JP4173077B2 - Reflector built-in lamp - Google Patents

Description

  The present invention relates to a reflector built-in lamp in which a reflecting surface is provided in a discharge space in which a pair of an anode and a cathode is disposed.

  A lamp that supplies illumination light includes a type with a built-in reflecting mirror that has a reflecting surface in a discharge space in which a pair of an anode and a cathode is arranged, in addition to a type that is used with a reflecting mirror attached to the lamp.

For example, as shown in FIG. 6, such a lamp with a built-in reflector includes a body 101 having a reflecting surface 101a having a paraboloid, and a discharge space S ′ formed inside the body 101 including the reflecting surface 101a. A pair of an anode 108 and a cathode 109 arranged at a predetermined interval, a feed ring 105 fixed to the body 101 and electrically connected to the cathode 109, and a flange closely fitted to the inner peripheral surface of the feed ring 105 A translucent window member 111 that is held by 110 and seals the discharge space S ′, and a conductive support member 112 that supports the cathode 109 at a predetermined position, and is in the discharge space S ′ sealed by the window member 111. Is filled with a light emitting substance (inert gas) mainly composed of Xe. Usually, the window member 111 is made of glass, and the flange 110 that holds the window member 111 is made of Kovar alloy (FeNiCo) having a thermal expansion coefficient substantially equal to that of glass. The conductive support member 112 has one end joined to the cathode 109 and the other end joined to the power supply ring 105 and abutted against the flange 110. As shown in FIG. 7, three conductive support members 112 are provided at regular intervals, for example, and are formed in a straight line connecting the cathode 109, the feed ring 105, and the flange 110 with the shortest distance.
JP-A-9-161727

  However, since the temperature of the anode 108 and the cathode 109 rises to about 1000 ° C. and the heat of the cathode 109 is transmitted to the flange 110 via the conductive support member 112 when the reflecting mirror built-in lamp having the above configuration is turned on. The flange 110 locally becomes a high temperature of about 250 to 300 ° C. at the position where the conductive support member 112 abuts. When the flange 110 becomes high temperature, the window member 111 joined to the flange 110 also becomes high temperature in a chain. As described above, the flange 110 is formed of a Kovar alloy having a thermal expansion coefficient substantially equal to that of the glass constituting the window member 111. However, the thermal expansion coefficient of the glass and the Kovar alloy is not exactly the same. The difference arises in the amount of deformation due to thermal expansion. Therefore, when the flange 110 and the window member 111 are excessively heated locally, a gap may be generated at the joint portion between the flange 110 and the window member 111 due to the difference in deformation due to the thermal expansion. It has been found that the sealing performance due to is reduced.

  The present invention has been made in view of the circumstances as described above, and an object thereof is to provide a reflector built-in lamp that can suppress a rise in the temperature of the flange and can maintain a good sealing property of the discharge space. To do.

The present invention includes a body having a concave reflecting surface at an open end, a pair of anode and cathode disposed at a predetermined interval in a discharge space formed inside the body including the reflecting surface, A power supply ring that is fixed to the open end of the fuselage and feeds power to the cathode, and one end and the other end are joined to the power feed ring and the cathode, and a conductive material that supports the cathode at a predetermined position on the central axis of the fuselage. A conductive support member, and the conductive support member has a spiral shape in which the inside of the discharge space is circulated a plurality of times around the cathode from one end joined to the cathode to the other end joined to the feeding ring. And the distance from the contact point with the cathode to the contact point with the feed ring is longer than the shortest distance connecting the cathode and the feed ring.

A cylindrical flange that is closely fitted is preferably formed on the inner peripheral surface of the power supply ring, and it is more preferable that a window member is held on the inner peripheral surface of the cylindrical flange.

According to the present invention, the conductive support member has a spiral shape in which one end is joined to the cathode, and is wound around the discharge space a plurality of times around the cathode, and the other end is joined to the feed ring. Therefore, it is more likely to be discharged into the discharge space while traveling through the conductive support member than when the conductive support member is formed in a straight line connecting the cathode and the feed ring at the shortest distance, and is transmitted to the flange via the feed ring. The amount of heat can be reduced. As a result, the rise in the temperature of the flange is suppressed, so that the difference in deformation due to thermal expansion between the flange and the window member joined to the flange is reduced, and the adhesion between the flange and the window member, that is, the sealing property in the discharge space. Can be kept good.

