JP3931529B2 - Light source unit - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a light source unit, and more particularly to a light source unit used for a backlight for a liquid crystal projector or a DLP (digital light processor).
[0002]
[Prior art]
The projector device is required to project an image uniformly on a rectangular screen with sufficient brightness, efficiency, and color rendering. For this reason, a metal halide lamp in which mercury or a metal halide is enclosed is used as a light source. Recently, further miniaturization and point light sources have been promoted, and lamps having a very small distance between electrodes have been put into practical use.
[0003]
Against this background, recently, instead of metal halide lamps, high-pressure mercury lamps have been proposed in which the mercury vapor pressure during lighting is hundreds of tens of atmospheres or more. This is intended to suppress (narrow down) the spread of the arc by increasing the mercury vapor pressure at the start of lighting, and to further improve the light output. For example, Japanese Patent Application Laid-Open No. 2-148561. And JP-A-6-52830.
[0004]
FIG. 2 shows a light source unit using such a discharge lamp 10 and a concave reflecting mirror 20. A concave reflecting mirror 20 is provided so as to surround the both-end sealed discharge lamp 10. A base member 30 is attached to the neck portion 21 of the concave reflecting mirror 20. The base member 30 has a two-stage cylindrical shape including a lamp holding portion 31 and a mirror fixing portion 32. One end of the discharge lamp 10 is fixed and held to the lamp holding portion 31 with an adhesive 41, and the mirror fixing portion 32 is fixed to the neck portion 21 of the concave reflecting mirror 20 with an adhesive 42. A light-transmitting front glass 50 is attached to the front opening of the concave reflecting mirror 20. The front glass 50 prevents the fragments from scattering when the discharge lamp 10 bursts. This is because when the discharge lamp 10 is a metal halide lamp or the above-described high-pressure mercury lamp, the inner pressure of the arc tube rises to about 20 to 150 atm during lighting, and the arc tube deteriorates after the discharge lamp is lit for a long time. It is caused by. A device in which the front opening of the concave reflecting mirror 20 is sealed with a front glass 50 is disclosed in, for example, Japanese Patent Laid-Open No. 5-251054.
[0005]
By the way, such a light source unit is remarkably required to be downsized. In particular, the light source unit for a projector apparatus is greatly affected by the fact that the projector apparatus itself is being downsized to B5 size, for example. An example of a reflecting mirror is a front opening size of 50 × 60 mm, a distance from the front opening to the neck tip of 60 mm, and an example of a discharge lamp is a discharge vessel internal volume of 250 mm ³ and an interelectrode distance of 1.5 mm. There is a strong demand for downsizing.
[0006]
On the other hand, since a high light output is required from the discharge lamp, the outer surface of the discharge vessel and the inner surface of the concave reflecting mirror become extremely hot. For this reason, it is necessary to flow cooling air in order to effectively cool the outer surface of the discharge vessel and the inner surface of the concave reflecting mirror. In other words, the light source unit needs to be provided with a front glass for the above-mentioned reasons, but on the other hand, the concave reflector cannot be completely sealed, and for this reason, it is used for cooling to flow cooling air into the reflector. It is necessary to provide an opening.
That is, the flow path is sucked into the reflecting mirror 20 through the opening 22 near the front surface of the concave reflecting mirror 20 and flows through the reflecting mirror 20 as shown in FIG. The air is exhausted or vice versa, and is sucked from the neck of the reflecting mirror, passes through the inside of the reflecting mirror, and is exhausted from the vicinity of the front opening.
For this reason, as shown in the figure, vent holes 22 and 23 are required in the front opening and the neck of the concave reflecting mirror.
[0007]
With such a structure, the light source unit has a mechanism for sufficiently cooling the discharge lamp 10 inside the reflecting mirror 20, but if the discharge lamp 10 is ruptured, the fragments are vent holes 22, 23. This causes the problem of being discharged from. In particular, the light source unit incorporated in the projector apparatus is extremely difficult to process fragments in combination with the downsizing of the apparatus as described above. The ventilation hole 22 on the front opening side of the reflecting mirror 20 is relatively easy to deal with in relation to the surrounding space and the like, but the neck side ventilation hole 23 of the reflecting mirror 20 is structurally complex and has a fragment. The fact is that once the water is discharged from the vents, the subsequent processing becomes difficult.
[0008]
[Problems to be solved by the invention]
The problem to be solved by the present invention is to provide, in a concave reflecting mirror having a vent hole, a structure that prevents a broken piece from being scattered by a simple means in the event that a discharge lamp inside the broken reflector breaks. It is.
