Patent Grant
8464771
The present invention relates generally to laser (or other high intensity light) markable media used, for example, as labels in labeling machines and/or in film printing for packaging, or for other printing applications, including point-of-sale, fax machines and laminate card (e.g. identity card) printers.
The present invention also provides an improved laser markable media having a clear or transparent substrate and a transparent carrier strip allowing significant advantages over the earlier, translucent substrate, as described below.
The present invention also provides an improved manual label applicator capable of utilizing and printing batches of labels using the novel media of the invention; wherein the batches of labels are programmable “on the fly”; a major improvement in the field of low cost produce labelers. A new rewind apparatus is also provided.
The labeling and packaging markets are demanding marking systems that are faster, more cost effective, capable of marking non-flat surfaces that have a longer lifetime, and which are capable of marking labels or packaging films “on the fly.”
As known in the prior art, direct laser array marking of high volume label media has a number of advantages: no ink or ribbon, non-contact (giving longer head lifetime), and allowing non-flat media or printing on non-flat substrates; see published PCT patent application WO 05/049332—published Feb. 6, 2005.
As is also known in the prior art, diode laser arrays provide a low cost, compact, high-speed, high reliability solution for marking rolls of labels to be applied to produce.
A major disadvantage of prior art direct laser marking systems is that they require media sensitive to NIR (near infrared) wavelength of diode lasers. The traditional approach requires an NIR (near infrared) absorber with a narrow absorption band, because any residual absorption in the visible wavelength range will cause visible coloration of the media. In most cases, white or clear media is preferred, so coloration is undesirable. Additionally, narrowband NIR absorbers can be costly, adding significantly to the cost of the media, when used in applications like packaging/product labeling, where costs need to be extremely low.
The present invention overcomes the aforementioned problems with the prior art systems.
The present invention includes a way to create laser markable media for NIR lasers, while avoiding the need for narrowband NIR absorbers.
More particularly, one embodiment of the invention includes a novel “indirect” light markable, multi-layer media wherein laser output light (or other high intensity light) is absorbed and converted into heat by one layer of the media, is immediately thermally conducted into selected portions of an adjacent, thermochromic layer, and forms the desired image. The “indirect” markable media preferably utilizes a three layer label laminate (in addition to any adhesive layer), including a layer of light absorbent material (preferably carbon black) which overlies or is embedded in the front surface of a translucent plastic substrate. The media can be “back marked” or “front marked.” In the case of “back marking,” in one embodiment the preferred carbon black absorbs the output light energy of the laser (or other high intensity light) output beam or beams, after the beam or beams have passed through the translucent label substrate, and converts the absorbed light energy into heat; the heat is conducted into a thermochromic front or visible layer, causing desired portions of the thermochromic layer to change color (or visual appearance) to produce the desired image.
In a “front marking” mode, in one embodiment the light output beam passes through the “front” of the media, that is the thermochromic layer first, then enters the light absorbent layer.
The present invention includes further features for optimizing the overall efficiency of the system, including the use of reflective materials either in the thermochromic coating or on the front surface of the thermochromic coating, and in the use of obscuration techniques, to obscure the carbon black (or other) light absorbent layer, described in detail below.
The laser markable label prior art includes (in addition to WO 05/049332 noted above) the use of carbon black as an ablatable layer and as a donor [see U.S. Pat. No. 6,001,530 (see col. 4, lines 53-58); U.S. Pat. No. 6,140,008 (see col. 2, lines 57-59); U.S. Pat. No. 6,207,344 (see col. 2, lines 47-50); US 2005/0115920 A1 (see page 2, paragraph [0016]) and U.S. Pat. No. 7,021,549 (see col. 3, lines 39-43)]. However, that prior art does not teach or suggest the use of carbon black as a light absorbent material wherein the absorbed light is converted to heat and conducted into an adjacent thermochromic layer; neither does it teach or suggest a three layer label laminate having a light absorbent central layer, a thermochromic layer and a substrate.
