Automated dye pattern application system

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AUTOMATED DYE PATTERN APPLICATION
SYSTEM

This is a divisional application of parent application , Ser. No. 07/406,367, filed Sept. 12, 1989, having a title of AUTOMATED DYE PATTERN APPLICATION SYSTEM; now U.S. Pat. No.. 4,979,380.

- FIELD OF THE INVENTION

The present invention relates to graphic art systems and, more particularly, to a dye plotter system for spraying dye in selected patterns onto media, such as mats.

BACKGROUND OF THE INVENTION

Applying patterns or designs to carpets, mats, and other similar media is a popular and useful practice. Such a process may be used to welcome visitors, advertise a product or display a company's logo, or for decorating purposes, to name only a few uses. For many years, manual airbrushing, which uses compressed air to atomize and spray the dye, has been the only method for applying dye to these types of materials in patterns other than repeating or random types of patterns. Application by hand, however, is a time consuming and labor intensive project which often yields inconsistent results. Manually applying dyes to carpets, mats, and the like is subject to many problems. Each step in a manual process is subject to human error, and as the number of carpets to be. finished with the sam design increases, so does the possibility of inconsistent results. Variances in the patterns, such as dye thickness and pattern accuracy, is possible.

Historically, masks have been used to create patterns on carpets. In such a process, masks are placed on the rug and the entire rug is dyed minus the pattern of the masks. This method wastes dye because of the excessive spray coverage. Time is also wasted by the need to create, place, and remove the masks. Stencils also have been used to transfer a dye pattern to the dye receiving material. This process is similar to the use of masks except that only portions of the carpet not covered by the cut-out areas are dyed. Likewise, the use of stencils wastes dye materials, because of overspray. Also, the use of stencils and masks is not conducive to positioning dye in detailed patterns. The capability of applying the same dye pattern to a series of media is also desirable. Consequently, a need exists in the present industry for a faster, more accurate, and more consistent system for applying dye to dye receiving materials.

There have been some attempts at automating the application of dyes to media such as carpets, particularly in large manufacturing installations. In a typical arrangement of this type, a reciprocating dye spray head is positioned over a web conveyor moving an extended length of carpet thereunder. Such a arrangement is particularly useful for applying dye to the carpet in a repeating pattern or in a random pattern. However, the large scale of such an installation makes it unsuitable for smaller jobs, such as the application of custom patterns on small media, such as relatively small rugs, mats, and the like. Additionally, the arrangements heretofore employed are not flexible enough for quick change of the dye pattern to be applied or in the types of patterns which can be applied.

SUMMARY OF THE INVENTION

The present invention provides apparatus and methods which greatly enhance the application of dye pat5 terns to relatively small media, such as rugs, mats, and the like. Essentially, the method of the present invention comprises digitizing a pattern or image to be applied to the media, storing the image in a computer, converting the image data into dye plotting commands,

10 and communicating the plotting commands to intelligent controllers controlling stepper motors driving an enlarged x-y plotter type of device which scans a dye spray head over the dye receiving medium and sprays the dye according to the plotting commands.

15 The plotter apparatus includes a flat dye medium support bed mounted on a pedestal. A fixed guide track having one end of a mobile guide track riding thereon is mounted on the bed, the opposite end of the mobile track riding on the support bed. A mobile track carrier

20 or bogie riding on the fixed track is configured to maintain a perpendicular relationship between the two tracks. A spray head carrier has a dye spray head mounted thereon and rides on the mobile track. A mobile track stepper motor is mounted on the fixed track

25 and is connected by a cable and pulleys to the mobile track bogie. Similarly, a spray head stepper motor is mounted on the mobile track and is connected by a cable and pulleys to the spray head carrier. Preferably, the tracks have a cross sectional shape formed by a pair

30 of downwardly projecting webs or flanges with inwardly turned ledges forming upwardly facing support shoulders. Each of the spray head carrier and mobile track bogie includes a carrier plate with sets of wheels positioned in a common plane. The wheels have-tread

35 surfaces which engage opposite faces of the webs and sidewall surfaces which engage the support shoulders of the ledges.

