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Capillary hollow fibers containing therein therapeutic and indicator agents and a method of employing such fibers, which method comprises placing the agent-filled, hollow capillary fibers into the oral cavity, and particularly about, adjacent or in contact with the teeth, at or about those areas where treatment of a dental disease is desired, or where indication of the presence of an oral or a dental disease is suspected, whereby such agent permeates from such capillary-hollow-fiber treatment into the localized area to treat the disease or to serve as an indication of dental disease in the area.
1. A capillary hollow fiber suitable for diagnostic use in the detection of a dental disease in the oral cavity of a patient, which fiber comprises a flexible, semipermeable, polymeric material having an outside diameter of not greater than 500 microns and a wall thickness of from about 1 to 100 microns, the lumen of the fiber containing a known quantity of an indicator-diagnostic agent wherein the indicator agent is selected from the group of acid-base indicator agents, oxidation-reduction indicators, tooth-corrosive-action indicators and proteinaceous proteolytic-action indicators which provides diagnostic information by undergoing chemical reaction with the products elaborated by the localized disease process in the oral cavity whose diagnosis is desired, the indicator agent capable of diffusing out of the fiber at a rate controlled by the permeability of the fiber.
2. The hollow fiber of claim 1 wherein the fiber has an outside diameter of from about 100 to 300 microns, and a wall thickness of from about 5 to 100 microns.
3. The hollow fiber of claim 1, which hollow fiber is a cellulose-acetate fiber.
4. The hollow fiber of claim 1 wherein the hollow fiber is preformed into a generally loop shape of sufficient size to be slipped over the crown of a tooth, and to rest about and be generally in contact with the tooth dental tissue surface.
5. The hollow fiber of claim 1, which fiber contains therein a known quantity of a calcium hydroxyapatite.
6. The hollow fiber of claim 1 wherein the hollow fiber is adhesively secured to a flexible, pharmaceutically acceptable string element, which string element is adapted to be tied about the tooth of a patient and to retain the hollow fiber against the tooth.
7. The hollow fiber of claim 1 wherein the ends of the hollow fiber are occluded.
8. The hollow fiber of claim 1 which is in a preformed loop of sufficient size for the loop to be inserted between adjacent teeth in the mouth of a user.
9. The hollow fiber of claim 1 which includes in the lumen a known quantity of precipitated hydroxyapatite crystals and wherein the ends of the fiber are occluded.
10. The hollow fiber of claim 1 which includes a short length of fiber adhesively secured to a fibrous, flexible suture-like material, whereby the fibrous material may be tied about a tooth and the short fiber length placed in direct contact with a tooth surface in the oral cavity.
11. A method for the localized diagnostic detection of diseases in the oral cavity, which method comprises:
(a) placing a semipermeable, polymeric, capillary hollow fiber, which contains a known quantity of a diagnostic-indicator agent within the lumen of the fiber, about or adjacent the tooth in the oral cavity where a dental or oral disease is suspected, the hollow fiber composed of a polymeric material which is permeable to the diagnostic agent therein, the indicator agent providing diagnostic information by chemical reaction with the products elaborated by the localized disease process in the oral cavity; and, thereafter,
(b) analyzing, after a designated period of time, the change in the nature or quantity of the diagnostic agent in the lumen as a measure of the dental disease in the localized area.
12. The method of claim 11 wherein the hollow fiber comprises a cellulose-acetate hollow fiber.
13. The method of claim 11 wherein the capillary hollow fiber is formed into a loop, and the step of placing includes slipping the preformed loop containing the therapeutic drug over the tooth and peripherally about the tooth.
14. The method of claim 11 wherein the step of placing includes placing a preformed loop of the hollow fiber adjacent and in between two teeth.
15. The method of claim 11 which includes placing the hollow fiber about the tooth by tying a hollow fiber about the periphery of the tooth.
16. The method of claim 11 which includes placing the hollow fiber adjacent or between the gum and the tooth to be treated.
17. The method of claim 11 wherein the diagnostic agent comprises calcium hydroxyapatite.
18. The method of claim 11 wherein the diagnostic agent comprises a known, measured amount of calcium hydroxyapatite within the lumen, and wherein the hollow fiber is removed and the amount of remaining calcium hydroxyapatite in the lumen is determined after a designated period of time to determine the degree of dental cariogenicity of the localized tooth area.
19. The method of claim 11 wherein the indicator agent is selected from the group of acid-base indicator agents, oxidation-reduction indicators, tooth-corrosive-action indicators and proteinaceous proteolytic-action indicators.
The treatment of dental diseases in the past has largely depended on surgical and restorative techniques. Compositions, such as toothpaste, gels, mouth washes and the like, containing fluorides and antibacterial agents have only met with some limited success and effectiveness, due in part to the very low time-retention rate of those agents after application in the oral cavity. In general drug therapy for dental diseases usually has been accomplished by the use of long-lasting tablets or capsules orally administered to the patient. For example, long-acting capsules or tablets containing odor-masking material or ingredients have been suggested for use in the oral cavity (see U.S. Pat. No. 3,911,099).
Other means for applying therapeutic agents to the oral cavity, and particularly to the teeth, have included the use of gels applied to teeth (see U.S. Pat. No. 3,679,360), the application of a plastic, hardenable mass to the teeth containing various agents (see U.S. Pat. No. 3,964,164), and the application of a foam-film device containing medication (see U.S. Pat. No. 3,844,286). In addition, fibers, as the carriers of therapeutic agents, also have been suggested, such as the impregnation of cotton twine with calcium hydroxyapatite for hemostasis of injured dental tissues (see U.S. Pat. No. 3,417,179); solid adsorbable fibers of polyglycolic acid with medicants incorporated therein (see U.S. Pat. No. 3,991,766); and impregnated dental floss for caries prevention (see U.S. Pat. No. 2,667,443). However, none of these suggested methods of therapeutic treatment has been wholly satisfactory nor widely adopted and accepted, due to a variety of causes and disadvantages associated with each technique.
The diagnosis of dental disease in current practice primarily relies on the use of dental radiographs and/or a manual probing and examination by a dentist of the oral cavity. Various indicators have been applied as oral devices to detect local changes in acidity and oxidation potential in the oral cavity for diagnostic purposes. Such prior diagnostic tests have been used to indicate a present condition, and have not provided any long-term indication of oral disease, or to monitor suspected oral disease.
My invention concerns polymeric, semipermeable, capillary hollow fibers which contain therein therapeutic and/or diagnostic agents, or combinations thereof, and a method for the treatment and diagnosis of dental diseases by the use of such agent-filled fibers.
My invention relates to a method for the localized treatment and diagnosis of dental disease by attachment of semipermeable hollow fibers to or about the tooth. In the treatment mode, an agent placed within the fiber is allowed to penetrate the semipermeable membrane at a controlled rate over a prolonged period of time in order to provide sustained localized therapy. In the diagnostic mode, an agent placed within the fiber is acted upon by a product of the disease process in order to provide an indication or a measure of localized disease activity of the region. The fibers are positioned between adjacent teeth or in the region surrounding the necks of teeth as being amenable to direct application of cylindrical fibers and as common sites of dental-caries activity. In particular, my invention relates to treatment and diagnosis of dental decay. Furthermore, the gum tissue surrounding the necks of the teeth is susceptible to inflammatory diseases termed periodontal disease or pyorrhea, and is likewise amenable to treatment or diagnosis by my hollow-fiber techniques.
In the treatment mode by semipermeable hollow fibers, therapeutic agents are administered directly to the locus of disease without suffering the dilution imposed by the blood and extracellular fluid compartments of the body. As a consequence of the reduced amount of drug necessary to render therapy, systemic reactions to the drug are dramatically decreased or eliminated, and the utility of drugs not generally administered for treatment of dental disease, because of their systemic effects, can be considered in therapy.
My invention also relates to an indicator or diagnostic system and method based on the qualitative or quantitative measurement and detection of respected diseases in the oral cavity, particularly localized disease about a tooth. For example, my method may be based on the erosion of tooth substances or a component of tooth substances as an indication of cariogenicity. My method may be employed in particular for the treatment of patients, and also for the assessment of the cariogenicity of food or food additives or the like, as well as for the diagnosis of disease in a human or an animal patient. For example, in one indicator system of dental-caries activity, a known amount of a powdered tooth enamel or other substance, or, for example, calcium or other salt hydroxyapatite crystals, may be introduced into the lumen of a capillary hollow fiber. The hollow fiber is then placed about the tooth, and, after suitable time, the hollow fiber is removed with its contents. The amount of calcified material remaining is then measured by any suitable procedure to determine the extent of dental-caries activity in the area.
The capillary hollow fibers useful in my invention may comprise a wide variety of semipermeable, polymeric materials, with, for example, a selection of a particular material and fiber depending upon the rate of permeation desired and other factors. Typically the hollow fibers employed should be composed of an inert, flexible, pharmaceutically acceptable material capable of being manufactured or formed into a loop or tied or otherwise interlaced into place about the tooth without breaking or being inordinately difficult in handling. Typically hollow fibers of my invention should not generally exceed about 500 microns in outside diameter; for example, from about 100 to 300 microns, with a wall thickness typically ranging from about as low as 1 micron; for example, from 5 to 100 microns. Capillary hollow fibers of such general type are commercially known and used (see, for example, U.S. Pat. No. 3,228,877, hereby incorporated by reference). The selected hollow fibers should have the ability to permit the desired gradual permeation of the particular treating or diagnostic agent over the desired time period, which may be as short as from 1 hour to 1 year or more; for example, 24 hours to 1 month. Typical hollow capillary fibers may be composed, for example, of synthetic or natural polymers, such as cellulosic polymers, and more particularly cellulosic esters and ethers, as well as a variety of other inert polymeric materials like nylon, polyglycolic polymers and copolymers, etc.
