JPH0557753U - Fluorescent display tube - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a fluorescent display tube that does not require a getter chamber and does not need to heat the getter at high temperature. [Structure] A field emission device is formed on the inner surface of the back plate 4. An anode having a phosphor layer is formed on the inner surface of the face plate 3. Both plates 3,
4 is sealed by a frame-shaped side seal 5. A getter chamber 7 communicating with the inside of the envelope 6 is provided at four corners of the side seal 5, and the getter chamber 7 accommodates a surface-active bulk getter 1 which is slightly smaller than the getter chamber 7. The inside of the envelope 6 is evacuated and is in a high vacuum state. During this evacuation, the envelope 6 is heated at 250 to 350 ° C., and the bulk getter 1 is activated.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a fluorescent display tube, and more particularly to a thin fluorescent display tube (hereinafter abbreviated as FED) using a field emission device which is a cold cathode as an electron source.

[0002]

[Prior Art]

 FIG. 6 is a sectional view showing an example of a conventional fluorescent display tube 100 using a field emission device. The envelope 101 of the fluorescent display tube 100 has a structure in which a cathode substrate 102 and an anode substrate 103 facing each other are sealed with a spacer 104 interposed therebetween. A field emission device is provided on the inner surface of the cathode substrate 102, and an anode electrode as a display unit having a phosphor layer is provided on the inner surface of the anode substrate 103 so as to face the field emission device. In the above structure, the field emission device and the anode electrode are as close to each other as possible, and the distance between them is, for example, about 0.2 mm. Therefore, the thickness of the spacer 104 is generally set to 1 mm or less, and the fluorescent display tube 100 is a thin display element. However, the conventional getter 105 is a scattered getter in which a getter material such as Ba-Al is filled in a metal container having an annular opening as shown in the figure, and the thickness thereof is about several mm. Therefore, conventionally, the getter 105 cannot be arranged in the envelope 101, and the box-shaped getter chamber 106 is provided on the back surface of the cathode substrate 102 of the envelope 101 as shown in FIG. The getter 105 was provided in the getter chamber 106 by connecting the inside of the envelope 101 with the exhaust hole 107. Then, the air in the envelope 101 and the getter chamber 106 is exhausted through the exhaust hole 108 and the exhaust pipe 109 provided in the getter chamber 106, and then the exhaust pipe 109 is sealed to enclose the envelope 101. The inside is kept in a high vacuum atmosphere. Then, the getter 105 is heated at high frequency by a bomber, and the getter material is deposited on the inner surface of the getter chamber 106 to form a getter film 110.

[0003]

[Problems to be solved by the device]

 The conventional FED described above has the following problems. (1) The getter chamber must be provided outside the thin envelope. Moreover, if there is no distance between the getter and the inner surface of the getter chamber, the vapor deposition area of the getter film becomes small and the adsorption efficiency deteriorates. For this reason, the size of the getter room must be large. (2) The scattered Ba-Al getter is heated to a high temperature of about 850 ° C. in a high frequency electric furnace to scatter only Ba metal. Therefore, when the getter and the substrate are close to each other, heat is transferred to the envelope, causing partial thermal expansion and causing cracks in the envelope.

The present invention can take advantage of the thinness of the FED that does not require a getter chamber, and eliminates the adverse effects of high temperature heating that was conventionally performed to form a getter film. It is intended to provide a display tube.

[0005]

[Means for Solving the Problems]

 The fluorescent display tube of the present invention is characterized in that a surface-active bulk getter is fixed to a predetermined position inside the envelope through a mounting means.

Further, according to the present invention, a getter chamber opened to a space inside the envelope is provided inside the envelope as the mounting means, and the surface-active bulk getter is provided in the getter chamber. It may be held.

Further, according to the present invention, the surface active bulk getter may be formed of Zr-Ni powder, or a field emission device may be used as a cathode that emits electrons in the envelope. Good.

[0008]

[Action]

 The surface-active bulk getter fixed inside the envelope has a getter function by activating the surface by heating at a relatively low temperature. Since this bulk getter is close to the display part inside the envelope, the getter effect works effectively.

[0009]

【Example】

 A first embodiment will be described with reference to FIGS. The getter used in this example is not a conventional scattered getter but a surface-active bulk type getter (bulk getter). The surface-active bulk getter 1 (hereinafter, simply referred to as bulk getter 1) according to the present embodiment is formed by molding Zr-Ni powder into a square or ribbon shape having a material thickness of 0.1 to 0.2 mm. is there. The surface of the bulk getter 1 is activated by heating to about 200 to 400 ° C. in a vacuumed state, and a getter function is obtained.

Now, as shown in FIGS. 1 to 3, the fluorescent display tube 2 of this embodiment is an FED, and a face plate 3 and a back plate 4 facing each other at a predetermined interval are integrally formed via a side seal 5. It has a fixed envelope 6. Although not shown, on the inner surface of the back plate 4, a field emission device including a cathode wiring, a cone-shaped emitter, an insulating layer, a gate, etc. is formed. Although not shown, on the inner surface of the face plate 3, an anode including an anode wiring, an anode conductor, a phosphor layer, etc. is formed.

