U.S. Philips Corporation

Gilles Delmas

Jean-Pierre Hazan

Michel Steers

Jean-Louis Nagel

Remy H Polaert

Guy N Martin

Michel Courdille

Johannes At Driessen

Michel G Lemonier

A vacuum cleaner has: an air outlet, an air inlet, a dust chamber in communication with the air inlet, a fan driven by a main motor provided in a housing in communication with the air outlet and the dust chamber, a pressure detector which provides a signal showing variations characteristic of the floor type being cleaned; and circuitry, including a neural network for recognizing and classifying the floor type as a function of these variations, a setpoint generator for determining a pressure setpoint as a function of the variations, and a control circuit for controlling the power of the main motor so as to maintain the pressure setpoint.

Vacuum cleaner with floor type detection means and motor power control

Force detector (5) fitted with a blade carrying a strain gauge (12) and with a fixed support (10) and a mobile support (11) in which are respectively accommodated a first and second end of the said blade, the relative displacements of the two supports enabling the forces applied to the mobile support to be detected. In order to accommodate at least one of the said ends in its own support, the said support comprises a U-shaped member (13), between the two branches of which is inserted the said end bearing on slightly elastic contacts. A tactile screen is formed with the help of a plurality of such force detectors accommodated in a mobile plate (22) and a fixed frame (21). By coupling the two latter elements by means of suspensions (24.sub.1, 24.sub.2) and elastic fasteners (25.sub.1, 25.sub.2), the pressure forces acting on the mobile plate are, in a vertical position, decoupled from the intrinsic weight of the latter.

Force detector and a tactile screen comprising such detector

A cook-top (10) includes a plurality of heating elements (11a, 12a) which are activated by function controls. The heating elements are covered by a plate (15) which are fixedly connected to strain-guage modules (30) which detect the forces exerted on the plate as a result of loads placed on the heating elements. By computing the center of gravity of the forces, controls (70, 75, 76) identify a heating element whose load has varied and influence its electric power supply. The power supply may then be turned off, reduced or controlled. The function controls may be pressure-sensitive touch controls.

Cook-top

A detection device for measuring force and pressure is disclosed which includes a monomode optical fiber (1) into which polarized light is fed and, at the output of the fiber, is detected by a detection arrangement (4, 80, 81, 30, 40, 31, 41), which is sensitive to the polarization of the light. The detection arrangement is provided with means (30A, 31A) for analyzing the light according to at least two different polarization directions, forming an angle comprised between 30.degree. and 60.degree. between them. According to the invention, the device is provided with means (70, 71, 2) for feeding several non-correlated light signals, each polarized differently, into the input of the fiber, and with means (4) for distinguishing between the light signals in the said detection arrangement at the output of the fiber, which light signals have been fed into the input of the fiber. The invention is applied in intrusion detection, monitoring and security systems.

Force/pressure detection device utilizing a monomode optical fiber

A refrigerating machine (10) of the refrigerator or freezer type comprises a device (33) for defrosting cold parts to transform the ice into water to be discharged. It has an end-of-defrosting detector (20) comprising:

Refrigerating machine comprising an end-of-defrosting detector

A fiber-optical pressure sensor, comprising a pressure member (21, 22) which encloses the optical fiber (20) in a sandwich-like manner, and used for the detection of intruders is provided. The pressure sensor is formed by a continuous cable which can be buried and which comprises at least one optical fiber (20) which is capable of detecting, along its entire length, components of a pressure applied to a surface zone of the ground, notably by an intruder. The cable can be wound along an axis of rotation which is substantially perpendicular to its longitudinal direction and can be bent in a direction which is substantially parallel to this axis of rotation. The pressure member may have a continuous or a segmented structure. It may be formed by plates (21, 22) or strips (21, 22) which are rigid or semi-rigid. The pressure member may comprise ribs (27, 28, 29) which serve to capture forces which act in the lateral direction.

Continuous cable fiber optical pressure sensor

A microwave oven which provides defrosting control for a frozen product to be defrosted. The oven comprises a microwave source and a detector arranged in the oven cavity in the proximity of the frozen product, the detector including a material which absorbs microwave energy, the absorption of microwave energy by the detector and by the frozen product causing their temperatures to rise and thereby defrosting such product. Variations in the detector temperature are measured by a measuring element which provides an electrical signal corresponding thereto. The detector is configured and insulated so as to have a heat exchange characteristic with its environment which results in its temperature detection sensitivity remaining constant during each of a plurality of successive defrosting operations of the oven. A computer control device evaluates when a defrosting operation has been completed by determining when the slope of the signal variation as a function of time remains the same at successive sampling instants.

Microwave oven providing defrosting control

A microwave oven which includes a defrosting detector in the oven cavity in the proximity of a frozen product to be defrosted, the detector including a material which absorbs microwave energy, the absorption of microwave energy by the detector and by the product causing their temperatures to rise. Variations in the detector temperature are measured by a measuring element producing an electrical signal corresponding thereto, such signal being used to control the defrosting process. The microwave absorbent material is in the form of a layer deposited on a carrier which is positioned behind the product so that most of the detector area can only receive microwave energy through the product, whereby the rate of change of detector temperature with time decreases as the product defrosts and becomes constant when defrosting has been completed. The carrier may be one of the walls of the oven cavity or the oven tray. The material may be a resistive ink deposited on the oven tray by screen-process printing.

Microwave oven comprising a defrosting detector

A microwave oven includes a microwave source and a defrost detector arranged in the oven cavity in the proximity of a frozen product to be processed, the absorption of microwave energy being distributed between the detector and the product and causing their temperature to rise, the temperature variation of the detector being measured by a measuring element producing a corresponding electrical signal. The oven also includes a computing control device which determines completion of defrosting of the product by computing the values at successive instants of the second derivative of such signal as a function of time. The computing control device controls the oven at the end of the defrosting cycle, which is when the value of such second derivative falls below a predetermined value.

Microwave oven detecting the end of a product defrosting cycle

A device for contolling the charging of rechargeable batteries comprises two temperature sensors deposited on a flexible thin thermally and electrically insulating sheet. The thin sheet is disposed around the rechargeable battery so that one of the sensors determines the temperature of the battery and the other sensor determines the ambient temperature. A charge stopping device stops the charging of the battery when the difference between the temperatures determined by the two sensors has reached a predetermined value. The sensors consist of resistors applied by silk screen printing and disposed in a Wheatstone bridge arrangement.

Device for controlling the charging of rechargeable batteries

A microwave oven with a door-closing safety device is provided wherein a movable door comprises a device wherein the beam of at least one light emitter is guided by means of light guides towards a light beam detector. The light guides are arranged along a substantial portion of at least one side of the oven door frame. The beam of light in its non-guided path between the emitter and the detector passes through diaphragms, integral with the oven door, each diaphragm having an aperture such that the light beam passes through it when the door is properly closed but wherein the light beam is intercepted by the edge of the diaphragm when the door is not properly closed. The detector activates a signal that actuates the magnetron when the light beam is received; however, when the beam is intercepted, activation of the magnetron is prevented thereby preventing leakage of microwave energy.

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Epinay sous Senart, France

Gilles Delmas