JPH11135016A - Phosphor slurry applying device and applying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain the specific gravity, and viscosity of phosphor slurry at certain values, and equalize the film thickness of a phosphor after its application by controlling the supply of the respective slurry. SOLUTION: The specific gravity and viscosity of phosphor slurry S are respectively measured by a specific gravity sensor 14 and a viscosity sensor 29. Based on the detection output, correction solution comprising the high viscosity phosphor slurry 21, the low specific gravity-low viscosity phosphor slurry 23, and the low specific gravity-high viscosity phosphor slurry 25 are respectively selectively supplied and controlled so as to synthetically control the specific gravity and viscosity. Thereby, the phosphor slurry S of the stable specific gravity and viscosity can be supplied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phosphor slurry coating apparatus and a phosphor slurry coating method for maintaining the specific gravity and viscosity of a phosphor slurry in a process of forming a phosphor film of a color cathode ray tube.

[0002]

2. Description of the Related Art A conventional phosphor slurry coating apparatus is disclosed in, for example, Japanese Patent Application Laid-Open No. 56-156639, in order to stabilize the specific gravity of a slurry liquid by using a detection output of a specific gravity sensor. Alternatively, the supply amount of the slurry having a low specific gravity was controlled.

FIG. 3 is a diagram showing a slurry injection path in which a conventional phosphor slurry dispenser is partially broken.

Here, the phosphor slurry S in the dispenser tank 1 passes through the delivery hose 3 by the snake pump 2 to the inside of the panel 5 as the injection solenoid valve 4 at the time of injection, and the return hose 6 from the injection electromagnetic valve 4 at the time of non-injection. To the dispenser tank 1 through

[0005] The slurry S injected into the inner surface of the panel 5 is collected by the recovery cover 10 by the high-speed rotation of the carrier 9.
It returns to the dispenser tank 1 as a collection slurry through the collection hose 11.

A part of the slurry S enters the mini hopper 13 through the bypass hose 8 by the pump 2.

The signal detected by the specific gravity sensor 14 provided in the mini hopper 13 is converted into an electric signal and enters the controller 27.

A high specific gravity tank 17 containing a high specific gravity slurry 16 and a low specific gravity tank 19 containing a low specific gravity slurry 18 are provided, and the high specific gravity slurry 16 and the low specific gravity A slurry 18 having a specific gravity is refilled into the dispenser tank 1.

When the slurry S of a value whose specific gravity is intermediate between the upper limit and the lower limit repeats the operation of injecting and collecting, the liquid level in the dispenser tank 1 is lowered and the specific gravity is lowered, and the lower limit or the specific gravity of the liquid level is lowered. Reaches one of the lower limits.

At this time, the slurry 16 having a high specific gravity is replenished by a signal from the controller 27, and the specific gravity increases with the liquid level. When the liquid level reaches the upper limit, the replenishment of the high specific gravity slurry 16 is stopped, and the slurry 16 returns to the initial state.

When the upper limit is reached, the replenishment of the high specific gravity slurry 16 is stopped and the slurry 16 returns to the initial state.

When the specific gravity reaches an appropriate value in the middle of the liquid level, the replenishment of the high specific gravity slurry 16 is stopped and the replenishment is switched to the low specific gravity slurry 18, and when the specific gravity reaches the liquid level upper limit point while decreasing the specific gravity. Then, the replenishment of the low specific gravity slurry 16 is stopped.

[0013]

However, in the conventional method, it is difficult to inject the slurry S having a constant specific gravity and viscosity at all times, and the amount of the slurry S injected into the inner surface of the panel 5 due to the fluctuation of the viscosity is low. The spread state changes, causing a difference in the phosphor film thickness of each panel 5, causing a problem that the white uniformity on the screen varies.

The reason is that only the specific gravity value is corrected in the conventional method, so that a high specific gravity slurry, a low specific gravity slurry,
This is because the variation in the viscosity in the dispenser tank 1 increases with the number of corrections due to the supply amount and the viscosity value of the recovered slurry, and it is difficult to inject the slurry S that is always constant in specific gravity and viscosity.

[0015]

A slurry supply method according to the present invention measures a specific gravity and a viscosity of a slurry sent from a dispenser tank using a specific gravity sensor and a viscosity sensor, and based on the detected output, a high specific gravity and a high viscosity. Slurry,
It is characterized in that a slurry having a low specific gravity and a low viscosity and a slurry having a low specific gravity and a high viscosity are selectively supplied and controlled.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described.
This will be described with reference to FIG.

The same parts as those in the route diagram of FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.

The present embodiment is characterized in that a mini-hopper 20 for receiving a detection end 15 of a specific gravity sensor 14 and a detection end of a viscosity sensor 29 is provided in a path of a bypass hose 8 of the dispenser tank 1, and a fluorescent substance in the dispenser tank 1 is provided. A part of the slurry S is caused to enter the mini hopper 20 through the bypass hose 8 by the snake pump 2.

The specific gravity / viscosity signal detected in the mini hopper 20 is changed into an electric signal and enters the controller 8.

The controller 28 can set and record the upper and lower limits of specific gravity and viscosity, and detect the upper and lower limits of the liquid level.

