JPS5922346B2 - Color cathode ray tube fluorescent surface manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This description relates to the fabrication of a fluorescent surface for a CPT color picture tube.

As a method of applying a phosphor to the inner surface of a face plate, a phosphor is mixed with a phosphor liquid (hereinafter referred to as phosphor slurry).

) was applied to the inner surface of the face plate to remove excess phosphor slurry (hereinafter referred to as recovered phosphor slurry).

) was recovered by high-speed rotation, and the amount of recovered phosphor slurry was mixed into a phosphor slurry (hereinafter referred to as gun slurry).

) has been proposed.

Conventionally, in order to compensate for the decrease in the concentration of the recovered slurry (because the phosphor settles on the face plate and only the upper part is recovered), a phosphor slurry with a high phosphor concentration (hereinafter referred to as filtration slurry) has been used.

) was added periodically to keep the specific gravity and viscosity of gun slurry constant.

When using the same coating machine as in the past, if the type of face plate is of the same type and area, the amount of recovered phosphor slurry is constant, the filler slurry composition is determined, and the viscosity of the applied slurry is determined.
The specific gravity (phosphor concentration) remains constant, but if face plates of different shapes and areas become more diverse, the composition and amount of recovered phosphor slurry become unstable.The viscosity and specific gravity of the gun slurry must be kept constant. difficult to maintain.

The present invention provides a device for automatically maintaining this.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The apparatus for automatically recording and correcting the viscosity and specific gravity of gun slurry in a phosphor slurry dispenser according to the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view and an injection path diagram inside a conventional phosphor stirrer.

The gun slurry in the agitator hopper 1 is now injected into the faceplate 6 via the injection solenoid valve 5.

After injection, the injection solenoid valve 5 is actuated to cause the gun slurry 2 to flow directly from the delivery hose 4 through the return hose 7 and into the agitator hopper 1 via the circulation mesh 8.

The recovered slurry 17 is recovered into the hopper 1 through the recovery receiving cover 16 by the high speed rotation of the carrier 18.

This injection operation is repeated and the gun slurry 2 in the agitator hopper 1 is reduced.The float switch 9 is activated and the filler slurry 10 with high specific gravity (high concentration of phosphor) passes through the supply hose 11 and filters through the mesh filter. 12 and is supplied from a filler dispenser 13.

This high specific gravity filler slurry 10 is stirred by the pump 3 during non-injection, by the agitator hopper 1, delivery hose 4, injection solenoid valve 5, return pipe 7, circulation mesh 8, and by the agitator hopper 1, and by the pump 3. Rotating shaft 1 inserted into gun slurry 2 in vessel hopper 1
The gun slurry 2 was made uniform by the agitation caused by the eccentric rotation of the resistor plate 15 and the gun slurry 2, and a constant gun slurry was always applied to maintain a constant thickness of the phosphor film within the face plate.

However, with such a constant gun slurry, the amount of returned phosphor slurry 17, phosphor concentration, viscosity, etc. become uneven, especially due to the diversification of face plates. ) The viscosity fluctuated, resulting in the disadvantage that a uniform gun slurry was not always injected.

The purpose of the present invention is to provide a correction method for improving the above-mentioned drawbacks of the conventional method by which the viscosity and specific gravity of the gun slurry 2 can be kept constant no matter what kind of recovered slurry 17 is mixed in, and the gun slurry can always be kept uniform. It is something to do.

To achieve this objective, the present invention includes a gun stirring dispenser 1, a viscometer 20 (including a constant temperature bath 21), a hydrometer 19,
A correction timer 29 and correction liquids 23, 24, and 25 are provided so that they can be linked to make corrections when an abnormality occurs.

Hereinafter, as an embodiment of the present invention, chemotaxis of gun slurry in a phosphor slurry coating dispenser used for manufacturing CP and T will be explained in detail by way of example.

Figure 2 shows the viscosity and specific gravity of the phosphor slurry of the present invention.
FIG. 2 is a diagram of a chemotactic device and an injection route.

This embodiment will be described without repeating the conventional example shown in FIG. 1. The difference from the conventional example is that the specific gravity of the filler slurry 10 is increased so that the specific gravity of the gun slurry 2 is increased. When the amount decreases, the filler slurry 10 with high specific gravity is transferred to the hose 1 by the pump 40 by the liquid level float 9.
In addition to the one that was supplied to the gun slurry 2 through 1, prepare a specific gravity correction liquid 23 that does not contain a phosphor, a high viscosity correction liquid 24, and a low viscosity correction liquid 25 for viscosity correction. Correct specific gravity and viscosity using correction liquid.

The hydrometer 19 is attached to the delivery hose 4, and the recorder 33 detects the specific gravity during actual injection.

The viscosity meter 20 is attached to the gun dispenser lid 41 so that it can be inserted into the gun slurry, and the viscosity at this time is recorded by the recorder 3.
Record according to 4.

The specific gravity/viscosity recorder is equipped with microswitches 35, 36, and 37 at certain controlled locations, and the liquid to be corrected is selected and additionally corrected by microswitch detection.

