DE102010039371A1 - Control apparatus for domestic appliance e.g. electric cooker, has detector that detects position of object in detection range and sends detection signal to control unit to control operations of operator and position of object - Google Patents

Abstract

The control apparatus has optical detection device (3) with a detector (5) which is adapted to detect the position of an object (10) within the detection range, and sends the detection signal to a control unit (7) to control operations of operator and/or position of object. An optical projection device has a light source (6a) that forms the image of a particular user interface in accordance with the coverage of the optical detection device. An independent claim is included for domestic appliance.

Description

The invention relates to a control device for a domestic appliance with a control unit. Furthermore, the invention relates to a domestic appliance with such a control device.

The control of household appliances is usually via a variety of switches, buttons and buttons. These are representational components that are firmly attached to the household appliance and allow operation by an operator. In addition, so-called touch or touch sensors are known. Specifically, these are resistive, capacitive and infrared touch sensors. The latter usually include a transmitting and receiving unit. Such touch sensors are today usually in the so-called white goods, z. B. in electric stoves used. Touchscreens or touchpanels have also been introduced in other areas. These screens typically use a resistive process (3-wire or 4-wire versions) and are particularly useful in PDA devices.

Recently, principles for position determination by means of CCD array or CCD line were known (CCD = Charge-Coupled Device). Here is the "Virtual Keyboard" (eg company VKB or company Canesta) to call the Seiko Notepad and the Pegasus Notepad. It is a projection of a keyboard by means of microdia and laser LED as light source. The image recognition takes place with the aid of an infrared auxiliary beam and the detection by means of a CCD chip. Other forms of video surveillance with image recognition are known.

For operating a household appliance, an operator usually requires a large amount of information. The individual functions of a control element, eg. As a button are usually printed directly on the control or read according to the respective operating position of the control. Changing information, such as the heating level of a stove or its temperature, can be displayed on various display devices. In the simplest case, these are printed numbers on a wheel, which are visible in a transparent section depending on the respective wheel position. In addition, a variety of electronic ads are in use. These include the LED display (LED = Light-Emitting Diode), the 7-segment display and the LC display (LC = Liquid Crystal).

Projection systems are known from presentation technology (eg beamer) and entertainment (eg laser TV, planetariums). In the low-price segment, this projection technology is also known by project-based alarm clocks. A special form of virtual projection, the so-called head-up projection, is used in aviation and increasingly also in the automotive industry.

It is an object of the present invention to simplify the operation and control of a domestic appliance.

This object is achieved by a control device having the features of claim 1, and a domestic appliance, which has the features of claim 11. The control device according to the invention comprises a control unit and an optical detection device with a detector. The control unit is in particular designed to control or regulate functions of the domestic appliance. For example, if the domestic appliance is a stove, the control unit allows, for. B. turn on or off individual hobs and adjust their temperature. According to the invention, the detector of the optical recognition device is designed to detect operating processes of an operator within a detection area and, based thereon, to send signals to the control unit. The detector is in particular a light-sensitive detector. The detection range of the detector is the spatial area within which changes and / or patterns and / or arrangements can be detected by the detector, ie can be detected. If the detector is, for example, a camera, the detection range is given by the field of view of the camera. The operating procedure of the operator may in particular be a movement of the hand or grasping. If the operator grasps the detection area or moves his hand within the detection area, this can be detected, for example, by the detector and signals can be generated in the detector which are passed on to the control unit.

In particular, the detector can also detect spatially resolved within the detection range, ie. H. he not only recognizes whether an operator reaches into the detection area or does not attack, but can, for. B. register the spatial position of the hand of the operator within the detection area. The signal generated by the detector will then differ depending on the spatial position of the hand, so that the control unit based on the different detector signals is able to make the respective control operation depending on the hand position.

