Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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A vessel for preparation or roo~i ng of e.g. food-stuff and
beverage~ by heating, and an information carrier for use
with such vessel~
The present invention relates to a vessel,
particularly to a vessel having walls of a material which
permits heating of the content of the vesssel by
radiation, in particular micro-wave radiation.
Such vessels, and the term vessel is used here to
include also packages and containers of different kinds
which normally, at least partially, have walls of
material which depends on the actual kind of heating. If
the heating takes place by heat radiation of the type
infrared heat radiation from e.g. a cooking plate, the
material may be metal, at least in the bottom. If the
heating takes place by means of the nowadays very common
heating type using micro-vawes, then the material may be
cardboard or plastics or the like. Below, to facilitate,
such vessels, along with the instant content in each case,
will sometimes be referred to as "object".
Common to all types of heating is the problem of
accurately controlling the temperature, e.g. to prevent
that the temperature is insufficient for the application
in question or to prevent that the vessel as used bursts
up and starts leaking due to too a high internal pressure
within the vessel, which may happen if the temperature has
unintentionally become too high.
The object of the present invention has been to
provide a vessel wherein this problem has been remedied,
and, in accordance therewith to provide an information
carrier for use with such vessels.
According to the invention this object has been
achieved in that the vessel is provided with an
information carrier having one or more optically readable
control information fields which information carrier is
adapted to be used in order to indicate the temperature of
the object as the object is heated in an oven. Here, it
is conceivable, for instance, to watch visually how the
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information carrier shifts color as the desired
temperature has been reached, so that the heating
procedure may be stopped then.
However, the information carrier is preferably
adapted to cooperate with an optical reading device of the
oven and a control device to control the heating procedure
at least partially in dependence of the read temperature
- information.
According to the invention it is preferred that the
information carrier is arranged directly on the heating
object, e.g. as a disposable label or, alternatively, as a
device for repeated use, which device is applied on the
object, its vessel, package or contaner, e.g. as the
heating is performed.
According to the invention it is preferred that the
label or device comprises a field of temperature sensitive
color which exhibits a color shift at the desired end
temperature of the object, preferably the ready-
temperatureof a food-stuff or a beverage.
It is conceivable, according to the invention, that
the information carrier has the shape of a label or a
device for use in an oven having a lighting within the
- oven cavity, in which case the information carrier
preferably is characterized in that the field with
temperature sensitive color is composed of two layers,
viz. an uppermost layer, which shifts from transparent
into non-transparent, or vice versa, at a color shift, and
a lowermost layer, which exhibits fluorescense at
activation by the oven cavity lighting.
Prior to describing the invention in more details
with reference to the figures in the drawin it might be
worthwhile to make some general remarks with respect to
the invention, viz. that the invention generally is based
on the concept that it is possible to utilize o-ptical
reading for the provision of a control system for an oven,
which is partially associated with the oven itself, and
the technical establishment thereof, and which is
438~
partially associated with the object or the food-stuff
which should be subjected to heating/preparation,and,
further, the realization that such a system, particularly
the case with feed-back control, which in known ovens is
solely associated with the technical establishment of the
oven, may achieve considerable simplifications in the
design of the control system of the oven and the general
operation of the oven, and that this may be achieved while
utilizing cost efficient technical solutions that are
known per se by those skilled in the art. There exists no
principal limit for how much control information may be
taken from the information carrier. Just as well as the
information carrier may hold information for choice of a
pre-set program with the control unit of the oven, the
information carrier itself may comprise the control
program, which is then read into the control unit at the
actual use. In the present case the term optical reading
is used, e.g. reading while using light vawelengts within
the optical range, but also other vawelengths may be
possible. Thus, the information carrier may comprise
fields with chrystalline or similar substances which at
activation by scanning radiation my be cauesd to emit
their information by discree vawelengths or within defined
vawelength-rangesa. A feedback control may be achieved in
that these substances are adapted to emit radiation of a
temperature dependent vawelength.
According to a further development of the invention
the vessel may be provided with a further characterizing
feature in the shape of an additional, temperature non-
sensitive color marking which is disposed in such a mannerthat it can be detected by a further detecting device,
adapted to control the start of the heating procedure.
