10 has two zones, a first zone 14 bearing a visual code 16 and a second detection zone 18 bearing a machine-readable code 20. In this embodiment the label 10 is self-adhesive whereby it may be temporarily affixed to a container or package for a product which is to be stored, or to the product itself, as applicable. The adhesive used is preferably sufficiently secure to retain the label in place for perhaps an extended period of time at the storage temperature, and to permit removal (and re-use) of the label when the product has been used. In addition, the label is preferably somewhat flexible so that it can conform to a curved surface if required. Furthermore, the label should be susceptible to cleaning without the adhesion being impaired.

A suitable material for the label is available from Nova of 73470 Novalaise, France (www.novasmic.com), and is made for computer mouse mats. The material has an adhesive applied thereto which is sufficiently secure for use with the present invention, and yet removable and reusable.

The visual code 16 comprises a two-letter combination. In other embodiments the visual code includes a colour code to make the label more easily identifiable to the user, and in yet other embodiments the visual code comprises numbers or number and letter combinations.

In this embodiment the chosen medium is electricity, and the machine-readable code 20 comprises a pattern of electrical contacts connected by conductive tracks. The electrical contacts comprise a first terminal 22 and a second terminal 24, which are electrically disconnected. The first terminal 22 is connected to a circular conductive bus 26 which surrounds the sensor contacts 30, 32, 34 36 and 38. The contact 40 is a control contact and is connected to the bus 26.

The visual code 16 and the machine-readable code 20 are both printed onto the label 10. As regards the machine-readable code 20, a conductive ink is used whereby electrical contact can be made between respective terminals and the sensor contacts. In this embodiment two different conductive inks are used so that more combinations are available from the four sensor contacts.

It will be recognised that if only one type of conductive ink were used then each sensor contact could have two possible states, i.e. it could be connected to the terminal 22 or to the terminal 24, giving only thirty two possible combinations (2⁵), whereas the use of two different conductive inks gives each sensor contact four possible states as above described, and gives one thousand and twenty four combinations (4⁵).

In the embodiment shown the number of possible combinations is limited by the visual code 16, there being six hundred and seventy six two-letter combinations, although the number of combinations for the visual code can be increased by adding a third letter, or using numbers and/or symbols as well as letters.

(It is recognised that each sensor contact could have an additional state of not being connected to either terminal, and perhaps the additional state of being connected to both terminals, but such arrangements are not preferred as the detection of a sensor contact which is not connected to either terminal could not be distinguished from a failed test in which the reader head did not engage that sensor contact, and the interconnection of both terminals upon the label would add considerable complexity to the determination of the code by the reader.)

If more or fewer combinations are required in a particular application the number of sensor contacts (and the number of different conductive inks) can be increased or decreased accordingly.

In one method of applying the conductive ink, a first layer of ink is applied, defining the terminals 22, 24, the bus 26, the sensor contacts 30-38, and the control contacts 40, together with the connections between the respective terminals and the chosen sensor contacts, and a second layer of ink is applied over the first layer of ink to increase the conductivity (or reduce the resistivity) of the bus, the terminals and contacts, and the chosen connections between the respective terminals and sensor contacts. In this way, certain connections between the respective terminals and the chosen sensor contacts can be of low conductivity whilst others are of high conductivity.

Alternatively, the label can be printed with two different types of ink, having different conductivity. Suitable conductive inks are available for example from {i} Creative Materials of Tyngsboro, MA, USA, with a more conductive ink being sold under the trade number 101-42 and a less conductive ink being sold under the trade number 104-18, and {ii} Sun Chemicals, of Bath UK, with a more conductive ink being sold under the trade number 26-8204 and a less conductive ink being sold under the trade number 26-8203.

In Fig.1, the sensor contact 30 is connected to the bus 26 (and thereby to the terminal 22) by way of a high-conductivity connection (shown as a double line), the sensor contact 32 is connected to the terminal 24 by way of a low-conductivity connection (shown as a single line), the sensor contact 34 is connected to the bus 26 by way of a high-conductivity connection, the sensor contact 36 is connected to the terminal 24 by way of a high-conductivity connection, and the sensor contact 38 is connected to the bus 26 (and thereby to the terminal 22) by way of a low-conductivity connection.

It will be noted that the control contact 40 is also connected to the bus 26 (and thereby to the terminal 22) by way of respective high-conductivity connection, and it is arranged that the control contact 40 for all of the labels of the apparatus are similarly connected. If the reader device is not able to confirm the connection between the terminal 22 and the control contact 40 this will indicate that the label is damaged (e.g. there is a break in the bus 26 or in a contact's connection), or the reader has not been correctly applied. The provision of a control contact therefore provides one method of checking that the determination of the code of the label is valid. Also, a break in the connection to a respective contact 30-38 will result in the contact becoming open circuit instead of at one of the defined voltages; the reader can be adapted to detect open circuit contacts as an additional check.

