JPH0650231U - Fluorescent discharge lamp - Google Patents

Abstract

(57) [Summary] [Objective] In fluorescent discharge using a structure containing a mercury-releasing alloy and an alloy getter as a discharge electrode, a mercury-releasing alloy and an alloy getter are required without shortening the effective light emission length even if the bulb diameter becomes thin. Make it easy to secure the quantity. A mercury-releasing alloy 5 mainly composed of an intermetallic compound of titanium and mercury, and an alloy getter 6 mainly composed of an intermetallic compound composed of one of zirconium or titanium and one of aluminum or nickel. , A cylindrical body 4 made of an electrode material having an opening end facing the center of the container 1 is press-fitted into the cylinder, and the end surface of the filled mercury-releasing alloy and alloy getter is the opening of the cylindrical body 4. A discharge electrode having a structure 3 which is recessed from the end to the back is adopted.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cold cathode type fluorescent discharge lamp, and more particularly, to an improvement of a discharge electrode structure accompanying a reduction in diameter of a container.

[0002]

[Prior art]

 In the manufacture of fluorescent discharge lamps, if mercury is filled in the bulb exhaust process, mercury vapor will be emitted to the vacuum system and the outside to some extent, so the amount of mercury supplied will be several to ten times more than the required amount. It The use of such a large amount of liquid mercury poses a problem in terms of pollution control, and excessive mercury supplied to the bulb contaminates the phosphor and reduces the light output. Therefore, a mercury-releasing alloy made of an intermetallic compound containing titanium and mercury was provided on one surface of the ribbon-shaped metal plate, and an alloy getter mainly made of an intermetallic compound made of zirconium and aluminum was provided on the other surface. The structure can be cut into a required size, and an appropriate number of cut parts can be welded to the inner leads for use. When this structure is heated to about 900 ° C. at high frequency after sealing the valve with exhaust gas, the intermetallic compound of mercury decomposes by this heat and releases mercury into the valve. Impurity gas such as oxygen is absorbed by the alloy getter activated by its heat. As a result, it is possible to regulate the amount of enclosed mercury without the mercury escaping to the outside and to maintain a high vacuum inside the bulb. An example of a document describing such a structure is Japanese Utility Model Publication No. 2-35167.

[0003]

[Problems to be solved by the device]

 However, when such a structure is applied to a fluorescent discharge lamp with a small bulb diameter, if the cut size of the structure is reduced according to the bulb diameter, the cut amount of mercury-silver-releasing alloy and alloy getter per piece is very small. Therefore, the required amount of mercury cannot be secured unless a large number of cut structures are connected to the inner leads, and the number of cut structures that can be built in is limited depending on the valve diameter. It was revealed by the present inventor that such a structure cannot be applied to a thin fluorescent discharge lamp. This is even more the case for thin and long valve diameters, because the required mercury amount increases further. In order to deal with this, it is possible to use a structure that is cut to be long in the axial direction of the bulb, but due to the property that the structure doubles as a discharge electrode, the effective light emission length becomes short and it is not practical. Further, the mercury-releasing alloy and alloy getter provided on the cut structure contain metal atoms as an electron emitting substance having a low work function to start discharge, and are exposed toward the inner surface of the bulb to some extent. The metal atoms of the mercury-releasing alloy and the alloy getter are sputtered by ion bombardment during discharge, and the sputtered metal atoms adhere to the surrounding phosphor screen to form a thin film, causing a so-called blackening phenomenon. The progress of such a blackening phenomenon gradually shortens the effective emission length, and at the same time forms a mercury compound to reduce the amount of mercury in the discharge lamp, thereby shortening the life of the fluorescent discharge lamp.

