GB2626609A

GB2626609A - Oven heating system and control system thereof

Info

Publication number: GB2626609A
Application number: GB2301304.8A
Authority: GB
Inventors: Wright Callum; Thomas Hamill Adam
Original assignee: Ooni Ltd
Current assignee: Ooni Ltd
Priority date: 2023-01-30
Filing date: 2023-01-30
Publication date: 2024-07-31
Also published as: WO2024161131A1; GB202301304D0

Abstract

A cooking apparatus 100 comprising an oven 110, a cooking chamber 105, a cooking support 135 and an oven door 130. The cooking chamber comprises a first heating element 115 beneath the cooking support and a second heating element 125 in an upper region internal to the cooking chamber. A method of selectively powering one of the heating elements at any one time and operating in a sequential heating mode that comprises progressing through predetermined heating stage(s), each comprising alternately powering the first and second heating elements. Preferably progressing from one heating stage to the next comprises progressively adjusting the duty cycle of the first and second heating elements from their initial duty cycles. Operating in the sequential heating mode may comprise progressing through one or more predetermined heating stages in dependence on a predefined heating stage dependent threshold and / or be in dependence on a target temperature. Preferably, changing the heating element that is powered corresponds to switching the heating elements and progressing from one heating stage to the next comprises adjusting the frequency of switching of the heating elements.

Description

1 OVEN HEATING SYSTEM AND CONTROL SYSTEM THEREOF

3 Field of the invention

4 The present invention relates to the field of electric pizza ovens and in particular electric pizza ovens with cooking chambers which are suitable for heating to temperatures 6 above 350 °C.

8 Background to the invention

9 Pizza ovens are commonly used for the cooking of baked goods and particularly pizzas. Such pizza ovens may be used to provide the very high cooking temperatures 11 required to cook dough-based products adequately and to provide pizzas with a 12 characteristically smoky or charred flavour. Before cooking any foodstuffs, the oven is 13 preheated to the desired high temperature. Reaching and maintaining temperatures in 14 excess of 350 °C presents serious technical challenges with some materials, components and heating procedures which would be usable at lower temperature

16 being unsuitable.

18 The pizza ovens typically include a pizza stone which functions as a cooking support 19 having an upper (cooking) surface on which pizza is cooked. It is important to heat the pizza stone to a high temperature to cook the base of the pizza whilst also protecting 21 the pizza stone from damage. It also desirable to heat the air inside the oven to cook 22 the toppings on the pizza. As a result, the temperature inside the oven is heated to 23 reach the desired temperature. In addition, it is desirable to maintain the desired 24 temperature following heat-up. This particularly relevant to electric pizza ovens, 1 because opening the door to the cooking chamber can lead to loss of heat from the 2 oven.

4 It is also desirable to provide a user of the pizza oven with information regarding cooking process and to allow the user to interact with the oven to control the cooking 6 process, if required.

8 It is within this context that the present disclosure has been devised.

Summary of the invention

12 According to an aspect of the present invention, there is provided a method of cooking 13 using a cooking apparatus comprising an oven, the oven comprising a cooking 14 chamber comprising a cooking support internal to the cooking chamber and an oven door separating the cooking chamber from an external environment of the cooking 16 apparatus. The cooking chamber comprises a first heating element positioned beneath 17 the cooking support to heat the cooking support and a second heating element 18 positioned in an upper region internal to the cooking chamber to heat the interior of the 19 cooking chamber. The method typically comprises powering at most one of the first heating element or the second heating element at any one time.

22 According to another aspect of the present invention, there is provided a cooking 23 apparatus comprising an oven, the oven comprising a cooking chamber comprising a 24 cooking support internal to the cooking chamber and an oven door separating the cooking chamber from an external environment of the cooking apparatus. The cooking 26 chamber comprising a first heating element positioned beneath the cooking support to 27 heat the cooking support and a second heating element positioned in an upper region 28 internal to the cooking chamber to heat the interior of the cooking chamber. The 29 cooking apparatus comprising a heating controller configured such that, at any one time, at most one of the first heating element or the second heating element is powered.

32 According to another aspect of the present invention, there is provided a method of 33 cooking using a cooking apparatus comprising an oven, the oven comprising a cooking 34 chamber comprising a cooking support internal to the cooking chamber and an oven door separating the cooking chamber from an external environment of the cooking 36 apparatus. The cooking chamber comprises a plurality of heating elements comprising 37 a first heating element positioned beneath the cooking support to heat the cooking 1 support and a second heating element positioned in an upper region internal to the 2 cooking chamber to heat the interior of the cooking chamber. The method typically 3 comprises powering at most one of the plurality of heating elements at any one time.

Thus, the first heating element heats the cooking support directly. The second heating 6 element will directly heat both the air above the cooking support and to some extent 7 also the upper surface of the cooking support. In use, the cooking support will be 8 heated through from both sides. The temperature of the cooking surface, being the top 9 of the cooking support, must be carefully regulated to ensure good pizza cooking.

11 It may be that the oven is (i.e. configured as) a portable oven. For example, the oven 12 may be smaller and/or lighter than a conventional oven such that the oven may be 13 moved easily by a user. It may be that the oven is provided with legs, feet, castors, 14 rollers, wheels and/or an oven stand such that the oven may be safely positioned on the floor or on a surface, such as a table or countertop, inside during use. The oven 16 may comprise legs extending from the base of the housing. It may be that a (i.e. 17 external) housing of the oven is (i.e. thermally) insulated such that a user may safely 18 handle one or more external portions of the oven during use.

It may be that the oven is a pizza oven. A pizza oven is an oven configured for cooking 21 one or more pizzas. The pizza oven may be an electric pizza oven. The electric pizza 22 oven may be suitable for domestic use by an individual or non-commercial user. It may 23 be that the cooking chamber is configured for cooking one or more pizzas at a 24 temperature of at least 300°C, at least 350°C at least 400°C or at least 450°C. It may be that the cooking chamber is dimensioned and sized for cooking one or more pizzas.

26 A cooking chamber configured for cooking one or more pizzas typically has a (e.g. 27 interior) length and/or a (e.g. interior) breadth (i.e. substantially) greater than a (e.g. 28 interior) vertical height of the cooking chamber.

The cooking chamber is typically internal to the oven, that is to say it is an internal 31 cooking chamber. The cooking chamber may define an (e.g. the) opening for access 32 into the cooking chamber. The housing may define an (e.g. the) opening for access 33 into the cooking chamber, for example an opening aligned with the cooking chamber 34 opening. The opening may be a food-receiving opening configured for access to the cooking chamber. The cooking chamber and/or the housing may each comprise (e.g. 36 be defined by) one or more walls. The housing and the cooking chamber) may 37 comprise a top, base, left side, right side and rear (e.g. in addition to the opening). An 1 internal space may be defined between the (e.g. walls of the) housing and the (e.g. 2 walls of the) cooking chamber.

4 It may be that the interior of the cooking chamber is bounded (i.e. at least in part) by two or more opposing interior walls. For example, it may be that the interior of the 6 cooking chamber is bounded by two or more opposing lateral interior walls. The two 7 or more opposing lateral interior walls are typically substantially vertical walls. It may 8 be that the cooking chamber is bounded by the two or more opposing lateral interior 9 walls and a rear interior wall. The rear interior wall typically faces a food-receiving open end of the cooking chamber. The two or more lateral interior walls typically 11 extend between the rear interior wall and the food-receiving opening of the cooking 12 chamber. The interior of the cooking chamber may be bounded by two interior walls 13 forming a roof (i.e. a top surface) and a base (i.e. a bottom surface).

The opening of the housing is typically positioned at the front of the oven. Indeed, the 16 front of the oven may be defined as the part of the oven at which access to the cooking 17 chamber is available via the opening when the oven door is opened. In other words, 18 the oven (and optionally the cooking chamber) may be understood to comprise a front 19 portion (e.g. half) and a rear portion (e.g. half) with the front portion being closer to the opening and the door, and the rear portion being further from the opening and the door.

22 The oven door is typically moveable between a closed position, in which the (i.e. interior 23 of the) cooking chamber is (i.e. at least partially) sealed from an external atmosphere 24 (i.e. outside the oven), and an open position, in which the (i.e. interior of the) cooking chamber is externally accessible (i.e. from outside the oven). The oven door may be 26 hingedly attached to the oven such that moving the oven door between the open and 27 closed positions comprises rotating the oven door about a hinge.

29 The oven door may be configured to close the opening. The oven door and housing may together define a first enclosed space (e.g. within which the cooking chamber is 31 retained) and optionally the oven door and the cooking chamber may together define 32 a second enclosed space (e.g. the space within the cooking chamber). The food- 33 receiving opening is typically accessible by a user (for example, for the provision, 34 inspection or removal of food items within the cooking chamber) when the oven door is provided in the open position. The oven door may comprise a window. The window 36 may be made of one or more transparent materials. The window may be made of glass.

1 The cooking support may comprise an upper surface, herein referred to as a cooking 2 surface, facing the second heating element. The cooking support may sit inside the 3 cooking chamber during use. The cooking support may sit on top of the base (i.e. 4 bottom surface) of the cooking chamber. The cooking surface is typically a surface upon which foodstuff may be placed during cooking. The foodstuff may be placed 6 directly on the cooking surface, or the foodstuff may be placed in a container and the 7 container may be placed on the cooking surface. The cooking support may have a high 8 resistivity to thermal shock so that it is able to withstand high temperatures of up to 9 850°C without damage (e.g. cracking). The cooking support may radiate and conduct heat evenly. The cooking support may be a pizza stone configured to cook pizza.

12 The oven may comprise one or more heat sources. The first and second heating 13 elements may be electric heat sources. The first heating element may be configured to 14 heat the interior of the cooking chamber (e.g. the cooking support) and the second heating element may be configured to heat the interior of the cooking chamber (e.g. air 16 in the cooking chamber). The first and second heating elements may be configured to 17 heat the interior of the cooking chamber via at least one of: radiation, conduction or 18 convection. The first and second heating elements may be a wire, ceramic or 19 semiconductor heating element.

21 The first heating element may be positioned underneath the cooking support. The first 22 heating element may be positioned between the cooking support and the base of the 23 cooking chamber. The first heating element may be positioned on the side of the 24 cooking support opposite to the cooking surface to which food is placed during cooking.

The first heating element may be mounted onto the base of the cooking chamber. The 26 first heating element may be mounted between the base of the cooking chamber and 27 the cooking support such that it is not in direct contact with either the base of the 28 cooking chamber or the cooking support. Alternatively, the heating element may be 29 mounted between the base of the cooking chamber and the cooking support such that it is in direct contact with at least one of: the base of the cooking chamber, and the 31 cooking support. The first heating element may be less than 3mm, less than 5mm, or 32 less than lOmm from the cooking support.

34 The second heating element may be positioned internal to and in an upper region of the cooking chamber. The second heating element may be positioned near a top 36 surface (i.e. a root) of the cooking chamber. The second heating element may be 37 positioned above the cooking support and above the cooking surface. The second 1 heating element may be mounted onto the top internal surface of the cooking chamber.

2 The second heating element may not be in direct contact with the top surface of the 3 cooking chamber. The second heating element may be greater than 700mm, greater 4 than 800mm or greater than 900mm from the cooking surface.

