JP2010015826A - Flat mercury lamp, and light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flat mercury lamp and a light-emitting device, capable of improving stability of light emission. <P>SOLUTION: Infrared-ray reflecting layers 40 are formed on an outer face of a peripheral-face wall 24 and at a region further at an outer periphery side of an outer periphery edge of a circular part 31 of a light-transmitting electrode 30 at the outer face of a front substrate 22. With these infrared-ray reflecting layers 40, infrared rays emitted at an inside space 28 during discharge at the peripheral face wall 24 and at an outer edge part of the front substrate 22 are reflected. With this, temperature retention at a non-discharge area A formed at the periphery face wall 24 is secured. Therefore, mercury is prevented from remaining as liquid around the non-discharge area A, and at the same time, temperature in the inside space 28 as a whole is raised and maintained at a temperature in which mercury can evaporate. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a flat mercury lamp in which discharge gas and mercury are enclosed, and a light emitting device including the flat mercury lamp.

Conventionally, a discharge gas is enclosed in a discharge vessel formed by facing a pair of rectangular glass substrates facing each other and sealed with a peripheral wall, and chromium is placed near the center of the outer surface of each glass substrate. A discharge lamp is known which is formed by laminating a layer and a nickel layer to form a rectangular electrode (see, for example, Patent Document 1). This discharge lamp can emit light by applying a high frequency voltage between the electrodes.
JP 2004-111326 A

  Here, in the discharge lamp as described above, the discharge is performed in the region near the central portion sandwiched between the electrodes provided on the glass substrate, but the region outside the outer peripheral edge of the electrode, In the region near the peripheral wall of the discharge vessel, no discharge is performed because the electrodes are not sandwiched between the electrodes. Thereby, a non-discharge region is formed in the vicinity of the peripheral wall of the discharge vessel (for example, a region indicated by A in FIG. 5). Therefore, when mercury is enclosed in such a discharge lamp and used as a flat mercury lamp, the discharge is not performed in the vicinity of the non-discharge area and the temperature becomes low, so that the evaporation of mercury in the area becomes insufficient and the liquid becomes liquid. As a result, the light emission may become unstable.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a flat mercury lamp and a light-emitting device that can improve the stability of light emission.

  The flat mercury lamp according to the present invention is made of a dielectric material, and includes a hermetic container formed in a flat plate shape by sealing a front substrate and a rear substrate, and sealing each outer peripheral edge with a peripheral wall. Discharge gas and mercury that are sealed in the internal space of the container and emit light when voltage is applied, and a front-side electrode that is provided on the outer surface of the front substrate of the hermetic container so that the generated light can be emitted. And a back-side electrode provided on the outer surface of the back substrate of the hermetic container and facing the electrode through the inner space, and an insulating infrared reflection that is provided on the outer surface of the hermetic container and reflects infrared radiation radiated in the inner space The outer peripheral edge of the front electrode is formed to be separated from the outer peripheral edge of the outer surface of the front substrate, and the infrared reflective layer is formed on the outer surface of the peripheral wall, and the front surface on the outer surface of the front substrate Side electrode Characterized in that it is formed in a region remote outer peripheral side.

  In this flat type mercury lamp, an infrared reflecting layer is formed on the outer surface of the peripheral wall and on the outer peripheral side of the front electrode on the outer surface of the front substrate. Thereby, infrared rays radiated in the internal space during discharge can be reflected by the outer peripheral portion of the peripheral wall and the front substrate, and heat retention in a non-discharge region formed in the vicinity of the peripheral wall can be ensured. . Accordingly, mercury can be prevented from remaining as a liquid in the vicinity of the non-discharge region, and the temperature of the entire internal space can be reliably raised to a temperature at which mercury can evaporate and maintained. Thereby, the stability of light emission can be improved.

  Further, in the planar mercury lamp according to the present invention, the infrared reflective layer in the front substrate extends from the outer peripheral edge of the outer surface of the front substrate toward the inner peripheral side, and is seen from the thickness of the peripheral wall as viewed from the thickness direction of the hermetic container. Also, it is preferable to extend to the inner peripheral side. As a result, it is possible to reflect infrared rays over a wide range of the outer peripheral portion of the front substrate, so that it is possible to improve heat retention in the non-discharge region.

