JP3107285B2 - Cold cathode low pressure discharge lamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold cathode low pressure discharge lamp, and more particularly, to a small, lightweight cold cathode low pressure discharge lamp suitable for a backlight.

[0002]

2. Description of the Related Art A liquid crystal display device is a word processor,
It has been widely used as a display unit for personal computers, liquid crystal televisions, and the like. In addition, this type of liquid crystal display device tends to be required to have a structure and a function that can be used in a variety of applications. It is rare.

[0003] A cold cathode discharge lamp is generally used as a light source for a liquid crystal backlight. For such an application, FIG. 5 and FIG. A cold cathode discharge lamp as shown is provided. That is, a phosphor layer 1 that emits light when stimulated by ultraviolet rays is provided on the inner wall surface, and a glass tube (glass bulb) 2 containing a rare gas and a pair of cold tubes sealed at both ends of the glass tube 2 are provided. One end is connected to the cathodes 3, 3 'and one pair of the cold cathodes 3, 3', and the other end is a lead-in wire 4, 4 'having a diameter of about 0.1 to 0.5 mm, which is sealed out from the glass tube 2.
It is composed of If necessary, the glass tube 2
An ultraviolet reflective layer may be interposed between the inner wall surface and the phosphor layer 1.

When used as a light source for a liquid crystal backlight, it is electrically connected to input terminal lines 5, 5 'of a light source unit for liquid crystal backlight (not shown) by soldering 6 or the like and fixed. I have.

[0005] This type of cold cathode discharge lamp has a lead-in line 4, 4 '.
The ions in the initial plasma generated by energizing each of the cold cathodes 3, 3 'through the
, Secondary electrons are emitted, and discharge starts in the glass tube 2. Then, ultraviolet rays are radiated by resonance transition of mercury atoms excited by discharge energy accompanying the start of discharge,
This ultraviolet light is converted into visible light by the phosphor layer 1 on the inner wall surface of the glass tube 2 and functions as a discharge lamp that emits visible light. In the case where the ultraviolet light reflecting layer is interposed, the ultraviolet light transmitted through the fluorescent material layer 1 is reflected by the ultraviolet light reflecting layer when the visible light is converted by the fluorescent material layer 1, is returned to the fluorescent material layer 1, and the visible light is returned. , The utilization efficiency of ultraviolet rays is increased, and as a result, the luminous efficiency can be increased.

[0006]

As described above, as for the cold cathode discharge lamps for liquid crystal backlights, the market trend is to make the backlight units more reliable and longer in life (durability) and more compact. Is considered important. In other words, not only can the cold cathode discharge lamp itself be miniaturized,
Attempts have been made to reduce the mounting space (mounting space) of the cold cathode discharge lamp by making the mounting mechanism of the cold cathode discharge lamp compact, and to make the backlight unit thinner and smaller.

[0007]

According to a first aspect of the present invention, there is provided a glass tube in which a phosphor layer is provided on an inner wall surface and in which a rare gas is filled , and a glass tube hermetically sealed and led out from the glass tube. A line, a plate-like spacer provided on the leading end side of the introduction line, and a glass tube inside introduction line of the introduction line.
Cold; and a cathode, out end side of the introduction line out end
Extends through the plate-shaped spacer in the plate thickness direction, and
Is bent to the spacer plane area side and soldered.
A cold-cathode low-pressure discharge lamp characterized by being fixed at

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a cold cathode low-pressure discharge lamp which not only enables the backlight unit to be thinner and lighter, but also has higher reliability.

[0009]

According to a first aspect of the present invention, there is provided a hard glass tube provided with a phosphor layer on an inner wall surface and containing a rare gas, and a pair of glass tubes sealed at both ends of the glass tube. The cold cathode, one end is electrically connected to the cold cathode, and the other end side is coaxially proximate to the hermetic sealing portions at both ends, and the lead-ins are provided so that both ends of the glass tube are hermetically sealed. A cold cathode low-pressure discharge lamp characterized in that the cold cathode low-pressure discharge lamp has a spacer which is inserted and fixed at an end of an introduction wire led out of a glass tube.

According to the present invention, an end of an introduction line led out from a hermetically sealed portion of a glass tube (light-emitting tube or light-emitting bulb) is fixedly connected to a spacer arranged close to the hermetically sealed portion, and is hermetically sealed. While absorbing and mitigating thermal and mechanical external forces applied to the stop, the end of the lead wire fixedly connected to the spacer is brought into engagement with the input / output terminal of the liquid crystal backlight unit so as to be in the axial direction. The main point is to reduce the space. That is, instead of keeping the leading end of the lead-in wire extended, it is fixedly connected to the adjacent spacer, and has a thermal and mechanical reinforcing action of the hermetic sealing portion, thereby improving reliability. On the other hand, the connection and mounting to the unit for the liquid crystal backlight are made compact. Here, the material of the glass tube is selected from hard glass. In other words, this is for avoiding the occurrence of cracks and damage to the sealing portion due to soldering heat or the like when the end of the introduction wire is fixedly connected to the spacer.

