KR20070031856A - Discharge lamp, electrode for discharge lamp, method for producing electrode for discharge lamp, and illuminating device - Google Patents

Abstract

Long life and thinning of a hot cathode discharge lamp are aimed at. The discharge lamp 1 has electrodes 3 at both ends. The electrode 3 has the heater 4 to which the 1st lead part 4b and the 2nd lead part 4c extended from the rear end side of the coil part 4a, and the electron emission substance 3a was apply | coated. . The electrode 3 has a first lead portion 4b connected to the first lead wire 6a, a second lead portion 4c connected to the second lead wire 6b, and the coil portion 4a It is arrange | positioned in the longitudinal direction to the tube axis of the glass tube 2. Moreover, the electrode 3 is equipped with the sleeve 7 which opens the surface which opposes the front end and the rear end of the coil part 4a, and covers the circumference | surroundings of the coil part 4a. The opening end face 7a of this sleeve 7 protrudes from the tip of the coil part 4a, and protects the coil part 4a.

Discharge lamp, lighting device, hot cathode type, welding, spiral structure

Description

Discharge lamp, electrode for discharge lamp, method for producing electrode for discharge lamp, and illuminating device}

The present invention relates to a hot cathode type discharge lamp, an electrode for discharge lamps, a manufacturing method of an electrode for discharge lamps, and a lighting device. Specifically, the thinning of the glass tube and the long life of the electrode can be achieved by using an electrode having a coil section along the tube axis of the glass tube.

Conventionally, discharge lamps using phosphors have been used for light sources. Among the discharge lamps, the hot cathode discharge lamps have high luminous efficiency and high luminance, and therefore are used as backlights for liquid crystal displays, in addition to those used for lighting.

The hot cathode type discharge lamp is provided with electrodes at both ends of the glass tube, a rare gas such as argon and mercury are enclosed in the space inside the glass tube, and a phosphor is coated on the inner surface of the glass tube.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the structural example of the conventional discharge lamp of a hot cathode type | mold. The discharge lamp 51 has electrodes 53 at both ends of the glass tube 52. A rare gas such as argon and mercury are encapsulated in the space inside the glass tube 52, and the phosphor 52a is applied to a predetermined range of the inner surface of the glass tube 52.

The electrode 53 is equipped with the heater 54 which has the coil part 54a. The heater 54 is coated with an electron emitting material 53a such as barium oxide. The heater 54 is lengthened by applying tension between two lead wires 55 inserted and held at the end of the glass tube 52. For this reason, the electrode 53 is arrange | positioned in the horizontal direction at which the coil part 54a of the heater 54 orthogonally crosses the tube axis of the glass tube 52.

Referring to the light emission principle of the hot cathode discharge lamp 51, the electrode 53 is energized, the electron-emitting material 53a is heated by the heater 54, and a high frequency voltage is applied between the positive electrodes 53. Electrons are emitted from the electron emission material 53a to generate an arc discharge between the electrodes 53.

Electrons emitted and accelerated from the electron-emitting material 53a collide with the mercury atoms to excite the mercury atoms. The excited mercury atoms emit ultraviolet light. This ultraviolet light is converted into visible light by the phosphor 52a, and the discharge lamp 51 emits light.

In a conventional hot cathode discharge lamp, there is a problem that so-called ion spattering, in which ions generated during discharge impinge on an electrode and scatter an electron emission material, occurs remarkably. That is, since the coil of the heater which comprises an electrode is arrange | positioned in the horizontal direction orthogonal to the tube axis of a glass tube, an ion collision occurs in the part with many coils. For this reason, ion sputtering arises remarkably. If ion spattering occurs remarkably throughout the coil, the electron-emitting material is depleted during discharge, and stable arc discharge cannot be maintained for a long time. Thus, there is a problem that the lifetime of the electrode is shortened.

In addition, since the electrode is disposed long by applying tension to the heater, there is a problem that the electrode is easily disconnected by long-term use.

In this way, when the life of the electrode is short, there is a problem that the life of the discharge lamp is shortened as a result.

Moreover, since a heater extended in the direction orthogonal to a tube axis, there existed a problem that a tube diameter could not be made small.

Moreover, although the lifetime of the cold cathode discharge lamp etc. which can make a diameter small is long, there existed a problem that efficiency was bad because the cathode drop voltage was large.

This invention is made | formed in order to solve such a subject, Comprising: It aims at providing high efficiency, long life, and the manufacturing method of a discharge lamp with a thin diameter, an electrode for discharge lamps, an electrode for discharge lamps, and a lighting apparatus.

In order to solve the above-mentioned problem, the discharge lamp which concerns on this invention has the heater which the 1st lead part and the 2nd lead part which are connected with the said coil part extend from the rear end side of a coil part, and discharge | emits an electron to the said heater. The electrode is coated with a material, the electrode is connected to the first connecting member is connected to the first lead line respectively provided on both ends of the glass tube coated with the phosphor on the inner surface of the gas containing the light emitting material, The said 2nd connection member is connected to the 2nd lead wire respectively provided in the both ends of a glass tube, and the said coil part is arrange | positioned longitudinally along the tube axis of the said glass tube.

