AU2015271874B2 - Ceramic metal halide lamp - Google Patents

Abstract

This lamp is a ceramic metal halide lamp encapsulating two arc tubes in an outer bulb connected to a base, configured to light always one arc tube which is easily lit, the ceramic metal halide lamp comprising: each of the two arc tubes being arranged to be tilted to a lamp axis at a different distance from the base inside the outer bulb; two supports in parallel to each other, extending along the lamp axis inside the outer bulb; and two cylindrical sleeves each of which housing an arc tube inside, and each of the sleeves is fixed to the supports at three points. 1 Oa 28a-1 18-2 14-1 16-1 -30 14-2 16-2 32 28a-2 10 c

Description

Australian Patents Act 1 990 - Regulation 3.2 2015271874 17 Dec 2015

ORI Gl NAL COMPLETE SPECI FI CATI ON STANDARD PATENT

Invention Title Ceramic metal halide lamp

The following statement is a full description of this invention, including the best method of performing it known to me/us:-1

Technical Field 2015271874 17 Dec 2015 [0001]

The present invention relates to a ceramic metal halide lamp. More specifically, the present invention relates to a ceramic metal halide lamp including two arc tubes in the outer bulb, configured to light always only one arc tube which is easily lit, and having relatively large lamp power.

Background Art [0002] A high intensity discharge lamp (HID lamp: such as a high-pressure mercury lamp, a high pressure sodium lamp, a metal halide lamp, and a ceramic metal halide lamp) emits light by using the discharge between electrodes. For this reason, the HID lamp has the features such as increased light flux and improved energy efficiency compared to the incandescent light bulb. In HID lamps, the metal halide lamp employing the metal halide as the light-emitting substance has excellent color rendering properties and high luminous efficiency compared to the high-pressure mercury lamp which emits the bluish-white light beam. Furthermore, the ceramic metal halide lamp using a translucent ceramic arc tube has the advantages such as the various kinds of metal halide can be used because ceramics hardly reacts with the metal halide inside and the heat resistance is excellent.

[0003]

The lifetime of the ceramic metal halide lamp is, for example, said to be about 24,000 hours. In contrast, the lifetime of the LED lamp is said to be nominally 40,000 hours. There is a request for a longer lifetime to the lamp in general..

[0004]

Regarding this request, the applicant has proposed a ceramic metal halide lamp encapsulating two arc tubes in the outer bulb, configured to light always one arc tube which is easily lit as shown in JP 2012-28096 A to provide to the market (see FIGS. 1A la and IB). The lamp using two arc tubes, configured to light always one arc tube which is easily lit has theoretically the total lifetime of two arc tubes, and therefore longer lifetime of 48,000 hours can be expected. 2015271874 17 Dec 2015 [0005]

In addition, the lamp shown in FIGS. 1A and IB can reduce the restart time compared to the lamp including one arc tube. That is, as for the lamp including one arc tube, the lamp cannot be relit until the warm arc tube after the lighting-off is cooled down to some extent (for example, until after the lapse of 20 minutes). However, the arc tube of the lamp shown in FIGS. 1A and IB is instantly relit because the arc tube is an arc tube in a relatively cold state due to the lighting-off state until then, rather than an arc tube immediately after the lighting-off. It should be noted that the ceramic metal halide lamp shown in FIGS. 1A and IB will be described in detail below.

[0006]

In this application document, it should be accepted that "a ceramic metal halide lamp encapsulating two arc tubes in the outer bulb, configured to light always one arc tube which is easily lit" is simply referred to as "a double tube lamp".

Citation List [0007]

Patent Literature PTL1:JP 2006-100089 A PTL2: WO 2011/056120 PTL3: JP 10-302721 A PTL4: JP 2012-28096 A PTL5: JP 2014-067663 PTL6: JP 2014-120462

SUMMARY OF INVENTION 2 2015271874 17 Dec 2015

Technical Problem [0008]

The conventional ceramic metal halide lamp shown in FIGS. 1A and IB has been a lamp having relatively small lamp power (for example, about 250 W). There is a request for higher illuminance to the lamp in general. When a ceramic metal halide lamp having relatively large lamp power (for example, about 360 W or more) is developed into product, it is necessary to employ an arc tube corresponding to the lamp. In this case, the size of the arc tube for comparatively large lamp power increases relatively compared to the size of the arc tube of the conventional lamp shown in FIGS. 1A and IB.

[0009]

As a result of the size of the arc tube being increased, the need to develop a new mount structure configured to properly position and to securely fix the two arc tubes in the outer bulb has arisen.

[0010]

Thus, the present invention has an object to provide a double tube lamp including a novel mount structure and having relatively large lamp power (a ceramic metal halide lamp encapsulating two arc tubes in the outer bulb, configured to light always one arc tube which is easily lit).

Solution to Problem [0011]

The ceramic metal halide lamp according to the present invention is a ceramic metal halide lamp encapsulating two arc tubes in an outer bulb connected to a base, the ceramic metal halide lamp configured to light always one arc tube which is easily lit, each of the two arc tubes being arranged to be tilted to a lamp axis at a different distance from the base inside the outer bulb, the ceramic metal halide lamp comprising: two supports in parallel to each other, extending along the lamp axis inside the outer bulb; 3 2015271874 17 Dec 2015 and two cylindrical sleeves each of which housing an arc tube inside, wherein each of the sleeves is fixed to the supports at three points.

[0012]

Furthermore, in the ceramic metal halide lamp, each of the two supports may be welded to a corresponding one of a pair of lead-in wires hermetically sealed in a stem tube, and the two supports may be positioned in parallel to each other by a wire bridged between the two supports in at least one place.

