Patent Application
20070110413
The present invention relates to an infrared ray lamp being used as a heat source and to a heating apparatus that uses the infrared ray lamp, such as electric heaters, cookers, driers and electronic apparatuses (including copying machines, facsimile machines and printers), and more particularly, to an infrared ray lamp that uses a carbonaceous substance as the material of heating elements and has excellent characteristics as a heat source and to a heating apparatus that uses the infrared ray lamp.
In conventional infrared ray lamps, a metallic electric heating wire made of tungsten or the like and formed into a coil shape or a heating element made of a carbonaceous substance and formed into a bar shape or a plate shape is disposed inside a glass tube (for example, refer to Japanese Patent Application Laid-Open No. JP-A-2001-155692).
The conventional infrared ray lamps configured as described above are used as the heat sources of heating apparatuses, such as electric heaters, cookers, driers, copying machines, facsimile machines and printers, and in recent years they are used for various applications as compact and efficient heat sources (for example, Japanese Patent Application Laid-Open No. JP-A-2003-35423).
Patent document 1: Japanese Patent Application Laid-Open No. JP-A-2001-155692 (pages 4 to 6, FIG. 7)
Patent document 2: Japanese Patent Application Laid-Open No. JP-A-2003-35423 (page 2, FIG. 1).
Problem to be Solved by the Invention
An infrared ray lamp serving as a heat source in a heating apparatus is required to be smaller in size and higher in efficiency and also required to be high in versatility so at to be easily adaptable to various applications. In this field, providing an infrared ray lamp capable of satisfying the above-mentioned requirements and a heating apparatus using the infrared ray lamp has been an objective to be achieved.
For the purpose of achieving the above-mentioned objective, the present invention is intended to provide an infrared ray lamp being small in size and high in efficiency and having high versatility so at to be easily adaptable to various applications, and to provide a heating apparatus using the infrared ray lamp.
Means for Solving Problem
An infrared ray lamp according to a first aspect of the present invention comprises:
An infrared ray lamp according to a second aspect of the present invention comprises:
An infrared ray lamp according to a third aspect of the present invention is characterized in that the cross-sectional shape of the heating elements in the infrared ray lamp according to the above-mentioned first or second aspect, cross-sectioned in a direction orthogonal to the longitudinal direction thereof, is a substantially polygonal shape, and that the flat faces having the largest area in the heating elements are disposed so as to be oriented in the same direction, whereby the heat radiation from the heating elements can be carried out while having high directivity.
An infrared ray lamp according to a fourth aspect of the present invention is characterized in that the end faces of the heating elements in the infrared ray lamp according to the above-mentioned first or second aspect, cross-sectioned in a direction orthogonal to the longitudinal direction thereof, is formed by a straight line and an arc line, and that the flat faces of the heating elements are disposed so as to be oriented in the same direction, whereby the heat radiation from the heating elements can be carried out while having high directivity.
An infrared ray lamp according to a fifth aspect of the present invention is characterized in that the heating element holding means in the infrared ray lamp according to the above-mentioned first or second aspect comprises holding blocks having thermal conductivity and a spacer having electric insulation, and that the flat faces of the heating elements are disposed so as to be oriented in the same direction by securing the heating elements into slits formed in the holding blocks and by fitting the holding blocks into cutouts formed in the spacer. With this configuration of the infrared ray lamp according to the fifth aspect, the heat radiation from the heating elements to an object to be heated can be carried out while having high directivity and the heating elements can be easily disposed at proper positions while having a desired space therebetween.
An infrared ray lamp according to a sixth aspect of the present invention is characterized in that the heating elements of the infrared ray lamp according to the above-mentioned first to fifth aspects are solid carbonaceous heating elements inclining a carbonaceous substance and a resistance adjustment substance, and formed by firing. In the infrared ray lamp according to the sixth aspect, configured as described above, the materials of the heating elements include a carbonaceous substance, and the carbonaceous heating elements are formed by firing, whereby the emissivity of the heating elements is higher than that of a metallic heating element by 80% or more. The heating elements made of this kind of material are formed to have flat faces and to provide high directivity; hence, primary radiation is surely applied to an object to be heated, and it is possible to configure an infrared ray lamp having high radiation efficiency.
An infrared ray lamp according to a seventh aspect of the present invention is characterized in that the heating elements of the infrared ray lamp according to the above-mentioned first to fifth aspects include a carbonaceous substance and a resistance adjustment substance, and are solid carbonaceous heating elements formed by firing. In the infrared ray lamp according to the seventh aspect, configured as described above, the materials of the heating elements include a carbonaceous substance and a resistance adjustment substance, and the heating elements are formed by firing, whereby the emissivity of the heating element is higher than that of a metallic one by 80% or more. Furthermore, the installation directions of the heating elements can have desired directions by using holding means having elasticity. Because the heating elements made of this kind of material are formed to have flat faces so as to have high directivity in desired directions, primary radiation is surely applied to an object to be heated, and it is possible to configure an infrared ray lamp having high radiation efficiency.
