JP3573158B2 - Light source device and projector using the same - Google Patents

Description

  The present invention relates to a light source device for a projector that projects video and character data on a screen, and a projector using the same.

  2. Description of the Related Art In recent years, projectors such as a liquid crystal display have made remarkable progress in technology, and many performance improvements such as high brightness, small size and light weight have been achieved.

  There has been a strong demand for lamps, which are light source units of projection type video equipment such as data projectors and projection TVs, to have higher brightness, and in recent years the arc area is smaller than that of conventional metal halide lamps which have been the mainstream until now. Ultra-high pressure mercury lamps, which have high light use efficiency because of their proximity to light sources, have been put to practical use and are being installed in various projectors.

  Ultra-high pressure mercury lamps emit high-pressure mercury inside the arc tube by arc discharge. It raises the level and emits light with wavelengths in the visible range.

  Therefore, since the pressure reaches about 150 to 200 atm during lighting, the arc tube formed of transparent quartz glass is thicker than a metal halide lamp so as to withstand the internal pressure. Also, at the end of the lamp life, the arc tube has a very high probability of thermal stress destruction due to blackening and devitrification. Therefore, when the arc tube is damaged as disclosed in Patent Documents 1 and 2, It has been proposed to provide a glass plate for explosion proof at the front opening of the reflector or to provide a translucent cylinder surrounding the arc tube so that the glass fragments and the enclosed mercury do not scatter inside the projector. ing.

In addition, the thickness of the glass, which is the base material of the reflecting mirror, is adjusted so that the reflecting mirror itself is destroyed by the impact when the shard of the arc tube collides with the reflecting mirror, and the shard of the arc tube and the shard of the reflecting mirror do not scatter outside. The reflector is hardly broken by being formed thick or using crystallized glass having relatively high strength as a base material of the reflector. In addition, reflecting mirrors have good mass productivity, excellent surface roughness accuracy on the inner surface of the coating of the reflective film, and can have heat resistance up to several hundred degrees from the state of use, and may be deformed at high temperatures and impair optical characteristics. Glass is generally used as a base material because it is required to have a low thermal expansion property or the like.
JP-A-5-251504 JP-A-8-329725

  However, the arc tube of an ultra-high pressure mercury lamp is formed thick, and its internal temperature is originally high, and the internal temperature of the lamp unit tends to increase due to the hermetic structure of explosion-proof glass. In order to prevent scattered to the outside, the thickness of the reflector is made thicker, or the base material of the reflector is made of crystallized glass that absorbs a large amount of the radiant light of the lamp. The heat radiated from the arc tube is trapped inside, and a heat problem arises in that the temperature inside the lamp unit increases. In the case of metal halide lamps, the arc tube can be directly cooled by a fan.However, in the case of ultra-high pressure mercury lamps, the explosion-proof structure of the lamp unit is difficult, so measures against this heat problem are extremely important. Has become.

  When the temperature of the arc tube rises, the tips of a pair of electrodes made of tungsten melt and the shape and spacing of the electrodes change, deteriorating the electrodes, and melting the tungsten into an arc tube made of transparent quartz glass. It adheres to the inner wall and raises the temperature of that part due to radiant heat, causing blackening of the arc tube and increasing the temperature of the arc tube itself, which promotes crystallization of quartz glass, and a part of the arc tube becomes white. And the temperature of that part rises due to radiant heat, causing thermal stress destruction of the arc tube, destruction of the arc tube, and deterioration of the weld between the molybdenum foil and the lead wire at the side tube end of the arc tube due to oxidation. Problems arise.

  In particular, with respect to blackening and devitrification, the probability that the arc tube is destroyed is increased. Therefore, in order to prevent the arc tube from being destroyed, it is necessary to lower the temperature inside the lamp unit.

  In addition, with respect to the reflector and explosion-proof glass, if the temperature exceeds the allowable temperature exceeding the strain point or transition point, distortion occurs during the temperature change process at the time of turning on and off, leading to thermal stress destruction, and the deposited reflective film There is also a problem that peeling occurs due to the difference in thermal expansion coefficient between the substrate and the glass as the base material.

  In view of the above problems, an object of the present invention is to provide a high-pressure mercury lamp unit without excessively increasing the temperature inside the unit, when the arc tube is damaged, the glass fragments and the enclosed mercury scatter outside. Is provided at a low cost with a simple configuration.