  Further, in the flat mercury lamp according to the present invention, it is preferable that a gap is formed between the inner peripheral edge of the infrared reflecting layer in the front substrate and the outer peripheral edge of the front electrode. Thus, by reliably separating the infrared reflective layer and the front side electrode, the material forming the infrared reflective layer adheres to the front side electrode, and the front side electrode and the power feeding portion for the front side electrode It is possible to prevent the occurrence of poor conduction between the two.

  In the flat mercury lamp according to the present invention, it is preferable that the hermetic container has a tip tube protruding outward from the peripheral wall, and an infrared reflecting layer is formed on the outer surface of the tip tube. On the outer surface side of the peripheral wall, a tip tube is formed which is used for evacuation and discharge gas enclosure in the housing during manufacture. The internal space of the tip tube is particularly configured to easily drop in temperature. However, by forming an infrared reflecting layer on the outer surface of the tip tube, it is possible to prevent mercury from remaining in the tip tube.

  In the flat mercury lamp according to the present invention, the infrared reflective layer is preferably coated with silicon dioxide. As a result, the infrared reflective layer can be prevented from being peeled off, and heat retention and insulation in the non-discharge region can be maintained even when used for a long time.

  Further, in the flat mercury lamp according to the present invention, the infrared reflecting layer is formed only on the outer surface of the peripheral wall and the outer surface of the front substrate, and the back electrode has the flat electrode in contact with the outer surface of the rear substrate. It is preferable that it is comprised. By adopting a configuration in which a flat plate-like back electrode is brought into contact with the back substrate, peeling of the back electrode can be prevented. In addition, since the infrared reflective layer is formed only on the outer surface of the peripheral wall and the outer surface of the front substrate, and is not formed on the outer surface of the rear substrate, the adhesion between the outer surface of the rear substrate and the rear electrode can be improved. .

  In the planar mercury lamp according to the present invention, the infrared reflective layer is preferably made of a metal oxide having a particle size of 0.8 μm or more. By using a metal oxide having such a particle size, it is possible to sufficiently ensure insulation and heat retention in a non-discharge region.

  The light emitting device according to the present invention accommodates the above-described flat mercury lamp and the flat mercury lamp, and has an opening formed on the front substrate side for allowing light from the flat mercury lamp to pass therethrough. And a support body that supports the lamp and is provided on the back substrate side. According to this light emitting device, since the above-described mercury lamp is provided, the stability of light emission can be improved.

  With the flat mercury lamp according to the present invention, the stability of light emission can be improved.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a preferred embodiment of a flat mercury lamp according to the invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view of a light emitting device including a flat mercury lamp according to an embodiment of the present invention. As shown in FIG. 1, the light emitting device 20 houses a rectangular flat plate-shaped mercury lamp 1 in a rectangular parallelepiped casing 4 and forms a rectangular opening 8 a in the center of an upper cover 8 of the casing 4. Thus, the light exit surface of the flat mercury lamp 1 is exposed. The light emitting device 20 is a device that emits light by applying a high frequency voltage to the discharge gas and mercury sealed in the internal space of the flat mercury lamp 1 and can extract the generated light from the opening 8a. A fan 14 for cooling the inside of the housing 4 is provided on a side wall on one end side in the longitudinal direction of the housing 4.

  FIG. 2 is an exploded perspective view of the light emitting device shown in FIG. As shown in FIG. 2, a flat mercury lamp 1 includes an airtight container 2 formed in a rectangular flat plate shape by a dielectric material transparent to outgoing light such as quartz glass, and a front surface of the airtight container 2 (the outer surface of the front substrate). ) A mesh-shaped light passing electrode (front side electrode) 30 formed over substantially the entire 2b, and a rectangular flat plate electrode facing the back surface 2c opposite to the back surface (outer surface of the back substrate) 2c of the airtight container 2 (Back side electrode) 3. The light passing electrode 30 is configured by forming a mesh-like electrode in an inner region of an electrode formed in a rectangular ring shape along the outer peripheral edge of the front surface 2b. The flat electrode 3 and the light passing electrode 30 of the flat mercury lamp 1 are opposed to each other through an internal space in which discharge gas and mercury are enclosed. Therefore, the light passing electrode 30 is set to the ground potential (ground potential), and a high frequency voltage is applied between the plate-like electrode 3 and the light passing electrode 30 to cause the discharge gas and mercury in the internal space to emit light, and the generated light is airtight. The light can be emitted from the front surface 2 b side of the container 2. A detailed description of the configuration of the flat mercury lamp 1 will be given later. The high frequency voltage is an alternating voltage having a frequency of 1 MHz or more.