The viscosity varies depending on the temperature of the phosphor slurry, so in order to keep the temperature constant, install constant temperature baths 21 and 22 on the gun dispenser. Circulate.

Gun slurry 2 is injected from the face plate 6, excess recovered slurry 17 returns to the hopper 1 through the hose 12, and the gun slurry decreases by the amount of phosphor slurry adhering to the face plate.

At this time, the electromagnetic valve 42 is activated by the detection of the float 9, and the filler slurry 10 passes through the supply hose 11 and is replenished into the hopper 1.The specific gravity of the filler slurry 10 is increased in advance so that the specific gravity of the gun slurry 2 is increased. Recorder 33
The indicator needle 38 gradually reaches the upper limit and the micro switch 35
Detect.

At this time, if the viscosity recorder detects the higher viscosity of the microswitch 37, the pump 28 is activated and the correction hose 3
A correction liquid 25 with low viscosity enters the hopper 1 through 2 and is corrected.

If the microswitch 36 with lower viscosity is detected, the pump 27 is activated and the higher viscosity correction liquid 24 enters the hopper 1 through the correction hose 31 and is corrected.

If the viscosity indicator needle 39 does not detect either micro, the pump 26 operates and the specific gravity correction liquid 23 flows into the correction hose 30.
is corrected into hopper 1.

When performing this correction, the time required for the gun slurry 2 to be stirred and completely mixed due to the stirring force of the dispenser (as described in the conventional example) is different, and the detection of the viscosity and specific gravity is delayed.Correction liquid 23.2
4.25 may be overcorrected, so use a timer, 2
9 is used to detect the micro switch and then timer 43
Set the time so that the correction fluid enters for an amount of time and operate it.

When the timer 43 expires, the timer 44 is activated and the correction liquid is not added for this period of time to provide stirring time.

If the specific gravity is still high, the timer 43 is linked to work again.

As a result, the gun slurry 2 always has a uniform viscosity and specific gravity, and a uniform gun slurry can be injected into the face panel 6, and the thickness of the fluorescent film after application can be made uniform, making it possible to obtain a good color television picture tube. .

The viscosity and specific gravity used here are detected using a recording device.
Although this is done by micro-detection, another method may be to detect the viscosity and specific gravity values using signals and operate the pump.

Furthermore, it goes without saying that the slurry temperature control may be performed using other methods other than those described above, such as a heater.

The above viscosity and specific gravity - When using a chemotaxis device, the specific gravity during conventional management is ±0.1, and the specific gravity is +0.00 compared to 5 cp on viscosity.
2. It becomes possible to control the viscosity within ±lcp.

The present invention is not limited to the above-mentioned embodiments, but is generally most suitable as a highly accurate dispensing method for viscous suspensions.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a phosphor slurry stirring dispenser used for a conventional color television picture tube for stirring and dispensing a viscous suspension, and FIG. 2 is a similar embodiment of a phosphor slurry stirring dispenser. FIG. 1 is a sectional view of a stirring dispersion device and a sectional view of a correction device according to the invention. 1... Gun dispenser (hopper), 2...
... Gun slurry, 3 ... Snake pump, 4 ... Delivery hose, 5 ... Injection solenoid valve, 6 ... Face plate, 7.・・・・・・
Return hose, 8... Circulation mesh, 9...
... Float switch, 10 ... Filler slurry 111 ... Supply hose, 12 ... Mesh filter, 13 ... Filler dispenser, 14 ... ... Rotating shaft, 15 ... Resistance plate, 16 ... Collection receiving cover, 17 ...
Recovered phosphor slurry, 18...Carrier, 1
9... Hydrometer, 20... Viscometer, 21
... Constant temperature bath, 22 ... Gun dispenser - temperature adjustment tank, 23 ... Specific gravity correction liquid, 24 ...
...Viscosity (high) correction liquid, 25...Viscosity (
Low) Correction fluid, 26... Specific gravity pump, 27...
...high viscosity pump, 28...low viscosity pump,
29... Timer, 30... Specific gravity correction hose, 31... Viscosity (high) correction hose, 32
...Viscosity (low) correction hose, 33...
Specific gravity recorder, 34...Viscosity recorder, 35...
...Specific gravity upper limit microswitch, 36...Viscosity lower limit microswitch, 37...Viscosity upper limit microswitch, 38...Specific gravity indicator needle, 39.
... Viscosity indicator needle, 40 ... Filler slurry snake pump, 41 ... Dispenser lid, 42 ... Filler slurry solenoid valve, 43 ...
...Replenishment timer, 44...Stop timer.

Claims (1)

[Claims] 1. In order to stabilize the viscosity and specific gravity of the phosphor coating slurry used in the phosphor surface manufacturing process of color cathode ray tubes, an automatic viscosity/specific gravity measurement device is used to stabilize the viscosity and specific gravity of the phosphor slurry applied as a correction liquid. If the specific gravity of the slurry is high, one type of viscosity correction liquid is used depending on the viscosity of the slurry. A method for manufacturing a fluorescent surface of a color cathode ray tube, characterized in that the specific gravity viscosity is made constant using the above viscosity correction liquid.