Liquid dye is supplied to the spray head and is driven therefrom by compressed air. The spray head is also 40 controlled pneumatically. An air compressor supplies compressed air to an air tank which communicates with a solenoid operated pneumatic air control valve, to a single input, multiple output pressure regulator manifold. A spray control valve line is routed from the regu45 lator manifold to a cylinder within the spray head in which a spring return spray valve actuator piston is positioned. A needle valve is connected to the piston and is seated to normally block flow from an orifice of the spray head. When the spray head cylinder is pres50 surized, the piston is driven back and opens the needle valve. A spray drive conduit communicates compressed air from the regulator to a mixing chamber of the spray head. Finally, a dye volume conduit communicates air pressure to one or more dye supply containers, which 55 may contain different color dyes. A dye conduit then communicates the liquid dye to the spray head mixing chamber and is connected thereto by a valving, quick disconnect connector. When the air control valve is opened by a signal from 60 the computer, compressed air is supplied to each of the compressed air lines at a pressure controlled by the regulator manifold. The liquid dye container is pressurized to positively supply the dye to the spray head. The spray control opens the needle valve, and the spray 65 drive air forces the dye from the orifice in small droplets, the pattern of which is controlled by the pressure in the spray drive conduit. The quick disconnect dye conduit allows the color of the dye to be changed conve10

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niently. Whenever the color is changed, the spray head may be purged by driving the new dye through the head for a short period. This may be controlled by a manually operated purge control. The support bed is provided with a purge funnel to receive the purge spray and route same to a suitable receptacle.

Each stepper motor is controlled by an analog controller interfaced by an intelligent indexer to the computer. One of the indexers is connected by a conventional serial interface to the computer, and has the other indexer "daisy chained" thereto. Each indexer is capable of controlling functions in addition to its motor. Specifically, the air control valve and a purge control switch are connected to a control port of one of the indexers. Each indexer has a limit switch connected thereto which is activated respectively by the mobile track bogie reaching a designated x-coordinate or the spray head carrier being driven to a designated y-coordinate. These designated coordinates define a hardware reference position to which all movement of the spray head is referenced.

The position of the spray head anywhere on the bed is determined in terms of stepper motor counts. Elongated mat position guides are mounted on the support bed and intersect at a starting position for the spray 25 head. Both the purge funnel and the starting position are calibrated from the reference position in terms of two dimensional stepper motor counts. When the system is powered up, the computer causes the motors to move the head to the reference position and, thereafter, parks the spray head over the purge funnel. Similarly, after an image has been sprayed, the spray head is again parked over the purge funnel.

The dye control computer may be any of a number of types of personal computers having a central processing unit, input/output ports, a keyboard, floppy and hard disk drives, an adequate amount of read/write memory, and preferably a high resolution graphics capability. The images to be reproduced may be composed on the dye control computer itself using one of a number of 40 conventional "paint" type programs capable of representing images in one of a number of standard image formats, or may be created on another computer. A mouse, or other type of pointing device, may be employed in such composition. The images may also be 45 generated by the use of an optical scanner to scan a pictorial image. The image may be edited, enhanced, cropped, or otherwise manipulated by the paint program. Alternatively, the images may be created using object oriented types of graphics software, such as the type used for computer aided drafting and design (CADD).

The screen display of images created by paint programs is in the form of horizontal lines of picture elements or pixels scanned from left to right and top to bottom on the video display of the computer. In a monochrome paint image, an image data file representing the image is an array of On and Off bits which is repeatedly read by the display circuitry in synchronism with the sweep of the CRT (cathode ray tube) electron beam on the screen. In a digital color image, the image data file may include color attributes for each pixel to control the activation and intensity level of one or more of the color beams (red, green, and blue) to display a multiple color image.

The dye application machinery, including the stepper motors and dye supply valves and collectively referred to as the dye plotter, is controlled by the dye control

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computer which executes a plotting program. While it would be possible for the plotting program to be implemented in such a manner as to process the image pixel data directly, it is preferred that the image data be converted into a more convenient format, due to the configuration of the plotter apparatus.

On the plotter apparatus, the fixed track extends in the direction of a designated x-axis, and the mobile track extends parallel to a designated y-axis. Thus, the mobile track is moved parallel to the x-axis while the spray head is moved parallel to the y-axis. The normal sweep pattern of a CRT is to sweep a horizontal line from left to right, retrace downward, and repeat to complete the frame. On the plotter, the spray head and carrier weigh less than the combination of the mobile track, the head carrier, and the head. Thus, it is more efficient to sweep the head in the y-direction during spraying and then to increment the mobile track in the x-direction at the end of a line. Additionally, retracing on the plotter would be wasted motion, such that bidirectional sweeping of the spray head is desirable.

