EP2784398A2 - Cooking device with door drive and contactless detector - Google Patents

Abstract

The cooking appliance (1) is equipped with user door (3) that is automatically operated between fully opened state and closed state, using door drive unit (4). A non-contact detector (6) is provided for activating the door drive unit, according to which the user door is fully opened and closed.

Description

Field of the invention

The invention relates to an oven with a user door, which has a closed state and an open state.

background

Household ovens usually have at the front of a user door, which has a closed state in which it closes the cooking chamber completely, as well as a fully open state in which it is open to the maximum and the cooking chamber releases.

If the user wants to insert a baking sheet or a grid into the oven, he must first open the user door. To do this, he must turn off the baking sheet or grid.

DE 102009026659 describes a domestic appliance, including an oven, which is provided with an actuating device to open the user door a crack. The actuator may be configured, inter alia, as a non-contact switch. If the switch is actuated, the door opens a little way, so that a handle device on the narrow side of the door is accessible. Although this solution is touted, among other things, for ovens, it is not very well suited for such appliances because of the inherent risk of burns.

Presentation of the invention

It has as its object to provide a cooking appliance in which the use over known devices is simplified.

This object is achieved by the cooking appliance according to claim 1. Accordingly, the cooking device has a door drive for automatically transferring the door from the closed to the fully opened state, and a non-contact detector for activating the door drive. The device is designed in such a way that the door drive completely opens the closed door when the detector is actuated.

In a cooking appliance designed in this way, the user can open the door without his hands being needed. For example, in the above-mentioned case, he does not need to place the baking sheet or the grid in order to then open the door.

Advantageously, the detector is designed such that it is able to detect a container located in front of the user door for food to be cooked, in particular a baking sheet, or a grate located in front of the user door. In this way, it is the detected presence of the container or the grating, which leads to the door opening.

• Der Detektor kann einen kapazitiven Sensor aufweisen, mit welchem ein elektrisch leitfähiger Gegenstand, insbesondere das Backblech bzw. der Gitterrost, vor der Benutzertüre detektierbar ist.
• Der Detektor kann einen induktiven Sensor aufweisen, d.h. einen Sensor mit einer Spule sowie einer Messschaltung, wobei mit der Messschaltung ein von der komplexen Impedanz der Spule abhängiges Signal gemessen werden kann. Wiederum ist der Sensor vorteilhaft so ausgestaltet, dass er in der Lage ist, eine durch das Backblech bzw. den Gitterrost bewirkte Änderung der Spulenimpedanz zu detektieren.

• Der Detektor kann einen optischen Sensor aufweisen, mit welchem ein Objekt vor der Benutzertüre erkennbar ist. In diesem Fall kann der Sensor ein passiver oder aktiver optischer Sensor sein. Ein passiver optischer Sensor ist ein Detektor ohne eigene Lichtquelle, welcher das Objekt vor der Türe im Umgebungslicht erkennt. Ein aktiver optischer Sensor ist ein Detektor mit eigener Lichtquelle, welcher Licht von der Lichtquelle misst, das durch das Objekt beeinflusst wird, z.B. wie bei einer Lichtschranke.
• Der Detektor kann auch einen akustischen Sensor aufweisen, der akustische Befehle (z.B. Sprachbefehle oder andere akustische Signale) detektiert.
• Der Detektor kann auch einen Radiosender und -empfänger aufweisen, mit welchem eine Oszillatorschaltung vor der Benutzertüre detektierbar ist. Diese Oszillatorschaltung kann beispielsweise im Backblech oder Grillrost oder z.B. in einem Handschuh oder Topflappen integriert sein.

For the design of the detector, there are various advantageous variants, which can be used individually or in any combination:

• The detector may have a capacitive sensor, with which an electrically conductive object, in particular the baking tray or the grate, in front of the user door is detectable.
• The detector may comprise an inductive sensor, ie a sensor with a coil and a measuring circuit, wherein the measuring circuit can be used to measure a signal which is dependent on the complex impedance of the coil. Again, the sensor is advantageously designed such in that it is able to detect a change in the coil impedance caused by the baking sheet or the grid.

• The detector may comprise an optical sensor with which an object in front of the user's door can be seen. In this case, the sensor may be a passive or active optical sensor. A passive optical sensor is a detector without its own light source, which detects the object in front of the door in the ambient light. An active optical sensor is a detector with its own light source that measures light from the light source that is affected by the object, such as a light barrier.
• The detector may also include an acoustic sensor that detects acoustic commands (eg, voice commands or other acoustic signals).
• The detector may also include a radio transmitter and receiver with which an oscillator circuit is detectable in front of the user's door. This oscillator circuit can be integrated, for example, in the baking sheet or grill or, for example, in a glove or pot holder.

