U.S. patent number RE36,724 [Application Number 09/074,141] was granted by the patent office on 2000-06-06 for visible light and infra-red cooking apparatus.
This patent grant is currently assigned to Quadlux, Inc.. Invention is credited to Robert I. Beaver, II, Eugene R. Westerberg.
United States Patent |
RE36,724 |
Westerberg , et al. |
June 6, 2000 |
Visible light and infra-red cooking apparatus
Abstract
An oven using one or more quartz tungsten light bulbs capable of
producing 1.5 kW of radiant energy of which a significant portion
is light energy in the 0.4 to 0.7 .mu.m wavelength range impinges
high intensity visible light wave radiation directly onto a food
item. Light sources can be positioned above and below the food item
and the inner walls of the oven are preferably highly reflective to
reflect light energy onto the food. The intensity of the visible
light source is automatically controllable and can be varied
throughout the cooking cycle.
Inventors: |
Westerberg; Eugene R. (Palo
Alto, CA), Beaver, II; Robert I. (Atherton, CA) |
Assignee: |
Quadlux, Inc. (Fremont,
CA)
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Family
ID: |
22723579 |
Appl.
No.: |
09/074,141 |
Filed: |
May 7, 1998 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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334697 |
Nov 7, 1994 |
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664494 |
Mar 5, 1991 |
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195967 |
May 19, 1988 |
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Reissue of: |
481153 |
Jun 7, 1995 |
05517005 |
May 14, 1996 |
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Current U.S.
Class: |
219/685; 219/405;
392/416; 392/433; 219/464.1; 219/462.1; 99/451; 219/719;
392/418 |
Current CPC
Class: |
A47J
37/0635 (20130101); F24C 7/06 (20130101); F24C
7/087 (20130101); A47J 36/32 (20130101); G05D
1/0816 (20130101); H05B 3/0076 (20130101); G01L
1/144 (20130101) |
Current International
Class: |
H05B
3/68 (20060101); H05B 6/80 (20060101); H05B
006/80 (); H05B 003/68 () |
Field of
Search: |
;219/685,718,719,405,458,461,464,339,342,352,354,461.1,462.1,464.1
;392/416,417,418,422,434 ;99/DIG.14,451,325 |
References Cited
[Referenced By]
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May 1994 |
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WO |
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Other References
Fostoria Corporation, "Heat Processing with Infrared", Feb. 1962,
pp 1-7. .
Summer, W. Dr., "Ultra-Violet and Infra-Red Engineering" 1962, pp
102-112. .
Beggs, E. W., "Quicker Drying with Lamps", Jul. 1939, vol. 97, No.
7, pp 88-89. .
Harold McGee, Book, "On Food and Cooling", Chapter 14, pp.
608-624..
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Primary Examiner: Leung; Philip H.
Attorney, Agent or Firm: Limbach & Limbach LLP
Parent Case Text
This is a continuation of application Ser. No. 08/334,697 filed on
Nov. 7, 1994, now abandoned, which was a continuation of Ser. No.
07/664,494, filed on Mar. 5, 1991, now abandoned, which was a
continuation of Ser. No. 07/195,967 filed on May 19, 1988, now
abandoned.
Claims
What is claimed is:
1. An oven for cooking and baking food comprising:
a. a cooking chamber having highly reflective and poorly absorptive
inner wall for reflecting radiant energy to a food position
centrally thereof;
b. a plurality of means for generating radiant energy having a
significant portion of energy in the visible light range of the
electromagnetic spectrum, said means for generating positioned
inside said cooking chamber and including at least one source
positioned above and at least one source positioned below said food
position for impinging at least a portion of said radiant energy
directly from said radiant energy generating means on said food and
reflecting from said inner wall radiant energy not impinging
directly on said food for impinging reflected radiant energy from
said radiant energy generating means to said food many times from
many angles; and
c. a support member which is transparent to said radiant energy for
supporting the food at said food position while cooking.
2. The oven according to claim 1 further comprising means for
differentially controlling each of said plurality of sources by
time and by intensity.
3. The oven according to claim 1 further comprising a microwave
radiation source.
4. The oven according to claim 1 further comprising a convection
oven cooking apparatus.
5. The oven according to claim 4 further comprising a microwave
radiation source.
6. The oven according to claim 1 wherein said means for generating
radiant energy comprises quartz body tungsten lamps.