According to the discharge lamp according to the present invention, an arc discharge is generated by energizing an electrode to heat an electron-emitting material to emit electrons, and at the same time applying a voltage to both electrodes at a high frequency. Accelerated electrons impinge upon the luminescent material, causing the luminescent material to excite, for example emitting ultraviolet light. The ultraviolet rays collide with the phosphors, are converted into visible light, and discharge lamps emit light.

The ions generated during the discharge impinge on the electrodes and cause scattering of the electron-emitting material. However, since the coil portions of the electrodes are arranged in the longitudinal direction along the tube axis of the glass tube, the ions mainly collide with the tip of the coil portion. For this reason, the scattering of an electron emission substance is suppressed in most coil parts.

The electrode for discharge lamps which concerns on this invention is the heater part by which the 1st lead part and the 2nd lead part which are connected with this coil part extend from the rear end side of the coil part of a coil part, and apply | coated the electron emission substance, and a coil part. It is provided with the scattering prevention member which opens the surface which opposes the front end and the rear end of and covers the circumference | surroundings of this coil part.

According to the electrode for discharge lamps which concerns on this invention, when attached to the edge part of a glass tube, the coil part of a heater is arrange | positioned in a vertical direction according to observation of a glass tube. Ions generated during discharge mainly collide with the tip of the coil portion. Further, the scattering preventing member disposed around the coil portion suppresses the collision of ions with respect to the side surface of the coil portion and also suppresses the evaporation of the electron emission material.

The manufacturing method of the electrode for discharge lamps which concerns on this invention WHEREIN: The coil process of forming the heater of the shape which extends a 1st lead part and a 2nd lead part from the rear end side of a coil part, and a 1st connection member, and a 1st. A connecting reinforcing member welding step of joining two connecting members at the connecting portion, welding the first lead portion of the heater to the first connecting member of the connecting reinforcing member, and welding the second lead portion to the second connecting member; An introduction portion for holding the heater with the connection reinforcing member, applying an electron emitting substance to the heater, welding the first lead wire to the first connecting member, and welding the second lead wire to the second connecting member. It consists of a welding process and the cutting process which cut | disconnects a connection part from a connection reinforcement member, and isolate | separates a 1st connection member and a 2nd connection member.

According to the manufacturing method of the electrode for electric discharge lamps which concerns on this invention, in the heater which wound the wire rod, a 1st lead part is connected to the 1st connection member of a connection reinforcement member, and a 2nd lead part is connected to a 2nd connection member. do. Since the 1st connection member and the 2nd connection member are integrated in the connection part during a manufacturing process, it has a function which hold | maintains the shape of a heater. Then, the coating step of the electron-emitting material and the welding step of the lead line are performed while the shape of the heater is maintained to prevent deformation of the heater in the manufacturing step.

The lighting apparatus which concerns on this invention is equipped with the above-mentioned discharge lamp.

1 is a cross-sectional view showing a configuration example of a conventional discharge lamp of a hot cathode type.

2A is a sectional view of principal parts showing a configuration example of a discharge lamp of the present embodiment.

2B is an overall sectional view showing a configuration example of a discharge lamp of the present embodiment.

3A is a perspective view illustrating a configuration example of an electrode for discharge lamps of the present embodiment.

3B is a perspective view illustrating a configuration example of the electrode for discharge lamp of the present embodiment.

4A is an explanatory diagram showing an example of the configuration of a heater.

4B is an explanatory diagram showing an example of a configuration of a heater.

4C is an explanatory diagram showing an example of a configuration of a heater.

5 is a graph comparing the lifespan of the discharge lamp of the present embodiment and a conventional discharge lamp.

6A is a flowchart showing an example of a method of manufacturing the electrode for discharge lamp of the present embodiment.

6B is a flowchart showing an example of a method of manufacturing the electrode for discharge lamp of the present embodiment.

6C is a flowchart showing an example of a method of manufacturing the electrode for discharge lamp of the present embodiment.

6D is a flowchart showing an example of a method of manufacturing the electrode for discharge lamp of the present embodiment.

6E is a flowchart showing an example of a method of manufacturing the electrode for discharge lamp of the present embodiment.

6F is a flowchart showing an example of a method of manufacturing the electrode for discharge lamp of the present embodiment.

6G is a flowchart showing an example of a method of manufacturing the electrode for discharge lamp of the present embodiment.

6H is a flowchart showing an example of a method of manufacturing the electrode for discharge lamp of the present embodiment.

6I is a flowchart showing an example of a method of manufacturing the electrode for discharge lamp of the present embodiment.

7 is a perspective view illustrating a configuration example of a heater tab.

8 is a schematic sectional view showing a configuration example of the lighting apparatus of the present embodiment.

Best Mode for Carrying Out the Invention Hereinafter, embodiments of a discharge lamp, an electrode for a discharge lamp, a manufacturing method of an electrode for a discharge lamp, and an illumination device of the present invention will be described with reference to the drawings.

1.Configuration of discharge lamp and electrode

2A and 2B are sectional views showing a structural example of a discharge lamp of this embodiment, and FIGS. 3A and 3B are perspective views showing a configuration example of an electrode for discharge lamps of this embodiment. Here, FIG. 2A is a sectional view of an essential part of the end of the discharge lamp cut into a plane along the tube axis, and FIG. 2B is an overall sectional view of the discharge lamp. 3A is a perspective view of the electrode seen from the front end side, and FIG. 3B is a perspective view of the electrode seen from the rear end side.

