JPH04300670A - Applicator for coating solution - Google Patents

Abstract

PURPOSE:To improve coating accuracy by moving a dispenser in X, Y or Z direction according to the form of a coating surface by means of a picture processing unit and by simultaneously moving a coating nozzle connected to the dispenser in Z direction corresponding to the height of coating. CONSTITUTION:The valve 2 of a W-shaped fluorescent lamp 1 is laid on a mounting table 10, and a picture photographed by a camera 20 is sent to a picture processing control 22 to obtain the locus of the valve 2 centerline. A coating head 12 is positioned to face the terminal surface of the valve 2 and is lowered with a Z-direction driving device 16 so that an upper surface guide roller 29 comes into contact with the upper face of the valve 2, while side face guide rollers 30, 30 are brought into contact with the side face of the valve 2. X- and Y-direction driving devices 14, 18 are actuated by the signal of the controller 22, and the coating head 12 moves along the locus of the valve 2 centerline. In this process, a resistance-heating paste in a dispenser 25 is supplied to a coating surface through a coating nozzle 26. The running speed of the coating nozzle 26 is regulated constant so that the upper face guide roller 29 rolls on the upper face of the valve 2 to trace the surface.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating liquid coating device that is effective for use in devices that automatically coat a resistance heating paste on the surface of a bent fluorescent lamp.

0002

2. Description of the Related Art Cold cathode fluorescent lamps used for backlighting of liquid crystal display devices have a lamp shape such as U-shape, S-shape, or As shown in FIG. 6, it has a bent shape such as a W-shape. This type of lamp 1 may be used in a low-temperature atmosphere, and in this case, cold cathode fluorescent lamps have low mercury vapor pressure inside the bulb, making it difficult to start up, or emit light because the mercury vapor pressure does not rise. There are problems such as low efficiency. To prevent this, it has been proposed to warm the lamp with a heater.

As the heater, a surface heater made of a ceramic heater or the like is used, and this surface heater is brought into contact with the outer surface of the bulb, or a paste made of an electrically resistive material is applied to the outer surface of the glass bulb and fired to form a resistance heating film. Other methods have been proposed.

However, the use of a surface heater increases the number of parts and requires time and effort to install, resulting in high costs.For this reason, a heater that forms a resistance heating film directly on the outer surface of the bulb has been adopted. There is. That is, in this type of W-shaped cold cathode fluorescent lamp, as shown in FIG. It forms a W-shaped coating pattern.

[0005] When forming the resistance heating coating 3 on one side of the bulb 2 in this way, a paste of the resistance heating element is applied to the bulb, dried and fired, but in this case, the paste has a coating thickness. It is also necessary to control the coating width with high precision. If the paste coating thickness and coating width vary, the amount of heat generated locally varies, causing a temperature difference that may cause damage to the valve.

Conventionally, a mimeograph type screen printing device as shown in FIG. 7 has been used to apply a resistive heating element paste to one side of the bulb 2.

That is, 5 is a film-like screen, and slits 6 having the pattern to be applied and the width of the application are formed. A highly viscous coating liquid, ie, paste 7, is supplied to the screen 5, and this paste 7 is stretched and spread over the upper surface of the screen 5 by sliding a squeegee 8 along the screen 5. By this movement of the squeegee 8, the paste 7 is supplied from the slit 6 to the valve 2 placed below.

When the bulb 2 is separated from the screen 5 by about 0.5 mm so that its coating surface faces the slit 6, and the squeegee 8 is slid along the screen 5, the paste 7 is stretched and supplied from the slit 6. Therefore, the paste is applied to the upper surface of the bulb 2 along the pattern of the slits 6 and in an amount commensurate with the width of the slits 6, thereby forming a coating surface.

[0009]

[Problems to be Solved by the Invention] However, when using the above-mentioned screen printing apparatus, since the W-shaped bulb 2 is made by heating and softening the glass tube and bending it, the bending shape may have molding variations. occurs. In other words, the distance between the straight parts forming the W-shape and the curvature of the bent part forming the U-shape vary from lamp to lamp, and even in the same bulb, variations occur from place to place.

