JPS61224256A - Planar light source - Google Patents

Abstract

PURPOSE:To obtain a planar light source having uniform distribution of brightness and long service life by providing a spacer comprised of a plurality of interval regulating heat-resistant insulators contacting against the inner planes of first and second base bodies and setting the distance between first and second base bodies highly accurately while improving the parallelism. CONSTITUTION:Electrodes 1511...15mn, lower layer dielectric material films 1611...16mn and protection layers 1711...17mn are formed onto the inner plane of first base body 14. While a spacer 28 is fitted into the rectangular hole of an insulation sheet 18 which is jointed through a glass frit 19 to the inner plane of first base body 14. Here, the spacer 28 is contacting with the inner face of the first base body 14. Then glass frits 26, 27 are applied onto the endface at one side of side wall body 20 and the inner wall face at the other end to joint the endface at one end of the sidewall body with the inner plane of the first base body 14 and to fit the second base body 22 to the inside face of the sidewall body 20 such that the inner plane will contact with the spacer 28. Thereafter, it is sealed under the temperature higher than the fusing temperature of the glass frits 26, 27 to secure the first and second base bodies 14, 22 and the sidewall body 20 tightly.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is applicable to 2 thin light sources such as rear light sources of transmissive liquid crystal display devices, rough reading light sources of information equipment, pixels of large screen display panels, or light sources for general illumination. The present invention relates to a flat light source that can be used as a light source.

[Conventional technology]

For example, as a transmission type color liquid crystal display device, the one shown in FIG. 3 is known. In FIG.
A first transparent electrode (3) formed on the inner surface of a liquid crystal sealed vacuum container (2), and a first liquid crystal light distribution film (4) provided so as to cover this first transparent electrode (3). )and.

A second liquid crystal-filled vacuum container (5) is disposed opposite to the first liquid-crystal-filled vacuum container (2), and an IJ box-shaped inner surface of the second liquid crystal-filled vacuum container (5) is provided. A plurality of second transparent electrodes (6a) (6b) (6c) formed in
...and these multiple transparent electrodes (6a) (6b) (
Colored layer (7a) formed on each upper surface of 6c)...
) (7b) (7c)... and these second transparent electrodes (6a) (Sb) ((Sc)... and colored layers (7a) (7b) (7C)... a second liquid crystal light distribution film (8) provided in the liquid crystal, and a liquid crystal (9) sealed between the first liquid crystal filled vacuum container (2) and the second liquid crystal filled vacuum container (5); .

A first polarizing plate disposed on the outer surface side of the first liquid crystal-filled vacuum container (2) and the second liquid crystal-filled vacuum container (5).
) and a second polarizing plate α1) disposed on the outer surface side of the polarizing plate α1). Reference numeral 02 denotes a straight tube type fluorescent lamp which serves as a rear light source and is disposed behind this liquid crystal display section (1), that is, on the second polarizing plate 011 side.
A plurality of them are arranged in parallel according to the display area. 03) Fi This fluorescent lamp and the above liquid crystal display section (]
) is a diffuser plate disposed between the fluorescent lamps a2 and the fluorescent lamps a2 to uniformize the luminous flux from the plurality of fluorescent lamps a2.

In the transmissive color liquid crystal display device configured in this way, the fluorescent lamp a4 is turned on, and the first transparent electrode (3) and the second transparent electrode (6a) are connected in accordance with the desired display pattern.
Apply a potential between (6b) and (6c). Then, in the liquid crystal (9), liquid crystal molecules (9a) with a molecular crystal structure that does not transmit light and liquid crystal molecules (9b) with a molecular crystal structure that transmits light are generated, and a desired display pattern can be obtained. It is.

However, with something configured like this.

Since a plurality of fluorescent lamps 02 are arranged in accordance with the display area, uneven brightness tends to occur on the light diffusing plate OJ. In order to prevent this uneven brightness, the distance between the fluorescent lamp 02 and the light diffusion plate (131) is increased.

9. The device itself is large, especially the thickness in the thickness direction.
If the number of fluorescent lamps O2 is increased, the power consumption of the light source will increase, and the temperature of the light source will rise, which will have an adverse effect.

This resulted in a problem that the advantage of using the liquid crystal display section (21) as a device was lost.

Therefore, a planar light source as shown in FIGS. 4 and 5, which has a thin (uniform brightness surface) and discharges at a low starting voltage, has recently been proposed as a rear marshall of a liquid crystal display device. In the figure, Oa is a first substrate made of flat glass or ceramic having an inner plane (14a), (151
1X1512)...(15mn) is mXn electrodes arranged in a matrix of m rows and n columns on the inner plane (14a) of this first substrate, and the distance between the electrodes is, for example, 2° to 100°.
A thick film layer of aluminum or other conductive metal with a thickness of 2 mm to 10 μm is deposited in the range of 2 mm to 10 μm. It is something that

(1611)...(16mn) is each of the above electrodes (151)
1)...0.1 to 100μ to cover (1amn)
The lower dielectric film is formed to a thickness of approximately fn and is made of a high withstand voltage material such as Ta205, 5i02 or 5i5N4.