The discharge lamp 1 of this embodiment is a hot cathode discharge lamp, and has electrodes 3 at both ends of a narrow glass tube 2 in a rod shape. The phosphor 2a is applied to the inner surface of the glass tube 2 in a predetermined range. In addition, a rare gas such as argon (Ar) or neon (Ne) and mercury (Hg), which is a light emitting material, are sealed in the glass tube 2.

The electrode 3 is provided with the coil part 4a, the heater 4 comprised from the 1st lead part 4b and the 2nd lead part 4c connected from this coil part 4a. The heater 4 is made of wire such as tungsten (W) or rhenium tungsten (Re-W). Compared with the tungsten wire rod, the rhenium tungsten wire rod is superior in strength at the time of heating, and thus, in this example, the rhenium tungsten is adopted.

4A to 4C are explanatory diagrams showing an example of the configuration of the heater 4. Although the manufacturing method of the heater 4 is mentioned later, For example, as shown in FIG. 4A, what wound the wire rods, such as a rhenium tungsten, in the spiral form, wound further spirally so that wires may not contact each other, The substantially cylindrical coil part 4a which has a structure is formed, and two lead parts 4b and 4c extend from the rear end of the coil part 4a.

In addition, as shown in the enlarged view of FIG. 4B, the wire wound in a spiral shape is further wound in a spiral shape, and as shown in the overall view of FIG. 4B, the wire wound in this spiral shape is further wound in a spiral shape. It is good also as a shape which forms the substantially cylindrical coil part 4a which has a spiral structure, and the two lead parts 4b and 4c extend from the rear end of the coil part 4a.

As described above, the double spiral structure in which the wire wound in a spiral shape is further wound in a spiral shape is called a double helical structure, and the triple spiral structure in which the wire wound in a spiral shape is wound in a spiral shape, and the wire wire is wound in a spiral shape. Is called a triple helical structure.

It is important that the heater 4 has the coil part 4a arrange | positioned longitudinally along a tube axis, As shown in FIG. 4C, you may have a single helical structure which wound only the wire rod in spiral shape.

In addition, the heater 4 is covered with a ternary alkaline earth metal oxide composed of barium (Ba), strontium (Sr), and calcium (Ca) as the electron emission material 3a. As the electron emission material 3a, a binary barium oxide may be used. Alternatively, as is generally known as an electron-emitting material such as a hot cathode discharge, zirconium oxide may be added in an amount of about 1 to 5% by weight of the above-described alkaline earth metal oxide.

4A and 4B, when the heater 4 has a double or triple helical structure, a long wire is required to form the coil portion 4a. That is, the surface area of the coil part 4a can be increased. As a result, the amount of the electron-emitting material 3a applied to the coil portion 4a can be increased, and the life of the electrode 3 can be increased. When the heater 4 has a triple spiral structure, the diameter of the coil part 4a becomes large. Therefore, in order to achieve the narrowing of the glass tube 2, the heater 4 preferably has a double spiral structure.

Here, as the wire rod forming the heater 4, a diameter of about 25 μm to 70 μm is used, but as a thickness capable of achieving both winding ease and strength when a double spiral structure is used, for example, about 45 μm to 55 μm Diameter is preferred.

The electrode 3 has a first heater tab 5a and a second heater tab 5b supporting the heater 4. The 1st heater tab 5a is a 1st connection member, and the rear end side of the 1st lead part 4b of the heater 4 is connected by welding. The 2nd heater tab 5b is a 2nd connection member, and the rear end side of the 2nd lead part 4c is connected by welding.

The 1st heater tab 5a and the 2nd heater tab 5b are board | plate materials, such as stainless steel (SUS304), for example, Although it demonstrates in the manufacturing method of the electrode 3 mentioned later, when manufacturing the electrode 3, The first heater tab 5a and the second heater tab 5b are integrally formed and function as a connection reinforcing member, and are separated during the manufacturing process.

The electrode 3 is connected to the first lead line 6a and the second lead line 6b through the first heater tab 5a and the second heater tab 5b. Since the 1st lead wire 6a and the 2nd lead wire 6b can be provided in the both ends of the glass tube 2, the edge part of the glass tube 2 penetrates from the outside to the inside substantially parallel to each other.

And the 1st heater tab 5a is connected by welding to the front end side of the part which extends inside the glass tube 2 of the 1st lead wire 6a, and the glass tube of the 2nd lead wire 6b The 2nd heater tab 5b is connected by welding to the front end side of the part extended in 2).

In this way, the electrode 3 supported by the first lead wire 6a and the second lead wire 6b has a coil portion 4a of the heater 4 vertically along the tube axis of the glass tube 2. It shall be arranged. For this reason, the ions generated by the discharge mainly collide with the tip of the coil portion 4a, and the side of the coil portion 4a is less likely to scatter the electron-emitting material 3a due to the collision of ions. .

In addition, since the electrode 3 supports the heater 4 on the lead line at two lead portions extending from the rear end side of the coil portion 4a, the heater 4 is structured such that tension is not applied to the heater 4, and disconnection hardly occurs. It becomes a composition.