6 The first and second heating elements may be configured to heat the cooking chamber 7 to a temperature of at least 400 °C. The oven may be suitable for use at temperatures 8 (e.g. up to and) above 350 °C, e.g. up to 450 °C, or up to 500 °C, or up to 550 °C. The 9 first and second heating elements may heat the interior of the cooking chamber through temperatures from room temperature (e.g. 29 °C) up to a temperature at least 350 °C, 11 or at least 400 °C, or at least 450 °C, or at least 500 °C. Where cooking chambers have 12 temperatures above 350 °C, it is particularly helpful to have a controlled way to heat 13 up the interior of the cooking chamber. The oven may comprise heating controller 14 configured to regulate the temperature within the cooking chamber thermostatically, to thereby cause the temperature to be maintained at a setpoint. The setpoint (e.g. a 16 target temperature) may be at least 400 °C, or at 35 least 450 °C, or at least 500 °C. In 17 an example, the setpoint (e.g. target temperature) may be 400 °C ± 5 °C.

19 The heating controller may comprise one or more processors. The controller may comprise a non-transitory computer readable memory storing instructions. The 21 instructions, when executed by the one or more processors may cause the heating 22 controller to operate the first and second heating elements and the duty cycles thereof 23 as described herein. The one or more processors may be located in a single unit. In 24 other examples, where the one or more processors is a plurality of processors, the heating controller may be distributed, which is to say that at least one of the plurality of 26 processors may be located separated from at least one other of the plurality of 27 processors. The heating controller may be configured to receive at least one input from 28 the one or more components of the oven, for example the temperature sensor. The 29 heating controller may be configured to transmit at least one output to at least one of: the first heating element and the second heating element. Typically, the cooking 31 apparatus comprises the heating controller, but in other examples, the heating 32 controller may be provided separate from the cooking apparatus and in wireless data 33 communication therewith.

It may be that the first heating element is provided to heat the cooking support. It may 36 be that the first heating element is provided in a lower region of the cooking chamber.

1 It may be that the cooking apparatus comprises one or more additional heating 2 elements. The one or more additional heating elements are typically in addition to the 3 first and second heating elements of the plurality of heating elements. That is, the total 4 number of heating elements may be three, in which case there is one additional heating element, or four, in which case there are two additional heating elements. The one or 6 more additional heating elements may be controlled independently from one another.

7 The one or more additional heating elements may be controlled independently from 8 the first and second heating elements forming the plurality of heating elements. It may 9 be that the one or more additional heating elements are controlled differently to the first and second heating elements in that the one or more additional heating elements may 11 be continuously powered. It may be that the one or more additional heating elements 12 are part of the plurality of heating elements such that only one of the first heating 13 element, the second heating element and the one or more additional heating elements 14 are powered at any one time. The one or more additional heating elements may be positioned within the cooking chamber.

17 It may be that powering either only the first heating element or only the second heating 18 element at any one time comprises powering only one heating element at once. It may 19 be that the method comprises operating the heating elements such that either the first heating element is heating the cooking support, or the second heating element is 21 heating the aft within the cooking chamber, typically the air near the top of the cooking 22 chamber. It may be that each of the heating elements are configured to consume the 23 maximum wattage when powered is supplied to the heating element. For example, the 24 first and second heating elements may have a maximum wattage rating of 1600W.

26 Advantageously, not only does powering only one heating element at once comply with 27 maximum allowable current ratings in many electricity supply systems, this also allows 28 for greater temperature control within the oven as heat can be directed towards desired 29 regions within the cooking chamber.

31 It may be that the method comprises controlling the first and second heating elements 32 independently from one another. That is, it may be that the control the first heating 33 element does not affect the control of the second heating element. Alternatively, it may 34 be that the method comprises controlling the first and second heating elements in dependence on one another. That is, it may be that the control the first heating element 36 affects the control of the second heating element. For example, it may be that only one 1 heating element is directly controlled and the other heating element is controlled in 2 dependence on the directly controlled heating element.

4 It may be that the method comprises selectively powering at most one of the plurality of heating elements at any one time. Advantageously, selective powering of the first 6 heating element and the second heating element allows for greater control over the 7 temperature inside the cooking chamber.

9 It may be that the method comprises selectively powering at most one of the plurality of heating elements at any one time in dependence on a measured temperature inside 11 the cooking chamber and/or in dependence on a user input. Typically, the method may 12 comprise determining whether to power a heating element in dependence on the 13 measured temperature and/or the user input. Typically, the method may comprise 14 determining which of the first heating element and the second heating element to power in dependence on the measured temperature and/or the user input. Typically, the 16 method may comprise determining which heating element to power using stored 17 instructions which define which heating element to power for a given measured 18 temperature and/or a particular user input. It may be that changing the heating element 19 that is powered comprising switching the power to the heating elements. It may be that changing which heating element is powered comprises switching.

22 Advantageously, selective powering of the first heating element and the second 23 heating element in dependence on the measured temperature allows for greater 24 automated control over the temperature inside the cooking chamber and quick response to changes in temperature within the cooking chamber, which in turns 26 improves cooking efficiency and quality. Advantageously, selective powering of the first 27 heating element and the second heating element in dependence on the user input 28 allows for the user to have control over the temperature inside the cooking chamber, 29 which in turns improves user interaction, cooking efficiency and quality.

31 It may be that the method comprises operating in a sequential heating mode. It may be 32 that the sequential heating mode progresses through one or more predetermined 33 heating stages, each predetermined heating stage comprising alternately powering the 34 first and second heating elements.

36 Accordingly, thus the present invention extends to an aspect providing a method of 37 cooking using a cooking apparatus comprising an oven, the oven comprising a cooking 1 chamber comprising a cooking support internal to the cooking chamber and an oven 2 door separating the cooking chamber from an external environment of the cooking 3 apparatus, the cooking chamber comprising a plurality of heating elements comprising 4 a first heating element positioned beneath the cooking support to heat the cooking support and a second heating element positioned in an upper region internal to the 6 cooking chamber to heat the interior of the cooking chamber, wherein the method 7 comprises: selectively powering at most one of the plurality of heating elements at any 8 one time; and operating in a sequential heating mode, wherein the sequential heating 9 mode comprises progressing through one or more predetermined heating stages, each predetermined heating stage comprising alternately powering the first and second 11 heating elements.

13 Another aspect of the invention provides a cooking apparatus comprising an oven, the 14 oven comprising a cooking chamber comprising a cooking support internal to the cooking chamber and an oven door separating the cooking chamber from an external 16 environment of the cooking apparatus, the cooking chamber comprising a plurality of 17 heating elements comprising a first heating element positioned beneath the cooking 18 support to heat the cooking support and a second heating element positioned in an 19 upper region internal to the cooking chamber to heat the interior of the cooking chamber, the oven comprising a heating controller configured such that, at any one 21 time, at most one of the plurality of heating elements is powered, and the heating 22 controller is configured to control the oven to operate in a sequential heating mode, 23 wherein the sequential heating mode comprises the heating controller controlling the 24 oven to progress through one or more predetermined heating stages, each predetermined heating stage comprising alternately powering the first and second 26 heating elements.

28 Typically, the predetermined heating stages are pre-programmed sequences for 29 controlling when power provided to which heating elements. That is, the cooking apparatus may switch the heating elements and the method may comprise switching 31 the heating elements, in the sequential heating mode.

33 Advantageously, alternately powering the first and second heating elements allows for 34 an optimum balance between the temperature of the cooking support and the temperature inside the cooking chamber. When the sequential heating mode is used 36 as a heat up mode, it ensures that the cooking support and air temperature within the 37 cooking chamber are optimised for cooking the foodstuff inside the oven, e.g. the first 1 pizza. If too much heat is applied to second heating element, the oven reaches the 2 target temperature before the cooking support has heated up to the correct 3 temperature. Conversely, if too much heat is applied to the first element, the cooking 4 support overheats before the temperature of air inside the cooking chamber reaches the target temperature. In addition, applying alternate power to the heating elements 6 prevents the cooking support from cracking.

8 It may be that progressing from one predetermined heating stage to the next comprises 9 progressively adjusting the duty cycle of the first heating element from an initial duty cycle of the first heating element. It may be that progressing from one predetermined 11 heating stage to the next comprises progressively adjusting the duty cycle of the 12 second heating element from an initial duty cycle of the second heating element. It may 13 be that the duty cycle of the first and second heating elements correspond to a 14 percentage of time during which the respective heating element is powered. Typically, the initial duty cycle of the first heating element and the initial duty cycle of the second 16 heating element is 50%.

18 Each of the one or more predetermined heating stages may correspond to a 19 predetermined ratio of time for powering the first heating element to time for powering the second heating element within the heating stage for the measured temperature to 21 reach the respective predefined heating stage dependent threshold. Each 22 predetermined heating stage may correspond to a different predetermined ratio. The 23 heating stages may also be referred to as a "balance or "setting" herein. It may be that 24 the sequential heating mode comprises a plurality (e.g. four, five or six) heating stages.

26 The term "duty cycle" is a known terminology to refer to the percentage of time in which 27 an electrical device is on during a period of time. In the context of the present invention, 28 the "duty cycle" of the respective heating element is herein intended to refer to as a 29 percentage of time during which the respective heating element is powered on during a time period. As the first and second heating elements are not operated at the same 31 time, the sum of the duty cycle of the first hearing elements and the second heating 32 elements cannot exceed 100%, however it may be less than or equal to 100%. The 33 time period may be determined by the predetermined heating stage in which the 34 cooking apparatus operates, as discussed below. The method of operating in the sequential heating mode may comprise powering each heating element for a time 36 period corresponding to the duty cycle percentage of the overall time period for each 37 predetermined heating stage.

2 It may be that the initial duty cycle of the first heating element and the initial duty cycle 3 of the second heating element are different or the same. It may be that the initial duty 4 cycle of the first heating element is a maximum of 70%, 50% or 30%. It may be that the initial duty cycle of the second heating element is a maximum of 70%, 50% 01 30%. It 6 may be that the duty cycle of the first and second heating elements sums to 100%.

8 It may be that progressively adjusting the duty cycle of the first heating element from 9 an initial duty cycle of the first heating element comprises decreasing the duty cycle of the first heating element. It may be that progressively adjusting the duty cycle of the 11 second heating element from an initial duty cycle of the second heating element 12 comprises increasing the duty cycle of the second heating element.

14 It may be that progressively adjusting the duty cycle of the first heating element from an initial duty cycle of the first heating element comprises increasing the duty cycle of 16 the first heating element. It may be that progressively adjusting the duty cycle of the 17 second heating element from an initial duty cycle of the second heating element 18 comprises decreasing the duty cycle of the second heating element.

It may be that progressing from one predetermined heating stage to the next comprises 21 incrementally decreasing the duty cycle of the first heating element from an initial duty 22 cycle of the first heating element. It may be that progressing from one predetermined 23 heating stage to the next comprises incrementally increasing the duty cycle of the 24 second heating element from an initial duty cycle of the second heating element. It may be that progressing from one predetermined heating stage to the next comprises 26 maintaining the duty cycle of either the first heating element or the second heating 27 element.

29 Typically, it may be that the method comprises alternately powering the first and second heating elements in each heating stage by supplying power to both heating 31 elements at some point within each heating stage but not at the same time.

33 The method may comprise incrementally changing the duty cycle of at least one of: the 34 first heating element and the second heating element when changing from operating in one heating stage to the next. The method may comprise changing the duty cycle of 36 at least one of: the first heating element and the second heating element in increments 37 of 1%, 5%, 10% 01 20%. The method may comprise incrementally decreasing the duty 1 cycle of the first heating element from an initial duty cycle of the first heating element 2 in 5% increments per heating stage. The method may comprise incrementally 3 increasing the duty cycle of the second heating element from an initial duty cycle of the 4 second heating element by 5% increments per heating stage.

6 It may be that the method comprises progressing through one or more predetermined 7 heating stages in dependence on a predefined heating stage dependent threshold.