  On the front surface 2 b side of the airtight container 2, a rectangular annular frame-shaped thin plate made of a conductive material, for example, a stainless steel thin plate, so as to cover the outer peripheral edge portion of the front surface 2 b and the rectangular annular outer peripheral edge portion of the light passing electrode 30. 26 is arranged. The frame-shaped thin plate 26 has an outer periphery that has substantially the same shape as the outer periphery of the front surface 2 b of the airtight container 2, and an inner periphery that has substantially the same shape as the rectangular annular edge of the light passing electrode 30. The frame-like thin plate 26 is joined to the airtight container 2 by brazing or the like.

  The flat electrode 3 on the back surface 2 c side of the hermetic container 2 functions as an anode of the flat mercury lamp 1 and is provided separately from the flat mercury lamp 1. The rectangular plate is made of an aluminum rectangular plate having substantially the same shape as the rectangular annular outer peripheral edge of the light passing electrode 30. Therefore, problems such as electrode peeling are unlikely to occur. The flat electrode 3 is disposed in contact with the back surface 2 c so as to face the back surface 2 c of the hermetic container 2. A wiring 15 connected to a high frequency power source is attached to the flat electrode 3 at the outer edge. The front surface 3a serving as a contact surface with the hermetic container 2 is mirror-finished so as to reflect the light generated inside the hermetic container 2 toward the front surface 2b. Instead of the mirror finishing of the flat electrode 3, the electrode layer / reflecting mirror may be formed directly on the back surface 2 c of the hermetic container 2 by vapor deposition of metal such as aluminum. In this case, the flat electrode 3 may be used as a power supply member for supplying power to the electrode layer, or a separate power supply member may be provided instead of the flat electrode 3.

  The casing 4 that accommodates the flat mercury lamp 1 is made of a conductive material, and the flat mercury lamp 1 is disposed inside a rectangular aluminum case 6 whose upper surface is open, and the rectangular upper lid 8 is placed upward. It is comprised by covering. In the upper lid 8, a substantially rectangular opening 8 a is formed in a region facing the flat mercury lamp 1. Further, wide portions 8b and 8c are provided at both ends in the longitudinal direction of the opening 8a so that rectangular pressing plates 9A and 9B for pressing the longitudinal end of the flat mercury lamp 1 from above can be fitted. By being formed, the opening 8a is formed in a substantially I shape. Further, a support base (support portion) 7 for supporting and positioning the accommodated flat type mercury lamp 1 is provided on the bottom plate side inside the case 6 of the housing 4.

  The pressing plates 9A and 9B fitted into the wide portions 8b and 8c at both ends of the opening 8a of the upper lid 8 are configured in a rectangular shape by a conductive material such as aluminum. The pressing plates 9A and 9B are formed so as to cover the end portions of the flat mercury lamp 1, respectively. Further, through holes for inserting screws are formed at both ends of the pressing plates 9A and 9B in the longitudinal direction.

  The support base 7 provided inside the case 6 is provided with a rectangular base plate 5 disposed so as to cover the bottom surface of the case 6, and provided on both end sides in the longitudinal direction on the base plate 5. Support members 11A and 11B for positioning the mercury lamp 1 in the planar direction, and elastic support portions 12 provided at a plurality of locations on the base plate 5 at predetermined intervals and supporting the planar mercury lamp 1 from below. It is prepared for. The support members 11 </ b> A and 11 </ b> B are configured by erecting substantially rectangular parallelepiped insulating members (for example, ceramics) that extend in the width direction of the flat mercury lamp 1 on both ends of the base plate 5. The distance between the side surfaces of the support members 11A and 11B facing each other is slightly narrower than the length of the flat mercury lamp 1 in the longitudinal direction.

  The base plate 5 covering the bottom surface of the case 6 is disposed so as to face the bottom surface of the case 6. By forming the base plate 5 with a heat insulating member, it is possible to ensure heat retention around the flat mercury lamp 1.

