JP2010251092A - Electrode structure, low-pressure discharge lamp, illumination device, and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To use a low-pressure discharge lamp having a large tube diameter by improving a sealing property of a glass tube having a large tube diameter. <P>SOLUTION: An electrode structure 100 includes: an electrode 101; a lead line 102 of which one end is connected to the electrode 101; and a glass bead 103 formed to cover at least a part of the lead line 102. The glass bead 103 has a multilayer structure. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electrode structure, a low-pressure discharge lamp, an illumination device, and an image display device.

  A sectional view including the tube axis of a conventional low-pressure discharge lamp is shown in FIG. A conventional low-pressure discharge lamp 1 (hereinafter referred to as “lamp 1”) is, for example, a cold cathode discharge lamp, and includes a glass tube 2 and electrode structures 3 sealed at both ends of the glass tube 2. . The electrode structure 3 includes an electrode 4, a lead wire 5 connected to the electrode 4, and a glass bead 6 attached to the lead wire 5.

  Then, as shown in FIG. 14 (b), the electrode structure 3 is formed by resistance welding the electrode 4 and the lead wire 5, and then fitting a cylindrical glass bead 6 on the lead wire 5. Is manufactured by heating and melting (see, for example, Patent Document 1).

JP-A-8-236023

  When the tube diameter of the glass tube 2 is large, it is necessary to increase the thickness of the glass bead 6. Since the glass bead 6 is produced by melting a glass tube (not shown), a thick glass tube is required to produce a thick glass bead.

  However, if an attempt is made to stretch a thick glass tube, the speed at which the glass tube is stretched must be slowed. In this case, the glass tube may sag and the shape may become unstable.

  Further, the thick glass bead 6 is difficult to cover the lead wire 5 because the heat is not easily transmitted to the inside of the glass tube when the glass tube is melted by heating to be processed into a glass bead. Since the portion covered with the glass bead 6 serves as a sealing portion of the lamp 1, when the glass bead 6 is not neatly covered with the lead wire 5, air enters the internal space of the glass tube 2, There is a possibility that the lamp 1 is not lit.

  Therefore, the electrode structure according to the present invention is intended to be sealed on a glass tube having a large tube diameter and to improve its sealing property.

  Another object of the low-pressure discharge lamp according to the present invention is to improve the sealing property when the diameter of the glass tube is increased.

  It is another object of the present invention to use a low pressure discharge lamp having a large tube diameter.

  In order to solve the above problems, an electrode structure according to the present invention includes an electrode, a lead wire having one end connected to the electrode, and a glass bead formed to cover at least a part of the lead wire. The glass bead has a multilayer structure.

  In the electrode structure according to the present invention, it is preferable that the glass bead has an inner layer longer than an outer layer in the linear axis direction of the lead wire.

  In the electrode structure according to the present invention, it is preferable that in the glass bead, an inner layer on the electrode side is longer than an outer layer in the linear axis direction of the lead wire.

  Further, in the electrode structure according to the present invention, the glass bead has a two-layer structure, and a ratio between a thickness of an inner layer and a thickness of an outer layer in the longitudinal direction of the electrode structure in the glass bead. Is preferably in the range of 1: 0.5 or more and 1: 2 or less.

  In the electrode structure according to the present invention, the glass bead has a ratio of a length in the longitudinal direction of the electrode structure to a length in a direction substantially perpendicular to the longitudinal direction of the electrode structure is 1: 1. It is preferable that it is in the range of 1: 4 or less.

  The low-pressure discharge lamp according to the present invention includes a glass tube and the electrode structure attached to at least one end of the glass tube.

  The low-pressure discharge lamp according to the present invention includes a glass tube and a glass bead having a multilayer structure sealed at at least one end of the glass tube.

  An illumination device according to the present invention includes the discharge lamp.

  The image display device according to the present invention includes the illumination device.

  The electrode structure according to the present invention can be sealed to a glass tube having a large tube diameter, and its sealing property can be improved.

  Moreover, the low-pressure discharge lamp according to the present invention can improve the sealing property when the diameter of the glass tube is increased.

  Furthermore, the illumination device and the image display device according to the present invention can use a low-pressure discharge lamp having a large tube diameter.

Sectional drawing containing the central axis of the longitudinal direction of the electrode structure which concerns on the 1st Embodiment of this invention (A) The conceptual diagram of the connection process of an electrode structure similarly, (b) The conceptual diagram of the insertion process of an electrode structure, (c) The conceptual diagram of the heating process of an electrode structure Sectional drawing containing the tube axis | shaft of the low voltage | pressure discharge lamp which concerns on the 2nd Embodiment of this invention. Sectional drawing containing the tube axis | shaft of the low voltage | pressure discharge lamp which concerns on the 3rd Embodiment of this invention. Sectional drawing containing the tube axis | shaft of the low pressure discharge lamp which concerns on the 4th Embodiment of this invention. Sectional drawing containing the central axis of the longitudinal direction of the electrode structure which concerns on the 5th Embodiment of this invention (A) The conceptual diagram of the connection process of an electrode structure similarly, (b) The conceptual diagram of the insertion process of an electrode structure, (c) The conceptual diagram of the heating process of an electrode structure Sectional drawing including the tube axis | shaft of the low pressure discharge lamp which concerns on the 6th Embodiment of this invention The disassembled perspective view of the illuminating device based on the 7th Embodiment of this invention. The partially cutaway perspective view of the illuminating device which concerns on the 8th Embodiment of this invention. (A) Front view of illuminating device according to ninth embodiment of the present invention, (b) Cross-sectional view taken along the line AA ′ of the illuminating device. The perspective view of the image display apparatus which concerns on the 10th Embodiment of this invention. (A) Sectional drawing including the central axis of the longitudinal direction of the modification 1 of the electrode structure which concerns on the 1st Embodiment of this invention, (b) Similarly including the central axis of the longitudinal direction of the modification 2 of an electrode structure Cross section (A) Sectional view including tube axis of conventional low-pressure discharge lamp, (b) Conceptual diagram of manufacturing process of conventional electrode structure

(First embodiment)
The cross-sectional view including a longitudinal central axis X ₁₀₀ of the electrode structure according to a first embodiment of the present invention shown in FIG. An electrode structure 100 (hereinafter referred to as “electrode structure 100”) according to the first embodiment of the present invention includes an electrode 101, a lead wire 102 having one end connected to the electrode 101, and at least one of the lead wires 102. And a glass bead 103 formed so as to cover a part.

  The electrode 101 has, for example, a bottomed cylindrical shape, and has an inner diameter of 2.4 [mm], an outer diameter of 2.7 [mm], a bottom thickness of 0.2 [mm], and a total length of 8.2 [mm]. mm] and made of nickel (Ni). The material of the electrode 101 is not limited to nickel, and an alloy containing one or more of niobium (Nb), molybdenum (Mo), tantalum (Ta), and tungsten (W) can be used. The electrode 101 is connected to one end surface of the lead wire 102 at a substantially central portion of the outer bottom surface. The electrode 101 and the lead wire 102 may be directly connected, or may be connected via a brazing material made of nickel foil or Kovar foil, for example. As a connection method, laser welding, resistance welding, or the like can be used.

  In the lead wire 102, for example, the outer bottom surface and one end surface of the electrode 101 are connected, and the inner lead 102a line covered with the glass bead 103 is connected to a part of the side surface and the other end surface and one end surface of the inner lead wire 102a are connected. It consists of a connection with the external lead wire 102b.