A heating apparatus according to an eighth aspect of the present invention comprises an infrared ray lamp having:
A heating apparatus according to a ninth aspect of the present invention is characterized in that the cross-sectional shape of the reflector of the heating apparatus according to the above-mentioned eighth aspect, cross-sectioned in the direction orthogonal to the longitudinal direction thereof, has a convex portion protruding at the central portion of the reflection face thereof in the direction opposed to the flat faces of the heating elements. Because the heating apparatus according to the ninth aspect, configured as described above, can be configured so that the heat rays from the heating elements are diffusely reflected by the convex portion of the reflector, the radiation heat generated from the heating elements can be radiated efficiently in a wide range from the reflection face having the convex portion.
A heating apparatus according to a tenth aspect of the present invention is characterized in that the convex portion formed on the reflection face of the heating apparatus according to the above-mentioned ninth aspect is configured so that the heat rays from the heating elements are not radiated to the heating elements. Because the heating apparatus according to the tenth aspect, configured as described above, can be configured so that the heat radiation from the heating elements is not applied to the heating elements using the convex portion of the reflector, the radiation heat generated from the heating elements can be radiated efficiently in a wide range from the reflection face having the convex portion. In the heating apparatus according to the present invention, because the reflector has a shape so that the radiation heat generated from the heating elements to the reflector is not radiated to the heating elements, the secondary heating to the heating elements due to the reflector is suppressed; as a result, abnormal temperature rise in the heating elements is prevented, and the stability of the heating elements can be attained.
For example, the rate of resistance change of the heating elements has a negative or positive characteristic in most cases. This represents that the resistance value changes depending on the temperature of the heating elements. Furthermore, in the case that the rating of the heating elements is set, the rating is set in a self heat radiation state at an applied voltage in most cases. In the case that the heating elements being set as described above is built in a heating apparatus, if the temperature of the heating elements rises owing to the shape of the reflector, the rated input is changed despite designer's intentions. For the purpose of avoiding this kind of problem, it is preferable that the heating elements should be configured so as not to be affected by the radiation from the reflector.
A heating apparatus according to an 11th aspect of the present invention is characterized in that the cross-sectional shape of the reflector of the heating apparatus according to the above-mentioned eighth aspect, cross-sectioned in the direction orthogonal to the longitudinal direction thereof, is a parabolic shape, and that the substantially central point of heating in a heating element group consisting of the plural heating elements is disposed at the position of the focal point of the parabola. Because the substantially central point of heating in the heating element group of the heating apparatus according to the 11th aspect, configured as described above, is disposed at the position of the focal point of the parabola, the heat rays radiated from the heating element group and reflected by the reflector are radiated in parallel in the front direction of the apparatus, whereby parallel radiation is possible in a wide range. Moreover, in the heating apparatus configured as described above, the radiation heat reflected by the reflector further heats the heating elements; hence, the temperature of the heating elements can be raised higher, and high energy is radiated in the same direction from the flat faces of the heating elements, and the object to be heated can be heated to high temperature.
A heating apparatus according to a 12th aspect of the present invention is characterized in that the cross-sectional shape of the reflector of the heating apparatus according to the above-mentioned eighth aspect, cross-sectioned in the direction orthogonal to the longitudinal direction thereof, is a combination shape of plural parabolas, and that the substantially central point of heating in each heating element is disposed at the position of the focal point of each parabola. In the heating apparatus according to the 12th aspect, configured as described above, because the substantially central point of heating in each heating element is disposed at the position of the focal point of each parabola, the heat rays radiated from the plural heating elements and reflected by the reflector are radiated in parallel in the front direction of the apparatus, and parallel radiation is made possible in a wide range.
A heating apparatus according to a 13th aspect of the present invention is characterized in that the cross-sectional shape of the reflector of the heating apparatus according to the above-mentioned eighth aspect, cross-sectioned in the direction orthogonal to the longitudinal direction thereof, has a convex face protruding in a direction being opposed to the flat faces of the heating elements at the central portion of the reflection face thereof, and is configured so that the heat rays from the heating elements are diffusely reflected by the convex face. Because the heating apparatus according to the 13th aspect, configured as described above, is configured so that the heat rays from the heating elements are diffusely reflected by the convex face of the reflector, the radiation heat generated from the heating elements can be radiated efficiently from the reflection face in a wide range.
A heating apparatus according to a 14th aspect of the present invention is characterized in that the cross-sectional shape of the reflector of the heating apparatus according to the above-mentioned eighth aspect, cross-sectioned in the direction orthogonal to the longitudinal direction thereof, has a concave-convex face positioned so as to be opposed to the flat faces of the heating elements at the central portion of the reflection face thereof, and so that the heat rays from the heating elements are diffusely reflected by the concave-convex face. Because the heating apparatus according to the 14th aspect, configured as described above, is configured so that the heat rays from the heating elements are diffusely reflected by the concave-convex face of the reflector, the radiation heat generated from the heating elements can be radiated efficiently from the reflection face in a wide range.