In addition, in the present embodiment, the sleeve 3 is provided on the electrode 3 to prevent scattering and evaporation of the electron emission material 3a. The sleeve 7 is an example of a scattering prevention member, and is comprised of nickel (Ni), molybdenum (Mo), etc., and has a cylindrical shape which opened at both ends.

The sleeve 7 is inserted in the direction in which the coil portion 4a of the heater 4 is substantially parallel to the inside thereof and is mounted to the first heater tab 5a by the sleeve lid 8. Thereby, the sleeve 7 covers the circumference | surroundings of the coil part 4a in the form which opened the front end side and the rear end side of the coil part 4a.

The sleeve lid 8 is made of, for example, stainless steel SUS304, like the first heater tab 5a and the second heater tab 5b. In this example, the sleeve lead 8 is fixed to the first heater tab 5a. However, the sleeve lead 8 may be fixed to the second heater tab 5b. Here, the inner diameter of the sleeve 7 is larger than the outer diameter of the coil portion 4a of the heater 4, and the coil portion 4a of the heater 4 is inserted in a direction substantially parallel to the inside of the sleeve 7. At this time, the coil part 4a does not come into contact with the sleeve 7.

Moreover, the outer diameter of the sleeve 7 is smaller than the inner diameter of the glass tube 2, and is comprised so that the sleeve 7 and the glass tube 2 may not contact.

Moreover, the installation position of the sleeve 7 is set so that it may become a positional relationship in which the front-end | tip part of the coil part 4a does not protrude rather than the opening end surface 7a of the sleeve 7. On the other hand, the positional relationship between the sleeve 7 and the heater 4 is preferably a positional relationship where the tip end portion of the coil portion 4a enters inward from the opening end face 7a of the sleeve 7. The tip end of the opening end face 7a and the coil part 4a may be located in the same surface.

Moreover, the length of the sleeve 7 is made longer than the length of the coil part 4a, and it is set as the shape in which the whole side surface of the coil part 4a is covered by the sleeve 7. As shown in FIG.

In addition, the application | coating range of the fluorescent substance 2a of the inner surface of the glass tube 2 mentioned above is made into the position which becomes slightly outside from the opening end surface 7a of the sleeve 7 of the electrode 3. The range in which the phosphor 2a is applied becomes the light emitting portion of the discharge lamp 1.

2. Operation of discharge lamp

Next, operation | movement of the discharge lamp 1 of this embodiment is demonstrated. First, for example, 5 V between the first lead line 6a and the second lead line 6b in order to apply a voltage between the lead portions 4b and 4c of the heater 4 constituting each electrode 3. A voltage of a degree is applied, and the electron emission material 3a is heated by the heater 4. Then, a voltage of, for example, about 300V is applied at a high frequency between the positive electrodes 3. As a result, electrons are emitted from the electron-emitting material 3a to generate an arc discharge between the electrodes 3.

After the arc discharge is generated between the electrodes 3, the control is performed to apply a voltage of, for example, about 100V between the positive electrodes 3, and to apply a voltage of, for example, about 2V to each electrode 3. Is carried out. On the other hand, it is not necessary to apply a voltage to each electrode 3, but as described above, applying a voltage of about 2V leads to a longer life.

However, electrons emitted from the electron-emitting material 3a and accelerated collide with the mercury atoms to excite the mercury atoms. The excited mercury atoms emit ultraviolet light. This ultraviolet light is converted into visible light by the phosphor 2a, and the discharge lamp 1 emits light.

The ions generated during discharge impinge on the electrode 3 and cause scattering of the electron-emitting material 3a. However, since the coil portion 4a is disposed vertically along the tube axis of the glass tube 2, the ions are mainly in the coil portion. It collides with the tip of (4a). For this reason, the scattering of the electron emission substance 3a is suppressed in the most part of the side surface of the coil part 4a.

In addition, since the coil section 4a is inserted into the sleeve 7 and the opening end face 7a of the sleeve 7 protrudes from the tip of the coil 4a, the collision of ions at the tip of the coil 4a is also achieved. Is reduced. Thereby, exhaustion of the electron emission substance 3a can be suppressed over a long period of time. Therefore, the electrode 3 can emit electrons over a long period of time, thereby extending the life of the electrode 3.

In addition, the electron-emitting material 3a evaporates by the heating of the heater 4. When the sleeve 7 is not provided, the evaporated electron-emitting material 3a is deposited on the inner surface of the glass tube 2. On the contrary, the coil portion 4a is inserted into the sleeve 7 and the heater ( The electron emitting material 3a evaporated from 4 is deposited on the inner surface of the sleeve 7. As the heater 4 is heated, the sleeve 7 is also heated, and electrons are also emitted from the electron emission material 3a attached to the sleeve 7. Therefore, the lifetime of the electrode 3 can be extended.

Thus, since the lifetime of the electrode 3 can be extended, long lifetime of discharge etc. can be aimed at. Moreover, since the heater 4 is inserted in the sleeve 7, it can be heated to a desired temperature by the low voltage by heat radiation. For example, the voltage applied during preheating can be lowered from, for example, about 5V to about 3V, for example.