  The internal lead wire 102a has a wire diameter of 0.8 [mm] and is made of tungsten. The internal lead wire 102a is preferably made of a material that matches the thermal expansion coefficient of the glass used as the material of the glass bead 103. For example, when the glass bead is borosilicate glass for sealing Kovar wire, it is preferable to use an alloy of iron, nickel, and cobalt (Kovar). Moreover, when the glass bead 103 is soft glass such as lead-free glass or soda glass, it is preferable to use an alloy of iron and nickel.

  Note that an oxide film (not shown) is preferably formed on the surface of at least a portion of the internal lead wire 102a covered with the glass bead 103. In this case, the sealing property between the internal lead wire 102a and the glass bead 103 can be improved. Further, the oxide film preferably contains FeO. In this case, the sealing property between the internal lead wire 102a and the glass bead 103 can be further improved.

  The external lead wire 102b has a wire diameter of 0.6 [mm] and is made of nickel. The external lead wire 102b is not limited to nickel, and an alloy of nickel and manganese, jumet or the like may be used. Note that the surface of the external lead wire 102b may be covered with solder to prevent oxidation of the external lead wire 102b.

  The glass bead 103 has a substantially spherical shape, covers (seals) the internal lead wire 102a along its substantially central axis, and is made of borosilicate glass for sealing a tungsten wire. The glass bead 103 has a two-layer structure, and includes an inner layer 103a that covers the inner lead wire 102a and an outer layer 103b that covers the inner layer. Thereby, it is easy to mold the glass tube as the material of the glass bead 103, and when processing from the glass tube to the glass bead, it can be sufficiently heated and melted for one layer of the glass bead, The outer diameter of the glass bead can be increased and sealed to a glass tube having a large tube diameter, and the sealing property can be improved.

  Note that the glass bead 103 is not limited to a two-layer structure, and may have a multilayer structure such as a three-layer structure or a four-layer structure according to the inner diameter of a glass tube to be sealed using the electrode structure 100. Further, from the viewpoint of sealing properties, the glass bead 103 is preferably made of a material having the same thermal expansion coefficient as that of the material to be sealed (in the case of a discharge lamp, the glass tube 201) or a material similar thereto.

  A method for manufacturing the electrode structure 100 will be described in detail below. The manufacturing method of the electrode structure 100 includes a connecting step of connecting the electrode 101 and the lead wire 102, an inserting step of inserting the lead wire 102 into the cavities of the multiple glass tubes 104 that are the material of the glass beads 103, and a glass tube. A heating step of heating and melting 104. Hereafter, each process is demonstrated in detail using FIG.

  As shown in FIG. 2A, in the connecting step, one end surface of the lead wire 102 is brought into contact with the outer bottom surface of the electrode 101 and connected by, for example, resistance welding. The connection method is not limited to resistance welding, and laser welding or the like may be used.

  Next, as shown in FIG. 2B, in the insertion step, the lead wire is inserted into the hollow portion of the cylindrical glass tube 104 from the end opposite to the side to which the electrode is connected. Since the glass tubes 104 are multiple, the lead wire 102 may first be inserted into the hollow portion of the glass tube 104a with a small diameter, and then the glass tube 104a with a small diameter may be inserted into the glass tube 104b with a large diameter. Then, the lead wire 102 may be inserted into the hollow portion of the glass tube 104a having a small diameter while the glass tube 104a having a small diameter is inserted into the hollow portion of the glass tube 104b having a large diameter.

  Thereafter, as shown in FIG. 2B, the lead wire 102 is inserted and fixed in a fixing hole 105a provided on one end surface of the jig 105.

  Subsequently, as shown in FIG. 2C, in the heating step, the glass tube 104 is heated by, for example, a gas burner 106 in a state where the lead wire 102 is inserted and fixed in the fixing hole 105 a of the jig 105. Thereby, the glass bead 103 covered with the lead wire 102 is formed by melting both the glass tube 104a having a small diameter and the glass tube 104b having a large diameter.

  As described above, the electrode structure 100 according to the first embodiment of the present invention can be sealed to a glass tube having a large tube diameter, and its sealing property can be improved.

  The glass bead 103 has a two-layer structure, and the ratio of the thickness m of the inner layer 103a and the thickness n of the outer layer 103b at the middle portion of the electrode structure in the glass bead 103 is 1: It is preferably within the range of 0.5 or more and 1: 2 or less. In this case, the glass tube used as the material of the inner layer 103a and the outer layer 103b can be sufficiently melted to form a glass bead having a stable shape. Further, the ratio of m: n is more preferably in the range of 1: 0.8 or more and 1: 1.5 or less.

  In the glass bead 103, the ratio of the length r in the longitudinal direction of the electrode structure to the length s in the direction substantially perpendicular to the longitudinal direction of the electrode structure is in the range of 1: 1 to 1: 4. It is preferable to be within. In this case, when the glass tube is melted to form a glass bead, the inside of the glass tube can be sufficiently melted to improve the sealing property. Furthermore, the ratio of r: s is more preferably in the range of 1: 1 or more and 1: 2 or less.

(Second Embodiment)
FIG. 3 shows a cross-sectional view including the tube axis X ₂₀₀ of the low-pressure discharge lamp according to the second embodiment of the present invention. A low-pressure discharge lamp 200 (hereinafter referred to as “lamp 200”) according to the second embodiment of the present invention is a cold cathode fluorescent lamp, and is provided at a glass tube 201 and at least one end of the glass tube 201. The electrode structure 100 is provided.

  The glass tube 201 is a straight tube, and a cross section cut perpendicularly to the tube axis has a substantially annular shape. The glass tube 201 has, for example, an outer diameter of 6 [mm], an inner diameter of 5 [mm], and an overall length of 1026 [mm], and the material thereof is, for example, borosilicate glass. The dimensions of the lamp 200 shown below are values corresponding to the dimensions of the glass tube 201 having an outer diameter of 6 [mm] and an inner diameter of 5 [mm]. Mercury and a rare gas are sealed inside the glass tube 201. For example, 3.5 [mg] mercury is enclosed in the mercury. As for the rare gas, for example, neon and argon are sealed at a pressure of 60 [Torr] with a mixed gas having a molar ratio of Ar: 5 [mol%] and Ne: 95 [mol%].

A phosphor layer 202 is formed on the inner surface of the glass tube 201. The phosphor particles used for the phosphor layer 202 are, for example, red phosphor particles (Y ₂ O ₃ : Eu ³⁺ ), green phosphor particles (LaPO ₄ : Ce ³⁺ , Tb ³⁺ ), and blue phosphor particles ( BaMg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ ).

Further, between the inner surface of the glass tube 201 and the phosphor layer 202, for example, yttrium oxide (Y ₂ O ₃ ), silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), zinc oxide (ZnO), oxide A protective film (not shown) of a metal oxide such as titanium (TiO ₂ ) may be provided. Thereby, a brightness | luminance maintenance factor can be improved by suppressing reaction with the sodium component of a glass tube, and mercury.

  In addition, it is preferable that the internal diameter of the glass tube 201 exists in the range of 3 [mm] or more and 9 [mm] or less. In this case, it is difficult to seal the glass tube 201 with a single glass bead, and it is possible to seal with a multi-layer glass bead. Furthermore, the inner diameter of the glass tube 201 is more preferably in the range of 4 [mm] to 9 [mm]. In this case, it is particularly difficult to seal the glass tube 201 with a single glass bead, and the glass tube 201 can be sealed with a multilayer glass bead.

