JP4613885B2 - Lamp with reflector - Google Patents

Description

  The present invention relates to a lamp with a reflecting mirror in which a high-pressure discharge lamp is mounted integrally with a concave reflecting mirror, and in particular, is emitted to the arc tube of the high-pressure discharge lamp from the light emitting portion to the opening side of the concave reflecting mirror. The present invention relates to a lamp with a reflecting mirror to which a sub-reflecting mirror that reflects light toward a light emitting unit to increase the light use efficiency of the lamp is mounted.

As shown in FIG. 8, a lamp with a reflector used as a light source for a liquid crystal projector or a light source for a projection TV has a pair of tungsten electrodes 2R and 2L each having a coil 4 wound around the tip side of the electrode shaft 3 and is made of a quartz glass tube. A high pressure discharge lamp which is disposed in the light emitting part 6 of the arc tube 5 so as to face each other, and a pair of sealing parts 7R, 7L for fixing the electrode shafts 3 of the electrodes 2R, 2L are formed on both sides of the light emitting part 6. 1, one sealing portion 7 </ b> R is arranged on the opening 9 side of the concave reflecting mirror 8, and the other sealing portion 7 </ b> L is arranged on the bottom portion 10 side of the concave reflecting mirror 8 so as to be integrated with the concave reflecting mirror 8. Attached. In order to increase the light utilization efficiency of the high-pressure discharge lamp 1, this type of lamp with a reflecting mirror radiates from the light emitting portion 6 to the opening 9 side of the concave reflecting mirror 8. In some cases, the sub-reflecting mirror 11 that reflects the emitted light toward the light emitting unit 6 is mounted, and in other cases, a reflective film is provided on the outer surface of the light emitting unit (see Patent Documents 1, 2, 3, and 4).
JP 2005-309372 A Japanese Patent No. 3184404 Japanese Patent No. 3204733 JP 2005-505909 A

In the high-pressure discharge lamp 1, a pair of tungsten electrodes 2R and 2L are disposed in the light emitting portion 6 of the arc tube 5 so as to face each other, and mercury, halogen such as bromine and iodine, argon gas, and the like. By the tungsten-halogen cycle action in which the starting rare gas is sealed and tungsten evaporated from the electrodes 2R, 2L and adhering to the inner surface of the light emitting portion 6 is re-evaporated to return to the electrodes 2R, 2L. While preventing the early blackening of the light emitting part 6 which impairs the life, the distance between the electrodes 2R, 2L is shortened to shorten the arc length, and the amount of mercury enclosed per unit volume of the light emitting part 6 is increased to light the lamp. A short arc type high-pressure mercury vapor discharge lamp that is small in size and capable of obtaining high-intensity light emission close to a point light source by increasing the mercury vapor pressure in the light emitting section 6 at the time Have been used (see Patent Document 5).
JP 2005-56646 A

  The electrodes 2R and 2L of the high-pressure discharge lamp 1 are obtained by melting and integrating the tip of the electrode shaft 3 and a part of the coil 4 wound by closely winding a tungsten wire in two upper and lower layers on the tip side. Thus, a spherical or convex curved electrode tip portion 13 is formed, and the rear end of the electrode shaft 3 is welded to one end of the molybdenum foil 14 sealed to the sealing portions 7R and 7L, respectively. The lamp power is supplied via a power supply lead wire (not shown) connected to a lead rod 15 welded to the other end of 14.

  The sub-reflecting mirror 11 provided on the arc tube 5 of the high-pressure discharge lamp 1 reflects the light radiated from the light emitting part 6 of the arc tube 5 to the opening 9 side of the concave reflecting mirror 8 toward the light emitting part 6 side. It is guided to the reflecting surface of the concave reflecting mirror 8 that is a mirror, and is reflected in the direction of the object to be irradiated by the reflecting surface to improve the light use efficiency of the lamp. The reflecting mirror 11 has a cylindrical bottom portion 16 as shown in FIG. 8 that is externally fitted to the sealing portion 7R of the arc tube 5, and maintains a constant distance from the light emitting portion 6 from the sealing portion 7R side. The bottom portion 16 that is mounted so as to face the outer surface of the sealing portion 7R is attached to the sealing portion 7R by the fixing material 12 such as an inorganic cement filled between the inner peripheral surface and the outer peripheral surface of the sealing portion 7R. It is fixed.

