EP2849206A1

EP2849206A1 - Heater lamp and heating module using the heater lamp

Info

Publication number: EP2849206A1
Application number: EP20140160402
Authority: EP
Inventors: Masaaki TAKATSUKA; Yoshitaka Fujita; Tsuyoshi Ohashi
Original assignee: Toshiba Lighting and Technology Corp
Current assignee: Toshiba Lighting and Technology Corp
Priority date: 2013-09-13
Filing date: 2014-03-18
Publication date: 2015-03-18
Also published as: JP2015056345A; CN104470007A

Abstract

A heater lamp (110, 111) includes a light-emitting tube (10), a filament (20) and a filler gas. The light-emitting tube (10) includes a bent part (14, 15) and is light transmissive. The filament (20) is provided in an inside space (30) of the light-emitting tube (10). The filler gas is filled in the space (30), and includes bromine, nitrogen, and a noble gas including at least one of argon, krypton and xenon. A lamp input power (Wa) per unit length supplied to the filament (20) is 70 W/cm or more. A nitrogen gas volume concentration Cv to the noble gas is 1 vol% or more and 30 vol% or less.

Description

FIELD

Embodiments described herein relate generally to a heater lamp and a heating module using the heater lamp.

BACKGROUND

For example, in a molding process of a resin container or the like, a heater lamp to heat the resin container and a heating module using the heater lamp are used. The life of the heater lamp is desired to be prolonged.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view illustrating a heater lamp of a first embodiment;
FIG. 2 is a view illustrating characteristics of the heater lamp of the first embodiment;
FIG. 3 is a schematic view illustrating another heater lamp of the first embodiment; and
FIG. 4 is a schematic view illustrating a heating module of a second embodiment.

DETAILED DESCRIPTION

In general, according to one embodiment, a heater lamp includes a light-emitting tube, a filament and a filler gas. The light-emitting tube includes a bent part and is light transmissive. The filament is provided in an inside space of the light-emitting tube. The filler gas is filled in the space and includes a noble gas including at least one of argon, krypton and xenon, bromine and nitrogen. A lamp input power per unit length supplied to the filament is 70 W/cm or more. A nitrogen gas volume concentration Cv to the noble gas is 1 vol% or more and 30 vol% or less.
Various embodiments will be described hereinafter with reference to the accompanying drawings.
Incidentally, the drawings are schematic or conceptual, and the relation between thickness and width of each portion and the ratio between sizes of portions are not necessarily equal to actual ones. Besides, even when the same portions are expressed, mutual dimensions and ratios may be expressed differently depending on the drawings.
Incidentally, in the specification and the respective drawings, a component similar to that descried previously with respect to a previously shown drawing is denoted by the same reference numeral and a detailed explanation thereof will be suitably omitted.