  Moreover, it is preferable that the thickness of a glass tube exists in the range of 0.3 [mm] or more and 1.2 [mm] or less. In this case, heat necessary for sealing the glass beads can be easily transmitted when sealing to the glass tube. Furthermore, the thickness of the glass tube is more preferably within a range of 0.4 [mm] to 0.8 [mm].

  The electrode structure 100 is substantially the same as the electrode structure 100 according to the first embodiment of the present invention, and is sealed at both ends of the glass tube 201.

  As described above, according to the configuration of the low-pressure discharge lamp 200 according to the second embodiment of the present invention, the sealing property can be improved when the tube diameter of the glass tube 201 is increased.

(Third embodiment)
FIG. 4 shows a cross-sectional view including the tube axis X ₃₀₀ of the low-pressure discharge lamp according to the third embodiment of the present invention. The low-pressure discharge lamp 300 (hereinafter referred to as “lamp 300”) according to the first embodiment of the present invention is an internal / external electrode fluorescent lamp.

  The lamp 300 has an external electrode 301 on the outer surface of one end thereof, and has substantially the same configuration as the low-pressure discharge lamp 200 according to the second embodiment of the present invention, except for the configuration associated therewith. . Therefore, the external electrode 301 and the configuration associated therewith will be described in detail, and the other points will be omitted.

  The external electrode 301 is made of, for example, solder and is formed so as to cover the outer surface of one end portion of the glass tube 201.

  Further, the external electrode 301 may be formed by applying silver paste to the entire circumference of the electrode forming portion of the glass tube 201, or a metal cap may be put on one end of the glass tube 201. Further, an aluminum metal foil may be attached so as to cover the entire outer peripheral surface of one end of the glass tube 201 with a conductive adhesive (not shown) in which metal powder is mixed with silicone resin. . In addition, in a conductive adhesive, you may use a fluororesin, a polyimide resin, or an epoxy resin instead of a silicone resin.

Further, for example, a protective film of yttrium oxide (Y ₂ O ₃ ) may be provided on the inner surface of the glass tube 201 and in the region where the external electrode 301 is formed. By providing a protective film (not shown), it is possible to prevent glass scraping and pinholes that occur when mercury ions bombard that portion of the glass tube 201.

The protective film may be made of metal oxide such as silica (SiO ₂ ), alumina (Al ₂ O ₃ ), zinc oxide (ZnO), titania (TiO ₂ ), for example, instead of yttrium oxide. In particular, when the protective film is formed of yttrium oxide or silica, mercury hardly adheres to the protective film, and mercury consumption is low.

  However, the protective film is not an essential component in the present invention and may not be formed at all, or may be formed over the entire inner surface of the glass tube 201.

  In addition, the one end part of the glass tube may be sealed by heating and melting one end part of the glass tube 201 without using the glass bead, or the electrode according to the first embodiment of the present invention. A glass bead 103 similar to that of the structure body 100 may be used for sealing.

  As described above, according to the configuration of the low-pressure discharge lamp 300 according to the third embodiment of the present invention, the sealing performance can be improved when the tube diameter of the glass tube 201 is increased.

(Fourth embodiment)
FIG. 5 shows a cross-sectional view including the tube axis X ₄₀₀ of the low-pressure discharge lamp according to the fourth embodiment of the present invention. A low-pressure discharge lamp 400 (hereinafter referred to as “lamp 400”) according to the fourth embodiment of the present invention is an external electrode fluorescent lamp.

  The lamp 400 has external electrodes 301 on the outer surfaces of both end portions thereof, and has substantially the same configuration as the low-pressure discharge lamp 300 according to the second embodiment of the present invention except for the configuration associated therewith. . Therefore, the external electrode 301 and the configuration associated therewith will be described in detail, and the other points will be omitted.

  The lamp 400 includes a glass tube 201 and a glass bead 103 having a multilayer structure that is sealed to at least one end of the glass tube 201. Specifically, in the lamp 400, one end of the glass tube 201 is sealed with a glass bead 103 having a multilayer structure, and the other end is sealed without using a glass bead. The multilayer glass bead 103 is substantially the same as the glass bead 103 according to the first embodiment of the present invention. Note that both ends of the glass tube 201 may be sealed with a multilayer glass bead 103.

  As described above, according to the configuration of the low-pressure discharge lamp 400 according to the fourth embodiment of the present invention, the sealing performance can be improved when the tube diameter of the glass tube 201 is increased.

(Fifth embodiment)
FIG. 6 shows a cross-sectional view including the central axis in the longitudinal direction of the electrode structure according to the fifth embodiment of the present invention. An electrode structure 500 according to a fifth embodiment of the present invention (hereinafter referred to as “electrode structure 500”) includes an electrode 501, a lead wire 502 having one end connected to the electrode 501, and at least one of the lead wires 502. A glass bead 503 formed so as to cover a part thereof. Specifically, as shown in FIG. 6, the electrode structure 500 includes an electrode 501, a pair of lead wires 502 that respectively support both ends of the electrode 501, and a glass bead 503.

  The electrode 501 is a filament coil made of tungsten, for example. The electrode 501 has an emitter (not shown) attached to its winding portion. For the emitter, for example, (Ba, Sr, Ca) O or the like can be used. The electrode 501 is not limited to a filament coil made of tungsten, and a filament coil made of rhenium tungsten can also be used. In this case, the strength when the electrode 501 is heated by lamp lighting or the like can be improved. Further, the electrode 501 may have a double spiral structure in which the central axis of the electrode structure is a turning axis.

  The lead wire 502 is made of an alloy of iron (Fe) and nickel (Ni), for example. Specifically, it is preferably made of an alloy of nickel in the range of 50 [wt%] to 52 [wt%] and the remaining iron.

  The glass bead 503 has a substantially egg shape, and a cross section perpendicular to the line axis of the lead wire 502 has a substantially elliptical shape, and a midpoint of the two lead wires 502 passes through a substantially midpoint of the glass bead 503. In this way, the lead wire 502 is sealed, for example, made of lead-free glass.

  The glass bead 503 has a two-layer structure, and includes an inner layer 503 a that covers a pair of lead wires 502 and an outer layer 503 b that covers each inner layer. Thereby, it is easy to form a glass tube as a material of the glass bead, and when processing from the glass tube to the glass bead, it can be sufficiently heated and melted for one layer of the glass bead. By increasing the outer diameter of the bead, it can be sealed to a glass tube having a large tube diameter, and its sealing property can be improved. Specifically, the inner layer 503a is formed so as to cover the pair of lead wires 502, and the inner layer 503a is formed so that the outer layer 503b collectively covers the inner layers 503a.

  Note that the glass bead 503 is not limited to a two-layer structure, and may have a multilayer structure such as a three-layer structure or a four-layer structure in accordance with the inner diameter of a glass tube sealed using the electrode structure 500. Further, the glass bead 503 is preferably made of the same material as or a material similar to the material of the sealing partner (in the case of a discharge lamp, the glass tube 201) from the viewpoint of sealing properties.