Alternatively or additionally, it is provided according to the invention that the detector is designed to detect a position of an object and / or to detect an extension of an object within a coverage area. The article may be, for example, a pot. For example, if the detection area includes the hob of a cooker, the detector is capable of detecting e.g. B. to determine the position of the pot. In addition, if necessary, the detector is also designed to detect the extent, ie the spatial size of the pot, and to pass on corresponding signals to the control unit. So it is both a position detection or location possible and possibly an image or pattern recognition. The detection area can be in free space; However, he can also on all surfaces, eg. As walls, worktops, equipment fronts, floors, etc. relate. The information transmission from the detector to the control unit and / or the information or signal output by the control unit may be wireless (eg radio, infrared radiation) or wired (eg powerline, bus).

A control device designed in this way allows a simple, flexible and uncomplicated control of a domestic appliance. Individual control elements no longer need to be pressed, touched, rotated or otherwise mechanically actuated with respect to their orientation or position. For example, keys for an operator within the detection area on a control panel are merely marked or printed. The buttons thus applied on a surface are then no longer keys in the true sense, since their direct contact no longer brings about a local effect (eg electrical signal). Such key markers then merely represent symbols that make it easier for the operator to identify a location. For example, if an operator grasps a so-marked virtual key, the location of the hand is detected by the detector and a signal specific to the location is sent to the control unit.

For example, glass ceramic hobs of a cooker create a soothing and visually pleasing surface on which individual hobs are not readily apparent to a user. The location of a stove plate is usually symbolized to the user via a printed circle. If a pot is placed on one of the displayed cooking plates by the operator, this can be automatically detected, for example, by the optical detection device. Does the operator then z. B. the operation of turning on a stove, then the control device, depending on the automatically detected position of the pot exclusively the respective stove plate on which the pot is turned on.

With the aid of the control device according to the invention z. B. be dispensed with conventional controls. It is possible to create a mechanically stable, vandal-proof user platform or user interface. Such a surface is then less susceptible to wear, since the controls are only virtually realized via the optical detection device. For example, printed markings can also be completely eliminated, so that a particularly visually appealing and calm user interface is created. Then the position of the respective operating positions or virtual buttons within the detection range can also be made very variable. For example, the detector and / or the control unit can be informed via a new software that a modified partial area of the detection area now corresponds to a new functionality. Thus, the control device can be very variably adapted to the use in different household appliance.

Preferably, the control device also has an optical projection device. This comprises a first light source, which is designed to project an image at least into the detection area of the recognition device. The image may generally be the visual presentation of information to a user, e.g. B. in the form of writing, symbolic representations or photographic illustrations. In particular, the image is the image of a user interface. The projected image then creates a virtual user interface. In order to project the image into the detection area of the recognition device, it is particularly advantageous to provide a suitable projection area within the detection area.

In addition to the first light source, the optical projection device can in particular also include a beam-shaping optical system, a projection object, a magnifying optical system and an exit optical system. The first light source is in particular a point source. Accordingly, light sources with the smallest possible geometric source dimensions and small divergences (emission angles) are to be preferred. The closest comes, for example, a laser (eg, laser diode), a conventional and high-intensity LED or a halogen light source. Depending on the required projection color, the corresponding color tone (wavelength) can be selected for the light source. This is possible in particular with lasers and LEDs. Alternatively, one can also use a color filter, especially in halogen light. Depending on the type of projection object, a projection can also take place with separate basic projection colors (RGB = red, green, blue), which can later be overlaid optically. For temporally rapidly changing projection objects, a time-sequential lighting with the RGB basic colors is also suitable. For colored projection objects can Also, a white light source may be provided as a first light source.

In the optical projection apparatus, a beam shaping optics can also be provided, which in particular serves for collimating (parallelizing) the beam path of the first light source and for shaping the beam to a suitable size. Then it can be achieved that almost the entire beam illuminates the projection object, so that high projection intensities are achieved.