  1 to 3 illustrate a reflector built-in lamp L according to an embodiment of the present invention. The reflector built-in lamp L includes a cylindrical body 1. The body 1 has a concave reflecting surface 1 a formed at the opening end, and a support hole 1 b for the anode penetrating the central axis of the body 1. The body 1 is formed into a predetermined shape using an insulating ceramic material, sintered, and then subjected to a reflection process for forming a metal vapor-deposited film such as silver or aluminum or a dielectric multilayer film. Is formed. In the body 1, a metal block 3 is fixed by a first metal ring 4 on one end side in the central axis direction, and a feed ring 5 is provided on the other end (opening end) side where the reflection surface 1 a is formed. It is fixed by the ring 6. A hollow spacer (anode support member) 2 is fitted into the support hole 1b from one end side (metal block 3 side) of the body 1.

  The metal block 3 has a connecting portion 3 a formed with substantially the same outer diameter as that of the body 1, and this connecting portion 3 a holds the spacer 2 and abuts the body 1. An insertion hole 3 b communicating with the support hole 1 b in which the spacer 2 is inserted is formed in the center of the metal block 3 so as to penetrate the metal block 3. The anode 8 is inserted into the insertion hole 3b of the metal block 3 and the support hole 1b of the body 1 in which the spacer 2 is inserted, and is supported by the body 1 and the metal block 3 in a state of partially protruding on the reflection surface 1a. The anode 8 and the metal block 3 are electrically connected. The metal block 3 functions as a power feeding body for the anode 8 and as a heat absorber for the body 1 and the anode 8. The metal block 3 is made of a metal material having high thermal conductivity such as Kovar. Further, as shown in FIG. 2, the rear end portion (the left end portion in FIG. 1) of the metal block 3 is fixed at a plurality of locations (three locations on concentric circles in the present embodiment) by pins P. Cannot rotate. Through this metal block 3, the reflector built-in lamp L is mounted on the heat sink 40 of the light source device.

  The first metal ring 4 has an inner diameter corresponding to the outer diameters of the body 1 and the metal block 3, covers the outer periphery of the body 1 and the outer periphery of the connecting portion 3 a of the metal block 3, and fixes the body 1 and the metal block 3. To do. The first metal ring 4 is made of a low-resistance metal material, and functions as a power feeder to the anode 8 together with the metal block 3.

  The feed ring 5 has a ring shape having an outer diameter substantially equal to the outer diameter of the body 1, and is in contact with the body 1 via a ceramic ring 7 having an outer diameter substantially equal to the outer diameter of the body 1. The power supply ring 5 is a power supply body to the cathode 9 and is made of a metal material. A cylindrical flange 10 that is in contact with the inner peripheral surface is closely fitted to the inner peripheral surface of the power supply ring 5. The flange 10 holds a circular window member 11 that is in close contact with the inner peripheral surface. Yes. The window member 11 has translucency that allows visible light to pass therethrough. It is preferable that the flange 10 and the window member 11 are made of a material having a close thermal expansion coefficient so as to maintain good adhesion to each other. In the present embodiment, the flange 10 is made of Kovar alloy (FeNiCo), and the window member 11 is made of glass.

  The second metal ring 6 has an inner diameter corresponding to the outer diameters of the fuselage 1, the feed ring 5 and the ceramic ring 7, and the fuselage 1 and the feed ring on the side opposite to the side on which the metal block 3 is fixed. 5 and the ceramic ring 7 are covered, and the feeding ring 5 and the ceramic ring 7 are fixed to the body 1. The second metal ring 6 is formed of a low-resistance metal material, and functions as a power supply body to the cathode 9 together with the power supply ring 5.