A heating apparatus according to a 15th aspect of the present invention comprises an infrared ray lamp having:
A heating apparatus according to a 16th aspect of the present invention comprises an infrared ray lamp having:
A heating apparatus according to a 17th aspect of the present invention is characterized in that the heating apparatus according to the above-mentioned eighth to 16th aspects further comprises:
A heating apparatus according to an 18th aspect of the present invention is characterized in that the control circuit of the heating apparatus according to the above-mentioned 17th aspect is configured so that circuits for ON-OFF control, power application ratio control, phase control and zero-cross control are used independently or at least two of the circuits are used in combination. In the heating apparatus according to the 18th aspect, configured as described above, because the control circuit is configured so that circuits for ON-OFF control, power application ratio control, phase control and zero-cross control are used independently or at least two of the circuits are used in combination, the heating apparatus can carry out highly accurate temperature control. Furthermore, because the heating apparatus according to the present invention is equipped with the plural heating elements, highly accurate temperature control capable of carrying out stable heating at a desired temperature with little variation is made possible by controlling part of the heating elements while electric power is supplied to required heating elements.
A heating apparatus according to a 19th aspect of the present invention is characterized in that the heating elements of the heating apparatus according to the above-mentioned 16th aspect are carbonaceous heating elements including a carbonaceous substance and formed by firing. In the heating apparatus according to the 19th aspect, configured as described above, the materials of the heating elements include a carbonaceous substance, and the heating elements are formed by firing, whereby the emissivity of the heating elements is higher than that of a metallic heating element by 80% or more. The heating elements made of this kind of material are formed to have flat faces and to provide high directivity; hence, primary radiation is surely applied to an object to be heated, and it is possible to configure a heating apparatus having high radiation efficiency.
A heating apparatus according to a 20th aspect of the present invention is characterized in that the heating elements of the heating apparatus according to the above-mentioned eighth to 16th aspects are solid carbonaceous heating elements including a carbonaceous substance and a resistance adjustment substance, and formed by firing.
Effect of the Invention
In the heating apparatus according to the present invention, configured as described above, because the materials of the heating elements include a carbonaceous substance and a resistance adjustment substance, and the heating elements are formed by firing, the emissivity of the heating elements is higher than that of a metallic heating element by 80% or more. Furthermore, the installation directions of the heating elements can have desired directions using securing means having elasticity. Because the heating elements made of such materials are formed to have flat faces so as to have high directivity in a desired direction, primary radiation is surely applied to an object to be heated, and it is possible to configure a heating apparatus having high radiation efficiency.
1 glass tube
Embodiments specifically indicating the best modes for embodying the infrared ray lamp and the heating apparatus according to the present invention will be described below referring to the accompanying drawings. In the figure showing the whole of the infrared ray lamp according to each embodiment described below, because the infrared ray lamp is long, the intermediate portion thereof is cut away and not shown.
FIGS. 1 to 3 are views showing an infrared ray lamp according to Embodiment 1 of the present invention.
In the infrared ray lamp according to Embodiment 1, two heating structures 100 and 100 are disposed in parallel inside a glass tube 1 formed of a quartz glass tube, and the both ends of the glass tube 1 are melted, flattened and sealed. The interior of the glass tube 1 is filled with an inert gas, such as argon, or a mixed gas of argon and nitrogen. Each heating structure 100 comprises a heating element 2A or 2B having a long flat plate shape and serving as a heat radiator, holding blocks 3 secured to both ends of this heating element 2A or 2B, internal lead wire portions 11 connected to the ends of the holding blocks 3, and molybdenum foils 8 that electrically connect the internal lead wire portions 11 to external lead wires 9A and 9B. The portions in which the molybdenum foils 8 are disposed are the sealed portions of the glass tube 1.
For the purpose of disposing the two heating structures 100 and 100 in parallel so at to have a desired space therebetween, spacers 4 are provided for mutually securing the holding blocks 3 and 3 of the heating structures 100 and 100. In the infrared ray lamp according to Embodiment 1, the holding block 3 and the spacer 4 constitute a heating element holder 10.
As shown in
The lead wires 7 are joined near one ends of the molybdenum foils 8 by welding, and the external lead wires 9A and 9B that supply a power source voltage to the heating elements 2A and 2B are joined near the other ends of the molybdenum foils 8 by welding.
The two heating structures 100 and 100 configured as described above are disposed at desired positions inside the glass tube 1, and the glass tube 1 is flattened and sealed at the joint portions of the lead wires 7, the molybdenum foils 8 and the external lead wires 9A and 9B. The inert gas, such as argon, or the mixed gas of argon and nitrogen filled inside the glass tube 1 is used to prevent the oxidation of the heating elements 2A and 2B made of a carbonaceous substance.
As shown in
The holding block 3 produced as described above is made of a material that is difficult to transfer heat from the heating element 2A or 2B to the coil portion 5 of the internal lead wire portion 11. In addition, the holding block 3 is bonded to the heating element 2A or 2B using a carbonaceous adhesive. The carbonaceous adhesive being used in Embodiment 1 is a paste-like adhesive made by mixing the fine powder of graphite or carbon in a thermoplastic or thermosetting resin.
In Embodiment 1, an example of bonding in which the holding block 3 is bonded to the heating element 2A or 2B using a carbonaceous adhesive is described; however, any well-known joining method can be used without causing problems, provided that the holding block 3 is joined securely and electrically to the heating element 2A or 2B.
As shown in
In the heating structures 100 according to Embodiment 1, the holding block 3 to which the heating element 2A is secured and the holding block 3 to which the heating element 2B is secured as described above can be assembled easily and integrally in the assembly step of the infrared ray lamp so that they have the desired space therebetween and the flat face portions are oriented in the desired direction, whereby the step for inserting and sealing the heating structures into the glass tube is made easy. Hence, according to Embodiment 1, an infrared ray lamp having high heat radiation directivity in comparison with conventional infrared ray lamps can be produced easily.