  However, if the sub-reflecting mirror 11 is mounted on the sealing portion 7R so as to face the light emitting portion 6 of the high-pressure discharge lamp 1, the light emitting portion 6 is sealed by an air cooling means such as a cooling fan equipped on the lamp with the reflecting mirror. The portion on the stop portion 7R side cannot be cooled sufficiently, and high-temperature hot air stays in the gap between the light emitting portion 6 and the sub-reflecting mirror 11, and the portion on the sealing portion 7R side of the light emitting portion 6 becomes Overheating may cause the portion to swell or cause the light emitting portion 6 to burst. In particular, a lamp with a reflecting mirror in which a front glass is mounted in the opening 9 of the concave reflecting mirror 8 serving as the main reflecting mirror significantly increases the outer surface temperature of the light emitting portion 6 facing the sub-reflecting mirror 11, and thus emits light. There was a high risk that part 6 would burst.

  In addition, in order to prevent local overheating of the light emitting unit 6, an attempt has been made to reduce the tube wall temperature of the portion of the light emitting unit 6 on the sealing portion 7R side to reduce the tube wall temperature of the portion. However, it is very difficult to design and process the tube wall load of the light emitting unit 6 locally so that the evaporation of mercury enclosed in the light emitting unit 6 is not hindered and the optical characteristics are not impaired. there were.

  The present invention prevents high temperature hot air from staying in the gap between the sub-reflecting mirror mounted on the arc tube sealing portion of the high pressure discharge lamp and the arc tube light emitting portion, The technical challenge is to prevent the explosion from occurring.

  In order to solve the above-described problems, the present invention provides a pair of electrodes disposed in the light emitting portion of the arc tube so as to face each other, and a pair of sealing portions for fixing the electrode axis of each electrode is formed on both sides of the light emitting portion. The high pressure discharge lamp is mounted integrally with the reflecting mirror so that one sealing part is arranged on the opening side of the concave reflecting mirror and the other sealing part is arranged on the bottom side of the concave reflecting mirror. In addition, in the lamp with a reflecting mirror, the sub-reflecting mirror in which the light emitted from the light emitting part to the opening side of the concave reflecting mirror is reflected to the light emitting part side is attached to the one sealing part. The reflecting mirror is fitted to the sealing portion by fitting the bottom portion to the one sealing portion, and a gap is formed on the bottom portion side from the front side to the back side of the sub-reflecting mirror. It is characterized by that.

  In the lamp with a reflector according to the present invention, a gap is formed on the bottom portion side of the sub-reflecting mirror attached to the sealing portion of the arc tube of the high-pressure discharge lamp so as to communicate from the front side to the back side of the sub-reflecting mirror. Therefore, a part of the convection generated when the lamp is turned on and the air flow of the cooling air supplied by the cooling fan is circulated in the gap between the sub-reflector and the light emitting part of the arc tube. The hot air is prevented from staying in the gap, and the swelling and rupture due to overheating of the light emitting part is prevented.

  In the best embodiment of the lamp with a reflector according to the present invention, a high-purity tungsten wire is densely wound in two upper and lower layers on the tip side of an electrode shaft made of a tungsten rod in a light emitting portion of a light emitting tube made of a quartz glass tube. A pair of tungsten electrodes wound with a coil consisting of coils are arranged facing each other with a narrow inter-electrode distance of about 1 mm, and starting gas such as mercury, halogen such as bromine and iodine, and argon gas. And a short arc type high-pressure mercury vapor discharge lamp in which a pair of sealing parts are formed on both sides of the light emitting part to fix the electrode shaft of each electrode. It is arranged on the part side, and the other sealing part is integrally attached to the reflecting mirror so as to be arranged on the bottom part side of the concave reflecting mirror.

