Incandescent lamp

Abstract

Provided is an incandescent lamp which can suppress short circuit of a filament even when the filament is elongated in a tube axis direction, thereby having excellent life time. The incandescent lamp includes: a light emitting tube having a power supply portion formed on a first end portion side; a filament having a plurality of coil parts and connecting parts, the coil parts and the connecting parts being alternately connected between the pair of power supply parts; the supporting component is fixed on the second end part side of the light emitting tube; and a holder having a fixed portion supported by the support member, a bent portion, a first portion connecting one end portion of the bent portion and the fixed portion, and a second portion extending from the other end portion of the bent portion, the bent portion being engaged with the connection portion of the filament in a state supported by the support member, and the second portion being engaged with the connection portion of the filament in a state supported by the support member. The first part and the second part are separated from the tube shaft of the light-emitting tube along with the distance from the lamp filament or are separated from the tube shaft at a constant distance.

Description

Technical Field

[0001] The invention relates to an incandescent lamp for heating. Background Art

[0002] Conventionally, in optical heating devices for heat-processing semiconductor wafers, single-ended incandescent lamps have been widely used as point-light-source type heating sources (see Patent Document 1 listed below).

[0003] In the optical heating device, a large amount of light for heating (hereinafter referred to as "heating light") is required to make the temperature of the wafer high, for example, above 1000°C. Therefore, in order to increase the heat radiation from the filament, an incandescent lamp is used in which a plurality of coil parts are provided on the filament and the plurality of coil parts are arranged around the tube axis of the light-emitting tube. For example, as shown in the following patent document 2, a holder engaged with a portion connecting the plurality of coil parts (hereinafter referred to as "connecting portion") is provided in the incandescent lamp, and the holder holds the filament in the light-emitting tube.

[0004] In addition, in the optical heating device, from the viewpoint of making the temperature in the surface of the wafer uniform, a plurality of single-ended incandescent lamps are arranged opposite to the peripheral end portion where more heating light is required than the central portion of the wafer. That is, in such an optical heating device, the tube axis of the incandescent lamp is arranged parallel to the main surface of the wafer (also refer to Patent Document 1).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent No. 2945661

[0008] Patent Document 2: Japanese Patent Application Publication No. 2002-56817 Summary of the invention

[0009] Problems to be solved by the invention

[0010] However, in an optical heating device in which the tube axis of the incandescent lamp is arranged parallel to the main surface of the wafer, more heating light travels to the opposite side of the wafer, and there is a problem that the efficiency of the optical heating device is poor.

[0011] Therefore, from the viewpoint of allowing more heating light to reach the wafer, a reflector that reflects the heating light is provided on the side opposite to the wafer across the incandescent lamp. However, part of the light reflected by the reflector (hereinafter referred to as "reflected light") is blocked by the incandescent lamp before irradiating the wafer, so there is a situation in which the reflected light is not easy to irradiate the wafer. Therefore, research is being conducted on a light heating device in which the incandescent lamp is arranged perpendicularly to the main surface of the wafer.

[0012] By arranging the single-ended incandescent lamp perpendicularly to the main surface of the wafer, a reflector that reflects the heating light can be arranged around the light-emitting tube of the incandescent lamp. Therefore, compared with the case where the incandescent lamp is arranged parallel to the main surface of the wafer, the reflected light absorbed by the incandescent lamp is reduced, and the efficiency of the optical heating device can be expected to be improved.

[0013] In the optical heating device, the direction perpendicular to the main surface of the wafer is typically the vertical direction. In view of this, the inventors studied arranging the tube axis of the incandescent lamp in the vertical direction and lighting it, and noticed that a plurality of coils arranged in the arc tube are easily in contact with each other and short-circuited.

[0014] Fig.14 2 is a cross-sectional view schematically showing a part of the structure of a conventional incandescent lamp 51 represented by Patent Document 2. Fig.14 , the portion where the bracket 50 fixed to the supporting member 4a and the filament 3 engage with each other is shown. Fig.14 In the embodiment, an XYZ coordinate system is described in which the direction in which the tube axis A1 of the light emitting tube 2 extends is set as the Z direction and the plane perpendicular to the Z direction is set as the XY plane. Fig.14 As shown, in the incandescent lamp 51 , the holder 50 is engaged with the connecting portion 11 of the filament 3 to hold the filament 3 .

[0015] The incandescent lamp has the following property: when lit, the filament 3 in the arc tube 2 reaches a high temperature, whereby the wire material constituting the filament 3 softens and stretches due to its own weight. Therefore, if the incandescent lamp 51 is arranged so that the +Z direction corresponds to the vertical downward direction, the filament 3 stretches in the +Z direction.

[0016] That is, when the connection portion 11 of the filament 3 is held by the holder 50, the filament 3 stretches in the +Z direction and the connection portion 11 moves along the holder 50. Therefore, the inventors presume that the filament 3 is easily short-circuited by the deformation of the plurality of coil portions 10 approaching each other.

[0017] In an incandescent lamp, for example, a tungsten filament evaporates when it is lit or wears out due to repeated temperature rises and falls, and at a certain stage it disconnects and reaches the end of its life (natural life). However, if the filament is short-circuited, the life of the incandescent lamp will be shortened. This is based on the fact that, for example, by short-circuiting the coil portion of the filament, the resistance value of the filament decreases, and as a result, a large current flows, the temperature of the filament increases significantly, and the filament melts. In other words, from the perspective of extending the life of an incandescent lamp, it is important to suppress the short circuit of the filament.