The present invention in one embodiment is applicable to the automatic labeling of fruit and vegetables. More particularly, the invention provides an improved laminated label structure for use in a system for applying variable information “on the fly” to labels for single items of produce. The invention greatly reduces the number of labeling machines, label designs, and label inventory needed to automatically apply labels to produce. The invention simplifies packing operations and reduces costs by reducing the labor and label inventory required to automatically label produce.
The present invention pertains also to handheld manually operated labeling machines utilizing an improved and novel media. More particularly, the invention provides an ergonomic, manually operated labeling machine for produce items that allows higher labeling speeds and eliminates problems with prior art labeling machines.
Prior art manual labeling machines are typically heavy and require repetitive motion by the user. The speed of labeling is inherently limited by the weight of the labelling machine, in that the user can only move the heavy machine from item to item at a limited speed. The labelling of produce items requires that the user label each individual produce item. Many thousands of labels are applied by a single user during a normal work day. The typical prior art labeling machine can only carry relatively small reels of labels requiring frequent reload operations causing unwanted downtime; and is relatively heavy, compared to the label applicator of this invention. In addition to a limited labeling speed and repetitive motion injuries suffered by the user, the machines are often dropped and damaged. The damaged machine can delay the labeling process, causing expensive “downgrading” of the produce items waiting to be labeled. Fines also may be levied against owners of the produce for substandard labeling by damaged label applicators.
What is needed in this art is a manually operated labelling machine that allows faster labelling speeds, reduces injury and fatigue to the user, and which also minimizes damaged machines and “down time” caused by dropped labelling machines.
The present invention eliminates the above described problems. For the first time, the present invention provides a manually actuated label applicator that is tethered to, and suspended from, an articulating boom. The boom supports the weight of the labeler while allowing the label applicator to be easily and quickly moved through an adequate range of motion. Repetitive motion injuries and fatigue are either reduced significantly or eliminated. In addition, the articulating boom is connected to a support structure housing a large label roll. Since the label roll is not carried by the user, larger rolls with more labels can be used. The labels are transported across the boom to the label applicator. The result is an extremely lightweight label applicator (since the weight of the labeller is carried by the boom) which can achieve much higher labelling speeds than prior art manual labeling machines with reduced fatigue and repetitive motion injuries suffered by the user. By using larger label rolls, the present invention reduces the down time required to change label rolls in prior art hand labellers.
Articulating tool supports are known in the prior art as shown by U.S. Pat. Nos. 3,917,200; 6,711,972; 7,055,789 and 7,325,777. Counterbalancing mechanisms are also known as shown by U.S. Pat. No. 4,166,602, which teaches such a mechanism for supporting an X-ray tubehead.
None of the above referenced prior art deals with produce labeling machines. Furthermore, and perhaps/more importantly, the above prior art does not teach the feeding of working material to the supported tool along the pathway of the articulating support mechanism.
In contrast to the prior art noted above, the present invention provides, for the first time, an articulating support for a handheld manually operated produce labeling machine. Furthermore, the present invention provides a feed mechanism for labels wherein the labels are fed to the supported tool along the pathway of the articulating support! By continuously feeding the labels to the hand tool along the articulating support, the mass of the labeling applicator is kept to a minimum. Minimizing the mass of the label applicator while simultaneously supporting the weight of the applicator by the present invention has effectively nearly doubled the output of prior art hand manual labeling machines. The present invention allows a user to apply about 180 labels per minute, compared to about 90-100 labels per minute with prior art hand labelers.
Another significant aspect of the present invention is that it is a cost effective improvement to manual label applicators. The present invention nearly doubles the output of conventional hand labelers at a cost less than a conventional hand labeler!
The present invention also provides a low cost, manually operated produce labeler that utilizes an improved media, allowing production of “on the fly” batches of variable labels for the first time in manually operated labelers.
A primary object of the invention is to provide a laser (or other high intensity light source) markable, multi-layer media for use as labels or in film printing incorporating a low cost light absorbent layer for NIR lasers, while avoiding the need for expensive narrowband NIR absorbers and removing residual media coloration.
A further object of the invention is to provide an “indirect” laser (or other high intensity light source) markable, multi-layer media which can be marked either through the front or back surface of the media.