  In order to solve this problem, a light source device according to the present invention has a discharge lamp having an outer shape formed of glass and having an arc tube that emits light by discharge, and a curved surface that reflects light of the arc tube to a front surface, A concave reflector having glass as a base material provided with a reflective film on an inner surface of a curved surface, and a transparent partition provided in a reflector front opening for transmitting light reflected by the reflector; On the outer wall surface of the curved surface of the mirror, provided is a sheet or film-like heat-resistant scattering prevention means for preventing scattering of fragments due to destruction of the reflecting mirror, and the scattering prevention means transmits visible light or infrared light. It is characterized by having translucency.

  In addition, the present invention provides a projector including the light source device described above, in which a rise in the temperature of the lamp unit is suppressed, and even if the reflector is damaged due to damage to the arc tube, fragments thereof may be scattered inside the projector, No special measures are required, since it is prevented from being scattered outside of the projector through the ventilation opening.

  According to the light source device of the present invention, when the arc tube is damaged, even if the reflector is broken by the fragments, the fragments can be prevented from scattering to the outside by the scattering prevention means, and the scattering prevention means is visible. Since the scatter prevention device transmits the light radiated from the lamp by absorbing light or infrared light, the scattering prevention device absorbs the scattered light and transmits the temperature of the inner and outer walls of the curved surface of the reflecting mirror. , The temperature of the entire lamp unit including the arc tube can be prevented from rising.

  In addition, the present invention provides a projector including the light source device described above, in which a rise in the temperature of the lamp unit is suppressed, and even if the reflector is damaged due to damage to the arc tube, fragments thereof may be scattered inside the projector, The effect is obtained that scattering to the outside of the projector through the ventilation hole is prevented.

  Hereinafter, first and second embodiments of the light source device of the present invention will be described with reference to the drawings.

  First, FIG. 1 is a perspective view of a light source device according to a first embodiment of the present invention as viewed from behind, FIG. 2 is an internal perspective view cut along a vertical section to show the internal configuration, and FIG. FIG.

  FIG. 4 is a longitudinal sectional view of a light source device according to a second embodiment of the present invention, and FIG. 5 is a schematic layout diagram of a projector using the light source device of the present invention.

  First, a light source device according to a first embodiment of the present invention will be described with reference to FIGS.

  1, 2 and 3, a lamp unit 9 includes a reflecting mirror 1 having a concave surface formed by a curved surface 8 such as an elliptical surface or a parabolic surface, and an inner portion of the reflecting mirror 1 at an opening of the reflecting mirror 1. It comprises a transparent explosion-proof glass 2 provided to hermetically seal and an ultra-high pressure mercury lamp 10 provided at the center of the optical axis inside the reflecting mirror 1.

  The reflecting mirror 1 has a reflecting film 6 made of hard glass or Pyrex (registered trademark) glass formed of tantalum pentoxide, silicon dioxide, or the like in order to reflect the light of the ultra-high pressure mercury lamp 10 to the front opening. The inner surface of the curved surface 8 of the mirror base material 7 is vapor-deposited and coated, and after adjusting the ultrahigh-pressure mercury lamp 10 to the center position of the optical axis, the structure is fixed to the neck 12 with a filling adhesive 11 such as cement.

  The ultra-high pressure mercury lamp 10 is an AC type discharge lamp. The arc tube 3 is formed of transparent quartz glass, and a pair of electrodes formed of tungsten and facing each other at a predetermined distance along the optical axis. 14A, 14B, electrode lead-out lines 15A, 15B, and a base 13 for connecting the electrode lead-out line 15A to a power source.

  The inside of the arc tube 3 is a closed space of an elliptical sphere filled with mercury, halogen gas and the like, a tube portion 4 having a pair of electrodes 14A and 14B disposed in the center, and a side tube for sealing both ends thereof. 5A and 5B.

  On the outer wall surface of the curved surface 8 of the reflecting mirror 1, a scattering prevention film 17 having heat resistance is provided in a direction perpendicular to the optical axis with respect to the curved surface 8 of the reflecting mirror 1 from the tube end 16 on the side tube 5B side. An extended straight line is provided on the entire outer surface of the curved surface 8 of the reflecting mirror 1 in a range from an intersection 20 intersecting the outer wall surface of the reflecting mirror 1 to the rear neck portion 12.

  The shatterproof film 17 has a property of transmitting a part of visible light and infrared light, has an adhesive property on one side, and is bonded to a curved surface 8 of the reflecting mirror 1 and an outer wall surface. , And a polyimide film 19 as a base material, and the upper limit of the heat resistance temperature is 250 ° C.

  The operation and effects of the light source device according to the first embodiment of the present invention described above will be described below.