For this reason, when the bulb 2 is placed opposite the screen 5, the central axis of the bulb does not necessarily face the slit 6 correctly, which causes variations in the width and amount of paste 7 applied.

Further, the W-shaped valve 2 is shown in FIG. 6(B).
As shown in the figure, there are also differences in the height of each location, that is, the position in the Z direction. For such a valve 2, the screen 5 is bent by pressing the squeegee 8, thereby forcing the screen 5 to press against the valve 2, but the pressing force of the squeegee 8 is not applied to the valve 2. This may cause damage to the valve 2, and if the heights of the straight portions are different, there may be problems such as the screen 5 not being in close contact with the entire portion.

[0012] Therefore, in the conventional case, the paste application position, application thickness, and application width vary, and there is a drawback that highly accurate application cannot be performed.

The present invention has been made based on the above circumstances, and provides a coating liquid that can be applied with high precision, with little variation in coating position, coating thickness, coating width, etc., even for patterns with complex shapes. The present invention aims to provide a coating device.

[0014]

[Means for Solving the Problems] The first aspect of the present invention is to provide an image processing device that detects the shape of the coated surface by photographing the coated surface on the XY coordinate plane of an object to be coated with a coating liquid; A coating head that is driven in the X and Y directions via a drive device along the shape of the coating surface detected by the image processing device, and a coating head that is movable in the Z direction and rotates around the Z axis with respect to the coating head. a dispenser that is freely attached and supplies the coating liquid; a coating nozzle that is integrally connected to the dispenser and discharges the coating liquid onto the coating surface; and a coating nozzle that is provided on the coating head and that slides or rolls into contact with the coating surface. The height of the coating surface in the Z direction is detected and the tip of the coating nozzle is kept at a predetermined distance from the coating surface, and when the coating nozzle is moved in the X and Y directions, it is placed in front of the coating nozzle in the direction of movement. an upper surface guide and a side surface that slides or rolls into contact with the side surface of the object to be applied to copy the shape of the object in the X and Y directions and regulates the line connecting the upper surface guide and the application nozzle to follow the shape of the surface to be applied; It is characterized by being equipped with a guide.

The second aspect of the present invention is that instead of the side guide, the upper guide and the coating nozzle are connected according to the shape of the coating surface so that the line connecting the upper guide and the coating nozzle follows the shape of the coating surface. The present invention is characterized in that it includes a rotational drive means for rotationally driving around the Z-axis.

The third aspect of the present invention is to detect the height of the coating surface in the Z direction and drive the coating nozzle in the Z direction, instead of using the top guide and the side guide. It is characterized by being equipped with a height detection sensor that maintains the height at a predetermined distance.

[0017]

[Operation] According to the present invention, the dispenser is moved in the X and Y directions according to the shape of the coating surface by image processing, and the coating nozzle connected to this dispenser is moved to the height of the coating surface. Since the distance between the coating nozzle and the coating surface is kept constant, the coating position, coating thickness, coating width, etc. can be controlled with high precision by applying the coating liquid to the complex-shaped coating surface. It can be applied in a controlled manner.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below based on a first embodiment shown in FIGS. 1 and 2.

In the figure, reference numeral 10 denotes a mounting table on which an object to be applied, for example, a bulb 2 of a W-shaped fluorescent lamp 1 is mounted. The bulb 2 is supported by a valve holder 11, and is arranged so that its W-shaped coating surface corresponds to the XY plane in the XYZ coordinates.

A coating head 12 is arranged above the mounting table 10, that is, in the Z direction. The coating head 12 is guided by an X-direction guide arm 13 and is movable in the X-direction by an X-direction drive device 14 . The X-direction guide arm 13 is connected to the Z-direction guide arm 15.
It is guided by and movable in the Z direction by a Z direction drive device 16. Further, the Z direction guide arm 15 is guided by a Y direction guide arm 17 and is movable in the Y direction by a Y direction drive device 18.