[0013]

Furthermore, in the ceramic metal halide lamp, each of the sleeves may include respective annular metal belts wound around an upper end and a lower end of a cylindrical shape and a metal tab piece extending from the annular metal belt, and each of the sleeves may be fixed to the support by the metal tab piece being welded to the support.

[0014]

Furthermore, in the ceramic metal halide lamp, each of the sleeves may include respective annular metal belts wound around an upper end and a lower end of a cylindrical shape and a metal tab piece extending from the annular metal belt, and the metal tab piece may be fixed to the support by using a wire with an insulating member interposed at midpoint.

[0015]

Furthermore, in the ceramic metal halide lamp, lamp power of the lamp may be in a range of 270 to 700 W.

[0016]

Furthermore, the ceramic metal halide lamp according to the present invention is a ceramic metal halide lamp encapsulating at least one arc tube in the outer bulb connected to the base, and the arc tube is arranged by being tilted at a tilt angle of 20° to 30° to the lamp axis. 4 [0017] 2015271874 17 Dec 2015

Furthermore, in the ceramic metal halide lamp, the arc tubes may include two arc tubes configured to light always one arc tube which is easily lit, and each of the two arc tubes may be arranged by being tilted at a tilt angle of 20° to 30° to the lamp axis at a different distance from the base inside the outer bulb.

[0018]

Furthermore, in the ceramic metal halide lamp, the lamp power may be adjusted by reducing the amount of mercury in the arc tube as much as the amount corresponding to the rising lamp power by the arc tube being tilted.

[0019]

Furthermore, in the ceramic metal halide lamp, the lamp power of the lamp may be in the range of 270 to 700 W.

[0020]

Furthermore, the ceramic metal halide lamp according to the present invention is a ceramic metal halide lamp encapsulating two arc tubes in an outer bulb connected to a base, the ceramic metal halide lamp configured to light always one arc tube which is easily lit, each of the two arc tubes being arranged to be tilted to a lamp axis at a different distance from the base inside the outer bulb: the ceramic metal halide lamp comprising; two supports in parallel to each other, extending along the lamp axis inside the outer bulb; and two cylindrical sleeves each of which receives an arc tube inside; and wherein the sleeve includes the partial blockage lids configured to partially close the respective openings at both ends, and prevents the debris from jumping out in the case of the arc tube burst.

[0021]

Furthermore, in the above ceramic metal halide lamp, the sleeve may include respective annular metal belts wound around an upper end and a lower end of a cylindrical shape, and thereby the sleeve may be mechanically reinforced. 5 2015271874 17 Dec 2015 [0022]

Furthermore, in the above ceramic metal halide lamp, the sleeve may include a metal tab piece extending from the annular metal belt and being welded to the support.

[0023]

Furthermore, in the above ceramic metal halide lamp, the partial blockage lid may be formed integrally with the annular metal belt.

[0024]

Furthermore, the ceramic metal halide lamp according to the present invention is a ceramic metal halide lamp encapsulating two arc tubes in an outer bulb connected to a base, the ceramic metal halide lamp configured to light always one arc tube which is easily lit, the ceramic metal halide lamp comprising: two L-shaped frame members connected to the respective two main power feed inscribed lines of the stem inside the base to achieve the power supply function to the arc tube, the frame members extending in parallel to each other along the lamp axis inside the outer bulb; a first support plate connected to the frame member in the vicinity of the top portion of the lamp, part thereof being pressed against an inner circumferential surface of the outer bulb by elastic deformation; and a second support plate connected to the frame member in the vicinity of the neck portion of the lamp, part thereof being pressed against an inner circumferential surface of the outer bulb by elastic deformation, and wherein the second support plate is formed thick in plate thickness compared to the first support plate.

[0025]

Furthermore, in the above ceramic metal halide lamp, the second support plate may be formed wide compared to the first support plate.

[0026]

Furthermore, in the above ceramic metal halide lamp, any of the first support plate and the second support plate may be formed of the leaf spring.

[0027] 6 2015271874 17 Dec 2015

Furthermore, in the above ceramic metal halide lamp, the second support plate may be formed 1.5 to 2.0 times in plate thickness compared to the first support plate, and the second support plate may be formed 1.3 to 2.0 times in width compared to the first support plate.

[0028]

Furthermore, in the above ceramic metal halide lamp, the deformation ratio M/L3 of the second support plate may be within the range of 0.3 to 0.5.

Advantageous Effects of Invention [0029]

According to the present invention, a double tube lamp including a novel mount structure and having relatively large lamp power can be provided.