[0018] In view of the above circumstances, an object of the present invention is to provide an incandescent lamp which can suppress short circuit of the filament even when the filament is elongated in the tube axis direction and has an excellent life time.

[0019] Means for solving problems

[0020] The incandescent lamp according to the present invention is characterized in that it has:

[0021] The light-emitting tube has a pair of power supply parts formed on the first end side;

[0022] A filament having a plurality of coil portions and at least one connecting portion, wherein the coil portions and the connecting portion are alternately connected between the pair of power supply portions;

[0023] a supporting member fixed to a second end portion of the light emitting tube opposite to the first end portion; and

[0024] The bracket comprises a fixing portion supported by the supporting member, a bent portion, a first portion connecting one end of the bent portion and the fixing portion, and a second portion extending from the other end of the bent portion, wherein the bent portion is engaged with the connecting portion of the filament when supported by the supporting member.

[0025] The first portion and the second portion are shaped to be separated from the tube axis of the light emitting tube as they are away from the filament or are shaped to be spaced at a constant distance from the tube axis.

[0026] As a result of the inventor's intensive research, it was found that: Fig.14 As described above, when the filament is lit, it stretches in the tube axis direction, and the connection part of the filament engaged with the bracket moves along the bracket. That is, due to the shape of the bracket, the filament is deformed so that the multiple coils arranged in the light-emitting tube are close to each other, and the coils come into contact with each other and short-circuit.

[0027] In contrast, in the above structure, the first and second parts of the bracket are shaped to be separated from the tube axis of the light-emitting tube as they are separated from the filament. Thus, even if the filament is extended in the tube axis direction and the connecting part of the filament moves along the bracket, the plurality of coil parts are deformed to be separated from each other, thereby preventing the filament from short-circuiting.

[0028] Furthermore, when the first and second portions of the holder are shaped so as to be spaced at a constant distance from the tube axis of the light-emitting tube, even if the connecting portion of the filament moves along the holder as described above, the coil portions can be prevented from approaching each other. That is, according to the above configuration, short circuits between the coil portions caused by deformation of the filament can be prevented.

[0029] In the above incandescent lamp, the first portion and the second portion may be in a straight line shape.

[0030] Here, "straight line" means that when observing a line connecting two points and an imaginary line connecting the two points at the shortest distance, the displacement of the line of the object relative to the imaginary line in a direction perpendicular to the imaginary line is within 10% of the length of the imaginary line.

[0031] If the coil portion is bent when the filament is extended and the connecting portion moves along the bracket, the coil portions are close to each other, and as a result, the filament becomes easy to short-circuit. In contrast, according to the above structure, when the filament is deformed, the filament moves more smoothly along the first part or the second part of the bracket. That is, by the smooth movement of the filament on the bracket, the bending of each coil portion when the filament is extended can be suppressed, so the above structure is suitable.

[0032] In addition, in the above-mentioned incandescent lamp, it may be that

[0033] The first portion and the second portion are shaped to be separated from the tube axis of the arc tube as they are away from the filament. When an angle formed by the first portion and the tube axis is θ1, θ1 satisfies the following formula (1).

[0034] 0°<θ1≤30° (1)

[0035] According to the above structure, an incandescent lamp with a better life is provided. The details will be described in the "Specific Implementation Method" below.

[0036] In the above incandescent lamp, it can be,

[0037] The second portion is arranged at a position farther from the tube axis than the first portion.

[0038] When the angle formed by the first portion and the tube axis is θ1 and the angle formed by the second portion and the tube axis is θ2, θ1 and θ2 satisfy the following formula (2).

[0039] θ1<θ2 (2)

[0040] According to the above structure, when the filament is extended in the tube axis direction, it is easy to move along the second portion arranged outside the first portion. Therefore, it is easy to deform the filament so that the coil portion moves outward, so the above structure is suitable.

[0041] In the above incandescent lamp, it can be,

[0042] The length of the portion of the second portion extending from the bent portion in the tube axis direction is equal to or greater than 1 / 4 of the length of the coil portion.

[0043] The details will be described in the verification section below, but according to the above structure, an incandescent lamp with excellent life can be realized with a simpler structure. It should be noted that the length of the portion extending from the bent portion of the second portion is described with reference to the drawings for each embodiment.

[0044] Furthermore, the bracket may include a third portion extending from an end portion of the second portion on the opposite side to the bent portion and in contact with the first portion.

[0045] Effects of the Invention

[0046] According to the present invention, there is provided an incandescent lamp which can suppress short circuit of the filament even when the filament is elongated in the tube axis direction and has an excellent life time. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a cross-sectional view schematically showing one embodiment of an incandescent lamp.

[0048] Figure 2 Yes Figure 1 A cross-sectional view of the incandescent lamp in question when viewed in the Y direction.

[0049] Figure 3 This is a plan view schematically showing the structure of a filament included in an incandescent lamp.

[0050] Figure 4 Yes Figure 1 The +Z side of the light-emitting tube is shown enlarged in the drawing.

[0051] Figure 5 Yes Figure 4 The bracket is shown enlarged in the accompanying drawings.

[0052] Figure 6 It is a figure which shows another structural example of a bracket.

[0053] Figure 7 This is a diagram showing the definition of the positive and negative of the angle θ1 in Verification 1.

