JP2000030611A - Panel drying method for color cathode ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a panel drying method for a cathode ray tube preventing its quality from being deteriorated by providing the most proper drying condition, even if a tube type size changes in a mixed production method. SOLUTION: A heater device 1 is equipped with plural heater elements 2 almost flatly placed, a drive part 4 connected to the heater element 2 through a support part 3 and a control part 5 to control the drive part 4. The heater element 2 is disposed opposite to a panel 22, and a temperature distribution and a drying condition of the panel are uniformized by adjusting its distance from the panel 22 by moving each heater element 2 back and forth in accordance with a tube size signal S and a panel temperature signal T.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of drying a coated panel of a color cathode ray tube, and more particularly to a method of drying a panel of a color cathode ray tube in which drying conditions can be optimized for each panel type.

[0002]

2. Description of the Related Art Along with the progress of the information society, a color cathode ray tube 21 suitable for displaying images such as a computer terminal display and a high-definition television includes a glass panel 22 and a glass funnel 23 as shown in FIG. A phosphor screen 2 having a bulb 25 integrally joined by glass solder 24 and emitting green, blue, and red light inside the panel.
A color selection electrode such as a shadow mask 27 having a large number of electron beam passage holes formed at a predetermined interval behind the phosphor screen 26 is attached to the inside of the funnel neck. An electron gun 28 for emitting three electron beams is provided. Phosphor screen 2
6, green, blue, and red fluorescent films 32, 33, and 34 are formed in a predetermined positional relationship in the openings of the black matrix film 30 with openings formed on the panel 22 in advance, as shown in FIG. An electron beam corresponding to green, blue, and red selected by the shadow mask is irradiated on each fluorescent film to emit light. The phosphor used for the phosphor film is a green light-emitting phosphor 3
5 is a copper-activated zinc sulfide phosphor (ZnS: Cu), and a blue-activated phosphor 36 is a silver-activated zinc sulfide phosphor (ZnS:
Ag) and the europium-activated yttrium oxysulfide phosphor (Y2O2S: Eu) as the red light emitting phosphor 37.

[0003] In a color cathode ray tube manufacturing line, usually,
A mixed production system is adopted, and panels with different pipe types are mixed and supplied. The panel carrier holding and mounting the glass panel 22 performs the processes described below while sequentially moving the coating position, the drying position, and the like at regular intervals. For example, the phosphor screen 26 of the color cathode ray tube is formed as follows. First, a photosensitive resin is thinly and uniformly applied on the glass panel 22 with a spinner or the like, and dried to form a photosensitive film. Next, it is exposed to ultraviolet light through a shadow mask,
A crosslinking reaction is caused at a position corresponding to the irradiation position of the blue and red electron beams, and then developed to leave only the exposed portion of the photosensitive film. Next, a slurry containing graphite is applied to the entire surface and dried. Next, the black matrix film 30 having an opening is formed by swelling the remaining photosensitive film and exfoliating the graphite on the photosensitive film together. Next, a slurry in which the green light-emitting phosphor 35, polyvinyl alcohol, and ammonium bichromate are mixed is applied to the inner surface of the panel and dried to form a uniform film. Next, this film is exposed to ultraviolet light through a shadow mask or a specific photomask to cause a crosslinking reaction at a position corresponding to the irradiation position of the electron beam for green, and then developed and dried with warm water to form a black matrix film. A green fluorescent film 32 is formed in the opening. Hereinafter, the same process is repeated for the blue light emitting phosphor and the red light emitting phosphor, and the blue phosphor film 33 arranged in a predetermined pattern is formed.
And a red fluorescent film 34 is formed.

In each of the drying steps in the formation of the black matrix film and the fluorescent film, the coated panel is dried by a heater. As shown in FIG. 5, the heater 40 has a large number (for example, 24) of ceramic heater elements 41 arranged in a plane of, for example, 4 rows and 6 columns, and faces the inner surface of the coated panel 50. It is arranged. Panel 50
The temperature of the ceramic heater element (shaded area) at the peripheral edge of the heater device is reduced by the temperature of the ceramic heater element at the central area because the peripheral portion of the heater device is less likely to rise in temperature due to the influence of the panel side portion and is less likely to dry than the central portion. The temperature is set higher than the temperature to equilibrate the dry state.

[0005]

In the conventional method of manufacturing a color cathode ray tube, glass panels having different tube types are mixed and charged, so that panels of various tube types are continuously provided even in the drying step. It moves inside the heater device. For this reason, it is desirable that the temperature distribution given to the heater be changed according to the panel tube size. However, since the transfer index of the panel is as small as ten and several seconds, even if the electric input to the heater is changed, the thermal inertia is not changed. Temperature cannot follow the index quickly. Therefore, the temperature distribution of the heater is fixed for an intermediate-sized panel. As a result, there is a problem that the temperature distribution of the heater does not match between the large-sized panel and the small-sized panel, and the drying state and the temperature of the panel fluctuate, which adversely affects the next process. In particular, in the black matrix film forming step, a photosensitive resin is thinly and uniformly applied on a glass panel, dried to form a photosensitive film, then exposed to cause a crosslinking reaction, and then developed and exposed. The opening is formed leaving only the photosensitive film in the portion where the photosensitive film is dried, but the sensitivity of the photosensitive film changes depending on the drying state of the photosensitive resin, the temperature, etc., and the patterning quality is extremely large, such as a change in the diameter of the opening. Have an effect.