First Embodiment

FIG. 1 is a schematic view illustrating a heater lamp of a first embodiment.
As shown in FIG. 1, a heater lamp 110 of the embodiment includes a light-emitting tube 10 and a filament 20.
The light-emitting tube 10 includes a bent part. That is, the light-emitting tube 10 includes a straight part 11, a straight part 12, a straight part 13, a bent part 14 provided between the straight parts 11 and 12, and a bent part 15 provided between the straight parts 11 and 13. The straight part 11 includes one end 11a and the other end 11b.
In the embodiment, an angle between a direction in which the straight part 11 extends and a direction in which the straight part 12 extends is arbitrary. The straight part 12 is connected to the one end 11a of the straight part 11 through the bent part 14. That is, one end 12a of the straight part 12 is connected to the one end 11a of the straight part 11. A direction in which the light-emitting tube 10 extends may be continuously smoothly changed between the straight part 11 and the straight part 12.
In the embodiment, an angle between the direction in which the straight part 11 extends and a direction in which the straight part 13 extends is arbitrary. For example, in the embodiment, the straight part 13 is parallel to a plane including the straight part 11 and the straight part 12.
The straight part 13 is connected to the other end 11b of the straight part 11. That is, one end 13a of the straight part 13 is connected to the other end 11b of the straight part 11.
For example, the straight part 13 and the straight part 12 are arranged side by side along the direction in which the straight part 11 extends. That is, a direction directed from the straight part 12 toward the straight part 13 is parallel to the direction in which the straight part 11 extends. The light-emitting tube is, for example, C-shaped.
The inside of the light-emitting tube 10 is blocked from the outside. The inside of the light-emitting tube 10 is hermetically sealed. That is, in the embodiment, the other end 12b of the straight part 12 of the light-emitting tube 10 is a first sealing part 12c. The other end 13b of the straight part 13 of the light-emitting tube 10 is a second sealing part 13c.
The filament 20 is provided in an inside space 30 of the light-emitting tube 10. For example, the filament 20 extends from the first sealing part 12c to the second sealing part 13c through the straight part 12, the bent part 14, the straight part 11, the bent part 15 and the straight part 13.
A first end 20a of the filament 20 on the first sealing part 12c side is connected to a first conductive part 31 sealed in the first sealing part 12c. A second end 20b of the filament 20 on the second sealing part 13c side is connected to a second conductive part 32 sealed in the second sealing part 13c.
The other end of the first conductive part 31 is connected to an outer lead 41. At least a part of the outer lead 41 is positioned outside the light-emitting tube 10 (outside the first sealing part 12c). The other end of the second conductive part 32 is connected to an outer lead 42. At least a part of the outer lead 42 is positioned outside the light-emitting tube 10 (outside the second sealing part 13c).
For example, an anchor member to hold the filament 20 may be provided in the light-emitting tube 10.
A filler gas (not shown) is filled in the inside space of the light-emitting tube 10. The filler gas includes a noble gas (noble gas element), bromine and nitrogen (for example, nitrogen molecules). The noble gas includes at least one of argon, krypton and xenon.
For example, quartz glass is used for the light-emitting tube 10. A cross section of the light-emitting tube 10 cut at a plane perpendicular to the direction in which the light-emitting tube 10 extends is, for example, circular.
For example, a Mo foil is used for the first conductive part 31 and the second conductive part 32. Besides, for example, a Mo rod is used for the outer lead 41 and the outer lead 42.
In the embodiment, a nitrogen molecule volume concentration Cv to the noble gas is 1 vol% or more and 30 vol% or less. The nitrogen molecule volume concentration to the noble gas can be obtained by, for example, a so-called GC-MS method in which the heater lamp 110 is broken in a closed space to collect the gas, the gas is separated by gas chromatography, and molecules are identified by mass spectrometry.
The lamp input power per unit length of the heater lamp 110 is 70 W/cm or more. The lamp input power per unit length is expressed by a value obtained by dividing the power supplied to the heater lamp 110 by the lamp length, in the embodiment, the filament length (cm). In the embodiment, for example, the lamp input power is 2000 W (Watt). The length of the heater lamp 110 is 26 cm (centimeter). The lamp input power per unit length is 76.9 W/cm. The lamp input power per unit length is preferably 70 W/cm or more and is more preferably 75 W/cm or more. This is because when the lamp input power per unit length is 70 W/cm or more, infrared rays can be efficiently radiated to a target of the heater lamp 110. When the lamp input power per unit length is 75 W/cm or more, infrared rays can be more efficiently radiated. The lamp length is preferably in a range of 15 to 50 cm, and more preferably, 20 to 40 cm. When the lamp length is less than 10 cm, the formation of the heater lamp having the bent part is difficult. When the lamp length is longer than 50 cm, the power source for supplying power to the lamp becomes large, and this is not realistic.
