Abstract: A table fan includes a fan generating a flow of air, a cleaning device including a circulation system for guiding cleaning liquid in a cleaning circuit, a filter chamber having a suction opening via which air is suctioned downwards, and a filter element arranged in the filter chamber and having at least one portion which is located in the cleaning circuit.

Abstract: An induction heating cooker for achieving high output of power and small thickness is provided. The induction heating cooker includes a main body provided at an upper side with a top plate, a heating coil to induction-heat a heating object loaded on the top plat, and a blower device configured to draw external air into the main body and blow the air into the heating coil. The heating coil and the blower device are accommodated in the main body. The main body is provided therein with a first flow path allowing air blown by the blowing device to be supplied toward the heating coil from an outer periphery side and a second flow path allowing air blown by the blowing device to be supplied toward the heating coil from a lower side.

Abstract: An electric range includes a case and a cover plate coupled to an upper surface of the case to place an object. Further, the electric range includes a plurality of heating portions disposed below the cover plate to heat the object and an upper bracket disposed under the heating portion to support the heating portion a control board disposed between the cover plate and the upper bracket. Furthermore, the electric range includes a support member having a first end disposed under the control board and a second end disposed on the upper bracket to support the control board and a base bracket disposed under the upper bracket and comprising a printed circuit board.

Abstract: An electric range in one embodiment includes a case and a cover plate coupled to an upper end of the case to allow an object to be heated to be placed on an upper surface thereof The electric range further includes a plurality of heating parts disposed under the cover plate and configured to heat the object to be heated, an upper bracket disposed under the heating part and configured to support the heating part, a base bracket disposed under the upper bracket to allow a printed circuit board to be mounted thereon, and a cover bracket disposed outside the upper bracket and the case coupled to the case and configured to support the cover plate.

Abstract: The invention relates to a vapour extraction device for extracting cooking vapours downward. The vapour extraction device comprises a fan apparatus for sucking in the cooking vapours having a fan impeller which can be driven in rotation, a fan motor for supplying a drive torque, and a releasable fan coupling for transmitting the drive torque to the fan impeller.

Abstract: An intermediate device for supporting a power transfer to an electromagnetic load (505) from a power transmitter (201) providing a power transfer electromagnetic signal comprises a resonance circuit (507) that includes a coil (701) and a capacitor (703). The coil (701) is arranged to electromagnetically couple to the power transmitter (201) and to the electromagnetic load (505) such that energy of the power transfer electromagnetic signal from the power transmitter (201) is concentrated towards the electromagnetic load (505). A hollow support structure (1001) has a laterally positioned air inlet (1205) and a centrally positioned air outlet (1207). The coil (701) is mounted on the hollow support structure (1001) and disposed around the central air outlet (1207). The device further comprises an air flow generator (901) for creating a flow of air into the air inlet (1205).

Abstract: An electrical machine (10), in particular a machine which can be operated in electric generator mode and/or in electric motor mode, comprising a rotor (14) which has a shaft (13), wherein a part of a turbomachine (68) is formed on the shaft (13) and the part is a fan (60), wherein the fan (60) has a circumference (83) with a circumferential direction (85), and a housing (63) of an electrical unit (45) is adjacent to the fan (60) and serves as a housing of the turbomachine (68), and there is a gap (65) between the fan (60) and the housing (63) of the electrical unit (45), characterized in that the gap (65) has a radial width (B65R) which has a different magnitude depending on a circumferential position (U602) on the fan (60) which is arranged on the shaft (13).

Abstract: Systems, devices and methods are provided herein for measuring a junction temperature of a transistor. A system includes a power inverter configured to supply power to a load, the power inverter including the transistor that is configured to switch between an on-state and an off-state and generate a load current during the on-state; a current sensor configured to measure the load current; a voltage transit slope detection circuit configured to determine a voltage transit slope corresponding to a voltage across the transistor during a turn-off period of the transistor during which the transistor is in the off-state; and a processing unit configured to determine the junction temperature of the transistor based on the measured load current and the determined voltage transit slope.

Abstract: An induction hob including at least one switching element and at least one induction coil is provided. The switching element provides an alternating current flow through the induction coil. Cooling means provide airflow through the induction hob for cooling the switching element and the induction coil. The induction coil is arranged at a first side of a first plate-shaped support element and the switching element is arranged at a first side of a second plate-shaped support element. The first support element and the second support element are connected to one another and are arranged at a distance in order to form an air channel therebetween. The cooling means are arranged such that airflow is provided through the air channel.