The present invention has been proposed in view of the above problems, and has as its object to optimize the drying conditions and prevent color deterioration even if the panel tube size varies in a mixed production system. An object of the present invention is to provide a method for drying a panel of a cathode ray tube.

[0007]

A panel drying method for a color cathode ray tube according to the present invention comprises a plurality of heater elements arranged substantially in a plane, a driving unit connected to the heater elements, and a driving unit. A heater element of a heater device having a control unit for controlling is arranged so as to face the panel, and each heater element is moved to adjust a distance from the panel, thereby optimizing a temperature distribution of the panel. By this means, for example, by bringing the heater element at the peripheral portion of the heater device closer to the panel or by moving the heater element at the central portion of the heater device away from the panel, the temperatures at the peripheral portion and the central portion are made uniform and the drying state is the same. Thus, quality fluctuation can be prevented. In particular, since the distance between the heater element and the panel is changed without changing the input of the heater element, the responsiveness of the temperature change of the panel is fast, and panels of various sizes are mixed at a high index and flow on the line. However, the dry state of each panel can be quickly optimized.

[0008] Also, detecting the pipe type size information of the panel,
The temperature distribution of the panel is optimized by moving each heater element in accordance with the detection signal and adjusting the distance to the panel. By this means, the distance between each heater element and the panel can be easily adjusted for each pipe type size of the panel, so that the temperature distribution can be easily optimized for each pipe type size and fluctuations in the dry state can be prevented. Here, the pipe type size information is
This is information on panels that affect drying, and includes all information on panels with different specifications other than size, such as coating specifications, even if they are the same size, as well as the panel size.

Further, the panel tube size and the panel temperature are detected, and according to the detection signal, each heater element is moved to adjust the distance from the panel, thereby optimizing the temperature distribution of the panel. And By this means, pipe type size,
Variations in the dry state of each panel can be more easily and quickly prevented.

[0010] Further, by bringing the heater element at the peripheral portion of the heater device closer to the panel, or by moving the heater element at the center portion of the heater device away from the panel, the heating effect of the heater element at the peripheral portion can be enhanced more than at the central portion. The temperature distribution of the panels can be made uniform and the drying state can be made the same, thereby preventing quality fluctuation.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a method for drying a panel of a color cathode ray tube according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of an apparatus for explaining a panel drying method of the present invention. As an example, a drying position of a photosensitive resin in a black matrix film forming step will be described. In the figure, a heater device 1 used at this position has a plurality of heater elements (for example, 400 watts / piece ceramic heater) arranged in a substantially planar shape.
2, a support section 3 for the heater element 2, a drive section 4 for independently moving each heater element, and a control section 5 for sending a control signal to the drive section. . The basic difference from the conventional drying heater is that the conventional drying heater is fixed, whereas the heater device 1 has a plurality of individually movable heater elements 2,
The difference is that the distance between the inner surface of the glass panel 22 and each heater element can be changed according to the tube type size. On the other hand, in front of the heater device 1, a coating panel 50 is provided to face the heater with the coating surface facing the heater.

In the coating panel 50, a photosensitive resin solution is thinly and uniformly coated on the inner surface of, for example, a 21-inch glass panel 22 by a spinner in a previous step (coating).
0 is formed. The application panel 50 is mounted on a panel carrier (not shown), moves from the application position to the drying position, and automatically stops at a position where the center axis of the heater device 1 and the center axis of the panel 50 match. In the drying position, the tube type size information S detected in advance
(Eg, a signal indicating that the panel is 21 inches)
A drive signal is output from the control unit 5 in response to
Operates to position each heater element at a position suitable for a 21 inch panel. The position of each heater element is adjusted so that the photosensitive resin layer 10 formed on the inner surface of the panel is in the same dry state over the entire surface. Normally, when the coating panel 50 is dried by the flat opposed heater, the peripheral portion 10a of the photosensitive resin layer 10 is moved to the center 10c by the influence of the edge 22a of the glass panel 22.
Lower temperature and harder to dry. For this reason, the dry state differs between the peripheral portion and the central portion, which has an adverse effect on the next and subsequent steps, and a uniform photosensitive film cannot be obtained. To avoid this,
A heater element (for example, 2a, 2b, etc.) corresponding to the peripheral portion is brought closer to panel 50 so that the peripheral portion has a higher heating effect than the central portion. Alternatively, the heater element (for example, 2d, 2e, etc.) corresponding to the center portion is relatively
Move away from 0. The heater element 2c is set at an intermediate position. With such an arrangement of the heater elements, a uniform temperature distribution of the panel can be obtained, and a uniform dry state can be realized.
Basically, all heater elements are individually positioned by each connected drive unit, but the heater block (for example,
The central block composed of the heater elements 2d and 2e, the intermediate block composed of 2c, the peripheral block composed of 2a and 2b, etc.) may be driven collectively. The pipe type size information can be detected by various methods. For example, it can be detected by reading a barcode label attached to each panel, and in a computer-controlled production line, information registered in the information system can be used when the panel is turned on.