  FIG. 3 is an enlarged perspective view of the support member. As shown in FIG. 3, the support member 11 </ b> A disposed on one end side of the base plate 5 is formed in a substantially rectangular parallelepiped shape. At the edge of one long side of the support member 11A, a rectangular cutout extending in the long side direction is provided so as to leave part of both ends in the long side direction. By providing this notch, it is possible to form a step surface 11a extending horizontally and a notch surface 11b extending vertically. The step surface 11 a can function as a mounting surface for mounting the flat mercury lamp 1, and the notch surface 11 b functions as a stopper surface for positioning the flat mercury lamp 1 in the longitudinal direction. Can be made. Note that the stepped surface 11a can be brought into contact with the flat mercury lamp 1 only at two locations on both ends by forming a rectangular cutout portion 11c at the center position in the longitudinal direction. In addition, since the distance between the inner side surfaces of the remaining portions 11d and 11e on both ends in the longitudinal direction of the notch portion is substantially the same as the length in the width direction of the flat mercury lamp 1, the remaining portions 11d and 11e are The flat mercury lamp 1 can function as a stopper for positioning in the width direction. Also, a plurality of grooves extending in the horizontal direction are formed in the vertical direction on the inner surface of the cut-out surface 11b and the remaining portions 11d and 11e facing the peripheral wall 24 of the flat mercury lamp 1.

  The upper surface 11f of the support member 11A can function as a seating surface for attaching the pressing plate 9A, and a pair of screws for screwing screws for fixing the pressing plate 9A is screwed to both longitudinal ends of the upper surface 11f. A screw hole 11g is formed. A flat ground terminal 11h that is electrically connected to the pressing plate 9A is provided at a position where one screw hole 11g is formed. The ground terminal 11h has a through hole communicating with the screw hole 11g on the upper surface side, and a bent portion bent downward in an L shape along the side surface on the other long side of the support member 11A. The bent portion is fixed by being screwed to the side surface of the support member 11A (see FIG. 4). Wiring is simultaneously fixed to the screwed portion, and the ground terminal 11h is electrically connected to the ground terminal of the high-frequency power source via the wiring.

  4 is a cross-sectional view taken along the line IV-IV shown in FIG. 1, and is an enlarged view of one end side of the flat mercury lamp. As shown in FIG. 4, the base plate 5 of the support base 7 is disposed apart from the bottom surface 6 a of the case 6 through the spacer 13 inside the light emitting device 20. A flat plate electrode 3 of the flat mercury lamp 1 is placed on the step surface 11 a of the support member 11 </ b> A provided on the end side in the longitudinal direction of the base plate 5. Since the step surface 11a is configured to be in contact with the hermetic container 2 only at both ends in the width direction (see FIG. 3), the area of the contact portion between the support member 11A and the flat mercury lamp 1 is made as small as possible. ing. The mounted flat mercury lamp 1 is arranged so that the peripheral surface thereof faces the cutout surface 11b of the support member 11A, and the movement in the longitudinal direction in the plane direction is restricted by the cutout surface 11b. Furthermore, the movement of the planar mercury lamp 1 in the width direction in the planar direction is restricted by the inner surfaces (see FIG. 3) of the remaining portions 11d and 11e. Even when the peripheral surface of the flat mercury lamp 1 and the cutout surface 11b are in contact with each other by the plurality of grooves formed on the inner surface of the cutout surface 11b and the remaining portions 11d and 11e, the flat mercury lamp 1 Creeping discharge between the light passing electrode 30 and the flat electrode 3 can be suppressed.

  A pressing plate 9A fitted in the opening 8a of the upper lid 8 is placed on the upper surface 11f of the support member 11A, and the lower surface of the frame-shaped member 9 and the ground terminal 11h are in contact with each other. Further, the width in the short side direction of the pressing plate 9A is made larger than the width in the short side direction of the upper surface 11f of the support member 11A, and the long edge protruding from the upper surface 11f is an edge on one end side of the flat mercury lamp 1 Covers the part. The lower surface of the long edge portion of the pressing plate 9A is in contact with the frame-shaped thin plate 26 that is electrically connected to the outer edge portion of the light passing electrode 30 of the flat mercury lamp 1. Accordingly, the pressing plate 9A and the frame-like thin plate 26 function as an energizing member for electrically connecting the ground terminal 11h and the light passing electrode 30 of the flat mercury lamp 1. Further, the pressing plate 9A is screwed into the support member 11A by passing the bolt 25 from above and screwed into the screw hole 11g, whereby the flat mercury lamp 1 is moved downward (on the flat electrode 3 side). Can be pressed. It should be noted that the other end side (not shown) of the flat mercury lamp 1 has the same configuration.

