JP2010015827A - Flat lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flat lamp with mechanical strength improved and capable of restraining loss of discharge energy. <P>SOLUTION: With the flat lamp, a front substrate 21 and a rear-face substrate 22 are coupled with a spacer 26, so that, even if positive pressure is added due to cubical expansion of discharge gas at discharge, an interval of the substrates 21, 22 can be retained to prevent them from damage. Since a concave part 28 is formed at a position where the spacer 26 is coupled on an outer face of the rear-face substrate 22, a space 29 can be formed functioning as an insulation area between a rear face 2c and a flat-plate electrode 3. With this, discharge itself at an area near the spacer 26 can be restrained, so that creeping discharge can be restrained. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a flat lamp in which discharge gas is enclosed.

As a conventional flat lamp, a discharge cell (airtight container) having a discharge space having a flat and uniform thickness, a discharge gas accommodated in the discharge cell, and an outer surface of the discharge cell What is provided with the main electrode and sub electrode which are made is known (for example, refer patent document 1). This flat lamp can emit light by applying a high frequency voltage between the main electrode and the sub electrode.
JP 2002-15705 A

  Here, in the flat lamp as described above, when the thickness of the glass substrate of the discharge cell is made thin in order to improve the light transmittance, it is negative when the internal space is evacuated at the time of manufacture. There is a possibility of damage due to pressure. Therefore, a configuration is employed in which a spacer is provided on one glass substrate and the other glass substrate is supported when a negative pressure is applied to prevent breakage. However, in such a configuration, since the other glass substrate and the spacer are not connected, when the discharge gas is volume-expanded and positive pressure is applied at the time of discharge, the distance between the glass substrates is increased. There was a problem that it could not be suppressed by the spacer and was damaged. In addition, since the spacer supports the glass substrates to which a voltage is applied, creeping discharge is generated on the surface, and there is a possibility that a loss of discharge energy occurs.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a flat lamp capable of improving mechanical strength and suppressing loss of discharge energy.

  The flat lamp according to the present invention is made of a dielectric, and has an airtight container formed into a flat plate shape by facing the front substrate and the back substrate and sealing the outer peripheral edges thereof with a peripheral wall, and an airtight container A discharge gas which emits light when a voltage is applied, a front electrode provided on the outer surface of the front substrate of the hermetic container and formed so as to be able to emit generated light, A back side electrode provided on an outer surface of the back substrate of the container and facing the electrode through the internal space; and a spacer disposed in the internal space and extending between the front substrate and the back substrate, the spacers having both end portions The front substrate and the rear substrate are connected to each other, and the outer surface of the rear substrate is formed with a recess that is recessed toward the inner space at a position where the spacer is connected.

  In this flat type lamp, since the spacers connect the substrates of the hermetic container, even when the discharge gas is volume-expanded and a positive pressure is applied at the time of discharge, the distance between the substrates can be maintained and damaged. Can be prevented. In addition, since a recess is formed on the outer surface of the back substrate at a position where the spacer is connected, an insulating region can be formed between the outer surface of the back substrate and the back electrode. As a result, since the discharge itself in the region near the spacer can be suppressed, the creeping discharge in the spacer can be suppressed. As described above, the mechanical strength can be improved and the loss of discharge energy can be suppressed.

  Further, in the flat lamp according to the present invention, it is preferable that the recess is formed so as to include a cross section of the lower end portion of the spacer when viewed from the thickness direction of the hermetic container. By forming the concave portion so as to include the cross section of the lower end portion of the spacer, an insulating region larger than the cross section of the lower end portion of the spacer can be formed between the spacer and the back side electrode, and the creeping discharge is further reduced. It can be effectively suppressed.

  Further, in the flat lamp according to the present invention, the recess is formed in a bowl shape, and the back substrate is pushed into the internal space so that the thickness at the position of the recess is substantially constant, whereby the inner surface of the back substrate and the spacer It is preferable that a curved surface along the recess is formed at the corner between the two. As a result, the curved surface formed at the corner between the inner surface of the back substrate and the spacer can efficiently disperse the stress concentrated on the connecting portion between the back substrate and the spacer, and the mechanical strength can be further improved. it can.

  In the flat lamp according to the present invention, it is preferable that the concave portion is filled with a dielectric. By filling the recess with a dielectric, the distance between the back substrate and the back electrode can be reliably ensured in the recess even when the back electrode is formed by metal deposition or the like.