BRIEF DESCRIPTION OF DRAWINGS

[0030] FIGS. 1A and IB are diagrams illustrating the conventional ceramic metal halide lamp. Here, FIG. 1A is a cross-sectional structural view taken along the lamp axis and the axis of the two arc tubes of the conventional double tube lamp. FIG. IB is a diagram illustrating the mount used in the lamp in FIG. 1A, and is a cross-sectional structural view taken along the plane perpendicular to the paper surface passing through the lamp axis in FIG. 1A; FIG. 2 is an outline drawing of the ceramic arc tube; FIG. 3 is part of a flowchart of the manufacturing processes for the double tube lamp, and a simple diagram of a lamp in the corresponding stage is shown on the right side of each step; FIG. 4 is a view illustrating the double tube lamp having relatively large lamp power according to the present embodiment, and is a cross-sectional structural view taken along the lamp axis and the axis of the two arc tubes; 7 FIG. 5 is a diagram illustrating the mount used in the double tube lamp shown in FIG. 4, and in particular, is a diagram illustrating the structure positioning and supporting the components; 2015271874 17 Dec 2015 FIG. 6 is a diagram illustrating the mount used in the double tube lamp shown in FIG. 4, and in particular, is a diagram illustrating the tilt angle of the arc tube to the lamp axis; FIG. 7 A is an enlarged view of the peripheral portion of the arc tube in FIG. 4; FIGS. 7B(A) to 7B(C) are diagrams showing (B) a sleeve, (A) a sleeve holding metal fitting attached to one end portion of the sleeve, and (C) a sleeve holding metal fitting attached to the other end portion; FIG. 8 is a diagram showing a lamp having the fundamentally same structure as the double tube lamp shown in FIG. 4; FIG. 9A is a view showing a support plate disposed on the top side of the double tube lamp (FIG. 8); FIG. 9B is a view showing a support plate disposed on the neck side of the double tube lamp (FIG. 8); FIG. 10A is a diagram of the vicinity of the neck portion of the lamp illustrating the situation of connecting the support plate to the supports by welding; FIG. 10B is a cross-sectional view of the plane perpendicular to the lamp axis of the double tube lamp (FIG. 8), and is a diagram illustrating the relation between the support plate including leaf spring, the supports, and the outer bulb; FIG. 11A is a diagram of when the free end is bent by v due to the load F being applied to the free end of the cantilever beam having the length 1; and FIG. 1 IB is a cross-sectional view of the cantilever beam. It is a diagram illustrating the behavior of half of the support plate (leaf spring) shown in FIG. 9B, that is, the part from the central part to be welded to the support to the end portion. 8

DESCRIPTION OF EMBODIMENTS 2015271874 17 Dec 2015 [0031]

In the following, the embodiment of a ceramic metal halide lamp according to the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in the figures, the same elements will be denoted by the same reference numerals, and an overlapping description will be omitted.

[0032]

The ceramic metal halide lamp according to the present embodiment can be easily understood by comparison with the conventional ceramic metal halide lamp. Therefore, first, the structure of the conventional ceramic metal halide lamp will be simply described.

[0033] [Conventional Double Tube Lamp] FIGS. 1A and IB are diagrams illustrating a conventional ceramic metal halide lamp 100. Here, FIG. 1A is a cross-sectional structural view of the conventional double tube lamp 100 taken along the lamp axis 100c and the axis of the two arc tubes. FIG. IB is a diagram illustrating a mount 240 used in the lamp in FIG. 1A, and is a cross-sectional structural view taken along the plane perpendicular to the paper surface passing through a lamp axis 100c in FIG. 1A. It should be noted that the mount 240 shows the mount structure at the stage before the insertion into the lamp outer bulb at the time of manufacturing the lamp.

[0034]

The lamp 100 encapsulates two arc tubes 140-1 and 140-2 inside an outer bulb 120. The arc tubes 140-1 and 140-2 are incorporated within the sleeves (also referred to as "inner tubes") 160-1 and 160-2, respectively. E-type base 200 is joined to one end of the outer bulb 120. The two arc tubes 140-1 and 140-2 are arranged in parallel with each other along the lamp axis 100c at the same distance from the base 200 within 9 the outer bulb 120. 2015271874 17 Dec 2015 [0035]

The mount 240 of the double tube lamp 100 includes, as the main components, a stem tube 220 where a pair of lead-in wires are hermetically sealed; supports 180-1 and 180-2 making of a metal round rod molded into a frame shape, each connected to one of the lead-in wires; and some wires such as nickel-plated iron wires, connected to the supports.

[0036]

The power is supplied to the arc tubes 140-1 and 140-2 through the supports 180-1 and 180-2 as feeder lines. That is, the power is supplied to one of the lead wires of the arc tubes 140-1 and 140-2 from one of the feeder lines of the stem tube 220 through the supports 180-1 and 180-2, and furthermore through the iron wires 180-3 and 180-4. Furthermore, the power reaches the other feeder line of the stem tube 220 from the other lead wire of the arc tubes 140-1 and 140-2 through the iron wires 180-5 and 180-6. Therefore, the supports 180-1 and 180-2 serving also as a feeder line have the same electric potential.

[0037]

The arc tubes 140-1 and 140-2 are incorporated in the sleeves 160-1 and 160-2, respectively. Each of the sleeves is connected to the supports 180-1 and 180-2 at two spots on the upper and lower sides to be firmly fixed by using the fixing metal belts 300-1 and 300-2. Although not apparent in the figure, each of the fixing metal belts has a shape that two annular members to hold each of the sleeves are welded to both surfaces of the plate-like member bridged between the supports 180-1 and 180-2 having the same potential. In this way, the arc tubes 140-1 and 140-2 are firmly supported in a predetermined position by the mount 240 by using the sleeves 160-1 and 160-2.

[0038]

The constituent elements of the lamp 100 will be briefly described. 10

The outer bulb 120 is, for example, made of translucent hard glass. The outer bulb 120 has a BT-type including the central part with the maximum diameter, the top portion on the lower side, and the neck portion connected to the base on the upper side. The outer bulb 120 includes a transparent-type outer bulb transmitting the rays from the arc tubes 140 directly and linearly, and a diffusion-type outer bulb with the inner surface of white frosted glass-like, diffusing the rays to some extent to transmit. Any of them may work. 2015271874 17 Dec 2015 [0039]

The two arc tubes 140-1 and 140-2 are manufactured according to the same specification.