As the head is stepped to the end of a line, its position is maintained as the mobile track is incremented, then the head is stepped in the opposite direction. Finally, it would be possible for the spray head to be turned On and Off at each coordinate to be sprayed; however, this would slow the dye application process and would unnecessarily work the spray supply valves.

The present invention provides an image data format conversion program which processes the standard pixel data into a format which is used by the dye control . computer to more efficiently control the plotter apparatus. The conversion converts the x-axis or horizontally oriented image data format used by the video display into a y-axis or vertically oriented format for use by the plotter apparatus. Every other y-axis line is inverted to allow bidirectional sweeping of the spray head. Bits in contiguous groups of similar bits are counted and saved with the bit state (On or Off) as plotter commands.

The plotter commands for an image are compiled into a plotter data file for that image. The plotter commands are processed by the plotting program to sweep the spray head over the dye receiving medium and to activate the spray head according to the location of the spray head. The conversion program may also perform a type of color separation function on a color image to allow spraying an image in multiple colors or colors to be assigned to certain regions of the image may be selected by the operator. In such a process, the color attributes of the image pixels are processed to form a plotter data file for each of a plurality of individual colors for a color image. During processing of such multiple color data file, each color is sprayed individually, and the spray head is parked at the purge funnel after each pass for a changeover of dye color.

OBJECTS OF THE INVENTION

The principal objects of the present invention are: to provide an improved system for applying dyes and similar types of materials in selected patterns and designs to media such as carpets, mats, and the like; to provide such a system which increases the flexibility of the types of designs and images which can be applied as dyes to media and the convenience with which changes of designs can be accomplished; to provide such a system which enhances the consistency of applying the same dye design repeatedly; to provide such a system which is quickly adaptable to applying designs to differ

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bed 6 to be tilted in a plurality of orientations and thereafter locked in position, as shown in FIG. 11, to facilitate some operations with the system 1. The support bed 6 is a rectangular structure with a flat upper support surface 20 which is sized to accommodate a variety of 5 sizes of mats 7. The illustrated support bed 6 is formed of a plurality of rectangular subsections 21 which are joined by fasteners 22, such as bolts and nuts (FIG. 6). The sectional configuration of the support bed 6 allows the support structure 2 to be disassembled for conve- 10 nience in transportation. Although the bed 6 is often employed in a level orientation, orientation of the support bed 6 will be referred to herein by a designated top edge 23, bottom edge 24, a left edge 25, and a right edge 26 (see FIG. 5). A pair of perpendicularly oriented mat 15 guides 27 and 28 are mounted on the upper surface 20 of the bed 6 and intersect at a dye spray starting position 29, which is just below the spray head 8 in FIG. 5. The mat guide 27 forms an x-axis or horizontal axis of the support bed 20, while the mat guide 28 forms a y-axis or 20 vertical axis thereof. A purge funnel 30 is positioned on the bed 6 at a position in close proximity to the spray starting position 29 and at an integral number of steps of the motors 12 and 13 therefrom.

Referring to FIGS. 5, 6, and 9, the fixed x-axis track 25 10 is connected to the bed 6 along the front edge 23 thereof. The track 10 is an extrusion and includes a lower channel section formed of depending flanges or webs 33 with grooves formed along, inside faces to define inwardly directed ledges 34 having upwardly 30 facing support shoulders 35. An upper tubular chamber 36 is formed by an upper wall 37 and a center wall 38. The mobile y-axis track 11 is supported on the fixed track 10 by a mobile track carrier or bogie 39 formed of a support plate 40 having multiple sets of wheels 41 35 journaled on axles 42 and mounted thereon. The wheels 41 have tread surfaces 43 and sidewall surfaces 44. The axles 42 are oriented vertically and mutually parallel such that the wheels 41 are positioned in a common plane. The treads 43 ride in the grooves of the flanges 40 33, and the weight carried by the bogie 39 is supported by engagement of the sidewalls 44 with the support shoulders 35.