On the other hand, if the coil part 4a and the sleeve 7 contact, it will cause the temperature of the heater 4a to fall, and it will become necessary to apply a higher voltage in order to heat to desired temperature. For this reason, the coil part 4a and the sleeve 7 are made into non-contact as mentioned above.

In the discharge lamp 1 of this embodiment, since the coil part 4a of the heater 4 is arrange | positioned longitudinally along the tube axis of the glass tube 2, the diameter of the glass tube 2 is the diameter of the coil part 4a. It is possible to fine-tune in accordance with. In the hot cathode type discharge lamp of the conventional structure, the outer diameter of the glass tube was limited to about 6.2 mm. On the other hand, in the discharge lamp 1 of this embodiment, the external shape of the glass tube 2 can be made thin to about 2-3 mm. And since the coil part 4a is arrange | positioned longitudinally along the tube axis of the glass tube 2, the coil part 4a can ensure the length which can apply | coat an electron emission substance 3a in sufficient quantity. In addition, the heater 4 may be, for example, a double helix structure, whereby a larger amount of the electron emission material 3a can be applied.

By the way, as a direct backlight of a liquid crystal display, in order to aim at thinning of a display, the cold cathode discharge lamp of thin diameter was used. On the other hand, since the discharge lamp 1 of this embodiment arrange | positions the coil part 4a in a vertical form, narrowing of the glass tube 2 is possible. Thereby, even when the discharge lamp 1 of this example is used as a direct type backlight of a liquid crystal display, thickness reduction of a display can be attained.

Here, it is known that the hot cathode type discharge lamp has better luminous efficiency as compared to the cold cathode type discharge lamp, and the hot cathode type discharge lamp is known to have twice the efficiency and twice the luminance as the cold cathode type discharge lamp. . In general, it is known that in discharge lamps, the luminance is improved by narrowing the diameter of the glass tube.

For this reason, when the discharge lamp 1 of this example is used as a direct backlight of a liquid crystal display, and the brightness | luminance of the same grade as the case of using a cold-cathode discharge lamp is obtained, the number of the discharge lamps 1 to be used will be about half. Can be reduced.

In addition, when 10 discharge lamps 1 are used as a direct backlight of a 20-inch liquid crystal display, power consumption is about 33 watts. Since the power consumption of the backlight using the same number of cold cathode discharge lamps of the same size is about 55 watts, when the discharge lamp 1 of this example is used, the power consumption is reduced by about 40 percent. Thereby, compared with a cold cathode discharge lamp, brightness can be improved and power consumption can be reduced.

And since the coil part 4a can ensure the length which can apply | coat a sufficient quantity of the electron emission substance 3a, even if the glass tube 2 is made thin, long life can be attained.

FIG. 5 is a graph comparing the lifespan of the discharge lamp 1 of the present embodiment and the conventional discharge lamp, which is described above in the discharge lamp 1 of the present embodiment described with reference to FIGS. 2A, 2B, 3A, and 3B. As described above, the change in luminance when the voltage applied to each electrode 3 is 2 V is indicated by a broken line Ll. In addition, in the discharge lamp 1 of this embodiment, the change of the luminance when there is no voltage application to each electrode 3 is shown by the dotted dotted line L2. In addition, the change of the brightness | luminance of the discharge lamp of the conventional structure shown in FIG. 1 is shown by the solid line L3.

The discharge lamp of the conventional structure shown in FIG. 1 has a rapid decrease of an electron emission substance by ion sputtering, and the brightness | luminance falls to 50% of the brightness | luminance at the beginning of use about 7000 hours. Then, before reaching 10,000 hours, depletion of the electron-emitting material or disconnection of the electrode occurs.

On the other hand, in the discharge lamp 1 of this embodiment described with reference to FIGS. 2A, 2B and 3A, 3B, ion sputtering is unlikely to occur, and a sufficient amount of electron-emitting substance is irrespective of the diameter of the glass tube 2. Since 3a can be applied to the heater 4, when no voltage is applied to each of the electrodes 3, the relative luminance becomes 50% or more until about 35000 hours, and each electrode 3 has about 2V. When a voltage is applied, the relative luminance becomes 50% or more even after 60000 hours, and depletion of the electron emission material 3a does not occur.

In addition, since tension is not applied to the heater 4, ion sputtering is suppressed and disconnection of the heater 4 does not occur. As mentioned above, it was judged that the discharge lamp 1 of this embodiment has a lifetime of about 5 to 10 times compared with the conventional discharge lamp.

3. Manufacturing Method of Electrode

As mentioned above, since the electrode part 3 of this embodiment arranges the coil part 4a of the heater 4 along the tube axis of the glass tube 2, it extends from the rear end side of the coil part 4a. It is the structure which supports the heater 4 by a lead wire in two lead parts.

For this reason, it is the structure which does not apply tension to the heater 4, and it is a subject to hold | maintain the shape of the heater 4 at the time of manufacture of the electrode 3. Therefore, the lead portion and the lead wire are connected via the heater tab, the heater tab functions as a connection reinforcing member, and the shape of the heater 4 is maintained.

6A-6I are process charts showing an example of a method of manufacturing the electrode for discharge lamp of the present embodiment, and a method of manufacturing the electrode 3 using the heater tab will be described below.