  A method for manufacturing the electrode structure 500 will be described in detail below. The manufacturing method of the electrode structure 500 includes a connecting step of connecting the electrodes 501 and the lead wires 502, an inserting step of inserting the lead wires 502 into the cavities of the multiple glass tubes 504 that are the materials of the glass beads 503, and a glass tube. A heating step of heating and melting 504. Hereafter, each process is demonstrated in detail using FIG.

  As shown in FIG. 7A, in the connection step, both ends of the electrode 501 are supported by two lead wires 502, respectively. Specifically, each of the pair of lead wires 502 is supported by bending one end and sandwiching both ends of the electrode 501 and caulking.

  Next, as shown in FIG. 7B, in the insertion step, the lead wire 502 is inserted into the hollow portion of the cylindrical glass tube 504 from the end opposite to the side to which the electrode 501 is connected. Since the glass tube 504 is multiple, first, the two lead wires 502 are respectively inserted into the hollow portions of the glass tube 504a having a small diameter, and then the glass tube 504a having a small diameter is put together with the glass tube 504b having a large diameter. The two lead wires 502 may be inserted into the hollow portions of the small-diameter glass tube 504a in a state where two small-diameter glass tubes 504a are inserted into the hollow portion of the large-diameter glass tube 504b. May be.

  Thereafter, as shown in FIG. 7B, the lead wire 502 is inserted and fixed in a fixing hole 505 a provided on one end surface of the jig 505.

  Note that the connecting step may be performed after the inserting step. In this case, the distance between the two lead wires can be regulated by the jig, and variations in the shape and pitch of the filament coil as an electrode can be suppressed.

  Subsequently, as shown in FIG. 7C, in the heating step, the glass tube 504 is heated by, for example, a gas burner 506 in a state where the lead wire 502 is inserted and fixed in the fixing hole 505 a of the jig 505. Thereby, the glass bead 503 attached to the lead wire 502 is formed by melting both the glass tube 504a having a small diameter and the glass tube 504b having a large diameter.

  Note that the connecting step may be performed after the heating step. In this case, it is possible to prevent the electrode from being oxidized in the heating step.

  As described above, the electrode structure 500 according to the fifth embodiment of the present invention can be sealed to a glass tube having a large tube diameter, and its sealing property can be improved.

(Sixth embodiment)
The cross-sectional view including a low-pressure discharge lamp of the tube axis X ₆₀₀ according to a sixth embodiment of the present invention shown in FIG. A low-pressure discharge lamp 600 according to the sixth embodiment of the present invention (hereinafter referred to as “lamp 600”) is a hot cathode fluorescent lamp, and includes an electrode structure 500 according to the fifth embodiment of the present invention. Is substantially the same as the low-pressure discharge lamp 200 according to the second embodiment of the present invention.

  As described above, according to the configuration of the low-pressure discharge lamp 600 according to the sixth embodiment of the present invention, the sealing performance can be improved when the diameter of the glass tube is increased.

(Seventh embodiment)
FIG. 9 shows an exploded perspective view of the lighting apparatus according to the seventh embodiment of the present invention. An illuminating device 700 (hereinafter referred to as “illuminating device 700”) according to a seventh embodiment of the present invention is a direct-type backlight unit, and has a rectangular parallelepiped casing 701 having one surface opened, and the casing. A plurality of lamps 200 housed inside 701, a pair of sockets 702 for electrically connecting the lamps 200 to a lighting circuit (not shown), and optical sheets 703 covering an opening of the housing 701, It has. The lamp 200 is the low-pressure discharge lamp 200 according to the second embodiment of the present invention.

  The housing 701 is made of, for example, polyethylene terephthalate (PET) resin, and a reflective surface 704 is formed on the inner surface thereof by vapor deposition of a metal such as silver. Note that the material of the housing 701 may be made of a material other than resin, for example, a metal material such as aluminum or a cold rolled material (for example, SPCC). In addition to the metal vapor-deposited film, the reflective surface 704 on the inner surface is, for example, a film in which a reflective sheet whose reflectance is increased by adding calcium carbonate, titanium dioxide or the like to polyethylene terephthalate (PET) resin is attached to the housing 701. May be.

  Inside the housing 701, a socket 702, an insulator 705, and a cover 706 are arranged. Specifically, the sockets 702 are provided at predetermined intervals in the lateral direction (vertical direction) of the housing 701 corresponding to the arrangement of the lamps 200. The socket 702 is obtained by processing a plate material made of stainless steel or phosphor bronze, for example, and has a fitting portion 702a into which the lead wire 102 is fitted. Then, the lead wire 102 is elastically deformed so as to expand the fitting portion 702a. As a result, the lead wire 102 fitted in the fitting part 702a is pressed by the restoring force of the fitting part 702a and is difficult to come off. Accordingly, the lead wire 102 can be easily fitted into the fitting portion 702a, but can be made difficult to come off.

  The socket 702 is covered with an insulator 705 so as not to short-circuit between adjacent sockets 702. The insulator 705 is made of, for example, polyethylene terephthalate (PET) resin. Note that the insulator 705 is not limited to the above structure. Since the socket 702 is in the vicinity of the electrode 101 that becomes relatively hot during operation of the lamp 200, the insulator 705 is preferably made of a heat-resistant material. As a material for the heat-resistant insulator 705, for example, polycarbonate (PC) resin, silicon rubber, or the like can be used.

  A lamp holder 707 may be provided inside the housing 701 at a place as necessary. The lamp holder 707 that fixes the position of the lamp 200 inside the housing 701 is, for example, polycarbonate (PC) resin, and has a shape that follows the outer shape of the lamp 200. The “location as necessary” means that the deflection of the lamp 200 is caused when the lamp 200 has a long length exceeding, for example, 600 [mm], as in the vicinity of the central portion of the lamp 200 in the longitudinal direction. It is a place necessary to eliminate.

  The cover 706 separates the socket 702 from the space inside the housing 701. The cover 706 is made of, for example, polycarbonate (PC) resin, keeps the periphery of the socket 702 warm, and highly reflects at least the surface on the housing 701 side. By reducing the brightness, a decrease in luminance at the end of the lamp 200 can be reduced.

  The opening of the housing 701 is covered with a light-transmitting optical sheet 703 and is sealed so that foreign matters such as dust and dust do not enter inside. The optical sheet 703 is formed by laminating a diffusion plate 708, a diffusion sheet 709, and a lens sheet 710.

  The diffusion plate 708 is a plate-like body made of, for example, polymethyl methacrylate (PMMA) resin, and is disposed so as to close the opening of the housing 701. The diffusion sheet 709 is made of, for example, a polyester resin. The lens sheet 710 is, for example, a laminate of an acrylic resin and a polyester resin. These optical sheets 703 are arranged so as to be sequentially superimposed on the diffusion plate 708.

  As described above, according to the configuration of the lighting apparatus 700 according to the seventh embodiment of the present invention, a low-pressure discharge lamp having a large tube diameter can be used.

(Eighth embodiment)
FIG. 10 shows a partially cutaway perspective view of a lighting apparatus according to the eighth embodiment of the present invention. An illuminating device 800 according to an eighth embodiment of the present invention (hereinafter referred to as “illuminating device 800”) is an edge light type backlight unit, and includes a reflector 801, a lamp 200, a socket (not shown), and a light guide plate. 802, a diffusion sheet 803, and a prism sheet 804.