In the present invention, if necessary, a structure may be employed in which a phosphor layer is provided on the inner wall surface of the light emitting glass tube via an ultraviolet reflecting layer which is transparent to visible light and reflects ultraviolet light. That is, in a structure in which a visible light reflecting film is provided on the inner wall surface of the phosphor layer, if an ultraviolet reflecting layer that reflects ultraviolet light while transmitting visible light is interposed as a base layer of the phosphor layer, the phosphor due to ultraviolet light The luminous efficiency of visible light in the layer is also improved. Here, in order to increase the reflectance of the ultraviolet ray having the wavelength λ emitted by the excitation of the discharge medium, a multilayer type ultraviolet reflecting layer is desirable. That is, the thickness of each of the material layer having a high refractive index and the material layer having a low refractive index is λ.
It is desirable to set the thickness to / 4n to form a stacked type (n is the refractive index of each substance).

As described above, when the ultraviolet reflection layer is provided, the efficiency of light emission of the cold cathode low pressure discharge lamp is enhanced. In other words, the phosphor in the phosphor layer is excited, and the ultraviolet light converted into the required visible light is reflected by the reflection layer, and again contributes to the excitation of the phosphor, so that more efficient visible light conversion is achieved. The luminous efficiency is greatly improved.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment will be described with reference to FIGS. 1, 2 (a) and 2 (b), FIGS. 3 and 4 (a) and 4 (b).

FIG. 1 is an enlarged sectional view of a main part of the cold cathode low-pressure discharge lamp of the first embodiment, FIG. 2A is a front view of a washer-like spacer, and FIG. It is a cross-sectional view of a washer-shaped spacer. In FIG. 1, reference numeral 8 denotes a hard glass glass tube having an outer diameter of 3.0 mm and an inner diameter of 2.0 mm in which a phosphor layer 9 which emits light upon stimulation by ultraviolet rays is provided on the inner wall surface and seals a discharge medium such as a rare gas or mercury. 10 and 10 'are a pair of cold cathodes respectively sealed at both ends of the glass tube 8, and 11 and 11' are connected to the cold cathodes 10 and 10 'at one end and the other end is hermetically sealed from the glass tube 8. Part 12,
12 'is the derived introductory line. Here, introduction lines 11, 1
1 ′ is a Kovar wire having a diameter of about 0.6 mm, and is a lead-in wire 1 derived from the hermetically sealed portions 12, 12 ′ of the glass tube 8.
The tip portions of 1, 11 'are fitted with, for example, metal washer-like spacers 13, 13' as shown in FIGS. Are connected by crushing or caulking, and are further soldered. In FIGS. 2A and 2B, 13
a and 13a 'are insertion holes into which the leading ends of the introduction wires 11 and 11' are inserted.

In the above-mentioned cold cathode discharge lamp, the tips of the lead wires 11, 11 'fixedly connected to the washer-shaped spacers 13, 13' are engaged with the input / output terminals of the backlight unit so as to be engaged. , 10 ′, secondary electrons are emitted from each of the cold cathodes 10, 10 ′ by the ions in the initial plasma generated by the energization, and discharge starts in the glass tube 8. The discharge energy accompanying the start of the discharge radiates ultraviolet rays by resonance excitation of, for example, mercury atoms as a discharge medium (filled gas). The emitted ultraviolet light is absorbed and excited by the phosphor layer 9 on the inner wall surface of the glass tube 8, and is converted into visible light to contribute to light emission. Then, the visible light emitted to the tube wall side of the discharge lamp (glass tube 8) passes through the tube wall and is emitted outside the discharge lamp.

On the other hand, in the process of handling the discharge lamp (glass tube 8), not only the lengths of the introduction wires 11, 11 'extending in the axial direction are shortened, but also the tips are fixed to the spacers 13, 13'. As a result, even if external stress or heat is applied, the stress is relaxed and absorbed by the spacers 13 and 13 '. It was confirmed to function as a fluorescent lamp.