Abstract: An induction cooking device includes: a housing in which at least one of a heat generating component and a heat dissipating component is disposed; a top plate which is held at an upper portion of the housing and on which an object to be heated is to be placed; a heating coil unit disposed inside the housing, below an undersurface of the top plate; a first cooling fan which is disposed inside the housing, and blows first cooling air to cool the at least one of the heat generating component and the heat dissipating component; a second cooling fan which is disposed inside the housing, takes in at least a portion of the first cooling air, and blows second cooling air to cool the heating coil unit; and an air guide which guides the second cooling air to the heating coil unit.

Abstract: Apparatus and methods for sequencing outputs in a multi-output power converter system are disclosed herein. During start-up multiple CC/CV outputs may be sequenced so that energy is first provided to a highest voltage secondary output and subsequently provided to a lowest voltage secondary output. Additionally, control may be exerted so as to concurrently and monotonically increase voltages during at least part of the start-up transient; and concurrent control may be further implemented using control circuitry and a variable reference generator. In some embodiments a variable reference may be generated from a capacitor voltage.

Abstract: A power conversion device is configured to have reactors and is configured to have chopper circuit units, connected in series, that chop the output of a rectifier configured to rectify an AC voltage from an AC power supply. The power conversion device includes: an AC switch disposed on a side closer to the AC power supply than the chopper circuit units; an AC reactor that is connected in parallel to the AC switch; and a switching control unit that stops the switching of the switching elements when the contact of the AC switch is open.

Abstract: A countertop mounted cooking appliance includes a chassis upon which is arranged a cooktop. A peripheral side portion of the chassis includes at least one opening and a control box is mounted in the chassis for housing control elements and associated electronics. An inner duct extends over at least a portion of the control box, while an outer duct extends across the at least one opening along the peripheral side portion to the countertop. A fan is mounted within the chassis wherein, when the fan is activated, a cooling airflow is developed and directed through the inner duct, out of the chassis, and through the outer duct prior to being exhaust through a gap created between the cooktop and the countertop by a trim piece.

Abstract: A power supply unit for use with thermostats or other like devices requiring power. A power supply unit may be designed to keep electromagnetic interference emissions at a minimum, particularly at a level that does not violate governmental regulations. A unit may be designed so that there is enough power for a triggering a switch at about a cross over point of a waveform of input power to the unit. Power for triggering may come from a storage source rather than line power to reduce emissions on the power line. Power for the storage source may be provided with power stealing. Power stealing may require switching transistors which can generate emissions. Gate signals to the transistors may be especially shaped to keep emissions from transistor switching at a minimum.

Abstract: A cooking appliance and method, the appliance including: at least one temperature controlled heating element; a user interface for enabling a user to select a predefined subject for cooking; and a processor module that maintains a cooking data for cooking the selected predefined subject, and provides prompts to the user during cooking. The cooking data can be indicative of a cooking sequence or procedure. A cookware sensor can automatically identifying cookware being used.

Abstract: A heat dissipating mechanism includes a first housing, a second housing and a tributary hole structure. The first housing is installed on a host casing. At least one inlet and at least one outlet are formed on two sides of the first housing. The second housing combines with the first housing, and the second housing and the host casing form a flow channel for communicating with the at least one inlet and the at least one outlet, so as to guide liquid from the at least one inlet to the at least one outlet. The tributary hole structure is formed on the flow channel and located in a position between the at least one inlet and the at least one outlet. The tributary hole structure is higher than the at least one outlet for guiding air from the at least one inlet to a fan.

Abstract: An indoor or outdoor induction cook top with a heat management system is disclosed. The cook top controls heat generated by various components, including the electronic controller, mechanical controls, and the induction generators. The heat management system provides precise temperature control and an efficient way of removing heat from the cooktop. The cook top construction provides the ability to incorporate a smooth ceramic glass cook top and a number of induction hobs in multiple arrangements. The cook top also features a reduction in the number of components, the efficient removal of generated heat, the reduction of noise, an increase in performance and a barrier airflow director. Consequently, the cook top may be installed in a countertop without the need for venting above the counter.