In order to smooth the temperature distribution, it is better to increase the number of heater elements. For example, in the case of 21 inches, 24 or more are desirable. Further, the heater element is not limited to the ceramic heater, and may be another element. Further, as a specific mechanism of the driving unit 4, a general mechanism such as a linear motor, a combination of a motor and a gear, and an air cylinder can be used.

Next, when a small-sized coated panel (for example, 15 inches) is conveyed, as shown in FIG. 2, a heater element (for example, 2c) closer to the center than in FIG. Approach. The heater elements (for example, 2a, 2b, etc.) located outside the panel become unnecessary, and are kept away from the panel. As a result, even with a small-sized application panel, the temperature distribution can be made uniform, and the drying state can be made uniform.

Next, a second embodiment of the color cathode ray tube panel drying method of the present invention will be described with reference to the drawings. Normally, the coating and drying process itself is performed under constant temperature and humidity, but the temperature of the panel at the time of reaching the drying process due to various factors such as fluctuations in processing time due to storage of the panel and changes in specifications may differ depending on the pipe type. However, the panel temperature may be different even for the same size. Therefore, the first
When the heater element is positioned according to the tube type size as described in the embodiment, even if the tube type is the same, the panel temperature distribution is different and the dry state is different. Therefore, a feature of the second embodiment is that not only the pipe type size but also information about the panel temperature before drying is reflected in the positioning of the heater element. That is, the inner surface temperature of the panel is detected using an infrared thermometer at a predetermined position (for example, between the panel cleaning step and the photosensitive resin coating step) before being conveyed to the drying step, and the temperature is determined as shown in FIG. Signal T
Is input to the control unit 5 together with the tube type size signal S, and the driving unit 4 is controlled by these signals to position each heater element. Thereby, the temperature distribution of the panel can be strictly optimized, and the dry state can be controlled with high accuracy. Note that the temperature measurement position is desirably immediately before the drying position for accuracy, but is set as described above due to restrictions on the manufacturing apparatus. Further, the temperature measuring means may be any of a contact thermometer such as a thermocouple and a non-contact thermometer such as a radiation thermometer. Also,
The measurement site is desirably at least at the center and the periphery of the panel for accuracy.

[0016]

As described above, according to the method for drying a panel of a color cathode ray tube of the present invention, a heater device in which a plurality of heater elements are disposed in a substantially planar shape is arranged to face the panel, and the state of the panel (tube (E.g., seed size, temperature, etc.), the heater elements are moved back and forth to adjust the distance to the panel, thereby making the temperature distribution of the panel uniform. For example, the heating effect of the peripheral portion of the panel can be set higher than the heating effect of the central portion by moving the heater element at the peripheral portion of the heater device closer to the panel or by moving the heater element at the central portion of the heater device away from the panel. In addition, the panel temperature at the peripheral portion and the central portion can be made uniform, and the drying state can be made uniform, thereby preventing fluctuation in quality. Moreover, since the distance between the heater element and the panel is variable, the response to the temperature change of the panel is fast. For this reason, even if panels of various sizes are mixed at a high index and flow on the line, the dry state of each panel can be quickly optimized. In addition, since the distance between each heater element and the panel can be easily adjusted for each panel type size and panel temperature, the temperature distribution can be easily and highly accurately uniformed for each tube type size to optimize the dry state. .

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a color cathode ray tube panel drying method of the present invention.

FIG. 2 is a diagram showing another embodiment of the panel drying method of the present invention.

FIG. 3 is a partially cutaway side view showing the structure of a conventional color cathode ray tube.

FIG. 4 is an enlarged sectional view of a main part of a phosphor film pattern of a conventional color cathode ray tube.

FIG. 5 is a perspective view showing a conventional panel drying method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heater apparatus 2 Heater element 3 Heater support part 4 Drive part 5 Control part 10 Photosensitive resin layer 22 Panel 50 Coating panel

Claims (4)

[Claims] A plurality of heater elements disposed in a substantially planar shape;
A driving unit connected to the heater element, and a heater element of a heater device including a control unit for controlling the driving unit are arranged to face the panel, and each heater element is moved to adjust a distance between the panel and the panel. A panel drying method for color cathode ray tubes that optimizes the temperature distribution. 2. A panel drying method for a color cathode ray tube according to claim 1, wherein each heater element is moved to adjust a distance from the panel in accordance with the tube type size information of the panel to optimize a temperature distribution of the panel. . 3. The color cathode ray tube according to claim 1, wherein each heater element is moved to adjust a distance from the panel in accordance with the panel tube size information and the panel temperature, thereby optimizing the temperature distribution of the panel. Panel drying method. 4. The temperature distribution of the panel is optimized by moving a heater element for heating a peripheral portion of the panel closer to the panel or by moving a heater element for heating a central portion of the panel away from the panel. 3. The method for drying a panel of a color cathode ray tube according to item 1.