JPS584247A - Projection-type cathode-ray tube - Google Patents

Abstract

PURPOSE:To improve the thermal-radiation characteristic of the face of a projection-type cathode-ray tube by adjusting the pressure of a space provided between the said face and a front glass plate to be smaller than the atmospheric pressure and larger than the internal pressure of the tube. CONSTITUTION:A front glass plate 7 is airtightly stuck to the outside of a face part 2 with an adhesive 6 by being fixed at the opening end of a side wall 10. In addition, a space 11 formed between a glass cylnder 9 and the face part 2 is maintained at a pressure smaller than the atmospheric pressure (1 atmospheric pressure) and larger than the internal pressure of a tube (10<-6> or 10<-7> Torr). Owing to the above constitution, since the face part 2 on which an electron beam discharged from an electron gun 4 directly falls on, is in contact with the external air with a vacuum space 11 with low pressure interposed between the part 2 and the external air, the intensity of the part 2 can be maintained, and a sufficient thermal-radiation effect can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a development of a projection type cathode ray tube in which a front glass plate is provided on the outside of the face portion.

Most home-use 0-projection televisions employ a method in which a high-brightness image on a cathode ray tube is enlarged and projected onto a projection screen using a refractive lens.

As is well known, refractive lenses have two types of aberrations:
There are field curvature aberration and spherical convergence in a broad sense, and the key to lens design is to reduce both ζO by Iib at t.However, these two terms are generally contradictory, and in particular refraction For single-refraction lenses that use plastic with a relatively small index, it is necessary to add a lens for image plane correction, which is not a stupid thing that has become a huge obstacle to improving the performance of refraction lenses. In order to solve these drawbacks, a projection type cathode ray tube S as shown in No. 1g1K has been proposed.
Reference numeral 1) is a cathode ray tube, which includes therein a fluorescent light 11 (3) coated on the inner surface of a face M (2) and an electron gun (4) for emitting an electron beam. The characteristic J:+ of this cathode ray tube (1) is that the shape of the inner and outer surfaces of the face ms (2) is the same as that of the refractive lens system (5), which is concave, Lle, and 6C.
&ru・This is a surface that is blurred by connecting the optimal focus points of the refractive lens system (6), so-called the optimal image surface is on the side of the refractive lens system (6) TIcl! In order to reduce the field curvature aberration, which is caused by l, we try to flatten the optimal image plane by increasing the magnification of the optical system on one side of the screen to a high <L, and at the center, decreasing the magnification of the optical system to 5+. -So64 This proposal is certainly
Although this system improves the performance and lowers the price of the refractive lens system (6), it has been found that it has a serious drawback in that it reduces the reliability of the single projection cathode tube.
The projection WI cathode-wrapped tube as shown in Figure 1wi is vulnerable to atmospheric pressure because the face (2) serves as a mouth toward the polarization of the refractive lens system (5).

Figure 2 shows a projection cathode ray tube (1) with the above-mentioned improvement measures.
(2) Formation of fluorescent ElF(3)% on the inner surface of the
n”e4i 1st place M (6) ICJ, b y z -x
The electron gun (4) is then sealed and the exhaust device removes O gas such as the air inside (2). The gas is enriched by 111% through the gas contact hole (a) that penetrates in the thickness direction of the face part (2).
In the projection screen (1) created in this way, the atmospheric pressure that is conventionally applied to the face II ,
Since this front glass plate ('F) is a flat plate, a decrease in reliability due to atmospheric pressure is not a problem at all.

In addition, as shown in lll5lIIIvc, if you put a lens plate on the one-sided glass plate (γ) above, make the 7 ace side (7 &) of the front glass (7) flat, and the opposite side (7 &). 7b) may be constructed as a country. By doing so, it is possible to achieve at least a part of the effect of the glass plate (γ)K lens system (5), or at least the same effect as that of a curvature of field aberration lens. , As a result, the 7th construction department (
1) Internal and external [! m of the fluorescent surface (3)
Birds can be easily formed.

However, if we ignore all the peculiarities of the use of projection-carved cathode-wrapped tubes as described above, it turns out that there are 11 serious drawbacks, which are the general VC% projection type. Since the cathode-coated tube is used at a very high puff density (II pole applied voltage x unit - current density per tube), an increase in temperature of the fluorescent surface is observed, and this Therefore, in order to prevent temperature quenching of the phosphor, it is extremely important to fully absorb the heating effect. 4) The electron beam from
It has been found that the face part (8), which is the main part, is exposed to outside air in a high vacuum region, so that the temperature of the face part (8) constantly rises.