8 Typically, the predefined heating stage dependent threshold is an upper temperature 9 threshold associated with each heating stage and/or a predetermined time period associated with each heating stage. It may be that the method comprises measuring a 11 temperature inside the cooking chamber. It may be that the method comprises 12 progressing through each heating stage in dependence on the measured temperature 13 corresponding to the upper temperature threshold associated with respective heating 14 stage.

16 The predefined heating stage dependent threshold may typically have a different value 17 for each heating stage, such that each heating stage has a respective predefined 18 heating stage dependent threshold. It may be that the method of operating in the 19 sequential heating mode comprises operating in one of the one or more predetermined heating stages at any one time. The cooking apparatus may progress from one 21 predetermined heating stage to the next when the predefined heating stage dependent 22 threshold for the respective heating stage is met (e.g. fulfilled, satisfied).

24 It may be that the method comprises sequentially progressing through the predetermined heating stages by operating in a first heating stage until a predefined 26 first heating stage dependent threshold is met, then operating in a second heating 27 stage until a predefined second heating stage dependent threshold is met, and so on.

29 The upper temperature threshold may refer to a threshold within the sequential heating mode corresponding to an upper limit of the temperature range of each heating stage.

31 The upper temperature threshold for each heating stage may be predefined. Typically, 32 the method comprises progressing from one predetermined heating stage to the next 33 when the respective upper temperature threshold for that heating stage is met. The 34 method may comprise determining that the respective upper temperature threshold for each heating stage is met in dependence on a measurement of a temperature inside 36 the oven corresponding to the upper temperature threshold for the current heating 37 stage.

2 The method may comprise detecting data indicative of the temperature and 3 determining the temperature inside the cooking chamber from the data indicative of the 4 temperature. The method may comprise measuring the temperature of air inside the cooking chamber and/or the temperature of the cooking support and/or cooking 6 surface.

8 The cooking apparatus may comprise a temperature sensor configured to measure the 9 temperature inside the cooking chamber. The temperature sensor may be located within the cooking chamber. The temperature sensor may be configured to measure 11 the temperature of air inside the cooking chamber and/or the temperature of the 12 cooking support and/or cooking surface. For example, the temperature sensor may be 13 located in close proximity to the first heating element, the second heating element or 14 the cooking support or the cooking surface in particular. It may be that the temperature sensor is located at the rear, base, side wall or ceiling of the cooking chamber. It may 16 be that the temperature sensor is positioned near the oven door. It may be that the 17 cooking apparatus comprises a plurality of temperature sensors positioned at different 18 locations within the cooking chamber. The temperature sensor may be configured to 19 transmit data indicative of the temperature inside the cooking chamber, or the measured temperature to the heating controller of the cooking apparatus.

22 Typically, the method may comprise determining whether the measured temperature 23 corresponds to the upper temperature threshold for each heating stage. The method 24 may comprise determining that the respective upper temperature threshold for each heating stage is met in dependence on a measurement of a temperature inside the 26 oven corresponding to the upper temperature threshold for the current heating stage.

27 The method may comprise continually measuring the temperature inside the cooking 28 chamber and continually comparing the measured temperature inside the cooking 29 chamber to the upper temperature threshold. That is, progression from one heating stage to the next in the sequential heating mode may be entirely temperature 31 dependent.

33 Typically, the method may comprise measuring the temperature inside the cooking 34 chamber at regular intervals. Typically, the method may comprise comparing the measured temperature inside the cooking chamber to the upper temperature threshold 36 at regular intervals. It may be that, at the end of the total time period for one cycle of 37 each heating stage (i.e. the time period of the duty cycles of the first and second heating 1 elements), the controller determines whether the measured temperature corresponds 2 to (i.e. is equal to or greater than) the upper temperature threshold temperature for that 3 stage. If so, the sequence progresses to the next heating stage. If the measured 4 temperature is less than the upper temperature threshold temperature for that stage, the method may comprise repeating once cycle of the heating stage (i.e. the time 6 period of the duty cycles of the first and second heating elements). That is, progression 7 from one heating stage to the next in the sequential heating mode may be both time 8 and temperature dependent.

The cooking apparatus may be configured to operate in the sequential heating mode 11 in dependence on the measured temperature. It may be that the sequential heating 12 mode is initiated when the measured temperature inside the cooking chamber is equal 13 to or greater than the lower limit of a sequential heating mode temperature range, or 14 when a predefined time period has expired.

16 Advantageously, measuring the temperature inside the cooking chamber allows for 17 real time monitoring of the temperature inside the cooking chamber to improve 18 automated control over the cooking chamber temperature, which in turns improves 19 cooking efficiency and quality 21 It may be that the method comprises progressing through one or more predetermined 22 heating stages in dependence on a predetermined time period associated with each 23 heating stage. The predetermined time period associated with each heating stage may 24 be a time period for one cycle of the heating stage (i.e. the time period of the duty cycles of the first and second heating elements), or the time period for a set number of 26 cycles of the heating stage. That is, the method may comprise progressing from one 27 heating stage to the next depending on expiry of a predetermined time period. In this 28 way, progression from one heating stage to the next in the sequential heating mode 29 may be entirely time dependent.

31 The predetermined time period associated with each heating stage may be a time 32 period during which the temperature inside the oven is expected to rise from a lower 33 temperature to a higher temperature. The time period for operating in each heating 34 stage may be known in advance (i.e. calculated and pre-programmed onto the heating controller).

1 It may be that time in which the cooking apparatus operates in each heating stage is 2 predetermined based on known properties. It may be that time in which the cooking 3 apparatus operates each heating element within each heating stage is predetermined 4 based on known properties. The known properties may comprise at least one of: (e.g. specific) heat capacity of the cooking support, (e.g. specific) heat capacity of the air 6 inside the cooking chamber, (e.g. specific) heat capacity of other materials forming the 7 cooking apparatus (e.g. oven housing, glass in the oven door), power of the first 8 heating element and power of the second heating element. Since the upper 9 temperature thresholds of the heating stages are also known, it is possible to determine how long to operate the cooking apparatus for in each heating stage in order to reach 11 the upper temperature threshold of the respective heating stage.

13 As an example, it may be possible to determine it will take a predetermined time period 14 associated with the first heating stage (e.g. 100) seconds to increase the temperature inside the cooking chamber from a lower predefined sequential heating mode threshold 16 (e.g. 35°C) to the upper temperature threshold associated with the first heating stage 17 (e.g. 100°C). The first heating stage may comprise a 50% duty cycle of the first heating 18 element and a 50% duty cycle of the second heating element. Accordingly, the first 19 heating element will be powered for a total of 50 seconds of the time in which the cooking apparatus operates in the first heating stage and the second heating element 21 will be powered for a total of 50 seconds of the time in which the cooking apparatus 22 operates in the first heating stage. Since both heating elements cannot be powered at 23 the same time, they are alternately powered. The first heating element may be powered 24 for a continuous period of 50 seconds and the second heating element may then be powered for a continuous period of 50 seconds. The first heating element may be 26 powered for a continuous period of 10 seconds and the second heating element may 27 then be powered for a continuous period of 10 seconds. This may be repeated 5 times 28 such that the total period of time in which the first heating element is powered is 50 29 seconds and the total period of time in which the second heating element is powered is 50 seconds during the predetermined time period associated with the first heating 31 stage in which the cooking apparatus is operated in the first heating stage. The 32 continuous periods of the first and second heating elements do need to be equal. For 33 example, the first heating element may be powered for 25 seconds, the second heating 34 element for 50 seconds and then the first heating element again for 25 seconds. When the predetermined time period associated with the first heating stage has expired, the 36 method may progress to operating in the second heating stage. In this way, the 1 progression from one heating stage to the next is independent of the measured 2 temperature.

4 It may be that at the end of the predetermined time period associated with the first heating stage, the temperature inside the cooking chamber is measured and compared 6 to the upper temperature threshold of the first heating stage. If the measured 7 temperature is equal to or greater than the upper temperature threshold of the first 8 heating stage, the method may comprise progressing to the next heating stage. In this 9 way, progression from one heating stage to the next depends on the measured temperatures corresponding to (i.e. being greater than or equal to) the upper 11 temperature threshold for each heating stage and also the time period of the duty 12 cycles of the first and second heating elements.

14 It may be that the method comprises operating in the sequential heating mode in dependence on a target temperature.

17 The target temperature may typically correspond to a temperature selected by a user.

18 The target temperature may be directly or indirectly selected by the user. For example, 19 the user may directly select the target temperature using a user input indicative of a desired final temperature for inside the cooking chamber. Alternatively, the user may 21 indirectly select the target temperature using a user input indicative of a foodstuff to be 22 cooked (e.g. pizza, pie, meat etc.) The cooking apparatus may then determine the 23 target temperature based on the foodstuff to be cooked. The cooking apparatus may 24 receive the user input via a user interface of the cooking apparatus. The user interface may comprise an input device, such as a rotatable dial, a button, a keypad, a 26 touchscreen or microphone. Other types of user inputs will also be envisaged.

28 Typically, the method comprises operating in the sequential heating mode for a first 29 predetermined time period; and/or measuring a temperature inside the cooking chamber and operating the oven in the sequential heating mode in dependence on the 31 measured temperature.

33 It may be that the sequential progression through the one or more predetermined 34 heating stages continues until the temperature inside the oven corresponds to a target temperature. It may be that the method comprises operating in the sequential heating 36 mode for a first predetermined time period. The first predetermined time period may be 1 a period of time during which the temperature inside the oven is expected to reach the 2 target temperature.

4 It may be that the method comprises measuring a temperature inside the cooking chamber and operating the oven in the sequential heating mode until the measured 6 temperature corresponds to the target temperature.

8 In some examples, the cooking apparatus may operate in the sequential heating mode 9 within a sequential heating mode temperature range. It may be that the target temperature (e.g. set by the user) is greater than the upper limit of the sequential 11 heating mode temperature range. In this case, the method may comprise operating in 12 the sequential heating mode for the first predetermined time period corresponding to 13 the estimated time taken for the temperature inside the oven to reach the upper limit of 14 the sequential heating mode temperature range. It may be that the method comprises measuring a temperature inside the cooking chamber and operating the oven in the 16 sequential heating mode until the measured temperature corresponds to the upper limit 17 of the sequential heating mode.

19 The upper temperature thresholds of the predetermined heating stage may have values within the sequential heating mode range.

22 It may be that changing the heating element that is powered corresponds to switching 23 of the heating elements and wherein progressing from one heating stage to the next 24 comprises adjusting the frequency of switching of the heating elements.

26 Each of heating stage may have a predetermined frequency of switching within a given 27 time period. For example, in the first heating stage, the number of switches during a 28 given time period (e.g. 100 seconds) may be 9 switches. Between each switch, one of 29 the heating elements is continuously powered for a switching time period. For example, a switching frequency of 9 during a given time period of 100 seconds may correspond 31 to each of the first and second heating elements being continuously powered for a 32 switching time of 10 seconds. When the measured temperature corresponds to the 33 upper temperature threshold of the given heating stage or the predetermined time 34 period associated with the given heating stage expires, the frequency of switching across the same given time period may increase. For example, when the measured 36 temperature corresponds to 100°C (i.e. the upper limit of the first heating stage), the 37 switching frequency during the given time period (e.g. 100) seconds may increase to 1 18. This corresponds to each of the first and second heating elements being 2 continuously powered for a switching time of 5 seconds.

4 Advantageously, increasing the number of switches allows for an appropriate balance of energy between the cooking support and the air within the cooking chamber. The 6 cooking support is typically heated from below which loads it with heat and this will 7 gradually work its way through the thickness of the cooking support to the cooking 8 surface. To a lesser extent the cooking surface is heated from above via the second 9 heating element. It is desirable to prevent heating the cooking surface too quickly from one side so it needs time to soak and then be recharged through each heating stage.