  In the flat lamp according to the present invention, it is preferable that the back side electrode is formed in a flat plate shape. By adopting a configuration in which the back side electrode has a flat plate shape and has rigidity, the distance between the back substrate and the back side electrode can be reliably ensured by the recess.

  In the flat lamp according to the present invention, it is preferable that the back-side electrode has light reflectivity on the contact surface with the outer surface of the back substrate. The amount of light emitted from the front substrate side can be increased by reflecting the light generated in the internal space with the back side electrode.

  The flat lamp according to the present invention can improve mechanical strength and suppress loss of discharge energy.

  Hereinafter, a preferred embodiment of a flat lamp according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view of a light emitting device according to an embodiment of the present invention. As shown in FIG. 1, the light emitting device 20 accommodates the disk-shaped flat lamp 1 in a housing 4 having a square top and bottom surface, and forms a circular opening in the center of the upper cover 8 of the housing 4. Thus, the light exit surface of the flat lamp 1 is exposed. The light emitting device 20 is a device capable of emitting light by applying a high frequency voltage to a discharge gas sealed in the flat lamp 1 and taking out generated light from an opening. An annular frame member 9 is attached to the opening of the housing 4 so as to cover the outer edge of the flat lamp 1, and a fan 14 for cooling the inside of the housing 4 is provided on the side wall of the housing 4. Is provided.

  FIG. 2 is an exploded perspective view of the light emitting device shown in FIG. As shown in FIG. 2, the flat lamp 1 includes an airtight container 2 formed in a disc shape by a dielectric transparent to outgoing light such as quartz glass, and a front surface of the airtight container 2 (outer surface of the front substrate). 2b, a mesh-shaped light-passing electrode (front electrode) 10 and a disk-shaped flat electrode (rear surface) facing the back surface 2c facing the back surface (outer surface of the back substrate) 2c of the airtight container 2 Side electrode) 3. The flat electrode 3 and the light passage electrode 10 of the flat lamp 1 are opposed to each other through an internal space filled with a discharge gas. Accordingly, the light passing electrode 10 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 10 to cause the discharge gas in the inner space to emit light, and the generated light is emitted from the airtight container 2. Can be emitted from the front surface 2b side. The high frequency voltage is an alternating voltage having a frequency of 1 MHz or more.

  The hermetic container 2 of the flat lamp 1 is formed by sealing a disk-shaped front substrate and a rear substrate facing each other at a predetermined interval and sealing peripheral edges with a peripheral wall. The interior space is filled with a discharge gas such as Xe gas. On the back surface 2c of the airtight container 2, the tip tube used for exhausting the internal space and enclosing the discharge gas at the time of manufacture remains (not shown). A plurality of spacers 26 are provided in the internal space of the hermetic container 2 in order to withstand the atmospheric pressure during exhaust and the increase in discharge gas pressure due to the temperature increase during discharge (see FIG. 4). A detailed description of the configuration of the spacer 26 will be described later.

  The light passing electrode 10 formed on the front surface 2b of the airtight container 2 is formed by metal vapor deposition, and is formed on almost the entire surface except for the outer edge portion of the front surface 2b. More specifically, the light passing electrode 10 has an annular portion 10a formed in an annular shape along the outer edge portion of the front surface 2b, and a mesh portion 10b formed in a net shape in an inner region of the annular portion 10a. Yes. Since the light passing electrode 10 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 10 itself may be made of a light-transmitting material so that light can be emitted.

  The flat electrode 3 on the back surface 2 c side of the hermetic container 2 functions as an anode of the flat lamp 1 and is provided separately from the flat lamp 1. The flat electrode 3 is in direct contact with the back surface 2c, which is the glass surface of the hermetic container 2, and since it is a flat metal plate, the problem of electrode peeling hardly occurs. The flat electrode 3 is constituted by an aluminum disk having the same outer diameter as the annular portion 10 a of the light passing electrode 10. That is, both the light passing electrode 10 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. Therefore, the creeping distance between both electrodes can be ensured, and the creeping discharge between both electrodes can be prevented. The flat electrode 3 is disposed in contact with the back surface 2c of the hermetic container 2 so that the central axis of the hermetic container 2 coincides. A wiring 15 connected to a high frequency power source is attached to the outer edge of the flat electrode 3, and a through hole 3 b for avoiding the tip tube is formed at a position corresponding to the tip tube of the airtight container 2. ing. 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.

