Description

AN OVEN

[0001] The present invention relates to an oven wherein the operation of sources having enhanced and the cooking efficiency is controlled.

[0002] Nowadays, different cooking algorithms are being developed in order to cook various foods automatically. These are aimed at determining the operation durations of the light sources with respect to interior temperature of the oven, humidity or weight of food.

[0003] In order to achieve the desired quality and speed of frying/cooking, heaters operating with the radiation effect and employing light sources, such as halogen and infrared are being used. All foods in this type of ovens can be cooked without the need for pre-heating since radiation is transmitted directly on the foods. However, there is not a homogenous heat distribution in this type of oven cooking chambers, where only the light sources are employed for cooking; thus, creating a general cooking algorithm by means of temperature measurement is not possible.

[0004] In the state of the art European Patent Application No EP0701387, a humidity sensor is employed in the cooking chamber. By means of the signals taken from the humidity sensor, the change in humidity with the lapse of time is determined. By means of acquired humidity changes, the degree of doneness of the food, the approximately remaining cooking time and power level are determined.

[0005] In the state of the art Japanese Patent Application No JP6113714, a cake baking process in an oven with a microwave energy source is defined. In the oven, together with the microwave energy source used as heater, a radiative-type heater that allows browning the surface of a cake is used and thus two-step cooking process is applied. In the first phase of the cooking, by the use of microwave energy source the cake is baked until it shows rapid raising and in the second phase it is browned by means of radiation. The decision to shift from the first cooking phase to the second is made by a control unit and while making this decision a temperature sensor and/or a humidity sensor are used together with a weight sensor.

[0006] In the state of the art United States of America Patent No US5883362, it is

allowed to turn on, reduce and turn off the light sources at certain intervals with regards to the measured temperature inside the oven. Hereby selecting the total cooking period, the operation durations of the light sources are calculated. Since the radiation spread from the light sources heat only the food that it penetrates, the temperature measured in the environment does not reflect the temperature of the food.

[0007] The aim of the present invention is the realization of an oven wherein cooking efficiency is enhanced.

[0008] The oven realized in order to attain the aim of the present invention is explicated in the claims.

[0009] In the oven of the present invention, the operation of the light source in the heating, cooking and crusting phases are controlled based on the humidity value in the cooking chamber.

[0010] In the heating phase, employing the light source constantly heats all parts of the food. In the cooking phase where the humidity amount increases compared to heating phase, light source is employed at pre-determined intervals by the manufacturer. In the cooking phase, employing the light source by switching at pre-determined intervals prevents the early formation of crust on the food and enables the inside of the food to be cooked. In the crusting phase, where the humidity level is in the top level, the light source operates less comparing to the cooking phase. Thus, the crust formed on the food is cooked evenly without burning.

[0011] In another embodiment of the present invention, the ratio of the humidity value measured in the heating phase by the control unit is determined with regards to the initial humidity value measured via the humidity sensor and the light source operates constantly until this ratio reaches the pre-determined value set by the manufacturer. In the preferred embodiment of the present invention, this ratio is 20%.

[0012] In another embodiment of the present invention, the ratio of the humidity value measured in the cooking phase by the control unit is determined with regards to the initial humidity value measured via the humidity sensor and the light source operates at pre-determined intervals set by the manufacturer until this ratio reaches the pre-determined value set by the

manufacturer. In the preferred embodiment of the present invention, this ratio is 65%.

[0013] In another embodiment of the present invention, the ratio of the humidity value measured in the crust phase by the control unit is determined with regards to the initial humidity value measured via the humidity sensor and the light source operates less and stays closed for a longer time compared to the cooking phase until this ratio reaches the pre-determined value set by the manufacturer. In the preferred embodiment of the present invention, this ratio is 120%.

[0014] By means of the present invention, it is enabled to cook the food and make the crust formed on it at the level desired by realizing a more effective cooking process.

[0015] The oven realized in order to attain the aim of the present invention is illustrated in the attached figures, where:

[0016] Figure 1 - is the schematic view of an oven.

[0017] Elements shown in the figures are numbered as follows:

[0018] L Oven

[0019] 2. Cooking chamber

[0020] 3. Light source

[0021] 4. Humidity sensor

[0022] 5. Control unit

[0023] The oven (1) comprises a cooking chamber (2) wherein the cooking process is realized, at least one light source (3) inside the cooking chamber (2) enabling the operation of the cooking process with the light waves transmitted and a humidity sensor (4) that measures the humidity value in the cooking chamber (2).

[0024] The oven (1) further comprises a control unit (5) that separates the cooking process into a heating phase where heating process takes place, a cooking phase where cooking process takes place and a crust phase where crust forming process takes place with regards to initial humidity value (h,) measured by the humidity sensor and one or more light sources (3) that • operate constantly in the heating phase where the humidity amount is in

low level,

• operate at pre-determined intervals set by the manufacturer in the cooking phase where the humidity amount increases,

• operate less and stay closed for longer time in crust phase, where the humidity level is in the top level, compared to the cooking phase.

[0025] Thus, the cooking process is controlled by determining the operation durations of light sources (3) in the heating, cooking and crust phases with regards to the initial humidity value (h,) measured by the humidity sensor (4) in the cooking chamber (2) at the beginning of cooking process.

[0026] Infrared lamp that transmits light in the wavelength, preferably penetrating both into the surface and inside of the food, is used as a light source (3).

[0027] In the heating phase, by operating the light source (3) constantly, all parts of the food is heated. The humidity value measured in the cooking chamber (2) in the heating phase is low. In the cooking phase where the humidity amount increases compared to the heating phase, light source (3) is operated at pre-determined intervals by the manufacturer. In the cooking phase, operating the light source (3) by switching it at pre-determined intervals prevents the early formation of crust on the food and enables the inside of the food to be cooked. In the crust phase, where the humidity level is in the top level, the light source (3) operates less and stays closed for a longer time compared to cooking phase. In other words, the rate of staying closed for the light source (3) is reduced. Thus, the crust formed on the food is cooked evenly without burning.

[0028] In an embodiment of the present invention, the humidity sensor (4) is placed in the chimney of the oven (1). Thus, effective measurement of the humidity in the cooking chamber (2) is provided.

[0029] In another embodiment of the present invention, the ratio of the humidity value measured in the heating phase (h _A ) by the control unit (5) is determined with regards to the initial humidity value (h,) measured via the humidity sensor (4) and the light source (3) operates constantly until this ratio reaches the pre-determined value set by the manufacturer. When this ratio is reached, the heating phase is completed and the cooking phase is started. In a preferred embodiment of the present invention, this ratio is

20%.

[0030] In another embodiment of the present invention, the ratio of the humidity value (h _B ) measured in the cooking phase by the control unit (5) is determined with regards to the initial humidity value (h,) measured via the humidity sensor (4) and the light source (3) operates at pre-determined intervals set by the manufacturer until this ratio reaches the pre-determined value set by the manufacturer. When this ratio is reached, the cooking phase is completed and the crust phase is started. In a preferred embodiment of the present invention, this ratio is 65%.

[0031] In another embodiment of the present invention, the ratio of the humidity value (h _c ) measured in the crust phase by the control unit (5) is determined with regards to the initial humidity value (h,) measured via the humidity sensor (4) and the light source (3) is kept operating less and stays closed more than it is in the cooking phase until the ratio reaches the pre-determined value set by the manufacturer. When this ratio is reached, the crust phase is completed. In the preferred embodiment of the present invention, this ratio is 120%.

[0032] By means of the present invention, it is enabled to cook the food and make the crust formed on it at the level desired by realizing a more effective cooking process.