11 Therefore, by increasing the number of switches within a heating stage, there are more 12 opportunities to apply heat to the stone and air within each heating stage and the 13 heating process is more efficient.

It may be that the method comprises operating the oven in an initial mode, before the 16 sequential heating mode, wherein operating in the initial mode comprises powering 17 only the first heating element. The cooking apparatus may be configured to operate in 18 an initial mode in which only the first heating element is powered. In this way, the 19 maximum power is used to heat the cooking support. It may be that the initial mode is a start-up mode initiated when the oven is turned on, or initiated when a target 21 temperature (i.e. a final temperature) is set by a user.

23 Advantageously, the initial mode allows for maximum transfer of heat to the cooking 24 support to raise the temperature of the cooking support in a short period of time to a suitable temperature for cooking. However, it is desirable to reduce heat applied to 26 cooking support after a period of time in order to prevent damage to cooking support 27 due to overheating (e.g. cracking of the pizza stone). In addition, in the initial mode, the 28 air temperature within the cooking chamber gradually increases.

Typically, it may be that the first heating element only ever has a 100% duty cycle in 31 the initial mode and in response to a first user input (described below). Typically, it may 32 be that the first heating element has a maximum duty cycle of 50% in all other modes 33 of operating of the cooking apparatus except for the initial mode. Advantageously, 34 limiting the duty cycle of the first heating element to a maximum of 50% in the majority of operating modes of the cooking apparatus reduces the risk of the cooking support 36 from overheating, and potentially cracking.

1 It may be that the method comprises operating in the initial mode for a second 2 predetermined time period; and/or measuring a temperature inside the cooking 3 chamber and operating the oven in the initial mode in dependence on the measured 4 temperature.

6 It may be that the second predetermined time period is a period of time during which 7 the temperature inside the oven is expected to reach the lower limit of the sequential 8 heating mode temperature range.

Typically, the method may comprise operating in the initial mode whilst the measured 11 temperature corresponds to (e.g. is within) an initial mode temperature range, for 12 example any temperature below an upper limit of the initial mode temperature range 13 (e.g. 35°C). Typically, the method comprises either continually measuring, or 14 measuring at regular intervals, the temperature inside the cooking chamber and operating in dependence on the measured temperature being within the initial mode 16 temperature range. The regular intervals may correspond to the time period of one 17 cycle of the initial mode, which may be up to 20 seconds, up to 30 seconds, up to 50 18 seconds or up to 100 seconds. The time period of one cycle of the initial mode may be 19 preprogramed. The initial mode temperature range is typically independent of the target temperature. In the initial operating mode, there are typically no switches.

22 It may be that, the method comprises operating the oven in a second heating element 23 only mode, after the sequential heating mode, wherein operating in the second heating 24 element only mode comprises powering only the second heating element.

26 Typically, the method comprises operating in the second heating element only mode 27 at the highest target temperatures, which fall outside of the sequential heating mode 28 temperature range. Typically, there are no switches in the second heating element only 29 mode. Typically, the maximum allowable target temperature is within the temperature range in which the second heating element only mode occurs (i..e the second heating 31 element only mode temperature range). In the second heating element only mode, the 32 duty cycle of the first heating element may be 0% and the duty cycle of the second 33 heating element may be 100%.

Advantageously, the second heating element only mode allows for maximum transfer 36 of heat to the air inside the cooking chamber to raise the temperature of the air inside 1 the cooking chamber without raising the temperature of the cooking support 2 significantly at the same time.

4 It may be that the method comprises operating the oven in the second heating element only mode in dependence on a third predetermined time period; and/or measuring a 6 temperature inside the cooking chamber and operating the oven in the second heating 7 element only mode in dependence on the measured temperature.

9 It may be that the third predetermined time period is a period of time during which the temperature inside the oven is expected to increase from the upper limit of the 11 sequential heating mode temperature range to the target temperature.

13 Typically, the method may comprise operating in the second heating element only 14 mode when the measured temperature is greater than the upper limit of the sequential heating mode temperature range. Typically, the method comprises either continually 16 measuring, or measuring at regular intervals, the temperature inside the cooking 17 chamber and operating in dependence on the measured temperature being between 18 the upper limit of the sequential heating mode temperature range and the target 19 temperature. The regular intervals may correspond to the time period of one cycle of the initial mode, which may be up to 20 seconds, up to 30 seconds, up to 50 seconds 21 or up to 100 seconds. The time period of one cycle of the second heating element only 22 mode may be preprogramed. In the second heating element only mode, there are 23 typically no switches because the second heating element is always powered.

In the second heating element only mode, there may be periods of time where the 26 second heating element is not powered. In this case, there are no heating elements 27 powered.

29 It may be that the initial, sequential heating and second heating element only modes are part of a heat up cycle of the oven. It may be that the cooking apparatus is only 31 operated in the initial mode during the heat up cycle. It may be that, during the heat-up 32 cycle, the user is unable to adjust the balance, in order to ensure the oven heats up 33 both air and cooking support to the desired temperature, as quickly as possible.

The method of any preceding claim, comprising operating in an intermittent mode once 36 a target temperature is achieved, wherein the intermittent mode comprises a sequence 37 of powering only the first heating element, powering only the second heating element 1 and powering neither the first nor the second heating element in any order. It may be 2 that the method comprises operating in the intermittent mode in dependence on a 3 target temperature.

It may be that, when the measured temperature corresponds to the target temperature 6 or the time period over which the temperature inside the cooking chamber is expected 7 to correspond to the target temperature has expired, the cooking apparatus is 8 configured to operate in an intermittent mode, wherein the intermittent mode comprises 9 a sequence of powering the first heating element, powering the second heating element and powering neither the first nor the second heating element in any order. In 11 some examples, the sequence may comprise at least two of: powering the first heating 12 element, powering the second heating element and powering neither the first nor the 13 second heating element.

Advantageously, including a period of time in which neither the first nor the second 16 heating elements is powered allows for the temperature inside the cooking chamber 17 and the temperature of the cooking support to be more accurately maintained for 18 cooking. That is, the intermittent mode allows for the target temperature to be 19 maintained within the cooking chamber.

21 It may be that, in the intermittent mode, the duty cycles of the first and second heating 22 elements do not sum to 100%. In this case, the remainder of the period of time is spent 23 with both heating elements turned off. It may be that the intermittent mode comprises 24 intermittent mode stages. Each intermittent mode stage may comprise a ratio of time during which the first heating element is powered, the second heating element is 26 powered and neither the first nor the second heating element are powered. Each 27 intermittent mode stage may correspond to a different predetermined ratio.

29 It may be that the method comprises operating in one of the predetermined heating stages from the sequential heating mode, or even the heating stage of the second 31 heating element only mode (i.e. 100% duty cycle of the second heating element and 32 0% duty cycle of the first heating element), once the measured temperature 33 corresponds to the target temperature. This may be another method in which to 34 maintain the target temperature in order to allow food to be cooked at the desired temperature.

1 Controlling the first and second heating elements once the target temperature is 2 achieved may be referred to as a cook cycle. Advantageously, the cook cycle ensures 3 optimum cooking support and cooking chamber air temperatures during the cooking 4 process, ensuring best possible cooking results.

6 That is, the method may comprise operating in a particular intermittent mode stage 7 depending on the target temperature. The method may comprise determining a 8 corresponding intermittent mode stage in dependence on the target temperature.

9 Advantageously, the selection of an intermittent mode stage in dependence on the target temperature allows for the appropriate sequence of heating element powering 11 to be used to maintain the target temperature. For example, a higher target 12 temperature may correspond to an intermittent mode stage in which the ratio of time 13 spent with both heating elements off is lower than the total ratio of time spent with the 14 heating elements on.

16 Once the measured temperature has reached the target temperature, the user may be 17 able to adjust the duty cycles of at least one of the first heating element and the second 18 heating element via user input. Additionally, it may be that the user is able to adjust the 19 duty cycles provided that the measured temperature does not drop by more than a reheat amount (e.g. 100°C) during the cook cycle. Advantageously, this allows the user 21 to adjust the duty cycles of the first and second heating elements, despite the 22 measured temperature dropping when the oven door is opened to insert foodstuff into 23 the oven (e.g. to launch a pizza).

It may be that the method comprises measuring a temperature inside the cooking 26 chamber and, if the measured temperature falls from the target temperature by more 27 than a reheat amount, the method comprises operating in one of the initial, sequential 28 heating or second heating element only mode in dependence on the measured 29 temperature and the target temperature. It may be that, if the measured temperature falls from the target temperature by more than a reheat amount, the cooking apparatus 31 is configured to operate in one of the initial, sequential heating or second heating 32 element only mode in dependence on the measured temperature.

34 For small decreases in temperature (e.g. less than 100°C), the operation of the oven in the intermittent mode will cause the interior of the cooking chamber (air and cooking 36 support) to increase to return to the target temperature. The intermittent mode stage in 37 which is the cooking apparatus is operated in when the measured temperature 1 corresponds to the target temperature typically stays the same regardless of the drop 2 in temperature up to a reheat amount (e.g. 100°C) unless the user changes the duty 3 cycle of the first and/or second heating element via the user input.

If the measured temperature falls by the reheat amount or more (e.g. 100°C or more) 6 than the target temperature during cooking, the cooking apparatus may operate in one 7 of the initial, sequential heating or second heating element only mode. The cooking 8 apparatus may operate in the heating stage or operating mode whose temperature 9 range corresponds to the measured temperature and progress through the heating stages and/or modes until the target temperature is measured inside the cooking 11 chamber. This process may occur automatically once the measured temperature is 12 less than the target temperature by more than a reheat amount. For example, if the 13 sequential mode range is 80°C to 300°C and the measured temperature falls from the 14 target temperature of 350°C to 100°C, the method may comprise operating in the sequential heating mode up to 300°C and the second heating element only mode until 16 the measured temperature corresponds to 350°C. Once the measured temperature 17 again corresponds to the target temperature, the method may comprise operating in 18 the intermittent mode.

It may be that the method comprises receiving a user input to control at least one of: 21 the first heating element and the second heating element. It may be that the cooking 22 apparatus is configured to receive a user input to control at least one of: the first heating 23 element and the second heating element. The method may comprise powering the first 24 or second heating element in dependence on the user input. The method may comprise determining which of the heating elements to power in dependence on the user input.

26 The first and second heating elements may be controlled in dependence on the user 27 input in that the duty cycle of the first and second heating element may be adjusted 28 according to the user input. As mentioned above, the user interface may comprise an 29 input device, such as a rotatable dial, a button, a keypad, a touchscreen or microphone.

Other types of user inputs and user input devices will also be envisaged.

32 It may be that the method comprises receiving a first user input and operating in the 33 initial mode in dependence on the first user input, optionally operating in the initial 34 mode in dependence on the user input for up to a maximum predetermined initial mode time period. The cooking apparatus may be configured to receive a first user input. The 36 first user input may cause the cooking apparatus (e.g. the oven) to power only the first 37 heating element. In other words, the cooking apparatus may operate in the initial mode 1 On which the duty cycle of the first heating element is 100%) in dependence on the first 2 user input. However, the cooking apparatus may operate in the initial mode for a 3 maximum predetermined time period which is independent of the measured 4 temperature or target temperature. That is, when the cooking apparatus operates in the initial mode during the heat up cycle, the time for which the initial mode occurs is 6 dependent on the measured temperature. In contrast, when the cooking apparatus 7 operates in the initial mode in response to the first user input, the time for which the 8 initial mode occurs is independent of the measured and target temperatures. The 9 maximum predetermined time period may be 15, 30, 45 or 60 seconds. This mode of operation may be referred to as a "boost mode". In other example, the oven may return 11 to operating in the intermittent mode once the measured temperature inside the 12 cooking chamber corresponds to the target temperature. It may be that the first user 13 input can only be input if the measured temperature is less than a reheat amount from 14 the target temperature.