7. The oven according to claim 6 further comprising a plurality of
radiant energy transparent plates positioned in said chamber
between said food position and said lamps.
8. An oven for cooking and baking food comprising:
a. a cooking chamber having reflective inner walls for reflecting
radiant energy to a food position centrally thereof;
b. five 1.5 KW quartz-halogen lamps positioned inside said cooking
chamber above said food position and five 1.5 KW quartz-halogen
lamps positioned inside said cooking chamber below said food
position generating at least 6 KW of radiant power with a
significant portion of radiant energy in the visible light range of
the electromagnetic spectrum, said lamps positioned in said chamber
for impinging direct and reflected radiant energy on said food;
and
c. a support member which is transparent to said radiant energy for
holding the food at said food position while cooking.
9. A pizza oven for cooking and baking a raw pizza pie and forming
a cooked pizza therefrom, said pizza having a crust formed of dough
and toppings formed of any variety of foodstuffs comprising:
a. a cooking chamber having reflective inner walls for reflecting
radiant energy to a pizza location centrally thereof;
b. a plurality of 1.5 KW quartz halogen lamps generating at least 6
KW of radiant power with a significant portion of radiant energy in
the electromagnetic spectrum having wavelengths in the range of
visible light, said lamps having a first group of lamps inside said
cooking chamber positioned above said pizza location and a second
group of lamps inside said cooking chamber positioned below said
pizza location for impinging at least a portion of said radiant
energy directly onto said pizza;
c. a plurality of plates which are transparent to radiant energy
positioned between said pizza location and said lamps; and
d. means for controlling the first group of lamps and the second
group of lamps independently by time and intensity.
10. A pizza oven for cooking and baking a raw pizza pie and forming
a cooked pizza therefrom, said pizza having a crust formed of dough
and toppings formed of any variety of foodstuffs comprising:
a. a cooking chamber having reflective inner walls for reflecting
radiant energy to a pizza location centrally thereof;
b. a plurality of 1.5 KW quartz halogen lamps generating at least 6
KW of radiant power with a significant portion of radiant energy in
the electromagnetic spectrum having wavelengths in the range of
visible light, said lamps having a first group of five lamps inside
said cooking chamber positioned above said pizza location and a
second group of five lamps inside said cooking chamber positioned
below said pizza location for impinging at least a portion of said
radiant energy directly onto said pizza;
c. a plurality of plates which are transparent to radiant energy
positioned between said pizza location and said lamps; and
d. means for controlling the first group of lamps and the second
group of lamps independently by time and intensity.
11. A method of cooking and baking a raw pizza pie in a cooking
chamber having reflective inner walls comprising the steps of:
a. generating at least 6 KW of radiant power having substantially
ten percent of the radiant energy in the electromagnetic spectrum
having a wavelength in the order of 0.4 .mu.m to 0.7 .mu.m by using
a plurality of quartz body tungsten lamps, said lamps having a
first group of lamps inside said cooking chamber positioned above
said pizza and a second group of lamps inside said cooking chamber
positioned below said pizza for impinging at least a portion of
said radiant energy directly onto said pizza;
b. positioning a plurality of plates which are transparent to
radiant energy between said pizza and said lamps; and
c. controlling the first group of lamps and the second group of
lamps differentially by time and intensity.
12. An oven for cooking a food item having a first temperature,
wherein said oven comprises:
a. a cooking chamber having reflective inner walls for reflecting
radiant energy to a food position therein;
b. means mounted in said cooking chamber generating at least 6 KW
of radiant power with a substantial portion of radiant energy in
the electromagnetic spectrum having a range of wavelengths from 0.4
.mu.m to 4.5 .mu.m with a peak intensity at approximately 1.0 .mu.m
and including a significant portion having wavelengths in the range
of 0.4 to 0.7 .mu.m for impinging at least a portion of said energy
from said generating means directly on the food and for impinging
reflected energy from said generating means on the food; and
c. a support member which is transparent to said radiant energy for
supporting the food at said food position.
13. The oven of claim 12 wherein said portion of radiant energy in
said spectrum is substantially ten percent.