The surface charge of each electrode (1511) (ismn) is accumulated uniformly, and the response characteristics of the discharge application pulse are accelerated. (1711)...(1
7mn) are each electrode (1511) on these lower dielectric films.
...(15mm) Protective layers provided on the opposing parts, MgO, 0e02 with a film thickness of 100 to 5oooX
．． It is made of an inorganic oxide such as 0a09 or (Sr, 0a)0, and one with good secondary electron emission characteristics is selected. Reference numeral 08 denotes an insulating sheet made of glass or ceramic that is provided on these protective films and fixed to the first base +141 with a glass frit OI.
Through holes (j811)...(18 mn), which are slightly smaller than each electrode (1511)...('5 mn), are formed on the surface facing +)...(ismn), respectively. Each electrode (1511)...(15mn
) Avoid exposing the surrounding boundary directly to ion bombardment.

This alleviates the electric field concentration at the redundant electrode boundary. The canopy is a frame-shaped side wall body made of glass or ceramic whose one end is fixed to the first base body a41 with a glass frit through the insulating sheet, and an exhaust pipe til+ that penetrates the inside is provided on the - side. It is something. I22 is a flat second base made of glass which is closely fixed to the other end of this side wall body with a glass frit and hermetically sealed inside. 2 with light body
The spectral transmittance of the colored layers (7a) (7b) 16 is an ultraviolet-excited three-wavelength band-emitting phosphor based on the three primary colors of combined light, and a first range of 445 nm or more and 475 nm or less;
a second range of 525 nm or more and 555 nm or less, and 595 nm
It is mainly radiated in the third range of nm or more and 625 nm or less, and the sum of the radiant energy in these three ranges is 380 nm.
4 for radiant energy in the range of 780 nm or more
For example, it has a spectral distribution of 5 or more.

30 wt% Y2O2: ]lOu of phosphor and 49
wt % LaPO4: Oe, Tb phosphor and 21 wt % (Sr.

Ba)9(PO4)6SrO12: Ku phosphor is coated to a thickness of 100 μm or less, for example 60 μm. Then, the first base body 04. Inside the discharge vessel formed by the side wall body 03 and the second base body 5rn9~
20 mg range 1 e.g. 10Fn9 mercury and 1 TOrr
~ Several tens of Torr range 2 For example, 10 Torr of a mixed gas containing argon and xenon as main components is discharged from the exhaust pipe 01j.
It is enclosed from. In addition, each electrode (15+
+) ... (ismn) is connected to the drive circuit so that one sequential time division drive is performed between two poles, but the discharge current is 10
When the voltage exceeds 0mA, the electrode (1511)...(ISmn)
Because the deterioration of the light source progresses and it becomes difficult to maintain the lifespan of the light source for ioooo hours, it is set to 100 mA or less, and the scanning period of the discharge (for example, *pole (1511) + (1
512) starts from the discharge of the electrodes (ISmn-1), (I
One scan is required until the discharge of Smn). ) is set to be 3011z or higher because if it is lower than 3011z, you will experience light flickering, and it will cause eye fatigue when used for long periods of time, such as in OA display terminals.

The flat light source constructed in this manner is manufactured in a first-order manner. First, an electrode (151
1)...(ISmn), lower dielectric film (1611)
...(ISmn) and protective layer (1711)...(17
After forming mn), glass frit till is applied. Next, on the first substrate 04) formed in this way, each electrode (1511)...(ISmn) and the through hole (18
11)... (18mm) are joined through the glass frit (lI'fc) so that they face each other.After that, apply glass frit (4) on both end faces of the side wall body (c), and connect these end faces with each other. The inner surface of the first substrate (14) provided with an insulating sheet 0υ etc. and the second substrate (2) coated with a fluorescent material
Glass frit 0161 Qy
Sealing is carried out at a temperature higher than the melting temperature of 1, and the first base body I, second base body 02, and side wall body (2) are closely fixed.・After that.

Inside the discharge vessel c! 4) is brought to a near vacuum via the exhaust pipe 01).

After filling the mercury QQ and the mixed gas through the exhaust pipe (01), the bleed pipe (2++) is closed to complete the process.

[Problem that the invention seeks to solve]

However, in a flat light source configured in this way,
The distance between the first base body 0a) and the second base body Q2 is the side wall body (a)
Since it is determined by the height of the glass frit (glass frit) C119 (271) applied to both end surfaces of the side wall body (4), the distance between the first base body (141 and the second base body 0) is However, it is not always possible to seal the product to the specified dimensions.

The first base 0 xuan and the second base c! 3, the parallelism was not constant. If a light source in such a state is used as a light source, mechanical stress concentration will occur due to the increase in the light emitting area, which may damage the light source, and it may not be possible to project light with a uniform brightness distribution. This created the problem of not being able to do so.

This invention has been made in view of the above points, and allows the distance between the first base body and the second base body to be constant.