  When an arc discharge is caused between the electrodes 14A and 14B to cause the lamp to emit light, the vapor pressure of mercury and halogen gas increases with an increase in the temperature inside the bulb 4, and the internal pressure of the bulb 4 increases. This internal pressure reaches about 150 to 200 atm in an equilibrium state at the time of lighting. Therefore, at the end of the life of the lamp in which the arc tube 3 is blackened and devitrified, there is a very high possibility that the arc tube 3 is destroyed by thermal stress due to the internal pressure.

  Even if the arc tube 3 is damaged and the fragments of the arc tube 3 collide with the reflecting mirror 1 and the reflecting mirror 1 is destroyed by any shock, the scattering prevention film 17 is applied to the reflecting mirror 1 by the adhesive layer 18. Since the reflector 1 is adhered to the outer wall surface, even if the reflector 1 is disassembled into a plurality of glass pieces, the scattering prevention film 17 does not impair the original shape of the reflector 1. An excellent light source device that does not scatter to the outside can be realized with a simple configuration.

  Since the polyimide film 19 and the adhesive layer 18 of the shatterproof film 17 have sufficient heat resistance, they do not deteriorate even when the lamp is turned on for a long time, and are provided on the outer wall surface of the reflecting mirror. There is no problem at all, and since the scattering prevention film 17 has a light transmitting property of transmitting visible light or infrared light, the scattering prevention film 17 transmits radiation emitted from a lamp. By absorbing this, it is possible to prevent the temperature of the inner and outer walls of the curved surface 8 of the reflecting mirror 1 from rising, and prevent the temperature of the entire lamp unit 9 including the ultra-high pressure mercury lamp 10 from rising.

  Further, as the angle at which the glass shards of the arc tube 3 collide with the reflecting film 6 of the reflecting mirror 1 is nearly perpendicular, the impact energy given by the glass shards of the arc tube 3 to the reflecting mirror 1 increases. In the portion provided with the shatterproof film 17, the impact energy given by the glass fragments of the arc tube 3 to the reflecting mirror 1 is much larger than in the portion not provided with the shatterproof film 17. This is the location that is most likely to occur. Accordingly, since the outer wall of the reflecting mirror 1 is not excessively covered with the scattering prevention film 17 up to the portion where the possibility of the breaking of the reflecting mirror 1 is low, the temperature inside the lamp unit 9 should be excessively increased from this point as well. There is no.

  Further, as a second embodiment of the present invention, a scattering prevention sheet 21 made of silicon rubber is made to adhere to the outer wall surface of the reflecting mirror 1 by heat-shrinking. Even if 1 is broken, not only can the reflecting mirror 1 lose its original shape and the glass fragments of the arc tube 3 not be scattered to the outside, but also because the reflecting mirror 1 is not bonded and fixed to the reflecting mirror 1, There is an advantage that it can be easily disassembled and the waste can be easily separated.

  Next, a projector using the light source devices of the first and second embodiments will be described with reference to FIG. The projector 22 in the present embodiment focuses and irradiates a light beam from the lamp unit 9 to a light valve unit 24 having a liquid crystal panel, a DMD element, and the like by an illumination optical system unit 23, and causes the light valve unit (not shown) to condense the light beam. The image data formed in advance is enlarged and projected on a screen through the projection optical system unit 25. Further, the cooling configuration inside the housing of the projector 22 is configured such that the cooling air sucked from the ventilation port 27 by the cooling fan 26 is blown to the entire power supply unit 28 and the lamp unit 9 to cool the power supply unit 28 and the lamp unit 9. The heat energy to be discharged is discharged from the ventilation port 30 by the cooling fan 29. Here, the lamp unit 9 is located in the vicinity of the ventilation port 30 in order to improve the cooling efficiency, and the ventilation port 30 is located on the housing surface of the projector 22 so that the light emission of the lamp unit 9 is hard to be seen from outside the projector 22. It has a louver with a slit in the diagonal direction.

  In this projector 22, even if the arc tube 3 is damaged, glass and the like do not scatter outside the lamp unit 9, so that the arc tube 3 and the reflecting mirror are located between the lamp unit 9 and the ventilation port 30. It is not necessary to provide a filter for preventing one glass piece from scattering outside the projector 22.

  Therefore, in the projector according to the embodiment of the present invention, the lamp unit 9 can be provided in the vicinity of the ventilation port 30 without providing a scattering prevention filter that increases the ventilation resistance, and thus the lamp unit 9 and the projector 22 as a whole are provided. Cooling efficiency can be improved.