A further object of the invention is to provide a laser markable, multi-layer media in which a low cost, broadband light absorbent layer, such as carbon black, for example, absorbs laser light output and converts absorbed light into heat, and the absorbed heat is conducted into portions of an adjacent thermochromic layer to form the desired image.
Another object of the invention is to provide a laser (or other high intensity light source) markable, multi-layer media including a light absorbent layer as noted above together with obscuration means to prevent said light absorbent layer from being visible to the naked eye.
A further object of the present invention is to provide a multi-layered media for use in automatic labeling machines for applying labels to single items of produce wherein variable coded information is applied to each label immediately prior to its application to an item of produce.
A further object of the invention is to provide a laminated label design capable of having variable coded information applied to it after the label has been transferred to the tip of a bellows in a rotary bellows applicator, which requires only minor modifications to the rotary bellows label applicating machine.
A further object of the invention is to provide a laminated label capable of having variable coded information applied to it for use in a rotary bellows applicator without having to reduce the operating speed of the rotary bellows applicator.
A primary object of the invention is to provide a cost effective, high speed hand labeling machine for applying labels to individual items of produce.
A further object is to provide a hand operated or manual produce labeling machine that achieves reduced fatigue and injury to the operator and virtual elimination of instances of dropping of the labeling machine.
A further object is to provide a simple mechanism for achieving roughly twice the labeling speed of prior art hand or manual produce labeling machines.
A further object is to provide a low cost, handheld and manually actuated label applicator capable of printing variable batches of labels “on the fly” to be applied to batches of produce having variable characteristics.
Another object is to provide a multi-laminate media having a clear transparent plastic substrate wherein said media is used in the low cost applicator referred to in the preceding paragraph.
Another object is to provide a new rewind mechanism for providing partially finished and finished labels on label rolls usable on a variety of labeling machines.
Further objects and advantages will become apparent from the following description and drawings wherein:
“Back Side” Marking of Three Layer Media
One restriction of this design is that any substrate used as rear layer 61 must be translucent, to allow the light to reach the absorbing layer 62. The word “translucent,” as used herein and in the claims, means either transparent to or sufficiently transmissive of the light output beam to form the desired image. This may be a polymer, such as, for example and without limitation, polyethylene, polypropylene and polyester.
To achieve best sensitivity, the peak temperature at the color change layer 63 for a given laser energy should be maximized. This can be done by:
using a thin highly heat conducting and light absorbing layer 62 (an alternative to carbon black is graphite or carbon nanotubes which have an improved conductivity).
using a thin color change (thermochromic) layer 63, again with a good thermal conductivity to ensure that the heat reaches the top or front visible surface of the layer and the mark visibility is maximum.
using an absorbing layer 62 with less than 100% absorption, so that the distribution of absorption through the absorbing layer is shifted towards the surface close to the color change (thermochromic) layer 63.
if an overcoat layer (not shown) is used on top of the color change layer 63 (e.g., to provide solvent resistance), this layer should be as thin as possible.
It is significant to note that the “back side” laser marking of media 60, shown in
“Front Side” Marking of Three Layer Media
To maximize sensitivity in this case, a high absorption coefficient in the absorbing layer 162 is required to maximize the proximity of the generated heat to the thermochromic layer 163. Minimizing the thickness of the thermochromic layer 163 and any overcoat layer (not shown) will also maximize sensitivity by minimizing the heat spreading.
The marking systems shown in
Alternatively, the obscuration means 80 may comprise a variable obscuration layer 181 wherein the thermochromic affect is achieved through varying the degree of obscuration (i.e., not using leuko dyes). For example the layer 181 may be translucent in the absence of applied heat, and applied heat conducted from light absorbent layer 62 causes it to become opaque, for example, by formation of gas bubbles within a polymer matrix, thereby obscuring the absorbent layer. Alternatively, the obscuration layer 181 may have an opaque status in the absence of heat, and the heat conducted from light absorbent layer 62 makes the obscuration layer 181 translucent, for example, by melting of wax powder in a gas/wax mixture, thereby allowing the dark absorbing layer 62 to be seen in the exposed areas.