Furthermore, the cooking appliance can have a light source for illuminating a floor area in front of the cooking appliance, as well as an optical sensor for detecting a user in the floor area. The illuminated floor area indicates to the user where he is e.g. must come, so that the door opens.

The cooking appliance may also have an interface for connection to a portable communication device, in particular a portable telephone. In this case, the cooking appliance is configured to open the door drive to a command from the communication device.

Brief description of the drawings

• Fig. 1 einen schematischen Schnitt durch ein Gargerät,
• Fig. 2 einen kapazitiven Sensor,
• Fig. 3 einen induktiven Sensor,
• Fig. 4 einen optischen Sensor mit Kamera,
• Fig. 5 einen aktiven optischen Sensor,
• Fig. 6 einen akustischen Sensor mit Mikrophon,
• Fig. 7 einen aktiven akustischen Sensor,
• Fig. 8 einen Sensor mit Radiosender und -empfänger,
• Fig. 9 ein Gerät mit Mitteln zum Beleuchten eines Bereichs des Bodens und
• Fig. 10 eine Ausführung mit einer Schnittstelle zu einem tragbaren Kommunikationsgerät.

Further embodiments, advantages and applications of the invention will become apparent from the dependent claims and from the following description with reference to FIGS. Showing:

• Fig. 1 a schematic section through a cooking appliance,
• Fig. 2 a capacitive sensor,
• Fig. 3 an inductive sensor,
• Fig. 4 an optical sensor with camera,
• Fig. 5 an active optical sensor,
• Fig. 6 an acoustic sensor with microphone,
• Fig. 7 an active acoustic sensor,
• Fig. 8 a sensor with radio transmitter and receiver,
• Fig. 9 a device with means for illuminating a portion of the floor and
• Fig. 10 an embodiment with an interface to a portable communication device.

Ways to carry out the invention definitions

Terms of the kind "before" or "behind" are to be understood in the present context from the perspective of the user. For example, the user door is located (in the closed state) in front of the cooking chamber, or the cooking chamber is located behind the user door, and the user himself is standing in front of the user door.

An optical detector is a detector capable of processing light in the near infrared, visible or ultraviolet, i. in a spectral range between 2 μm and 200 nm.

basic structure

Fig. 1 shows a cooking appliance 1, which is in particular an oven, a steam cooker or a microwave oven or a combination of at least two of these types of appliances. The device has a cooking chamber 2 for receiving the food to be cooked. The cooking chamber 2 is closed to the front of a user door 3. The user door 3 has a (in Fig. 1 shown in solid lines) completely closed state in which it closes the cooking chamber 2. Next she owns a (in Fig. 1 shown with dotted lines) fully open state in which it releases the cooking chamber 2. For most devices, the user door is pivotable for this purpose about a horizontal pivot axis in the region of its lower edge. When closed, the door is arranged vertically, horizontally in the fully open state.

To open the door 3, the device has an electrically operated door drive. 4

A controller 5 controls the device. The controller 5 controls in a known manner the cooking and baking functions of the device, but also the automatic opening of the door 3 described in more detail below.

The controller 5 is connected to a non-contact detector 6, the task of which is to generate a signal for activating the door drive 4.

As mentioned above, the detector 6 can be designed in various ways. In principle, however, it serves to recognize the user's desire for opening the door. Several variants for the design of the detector 6 will be described in more detail below.

The cooking chamber 2 is adapted to receive the food, for example, on a baking tray 7 or a grid. In the following, for the sake of simplicity, we are always talking about a baking tray, but this is possible also another, in the cooking chamber insertable container for food or a grid should be meant.

Detection of a baking tray

In one embodiment, the detector 6 may be configured to recognize a baking tray 7 or other container for the food to be cooked, if this is located in a predetermined area in front of the cooking appliance. As soon as such a baking tray is detected and the appliance is in operation, the door 3 is opened. As a result, the door opens automatically when the user approaches the cooking appliance with a baking sheet in his hand.

There are various possibilities for recognizing the baking tray 7. Thus, the detector 6 may comprise a capacitive or inductive sensor, with which the baking tray 7 can be detected. It may also have an optical sensor, e.g. a camera to detect the baking tray.

In the following, such and other variants of the detector 6 are described in more detail.

Capacitive sensor

As mentioned, the detector 6 may comprise a capacitive sensor. Such a sensor is basically suitable for detecting conductive objects in front of the cooking appliance, such as e.g. the mentioned baking tray 7 or the user himself or other objects.