16 Advantageously, this allows the temperature of the cooking support to be raised as 17 quickly as possible (i.e. "recharging" the cooking support). The maximum 18 predetermined time period is set so as to prevent the cooking support from overheating.

It may be that the user is able to terminate the cooking apparatus from powering only 21 the first heating element prior to expiry of the maximum predetermined initial mode time 22 period. When the cooking apparatus terminates operating in the boost mode, the 23 cooking apparatus may return to operating in one of the intermittent mode stages for 24 maintaining the target temperature. It may be that the "boost mode" is prohibited from operation for a period of time corresponding to the time for which the "boost mode" was 26 activated, or for a period of time corresponding to the maximum predetermined initial 27 mode time period.

29 Typically, the method may comprise receiving a receiving a balance control user input by a user input element associated with a visual indication, wherein the visual 31 indication comprises a balance indicator indicative of a ratio of the duty cycle of the first 32 and second heating elements. It may be that the method comprises changing the visual 33 indication in dependence on the second balance control user input.

Accordingly, thus the invention extends to an aspect providing a method of cooking 36 using a cooking apparatus. The cooking apparatus comprises an oven, the oven 37 comprising a cooking chamber comprising a cooking support internal to the cooking 1 chamber and an oven door separating the cooking chamber from an external 2 environment of the cooking apparatus, the cooking chamber comprising a plurality of 3 heating elements comprising a first heating element positioned beneath the cooking 4 support to heat the cooking support and a second heating element positioned in an upper region internal to the cooking chamber to heat the interior of the cooking 6 chamber. The method comprises: selectively powering at most one of the plurality of 7 heating elements at any one time; and receiving a balance control user input by a user 8 input element associated with a visual indication, wherein the visual indication 9 comprises a balance indicator indicative of a ratio of the duty cycle of the first and second heating elements. The method comprises changing the visual indication in 11 dependence on the second balance control user input.

13 According to another aspect of the invention there is provided a cooking apparatus 14 comprising an oven, the oven comprising a cooking chamber comprising a cooking support internal to the cooking chamber and an oven door separating the cooking 16 chamber from an external environment of the cooking apparatus. The cooking chamber 17 comprises a plurality of heating elements comprising a first heating element positioned 18 beneath the cooking support to heat the cooking support and a second heating element 19 positioned in an upper region internal to the cooking chamber to heat the interior of the cooking chamber. The oven comprises a heating controller configured such that, at any 21 one time, at most one of the plurality of heating elements is powered. The oven 22 comprises a user input element, configured to receive a balance control user input, 23 associated with a visual indication. It may be that the visual indication comprises a 24 balance indicator indicative of a ratio of the duty cycle of the first and second heating elements. It may be that the heating controller is configured to change the visual 26 indication in dependence on the balance control user input.

28 According to another aspect of the present invention, there is provided a method of 29 cooking using a cooking apparatus comprising an oven, the oven comprising a cooking chamber comprising a cooking support internal to the cooking chamber and an oven 31 door separating the cooking chamber from an external environment of the cooking 32 apparatus. The cooking chamber comprises a plurality of heating elements comprising 33 a first heating element positioned beneath the cooking support to heat the cooking 34 support and a second heating element positioned in an upper region internal to the cooking chamber to heat the interior of the cooking chamber, wherein the oven 36 comprises a user interface comprising a user input element associated with a visual 37 indication for receiving a user input. The method comprises selectively powering at 1 most one of the plurality of heating elements at any one time; and controlling a duty 2 cycle of the second heating element, and optionally a duty cycle of the first heating 3 element, in dependence the received user input, wherein the duty cycle of the first and 4 second heating elements correspond to a percentage of time during which the respective heating element is powered.

7 According to another aspect of the present invention, there is provided a cooking 8 apparatus comprising an oven, the oven comprising a cooking chamber comprising a 9 cooking support internal to the cooking chamber and an oven door separating the cooking chamber from an external environment of the cooking apparatus, the cooking 11 chamber comprising a plurality of heating elements comprising a first heating element 12 positioned beneath the cooking support to heat the cooking support and a second 13 heating element positioned in an upper region internal to the cooking chamber to heat 14 the interior of the cooking chamber, wherein, at any one time, at most one of the plurality of heating elements is powered, wherein the oven comprises a user interface 16 comprising user input element associated with a visual indication for receiving a user 17 input, wherein a duty cycle of the second heating element, and optionally a duty cycle 18 of the first heating element, is controlled in dependence the rotation of the dial, wherein 19 the duty cycle of the first and second heating elements correspond to a percentage of time during which the respective heating element is powered.

22 The user input element is typically accessible to the user when the cooking apparatus 23 is in use. The user input element may be on the oven door and/or on an oven housing 24 (i.e. oven body).

26 The balance control user input may be indicative of a desired ratio of the duty cycles of 27 the first and second heating elements. The method may comprise adjusting of at least 28 one of the duty cycle of the first and second heating elements, in dependence the 29 received balance control user input. Advantageously, controlling the duty cycle of the second heating element and/or the duty cycle of the first heating element, in 31 dependence the received balance control user input, the user is able to adjust the 32 temperature inside the cooking chamber during cooking. This allows the user better 33 control over the cooking process and also improves the cooking quality and efficiency.

Typically, the visual indication conveys information regarding operation of the oven to 36 the user. Typically, the visual indication visually changes in response to the balance 37 indicator. Typically, the balance indicator is indicative of which heating element has the 1 larger duty cycle. The visual indication may also be provided independently of the 2 balance control user input. For example, the visual indication may be provided in 3 dependence on the operating mode and/or the heating stage in which the cooking 4 apparatus is operating during the heat-up cycle. Advantageously, the visual indication conveys information regarding the duty cycles of the first and second heating elements 6 in a user-friendly and convenient manner.

8 It may be that the user input element comprises a rotatable dial. It may be that the 9 balance indicator comprises a plurality of lights. It may be that the plurality of lights forms an arc of at least 120° around the user input element.

12 The user input element may be part of a user interface which may comprise a plurality 13 of input devices. For example, the user interface may comprise a plurality of dials. The 14 user interface may comprise a first dial which is used to for the balance control user input to allow the user to control the duty cycle of the second, and optionally the first 16 heating elements. The user interface may comprise a second dial which is used by the 17 user to select the target temperature. The user interface may comprise a third dial 18 which is used by the user as a timer for the cooking apparatus.

However, the user input element may instead comprise a button, a slider or a 21 touchscreen. Other form of user input elements will also be envisaged.

23 The plurality of lights may be a plurality of LEDs. The method may comprise 24 determining which subset of the plurality of lights to light in dependence on the balance control user input received via the user input element. The subset of the plurality of 26 lights may be indicative of a comparison of the duty cycles of the first and second 27 heating elements in that the position of the subset of the plurality of lights around the 28 dial is indicative of ratio of the duty cycles of the first and second heating elements.

Typically, the subset of the plurality of lights may form an arc of at least 60°, at least 31 80°, at least 1000, at least 120°, at least 140° or at least 160°. It may be that the arc 32 appears to move around the user input element (e.g. dial) as the subset of the plurality 33 of lights which are lit changes in dependence on the user-selected duty cycles of the 34 first and second heating elements.

36 It may be that the user input element is moveable in a first direction and a second 37 direction into a plurality of balance positions. Typically, each of the first and second 1 directions are in a direction away from an intermediate position of the user input 2 element. The method typically comprises, for each balance position in the first direction 3 away from the intermediate position, adjusting the duty cycle of the first heating 4 element by a first amount compared to the duty cycle of the first heating element when the user input element is in the intermediate position. The method typically comprises, 6 for each balance position in the first direction away from the intermediate position, 7 adjusting the duty cycle of the second heating element by a second amount compared 8 to the duty cycle of the second heating element when the user input element is in the 9 intermediate position. It may be that the first and second amounts are equal to 5%. It may be that the user input element is moveable in a first direction and a second 11 direction into a plurality of balance positions. Typically, each of the first and second 12 directions are in a direction away from an intermediate position of the user input 13 element. It may be that the heating controller is configured to, for each balance position 14 in the first direction away from the intermediate position, adjust the duty cycle of the first heating element by a first amount compared to the duty cycle of the first heating 16 element when the user input element is in the intermediate position. It may be that the 17 heating controller is configured to, for each balance position in the first direction away 18 from the intermediate position, adjust the duty cycle of the second heating element by 19 a second amount compared to the duty cycle of the second heating element when the user input element is in the intermediate position. It may be that the first and second 21 amounts are equal to 5%.

23 It may be that the first direction is clockwise, and the second direction is anticlockwise 24 or vice versa. The first direction may be right, and the second direction may be left. The intermediate position may correspond to a predefined central position of the user input 26 element. The balance positions may correspond to predetermined positions of the user 27 input element on either side of the intermediate position. The intermediate position may 28 correspond to a duty cycle of 50% for both the first and second heating elements. For 29 each balance position in the first direction, the duty cycle of second heating element may be adjusted by a second amount (e.g. 5% or 10% of a predetermined total period 31 or a predetermined amount e.g. 5 seconds, 10 seconds) compared to the duty cycle of 32 second heating element at the intermediate position. For each balance position in the 33 first direction, the duty cycle of first heating element may be adjusted by a first amount 34 (e.g. 5% or 10% of a predetermined total period or a predetermined amount e.g. 5 seconds, 10 seconds) compared to the duty cycle of second heating element at the 36 intermediate position. For each balance position in the second direction, the duty cycle 37 of second heating element may be adjusted by a second amount (e.g. 5% or 10% of a 1 predetermined total period or a predetermined amount e.g. 5 seconds, 10 seconds 2 compared to the duty cycle of second heating element at the intermediate position. For 3 each balance position in the second direction, the duty cycle of first heating element 4 may be adjusted by a first amount (e.g. 5% or 10% of a predetermined total period or a predetermined amount e.g. 5 seconds, 10 seconds) compared to the duty cycle of 6 second heating element at the intermediate position. However, the duty cycle of the 7 first heating element may remain the same.

9 The balance positions of the rotatable dial may correspond to discrete sectors of rotation. The one or more discrete sectors may each be of up to 15°, up to 18°, up to 11 20° or up to 25°.

13 It may be that adjusting the duty cycle of the first heating element by a first amount 14 compared to the duty cycle of the first heating element when the user input element is in the intermediate position comprises reducing the duty cycle of the first heating 16 element by the first amount. It may be that adjusting the duty cycle of the second 17 heating element by a second amount compared to the duty cycle of the second heating 18 element when the user input element is in the intermediate position comprises 19 increasing the duty cycle of the second heating element by the second amount. It may be that, for each balance position in the second direction away from the intermediate 21 position beyond a lower balance position, the method comprises increasing the duty 22 cycle of the first heating element by a third amount compared to the duty cycle of the 23 first heating element when the user input element is in the intermediate position. It may 24 be that, for each balance position in the second direction away from the intermediate position, the method comprises providing no power to the second heating element.