That is, the coating head 12 is movable in the XYZ directions by the XYZ robot.

A camera 20 is attached to the coating head 12 via a bracket 21. The camera 20 photographs the shape of the bulb 2 of the W-shaped fluorescent lamp placed on the mounting table 10, and photographs the planar shape of the bulb 2, and this image data is sent to the image processing controller 22. The image processing controller 22 subjects the image to, for example, thinning processing, thereby recognizing the shape of the bulb 2 and determining the locus of the center line of the bulb 2. Since the locus of this center line becomes a W-shape, the image processing controller 22 issues a signal to the X-direction drive device 14 and the Y-direction drive device 18 based on this recognition pattern. The device 18 is activated. By these operations, the coating head 12 is moved in the X and Y directions along the locus of the center line of the bulb 2.

The coating head 12 also includes a dispenser 2.
5 is installed. The dispenser 25 stores a coating liquid, for example, a resistance heating paste, and as shown in FIG. 2, a coating nozzle 26 is integrally connected to the lower part of the dispenser 25 and hangs down therefrom. The lower end of this application nozzle 26 is opposed to the application surface, that is, the upper surface, of the bulb 2, and the paste is discharged from the tip. The dispenser 25 is supported by a bearing 27 so that the dispenser 25 is movable in the Z direction, that is, in the up and down direction within a predetermined stroke range, and is rotatable around the Z axis.

A roller holder 28 is attached to the bearing 27, and this roller holder 28 is attached to the dispenser 2.
5 and is supported so as to be movable in the Z direction and rotatable around the Z axis.

A top guide is attached to the roller holder 28 and can come into contact with the application surface, that is, the top surface, of the valve 2, and the top guide in this embodiment is formed by a roller 29. This upper surface guide roller 29 is designed to come into rolling contact with the upper surface of the valve 2, and moreover, the above-mentioned application nozzle 2
6 is disposed in front of the coating nozzle 26 in the traveling direction when the coating nozzle 6 is moved in the X and Y directions. The upper surface guide roller 29 comes into contact with the upper surface of the valve 2 and follows the upper surface of the valve 2. Therefore, the height of the upper surface of the valve is detected and the tip of the application nozzle 26 and the upper surface of the valve are maintained at a predetermined distance. It looks like this.

A side guide that can slide on the side surface of the valve 2 is attached to the roller holder 28, and the side guide in this embodiment is also formed by rollers 30, 30. These side guide rollers 30, 30 are adapted to roll into contact with each other across the side surface of the valve 2. These side guide rollers 30, 30 are in rolling contact with the side surfaces of the valve 2, so that the line connecting the coating nozzle 26 and the upper guide roller 29 is regulated to follow the shape of the coating surface, that is, the locus of the center line of the valve 2. It is supposed to be done.

The operation of the first embodiment with such a configuration will be explained.

The bulb 2 of the W-shaped fluorescent lamp 1 is placed lying down on the mounting table 10 and photographed by the camera 20. The camera 20 photographs the shape of the bulb 2 of the W-shaped fluorescent lamp and sends this image to the image processing controller 22 . The image processing controller 22 subjects the image data to line thinning processing, thereby recognizing the shape of the bulb 2 and determining the locus of the center line of the bulb 2. Since the locus of this center line becomes a W-shape, the controller 22 uses the X-direction drive device 1 based on this recognition pattern.
4 and the Y-direction drive device 18 to operate the X-direction drive device 14 and the Y-direction drive device 18.

In this case, the coating head 12 is placed opposite the end of the valve 2, and the Z-direction driving device 16 is operated to lower the coating head 12. This lowering causes the top guide roller 29 to come into contact with the top surface of the valve 2, and the side guide rollers 30, 30 to come into contact with the side surface of the valve 2. After such contact, the Z-direction drive device 16 is not operated until the application to the application surface is completed, so that the movement of the roller holder 28 and the dispenser 15 is not restricted.