The obscuration means 80 and/or 85 can also be applied to the media 160 illustrated in
As an alternative to embedding the light absorbent layer in substrate 61, as shown in
Use of Multi-Layer Laminate for Labeling Produce
The prior art typically requires separate labeling machines and label designs for each price look up or “PLU” number. PLU numbers are required by retailers to facilitate quick handling and accurate pricing of produce at checkout. For example, in order to apply labels denoting “small” or “medium” or “large” size designations for apples, the prior art typically requires three separate labeling machines, three separate label designs, and three label inventories. If a packhouse packs more than one brand, the equipment configuration is duplicated. This label application equipment is expensive, requires maintenance, and requires a significant amount of physical space on the sizer and thereby restricts where the packing operation may place their drops to further pack the produce. The present invention facilitates the same labeling in the above example with only one labeling machine and one label design.
The most widely used type of produce labeling machine utilizes a rotary bellows applicator. It is advantageous to minimize any modifications to existing produce labeling machines in creating a system for applying variable coding “on the fly.” Similarly, the operating speed of existing labeling machines must be maintained.
The present invention solves the problem of applying variable coded information “on the fly.” No significant modification of existing rotary bellows applicators is required. No reduction of labeling speed is required. In a preferred embodiment, the invention uses one or more laser output beams to pass through the back or reverse surface of the label (on which an adhesive layer is carried), through the label substrate, and to cause an image to be formed on the front or visible surface of the label.
The prior art includes various attempts to meet the increasing demand for a greater variety of labels and variable information. One approach by the prior art (U.S. Pat. No. 6,179,030) is to position produce labeling machines downstream of sizing equipment so that all labels indicate the same size of produce. Of course, this approach involves the expense of modifying conveying equipment and is limited to the application of sizing information.
Another attempted solution of the prior art has been to apply variably coded information to the front or visible label surface before the label is transferred to the tip of a bellows (see U.S. Pat. No. 6,257,294). The difficulty with that attempted solution is that the label is being printed as it is twisting and bending as it is transferred from the label carrier strip to the tip of the bellows. A complex array of air streams is provided to try to control the label and to dry the ink. The applicants herein are aware of that apparatus and the understanding of applicants is that approach has not been accepted commercially.
Another possible approach is to apply variable information to the labels upstream of the point at which the labels are transferred to the rotary bellows. The difficulty with that approach is that the requirements for sensors and timing devices increases the cost significantly. For example, to sense the variable information for 24 items of produce, and to be able to apply a newly printed label to a piece of produce that is 24 “slots” away from being labeled, requires the use of greater memory and complex timing and synchronization circuitry to assure that the proper information is applied to the proper item of produce; all at prohibitive cost.
The present invention overcomes the above-mentioned difficulties of the prior art attempts. The present invention avoids the reconfiguration of sizing and conveying equipment required by U.S. Pat. No. 6,179,030. The present invention, in sharp contrast to U.S. Pat. No. 6,257,294, applies the variable coded information to the label after the label is transferred to the tip of a rotary bellows, and avoids the problems inherent in that prior art attempted solution. Furthermore, the present invention, in further contrast to U.S. Pat. No. 6,257,294, avoids the use of sprayed ink and the required drying time by utilizing one or more laser beams that react instantly with the novel label laminate of the invention. The present invention also avoids the use of costly sensing and timing circuits by applying the variably coded information immediately before the label is applied to the appropriate produce item.
The present label laminate invention is designed particularly for use in conjunction with the system disclosed in U.S. patent application Ser. No. 11/069,330, filed Mar. 1, 2005, and entitled “Method and Apparatus for Applying Variable Coded Labels to Items of Produce,” which application is incorporated herein by reference as though set forth in full (the '330 application). Pertinent aspects of the '330 application are included below for the sake of explaining the present invention. A more complete description of the labeling machinery is contained in the '330 application and references referred to therein. The use of rotary bellows applicators, as shown in the '330 application, has become the standard of the produce labeling industry. Any departure from the use of a rotary bellows applicator head would require significant investment in new labeling apparatus.