  When the window member 11 is tightly fitted to the power supply ring 5 via the flange 10, a sealed space including the reflecting surface 1 a is formed on the other end side of the body 1. This sealed space is referred to as a discharge space S in this embodiment. In the discharge space S, a light emitting substance (inert gas) mainly composed of Xe is enclosed, and a pair of anode 8 and cathode 9 are arranged at a predetermined interval. The distance between the anode 8 and the cathode 9 in this embodiment is about 1 to 2 mm. Since the anode 8 and the cathode 9 become high temperature when the lamp is turned on, they are made of a metal material having excellent heat resistance such as tungsten. As described above, the anode 8 is supported by the body 1 and the metal block 3 so as to partially protrude from the reflecting surface 1a. On the other hand, the cathode 9 is supported by the conductive support member 12 so that the axial direction thereof coincides with the axial direction of the anode 8. The conductive support member 12 has one end joined to the cathode 9 and the other end joined to the inner peripheral surface of the power supply ring 5 to electrically connect the cathode 9 and the power supply ring 5. The conductive support member 12 is also in contact with the flange 10 at the other end joined to the power supply ring 5. The conductive support member 12 is formed of a metal material having excellent conductivity, such as copper.

  When a voltage is applied to the anode 8 via the first metal ring 4 and the metal block 3 and to the cathode 9 via the second metal ring 6, the feeding ring 5 and the conductive support member 12, the voltage from the cathode 9 toward the anode 8 is increased. The emitted electrons excite the luminescent material in the discharge space S, and a bright spot is generated between the anode 8 and the cathode 9. That is, the reflector built-in lamp L is turned on. The light generated between the anode 8 and the cathode 9 is reflected by the reflecting surface 1 a and is emitted from the discharge space S to the outside of the window member 11 and the window member 11. The light reflected by the reflecting surface 1a of the present embodiment is emitted outward as parallel light. Whether the light emitted from the reflecting mirror built-in lamp L is parallel light or condensing depends on the shape of the reflecting surface 1a provided in the discharge space S.

  When the lamp L with built-in reflector is turned on, the temperature of the anode 8 and the cathode 9 rises to about 1000 ° C., and the temperature of the discharge space S also rises due to heat generated from the anode 8 and the cathode 9. At this time, as described above, the metal block 3 functions as a heat absorber for the body 1 and the anode 8 to prevent the temperature in the anode 8 and the discharge space S from excessively rising. That is, the heat of the anode 8 is absorbed by the metal block 3, and the heat of the discharge space S is absorbed by the metal block 3 through the body 1. The heat absorbed by the metal block 3 is released from the metal block 3 to the heat sink 40. On the other hand, the heat of the cathode 9 is transmitted to the conductive support member 12.

  The reflecting mirror built-in type lamp L having the overall configuration described above is characterized by the shape of the conductive support member 12.

  The conductive support member 12 has a thin plate shape, and is formed in a spiral shape centered on the cathode 9 (one end joined to the cathode 9) as shown in FIG. The conductive support member 12 has a longer overall length than the case where the conductive support member 12 is formed in a straight line in which the distance from the cathode 9 to the feed ring 5 and the flange 10 is the shortest as shown in FIG. If the total length of the conductive support member 12 is increased, the surface area of the conductive support member 12 is also increased, so that the heat dissipation of the conductive support member 12 is improved. The heat generated in the cathode 9 is emitted from the conductive support member 12 to the discharge space S while being transmitted through the conductive support member 12 joined to the cathode 9 and is transmitted to the other end of the conductive support member 12. Will be reduced. As a result, when the temperature in the discharge space S rises, the amount of heat transmitted to the portion where the other end portion of the conductive support member 12 contacts the power supply ring 5 and the flange 10 is suppressed. Thereby, the flange 10 does not have to be locally excessively hot at the part where the other end of the conductive support member 12 abuts, so that the deformation amount due to thermal expansion of the flange 10 and the window member 11 is substantially equal. Good adhesion between the flange 10 and the window member 11 can be maintained.

  The conductive support member 12 is formed in a clockwise spiral shape, but may be a clockwise spiral shape or a counterclockwise spiral shape.