  As described above, by adopting the configuration of the light source device according to the first embodiment and the second embodiment of the present invention, the internal temperature of the ultra-high pressure mercury lamp unit becomes excessively high, and the cooling of the projector 22 is stopped. Increasing the size of the fan 26 not only increases the size of the projector 22 and prevents the noise level from being increased, but also, in the event that the arc tube 3 is damaged, glass fragments and enclosed mercury are discharged to the outside. A highly reliable projector light source device that prevents scattering can be realized at a low cost with a simple configuration.

  As described above, according to the light source device according to the embodiment of the present invention, by providing the scattering prevention means on the outer wall surface of the curved surface of the reflecting mirror made of glass, the arc tube bursts, and the glass of the arc tube is broken. An excellent light source device that does not scatter the fragments to the outside even when the fragments collide with the inner surface of the reflector and breaks the reflector can be realized with a simple configuration. Since the scattering prevention means has sufficient heat resistance, there is no problem even if it is provided on the outer wall surface of the reflecting mirror.

  Further, since the scattering prevention means has a light transmitting property of transmitting visible light or infrared light, the scattering prevention means absorbs the radiation light radiated from the lamp because it transmits the radiation light. There is an effect of preventing the temperature of the inner and outer walls of the reflecting mirror from being increased due to the rise in the temperature of the inner and outer walls of the curved surface of the reflecting mirror.

  In addition, since the entire surface of one side of the scattering prevention means has adhesiveness and is adhered to the outer wall surface of the reflecting mirror, when the reflecting mirror is broken, the reflecting mirror is disassembled into a plurality of glass pieces and the reflecting mirror is separated. The effect of preventing the original shape from being damaged is large.

  In addition, the scattering prevention means is formed of silicone rubber, and the scattering prevention sheet is thermally contracted to adhere to the outer wall surface of the reflecting mirror. Not only can the effect of preventing the reflective mirror from being disassembled and disturbing the original shape of the reflector is great, but also the parts can be easily disassembled because they are not adhesively fixed to the reflector. There is a merit that it can be easily performed.

  In addition, a straight line extending in a direction perpendicular to the optical axis from the front end of the bulb of the arc tube to the curved surface of the reflecting mirror has an outer wall portion rearward from a position where the straight line intersects the outer wall surface of the reflecting mirror. Since the glass fragments of the tube give the greatest impact energy to the reflector and are the most likely to cause the reflector to break, the scattering prevention means must be changed to the entire outer wall of the reflector behind the intersection. By providing the peripheral portion, the outer wall of the reflecting mirror is not excessively covered with the scattering prevention means, and the effect of not excessively increasing the temperature inside the lamp unit can be improved.

  Also, even if the arc tube is damaged, glass and the like do not scatter outside the lamp unit, so that the lamp unit cools the inside of the projector housing without providing a scattering prevention filter that increases the ventilation resistance. Therefore, the cooling efficiency of the lamp unit and the projector as a whole can be improved because it can be provided in the vicinity of the ventilation opening for inflow or outflow of the cooling air.

  INDUSTRIAL APPLICABILITY The present invention is extremely useful as a light source device for a projector that projects video and character data on a screen and a projector using the same.

1 is a perspective view of a light source device according to a first embodiment of the present invention. Internal perspective view cut along a longitudinal section to show the internal configuration. Longitudinal sectional view of the light source device Longitudinal sectional view of a light source device according to a second embodiment of the present invention. Schematic layout diagram of a projector using the light source device of the present invention

Explanation of reference numerals

REFERENCE SIGNS LIST 1 reflector 2 explosion-proof glass 3 arc tube 4 tube 8 curved surface 9 lamp unit 10 ultra-high pressure mercury lamp 12 neck 13 base 16 tube end 17 shatterproof film 20 intersection point

Claims (2)

A discharge lamp having an arc tube whose outer shape is formed of glass and emits light by discharge,
A concave reflecting mirror having a curved surface for reflecting the light of the arc tube to the front surface, and having glass as a base material provided with a reflective film on the inner surface of the curved surface;
Along with sealing the reflecting mirror, having a transparent partition provided in the reflecting mirror front opening that transmits light reflected by the reflecting mirror,
Provided on the outer wall surface of the reflecting mirror, a sheet or film-like heat-resistant scattering preventing means for preventing scattering of fragments due to the destruction of the reflecting mirror,
The light source device, wherein the scattering prevention means has a light-transmitting property to transmit visible light or infrared light. A projector comprising the light source device according to claim 1.

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