  The base plate 5 is provided with an elastic support portion 12 so as to be separated from the support member 11A at a predetermined interval in the plane direction. The elastic support portion 12 is configured by loading a bar-like member 16 extending upward into a guide hole of a boss portion 17 fixed to the base plate 5. The boss portion 17 has a guide hole penetrating in the vertical direction at the center thereof, and is fixed to the base plate 5 by screwing from the upper surface side so as to penetrate the base plate 5, and the lower end of the guide hole is A cap 17 a for sealing is provided on the lower surface side of the base plate 5.

  The rod-shaped member 16 extends substantially vertically from the bottom surface 6a side toward the upper flat plate electrode 3, and supports the flat mercury lamp 1 so as to be separated from the bottom surface 6a. The flat plate electrode 3 is supported from the bottom surface 6a. The distance is about 20 mm. This rod-shaped member 16 is formed of an insulator such as ceramics having an outer diameter of about 6 mm, and its upper end portion is reduced in diameter and tapered. Therefore, since the area of the tip portion of the bar-shaped member 16 can be made extremely small with respect to the entire area of the back surface of the flat-plate electrode 3, the bar-shaped member 16 supports the flat-plate electrode 3 substantially in point contact. be able to. Further, since a compression spring 18 for applying an elastic force to the rod-shaped member 16 is disposed at the bottom of the guide hole of the boss portion 17, the rod-shaped member 16 is flat on the back surface 2 c of the airtight container 2 of the flat mercury lamp 1. The electrode 3 can be energized.

  Here, a detailed configuration of the flat mercury lamp 1 will be described with reference to FIG. FIG. 5 is a partial cross-sectional perspective view of the flat mercury lamp 1.

  A flat airtight container 2 of the flat mercury lamp 1 is formed of a rectangular flat plate-like front substrate 22 made of quartz glass, and is made of the same material and shape as the front substrate 22 and faces the front substrate 22 at a predetermined interval. And a rear substrate 23 arranged to do so. When viewed from the thickness direction, the four outer edges of the front substrate 22 and the four outer edges of the back substrate 23 are arranged to coincide with each other. The “thickness direction” indicates a direction in which the front substrate 22 and the rear substrate 23 face each other, that is, a direction perpendicular to the front surface 2b and the back surface 2c. In this airtight container 2, the airtightness of the internal space 28 is maintained by sealing the four outer peripheral edges of the front substrate 22 and the back substrate 23 with a rectangular annular peripheral wall 24 made of quartz glass. . Specifically, the peripheral wall 24 includes a pair of side walls that connect the pair of long edges of the front substrate 22 and the pair of long edges of the back substrate 23 over the entire length in the longitudinal direction, and a pair of short edges of the front substrate 22. A pair of side walls that join and connect the edge and the pair of short edges of the back substrate 23 over the entire length in the width (short) direction are configured. The four side walls constituting the peripheral wall 24 are erected so as to be perpendicular to the substrates 22 and 23, respectively. The plate thicknesses of the front substrate 22, the rear substrate 23, and the peripheral wall 24 are all the same.

  A tip tube 27 used for exhausting the internal space 28 and enclosing a discharge gas and mercury is formed on the peripheral wall 24 on one end side in the longitudinal direction of the hermetic container 2. The tip tube 27 is joined to the center position in the width direction of the hermetic container 2.

  The light passing electrode 30 formed on the front surface 2b of the airtight container 2 is formed of a metal film, and is formed on almost the entire surface except for the outer edge portion of the front surface 2b. More specifically, the light passage electrode 30 includes an annular portion 31 formed in a rectangular ring shape along the outer edge portion of the front surface 2b, and a mesh portion 32 formed in a net shape in an inner region of the annular portion 31. Yes. Since the light passing electrode 30 is formed in a net shape over substantially the entire front surface 2b, the light generated in the internal space can be emitted from the front surface 2b. The light passing electrode 30 itself may be made of a translucent material so that light can be emitted.