[0054] Fig. 8A It is schematically shown from Figure 4 FIG. 5 is a diagram showing the state where the filament is stretched in the +Z direction.

[0055] Figure 8B Is to imitate Fig. 8A The schematic diagram shows Fig.14 FIG. 5 is a diagram showing the state where the filament is stretched in the +Z direction.

[0056] Fig. 9 This is a diagram schematically showing the structure of the stent when the first portion and the second portion are parallel to the tube axis.

[0057] Fig.10 Is to imitate Figure 5 The accompanying drawings schematically show another structural example of the bracket.

[0058] Fig.11A 2 is a diagram showing still another structural example of the bracket.

[0059] Fig. 11B Yes Fig.11A The bracket is shown enlarged in the accompanying drawings.

[0060] Fig. 12A Is to imitate Fig.10 The following is a drawing showing another structural example of the bracket.

[0061] Fig. 12B Yes Fig. 12A The bracket is shown enlarged in the accompanying drawings.

[0062] Fig.13A 2 is a diagram showing still another structural example of the bracket.

[0063] Fig. 13B Yes Fig.13A The bracket is shown enlarged in the accompanying drawings.

[0064] Fig.14 This is a cross-sectional view schematically showing a part of the structure of a conventional incandescent lamp. DETAILED DESCRIPTION

[0065] The embodiments of the incandescent lamp according to the present invention will be described with reference to the accompanying drawings as appropriate. It should be noted that the following drawings are schematic illustrations, and the dimension ratios on the drawings are not necessarily consistent with the actual dimension ratios. In addition, the dimension ratios between the drawings are not necessarily consistent.

[0066] In addition, in the following figures, Fig.14 Likewise, description will be made with reference to an XYZ coordinate system in which the tube axis direction of the arc tube of the incandescent lamp is defined as the Z direction and a plane perpendicular to the Z direction is defined as the XY plane. Figure 1 is a cross-sectional view schematically showing an embodiment of an incandescent lamp, Figure 2 Yes Figure 1 A cross-sectional view of the incandescent lamp when viewed in the Y direction. Figure 3 This is a plan view schematically showing the structure of a filament included in an incandescent lamp.

[0067] It should be noted that in the following description, when a direction is expressed with distinction between positive and negative directions, it is recorded with positive and negative signs such as "+X direction" and "-X direction". In addition, when a direction is expressed without distinction between positive and negative directions, it is simply referred to as "X direction". That is, in this specification, when it is simply referred to as "X direction", both "+X direction" and "-X direction" are included. The same applies to the Y direction and the Z direction.

[0068] like Figure 1 As shown, the incandescent lamp 1 includes a light-emitting tube 2, a filament 3, support members (4a, 4b), brackets (5a, 5b) and a lamp holder 14.

[0069] The arc tube 2 is made of a glass material such as quartz glass, and has a sealing portion 9 at the end 30 on the -Z side and an exhaust pipe remaining portion 13 at the end 31 on the +Z side. The sealing portion 9 is flat when viewed from the X direction (see Figure 1 In the present embodiment, the end 30 corresponds to the "first end" and the end 31 corresponds to the "second end". In the internal space of the arc tube 2, a halogen gas such as iodine, bromine or chlorine is sealed together with an inert gas such as nitrogen or argon.

[0070] As an example, the inner diameter of the arc tube 2 is 2.5 cm, and the entire length of the arc tube 2, that is, the distance between the end portions 30 and 31 in the Z direction is 10.5 cm.

[0071] A power supply portion 6 is formed by embedding a pair of metal foils (7a, 7b) in the sealing portion 9 of the arc tube 2. The metal foils (7a, 7b) are made of a metal material such as molybdenum.

[0072] In addition, the light emitting tube 2 has a pair of internal leads (8a, 8b) in the internal space. One end of the internal lead 8a is wound around and connected to the end 3a of the filament 3, and the other end is connected to the metal foil 7a. In addition, one end of the internal lead 8b is wound around and connected to the end 3b of the filament 3, and the other end is connected to the metal foil 7b.

[0073] The lamp holder 14 is made of an insulating material such as alumina, and has a bottomed hole (not shown) on the +Z side for inserting the sealing portion 9 of the light emitting tube 2. By inserting the sealing portion 9 into the bottomed hole, the lamp holder 14 and the light emitting tube 2 are fixed integrally. Figure 1 and Figure 2 As shown, a terminal 15 for supplying power to the filament 3 protrudes from the -Z side of the lamp holder 14. A pair of terminals 15 are provided, and each terminal 15 is connected to the metal foil (7a, 7b) respectively, so that power is supplied to the filament 3 from the outside through the terminal 15. That is, the incandescent lamp 1 is a single-ended type having a pair of terminals 15 on the -Z side.

[0074] like Figure 3As shown in FIG. 1 , the filament 3 is formed by alternately forming a plurality of coil portions 10 and a connecting portion 11 connecting the coil portions 10. The filament 3 is formed by winding a wire material made of tungsten, for example. Figure 3 In the figure, the number of coil portions 10 is omitted for convenience of illustration, but in the present embodiment, the filament 3 having eight coil portions 10 is accommodated in the light emitting tube 2.

[0075] In a single-ended incandescent lamp used in an optical heating device, the length L1 of the coil portion 10 of the filament 3 is typically 20 mm to 26 mm. In the present embodiment, as an example, the length L1 of the coil portion 10 of the filament 3 is 24 mm.