An object of the present invention is to provide a mercury-emitting alloy and an alloy getter in a fluorescent discharge in which a structure including a mercury-releasing alloy and an alloy getter is used as a discharge electrode without shortening an effective light emission length even if a bulb diameter becomes thin. The purpose is to easily secure the amount, to increase the concentration or directivity of the discharge, and to alleviate the blackening of the bulb near the discharge electrode. The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0005]

[Means for Solving the Problems]

 The fluorescent discharge lamp according to the present invention is mainly composed of a mercury emitting alloy mainly composed of an intermetallic compound of titanium and mercury, and an intermetallic compound composed of one kind of zirconium or titanium and one kind of aluminum or nickel. The alloy getter is mixed and press-filled into a cylinder of a cylindrical body made of an electrode material with the opening end facing the center of the container, and the end surface of the filled mercury-releasing alloy and alloy getter. Is composed of a discharge electrode having a structure in which a hollow is formed from the open end of the cylindrical body to the inside thereof, and leads electrically connected to the cylindrical body of the structure are led out of the container. To be done. Such an electrode structure is most suitable for a fluorescent lamp of a container having an outer diameter of 2 mm to 4 mm and an overall length of 50 mm to 300 mm.

For the electrical connection between the structure and the lead, a cap integrally fitted with the base end of the structure and formed by press working together with the lead can be used. In order to be applicable to leads and structures universally, it is advisable to adopt a connector that holds the outer circumference of the lead at one end and the outer circumference of the tubular body at the other end.

[0007]

[Action]

 According to the above means, the structure in which the mercury-releasing alloy and the alloy getter are press-filled into the tubular body has a length of less than half the length of the plate-like structure having the mercury-releasing alloy and the alloy getter on the surface ( The same amount of contained mercury can be obtained (with the same width). This means that the effective emission length can be extended even when a mercury discharge alloy and alloy getter are used to construct a fluorescent discharge lamp with a very small bulb diameter of about several mm, and the amount of light emission with respect to the entire length of the fluorescent discharge tube is increased. Can be increased.

In addition, since the mercury-releasing alloy and the alloy getter are recessed with respect to the cylindrical body at the tip of the structure, the discharge electrode formed by the structure realizes a hollow cathode, and the concentration or directivity of the discharge is achieved. To improve the brightness or the stability of discharge. In particular, the recess can be formed by the release of mercury from the mercury emitting structure during the manufacturing process.

Further, the mercury-releasing alloy and the alloy getter are susceptible to sputtering due to ion bombardment due to their composition, but since the surroundings are covered with a cylindrical body made of an electrode material, spattering due to ion bombardment during discharge, etc. The metal atoms of the released mercury-releasing alloy and alloy getter are prevented from easily adhering to the fluorescent surface near the discharge electrode, and the blackening of the bulb near the discharge electrode is mitigated.

Since the mercury-releasing alloy and the alloy getter have a small surface area in contact with air in the tubular structure as compared with the plate-like structure, the mercury-releasing alloy and alloy getter are stored when the structure is stored as a component or in the manufacturing process. Less natural oxidation. Therefore, the adoption of such a structure suppresses the situation where impurities such as mercury oxide are directly enclosed in the bulb, and also suppresses the progress of blackening due to the sputtering of such impurities.

When a cylindrical structure is adopted, oxidation of the mercury-releasing alloy and alloy getter in the cylinder is almost blocked, and mercury is easily released, and an oxide film is formed only on the surface of the structure tip. It's just that. Therefore, the mercury in the bulb sealing process can be easily released without the need for a mercury release process in which the heating temperature and time are specially controlled, and a small amount of mercury is continuously released by the heating by the lighting drive. Therefore, even if the mercury is gradually consumed by forming a compound with the residual gas in the bulb or the electrode material or the phosphor during lighting, the mercury can be replenished from the mercury-releasing alloy of the structure. In this respect as well, the life of the fluorescent discharge lamp is extended.

[0012]

【Example】

 FIG. 1 shows a cold cathode fluorescent discharge lamp according to an embodiment of the present invention. In the same figure (A), the vicinity of the discharge electrode on the left side of the fluorescent discharge lamp is typically shown, but the opposite side is also symmetrically configured. The fluorescent discharge lamp of the present embodiment consumes a few watts and is a small one used as a backlight for liquid crystal displays. In FIG. 1, reference numeral 1 denotes a straight-tube type glass bulb, which is an example of a container, and has an outer diameter of 2 mm to 4 mm and a total length of 50 mm to 300 mm. The bulb 1 has a phosphor coating (not shown) formed on the inner surface thereof, is filled with an inert gas such as a mixture of neon and argon at 50 Torr, and has an end electrically connected to a lead 2 for discharge. The structure 3 as an electrode is built in and hermetically sealed. The power consumption of the fluorescent discharge lamp according to the present embodiment is about 1.5 to 2.0 watts when the outer diameter of the bulb is 3 mm and the total length is 200 mm. It is a power consumption type.