  In this embodiment, the cathode 9 is supported by one conductive support member 12, but a plurality of conductive support members 12 may be provided. However, when a plurality of conductive support members 12 are provided, it is necessary to adjust the position of each conductive support member 12 so that the conductive support member 12 does not block the light reflected by the reflecting surface 1a.

  FIG. 4 shows a conductive support member provided in the reflector built-in lamp according to the second embodiment of the present invention. In this second embodiment, instead of the spiral conductive support member 12 described above, three bent conductive support members 22 having three bent portions are provided at equal intervals. The configuration other than the conductive support member 22 is the same as that of the first embodiment. In FIG. 4, components having the same functions as those in the first embodiment are denoted by the same reference numerals as in FIG.

  Each conductive support member 22 has one end portion and the other end portion joined to the cathode 9 and the power supply ring 5, and the other end portion is in contact with the flange 10. The conductive support member 22 has, for example, a thin plate shape made of a heat-resistant metal material, and has a bent portion that is bent at an acute angle. Thereby, the full length of the electroconductive support member 22 is extended longer than the case where it forms in the shape of a straight line where the distance from the cathode 9 to the feed ring 5 and the flange 10 is the shortest as shown in FIG. If the total length of the conductive support member 22 is thus extended, the heat generated in the cathode 9 is reduced until it is transferred to the other end of the conductive support member 22 as in the first embodiment. The flange 10 is not locally excessively heated at the portion where the other end of the conductive support member 12 abuts. Also according to the second embodiment, the adhesion between the flange 10 and the window member 11 can be kept good. Each conductive support member 22 is adjusted in position so as not to block the light reflected by the reflecting surface 1a.

  In the second embodiment, the conductive support member 22 has three bent portions, but the number of bent portions can be set as appropriate. Further, the conductive support member 22 having the bent portion is formed in a spiral shape centering on the cathode 9 (one end portion joined to the cathode 9) as in the first embodiment, and the entire length thereof is further increased. Is also possible.

In the second embodiment, the conductive support member 22 is bent in a cross section perpendicular to the axial direction of the cathode 9 as shown in FIG. 4, but the conductive support member is a cathode as shown in FIG. The structure bent in the cross section of the direction parallel to the axial direction of 9 may be sufficient.

FIG. 4 shows a main structure of the reflector built-in lamp according to the first embodiment of the present invention, and is a cross-sectional view taken along line II of FIG. 3. It is a top view which shows the metal block of the lamp | ramp with a built-in reflecting mirror seen from a rear end. It is a top view which shows the planar shape of the electroconductive support member of the lamp | ramp with a built-in reflector. It is a top view which shows the planar shape of the electroconductive support member with which the reflector built-in type lamp | ramp of 2nd Embodiment by this invention was equipped. It is sectional drawing which shows the electroconductive support member formed in the aspect different from FIG. It is sectional drawing which shows the main structures of the conventional reflector built-in type | mold lamp. It is a top view which shows the planar shape of the reflector built-in type lamp | ramp shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Body 1a Reflecting surface 2 Spacer 3 Metal block 4 1st metal ring 5 Feed ring 6 2nd metal ring 7 Ceramic ring 8 Anode 9 Cathode 10 Flange 11 Window member 12 Conductive support member 40 Heat sink

Claims (3)

A fuselage having a concave reflecting surface at the open end;
A pair of an anode and a cathode disposed at a predetermined interval in a discharge space formed inside the body including the reflective surface;
A feeding ring fixed to the open end of the body and feeding the cathode ;
One end portion and the other end portion are joined to the feeding ring and the cathode, and a conductive support member that supports the cathode at a predetermined position on the central axis of the body,
The conductive support member is
From the one end joined to the cathode to the other end joined to the power supply ring, a spiral shape is formed in which the inside of the discharge space is rotated a plurality of times around the cathode,
as well as,
The distance from the contact with the cathode to the contact with the feed ring is longer than the shortest distance connecting the cathode and the feed ring;
Reflector built-in type lamp. Further comprising a cylindrical flange tightly fitted to the inner peripheral surface of the power supply ring,
The reflector built-in type lamp according to claim 1. Further comprising a window member held on the inner peripheral surface of the cylindrical flange;
The reflector built-in lamp according to claim 2.

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