FIG. 3 is an enlarged sectional view of a main part of the cold cathode low-pressure discharge lamp of the second embodiment, FIG. 4 (a) is a front view of a washer-shaped spacer, and FIG. It is a cross-sectional view of a washer-shaped spacer. In FIG. 3, reference numeral 8 denotes a hard glass tube having an outer diameter of 3.0 mm and an inner diameter of 2.0 mm in which a phosphor layer 9 that emits light upon stimulation by ultraviolet rays is provided on the inner wall surface and seals a discharge medium such as a rare gas or mercury. 10 and 10 'are a pair of cold cathodes respectively sealed at both ends of the glass tube 8, and 11 and 11' are connected to the cold cathodes 10 and 10 'at one end and the other end is hermetically sealed from the glass tube 8. Part 12,
12 'is the derived introductory line. Here, introduction lines 11, 1
1 ′ is a Kovar wire having a diameter of about 0.6 mm, and is a lead-in wire 1 derived from the hermetically sealed portions 12, 12 ′ of the glass tube 8.
The distal ends of 1, 1 'are metal washer-like spacers 13, 13' which are curved along the surfaces of the hermetically sealed portions 12, 12 'as shown in FIGS. 4 (a) and 4 (b). Is connected, bent and connected to the washer-shaped spacers 13 and 13 'by crushing or caulking, and further soldered.
In FIGS. 2 (a) and 2 (b), 13a and 13a 'are insertion holes into which the distal ends of the introduction wires 11 and 11' are inserted.

In the cold cathode discharge lamp, the leading ends of the lead wires 11, 11 'fixedly connected to the washer-shaped spacers 13, 13' are engaged with the input / output terminals of the backlight unit. , 10 ′, secondary electrons are emitted from each of the cold cathodes 10, 10 ′ by the ions in the initial plasma generated by the energization, and discharge starts in the glass tube 8. The discharge energy accompanying the start of the discharge radiates ultraviolet rays by resonance excitation of, for example, mercury atoms as a discharge medium (filled gas). The emitted ultraviolet light is absorbed and excited by the phosphor layer 9 on the inner wall surface of the glass tube 8, and is converted into visible light to contribute to light emission. Then, the visible light emitted to the tube wall side of the fluorescent lamp (glass tube 8) passes through the tube wall and is emitted outside the discharge lamp.

On the other hand, in the process of handling the discharge lamp (glass tube 8), not only the lengths of the introduction wires 11, 11 'extending in the axial direction are shortened, but also the tips are fixed to the spacers 13, 13'. As a result, even if external stress or heat is applied, the stress is relaxed and absorbed by the spacers 13 and 13 '. It was confirmed to function as a fluorescent lamp.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the invention. For example, the material and diameter of the glass tube, the configuration of the cold cathode, the diameter of the straight portion of the lead wire, and the phosphor in the phosphor layer are not particularly limited.

[0021]

According to the cold-cathode low-pressure discharge lamp of the present invention, while the strength of the sealing portion of the lead wire is improved, the lead wire from the hermetically sealed portion in the axial direction of the glass tube is taken. The derived length has also been reduced. Therefore, during the test / inspection process, the attachment / detachment operation to the backlight unit, etc.
Even when stress, heat, or the like is applied from the outside, the possibility of damage is greatly reduced, so that the reliability is improved or the life is extended.

This high reliability, together with the simplification and downsizing of the cold cathode low-pressure discharge lamp mounting mechanism, contribute to the realization of, for example, a small, high-quality liquid crystal display device.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view showing an example of a configuration of a main part of a first embodiment.

FIGS. 2A and 2B show a main configuration of a spacer included in the cold cathode low-pressure discharge lamp of the first embodiment, wherein FIG. 2A is a front view and FIG.

FIG. 3 is an enlarged sectional view showing a configuration example of a main part of a second embodiment.

FIGS. 4A and 4B are diagrams showing a main configuration of a spacer included in the cold cathode low pressure discharge lamp of the second embodiment, wherein FIG. 4A is a front view and FIG.

FIG. 5 is a cross-sectional view showing a configuration of a main part of a conventional cold cathode low pressure discharge lamp.

FIG. 6 is an enlarged sectional view showing a configuration of a main part of the cold cathode low pressure discharge lamp.

[Explanation of symbols]

 1, 9 phosphor layer 2, 8 glass tube 3, 3 ', 10, 10' cold cathode 4, 4 ', 11, 11' introduction wire 5, 5 'input / output terminal 6. Soldering 7, 7 ', 12, 12' ... Hermetic sealing of lead-in wires 13, 13 '... Spacer

Claims (1)

(57) [Claims] 1. A glass tube provided with a phosphor layer on an inner wall surface and enclosing a rare gas, a lead-in which is hermetically sealed from the inside of the glass tube, and a lead-out end of the lead-in line. a plate-shaped spacer provided, and a cold cathode formed in the glass tube-side inlet line of the lead-in wire
Comprising a derivation end side of the lead-in wire, the spacer out end of the plate
Through the sheet in the thickness direction, and extend the
A cold-cathode low-pressure discharge lamp characterized in that it is bent to the surface side of the laser and fixed with solder .