Abstract: A linked semiconductor module unit links a plurality of semiconductor modules by a first bus bar and a second bus bar, which are embedded in resin parts. The linked semiconductor module unit is disposed in a place other than on a printed circuit board. The semiconductor module linking structure is implemented readily by molding the bus bars together with semiconductor chips and lands to form the resin parts.

Abstract: A heating cooker of the present invention includes a plurality of light emitting indicator units. The light emitting indicator units each have a temperature sensing unit that senses an ambient temperature of a light emission source. Therefore, deterioration of the light emission source of each of the light emitting indicator units can be suppressed to realize a further reduction in thickness, and to improve visibility of the indicator sheet.

Abstract: An indoor or outdoor induction cook top with a heat management system is disclosed. The cook top controls heat generated by various components, including the electronic controller, mechanical controls, and the induction generators. The heat management system provides precise temperature control and an efficient way of removing heat from the cooktop. The cook top construction provides the ability to incorporate a smooth ceramic glass cook top and a number of induction hobs in multiple arrangements. The cook top also features a reduction in the number of components, the efficient removal of generated heat, the reduction of noise, an increase in performance and a barrier airflow director. Consequently, the cook top may be installed in a countertop without the need for venting above the counter.

Abstract: An induction cook top may include a heat management system. The heat management system controls heat produced both internally by the electronic components within the cook top as well as heat produced above the cook top when cooking. The heat management system provides improved air flow past and around the internal electronic components. The cook top features an efficient removal of generated heat and may optionally provide a vented housing and direct airflow into and out of the housing or provide a thermoelectric cooling device which permits a ventless housing.

Abstract: An induction heating cooking apparatus includes a magnetic flux-shielding plate 28 to restrain magnetic flux leakage from a heating coil 24 and define a cooling air trunk 33, through which cooling air from a fan 32 passes. An infrared sensor 26 for detecting infrared rays emitted from a cooking container 22 and a control circuit 27 for controlling an output of a heating coil 24 depending on an output from the infrared sensor 26 are accommodated within the same space with respect to the magnetic flux-shielding plate 28 to thereby enhance assemblage. Also, the infrared sensor 26 is mainly cooled by cooling air passing through a cooling air trunk 33 to thereby enhance the cooling efficiency of the infrared sensor 26 and conduct correct temperature detection.

Abstract: An induction cooking utensil is constructed such that it cooks food within its chamber while maintaining a relatively cool outer surface (e.g., preferably an outer surface that is cool enough to pick up with one's bare hands). The cooking utensil includes an inner wall that is made at least in part of an electrically conductive material and an outer wall that is made at least in part of the electrically non-conductive material. A reflective layer, a vacuum-sealed thermal insulator and/or a gas more resistant to conducting heat than air is disposed between the inner and outer walls to resist the transfer of heat from the inner wall to the outer wall.

Abstract: An electrical apparatus includes a casing, a circuit board, a top cover and an active heat-dissipating element. The casing includes a first entrance, a first receptacle, a first sidewall, and a first bottom surface. An air inlet hole is formed in the first bottom surface. A concave region is defined at a junction between the first sidewall and the first bottom surface. An air outlet hole is formed in the concave region. The circuit board is disposed within the first receptacle and has at least one electronic component mounted thereon. The top cover shelters the first entrance. The active heat-dissipating element is disposed within the first receptacle and arranged over the air inlet hole. Ambient air is inhaled into the first receptacle by the active heat-dissipating element and exhausted out of the casing through the air outlet hole, thereby removing heat generated from the electronic component.

Abstract: A linked semiconductor module unit links a plurality of semiconductor modules by a first bus bar and a second bus bar, which are embedded in resin parts. The linked semiconductor module unit is disposed in a place other than on a printed circuit board. The semiconductor module linking structure is implemented readily by molding the bus bars together with semiconductor chips and lands to form the resin parts.

Abstract: A food heating and/or cooling device is provided. The device has a housing with a food heating-cooling region and an opening that provides access to the heating-cooling region. An induction heating element and a cooling device is contained within the housing. A food container dimensioned to fit through the opening and within the food heating-cooling region is included, the food container having an electrically conductive element that can be heated by the induction heating element contained within the housing. Furthermore, the cooling device is operable to cool the food when it is placed within the food heating-cooling region. As such, food that is located on or within the food container and placed within the food heating-cooling region can be heated and/or cooled.