26 Typically, the third amount is equal to 5%. It may be that the heating controller is 27 configured to adjust the duty cycle of the first heating element by a first amount 28 compared to the duty cycle of the first heating element when the user input element is 29 in the intermediate position by reducing the duty cycle of the first heating element by the first amount. It may be that the heating controller is configured to adjust the duty 31 cycle of the second heating element by a second amount compared to the duty cycle 32 of the second heating element when the user input element is in the intermediate 33 position by increasing the duty cycle of the second heating element by the second 34 amount. It may be that, for each balance position in the second direction away from the intermediate position beyond a lower balance position, the heating controller is 36 configured to increase the duty cycle of the first heating element by a third amount 37 compared to the duty cycle of the second heating element when the user input element 1 is in the intermediate position. It may be that, for each balance position in the second 2 direction away from the intermediate position, the heating controller is configured to 3 provide no power to the second heating element. It may be that the third amount is 4 equal to 5%.

6 That is, when the user moves the user input element in the first direction, into a balance 7 position, the duty cycle of the first heating element may be reduced, to reduce the 8 amount of time the bottom heating element is powered on over a given time period, 9 and the duty cycle of the second heating element may be increased, to increase the amount of time the upper heating element is powered on over the same given time 11 period. In this case, the first and second amounts may be equal.

13 When the user input element is in a balance position that is in the first direction from 14 the intermediate position, the cooking apparatus may adjust the duty cycles of the first and second heating elements in a way that may be intuitive for the user. By this, it is 16 meant that the user would expect the change in the duty cycle of one heating element 17 to be matched by a change in the duty cycle for the other heating element in duty cycle.

18 The cooking apparatus achieves this by changing the duty cycles of the first and 19 second heating elements by the same amount, such that the first and second amounts are equal. In this way, by rotating the dial clockwise, the second heating element is 21 powered for more time over a given time period and the first heating element is 22 powered for less time over the same given time period. Advantageously, this improves 23 usability of the cooking apparatus because the user can control the cooking apparatus 24 as desired to increase the temperature of the air inside the oven at a higher rate than the temperature of the cooking support. However, in some cases it may be necessary 26 to prevent the user from being able to adjust the duty cycle of a specific heating 27 element.

29 It may be that the method comprises, for each balance position in the second direction away from the intermediate position, increasing the duty cycle of the first heating 31 element by a first amount compared to the duty cycle of the first heating element when 32 the user input element is in the intermediate position. It may be that the method 33 comprises, for each balance position in the second direction away from the 34 intermediate position, reducing the duty cycle of the second heating element by a second amount compared to the duty cycle of the second heating element when the 36 user input element is in the intermediate position. It may be that the heating controller 37 is configured, to for each balance position in the second direction away from the 1 intermediate position, increase the duty cycle of the first heating element by a first 2 amount compared to the duty cycle of the first heating element when the user input 3 element is in the intermediate position. It may be that the heating controller is 4 configured to, for each balance position in the second direction away from the intermediate position, reduce the duty cycle of the second heating element by a second 6 amount compared to the duty cycle of the second heating element when the user input 7 element is in the intermediate position.

9 That is, when the user moves the user input element in the second direction, into a balance position, the duty cycle of the first heating element may be increased, to 11 increase the amount of time the bottom heating element is powered on over a given 12 time period, and the duty cycle of the second heating element may be reduced, to 13 reduce the amount of time the upper heating element is powered on over the same 14 given time period.

16 It may be that, for each balance position in the second direction away from the 17 intermediate position beyond the lower balance position, the method comprises 18 making no change to the duty cycle of the second heating element. Typically, the third 19 amount is equal to 5%.

21 Typically, the lower balance position is a threshold on the dial, beyond which any 22 rotation causes no power to be provided to the second heating element. The duty cycle 23 of the first heating element may be increased to a maximum of 50%.

When the user input element is in a balance position that is in the second direction and 26 beyond the lower balance position, the cooking apparatus may adjust the duty cycles 27 of the first heating element, but does not change the duty cycle of the second heating 28 element. In this way, the control of the duty cycles when the user input element is 29 adjusted in the second direction may be counter-intuitive to the user but is optimised for preventing damage to the cooking apparatus. The cooking apparatus achieves this 31 by changing the duty cycle of the first heating element by a third amount but not 32 changing the duty cycle of the second heating element, or providing no power to the 33 second heating element. Advantageously, this improves allows the user to control the 34 temperature to reduce the temperature inside the cooking chamber whilst preventing the cooking support from overheating, and potential damage.

1 Typically, since the maximum duty cycle of the first heating element is 50% (unless the 2 cooking apparatus is operating in the initial mode or the boost mode), the duty cycle of 3 the first heating element may be reduced in discrete amounts, but may be unable to be 4 increased to a duty cycle greater than 50%.

6 It will be understood that an electric pizza oven is a pizza oven that is powered by 7 electricity. For example, it may be a pizza oven having one or more electric heating 8 means (e.g. electric heating elements).

According to another aspect of the present invention, there is provided a controller 11 configured to perform a method according to any method described herein.

13 It may be that the cooking apparatus comprises a controller configured to perform any 14 of the methods described herein.

16 The controller may comprise one or more processors. The controller may comprise a 17 non-transitory computer readable memory storing instructions. The instructions, when 18 executed by the one or more processors may cause the controller to operate the oven 19 as described herein. The one or more processors may be located in a single unit. In other examples, where the one or more processors is a plurality of processors, the 21 controller may be distributed, which is to say that at least one of the plurality of 22 processors may be located separated from at least one other of the plurality of 23 processors. The controller may be configured to receive at least one input from the one 24 or more components of the oven, for example the temperature sensor. The controller may be configured to transmit at least one output to at least one of: the first heating 26 element and the second heating element. Typically, the cooking apparatus comprises 27 the controller, but in other examples, the controller may be provided separate from the 28 cooking apparatus and in wireless data communication therewith. The controller may 29 be a 'main controller' with additional controllers (e.g. secondary controllers or microcontrollers) also included in the cooking apparatus.

32 It will be understood that any features described above in relation to the apparatus may 33 also be optional features of the other aspects of the invention. Steps in the method may 34 be carried out in the order described herein, or in some cases in another order. In some cases, one or more steps in the method may be carried out simultaneously.

37 Description of the Drawings

2 An example embodiment of the present invention will now be illustrated with reference 3 to the following Figures in which: Figure 1 illustrates a schematic of a cooking apparatus according to an aspect of the 6 present invention; 8 Figure 2 illustrates a schematic of a cooking apparatus according to an aspect of the 9 present invention; 11 Figure 3 illustrates a flowchart of a method according to an aspect of the present 12 invention; 14 Figure 4 illustrates a flowchart of a method according to an aspect of the present invention; 17 Figure 5 illustrates a flowchart of a method according to an aspect of the present 18 invention; Figures 6 to 8 illustrate a user interface according to an aspect of the present invention; 22 Figure 9 illustrates a flowchart of a method according to an aspect of the present 23 invention; Figure 10 illustrates a flowchart of a method according to an aspect of the present 26 invention; and 28 Figure 11 illustrates a schematic of a controller according to an aspect of the present 29 invention

31 Detailed Description of an Example Embodiment

32 Figure 1 illustrates a schematic of a cooking apparatus 100 according to an aspect of 33 the present invention. In particular, Figure 1 illustrates the front of the cooking 34 apparatus 100. The cooking apparatus 100 comprises an oven 110 which comprises a housing or body 120 and an oven door 130. The oven 110 comprises feet 140 on the 36 base. The oven door 130 comprises a handle 150 and a window 160. The oven door 37 130 also comprises a dial 170, functioning as the user input element, for controlling the 1 duty cycle of heating elements within the interior of the oven (i.e. the cooking chamber) 2 and for the user to input the balance control user input. The oven door 130 also 3 comprises a dial 180 to select a target temperature and a dial 190 to select the time for 4 which the cooking apparatus is on. The oven door 130 comprises a button 195, which is a user input device and may be used to initiate 'boost mode'. The cooking apparatus 6 100 comprises a heating controller 175 to control the heating elements inside the oven 7 110. Figure 1 shows the heating controller on the exterior of the oven door 130 for 8 illustrative purposes. However, it will be appreciated that the heating controller is 9 interior to the oven door 130 or may be interior to the oven housing 120. The heating controller 175 controls the duty cycles of the heating elements.

12 Figure 2 illustrates a schematic of a cooking apparatus 100 according to an aspect of 13 the present invention. In particular, Figure 2 illustrates the inside of the cooking 14 apparatus 100 from Figure 1. When the oven door 130 is open, the cooking chamber 105 is accessible. Inside the cooking chamber 105, there is a first heating element 115 16 (also referred to as a bottom heating element) near the bottom of the cooking chamber 17 105 to heat the cooking support 135, in particular the cooking surface 136. Near the 18 top of the cooking chamber 105, there is a second heating element 125 to heat the air 19 within the cooking chamber 105. The cooking support 135 is supported by shelves (not illustrated) such that the cooking support 135 is not in direct contact with the first 21 heating element 115. The oven 110 also comprises a temperature sensor 145, in the 22 rear wall of the cooking chamber 105. The temperature sensor 145 is configured to 23 measure the temperature inside the cooking chamber 105. The temperature sensor 24 145 may be positioned in other places, such as the ceiling. The oven door 130 is connected to the oven 110 by hinges 155.

27 Figure 3 illustrates a flowchart of a method 300 according to an aspect of the present 28 invention. The method includes selectively powering 310 either only the first heating 29 element 115 or only the second heating element 125 at any one time. When each heating element 115, 125 is powered, it consumes the maximum power corresponding 31 to the power rating of the heating element. The method also comprises operating in a 32 sequential heating mode. In the sequential heating mode, the first and second heating 33 elements 115, 125 are controller such that, at any one time, only one heating element 34 is powered.

36 The sequential heating mode involves progressing through a sequence of heating 37 stages. The oven progresses through the heating stages by moving from one heating 1 stage to the next when each upper threshold temperature (i.e. the upper limit of the 2 range for each heating stage) is measured by the temperature sensor 145, or a 3 predefined time period has passed. The method includes determining (or the controller 4 determines) the time period for how long it will take to achieve the upper threshold temperatures for each heating stage based on the ranges and thresholds shown in the 6 table above. The temperature readings within the cooking chamber are determined by 7 the controller using data from the temperature sensor method comprises determining 8 (or the controller determines) the current temperature readings from the temperature 9 sensor 145.

11 Table 1 below shows exemplary operating modes and heating stages of the cooking 12 apparatus. The operating modes and heating stages may be collectively referred to by 13 "Setting Numbers". As previously discussed, the percentage of available time spent 14 with a specific heating element turned on, or no heating element turned on, is known as the duty cycle.

Setting Second First First and Second Elements Off Duty Cycle (%) User Oven Operating Heating stage Number Element Element Selectable Cycle Mode Duty Cycle Duty Cycle (%) (%) 1 0 100 0 No Heat-up Initial N/A 12 0 50 50 Yes Cook Intermittent First / Cook 11 10 50 40 Second 20 50 30 Third 9 30 50 20 Fourth 8 40 50 10 Fifth 2 50 50 0 Heat-up Sequential First heating 3 60 40 0 Second 4 70 30 0 Third 80 20 0 Fourth 6 90 10 0 Fifth 7 100 0 0 Second heating element only N/A 2 Table 2 below shows exemplary temperature thresholds for sequentially progressing 3 through 5 heating stages forming the sequential heating mode and the second 4 heating element only mode (labelled as Setting number 7).