The structure 3 is mainly composed of an intermetallic compound of titanium and mercury in a cylinder of a cylindrical body 4 made of an electrode material (for example, stainless steel or nickel) having an opening end facing the center of the bulb 1. And the alloy getter 6 mainly composed of an intermetallic compound consisting of one kind of zirconium or titanium and one kind of aluminum or nickel. The end faces of the mercury-releasing alloy 5 and the alloy getter 6 are recessed from the open end of the cylindrical body 4 to the inner part of the cylinder (this recess is hereinafter also simply referred to as a recess 7). As is clear from its composition, the alloy getter 6 has an electron emission action for increasing secondary electron emission due to γ action at the start of discharge, and a getter action for absorbing impure gas inside the valve. . The mercury-releasing alloy 5 and the alloy getter 6 are powders, and they are mixed and press-filled into the tubular body 4. In this embodiment, the electrical connection between the tubular body 4 and the lead 2 is not particularly limited, but the outer peripheral portion of the lead 2 is sandwiched at one end and the outer peripheral portion of the tubular body 4 at the other end. It is performed by using a connecting tool 8 for holding the. The connector 8 is made of an electrode material (such as a nickel-plated iron plate), and a split end portion 9 is formed at each sandwiched portion. Is versatile.

In obtaining the fluorescent discharge lamp of the present embodiment, the mercury-releasing alloy 5 is decomposed by the heat of about 800 ° C. when the glass bulb 1 is hermetically sealed, and a required amount of mercury is generated in the bulb 1. It is released inside. For example, when the outer diameter of the structure 3 is 1 mm, about 0.7 mg of mercury is released. This is because when the cylindrical structure 3 is adopted, the mercury-releasing alloy 5 and the alloy getter 6 in the cylinder are almost prevented from being oxidized and mercury is easily released, and the oxide film is formed only on the surface of the tip of the structure 3. However, the oxide film can be removed by shaving it in the manufacturing process to form the recess 7. Therefore, the mercury is released by the heat of the bulb sealing step even if the mercury releasing step in which the heating temperature and the time are specifically controlled is not performed. In the mercury release by this, since the temperature and heating time control for that purpose are not performed, for example, when the outer diameter of 3 of the structure is 1 mm, about 0.7 mg of mercury is released. If the size of the bulb is about 3 mm × 200 mm, this is a sufficient amount of mercury. Since the required amount of mercury is proportional to the volume of the bulb, if the above amount of mercury is not sufficient, the structure 3 is heated from the outside of the bulb 1 with a high-frequency coil (not shown) after sealing, depending on the heating temperature and time. Further, mercury is released from the mercury releasing alloy 5. As a result, decomposition products having a reduced mercury content remain in the mercury-releasing alloy 5. At this time, as shown in FIG. 1 (B), even if the structure 4 in which the mercury-releasing alloy 5 and the alloy getter 6 are press-fitted into the entire cylindrical body 4 is used, the mercury is not added during the manufacturing process. Forming the concave portion 7 by releasing the concave portion 7 can be formed in a later step without forming the concave portion 7 in the structure 3 in advance. When mercury is released from the mercury-releasing alloy 5, impure gas such as water vapor and oxygen is also released, but this impure gas is absorbed by the alloy getter 6 activated by the heat and the inside of the valve 1 is made into a high vacuum. keep. The alloy getter 6 in the fluorescent discharge lamp completed through the mercury emission treatment contains a reaction product in which an impure gas is adsorbed.