  In addition, the arc tube of the high-pressure mercury vapor discharge lamp has a sub-reflecting mirror that reflects light emitted from the light-emitting part toward the opening side of the concave reflecting mirror toward the light-emitting part side, and the bottom part is the opening part of the concave reflecting mirror. A gap is formed on the bottom side of the sub-reflecting mirror from the front side to the back side.

  The bottom part of the sub-reflecting mirror is formed in a cylindrical shape, and a plurality of ribs extending from the front side to the back side of the sub-reflecting mirror are formed at intervals on the inner peripheral surface of the cylindrical bottom part. Each rib abuts on the outer peripheral surface of the sealing portion of the arc tube, so that the sub-reflecting mirror is coaxially mounted on the sealing portion, and the outer peripheral surface of the sealing portion and the cylindrical bottom portion A plurality of gaps are formed between the inner peripheral surface and the sub-reflecting mirror from the front side to the rear side, and a fixing material such as an inorganic cement that fixes the cylindrical bottom portion to the sealing portion is formed in a part of the gap. By being filled, the sub-reflecting mirror is fixed at a position facing the light emitting portion of the arc tube with an appropriate distance.

  In addition, the bottom part of the sub-reflecting mirror collects the air flow flowing toward the back side of the sub-reflecting mirror and introduces it into the gap formed on the bottom part side, and the air flow introduced into the gap In order to increase the cooling speed of the bottom part and arc tube sealing part by the air flow by increasing the flow velocity, is an annular projecting piece protruding in the radial direction of the bottom part formed along the edge of the bottom part? Or the bottom part is shape | molded in the trumpet shape thru | or funnel shape diameter-expanded from the front side of the sub-reflection mirror to the back side.

  FIG. 1 is a longitudinal sectional view of an essential part showing a first embodiment of a lamp with a reflector according to the present invention, and FIGS. 2A and 2B are a front view and a rear view of a sub-reflector. FIGS. 3A and 3B are rear views of the sub-reflecting mirror mounted on the arc tube of the high-pressure discharge lamp, and FIG. 3A shows the bottom portion of the sub-reflecting mirror as a sealing portion of the arc tube. FIG. 5B is a diagram showing a state in which the bottom portion is fixed to the sealing portion of the arc tube with a fixing material. In addition, parts common to the conventional lamp with the reflector shown in FIG. 8 will be described with reference to FIG.

The high-pressure discharge lamp 1 used in the lamp with a reflector of this example is, for example, a high-pressure mercury vapor discharge lamp with a rated lamp power of 150 W, and is disposed at the tip side of the electrode shaft 3 made of a high-purity tank stainless bar having a diameter of 0.3 mm. A pair of tungsten electrodes 2R and 2L wound with a coil 4 formed by closely winding a high-purity tungsten wire W having a diameter of 0.22 mm in two upper and lower layers are disposed in the light emitting portion 6 of the arc tube 5 made of a quartz glass tube. The electrodes are arranged so as to face each other with a distance between the electrodes of about 1.1 mm, and each electrode shaft 3 is fixed to a pair of sealing portions 7R and 7L formed on both sides of the light emitting portion 6. The light emitting section 6 is formed into a spheroid having a maximum outer diameter of about 10 mm, an average wall thickness of 2.3 mm, and an internal volume of about 85 mm ³ , and mercury is about 0.24 mg / mm ³ , bromine inside 1.9 × 10 ⁻⁴ μmol / mm ³ , and argon gas is sealed in about 2 × 10 ⁴ Pa.

  Further, as shown in FIG. 8, the high-pressure discharge lamp 1 has one sealing portion 7 </ b> R disposed on the opening 9 side of the concave reflecting mirror 8 and the other sealing portion 7 </ b> L on the bottom portion 10 side of the concave reflecting mirror 8. The reflector 8 is integrally attached so as to be disposed. Then, in the sealing portion 7R disposed on the opening 9 side of the concave reflecting mirror 8, the cylindrical bottom portion 16 in which the sub-reflecting mirror 11 shown in FIG. 2 is formed in a cylindrical shape emits light as shown in FIGS. The tube 5 is fitted to the sealing portion 7R of the tube 5 so as to be fitted.