In particular, a suitable projection object can serve to generate the projected image. In the simplest case, the projection object may be a slide, ie a translucent photographic image. The projection object may also be a so-called microdisplay, which may be formed according to the prior art by an LC display, a ferroelectric display or a DLP (Digital Light Processing). But also future types of reflective or transmissive display modules (eg displays, DLPs) are suitable. Decisive for their projection suitability is here only the highest possible reflectivity and / or transmissivity. While LC displays can usually be operated both transmissively and reflectively, ferroelectric displays and DLPs can generally only be operated in a reflective manner. In the transmissive version, the projection object or display is irradiated by the luminous flux. In the reflective embodiment, the projection object or microdisplay is illuminated frontally, with the correspondingly active regions of the projection object reflecting the incident light. With this type of lighting, the angles of the components are very important. Alternatively, a beam splitter device may be used. Depending on the type of microdisplay, in turn, a simultaneous projection with separate basic projection colors with subsequent superimposition in the projection plane, or a time-sequential overlaid projection of individual images of the three primary colors can take place.

It can be provided a magnification and exit optics. Here, the corresponding geometry is subject to the laws of geometric optics. The optical components can preferably be made entirely of inexpensive plastic. For example, plastic lenses can be used. The exit opening for the light emitted by the light source may consist of a tempered glass or plastic window. But it can also be optionally executed as a lens.

A special feature, especially for beam guidance in front projection, is the image guidance by means of optical fiber. Here, the original image (display display) is coupled into a fiber bundle and expanded on the projection side by means of magnifying optics to the projection size.

The projection device may also be designed to perform a so-called keystone correction. This will be briefly described. With any kind of projection, there are no problems as long as you plan them symmetrically and axially. However, if one projects at an angle other than 90 °, ie perpendicular to the projection surface, distortions result. This effect can be compensated within certain limits by means of a pictorially opposing predistortion or by appropriately designed magnification optics. This predistortion is called keystone correction.

Via the optical projection device, visually prepared information can be projected into the detection area of the recognition device. In particular, this information can be symbols, lines, markers and simple graphical representations. For example, they symbolize an operator that grasping in the area thus marked triggers an operating procedure. It can be created in this way so virtual panels. A virtual user interface is created which, in cooperation with the optical recognition device, exhibits its main advantages. It then comes namely to a combination of projection on the one hand and position detection of the corresponding user action on the other. The operator is presented on the projection device, the image of a user interface on which they can make operations in the usual manner. However, the pictorial controls are not actually served. Rather, the actions performed are registered by the recognition device, properly rendered, passed to the control unit and processed there to perform actual control operations. For example, the operator touches the image of a button projected by the projection device. The position of the finger of the operator is registered by the recognition device and it is (in spatially resolved detection) associated with a location coordinate. This location coordinate then corresponds to a particular control operation performed by the control unit (eg, turning on a stove top).

By changing the projected images and changing the assignment rule, a completely new functionality can be achieved in such a simple and uncomplicated way. In addition, an almost arbitrarily large display area with a correspondingly large user area can be achieved by the projection. The projection is also on the most diverse Devices and surfaces in a variety of positions and locations possible.

In a special embodiment, the direct projection onto real operating units (eg keys) and / or on the actuators (eg cooktop) can also take place. This special type of projection can be based on the principle of virtual operation.

Preferably, the projection device comprises imaging optical components and is configured to project the image in an optically imaging method. The optically imaging process simultaneously projects all the points of the image. This is done in particular by the fact that all points of the projection object are penetrated simultaneously by an expanded beam and then by suitable beam-forming components, eg. As lenses, are displayed on a projection screen. It is therefore an imaging method, as in the prior art z. B. of slide projectors and film projectors is known.

Preferably, however, the projection device can also be designed to project the image in a raster process. In a raster method, the entire image to be displayed is not simultaneously projected on the projection surface, but constructed point by point. For example, there is the possibility of realizing a virtual user interface by means of a scanning unit (cf., for example, laser TV). In this case, a collimated light beam or a laser beam can be used by means of an XY deflection unit for image construction. In this embodiment, suitable light sources are in particular high-power lamps, semiconductor lasers or other powerful light sources. Conventional light sources require focusing and collimating the light beam. This is usually omitted with a laser light source. The XY deflector is necessary for column and line feed. By using a light color you can create a monochrome image. If RGB basic colors are used, a full color representation is possible. The raster method generally allows a very flexible and adapted representation with simultaneously high light intensity. A projection object can optionally be omitted in this embodiment, since the image is built up in sections by the rastering light beam itself.