According to the above embodiment, the following effects are obtained. (1) By adopting the structure 3 in which the mercury-releasing alloy 5 and the alloy getter 6 are press-filled in the cylindrical body 4, the axial direction of the structure required to secure the required amounts of the mercury-releasing alloy and the alloy getter. The length can be halved compared to the case where a plate-like structure having a mercury-releasing alloy and an alloy getter on the surface is adopted. Therefore, even if the mercury discharge alloy 5 and the alloy getter 6 are used to construct a fluorescent discharge lamp with a very small bulb diameter of about several mm, the effective light emission length can be increased and the light emission amount with respect to the entire length of the fluorescent discharge tube can be increased. You can When the length of the discharge tube is long and the bulb volume is large, the amount of mercury can be easily increased by increasing the length of the structure 3 or by increasing the diameter of the structure 3. Can be handled extremely easily. (2) Since the concave portion 7 is formed at the projecting end of the structure 3, the discharge electrode formed by the structure 3 realizes a hollow cathode, and the concentration or directivity of discharge is increased to improve the brightness or discharge. Can achieve stability. In particular, the recess 7 can be formed by releasing mercury from the mercury emitting structure 5 in the manufacturing process. (3) The mercury-releasing alloy 5 and the alloy getter 6 are more susceptible to spatter due to ion bombardment or the like than the cylindrical body 4 made of an electrode material because of its composition, but the periphery thereof is covered with the cylindrical body 4. Therefore, it is necessary to prevent the metal atoms of the mercury-releasing alloy and alloy getter sputtered by ion bombardment during discharge from easily adhering to the fluorescent surface near the discharge electrode, and to mitigate the blackening of the bulb near the discharge electrode. You can (4) Compared to the plate-shaped structure, the cylindrical structure 3 has a smaller surface area where the mercury-releasing alloy 5 and the alloy getter 6 come into contact with the air, so that the structure 3 is stored as a component or during the manufacturing process. There is little natural oxidation of the emission alloy 5 and the alloy getter 6. Therefore, if such a structure 3 is adopted, it is possible to suppress the situation where impurities such as mercury oxide are directly sealed in the bulb, and it is also possible to suppress the progress of blackening due to the sputtering of such impurities. (5) When the tubular structure 3 is adopted, the mercury-releasing alloy 5 and the alloy getter 6 in the cylinder are placed in a state in which oxidation is almost blocked and mercury is easily released, similarly to the above. The oxide film is formed only on the surface of the. Therefore, it is possible to easily release mercury by the heat of the sealing process of the bulb 1 without passing through the mercury releasing process of which the heating temperature and time are specially controlled, and the minute amount of mercury is gradually released by the heating by the lighting drive. Since it is possible to continue, even if mercury is gradually consumed by forming a compound with the residual gas in the bulb or the electrode substance or the fluorescent substance during lighting, the mercury is gradually consumed from the mercury-releasing alloy 5 of the structure 3. It can be replenished, and the life of the fluorescent discharge lamp can be extended in this respect as well.

FIG. 2 shows another embodiment of the present invention. The embodiments shown in FIGS. 9A to 9C are different from the embodiment shown in FIG. 1 in the manner of conductive connection between the structure 3 and the leads 2. In the embodiment shown in FIG. 2A, a cap 10 for fitting and fixing the base end of the structure 3 is integrally formed with the lead 2 by press working. For such integral press shaping of the cap 10 and the lead 2, a round bar having an outer diameter required for the cap 10 may be used. When such an electrode structure is adopted, the number of parts of the discharge electrode can be reduced as compared with FIG. However, in order to change the outer diameters of the lead 2 and the structure 3, it is necessary to create a new press die according to the change. The embodiment shown in FIG. 2B has a structure in which the valve 1 having both ends opened is hermetically sealed by the metal cap 2, and the structure 3 is fitted and fixed in the concave portion of the metal cap 2. In this embodiment, the metal cap 2 constitutes a lead. The embodiment shown in FIG. 2C has a structure in which the cylindrical body 4 of the structure 3 is welded and fixed to the disk 11 provided at the tip of the lead 2. However, in the case of spot welding, the influence of heat during welding on the mercury-releasing alloy 5 and the alloy getter 6 must be taken into consideration. Also in each of the embodiments shown in FIG. 2, the same effect as in FIG. 1 is obtained.