In the heater lamp 110, when the lamp input power per unit length is 70 W/cm or more, a color temperature T of the heater lamp 110 at the time of operation is 2600 K (Kelvin) or higher. That is, the color temperature T of light outside the light-emitting tube 10, which is generated when the power is supplied to the filament 20 so as to satisfy that the lamp input power per unit length is 70 W/cm or more, is 2600 K (Kelvin) or higher. The color temperature T can be measured in such a way that for example, a spectrometer MSR-7000 of Opto Research Corporation is used, the lamp is lit, and a detector of the spectrometer is arranged at a position separated by 1 m.
According to the embodiment, electric discharge in the filler gas is suppressed, and the life can be prolonged. According to the embodiment, the heater lamp with long life can be provided.
When the filament provided inside the heater lamp is broken during lighting, high voltage is applied between the broken filaments, and electric discharge may be generated between the broken filaments. However, the inventor found that the electric discharge could occur in spite of not being the broken state. Especially, this phenomenon occurs at high load and in the heater lamp having the bent part, not in a straight tube. When the phenomenon was studied, a phenomenon was observed in which arc discharge occurred in the whole inside of the heater immediately after lighting. The heater bursts by the arc discharge. The inventor paid attention to this phenomenon.
In the heater lamp with high load, electric discharge becomes liable to occur in the heater lamp by thermionic electron emission from a coil (filament 20) or ionization of the filler gas. At this time, an electric current flows more easily through the gas (filler gas) than through the filament. Especially, when the bent part is provided, since the light-emitting tubes of the heater lamp approach each other more than a straight tube, the electric current flows more easily through the gas of the heater lamp. The color temperature of light emitted from the filament 20 correlates with the thermionic electron emission from the filament. As the color temperature of the filament becomes high, the thermionic electron emission from the filament increases. The inventor found the electric discharge was liable to occur under the condition that the color temperature of light emitted from the light-emitting tube was 2600 K or higher.
The inventor performed an experiment while changing components of the filler gas. By this, the inventor found that as compared with a case where bromine with electron adsorption properties and noble gas (at least one of Ar, Kr and Xe) were used as the filler gas, when nitrogen was further introduced to the filler gas, the electric discharge was suppressed. The discharge start voltage of nitrogen is higher than that of bromine and noble gas. The electric discharge can be suppressed by introducing such nitrogen.
At this time, if the concentration of nitrogen in the filler gas is excessively high, damage of the filament 20 becomes severe. There is a concentration of nitrogen suitable to suppress the damage of the filament while the electric discharge is suppressed.
In the embodiment, the concentration of nitrogen in the filler gas is suitably set. For example, the volume concentration Cv of nitrogen molecules to the noble gas is 1 vol% or more and 30 vol% or less. By this, the damage of the filament 20 is suppressed while the electric discharge is suppressed.
Here, when the nitrogen gas is added to the inert gas, as compared with the case of only the inert gas, the aerial discharge can be suppressed. Although the reason why the aerial discharge is suppressed is not necessarily clear, for example, the following is conceivable.
The breakdown voltage of a simple substance, such as argon, krypton or xenon, or an inert gas including at least two kinds of these, to which the nitrogen gas is added is higher than the breakdown voltage of the simple substance, such as argon, krypton or xenon, or a mixture gas of only the inert gas including at least two kinds of these.
That is, when the nitrogen gas is added to the inert gas, the breakdown voltage can be increased, and therefore, the occurrence of the aerial discharge can be suppressed.
FIG. 2 is a view illustrating characteristics of the heater lamp of the embodiment.
Here, in order to find a condition of not generating electric discharge, the inventor obtained lamp input power [W/cm] per unit length, lamp color temperature T [K], and nitrogen gas volume concentration Cv [vol%]. FIG. 2 shows the results.
In FIG. 2, a "O" mark indicates that the electric discharge did not occur. Besides, a "X" mark indicates that the electric discharge occurred.