The spacer 4 according to Embodiment 1 is made of a material having thermal resistance and insulation, such as alumina ceramic. In Embodiment 1, an example in which the spacer 4 is made of alumina ceramic is described; however, materials having thermal resistance, insulation and ease of machinability, such as steatite ceramics and machinable ceramics, can be used as the spacer 4.
In the infrared ray lamp according to Embodiment 1 configured as described above, when a desired voltage is applied to the external lead wires 9A and/or 9B respectively derived from both ends thereof, the desired voltage is applied from the internal lead wires 4A and/or 4B connected to the external lead wires 9A and/or 9B via the molybdenum foils 8 to the corresponding heating elements 2A and/or 2B, a current flows through the heating elements 2A and/or 2B, and heat is generated by virtue of the resistance of the heating elements 2A and/or 2B. Infrared rays are radiated from the heating elements 2A and/or 2B being heated at this time.
The heating elements 2A and 2B in the infrared ray lamp according to Embodiment 1 are made of a carbonaceous substance and formed into a long flat plate shape, and the carbonaceous substance is made of a mixture obtained by adding a nitrogen compound serving as a resistance value adjustment substance and amorphous carbon to a base material made of crystallized carbon, such as graphite.
In the infrared ray lamp according to Embodiment 1, the heating elements 2A and 2B serving as resistance heating elements and formed of a sintered body made of a carbonaceous substance were produced as described below.
First, 45 weight parts of chlorinated vinyl chloride resin and 15 weight parts of furan resin are mixed to form a first mixture. Next, 10 weight parts of fine powder of natural graphite (average grain size: 5 μm) and 60 weight parts of the first mixture are mixed to form a second mixture. Then, 30 weight parts of boron nitride (average grain size: 2 μm), 70 weight parts of the second mixture and 20 weight parts of diallyl phthalate monomer (plasticizing agent) are dispersed and mixed to form a third mixture. The third mixture formed as described above is molded into a plate shape by using an extrusion molding machine. The plate-shaped material formed as described above is fired in a firing furnace at 1000° C. for 30 minutes under nitrogen gas atmosphere. In addition, the material is heat-treated again in a vacuum of 1×10−2 Pa or less so that the resistance temperature characteristic of the material has a desired characteristic. The heat treatment temperature at this time is set depending on the composition and shape of the material. The temperature is selected from the range of 1500° C. to 1900° C. in Embodiment 1. The change ratio of the electric specific resistance value [Ω·cm] of the heating element produced as described above is set in the range of −20% to +20% at 20° C. and 1200° C. It is preferable that the change ratio should be set in the range of −10% to +10%.
In the infrared ray lamp according to Embodiment 1, the heating elements 2A and 2B produced as described above have a plate width W of 6.0 mm, a plate thickness T of 0.5 mm and a length of 300 mm, for example. It is desirable that the ratio (W/T) of the plate width W and the plate thickness T in the heating elements 2A and 2B should be 5 or more. When the heating element is formed into a flat plate shape in which the plate width W is five or more times larger than the plate thickness T, the amount of heat radiated from the flat face (plate width W) is made larger than the amount of heat radiated from the narrow side face (plate thickness T) as a matter of course, and the heat radiation from the heating elements 2A and 2B having a flat plate shape can be provided with directivity.
In the heating elements 2A and 2B made of a carbonaceous substance and used in Embodiment 1, heating efficiency is high, time required to reach the rated temperature from the start of heating is very short, and no rush current flows at the time of lighting up, whereby flicker that occurs during control can be reduced. Because the infrared ray lamp according to Embodiment 1 uses the heating elements 2A and 2B made of a carbonaceous substance, its service life is approximately 10,000 hours, that is, approximately twice the service life of a tungsten infrared ray lamp being used in similar service conditions, although the service life differs depending on the service conditions.
In addition, in the infrared ray lamp according to Embodiment 1, the two heating elements 2A and 2B made of a carbonaceous substance are provided in parallel. The resistance value of the heating element made of a carbonaceous substance differs depending on the shape and size thereof; as a result, the power consumed in the heating element also differs greatly. Hence, when an infrared ray lamp having a desired size is configured to have a desired power consumption amount, it is difficult to satisfy the need using one heating element, but it is easy to satisfy the need using two or more heating elements made of a carbonaceous substance. Furthermore, a desired amount of heat can be radiated stepwise by controlling the voltage applied to each heating element; still further, radiation heat can be adjusted stepwise by providing heating elements having different power consumption amounts in parallel.
In the infrared ray lamp according to Embodiment 1, the configuration in which the two heating elements 2A and 2B made of a carbonaceous substance are provided in parallel is described; however, the present invention is not limited to the configuration having two heating elements, but can be configured using three or more heating elements. Even in such a case, heating elements having a flat plate shape are provided in parallel on the center line in the cross section of the glass tube 1, and they are disposed so that their flat face portions are oriented in the same direction.