For this purpose, at least one electrode is arranged in the region of the front of the device.

If only one electrode is used, the detector 6 has a circuit for measuring the capacitance of the electrode to ground. When a conductive object enters the area in front of the cooking appliance, this capacity changes, which can be detected by the measurement.

If two electrodes are used, the detector 6 can also have a circuit for measuring the capacitance between the electrodes. This also changes when a conductive object enters the area in front of the cooking appliance.

In both cases, the range of the measurement is usually a few centimeters. To effect the door opening, the user holds the baking sheet e.g. in front of the controls of the device, in the area of the capacitive sensor is arranged. He triggers the door opening.

Fig. 2 shows a corresponding sensor with two electrodes 10, 11, which is connected to a measuring circuit 12. The measuring circuit 12 is, for example, an oscillator whose frequency depends on the capacitance between the electrodes 10, 11. The electrodes 10, 11 may be arranged, for example, behind the non-conductive front wall 13 of the device.

Inductive sensor

Further, the detector 6 may comprise an inductive sensor. Such a sensor is also suitable for detecting conductive objects in front of the cooking appliance.

As an inductive sensor, at least one electric coil is arranged in the region of the front side of the device, which is oriented such that the magnetic field generated by the coil during current flow extends into the region in front of the cooking device and defines the measuring range.

If a conductive object now enters the measuring range, the impedance (real and / or imaginary part) of the coil changes. The detector is equipped with a circuit which generates an impedance-dependent signal, whereby the presence of the object can be detected.

Fig. 3 shows a corresponding sensor with a coil 15, which is arranged behind the front wall 13 is. The coil 15 is connected to a measuring circuit 16. This may in turn be, for example, an oscillator whose frequency depends on the impedance of the coil 15.

Optical sensor

The detector 6 may also include an optical sensor.

Fig. 4 shows an embodiment of a passive optical sensor with a camera 18. This camera is aligned to a measuring range in which an object, in particular a baking sheet or the user to be detected. Again, the camera 18 may be located behind the (in this case transparent) front wall 13 of the device.

The images from the camera are fed to an image recognition circuit 19 which is capable of displaying the object e.g. due to its shape.

Another embodiment of an optical sensor, in this case an active optical sensor, is shown in FIG Fig. 5 shown. This embodiment has a light source 20 and a light detector 21, which are arranged behind the transparent to the light of the light source 20 front wall 13 of the device. The light source 20 and the light detector 21 are connected to an evaluation circuit 22.

The evaluation circuit 22 can generate in one embodiment, for example, short current pulses, with which the light source 20 is excited to emit light pulses. The light detector 21 then measures how much light the light pulses are reflected back. If the evaluation circuit 22 determines that the amount of reflected light is increasing, it concludes that an object, eg a baking tray 7, has entered the measuring area, whereupon the user door 3 of the appliance is opened.

By using a light source 20, in particular a pulsed light source, the measurement is independent of ambient light.

Acoustic sensor

Fig. 6 shows a first embodiment of an acoustic sensor with a microphone 25 and an associated with the microphone command recognition 26th

The microphone 25 may in turn be arranged behind the front wall 13, preferably behind a perforated region thereof. The command recognition 26 serves to detect at least one acoustic command which is associated with the opening of the door 3. This command may be a particular word or word combination (e.g., "open door"). But it can also be a different type of noise, in particular one which the user can produce without further aids and without the aid of his hands, e.g. a whistling or snapping. Advantageously, the command recognition 26 is programmable by the user, so that the user himself can set a desired acoustic command to open the door.

Fig. 7 shows a further embodiment of an acoustic sensor, in this case an active acoustic sensor. This embodiment has an ultrasonic signal generator 28, with which ultrasonic pulses are sent, and an ultrasonic receiver 29, with which reflected pulses are detected. Next, an evaluation circuit 30 is provided.

Similar to the active optical sensor according to Fig. 5 This solution is based on the fact that the signals are reflected by the ultrasonic signal generator 28 from an object 7 and detected by the ultrasonic receiver 29. In addition, the distance of the object from the device can be estimated from the transit time of the signals.

The evaluation circuit 30 is e.g. designed to detect changes in the reflected signal and make it e.g. deduce whether an object is approaching the device, in which case the door is opened.

Radio station and receiver

In the execution after Fig. 8 the detector has a radio transmitter and receiver 33. This sends out a radio signal with which an oscillator circuit 34 can be excited in front of the user door, if this circuit is tuned to the frequency of the radio transmitter and receiver 33. The oscillator circuit 34 in turn emits a signal which can be detected by the radio transmitter and receiver 33.