14. An oven for cooking a food item having a first temperature,
wherein said oven comprises:
a. quartz body tungsten-halogen lamp means generating at least 6 KW
of radiant power with radiant energy only, said radiant energy
having a range of wavelengths from 0.4 to 4.5 .mu.m with a peak
intensity at approximately 1.0 .mu.m and including a significant
portion having a significant portion of radiant energy in the
electromagnetic spectrum having wavelengths in the range of 0.4
.mu.m to 0.7 .mu.m;
b. an enclosure surrounding said lamp means, said enclosure having
an outer surface and an inner surface, said inner surface being
reflective of said radiant energy to a food position centrally of
said inner surface and
c. means for mounting said lamps in said enclosure whereby portions
of said energy will impinge directly on at least opposite sides of
the food in order to bring the food to a specified second
temperature, said second temperature being higher than said first
temperature.
15. A method of cooking a food item having a first temperature,
comprising the steps of:
a. generating at different positions for impingement on opposite
sides of food a significant portion of radiant energy in the
electromagnetic spectrum having wavelengths in the range of visible
light;
b. directing a first portion of said energy to impinge directly on
opposite sides of the food in a food position in order to bring the
food to a specified second temperature, said second temperature
being higher than said first temperature; and
c. reflecting a second portion of said energy to the food position
to strike the food many times from many angles.
16. A method of cooking a food item having a first temperature,
comprising the steps of:
a. generating at least 6 KW of radiant power having a substantially
10% portion of radiant energy in the electromagnetic spectrum
having wavelengths in the range of visible light;
b. directing a first portion of said energy to impinge directly on
the food in a food position in order to bring the food to a
specified second temperature, said second temperature being higher
than said first temperature; and
c. reflecting a second portion of said energy to the food
position.
17. A method of cooking and baking a raw pizza pie and forming a
cooked pizza therefrom, said pizza having a crust formed of dough
and toppings formed of any variety of foodstuffs comprising:
a. generating radiant power of at least 6 KW having radiant energy
in the electromagnetic spectrum having approximately 10% of its
wavelengths in the range of visible light by energizing lamps
positioned above and below the pizza;
b. directing energy to impinge directly on the pizza; and
c. controlling the lamps independently by time and intensity.
18. An oven for cooking a food item having a first temperature,
wherein said oven comprises:
a. a first group of quartz body tungsten halogen lamps and a second
group of quartz body tungsten halogen lamps, each group including
five lamps, said lamps generating at least 6 KW of radiant power
and generating a significant portion of radiant energy in the
electromagnetic spectrum having a wavelength in the range of 0.4
.mu.m to 0.7 .mu.m; and
b. an enclosure surrounding said lamps, the enclosure having an
outer surface and an inner surface, said inner surface being
reflective of said radiant energy to a food position within said
inner surface and
c. means for mounting said lamps in said enclosure whereby portions
of said energy will impinge directly on at least opposite sides of
the food in order to bring the food to a specified second
temperature, said second temperature being higher than said first
temperature.
19. An oven for cooking and baking food comprising:
a. a cooking chamber having reflective inner walls for reflecting
radiant energy to a food position centrally thereof;
b. at least five quartz body tungsten lamps positioned inside said
cooking chamber above said food position and at least five quartz
body tungsten lamps positioned inside said cooking chamber below
said food position, said lamps generating at least 6 KW of radiant
power and generating radiant energy having a significant portion of
energy in the visible light range of the electromagnetic spectrum,
said lamps positioned for impinging at least portions of said
radiant energy directly on said food; and
c. a container which is transparent to said radiant energy for
holding the food at said food position while cooking.
20. A pizza oven for cooking and baking a raw pizza pie and forming
a cooked pizza therefrom, said pizza having a crust formed of dough
and toppings formed of any variety of foodstuffs comprising:
a. a cooking chamber having reflective inner walls for reflecting
radiant energy to a pizza location centrally thereof;
b. a plurality of quartz body halogen lamps for generating a
significant portion of radiant energy in the electromagnetic
spectrum having wavelengths in the range of visible light, said
lamps having a first group of five lamps inside said cooking
chamber positioned above said pizza location and a second group of
five lamps inside said cooking chamber positioned below said pizza
location, said lamps generating at least 6 KW of radiant power for
impinging at least a potion of said radiant energy directly onto
said pizza;
c. a plurality of plates which are transparent to radiant energy
positioned between said pizza location and said lamps; and
d. means for controlling the first group of lamps and the second
group of lamps independently by time and intensity. .Iadd.