It is particularly preferred if the projection device is designed to project temporally changing images. Then, for example, a time-varying user interface can be displayed, which adapts individually to the operations of an operator. For example, by operating a projected virtual control element, an operator can achieve that the virtual control elements previously shown are no longer projected, but new virtual control elements are presented which are particularly relevant for the respective control operation. A control operation specially adapted to the operating procedure becomes possible as a result. Such a dynamic projection can z. B. done via a slide change. It is also possible that a movie is being drawn. The microdisplays according to the prior art, which have already been described in detail, likewise permit a temporally dynamic image sequence.

Preferably, the detection device comprises optically imaging elements which are arranged such that they image at least a partial area of the detection area onto the detector. The imaging optics allow a particularly good spatial resolution of the detection area. The detector can then operate according to a video surveillance with image recognition, for example. A high spatial resolution allows the operator's operations and / or a position of an object to be detected very accurately. The extent of an object can also be determined well by means of a high spatial resolution.

Preferably, the detector is an integrated semiconductor device, in particular a so-called charge-coupled device (CCD). As a result, a cost-effective implementation with high detection efficiency and very good spatial resolution is possible.

Preferably, the recognition device comprises a second light source. The second light source emits light rays for which the detector is sensitive. These light beams then form reference beams, which facilitate detection of the operations of an operator and / or the detection of a position of an object and / or the determination of the extent of an object. The reference beams emitted by the second light source preferably illuminate the detection area and are the light signals that can be detected by the detector. By objects in the detection area, the reference beams are then blocked or scattered in particular on their way to the detector. The second light source thus provides the basis for providing sufficient contrast to the detector. Since objects within the detection area usually do not emit light themselves, the second light source is required to provide sufficient illumination for the objects.

The second light source and the detector may be disposed opposite each other, the detection area extending between the detector and the second light source. The second The light source and the detector can also be arranged next to each other, wherein the detection area extends perpendicular to the detector and to the second light source. However, any relative arrangements between the detector and the second light source are possible as long as the second light source illuminates, in particular, a subarea of the detection area. In particular, the second light source of the recognition device and the first light source of the projection device can be accommodated in the same housing and optionally also use the same magnification or exit optics. The first light source may in particular also be identical to the second light source.

It is particularly preferred if the second light source emits its light pulsed in time. In particular, the frequency of the modulation of the second light source can be selected to be sufficiently high, so that a clear distinction from other light sources, such as sunlight or a 50/60 Hertz room lighting is possible. The detector may then be configured to be tuned to this modulation of the second light source. This allows the detector to be protected from false light coming from surrounding light sources. Is the second light source z. B. modulated with high frequency, so you can use a high-pass filter at the detector to filter out the low-frequency components (eg., Sunlight, 50/60-Hertz lamps). As a result, it is possible to achieve the greatest possible insensitivity to stray light. When determining the filter limit, common test methods can be taken into account (eg EMC). Optionally, one can also work with a band filter at the detector in order to filter out possibly interfering wavelength ranges.

The second light source is preferably designed to emit electromagnetic radiation of one wavelength or several wavelengths from the range of 0.78 μm to 1000 μm, that is to say wavelengths from the infrared range. It is particularly preferred in this case if the values of the wavelength or of the wavelengths are from the range 0.78 μm to 3 μm. Then the second light source emits near-infrared light. Very particular preference is given here to wavelengths from the near-infrared spectral range of less than 1 μm. Then can be used as a material in the detector cost-effective silicon. In addition, a good distinction from the visible radiation of the first light source of the projection device is possible.

Furthermore, it is preferred if the second light source is designed to project the image of a grid into the detection area. The projected stripe or check pattern makes it possible to close the position and / or shape of an object in a particularly simple manner. If, for example, the projected grid is interrupted by an object (eg pot, finger), then one can infer the corresponding position of the object. Simply count from the center the number of vertical and horizontal grid lines up to the position where the line shape is interrupted. One can also infer the shape of the object (pattern recognition). Finally, based on geometric conditions, the distance to the user interface on which the projection takes place can be closed and, if necessary, the brightness and sharpness of the projection can be readjusted.