This invention has been developed to overcome the above-mentioned drawbacks.
The pressure in the space between the face part and the glass plate on the first side is equal to atmospheric pressure, and the pressure inside the pipe is determined by improving the heat dissipation characteristics of the face part. The purpose is to provide cathode ray tubes.

An embodiment of the present invention will be described below with reference to FIG. 1i.

FIG. 44 is a partially cutaway side view of the projection type cathode-bound bud according to the present invention. At this W, move one end of the (・) bar to the Sekiro Lm.
In a glass tube - The end face of this glass tube (@ is the cathode ray 1j (
The front glass plate (?) facing the 7th floor part (2) of 1)
Therefore, to attach the lever, attach it to the opening edge of the glass plate (Gin is on the side wall) on the side of the glass plate (Gin is on the side wall), and apply the adhesive (@) to the face part ( 2) Adhesive glue is attached to the outside of the glass tube.
Ace III
E (1% IE) - small irises (, pressure inside the pipe (1 "6 is I Q rorr) - maintain the pressure state,
And the exhaust of the turtle v111I@ is on the above side l1o4
Horse mackerel, 11
In Figure 4, #f-this #stomata trout shows the sealed layer in a.

In the above configuration, the electron beam from the electron gun (4) directly contacts the outside air across the 7 Ace II (2) low vacuum region □ space (B), so the face II (υ0 intensity is According to experiments, the pressure in the above air W4 (b) is 10-
5DtJtorr a["t',?!-xgcaa strong g
It turns out that there is a sufficient effect in relation to and enthusiasm.Also, once this space is filled with vacuum, #e%
Air) A gas with a slightly high molecular weight, such as hydrogen and helium, is substituted with the EfE force and has a thermal effect M.
As shown in the ms figure, it was possible to form a separate Wc from the 9-sided glass plate (η and side). This true book (γ)
, 11 by joining the gate with adhesive (6) +
The same effect as in the case of 411 can be obtained by using the front glass plate (with a flange) and the tortoise, but with any IC1 in the cross-sectional shape! For example, it is possible to create a white surface as shown in Fig. 3. Also, the fluorescent surface of the face part (2) ) I
When Ic is formed, seven will appear.

As can be seen from the above explanation, the present invention allows the pressure in the space between the first floor and the front glass plate glued to the outside to be slightly higher than atmospheric pressure (and to reduce the pressure loss by 1 compared to the pressure inside the pipe). Therefore, we would like to provide a projection cathode ray tube that improves image quality by modifying the heat characteristics of the upper e-face and armpit where the electron beam is directed.

[Brief explanation of drawings]

Figure I11 is a cutaway side view of a conventional projection cathode ray tube. Section 411 is an embodiment of the present invention.
IIS■ is a partially cut-out side surface of a projection-engraved cathode tube according to another embodiment of the present invention.
-Front glass plate, (b) -am In addition, the same reference numerals in the drawings indicate parts corresponding to the same number. Agent Ge Shuxin - (1 other person) Figure 2 Figure 4 Procedural amendment (voluntary) 6. Supplementary Patent Office 12 Offices 1 Supplementary Patent Office (1) 2. Title of the invention
and the projection type cathode tube 3, the "Claims" and "Detailed Description of the Invention" columns of the subject specification of the person making the amendment. Correct description of contents: The claims are amended as shown in the attached sheet. @Page 6, line 20 Customer “10→=.γ500T0..J and Atro, 1~
``'Torr J Corrected. Above appendix: Scope of patent claims after amendment (1) At least one outer surface of the face portion having an original image is concave, and 1 mK in front of the outside of the queen face portion 1. A projection cathode ray tube to which a glass plate is bonded, characterized in that a space between the face portion and the front glass plate is smaller than a large voltage and larger than an internal pressure of the tube. (21) A projection type cathode ray tube according to claim 1, in which the pressure in the space is set to t0.1 to ''' Torr. (4) The projection cathode ray tube according to claim 5, wherein the gas contained in the space is helium or hydrogen.

Claims (4)

[Claims] (1) In a projection cathode ray tube in which at least the outer surface of the 7-piece portion having a fluorescent surface is concave and a front glass plate is adhered to 1g outside the 7-piece portion, the face portion and A projection cathode ray tube characterized in that the space between the front glass plate and the front glass plate is smaller than atmospheric pressure and larger than the pressure inside the tube. (2) The projection type cathode ray tube according to claim 1, wherein the pressure in the space is 10 to S OOTart . (3) The projection type cathode-wrapped tube according to claim 1 or 2, wherein the gas contained in the space has a molecular weight smaller than that of air. (4) The projection cathode ray tube according to claim @11M5, wherein the gas contained in the space is helium or hydrogen.