It is also an object of the present invention to obtain a flat light source that can easily obtain parallelism and is suitable for mass production.

[Failure to solve the problem]

In the flat light source according to the present invention, a plurality of spacers made of a heat-resistant insulator for distance adjustment are arranged in contact with the inner plane of the first base and the inner plane of the second base.

[Effect]

In this invention, the spacer regulates the distance between the first base body and the second base body, improves the parallelism, and
Also, the influence of the glass frit that tightly fixes the second base body and the side wall body is minimized.

〔Example〕

An embodiment of the present invention will be explained below based on FIGS. 1 and 2. In FIG.
Four heat-resistant insulators for distance adjustment that penetrate through square holes (18a) formed in the corners and are arranged in contact with the inner plane of the first base α and the inner plane of the second base 03. A prismatic spacer made of 1, for example, quartz that can transmit light with a wavelength of 100 nm to 11000 nm, M, F2. aay2゜MnF
It is a 2nd class transparent object.

The flat light source constructed in this manner is manufactured as shown in FIG. First, an electrode (1511)...('' m n) + lower dielectric film (1611)...(16,1on) and a
(17t+)·(17mn) is formed. On the other hand, Figure 2 (
Insert the spacer (c) into the square hole of the insulation sheet 0 as shown in a), and insert the spacer c! as shown in FIG. 2(b). 8) The insulating sheet θ barrel inserted therein is joined to the inner surface of the first base body 041 via a glass frit holder. At this time, the spacer (c) is in contact with the inner plane of the first base 041. after that.

Glass frits on one end of the side wall and the inner wall on the other end)
CI'fH7) is applied, one end surface of this side wall body is joined to the inner plane of the first base body I, and the inner plane of the second base body Q is in contact with the spacer (towards). ) into the inner surface. And glass frit (c) +27
Sealing is performed at a temperature higher than the melting temperature of the first substrate Q41.
．． The second base body 0 side and the side wall body (2) are tightly fixed.

After that, the inside of the discharge vessel c! A is made into a substantially vacuum via the bleed pipe QD, mercury (C) and a mixed gas are sealed in via the exhaust pipe Qυ, and then the exhaust pipe Qυ is closed to complete the process.

In the flat light source configured in this way, the first base 0
By simply bringing the shaft and the second substrate into contact with the spacer track, it is possible to obtain a distance of a set dimension and to obtain accurate parallelism.

Note that the glass frit @cl! adheres the side wall body (c) and the first and second base bodies 04 (c). The difference in thermal expansion coefficient between the side wall body (a) and the first and second base bodies o4r:a shall not exceed 20 inches, and the thermal expansion coefficient of the insulation sheet H11O shall also be between the side wall body (a) and the first and second base bodies A good discharge vessel can be constructed by making sure that the difference between the coefficients of thermal expansion of the first and second bases (+41(2)) does not exceed 2096.

〔Effect of the invention〕

As described above, this invention has the inner plane of the first base body and the second base body.
Since a plurality of spacers made of heat-resistant insulators are provided for adjusting distances in contact with the inner plane of the base body, the distance between the first base body and the second base body can be set with high accuracy, and the parallelism can be maintained well. This has the effect that a long-life flat light source having a uniform luminance distribution can be obtained.

[Brief explanation of the drawing]

FIGS. 1 and 2 show an embodiment of the present invention. Fig. 1 is a cross-sectional view, Fig. 2 is an assembly diagram of main parts, Fig. 3 is a view showing an example of a transmissive color liquid crystal display device, Fig. 4 is a cross-sectional view showing an example of a flat light source, and Fig. 5 is a cross-sectional view showing an example of a flat light source. Multiple electrodes ('j51
1)...(1smn) is a partial diagram for showing. In the figure, 04 is the first base + (1511)...(
15 mm) is an electrode, (a) is a side wall body, (2) is a second base body, and @ is a spacer. In addition, the same symbols in each figure indicate the same or corresponding parts.

Claims (4)

[Claims] (1) A first base body with a plurality of electrodes arranged on its inner plane, a frame-shaped side wall body with one end tightly fixed to the first base body, and a frame-shaped side wall body closely fixed to the other end of this side wall body, the inside of which is hermetically sealed. a second base for stopping the first and second bases, a plurality of spacers made of heat-resistant insulators for adjusting distances disposed in contact with the inner surfaces of the first base and the second base; A flat light source in which at least mercury and a rare gas are sealed inside an interior formed by a second base body and a side wall body. (2) Spacer has a wavelength of 100 nm to 1000 nm
2. The flat light source according to claim 1, wherein the flat light source is a transparent body capable of transmitting light. (3) The flat light source according to claim 1 or 2, wherein the spacers are arranged at four corners of the first base. (4) The first base body and the side wall body are closely fixed together at the inner surface circumferential edge of the first base body and the end face of one end of the side wall body, and the second base body and the side wall body are closely fixed together at the second base body and the side wall body. 4. The flat light source according to claim 1, wherein the light source is formed on the peripheral end surface of the base body and the inner surface on the other end side of the side wall body.