The correction liquid supplied to the dispenser tank 1 is a high specific gravity and high viscosity phosphor slurry (hereinafter, slurry A) 2
1, a tank 24 containing a low specific gravity, low viscosity phosphor slurry 23 (hereinafter, slurry B), and a tank 26 containing a low specific gravity, high viscosity phosphor slurry 25 (hereinafter, slurry C). The slurry A21, the slurry B23, and the slurry C25 are supplied by a signal of the controller 28.

The method of selecting and supplying the supply slurry in each state of the phosphor slurry S will be described below with reference to the flowcharts of FIGS.

The phosphor slurry S in the dispenser tank 1
When the liquid level is at an intermediate position between the upper limit and the lower limit, based on the output of the specific gravity sensor 14, when the specific gravity is lower than the appropriate value, only the slurry A21 is supplied, and when the viscosity is higher than the appropriate value, the viscosity sensor 29 is used. When the viscosity is higher than the appropriate value, only the slurry B23 is supplied, and when the viscosity is lower than the appropriate value, the slurry C25 is supplied.

If the liquid level of the phosphor slurry S in the dispenser tank 1 is below the lower limit, the slurry A 21
When the viscosity is higher than the appropriate value, the slurry B23 is supplied based on the output of the viscosity sensor 29, and when the viscosity is lower than the appropriate value, the slurry C25 is supplied.

As described above, by controlling the supply of each slurry, the specific gravity and viscosity of the phosphor slurry S are kept constant, and the phosphor film thickness after application is made uniform.

[0026]

According to the present invention, the specific gravity of the phosphor slurry
The viscosity is kept constant, the thickness of the phosphor after coating is also made uniform, and a color cathode ray tube with good white uniformity on the screen can be obtained.

Specifically, this apparatus makes it possible to set the conventional viscosity control range to ± 0.5 CP, compared to ± 1.5 CP.

The reason is that the specific gravity and the viscosity of the phosphor slurry are measured and the specific gravity and the viscosity are simultaneously controlled.

[Brief description of the drawings]

FIG. 1 is a diagram showing a slurry injection path of a phosphor slurry applying apparatus of the present invention.

FIG. 2 is a flowchart showing the control status of the slurry according to the present invention.

FIG. 3 is a diagram showing a slurry injection path of a conventional phosphor slurry coating device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dispenser tank 2 Snake pump 4 Injection solenoid valve 5 Panel 6 Return hose 7 Mesh filter (filter) 8 Bypass hose 9 Carrier 10 Collection cover 11 Collection hose 12 Sea level sensor 14 Specific gravity sensor 15 Specific gravity sensor detection end 20 Mini hopper 21 High specific gravity・ High viscosity phosphor slurry (Slurry A) 22 High specific gravity / High viscosity phosphor slurry tank 23 Low specific gravity / Low viscosity phosphor slurry (Slurry B) 24 Low specific gravity / Low viscosity phosphor slurry tank 25 Low specific gravity / High viscosity fluorescence Body slurry (slurry C) 26 Low specific gravity / high viscosity phosphor slurry tank 28 Controller 29 Viscosity sensor S Phosphor slurry

Claims (6)

[Claims] 1. A first tank containing a slurry having a high specific gravity and a high viscosity containing a phosphor, a second tank containing a slurry having a low specific gravity and a low viscosity, and a slurry containing a low specific gravity and a high viscosity slurry. A third tank connected to each of the tanks, first, second, and third valves for controlling opening and closing, and a dispenser tank for storing slurry selectively supplied by the respective valves through a filter. , A level sensor that detects the amount of slurry in the dispenser tank, a coating nozzle that injects the slurry sent from the dispenser tank into a rotating panel, and a viscosity and specific gravity of the slurry sent from the dispenser tank. Viscosity sensor and specific gravity sensor, a collection cover that is placed opposite the panel and receives the slurry shaken off by centrifugal force, A return hose for returning the collected excess slurry to the dispenser tank through a filter, and a controller for controlling opening and closing of the first, second, and third valves based on respective detection outputs of a specific gravity sensor, a viscosity sensor, and a level sensor. A phosphor slurry coating device, comprising: 2. The method according to claim 1, wherein the first, second, and / or third slurry is applied based on the amount of slurry or the number of times of application.
A method for applying a phosphor slurry, comprising: controlling a supply amount of each slurry contained in a third tank to a dispenser tank. 3. When the amount of slurry in the dispenser tank is at an intermediate position between the upper limit and the lower limit, the amount stored in the first, second, and third tanks is determined based on the output of the specific gravity sensor and the viscosity sensor. 3. The method according to claim 2, wherein the amount of the slurry supplied to the dispenser tank is controlled. 4. When the specific gravity of the slurry in the dispenser tank is lower than a predetermined value based on the detection output of the specific gravity sensor,
4. The method according to claim 3, wherein only the slurry in the first tank is supplied. 5. When the amount of slurry in the dispenser tank exceeds a predetermined lower limit level, the slurry in the first tank is supplied, and when the viscosity is lower than a predetermined value based on a detection output of a viscosity sensor, the second tank is supplied. 3. The phosphor slurry coating method according to claim 2, wherein the slurry in the third tank is supplied when the viscosity is equal to or more than a predetermined value. 6. When the specific gravity of the slurry is higher than a predetermined value based on the detection output of the specific gravity sensor, the slurry in the second tank is removed based on the detection output of the viscosity sensor when the viscosity is equal to or lower than the predetermined value. The slurry in the third tank is supplied when the value is equal to or more than a predetermined value.
The phosphor slurry coating method as described in the above.