  The annular portion 31 of the light passing electrode 30 includes a long side portion 31a extending along one outer peripheral edge 22a on the long side of the front surface 2b and a long side portion 31b extending along the other outer peripheral edge 22b. And. Further, the annular portion 31 includes a short side portion 31c extending along one outer peripheral edge 22c on the short side of the front surface 2b, and a short side portion extending along the other outer peripheral edge ( The other outer peripheral edge and the corresponding short side portion are not shown). The long side portions 31a and 31b and the short side portion 31c of the annular portion 31 are formed such that the outer peripheral edges thereof are spaced apart from the outer peripheral edges 22a, 22b and 22c of the front surface 2b, respectively, as viewed from the thickness direction of the airtight container 2. It is preferable that they are at least separated from the thickness of the peripheral wall 24. Note that the other short side portion (not shown) is also spaced apart by the same amount. For example, when an airtight container is formed with a plate thickness of about 1.3 mm, the outer peripheral edge of the annular portion 31 is preferably separated from the outer peripheral edge of the front surface 2b by about 1.3 to 5 mm.

  The mesh portion 32 formed in the inner region of the annular portion 31 has a plurality of linear electrode patterns parallel to the long side portions 31a and 31b at equal intervals so as to connect the short side portions on both sides of the annular portion 31. In addition to the formation, a plurality of linear electrode patterns parallel to the short side portion 31c are formed at equal intervals so as to connect the long side portions on both sides. Note that the thickness of the linear electrode pattern constituting the mesh portion 32 is smaller than the long side portions 31a and 31b and the short side portion 31c of the annular portion 31, and is generated in the internal space 28 of the airtight container 2. It is configured so that sufficient light can be emitted.

  The flat electrode 3 in contact with the back surface 2c of the airtight container 2 has a slightly larger shape than the annular portion 31 while the outer edge portion of the back surface 2c is exposed, and overlaps with the annular portion 31 when viewed from the thickness direction. Is arranged. As a result, in the internal space 28 of the hermetic container 2, a region sandwiched between the light passing electrode 30 and the plate electrode 3 is a discharge region to which a high frequency voltage is applied, and a region not sandwiched on the outer peripheral side is a high frequency voltage. A non-discharge region where no voltage is applied. This non-discharge region is a region indicated by A in FIG. Further, since both the light passing electrode 30 and the plate-like electrode 3 are arranged except for the outer edge portions of the front surface 2b and the back surface 2c of the hermetic container 2, a creepage distance between both electrodes can be secured, It is possible to prevent creeping discharge.

  An insulating infrared reflecting layer 40 is provided on the outer surface of the hermetic container 2 by applying a metal oxide that reflects infrared rays. As shown in FIG. 5, the infrared reflection layer 40 is formed in a region where a satin pattern finer than the satin pattern applied to the light passing electrode 30 is applied. The infrared reflection layer 40 is formed only on the outer peripheral surface of the peripheral wall 24 and the outer peripheral edge of the outer surface of the front substrate 22 (that is, the front surface 2b), and is not formed on the outer surface of the rear substrate 23 (that is, the rear surface 2c). .

  Specifically, the infrared reflecting layer 40 is formed over the entire outer surface of the four side walls constituting the peripheral wall 24, and the infrared reflecting layer 40 is also formed over the entire outer surface of the tip tube 27 protruding from the peripheral wall 24. Has been.

  The infrared reflection layer 40 on the front substrate 22 side covers the entire region on the outer peripheral side of the annular portion 31 of the light passing electrode 30 and is formed in a rectangular annular shape so as to surround the light passing electrode 30. The infrared reflective layer 40 is formed so as to extend from the outer peripheral edges 22a to 22c toward the inner peripheral side, and to extend to the inner peripheral side from the thickness of the peripheral wall 24 as viewed from the thickness direction of the airtight container 2. Yes. Thus, the infrared reflective layer 40 on the front substrate 22 side is configured to cover almost all positions corresponding to the non-discharge area A. However, a gap as shown by B in FIG. 5 is provided between the outer peripheral edge of the annular portion 31 and the inner peripheral edge of the infrared reflecting layer 40. The gap is formed in a rectangular annular shape so as to surround the annular portion 31 and has a width of about 1 mm, for example.