As is apparent from FIG. 2, when the lamp input power per unit length is 70 W/cm or more, and when the nitrogen gas volume concentration Cv is 1 vol% or more, the electric discharge does not occur. That is, when the color temperature T is 2600 K or higher, the lamp input power per unit length is 70 W/cm or more, and the nitrogen gas volume concentration Cv is 1 vol% or more, the electric discharge does not occur.
However, if the nitrogen gas volume concentration Cv is excessively increased, a phenomenon occurs in which tungsten nitride is generated, and the filament 20 is damaged. As a result, for example, the inside of the light-emitting tube 10 is blackened, or the filament 20 itself is broken. When the inside of the light-emitting tube 10 is blackened, the light-emitting performance of the heater lamp 110 is reduced. Thus, the quality of the heater lamp 110 is reduced. Besides, when the filament 20 itself is broken, the aerial discharge occurs in the heater lamp 110, and there is a fear that the heater lamp 110 is damaged.
According to the knowledge obtained by the inventor, in order to suppress the aerial discharge and the damage of the filament 20, the volume concentration Cv of nitrogen gas is preferably 30 vol% or less.
Besides, the similar tests were performed while the similar light-emitting tubes 10 were used, and the heater lamps 110 were formed under the conditions that the length of the lamp was 26 cm and the lamp input power was 3500 W (lamp input power per unit length: 135 W/cm), the length of the lamp was 28 cm and the lamp input power was 3000 W (lamp input power per unit length: 107 W/cm), and the length of the lamp was 50 cm and the lamp input power was 7000 W (lamp input power per unit length: 140 W/cm). When the lamp input power per unit length was 70 W/cm or more, and the color temperature T was 2600 K or higher, and when the nitrogen gas volume concentration Cv was 1 to 30 vol%, the electric discharge was suppressed.
According to the embodiment, the electric discharge can be suppressed. Besides, the damage of the filament can also be suppressed. By this, the life of the heater lamp can be prolonged.
Incidentally, an attempt is made to reduce a resistance difference between the time of normal temperature and the time of lighting and to reduce a rush current by adding rhenium to the filament. However, an electron emission property is increased by the addition of rhenium and a filament resistance value at the time of start is increased. Thus, the aerial discharge becomes liable to occur.
In the embodiment, the increase of the electron emission property and the increase of the filament resistance value at the time of start do not substantially occur.
The heater lamp 110 of the embodiment is used for, for example, molding of a resin container (for example, PET bottle). An irradiation target heated by the heater lamp 110 of the embodiment is arbitrary.
According to the embodiment, the heater lamp with long life can be provided.
FIG. 3 is a schematic view illustrating another heater lamp of the embodiment.
As shown in FIG. 3, a heater lamp 111 includes a light-emitting tube 10, sealing parts 11c and 11d, a bent part 14, a filament 20, an anchor 21, a first conductive part 31, a second conductive part 32, outer leads 41 and 42, and a chip 50.
The anchor 21 supports the filament 20. In this case, the anchor 21 supports the filament 20 at substantially the center of the inside of the light-emitting tube 10. The anchors 21 can be provided at substantially equal intervals to the filament 20. The anchor 21 can be formed by, for example, winding a wire rod having heat resistance. The anchor 21 can be formed by winding a wire rod of, for example, tungsten.
Incidentally, the form, size, material, number, arrangement and the like of the anchor 21 are not limited to illustrated ones, and can be suitably changed.
The chip 50 is provided at substantially the center of the light-emitting tube 10. The chip 50 is a residue obtained in such a way that a glass tube (not shown) for filler inert gas, nitrogen gas and bromine (not shown) is provided in an inside space 30 of the hermetically sealed light-emitting tube 10, is heated and is burned out after the inert gas, nitrogen gas and bromine are sealed. The chip 50 is made of, for example, quartz glass similarly to the light-emitting tube 10. However, the material of the chip 50 is not limited to the illustrated one, and can be suitably changed.
As shown in FIG. 3, in the heater lamp 111, the light-emitting tube 10 can be made, for example, a curved tube body as a whole. For example, the light-emitting tube 10 can be made substantially U-shaped.
Incidentally, since the volume concentration Cv of nitrogen gas to the filler gas can be made the same as the foregoing, a detailed explanation is omitted.
Besides, the lamp input power per unit length is 70 W/cm or more.
Also in the heater lamp 111 of the embodiment, similarly to the heater lamp 110, the occurrence of aerial discharge can be suppressed.
As illustrated above, when the nitrogen gas volume concentration Cv to the filler gas is set as described before, the occurrence of aerial discharge can be suppressed irrespective of the outer form of the heater lamp.