21. The oven according to claim 1 wherein said means for generating
radiant energy generates energy in the electromagnetic spectrum
having a range of wavelengths from 0.4 .mu.m to 4.5 .mu.m with a
peak intensity at approximately 1.0 .mu.m. .Iaddend..Iadd.22. The
oven according to claim 1 wherein said significant portion of
energy in the visible light range is approximately seven percent.
.Iaddend..Iadd.23. The oven according to claim 1 wherein said
significant portion of energy in the visible light range is
approximately seven percent and higher. .Iaddend..Iadd.24. The
method of claim 15 wherein said energy in the electromagnetic
spectrum has a range of wavelengths from 0.4 .mu.m to 4.5 .mu.m
with a peak intensity at approximately 1.0 .mu.m.
.Iaddend..Iadd.25. The method of claim 15 wherein said significant
portion of energy in the range of visible light
is approximately seven percent. .Iaddend..Iadd.26. The method of
claim 15 wherein said significant portion of energy in the range of
visible light is approximately seven percent and higher.
.Iaddend..Iadd.27. An oven for cooking and baking food
comprising:
a. a cooking chamber having a highly reflective and poorly
absorptive inner wall for reflecting radiant energy to a food
position centrally thereof;
b. a plurality of means for generating radiant energy having energy
in the infrared range and in the visible light range of the
electromagnetic spectrum and wherein said means for generating
radiant energy generates energy in the electromagnetic spectrum
having a range of wavelengths from 0.4 .mu.m to 4.5 .mu.m with a
peak intensity at approximately 1.0 .mu.m, said means for
generating positioned inside said cooking chamber and including at
least one source positioned above and at least one source
positioned below said food position for impinging at least a
portion of said radiant energy directly from said radiant energy
generating means on said food and reflecting from said inner wall
radiant energy not impinging directly on said food for impinging
reflected radiant energy from said radiant energy generating means
to said food many times from many angles; and
c. a support member which is transparent to said radiant energy for
supporting the food at said food position while cooking.
.Iaddend..Iadd.28. An oven for cooking and baking food
comprising:
a. a cooking chamber having a highly reflective and poorly
absorptive inner wall for reflecting radiant energy to a food
position centrally thereof;
b. a plurality of means for generating radiant energy having energy
in the infrared range and in the visible light range of the
electromagnetic spectrum and wherein the portion of energy in the
visible light range is approximately seven percent, said means for
generating positioned inside said cooking chamber and including at
least one source positioned above and at least one source
positioned below said food position for impinging at least a
portion of said radiant energy directly from said radiant energy
generating means on said food and reflecting from said inner wall
radiant energy not impinging directly on said food for impinging
reflected radiant energy from said radiant energy generating means
to said food many times from many angles; and
c. a support member which is transparent to said radiant energy for
supporting the food at said food position while cooking.
.Iaddend..Iadd. An oven for cooking and baking food comprising:
a. a cooking chamber having a highly reflective and poorly
absorptive inner wall for reflecting radiant energy to a food
position centrally thereof;
b. a plurality of means for generating radiant energy having energy
in the infrared range and in the visible light range of the
electromagnetic spectrum and wherein the portion of energy in the
visible light range is approximately seven percent and higher, said
means for generating positioned inside said cooking chamber and
including at least one source positioned above and at least one
source positioned below said food position for impinging at least a
portion of said radiant energy directly from said radiant energy
generating means on said food and reflecting from said inner wall
radiant energy not impinging directly on said food for impinging
reflected radiant energy from said radiant energy generating means
to said food many times from many angles; and
c. a support member which is transparent to said radiant energy for
supporting the food at said food position while cooking.
.Iaddend..Iadd.30. A method of cooking a food item having a first
temperature, comprising the steps of:
a. generating at different positions for impingement on opposite
sides of food radiant energy in the electromagnetic spectrum having
wavelengths in the range of visible light and wherein said energy
in the electromagnetic spectrum has a range of wavelengths from 0.4
.mu.m to 4.5 .mu.m with a peak intensity at approximately 1.0
.mu.m;
b. directing a first portion of said energy to impinge directly on
opposite sides of the food in a food position in order to bring the
food to a specified second temperature, said second temperature
being higher than said first temperature; and
c. reflecting a second portion of said energy to the food position
to
strike the food many times from many angles. .Iaddend..Iadd.31. A
method of cooking a food item having a first temperature,
comprising the steps of:
a. generating at different positions for impingement on opposite
sides of food radiant energy in the electromagnetic spectrum having
wavelengths in the range of visible light and wherein the portion
of energy in the range of visible light is approximately seven
percent;
b. directing a first portion of said energy to impinge directly on
opposite sides of the food in a food position in order to bring the
food to a specified second temperature, said second temperature
being higher than said first temperature; and
c. reflecting a second portion of said energy to the food position
to strike the food many times from many angles. .Iaddend..Iadd.32.