[0040]

The two sleeves 160-1 and 160-2 are also manufactured according to the same specification. Each of the sleeves 160 includes two short test tube-like transparent quartz glass tubes having slightly different diameters, and each has a both-end closed-type structure where the thinner tube is inserted from the opening end of the thicker tube to be incorporated. Small holes through which the lead wires of the arc tube 140 penetrate are formed at both ends of the sleeve 160. The sleeve 160 is disposed for protecting the outer bulb, so that the debris does not collide with the outer bulb 120 to damage when the ceramic arc tube 140 burst because of a high-temperature and high-pressure state at the time of lighting.

[0041] A metal reinforcing winding 142 is helically wound around the sleeves 160-1 and 160-2. The reinforcing winding 142 reinforces the mechanical strength of the sleeve 160, and prevents the debris of the arc tube 140 or the sleeve 160 from jumping out toward the outer bulb 120 direction when the arc tube bursts.

[0042] [Double Tube Lamp having Relatively Large Lamp Power according to the 11

Present Embodiment] 2015271874 17 Dec 2015 (History of the Development)

The size of the arc tube is increased in order to implement the double tube lamp having relatively large lamp power. FIG. 2 is an outline drawing of the ceramic arc tube. The maximum inner diameter d of the arc tube becomes thicker. Table 1 is a table comparing the sizes between the 250 W lamp arc tube shown in FIGS. 1A and IB and, for example, the 360 W lamp arc tube.

[0043]

Table 1: Comparison between the conventional arc tube and the arc tube of the present embodiment

No. Arc tube maximum inner Remarks diameter d [mm] 1 250 W lamp arc tube (A) 14.9 conventional 2 360 W lamp arc tube (B) 18.0 the present embodiment 3 Comparison (B/A) 1.21 [0044] FIG. 3 is part of a flowchart of the manufacturing processes for the double tube lamp, and a simple diagram of a lamp in the corresponding stage is shown on the right side of each step.

In the mount assembly process in step SI, the sleeve incorporating the arc tube is positioned and fixed to the support. The other necessary components are attached to form the mount, and the stem is attached to the lower end.

In the sealing process in step S2, the mount is inserted from the opening to the inside of the outer bulb, and the stem at the lower part of the mount and the outer bulb are heated by a burner to be sealed.

In the exhausting process in step S3, the gas inside the already-sealed outer bulb is once evacuated to a vacuum state through the exhaust pipe. Then, a gas such as 12 helium is encapsulated, and the exhaust pipe is chipped off (the exhaust pipe is sealed by being dissolved in the burner). 2015271874 17 Dec 2015

In the base-attaching process in step S4, the lead-in wires linked to the arc tube are soldered to the top portion and the side portion of the base and the base is joined to the outer bulb.

Through the lighting test and inspection in step S5, the double tube lamp is completed.

[0045]

Here, if the size of the arc tube is increased, it is no longer possible to employ a structure of the double tube lamp shown in FIGS. 1A and IB. That is, if a structure where the two arc tubes 140-1 and 140-2 as shown in FIGS. 1A and IB are arranged in parallel along the lamp axis 100c is employed, in the sealing process in step S2, the mount fixing the arc tubes cannot be inserted from the opening to the inside of the outer bulb. There is a certain limit to the opening of the outer bulb due to the E-type base (model number E39) to be attached in a subsequent step, and the size cannot be further increased.

[0046]

Therefore, there has been a need to develop a new mount structure configured to properly position and to securely fix the two arc tubes in the outer bulb.

Thus, the present inventors have developed a new mount structure shown in FIGS. 4 to 8.

[0047] (Overall Structure) FIG. 4 is a view illustrating a double tube lamp 10a having relatively large lamp power according to the present embodiment, and is a cross-sectional structural view taken along the lamp axis 10c and the axis of the two arc tubes. The lamp 10a encapsulates two arc tubes 14-1 and 14-2 inside the outer bulb 12. The arc tubes 14-1 13 2015271874 17 Dec 2015 and 14-2 are incorporated inside the sleeves 16-1 and 16-2, respectively. E-type base 20 is joined to one end of the outer bulb 12.

[0048]

As a result of employing the arc tubes 14-1 and 14-2 increased in size, the double tube lamp 10 according to the present embodiment in FIG. 4 differs in the following respects regarding the mount structure as compared to the conventional double tube lamp 100 in FIGS. 1A and IB. (1) The lamp power is relatively large, and is intended for the range of 270 to 700 W. (2) As a result of the size of the arc tube being increased, each of the two arc tubes 14-1 and 14-2 is arranged to be tilted to the lamp axis 10c at a different distance from the base 20 inside the outer bulb 12. (3) As a result of the size of the arc tube being increased, the structure positioning and fixing the arc tubes 14-1 and 14-2 to a mount 24 becomes novel. (4) As a result of the size of the arc tube being increased, the sleeves 16-1 and 16-2 around the arc tubes 14-1 and 14-2 employ a cylindrical open-ended type. (5) A new damage preventing structure for the outer bulb is employed because a cylindrical open-ended sleeve is employed.

[0049]

In the following, the features of a novel mount structure of the double tube lamp 10a according to the present embodiment in FIG. 4 will be described.

[First Feature: Holding Structure of Sleeves and the like] FIG. 5 is a diagram illustrating the mount 24 used in the double tube lamp 10a, and in particular, is a diagram illustrating the structure positioning and supporting the components. It should be noted that the places A to D surrounded by ellipses of the dashed line are the features of the mount structure.