Second Embodiment

The embodiment relates to a heating module. The heating module includes one of the heater lamps described in the first embodiment or a modified heater lamp thereof. In the following example, a case where the heater lamp 110 is used will be described.
FIG. 4 is a schematic view illustrating the heating module of the second embodiment.
As shown in FIG. 4, a heating module 210 of the embodiment includes the heater lamps 110. In this example, the plural heater lamps 110 are provided. A holding part 150 is further provided in the heating module 210. The holding part 150 holds the heater lamps 110.
According to the heating module 210 of the embodiment, the heating module with long life can be provided.
Incidentally, in this specification, the words "perpendicular" and "parallel" are not limited to the strict senses of the words "perpendicular" and "parallel", but include variations in a manufacture process, and may be interpreted as meaning "substantially perpendicular" and "substantially parallel".
In the above, the exemplary embodiments are described while referring to the specific examples. However, the invention is not limited to these specific examples. For example, with respect to the specific structures of the respective components, such as the light-emitting tube, the filament, the conductive part and the electrode, included in the heater lamp and the heating module, ones appropriately selected from a well-known range by a person skilled in the art are also included in the scope of the invention as long as the invention is similarly carried out and the same effects can be obtained.
Besides, a combination of two or more components of the respective specific examples within a technically possible range is also included in the scope of the invention as long as the gist of the invention is included.
In addition, all heater lamps and all heating modules which are appropriately designed, changed and operated by a person skilled in the art on the basis of the forgoing heater lamps and the heating modules of the embodiments are also included in the scope of the invention as long as the gist of the invention is included.
In addition, a person skilled in the art can easily made various modifications and corrections within the conceptual scope of the invention, and those modified examples and corrected examples are also included within the scope of the invention.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.

Claims

A heater lamp (110, 111) comprising:
a light transmissive light-emitting tube (10) including a bent part (14, 15);

a filament (20) provided in an inside space (30) of the light-emitting tube (10); and

a filler gas filled in the space (30) and including a noble gas including at least one of argon, krypton and xenon, bromine and nitrogen,

a lamp input power (Wa) per unit length supplied to the filament (20) being 70 W/cm or more, and

a nitrogen gas volume concentration Cv to the noble gas being 1 vol% or more and 30 vol% or less.
The lamp (110, 111) according to claim 1, wherein a color temperature T of light outside the light-emitting tube (10) generated when the lamp input power (Wa) per unit length is supplied to the filament (20) is 2600 K (Kelvin) or higher.
The lamp (110, 111) according to claim 1 or 2, wherein the filler gas includes argon.
The lamp (110, 111) according to any one of claims 1 to 3, wherein the filler gas includes krypton.
The lamp (110, 111) according to any one of claims 1 to 4, wherein the filler gas includes xenon.
The lamp (110, 111) according to any one of claims 1 to 5, wherein the lamp input power (Wa) per unit length is 75 W/cm or more.
The lamp (110, 111) according to any one of claims 1 to 6, wherein a length of the heater lamp (110, 111) is 15 centimeters or more and 50 centimeters or less.
The lamp (110, 111) according to any one of claims 1 to 7, wherein a length of the heater lamp (110, 111) is 20 centimeters or more and 40 centimeters or less.
The lamp (110) according to any one of claims 1 to 8, wherein
the light-emitting tube (10) further includes a first straight part (11, 12, 13) connected to one end of the bent part (14, 15) and a second straight part (11, 12, 13) connected to one other end of the bent part (14, 15).
The lamp (111) according to any one of claims 1 to 9, wherein a shape of the light-emitting tube (10) is a curved tube shape as a whole.
The lamp (110, 111) according to any one of claims 1 to 10, wherein a cross section of the light-emitting tube (10) cut at a plane perpendicular to a direction in which the light-emitting tube (10) extends is circular.
The lamp (110, 111) according to any one of claims 1 to 11, further comprising:
a sealing part (11c, 11d, 12c, 13c) provided at an end (12b, 13b) of the light-emitting tube (10); and

a conductive part (31, 32) sealed in the sealing part (11c, 11d, 12c, 13c) and connected to the filament (20).
The lamp (111) according to any one of claims 1 to 12, wherein the light-emitting tube (10) further includes an anchor (21) to hold the filament (20).
A heating module (210) comprising the heater lamp (110, 111) according to any one of claims 1 to 13 in a plurality.