  Infrared shielding titanium oxide (for example, “JR-1000” manufactured by Teika Co., Ltd.) is used as the metal oxide constituting the infrared reflecting layer 40. This infrared shielding titanium oxide is, for example, a white powdery metal oxide having an average particle diameter of 1.0 μm, a refractive index of 2.72, a specific gravity of 4.2, and a titanium oxide crystal form of a rutile form. The infrared reflecting layer 40 is formed by dissolving the infrared shielding titanium oxide powder in water at a ratio of 1: 1 and applying it to the airtight container 2 with a brush. Furthermore, the surface of the infrared reflective layer 40 is coated with silicon dioxide to prevent the infrared reflective layer from peeling off.

  In the flat type mercury lamp 1 configured in this way, for example, the length of the hermetic container 2 is about 500 mm, the width is about 50 mm, the plate thickness is about 1.3 mm, and between the front substrate 22 and the rear substrate 23. When a discharge distance of about 8 mm is secured and Xe gas and mercury are sealed in the internal space 28, the lighting frequency is 2020 kHz (about 2 MHz) and the lamp discharge voltage is about 2.5 kVp-p.

  Next, functions and effects of the flat mercury lamp 1 according to this embodiment will be described.

  In the flat mercury lamp 1 according to the present embodiment, the infrared reflecting layer 40 is formed on the outer surface of the peripheral wall 24 and the outer peripheral surface of the annular portion 31 of the light passage electrode 30 on the outer surface of the front substrate 22. ing. By this infrared reflecting layer 40, infrared rays radiated in the internal space 28 during discharge can be reflected at the outer peripheral portion of the peripheral wall 24 and the front substrate 22. Thereby, the heat retention in the non-discharge region A formed in the vicinity of the peripheral wall 24 can be ensured. Therefore, it is possible to prevent mercury from remaining as a liquid in the vicinity of the non-discharge region A, and it is possible to reliably raise and maintain the temperature of the entire internal space 28 to a temperature at which mercury can be evaporated. Thereby, the stability of light emission can be improved.

  If the infrared reflective layer 40 is formed on the inner surface side of the hermetic container 2, the infrared reflective layer 40 is directly exposed to discharge, so that it deteriorates and peels even if it is coated with silicon dioxide. There is a possibility. The same applies even if the infrared reflective layer is coated with silicon dioxide. On the other hand, in this embodiment, since the infrared reflective layer is formed on the outer surface of the airtight container 2, it can be used for a long time.

  Further, the infrared reflective layer 40 in the front substrate 22 extends from the outer peripheral edges 22 a to 22 c toward the inner peripheral side, and extends to the inner peripheral side from the thickness of the peripheral wall 24 as viewed from the thickness direction of the airtight container 2. Therefore, it is possible to reflect infrared rays over a wide range of the outer peripheral portion of the front substrate 22 and improve heat retention in the non-discharge region.

  Further, a gap is formed between the inner peripheral edge of the infrared reflecting layer 40 in the front substrate 22 and the outer peripheral edge of the annular portion 31 of the light passing electrode 30. Thus, by reliably separating the annular portion 31 and the infrared reflecting layer 40, metal oxides adhere to the annular portion 31, and the annular portion 31 and the frame-shaped thin plate 26 serving as a power supply member (FIG. 2). Occurrence of a continuity failure can be prevented.

  Further, since the infrared reflecting layer 40 is also formed on the outer surface of the tip tube 27 that is particularly configured to easily lower the temperature because it protrudes to the outside, it is possible to prevent mercury from remaining in the tip tube 27. Can do.

  Here, if the infrared reflective layer 40 is provided near the outer peripheral edge of the outer surface of the back substrate 23, when the outer peripheral edge of the flat electrode 3 and the infrared reflective layer 40 are in contact, the contact portion Thus, the flat electrode 3 is slightly lifted from the back substrate 23, and the adhesion between the flat electrode 3 and the back substrate 23 may be impaired. However, in this embodiment, since the infrared reflective layer 40 is formed only on the outer surface of the peripheral wall 24 and the outer surface of the front substrate 22, the adhesion between the plate-like electrode 3 and the rear substrate 23 can be improved.

  Further, by coating the infrared reflective layer 40 with silicon dioxide, the infrared reflective layer 40 is prevented from being peeled off, and heat retention and insulation in the non-discharge region can be maintained even when used for a long time.

  The present invention is not limited to the embodiment described above.

  For example, in the flat mercury lamp 1 according to the present embodiment, infrared shielding titanium oxide is used as the metal oxide constituting the infrared reflecting layer 40, but zirconium oxide or the like may be used instead. In addition, it is preferable to use a metal oxide having a particle size of 0.8 μm or more as a material constituting the infrared reflective layer. By using a metal oxide having such a particle size, it is possible to sufficiently ensure insulation and heat retention in a non-discharge region.