Measured Temperature Setting Operating Heating stage (°C/°F) Number mode 35-99°C / 95-211°F 2 Sequential First heating 100-174°C /212-346°F 3 Second 175-249°C / 347-482°F 4 Third 250-299°C /483-571°F 5 Fourth 299-349°C / 572-662°F 6 Fifth 350-450°C / 663-850°F 7 Second N/A heating element only As an example, the user sets the target temperature using dial 180 as 400°C. The cooking apparatus 100 begins operating in the initial mode (Setting number 1) in which the bottom heating element 115 is the only heating element powered for the entire duration of time operating in the initial mode. The temperature sensor 145 measures a temperature of 35°C in the cooking chamber 105 (i.e. the upper limit of the initial mode temperature range). The cooking apparatus 100 begins operating the sequential heating mode. In particular the cooking apparatus 100 begins operating in the first heating stage of the sequential heating mode (Setting number 2), in which the top heating element 125 is powered for 50% of the duration of the first heating stage and the bottom heating element 115 is powered for 50% of the duration of the first heating stage. It is known that the time taken for the temperature within the cooking chamber 105 to increase from the lower limit to the upper limit of the temperature range for each heating stage is 30 seconds. Therefore, the top heating element 125 is powered for 15 seconds and the bottom heating element 115 is powered for 15 seconds. This occurs in 7.5 second intervals, however it will be appreciated that other intervals could be 1 used. When the upper temperature threshold associated with the first heating stage is 2 measured by the temperature sensor 145, either as a one of a continuous set of 3 measurements or as a measurement at a regular time interval, or when the 4 predetermined time period associated with the first heating stage expires, the cooking apparatus 100 begins to operate in the second heating stage (Setting number 3) in 6 which the duty cycle of the top heating element 125 increases by 10% and the duty 7 cycle of the bottom heating element 115 decreases by 10%. The sequence continues 8 until the temperature sensor 145 measures a temperature of 349°C (i.e. the upper limit 9 of the sequential heating mode temperature range), or until the first predetermined time period for heating the cooking chamber through the sequential heating mode 11 temperature range has passed. The cooking apparatus 100 begins operating in the 12 second heating element only mode in which the top heating element 125 is the only 13 heating element powered for the duration of the second heating element only mode. In 14 this operating mode, the temperature sensor 145 measures the temperature inside the cooking chamber 105 as 400°C.

17 As another example, the user sets the target temperature using dial 180 as 400°C. The 18 cooking apparatus 100 begins operating in the initial mode (Setting number 1) in which 19 the bottom heating element 115 is the only heating element powered for the entire duration of time operating in the initial mode. There is no switching in this mode. The 21 temperature sensor 145 measures a temperature of 35°C in the cooking chamber 105 22 (i.e. the first maximum threshold of the initial mode). The cooking apparatus 100 begins 23 operating the sequential heating mode. In this example of the sequential heating mode, 24 although the amount of time it will take to move from the lower to the upper limit of the temperature range for each stage is not known, the number of switches within each 26 heating stage and the switching period is known. Therefore, the cooking apparatus 100 27 begins operating in the first heating stage of the sequential heating mode, in which the 28 frequency of switches of the heating elements is predetermined as 3 during a 30 29 second given time period. In this example, the first and second heating elements have equal switching periods (although in other cases, the switching periods of the heating 31 elements may be different). As such, in the first heating stage, the first heating element 32 is powered for 7.5 seconds, then there is a first switch to power the second heating 33 element for 7.5 seconds, then there is a second switch to power the first heating 34 element for 7.5 seconds, and then there is a third switch to power the second heating element for 7.5 seconds. This continues until the measured temperature corresponds 36 to the upper limit of the temperature range for the first heating stage, the cooking 37 apparatus 100 begins to operate in the second heating stage in which the frequency of 1 switches in increased. In this example, in the second heating stage, the number of 2 switches per 30 seconds is 6. The sequence continues until the temperature sensor 3 145 measures a temperature of 349°C (i.e. the second maximum threshold of the 4 sequential heating mode). The cooking apparatus 100 begins operating in the second heating element only mode in which the top heating element 125 is the only heating 6 element powered for the duration of the second heating element only mode. In this 7 operating mode, the temperature sensor 145 measures the temperature inside the 8 cooking chamber 105 as 400°C.

Figure 4 illustrates a flowchart of a method 400 according to an aspect of the present 11 invention. The method 400 includes the optional step of measuring 410 a temperature 12 inside the cooking chamber 105. The method 400 includes operating 420 in an initial 13 mode. The method of operating 420 in the initial mode involves powering only the first 14 heating element 115 to heat the cooking support 135. The method 400 also includes operating 430 in a sequential heating mode. The method of operating 430 in the 16 sequential heating mode includes operating one of one or more heating stages as 17 described above. The method of operating in one of the heating stages involves 18 alternately powering the first and second heating elements 115, 125.

The method 400 comprises the optional method step of operating 440 in a second 21 heating element only mode in which only the second heating element 125 is powered.

22 This occurs if the user has set the target temperature as higher than the upper limit of 23 the sequential heating mode temperature range.

The method 400 comprises operating 460 in an intermittent mode, which involves 26 controlling the first and second heating elements 115, 125 in a sequence of powering 27 the first heating element 115, powering the second heating element 125 and powering 28 neither the first nor the second heating element. This sequence may occur in any order.

29 In the intermittent mode, the first heating element 115 always has a duty cycle of 50% such that only the duty cycle of the second heating element 125 changes. The 31 intermittent mode includes intermittent mode stages which correspond to Setting 32 number 8 to Setting number 11 shown in Table 1. In the Setting number 12, the top 33 heating element 125 is not powered at all, whilst the maximum duty cycle of the bottom 34 heating element 115 is 50% and the remaining time is spent with neither heating element powered.

1 In some other examples, the heat inside the oven 110 may be maintained using a 2 heating stage of the sequential heating mode. The table below includes an example of 3 which heating stage the cooking apparatus operates in, depending on the target 4 temperature, once the target temperature has been reached by the measured temperature inside the cooking chamber 105. In this example, the target temperature 6 is set by the user using dial 180 in increments of 25°C (or 50°F) from a minimum of 7 150°C (or 250°F) to a maximum of 450°C (or 850°F). In this example, the heating 8 stages once the target temperature has been reached correspond to the predetermined 9 duty cycles, but it could be that the heating stages correspond to the predetermine number of switches.

12 Table 3 below shows an example of which heating stages may correspond to the target 13 temperature for cooking food once the target temperature is reached.

Target Temperature (°C/°F) Setting Heating Number stage 150°C, 175°C, 200°C / 250°F, 300°F, 350°F 2 First 225°C, 250°C / 400°F, 450°F 3 Second 275°C, 300°C/ 500°F, 550°F 4 Third 325°C, 350°C/ 600°F, 650°F 5 Fourth 375°C, 400°C/ 700°F, 750°F 6 Fifth 425°C, 450°C /800°F, 850°F 7 Sixth 16 Using the example above, the cooking apparatus will operate in the fifth heating stage 17 (Setting number 6) to maintain the target temperature of 400°C.

19 Figure 5 illustrates a flowchart of a method 500 according to an aspect of the present invention. The method 500 comprises receiving 510 a first user input. The first user 21 input is received in the form of the button 195. The method 500 comprises powering 22 520 only the first heating element 115 in response to the user pressing the button 195.

23 In effect, this is the same as operating in the initial mode of the heat up cycle.

Figures 6 to 8 illustrate a user interface according to an aspect of the present invention.

26 The user interface comprises the dial 170 for controlling the duty cycles once a target 27 temperature has been reached. The dial 170 is surrounded a plurality of lights 171 1 (shown as circles). A subset of the lights 172 (shown as black circles) are lit to indicate 2 a comparison of the duty cycle of one heating element compared to the other. The 3 subset of lights 172 comprises 10 of the total of 20 lights. The subset of lights 172 form 4 an arc around the circle. Figure 6 shows the dial 170 in the intermediate position represented by indicator 173. The intermediate position is when the duty cycles of the 6 first and second heating elements 115, 125 are equal and the subset of lights 172 is 7 shown in the centre of the arc formed by all of the lights 171. When dial is rotated 8 anticlockwise, the subset of lights 172 moves anticlockwise as shown in Figure 7.

9 Figure] shows the dial 170 in a balance position in an anticlockwise direction from the intermediate position 173. When dial is rotated clockwise, the subset of lights 172 11 moves clockwise as shown in Figure 8. Figure 8 shows the dial 170 in a balance 12 position in a clockwise direction from the intermediate position 173. Figures 6 to 8 show 13 a lower balance position 174. If the user rotates the dial 170 past the lower balance 14 position 174, the first and second heating elements 115, 125 may be controlled differently than when the dial 170 is not rotated as far as the lower balance position 16 174.

18 Figure 9 illustrates a flowchart of a method 900 according to an aspect of the present 19 invention. The method 900 comprises selectively powering 910 either only the first heating element or only the second heating element at any one time. The method 900 21 comprises the user rotating the dial 170 to a balance position to select a setting number 22 which is indicative of a desired ratio between the duty cycles of the first and second 23 heating elements 115, 125. The method 900 comprises then changing 930 the 24 appearance of the visual indication by lighting up a different subset 172 of lights in response to the user rotating the dial 170.

27 Figure 10 illustrates a flowchart of a method 1000 according to an aspect of the present 28 invention The method 1000 comprises receiving 1010 the balance control user input 29 which corresponds to moving the dial 170 into a desired balance position. The duty cycles of the top heating element 125, and optionally also the bottom heating element 31 115, are controlled depending on the balance position of the dial 170. In use, when the 32 user turns 1010 the dial 170, the heating controller 175 determines by what angle the 33 dial 170 has been rotated and therefore which balance position it is in, and lights up 34 920 a subset 172 of lights forming an arc which has the same angle as rotation of the dial 170. Thus, the position of the subset 172 arc of lights shows the user information 36 about the duty cycles of the bottom 115 and top 125 heating elements. In the method 37 steps 1020, 1030, the duty cycle of at least the first heating element 115, and in some 1 circumstances also the second heating element 125, are varied. The method 1000 2 comprises adjusting 1020 the duty cycle of the first heating element 115, which in this 3 example is a reduction by 5% (i.e. a first amount) for each clockwise balance position.

4 The method step 1030 comprises adjusting the duty cycle of the second heating element 125 by 5% (i.e. a second amount), which in this example is an increase, for 6 each clockwise balance position.

8 The method 1000 may comprise increasing the duty cycle of the first heating element 9 115 e.g. by 5% (i.e. a third amount) for each anticlockwise balance position that is further anticlockwise than the lower balance position 174. When the dial 170 is rotated 11 past the lower balance position 174, the method 1000 may comprise providing no 12 power to the second heating element 125, such that the duty cycle of the second 13 heating element 125 is zero. In other examples, the duty cycle of the second heating 14 element 125 may be maintained such that no change is made to the duty cycle of second first heating element 125 for each balance position beyond the lower balance 16 position 174.

18 The user can rotate the dial 170 arc before the heat-up cycle is complete. The heating 19 controller 175 will not control the duty cycles of the top, and optionally bottom, heating elements (i.e. perform the relevant method steps of 1020, 1030) until the heat-up cycle 21 is complete. In this way, user control is 'locked' until the oven 110 has heated up to the 22 target temperature. Once the heat-up cycle is complete, in that the temperature 23 measured by the temperature sensor 145 reaches the target temperature, the heating 24 controller 175 controls the duty cycles of the heating element(s). Therefore, the dial 170 may be used to set the duty cycle desired after initial heating up and also to vary 26 duty cycle thereafter if the user wants to do so. The heating controller 175 may also not 27 light the subset 172 arc of lights (i.e. perform the relevant method step of 920) until the 28 heat-up cycle is complete.