  In the flat lamp 1 configured in this manner, for example, when Xe gas is sealed with a discharge distance of about 5 mm between a pair of synthetic quartz glasses having an outer diameter of about 300 mm and a thickness of about 2 mm, The capacity is about 100 pF. As an example of the discharge conditions, the lighting frequency is 2050 kHz (about 2 MHz), the lamp discharge voltage is about 6 kVp-p, and the lamp voltage is about 3 kVp-p.

  The casing 4 that accommodates the flat lamp 1 is made of a conductive material, and the flat lamp 1 is arranged so that the bottom axis of the case 6 and the central axis coincide with the inside of the bottom case square aluminum case 6 that is open on the upper surface side. And a square plate-shaped upper lid 8 is covered from above. The upper lid 8 is formed with an opening 8 a having a central axis coincident with that of the flat lamp 1 and having a diameter larger than that of the flat lamp 1. A frame-like member 9 for pressing the flat lamp 1 from above is fitted into the opening 8a. Further, a support base 7 for supporting and positioning the accommodated flat lamp 1 is provided on the bottom plate side inside the case 6 of the housing 4.

  The annular frame-shaped member 9 fitted into the opening 8a of the upper lid 8 is made of a conductive material such as aluminum, and the outer diameter thereof is the same as the inner diameter of the opening 8a. The diameter on the side is substantially the same as the inner diameter of the annular portion 10 a of the light passing electrode 10. On the lower surface side of the frame-shaped member 9, a step portion 9a having a diameter larger than that of the flat lamp 1 is provided so that the outer peripheral side is thicker than the inner peripheral side (see FIG. 4).

  The support base 7 provided inside the case 6 is provided with a substantially square base plate 5 disposed so as to cover the bottom surface of the case 6 and the four corners of the base plate 5. It comprises a support member 11 for positioning in the direction and an elastic support portion 12 provided at a plurality of locations on the base plate 5 at predetermined intervals and supporting the flat lamp 1 from below.

  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 so that the central axes coincide with each other. When using a lamp that requires heat dissipation, such as an excimer lamp, the base plate 5 is formed of a member having high thermal conductivity such as metal, thereby ensuring heat dissipation around the flat lamp 1. it can. On the other hand, when a lamp such as a mercury lamp that requires heat insulation is used, the heat insulation around the flat lamp 1 can be ensured by forming the base plate 5 with a heat insulating member.

  FIG. 3 is an enlarged perspective view of the support member. As shown in FIG. 3, the support members 11 at the four corners of the base plate 5 are configured by a substantially rectangular parallelepiped insulating member made of ceramics or the like, and one side surface of the insulating member faces the central axis side of the base plate 5. Are arranged so that each. A stopper 11 b for positioning the flat lamp 1 is formed on a part of the upper surface of the support member 11 by erecting a wall portion surrounding the central axis of the base plate 5. The stopper 11b is formed in a gentle arc shape surrounding the central axis, and the diameter of the inner peripheral surface of the stopper 11b is slightly larger than the outer diameter of the airtight container 2 of the flat lamp 1, The diameter of the arc of the surface is the same as the inner diameter of the step portion 9a on the lower surface side of the frame-shaped member 9 (see FIG. 4). Further, a plurality of grooves extending in the circumferential direction are formed on the inner circumferential surface of the stopper 11b in the vertical direction.

  Of the upper surface of the support member 11, a region on the inner peripheral side with respect to the stopper 11 b serves as a mounting portion 11 a for mounting the flat lamp 1, and a region on the outer peripheral side with respect to the stopper 11 b screws the frame-shaped member 9. The seating surface 11c is used for mating. The mounting portion 11a on the inner peripheral side can be brought into contact with the flat lamp 1 only at two locations on both ends in the circumferential direction by forming a rectangular cutout portion 11e at the center position in the circumferential direction. . In addition, a flat ground terminal 11d that is electrically connected to the frame-like member 9 is provided on the outer peripheral seating surface 11c. The ground terminal 11d has a screw hole 11f on the upper surface side, and a bent portion that is bent downward in an L shape along the outer peripheral side surface of the support member 11. The bent portion is screwed on the side surface. It is fixed by being joined (see FIG. 4). Wiring is simultaneously fixed to the screwed portion, and the ground terminal 11d is electrically connected to the ground terminal of the high-frequency power source via the wiring.

  FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 1 and is an enlarged view of one end side of the flat 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. The flat electrode 3 of the flat lamp 1 is placed on the placement portion 11 a of the support member 11 provided at the corner of the base plate 5. Since the mounting portion 11a is configured to be able to contact the flat electrode 3 only at both ends in the circumferential direction (see FIG. 3), the area of the contact portion between the support member 11 and the flat lamp 1 is as small as possible. Has been. The mounted flat lamp 1 is disposed so that the peripheral surface 2e faces the inner peripheral surface of the stopper 11b of the support member 11, and movement in the plane direction is restricted by the inner peripheral surface of the stopper 11b. Yes. Even if the peripheral surface 2e of the flat lamp 1 and the inner peripheral surface of the stopper 11b are in contact with each other by the plurality of grooves formed on the inner peripheral surface of the stopper 11b, the light passing electrode 10 of the flat lamp 1 is used. And creeping discharge between the flat electrode 3 can be suppressed.

  A frame-like member 9 fitted in the opening 8a of the upper lid 8 is placed on the outer peripheral seat surface 11c of the stopper 11b. The frame-like member 9 is formed with a thick outer peripheral side and a thin part on the inner peripheral side, and the lower surface of the thick outer peripheral part is in contact with the ground terminal 11d of the seat surface 11c. Further, the thin portion on the inner peripheral side of the frame-shaped member 9 covers the upper surface of the stopper 11b and the outer edge portion of the flat lamp 1, and contacts the annular portion 10a of the light passing electrode 10 of the flat lamp 1 on the lower surface side. ing. Thus, the frame-shaped member 9 functions as an energizing member for electrically connecting the ground terminal 11d and the light passing electrode 10 of the flat lamp 1. Further, the frame-like member 9 is screwed into the support member 11 by passing the bolt 25 from above and screwed into the screw hole 11f, whereby the flat lamp 1 is lowered (on the flat electrode 3 side). Can be pressed. The frame-like member 9 is also screwed to the other three support members 11 not shown.

  The base plate 5 is provided with an elastic support portion 12 so as to be separated from the support member 11 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 perpendicularly from the bottom surface 6a toward the upper flat plate electrode 3, and supports the flat lamp 1 so as to be separated from the bottom surface 6a. The flat plate electrode 3 is supported by 20 mm from the bottom surface 6a. They are separated by a certain amount. 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. In addition, since a compression spring 18 that applies 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 lamp 1. The electrode 3 can be energized. A plurality of elastic support portions 12 are provided so that the flat lamp 1 can be supported in a balanced manner, but at least three elastic support portions 12 need to be provided, and about 10 are preferably provided.

  Here, the detailed configuration of the spacer 26 will be described with reference to FIG. FIG. 5 is an enlarged view of the vicinity of the spacer in FIG.

  The spacer 26 is a cylindrical member that is disposed in the internal space 24 of the hermetic container 2 and extends from the front substrate 21 toward the rear substrate 22, and is formed of quartz glass like each of the substrates 21 and 22. The upper end portion 26 a of the spacer 26 is joined and connected to the front substrate 21, and the lower end portion 26 b is joined and connected to the rear substrate 22.

  On the lower end portion 26 b side of the spacer 26, the back surface (outer surface) 2 c of the back substrate 22 is recessed toward the internal space 24, thereby forming a recess 28. The recess 28 is formed by extruding a part of the back substrate 22 toward the internal space 24 so that the thickness becomes substantially constant while heating. The recess 28 is formed by providing, on the back surface 2 c of the back substrate 22, a bowl-shaped depression that matches the center axis in the direction in which the spacer 26 extends and the center axis. Thereby, a space 29 functioning as an insulating region is formed between the plate-like electrode 3 and the back substrate 22.

  The diameter R of the edge 28 a on the opening side, which is the maximum diameter of the recess 28, is larger than the diameter r of the outer peripheral surface of the spacer 26. Therefore, when viewed from the thickness direction of the hermetic container 2, the concave portion 28 has a shape including the cross section of the lower end portion 26 b of the spacer 26. The “thickness direction” of the hermetic container 2 indicates a direction in which the front substrate 21 and the rear substrate 22 face each other, that is, a direction perpendicular to the front surface 2b and the rear surface 2c. As a result, the maximum diameter of the space 29 becomes larger than the diameter of the spacer 26 and an insulating region larger than the cross section of the spacer 26 is formed. The depth of the recess 28 is deeper than the thickness of the back substrate 22.