In the configuration shown in (a) of
In
In
In
As described above, in the infrared ray lamp according to Embodiment 1 of the present invention, plural heating elements serving as carbonaceous resistors having high emissivity and large radiation energy amounts are disposed at desired positions and desired angles, and sealed inside a glass tube, whereby radiation heat can be radiated efficiently from the heating elements to an object to be heated, and primary radiation to the object to be heated can be enhanced. Therefore, the infrared ray lamp according to Embodiment 1 can provide a highly efficient heating apparatus capable of quickly heating an object to be heated to a desired temperature.
An infrared ray lamp according to Embodiment 2 of the present invention will be described below using the accompanying
The infrared ray lamp according to Embodiment 2 differs from the infrared ray lamp according to Embodiment 1 described above in the configuration of the heating element holder that holds the two heating elements having a flat plate shape. As shown in
In the infrared ray lamp according to Embodiment 2, the two heating elements 2A and 2B formed into a long flat plate shape are disposed inside the glass tube 1 formed of a quartz glass tube, and the holding blocks 3 are respectively secured to one ends (the lower ends in
On the other hand, a holding block 30 that secures the two heating elements 2A and 2B so that a predetermined space is provided therebetween is provided at the other ends (the upper ends in
As shown in
As described above, the infrared ray lamp according to Embodiment 2 is configured so that either one ends of the heating elements are secured in common using the holding block and so that the heating elements are held while having a constant space therebetween. Hence, in the infrared ray lamp according to Embodiment 2, the spacer 4 should only be disposed only on one end sides of the heating elements; therefore, the configuration can be made simple, and the number of the connection points to the external lead wires can be reduced.
A heating apparatus according to Embodiment 3 of the present invention will be described below using the accompanying FIGS. 8 to 13.
The heating apparatus according to Embodiment 3 uses the infrared ray lamp according to Embodiment 2 described above as a heat radiation source. The heating apparatus according to Embodiment 3 is configured so that the reflector is provided behind the glass tube in the infrared ray lamp according to Embodiment 2 described above. As shown in
In the infrared ray lamp according to Embodiment 3, two heating elements 2A and 2B formed into a long flat plate shape are disposed inside the glass tube 1, and the flat face portions of the heating elements 2A and 2B are disposed so as to be oriented in the same direction. The holding blocks 3 are respectively secured to one ends (the lower ends in
In the infrared ray lamp according to Embodiment 3, the two heating elements 2A and 2B each having a flat plate shape are provided accurately in parallel on the center line in the cross section of the glass tube 1, and disposed so that their respective flat face portions are oriented in the same direction. Hence, the heating apparatus according to Embodiment 3 is configured so that the highest amount of heat is radiated in the directions in which the flat face portions of the two heating elements 2A and 2B are oriented.
In the heating apparatus according to Embodiment 3, the infrared ray lamp configured as described above is provided as a heat radiation source; one of the two directions in which the flat face portions of the heating elements 2A and 2B of the infrared ray lamp are oriented is the front direction of the heating apparatus, and the other direction is the rear direction of the heating apparatus. In the perspective view of
As shown in
The reflector 50 is formed so at to cover the rear sides of the heating elements 2A and 2B of the infrared ray lamp while having the same cross section along the extension direction (the up-down direction in
As shown in
As a result, in the heating apparatus according to Embodiment 3, together with the heat rays radiated from the front-side flat face portions of the heating elements 2A and 2B, the heat rays radiated from the rear-side flat face portions of the heating elements 2A and 2B are radiated in the front direction of the infrared ray lamp using the reflector 50, thereby efficiently heating an object to be heated that is disposed in the front direction of the heating apparatus.
Furthermore, the heating apparatus according to Embodiment 3 is configured so that the heat rays radiated from the rear-side flat face portions of the heating elements 2A and 2B are reflected in parallel in the front direction in the vicinities of the fringes of the reflector 50, whereby a hot plate 60 disposed so as to be opposed to the front sides of the heating elements 2A and 2B is heated in a wide range.
In the heating apparatus according to Embodiment 3 configured as described above, the heat radiation from the heating elements 2A and 2B is positively reflected in the front direction by the reflector 50, and the object 60 to be heated can be heated quickly and efficiently to a desired temperature.
In the description of Embodiment 3, the heating apparatus in which the flat face portions of the two heating elements are oriented in the same direction and disposed on the same straight line, that is, the heating elements are disposed so that their angles are 0°, is described; however, in the case that the two heating elements are disposed so as to have angles, a similar effect is obtained by changing the design of the shape of the reflector depending on the angles of the heating elements so that the heat radiation from the rear sides of the heating elements is reflected in the front direction. Furthermore, it is possible to increase the number of the heating elements to three or more depending on the specifications of the heating apparatus; even in that case, a similar effect is obtained by changing the design of the shape of the reflector depending on the locations of the heating elements.
FIGS. 10 to 13 are sectional views showing modification examples of the reflector in the heating apparatus according to Embodiment 3. FIGS. 10 to 13 are sectional views of the reflector cross-sectioned in the direction orthogonal to the extension direction (the longitudinal direction) of the heating elements. In these modification examples, the components having the same functions and configurations as those used in Embodiment 3 are made of the same materials and designated by the same numerals, and their descriptions are omitted.