[0009]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided a high pressure mercury lamp having a pair of electrodes opposed to a light emitting portion made of quartz glass having sealing portions formed at both ends, a concave reflecting mirror covering the high pressure mercury lamp, a high pressure mercury In a light source unit comprising a base member that holds one end of the lamp and is fixed on the outer surface of the neck of the concave reflecting mirror, and a front glass that substantially airtightly closes the front opening of the concave reflecting mirror, the base member and the neck of the concave reflecting mirror A cooling air opening that is spatially connected to the inside of the reflecting mirror is formed between the base member and a base ring portion that is mounted in contact with the lamp holding portion and the cooling air opening. A protective mesh member including a mesh portion provided so as to be closed is attached .
[0010]
Further, the base member has a two-stage cylindrical shape including a lamp holding portion and a mirror fixing portion, and the base ring portion of the protective mesh member is in contact with the side wall surface of the mirror fixing portion of the base member. It is characterized by. Further, the protective mesh member has a tongue-shaped fixing piece extending in a direction of detachment from the base member. Further, the tongue-like fixing piece is fixed to an adhesive filling opening provided in the base member. Further, the high-pressure mercury lamp is characterized in that 0.15 mg / mm ³ or more of mercury is enclosed.
[0011]
According to the above configuration, the high pressure discharge lamp can be cooled satisfactorily, and the protective mesh member can secure the arc tube fragments even in the event of a breakage or the like. .
In addition, by configuring the protective mesh member with a plate-like member having a C-shaped cross section, the protective mesh member can be easily attached and detached with a simple structure, and this protective mesh member can be used as a base. It can be brought into close contact with the member.
Furthermore, since the protective mesh member has a tongue-like fixing piece extending in the direction of detachment from the base member, the fixing piece can be locked in a hole or a recess provided in the base, and the insertion work is easy. Desorption is difficult, and the net member can be prevented from undesirably moving when the light source unit is used.
Furthermore, the tongue-shaped fixing piece is fixed and locked to the adhesive filling opening provided in the base member, so that it is not necessary to provide a special recess.
In addition, the high-pressure mercury lamp is sealed with 0.15 mg / mm ³ or more of mercury, so that high output and high color rendering properties can be obtained. Effective cooling and possible damage can be dealt with well.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a light source unit of the present invention. The light source unit has a short arc type high-pressure mercury lamp 10 and concave reflected light 20, and the lamp 10 includes a light emitting portion 11 and sealing portions 12 at both ends. The light emitting unit 11 has a pair of electrodes and is filled with mercury and a rare gas. A metal foil welded to the electrode is embedded in the sealing portion 12.
The discharge lamp may be a direct current lighting type or an alternating current lighting type.
[0013]
As an example of the mercury lamp 10, the amount of enclosed mercury is 0.16 mg / mm ³ , and argon gas is enclosed as a rare gas at a pressure of 10 KPa. Moreover, the distance between electrodes is 1.5 mm. The discharge vessel has an internal volume of 260 mm ³ , a rated voltage of 82 V, and a rated power consumption of 200 W. Of course, the numerical examples are not limited to these, but in order to use a short arc type high-pressure mercury lamp as a light source lamp for a projector apparatus, mercury may be contained in an amount of 0.15 mg / mm ³ or more. preferable.
[0014]
The concave reflecting mirror 20 is made of glass, for example, borosilicate glass, and the front opening has an inner diameter of about 120 mm. The reflecting surface of the concave reflecting mirror 20 is a rotating curved surface, and a vapor deposition film such as titania silica having excellent reflection characteristics is formed on the surface thereof.
A neck portion 21 is formed at the apex of the concave reflecting mirror 20, and one sealing portion 12 b of the discharge lamp 10 is inserted. The tip of the sealing part 12 b is fixed to the lamp holding part 31 of the base member 30 with an adhesive 41. Similarly, the mirror fixing portion 32 of the base member 30 is fixed to the neck portion 21 of the reflecting mirror 20 with an adhesive 42. The axis of the discharge lamp 10 coincides with the optical axis of the concave reflecting mirror 20, and the arc bright spot formed between the electrodes formed at the time of lighting is positioned at the first focal point of the concave reflecting mirror 20. Thus, the base member 30 is fixed.
[0015]
The front opening of the concave reflecting mirror 20 is covered with a glass plate 50 made of, for example, borosilicate glass so that, in the unlikely event that the discharge lamp 10 is ruptured, the fragments are not scattered from the front opening. The base member 30 has a shape as shown in FIGS. 4 and 5, which will be described later, and the lamp holding portion 31 has a cylindrical shape, and the sealing portion 12 of the discharge lamp 10 or the sealing portion is contained therein. A base attached to the part is inserted and fixed with an adhesive as described above. The mirror fixing portion 32 has a shape obtained by partially cutting a cylindrical shape, and when the reflecting mirror 20 is bonded, the notched portion 33 becomes an opening for cooling air described later. The base member 30 is made of ceramics such as alumina, for example.