  The reflection plate 801 is disposed so as to surround the periphery of the light guide plate 802 except for the liquid crystal panel side (arrow Q), and the side surface covering the bottom surface portion 801b covering the bottom surface and the side surface excluding the side where the lamp 200 is disposed. Part 801a and a curved lamp side surface part 801c covering the periphery of the lamp 200, and the light emitted from the lamp 200 is reflected from the light guide plate 802 to the liquid crystal panel (not shown) side (arrow Q). Let Moreover, the reflecting plate 801 is made of, for example, a film-like PET deposited with silver, or laminated with a metal foil such as aluminum.

  The socket has substantially the same configuration as the connection terminal 702 used in the lighting apparatus 700 according to the seventh embodiment of the present invention. In FIG. 10, the end of the lamp 200 is omitted for convenience of illustration.

  The light guide plate 802 is for guiding the light reflected by the reflection plate 801 to the liquid crystal panel side. The light guide plate 802 is made of, for example, translucent plastic, and is stacked on the reflection plate 801 provided on the bottom surface of the lighting device 800. It is weighted. Note that as a material of the light guide plate 802, polycarbonate (PC) resin or cycloolefin-based resin (COP) can be applied.

  The diffusion sheet 803 is for expanding the visual field, and is made of a film having a diffusion transmission function made of, for example, polyethylene terephthalate resin or polyester resin, and is stacked on the light guide plate 802.

  The prism sheet 804 is for improving luminance, and is made of, for example, a sheet obtained by bonding an acrylic resin and a polyester resin, and is laminated on the diffusion sheet 803. Note that a diffusion plate (not shown) may be further stacked on the prism sheet 804. In the case of the present embodiment, a reflective sheet (not shown) is provided on the outer surface of the glass tube 201 except for a part in the circumferential direction of the lamp 200 (the light guide plate 802 side when inserted into the lighting device 800). An aperture-type lamp may be used.

  As described above, according to the configuration of the illumination device 800 according to the eighth embodiment of the present invention, a low-pressure discharge lamp having a large tube diameter can be used.

(Ninth embodiment)
FIG. 11A shows a front view of a lighting apparatus according to a ninth embodiment of the present invention, and FIG. 11B shows a cross-sectional view taken along the line AA ′ of FIG. An illuminating device 900 (hereinafter referred to as “illuminating device 900”) according to a ninth embodiment of the present invention is a luminaire using an annular fluorescent lamp for general illumination.

  The lighting device 900 includes a main body portion 901, a plate-like portion 902, a lamp holder 903, a socket 904, and a lamp 905.

  The main body 901 accommodates a lighting circuit (not shown) and the like inside, for example, and an electrical connection part (not shown) is led out from the upper part, for example, the base 906 of the lamp 905 and the electric part from the side part. A socket 904 for connection is provided.

  The disc-like portion 902 is a member that supports the main body portion 901 and the lamp holder 903, and has, for example, a disc-like shape.

  The lamp holder 903 is attached to the lower surface of the plate-like portion 902, and the lamp 905 can be held by, for example, a C-shaped sandwiching piece provided at the lower end thereof to prevent the lamp 905 from falling.

  The lamp 905 is an annular hot-cathode fluorescent lamp, and the low-pressure discharge lamp 600 according to the sixth embodiment is the same as the low-pressure discharge lamp 600 according to the sixth embodiment except that the shape is annular and the base 906 is located in the middle of the lamp 905. It has substantially the same configuration.

  As described above, according to the configuration of the illumination device 900 according to the ninth embodiment of the present invention, a low-pressure discharge lamp having a large tube diameter can be used.

(Tenth embodiment)
An outline of an image display apparatus according to the tenth embodiment of the present invention is shown in FIG. As shown in FIG. 12, an image display device 1000 is, for example, a 32 [inch] liquid crystal television (liquid crystal display device), a liquid crystal screen unit 1001 including a liquid crystal panel and the like, and an illumination device 700 according to the seventh embodiment of the present invention. And a lighting circuit 1002.

  The liquid crystal screen unit 1001 is a known one and includes a liquid crystal panel (color filter substrate, liquid crystal, TFT substrate, etc.) (not shown), a drive module, etc. (not shown), and is based on an image signal from the outside. To form a color image.

  The lighting circuit 1002 turns on the lamp 200 in the lighting device 700. The lamp 200 is operated at a lighting frequency of 40 [kHz] to 100 [kHz] and a lamp current of 3.0 [mA] to 25 [mA].

  Note that FIG. 12 illustrates the case where the low pressure discharge lamp 200 according to the second embodiment is inserted into the illumination device 700 according to the seventh embodiment of the present invention as the light source device of the image display apparatus 1000. Not limited to this, the low-pressure discharge lamp 300 according to the third embodiment of the present invention, the low-pressure discharge lamp 400 according to the fourth embodiment of the present invention, and the low-pressure discharge lamp 600 according to the sixth embodiment of the present invention are also applied. be able to. Moreover, also about the illuminating device, the illuminating device 800 which concerns on the 8th Embodiment of this invention can also be used.

  As described above, according to the configuration of the image display apparatus 1000 according to the tenth embodiment of the present invention, a low-pressure discharge lamp having a large tube diameter can be used.

(Modification)
As described above, the present invention has been described based on the specific examples shown in the above embodiments. However, the content of the present invention is not limited to the specific examples shown in the respective embodiments. Variations can be used.
1. Regarding the electrode structure (1) Modification 1 of the electrode structure
FIG. 13A is a cross-sectional view including the central axis X ₁₀₇ in the longitudinal direction of Modification Example 1 of the electrode structure according to the first embodiment of the present invention. In the modification 1 (hereinafter referred to as “electrode structure 107”) of the electrode structure according to the first embodiment of the present invention, the glass bead 108 is arranged in the direction of the axis of the lead wire 102, and the inner layer 108a is the outer layer. Except for the point shorter than 108b, it has the structure substantially the same as the electrode structure 100 which concerns on the 1st Embodiment of this invention. Specifically, in the linear axis direction of the lead wire 102, the end on the electrode 101 side in the inner layer 108a of the glass bead 108 is on the opposite side of the electrode 101 from the end on the electrode 101 side of the outer layer 108b. It is getting shorter. In this case, the contact area between the glass tube and the glass bead 108 can be increased without increasing the contact area between the lead wire 102 and the glass bead 108. When the electrode structure 107 is sealed to the glass tube, the glass tube Can be easily sealed without greatly deforming.

Note that the glass bead 503 is not limited to a two-layer structure, and may have a multilayer structure such as a three-layer structure or a four-layer structure in accordance with the inner diameter of a glass tube sealed using the electrode structure 100. In this case, for example, the innermost layer can be made shorter than the outermost layer in the direction of the axis of the lead wire 102. Furthermore, it is preferable that the lead wire 102 is shorter from the innermost layer toward the outermost layer in the direction of the axis of the lead wire 102. In this case, the glass tube can be further easily sealed.
(2) Modification 2 of electrode structure
FIG. 13B shows a cross-sectional view including the central axis X ₁₀₉ in the longitudinal direction of Modification 2 of the electrode structure according to the first embodiment of the present invention. In Modification 2 (hereinafter referred to as “electrode structure 109”) of the electrode structure according to the first embodiment of the present invention, the glass bead 110 has an inner layer 110a as an outer layer in the direction of the axis of the lead wire 102. Except for the point longer than 110b, it has the structure substantially the same as the electrode structure 100 which concerns on the 1st Embodiment of this invention. Specifically, in the axial direction of the lead wire 102, the end portion on the electrode 101 side of the inner layer 110a of the glass bead 110 is longer on the electrode 101 side than the end portion of the outer layer 110b. In this case, when the electrode structure 109 is sealed to the glass tube while increasing the contact area between the lead wire 102 and the glass bead 110 to further improve the sealing performance, the molten glass tube contacts the electrode 101. Can be prevented.