The reflector 51 shown in
The reflector 52 shown in
In the configuration shown in
The reflector 53 shown in
The reflector 54 shown in
As described above, in the configurations shown in
In the configurations shown in FIGS. 10 to 13, it is possible to increase the number of the heating elements to three or more depending on the specifications of the heating apparatus; even in that case, a similar effect is obtained by changing the design of the shape of the reflector depending on the locations of the heating elements.
The heating apparatus in which the infrared ray lamp and the reflector are used as a heat source as described above can carry out wide-range heating, heating using parallel heat rays, uniform heating by virtue of desired diffused reflection and highly efficient heating, thereby being a heating apparatus having high versatility suited for objects to be heated and usage environment.
Herein, as examples of the heating apparatus, electric radiation heaters, such as heaters for room heating, cookers for cooking and heating, driers for foods and the like, electronic apparatuses for toner fixation and the like in copying machines, facsimile machines, printers, etc., and apparatuses required to carry out heating to high temperature in a short time are included.
A heating apparatus according to Embodiment 4 of the present invention will be described below using the accompanying
The heating apparatus according to Embodiment 4 uses the infrared ray lamp according to Embodiment 2 described above as a heat radiation source. The heating apparatus according to Embodiment 4 is configured so that a reflection film is formed on the rear side of the glass tube in the infrared ray lamp according to Embodiment 2 described above. As shown in
In the infrared ray lamp according to Embodiment 4, two heating elements 2A and 2B formed into a long flat plate shape are disposed inside the glass tube 1 so that the flat face portions thereof are oriented in the same direction, and the holding blocks 3 are respectively secured to one ends (the lower ends in
As shown in
The heating elements 2A and 2B are disposed at the central portion of the substantially cylindrical portion of the glass tube 1, and a center line is disposed at the intermediate position between the two heating elements 2A and 2B in the extension direction of the glass tube 1. The reflection film 70 formed on the rear side of the glass tube 1 is formed at the positions opposed to the side faces of the heating elements 2A and 2B, that is, formed into a semicircular shape in cross section. In Embodiment 4, an example in which the reflection film 70 is formed at the positions opposed to the side faces of the heating elements 2A and 2B is taken and described; however, the reflection film should only be formed at least at the positions opposed to the rear-side flat face portions of the heating elements 2A and 2B.
The reflection film 70 is made of a material having high reflectivity; in Embodiment 4, the reflection film was produced by transferring foil including gold to the outer wall of the glass tube 1 and then by carrying out firing.
In the infrared ray lamp in the heating apparatus according to Embodiment 4 configured as described above, the heat rays radiated from the rear sides of the heating elements 2A and 2B are positively reflected by the reflection film 70 formed on the glass tube 1 to the heating elements 2A and 2B and in the front direction; therefore, heating having high radiation intensity can be carried out for the object 60 to be heated that is disposed on the front side of the glass tube 1.
According to the experiments conducted by the inventors, when an identical voltage is applied to the heating elements 2A and 2B, the temperature of the heating elements was 1100° C. without the reflection film 70, and the temperature thereof was 1200° C. with the reflection film 70. Hence, the heating elements themselves can be high-energy radiators by providing the reflection film 70 on the glass tube 1.
In addition, because the heating apparatus according to Embodiment 4 is configured so that no reflector is provided around the glass tube 1 but the reflection film 70 is formed near the heating elements, the heat loss from the heating elements can be reduced in comparison with the configuration in which heat radiation is reflected by a reflector.
In Embodiment 4, an example in which the reflection film 70 was produced by transferring foil including gold to the outer wall of the glass tube 1 and by carrying out firing was taken and described; however, the present invention is not limited to this example; a similar effect can also be obtained even when the reflection film is produced using a material having high reflectivity, such as titanium nitride, aluminum, nickel, chromium or aluminum oxide.
In the heating apparatus configured so that the infrared ray lamp having the reflection film 70 configured as described above is used as a heat source, wide-range heating with high efficiency and heating with low heat loss can be made possible by disposing the infrared ray lamp having the reflection film 70 inside the housing as shown in
Herein, as examples of the heating apparatus, electric radiation heaters, such as heaters for room heating, cookers for cooking and heating, driers for foods and the like, electronic apparatuses for toner fixation and the like in copying machines, facsimile machines and printers, and apparatuses required to carry out heating to high temperature in a short time are included.
A heating apparatus according to Embodiment 5 of the present invention will be described below using the accompanying
The heating apparatus according to Embodiment 5 uses the infrared ray lamp according to Embodiment 2 described above as a heat radiation source. The heating apparatus according to Embodiment 5 is configured so that a cylinder is disposed around the glass tube in the infrared ray lamp according to Embodiment 2 described above. As shown in
As shown in
In the case of heating foods, the cylinder 100 is formed of a glass tube and is configured so that the heat radiation from the flat face portions of the heating elements 2A and 2B is transmitted therethrough. By the use of the cylinder 100 provided around the glass tube 1, even if seasoning agents, broth, etc. are dispersed during food heating, the dispersed matter does not make direct contact with the infrared ray lamp.
If high-temperature seasoning agents and broth make direct contact with the infrared ray lamp, the surface of the glass tube 1 is devitrified, and this causes a problem of breaking the glass tube 1. However, in the heating apparatus according to Embodiment 5 of the present invention, the above-mentioned problem is prevented completely, and the service life thereof can be extended.