Furthermore, the invention relates to a domestic appliance, which has a control device according to the invention or an advantageous embodiment thereof. Under a household appliance is understood in the present case a device that is used for household management. This may be a large household appliance, such as a washing machine, a tumble dryer, a dishwasher, a cooking appliance, a cooker hood, a refrigerator, a fridge-freezer or an air conditioner. But it can also be a small household appliance, such as a coffee machine or a food processor. The household appliance is in particular a device for preparing food, and in particular a stove.

Preferably, the projection device and / or the second light source and / or the detector are installed in a common module. The individual components are therefore located in a common housing. This allows a particularly compact design of the control device and easy integration into a domestic appliance.

Preferably, the module is arranged so that it is retractable in the domestic appliance, wherein the projection device and / or the detection device are functional in the extended state and the projection device and / or the detection device in the retracted state are not functional. If the module is not needed with the control device, the module can be sunk and it results in a uniform and calm visual design of the household appliance. The operator can z. B. on the submerged module and also the cleaning of the household appliance can be facilitated.

The sinking and / or extension of the module can be done mechanically and / or magnetically and / or motorically and / or electrically and / or electromotively. In a mechanical embodiment, for example, a spring can be biased and holding done via a grid.

Preferably, such a domestic appliance also comprises a motion sensor and / or a brightness sensor, which are designed to control the sinking and / or extension of the module as a function of a detected movement or brightness. Such sensors then allow the activity of the control device or of the module to be adjusted according to the criterion of the presence of persons or to be adapted to the respective lighting conditions. For example, the module with its components can only become active as soon as the motion detector supplies a signal indicating the presence of an operator in the room with the domestic appliance. For example, the device can be set according to the respective needs via the distance setting in the motion detector for the area to be detected. So z. B. a constant activation and deactivation are prevented by the sole passing of the motion detector. In general, however, it can be provided that the module is extended and active as soon as a person is in the room or in the vicinity of the household appliance. Accordingly, it can be provided that the module is retracted or inactive when there is no person in the room or it is so far away from the household appliance that the motion detector does not provide a signal. Analog can be reacted to a change in lighting conditions.

In addition, it can be provided that the light intensity of the first and / or second light source is adapted to the respective lighting conditions. Information about this can go to the control device through the brightness sensor. For example, if the environment of the Haugeräts bright, so the projection light intensity of the first light source can be selected high. On the other hand, when the environment of the module is dark, a low display brightness is sufficient and the luminous flux of the first light source of the projection device can be made small. This is an automatic readjustment, which allows an individual adaptation to the respective environmental conditions, possible.

Furthermore, it is preferred that the module is separable from the domestic appliance. Such a module may then be designed to fit a single domestic appliance and be removed from it. Alternatively, however, the module can also be combined and used with a plurality of different types of domestic appliances. Then, the module is a multi-media and display device for several devices in the household appliance area. Even a universal use both in the kitchen and / or in the general home appliance sector and / or in the entire home (including brown goods, home networking, etc.) is conceivable. This creates an extremely flexible control device.

The preferred embodiments presented with reference to the control device according to the invention and their advantages apply correspondingly to the domestic appliance according to the invention.

Further features of the invention will become apparent from the claims, the figures and the description of the figures. The features and combinations of features mentioned above in the description as well as the features and feature combinations mentioned in the description of the figures and / or features and feature combinations shown alone in the figures are usable not only in the respectively specified combination but also in other combinations or alone, without departing from the scope of the invention.

Reference to exemplary embodiments, the invention is explained in more detail below. Show it:

1 a schematic perspective view of a domestic appliance with a control device according to a first preferred embodiment;

2 a schematic perspective view of a glass ceramic field with a control device according to a second preferred embodiment;

3 a schematic perspective view of a glass ceramic field with a control device according to a third preferred embodiment;

4 a schematic perspective view of a glass ceramic field with a control device according to a fourth preferred embodiment;

5 a schematic perspective view of a grid-like projection of an infrared reference pattern by the detection device; and

6 a sketch for the evaluation of the strip information in the reference pattern of 5 ,

In the figures, identical or functionally identical elements are provided with the same reference numerals.