Note that the glass bead 110 is not limited to a two-layer structure, and may have a multilayer structure such as a three-layer structure or a four-layer structure in accordance with the inner diameter of a glass tube sealed using the electrode structure 100. In this case, for example, the innermost layer can be made longer than the outermost layer in the direction of the axis of the lead wire 102. Furthermore, it is preferable that the lead wire 102 is shorter from the innermost layer toward the outermost layer in the direction of the axis of the lead wire 102. In this case, heating from the glass tube to the glass bead 110 can be facilitated.
2. Electron Emissive Material An electron emissive material layer (not shown) may be formed on the surface of the electrode 101. In this case, the lamp voltage can be lowered compared to a lamp not provided with an electron emissive material layer. Specifically, the electron-emitting material layer is formed on the inner surface of the electrode 101, for example. The electron emissive material layer includes, for example, a rare earth element. This is because the cold cathode fluorescent lamp is effective in reducing the lamp voltage. Furthermore, the rare earth element is more preferably one or more of lanthanum (La) and yttrium (Y).

  The electron-emitting material layer may be any one of silicon (Si), aluminum (Al), zirconium (Zr), boron (B), zinc (Zn), bismuth (Bi), phosphorus (P), and tin (Sn). It is preferable that 1 or more types are included. In this case, the lamp voltage reduction effect can be further sustained.

Furthermore, a cesium (Cs) compound may be included in the electron-emitting material layer. In this case, the dark start characteristics of the lamp can be further improved. In addition to the electron-emitting material layer, a cesium compound may be attached to the inner surface or outer surface of the electrode 101. As the cesium compound, for example, it is preferable to use at least one of cesium sulfate, cesium aluminate, cesium niobate, cesium tungstate, cesium molybdate, and cesium chloride. The cesium compound is more preferably attached to the outer side surface of the electrode 101. In this case, the cesium compound can be moderately activated easily in the manufacturing process of the cold cathode fluorescent lamp. Furthermore, it is even more preferable that the electrode 101 is attached to the tip of the lamp central portion on the outer side surface. In this case, the cesium compound can be more easily activated in the manufacturing process of the cold cathode fluorescent lamp.
3. About glass tube (1) The thermal expansion coefficient of the glass bead 103 and the glass tube glass tube 201 is in the range of 3.0 × 10 ⁻⁶ [K ⁻¹ ] or more and 10.0 × 10 ⁻⁶ [K ⁻¹ ] or less. Can be used. In particular, the thermal expansion coefficient of the glass tube 201 is preferably in the range of 8.0 × 10 ⁻⁶ [K ⁻¹ ] to 10.0 × 10 ⁻⁶ [K ⁻¹ ]. In this case, since the intensity | strength of glass becomes weak, the effect of this invention can be exhibited especially.
(2) About UV Absorption 254 [nm] or 313 [nm] UV can be absorbed by doping a glass, which is a material of the glass tube 201, with a predetermined amount of transition metal oxide depending on the type. Specifically, for example, in the case of titanium oxide (TiO ₂ ), by doping at a composition ratio of 0.05 [mol%] or more, ultraviolet rays of 254 [nm] are absorbed and the composition ratio is doped at 2 [mol%] or more. Thus, it is possible to absorb ultraviolet rays of 313 [nm]. However, when titanium oxide is doped more than the composition ratio of 5.0 [mol%], the glass is devitrified, so the composition ratio is 0.05 [mol%] or more and 5.0 [mol%] or less. It is preferable to dope in the range.

In the case of cerium oxide (CeO ₂ ), 254 [nm] ultraviolet rays can be absorbed by doping with a composition ratio of 0.05 [mol%] or more. However, when cerium oxide is doped more than 0.5 [mol%], the glass is colored, so cerium oxide has a composition ratio of 0.05 [mol%] to 0.5 [mol%]. It is preferable to dope in the following range. In addition, since coloring of glass by cerium oxide can be suppressed by doping tin oxide (SnO) in addition to cerium oxide, cerium oxide can be doped to a composition ratio of 5.0 [mol%] or less. . In this case, if cerium oxide is doped with a composition ratio of 0.5 [mol%] or more, ultraviolet rays of 313 [nm] can be absorbed. However, even in this case, when the composition ratio of cerium oxide is more than 5.0 [mol%], the glass is devitrified.

  In the case of zinc oxide (ZnO), ultraviolet rays having a wavelength of 254 [nm] can be absorbed by doping with a composition ratio of 2.0 [mol%] or more. However, when zinc oxide is doped more than 20 [mol%], the glass may be devitrified, so zinc oxide is in the range of 2.0 [mol%] to 20 [mol%]. It is preferable to dope.

Further, in the case of iron oxide (Fe ₂ O ₃ ), 254 [nm] ultraviolet rays can be absorbed by doping at a composition ratio of 0.01 [mol%] or more. However, when iron oxide is doped more than the composition ratio of 2.0 [mol%], the glass is colored, so the iron oxide is contained in the composition ratio of 0.01 [mol%] to 2.0 [mol%]. It is preferable to dope in the following range.
(3) Infrared transmission coefficient The infrared transmission coefficient indicating the moisture content in the glass that is the material of the glass tube 201 is in the range of 0.3 to 1.2, particularly in the range of 0.4 to 0.8. It is preferable to adjust so that. If the infrared transmittance coefficient is 1.2 or less, it is easy to obtain a low dielectric loss tangent applicable to a high voltage application lamp such as a long cold cathode discharge lamp, and if it is 0.8 or less, the dielectric loss tangent is sufficient. It becomes small and becomes applicable to a high voltage application lamp.

  The infrared transmittance coefficient (X) can be expressed by the following formula.

[Expression 1] X = (log (a / b)) / t
a: Transmittance [%] of a minimum point in the vicinity of 3840 [cm ⁻¹ ]
b: Transmittance [%] of a minimum point in the vicinity of 3560 [cm ⁻¹ ].
t: Thickness of glass (4) Lead-free glass The glass used for the glass tube 201 has an oxide conversion of SiO ₂ of 60 wt% to 75 wt% and Al ₂ O ₃ of 1 wt%. _{~5 [wt%], Li 2} O is 0 [wt%] ~5 [wt %], K 2 O is 3 [wt%] ~11 [wt %], Na 2 O is 3 [wt%] ~12 [Wt%], CaO is 0 [wt%] to 9 [wt%], MgO is 0 [wt%] to 9 [wt%], SrO is 0 [wt%] to 12 [wt%], and BaO is 0 You may have a composition of [wt%]-12 [wt%]. In this case, an environment-friendly cold cathode discharge lamp that does not contain a lead component can be provided. Furthermore, the glass used for the glass tube 201 has an oxide conversion of SiO ₂ of 60 [wt%] to 75 [wt%], Al ₂ O ₃ of 1 [wt%] to 5 [wt%], B _2. O ₃ is 0 [wt%] to 3 [wt%], Li ₂ O is 0 [wt%] to 5 [wt%], K ₂ O is 3 [wt%] to 11 [wt%], Na ₂ O Is 3 [wt%] to 12 [wt%], CaO is 0 [wt%] to 9 [wt%], MgO is 0 [wt%] to 9 [wt%], and SrO is 0 [wt%] to 12 [wt%]. It is more preferable that [wt%] and BaO have a composition of 0 [wt%] to 12 [wt%].