The present invention requires only minor modification to the standard rotary bellows applicators. The present invention does not utilize ink which requires relatively lengthy drying time. The present invention applies the information while each label is moving, but in a relatively stable position, after it has been transferred to the tip of a bellows, maximizing image clarity. The present invention is capable of forming images at a speed commensurate with maximum speeds of the existing rotary bellows label applicators.
As shown in
As shown in
As an alternative to embedding scattering material in the thermochromic layer 263, as illustrated in
Direct Laser Marking of Two Layer Media
In addition to the above embodiments, the invention also includes direct laser marking utilizing a two layer media having a plastic substrate layer and a thermochromic layer.
As shown schematically in
Laminated Label Material Requirements for Two Layer Media
The following is a general description of the laminated label requirements for a two layer label for achieving acceptable quality fruit and vegetable labels.
The laminate substrate 361 is preferably a Low Density Polyethylene (LDPE) film approximately 40 μm thick.
The media and its components must comply with governmental regulations concerning food, health and safety aspects that govern use of similar products.
The substrate 361 must be free of any slip agents or other additives with the exception of minimal amounts of natural silica anti-blocking agent and polymeric processing aid (not present in surface layer of finished film), also white master-batch in the case of the white film products.
The label film or substrate 361 is an extruded film with a white master-batch present. The white master-batch typically consists of TiO2, Lithopone, Kaolin Clay or other appropriate whitener.
Example Methods
There is no one method to achieve an acceptable mark on a PE label. However, there are several major components that must be tuned or addressed in order to create the desired result. Table 1 presents five example methods and the relative primary components that achieved acceptable marks on PE labels. Following the table, a detailed description of the various components for each example are defined and outlined.
1. Primary Components to Achieve Laser Marks
There are two different formulation systems to consider for the integration of a laser sensitive agent into or onto the base label material and include:
Key issues for the development of this material are as follows:
The coated and laser printed film, including the laser-activated area, must be acceptable for indirect food contact and must be non-toxic when ingested in very small amounts.
The following method describes how it is possible to use reflective coatings, surfaces or particles to optimize the available laser energy for variably coding laminated labels using the present invention for “on the fly” application for fresh produce. Reflective materials are described in part above in conjunction with FIGS. 5A and 10A-10F. This can be accomplished with all types of lasers specifically CO2 and diode based lasers.
By optimally selecting the material and the finish of the material that carries the laminated label, the laser energy can be directed back into the label to in-effect increase the exposure time. Therefore the overall energy density to which the label is exposed is improved and the resulting mark produced by the laser is darker or a similar mark can be achieved at a greater speed.
As light interacts with a given material it will be reflected, transmitted or absorbed. The thermochromic material applied to the face of the label has been selected to absorb the laser's energy. Even though, 50% or more of the laser energy can be lost (i.e., transmitted or reflected). Therefore, it is preferable to design the surface of the label carrier to reflect as much of the laser energy as possible back into the face of the label. Since lasers can be selected with different wavelength this material must be carefully selected for the desired laser.
Set-Up 1
Power was increased in 5% increments until the resultant mark was fully marked. For this setup the power level was 55%.
Set-Up 2
Again the power was increased in 5% increments until the resultant mark was fully marked. For this setup the power level was 45%. This was an 18% decrease in power or conversely an increase in overall performance.
Set-Up 1
Handheld Label Applicator
A suspension means 480 is connected to articulating boom 440 from base 445 for carrying at least a portion of the weight of handheld label applicator 420. In the embodiment shown in
A relatively large label roll 460 is a label supply means and is carried by support 450 in the embodiment shown in
Tape waste is rewound in the label applicator 420 as described below and disposed of by the operator. Alternately, tape waste could be transported back to the base station for continuous waste disposal with no operator intervention.
Labels 422a are manually applied by the operator on their target 406, typically fruit in boxes. The label applicator 420 automatically dispenses one label of the roll or reel for each labeling action or actuation of the applicator 420. Each labeling sequence is triggered automatically by pressure detection on the transfer roller 424, as is known in the labeling art.