The preferred hollow fibers made of cellulose acetate or similar material are manufactured and are commercially available which have an outside diameter of approximately 250 microns, an inside diameter of approximately 200 microns and an internal volume of approximately 0.3 microliter per linear centimeter. The hollow-fiber walls are made semipermeable to materials of different molecular sizes by controlling the degree of cross-linkage achieved within the polymer, or by the size of the pores during the manufacturing process. My invention, in its preferred embodiment, concerns utilization of fibers of this type for the treatment and diagnosis of oral diseases.
In the treatment or the diagnostic mode, the agent-filled hollow fibers are placed about or adjacent the teeth to be treated or diagnosed. The fibers may be inserted in short lengths between the teeth, or preformed into loops of a size which will generally fit snugly over the tooth and rest on the oral tissue surrounding and about the root of the tooth, or otherwise be placed over the tooth or between the teeth. My flexible, agent-filled, hollow fibers also may be employed by wrapping the fiber about the tooth and tying the fiber, or by interlacing the fiber between one or more teeth, or otherwise by placing the fiber into the localized area to be treated or diagnosed. Typically the hollow fiber should be positioned such as to be retained in place during normal functioning of the patient, and should be such as to be removed easily and rapidly. The hollow fiber may be retained in the oral cavity for as long as required or needed in either the diagnostic or the treating mode, depending upon the permeation rate from the fiber or of the particular agent.
It is recognized that other materials, besides the active therapeutic and treatment agents, may be incorporated into the luminal fiber together with such active materials, such as the use of liquid inert carriers, solvents, suspending agents, surfactants, viscosity-control agents, antibacterial agents, buffers, diluents, complexing agents, and other pharmaceutically acceptable materials which may be employed to solubilize or stabilize the materials in the lumen, or to control the rate of permeation or the action of the materials after permeation.
In the treatment mode, various therapeutic agents are introduced into the lumen of the fiber which is tied around the tooth at selected sites. The therapeutic agent diffuses out of the fiber at a rate controlled by the permeability of the fiber wall and the internal concentration of the agent to be delivered. The agent achieves a therapeutically active concentration in the immediate vicinity of the fiber (tooth and localized tissue) and is diluted to an inactive level as it escapes into the saliva.
A wide variety of therapeutic agents may be used in my invention. Some therapeutic agents, which are amenable to delivery by this means and are potentially of value for oral therapy, include, but are not limited to: antibacterial agents, such as iodine or chlorohexidine; antibiotics, such as tetracycline or penicillin; antifungal agents, such as nystatin; antiinflammatory agents, such as indomethacin or hydrocortisone; immune-supressive or stimulatory agents, such as methotrexate or levamasol; fluorides, such as calcium, sodium, stannous or amine fluoride; dentinal desensitizing agents, such as strontium chloride or sodium fluoride; recalcification solutions, such as saturated calcium phosphate; odor-masking or inhibiting agents, such as peppermint oil or chlorophyll; or oxygen-releasing agents, such as urea peroxide.
Several modified versions of my invention include the use of hollow fibers which are either wholly or in part made of biodegradable substances; for example, polyglycolic acid and various copolymers, which disintegrate or are body-absorbable after the agent is delivered. Fiber construction with intermittent occlusions prevent leakage from cut ends. Inclusion of nondialyzable binding substances with drugs, such as polyvinyl pyrrolidone, with iodine or complexing agents, such as calcium with tetracycline or procaine with penicillin to alter the release from hollow fibers, are effective in delaying drug release and constitute methods for regulating the rate at which agents are delivered.
In the diagnostic mode, various indicator materials are introduced into the lumen of the fiber to be acted upon by the local dental-disease process. The fiber provides mechanical support for the indicator material at sites between and around teeth, and allows access to substances eminating from these areas by diffusion through the hollow-fiber wall. The indicator substance provides diagnostic information by undergoing chemical reaction with the products elaborated by the localized disease process. Indicators applicable to this purpose include, but are not limited to, the following: acid-base indicators, such as methyl orange; oxidation-reduction indicators, such as methylene blue; indicators of corrosive action on tooth substances, such as the loss of hollow-fiber-incorporated ground tooth enamel, calcium salts or calcium hydroxyapatite; or indicators of proteolytic action eminating from the gums consisting of proteinaceous materials capable of being digested by specific enzymes, such as collagen or fluorescein-labeled hemoglobin.
The therapeutic treatment agents may be introduced into the lumen of the hollow fibers by a variety of techniques, either during manufacture or thereafter. Such techniques would include, but not be limited to: aspiration of a solution containing the active ingredients into the lumen; pumping of the solution into the lumen; or permeation or injection of solutions and agents into the lumen. After such introduction of the agents into the lumen to fill or fill partially the lumen, depending upon the amount of material to be dispensed over the time period, the hollow capillary fiber may be employed with open ends, or the ends may be occluded, such as by heat-sealing or by occluding polymers, or other techniques.
My invention will be described for the purpose of illustration only in connection with certain preferred embodiments, and it is recognized that certain changes and modifications may be made by a person skilled in the art, which changes and modifications are within the spirit and scope of my invention.
FIG. 1 is a schematic illustration showing the use of my hollow fiber about the teeth of a patient;
FIG. 2 is an enlarged schematic illustration of the localized, intraoral delivery of a drug by the use of a hollow fiber to a tooth;
FIG. 3 is an enlarged schematic illustration of the delivery of fluoride and/or calcium solution to a tooth surface by the use of a hollow fiber; and
FIG. 4 is an enlarged schematic illustration of the use of hollow fibers in the detection of dental disease about a tooth.
A length of cellulose-acetate hollow fiber, with a stated molecular-weight cutoff of 200 daltons, was cemented into the lumen of a 26-gage hypodermic needle. A saturated solution of tetracycline hydrochloride in water was pumped into the hollow fiber by means of a peristaltic pump with silicone-rubber-pump tubing. The needle was attached by a standard luer fitting to Teflon tubing which fit the inner bore of the silicone-pump tubing. After filling the fiber with the suspension, the distal end was occluded and the pumping maintained. The solvent (water), being smaller than a tetracycline molecule, more readily permeated the fiber wall. After a time, the fiber became completely filled with tetracycline. The average content of fibers so constructed was 224 micrograms per linear centimeter, 75% of the maximum theoretical content of 300 micrograms per centimeter.
The release of tetracycline from a test segment of this fiber into distilled water was measured spectrophotometrically and was found to persist for 3 to 6 hours, with the highest concentration being delivered after 30 minutes.
Tetracycline-filled fibers thus constructed were tied around the necks of teeth of a patient afflicted with periodontal disease, and were pressed used the margin of the gum tissue. Prior microbiological diagnosis revealed a preponderance of large spirochetes. A comparison of spirochete counts before and after placement of the fiber revealed that the spirochetes had been eliminated completely by a single application of tetracycline-filled fibers. Concomitantly signs of inflammation in the treated area disappeared. Thus a beneficial therapeutic result followed the placement of tetracycline-filled fibers about the necks of teeth. Other antibiotic drugs effective against Streptococcus mutans and other microorganisms also may be used.
A length of cellulose-acetate hollow fiber was prepared as described in the preceding example. Powdered polyvinyl pyrrolidone (viscosity-control agents) was added to a saturated solution of iodine in an alcohol (ethanol) to form a thick solution. After filling the fiber with this solution, it was dried and the needle was removed.
The release of iodine from a test segment of this fiber was studied spectrophotometrically, and was found to persist for more than 24 hours, with the highest concentrations being delivered during the first hour.
Iodine-filled, flexible fibers thus constructed were tied around the necks of teeth of a patient afflicted with periodontal disease. A comparison of bacterial counts before and after placement of the fiber revealed a reduction in numbers, and concomitantly signs of inflammation decreased. Thus a beneficial therapeutic result resulted from the placement of iodine-filled fibers about the necks of teeth.
A fiber of the same construction as previously described was filled with a saturated solution of sodium fluoride. After filling, the luer fitting connecting the fiber was removed and a solution of 0.1 molar calcium chloride was pumped in. With the entrance of a stream containing calcium, insoluble calcium fluoride precipitated, filling the inner lumen of the fiber.
A fiber thus constructed was applied about the neck of a tooth exhibiting dentinal sensitivity. Following a single application, the sensitivity was decreased, indicating that fluoride release had occurred and that local therapeutic activity had resulted.
Fibers of the type described were filled with a solution from which calcium hydroxyapatite was precipitated by solvent evaporation. Fibers were cut in lengths of 2 mm and were sealed at either end with silicone cement. A 2-millimeter fiber segment was coated with a drop of silicone cement, and a length of suture material was lowered in a controlled manner to contact the coated fiber. After contact had been established, the cement was allowed to dry to provide a length of suture material adhesively secured at one end to the middle of the fiber segment. The suture material, being flexible and pharmaceutically acceptable, provides a means of securing the agent-containing hollow fiber against the tooth or gum surface by tying the fiber about the tooth. This technique is desirable where the hollow-fiber material does not have the flexibility or strength to be tied, itself, directly to the tooth. String, dental floss and other fibrous suture-like materials or other means, such as adhesives, clamps, etc., may be employed to retain or hold the agent-containing fiber to the tooth or gum surface. Also in the treatment of some dental diseases, such as periodontal disease, the agent-containing hollow fiber may be inserted or implanted beneath the gum surface, such as tacked beneath the gum surface adjacent the tooth surface, for treatment or diagnosis of the area.
Fiber segments so prepared were tied between the teeth of a patient suspected of having active dental caries. The fibers were worn overnight and were analyzed the next day for the residual calcium content. Analysis indicated a loss of more than 50% of the calcium contained in the fibers. Since fibers placed on the teeth of patients without dental caries lose no more than 10% on an overnight application, and the variation between fibers produced is no greater than 5%, it was concluded that the loss of calcium from precipitated calcium hydroxyapatite was the result of dental-caries activity. Furthermore, the loss of calcium in this application acted as a diagnostic indicator of dental-caries activity.