In this state, the X-direction driving device 14 and the Y-direction driving device 18 are operated by a signal from the controller 22, and the coating head 12 is moved in the X and Y directions along the locus of the center line of the valve 2. let In other words, coating head 1
2 is moved along the W-shape. During this movement, the resistance heating paste stored in the dispenser 25 is discharged from the lower end of the application nozzle 26, and the application surface of the valve 2 is
In other words, it is supplied to the top surface.

In this case, the traveling speed of the application nozzle 26 is controlled to be constant, and the upper surface guide roller 29 rolls into contact with the upper surface of the valve 2, so that the valve 2
Since the tip of the application nozzle 26 and the top surface of the bulb are kept at a predetermined distance, the amount of paste applied can be kept constant even if the height of the top surface of the bulb changes, and the coating thickness can be kept constant. And the coating width can be regulated with high precision.

Furthermore, since the upper surface guide roller 29 is disposed in front of the coating nozzle 26 in the advancing direction, it does not come into contact with the paste discharged from the coating nozzle 26.

Further, the postures of the upper guide roller 29 and the coating nozzle 26 are similar to those of the side guide rollers 30 and 30.
This can be maintained by making rolling contact with the side surfaces of the valve 2 in between, and therefore, good coating can be performed even on a coating surface that is bent in a W-shape.

Note that the present invention is not limited to the above embodiments.

That is, FIGS. 3 and 4 show the second embodiment of the present invention.
An example is shown below. In the case of the first embodiment, side guide rollers 30, 30 are used to regulate the postures of the top guide roller 29 and the application nozzle 26 so that they are aligned in the direction of movement of the nozzle 26, that is, along the locus of the valve center line. However, in the case of the second embodiment, side guide rollers 30,
The difference is that instead of 30, a drive device, such as a motor 40, for rotating the coating head is used. As shown in detail in FIG. 4, a driving pulley 41 is attached to the motor 40, and a driven pulley 43 is attached to the rotating cylinder 42 supported by the bearing 27. A belt 44 is passed between the driving pulley 41 and the driven pulley 43, so that the rotary cylinder 42 is rotated by the motor 40. Therefore, the dispenser 15 and roller holder 28 attached to the rotary tube 42 are rotated around the Z-axis by the motor 40.

The motor 40 is controlled by the image processing controller 22 shown in FIG.
When the curve reaches the bend of the W-shaped coating surface, the motor 40 is activated to rotate the rotary cylinder 42, thereby aligning the posture of the upper guide roller 29 and the coating nozzle 26 arranged behind it with the center line. You can follow the trajectory.

FIG. 5 shows a third embodiment of the present invention.

In this embodiment, a height detection sensor 50 is provided at or near the coating head 12. This height detection sensor 50 is designed to detect the height of the W-shaped coating surface, that is, the top surface, of the valve 2, and based on this detection, the Z-direction drive device 16 is operated to adjust the height of the coating head 12. As a result, the tip of the coating nozzle 26 and the upper surface of the valve 2 can be maintained at a predetermined distance.

In this case, without using the top guide roller 29 and the side guide rollers 30, 30, the amount of paste applied can be kept constant even if the height of the valve changes, and the application thickness and width can be kept constant. can be regulated with high precision.

[0040] In the above embodiment, the case where the resistive heating paste is applied to the bulb of a W-shaped fluorescent lamp has been explained as an example, but the present invention is not limited thereto.

That is, the present invention can be applied not only to lamps but also to various objects, is not limited to a W-shaped coating pattern, and can be applied to various coating liquids other than resistance heating paste.

[0042]

Effects of the Invention As explained above, in each invention, the shape of the coating surface is measured by image processing, the dispenser is moved in the X and Y directions along this shape, and the coating nozzle connected to this dispenser is moved. The distance between the coating nozzle and the coating surface is kept constant by moving the coating liquid in the Z direction according to the height of the coating surface. It is possible to apply the coating while regulating the coating width etc. with high precision, improving the coating accuracy and preventing problems such as damage to the coated object.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an entire coating apparatus showing a first embodiment of the present invention.