Moreover, the glass used for the glass tube 201 is, in terms of oxide, SiO ₂ of 60 [wt%] to 75 [wt%], Al ₂ O ₃ of 1 [wt%] to 5 [wt%], Li ₂ O. 0.5 [wt%] to 5 [wt%], K ₂ O 3 [wt%] to 7 [wt%], Na ₂ O 5 [wt%] to 12 [wt%], and CaO 1 [Wt%] to 7 [wt%], MgO from 1 [wt%] to 7 [wt%], SrO from 0 [wt%] to 5 [wt%], BaO from 7 [wt%] to 12 [wt] %]. In this case, it is possible to provide an environment-friendly cold cathode fluorescent lamp that is easy to process into a lamp and does not contain a lead component.

Furthermore, the glass used for the glass tube 201 is, in terms of oxide, SiO ₂ of 65 [wt%] to 75 [wt%], Al ₂ O ₃ of 1 [wt%] to 5 [wt%], B ₂ O. ₃ 0 [wt%] ~3 [wt %], Li 2 O is 0.5 [wt%] ~5 [wt %], K 2 O is 3 [wt%] ~7 [wt %], Na 2 O is 5 [wt%] to 12 [wt%], CaO is 2 [wt%] to 7 [wt%], MgO is 2.1 [wt%] to 7 [wt%], and SrO is 0 [wt%]. ] To 0.9 [wt%], and BaO may have a composition of 7.1 [wt%] to 12 [wt%]. In this case, it does not contain a lead component, has an electrical insulating property suitable for lighting applications, and can prevent devitrification. Furthermore, the glass used for the glass tube 201 is, in terms of oxide, SiO ₂ of 65 [wt%] to 75 [wt%], Al ₂ O ₃ of 1 [wt%] to 3 [wt%], B ₂ O ₃ is 0 [wt%] to 3 [wt%], Li ₂ O is 1 [wt%] to 3 [wt%], K ₂ O is 3 [wt%] to 6 [wt%], Na ₂ O 7 [wt%] to 10 [wt%], CaO 3 [wt%] to 6 [wt%], MgO 3 [wt%] to 6 [wt%], SrO 0 [wt%] to 0 [wt%] It is more preferable that .9 [wt%] and BaO have a composition of 7.1 [wt%] to 10 [wt%].
(5) Shape of Glass Tube 201 The shape of the glass tube 201 is not limited to a straight tube shape, and may be, for example, an L shape, a U shape, a U shape, a spiral shape, or the like. Further, the cross section cut substantially perpendicular to the tube axis is not limited to a substantially circular shape, and may be a flat shape such as a track shape or a rounded round shape, an elliptical shape, or the like.
4). Regarding phosphors in the phosphor layer (1) UV absorption For example, in recent years, with the increase in size of liquid crystal color televisions, polycarbonate with good dimensional stability has been used for the diffusion plate that closes the opening of the backlight unit. ing. This polycarbonate is easily deteriorated by ultraviolet rays having a wavelength of 313 [nm] emitted from mercury. In such a case, a phosphor that absorbs ultraviolet light having a wavelength of 313 [nm] may be used. The following phosphors absorb 313 [nm] ultraviolet rays.

(A) Blue europium / manganese co-activated barium aluminate / strontium / magnesium [Ba _1-xy Sr _x Eu _y Mg _1-z Mn _z Al ₁₀ O ₁₇ ] or [Ba _1-xy Sr _x Eu _{y Mg 2-z Mn z Al} 16 O 27]
Here, x, y, and z are preferably numbers satisfying the conditions of 0 ≦ x ≦ 0.4, 0.07 ≦ y ≦ 0.25, and 0 ≦ z <0.1, respectively.

Examples of such phosphors include europium activated barium magnesium aluminate [BaMg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ ], [BaMgAl ₁₀ O ₁₇ : Eu ²⁺ ] (abbreviation: BAM-B), and europium attached. There are active barium aluminate / strontium / magnesium [(Ba, Sr) Mg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ ], [(Ba, Sr) MgAl ₁₀ O ₁₇ : Eu ²⁺ ] (abbreviation: SBAM-B), and the like.

(B) Green • Manganese inactive magnesium gallate [MgGa ₂ O ₄ : Mn ²⁺ ] (abbreviation: MGM)
Manganese activated cerium aluminate, magnesium, zinc [Ce (Mg, Zn) Al ₁₁ O ₁₉ : Mn ²⁺ ] (abbreviation: CMZ)
Terbium-activated cerium aluminate / magnesium [CeMgAl ₁₁ O ₁₉ : Tb ³⁺ ] (abbreviation: CAT)
Europium / manganese co-activated barium aluminate / strontium / magnesium [Ba _1-xy Sr _x Eu _y Mg _1-z Mn _z Al ₁₀ O ₁₇ ] or [Ba _1-xy Sr _x Eu _y Mg _{2 -z} Mn _z Al ₁₆ O _27]
Here, x, y and z are numbers satisfying the conditions of 0 ≦ x ≦ 0.4, 0.07 ≦ y ≦ 0.25, and 0.1 ≦ z ≦ 0.6, respectively, and z is 0.4 It is preferable that ≦ x ≦ 0.5.

Examples of such phosphors include europium / manganese co-activated barium aluminate / magnesium [BaMg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ , Mn ²⁺ ], [BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , Mn ²⁺ ] (abbreviation). : BAM-G), europium / manganese co-activated barium aluminate / strontium / magnesium [(Ba, Sr) Mg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ , Mn ²⁺ ], [(Ba, Sr) MgAl ₁₀ O ₁₇ : Eu ²⁺ , Mn ²⁺ ] (abbreviation: SBAM-G).

(C) Red • Europium activated phosphorus • Yttrium vanadate [Y (P, V) O ₄ : Eu ³⁺ ] (abbreviation: YPV)
Europium activated yttrium vanadate [YVO ₄ : Eu ³⁺ ] (abbreviation: YVO)
Europium-activated yttrium oxysulfide [Y ₂ O ₂ S: Eu ³⁺ ] (abbreviation: YOS)
Manganese-activated magnesium fluoride germanate [3.5MgO.0.5MgF ₂ .GeO ₂ : Mn ⁴⁺ ] (abbreviation: MFG)
Dysprosium-activated yttrium vanadate [YVO ₄ : Dy ³⁺ ] (red and green two-component phosphor, abbreviation: YDS)
In addition, you may mix and use the fluorescent substance of a different compound with respect to one type of luminescent color. For example, only BAM-B (absorbs 313 [nm]) in blue, LAP (does not absorb 313 [nm]) in green, BAM-G (absorbs 313 [nm]) in green, and YOX in red Alternatively, a phosphor of YVO (absorbs 313 [nm]) may be used. In such a case, as described above, the phosphor that absorbs the wavelength of 313 [nm] is adjusted so that the total weight composition ratio is larger than 50%, so that almost no ultraviolet rays leak out of the glass tube. Can be prevented. Therefore, when the phosphor layer 202 includes a phosphor that absorbs ultraviolet rays of 313 [nm], deterioration due to ultraviolet rays such as a diffusion plate made of polycarbonate (PC) that closes the opening of the backlight unit is suppressed, The characteristics as a backlight unit can be maintained for a long time.

