JPH01154027A - Plane type lighting equipment - Google Patents

Abstract

PURPOSE:To eliminate the need of an application process of glass frit to a spacer, and also, to thin the thickness of plate glass by enclosing an electrode and gas into a gap of two pieces of plate glass by pressure below the atmospheric pressure and sticking the peripheral edge part of the plate glass by low melting point glass without using the spacer. CONSTITUTION:As for two pieces of plate glass 3, 3, the peripheral edge parts are stuck by low melting point glass so as to have a prescribed gap and an adhesive part 4 is formed. In this gaps, an electrode 5 and mercury are enclosed, and it is prevented by a partition wall 6 that discharge by the electrodes 5, 5 leans to one side as a plane. Subsequently, air is exhausted from a gap by an exhaust pipe 7 and a small quantity of mercury is injected, and thereafter, the gap is sealed up. As for the adhesive part 4, since no spacer is used, the quantity of low melting point glass becomes large by that portion, and said part is heated at the time of adhesion and gets wet by plate glass and becomes a meniscus shape. In such a way, since no spacer is used, a process for applying frit to the spacer becomes unnecessary and the productivity is improved, and also, the sealed part forms a meniscus and stress is dispersed, therefore, thickness of the plate glass 3 can be thinned.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a flat lighting device.

(Prior Art) Transmissive liquid crystal display elements are used in portable computers, televisions, etc., and are usually equipped with a backlight to enable use in dark places.

The backlight needs to be a surface light source, and conventionally a plurality of small-diameter fluorescent lamps are used. Further, as shown in Fig. 4, glass frit l is applied to a spacer 2 made of metal or the like, and this spacer is placed around the periphery of two glass sheets 3 to bond the two glass sheets together, and at the same time, electrodes and gas are introduced into the gap between the glass sheets. It has also been proposed that the gas be sealed at a pressure below atmospheric pressure.

However, those using small-diameter fluorescent lamps emit linear light, resulting in uneven brightness, which requires a complex combination of diffusers, reflectors, etc. to reduce the amount of light, making the lighting device too heavy. , there was also the problem that it became too thick.

On the other hand, in the case of bonding two sheets of glass together, there is a process of applying glass frit to the spacer, which complicates the production process and tends to cause stress to concentrate at the bonded part, making it impossible to reduce the thickness of the glass sheet. Ta.

(Problems to be solved by the invention) The present invention solves the above-mentioned problems that the conventional technology had,
To provide a lighting device in which unevenness in brightness is less likely to occur, a step of applying glass frit to a spacer is unnecessary, stress concentration is less likely to occur in an adhesive part, and the thickness of a glass plate can be reduced.

(Means for Solving the Problems) The present invention provides a flat lighting device in which electrodes and gas are sealed in the gap between two sheets of glass at a pressure below atmospheric pressure, in which a spacer is used at the periphery of the glass sheets. The object of the present invention is to provide a flat lighting device characterized in that it is bonded with low melting point glass without melting.

The present invention is applied to the following. Fluorescent lights, i.e.
One that uses visible light from a phosphor layer that is filled with mercury at a pressure below atmospheric pressure and is excited by ultraviolet light emitted by an arc discharge in mercury vapor. It is applied to mercury lamps, sodium lamps that emit light from discharge in sodium vapor, etc.

In the present invention, the bonding temperature refers to a temperature at which sheet glass can be bonded airtightly.

The low melting point glass used in the present invention may be one that has an adhesion temperature lower than the transition temperature of sheet glass, but if a glass that has an adhesion temperature that is 70°C or more lower than the transition temperature of sheet glass is used, the glass sheet will be damaged by heating during bonding. This is particularly preferable in terms of workability since there is no risk of deformation.

Furthermore, in order to reduce the thermal stress generated by adhesion, it is preferable that the difference in thermal expansion coefficient between the plate glass and the low melting point glass is small. Specifically, if the coefficient of thermal expansion of low-melting point glass from room temperature to 300°C is α, and the coefficient of thermal expansion of plate glass is αP, then the value of ゛(αL-αP) is -20Xl0-77'C
A low melting point glass in the range of ~÷10X1O-77''0 is preferred.

Examples of low-melting glass having such characteristics include those having the following composition. That is, expressed in weight%, Pb0 55-75 8203 0-15 Zn0 0-15 SI02 1-25 A I2030-20 R200-20 (R20 is Na2O, and any one or two of 20
person).

On the other hand, in the present invention, examples of the gas to be sealed include mercury vapor, sodium vapor, argon gas, and xenon gas.

The following will explain based on the drawings. FIG. 1 is a plan view of a fluorescent lamp device according to the present invention, and FIG. 2 is a cross-sectional view taken along line AA in FIG.

As shown in the figure, the peripheral edges of two glass plates 3.3 are bonded with low melting point glass so as to have a predetermined gap to form a bonded portion 4. The electrode 5 and mercury are sealed in this gap. Reference numeral 6 denotes a partition wall that prevents the discharge at the electrode 5.5 from being biased in a plane. 7 is an exhaust pipe that exhausts air from the gap, injects a small amount of mercury, and then seals it.