  Further, since the back substrate 22 is pushed out toward the internal space 24 so that the thickness at the position of the recess 28 is substantially constant, the inner surface 22a side of the back substrate 22 corresponds to the shape of the recess 28. A hemispherical protrusion 27 that protrudes toward the internal space 24 is formed. The protrusion 27 has a larger outer diameter than the spacer 26 and the recess 28. As described above, the protrusion 27 is formed at the lower end portion 26 b of the spacer 26, so that the corner between the inner surface 22 a of the back substrate 22 and the spacer 26 enters the inner space 24 side along the recess 28. A curved surface 27a is formed. The corner between the inner surface 22a of the back substrate 22 and the spacer 26 is formed by connecting the back substrate 22 and the spacer 26 to the inner surface 22a of the back substrate 22 and the outer surface of the spacer 26. It is the boundary part between.

  On the outer surface side of the back substrate 22, the edge 28 a on the opening side of the recess 28 is rounded. Similarly, on the inner surface 22 a side of the back substrate 22, the corner portion 27 b between the protruding portion 27 and the inner surface 22 a and the corner portion 27 c between the protruding portion 27 and the spacer 26 are rounded. Also on the front substrate 21 side, the corner portion 21 a between the inner surface of the front substrate 21 and the spacer 26 is also rounded. Therefore, the stress concentrated in the vicinity of the joint portion between the spacer 26 and the front substrate 21 and the rear substrate 22 is efficiently dispersed.

  At the time of manufacturing, after sealing the peripheral wall with the rear substrate 22 in contact with the lower end portion 26b of the spacer 26 connected to the front substrate 21, the spacer 26 is used with a crimping tool inward from the back surface 2c side. On the other hand, the concave portion 28 and the curved surface 27a as described above are formed by thermocompression bonding of the rear substrate 22.

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

  FIG. 6 is a view showing a cross section of a conventional flat lamp, and corresponds to FIG. As shown in FIG. 6, in the conventional flat lamp, the lower end portion of the spacer 31 extending downward from the front substrate 30 supports and supports the rear substrate 33. In this flat lamp, since the electrode layer 32 is formed on the back surface 33a of the back substrate 33 by metal vapor deposition over substantially the entire surface, the electrode layer 32 exists on the back surface 33a at the contact position between the back substrate 33 and the spacer 31. ing. Therefore, when a high-frequency voltage is applied to the electrode layer 32, creeping discharge along the path P1 in the figure occurs on the surface of the spacer 31, and there is a possibility that discharge energy is lost. Further, when the discharge gas expands in volume due to high temperature during discharge and a positive pressure is applied, the spacer 31 cannot be prevented from increasing the distance between the front substrate 30 and the rear substrate 33 and is damaged. There is a possibility that.

  On the other hand, in the flat lamp 1 according to the present embodiment, as shown in FIG. 5, since the spacer 26 connects the front substrate 21 and the rear substrate 22, the discharge gas expands during discharge and the positive pressure is increased. Even if it is applied, the distance between the front substrate 21 and the rear substrate 22 can be maintained, and damage can be prevented. Further, since a recess 28 is formed in the back surface 2c of the back substrate 22 at a position where the spacer 26 is connected, a space 29 functioning as an insulating region can be formed between the back surface 2c and the flat electrode 3. it can. As a result, since the discharge itself in the region near the spacer 26 can be suppressed, the creeping discharge in the spacer 26 can be suppressed. As described above, the mechanical strength can be improved and the loss of discharge energy can be suppressed.

  Further, since the concave portion 28 is formed so as to include the lower end portion 26 b of the spacer 26 when viewed from the thickness direction of the hermetic container 2, the lower end portion of the spacer 26 is interposed between the spacer 26 and the flat electrode 3. An insulating region larger than 26b can be formed, and creeping discharge can be more effectively suppressed.

  Further, the concave portion 28 is formed in a bowl shape, and a curved surface 27 a along the concave portion 28 is formed at a corner portion between the inner surface 22 a of the rear substrate 22 and the spacer 26, thereby connecting the spacer 26 and the rear substrate 22. The stress concentrated on the portion can be efficiently dispersed, and the mechanical strength can be further improved.