In addition, the conductivity of the ink defining the bus 26 can be made greater than that of the ink connecting the contacts to the bus 26 or to the terminal 24, so that the conductivity of the bus 26 has an insignificant effect upon the measured conductivity for a given contact, and the relative distance between a contact and the terminal 22 can be ignored. The reader device 12 shown schematically in Fig.2 comprises a housing 42 containing the control electronics, battery etc. One end of the housing 42 is formed into a reader head 44 (see also Fig.3) adapted to engage the machine- readable portion 18 of the label 10.

The housing 42 carries a keyboard 46 and a display 50 (although a single touchscreen can replace these components if desired). The keyboard 46 preferably has "soft keys", i.e. a small number of (e.g. three) keys whose function depends upon what is shown on the display 50. Alternatively, the keyboard can be alphanumeric in which case the user can enter data in the form of letters and numbers, or can be numeric only in which case the user can enter numbers only.

The control means of the reader device (not shown) can have a record of commands for the user, and can display those commands on the display 50. The commands can for example be: "apply reader head to label" (after which the reader device determines that the reader head 44 is engaging the label by detecting the electrical connection between the control contacts 40 and the terminal 22, and thereafter identifies the label by way of the machine-readable code 20), followed by "insert use-by date" (after which the user enters the date by which the product to which the label is applied (or is to be applied) must be used - or at least should be removed from storage). The reader device 12 can undergo a check by displaying the visual code of the label, e.g. it can display "confirm label AV", asking the user to confirm the identity of the label before the use-by date is inserted.

The reader head 44 adapted for use with the label 10 is shown in Fig.3. The reader head comprises eight electrically conductive pins arranged in the same pattern as the terminals and contacts of the label 10.

The pin 52 is positioned to engage the terminal 22, the pin 54 is positioned to engage the terminal 24, the pins 56, 58, 60, 62 and 64 are positioned to engage the respective sensor contacts 30-38, and the pin 66 is positioned to engage the respective control contact 40. The pin 54 is connected to a source of electricity providing 5 V DC, and the pin 52 is connected to ground. The conductivity (or resistivity) of the low-conductivity connections and the high-conductivity connections is known, so that by determining the voltage detected by each of the sensor pins 56-62 the reader device 12 can determine which of the sensor contacts 30-38 is connected to the terminal 22 and which is connected to the terminal 24, and whether each of those connections is of low-conductivity or high- conductivity. The reader device 12 can thereby determine the machine-readable code 20 applied to the label 10, and since that code is unique to the label for each set of labels, the reader device can thereby identify the label.

In order to ensure that the reader head 44 is oriented correctly relative to the label 10, a mechanical coupling is provided in the form of a projection 68 upon the reader head 42 which fits snugly into a recess 70 in the label 10. In an alternative embodiment the reader head is adapted to engage part or all of the periphery of the label. The reader device 12 can be configured to emit an audible signal when it has been correctly applied and the respective electrical conductivities determined.

In the apparatus according to the second embodiment as shown in Figs. 4 and 5 the chosen medium is electromagnetic radiation. The reader device 112 is able to detect a pattern of varying conductivity (transmissivity) to a chosen part of the spectrum of electromagnetic radiation.

As with the reader device 12 in the embodiment of Fig. 1-3, the reader device 112 shown in Fig.4 comprises a housing 142 containing the control electronics, battery etc. The housing 142 has an opening 70 into which the label 110 can be inserted, as shown.

The housing 142 carries a set of soft keys 146 and a display 150 (although a single touch-screen can replace these components if desired). It will be understood that the function of the reader device 112 can be substantially similar to that of the reader device 12, so that repetition of those functions is not required. The label 110 is shown in Fig.5, and in this embodiment comprises a label similar to that provided by Linden International AB of Sweden (www.lindenint.se) and sold under the trade mark "Twixit". The label 110 comprises a body portion 72 and a clip portion 74, joined by a hinge 76, it being possible to pivot the clip portion 74 relative to the body portion 72 so as to secure a part of an item (typically a plastics bag) between the body portion 72 and the clip portion 74, and thereby secure the label 110 to the item.

According to the invention, part of the body portion 72 comprises a detection zone 118 which in this embodiment is made of a material which is generally totally or substantially opaque to visible light. In the label 110 shown in Fig.5 six holes 80,

82, 84, 86, 88 and 90 are formed through the body portion. It will be understood that when the label 110 is inserted into the reader 112, one or more sources of visible light placed to one side of the detection zone 118 will be detectable by optical sensors to the other side of the detection zone, it being possible to determine that the label 110 has six holes 80-90.