[0050] 14

The mount 24 includes, as the main components, a stem tube 22 where a pair of lead-in wires are hermetically sealed; a support 18-1 making of a metal round rod molded into a L shape, connected to one lead-in wire; a support 18-2 making of a metal round rod molded into a L shape, connected to the other lead-in wire; and some wires 26 made of nickel-plated iron wire, connecting between the supports. The wire 26 supports between the supports 18-1 and 18-2 electrically in an insulating state and mechanically firmly with a cylindrical ceramic insulating member 26s interposed in the middle portion of the wire. 2015271874 17 Dec 2015 [0051]

The arc tubes 14-1 and 14-2 respectively incorporated into the sleeves 16-1 and 16-2 are supported in predetermined positions by the mount 24, and are powered by the supports 18-1 and 18-2 as the feeder lines. That is, the power is supplied from one feeder line of the stem tube 22 to the lead wire on the upper side of the arc tube 14-1 through the support 18-1, and further through the conductive portion of the wire 26.

The power is supplied directly from the support 18-1 to the lead wire on the upper side of the arc tube 14-2. Similarly, the power is supplied from the other feeder line of the stem tube 22 to the lead wire on the lower side of the arc tube 14-1 through the support 18-2. The power is supplied to the lead wire on the lower side of the arc tube 14-2 through the support 18-2, and further through the conductive portion of the wire 26. Thus, the supports 18-1 and 18-2 also serving as feeder lines have different electric potentials that one potential is positive and the other potential is negative.

[0052]

The features of the mount 24 used in the double tube lamp 10a shown in FIG. 5 are as follows. (1) Each of the two supports 18-1 and 18-2 is welded to a corresponding one of a pair of lead-in wires hermetically sealed in the stem tube 22 at the place D, and the two supports 18-1 and 18-2 are positioned in parallel to each other and securely held by 15 the wires 26 bridged and welded between the supports 18-1 and 18-2 at the plurality of places C. As a result, the two supports 18-1 and 18-2 extend in parallel to each other in a solid state, along the lamp axis 10c in the internal space of the outer bulb 12. Therefore, the supports 18-1 and 18-2 are the bases for fixing the various components. That is, arc tubes 14 and sleeves 16 are positioned and fixed to the supports 18-1 and 18-2. 2015271874 17 Dec 2015 [0053] (2) Each of the two arc tubes 14-1 and 14-2 is arranged to be tilted to the lamp axis 10c at a different distance from the base 20 inside the outer bulb 12. However, the two arc tubes are lit alternately, and therefore the light-emitting portions of the arc tubes are arranged as close to the vicinity of the central part of the outer bulb as possible from the viewpoint of the light distribution characteristics.

In this case, the place M in FIG. 4 is the place where the two different electric potential conductors come closest to each other. With respect to this lamp, the maximum pulse voltage applied to during startup is 4.5 kV. The International Electrotechnical Commission (IEC) and the like define the minimum distance for the sine wave and the non-sinusoidal pulse voltage with respect to lighting equipment.

The minimum clearance is defined as 3 mm for the rated pulse-peak voltage of 4.0 kV, and 4 mm for that of 5.0 kV. The present applicant operates at the minimum distance 1 mm for the peak voltage 1 kV in anticipation of further safety.

[0054] (3) The sleeve 16 employs the open-ended cylindrical sleeve 16 made of transparent quartz glass tube as shown in FIG. 7B(B). It is because the supports 18-1 and 18-2 have different electric potentials, and therefore the mount structure, connecting the both-end closed-type sleeve as shown in FIGS. 1A and IB to the supports at two spots on the upper and lower sides by using the fixing metal belts 300-1 and 300-2, cannot be employed. 16 2015271874 17 Dec 2015 [0055] (4) Each of the sleeves 16 is positioned and supported at three points by the two supports 18-1 and 18-2. To support a component in a space, at least three-point support is necessary. It is because in the case of two-point support, when the vibration occurs, the component swings, rotates, and is broken around the line connecting the supporting points.

[0056]

As described below in relation to FIGS. 7B(A) to 7B(C), the arc tube 14 is housed in the cylindrical sleeve 16, and the sleeve 16 has one end where a sleeve holding metal fitting 30 is attached and the other end where a sleeve holding metal fitting 32 is attached, to be formed into the arc tube and sleeve assembly (see FIG. 7A).

[0057]

As shown in FIG. 5, in the place A, the sleeve holding metal fitting 32 of the sleeve 16-1 is welded and fixed to the support 18-1, and the sleeve holding metal fitting 30 is welded and fixed to the support 18-2. Furthermore, in the place B, the sleeve holding metal fitting 32 of the sleeve 16-1 is welded and fixed to the support 18-2 by using a wire 25 (the same wire as the wire 26). It is preferable to use two wires 25 so as to increase the mechanical strength.

[0058]

See the enlarged view of the place B. The respective metal portions 25c of the two wires 25 are welded to tab piece 32f of the sleeve holding metal fitting 32 fixing each of the sleeves 16. The metal portion 25c of the welding place of each wire 25 is bent so as to be substantially parallel to the central axis 16c of the sleeve 16, and two metal wires are welded side by side. By this structure, the contact area between the tab piece 32f and the metal portion 25c of the wire 25 can be increased, and sufficient welding strength can be secured. At the same time, even when the distance between the tab piece 32f and the insulating portion 25s becomes short, and the lamp is vibrated, 17 it is possible to reduce the vibration of the sleeve due to the deflection of the metal portion 25c. 2015271874 17 Dec 2015 [0059]

The mount structure has the following merits and advantage. (a) The two arc tubes with large lamp power can be securely held in the appropriate position. That is, the light-emitting portions of the two arc tubes can be arranged as close to the vicinity of the central part of the outer bulb as possible on the lamp axis from the viewpoint of the light distribution characteristics. (b) It is possible to provide a sleeve for each arc tube as a measure of safety so that the arc tube burst does not lead to the outer bulb breakage. Furthermore, the heat retaining properties and the color rendering properties of the arc tube are improved by the sleeve. Furthermore, as the lighting equipment for mounting the lamp, a front-open type equipment can be used.