(1) winding process

In the winding step, first, as shown in Fig. 6A, the wire 9 of, for example, the rhenium tungsten is spirally wound around the core wire 10 of molybdenum as the first coil step. Next, as the second winding process, as shown in FIG. 6B, the core wire 10 on which the wire rod 9 is wound is wound in a double spiral shape to form a substantially cylindrical coil portion 4a, and the coil portion 4a. The two lead portions 4b and 4c extend from the rear end of the cross section.

Here, in the coil portion 4a, adjacent wires 9 are formed so as not to contact each other. In this winding process, the heater 4 whose shape was hold | maintained by the core wire 10 is created. In addition, in this winding process, the process of taking the distortion of the wire rod 9 by heat treatment may be included.

(2) Heater tap welding process

In the heater tap welding step, the heater 4 is welded to the heater tap. 7 is a perspective view illustrating a configuration example of a heater tab. The heater tab 5 is a connection reinforcing member, and has the first heater tab 5a and the second heater tab 5b as described above.

Each of the first heater tab 5a and the second heater tab 5b has an L-shaped cross-sectional shape, and the L-shaped short side is connected to the connecting portion 5c to form the first heater tab 5a and the first heater tab 5a. The heater tab 5b of 2 is integrated.

In addition, a separation groove 5d is formed between the first heater tab 5a and the second heater tab 5b. The separating groove 5d extends to the connecting portion 5c and facilitates separation of the first heater tab 5a and the second heater tab 5b by cutting the connecting portion 5c described later.

Returning to FIGS. 6A-6I, in the heater tap welding step, as shown in FIG. 6C, the first heater tab 5a of the heater tab 5 integrated with the first heater tab 5a is shown in FIG. 6C. The rear end side of the lead portion 4b is welded. Moreover, the rear end side of the 2nd lead part 4c of the heater 4 is welded to the 2nd heater tab 5b. As a result, the heater assembly 11 in which the heater 4 and the heater tab 5 are integrated is created. In this heater tap welding step, since the shape of the heater 4 is maintained by the core wire 1, no shape collapse occurs.

(3) melting process

In the melting step, as shown in FIG. 6D, the molybdenum core wire 10 wound around the wire rod 9 of rhenium tungsten is melted. For example, the heater assembly 11 is immersed in a mixed acid solution of sulfuric acid and acetic acid to dissolve the core wire 10 of molybdenum. Here, since rhenium tungsten and stainless do not dissolve in the mixed acid solution, the heater 4 and the heater tab 5 remain as they are.

By the way, since the core 4 of molybdenum 10 melt | dissolves, the heater 4 weakens intensity | strength with respect to external force, but the heater 4 has the structure in which the 1st lead part 4b and the 2nd lead part 4c are integrated. Since it is supported by the heater tab 5 of the heater assembly 11, sufficient strength is maintained throughout the heater assembly 11 so that no form collapse occurs during operation.

(4) application process

In the application step, as shown in FIG. 6E, the electron-emitting material 3a is applied to the heater 4. In this example, (Ba, Sr, Ca) CO 3, which is a ternary barium oxide, is applied to the heater 4. Application of the electron-emitting material 3a is performed according to, for example, a spraying method. In the spraying method, for example, spraying the electron emitting material 3a on the heater 4 while rotating the heater assembly 11, the electron emitting material 3a at a uniform density to the inside of the coil portion 4a. Can be applied.

In addition, the application | coating of the electron emission substance 3a may be a dip method. That is, the heater 4 of the heater assembly 11 may be placed in a container in which the electron emission material 3a is placed, and the electron emission material 3a may be applied to the coil portion 4a.

Here, (Ba, Sr, Ca) CO 3 coated on the heater 4 changes to (Ba, Sr, Ca) 0 by heating in the manufacturing process. As for the film thickness of the electron emission material 3a apply | coated to the coil part 4a, about 3060 micrometer is preferable.

(5) Sleeve welding process

 In the sleeve welding step, first, as shown in FIG. 6F, the sleeve lead 8 is welded to the sleeve 7. Thereby, the sleeve assembly 12 in which the sleeve 7 and the sleeve lid 8 were integrated is produced. A heat treatment may be performed on the sleeve assembly 12 to add dirt or distortion.

Next, as shown in Fig. 6G, the assembly 11 and the sleeve assembly 12 where the application of the electron-emitting material 3a is finished are connected. First, the coil part 4a of the heater 4 is inserted in the sleeve 7. At this time, in the state where the sleeve lead 8 is located in the 1st heater tab 5a, the side of the coil part 4a is aligned so that it may not contact the inner surface of the sleeve 7. As shown in FIG.

Moreover, positioning is performed so that the tip end of the coil part 4a may be inward of the opening end surface 7a of the sleeve 7. And the sleeve lead 8 is connected to the 1st heater tab 5a by welding. As a result, the heater assembly 11 and the sleeve assembly 12 are integrated.

(6) lead wire welding process

In the lead-in welding process diagram, as shown in FIG. 6H, the heater assembly 11 which is completed until installation of the sleeve assembly 12 is connected to the first lead line 6a and the second lead line 6b.