In reference to the drawings, FIG. 1 shows therapeutic-agent- and diagnostic-agent-filled capillary hollow fibers, wherein a small, looped, hollow fiber 10, containing a solution of a treating or diagnostic agent, is placed between the teeth, and also wherein a preformed hollow-fiber loop 12 has been placed over the tooth and rests on or adjacent the oral tissue about the root of the tooth. Also an agent-filled hollow fiber 14 is tied with suture material 16 around a tooth. In all embodiments, as illustrated, the therapeutic or treatment agent is permeating from the lumen of the hollow fiber and through the walls thereof and to the tooth surface or to the tooth surface and/or the surrounding gum tissue of the tooth, to provide treatment or diagnostic detection.
FIG. 2 is a generally schematic enlarged illustration of a localized, intraoral drug delivery of a drug contained within the lumen of a large fiber, and the passage of the drug illustrated through the wall of the fiber and into the saliva to treat effectively the tissue or impose on the plaque surrounding the tooth.
FIG. 3 is an illustration illustrating the delivery of fluoride and/or calcification solutions containing fluoride, calcium and phosphate from the interior lumen of the hollow fiber adjacent the teeth to the tooth surface for the treatment and prevention of dental caries.
FIG. 4 schematically illustrates the employment of hollow fibers, as in Example 4, to detect the measurement of dental caries in a tooth and the amount of caries activity by the reduction of a hydroxyapatite salt of a known amount contained within the hollow fiber.
Patent Citations
Referenced by
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Alamo Colleges
The Alamo Colleges are dedicated to providing accessible and affordable higher education for all. Our five colleges fulfill this promise with a vast array of courses and two-year degrees — more than 425 associate degree and certificate programs.
Monthly Archive for July, 2010
Go SAC Sports
Fall classes at San Antonio College get under way Monday, Aug. 23, but sports tryouts are already in the works. Yes, SAC has sports. If you think your playing days are over because it was a long time since high school, think again. Baseball, softball, tennis, volleyball, golf, soccer, cheering and dance squad are sports […] [Read More]
Students Use Second Life Software to Learn in a Virtual World
Students in two Northeast Lakeview College classes used Second Life software technology to enhance their learning. Coordinated by English Instructor, Ellen Walroth, students in a World Literature class integrated a visit to an Islamic Mosque (the Alhambra) in virtual reality where students heard part of the Qu'ran read out loud. They had a discussion afterwards […] [Read More]
KSYM to host 'Stock the Pantry' food drive
KSYM 90.1 FM, San Antonio College's alternative FM radio station, is holding the second annual "Stock the Pantry" food drive this weekend. Last year more than 900 items were collected to stock the shelves at the Phi Theta Kappa (PTK) Food Pantry, located at the Catholic Student Center at SAC. The PTK Food Pantry benefits […] [Read More]
'Space Pirates' invade planetarium
"Attack of the Space Pirates" has joined the lineup of public shows at the Scobee Planetarium at San Antonio College. This summer matinee is presented at 3 p.m. Monday through Friday. This action/adventure takes viewers on a thrilling adventure that includes alien planets, exploding stars, black holes, evil villains and a series of space battles […] [Read More]
Palo Alto passport leads to success
If you've been accepted at Palo Alto College, you're ready for the next big step. Palo Alto, the only community college on the Southside, has launched its first-ever New Student Orientations – sessions throughout the summer that culminate with your getting registered for Fall classes. Coming to a college campus can be intimidating, so PAC […] [Read More]
Scholarships at Alamo Colleges
If you are looking for ways to pay for college, Alamo Colleges has numerous scholarships to offer students. There's scholarships in business, education, math, arts, media arts and pre-nursing. At each of the five colleges, there's also scholarships specific to the college. Some award opportunites are from $500 to $1,500 per semester. Students often don't […] [Read More]
SAC group explores language, culture in Japan
The Study Abroad Program returned to San Antonio June 28 following a two-week trip to Japan. The program, headed by Professor Yuko Kawabe, also includes three weeks of study at SAC. The group spent five days in Nara, five days in Kyoto and three days in Tokyo. Students studied the Japanese language, grammar and writing […] [Read More]
Continuing Education at Northwest Vista
Did you know that you can take Notary Public and Advanced Grant Writing classes at Northwest Vista College? These classes are a part of NVC's Continuing Education program to help people with specialized courses. The affordable classes, some as low as $36, are typically one- and two-day workshops. The program offers a variety of courses […] [Read More]
It's 'Eleemosynary' for theater lovers this weekend
The SAC Theatre and Speech Communication Department is presenting its annual SummerSet production. "Eleemosynary" is a drama/comedy written by Lee Blessing. The one-act play follows three generations of women (grandmother, mother, and daughter) through their dysfunctional relationship to reconciliation and self discovery. SAC is welcoming Dr. Mary Ellen Jacobs, Palo Alto College English professor, who […] [Read More]

subset: commoncrawl


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For The Children: We Have To Do Something
December 14, 2012
I am sitting here numb thinking about the 27 people, including 20 children, who were killed in a Connecticut elementary school today.
Children, god damn it, children.
Sad. Pained. Disgusted. Outraged. We have to do something about gun control. We have to do something about guns. Otherwise, when will this stop?
Filed under: Civics and Urban Life by admin · Comments Off


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Click on a thumbnail to go to Google Books.
Through the Embers of Chaos: Balkan Journeys
by Dervla Murphy
No current Talk conversations about this book.
The more of Dervla Murphy's later books you read the more you realize that she doesn't so much travel through places, as into them. Just as she dissected the entangled hatreds and lies that were (in the 1980's) built layer upon layer in Northern Ireland, here she turns her attention to the Balkans, the wreckage of Yugoslavia. She has the advantage over many writers of that scene in that she returned three times and was able to give some perspective and reflection on how things - I would have said 'developed', but 'fell apart' is a more apt expression.
Dervla's other great advantage over several other writers is her bicycle. Others have covered more ground, but I've found their stories impossibly hard to digest because there is so much evil and folly to relate that there's no space to give it any context. Dervla on the other hand rides through the context, and then lets the people tell their stories. It helps that she can reflect on her Northern Ireland experience, but more so than many others she lets other voices carry the message. Which is? Perhaps that there is a thread of normality, or longing for normality, amongst folk on the ground which may yet allow the return of civilized existence. But having said that, Dervla makes it clear that in the former countries of Yugoslavia perfectly civilized (seeming) people now in many cases believe that hatred and a willingness to kill the 'other' is normal.
Dervla is possibly the hardest drinking pensioner-lady cyclist in the world. She's also one of the greatest observers of arcane politics and the lives of ordinary folk. It's a testament to her ability to chart a road through this subject that I can now read those other accounts of the Balkan - and international - descent into insanity. Highly recommended.
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Definitions for =$word?>
Overview of verb rime
The verb rime has 2 senses? (no senses from tagged texts)
1. rhyme, rime
(be similar in sound, especially with respect to the last syllable; "hat and cat rhyme")
2. rhyme, rime
(compose rhymes)
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1. rhymed, rhyming, riming
(having corresponding sounds especially terminal sounds; "rhymed verse"; "rhyming words")


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Recent Frame-Off Rotisserie Restoration, clean Kentucky car, Show Quality Torch red paint, black vinyl interior, 454 ci engine, Muncie 4 speed manual transmission, Holley... More
Up for sale in our Houston showroom is one of the most popular compact cars Chevrolet had to offer the 1971 Nova. The Nova... More
Here we have a gorgeous 1971 Chevy Nova SS, with a non-numbers matching 375hp 396 engine that has 100 miles on a complete rebuild.... More
1971 Chevrolet Nova SS Coupe1971 Chevrolet Nova SS Coupe model in mint conditionBlack metallic exterior with two White Rally stripes plus a Grey cloth... More
Another new addition to our inventory is a 1971 Nova with SS badging that has a brand new GM 350 crate motor and also... More
Stun the crowd when you pull in with your new '71 Nova. Pay tribute to the legendary Nova SS 350 very respectfully in this... More
1971 Nova SS equipped with its Original 350ci V8 with Matching Numbers, 4 Speed Muncie Transmission, 3.42 Axle Ratio and 12-Bolt Rear. Code 53... More
Yep, you're seeing that right, there are not-so-subtle '502' badges on the front fenders of this 1971 Chevrolet Nova. Sure, GM played around with... More
1971 Chevrolet Nova 454 Big Block / 7.4 LiterThis awesome Muscle Car is in very good condition. The black-blue paint shines very bright and... More
Its true, tributes, and clones make up a significant part of the muscle car market, but when an ORIGINAL 1971 Chevrolet Nova SS comes... More
We'll admit that this 1971 Chevrolet Nova isn't exactly subtle, but what's under the skin is a lot more than most folks would have... More
You can always tell when a car has been loved. It definitely shows on this 1971 Chevrolet Nova, which is a step above the... More


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Planned Parenthood misconceptions
As a current student at Kent State and a strong supporter of Planned Parenthood, I am outraged by the recent allegations made by the Ohio Right to life advocate testifying on HB 497, which now includes a provision to defund family planning centers such as Planned Parenthood. An Ohio right to life advocate recently made the statement "We know why there are places like Planned Parenthood in Kent." I find this statement absurd and highly impertinent, especially to college students like myself.
As a young college woman, I've realized many people try to misrepresent young women in college by insinuating that they are being promiscuous by using Planned Parenthood's services. While students are away at college many are without their regular health-care provider. The Kent Planned Parenthood health center does not offer abortions and I find it sad that Ohio right to life advocates are implying incorrect information when students are using the health center for basic preventative healthcare needs.
I want to acknowledge and thank state Rep. Kathleen Clyde for standing up for women's health. I plan to continue to stress that 96 percent of Planned Parenthood services in Ohio are preventive: lifesaving cancer screenings, birth control, prevention and treatment of STDs, breast health services, Pap test, sexual health education, and information.
One in five women visits a Planned Parenthood health center during her lifetime because she trusts the quality, professionalism, and confidential care that she will receive.
