JP2002134022A - Method for manufacturing cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problems that in a frit baking process, heating takes a long time and has low efficiency, and insufficient baking elimination of organic materials contained inside makes electron beam irradiation ability reduced. SOLUTION: Heating valve 1 from inside and outside and evacuating the inside of the valve 1 allow the temperature rising speed of the valve to be high, so that the time for the frit baking process can be decreased, and the forced elimination of the organic materials can be performed, to keep the electron beam irradiation ability from reducing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube, and more particularly to a cathode ray tube manufacturing method.

[0002]

2. Description of the Related Art A CRT is a glass envelope (hereinafter, referred to as a glass envelope).
(Referred to as a valve), and comprises a panel constituting the valve, a funnel-shaped funnel, and a neck tube. In the cathode ray tube manufacturing process, after forming a fluorescent film on the inner surface of the panel, filming and formation of a metal back layer are performed. Next, the funnel coated with the interior graphite film and the panel are melted and joined with frit glass, and at the same time, a frit baking process is performed to thermally decompose an organic substance such as a fluorescent film.

[0003] The process is completed through processes such as sealing for mounting an electron gun, exhausting by vacuum heating, getter flash, aging, and inspection. In the above frit baking process, the bulb was placed in a heating furnace and fired at 400 to 600 ° C., and the gas in the bulb was discharged from the neck tube to the outside.

[0004] Such a conventional cathode ray tube manufacturing method is as follows.
It is described in JP-A-5-114361.

[0005]

The conventional frit baking process is a method in which a valve is placed in a heating furnace and heated externally at the ambient temperature. Therefore, the inside is heated through the glass with low thermal conductivity that forms the bulb, so the heating efficiency is poor and it takes a long time to heat, or it is said that the burning and removal of the organic substance such as the fluorescent film inside becomes insufficient. Challenges had arisen.

[0006] The organic substance heated and gasified is
Due to the structure in which the gas is naturally exhausted from the neck tube having a small cross-sectional area to the outside of the bulb, a part of the gasified organic substance remains in the bulb, causing a reduction in the electron beam irradiation capability of the electron gun.

An object of the present invention is to provide a method of manufacturing a CRT in which the heating efficiency is improved and the time required for the frit baking process is reduced. Another object of the present invention is to provide a method for manufacturing a cathode ray tube, which has a structure in which an organic substance inside a bulb is surely burned off to prevent a decrease in electron beam irradiation ability.

[0008]

In the frit baking process, heating is performed from outside the valve by a heating furnace while supplying heated compressed air into the valve. Further, the above object is achieved by evacuating the valve while the valve is at a high temperature.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG. The CRT comprises a panel 2 constituting a bulb 1, a funnel 3 having a funnel shape, and a neck tube 4. In the cathode ray tube manufacturing process, after a fluorescent film is formed on the inner surface, a filming and a metal back layer are formed, and a low melting point applied to a joint portion between a panel 2 on which a shadow mask or the like is attached and a funnel 3 coated with an interior graphite film. A frit baking process is performed in which the crystallized glass (frit glass) is melted and solidified to join the funnel 3 and the panel 2 together. Hereinafter, the process is completed through processes such as sealing for mounting an electron gun, exhausting by vacuum heating, chip-off, getter flash, aging, and inspection of electrical characteristics.

In the frit baking process, the valve 1 is mounted on the gantry 9 via the packing 6 and the neck tube 4 is mounted.
With the nozzle 8 inserted into the valve 1 through the heating furnace 5
Put in. The base 9 has a vacuum valve 10 and a rotary pump 11
The gas in the valve 1 is forcibly exhausted by pulling the gantry 9 to a vacuum with the rotary pump 11. Nozzle 8 has compressed air 12 heated by heater 7
Is supplied and discharged into the valve 1.

The heating furnace 5 and the heater 7 are driven to heat the valve 1 from the outside and inside to the maximum temperature of 450 ° C.
When the temperature reaches 0 ° C., the vacuum valve 10 and the air valve 13 are closed, and the rotary pump 11 is driven to evacuate the valve 1. Until the temperature reaches 450 ° C., the vacuum valve 10 is opened, and the gas in the valve 1 is released to the outside.

By heating the bulb 1 in this manner, the temperature reaches the maximum temperature in a shorter time than before, preventing damage to the bulb 1 due to thermal strain, promoting the calcination of the organic substance inside, and the gasified organic substance by the calcination. Substances can be forcibly removed by evacuation.

According to this embodiment, since the valve 1 is simultaneously heated from the inside and the outside, the rate of temperature rise can be increased, and the time required for the frit baking step can be reduced as compared with the conventional case.

Further, according to the present embodiment, the organic substance in the bulb 1 can be baked and forcibly removed, so that there is an effect that a decrease in the electron beam irradiation ability can be prevented.

[0015]

According to the present invention, the time required for the frit baking process can be shortened as compared with the prior art because the rate of temperature rise can be increased. Further, since the organic substance can be baked and forcibly removed, there is an effect of preventing a decrease in electron beam irradiation ability.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a main part of a frit baking process showing one embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Valve, 2 ... Panel, 3 ... Funnel, 4 ... Neck tube, 5 ... Heating furnace, 7 ... Heater, 8 ... Nozzle.

Claims (1)

[Claims] In a frit baking process in which a panel and a funnel are melted and joined with frit glass in a manufacturing process of a cathode ray tube having a valve comprising a panel, a funnel and a neck tube, the bulb is heated from the outside by a heating furnace and heated simultaneously. Sent compressed air into the valve,
Further, a method of manufacturing a cathode ray tube, wherein the inside of the bulb is evacuated.