Abstract: A method and cooktop include a cooktop panel, a cooking zone, and an induction heating device disposed below the cooktop panel. First, second and third heat sensor units are disposed beneath the cooktop panel in a region of a measuring spot. The first heat sensor unit is configured to measure heat flow from substantially only the cooktop panel. The second and third heat sensor units are configured to measure heat flow from the cooktop panel and a cooking utensil disposed thereon. A light source is provided for measuring an emissivity of the bottom of the cooking utensil. An auxiliary heater heats the region of the measuring spot. An electrical control system calculates a ratio from signals of the second and third heat sensor units and determines an actual temperature of the bottom of the cooking utensil from the ratio by using a temperature of a lower surface of the cooktop panel measured by the first sensor unit and a value of the emissivity of the cooking utensil bottom.

Abstract: A method for detecting the pan size and/or position in induction cooking hobs comprises providing at least a sensing circuit associated to a magnetic field concentrator, particularly a ferrite bar, and assessing an electrical parameter thereof correlated to the variation of the magnetic flux.

Abstract: Disclosed is an induction heating range with improved thermal resistance and impact resistance and, more particularly, to an induction heating range, which can prevent electronic devices inside the heating range from being damaged or malfunctioning due to heat transferred into the heating range from a heating target that receives heat in use of the induction heating range, thereby improving thermal resistance and impact resistance.

Abstract: A cooking appliance. The cooking appliance includes a cook top for a kitchen. One side of the cook top includes a cooking area with cooking areas. The cooking areas may be operated via an induction cooker. The bottom side of the cooking appliance has a display. The display can provide useful information thereon such as the time. The cook top can be arranged in a first horizontal position for use of the cooking areas, and folded to a second vertical position during non use to display information on the display. The cooking appliance also includes a data reader, such as an RFID reader or bar code scanner to obtain data from a food product package. The data may include suggested recipes, cooking temperatures, and/or cooking times. The obtained data may be used to assist in controlling the operation of the cooking areas.

Abstract: A method for detecting the presence of a cooking vessel on an induction heating element is disclosed. The induction element is placed below a glass surface and a conductive electrode placed below the glass surface to detect if a cooking utensil is placed on the induction heating element. The electrode measures capacitance, which indicates to the user whether the cooking utensil is present on one or more induction heating elements. After activation by a user, a second detection of the cooking utensil is accomplished by feeding power to the induction heating element and by assessing at least an electrical parameter of a power circuit thereof.

Abstract: Provided is an induction heater which induces an electric current in a metal utensil (e.g., a cooking utensil) using an electromagnetic force and can thus heat the metal utensil, and more particularly, an induction heater which can prevent electric devices sensitive to temperature from being overheated by forcefully blowing air to the front and the rear of an inverter circuit board. The induction heater is easy to be miniaturized, and a considerable number of devices can be integrated into the induction heater.

Abstract: An induction cooker includes a top plate (1) for placing an object to be heated thereon, a heating mode selection key (8) for allowing the user to select one control mode for heating the object to be heated between a manual heating mode in which the heat output is set by the user by using an output adjusting key (9) and at least another control mode in which the heat output is controlled automatically, and a heating off/on key (7) for starting to heat the object to be heated. In the standby mode, the controller starts heating only when the user operates the heating mode selection key (8) to change the mode to the cooking menu selection mode before operating the heating off/on key (7). When a predetermined time has elapsed in the cooking menu selection mode without a change in a selected control mode, the mode is changed to the standby mode.

Abstract: Provided is a built-in cooking appliance. According to the built-in cooking appliance, the inside of the cooking appliance is effectively cooled and the inside can be waterproofed without protruding the top plate above the cabinet. Therefore, cooling efficiency, stability in using, convenience in cleaning, esthetic feeling, and reliability of a product can be improved. The built-in cooking appliance includes a top plate, a main body below the top plate, a fan, a cabinet, a gap portion, and a top frame. At least a heating unit is disposed inside the main body. The fan forms a cooling passage inside the main body. The plate is installed on the cabinet. The gap portion defines at least a portion of the cooling passage, and is formed by at least an edge on one side of the top plate and the cabinet separated from each other. The top frame covers the gap portion.