Ashleigh Snodgrass, Akron
I hope at the end of her college career this young lady has a better handle on reality. Nearly all of the services she describes are out sourced by PP. Telling young ladies where to get these services is available from many sources. I also dispute that 96% figure. That is liberal math that can add ten negative balances and get a positive figure. Just like Mr Obama's cost cutting savings.
Here you go loaf.....
The truth is that many young women get valuable services from Planned Parenthood that have nothing to do with abortions. Planned Parenthood will always remain respected in our hearts.
Planned Parenthood is a valuable resources for women. It would be shortsighted to defund it.
Planned Parenthood was founded by Margaret Sanger a leader in the eugenics movement. She believed in the superiority of the white race. She advocated birth control to limit the black population and then abortion for blacks when the birth control failed.
Planned Parenthood makes the majority of its money from abortions. It is no accident that Planned Parenthoods are primarily situated in black communities.
Recently someone tested whether Planned Parenthood is still focused on white supremacy. They called Planned Parenthood and said that they "wanted to make a large donation, but the donation had to be only used to kill black babies" Planned Parenthood responded that they would gladly accept the donation and make sure that it would be used solely for that purpose.
An organization like this deserves to be defunded! Its a shame that the Ohio legislature has fallen for the lies of PP. Google "Margaret Sanger eugenics" or visit http://blackgenocide.org/sanger.html
Are you serious CommonSenseGuy?? You are NonSense Guy. You really are referring us to a 1920 article about a woman who founded a program back when it was LEGAL to discriminate against blacks. Please be serious, I know the right wingers need to defend anything about being a social policy nutjob, but we need to keep a straight face about this and use current facts.
Planned Parenthood. The nation's largest abortion business.
See my post #2. For those of you who didn't bother to look at it before you posted your nonsense.
Catherine, it is amazing that out of your 5 posts, three of them are misleading or wrong. Maybe you can make an argument that because it is a nationwide agency it does perform the most abortions as a single non-profit, but if you would take the time to look at actual facts like Peacelover has given, the agency itself only does about 3% of its business as performing abortions. I know you are being a good Catholic, but lets not distort the facts shall we??
The truth is that many young women get abortions from Planned Parenthood that many others find abhorrent. Planned Parenthood will always remain detested in our hearts.
All of PP's services can be found elswhere. It is another jobs program.
Also remember that the Hyde amendment prohibits use of taxpayer money for abortions. (unless the life of the mother is in danger or in cases of rape or incest).
Really? All of the services of Planned Parenthood can be found elsewhere?
Where could I have walked in, and asked for an explanation of the facts of life? And got it.
Did I then have sex? No. I then knew where my boyfriend was pressuring me. I had information to make a stand, information I did not get from parents, pastor, teachers.
"Swinger" you sound like one who would like to keep young woman in the dark, barefoot, and pregnant under your thumb.
Planned Parenthood opposed the Hyde Amendment, opposed the ban on partial birth abortions, opposes any informed consent laws, denies the statics about post abortion depression, and denies that abortion stops a beating hart or is terminating the life of a child.
Sorry for the inconvenient truth, but PP is the number 1 provided of abortions in the county, and they also oppose adoption over abortion.
Ed_Voter are you saying that you waited until you were old enough to walk into Planed Parenthood to learn the facts of life?
Two can play that intellectually dishonest game:
You sound like one who would enjoy murdering babies.


text:
A Pint With: Kelly Taylor, Brewmaster for Heartland Brewery and Kelso of Brooklyn
Kelly Taylor makes interesting, usual beers in Brooklyn, including Flemish-style sours, a beer brewed with Valrhona chocolate nibs and orange peel, and a collaboration with Blue Hill at Stone Barn that once included farm-fresh roasted beets. Nice guy that he is, Kelly joined me for a beer and the following interview. More


text:
Gear Review
Greg Gavin
The Cinch is great
Awesome belay device for anything! I've used it belaying arm burning sport climbs, and have also used it as a backup for jugging fixed lines. The Cinch glides up the rope as a superb big wall backup, and also locks up mighty quick if your buddy doesn't let you know he's going to whip. Great piece of gear.
View More Details on Trango Cinch Belay Device


text: Frank Dow Merrill was born on December 4, 1903. He enlisted in the Regular Army in 1922 and graduated from West Point in 1929. He obtained his B.S. degree in military engineering from Massachusetts Institute of Technology. In 1938, Merrill studied Japanese and Chinese while working as the assistant military attaché at the United States Embassy in Tokyo. By October 1941 he was promoted to major and assigned to Manila as General Douglas MacArthur's intelligence officer. When the Japanese bombed Pearl Harbor, Merrill was in Rangoon, Burma on a flying mission for MacArthur. He remained there to become General Joseph W. Stilwell's aid in the China-Burma-India Theater. In the Spring of 1942 Merrill was promoted to lieutenant colonel. In July he was awarded the Order of the Purple Heart for his meritorious actions in Burma between March and May 1942. In October 1943 Merrill prepared a long-range penetration group of about 3000 U.S. infantrymen, for a hazardous mission in Burma. After intensive training in jungle warfare, Merrill's Marauders became the first American infantrymen to fight on the Asiatic mainland. In March 1944, after a 100-mile march, they surprised the enemy by blocking the only Japanese supply line in the Hukawng Valley. In September of 1944, Merrill was promoted to major general. Towards the end of his active military career, he suffered from heart problems, as a result of which he was relieved of his command. In 1945 he served as General Stilwell's Chief of Staff and later as commander of the Sixth Army at San Francisco. After retirement from the Army, Merrill moved back to New Hampshire with his wife and two sons to become New Hampshire's Highway Commissioner. He died December 12, 1955 of a heart attack after attending a meeting of the American Association of State Highway Officials in New Orleans, where he had just been elected president of that organization.


text:
Anti-copying protection for video material is provided wherein at least one high-amplitude pulse is inserted into various lines of the video signal, in and immediately preceding the vertical interval associated with each field, during the process of preparing a master recording for use in the high-speed duplication of legitimate recordings of the video material. A preferred embodiment of the present system and method is directed to videotape-to-videotape anti-copying protection. A high-amplitude pulse is inserted in the back porch region of horizontal sync pulses, and immediately following certain equalizing and vertical sync pulses, at an intermediate stage in the mastering process, whereby the pulse is inserted into a separated luminance component of the video signal, which is later recombined with the chromenance signal. Such method allows for the insertion of an higher amplitude pulse than would otherwise be possible, and yields a pulse of the desired final width, without the occurrence of such undesirable effects as loss of color lock or darkening of the picture with respect to legitimate recordings. The resulting modified video material may be viewed properly on a TV receiver or other display, but when coping from the legitimate source is attempted, the copy will yield a video signal which is too distorted for proper viewing. A further modification of the value of negative-going horizontal sync pulses provides additional synchronization error in recorded copies of legitimately recorded video material so as to further render such materials effectively non-copiable.
1. A method of encrypting a video signal to be placed legitimately onto a recording medium so as to prevent the useful copying of said video signal from that medium, said video signal comprising consecutive frames of picture information, each of said frames being represented in two fields, each of said fields having a vertical interval associated therewith which indicates the start of each said field, and each of said fields further comprising lines, including active and viewable lines, active but non-viewable lines, and non-active lines, and each of said lines having horizontal sync pulses or other reference points for performing horizontal synchronization function indicating the end of each of said lines, comprising the steps of:
separating said video signal into a luminance component and a chromenance component;
inserting a high-amplitude pulse having a width of no more than about three microseconds into said luminance component of said video signal immediately after said horizontal sync pulse or other reference point for performing a horizontal synchronization function in certain of said active bun non-viewable lines and certain of said non-active lines;
mixing said luminance component and said chromenance component to yield an encrypted video signal, wherein the width of said high-amplitude pulse in said encrypted video signal is less than the width of said high-amplitude pulse as inserted into said luminance component; and,
transferring said encrypted video signal onto the recording medium.
2. The method of claim 1 wherein said two fields comprise a first field and a second field, said first field further comprising two-hundred sixty two of said lines and said second field comprising two-hundred sixty three of said lines, and wherein said high-amplitude pulse is inserted in the first eighteen and the last twelve of said lines of said first field and in the first eighteen and the last thirteen lines of said second field.
3. The method of claim 1 wherein said high-amplitude pulse has an amplitude of 130 IRE units and a width of three microseconds when inserted into said luminance component and an amplitude of 130 IRE units and a width of two microseconds after said mixing of said luminance component and said chromenance component.
4. A video mastering system comprising:
separator circuitry for receiving a video signal comprising lines of video information and for separating said video signal into a luminance component and a chromenance component;
copy protect circuitry for generating a high-amplitude pulse having a width of no more than about three microseconds and for effecting the insertion of said high-amplitude pulse into said luminance component in at least one position corresponding to a line of said video signal; and,
output circuitry for combining said chromenance signal with said luminance signal having said high-amplitude pulse inserted therein and for presenting said combined signal for preparation of a video master recording, wherein the width of said high-amplitude pulse in said combined signal is less than the width of said high-amplitude pulse as inserted into said luminance component.
5. The video mastering system of claim 4 wherein said high-amplitude pulse generated has an amplitude of 130 IRE units and said copy protect circuitry effects insertion of said high-amplitude pulse so as to maintain an amplitude of 130 IRE units throughout said output circuitry.
6. The video mastering system of claim 4 wherein said high-amplitude pulse generated has a width of three microseconds.
7. The video mastering system of claim 6 wherein said output circuitry results in reduction of the width of said high-amplitude pulse from three microseconds to two microseconds in said combined signal.