[0016]
A cooling air opening 22 for cooling the inside of the reflecting mirror is provided in the vicinity of the front of the concave reflecting mirror 20. Further, as shown in FIG. 2, a cooling air opening (23) is also provided on the neck side of the reflecting mirror 20. By these two openings, the cooling air flows from one opening and is discharged from the other opening, so that the cooling air flows well inside the reflecting mirror 20 and cools the inner surface of the discharge lamp 10 and the reflecting mirror 20. Can do. The opening 22 is not limited to the case where the opening 22 is provided in the reflecting mirror, and may be provided as a gap between the front opening edge of the reflecting mirror 20 and the front glass 50, or the opening of the front glass 50 may be provided. Good.
[0017]
Here, the light source unit of the present invention is characterized in that a protective mesh member 60 is provided in the cooling air opening 23. As will be described in detail in FIGS. 6 to 10, the protective mesh member 60 is provided so as to close the base ring portion 61 mounted in contact with the lamp fixing portion 31 of the base member 30 and the cooling air opening 23. The mesh portion 62 is formed. Protective net member 60 is made of for example stainless steel, the opening of the order of area 4 mm ² are found provided. Note that the openings of the mesh portion 62 may have a lattice shape as shown in FIG. 6, a round hole shape as shown in FIG. 7, or a mesh shape as shown in FIG. Further, the opening area or the like is sufficient if it can sufficiently capture the fragments of the discharge lamp. Furthermore, the opening area be those that inhibit the cooling of the lamp must not, must in some extent to the total area of the entire aperture. In other words, one opening area is preferably small, but the total area of the entire opening is required to some extent. One opening area is required to be 2.8 mm or less diagonally in the case of a lattice-shaped opening, 2.8 mm or less in the case of a round hole-shaped opening, and 2.8 mm or less in the case of a mesh-shaped opening. This is based on the fact that the inventor has intensively studied and found that a light source unit used in such a projector apparatus is often about Φ3.0 mm, and that if it is smaller than this, there is no practical problem. . Further, the total area of the openings needs to be 60 mm ² or more. This has also been found by the inventor in the relationship with cooling of the discharge lamp after extensive studies.
[0018]
By providing the protective mesh member 60 so as to block the cooling opening 23 in this way, even if the discharge lamp 10 is ruptured or the like, the fragments are scattered and discharged from the opening 23 to be scattered inside the projector apparatus. Can be prevented satisfactorily. On the other hand, since the light source unit is provided with a cooling mechanism, it is possible to reduce both the size of the light source unit and the light output of the discharge lamp.
[0019]
FIG. 3 shows a cross-sectional view taken along the line AA ′ of the light source unit shown in FIG. Base members 30 and cooling air openings 23 are alternately formed. In the opening 23, there is a mesh portion 62 of the protective mesh member 60. A space 70 connected to the reflecting mirror 20 is formed around the sealing portion 12b.
Then, cooling air as shown by arrows in the figure flows from the protective mesh member 60.
[0020]
The base ring portion 61 of the protective mesh member 60 may not be circular as shown in FIGS. 6 to 8, and may be a C-shaped plate member having a notch in a part as shown in FIG. 9. Good. In this case, the protective mesh member 60 can be brought into close contact with the base member 30 and the positional relationship with the cooling opening of the mesh portion 62 can be ensured, and the protective mesh member 60 can be attached and detached. It has the advantage of being easy to do. The shape of the base ring portion 61 is not limited to a circular shape or a C shape, but may be a structure in which both ends overlap, for example, as shown in FIG.
[0021]
Here, as shown in FIGS. 6 to 9, the protective mesh member 60 is provided with a tongue-like fixing piece 63 on the base ring portion 61. The tongue-shaped fixing piece 63 extends in a direction in which the protective mesh member 60 is attached to and detached from the base member 30. For example, when the tongue-shaped fixing piece 63 is attached to the base member 30, it can be locked in the hole 34 provided in the base member 30. it can. In other words, when the protective mesh member 60 is inserted into the base member 30, it can be easily performed, but once the fixing piece 63 is locked in the hole 34, the protective mesh member 60 is firmly fixed, for example, moving the projector device or the like. If you do, you will not move accordingly. The fixed piece 63 is preferably slightly bent inward.