[0076] The support member 4a is fixed to the end 31 side of the arc tube 2 (see Figure 1 and Figure 2 ). Figure 4 Yes Figure 1 FIG. 3 is an enlarged view of the end 31 side of the light emitting tube 2. Figure 4 As shown, the bracket 5a and the support rod 12 are embedded in the support member 4a.

[0077] In addition, in this embodiment, if Figure 1 and Figure 2 As shown, a support member 4b is fixed to the end 30 side of the arc tube 2. A pair of inner lead wires (8a, 8b), a bracket 5b and a support rod 12 are embedded in the support member 4b.

[0078] The support members (4a, 4b) are made of glass materials such as quartz glass. For example, by inserting the support member 5a and the support rod 12 into the support member 4a in a heated and molten state and then cooling the support member 4a to solidify, the support member 4a can be embedded with the support member 4a. In order to prevent the support member 5a and the support rod 12 from being electrically connected, an insulating material is selected for the support member 4a. The same is true for the support member 4b.

[0079] The shape of the supporting members (4a, 4b) is arbitrary, but as an example, the following can be adopted: Figure 1 and Figure 2 A cylindrical component as shown.

[0080] One end of the support rod 12 is disposed on the exhaust pipe remaining portion 13 (see Figure 1 The supporting members (4a, 4b) are fixed in the light emitting tube 2 via the supporting rod 12.

[0081] Figure 5 This is a diagram in which the filament 3 and the like are removed. Figure 4 The bracket 5a is enlarged in the figure. Figure 5As shown, the bracket 5a has a fixing portion 20 supported by the supporting member 4a, a bent portion 24, a first portion 21 connecting one end of the bent portion 24 and the fixing portion 20, and a second portion 22 extending from the other end of the bent portion 24, forming a U-shape. The bent portion 24 engages with the connecting portion 11 of the filament 3.

[0082] In more detail, the fixing portion 20 corresponds to the portion supported by the supporting member 4a in the bracket 5a. In addition, the second portion 22 of the present embodiment corresponds to the portion extending from the portion closest to the -Z side toward the end furthest away from the tube axis A1 in the bracket 5a. The first portion 21 corresponds to the portion between the fixing portion 20 and the second portion 22 of the bracket 5a that moves away from the tube axis A1 as it moves toward the +Z side. Furthermore, the bent portion 24 corresponds to the position between the first portion 21 and the second portion 22 of the bracket 5a.

[0083] The bend 24 engages with the connection portion 11 of the filament 3, so that the winding axis of each coil 10 is arranged substantially parallel to the tube axis A1 of the arc tube 2. It should be noted that “substantially parallel” means that the angle between the winding axis of the coil 10 and the tube axis A1 is within 5°.

[0084] In the present embodiment, the fixing portion 20 has a shape extending in a direction parallel to the XY plane.

[0085] like Figure 5 As shown, the first portion 21 and the second portion 22 are shaped to be separated from the tube axis A1 of the light emitting tube 2 as they are away from the filament 3. The first portion 21 being shaped as described above means that the angle θ1 formed by the first portion 21 and the tube axis A1 is larger than 0°.

[0086] In addition, in the present embodiment, the first portion 21 and the second portion 22 are configured to be parallel. That is, in the present embodiment, the angle θ2 (also referred to below) formed between the second portion 22 of the bracket 5a and the tube axis A1 is Fig.10 ) is equal to angle θ1.

[0087] In addition, Figure 5 , length d1 and length d2 are shown. Length d1 corresponds to the length of the first portion 21 in the Z direction. Length d2 corresponds to the length of the second portion 22 extending from the bent portion 24 in the Z direction. In this embodiment, length d2 is 6 mm.

[0088] As described above, when the incandescent lamp 1 is lit, the filament 3 is extended, and the filament 3 moves along the first portion 21 and the second portion 22. Therefore, if the length d2 is too short, it is easy to assume that the filament 3 will fall off the bracket 5a. The length d2 is preferably 1 / 4 or more of the length L1 of the coil portion 10, and the details will be described in the "Verification 2" below.

[0089] The incandescent lamp 1 according to this embodiment includes a holder 5b disposed on the -Z side of the filament 3 and engaged with the connection portion 11 of the filament 3. The holder 5b has a shape in which the first portion 21 and the second portion 22 are separated from the tube axis A1 as they are away from the filament 3, similarly to the holder 5a.

[0090] The brackets (5a, 5b) are made of metal wires such as tungsten.

[0091] Figure 6 FIG. 5 is a diagram showing another structural example of the bracket 5a. Figure 4 In FIG. 5 , an example is shown in which the fixing portion 20 of the bracket 5a is parallel to the XY plane, but Figure 6 As shown, the fixing portion 20 may also be non-parallel to the XY plane. Figure 6 As shown, the second portion 22 may also be arranged close to the inner wall surface of the light emitting tube 2 .

[0092] [Verification 1]

[0093] The influence of the structure of the holder 5 a on the life of the incandescent lamp 1 has been verified and will be described below.

[0094] In this verification, incandescent lamps were manufactured with different angles θ1 between the first portion 21 of the bracket 5a and the tube axis A1, and the life of each incandescent lamp was tested. It should be noted that in this verification, as a comparative example, the reference Fig.14 As described above, the holder 5 a has a shape that approaches the tube axis A1 as it moves away from the filament 3 .