In the case that the heating apparatus according to Embodiment 5 is used for toner fixation in electronic apparatuses, such as copying machines, facsimile machines and printers, the infrared ray lamp is disposed in the cylinder 100 which serves as a fixation roller. With this configuration of the electronic apparatus, the electronic apparatus can be configured so that the heat radiation having high directivity and generated from the flat face portions of the heating elements 2A and 2B inside the infrared ray lamp is applied to the fixation portion of the toner fixation apparatus, and it is possible to have a configuration in which the fixation portion is heated efficiently. By the use of the infrared ray lamp having high directivity as described above and being capable of carrying out quick heating to a desired temperature, the electronic apparatus can intensively heat the fixation face, and efficient operation can be carried out at the time of start, standby and the like of the apparatus.
By the use of the infrared ray lamp capable of carrying out heat radiation having high directivity and by the installation of the cylinder 100, having a different configuration depending on the purpose, around the infrared ray lamp as described above, the infrared ray lamp can be protected, and a heating apparatus being capable of carrying out quick heating and having high heating efficiency can be provided.
Herein, as examples of the heating apparatus, electric radiation heaters, such as heaters for room heating, cookers for cooking and heating, driers for foods and the like, and electronic apparatuses for toner fixation and the like are included.
A heating apparatus according to Embodiment 6 of the present invention will be described below using the accompanying
The heating apparatus according to Embodiment 6 uses the infrared ray lamp according to Embodiment 1 described above as a heat radiation source, and is characterized in the method for controlling the heat radiation. The two heating elements 2A and 2B provided in the infrared ray lamp will be described below as a first heating element 2A and a second heating element 2B, respectively.
The circuit diagram shown in
Furthermore, the control circuit in the heating apparatus according to Embodiment 6 is provided with three power source terminals 115, 116 and 117 connected to a power source V. The first power source terminal 115 is configured so that it can be connected simultaneously to both the first external terminal 110 and the third external terminal 112 or only to the first external terminal 110. The second power source terminal 116 is configured so that it can be connected simultaneously to both the second external terminal 111 and the fourth external terminal 113. Moreover, the third power source terminal 117 is configured so that it can be connected only to the third external terminal 112 when the first power source terminal 115 is connected only to the first external terminal 110. Still further, the second external terminal 111 of the first heating element 2A and the fourth external terminal 113 of the second heating element 2B are configured so as to be electrically connected to each other.
In the control circuit configured as described above, the power application control for the first heating element 2A and the second heating element 2B in the infrared ray lamp is carrying out as described below.
[Parallel Power Application Control]
In the case that power is applied to the first heating element 2A and the second heating element 2B in parallel, the first external terminal 110 of the first heating element 2A and the third external terminal 112 of the second heating element 2B are connected to the first power source terminal 115. At the same time, the second external terminal 111 of the first heating element 2A and the fourth external terminal 113 of the second heating element 2B are connected to the second power source terminal 116. With these connections in the control circuit, if both the first heating element 2A and the second heating element 2B have a power consumption of 500 W when 100 V is applied according to their specifications, for example, the power consumption of the infrared ray lamp is 1000 W when 100 V is applied from the power source V. Furthermore, if the first heating element 2A and the second heating element 2B have a heating element temperature of 1100° C. when 100 V is applied, both the first heating element 2A and the second heating element 2B respectively carry out heat radiation at a heating element temperature of 1100° C.
[Series Power Application Control]
In the case that power is applied to the first heating element 2A and the second heating element 2B in series, the first external terminal 110 of the first heating element 2A is connected to the first power source terminal 115. At the same time, the second external terminal 111 of the first heating element 2A and the fourth external terminal 113 of the second heating element 2B are electrically connected to each other. In addition, the third external terminal 112 of the second heating element 2B is connected to the third power source terminal 117. With these connections in the control circuit, in the case that the first heating element 2A and the second heating element 2B have the above-mentioned specifications, the power consumption of the infrared ray lamp is 500 W when 100 V is applied from the power source V. Furthermore, in the case that the first heating element 2A and the second heating element 2B that have a heating element temperature of 1100° C. when 100 V is applied are used, both the first heating element 2A and the second heating element 2B carry out heat radiation at a heating element temperature of approximately 700° C.
[Independent Power Application Control]
For example, in the case that power is applied only to the first heating element 2A independently, the first external terminal 110 of the first heating element 2A is connected to the first power source terminal 115. At the same time, the second external terminal 111 of the first heating element 2A is connected to the second power source terminal 116. At this time, no voltage is applied to the second heating element 2B. With these connections in the control circuit, in the case that the first heating element 2A has the above-mentioned specifications, the power consumption of the infrared ray lamp is 500 W when 100 V is applied from the power source V. In addition, the first heating element 2A carries out heat radiation at a heating element temperature of 1100° C.
By the provision of the three power source terminals as described above, heating adjustment is made possible by changing the temperature of the heating elements through power application circuit selection, even if an identical input is applied to the infrared ray lamp. Hence, in the heating apparatus according to Embodiment 6, the flat face portions of the heating elements are oriented in desired directions; furthermore, by carrying out power application control, the heat radiation has excellent directivity, whereby the heating temperature can be controlled easily so as to be adapted for an apparatus to be heated.