  Further, since the plate electrode 3 having rigidity is used as the electrode on the back side, the distance between the back substrate 22 and the plate electrode 3 can be reliably ensured by the recess 28.

  Further, in the case of the above-described configuration, the surface of the creeping discharge is upward from the contact portion between the edge of the recess 28 and the flat electrode 3 as indicated by P2 in the figure, and the curved surface of the protrusion 27. It becomes the path | route which goes upward along the surface of the spacer 26 through 27a. Thus, according to the planar lamp 1 according to the present embodiment, the distance of the path can be made longer than the path P1 (see FIG. 6) of the creeping discharge in the conventional planar lamp. It can be made difficult to occur.

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

  For example, in the flat lamp 1 according to the present embodiment, a space 29 is formed between the recess 28 and the plate-like electrode 3, and further, as shown in FIG. May be. The dielectric 40 has a flat outer surface so as to completely fill the recess 28 and form the same surface as the back surface 2c. The dielectric 40 can be filled with alumina, mica, or glass beads. In this way, if the recesses 28 are filled with the dielectric 40, the electrode layer 32 is provided by directly depositing a metal such as aluminum on the back surface 2 c of the back substrate 22 instead of using the plate-like flat electrode 3. Is possible.

  In the present embodiment, the flat lamp 1 has a disc shape, but is not limited thereto, and may be a rectangular flat plate shape. Moreover, although the shape of a recessed part is made into bowl shape, you may form recessed parts, such as not only this but a cone shape or a column shape. Further, the hermetic container 2 of the flat lamp 1 is formed with a disk-shaped front substrate and a rear substrate facing each other at a predetermined interval, which are transparent to the emitted light, but only the glass substrate on the front surface 2b side. May be formed of a material that is transparent to the emitted light, and the other components may be formed of a material that is not transparent to the emitted light. In addition, when each electrode is formed of a metal film, an SiO2 film may be provided on each electrode with a thickness within a range that does not affect power feeding for protection.

1 is a perspective view of a light emitting device according to an embodiment of the present invention. It is a disassembled perspective view of the light-emitting device shown in FIG. FIG. 3 is an enlarged perspective view of a support member shown in FIG. 2. It is sectional drawing which follows the IV-IV line of FIG. 1, and is a figure which expands and shows the one end side of a flat type lamp. FIG. 5 is an enlarged view of the vicinity of the spacer in FIG. 4. It is a figure which shows the cross section of the conventional flat type lamp, and is a figure corresponding to FIG. It is a figure which shows the cross section of the flat type lamp | ramp which concerns on a modification, and is a figure corresponding to FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Flat type lamp, 2 ... Airtight container, 2b ... Front surface (outer surface of front substrate), 2c ... Back surface (outer surface of rear substrate), 3 ... Flat plate electrode (back side electrode), 10 ... Light passing electrode (front side) Electrode), 20 ... Light emitting device, 21 ... Front substrate, 22 ... Back substrate, 22a ... Inner surface, 24 ... Inner space, 26 ... Spacer, 27a ... Curved surface, 28 ... Recess, 40 ... Dielectric.

Claims (6)

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 that is sealed in the internal space of the hermetic vessel and emits 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 an outer surface of the back substrate of the hermetic container and facing the electrode through the internal space;
A spacer disposed in the internal space and extending between the front substrate and the back substrate,
The spacer is connected to the front substrate and the back substrate at both ends,
A flat lamp, wherein a concave portion is formed on the outer surface of the rear substrate so as to be recessed toward the inner space at a position where the spacer is connected.   2. The flat lamp according to claim 1, wherein the concave portion is formed so as to include a cross section of a lower end portion of the spacer when viewed from a thickness direction of the hermetic container. The recess is formed in a bowl shape,
3. The flat lamp according to claim 1, wherein a curved surface is formed in a corner portion between the inner surface of the rear substrate and the spacer following the concave portion.   The flat lamp according to any one of claims 1 to 3, wherein the concave portion is filled with a dielectric.   The flat lamp according to any one of claims 1 to 4, wherein the back-side electrode is formed in a flat plate shape.   The flat lamp according to any one of claims 1 to 5, wherein the back-side electrode has light reflectivity on a contact surface with the outer surface of the back substrate.

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