[0095] Figure 7 1 is a diagram showing the definition of the positive and negative angle θ1 in this verification. Specifically, in this verification, Figure 7 As shown, when the imaginary line B1 passing through the connection between the first portion 21 and the bent portion 24 of the bracket 5a and parallel to the tube axis A1 is used as a reference, the case where the first portion 21 is tilted away from the tube axis A1 relative to the imaginary line B1 is defined as a case where θ1 takes a positive value. On the other hand, for convenience, the case where the bracket 5a is tilted relative to the imaginary line B1 so as to approach the tube axis A1 is defined as a case where θ1 takes a negative value. That is, Figure 7 In the example, the direction of the imaginary line B1 moving toward the direction C1 corresponds to the positive direction of θ1, and the direction of the imaginary line B1 moving toward the direction C2 corresponds to the negative direction of θ1. In this verification, the case where θ1 takes a negative value corresponds to the comparative example (also refer to Fig.14 ).

[0096] In this verification, as described above, the incandescent lamp structure of the above-described embodiment was adopted except that the angle θ1 was made different in each incandescent lamp. In addition, the incandescent lamps were arranged so that the Z direction corresponded to the vertical downward direction.

[0097] In the optical heating device, in order to make the temperature condition of the wafer a desired temperature, the operation of, for example, raising and lowering the voltage applied to the incandescent lamp is repeated. Therefore, in this verification, the operation of repeatedly switching between a first state in which the desired brightness is obtained from the incandescent lamp and a second state in which the brightness is obtained below a certain threshold is actually performed according to the lighting operation in the optical heating device.

[0098] In addition, as mentioned above, in an incandescent lamp, the life span is reached when the filament 3 is disconnected. This includes the natural life span caused by evaporation and loss of the filament and the life span caused by the short circuit of the coil part 10. In view of this, in this verification, the above operation is repeated, and the time until the filament 3 is disconnected is evaluated as the life span of the incandescent lamp.

[0099] In this verification, 3 incandescent lamps were tested with respect to each 01 condition.

[0100] [Results and observations of Verification 1]

[0101] The results obtained in this verification are shown in Table 1. Table 1 shows the average value of the life of the incandescent lamp obtained for each θ1.

[0102]

Table 1

[0103] θ1[°] -45 -30 -15 0 15 30 45 Lamp life [h] 120 130 160 250 300 280 260

[0104] It can be understood from Table 1 that the life of the incandescent lamp is affected by the angle θ1. This is because, when the filament 3 is extended in the tube axis direction during lighting, the connection portion 11 of the filament 3 engaged with the holder 5a moves along the holder 5a.

[0105] The inventors have observed that when θ1 is a negative value, the filament 3 deforms due to lighting, resulting in short circuits in the plurality of coils 10 of the filament 3. On the other hand, when the angle θ1 is in the range of 0° or more, even if the filament 3 deforms due to lighting, short circuits in the plurality of coils 10 are not observed.

[0106] In this regard, use Fig. 8A and Figure 8B To explain. Fig. 8A It is schematically shown from Figure 4 The filament 3 is heated to a high temperature and deformed in the +Z direction. Figure 8B Is to imitate Fig. 8A The schematic diagram shows Fig.14FIG. 5 is a diagram showing a state in which the filament 3 becomes hot from the state in which the filament 3 is deformed so as to be extended in the +Z direction.

[0107] like Fig. 8A As shown in FIG. 1 , when the first portion 21 is shaped to move away from the tube axis A1 as it moves away from the filament 3, the connection portion 11 of the filament 3 moves along the first portion 21 or the second portion 22, and the coil portion 10 moves away from the other coil portion 10. More specifically, Fig. 8A In the example shown, even if the filament 3 is extended in the +Z direction, the plurality of coil portions 10 on the +Y side of the tube axis A1 are separated from the plurality of coil portions 10 on the -Y side of the tube axis A1. Therefore, short circuit of the filament 3 caused by contact of the plurality of coil portions 10 can be suppressed. Fig. 8A , the moving direction of the coil portion 10 is schematically indicated by a double arrow A2.

[0108] On the other hand, Figure 8B As shown in FIG. 1 , when the holder 5a is in a shape that approaches the tube axis A1 as it moves away from the filament 3, the result of the connection portion 11 of the filament 3 moving along the holder 5a is that the coil portion 10 approaches the tube axis A1. As a result, the plurality of coil portions 10 are easily in contact with each other, and the filament 3 is short-circuited. This is consistent with the fact that the life becomes shorter as θ1 increases in the negative direction in Table 1. In other words, if θ1 increases in the negative direction, the short circuit between the coil portions occurs earlier.

[0109] in addition, Fig. 9 2 is a diagram schematically showing the structure of the bracket 5a when the first portion 21 and the second portion 22 are in a shape with a constant distance from the tube axis A1. Fig. 9 The example corresponds to the case where θ1 is 0° in this verification 1. Fig. 9 As shown in FIG. 1 , when the first portion 21 and the second portion 22 are parallel to the tube axis A1, it can be considered that as a result of the filament 3 extending in the +Z direction, the connecting portion 11 also moves in the +Z direction. In other words, in this case, the coil portions 10 of the filament 3 are also prevented from approaching each other. Therefore, it can be considered that the life of the incandescent lamp is similar to that of the reference lamp. Figure 8B The narrative is relatively longer (Table 1).