8. The video mastering system of claim 4 wherein the medium utilized for said video master recording is videotape.
9. A copy protect circuit for generating a high-amplitude pulse and effecting insertion of said high amplitude pulse into a video signal at a predetermined point, comprising:
an oscillator providing an oscillator signal;
a control circuit, said control circuit receiving said oscillator signal and a signal relative to said video signal, said control signal further providing an output; and,
a pulse generator, said pulse generator receiving said output of said control circuit and providing a high-amplitude pulse having a width of no more than about three microseconds at an output thereof, wherein said video signal comprises separated luminance and chromenance components and said high amplitude pulse is inserted into the luminance component for later combination of said luminance and chromenance components so as to yield an output video signal wherein the width of said high amplitude pulse is less than the width of said high amplitude pulse as inserted into said luminance component.
10. The copy protect circuit of claim 9 wherein said high-amplitude pulse comprises a pulse of 130 IRE units amplitude and three microseconds pulse width.
11. The copy protect circuit of claim 9 wherein said pulse generator further provides a sync clip signal for clipping negative values of said video signal to minus thirty IRE units.
The field of the present invention relates to encryption of video signals and, in particular, to a system and method for encrypting a video signal, to be placed legitimately onto a videotape(s), in order to effectively prevent useful copying of that signal on the legitimate videotape(s) to another videotape(s).
The unauthorized reproduction of videotaped materials presents a major problem for the producers, manufacturers, and distributors of such materials. The value to these entities, and their incentives for continuing to provide videotaped materials, are directly related to their ability to effectively market these products and to recover their development and other costs through sale or rental. Without protections which inhibit the making of unauthorized copies of these materials, pirate companies could readily appropriate materials prepared legitimately and could profit through the distribution of copies of these materials. Further, since such pirate companies would not have had to incur the development and production expense associated with the original preparation of videotaped materials, they could discount prices charged and, thus, undercut the sales of legitimate videotape producers. This possibility erodes the value, to legitimate videotape producers, of preparing original videotape materials since they would be uncertain of recouping the production expenses while still realizing sufficient profits.
Although the actions of pirate companies may, in the short run, result in cheaper prices to the consumer, ultimately, the public does not benefit from such activity. In the first place, pirated copies of videotape materials are often of a lower quality than would be satisfactory to the viewing consumer--a factor which may also negatively impact the goodwill of legitimate videotape producers in cases where there is confusion as to the true source of such materials. More importantly, however, the public is harmed by the fact that pirate activities could result in fewer videotape materials being made available since few companies would likely continue to be willing to risk incurring the development, production, and distribution expenses without assurance that they would profit from the unfettered sale of their materials.
The availability of copyright protections for the unauthorized duplication of videotape materials, and the attendant incorporation into such materials of notices and warnings concerning violation of these rights, offer little solace to legitimate videotape producers. The fact that violations of copyrights through the unauthorized reproduction and sale of videotaped materials are virtually impossible to police, and that such rights can be expensive to enforce at best, necessitates that other forms of protection be devised and implemented. Consequently, videotape producers have turned to methods of protection which physically inhibit the copying of materials from one videotape to another videotape or other recording medium. Of concern with respect to any such methods, however, is the fact that legitimate videotaped materials must remain viewable by the user on conventional televisions, monitors, or other such displays. Accordingly, any anti-copying method must be operative only when an attempt to record the video signal from the recording medium (e.g., videotape) is made, not merely when the video signal is played back.
Since most video manufacturers cannot control the design of any, let alone all, of the video recording equipment, e.g., Videocassette Recorders (VCR's), manufactured, any anti-copying method must effectively be self-contained within the videotape or other recording medium (e.g., encrypted into the video signal) itself. It is particularly evident that modifications to VCR recording circuitry would not provide adequate solution to the problem of videotape piracy since it is the main purpose of VCR's to record video signals, and, attempts to design all VCR's to distinguish legitimate signals (i.e., those that the user is free to reproduce), from pirated signals (i.e., unauthorized copies) would be complex and would require universal standards applicable to both equipment manufacturers and video producers. Such situation is highly unlikely under present circumstances.
In light of the above factors, existing anti-copying methods have focussed on a variety of techniques for modifying the video signals reproduced legitimately on videotapes (or other recording media) in such a way that a video signal which cannot be played back on a display without significant distortion results when the original signal is copied; however, when the original signal itself is played back on a display, viewing of the signal is not significantly affected. Use of such methods, while not prohibiting copying of the original video signal, does inhibit copying since the resulting distortion when viewing a copy of such modified signal is annoying, at best, to the viewer. Indeed, a goal of such methods is to maximize the distortion resulting from a copied signal (and, thus, make viewing of such signal so annoying as to prevent copying in the first place), while not perceptibly affecting the viewing of the original signal at all.
One such method directed toward this latter goal is identified in U.S. Pat. No. 5,130,810 ('810 patent) to Ryan wherein pulses are inserted following the horizontal sync pulse in active video lines of a video signal recorded on videotape in order to effect the desired distortion from copies of that signal. The '810 patent describes the insertion of a pulse of amplitude 100 IRE units and width four microseconds in the active video lines (lines twenty-two through two-hundred-sixty-three of a video field), but not in the lines of the vertical interval (lines one through twenty-one). Such inserted pulses are intended to confuse the Automatic Gain Control (AGC) circuitry of a recording VCR such that the level of the signal is improperly recorded and, consequently, the signal is distorted when played back and viewed on a display. As these pulses are inserted into active video lines, however, their presence may also undesirably affect viewing of the original signal on a display. The '810 patent provides for distributed spacing of such pulses within the active video lines, i.e., every one of "n" lines as opposed to all lines in the active video, in order to reduce undesirable affects. The results of testing by the present inventors have indicated that placement of pulses in the active video lines only, as provided in the '810 patent, would not yield adequate anti-copying protection, and could result in distortion of the picture on many displays (e.g., TV receivers) even when the legitimate signal is played back.
U.S. Pat. No. 4,819,098 ('098 patent), also to Ryan, describes a similar pulse to that of the '810 patent, but provides for the insertion of such in a cluster of lines "at" the vertical blanking interval, which is defined therein as possibly including some active video lines (the specification suggests insertion of pulses in 20-30 lines; the vertical interval typically comprises 21 lines). The '098 patent further notes that the lines surrounding the vertical interval are often non-viewable and, thus, inclusion of additional pulses in these lines would provide negligible interference with playback of the legitimate signal. While attempting to address the problems associated with insertion of pulses in the active, viewable lines of the video signal, the '098 patent, like the '810 patent, suggests insertion of a pulse of 100 IRE units (i.e., the maximum white level) and four microseconds width.
Testing by the present inventors indicates that the amplitude and width values (100 IRE and 4 microseconds, respectively) identified in the preferred embodiment of the '810 and '098 patents may not provide the maximum distortion from playback of a copy of such signal, and may result in color loss and darkening of the picture when the original signal is played back. Of further relevance to the present system and method, if a signal with such inserted pulses is used as an input to certain equipment utilized for the preparation of master videotapes (e.g., a Sony MMV-800 VTR) prior to mass-duplication onto other videotapes, a loss of color lock may result when recording onto the master. As well, such mastering equipment incorporates a clamp limit such that the amplitude of the added pulse may not be increased to an optimum level for maximum distortion of a copied video signal.
Accordingly, the present system and method provides one or more of the following advantages and objects, intended in part to overcome the drawbacks identified above:
to provide a system and method for encrypting a video signal, to be placed legitimately onto a videotape, in order to effectively prevent the useful copying thereof;
to provide such a system and method whereby playback of a copy of such encrypted video signal is too distorted for proper viewing, while playback of the original video signal is appreciably unaffected;
to provide such a system and method whereby a video signal may be optimally encrypted in the process of preparing masters for use in high-speed duplication of the video signal;
to provide such a system and method in which the potential for loss of color lock is eliminated; and,
to provide such a system and method which results in the maximum results over the broadest range of TV receivers and VCRs.
Other objects and advantages of the present invention will become apparent from a review of the accompanying drawings and the detailed description which follows.
The present invention is a system and method for encrypting a video signal, to be placed legitimately onto a videotape(s), in order to effectively prevent useful copying of that signal to another videotape(s).
In accordance with the present system and method, anti-copying protection of videotaped material is effected by the insertion of a high-amplitude pulse into the video signal as further described hereinbelow. This pulse is inserted in such manner as to cause the Automatic Gain Control (AGC) circuitry of a recording VCR to `misread` the real video signal level when an attempt to copy the material to another videotape is made. Accordingly, upon playback of the copy tape, the signal is too distorted for proper viewing. Since typical viewing displays (e.g., TV receivers, monitors, etc.) do not incorporate AGC circuitry similar to that of VCR's, playback of the legitimate videotape is unaffected by the inserted pulse.
As will be further explained in the detailed description which follows, the high amplitude pulse is inserted immediately after the horizontal sync pulse (or other reference points which perform equivalent horizontal synchronization function) in each of lines two hundred fifty (at the end of one field) through line eighteen (at the beginning of the following field). The majority of such lines comprise non-active lines in the vertical interval associated with each video field; the remainder, though active lines, are typically non-viewable and, thus, any effects of the signal modifications herein proposed are not detectable when the legitimate video signal is played back on a TV receiver/monitor. When recording (i.e., copying onto another videotape) of the signal as modified herein is attempted, distortion of the signal level, including that of active, otherwise viewable lines, occurs in the recorded copy which, when played back on a TV receiver/monitor, effectively prevents viewing of the video material.
The high amplitude pulse herein is inserted into the video signal during the initial mastering process, involved in the mass-reproduction of legitimate videotapes, in such a manner as to preferably yield a maximum obtainable pulse of 130 IRE units magnitude (amplitude) and two (2) microsecond duration (width) in the final signal as duplicated onto videotapes for which anti-copy protection is desired. A preferred embodiment herein realizes this end through circuit modifications to the mastering equipment within the duplication system (which may, for example, comprise a high speed duplication system). Such circuit modifications effect the insertion of a pulse of 130 IRE units and three (3) microsecond duration into the luminance component of the video signal. Upon further processing and recombination of the luminance and chromenance components of the video signal, a pulse of 130 IRE units and two (2) microseconds duration (width) results in the final video signal output from the mastering equipment. Also, by inserting the high amplitude pulse in the separated luminance component available in the mastering equipment, otherwise possible color loss and darkening are minimized since the more sensitive circuitry associated with processing of the chromenance signal in the mastering equipment is bypassed. This signal is then duplicated onto multiple videotapes, or other recording media, for which anti-copy protection is desired.