Abstract: To reduce the air exhausted to outside a main body after cooling a heat generating component from being taken in again from an intake port. The flow of cooling wind cooled the heat generating component is discharged from an exhaust port 21 at other than a first peripheral wall 19 with the flow bent inside the main body. When rectified inside the main body and discharged from the exhaust port 21, the cooling wind grows to a flow speed of a certain extent to become an exhaust air that a flowing direction is clearly defined, so that it is less likely to be taken in again from the intake port 20, it is less likely to be subjected to the influence of obstacles of the exhaust port, use can be made in a kitchen cabinet of the intake and exhaust air at the back side, and it is satisfactory and is less likely to be damaged without involving sense of unpleasantness by the exhaust air to the user.

Abstract: An object of the present invention is to provide an induction heating cooker with improved assemblability, and with which a reduction in the temperature sensing precision of an infrared sensor can be suppressed and a reduction in the thickness of the induction heating cooker can be achieved. To this end, the induction heating cooker of the present invention includes a duct 33 that forms a cooling air path for guiding the cooling air produced by the air blower 32 to a control circuit 27 and to an infrared sensor 26. The infrared sensor 26 and the control circuit 27 are disposed at positions lower than the top wall of the duct 33.

Abstract: Waste heat of a high temperature inside a main body is designed to be discharged to the outside of the main body by means of a discharge fan through a first suction air flow passage and a first discharge air flow passage. Also, through a second air flow passage communicating from a second discharge fan suction port to a discharge fan suction portion, air from the outside of the main body or air at a site of the main body, where the temperature is low, is sucked by a discharge fan so that the air of a low temperature can pass outside the drive motor to cool the latter. With this construction, the interior of the main body and the drive motor can be cooled efficiently.

Abstract: A cooking appliance includes at least one heating element; a heat sink connected to the heating element, to radiate heat generated by the heating element; a cooling fan located at one side of the heat sink, to blow cooling air to the heat sink; and a flow guide covering at least a portion of the heat sink and guiding a portion of the cooling air to flow to the heating element.

Abstract: An indoor or outdoor downdraft ventilator moves via an electronic controller through preferably a touch keypad. This provides precise control and an efficient way of removal of gases/fumes off a cook top. The electronically controlled telescoping downdraft creates a nearly infinite and selectable range of heights above a cook top from which to properly collect and draw in, filter, re-circulate, or expel exhaust. The downdraft incorporates a lighting system to illuminate the work surface and sensors to detect temperature, filter change requirements, speed, stop points, power, resistance, voltage, and program med operations.

Abstract: An electrical apparatus includes a casing, a circuit board, a top cover and an active heat-dissipating element. The casing includes a first entrance, a first receptacle, a first sidewall, and a first bottom surface. An air inlet hole is formed in the first bottom surface. A concave region is defined at a junction between the first sidewall and the first bottom surface. An air outlet hole is formed in the concave region. The circuit board is disposed within the first receptacle and has at least one electronic component mounted thereon. The top cover shelters the first entrance. The active heat-dissipating element is disposed within the first receptacle and arranged over the air inlet hole. Ambient air is inhaled into the first receptacle by the active heat-dissipating element and exhausted out of the casing through the air outlet hole, thereby removing heat generated from the electronic component.

Abstract: An induction heating device for a glass ceramic hob or cooktop is embodied as an autonomous component. Said induction heating device comprises a bearing device which, in addition to the induction coil, supports a component support comprising power electronics and control electronics. Only the control connections for the control signals in relation to the power of a line and a direct connection to the household power are provided on said induction heating device. The control electronics ensure the power of a line to the power electronics. Advantageously, said induction heating devices have external dimensions which are the same as traditional radiant heating bodies and thus can easily be used in lieu of said traditional radiant heating bodies when constructing said hob.

Abstract: An indoor or outdoor induction cook top system with integrated downdraft or telescoping ventilator uses cross flow or centrifugal blower technology. The system is controlled by an electronic or mechanical controller through a touch device, a slide, or knob. These provide precise control and an efficient way of removal of gases/fumes. A smooth glass cook top incorporates the induction hobs and a downdraft. The ventilator's blower assembly has a fan and a filter. The system uses sensors to detect temperature, fire, effluent, filter change requirements, fan speed, power, and voltage. The system has programmable operations and numerous set points.