1 shows a stove 1 with a glass ceramic field 2 on which there are several hotplates 9 are located. The hotplates 9 are on the top O of the glass ceramic field 2 arranged. On them objects can be turned off, which are to be heated, z. B. a pot 10 , The stove 1 further comprises a projection device 4 , which above the glass ceramic field 2 is appropriate. The projection device 4 includes a first light source 6a , which is adapted to send light rays La on the glass ceramic field. By in the 1 represented four light beams La is thus given a projection range. Inside the projection device 4 There is also a suitable projection object whose image is on the glass ceramic field 2 is projected. In the exemplary embodiment, this image is circular markings for the hobs 9 as well as rectangular key marks, which are virtual controls 11 form. Opposite the underside U of the glass ceramic field 2 is a detector 5 arranged. The detector 5 is part of the recognition device 3 which is also the second light source 6b includes, in a common housing with the first light source 6a is installed. The detector 5 In the exemplary embodiment is a CCD camera, which is sensitive to infrared radiation. Their detection range is through the four lines S in the 1 shown schematically. At the second light source 6b it is an infrared light source with an emission wavelength of 1 micron, which is a light beam with the light beams Lb on the glass ceramic field 2 applied. The first light source 6a and the second light source 6b use a common projection optics 8th , The detector 5 is with a control unit 7 over a cable 13 connected. The glass ceramic field 2 is in the embodiment of 1 at least partially transparent to at least the light beams Lb of the second light source 6b ,

In the embodiment, the entire surface of the glass ceramic field 2 by means of the expanded beam of the second light source 6b irradiated. Now, the reference beam, limited by the light beams Lb, by an object (eg., The pot 10 ) or interrupted by operations of an operator, this is spatially resolved by the detector 5 registered. The detector 5 gives this information in the form of appropriate signals over the cable 13 to the control unit 7 Next, which then the specific control of the cooker 1 causes. Exemplary is the pot in the embodiment 10 drawn on which one of the stove plates 9 stands. The pot 10 hinders the beam path of the second light source 6b emitted infrared beam with the light beams Lb, so that on the detector 5 gives a corresponding shadow, which can be detected spatially resolved. This is shown schematically by the lines Z.

While in the embodiment of 1 the controls 11 purely virtual in nature, since they are projected by means of the projection device 4 come about, are the controls 11 of the 2 firmly on the surface of the glass ceramic field 2 applied. At the controls 11 of the 2 These are keys which are indicated by rectangular markings on the glass ceramic field 2 are drawn. projection device 4 and recognition device 3 are in this embodiment in a common module 12 compactly housed. The information projection is again using a first light source 6a , wherein the outlet opening for the light beam with the outlet opening for the light of the second light source 6b the recognition device 3 matches. In addition to this outlet opening is on the module 12 the detector 5 appropriate. About the first light source 6a can be an information projection on or next to the highlighted controls 11 respectively. Such a projection can also be omitted, since the buttons are already controlled by controls 11 are marked.

With the module 12 Both the complete operation and the display of the user interfaces can be solved. The module 12 is particularly suitable for the realization of a so-called virtual keyboard. The arrow next to the module 12 indicates that the module 12 is designed retractable. It can be moved so that its top with the top O of the glass ceramic field 2 in the sunk state completes. In the extended state, however, at least the outlet opening of the first light source 6a and the second light source 6b above the top O of the glass ceramic field 2 to come to rest. The detector 5 then sits below the bottom U of the glass ceramic field 2 ,

This situation is in 3 shown schematically. The infrared light beams Lb of the second light source 6b become laterally on the glass ceramic field 2 emitted or projected and let by a detector 5 , which extends below the underside U of the glass-ceramic field 2 is detected. The operator grasps the glass ceramic field 2 in the place of one of the marked controls 11 , then light beams Lb z. B. reflected by the operator's finger and in the detector 5 recorded in a spatially resolved manner. The reference light beams Lb are emitted over the semi-transparent surface (area beam). If this beam is interrupted, the beam is diffusely reflected in all directions starting from the point of interruption. This reflection can be achieved by means of the detector located below the partially transparent surface 5 be detected.