Incoming labels 422a are positioned on a backing tape 422b conforming a “web” or strip of labels 479. This web or strip is driven by a motorized sprocket wheel 427. As the web is driven forward, the labels 422a are stripped from their backing tape 422b through the stripper plate 425 and transferred to the target 406 with the aid of the transfer roller 424 during the application action of the operator which actuates the label applicator 420. The backing tape 422b waste is then rewound on the rewind reel 428.
The sprocket wheel 427 is driven by a position drive or drive controller 429 that accurately advances the tape 422b the exact length of a whole label pitch on each labeling sequence by rotating sprocket 427.
This method alone can position several tens of labels in an “open loop” fashion; however, due to system's tolerances and drag, the label starts losing position.
To overcome this problem, the label applicator 420 utilizes a novel method of synchronization or registration for accurately positioning or registering labels on the transfer roller; an optical label sensor 423 is used to detect the edge of the labels and feedback position to the sprocket wheel 427 position drive through drive controller 429. Drive controller 429 is connected to and responsive to optical label sensor 423. If the labels are not properly registered or aligned with the actuation mechanism of the applicator, drive control 429 causes sprocket 427 to advance until the labels are aligned or registered. In this manner a label registration means is formed comprising optical label sensor 423, drive controller 429 and sprocket 427 for repositioning the label strip in applicator 420 by advancing the strip until the labels are aligned with the actuation mechanism of applicator 420.
The label sensor 423 utilizes an optical principle; it “sees through” the incoming labels' web and detects variations in transparency between the backing tape alone 422b and the backing tape with a label 422a to determine the edge position of a label.
The sensor is capable of “self calibrating” to different environmental conditions, e.g.: variations in tape and label thickness and transparency, dirt, ambient light, etc. As part of the detection process, the sensor can dynamically calibrate a) its transmitting power, b) its receiver sensitivity and c) the detection threshold.
Because label position is kept for a relatively large amount of labels by the sprocket wheel 427, the sensor has enough time to dynamically adapt to changing environmental conditions; as labels are applied the sensor can produce one valid edge detection signal after several labels (for example: one valid position signal every ten labels).
Upon valid edge detection from the sensor 423, the drive controller 429 of the sprocket wheel 427 compensates position accordingly and the cycle starts over again.
A movable lever or handle 431 is pivotally mounted by pin 432 to base 445 of boom 440. The proximal end 431a of lever or handle 431 is easily grasped by the user and moved upwardly or downwardly as shown by arrow 499. The distal end 431b of handle 431 carries spring 482 which is connected to the proximal end 441a of primary arm 441 by pin 441c. As the proximal end 431a of handle 431 is raised, spring 482 is extended, carrying more of the weight of applicator 420. Conversely, if lever or handle 431 is lowered, the spring 482 is shortened, and less of the weight of applicator 420 is carried by spring 482. A retaining knob 433 is carried by handle 431. Knob 433 carries a spring loaded pin (not visible in
Light source means 510 is positioned between the handheld, manually operated label applicator 520 and the label supply 560. A sensor for detecting the presence of a label is utilized in conjunction with light source 510. Such sensors are known in the art and are not shown for clarity. Label supply 560 includes a large roll of unfinished labels on a carrier strip 570. The labels on strip 570 are preferably the three layer laminate media described above, and most preferably utilizing the “back marking” technique with a clear, transparent substrate 61 as shown in
Label applicator 520 is preferably supported by a suspension means 540 (not shown in detail in
The label supply 560 houses a carrier strip 570 with a plurality 572 of unfinished labels, i.e. the labels must be marked by light source means 510 to be finished or readable. Label supply 560 is mounted remotely from applicator 520 in the sense that its weight is not carried by applicator 520.
Rollers 591 and 592 are positioned on both sides of light source means 510 to move the labels 572 across the path of the output of the light source means 510.
The foregoing description of the invention has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teaching. The embodiments were chosen and described to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best use the invention in various embodiments and with various modifications suited to the particular use contemplated.
This application is a continuation-in-part of U.S. application Ser. No. 11/511,103 filed Aug. 28, 2006 now U.S. Pat. No. 7,837,823.
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| Number | Date | Country | |
|---|---|---|---|
| 20110146912 A1 | Jun 2011 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11511103 | Aug 2006 | US |
| Child | 12927394 | US |