In a simple embodiment, the oscillator circuit 34 may be a passive RC resonant circuit, as is known, for example, from anti-theft devices. However, the oscillator circuit 34 may be e.g. also be designed as an RFID tag, which has a memory module 35 which contains an identifier which is sent back in response to the received signal, so that detection with higher reliability or differentiation of different objects is possible.

The oscillator circuit 34 may be e.g. be integrated in the baking tray. However, it can also be arranged on other objects, e.g. on a glove or a potholder.

Illumination of the ground area

Fig. 9 shows an embodiment of the cooking appliance 1 in the installed state. The appliance is located at a certain distance from the floor 38 of the kitchen. The apparatus in this embodiment has a light source 39 for generating visible light. The light source 39 is configured to provide a bottom area 40 in front of the cooking appliance illuminated and there generates a visible optical mark. This will tell the user where to stand in order to open the door.

Further, the device has a sensor configured to detect the user when he stands in the floor area 40. This may be one of the above-mentioned sensors. Particularly advantageous is the use of the active optical sensor according to Fig. 5 , because in this case the light source 39 of Fig. 9 the role of the light source 20 of Fig. 5 ie, the light detector 21 is configured to receive light from the light source 39 that has been reflected.

As the light source 39, e.g. a laser light source may be used which creates a spot or pattern in the bottom area 40. However, it is also possible to use a different type of light source, if necessary combined with a suitable projector optics.

The light source 39 is preferably adjustable so that it can be adapted to the height of the device 1 above the floor 38.

Interface to communication device

In the execution after Fig. 10 the detector 6 has an interface 45 to a portable communication device 46, in particular a smartphone, which the user can carry. For example, this may be a Bluetooth interface or a Wi-Fi interface. An application in the communication device 46 communicates with the interface 45 of the cooking appliance and commands it to open the user's door. This can happen, for example, when the user enters a specific command via the application.

Remarks

As mentioned, the device is advantageously designed such that a door opening takes place automatically only when the active device is switched on. Otherwise, the door opening must be done manually.

The closing of the door is preferably always done manually. However, it is also conceivable that the closing of the door takes place automatically, e.g. when the detector 6 detects that the user is away from the device.

The apparatus may also be configured to detect other components for insertion into the cooking chamber in addition to the baking sheet, such as e.g. a grill skewer located in front of the appliance. If the device detects such a component, the door opens automatically.

While preferred embodiments of the invention are described in the present application, it is to be understood that the invention is not limited thereto and may be embodied otherwise within the scope of the following claims.

Claims (11)

Cooking appliance, in particular oven, with a user door (3) which has a closed state and a fully opened state,
characterized in that the oven has a door drive (4) for automatically transferring the door from the closed to the fully opened state and a non-contact detector (6) for activating the door drive (4), such that the door drive (4) upon actuation of the Detector (6) the closed user door (3) completely opens. Cooking appliance according to claim 1, wherein the detector (6) is designed to detect a container located in front of the user door (3) for food to be cooked, in particular a baking tray, or a grate located in front of the user door (3). Cooking appliance according to one of the preceding claims, wherein the detector (6) comprises a capacitive sensor (10 - 12), with which an electrically conductive object in front of the user door (3) is detectable without contact. Cooking appliance according to one of the preceding claims, wherein the detector (6) comprises an inductive sensor (15, 16). Cooking appliance according to one of the preceding claims, wherein the detector (6) comprises an optical sensor (18-22), in particular a passive optical sensor or an active optical sensor. Cooking appliance according to claim 5, wherein the detector (6) comprises a camera (18) and an image processor (19) for processing images from the camera (18). Cooking appliance according to one of the preceding claims, wherein the detector (6) comprises an acoustic sensor (25, 26; 28-30). Cooking appliance according to claim 7, wherein the detector (6) comprises a microphone (25) and an instruction recognition (26) for recognizing user-generated acoustic commands. Cooking appliance according to one of the preceding claims, wherein the detector (6) has a radio transmitter and receiver (33) with which an oscillator circuit (34) in front of the user door (3) can be detected. Cooking appliance according to one of the preceding claims, wherein the cooking appliance has a light source (39) for illuminating a floor area (40) in front of the cooking appliance, and a sensor for detecting a user in the floor area. Cooking appliance according to one of the preceding claims, wherein the cooking appliance has an interface (45) for connection to a portable communication device and is adapted to open the door drive (4) to a command from the communication device.

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