[0110] Thus, it can be understood that when the angle θ1 is 0° or more, even if the filament 3 is deformed to extend in the +Z direction, the plurality of coil portions 10 are not easily close to each other. In other words, when the angle θ1 is 0° or more, the short circuit of the filament 3 can be suppressed, and as a result, the life of the incandescent lamp is prolonged (Table 1).

[0111] It should be noted that it is preferable to set the angle θ1 to a positive value from the viewpoint of reducing the possibility of short-circuiting the filament 3. This can be understood from the fact that the life of the incandescent lamp is longer when θ1 is 15° or 30° than when θ1 is 0°.

[0112] When θ1 is 45°, the life is shorter than when θ1 is 30°. Based on this, it is speculated that as θ1 increases, the pressure applied to the filament 3 increases when the filament 3 is greatly deformed along the holder 5a. Based on the above, θ1 is more preferably 0°<θ1≤30°.

[0113] It should be noted that, in view of the results of this verification, it can be understood that θ1 may be different in each bracket 5 a in the arc tube 2 .

[0114] In addition, whether the first portion 21 and the second portion 22 of the bracket 5a are parallel or not is arbitrary. Fig.10 Is to imitate Figure 5 The accompanying drawings schematically show another structural example of the bracket 5a. Fig.10 As shown, the angle θ2 formed between the second portion 22 and the tube axis A1 and the angle θ1 formed between the first portion 21 and the tube axis A1 may be different, and the bracket 5a may be V-shaped.

[0115] In view of the results of this verification, the angle θ2 formed by the second portion 22 and the tube axis A1 can be discussed in the same way as θ1. That is, the angle θ2 is preferably greater than 0°, and more preferably 0°<θ2≤30°. Fig.10 It is suitable to make θ1<θ2 as shown in the figure, so that the filament 3 can be easily deformed along the second portion 22.

[0116] As described above, in view of the results of Verification 1, it can be understood that an incandescent lamp having an excellent life time can be realized by configuring the holder 5a to have the structure described in the above embodiment.

[0117] [Verification 2]

[0118] As mentioned above, if the length d2 of the second portion 22 is too short, it is easy to imagine that the filament 3 will fall off the bracket 5a when the filament 3 is extended. If the engagement between the filament 3 and the bracket 5a is loose, it becomes difficult to control the position of the filament 3 in the light-emitting tube 2, and the filament 3 may easily short-circuit due to contact with other filaments 3. In view of this, it is considered preferable to refer to Figure 6 As described above, the end of the second portion 22 is close to the inner wall surface of the light emitting tube 2. In other words, according to Figure 6 With the structure, even if the connecting portion 11 of the filament 3 moves along the second portion 22, the movement of the filament 3 is restricted by the inner wall of the arc tube 2, thereby preventing the filament 3 from falling off from the holder 5a.

[0119] However, when the holder 5a and the inner wall of the light emitting tube 2 are brought close to each other, there is a high possibility that the inner wall of the light emitting tube 2 will be damaged when the holder 5a is placed in the light emitting tube 2. In order to prevent such damage, careful attention is required when manufacturing the incandescent lamp 1. This is because if the inner wall of the light emitting tube 2 is damaged, the thermal stress caused by the temperature rise accompanying the light emission will concentrate and the light emitting tube 2 may be broken. Therefore, for example, Figure 6 The illustrated structure has a high probability of making the manufacture of the incandescent lamp 1 difficult.

[0120] In view of the above, it is preferable to construct a bracket 5a that is easy to be engaged with the filament 3 even if the filament 3 is extended in the Z direction. In view of this, the inventors have made a bracket 5a in which the length d2 of the extension portion of the second portion 22 from the bent portion 24 is 100 mm (see FIG. 1 ). Figure 5 ) and each incandescent lamp was lit in the same manner as described in the above-mentioned Verification 1. Furthermore, the preferred length d2 for suppressing the loosening of the engagement between the connecting portion 11 of the filament 3 and the bracket 5a was studied.

[0121] In this verification, incandescent lamps were made with the length L1 of the coil part 10 being 24 mm and the length d2 being different, and a lighting test was performed in the same manner as in the above-mentioned Verification 1. In addition, in this verification, θ1 was set to 30° in view of the results of the above-mentioned Verification 1. The other conditions of the incandescent lamps were the same as those in Verification 1.

[0122] [Results and observations of Verification 2]

[0123] The evaluation results of the incandescent lamps under the conditions of each d2 are shown in the following Table 2. The evaluation criteria in Table 2 are as follows.

[0124] Evaluation (A): No detachment of the filament 3 was observed.

[0125] Evaluation (B): The ratio of incandescent lamps in which the filament 3 fell off from the holder 5a (hereinafter referred to as "falling-off ratio" for convenience) relative to the total number of the same sample is 10% or less

[0126] Evaluation (C): The shedding ratio is 50% or more

[0127]

Table 2

[0128] d2[mm] 3 4 5 6 7 8 9 10 evaluate C C C B A A A A

[0129] According to Table 2, it can be understood that if the length d2 is 6 mm or more, that is, if the length d2 is 1 / 4 or more of the length L1 of the coil portion 10, the filament 3 can be prevented from falling off from the holder 5a. It should be noted that this verification was carried out in an environment where the load on the filament 3 is higher than when an actual incandescent lamp is used. In this verification, it can be considered that if the falling ratio is 10% or less (evaluation B), there is substantially no problem with the product.