Figure 11 illustrates a schematic of a controller according to an aspect of the present 31 invention. The controller 1110 represents the heating controller 175 and may also 32 represent a main controller. The controller 1110 comprises one or more processors 33 1120 and a non-transitory computer readable memory 1130. The non-transitory 34 computer readable memory 1130 stores instructions which, when executed by the one or more processors 1120, causes operation of the methods described herein. The one 36 or more processors 1120 calculate timings for the duty cycles of the first and second 37 heating elements. The controller 1110 is part of the cooking apparatus 100. The 1 controller 1110 exchanges and/or transmits data and/or control signals 1125 with other 2 components 1140 of the cooking apparatus. In this example, the controller 1110 3 receives data indicative of the measured temperature from the temperature sensor 145 4 and transmits control signals to power the first heating element 115 and the second heating element 125, being among the other components 1140 of the cooking 6 apparatus 100. The controller 1110 causes the operation of the first and second 7 heating elements in all operating modes and heating stages. Alternatively, the 8 controller 1110 may be separate to the cooking apparatus 100 or distributed between 9 the cooking apparatus 100 and a device external to the cooking apparatus 100. The controller 1110 may exchange and/or transmit data and/or control signals with 11 components external to the cooking apparatus 100.

Claims

1 Claims 3 1. A method of cooking using a cooking apparatus comprising an oven, the 4 oven comprising a cooking chamber comprising a cooking support internal to the cooking chamber and an oven door separating the cooking chamber 6 from an external environment of the cooking apparatus, the cooking 7 chamber comprising a plurality of heating elements comprising a first 8 heating element positioned beneath the cooking support to heat the cooking 9 support and a second heating element positioned in an upper region internal to the cooking chamber to heat the interior of the cooking chamber, 11 wherein the method comprises: 12 selectively powering at most one of the plurality of heating elements at 13 any one time; and 14 operating in a sequential heating mode, wherein the sequential heating mode comprises progressing through one or more predetermined heating 16 stages, each predetermined heating stage comprising alternately powering 17 the first and second heating elements.19

2. The method of claim 1, wherein progressing from one predetermined heating stage to the next comprises progressively adjusting the duty cycle 21 of the first heating element from an initial duty cycle of the first heating 22 element and progressively adjusting the duty cycle of the second heating 23 element from an initial duty cycle of the second heating element, optionally, 24 wherein the duty cycle of the first and second heating elements correspond to a percentage of time during which the respective heating element is 26 powered, optionally, wherein the initial duty cycle of the first heating 27 element and the initial duty cycle of the second heating element is 50%.29

3. The method of any preceding claim, wherein progressively adjusting the duty cycle of the first heating element from an initial duty cycle of the first 31 heating element comprises decreasing the duty cycle of the first heating 32 element and progressively adjusting the duty cycle of the second heating 33 element from an initial duty cycle of the second heating element comprises 34 increasing the duty cycle of the second heating element.36

4. The method of any preceding claim, comprising progressing through one or 37 more predetermined heating stages in dependence on a predefined heating 1 stage dependent threshold, optionally wherein the predefined heating stage 2 dependent threshold is an upper temperature threshold associated with 3 each heating stage and/or a predetermined time period associated with 4 each heating stage, optionally, wherein the method comprises measuring a temperature inside the cooking chamber and progressing through each 6 heating stage in dependence on the measured temperature corresponding 7 to the upper temperature threshold associated with respective heating 8 stage.

5. The method of any preceding claim, comprising operating in the sequential 11 heating mode in dependence on a target temperature.13

6. The method of any preceding claim, comprising: operating in the sequential heating mode for a first predetermined time 16 period; and/or 18 measuring a temperature inside the cooking chamber and operating the 19 oven in the sequential heating mode in dependence on the measured temperature.22

7. The method of any preceding claim, wherein changing the heating 23 element that is powered corresponds to switching of the heating elements 24 and wherein progressing from one heating stage to the next comprises adjusting the frequency of switching of the heating elements.27

8. The method of any preceding claim, comprising operating the oven in an 28 initial mode, before the sequential heating mode, wherein operating in the 29 initial mode comprises powering only the first heating element.31

9. The method of claim 8, comprising: 33 operating in the initial mode for a second predetermined time period; and/or measuring a temperature inside the cooking chamber and operating the 36 oven in the initial mode in dependence on the measured temperature.1

10. The method of any preceding claim, comprising operating the oven in a 2 second heating element only mode, after the sequential heating mode, 3 wherein operating in the second heating element only mode comprises 4 powering only the second heating element.6

11. The method of claim 10, comprising: 8 operating the oven in the second heating element only mode in dependence 9 on a third predetermined time period; and/or 11 measuring a temperature inside the cooking chamber and operating the 12 oven in the second heating element only mode in dependence on the 13 measured temperature.

12. The method of any preceding claim, wherein the initial, sequential heating 16 and second heating element only modes are part of a heat up cycle of the 17 oven.19

13. The method of any preceding claim, comprising operating in an intermittent mode once a target temperature is achieved, wherein the intermittent mode 21 comprises a sequence of powering only the first heating element, powering 22 only the second heating element and powering neither the first nor the 23 second heating element in any order, optionally comprising operating in the 24 intermittent mode in dependence on a target temperature.26

14. The method of claim 13, comprising measuring a temperature inside the 27 cooking chamber and, if the measured temperature falls from the target 28 temperature by more than a reheat amount, the method comprises 29 operating in one of the initial, sequential heating or second heating element only mode in dependence on the measured temperature and the target 31 temperature.33

15. The method of any preceding claim, comprising receiving a first user input 34 and operating in the initial mode in dependence on the first user input, optionally comprising operating in the initial mode in dependence on the 36 user input for up to a maximum predetermined initial mode time period.1

16. A method of cooking using a cooking apparatus comprising an oven, the 2 oven comprising a cooking chamber comprising a cooking support internal 3 to the cooking chamber and an oven door separating the cooking chamber 4 from an external environment of the cooking apparatus, the cooking chamber comprising a plurality of heating elements comprising a first 6 heating element positioned beneath the cooking support to heat the 7 cooking support and a second heating element positioned in an upper 8 region internal to the cooking chamber to heat the interior of the cooking 9 chamber, wherein the method comprises: selectively powering at most one of the plurality of heating elements at any 11 one time; and 12 receiving a balance control user input by a user input element associated 13 with a visual indication, wherein the visual indication comprises a balance 14 indicator indicative of a ratio of the duty cycle of the first and second heating elements; and 16 changing the visual indication in dependence on the balance control user 17 input.19

17. The method according to claim 16, wherein the user input element comprises a rotatable dial, optionally wherein the balance indicator 21 comprises a plurality of lights, and optionally wherein the plurality of lights 22 forms an arc of at least 120° around the user input element.24

18. The method of claim 16 or claim 17, wherein the user input element is moveable in a first direction and a second direction into a plurality of 26 balance positions, each of the first and second directions in a direction away 27 from an intermediate position of the user input element, wherein the method 28 comprises, for each balance position in the first direction away from the 29 intermediate position, adjusting the duty cycle of the first heating element by a first amount compared to the duty cycle of the first heating element 31 when the user input element is in the intermediate position and adjusting 32 the duty cycle of the second heating element by a second amount compared 33 to the duty cycle of the second heating element when the user input element 34 is in the intermediate position, optionally wherein the first and second amounts are equal to 5%.1

19. The method of claim 18, wherein adjusting the duty cycle of the first heating 2 element by a first amount compared to the duty cycle of the first heating 3 element when the user input element is in the intermediate position 4 comprises reducing the duty cycle of the first heating element by the first amount, and adjusting the duty cycle of the second heating element by a 6 second amount compared to the duty cycle of the second heating element 7 when the user input element is in the intermediate position comprises 8 increasing the duty cycle of the second heating element by the second 9 amount, optionally, wherein the method comprises, for each balance position in the second direction away from the intermediate position beyond 11 a lower balance position, increasing the duty cycle of the first heating 12 element by a third amount compared to the duty cycle of the first heating 13 element when the user input element is in the intermediate position, and 14 providing no power to the second heating element, optionally wherein the third amount is equal to 5%.17

20. A controller configured to perform a method according to any preceding 18 claim.

21. A cooking apparatus comprising an oven, the oven comprising a cooking 21 chamber comprising a cooking support internal to the cooking chamber and 22 an oven door separating the cooking chamber from an external environment 23 of the cooking apparatus, the cooking chamber comprising a plurality of 24 heating elements comprising a first heating element positioned beneath the cooking support to heat the cooking support and a second heating element 26 positioned in an upper region internal to the cooking chamber to heat the 27 interior of the cooking chamber, the oven comprising a heating controller 28 configured such that, at any one time, at most one of the plurality of heating 29 elements is powered, and the heating controller is configured to control the oven to operate in a sequential heating mode, wherein the sequential 31 heating mode comprises the heating controller controlling the oven to 32 progress through one or more predetermined heating stages, each 33 predetermined heating stage comprising alternately powering the first and 34 second heating elements.1

22. A cooking apparatus comprising an oven, the oven comprising a cooking 2 chamber comprising a cooking support internal to the cooking chamber 3 and an oven door separating the cooking chamber from an external 4 environment of the cooking apparatus, the cooking chamber comprising a plurality of heating elements comprising a first heating element positioned 6 beneath the cooking support to heat the cooking support and a second 7 heating element positioned in an upper region internal to the cooking 8 chamber to heat the interior of the cooking chamber, the oven comprising 9 a heating controller configured such that, at any one time, at most one of the plurality of heating elements is powered, and a user input element, 11 configured to receive a balance control user input, associated with a visual 12 indication, wherein the visual indication comprises a balance indicator 13 indicative of a ratio of the duty cycle of the first and second heating 14 elements, and wherein the heating controller is configured to change the visual indication in dependence on the balance control user input.17

23. The cooking apparatus according to claim 22, wherein the user input 18 element comprises a rotatable dial, optionally wherein the balance 19 indicator comprises a plurality of lights, and optionally wherein the plurality of lights forms an arc of at least 1200 around the user input element.22

24. The cooking apparatus of claim 22 or claim 23, wherein the user input 23 element is moveable in a first direction and a second direction into a plurality 24 of balance positions, each of the first and second directions in a direction away from an intermediate position of the user input element, wherein the 26 heating controller is configured to, for each balance position in the first 27 direction away from the intermediate position, adjust the duty cycle of the 28 first heating element by a first amount compared to the duty cycle of the first 29 heating element when the user input element is in the intermediate position and adjust the duty cycle of the second heating element by a second 31 amount compared to the duty cycle of the second heating element when the 32 user input element is in the intermediate position, optionally wherein the first 33 and second amounts are equal to 5%.

25. The cooking apparatus of claim 24, wherein the heating controller is 36 configured to adjust the duty cycle of the first heating element by a first 37 amount compared to the duty cycle of the first heating element when the 1 user input element is in the intermediate position by reducing the duty cycle 2 of the first heating element by the first amount, and adjust the duty cycle of 3 the second heating element by a second amount compared to the duty cycle 4 of the second heating element when the user input element is in the intermediate position by increasing the duty cycle of the second heating 6 element by the second amount, optionally wherein the heating controller is 7 configured to, for each balance position in the second direction away from 8 the intermediate position beyond a lower balance position, increase the 9 duty cycle of the first heating element by a third amount compared to the duty cycle of the first heating element when the user input element is in the 11 intermediate position, and provide no power to the second heating element, 12 optionally wherein the third amount is equal to 5%.14

26. A method of cooking using a cooking apparatus comprising an oven, the oven comprising a cooking chamber comprising a cooking support internal 16 to the cooking chamber and an oven door separating the cooking chamber 17 from an external environment of the cooking apparatus, the cooking 18 chamber comprising a first heating element positioned beneath the 19 cooking support to heat the cooking support and a second heating element positioned in an upper region internal to the cooking chamber to 21 heat the interior of the cooking chamber, wherein the method comprises 22 powering at most one of the first heating element or the second heating 23 element at any one time.