3 contains superimposed also shown a further embodiment that can be combined with any of the described here. The detector 5 namely, even below the glass ceramic field 2 and be arranged parallel to this. The detection range is shown by way of example by the lines S. Alternatively or additionally, also a first light source 6a be provided, which in the embodiment emitted visible light and an image on the glass ceramic field 2 projected. Also in this embodiment, the glass ceramic field 2 be made partially transparent, so that the light beams Lb of the reference beam from the second light source 6b below the bottom U of the detector 5 can be detected.

An alternative to this is in the embodiment of 4 shown. As in the embodiment of 1 is the detector 5 again below the bottom U of the glass ceramic field 2 , He is able to cover the entire surface of the glass ceramic field 2 capture. Now, however, there are two separate light sources 6b intended for the reference light. Both light sources 6b illuminate different area of the bottom U of the glass ceramic field 2 , In addition, there is also a light source 6a the projection device 4 provided, which the cutout with the controls 11 illuminates. In the right half of the 4 So there is a projection of the entire user interface with the controls 11 and a separate illumination of this area with the infrared light source 6b , In the left area of the glass ceramic field 2 but are the hobs 9 firmly recorded and do not have the projection device 4 be projected. This eliminates the projecting light source for this area 6a and it is merely an illumination by means of the infrared light source 6b required. The entire glass ceramic field 2 is within the detection range of the detector 5 , which is symbolically staked by the lines S. The detector 5 Consequently, both the position of the pot 10 capture, as well as detect when an operator's finger on one of the projected virtual controls 11 suppressed.

In a further modified form ( 5 ) you can turn the principle of a virtual keyboard advantage. Here, the reference light beams Lb are not a sheet-shaped infrared ray bundle, but an infrared grid mesh with a reference pattern G is projected onto the respective work surface, e.g. B. the glass ceramic field 2 , By recording and evaluating the mesh information reflected from a body, one can infer both the position in the plane and in depth. Since the reference pattern G is formed by light in the infrared wavelength region, it remains from the projection by the projection device 4 unaffected, which takes place in the visible range. Since the projection of the reference pattern G is a magnifying projection, it is possible to deduce both the depth information (line information) and the column information by means of the geometric optics (sets of rays). Compared to a conventional virtual keyboard, the lower susceptibility to contamination and unevenness of the surface should be emphasized here.

Considering the geometric relationships of a projected fringe pattern, one can conclude the distance with knowledge of the aperture angle of the lens and the strip distances to each other. This is based on the 6 explained in more detail. The from the second light source 6b emitted light beams Lb pass through a slide 14 on which a grid with grid spacing x is applied. This grid will have a magnifying optic 15 displayed. If you now let the grid distance x go to zero, you get a triangular shape, as in 6 shown. Based on this triangular shape, it is now possible, by means of the known opening angle d and the distance a of two lines projected on any surface, to the distance c from the projection unit (which is represented by the elements 6b . 14 and 15 is formed) close: c = a / sin d

The assumption, however, is that imaged adjacent lines are approximately in one plane. By counting the individual grid lines can also be closed to the position in the grid network. In addition, one can close the distance of the surface to the projection unit by means of the given formulas.

These simple relationships allow using the embodiment of the 5 to trigger an operation by the gripping in the projection beam path with the light beams Lb. In particular, there is no "hard" switching point.

• – erste Lichtquelle 6a und zweite Lichtquelle 6b oberhalb der Oberseite O und Detektor 5 unterhalb der Unterseite U. Das Glaskeramikfeld 2 ist teiltransparent ausgebildet;
• – zweite Lichtquelle 6b oberhalb der Oberseite O und erste Lichtquelle 6a sowie Detektor 5 unterhalb der Unterseite U. Das Glaskeramikfeld 2 ist teiltransparent ausgebildet;
• – erste Lichtquelle 6a, zweite Lichtquelle 6b und Detektor 5 unterhalb der Unterseite U. Als Material des Glaskeramikfeldes 2 wäre ein teiltransparentes Material erforderlich; und
• – erste Lichtquelle 6a, zweite Lichtquelle 6b und Detektor 5 oberhalb der Oberseite O. Als Oberflächenmaterial des Glaskeramikfeldes 2 würde sich ein teiltransparentes oder nicht transparentes Material eignen.