[0022]
Furthermore, the structure of the tongue-shaped fixing piece 63 is not limited to the shape protruding from the base ring portion 61 as shown in FIGS. 6 to 9, but a part of the ring portion 61 is formed as shown in FIG. It can also be formed by bending. As shown in FIG. 5, the hole of the base member 30 with which the tongue-shaped fixing piece 63 engages may have a groove-like shape, and any structure that can be engaged as a recess is sufficient.
[0023]
The base member 30 and the lamp sealing portion are fixed with an adhesive, but the base member 30 may be provided with a filling opening for filling the adhesive. Specifically, after the lamp sealing portion is inserted into the lamp fixing portion 31 of the base member 30, an adhesive is filled from the filling opening to bond them together. Then, by using the filling opening for the tongue-like fixing piece 63 , it is not necessary to provide a dedicated hole or recess in the base member 30.
[0024]
【The invention's effect】
According to the first aspect of the present invention, there is provided a high pressure mercury lamp having a pair of electrodes opposed to a discharge vessel made of quartz glass having sealing portions formed at both ends, a concave reflecting mirror covering the high pressure mercury lamp, a high pressure mercury In a light source unit comprising a base member that holds one end of the lamp and is fixed on the outer surface of the neck of the concave reflecting mirror, and a front glass that substantially airtightly closes the front opening of the concave reflecting mirror, the base member and the neck of the concave reflecting mirror A cooling air opening that is spatially connected to the inside of the reflecting mirror is formed between them, and a protective net member for fragments that forms an arc tube is attached to the opening.
With such a configuration, the high-pressure discharge lamp can be cooled satisfactorily, and the protective mesh member can secure the fragments of the arc tube well even in the event of breakage or the like. .
[0025]
Furthermore, the protective mesh member is a plate-shaped member having a C-shaped cross section, so that the protective mesh member can be easily attached and detached with a simple structure, and the protective mesh member can be used as a base. It can be brought into close contact with the member.
Further, the protective mesh member has a tongue-like fixing piece extending in the direction of detachment from the base member, so that the fixing piece can be locked in a hole or a recess provided in the base, and the insertion operation is not easy. However, it is difficult to attach and detach, and it is possible to prevent the net member from moving undesirably when the light source unit is used.
Further, the tongue-shaped fixing piece is fixed to the adhesive filling opening provided in the base member, so that it is not necessary to provide a special recess.
Furthermore, the high-pressure mercury lamp contains 0.15 mg / mm ³ or more of mercury so that high output and high color rendering properties can be obtained, and the lamp is effective despite the high mercury vapor pressure. It can cope well with cooling and possible damage.
[Brief description of the drawings]
FIG. 1 shows a light source unit of the present invention.
FIG. 2 shows a conventional light source unit.
FIG. 3 shows a cross-sectional view of the light source unit of the present invention.
FIG. 4 shows a base member of the present invention.
FIG. 5 shows a base member of the present invention.
FIG. 6 shows a protective mesh member of the present invention.
FIG. 7 shows a protective mesh member of the present invention.
FIG. 8 shows a protective mesh member of the present invention.
FIG. 9 shows a protective mesh member of the present invention.
FIG. 10 shows a protective mesh member of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Discharge lamp 20 Concave reflector 30 Base member 50 Front glass 60 Protective net member

Claims (5)

A high-pressure mercury lamp in which a pair of electrodes are opposed to a light-emitting portion made of quartz glass with sealing portions formed at both ends, a concave reflector that covers the high-pressure mercury lamp, and a concave surface that holds one end of the high-pressure mercury lamp In the light source unit consisting of a base member fixed on the outer surface of the neck of the reflecting mirror and a front glass that closes the front opening of the concave reflecting mirror in a substantially airtight manner,
Between the base member and the neck of the concave reflecting mirror, an opening for cooling air that is spatially connected to the inside of the reflecting mirror is formed,
The base member is provided with a protective mesh member comprising a base ring portion mounted in contact with the lamp holding portion and a mesh portion provided so as to close the cooling air opening. Light source unit. The base member has a two-stage cylindrical shape including a lamp holding portion and a mirror fixing portion, and the base ring portion of the protective mesh member is in contact with a side wall surface of the mirror fixing portion of the base member. The light source unit according to claim 1.   2. The light source unit according to claim 1, wherein the protective mesh member has a tongue-like fixing piece extending in a direction of detachment from the base member.   4. The light source unit according to claim 3, wherein the tongue-shaped fixing piece is fixed to an adhesive filling opening provided in the base member. The light source unit according to claim 1, wherein the high-pressure mercury lamp is filled with 0.15 mg / mm ³ or more of mercury.

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