Other labels in a set of labels for a particular apparatus can omit one or more of the holes 80-90, so that the label having six holes 80-90 is unique in the set of labels. The reader device 112 can have an optical sensor aligned with each of the holes 80-90, so that when a particular label 110 is inserted into the reader device 112 the reader device can determine the presence or absence of a hole 80-90 and thereby read the pattern of holes. A detection zone 118 having provision for six holes, each of which may be present or absent, results in a set of labels having sixty four (2⁶) possible combinations.

Clearly, the holes do not need to be formed in a single row, and there can be more or fewer hole positions, as desired.

In alternative embodiments, the detection zone 118 can be made of a material which is substantially transparent to a particular part of the spectrum of electromagnetic radiation, for example transparent to infrared radiation. The holes 80-90 can be replaced by areas to which an ink or other material is applied, which material is substantially opaque to infrared radiation.

Normally, each label 110 would also be provided with a visual code, suitably carried by the part 114 of the body 72, the visual code being unique to a particular label within the set of labels and stored in the memory of the reader device.

In order to ensure that the detection zone 118 of the label 110 is oriented correctly relative to the optical sensor(s) of the reader 112, the label 110 is a relatively tight fit into the opening 70, and must be pushed in to engage a positive stop. The reader device 112 can incorporate means to determine that the label 110 has been inserted correctly.

The reader device 12, 112 has a memory in which it retains a record of the use-by dates and compares them with the timer or calendar which is also stored in its memory. The reader device can be configured to alert the user (preferably by way of an audible alarm) a predetermined period of time before a given use-by date. The user can determine the period of time at the same time as entering the use-by date. The user can be alerted by an audible alarm, and/or by the reader displaying the visual code of the label concerned.

In commercial or industrial applications where a product may be stored in a number of different storage areas, the reader device 12, 112 can be configured also to permit the user to enter data corresponding to the name or identity of the location, so that the user is directed to the particular location where the labelled product has been stored. Alternatively or additionally, the labels can include a colour as part of the visual code, and can be grouped into separate colours, with each colour being used for a particular storage area, so that the user is alerted to the approaching use-by date by the display showing "blue label AV" or the like, and recognising that blue labels are used in the freezer and the label bearing the visual code "AV" can be located therein. It is envisaged that the reader device 12, 112 has a battery, preferably a rechargeable battery, and can be stored in a docking station (not shown) which includes a recharger. In this way, it can be better ensured that the reader device 12, 112 will not fail to issue the appropriate alert to the user, and will not lose the recoded calendar or other data, because of battery failure.

Claims

1. An identification and recordal apparatus comprising: a set of labels, each label having a unique machine-readable code, and a reader adapted to read the machine-readable code whereby each label can be distinguished from the other labels in the set by the reader, the reader having a memory to store the identity of the label and data associated with the label, each label having a detection zone, the detection zone having non-uniform conductivity to a chosen medium whereby the pattern of non-uniform conductivity is detectable to the reader as the machine-readable code.

2. An identification and recordal apparatus according to Claim 1 in which the reader has a timer whereby time periods can be monitored.

3. An identification and recordal apparatus according to Claim 1 in which the reader also has a data-entry element whereby the user can enter data into the reader.

4. An identification and recordal apparatus according to Claim 1 in which each label also carries a visual code and the reader has a record of the visual code and the machine-readable code for each label in the set.

5. An identification and recordal apparatus according to Claim 4 in which the visual code is a colour and/or letter and/or number combination.

6. An identification and recordal apparatus according to Claim 1 in which the chosen medium is electricity, in which each label in the set has at least one electrically conductive pathway formed thereupon, and in which the reader has a reader head carrying electrical contacts configured to match the electrically conductive pathway(s) on each label in the set.

7. An Identification and recordal apparatus according to Claim 6 in which the electrically conductive pathways comprise a number of terminals and a number of sensor contacts.

8. An identification and recordal apparatus according to Claim 7 in which separate electrical contacts of the reader head are configured to be engageable with each of the terminal and sensor contacts.

9. An identification and recordal apparatus according to Claim 8 in which there are two terminals, and in which the electrical contact which is engageable with one of the two terminals is connected to a first electrical voltage and the electrical contact which is engageable with the other of the two terminals is connected to a second electrical voltage, the second electrical voltage being different to the first electrical voltage.

10. An identification and recordal apparatus according to Claim 6 in which the label has at least one control contact which can be used to ensure that correct electrical contact has been made between the reader and the label.

11. An identification and recordal apparatus according to Claim 1 in which the label and the reader head have complementary location means.

12. A label for use in an identification and recordal apparatus, the label having a chosen machine-readable code comprising a pattern of non-uniform conductivity to a chosen medium.