FIG. 2 shows the coating head portion of the same embodiment, with (a) being a side view and (b) being a sectional view.

FIG. 3 is a perspective view showing the entire coating device according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing the coating head section of the same embodiment.

FIG. 5 is a perspective view showing the entire coating device according to a third embodiment of the present invention.

FIG. 6 shows a W-shaped fluorescent lamp, where (a) is a plan view and (b) is a cross-sectional view.

FIG. 7 is a perspective view showing a conventional screen printing coating device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Fluorescent lamp, 2... W-shaped bulb, 3... Resistance heating coating, 10... Mounting table, 12... Coating head, 13, 15, 1
7... Guide arm, 14, 16, 18... Drive device, 20
...Camera, 22...Image processing controller, 25...Dispenser, 26...Coating nozzle, 28...Roller holder, 29...Top guide roller, 30...Side guide roller, 40...Motor, 50...Height detection sensor.

Claims (3)

[Claims] [Claim 1] X of the coating material to which the coating liquid is to be applied
An image processing device that photographs the coated surface corresponding to the Y coordinate plane and detects the shape of the coated surface, and a drive device that moves in the X and Y directions along the shape of the coated surface detected by the image processing device. A coating head that is driven, a dispenser that is attached to the coating head so as to be movable in the Z direction and rotatable around the Z axis and supplies a coating liquid, and a dispenser that is integrally connected to the dispenser and is attached to the coating surface. A coating nozzle for discharging a coating liquid, and a coating head that is provided in sliding or rolling contact with the coating surface to detect the height of the coating surface in the Z direction and maintain a predetermined distance between the tip of the coating nozzle and the coating surface. When the coating nozzle is moved in the X and Y directions, an upper surface guide disposed in front of the coating nozzle in the traveling direction and sliding or rolling contact with the side surface of the coating material in the X and Y directions of the coating material. and a side guide that follows the shape of the top guide and the coating nozzle so that the line connecting the top guide and the coating nozzle follows the shape of the coating surface. [Claim 2] X of the coating material to which the coating liquid is to be applied.
An image processing device that photographs the coated surface on the Y coordinate plane and detects the shape of the coated surface;
a coating head that is driven in the Z direction, a dispenser that is attached to the coating head so as to be movable in the Z direction and rotatable around the Z axis and supplies a coating liquid, and a dispenser that is integrally connected to the dispenser and that is connected to the coating A coating nozzle that discharges a coating liquid onto the coating surface of the object, and a coating nozzle provided on the coating head that slides or rolls into contact with the coating surface of the coating material to detect the height of the coating surface in the Z direction, and a tip of the coating nozzle. The coating surface is maintained at a predetermined distance, and when the coating nozzle is moved in the X and Y directions, an upper surface guide is arranged in front of the coating nozzle in the traveling direction, and the coating surface is connected to the upper surface guide according to the shape of the coating surface. A coating liquid coating device comprising: a rotation drive means for rotationally driving the upper surface guide and the coating nozzle around a Z-axis so that a line connecting the nozzle follows the shape of the coating surface. . [Claim 3] X of the coating material to which the coating liquid is to be applied
An image processing device that photographs the coated surface on the Y coordinate plane and detects the shape of the coated surface;
a coating head that is driven in the Z direction, a dispenser that is attached to the coating head so as to be movable in the Z direction and rotatable around the Z axis and supplies a coating liquid, and a dispenser that is integrally connected to the dispenser and that is connected to the coating A coating nozzle that discharges a coating liquid onto the coating surface of an object, and a height detection device that detects the height of the coating surface in the Z direction and drives the coating nozzle in the Z direction to maintain a predetermined distance between the tip of the coating nozzle and the coating surface. A coating liquid coating device comprising: a sensor;