A method of cooking a food item having a first temperature,
comprising the steps of:
a. generating at different positions for impingement on opposite
sides of food radiant energy in the electromagnetic spectrum having
wavelengths in the range of visible light and wherein the portion
of energy in the range of visible light is approximately seven
percent and higher;
b. directing a first portion of said energy to impinge directly on
opposite sides of the food in a food position in order to bring the
food to a specified second temperature, said second temperature
being higher than said first temperature; and
c. reflecting a second portion of said energy to the food position
to strike the food many times from many angles. .Iaddend.
Description
FIELD OF THE INVENTION
This invention relates to the field of cooking apparatus. More
particularly, this invention relates to baking and cooking
processes that are substantially faster than such processes in
conventional ovens, and offer sensory improvements in quality for
many foodstuffs.
BACKGROUND OF THE INVENTION
Ovens for cooking food have been known and used for thousands of
years. Basically, oven types can be categorized in four different
forms. The simplest and probably the oldest cooking resulted when
man put some vegetable or grain products on a hot rock next to a
fire, and cooked them essentially by the heat transfer method of
conduction. With a little more refinement, an enclosure surrounding
the heating element entrapped the heated air giving rise to cooking
by convective heat transfer. This was the prototype for the modern
gas or electric oven. In the past century, radiant energy from
infra-red radiation sources has been used to heat and cook
foodstuffs directly. Within the past few decades, microwave
radiation has proved useful in allowing very short cooking times
for many types of food.
It has generally been believed that radiation with wavelengths much
shorter than 1 .mu.m is not of much value in cooking or baking
processes, partly because of the weaker interaction of the shorter
wavelengths with the foodstuff molecules in terms of general heat
transfer, and partly due to the inferior penetrating properties of
such radiation. In particular, it has seemed that visible light,
i.e., radiation with a wavelength in the range of 0.4 to 0.7 .mu.m,
is not very useful in the cooking process. However, if one provides
a sufficiently intense source of visible light radiation in
conjunction with infra-red radiation, a novel and very effective
cooking apparatus results. The combination of the deeply
penetrating infra-red and the intense visible radiations
establishes a temperature gradient within the interior of the
foodstuff. This strong gradient created by the differential
absorbtion of the infra-red and visible radiations ensures that the
surface temperature of the foodstuff is hotter than the interior,
and the products of the cooking, i.e., the water vapor and gases
like CO.sub.2, are quickly driven to the surface and out of the
foodstuff. This process results in a very rapid cooking of the
foodstuff.
Using intense visible and infra-red radiation to cook food has a
number of significant advantages. First of all, the cooking process
is very fast. Bakery products, like pizza crust for example, can be
baked 5 to 10 times faster than ovens that use only infra-red
energy or rely on conventional convection and conduction processes.
Secondly, the quality of the cooking process is enhanced for many
foodstuffs. For example, crusts become fully cooked with crispy
exteriors and moist, chewy interiors. Vegetables are cooked so fast
that they are virtually steamed in their own water vapor, leaving
them hot, but with very little loss of any of their nutritive
values.
In general, this is a new mode of cooking. The potentialities of
using this enhanced range of wavelengths for cooking and baking are
just starting to be explored, and a whole new range of cooking
techniques should result from the invention.
SUMMARY OF THE INVENTION
An oven is disclosed for the high-speed, high-quality cooking of
food items. The oven includes a means for impinging high-intensity
visible and infrared radiations onto a food item, thereby cooking
the item at an accelerated rate over the use of infra-red cooking
alone. This cooking process can be aided by conduction. Ordinarily,
the radiation impinging means is one or more quartz halogen
tungsten lamps, or equivalent means such as quartz arc lamps.