  The sub-reflecting mirror 11 is made of a quartz reflecting mirror having a reflection effective diameter of 14 mm in which a dielectric sputter film forming a reflecting surface is formed on the front side of the cast-molded reflecting mirror base, and is attached to the sealing portion 7R of the arc tube 5. Ribs 17a, 17b, 17c and 17d extending from the front side to the back side of the sub-reflecting mirror are formed equiangularly at intervals of 90 ° on the inner peripheral surface of the bottom portion 16 to be fitted, and each of the ribs 17a to 17d is formed. By making contact with the outer peripheral surface of the sealing portion 7R, the sub-reflecting mirror 11 is coaxially mounted on the sealing portion 7R, and at the same time, the outer peripheral surface of the sealing portion 7R and the inner peripheral surface of the bottom portion 16 The gaps 18 are divided into four by the ribs 17a to 17d, and the gaps 18a, 18b, 18c, and 18d that pass from the front side to the back side of the sub-reflecting mirror 11 are formed as shown in FIG. It is like that.

That is, the ribs 17a to 17d formed on the inner peripheral surface of the bottom portion 16 of the sub-reflecting mirror 11 are
A plurality of gaps 18a to 18d that lead from the front side to the back side of the sub-reflecting mirror 11 are formed on the bottom portion 16 side, and at the same time, as positioning spacers that align the optical axes of the sub-reflecting mirror 11 and the arc tube 5 It has a function. Further, in order to reduce the temperature of the hot air generated between the light emitting part 6 of the arc tube 5 and the sub-reflecting mirror 11, a plurality of parts reaching the rear side of the sub-reflecting mirror 11 from the front end to the rear end of the bottom part 16. Are formed equiangularly at intervals of 45 °, for example.

  3A, the sub-reflecting mirror 11 having the bottom portion 16 externally fitted to the sealing portion 7R of the arc tube 5 transmits the light emitted from the light emitting portion 6 of the arc tube 5 to the center of the light emitting portion 6. The gap between the light emitting portion 6 and the light emitting portion 6 is appropriately adjusted so that the light can be reflected toward the bottom portion 16, and then, in the partial gaps 18 a and 18 c formed on the bottom portion 16 side, as shown in FIG. The fixing member 12 such as cement is filled, and the bottom portion 16 is fixed to the outer peripheral surface of the sealing portion 7R.

  In the lamp with a reflector configured as described above, a part of the convection generated when the lamp is heated and the airflow of the cooling air supplied by the cooling fan is formed on the bottom 16 side of the sub-reflector 11. Through the air gaps 18b and 18d, the air flows into the gap between the sub-reflecting mirror 11 and the light emitting portion 6 of the arc tube 5. As a result, the hot air generated in the gap is carried by the air flow and escapes outside the gap, so that the hot surface of the hot light stays in the gap and the outer surface of the light emitting unit 6 facing the sub-reflecting mirror 11. Is prevented from being overheated, and the risk of swelling and bursting due to overheating of the light emitting portion is eliminated.

  FIG. 4 is a longitudinal sectional view of an essential part showing a second embodiment of a lamp with a reflector according to the present invention, and FIG. 5A is a sub-reflection in which a bottom part is fitted around a sealing part of an arc tube of a high-pressure discharge lamp. FIG. 5B is a rear view of the sub-reflector in which a partial gap formed on the bottom portion side is filled with a fixing material and the bottom portion is fixed to the sealing portion of the arc tube. Thus, the lamp with a reflector of this example is formed on the bottom portion 16 side by collecting the air flow flowing toward the back side of the sub-reflection mirror 11 along the edge of the bottom portion 16 of the sub-reflection mirror 11. An annular projecting piece 19 for introduction into the gaps 18b and 18d is characterized in that it protrudes in the radial direction of the bottom portion 16, and the other configuration is the same as that of the lamp with a reflector of the first embodiment. is doing.