In summary, let us once again select from possible arrangements of the first light source 6a , second light source 6b and detector 5 specified. The relative positions are in this case with respect to the top O and bottom U of the glass ceramic field 2 stated:

• - first light source 6a and second light source 6b above the top O and detector 5 below the bottom U. The glass ceramic frame 2 is partially transparent;
• - second light source 6b above the top O and first light source 6a as well as detector 5 below the bottom U. The glass ceramic frame 2 is partially transparent;
• - first light source 6a , second light source 6b and detector 5 below the underside U. As material of the glass ceramic field 2 a partially transparent material would be required; and
• - first light source 6a , second light source 6b and detector 5 above the top O. As a surface material of the glass ceramic field 2 a partially transparent or non-transparent material would be suitable.

LIST OF REFERENCE NUMBERS

1

stove

2

Ceramic field

3

recognizer

4

projection device

5

detector

6a

first light source

6b

second light source

7

control unit

8th

projection optics

9

hotplate

10

pot

11

operating element

12

module

13

electric wire

14

slide

15

magnification optics

La, Lb

beam of light

S

line

G

reference pattern

U

bottom

O

top

Z

line

Claims (15)

Control device for a domestic appliance ( 1 ) with a control unit ( 7 ) characterized by an optical recognition device ( 3 ) with a detector ( 5 ), which is adapted to operations of an operator and / or a position of an object ( 10 ) and / or an extent of an object ( 10 ) within a detection area and signals to the control unit ( 7 ) to send. Control device according to Claim 1, characterized by an optical projection device ( 4 ) with a first light source ( 6a ), which is designed to form an image, in particular an image of a user interface, at least into the detection range of the recognition device ( 3 ) to project. Control device according to claim 2, characterized in that the projection device ( 4 ) is adapted to project the image in a raster process. Control device according to claim 2, characterized in that the projection device ( 4 ) imaging optical components ( 8th ) and configured to project the image in an optically imaging process. Control device according to one of claims 2 to 4, characterized in that the projection device ( 4 ) is adapted to project temporally changing images. Control device according to one of the preceding claims, characterized in that the recognition device ( 3 ) comprises optically imaging elements which are arranged such that they project at least a portion of the detection area onto the detector ( 5 ) depict. Control device according to one of the preceding claims, characterized in that the detector ( 5 ) is an integrated semiconductor device, in particular a charge coupled device. Control device according to one of the preceding claims, characterized in that the recognition device ( 3 ), in particular temporally pulsed, second light source ( 6b ). Control device according to Claim 8, characterized in that the second light source ( 6b ) is adapted to emit electromagnetic radiation of one wavelength or several wavelengths from the range of 0.78 μm to 1000 μm, in particular from the range of 0.78 μm to 3.0 μm. Control device according to Claim 8 or 9, characterized in that the second light source ( 6b ) is adapted to project the image (G) of a grid into the detection area. Domestic appliance ( 1 ), in particular for the preparation of food, with a control device according to one of the preceding claims. Domestic appliance ( 1 ) according to claim 11, characterized by a module ( 12 ), which the projection device ( 4 ) and / or the second light source ( 6b ) and / or the detector ( 5 ). Domestic appliance ( 1 ) according to claim 12, characterized in that the module ( 12 ) in the household appliance ( 1 ) is retractable, wherein the projection device ( 4 ) and / or the recognition device ( 3 ) in the extended state are functional and the projection device ( 4 ) and / or the recognition device ( 3 ) in the retracted state are not functional. Domestic appliance ( 1 ) according to claim 13, characterized by a motion sensor and / or a brightness sensor, which are designed, depending on a detected movement or brightness, the sinking and / or extension of the module ( 12 ) to control. Domestic appliance ( 1 ) according to one of claims 12 to 14, characterized in that the module ( 12 ) from the household appliance ( 1 ) is separable.

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