Abstract: An induction cooking utensil is constructed such that it cooks food within its chamber while maintaining a relatively cool outer surface (e.g., preferably an outer surface that is cool enough to pick up with one's bare hands). The cooking utensil includes an inner wall that is made at least in part of an electrically conductive material and an outer wall that is made at least in part of the electrically non-conductive material. A reflective layer, a vacuum-sealed thermal insulator and/or a gas more resistant to conducting heat than air is disposed between the inner and outer walls to resist the transfer of heat from the inner wall to the outer wall.

Abstract: An indoor or outdoor induction cook top with a heat management system is disclosed. The cook top controls heat generated by various components, including the electronic controller, mechanical controls, and the induction generators. The heat management system provides precise temperature control and an efficient way of removing heat from the cooktop. The cook top construction provides the ability to incorporate a smooth ceramic glass cook top and a number of induction hobs in multiple arrangements. The cook top also features a reduction in the number of components, the efficient removal of generated heat, the reduction of noise, an increase in performance and a barrier airflow director. Consequently, the cook top may be installed in a countertop without the need for venting above the counter.

Abstract: An electric cooker having a composite heat source includes an external case having an air inlet and an air outlet, a cooking plate mounted on an upper surface of the external case to be a top plate thereof, a heat generating unit mounted between the external case and the cooking plate, the heat generating unit including a work coil and an electric heater and arranged coaxially with the air inlet with respect to a center of the air inlet, a cooling unit coaxially arranged with respect to the center of the air inlet between the air inlet and the heat generating unit, the cooling unit cooling the heat generating unit, an air duct provided below the heat generating unit, and a reflector forming an outer cover of the electric heater.

Abstract: An induction heating cooker with improved discharge capability and cooling performance comprises a cooking plate 200 formed with a cooking vessel thereon; a cooking body 310 coupled to the cooking plate 200 to define a receiving space 311 therebetween and having an exhaust port 312 communicating with the receiving space 311; a plurality of unit induction heating modules 410 and 420 installed within the receiving space 311 to be partitioned from each other, each having a heating unit 412 or 422, a blowing fan 413 or 423 disposed close to the heating unit to cool the heating unit 412 or 422, and an exhaust passage 415 or 425 for allowing exhaust air generated by the blowing fan 413 or 423 to be guided to and discharged through the exhaust port 312; and a bridge duct 810 for allowing the exhaust passages 415 and 425 of the unit induction heating modules 410 and 420 to communicate with each other, to thereby enable to improve the cooling performance.

Abstract: A composite cooking apparatus having a body, a heating unit, and an induction heating unit. The heating unit is positioned in the body to generate heat used to heat food. The induction heating unit is positioned adjacent to the heating unit to generate a magnetic field to cook the food by induction heating. The induction heating unit has at least one wire, a coating of which is exposed to an electron beam to strengthen a heat resistance thereof.

Abstract: A refrigerated oven comprising a cooking chamber in which is provided a heating elements and a refrigeration unit chamber in which is provided a refrigeration unit. The refrigeration unit is fluidly connected to the cooking chamber. Both the heating element and the refrigeration unit are selectively operable to either cool or heat the cooking chamber to thereby cool or heat a food item located therein. The refrigeration unit as preferably modular refrigeration unit that the slid into and out of the refrigeration unit chamber. Preferably, the refrigeration unit includes an evaporator that is thermally isolate is from a condenser. The condenser as preferably conductively coupled to a base supporting the elements of the modular refrigeration unit.

Abstract: A core structure for induction heating apparatus consists of radially disposed core parts carrying cylindrical coils for energization. The core parts join the outer end to form a rim and at the center to form a central pole.

Abstract: An electric cooker is provided, which can grill foods by heat rays from a metal heating member using induction heating and is hardly affected by drops from the foods. This electric cooker comprises a work coil wound in a substantially pipe-like shape for generating an alternating magnetic flux, a metal heating member having a substantially pipe-like shape disposed inside and coaxially with the work coil for being heated by the alternating magnetic flux generated by the work coil so as to generate heat rays, and an insulator having a substantially pipe-like shape disposed between the work coil and the metal heating member. A wire mesh for supporting the foods is disposed adjacent to the upper opening of the insulator. A receiving pan is disposed adjacent to the lower opening of the insulator for receiving drops from the foods. The metal heating member preferably has a shape suitable for collecting the heat rays to the upper opening.