  Moreover, although the infrared reflective layer 40 was coated with silicon dioxide, it may replace with this and may coat with water glass. When water glass is used, instead of coating, infrared shielding titanium oxide powder may be dissolved in water glass and applied to the airtight container 2.

  In the present embodiment, the flat mercury lamp is rectangular, but the present invention is not limited to this and may be a disk. The airtight container 2 of the flat mercury lamp 1 is made of quartz glass that is transparent to the emitted light. However, only the front substrate 22 is made of a material that is transparent to the emitted light, and other configurations. The member may be formed of a material that is not transparent to the emitted light.

It is a perspective view of a light-emitting device provided with the flat type mercury lamp which concerns on embodiment of this invention. It is a disassembled perspective view of the light-emitting device shown in FIG. It is an expansion perspective view of a supporting member. It is sectional drawing which follows the IV-IV line | wire shown in FIG. 1, and is a figure which expands and shows the one end side of a flat type mercury lamp. It is a partial section perspective view of a flat type mercury lamp.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Flat type mercury lamp, 2 ... Airtight container, 2b ... Front (outside surface of front substrate), 2c ... Back surface (outside surface of back substrate), 3 ... Flat plate type electrode (back side electrode), 4 ... Housing, 7 ... Support Base (support part), 8a ... opening, 20 ... light emitting device, 22 ... front substrate, 22a, 22b, 22c ... outer peripheral edge (outer peripheral edge of outer surface of front substrate), 23 ... rear substrate, 24 ... peripheral wall, 27 ... chip tube, 28 ... internal space, 30 ... light passing electrode (front side electrode), 40 ... infrared reflection layer.

Claims (8)

An airtight container formed of a dielectric material and formed in a flat plate shape by sealing the outer peripheral edge portions of the front substrate and the rear substrate with a peripheral wall,
A discharge gas and mercury that are sealed in the internal space of the hermetic vessel and emit light when a voltage is applied;
A front-side electrode provided on the outer surface of the front substrate of the hermetic container and formed so that the generated light can be emitted;
A back-side electrode provided on the outer surface of the back substrate of the hermetic container and facing the front-side electrode through the internal space;
An insulating infrared reflection layer provided on an outer surface of the hermetic container and reflecting infrared rays radiated in the internal space;
The outer peripheral edge of the front electrode is formed so as to be separated from the outer peripheral edge of the outer surface of the front substrate,
The planar mercury lamp, wherein the infrared reflection layer is formed on an outer surface of the peripheral wall and is formed in a region on the outer peripheral side of the front electrode on the outer surface of the front substrate.   The infrared reflective layer in the front substrate extends from the outer peripheral edge of the outer surface of the front substrate toward the inner peripheral side, and extends to the inner peripheral side from the thickness of the peripheral wall as viewed from the thickness direction of the hermetic container. 2. The flat mercury lamp according to claim 1, wherein the flat mercury lamp is provided.   3. The flat mercury lamp according to claim 1, wherein a gap is formed between an inner peripheral edge of the infrared reflecting layer and an outer peripheral edge of the front electrode on the front substrate.   The said airtight container has a tip pipe | tube protruding outside from the said surrounding surface wall, The said infrared reflective layer is formed in the outer surface of the said tip pipe | tube, The Claim 1 characterized by the above-mentioned. Flat mercury lamp.   The flat mercury lamp according to any one of claims 1 to 4, wherein the infrared reflecting layer is coated with silicon dioxide. The infrared reflection layer is formed only on the outer surface of the peripheral wall and the outer surface of the front substrate,
The flat mercury lamp according to any one of claims 1 to 5, wherein the back electrode is configured by bringing a flat electrode into contact with an outer surface of the back substrate.   The flat mercury lamp according to any one of claims 1 to 6, wherein the infrared reflective layer is made of a metal oxide having a particle size of 0.8 µm or more. The flat mercury lamp according to claim 1,
An opening for receiving the flat mercury lamp and allowing light from the flat mercury lamp to pass therethrough is formed on the front substrate side, and a support portion for supporting the flat mercury lamp is provided on the back substrate side. A light emitting device comprising: a housing.

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