The side seal 5 that seals the back plate 4 and the face plate 3 is made of a glass adhesive material having a low melting point glass as a main component, and is formed into a frame-shaped pattern having a predetermined thickness. There is. At the four corners, a getter chamber 7 is formed in a shape that matches the bulk getter 1 and communicates with the internal space of the envelope 6, and the plate-shaped bulk getter 1 described above is housed and held therein. ing. The thickness of the bulk getter 1 is smaller than the height of the getter chamber 7, and the surface of the bulk getter 1 is exposed to the space inside the envelope 6. That is, in this embodiment, the getter chamber 7 serves as a mounting means for fixing the bulk getter 1 at a predetermined position in the envelope 6.

Next, the manufacturing process will be described. The side seal 5 is printed on the back plate 4 with the above-described pattern and a predetermined thickness by using a screen printing method. The bulk getter 1 is placed in the getter chamber 7, and the face plate 3 is overlaid. Then, this is fired to seal the back plate 4 and the face plate 3 to form the envelope 6.

Next, the inside of the envelope 6 is evacuated from the exhaust hole 8 provided in the back plate 4 to make a vacuum, and the exhaust hole 8 is sealed by the lid member 9. In this exhaust step, the envelope 6 is heated from the surroundings at a temperature of 250 to 350 ° C. in order to improve the exhaust efficiency. By this heating, the surface of the bulk getter 1 is activated and the getter action is increased.

As the getter material, Ta, Ti, Th, Nb, Ce or the like can be used in addition to the Zr—Ni powder described above, and a plate-shaped material of these materials may be used.

A second embodiment will be described with reference to FIG. In this embodiment, the getter chamber 10 which is a means for mounting the bulk getter 1 having a thickness of 0.1 mm is constructed by using the spacer 11 made of photosensitive glass. The spacer 11 made of photosensitive glass is a square frame-shaped member having a thickness of 0.2 mm. At the four corners, recesses to be the getter chambers 10 are formed by using photolithography. The shape, structure, dimensions, etc. of the getter chamber 10 are almost the same as those of the getter chamber 7 of the first embodiment, that is, the getter chamber 10 which is slightly larger than the bulk getter 1 communicates with the inside of the envelope 12.

A seal glass 14 is provided in front of the spacer 11 fixed on the back plate 13 via an adhesive glass. Further, a fixing adhesive glass 15 is also provided on the upper surface of the spacer 11. The bulk getter 1 is housed in the getter chamber 10, and the face plate is sealed to face the back plate 13 to form the envelope 12. The steps of exhausting / sealing the envelope 12 and activating the bulk getter 1 are the same as in the first embodiment.

In each of the embodiments described above, the getter chambers 7 and 10 communicating with the spaces inside the envelopes 6 and 12 are provided inside the envelopes 6 and 12 as the attachment means of the bulk getter 1. As a structure in which such a getter chamber is provided in the envelope, as shown in FIG. 5, the substrate 20 forming the envelope is provided with a recess serving as the getter chamber 21 to accommodate the bulk getter 1 as shown in FIG. However, the bulk getter 1 may be held in the getter chamber 21 by the lid 22 having a hole.

Further, the mounting means of the bulk getter is not limited to the getter chamber, and for example, the glass getter may be used as the mounting means to directly fix the bulk getter to a key place in the envelope. ..

[0019]

[Effect of the device]

 Since the fluorescent display tube of the present invention has a structure in which a bulk getter is directly fixed inside the envelope, it has the following effects. (1) The bulk getter can be activated only by heating to a temperature of about 200 to 400 ° C. in vacuum. Therefore, the conventional high-frequency heating furnace is not required, the getter flash step can be omitted, and the getter can be activated at the same time in the exhaust step.

(2) It is not necessary to provide a getter chamber in the FED, and a thin fluorescent display tube can be manufactured.

(3) The structure for simplifying the structure becomes unnecessary because a conventional member for supporting the scattered getter, a metal container capable of high-frequency heating, and the like are unnecessary.

(4) Since the bulk getter is close to the display section, the getter effect works effectively.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a first embodiment.

FIG. 2 is an enlarged perspective view of a portion A of FIG.

FIG. 3 is a sectional view of the first embodiment.

FIG. 4 is a sectional view of a second embodiment.

FIG. 5 is an enlarged cross-sectional view of a main part of another embodiment.

FIG. 6 is a cross-sectional view of a conventional fluorescent display tube.

[Explanation of symbols]

 1 Surface active type bulk getter (bulk getter) 2 Fluorescent display tube 6,12 Envelope 7,21 Getter chamber as mounting means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Mikio Yokoyama 629 Oshiba, Mobara, Chiba Prefecture Futaba Electronics Co., Ltd. (72) Creator Takeshi Tonegawa 629 Oshiba, Mobara City, Chiba Futaba Electronics Co., Ltd. (72) Creator Takehiro Niiyama 629 Oshiba, Mobara-shi, Chiba Futaba Electronics Co., Ltd.

Claims (4)

[Scope of utility model registration request] 1. A fluorescent display tube characterized in that a surface-active bulk getter is fixed to a predetermined position inside an envelope via a mounting means. 2. A getter chamber opened to a space inside the envelope is provided inside the envelope as the mounting means, and the surface-activated bulk getter is held in the getter chamber. The fluorescent display tube according to claim 1. 3. The surface active form of the bulk getter is Zr.
-The fluorescent display tube according to claim 1, which is mainly composed of Ni powder. 4. The fluorescent display tube according to claim 1, wherein the cathode that emits electrons in the envelope is a field emission device.