Reflector with the lamp of the present embodiment, the air flow F ₁ flowing toward the front side of the sub-reflecting mirror 11, is collected in the sub-reflecting mirror 11, the reflection mirror of the bottom portion 16 side formed gaps 18b, The air flow F ₂ introduced into the inner part 18 d and flowing toward the back side of the sub-reflecting mirror 11 is collected by the annular projecting piece 19 formed at the end edge of the bottom part 16, and is inserted into the gaps 18 b and 18 d. Therefore, even if the cooling means (not shown) installed in the lamp supplies cooling air from the front side or the back side of the sub-reflecting mirror 11, the cooling air A part of the air can flow through the gap between the sub-reflecting mirror 11 and the light-emitting portion 6 of the arc tube 5, and hot air can be reliably prevented from staying in the gap. The surface of the light emitting unit 6 facing the reflecting mirror 11 can be cooled. The annular protrusion 19 formed on the bottom portion 16 also functions as a heat radiating fin that lowers the temperature of the sub-reflecting mirror 11.

Further, when the air flows F ₁ and F ₂ collected by the sub-reflecting mirror 11 and the annular projecting piece 19 are introduced into the gaps 18 b and 18 d having a smaller diameter than the sub-reflecting mirror 11 and the annular projecting piece 19, the air gaps F ₁ and F ₂ are introduced. The flow velocity of the air flow passing through the interiors 18b and 18d is increased, and the bottom portion 16 of the sub-reflecting mirror 11 and the sealing portion 7R of the arc tube 5 are effectively cooled. The air flow F ₁ collected in the sub-reflecting mirror 11, by a narrow gap 18b, when introduced into the 18 d, venturi effect to draw the ambient air by negative pressure generated around the air flow, the secondary reflecting High-temperature hot air existing in the gap between the mirror 11 and the light-emitting portion 6 of the arc tube 5 is sucked into the gaps 18b and 18d, and is quickly discharged to the back side of the sub-reflecting mirror 11 through the inside. Therefore, the swelling and rupture due to overheating of the light emitting unit 6 are surely prevented.

  The annular projecting piece 19 formed on the bottom portion 16 of the sub-reflecting mirror 11 is reflected by the reflecting surface of the concave reflecting mirror 8 which is the main reflecting mirror, passes through the outside of the sub-reflecting mirror 11, and irradiates the irradiated object. When the concave reflecting mirror 8 of the main reflecting mirror is an ellipsoidal reflecting mirror, the maximum diameter portion of the sub-reflecting mirror 11 and the secondary focus of the concave reflecting mirror 8 are connected. When the concave reflecting mirror 8 is a parabolic reflecting mirror, it is formed with an outer diameter equal to or smaller than the maximum diameter portion of the sub-reflecting mirror 11.

  FIG. 6 is a longitudinal sectional view of an essential part showing a third embodiment of the lamp with a reflector according to the present invention, and FIG. 7A is a sub-reflection in which the bottom part is externally fitted to the sealing part of the arc tube of the high pressure discharge lamp. FIG. 7 (b) is a rear view of the sub-reflector in which a part of the gap formed on the bottom portion side is filled with a fixing material and the bottom portion is fixed to the sealing portion of the arc tube. Thus, the reflector-equipped lamp of this example is characterized in that the bottom portion 16 of the sub-reflecting mirror 11 is formed into a trumpet shape or a funnel shape whose diameter is increased from the front side to the back side of the sub-reflecting mirror 11. . The maximum diameter of the bottom portion 16 is selected so as not to block the light that passes through the outside of the sub-reflecting mirror 11 and is irradiated on the irradiated object.

Thus if the bottom portion 16 of the sub-reflecting mirror 11 is formed into a shape enlarged toward the rear side from the front side of the sub-reflecting mirror 11, the air flow F ₂ flowing toward the rear side of the sub-reflecting mirror 11 More air can be introduced into the gaps 18b and 18d formed on the bottom 16 side, and the pressure loss in the gaps 18b and 18d is reduced, so that it can be introduced from either the front side or the back side of the sub-reflecting mirror 11. Since air easily flows in and out, the velocity of the air flow passing through the gaps 18b and 18d is faster than in the second embodiment, and at the same time, the Venturi effect is enhanced, so that the space between the sub-reflecting mirror 11 and the light emitting portion 6 of the arc tube 5 It is possible to more reliably prevent high-temperature hot air from staying in the gaps, and the effect of cooling the outer surface of the light emitting unit 6 to lower the surface temperature is also enhanced.