[0130] In addition, in the aforementioned verification 1, d2 was 6 mm. Therefore, in the verification 1, it can be said that the filament 3 was not seen to fall off from the holder 5a.

[0131] The filament 3 softens due to the high temperature and droops in the direction of gravity due to its own weight. In view of this, it can be considered that the length of the filament 3 extended when it reaches a high temperature depends on the length L1 of the coil part 10. As mentioned above, in a single-ended incandescent lamp for heating, the length L1 of the coil part 10 is typically 20mm to 26mm. In this verification, as an example, an incandescent lamp with L1 of 24mm was used, but it is presumed that the same tendency can be obtained within the above-mentioned range of length L1. Therefore, it can be said that: with respect to the tube axis direction, by making the length d2 of the second part 22 extended to be more than 1 / 4 of L1, the filament 3 can be suppressed from falling off from the bracket 5a.

[0132] In addition, by making the length d2 equal to or greater than 1 / 4 of the length L1 of the coil portion 10, even if the Figure 6 As shown in FIG. 1 , the second portion 22 is brought close to the inner wall of the light emitting tube 2, and the filament 3 can be prevented from falling off from the holder 5a. That is, by setting the length d2 to the above-mentioned length, an incandescent lamp in which the filament 3 is prevented from falling off can be easily manufactured.

[0133] It should be noted that when the lengths L1 of the plurality of coil portions 10 of the filament 3 are different, the length d2 of the extension of the second portion 22 of the holder 5a may be determined based on the length L1 of the coil portion 10 connected to the connection portion 11 engaged with the holder 5a.

[0134] In addition, according to the results of this verification, the length d1 of the first portion 21 in the Z direction (see Figure 5 ) is preferably 1 / 4 of the length L1 of the coil portion 10 or more. Since the first portion 21 is connected to the fixing portion 20 of the bracket 5a, even if the length d1 is shorter than 1 / 4 of L1, the possibility of the filament 3 falling off the bracket 5a is low. However, from the range of the elongation of the filament 3 at high temperature, such as Fig. 8A From the viewpoint of moving the coil unit 10 away from the tube axis A1 as described above, the length d1 is preferably equal to or larger than 1 / 4 of the length L1 of the coil unit 10 .

[0135] [Modifications]

[0136] Hereinafter, modifications of the incandescent lamp according to the present invention will be described.

[0137] <1> Fig.11A FIG. 2 is a diagram showing another structural example of the bracket 5a of the incandescent lamp 1. In the above description, the first portion 21 and the second portion 22 are described as being linear. Fig.11A As shown, the bracket 5a may also have a first portion 21 and a second portion 22 that are curved.

[0138] Fig. 11B Yes Fig.11A The bracket 5a shown is enlarged in the drawing. Fig. 11B In the example of FIG. 1 , similarly to the above-described embodiment, the second portion 22 corresponds to a portion extending from the portion closest to the -Z side toward the end furthest away from the tube axis A1 in the bracket 5a, and the first portion 21 corresponds to a portion between the fixing portion 20 and the second portion 22 that moves away from the tube axis A1 as it moves toward the +Z side. The same is true for the fixing portion 20 and the bent portion 24.

[0139] like Fig.11A and Fig. 11B As shown, even when the holder 5 a is bent, the first portion 21 and the second portion 22 are shaped to be separated from the tube axis A1 as they are away from the filament 3 , thereby preventing the plurality of coil units 10 from short-circuiting.

[0140] <2> Fig. 12A Is to imitate Fig.11A The figure shows another structural example of the bracket 5a of the incandescent lamp 1. Fig. 12B Yes Fig. 12A The bracket 5a shown is enlarged in the accompanying drawing. Fig. 12A As shown, the second portion 22 of the bracket 5a may be arranged on a side closer to the tube axis A1 than the first portion 21 .

[0141] exist Fig. 12A and Fig. 12B In the example of , the fixing portion 20 corresponds to the portion supported by the support member 4a in the bracket 5a. In addition, the first portion 21 is connected to the fixing portion 20, and corresponds to the portion extending from the portion closest to the -Z side in the bracket 5a toward the fixing portion 20 in a manner that moves away from the tube axis A1 as it moves toward the +Z side. The bent portion 24 is a portion extending from the first portion 21 on the side opposite to the fixing portion 20, and the second portion 22 corresponds to a portion extending from the bent portion 24 on the side opposite to the first portion 21 in a manner that moves away from the tube axis A1 as it moves toward the +Z side.

[0142] <3> in addition, Fig.13A 1 is a diagram showing another structural example of the bracket 5a of the incandescent lamp 1. Fig. 13BYes Fig.13A The bracket 5a shown is enlarged in the accompanying drawing. Fig.13A As shown, the bracket 5 a may include a third portion 23 extending from the end of the second portion 22 on the opposite side to the bent portion 24 and contacting the first portion 21 .

[0143] like Fig.13A As shown, by holding the filament 3 in a closed area formed by the first part 21, the second part 22, the third part 23 and the bent portion 24, the filament 3 can be prevented from falling off the bracket 5a, for example, during the impact during the transportation of the incandescent lamp 1 or during the installation operation relative to the light heating device.