Here, “absorbing ultraviolet rays of 313 [nm]” means an excitation wavelength spectrum near 254 [nm] (excitation wavelength spectrum means excitation light emission while changing the wavelength of the phosphor, and the excitation wavelength and emission intensity are changed. The intensity of the excitation wavelength spectrum at 313 [nm] is defined as 80 [%] or more. That is, the phosphor that absorbs ultraviolet rays of 313 [nm] is a phosphor that can absorb ultraviolet rays of 313 [nm] and convert it into visible light.
(2) High color reproduction Liquid crystal display devices typified by liquid crystal color televisions have been used as a light source for a backlight unit of the liquid crystal display device in accordance with the recent high color reproduction that has been made as part of higher image quality. There is a need to expand the reproducible chromaticity range in cathode discharge lamps and external electrode discharge lamps.

  In response to such a request, for example, by using the following phosphor, the chromaticity range can be expanded as compared with the case of using the phosphor in the embodiment. Specifically, in the CIE 1931 chromaticity diagram, the chromaticity coordinate value of the phosphor for high color reproduction includes a triangle formed by connecting the chromaticity coordinate values of the three phosphors used in the embodiment. Located at the coordinates that expand the reproduction range.

(A) Blue • Europium activated strontium chloroapatite [Sr ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ ] (abbreviation: SCA), chromaticity coordinates: x = 0.151, y = 0.065
In addition to the above, europium-activated strontium, calcium, barium, chloroapatite [(Sr, Ca, Ba) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ ] (abbreviation: SBCA) can also be used, and the wavelength 313 (nm) SBAM-B, which can absorb the ultraviolet rays, can also be used for high color reproduction.

(B) Green BAM-G, chromaticity coordinates: x = 0.139, y = 0.574
CMZ, chromaticity coordinates: x = 0.164, y = 0.722
CAT, chromaticity coordinates: x = 0.267, y = 0.663
As described above, these can also absorb ultraviolet rays having a wavelength of 313 [nm], and in addition to the three phosphor particles described here, MGM can also be used for high color reproduction.

(C) Red • YOS, chromaticity coordinates: x = 0.651, y = 0.344
YPV, chromaticity coordinates: x = 0.658, y = 0.333
MFG, chromaticity coordinates: x = 0.711, y = 0.287
As described above, these can also absorb ultraviolet rays having a wavelength of 313 [nm], and besides the three phosphor particles described here, YVO and YDS can also be used for high color reproduction.

  In addition, the chromaticity coordinate values shown above are representative values measured only with each phosphor powder, and due to the measurement method (measurement principle), etc., the chromaticity coordinates indicated by each phosphor powder The value may be slightly different from the value listed above. For reference, the chromaticity coordinate values of the phosphor powders of the first embodiment are YOX (x = 0.644, y = 0.353), LAP (x = 0.351, y = 0.585). , BAM-B (x = 0.148, y = 0,056).

  Furthermore, the phosphor used for emitting each color of red, green, and blue is not limited to one type for each wavelength, and a plurality of types may be used in combination.

  Here, a case where the phosphor layer 202 is formed using the above-described phosphor particles for high color reproduction will be described. In this evaluation, there are three evaluations in the case of using a phosphor for high color reproduction based on the area of NTSC triangle (NTSC triangle) connecting the chromaticity coordinate values of the three primary colors of the NTSC standard in the CIE1931 chromaticity diagram. It is performed by a ratio of the area of a triangle formed by connecting chromaticity coordinate values (hereinafter referred to as NTSC ratio).

  For example, when BAM-B is used as blue, BAM-G as green, and YVO as red (Example 1), the NTSC ratio is 92%, and SCA is used as blue, BAM-G as green, and YVO as red. (Example 2) When NTSC ratio is 100%, SCA is used as blue, BAM-G is used as green, and YOX is used as red (Example 3), NTSC ratio is 95%. The luminance can be improved by 10 [%] as compared with the above.

Note that the chromaticity coordinate values used for the evaluation here are measured in the state of a liquid crystal display device in which a lamp or the like is incorporated, so that the color reproduction range is around the above value depending on the combination with the color filter. there is a possibility.
5). About Filling Gas The rare gas may contain krypton. In this case, infrared radiation can be suppressed when the low-pressure discharge lamp is a cold cathode fluorescent lamp. Furthermore, it is preferable that krypton is contained in the rare gas within a range of 0.5 [mol%] to 5 [mol%]. In this case, infrared radiation of the cold cathode fluorescent lamp can be suppressed without greatly changing the lamp voltage. For example, argon is in the range of 0 [mol%] to 9.5 [mol%], neon is in the range of 90 [mol%] to 95.5 [mol%], and krypton is 0.5 [mol%]. ] In the range of 5 [mol%] or less. Furthermore, it is more preferable that krypton is contained in the rare gas within a range of 0.5 [mol%] to 3 [mol%]. Furthermore, it is even more preferable that krypton is contained in the rare gas in the range of 1 [mol%] to 3 [mol%].
6). Regarding the types of lamps In the above embodiments, the cold cathode fluorescent lamp, the internal / external electrode fluorescent lamp, the external electrode fluorescent lamp and the hot cathode fluorescent lamp have been mainly described as the low-pressure discharge lamp. It may be an ultraviolet lamp in which no body layer is formed.

  Moreover, it is not limited to a straight tube lamp, but may be an L shape, a U shape, a U shape, a spiral shape, or the like.

  The present invention can be widely applied to electrode structures, low-pressure discharge lamps, lighting devices, and image display devices.

100, 107, 109, 500 Electrode structure 101, 501 Electrode 102, 502 Lead wire 103, 108, 110, 503 Glass beads 103a, 108a, 110a Inner layer 103b, 108b, 110b Outer layer 200, 300, 400, 600 Low-pressure discharge lamp 201 Glass tube 700, 800, 900 Illuminating device 1000 Image display device

Claims (9)

An electrode structure having an electrode, a lead wire having one end connected to the electrode, and a glass bead formed so as to cover at least a part of the lead wire,
The glass bead has a multilayer structure. 2. The electrode structure according to claim 1, wherein an inner layer of the glass bead is longer than an outer layer in a direction of a line axis of the lead wire. The electrode structure according to claim 2, wherein the glass bead has an inner layer on the electrode side longer than an outer layer in the direction of the axis of the lead wire. The glass bead has a two-layer structure, and the ratio of the thickness of the inner layer to the outer layer at the intermediate portion in the longitudinal direction of the electrode structure in the glass bead is 1: 0.5. The electrode structure according to any one of claims 1 to 3, wherein the electrode structure is in the range of 1: 2 or less. The glass bead has a ratio of a length in the longitudinal direction of the electrode structure and a length in a direction substantially perpendicular to the longitudinal direction of the electrode structure in a range of 1: 1 to 1: 4. The electrode structure according to any one of claims 1 to 4, wherein: A low-pressure discharge lamp comprising: a glass tube; and the electrode structure according to any one of claims 1 to 5 sealed at at least one end of the glass tube. A low-pressure discharge lamp comprising a glass tube and a multi-layer glass bead sealed at at least one end of the glass tube. An illumination device comprising the low-pressure discharge lamp according to claim 6. An image display device comprising the illumination device according to claim 8.

Images