Only vessels having a marking that controls the stop of
the heating are provided with the additional color
marking, which results in that if a vessel that lacks both
kinds of markings is inserted into e.g. a microvawe oven
having an indicator for stopping of the heating then no
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heating can be started. In this way it is prevented that a
heating is started that cannot be automatically in-
terrupted at the desired temperature.
The temperature sensitive color can be applied by
painting or by printing the color directly on at least one
of the valls of the vessel. As the temperature sensitive
color may contain liquid chrystals and may be difficult to
apply by printing procedures it may be advantageous to
have to color applied to a base having a self-adhering
glue on one side thereof, by means of which the color
marking may be affixed to at least one of the walls of the
vessel. If the vessel has a plastic covered surface then
the marking may be detached after use in to be used
repeatedly. Such color markings, having different
temperature definitions, may be stored on a storage sheet
and may be moved to and from a vessel as desired.
Tests have verified that the temperature of the
content of the vessel is only slightly higher than the
temperature of the outer surface of the vessel. Only at
temperature higher than about 65 C and up to 95 C will
the temperature of the surface be about 5 C lower. It is
possible to compensate for this by the manufacture of the
colormarkings, e.g. by disposing the color markings
interiorly of a vessel made wholly or partly of a
transparent material, so that the color marking is visible
from the outer side.
The invention is disclosed in more details below with
reference had to the accompanying drawings which
schematically show various exaples of vessels according to
the invention and wherein figure 1 is a perspective view
of a vessel according to a first embodiment, used as an
example, figure 2 is a side elevation of a vessel
according to a second example, disposed in a micro-vawe
oven, figure 3 is a side elevation of a vessel according
to a third embodiment disposed on a heating plate, figure
4 is a perspective view of a vessel acording to a further
embodiment, and figure 5 is view of a chart of color mar-
- 4 -
2154384
kings and a partial view of a vessel having a marking for
disposition of color marks.
Figure 1 shows a container or vessel of conventional
type, containing water and a capsule with instant coffee
powder (not shown). The content of the capsule should be
heated up to 93 C in order for the capsule to open, and,
thus, in order for the coffee so produced to have the
correct serving temperature. Therefore, the container is
provided with a temperature sensitive color marking 2
which shifts color at a temperature of the outer surface
of the vessel that corresponds to a temperature of 93 C of
the coffee within the vessel with a ordinary performed
cooking, which has to be determined from case to case. On
an adjacent side the container is provided with another
temperature-sensitive color marking 3 which shifts its
color at a temperature of 80 C of the content of the
container. Further, the continer 1 is provided with a
color mark 4 which denotes that the container is intended
to be used for heating in a micro-vawe oven having
automatic means for control of the heating up to the
desired temperature.
Such an oven 5 is shown schematically in figure 2. A
container 1 of the kind as shown in figure 1, although
made from a transparent material and having a color
marking 9 disposed internally of the container, is placed
in the oven in a guide 6 for the lowermost part of the
container with the color marking 2 facing a sensing
device 7. Simultaneously, the color mark 4 is positioned
opposite a second sensing device 8. When the oven is
switched on the sensing device 8 senses the existence of
the color mark 4 nd activates a relay or the like so that
the oven starts the heating. Within a few minutes the
content of the container has reached the desired 93 and
the color mark 2 shifts color which is sensed by the
sensing device 7 which interrupts the heating through a
relay or the like (not shown). In case a heating to only
80 C had been desired then the container should have been
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placed in the oven with the color mark 3 facing the
sensing device 7.
The design of the oven 5 and of the devices 7 and 8
do not form a part of the invention, and therefore they
are not described in more details here.
Sometimes, particularly with containers that may be
opened and resealed, it is desirable to determine the
heating temperature from case to case. It is then possible
to use self-adhering color markings that are applied to
the container in question. Such color markings on a
carrier 21 of self-adhering plastics are shown in figure 5
and are denoted 22, 23 and 24 for the temperatures 60 C,
80 C and 93 C, respectively, and are affixed to a chart
25. To facilitate detaching the carriers 21 are provided
with a flap, that is non-adhering and on which the
temperature values are preferably printed. One such color
marking is adapted to be affixed to a container which is
provided with a an indication 30 where the color marks 22,
23 och 24 are to be placed in order to get a correct
position within the micro-vawe oven. If desired,the color
markings may be detached from the container 1 after use,
and again affixed to the chart 25 for repeated use a
number of times.