Typical quartz-halogen lamps of this type convert electrical energy
into black body radiation having a range of wavelengths from 0.4
.mu.m to 45 .mu.m with a peak intensity at approximately 1 .mu.m.
.Iadd.Such lamps produce approximately 7% of their radiant energy
in the visible range of 0.4 to 0.7 .mu.m at peak intensity.
.Iaddend.Each lamp provides about 1.5 kW of radiant energy with a
significant portion of the energy in the visible light spectrum.
Typical configurations can use one to as many as ten lamps operated
in unison, and larger ovens could use even more lamps.
One or more of the radiation source lamps may be used in the
cooking process as necessary. These radiation sources are
ordinarily positioned above and below the food item. Certain
applications may require that radiation sources surround the food
item. The walls of the surrounding food chamber are preferably
treated to be highly reflective. The visible and infrared waves
from the radiation sources impinge directly on the food item and
are also reflected on this inner surface of the oven to strike the
food item many times and from many angles. This reflecting action
results in a greater uniformity of cooking, and since very little
of the radiation is absorbed in the surrounding reflecting surface,
almost all of the radiant energy is converted into heat upon and
within the foodstuff. Hence, this process is a very efficient mode
of transferring energy to the foodstuff for cooking, and operation
is very economical.
For certain cooking applications, the food item may be placed on a
radiant energy absorbing and heat conductive support platter. Such
platter can be selectively heated by means of the bottom set of
lamps to increase its temperature to a point where it can aid the
cooking process by conductive heating, if desired. The platter may
be perforated in such a manner so as to facilitate the removal of
internal water vapor and gases from the bottom of the
foodstuff.
The intensity of the radiation from the lamps is controllable. Each
lamp can be individually controlled or the lamps can be operated in
unison to provide the desired cooking result. It is necessary that
this control be performed quickly, because of the inherent speed of
the cooking process. For certain food products, it is necessary
that the intensity be varied throughout the cooking cycle. Such
fast and variable intensity control is preferably managed through
automatic means, such as computer or microprocessor circuits.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front cross section of a preferred embodiment of the
present invention.
FIG. 2 shows a side cross section of the preferred embodiment of
the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a front cross section of the preferred embodiment of the
present invention. The oven in FIG. 1 includes an outer enclosure
10. The enclosure has an inner wall 12 coupled to the outer wall
10. Ordinarily, an insulating layer 14 is formed between the outer
enclosure 10 and the inner wall 12. Because of the inherent speed
of the cooking cycle, the insulating layer 14 may be a layer of
air.
The energy for cooking is supplied by the lower radiation heating
lamps 16 and the upper radiation heating lamps 18. These lamps are
generally any of the quartz body, tungsten-halogen lamps
commercially available, e.g., 1.5 KW 208 V quartz-halogen lamps.
The oven according to the preferred embodiment utilizes ten such
lamps and cooks with an average of 10% of the energy in the visible
light portion of the spectrum, which is significant. The inner
surface of the inner wall 12 is preferably a highly polished,
poorly absorptive surface, so that it appears to be very reflective
to the wide spectrum of wavelengths from the radiant lamps. Two
radiation transparent plates 20 and 24 are used to isolate the
cooking chamber from the radiant sources. These plates can be
formed from such materials as quartz or a glass that transmits both
visible and infra-red radiations. The lower transparent plate 20 is
supported by brackets 22a and 22b and is positioned above the lower
lamps 16. The upper transparent plate 24 is supported by brackets
26a and 26b and is positioned below upper lamps 18.
Brackets 28a and 28b support platter 30. The platter 30 is
positioned above the lower transparent plate 20 and below the upper
glass plate 24. A food item 32 is positioned on platter 30 to be
cooked. The control circuit 34, shown as a circuit block, controls
the operation of lamps 16 and 18.
The lamps 16 and 18 produce very high intensity visible and
infra-red radiations. Prior art use of radiant energy heat sources
teach cooking using radiation in the infra-red portion of the
electro-magnetic spectrum. For example, see Malick U.S. Pat. Nos.
4,481,405 and Bassett 4,486,639. Burkhart, in 4,516,486, discloses
a radiant energy cooker for the exclusive purpose of charring the
surface of foods, particularly meats.
The use of both high intensity visible and infrared radiations
provides a very rapid method of high-quality cooking and baking.