In the heating apparatus according to Embodiment 6, an example in which heat radiation is controlled using the infrared ray lamp according to Embodiment 1 is taken and described; however, the present invention is not limited to this kind of control method, but the heat radiation can also be controlled using the infrared ray lamps according to Embodiment 2 to Embodiment 5 described above as a heat radiation source. In the case of such a configuration, the second power source terminal 116 shown in
In addition, in the heating apparatus according to Embodiment 6, temperature control can be added as a selection condition in the case of carrying out power application control. For temperature control, ON-OFF control in which a temperature detecting means, such as a thermostat, is used, input power source phase control in which a temperature sensor that accurately senses temperature is used, power application ratio control and zero-cross control are carried out independently or in combination, whereby it is possible to realize a heating apparatus capable of carrying out highly accurate temperature control. Hence, with the heating apparatus according to Embodiment 6 configured as described above, heating being excellent in radiation characteristics and highly accurate temperature control can be attained by the directivity control at the flat face portions of the heating elements and by the power application control.
As clarified by the descriptions of the respective embodiments described above, according to the present invention, the primary radiation from the heating elements to an object to be heated can be carried out efficiently by accurately disposing plural heating elements formed of a carbonaceous resistor having high emissivity and large radiation energy at desired positions and desired angles and by sealing them inside a glass tube. In addition, in the infrared ray lamp according to the present invention, the primary radiation from the heating elements to the object to be heated can be enhanced by forming a reflector or a reflection film having a desired shape, and the secondary radiation to the object to be heated can also be enhanced by efficiently reflecting the heat radiated from the heating elements in directions different from the direction of the object to be heated. Furthermore, the present invention can provide a highly efficient apparatus capable of quickly heating the object to be heated up to a desired temperature by providing the infrared ray lamp configured as described above as a heat source in the heating apparatus.
In the infrared ray lamp according to the present invention, because the flat faces of the plural heating elements provided in parallel are disposed so as to be surely oriented in the same direction, the heat radiation from the heating elements has directivity, and an object to be heated can be heated efficiently by the primary radiation heat from the heating elements.
In the infrared ray lamp according to the present invention, because the flat faces of the plural heating elements provided in parallel are disposed so as to have a predetermined angle with respect to a reference face, the heat radiation from the heating elements can be carried out efficiently while having high directivity in a desired direction.
In the heating apparatus according to the present invention, because the flat faces of the plural heating elements provided in parallel are disposed so as to be surely oriented in the same direction, the heat radiation from the heating elements has directivity, and the primary radiation heat from the heating elements can be applied efficiently to the object to be heated.
In the heating apparatus according to the present invention, part of the reflector is configured so that the heat radiation from the heating elements is not applied to the heating elements; hence, the secondary heating to the heating elements due to the reflector is suppressed, abnormal temperature rise in the heating elements is prevented, and the stability of the heating elements can be attained.
Because the substantially central point of the heating of the heating elements of the heating apparatus according to the present invention is disposed at the position of the focal point of the parabola, the heat rays radiated from the heating elements and reflected by the reflector are further radiated in parallel in the front direction of the apparatus, and an object to be heated can be heated efficiently by the wide-range parallel radiation.
The heating apparatus according to the present invention is configured so that the heat rays from the heating elements are reflected by the reflection film provided on the glass tube; hence, the radiation heat from the heating elements is radiated efficiently, and high energy is radiated in the same direction from the flat faces of the heating elements, whereby the object to be heated can be heated to high temperature.
Because the heating apparatus according to the present invention is provided with the cylinder that covers the heating elements, foreign matter generated from an object to be heated and the like, such as broth or seasoning agents, is shielded by the cylinder and does not make direct contact with the infrared ray lamp; hence, breakage and wire disconnection due to deterioration in the surface of the infrared ray lamp can be prevented, and the apparatus can have long service life. Furthermore, when the cylinder that covers the heating elements is used as a toner fixation roller, it is possible to build an electronic apparatus that can efficiently heat the portion at which the toner fixation roller makes contact with paper.
In the heating apparatus according to the present invention, by the selective connection of the external terminals provided separately in the plural heating elements of one infrared ray lamp, the plural heating elements can be set in a series, parallel or independent power application state, and the input power and the temperature of the heating elements can be changed easily at the same rating.
The control circuit of the heating apparatus according to the present invention is configured so that circuits for ON-OFF control, power application ratio control, phase control and zero-cross control are used independently or at least two of the circuits are used in combination; hence, the heating apparatus can carry out highly accurate temperature control.
Because the heating apparatus according to the present invention uses the carbonaceous heating elements made of a material including a carbonaceous substance and formed by firing, primary radiation is positively applied to an object to be heated, and it is possible to configure a heating apparatus having high radiation efficiency.
Although the present invention has been described with respect to its preferred embodiments in some detail, the disclosed contents of the preferred embodiments may change in the details of the structure thereof, and any changes in the combination and sequence of the components may be attained without departing from the scope and spirit of the claimed invention.
The heating apparatus that uses the infrared ray lamp according to the present invention as a heat source can be used as a heating unit for electric heaters (heaters for room heating and the like), electric cookers and electronic apparatuses, for example, has excellent heating functions, and is useful.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2003-391214 | Nov 2003 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP04/16886 | 11/12/2004 | WO | 5/17/2006 |