  The sub-reflecting mirror 11 is not limited to a quartz reflecting mirror, and may be a metallic reflecting mirror that has better heat dissipation than quartz. Further, if an inorganic cement containing aluminum nitride having excellent thermal conductivity is used as the fixing material 12 for fixing the bottom portion 16 of the sub-reflecting mirror 11 to the sealing portion 7R of the arc tube 5, the light emitting portion 6 is more overheated. It can be surely prevented. In the embodiment, the four ribs 17a to 17d are formed at 90 ° intervals on the inner peripheral surface of the bottom portion 16 of the sub-reflecting mirror 11. For example, the ribs are formed at 120 ° intervals. When the size of each void formed is increased, the air permeability is improved. Moreover, the radiation fin 20 as shown to a 1st Example can be formed also in the subreflector 11 which concerns on a 2nd and 3rd Example.

  The present invention contributes to improving the quality and reliability of a lamp with a reflector used as a light source for a liquid crystal projector or a projection TV.

The longitudinal cross-sectional view of the principal part which shows 1st Example of the lamp with a reflector which concerns on this invention Front and rear views of a sub-reflector used in the lamp of FIG. The rear view which shows the mounting state of the subreflector used for the lamp | ramp of FIG. The longitudinal cross-sectional view of the principal part which shows 2nd Example of the lamp with a reflector which concerns on this invention The rear view which shows the mounting state of the subreflector used for the lamp | ramp of FIG. The longitudinal cross-sectional view of the principal part which shows 3rd Example of the lamp with a reflector which concerns on this invention The rear view which shows the mounting state of the subreflector used for the lamp | ramp of FIG. Longitudinal sectional view showing a conventional lamp with a reflector

Explanation of symbols

1 .... High pressure discharge lamp 2R ... Electrode 2L ... Electrode 3 .... Electrode shaft 5 .... Aluminum tube 6 .... ... Light emitting part 7R ... Sealing part 7L ... Sealing part 8 ... Concave reflector (main reflector)
9... Concave mirror opening 10... Concave mirror bottom 11 Sub reflector 12 Adhering material 16 ························································ Ribs 18a to 18d

Claims (4)

A high-pressure discharge lamp in which a pair of electrodes are arranged opposite to each other in the light emitting portion of the arc tube, and a pair of sealing portions for fixing the electrode shafts of the electrodes on both sides of the light emitting portion is formed. It is arranged on the opening side of the concave reflecting mirror, and the other sealing part is attached integrally with the reflecting mirror so as to be arranged on the bottom part side of the concave reflecting mirror. In a lamp with a reflecting mirror mounted with a sub-reflecting mirror that reflects light radiated from the light-emitting unit toward the opening of the concave reflecting mirror toward the light-emitting unit, the sub-reflecting mirror has its bottom portion sealed on the one side. A lamp with a reflector, wherein the lamp is fitted on the sealing portion by being externally fitted to a stop portion, and a gap is formed on the bottom portion side so as to communicate from the front side to the back side of the sub-reflector. The bottom portion of the sub-reflecting mirror is formed in a cylindrical shape, and a plurality of ribs extending from the front side to the back side of the sub-reflecting mirror are formed at intervals on the inner peripheral surface of the cylindrical bottom portion, Each of these ribs is in contact with the outer peripheral surface of the one sealing portion, and the sub-reflecting mirror is coaxially attached to the sealing portion, and the outer peripheral surface of the sealing portion and the cylindrical bottom portion A plurality of gaps are formed between the inner peripheral surface and the sub-reflecting mirror from the front side to the back side, and a part of the gap is filled with a fixing material that fixes the cylindrical bottom portion to the sealing portion. The lamp with a reflector according to claim 1. The lamp with a reflecting mirror according to claim 2, wherein an annular projecting piece protruding in a radial direction of the bottom portion is formed along an edge of the cylindrical bottom portion. The lamp with a reflecting mirror according to claim 2, wherein the cylindrical bottom portion is formed in a shape whose diameter is increased from the front side to the back side of the sub-reflecting mirror.

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