[0060] [Second Feature: Tilt Angle of the Arc Tube] FIG. 6 is a diagram illustrating the mount 24 used in the double tube lamp 10a, and in particular, is a diagram illustrating the tilt angle to the lamp axis 10c of the arc tubes 14-1 and 14-2.

[0061]

The second feature is based on the premise that the lamp 10a is a vertical lighting. Furthermore, the second feature is an embodiment relating to the tilt angle of the arc tube, is not limited to the case where the number of the arc tubes 14 of the lamp is two, and can also be applied to the case where the number is one.

[0062]

With respect to the ceramic metal halide lamp, the lamp voltage VL is found to be relatively large at the time of horizontal lighting compared to the time of vertical lighting. The lamp voltage VL corresponds to the resistance value of the lamp during 18 lighting, and has the property proportional to the amount of mercury. That is, it is because the evaporated mercury in the arc tube hinders the movement of electrons. 2015271874 17 Dec 2015

The evaporation amount of the light-emitting substance of the lamp is determined by the coldest part temperature. The coldest part temperature of the horizontal lighting lamp becomes higher than the coldest part temperature of the lower end of the vertical hghting lamp. As a result, it is considered that the internal vapor pressure of the horizontal hghting lamp becomes relatively high, that the resistance value is increased, and that the lamp voltage rises. Furthermore, the arc of the horizontal hghting lamp floats, is bent, and is lengthened under the influence of gravity, and therefore it is considered that the probability of collision to the mercury vapor is increased, that the resistance value is increased, and that the lamp voltage rises.

[0063]

Mercury is an environmental load substance, and it is desired to reduce the use amount as much as possible. Here, in one aspect, the lamp voltage VL is considered to be controlled by the amount of mercury. That is, the vertical hghting arc tube is tilted at a certain angle, whereby the lamp voltage VL can be raised. Table 2 is a result of measuring the change in the lamp voltage VL in response to the change in the tilt angle of the arc tube. 19 [0064]

Table2: Relation between Tilt angle of the arc tube and Lamp voltage VL

Tilt angle of arc tube [°] Lamp voltage VL [V] 0 (verticality) 114 20 121 30 120 2015271874 17 Dec 2015 [0065]

Due to Table 2, it is found that the lamp voltage VL is increased about 5 to 6% when the tilt angle = 20° to 30° compared to the case where the arc tube is vertically arranged. Therefore, when a predetermined lamp power is implemented, compared to the case of the vertical arrangement, the arc tube is tilted at the tilt angle = 20° to 30° and the lamp voltage VL is raised, whereby the lamp power is increased, and therefore the amount of mercury corresponding to the increase can be reduced.

[0066]

It should be noted that when the tilt angle exceeds 30°, the lateral dimensions of the mount are increased, and the mount cannot be inserted into the outer bulb as described in relation to FIG. 3.

[0067]

The mount structure has the following merits and advantage. (a) The arc tube is tilted at the tilt angle = 20° to 30°, whereby the predetermined lamp power can be secured with a smaller amount of mercury.

[0068] [Third Feature: Outer Bulb Damage Preventing Structure] FIG. 7A is an enlarged view of the peripheral portion of the arc tube 14-1 in FIG. 4. FIGS. 7B(A) to 7B(C) are diagrams showing (B) a sleeve 16, (A) a sleeve holding metal fitting 30 attached to one end portion of the sleeve, and (C) a sleeve holding metal fitting 32 attached to the other end portion. 20 2015271874 17 Dec 2015 [0069]

Conventionally, the both-end closed-type sleeves 160-1 and 160-2 are employed as shown in FIGS. 1A and IB, and therefore the debris of the burst arc tube can be blocked in the directions of 360°.

[0070]

However, the size of the arc tube 14 is increased, and the supports 18-1 and 18-2 have different electric potentials, and therefore the fixing metal belts 300-1 and 300-2 connecting between the supports as shown in FIGS. 1A and IB cannot be employed.

[0071]

Thus, in the present embodiment, the open-ended cylindrical sleeves 16-1 and 16-2 as shown in FIG. 4 are employed. As a result, as shown in FIG. 7A, in the place N, part of the outer bulb 12 is positioned in the vicinity of the open end of the sleeve 16-1, and the damage may occur. It should be noted that the same is true for the sleeve 16-2.

[0072]

For this reason, a new outer bulb damage preventing structure is employed.

As shown in FIGS. 7B(A) to 7B(C), the sleeve holding metal fitting 30 is pushed and attached to one end and the sleeve holding metal fitting 32 is pushed and attached to the other end so that the sleeve 16 is fixed to the support 18. The difference between the sleeve holding metal fittings 30 and 32 is that the metal fitting 30 is a metal fitting to be attached to the support 18 in one place, and the metal fitting 32 is a metal fitting to be attached to the support 18 in two places.

[0073]

The sleeve holding metal fitting 30 includes, in terms of the sleeve holding function, an annular metal belt 30a configured to engage with the outer peripheral end of the sleeve 16, a plurality of locking metal fittings 30d configured to engage with the 21 2015271874 17 Dec 2015 inner peripheral end, and a tab piece 30e configured to be welded and fixed to the support 18. The sleeve holding metal fitting 32 is also the same except that it includes two tab pieces 32e and 32f configured to be welded and fixed to the support 18.