First, the 1st lead wire 6a and the 2nd lead wire 6b are integrated by the stem glass 13. The first lead wire 6a and the second lead wire 6b are supported by the stem glass 13 in substantially parallel at predetermined intervals so that they do not contact each other.

And the 1st lead wire 6a and the 1st heater tab 5a are connected by welding, and the 2nd lead wire 6b and the 2nd heater tab 5b are connected by welding.

By the way, the space between the first lead portion 4b and the second lead portion 4c of the heater 4 and the first lead line 6a and the second lead line supported by the stem glass 13 are supported. In the case where the spacing of (6b) is different, bending processing is required if the lead portion and the lead line are to be directly connected. On the other hand, when a lead part and a lead wire are connected through the 1st heater tab 5a and the 2nd heater tab 5b, a bending process becomes unnecessary. In addition, the lead portion and the lead wire are welded to the plate-shaped heater tab to facilitate alignment. Moreover, connection strength improves.

(7) cutting process

In a cutting process, the connection part 5c of the heater tab 5 shown in FIG. 7 is cut | disconnected with a laser etc. Although the cutting | disconnection position C of the connection part 5c is shown by the dashed-dotted line, the heater tab 5 is the separation groove 5d between the 1st heater tab 5a and the 2nd heater tab 5b. Since the connection part 5c is cut | disconnected, since the clearance gap is formed between the 1st heater tab 5a and the 2nd heater tab 5b, both are electrically independent.

In the above process, as shown in FIG. 6I, the electrode 3 is completed. Here, in the lead-in welding process from the application | coating process mentioned above, the heater 4 is supported by the heater tab 5 in which the 1st heater tab 5a and the 2nd heater tab 5b are integrated. For this reason, the shape collapse of the heater 4 does not occur.

And in the step of separating the first heater tab 5a and the second heater tab 5b in the cutting step, the first lead wire 6a and the second lead wire supported by the stem glass 13 are supported. The heater 4 becomes the form supported by 6b, and form collapse does not occur again.

As mentioned above, the electrode 3 can be manufactured by maintaining the shape of the heater 4 by the heater tab 5, and the deformation | transformation of the heater 4 in a manufacturing process can be prevented. Since the yield improves by this, the electrode 3 which has the heater 4 by which the coil part 4a is arrange | positioned longitudinally along the tube axis of the glass tube 2 can be manufactured at low cost.

On the other hand, since the first heater tab 5a and the second heater tab 5b are L-shaped even after the cutting of the connecting portion 5c, the strength can be increased. Thereby, the 1st heater tab 5a and the 2nd heater tab 5b function not only as a reinforcement member in a manufacturing process, but also as a reinforcement member when used as a product.

8 is a schematic cross-sectional view showing a configuration example of the lighting apparatus of the present embodiment. The lighting device 14 according to the present embodiment includes the discharge lamp 1, the diffusion plate 15, the luminance upsheet 16, and the reflective sheet 17 described in FIGS. 2A, 2B, 3A, and 3B. A case 18 is provided.

As for the lighting device 14, the reflective sheet 17 which reflects light is arrange | positioned on the front surface of the bottom face of the case 18, for example, and the discharge lamp 1 of several lines is provided above the reflective sheet 17, for example. For example, arranged side by side in parallel.

Further, a diffusion plate 15 is disposed above the discharge lamp 1 to diffuse the light emitted from the discharge lamp 1 so that the light quantity is uniform, and above the diffusion plate 15, the diffusion plate 15 is disposed. The luminance upsheet 16 for raising the luminance of the light emitted by the is arranged.

In the above configuration, when the discharge lamp 1 emits light, the direct light from the discharge lamp 1 is emitted. Reflected light from the reflecting sheet 17 enters and diffuses into the diffuser plate 15, and the luminance on the light emitting surface of the illuminating device 14 becomes almost uniform. The luminance upsheet 16 then raises the luminance of the light, and the illumination device 14 emits surface light.

2A and 2B, the discharge lamp 1 of this embodiment arrange | positions the coil part 4a of the heater 4 which comprises the electrode 3 along the tube axis of the glass tube 2 vertically. In addition, since the coil part 4a can ensure the length which can apply | coat a sufficient quantity of the electron emission substance 3a, even if the glass tube 2 is made thin, long life can be attained.

Thereby, using the discharge lamp 1 of this embodiment, the illuminating device 14 of a long life can be implement | achieved in thin form.

In the discharge lamp according to the present invention, the coil portion of the heater to which the electron-emitting material is coated has an electrode arranged vertically along the tube axis of the glass tube. In the electrode according to the present invention, the ions generated during discharge collide with the tip of the coil portion mainly, and ion sputtering can be suppressed on most of the side surfaces of the coil portion.

As a result, depletion of the electron emitting material can be suppressed, and electrons can be emitted over a long period of time. Moreover, since it is not the form which puts tension on a heater and arranges it for a long time, disconnection of a heater can be suppressed. Thus, the life of the electrode can be extended. Then, the life of the electrode can be extended, and the life of the discharge lamp can be extended.

Moreover, the electrode can thin the tube diameter of a glass tube, without shortening the length of a coil part in which the coil part of a heater is arrange | positioned longitudinally along the tube axis of a glass tube.