At least two longitudinally spaced sets of the wheels 41 are mounted on the plate 40, as indicated by the sets 45 of axles 42 seen in FIG. 6, to maintain the perpendicular relationship of the mobile track 11 with the fixed track 10. The mobile track motor 12 is drivingly engaged with the bogie 39 by means of a mobile track cable 45 connected to opposite ends of the plate 40 and trained 50 about a drive pulley (not shown) on a shaft of the motor 12 and an idler pulley 46 (FIG. 6) at an opposite end of the track 10 from the motor 12. An upper run of the cable 45 extends through the upper chamber 36.

Referring to FIG. 7, the mobile track 11 is a similar 55 type of extrusion to that of the fixed track 10 and includes depending flanges or webs 49 with grooves forming inwardly directed ledges 50 which define upwardly facing support shoulders 51. The spray head carrier 9 is formed by a hollow rectangular structure 60 including a lower carrier plate 52 having sets of wheels 53 journaled thereon and positioned in a common plane. The wheels 53 include tread surface 54 and. sidewall surfaces 55. The spray head carrier 9 is guided by the mobile track 11 by engagement of the treads 54 with the 65 grooves of the flanges 49 and supported by engagement of the sidewalls 55 with the support surfaces 51 of the ledges 50.

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The mobile track 11 is connected to the mobile track bogie 39 by a pivot bracket 57 which is attached to the track 11 at one end and which is pivotally connected to the bogie plate 40. At the opposite end from the bracket 57, a fixed orientation caster bracket 58 with a caster wheel 59 journaled thereon rides along the upper surface 20 of the support bed 6 to maintain the mobile track 11 parallel with the surface 20. The spray head carrier 9 includes at least two pairs of the wheels 53 positioned at longitudinally spaced locations to maintain the orientation of the carrier 9 with respect to the mobile track 11.

The carrier 9 includes upstanding side walls 61 and 62 connected to the plate 52. The side wall 62 has a spray head bracket 63 attached thereto which supports the spray head 8. The head carrier motor 13 is drivingly engaged with the carrier 9 by a head carrier cable 65 which is trained about a drive pulley (not shown) on the motor 13 and an idler pulley 66 (FIG. 10) positioned at an opposite end of the track 11 from the motor 13. The cable 65 is attached to opposite ends of the carrier plate 52 and extends through an upper chamber 67 of the mobile track 11.

Referring to FIGS. 7, 8, and 12, the spray head 8 includes a spray head body 71 having a spray valve cylinder 72 formed therein. A spray valve piston 73 is positioned within the cylinder 72 and has a needle valve member 74 connected thereto. A nozzle 75 with an orifice 76 formed therethrough is attached to an end of the body 71, and a valve seat member 77 is positioned between the nozzle 75 and has the needle valve 74 normally urged to close same by a piston return spring 78 engaged between the piston 73 and the body 71. A spray mixing chamber 79 is formed within the body 71 behind the valve seat member 77 and has a dye port 80 and a spray drive port 81 communicating therewith. A dye conduit 82 is connected to the dye port 80, and a spray drive compressed air line 83 is connected to the spray drive port 81. A spray valve control compressed air conduit 84 (FIGS. 7 and 8) is connected to a spray valve control port (not shown). Preferably, the dye conduit

82 is terminated by a valving quick disconnect connector 85 which closes upon disconnection from the dye port 80. This allows quick and convenient changeover of dye colors.

Referring to FIG. 13, the dye supply mechanism 4 includes an air compressor 90 communicating through a master air valve 91 with a set of air pressure regulators 92. The compressor 90 may include a compressed air reservoir tank (not shown), according to the configuration of the compressor 90. The regulators 92 may be individual regulators or a single input/multiple output manifold type of arrangement. The spray drive conduit

83 and spray valve control conduit 84 are connected to outputs of the regulators 92. A dye volume compressed air conduit 93 is connected to one or more dye supply containers 94 which contain different color dyes. The dye volume conduit 9 pressurizes the containers 94 to positively urge dye in the dye conduits 82 into the mixing chamber 77 of the spray head 8. In the illustrated system 1, the regulators 92 provide compressed air at pressures of 4 to 6 pounds per square inch (psi) to the dye containers 94, 7 to 8 psi to the spray drive conduit 83, and 25 to 30 psi to the spray valve control conduit 84.

When it is desired to cause dye to spray from the spray head 8, the master air valve 91 is opened. This supplies compressed air to the spray drive conduit 83, the spray valve control conduit 84, and the dye volume