[0074]

With respect to the sleeve holding metal fitting 30, a partial blockage lid 30b configured to partially close the opening of the sleeve 16 is provided as the outer bulb damage preventing function. An opening 30c is formed in the center of the partial blockage lid 30b, and the thin tube portion of the arc tube 14 passes through the opening 30c. The sleeve holding metal fitting 32 is also the same.

[0075]

The debris of the arc tube with the kinetic energy large enough to damage the outer bulb 12 has large mass, and therefore the size is also large. Therefore, to prevent this, it is sufficient to partially close the openings at both ends of the sleeve 16.

[0076]

The outer bulb damage preventing structure has the following merits and advantage. (a) The partial blockage lids 30b and 32b are disposed at the respective openings at both ends of the sleeve 16, whereby the possibility of the outer bulb damage due to the debris of the arc tube is gone. (b) The partial blockage lids 30b and 32b can be integrally formed with the sleeve holding metal fittings 30 and 32 having the object of the sleeve holding function. Therefore, the partial blockage lids 30b and 32b partially close the open end of the sleeve 16 only by the sleeve holding metal fittings 30 and 32 being pushed and attached to the sleeve 16. (c) The annular metal belts 30a and 32a reinforce the mechanical strength of the sleeve 16 and prevent the damage to the sleeve.

[0077] 22 [Fourth Feature: Structure where Vibration Resistance is Strengthened] 2015271874 17 Dec 2015 (Object)

As described in the above-mentioned "Overall Structure", the double tube lamp 10a according to the present embodiment is directed to a lamp with relatively large lamp power, and therefore the size of each of the arc tubes 14 and each of the sleeves 16 is large, and consequently is heavy in weight. In addition, as described in the "First Feature: Holding Structure of Sleeves and the like", the supports 18-1 and 18-2 serve as the feeder lines as well as the holding of the arc tube and the sleeve, and are in the relationship of the mutually different electric potentials. In the holding structure of the sleeves and the like in the first feature, the arc tube 14 and the sleeve 16 are firmly held to the support 18.

[0078]

With respect to the mount structure of this double tube lamp, furthermore, the vibration test is performed so that the most mechanically vulnerable place is found. It is because the mechanical strength is further increased by the vulnerable place being reinforced.

[0079]

When the vibration test is performed, the overall support firmly holding the arc tube and the sleeve (that is, the overall mount structure) wavers. When the vibration is further added continuously, the phenomenon occurs that the inscribed line of the feeder line of the stem (the line exposed inside the outer bulb of the feeder line), where the support 18 is welded to at the root, breaks at the welding place(the welding place is detached).

[0080]

When the related art relating to the connection between the support 18 and the feeder line of the stem tube 22 is examined, the configuration that reduces the shaking of the mount by sandwiching the pinched part of the stem between the two support 23 2015271874 17 Dec 2015 plates is disclosed in the above JP 2012-28096 A. In the above JP 2014-067663 A, the arc tube is one single type, and originally, the ceramic arc tube is light in weight compared to the quartz arc tube, and therefore a particular support plate is not provided, and the support is connected to the feeder line of the stem.

[0081]

In the "First Feature: Holding Structure of Sleeves and the like", the connection between the support 18, and the arc tube 14 and the sleeve 16 is solely focused on, and the connection is strengthened. In the "Fourth Feature: Structure where Vibration Resistance is Strengthened", it is an object to further increase the reliability of the mechanical strength by reinforcing the most vulnerable place found in the vibration test.

[0082] (Configuration) FIG. 8 is basically a diagram showing a lamp 10b having the same structure as the double tube lamp 10a shown in FIG. 4. In the double tube lamp 10a shown in FIG. 4, to lock the mount structure to the inner surface of the outer bulb, the support plate 28a-2 including the leaf spring is used in the top portion, and the support plate 28a-1 is used in the neck portion. The double tube lamp 10b shown in FIG. 8 employs the support plate 28b-1 including the novel large-in-size leaf spring in the vicinity of the neck portion so as to reinforce the respective vulnerable connections between the supports 18-1 and 18-2 and the inscribed lines 17-1 and 17-2 found in the vibration test. As compared to the support plate 28b-2 in the vicinity of the top portion, the support plate 28b-1 has a feature that the leaf spring has a wide width W. Furthermore, the support plate 28b-1 has a feature that the leaf spring has a thick plate thickness T.

[0083] FIGS. 9A and 9B are views illustrating the support plates including leaf springs. The upper stage of each figure is a plan view of the leaf spring, and the lower stage is a side view. FIG. 9A is a view showing a support plate 28b-2 disposed on the 24 top side of the double tube lamp 10b (FIG. 8). FIG. 9B is a view showing a support plate 28b-1 disposed on the neck side of the double tube lamp 10b (FIG. 8). 2015271874 17 Dec 2015 [0084]

For the support plate shown in each figure, the approximate values of the length L, the width W, and the plate thickness T are shown. When the 28b-2 in FIG. 9A is compared to the support plate 28b-1 in FIG. 9B, the nominal value of the plate thickness is T3/T2 = 0.25/0.15 = 1.67, and considering the tolerance, T3/T2 is within the range of 1.5 to 2.0. For the width of the support plates, the nominal value is W3/W2 = 10.0/6.5 = 1.53, and considering the tolerance, W3/W2 is within the range of 1.3 to 2.0. These leaf springs are typically formed of an iron-nickel alloy.

[0085] FIG. 10A is a diagram of the vicinity of the neck of the lamp 10b illustrating the situation of connecting the support plates 28b-1 to the supports 18-1 and 18-2 by welding. The inscribed lines 17-1 and 17-2 of the feeder lines extend from the stem tube 22, and are welded to the supports 18-1 and 18-2 respectively. Two support plates 28b-1 including the leaf spring are welded to the respective supports 18-1 and 18-2.