Although the diameter of a glass tube can be narrowed and brightness can be improved, since the coil part can ensure the length which can apply | coat a sufficient quantity of electron emission material, brightness can be improved while prolonging a lifetime.

The electrode for discharge lamps which concerns on this invention can arrange | position a scattering prevention member further around a coil part, and can suppress ion sputtering more. In addition, scattering of the surface or the phosphor caused by evaporation of the electron emitting material can be prevented, and depletion of the electron emitting material can be suppressed. Thereby, in the discharge lamp using the electrode which arrange | positioned the scattering prevention member around the coil part, further life extension can be aimed at.

In the manufacturing method of the electrode for discharge lamps which concerns on this invention, since a process, such as application | coating of an electron emission substance, is performed in the form which supported the heater with the connection reinforcement member, deformation of the heater in a manufacturing process can be prevented. As a result, the yield is improved, so that the electrode with the heater in which the coil portion is disposed vertically along the tube axis of the glass tube can be manufactured at low cost.

In the lighting apparatus according to the present invention, the above-described discharge lamp is provided, and the thickness and the life of the battery can be extended.

Since the present invention is a discharge lamp having a long tube life and a thin tube diameter, the present invention can be applied not only to lighting fixtures, but also to backlights such as liquid crystal displays, and to achieve high efficiency, long life, and thickness reduction of liquid crystal displays.

Claims (16)

A heater having a first lead portion and a second lead portion connected to the coil portion from a rear end side of the coil portion, the electrode having an electron-emitting material coated thereon; The electrode has a first lead portion connected to first lead lines respectively provided at both ends of a glass tube coated with a phosphor on an inner surface of a gas containing a light emitting material, and the second lead portion is connected to a second lead line. And the coil part is arranged in the longitudinal direction along the tube axis of the glass tube. The method of claim 1, And said heater is further wound in a spiral shape in a state where the spiral wires are in non-contact with each other, so that the coil part is constituted. The method of claim 1, And said electrode is provided with a scattering prevention member which opens the surface which opposes the front end and the rear end of the said coil part, and covers the circumference | surroundings of the said coil part. The method of claim 3, The scattering preventing member is a cylindrical sleeve having both ends opened, and the coil portion is inserted into the sleeve. The method of claim 4, wherein And said electrode has a distal end disposed inward from an opening end face on the distal end of the sleeve. The method of claim 1, The electrode has a first connecting member for connecting the first lead portion and the first lead wire and a second connecting member for connecting the second lead portion and the second lead wire, A discharge lamp comprising a connection reinforcing member in which a connection member of 1 and the second connection member are separated. The method of claim 4, wherein The electrode has a first connecting member for connecting the first lead portion and the first lead wire and a second connecting member for connecting the second lead portion and the second lead wire, And a connection reinforcing member in which the first connecting member and the second connecting member are separated, The said sleeve is supported by either one of the said 1st connection member and the said 2nd connection member, The discharge lamp characterized by the above-mentioned. A heater to which a first lead portion and a second lead portion connected to the coil portion extend from a rear end side of the coil portion, and to which an electron-emitting material is applied; And a scattering preventing member which opens a surface facing the front end and the rear end of the coil part to cover the periphery of the coil part. The method of claim 8, The heater is a discharge lamp electrode, characterized in that the coil portion is configured by winding more spirally in a state in which the wire wound in a spiral form is in contact with each other. The method of claim 8, The scattering preventing member is a cylindrical sleeve having both ends opened, and the coil part is inserted into the sleeve. The method of claim 10, A discharging lamp electrode, wherein the distal end of the coil portion is disposed inward from an opening end surface of the distal end of the sleeve. The method of claim 10, Connection which has a 1st connection member which connects with a said 1st lead part, and a 2nd connection member which connects with a said 2nd lead part, and the said 1st connection member and the said 2nd connection member are isolate | separated. With reinforcing members, And the sleeve is supported by either one of the first connecting member and the second connecting member. A winding step of winding the wire rod to form a heater having a shape in which the first lead portion and the second lead portion extend from the rear end side of the coil portion; The first connecting member of the heater is welded to the first connecting member of the connecting reinforcing member in which the first connecting member and the second connecting member are integrated at the connecting portion, and the second connecting member is welded to the second connecting member. A connecting reinforcing member welding step of welding a lead portion of the An application step of holding the heater with the connection reinforcing member and applying an electron emission material to the heater; An introduction part welding step of welding a first introduction line to the first connection member and a second introduction line to the second connection member; The manufacturing method of the electrode for discharge lamps comprised by the cutting process which cut | disconnects the said connection part from the said connection reinforcement member, and isolate | separates the said 1st connection member and the said 2nd connection member. The method of claim 13, The winding process, The first winding process of winding the wire rod to the core wire, And a second winding process of winding the wire wound around the core wire in a spiral shape which is non-contact with each other. A dissolution step of dissolving the core wire is performed after the connection reinforcing member welding step. The method of claim 13, A sleeve welding step of inserting the heater inside the cylindrical sleeve and welding the sleeve to either the first connecting member or the second connecting member is performed after the coating step. The manufacturing method of the electrode for discharge lamps made into. The electric discharge lamp of any one of Claims 1-7 is used.

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