A further feature of a preferred embodiment herein provides for the clipping of negative-going synchronization pulses from minus 40 to a limit of minus 30 IRE unit magnitude in order to assist in the loss of synchronization of the video signal, and thus effect further distortion, of any copy made of the signal as processed.
FIG. 1 illustrates how a screen image (one frame) is comprised of interleaved scan lines in two fields, and the line numbering associated therewith as referenced in accordance with a preferred embodiment herein;
FIG. 2 is a simplified representation of that portion of the video signal comprising the vertical interval and including vertical sync, horizontal sync, and equalization pulses;
FIG. 3 represents that portion of the video signal immediately surrounding a typical horizontal sync pulse (including the color burst area in the "back porch" of the sync pulse) in an active line of a video signal;
FIGS. 4(a) and 4(b) comparatively illustrate, respectively, a simplified, un-modified video signal (from lines two-hundred fifty through eighteen as provided above), and the same signal with pulses inserted in accordance with the preferred embodiment herein;
FIGS. 5(a) and 5(b) comparatively illustrate, respectively, a simplified, un-modified video signal equalizer pulse, and the same pulse as modified with a pedestal pulse following in accordance with the preferred embodiment herein;
FIGS. 6(a) and 6(b) comparatively illustrate, respectively, a simplified, un-modified video signal horizontal sync pulse, and the same pulse as modified with a pedestal pulse following in accordance with the preferred embodiment herein;
FIG. 7 is a block diagram representing mastering equipment, usable in conjunction with a high speed duplicating system, as modified to include the anti-copy encryption scheme circuitry in accordance with the teachings of the preferred embodiment herein;
FIG. 8 is a diagrammatic representation of circuit board providing the anti-copying encryption scheme circuitry of FIG. 7;
FIG. 9 is a schematic representation of the components incorporated in the circuit board of FIG. 8 in accordance with the preferred embodiment herein; and,
FIGS. 10 through 13 are a series of schematic representations of the logic incorporated into the field programmable gate array device of FIGS. 8 and 9 in accordance with the preferred embodiment herein.
FIGS. 1 through 3 illustrate aspects of existing video signal construction which are useful to understanding the systems and methods, including a preferred embodiment thereof, as presented hereinbelow.
With reference generally to FIG. 1 of the drawings, a representation of the interleaved scanning of a frame 10 of video illustrating numbering of the lines 15 of a frame 10 of video as referenced herein is provided. As is known in the television and video arts, a frame 10 (e.g., one complete picture image as would be seen on a TV screen) is comprised of two fields 20,25 which are scanned (such as by an electron beam) in an interlaced manner. According to present NTSC standards, five-hundred twenty five scanning lines 15 are utilized to recreate one frame 10 of video. Thus, each field comprises two-hundred sixty two and one-half such lines 15. Each of the lines 15 in a field 20,25 represents a horizontal scan (e.g., from left to right) of the frame 10 image. At the end of each scan line 15 the beam is shut off while it is repositioned to the beginning of the next scan line 15. A horizontal sync pulse 30 (see FIG. 2 and 3) positioned after the picture information 35 (see FIGS. 2 and 3) associated with a given line 15 of video triggers the occurrence of this action.
At the end of each field 20,25, i.e., the bottom of the frame 10, the beam is shut off while it is repositioned to the top in order to scan the next field image (which may be either the start of field two 25 of the same frame 10, or the start of field one 20 of the next frame 10). As with the horizontal sync pulses 30, synchronization pulses associated with a vertical retrace or vertical blanking interval (VBI) 40 (see FIG. 2), positioned at the end of the picture and related video signal information for the preceding field 20,25, of video trigger the occurrence of this action. For timing purposes, horizontal line scanning is still maintained during the VBI 40. In this period, equalization 45 and vertical sync 50 pulses perform the function otherwise performed by the horizontal sync pulses 30 with respect to the other video lines 15 in a field 20,25.
It is noted that some TV/Video art (not shown herein), with reference to the five-hundred twenty five lines of a frame of video, identify lines one to two-hundred sixty two and one-half in one field (e.g., field one) and from two-hundred sixty two one-half to five-hundred twenty five in the other (e.g., field two). Other art makes reference to an even/odd line breakdown between fields (e.g., odd number lines are associated with field one, even with field two). For purposes of the disclosure herein, and with reference to FIG. 1, the scanning lines 15 identified herein will be referenced in the immediately following manner.
The VBI 40 (which typically comprises about twenty-one lines) will be referenced herein as the first twenty-one lines (not shown on FIG. 1) of each field 20,25. In addition, the first scanned line 15 of each field 20,25 is referenced herein as line one; thus, the VBI 40 comprises lines one to twenty one each field 20,25. The remaining lines 15 are referenced herein as active video lines, i.e., viewable on a television or other display though, as will be further detailed hereinbelow, some of the lines 15 immediately adjacent the VBI 40 at the top or bottom of each field 20,25 may not actually be viewable depending on the display system used. Furthermore, field one 20 is referenced herein as comprising two-hundred sixty two lines 15 (numbered one to two-hundred sixty two) and field two 25 is referenced herein as comprising two-hundred sixty three lines 15 (numbered one to two-hundred sixty three). Lastly, and with reference to FIGS. 1 and 2, it may be understood that, for purposes herein, line one of each field 20,25 begins at a point corresponding to point a on FIG. 1; likewise, line twenty two of each field 20,25 commences from a point corresponding to that of point b on FIG. 1.
Scanning control (i.e., return of the beam after each horizontal scan and at the end of each field 20,25) is accomplished by means of known synchronization pulses (horizontal 30, vertical 50, and equalizing 45). FIG. 2 illustrates a waveform portion 55 immediately surrounding and including a vertical blanking interval 40. As may be seen, horizontal sync pulses 30 occur at the end of each line 15 in the active video portion 60 which also contains picture information 35 to be displayed. As mentioned above, horizontal scanning is also maintained throughout the VBI 40. Accordingly, horizontal sync pulses 30 are also found in the VBI 40. In addition to the horizontal sync pulses 30 in the VBI 40, certain equalizing pulses 45 and serrations 65 in the vertical sync pulse 50 act as pseudo-sync pulses 30' during a portion of the VBI 40.
In further detail, and with reference to FIGS. 2 and 3, horizontal synchronization in active video portion lines 60, and certain of the lines in the VBI 40, is accomplished via a synchronization pulse 30 incorporated within a horizontal blanking interval 70. As with the VBI 40, the scanning beam is shut off during the entirety of each horizontal blanking interval 70. Detection of a horizontal sync pulse 30 causes the scanning system to deflect the beam back to the opposite side of the image being recorded in order to scan the next line 15. In addition to the horizontal sync pulse 30, each horizontal blanking interval 70 within the active video portion (60 of FIG. 2) contains a back porch region 75 including a color burst portion 80 in which color information for the corresponding picture information 35 is encoded. As noted before, certain equalizing pulses 45, and the vertical sync pulse 50, by their structure, also provide pseudo-horizontal sync pulses 30' which perform the horizontal synchronization function within the VBI 40.
With respect to recording of video signal waveforms, e.g., on a videocassette recorder (VCR), no operation comparable to the retrace function of sync pulses is necessary; however, sync signal levels, and, in particular, horizontal sync pulse 30 levels, are utilized by many VCRs to adjust Automatic Gain Control (AGC) circuitry in order to maintain appropriate levels of the recorded signals for playback purposes. In this regard, VCRs so equipped detect the level of the horizontal sync pulses 30 and adjust the video signal 85 level accordingly, based on expected, standard relationships known in the art.
In accordance with the details set forth above, a preferred embodiment of a system and method for encrypting a video signal 85 in order to effectively prevent useful copying of that signal is described as follows. In brief, and with reference to FIGS. 4(a) and 4(b), a high-amplitude or pedestal pulse 90 is inserted into the video signal 85 following the horizontal sync pulse 30 (and certain of the equalizing pulses 45, as well as serrations 65 of the vertical sync signal 50, both of which serve as psuedo-horizontal sync pulses 30' within the vertical interval 40). In the preferred embodiment described herein, pedestal pulses 90 are inserted in lines two-hundred fifty to two-hundred sixty two of field one 20 (to two-hundred sixty three of field two 25) and lines one through eighteen of the next field 25,20. With respect to active video lines 60 (i.e., lines two-hundred fifty to two-hundred sixty two or two-hundred sixty three, depending upon which field 20,25 is referenced), the inserted high-amplitude pulses 90 are positioned in the color burst portion 80 (see FIG. 3) of the back porch region 75 (see FIG. 3). Thus, the high-amplitude pulse 90 would be inserted in the first eighteen lines 15 of each field 20,25 and in the last twelve to thirteen lines 15 of each field 20,25. These lines were selected based on comparative testing of TV and VCR systems which indicated that, for the majority of the systems, the high-amplitude pulse 90 could be placed as far up as line two-hundred fifty in a field without distortion (e.g., screen darkening, etc.) of the video picture information 35 to be displayed.
In further detail, FIG. 4a illustrates a normal NTSC video signal 85 waveform portion 95 including part of the VBI 40 and certain lines 15 of active video 60. The waveform portion 95 shows the placement of horizontal sync pulses 30, equalizing pulses 45 and the vertical sync pulse 50 (including serrated portions 65) which are used to maintain timing with respect to line 15 scanning within the VBI 40. Scan line 15 values corresponding to the waveform portions 95 are indicated with "L" followed by the line number (e.g., L250 indicates line two-hundred fifty). Waveform patterns for certain lines 15 (in both FIGS. 4a and 4b) have been omitted (e.g., lines two-hundred fifty one through two-hundred sixty one, and lines eleven through seventeen); the patterns for such lines are repetitive of immediately surrounding line patterns (i.e., lines two-hundred fifty and two-hundred sixty two, and lines ten and eighteen, respectively).