[0144] It should be noted that, when the bracket 5a has the third portion 23, Fig. 13B As shown, the length d2 of the extended portion of the second portion 22 corresponds to the length from the bent portion 24 to the third portion 23 in the tube axis direction. In view of the results of the above-mentioned verification 2, assuming that the length d2 is shorter than 1 / 4 of the length L1, after the filament 3 is stretched and abuts against the third portion 23, the filament 3 will further stretch in the tube axis direction. In this case, there is no place for the filament 3 to go, and the filament 3 will bend, thereby increasing the possibility of short circuiting with other filaments 3. In other words, the length d2 can also be said to be the range within which the filament 3 can move when stretched. Therefore, the length d2 is preferably greater than 1 / 4 of the length L1 of the coil portion 10.

[0145] It should be noted that in Fig.13A In the embodiment, the bracket 5a has the third portion 23 to form the closed region. However, the closed region may be formed by making the first portion 21 and the second portion 22 contact with each other so that 0°<θ2<θ1.

[0146] <4> In the above description, the filament 3 having eight coil portions is arranged in the arc tube 2, but the number of the coil portions 10 of the filament 3 is arbitrary.

[0147] For example, a filament 3 having two coil portions 10 and one connecting portion 11 may be arranged in the light emitting tube 2. In this case, one bracket 5a arranged on the +Z side of the light emitting tube 2 engages with the connecting portion 11 of the filament 3. That is, in the above, the bracket 5b arranged on the -Z side of the filament 3 is an arbitrary structure.

[0148] Even in this case, the bracket 5a has the structure described in the above embodiment, so that the connection portion 11 can be prevented from falling off from the bracket 5a when the filament 3 becomes hot and elongates. In addition, the bracket 5a restricts the movement direction of the two coil portions 10 to the direction away from the tube axis A1. Thus, the two coil portions can be prevented from moving in an unexpected direction, so that the short circuit of the filament 3 can be prevented, and as a result, the life of the incandescent lamp is prolonged.

[0149] <5> In the above, it is explained that the incandescent lamp 1 is configured and lit in a manner that the tube axis A1 extends in the vertical direction. However, the tube axis A1 of the incandescent lamp 1 may be configured to be inclined relative to the vertical direction. Even in this case, it is conceivable that the filament 3 is elongated in the tube axis direction due to the component related to the vertical direction of the weight of the filament 3. However, according to the incandescent lamp 1 of the above structure, even if the filament 3 is elongated in the tube axis direction, the short circuit of the filament 3 can be suppressed. Therefore, even when the incandescent lamp 1 is configured to be inclined relative to the vertical direction, the effect of obtaining an excellent life is achieved.

[0150] The structure of the incandescent lamp 1 according to the present invention is not limited to the above-mentioned embodiment.

[0151] Description of Reference Numerals

[0152] 1.51: Incandescent lamp

[0153] 2: LED

[0154] 3: Filament

[0155] 3a, 3b: Ends of the filament

[0156] 4a, 4b: Supporting components

[0157] 5a, 5b, 50: Bracket

[0158] 6: Power supply department

[0159] 7a, 7b: Metal foil

[0160] 8a, 8b: Internal leads

[0161] 9: Sealing part

[0162] 10: Coil

[0163] 11: Connection

[0164] 12: Support rod

[0165] 13: Exhaust pipe remaining part

[0166] 14: Lamp holder

[0167] 15: Terminal

[0168] 20: Fixed part

[0169] 21: Part 1

[0170] 22: Part 2

[0171] 23: Part 3

[0172] 24: Bending section

[0173] 30, 31: The end of the light-emitting tube

[0174] A1: Tube axis.

Claims

1. An incandescent lamp, characterized in that: have: The light-emitting tube has a pair of power supply parts formed on the first end side; A filament having a plurality of coil portions and at least one connecting portion, wherein the coil portions and the connecting portion are alternately connected between the pair of power supply portions; a supporting member fixed to a second end portion of the light emitting tube opposite to the first end portion; and The bracket comprises a fixing portion supported by the supporting member, a bent portion, a first portion connecting one end of the bent portion and the fixing portion, and a second portion extending from the other end of the bent portion, wherein the bent portion is engaged with the connecting portion of the filament when supported by the supporting member. The first portion and the second portion are shaped to be separated from the tube axis of the light emitting tube as they are away from the filament or are shaped to be spaced at a constant distance from the tube axis.

2. The incandescent lamp according to claim 1, characterized in that The first portion and the second portion are in a straight line shape.

3. The incandescent lamp according to claim 2, characterized in that The first portion and the second portion are shaped to be separated from the tube axis of the light-emitting tube as they are away from the filament. If the angle between the first portion and the tube axis is θ1, θ1 satisfies the following formula (1): 0°<θ1≤30°(1).

4. The incandescent lamp according to claim 2, characterized in that The second portion is arranged at a position farther from the tube axis than the first portion. When the angle between the first portion and the tube axis is θ1 and the angle between the second portion and the tube axis is θ2, the following formula (2) is satisfied: θ1<θ2(2).

5. The incandescent lamp according to any one of claims 1 to 4, characterized in that The length of the portion of the second portion extending from the bent portion in the tube axis direction is equal to or greater than 1 / 4 of the length of the coil portion.

6. The incandescent lamp according to claim 5, characterized in that The bracket includes a third portion extending from an end portion of the second portion on the opposite side to the bent portion and in contact with the first portion.

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