The invention made by the present inventor has been specifically described based on the embodiments, but the present invention is not limited thereto, and various modifications can be made without departing from the scope of the invention. Needless to say. For example, a container such as a glass bulb is not limited to a straight pipe type, and an appropriate shape can be adopted.

[0018]

[Effect of device]

 According to the device disclosed in the present application, the following effects are obtained. (1) By adopting a structure in which a mercury-releasing alloy and an alloy getter are press-filled into a cylindrical body, the mercury-releasing alloy and the alloy getter are used to form a fluorescent discharge lamp with an extremely thin bulb diameter of about several mm. In this case, the effective light emission length can be increased, and the light emission amount with respect to the entire length of the fluorescent discharge tube can be increased. In other words, in fluorescent discharge using the structure containing the mercury-releasing alloy and alloy getter as the discharge electrode, the required amount of the mercury-releasing alloy and alloy getter can be easily adjusted without shortening the effective emission length even if the bulb diameter becomes thin. Can be secured. (2) Since the discharge electrode composed of the structure realizes a hollow cathode, the concentration or directivity of discharge is increased, and the brightness is improved or the stability of discharge is increased. Furthermore, the hollow cathode-enabling depressions can be formed by mechanically scraping or by releasing mercury from the mercury-releasing structure during the manufacturing process. (3) By covering the periphery of the mercury-releasing alloy and the alloy getter with the cylindrical body made of the electrode material, the blackening of the bulb near the discharge electrode can be alleviated. (4) When the structure is stored as a part, the area where the mercury-releasing alloy and alloy getter contact the air is small, and the part that was in contact with the air can be mechanically scraped or removed, so oxidation It is possible to suppress the situation where impurities such as mercury are directly enclosed in the bulb, and it is also possible to suppress the progress of blackening due to the sputtering of such impurities. (5) Similarly, if a cylindrical structure is adopted, oxidation of the mercury-releasing alloy and alloy getter in the cylinder is almost blocked and mercury is easily released, and an oxide film is formed only on the surface of the structure. Since it is only formed, and its oxide film can be easily removed, the heat of the valve sealing process does not require the mercury release process, even if the mercury release process with a specially controlled heating temperature and time is not performed. Since it is possible to easily release a small amount of mercury by heating by driving the lighting, even if the mercury is gradually consumed during lighting, it can be replenished from the mercury-releasing alloy of the structure, Also in this respect, the life of the fluorescent discharge lamp can be extended.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a fluorescent discharge lamp according to the present invention.

FIG. 2 is an explanatory view showing another embodiment of the fluorescent discharge lamp according to the present invention.

[Explanation of symbols]

 1 Valve 2 Lead 3 Structure 4 Cylindrical Body 5 Mercury Emitting Alloy 6 Alloy Getter 7 Recess 8 Connection Tool 9 Split End

Claims (3)

[Scope of utility model registration request] 1. A discharge electrode is contained in a container having a phosphor coating on its inner surface, and the discharge electrode comprises a mercury-releasing alloy mainly composed of an intermetallic compound of titanium and mercury, and one of zirconium or titanium. An alloy getter mainly composed of an intermetallic compound consisting of one of aluminum and nickel is mixed in a cylinder of a cylindrical body made of an electrode material with an opening end facing the central part of the container and press-fitted. And a lead electrically connected to the cylindrical body, the end surface of the filled mercury-releasing alloy and alloy getter having a concave structure from the open end of the cylindrical body to the inner part of the cylindrical body. The fluorescent discharge lamp is characterized by being exposed to the outside of the container. 2. The electrical connection between the structure and the lead is:
2. The fluorescent emission according to claim 1, wherein the connection is performed by a connecting tool that holds the outer peripheral portion of the lead at one end and the outer peripheral portion of the tubular body at the other end. Electric light. 3. The container has an outer diameter of 2 mm to 4 mm.
3. The fluorescent discharge lamp according to claim 1, wherein the total length has a dimension of 50 mm to 300 mm.