FIG. 4b illustrates the same video waveform portion 95 of FIG. 4a modified in accordance with the preferred embodiment of the present system and method for anti-copying encryption. As shown in FIG. 4b, a high-amplitude or pedestal pulse 90 is inserted immediately following each horizontal sync pulse 30 in the back porch region 75 of the horizontal blanking interval 70 (see FIG. 3). Within the active video portion 60 (see FIG. 2) lines 15 this pedestal pulse 90 is inserted in the color burst portion 80 (see FIG. 3). Within the VBI 40, the pedestal pulse 90 is inserted after the horizontal sync pulses 30' of lines L10 through L18. In addition, a pedestal pulse 90 is inserted after certain equalizing pulses 45, and after certain serrations 65 of the vertical sync pulse 50, each of which serve to provide psuedo-horizontal sync pulses 30' for those corresponding lines L1 through L9 within the VBI 40. FIGS. 5(a), 5(b), 6(a) and 6(b) illustrate, in greater detail, the placement of the pedestal pulse 90 in relation to the normal equalizer pulses 45 (FIGS. 5(a) and (b)), and in relation to the normal horizontal sync pulse 30, 30' (FIGS. 6(a) and (b) ).
Insertion of the pedestal pulses 90 as provided above operates to inhibit effective copying of a video signal in the following manner. As noted previously, VCRs typically incorporate Automatic Gain Control (AGC) circuitry in conjunction with the recording circuitry therein. Such AGC circuitry is utilized to ensure that the video signal 85 is recorded at a proper level so that the signal, upon playback, may be properly detected by and viewed on a television or other display device. Since picture information 35 varies dramatically depending upon its subject matter, the AGC circuitry does not adjust signal levels based on this information. Instead, the AGC circuitry of most VCRs keys off of the more standardized levels comprising the sync signals, and, particularly, the horizontal sync pulses 30, 30' of the video signal 85 waveform.
Insertion of high-amplitude pulses 90 in accordance with the preferred embodiment herein operates to raise the effective level of the signal within the horizontal blanking interval. Accordingly, the AGC circuitry of a recording VCR detects this higher-level signal and reduces the gain of the recorded signal to compensate therefor. When this recorded signal is played back to a television or other display device, the reduction in signal level either results in a signal which is too low to detect at all, or one which is too distorted for proper viewing. Further, since display devices typically do not incorporate AGC circuitry similar to, or for the same purposes as, that used in VCRs, such devices would not alter the signal level in response to the added pedestal pulses 90. In addition, such inserted pulses 90 are added only to lines 15 in the VBI 40, and certain lines 15 in active video portions 60 which are generally not viewable or, if viewable, occur at the extreme top or bottom of the frame 10 of video, where any distortion is less noticeable.
FIG. 7 is a block diagram of an exemplary system 100 for applying pedestal pulses 90 to a video signal 85 according to the method of the present invention. In a preferred embodiment, a Sony MMV 800 Mirror Mother Video System, modified as detailed hereinbelow, is utilized to prepare masters of the video material to be mass-reproduced onto videotapes in a high-speed duplication system and process. According to the present method, the pedestal pulses 90 detailed above are encrypted into the video material in the course of the mirror mother mastering process as further described hereinbelow.
With reference to FIG. 7, a mastering system 100 as modified with a copy protect circuit 105 may be utilized as part of a high speed duplication system (not shown) to prepare videotapes in accordance with the present system and method. The system 100 comprises a video luminance/chromenance separator 110 which acts upon an incoming video signal on line 85 to separate that signal into components, on lines 115 and 120, respectively, representing a luminance signal and chromenance signal. Separation into these component signals is effected according to the normal operation of the mastering system 100 (Sony MMV-800), irrespective of whether or not the present system and method are employed, and for reasons of improved processability of the video signal known to those skilled in the art.
The separated luminance signal on line 115 is presented into a video luminance modulator circuit 125 and the chromenance signal is presented into a video chromenance modulator circuit 130. The video luminance modulator circuit 125 operates upon the luminance signal on line 115 to convert same to an FM modulated frequency for further processing as will be more fully described hereinbelow. The video chromenance modulator circuit 130 generates the color information associated with the video signal on line 85 and, in particular, the chromenance signal on line 120, under carrier frequency in a manner and for reasons known to those skilled in the art.
To the latter end above, the video chromenance signal on line 120 is provided to an Automatic Gain Control (AGC) circuit 135 which, in turn, is connected to a frequency conversion circuit 140 and an oscillator 145 (which may, for example, be set to establish a 3.58 Megahertz frequency). An Automatic Frequency Control (AFC) circuit 150 is connected between the oscillator 145 and the frequency conversion circuit 140 for further control of frequency in light of signal information provided by the luminance signal on line 115 as indicated hereinbelow. The video chromenance modulator circuit 130 also receives the luminance signal on line 115 into a sync separator circuit 155 which outputs sync information for use by the AFC circuit 150 in the color generation process. The sync separator circuit 155 further outputs a composite sync signal 160 which is input to the video luminance modulator circuit 125 for use in the frequency modulation process performed therein, and which is input into the copy protect circuit 105 as detailed below.
In accordance with the present method, the copy protect circuit 105 is utilized to generate and insert a pulse of three microsecond duration and 130 IRE units magnitude in positions associated with the horizontal synchronization of the video signal on line 85 from lines two-hundred fifty of one field 20,25 to line eighteen of a next field 25,20 (including, with reference to FIGS. 3 and 4, horizontal sync pulses 30, equalization pulses 45, and serrations 65 of the vertical sync pulse 50) as detailed hereinabove. The copy protect circuit 105 comprises an horizontal and vertical control circuit 165 receiving as one input the color sync signal 160 from the sync separator circuit 155 of the video chromenance modulator 130, an oscillator 170 (which may, for example be set to establish a 14.3 Megahertz frequency) providing another input to the horizontal and vertical control circuit 165, and a pulse generator 175 which receives the output from the horizontal and vertical control circuit 165 and generates a pulse insertion signal on line 180 which, in turn, is provided to the video luminance modulator circuit 125 to effect insertion of the pedestal pulse 90 (as shown in FIG. 4(b).
A sync clip signal on line 185 is also provided from the pulse generator 175 in order to limit negative going sync pulses 30 to a minus 30 IRE units magnitude. The negative going sync pulses are normally minus 40 IRE units in magnitude; reduction in accordance with the system and method herein serves to create additional synchronization errors adding to the resulting distortion of a copy of the video signal when played back on a display. Tests have shown that the parameters detailed above provide suitable performance across the widest variety of component (i.e., VCR and TV Received/Monitor) combinations presently available.
A video RF Equalizer circuit 190 is further incorporated into the mastering system 100 and comprises an equalizer circuit for channel A 195 and for channel B 200, and a mixing circuit for channel A 205 and for channel B 210. Both of the equalizer circuits 195, 200 receive, as an input, the FM modulated luminance signal on line 215 which is output from the video luminance modulator circuit 125. The output from the channel A equalizer circuit 195 is a signal on line 220 comprising channel A information which has been equalized in a manner known to those skilled in the art. Likewise, the output from the channel B equalizer circuit 200 is a signal on line 225 comprising channel B information which has been equalized. These equalized signals 220, 225 are passed, respectively, to the corresponding channel A mixing circuit 205 and channel B mixing circuit 210. A second input to each of the mixing circuits 205, 210 is the modulated chromenance signal on line 230 provided by the video chromenance modulation circuit 130, and which comprises color information generated under carrier frequency as detailed above.
The channel A mixing circuit 205 operates to combine the equalized channel A signal on line 220, representing luminance information associated with the video signal on line 85, with the modulated chromenance signal on line 230, representing color information associated with the video signal on line 85. Likewise, the channel B mixing circuit 210 operates to combine the equalized channel B signal on line 225, representing luminance information associated with the video signal on line 85, with the modulated chromenance signal on line 230, representing color information associated with the video signal on line 85. The channel A and channel B output signals on lines 235, 240 of the video RF equalizer circuit 190 are then input, respectively, into a channel A Record Amplifier circuit 245 and a channel B Record Amplifier circuit 250 to provide suitable amplification of these signals for high speed recording to videotape as known to those skilled in the art. In a final phase, the output signals on lines 255, 260, from of the channel A and channel B record amplifier circuits 245, 250 are presented, respectively, to corresponding channel A and channel B video heads 265, 270 for duplication of the video signal on line 85 as modified above onto videotape, and for subsequent high-speed duplication to other videotapes.
As noted previously, it has been found through comparative testing that a two microsecond pedestal pulse 90 (as measured with respect to the video signal on the videotape being copy protected) inserted in the back porch 75 of the horizontal sync 30, et al., pulses, yields the most suitable copy-protection performance (i.e., adequate distortion with respect to illegitimately copied tapes when played back, yet minimally perceived distortion of video material upon playback of legitimate videotape) over the widest array of VCR and TV Receiver/Monitor combinations presently in the market. As a result of bandwidth limiting in the electronics of the mastering equipment 100, i.e., the Sony MMV 800 in the preferred embodiment herein, it has been found that insertion of a three microsecond pulse from the pulse generator 175 into the luminance signal component on line 115 of the video signal on line 85 yields such a two microsecond pulse in the final signal on line 275 duplicated onto the copy-protected videotapes. Further, testing has indicated that a pulse 90 amplitude of 130 IRE units enables playback of legitimate tapes from a VCR without objectionable distortion, yet provides sufficient distortion when illegitimate copies are made. By inserting the additional pulse 90 in the manner indicated hereinabove, i.e., within the mastering equipment 100, the pulse may be driven to a maximum amplitude of 130 IRE units, as opposed to the 100 IRE units maximum if inserted in the original video signal on line 85 presented as an input to mastering equipment 100, before clipping takes place in the mastering equipment 100 electronics. The modification of the horizontal synchronization pulse 30 negative amplitude from a -40 IRE unit level to a -30 IRE unit level is envisioned to assist in the loss of synchronization of the video picture when viewing an illegitimate copy. It has been found that modification of the video signal as provided above does not cause any noticeable black shift in the range of TV receivers presently available, yet still provides the maximum video signal reduction by the AGC circuits of a recording VCR (and, thus, provides a highly distorted picture when the copy VCR tape is played back to a TV receiver).