The radiant energy from the lamps 16 and 18 radiates from the bulb
in all directions. A portion of the energy radiates directly onto
the food item 32. The remainder of the energy will be reflected off
the polished surface of the preferably metal inner wall 12 and
strike the food item 32 for more efficient cooking.
The platter 30 may be formed of a material similar to the
transparent plates 20 and 24 to allow even cooking of food item 32.
However, in some circumstances it may be desirable to crisp the
bottom of the food item 32. As a particular example, when cooking a
pizza, it is desirable that the crust be light and crispy, rather
than soggy and doughy. In such an application, the cooking platter
30 should be formed of a radiation absorbing, heat conducting
material, such as black anodized aluminum. In this way, the lower
lights 16 would rapidly heat the platter 30 to a high temperature
in order to crisp the bottom of the pizza. It may also be desirable
to perforate the platter 30 in order to allow steam to escape from
the cooking pizza dough. The platter 30 should touch the support
brackets 28a and 28b over very limited areas, so that the heat
delivered to platter 30 is not lost by conduction.
It is possible to control the lights 16 and 18 independently with
the control circuit 34. The control circuit 34, shown as a circuit
block in FIG. 1, may include a microprocessor or a microcontroller
and associated memory to store individual cooking recipes to
control proper heating of the food product.
For example, in cooking a pizza, it may be desirable to run the
upper lamps 18 at a reduced power level for a time. For a pizza
having fresh vegetables, this would prevent the overcooking of the
vegetables making them mushy. The lower lamps 16 might be operated
at a higher power level to make the pizza crust light and
crispy.
FIG. 2 shows a side cross section of the preferred embodiment of
the present invention. In the preferred embodiment, there are 5
lower lamps 16a through 16e and 5 upper lamps 18a though 18e. By
appropriately selecting the lateral spacing between the lamps
relative to the food, even cooking can be achieved over the entire
surface. A door 40 is also shown.
Microwave ovens cannot be used in cooking high quality freshly
prepared pizza. The commercially available frozen pizzas for
microwave ovens are precooked and then frozen. The pizza is merely
heated to the proper serving temperature in the microwave oven, but
the result is usually tough and soggy. A higher quality pizza can
be baked in a commercial grade conduction/convection oven. Here,
the pizza is placed directly on the hot floor of the oven to
properly crisp the bottom of the crust (up to 900.degree. F. in a
brick oven). Unfortunately, the ovens have various "hot" spots and
require constant operator attention to avoid over or under cooking
the pizza, i.e., consistency is a major problem. The ovens cook a
pizza in 5 to 20 minutes. Conveyorized infra-red and hot air
convection ovens can cook a pizza in 5 to 15 minutes, but have
great difficulty in properly crisping the bottom of the pizza. A
pizza can be cooked in the present invention in 35 to 45 seconds.
This speed is very important in the commercial pizza market because
it enables pizza to be produced in a manner that would qualify it
as a true fast-food.
The energy efficiency of the present invention is illustrated by
the fact that the energy cost to cook such a pizza is about $0.01.
The majority of the radiant energy produced by the oven is utilized
in cooking the pizza and after the cooking process is completed the
energy is turned off. In contrast, conventional commercial pizza
ovens must be preheated to desired
cooking temperatures. Ordinarily, the oven pizza restaurant is left
on all day, whether cooking a pizza or not, making the energy
consumption significant.
The oven of the present invention is not limited to cooking pizzas.
Certain foods are cooked with more consistent and reliable results
than with conventional techniques. For example, cooking vegetables,
such as broccoli, so that they retain good texture is difficult
using prior art techniques. Generally, such items are preferred al
dente. The short cooking times of the present invention, about 20
seconds for broccoli, bring the product to serving temperature so
rapidly that the vegetable maintains its crisp, firm texture.
The oven of the present invention may also be used cooperatively
with other cooking sources. For example, the oven of the present
invention may include a microwave radiation source. Such an oven
would be ideal for cooking a thick food item such as a roast beef.
The microwave radiation would be used to cook the interior portions
of the meat and the infra-red and visible light radiation of the
present invention would cook the outer portions. Further, the oven
according to the present invention could be used with a convection
oven or with both convention oven and microwave oven cooking
sources.
The present invention was described in relation to a preferred
embodiment. However, it will be apparent to one skilled in the art
that one can change the parameters and still practice an invention
within the spirit and scope of the present invention.
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