Since no spacer is used in the adhesive part 4, the amount of low-melting point glass increases accordingly, and when bonded, it is heated and wetted by the sheet glass, forming a meniscus shape as shown in the figure. It is not necessary to bond the entire periphery of the sheet glass with visible low melting point glass;
It is preferable that the portion where the electrode is inserted and the portion where the exhaust pipe is attached are bonded with a glass composition having a lower melting point to prevent deterioration of the electrode and the like.

On the other hand, it is preferable that the outer surface of the plate glass provided in the case where the light is emitted be rubbed to further improve the uneven brightness.

Such a device can be manufactured as follows.

As shown in FIG. 3, a rod-shaped low melting point glass 7 is placed on the periphery and center of one glass plate 3. The cross-sectional shape of this glass wire may be either circular or polygonal, but it is desirable to use one that is thicker than the intended gap between the glass sheets in order to achieve good sealing.

Specifically, when the cross section of the bar is converted into a circle, the diameter thereof is preferably about 0.2 to 0.5 mm larger than the gap between the glass plates. Note that the glass wire is not placed in the region where the electrode is inserted and the region where the exhaust pipe is connected.

Next, a holding member 8 that holds the desired gap between the glass sheets
After that, the other sheet of glass is placed and bonded by heating to near the transition point of the low melting point glass.

Since this holding member is removed after adhesion, it is made of heat-resistant P4 that does not deform at high temperatures or react with glass.

Next, the holding member is taken out, a phosphor is applied to the inner surface of the glass plate, and an electrode exhaust pipe is attached.

Next, the air is exhausted from the exhaust pipe to a pressure of about 10 −3 mmHg, and then mercury is injected and the exhaust pipe is melted and sealed to obtain the device of the present invention.

The attachment of the electrode and the exhaust pipe are sealed with a glass composition having a lower transition temperature than the above-mentioned low melting point glass.

The glass composition is expressed in % by weight.

PbO, 75-87% 8203 5-10 ZnOO-10 Si02 0NIO Al2O20-10 ROO-1O (RO is one or more of BaO, SrO, ill:aO, MgO) R200-1O (R20 is L s 20 * Na 20 m K 2
0 e Rb20 * Any one or more of C920) and a low expansion refractory filler such as cordierite or lead titanate in weight percent, or a zircon/tin oxide based filler Examples include medium-expansion refractory fillers containing 10 to 60% of one or more of these fillers.

Example thermal expansion coefficient 86X 1G-'/''C (at room temperature ~ 300°
C) A plate glass having a transition temperature of 560° C. and a thickness of 1.11 mm was prepared. The composition of this sheet glass was 5i0272.5 NatO13,5 Ca0 8 Mg0 4 Al2O2 in weight percent.

Then, the thermal expansion coefficient 84X 10-7/℃~+10×1
0-7/℃ (room temperature to 300℃), transition temperature 370℃
A 2.1 mm square rod was formed using C low melting point glass. The composition of this glass was pbo sθ B2O312 Zn0 9 Si02 4 Al2O2B in weight percent.

Next, these glass wires 3 and 7 were placed on a glass plate 3 as shown in Fig. 3, and a holding member 8 made of stainless steel with a thickness of 2.0 mm was placed thereon.Next, the other glass plate was placed on top of this and placed in an electric furnace. Te5
Two sheets of glass were bonded together by holding the glass at 50° C. for 10 minutes. Then, a phosphor was applied to the inner surface of the glass sheet, and an electrode exhaust pipe was attached using a glass composition paste. This was achieved by holding the glass paste at 430°C for 10 minutes in an electric furnace. The glass composition of this paste has a transition temperature of 310°C.
Thermal expansion coefficient 72X 1G-7/'0 (at room temperature ~ 300
℃), and its composition was 5th order by weight.

Pb0 83 B203 12 2n0 2 A1□0. 60% glass powder with the composition of 1.5 SiO A flat lighting device was manufactured by sealing.

The cross section of the sealing portion of this device formed a meniscus as shown in FIG.

(Effects of the Invention) According to the present invention, since no spacer is used, the process of applying frit to the spacer is unnecessary, productivity is improved, and the sealing part forms a meniscus and stress is dispersed, so the thickness of the glass plate can be reduced. It can be made thinner and the device can be made smaller and lighter.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a device according to the invention. Figure 2 shows the AAgllr surface view l height r of Figure 1. FIG. 3 is an explanatory diagram for manufacturing the device according to the invention. FIG. 4 is a sectional view of a conventional device a. 2... Spacer, 3... Sheet glass, 4... Adhesive part, 5... Electrode. Figure 1 Figure 3 Figure 4

Claims (4)

[Claims] (1) A flat lighting device in which electrodes and gas are sealed in the gap between two sheets of glass at a pressure below atmospheric pressure, characterized in that the peripheral edges of the sheets of glass are bonded with low melting point glass without using a spacer. A flat lighting device. (2) The lighting device according to claim 1, wherein the bonding temperature of the low melting point glass is lower than the transition temperature of the plate glass. (3) When the coefficient of thermal expansion of the low melting point glass is α_L and the coefficient of thermal expansion of the plate glass is α_P (α_L−α
_P) is -20 x 10^-^7/℃ ~ +10 x 10^-
Claim 2 having characteristics in the range of ^7/°C
The lighting device described in Section 1. (4) The lighting device according to claim 1 or 3, wherein the outer surface of the plate glass provided on the light emitting side is polished.