FIG. 8 illustrates the components of a logic board 280 which may be incorporated as a modification to a mastering system 100 (see FIG. 7), such as a Sony MMV-800 Mirror Mother System, in order to provide for the insertion of pedestal pulses 90 in accordance with the preferred embodiment herein. As shown in FIG. 8, and further explained in detail hereinbelow with respect to the remaining FIGS., the logic board 280 comprises a Field Programmable Gate Array (FPGA) component 285, an external clock 290, and a discrete component 295.
With reference back to FIGS. 1-6, the logic board 280 of FIG. 8 is interfaced with the existing video luminance modulation circuit 125 (e.g., the "YMD board" of the MMV-800 system) to provide the ability to add a high level pedestal pulse 90 (130 IRE) to the back porch 75 of the horizontal sync pulse 30 starting at line two hundred and fifty at the end of a field 20,25 and continuing through the vertical interval 40 to line eighteen of the next field 25,20. The presence of these pedestal pulses 90 in the mirror mother tape will be transferred during the high speed duplication process to standard VCR cassettes. A second function provided by the logic board 280 allows for the previously noted reduction of the negative going synchronization pulses in the video signal on line 85 from a minus forty (-40) IRE level to a minus thirty (-30) IRE level. When a copy of the primary VCR cassette is attempted, the AGC circuit in the input of the copying VCR will sample the high amplitude pulses 90 on the back porch 75 of the synchronizing pulses 30 and reduce the amplitude of the video signal on line 85 being recorded to a level that, when played back, will be further distorted and non-viewable.
A more detailed schematic representation of the logic board 280 of FIG. 8 is provided in FIG. 9. With reference to this latter figure, all timing is derived by logic contained in a Field Programmable Gate Array logic chip (FPGA) 285, which may, e.g., be an Actel 1020A chip as manufactured by Actel Corporation. External clocking 290 is provided by a crystal controlled oscillator 300 comprised of a 74LS04 chip 305, a capacitor 310, two resistors 315, 320, and a crystal 325 of, e.g., 14.3 MHZ frequency. The oscillator 300 provides complementary output signals 330, 330' to the FPGA chip 285. With reference to both FIGS. 7 and 9, the FPGA chip 285 also receives as an input the composite sync signal (CSYNC) 160 from the video luminance modulator circuit 125 (e.g., pin 32A of the YMD board of the Sony MMV-800 system). The circuitry in the FPGA chip 285 synchronizes with the composite sync signal 160 and generates an HPLS/signal 335. The HPLS/signal 335 is, in turn, provided to the discrete component 295 and is used to drive transistor Q1 340 and transistor Q2 345 which will provide a positive pulse on the pedestal pulse insertion line 350. A switch (S1) 355 controls application of this positive pulse on the pedestal pulse insertion line 350, which is then provided back to the video luminance modulator circuit 125 (e.g., at the junction of R49 & R183 & C129 of the "YMD board" of the Sony MMV-800 system). As will be further detailed hereinbelow, the FPGA chip 285 adjusts the timing of the HPLS/signal 335 in order to compensate for any circuit propagation delays that may occur in the video luminance modulator circuitry 125.
The negative synchronization pulse reduction (which, as previously identified is a second function provided by the logic board 280) is accomplished by a clipping circuit 360 comprising a potentiometer 365, two capacitors 370, 375, and a diode 380. The clipping circuit 360 limits the negative excursion of the video signal on line 85 and, therefore, clips the normal negative-going horizontal synchronization pulses 30 (with reference to FIGS. 4(a) and (b)). A switch (S2) 385 on the sync reduction line 390 controls application of the synchronization pulse reduction function to the video luminance modulator circuit 125. Since the entire video signal on line 85 sits at a positive level in the video luminance modulator circuit 125 (e.g., at the junction of R49 and R183 of the "YMD board" of the Sony MMV-800 System) where the sync reduction line 390 of the logic board 280 interfaces (at the junction of Pin 10 & C13), adjusting the D.C. voltage provided by the potentiometer 365 limits the negative direction of the signal if it is more negative than the voltage provided to the diode 380.
With reference to FIGS. 10 through 13, the programming of the FPGA chip 285 circuitry of FIGS. 8 and 9 is described in greater detail hereinbelow. The composite sync signal (CSYNC) 160 is input to pin ten 395 of the FPGA chip 285. This CSYNC signal 160 is buffered and inverted to provide signals SYNC 400 and SYNC/405. As shown on FIG. 12, the SYNC signal 400 is input to a D flip-flop 410 at the initial stage of a sub-circuit 415 which generates the pulse HDRCLR/pulse 420 (which may, for example, be a 70 nanosecond pulse) at the leading edge of the SYNC pulse 400. The HDRCLR/pulse 420 is provided to a J-K flip-flop 425 and sets the output, signal HDR 430. The HDRCLR/pulse 420 is also provided to a three stage counter 435, via signal HDRCLRA/440, HDRCLRB/445, and HDRCLRC/450, and is used to clear the counter 435. The HDR signal 430 remains set until the counter 435 reaches a count of 640, which is past the half interval, thus resetting the flip-flop 425, and signal HDR 430 (which may, for example, provide the equivalent of a 45 microsecond delay). The HDR signal 430 is a gating function for the generation of the signal HDRCLR/420, thus it blocks any half line equalizer pulses that are contained in the composite sync.
The HDR signal 430 is also brought to a D flip-flop 455 (as shown in FIG. 10) where an HDRD pulse 460 is generated (which may, for example, be a 70 nanosecond pulse) to provide a clearing function for the horizontal timing counter 465 and a clock for the vertical line counter 470 via signal HCLR/475. The vertical line counter 470 is cleared by the END signal 480 which represents the end of field.
Generation of the END signal 480 is illustrated in FIG. 11, and is achieved in two ways. An equalizer pulse 45 is detected in the place of a horizontal sync pulse 30 at the end of field one 20 by signal TST1ST 485, which is sync detected at a timing sample (which may, e.g., be 0.7 microseconds) from the lead edge of the SYNC pulse 400. The TST1ST 485 signal is reset by the signal RSTHDR/490, which occurs at a second timing sample (which may, e.g., be 7 microseconds) from the lead edge of the SYNC pulse 400. If the SYNC pulse 400 has ended before the EQSEEN signal 495 is set (which, in a preferred embodiment may be a 2.52 microsecond period deriving from the lower logic rail of the "EQSEEN" function 495), the END signal 480 is set after a certain time period (which may, e.g., be 2.8 microseconds) from the lead edge of the SYNC pulse 400. The END pulse 480 is also provided to the J-K flip-flop 500 (as shown on FIG. 13) and sets the VPER signal 505. This VPER signal 505 blocks the gating chains 510 (as shown on FIG. 11) from looking at the sync train during the vertical interval 40. The VPER signal 505 is reset by the first full width horizontal SYNC pulse 400 detected by the HSEEN/circuit 515 (as shown in FIG. 11). The HSEEN/circuit 515 tests the SYNC pulse 400 at a certain time period (which may, e.g., be 3.9 microseconds) from the lead edge of the SYNC pulse 400 to see if it is wide enough using the TSTHDR signal 520 and then generates the HSEEN/signal 525 at a sample time (which may, e.g., be 5.8 microseconds) from the lead edge of SYNC 400. The first normal width horizontal sync pulse occurs in vertical line ten 530 (see FIG. 4(b)).
The END pulse 480 for field two 25 is generated (by the upper logic rail of "EQSEEN" function 495) by the TST2ND/signal 535 which detects a SYNC pulse 400 at a half line interval (e.g., 32.6 microseconds) and remembers it until the VPER signal 505 is set. An END pulse 480 is then caused to be generated upon the next occurrence of a SYNC pulse 400.
The back porch 75 pedestal pulse 90 is provided as the HPLS signal 540, which may be generated by circuitry as illustrated in FIG. 13. A J-K flip-flop 545 controls the pulse generation in the vertical interval 40 through the ALV signal 550 output therefrom. A SETVINT signal 555 is generated by a line count of 249 on lines 560 provided from a counter 470 (as shown on FIG. 10), and is provided to the J-K flip-flop 545 to set the ALV signal 550. The ALV signal 550 is reset by a line count of 18 on lines 560 from the counter 565. When the ALV signal 550 is set, the HPLS signal 540 will be set at a certain time period (e.g., 4.69 microseconds) from the lead edge of SYNC 400, and will reset at a second time period (e.g., 7.63 microseconds) from the lead edge of SYNC 400, in order to provide a pulse 90 of approximately 3.0 microseconds duration (width).
It is noted that the delay in the start of the pulse 90 is to compensate for the propagation delay that exists between the CSYNC signal 160 (on the "YMD board" of the Sony MMV-800), and the video signal on line 85 (at the junction R49 and R183 on that board). It is further noted that the values herein identified are meant to be exemplary of possible operation according to the preferred embodiment herein. Such values are not meant to be limiting of the scope of the system or method herein described, nor of the claims appended hereto. Indeed, certain of the values herein provided, including those related to modifications of the video signal and those related to the circuit modifications to the mastering equipment, derive from testing on presently available TV receivers, VCRs, and from the use of a Sony MMV-800 mastering system in accordance with the preferred embodiment described herein. Some modification of values provided herein may be expected for application of the present system and method with other combinations of equipment; and, such modifications are intended to be within the scope of the present system and method. To be sure, having described the invention in detail, and by reference to preferred embodiments thereof, it will be apparent that other modifications and variations are possible without departing from the spirit and scope of the invention defined in the appended claims.
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