The supports 18-1 and 18-2 have different potentials, and therefore such a support plate as to extend over the supports cannot be employed.

[0086] FIG. 10B is a cross-sectional view of the plane perpendicular to the lamp axis of the double tube lamp 10b (FIG. 8), and is a diagram illustrating the relation between the support plates 28b-1 including the leaf spring, the supports 18-1 and 18-2, and the outer bulb 12. The leaf spring 28b-1 is forcibly bent around the support 18 connecting portion, and the mount is inserted into the outer bulb 12. In FIG. 10B, the leaf springs 28b-1 before the insertion into the outer bulb 12 are indicated by a broken line, and the leaf springs 28b-1 after the insertion are indicated by a solid line. After the insertion, when the forced bending is released, the circular protrusions of the leaf spring engage 25 with the outer bulb inner circumferential surface, restrain the supports 18-1 and 18-2 from moving, and prevent the break at the welding place between the inscribed lines and the supports when the mount is vibrated. 2015271874 17 Dec 2015 [0087]

With reference to FIG. 10B again, when the deformation ratio of the support plate 28b-1 is defined as M/L3 by using the half length of the support plate L3 and the bending amount M, the nominal value of the deformation ratio is M/L3 = 11.31/28.5 = 0.40. In consideration of the tolerance, the deformation amount M/L3 is in the range of 0.30 to 0.40.

[0088] (Effect) FIG. 11A is a diagram of when the free end is bent by v due to the load F being applied to the free end of the cantilever beam having the length 1. FIG. 1 IB is a cross-sectional view of the cantilever beam. It is a diagram illustrating the behavior of half of the support plate (leaf spring) 28b-1 shown in FIG. 9B, that is, the part from the central part to be welded to the support to the end portion. There is a relation of 1 = F3/2.

[0089]

The deflection v and the load F have a relation in formula (1). v = (F13)/(3EI) (1) where F is the load applied to the free end, E is the elastic coefficient determined by the material, I is the geometrical moment of inertia determined by the shape. El represents the rigidity.

[0090]

Formula (1) is transformed into formula (2) that determines how much of the load F is applied to when a certain amount of deflection v occurs. F = (3EI-v)/l3 (2) 26 2015271874 17 Dec 2015 [0091]

As shown in FIG. 1 IB, assuming that the width of the cantilever beam W = b and the thickness T = h, the geometrical moment of inertia I can be determined by formula (3). I = (1/12) bh3 (3) [0092]

When formula (3) is substituted into formula (2), formula (4) is obtained. F = (3EI-v)/l3 = bh3v/(413) (4)

From formula (4), for the same support plate (leaf spring), the load F applied to the outer bulb inner circumferential surface is proportional to the width b of the support plate, proportional to the cube of the thickness h, proportional to the amount of deflection v, and inversely proportional to the cube of length 1 (in the leaf spring, the length from the point fixed to the support to the contact point of the rounded protrusion).

[0093]

In the present embodiment, as shown in FIGS. 9A and 9B, the thickness h is thickened from T2 = 0.15 mm to T3 = 0.25 mm, whereby the load F increases (0.25/0.15) = 4.6 times. Furthermore, the width b is widened From W2 = 6.5 mm to W3 = 10.0 mm, whereby the load F increases (10.0/6.5) = 1.5 times. Eventually, the thickness h of the support plate is thickened and the width W is widened, whereby the load F increases (0.25/0.15)3· (10.0/6.5) = 6.9 times.

[0094] [Modification and the like]

In the above, although the embodiments according to the present invention are described, these are exemplary, and the present invention is not intended to be limited to these. The addition, deletion, change, improvement, and the like to the present embodiments, which those skilled in the art can easily perform, are within the scope of 27 the present invention. The technological scope of the present invention is determined by the scope of the appended claims. 2015271874 17 Dec 2015 [0095]

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

[0096]

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavor to which this specification relates. 28

Claims (3)

1. A ceramic metal halide lamp encapsulating two arc tubes in an outer bulb connected to a base, the ceramic metal halide lamp configured to light always one arc tube which is easily lit, the lamp power of the lamp being in a range of 270 to 700 W, the ceramic metal halide lamp comprising: two supports in parallel to each other, extending along the lamp axis inside the outer bulb, the two supports being welded to a pair of lead-in wires, respectively, which are hermetically sealed in a stem tube and the two supports being positioned in parallel to each other in a solid state by using a wire with insulating member interposed in the middle portion thereof which is bridged between the two supports in at least one place; and two cylindrical sleeves each of which housing an arc tube inside, wherein each of the sleeves is fixed to the supports at three points, and wherein each of the two arc tubes is arranged to be tilted to a lamp axis and is positioned and fixed to the supports at a different distance from the base inside the outer bulb.

2. The ceramic metal halide lamp according to claim 1, wherein the two cylindrical sleeves each include two annular metal belts wound around an upper end and a lower end of a cylindrical shape and metal tab pieces extending from the annular metal belts, respectively, and the sleeves each are fixed to the support by one of the metal tab pieces being welded to the support.

3. The ceramic metal halide lamp according to claim 1, wherein the two cylindrical sleeves each include two annular metal belts wound around an upper end and a lower end of a cylindrical shape, respectively, and metal tab pieces extending from the annular metal belts, respectively, and the sleeves each are fixed to the support by the other of the metal tab pieces welded to the support using a wire which is interposed with an insulating member at midpoint.